01629nas a2200217 4500008004100000022001400041245007400055210006900129260001200198300001200210490000600222520097000228100002101198700002201219700002401241700001901265700002101284700002101305700001701326856006801343 2022 eng d a2378-224200aBarotropic seiches in a perennially ice-covered lake, East Antarctica0 aBarotropic seiches in a perennially icecovered lake East Antarct c02/2022 a26 - 330 v73 a
Water movement in ice-covered lakes is known to be driven by wind, sediment heat flux, solar radiation, saline density flows, and advective stream discharge. In large ice-covered lakes, wind-induced oscillations have been found to play a major role in horizontal flows. Here, we report recurrent, wind-driven, barotropic seiches in a small lake with a thick (4 m) permanent ice-cover. Between 2010 and 2016, we recorded 10.5- to 13-min oscillations of the hydrostatic water level in Lake Hoare, McMurdo Dry Valleys, East Antarctica, using pressure transducers moored to the lake bottom and suspended from the ice cover. Theoretical calculations showed a barotropic seiche should have a period of 12.6 min. Barotropic seiches were most frequent during high wind events (> 5 m s-1) in winter months (February–November). The period increased during summer months (December–January) when fast ice thinned and melted along the shoreline.
1 aCastendyk, Devin1 aDugan, Hilary, A.1 aGallagher, Hugh, A.1 aPujara, Nimish1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry uhttps://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.1022602367nas a2200289 4500008004100000245011400041210006900155260001200224300001400236490000600250520147700256653001501733653002201748653002201770653001001792100002601802700002401828700002701852700002101879700001801900700001701918700002001935700001701955700001701972700002401989856006402013 2022 eng d00aElevational constraints on the composition and genomic attributes of microbial communities in Antarctic soils0 aElevational constraints on the composition and genomic attribute c01/2022 ae01330-210 v73 aThe inland soils found on the Antarctic continent represent one of the more challenging environments for microbial life on Earth. Nevertheless, Antarctic soils harbor unique bacterial and archaeal (prokaryotic) communities able to cope with extremely cold and dry conditions. These communities are not homogeneous, and the taxonomic composition and functional capabilities (genomic attributes) of these communities across environmental gradients remain largely undetermined. We analyzed the prokaryotic communities in soil samples collected from across the Shackleton Glacier region of Antarctica by coupling quantitative PCR, marker gene amplicon sequencing, and shotgun metagenomic sequencing. We found that elevation was the dominant factor explaining differences in the structures of the soil prokaryotic communities, with the drier and saltier soils found at higher elevations harboring less diverse communities and unique assemblages of cooccurring taxa. The higher-elevation soil communities also had lower maximum potential growth rates (as inferred from metagenome-based estimates of codon usage bias) and an overrepresentation of genes associated with trace gas metabolism. Together, these results highlight the utility of assessing community shifts across pronounced environmental gradients to improve our understanding of the microbial diversity found in Antarctic soils and the strategies used by soil microbes to persist at the limits of habitability.
10aAntarctica10amicrobial ecology10asoil microbiology10asoils1 aDragone, Nicholas, B.1 aHenley, Jessica, B.1 aHolland-Moritz, Hannah1 aDiaz, Melisa, A.1 aHogg, Ian, D.1 aLyons, Berry1 aWall, Diana, H.1 aAdams, Byron1 aFierer, Noah1 aMackelprang, Rachel uhttps://journals.asm.org/doi/full/10.1128/msystems.01330-2102944nas a2200301 4500008004100000022001400041245009600055210007100151260001200222490000700234520204100241653001702282653001902299653002002318653001402338653002302352653002302375100002602398700001702424700002102441700002402462700002602486700001702512700001702529700001802546700002002564856005802584 2022 eng d a1354-101300aResponse of Antarctic soil fauna to climate‐driven changes since the Last Glacial Maximum0 aResponse of Antarctic soil fauna to climate‐driven changes since c01/20220 v283 aUnderstanding how terrestrial biotic communities have responded to glacial recession since the Last Glacial Maximum (LGM) can inform present and future responses of biota to climate change. In Antarctica, the Transantarctic Mountains (TAM) have experienced massive environmental changes associated with glacial retreat since the LGM, yet we have few clues as to how its soil invertebrate-dominated animal communities have responded. Here, we surveyed soil invertebrate fauna from above and below proposed LGM elevations along transects located at 12 features across the Shackleton Glacier region. Our transects captured gradients of surface ages possibly up to 4.5 million years and the soils have been free from human disturbance for their entire history. Our data support the hypothesis that soils exposed during the LGM are now less suitable habitats for invertebrates than those that have been exposed by deglaciation following the LGM. Our results show that faunal abundance, community composition, and diversity were all strongly affected by climate-driven changes since the LGM. Soils more recently exposed by glacial recession (as indicated by distances from present ice surfaces) had higher faunal abundances and species richness than older exposed soils. Higher abundances of the dominant nematode Scottnema were found in older exposed soils, while Eudorylaimus, Plectus, tardigrades, and rotifers preferentially occurred in more recently exposed soils. Approximately 30% of the soils from which invertebrates could be extracted had only Scottnema, and these single-taxon communities occurred more frequently in soils exposed for longer periods of time. Our structural equation modeling of abiotic drivers highlighted soil salinity as a key mediator of Scottnema responses to soil exposure age. These changes in soil habitat suitability and biotic communities since the LGM indicate that Antarctic terrestrial biodiversity throughout the TAM will be highly altered by climate warming.
10abiodiversity10aclimate change10aglacial retreat10anematodes10aShackleton Glacier10asoil invertebrates1 aFranco, André, L. C.1 aAdams, Byron1 aDiaz, Melisa, A.1 aLemoine, Nathan, P.1 aDragone, Nicholas, B.1 aFierer, Noah1 aLyons, Berry1 aHogg, Ian, D.1 aWall, Diana, H. uhttps://onlinelibrary.wiley.com/doi/10.1111/gcb.1594002885nas a2200241 4500008004100000245006300041210006200104260004100166300001200207520209300219653003102312653003602343653002402379653001902403653002402422100001602446700001702462700002302479700001702502700002402519700002502543856007502568 2021 eng d00aChemical weathering in the McMurdo Dry Valleys, Antarctica0 aChemical weathering in the McMurdo Dry Valleys Antarctica aHoboken, NJbJohn Wiley & Sons, Inc. a205-2163 aWhile chemical weathering has not always been considered an active process in the McMurdo Dry Valleys (MDV), Antarctica, long‐term geochemical and hydrological investigations have provided an overall better understanding of chemical weathering in this polar desert environment. Liquid water on the landscape is limited to stream channels as well as shallow subsurface melt features, as there is no overland flow. Stream total suspended sediment loads are low, with the sources of sediment from stream channels, aeolian input, and/or from the surfaces of glaciers. MDV soils contain high concentrations of soluble salts with little clay material, but since absent of water, these soils are a minimal location of chemical weathering. Hyporheic zones exchange water during streamflow, and these areas control the stream geochemistry over various temporal scales. Hyporheic zones promote rapid aluminosilicate weathering by moving dilute glacial meltwater into intimate contact with sediment surfaces. Rapid weathering of the aluminosilicates in the streambed and hyporheic zones is the most plausible explanation for chemostasis observed in these streams, indicating that little to no catchment processes are necessary to explain the observed chemostasis in the MDV. Shallow subsurface waters with distinct geochemical signatures have much higher dissolved Si concentrations than the stream waters and indicate that they are responsible for enhanced aluminosilicate weathering in this polar desert environment. The dissolution of CaCO3 is also a major process in the hyporheic zones as generally the streams are unsaturated with respect to calcite. Cation‐exchange reactions are also important in the evolution from Na‐Cl brines to Ca‐Cl brines within the soil column, while authigenic CaCO3 can both dissolve and precipitate depending on the condition of the system. Recently, stream channel landscapes are changing due to the melting of buried ice, creating thermokarst and water track features, resulting in a sediment and solute influx to the stream.
10aaluminosilicate weathering10aCaCO3 dissolution/precipitation10achemical weathering10ahyporheic zone10aMcMurdo Dry Valleys1 aHunt, Allen1 aEgli, Markus1 aFaybishenko, Boris1 aLyons, Berry1 aLeslie, Deborah, L.1 aGooseff, Michael, N. uhttps://agupubs.onlinelibrary.wiley.com/doi/10.1002/9781119563952.ch1102506nas a2200289 4500008004100000022001400041245006300055210006300118260001200181490000800193520169900201653001501900653001701915653001301932653001801945653001001963653001001973100002601983700002102009700001802030700001702048700002002065700002002085700002102105700001702126856007302143 2021 eng d a2169-895300aExploring the boundaries of microbial habitability in soil0 aExploring the boundaries of microbial habitability in soil c06/20210 v1263 aMicrobes are widely assumed to be capable of colonizing even the most challenging terrestrial surface environments on Earth given enough time. We would not expect to find surface soils uninhabited by microbes as soils typically harbor diverse microbial communities and viable microbes have been detected in soils exposed to even the most inhospitable conditions. However, if uninhabited soils do exist, we might expect to find them in Antarctica. We analyzed 204 ice-free soils collected from across a remote valley in the Transantarctic Mountains (84–85°S, 174–177°W) and were able to identify a potential limit of microbial habitability. While most of the soils we tested contained diverse microbial communities, with fungi being particularly ubiquitous, microbes could not be detected in many of the driest, higher elevation soils—results that were confirmed using cultivation-dependent, cultivation-independent, and metabolic assays. While we cannot confirm that this subset of soils is completely sterile and devoid of microbial life, our results suggest that microbial life is severely restricted in the coldest, driest, and saltiest Antarctic soils. Constant exposure to these conditions for thousands of years has limited microbial communities so that their presence and activity is below detectable limits using a variety of standard methods. Such soils are unlikely to be unique to the studied region with this work supporting previous hypotheses that microbial habitability is constrained by near-continuous exposure to cold, dry, and salty conditions, establishing the environmental conditions that limit microbial life in terrestrial surface soils.
10aAntarctica10aastrobiology10abacteria10aextremophiles10afungi10asoils1 aDragone, Nicholas, B.1 aDiaz, Melisa, A.1 aHogg, Ian, D.1 aLyons, Berry1 aJackson, Andrew1 aWall, Diana, H.1 aAdams, Byron, J.1 aFierer, Noah uhttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JG00605202615nas a2200229 4500008004100000245011400041210006900155260001200224300001600236490000700252520188900259100002102148700002902169700002102198700002002219700002102239700002002260700001802280700001702298700001702315856005302332 2021 eng d00aGeochemical zones and environmental gradients for soils from the central Transantarctic Mountains, Antarctica0 aGeochemical zones and environmental gradients for soils from the c03/2021 a1629 - 16440 v183 aPrevious studies have established links between biodiversity and soil geochemistry in the McMurdo Dry Valleys, Antarctica, where environmental gradients are important determinants of soil biodiversity. However, these gradients are not well established in the central Transantarctic Mountains, which are thought to represent some of the least hospitable Antarctic soils. We analyzed 220 samples from 11 ice-free areas along the Shackleton Glacier (~85°S), a major outlet glacier of the East Antarctic Ice Sheet. We established three zones of distinct geochemical gradients near the head of the glacier (upper), its central part (middle), and at the mouth (lower). The upper zone had the highest water-soluble salt concentrations with total salt concentrations exceeding 80 000 µg g-1, while the lower zone had the lowest water-soluble N:P ratios, suggesting that, in addition to other parameters (such as proximity to water and/or ice), the lower zone likely represents the most favorable ecological habitats. Given the strong dependence of geochemistry on geographic parameters, we developed multiple linear regression and random forest models to predict soil geochemical trends given latitude, longitude, elevation, distance from the coast, distance from the glacier, and soil moisture (variables which can be inferred from remote measurements). Confidence in our random forest model predictions was moderately high with R2 values for total water-soluble salts, water-soluble N:P, ClO4-, and ClO3- of 0.81, 0.88, 0.78, and 0.74, respectively. These modeling results can be used to predict geochemical gradients and estimate salt concentrations for other Transantarctic Mountain soils, information that can ultimately be used to better predict distributions of soil biota in this remote region.
1 aDiaz, Melisa, A.1 aGardner, Christopher, B.1 aWelch, Susan, A.1 aJackson, Andrew1 aAdams, Byron, J.1 aWall, Diana, H.1 aHogg, Ian, D.1 aFierer, Noah1 aLyons, Berry uhttps://bg.copernicus.org/articles/18/1629/2021/02603nas a2200181 4500008004100000245007200041210006900113260001200182300001200194490000800206520196600214100002402180700002402204700001702228700002402245700002402269856012802293 2021 eng d00aGeochemistry of contrasting stream types, Taylor Valley, Antarctica0 aGeochemistry of contrasting stream types Taylor Valley Antarctic c01/2021 a425-4480 v1333 aThe McMurdo Dry Valley region is the largest ice-free area of Antarctica. Ephemeral streams flow here during the austral summer, transporting glacial meltwater to perennially ice-covered, closed basin lakes. The chemistry of 24 Taylor Valley streams was examined over the two-decade period of monitoring from 1993 to 2014, and the geochemical behavior of two streams of contrasting physical and biological character was monitored across the seven weeks of the 2010–2011 flow season. Four species dominate stream solute budgets: HCO3–, Ca2+, Na+, and Cl–, with SO42–, Mg2+, and K+ present in significantly lesser proportions. All streams contain dissolved silica at low concentrations. Across Taylor Valley, streams are characterized by their consistent anionic geochemical fingerprint of HCO3 > Cl > SO4, but there is a split in cation composition between 14 streams with Ca > Na > Mg > K and 10 streams with Na > Ca > Mg > K.
Andersen Creek is a first-order proglacial stream representative of the 13 short streams that flow <1.5 km from source to gage. Von Guerard is representative of 11 long streams 2–7 km in length characterized by extensive hyporheic zones. Both streams exhibit a strong daily cycle for solute load, temperature, dissolved oxygen, and pH, which vary in proportion to discharge. A well-expressed diurnal co-variation of pH with dissolved oxygen is observed for both streams that reflects different types of biological control. The relative consistency of Von Guerard composition over the summer flow season reflects chemostatic regulation, where water in transient storage introduced during times of high streamflow has an extended opportunity for water-sediment interaction, silicate mineral dissolution, and pore-water exchange.
The purpose of this study is to assess the concentrations of Barium (Ba), Copper (Cu), Iron (Fe), Lead (Pb), and Zinc (Zn) in sediment samples obtained from the Wales and Commonwealth streams located in Taylor Valley, Antarctica. These samples were collected at seven sample sites (three in Wales Glacier and four in Commonwealth Glacier) in 0 to 2 cm, 2 to 4 cm, 4 to 6 cm, and 6 to 8 cm depth increments which resulted in 28 total samples. After the collection process, these samples underwent a volumetric 1:5 sediment: 10% HCl leach for 48 hours, filtration through 4-µm pore-size, cellulose acetate membrane filters, and inductively coupled plasma mass spectrometry (ICP-MS) analyses in the Trace Element Research Laboratory at The Ohio State University. Upon completion of the analyses, results showed that the Wales samples had a higher average concentration of every metal element overall and at each depth increment when compared to the Commonwealth samples. In addition to the weak-acid leachate metal analyses, a second aliquot of one sediment profile from each stream was analyzed at Villanova University for the 210Pb activity via gamma spectroscopy. This was done to estimate the sedimentation rates at each of these sites. From the sedimentation rates, sedimentation fluxes were calculated for each element for each sediment profile at each of these sites. The data demonstrated that Fe is the most abundant element while Pb is the least abundant. Lastly, upon examination of results, it was found that the concentrations of these metals are often higher in samples collected closer to the surface. These findings suggest these streams, and their sources, have had little, if any, impact by anthropogenic input of metals, and that metal fluxes to the sediments are low.
10aacid-leachable metal10aAntarctica10ageochemistry10aMcMurdo Dry Valleys10apolar sediments10asedimentation rate1 aPiergallini, Brianna1 aLyons, Berry uhttp://hdl.handle.net/1811/9177202303nas a2200265 4500008004100000245012500041210006900166260001200235520144100247653001901688653002001707653002001727653001901747653002901766100002301795700001801818700001801836700002501854700001901879700001701898700001701915700002001932700002401952856006101976 2020 eng d00aGenetic diversity of soil invertebrates corroborates timing estimates for past collapses of the West Antarctic Ice Sheet0 aGenetic diversity of soil invertebrates corroborates timing esti c08/20203 aDuring austral summer field seasons between 1999 and 2018, we sampled at 91 locations throughout southern Victoria Land and along the Transantarctic Mountains for six species of endemic microarthropods (Collembola), covering a latitudinal range from 76.0°S to 87.3°S. We assembled individual mitochondrial cyto-chrome c oxidase subunit 1 (COI) sequences (n = 866) and found high levels of sequence divergence at both small (<10 km) and large (>600 km) spatial scales for four of the six Collembola species. We applied molecular clock estimates and assessed genetic divergences relative to the timing of past glacial cycles, including collapses of the West Antarctic Ice Sheet (WAIS). We found that genetically distinct lineages within three species have likely been isolated for at least 5.54 My to 3.52 My, while the other three species diverged more recently (<2 My). We suggest that Collembola had greater dispersal opportunities under past warmer climates, via flotation along coastal margins. Similarly increased opportunities for dispersal may occur under contemporary climate warming scenarios, which could influence the genetic structure of extant populations. As Collembola are a living record of past landscape evolution within Antarctica, these findings provide biological evidence to support geological and glaciological estimates of historical WAIS dynamics over the last ca. 5 My.
10aclimate change10amicroarthropods10amolecular clock10aphylogeography10aterrestrial biodiversity1 aCollins, Gemma, E.1 aHogg, Ian, D.1 aConvey, Peter1 aSancho, Leopoldo, G.1 aCowan, Don, A.1 aLyons, Berry1 aAdams, Byron1 aWall, Diana, H.1 aGreen, T., G. Allan uhttps://www.pnas.org/content/early/2020/08/19/200792511702540nas a2200289 4500008004100000245012600041210006900167260001200236490000800248520163000256653002101886653001501907653001701922653001501939653002401954653001901978100002101997700002102018700001902039700002402058700001902082700001702101700002402118700001902142700001702161856007202178 2020 eng d00aGeochemistry of aeolian material from the McMurdo Dry Valleys, Antarctica: Insights into Southern Hemisphere dust sources0 aGeochemistry of aeolian material from the McMurdo Dry Valleys An c10/20200 v5473 aIn the Southern Hemisphere, the major sources of dust and other aeolian materials are from Patagonia, South Africa, Australia, and New Zealand. Dust from Patagonia and New Zealand has been identified in ice cores throughout Antarctica, suggesting that during arid and windy periods, such as glacial periods, dust can be entrained and transported onto the continent. However, little information exists on modern Antarctic dust sources, transport, and its role in the Southern Hemisphere dust cycle. We present the first geochemical characterization of aeolian materials collected at five heights (between 5 cm and 100 cm) above the surface in four valleys within the McMurdo Dry Valleys, the largest ice-free area in Antarctica. Our mineralogy data indicate that these materials are primarily derived from local rocks of the McMurdo Volcanics, Ferrar Dolerite, Beacon Sandstone and Granite Harbor Intrusives, with varying contributions of each rock type dependent on the valley location. While major oxide, trace element and rare earth element data show that low elevation and coastal locations (with respect to the Ross Sea) are dominated by local sources, high elevation and inland locations have accumulated both local materials and dust from other distant Southern Hemisphere sources. This far-traveled material may not be accumulating today, but represents a paleo source that is resuspended from the soils. By geochemically “fingerprinting” aeolian materials from the MDV, we can better inform future studies on the transport of materials within Antarctica and between Southern Hemisphere land masses.
10aaeolian material10aAntarctica10amajor oxides10amineralogy10arare earth elements10atrace elements1 aDiaz, Melisa, A.1 aWelch, Susan, A.1 aSheets, J., M.1 aWelch, Kathleen, A.1 aKhan, Alia, L.1 aAdams, Byron1 aMcKnight, Diane, M.1 aCary, Craig, S1 aLyons, Berry uhttps://www.sciencedirect.com/science/article/pii/S0012821X2030404002966nas a2200205 4500008004100000245011200041210006900153260001200222490000600234520228000240100002102520700002202541700002302563700002602586700002102612700001502633700002402648700001702672856007102689 2020 eng d00aSilicon isotopes reveal a non-glacial source of silicon to Crescent Stream, McMurdo Dry Valleys, Antarctica0 aSilicon isotopes reveal a nonglacial source of silicon to Cresce c06/20200 v83 aIn high latitude environments, silicon is supplied to river waters by both glacial and non-glacial chemical weathering. The signal of these two end-members is often obscured by biological uptake and/or groundwater input in the river catchment. McMurdo Dry Valleys streams in Antarctica have no deep groundwater input, no connectivity between streams and no surface vegetation cover, and thus provide a simplified system for us to constrain the supply of dissolved silicon (DSi) to rivers from chemical weathering in a glacial environment. Here we report dissolved Si concentrations, germanium/silicon ratios (Ge/Si) and silicon isotope compositions (δ30SiDSi) in Crescent Stream, McMurdo Dry Valleys for samples collected between December and February in the 2014−2015, 2015−2016, and 2016−2017 austral seasons. The δ30SiDSi compositions and DSi concentrations are higher than values reported in wet-based glacial meltwaters, and form a narrow cluster within the range of values reported for permafrost dominated Arctic Rivers. High δ30SiDSi compositions, ranging from +0.90‰ to +1.39‰, are attributed to (i) the precipitation of amorphous silica during freezing of waters in isolated pockets of the hyporheic zone in the winter and the release of Si from unfrozen pockets during meltwater-hyporheic zone exchange in the austral summer, and (ii) additional Si isotope fractionation via long-term Si uptake in clay minerals and seasonal Si uptake into diatoms superimposed on this winter-derived isotope signal. There is no relationship between δ30SiDSi compositions and DSi concentrations with seasonal and daily discharge, showing that stream waters contain DSi that is in equilibrium with the formation of secondary Si minerals in the hyporheic zone. We show that δ30SiDSi compositions can be used as tracers of silicate weathering in the hyporheic zone and possible tracers of freeze-thaw conditions in the hyporheic zone. This is important in the context of the ongoing warming in McMurdo Dry Valleys and the supply of more meltwaters to the hyporheic zone of McMurdo Dry Valley streams.
1 aHirst, Catherine1 aOpfergelt, Sophie1 aGaspard, François1 aHendry, Katharine, R.1 aHatton, Jade, E.1 aWelch, Sue1 aMcKnight, Diane, M.1 aLyons, Berry uhttps://www.frontiersin.org/articles/10.3389/feart.2020.00229/full02674nas a2200253 4500008004100000245007700041210006900118260001200187490000600199520187800205100002102083700002602104700002102130700002202151700001902173700002502192700002102217700002202238700001702260700002302277700002502300700002402325856007102349 2020 eng d00aSilicon isotopic composition of dry and wet-based glaciers in Antarctica0 aSilicon isotopic composition of dry and wetbased glaciers in Ant c07/20200 v83 aGlaciers and ice sheets export significant amounts of silicon (Si) to downstream ecosystems, impacting local and potentially global biogeochemical cycles. Recent studies have shown Si in Arctic glacial meltwaters to have an isotopically distinct signature when compared to non-glacial rivers. This is likely linked to subglacial weathering processes and mechanochemical reactions. However, there are currently no silicon isotope (δ30Si) data available from meltwater streams in Antarctica, limiting the current inferences on global glacial silicon isotopic composition and its drivers. To address this gap, we present dissolved silicon (DSi), δ30SiDSi, and major ion data from meltwater streams draining a polythermal glacier in the region of the West Antarctic Peninsula (WAP; King George Island) and a cold-based glacier in East Antarctica [Commonwealth Stream, McMurdo Dry Valleys (MDV)]. These data, alongside other global datasets, improve our understanding of how contrasting glacier thermal regime can impact upon Si cycling and therefore the δ30SiDSi composition. We find a similar δ30SiDSi composition between the two sites, with the streams on King George Island varying between -0.23 and +1.23‰ and the Commonwealth stream varying from -0.40 to +1.14‰. However, meltwater streams in King George Island have higher DSi concentrations, and the two glacial systems exhibit opposite DSi – δ30SiDSi trends. These contrasts likely result from differences in weathering processes, specifically the role of subglacial processes (King George Island) and, supraglacial processes followed by in-stream weathering in hyporheic zones (Commonwealth Stream). These findings are important when considering likely changes in nutrient fluxes from Antarctic glaciers under climatic warming scenarios and consequent shifts in glacial thermal regimes.
1 aHatton, Jade, E.1 aHendry, Katharine, R.1 aHirst, Catherine1 aOpfergelt, Sophie1 aHenkel, Susann1 aSilva-Busso, Adrián1 aWelch, Susan, A.1 aWadham, Jemma, L.1 aLyons, Berry1 aBagshaw, Elizabeth1 aStaubwasser, Michael1 aMcKnight, Diane, M. uhttps://www.frontiersin.org/articles/10.3389/feart.2020.00286/full01931nas a2200229 4500008004100000245010800041210006900149260001200218490000700230520115400237100002101391700001701412700001701429700002401446700002401470700001601494700001601510700001701526700001501543700002301558856012001581 2019 eng d00aDiurnal chemistry of two contrasting stream types, Taylor Valley, McMurdo Dry Valley Region, Antarctica0 aDiurnal chemistry of two contrasting stream types Taylor Valley c06/20190 v983 aNumerous ephemeral streams flow within the McMurdo Dry Valley Region of Antarctica that transport glacial meltwater to perennially ice-covered, closed-basin lakes during the austral summer. The diurnal behavior for two Taylor Valley streams of different character was examined during the summer of 2010-11. Andersen Creek is a short, 1st-order proglacial stream, whereas Von Guerard Stream is a long, high-order stream with an extensive hyporheic zone that has a substantial cyanobacterial algal mat community in its middle reaches. Both streams display strong daily cycles for temperature, electrical conductivity, dissolved oxygen, and pH. Conductivity varies in concert with flow, with solute dilution occurring during the daily high-flow pulse. Dissolved oxygen co-varies strongly with pH at Andersen Creek but not for Von Guerard Stream. Each stream has a distinct geochemical character that for Andersen Creek is a direct reflection of its glacial source, unmodified by secondary effects, whereas that for Von Guerard Stream is modulated by its resident algal mat community and through extensive hyporheic zone interaction and exchange.
1 aHarmon, Mark, E.1 aLeslie, D.L.1 aLyons, Berry1 aWelch, Kathleen, A.1 aMcKnight, Diane, M.1 aChudaev, O.1 aKharaka, Y.1 aHarmon, R.S.1 aMillot, R.1 aShouakar-Stash, O. uhttps://www.e3s-conferences.org/articles/e3sconf/abs/2019/24/e3sconf_wri-162018_01020/e3sconf_wri-162018_01020.html02504nas a2200229 4500008004100000245007200041210006700113260001200180490000800192520178600200100001701986700002202003700002202025700002402047700001502071700002902086700002502115700002102140700002002161700002002181856007302201 2019 eng d00aThe Geochemistry of Englacial Brine From Taylor Glacier, Antarctica0 aGeochemistry of Englacial Brine From Taylor Glacier Antarctica c03/20190 v1243 aBlood Falls is a hypersaline, iron‐rich discharge at the terminus of the Taylor Glacier in the McMurdo Dry Valleys, Antarctica. In November 2014, brine in a conduit within the glacier was penetrated and sampled using clean‐entry techniques and a thermoelectric melting probe called the IceMole. We analyzed the englacial brine sample for filterable iron (fFe), total Fe, major cations and anions, nutrients, organic carbon, and perchlorate. In addition, aliquots were analyzed for minor and trace elements and isotopes including δD and δ18O of water, δ34S and δ18O of sulfate, 234U, 238U, δ11B, 87Sr/86Sr, and δ81Br. These measurements were made in order to (1) determine the source and geochemical evolution of the brine and (2) compare the chemistry of the brine to that of nearby hypersaline lake waters and previous supraglacially sampled collections of Blood Falls outflow that were interpreted as end‐member brines. The englacial brine had higher Cl− concentrations than the Blood Falls end‐member outflow; however, other constituents were similar. The isotope data indicate that the water in the brine is derived from glacier melt. The H4SiO4 concentrations and U and Sr isotope suggest a high degree of chemical weathering products. The brine has a low N:P ratio of ~7.2 with most of the dissolved inorganic nitrogen in the form of NH4+. Dissolved organic carbon concentrations are similar to end‐member outflow values. Our results provide strong evidence that the original source of solutes in the brine was ancient seawater, which has been modified with the addition of chemical weathering products.
1 aLyons, Berry1 aMikucki, Jill, A.1 aGerman, Laura, A.1 aWelch, Kathleen, A.1 aWelch, Sue1 aGardner, Christopher, B.1 aTulaczyk, Slawek, M.1 aPettit, Erin, C.1 aKowalski, Julia1 aDachwald, Bernd uhttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JG00441102216nas a2200193 4500008004100000245012200041210006900163260001200232520155300244653001501797653001701812653002101829653002901850653001801879100002101897700001501918700001701933856007201950 2019 eng d00aThe geochemistry of glacial deposits in Taylor Valley, Antarctica: Comparison to upper continental crustal abundances0 ageochemistry of glacial deposits in Taylor Valley Antarctica Com c05/20193 aWet-based glacial deposits have been used traditionally as an analog for upper continental crust (UCC) abundances. To provide more information on the validity of using glacial deposits from wet-based glaciers, samples deposited by the dry-based polar glaciers located in Taylor Valley, Antarctica, were collected. Stream channel sediments, comprised of igneous, metamorphic, and sedimentary rocks initially deposited as glacial tills by polar glaciers, were analyzed by XRF, ICP-MS, and SEM. Based on the Chemical Index of Alteration values and A–CN–K ternary diagram, there are low levels of chemical weathering in these tills. Additionally, major and trace element geochemical data are compared to the average UCC values. The observed discrepancies between the mean UCC and Antarctic samples develop from the existence of mafic components, most likely the McMurdo Volcanic Group and Ferrar Dolerite, being present in the Taylor Valley tills. Even though the mafic material typically comprises 3–7% of the till, the volcanic rocks have a significant influence on the tills’ bulk geochemistry. The existence of this mafic fraction in the dry-based glacial tills results from the reduced rate of weathering, as compared to wet-based glaciers. Geochemical analyses of the dry-based glacial tills in polar deserts, such as those found in Taylor Valley, may provide a better representative composition of the original material than wet-based glaciers and need to be incorporated into upper continental crust calculations.
10aAntarctica10ageochemistry10aglacial deposits10apolar dry-based glaciers10aTaylor Valley1 aDowling, Carolyn1 aWelch, Sue1 aLyons, Berry uhttps://www.sciencedirect.com/science/article/pii/S088329271930124602639nas a2200301 4500008004100000245008400041210006900125260001200194520169800206653001501904653002101919653002401940653002701964653001301991100002102004700002602025700001702051700001602068700002502084700002502109700001702134700002202151700002302173700002002196700002402216700002402240856007302264 2019 eng d00aThe hydroecology of an ephemeral wetland in the McMurdo Dry Valleys, Antarctica0 ahydroecology of an ephemeral wetland in the McMurdo Dry Valleys c11/20193 aThe McMurdo Dry Valleys (MDV) is a polar desert on the coast of East Antarctica where ephemeral wetlands become hydrologically active during warm and sunny summers when sub‐surface flows are generated from melting snowfields. To understand the structure and function of polar wetland ecosystems, we investigated the hydroecology of one such wetland, the Wormherder Creek wetland, during the warm and sunny summer of 2008 – 2009, when the wetland was hydrologically reactivated. Conservative tracer (LiCl) was injected for a 2‐hour period into a stream above the wetland to determine flow path orientations and hydrologic residence times. Tracer results indicated that surface water is rapidly exchanged with wetland groundwater and wetland residence times may exceed two austral summers. Major ion concentrations were uniform in samples from surface water and shallow groundwater throughout the wetland. Microbial mats in the wetland had high autotrophic index values (the ratios of chlorophyll a [Chl‐a]/ash‐free dry mass [AFDM]), ranging from 9‐38 μg Chl‐a/mg AFDM, indicative of actively photosynthesizing mat communities. The diatom communities in the mats were relatively uniform compared to those in mats from regularly flowing MDV streams, with four endemic and one widespread diatom taxa of the genus Luticola accounting for an average of 86% of the community. These results indicate that the hydrologic characteristics of the wetland contribute to uniform geochemical conditions. In turn, uniform geochemical conditions may explain the high autotrophic index values of the microbial mats and relatively low spatial variation of the diatom community.
10aAntarctica10adesert hydrology10adiatom biodiversity10ahyporheic interactions10awetlands1 aWlostowski, Adam1 aSchulte, Nicholas, O.1 aAdams, Byron1 aBall, Becky1 aEsposito, Rhea, M.M.1 aGooseff, Michael, N.1 aLyons, Berry1 aNielsen, Uffe, N.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aWelch, Kathleen, A.1 aMcKnight, Diane, M. uhttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JG00515302534nas a2200229 4500008004100000245010900041210006900150260001200219300001600231490000800247520179600255100002102051700001702072700002402089700001502113700002302128700001902151700002402170700001902194700001702213856007402230 2018 eng d00aAeolian material transport and its role in landscape connectivity in the McMurdo Dry Valleys, Antarctica0 aAeolian material transport and its role in landscape connectivit c12/2018 a3323 - 33370 v1233 aArid regions, particularly polar and alpine desert environments, have diminished landscape connectivity compared to temperate regions due to limited and/or seasonal hydrological processes. For these environments, aeolian processes play a particularly important role in landscape evolution and biotic community vitality through nutrient and solute additions. The McMurdo Dry Valleys (MDV) are the largest ice-free area in Antarctica and are potentially a major source of aeolian material for the continent. From this region, samples were collected at five heights (~5, 10, 20, 50, and 100 cm) above the surface seasonally for 2013 through 2015 from Alatna Valley, Victoria Valley, Miers Valley, and Taylor Valley (Taylor Glacier, East Lake Bonney, F6 (Lake Fryxell), and Explorer’s Cove). Despite significant geological separation and varying glacial histories, low-elevation and coastal sites had similar major ion chemistries, as did high-elevation and inland locations. This locational clustering of compositions was also evident in scanning electron microscopy images and principal component analyses, particularly for samples collected at ~100 cm above the surface. Compared to published soil literature, aeolian material in Taylor Valley demonstrates a primarily down-valley transport of material toward the coast. Soluble N:P ratios in the aeolian material reflect relative nutrient enrichments seen in MDV soils and lakes, where younger, coastal soils are relatively N depleted, while older, up-valley soils are relatively P depleted. The aeolian transport of materials, including water-soluble nutrients, is an important vector of connectivity within the MDV and provides a mechanism to help “homogenize” the geochemistry of both soil and aquatic ecosystems.
1 aDiaz, Melisa, A.1 aAdams, Byron1 aWelch, Kathleen, A.1 aWelch, Sue1 aOpiyo, Stephen, O.1 aKhan, Alia, L.1 aMcKnight, Diane, M.1 aCary, Craig, S1 aLyons, Berry uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2017JF00458901847nas a2200193 4500008004100000022001400041245005200055210005200107260001200159300001400171490000700185520124200192100002201434700002901456700002401485700001501509700001701524856011201541 2018 eng d a0091-761300aBarium and barite dynamics in Antarctic streams0 aBarium and barite dynamics in Antarctic streams c08/2018 a811 - 8140 v463 aMost natural waters are undersaturated with respect to barite (BaSO4), and while much work has focused on the processes of microbially mediated barite precipitation in undersaturated solutions, particularly in marine environments, little documentation exists on the changes in barite saturation in stream waters. We examined ephemeral glacial meltwater streams in the McMurdo Dry Valleys, Antarctica, that undergo large variations in streamflow and temperature on both a diel and seasonal basis. We measured dissolved Ba in stream water in downstream transects and on a diel cycle, total Ba in stream sediments, algal mats, and lake sediments. Ba concentrations decreased downstream in all four transects, and mineral saturation modeling indicates these waters go from supersaturated to undersaturated with respect to barite in very short distances. Ba is concentrated in stream benthic algal mats at a factor less than observed in marine systems. Both seasonal and diel changes in stream water temperature affect the solubility of barite near glacial sources. Our work shows that both changing stream temperature and the presence of algal materials likely play significant roles in controlling Ba concentrations in polar streams.
1 aSaelens, Elsa, D.1 aGardner, Christopher, B.1 aWelch, Kathleen, A.1 aWelch, Sue1 aLyons, Berry uhttps://pubs.geoscienceworld.org/gsa/geology/article/545184/Barium-and-barite-dynamics-in-Antarctic-streams02347nas a2200193 4500008004100000022001300041245009200054210006900146260001200215300001200227490000800239520173400247100002101981700001702002700001502019700002402034700002302058856007202081 2018 eng d a0016706100aBiogeochemical weathering of soil apatite grains in the McMurdo Dry Valleys, Antarctica0 aBiogeochemical weathering of soil apatite grains in the McMurdo c01/2018 a136-1450 v3203 aThe biogeochemical weathering of the mineral apatite links the lithosphere to the biosphere by releasing the essential nutrient phosphorus (P) into the soil ecosystem. In Taylor Valley, Antarctica, faster rates of apatite weathering may be responsible for the higher concentrations of bioavailable soil P that exist in the Fryxell Basin as compared to the Bonney Basin. In this study, we use scanning electron microscopy to quantify the morphology and surface etching of individual apatite grains to determine whether the degree of apatite weathering differs between the Fryxell and Bonney Basins as well as saturated and dry soil sediments. We show that apatite grains from the Fryxell Basin are rounder, have fewer intact crystal faces, and are more chemically etched than grains from the Bonney Basin. In the Bonney Basin, apatite grains from dry soils show few signs of chemical dissolution, suggesting that soil moisture is a stronger control on the rate of apatite weathering in the Bonney Basin than in the Fryxell Basin. In addition, etch-pit morphologies in the Bonney Basin are more clearly controlled by the hexagonal crystal structure of apatite, while in the Fryxell Basin, etch pits demonstrate a wide range of morphologies without clear crystallographic control. Higher rates of apatite weathering in the Fryxell Basin may be due to the legacy of the physical abrasion of apatite grains during transport by a warm-based ice sheet, as well as the higher levels of precipitation and soil moisture closer to the coast. Our grain-scale approach provides a new perspective on P cycling in the McMurdo Dry Valleys and has implications for apatite weathering and P dynamics in the early stages of soil development.
1 aHeindel, Ruth, C1 aLyons, Berry1 aWelch, Sue1 aSpickard, Angela, M1 aVirginia, Ross, A. uhttps://www.sciencedirect.com/science/article/pii/S001670611732069402146nas a2200193 4500008004100000245011200041210006900153260001200222490000600234520149600240653001501736653002101751653002701772653002501799653001901824100001901843700001701862856007301879 2018 eng d00aDissolved Trace and Minor Elements in Cryoconite Holes and Supraglacial Streams, Canada Glacier, Antarctica0 aDissolved Trace and Minor Elements in Cryoconite Holes and Supra c04/20180 v63 a
We present a synthesis of the trace element chemistry in melt on the surface Canada Glacier, Taylor Valley, McMurdo Dry Valleys (MDV), Antarctica (∼78◦S). The MDV is largely ice-free. Low accumulation rates, strong winds, and proximity to the valley floor make these glaciers dusty in comparison to their inland counterparts. This study examines both supraglacial melt streams and cryoconite holes. Supraglacial streams on the lower Canada Glacier have median dissolved (<0.4 μm) concentrations of Fe, Mn, As, Cu, and V of 71.5, 75.5, 3.7, 4.6, and 4.3 nM. All dissolved Cd concentrations and the vast majority of Pb values are below our analytical detection (i.e., 0.4 and 0.06 nM). Chemical behavior did not follow similar trends for eastern and western draining waters. Heterogeneity likely reflects distinctions eolian deposition, rock:water ratios, and hydrologic connectivity. Future increases in wind-delivered sediment will likely drive dynamic responses in melt chemistry. For elements above detection limits, dissolved concentrations in glacier surface melt are within an order of magnitude of concentrations observed in proglacial streams (i.e., flowing on the valley floor). The Fe enrichment of cryoconite water relative to N, P, or Si exceeds enrichment observed in marine phytoplankton. This suggests that the glacier surface is an important source of Fe to downstream ecosystems.
10aAntarctica10acryoconite holes10aglacier melt chemistry10asupraglacial streams10atrace elements1 aFortner, Sarah1 aLyons, Berry uhttp://journal.frontiersin.org/article/10.3389/feart.2018.00031/full01630nas a2200169 4500008004100000245008200041210006900123260001200192490000600204520109200210100002201302700002401324700002101348700001701369700001601386856005801402 2018 eng d00aDrivers of solar radiation variability in the McMurdo Dry Valleys, Antarctica0 aDrivers of solar radiation variability in the McMurdo Dry Valley c03/20180 v83 a
Annually averaged solar radiation in the McMurdo Dry Valleys, Antarctica has varied by over 20 W m−2 during the past three decades; however, the drivers of this variability are unknown. Because small differences in radiation are important to water availability and ecosystem functioning in polar deserts, determining the causes are important to predictions of future desert processes. We examine the potential drivers of solar variability and systematically eliminate all but stratospheric sulfur dioxide. We argue that increases in stratospheric sulfur dioxide increase stratospheric aerosol optical depth and decrease solar intensity. Because of the polar location of the McMurdo Dry Valleys (77–78°S) and relatively long solar ray path through the stratosphere, terrestrial solar intensity is sensitive to small differences in stratospheric transmissivity. Important sources of sulfur dioxide include natural (wildfires and volcanic eruptions) and anthropogenic emission.
1 aObryk, Maciek, K.1 aFountain, Andrew, G1 aDoran, Peter, T.1 aLyons, Berry1 aEastman, R. uhttp://www.nature.com/articles/s41598-018-23390-7.pdf02262nas a2200181 4500008004100000022001400041245010300055210006900158260001200227300001600239490000800255520165500263100002201918700001701940700001501957700002401972856008401996 2018 eng d a2169-895300aFe and Nutrients in Coastal Antarctic Streams: Implications for Primary Production in the Ross Sea0 aFe and Nutrients in Coastal Antarctic Streams Implications for P c12/2018 a3507 - 35220 v1233 a
The Southern Ocean (SO) has been an area of biogeochemical interest due to the presence of macronutrients (N, P, and Si) but lack of the expected primary production response, which is thought to be primarily due to Fe limitation. Because primary production is associated with increased drawdown of atmospheric CO2, it is important to quantify the fluxes of Fe and other nutrients into the SO. Here we present data from subaerial streams that flow into the Ross Sea, a sector of the coastal SO. Water samples were collected in the McMurdo Dry Valleys, Antarctica, and analyzed for macronutrients and Fe to determine the potential impact of terrestrial water input on the biogeochemistry of coastal oceanic waters. The physiochemical forms of Fe were investigated through analysis of three operationally defined forms: acid-dissolvable Fe (no filtration), filterable Fe (<0.4 μm), and dissolved Fe (<0.2 μm). The combined average flux from two McMurdo Dry Valley streams was approximately 240 moles of filterable Fe per year. The dissolved fraction of Fe made up 18%–27% of the filterable Fe. The stream data yield an average filterable stoichiometry of N3P1Si100Fe0.8, which is substantially different from the planktonic composition and suggests that these streams are a potential source of Fe and P, relative to N and Si, to coastal phytoplankton communities. While the Fe flux from these streams is orders of magnitude less than estimated eolian and iceberg sources, terrestrial streams are expected to become a more significant source of Fe to the Ross Sea in the future.
1 aOlund, Sydney, A.1 aLyons, Berry1 aWelch, Sue1 aWelch, Kathleen, A. uhttps://agupubs.pericles-prod.literatumonline.com/doi/full/10.1029/2017JG00435202094nas a2200241 4500008004100000245014400041210006900185260001200254490000600266520131100272653002001583653001401603653001701617653001501634653001501649653002401664653001301688653002201701100001701723700002201740700002401762856006601786 2018 eng d00aThe impact of fossil fuel burning related to scientific activities in the McMurdo Dry Valleys, Antarctica: Revisited0 aimpact of fossil fuel burning related to scientific activities i c04/20180 v63 a
Fossil fuel use associated with scienti c activities in the Taylor Valley, Antarctic has been examined to determine the fluxes of particulate organic and elemental carbon and nitrogen as well as NOx for the 2015–2016 austral summer field season. These carbon and nitrogen fluxes are compared to our previously published calculations for the 1997–1998 austral summer. In addition, we compile fossil fuel usage and resulting C and N fluxes from the major field camp in Taylor Valley, Lake Hoare Camp (LHC) from the late 1990’s through 2017. In general, the annual fluxes do vary from year to year, but there is no significant trend, at least during the primary summer field season. There is indication that increasing the length of scientific operations does increase the C and N inputs via fossil fuel burning. This works supports our original results demonstrating that over long periods of time the anthropogenic flux of N from local fossil fuel burning could become quantitatively important in the region. Although the particulate C fluxes remain very low, the recent finding of black carbon in the Taylor Valley landscape indicates more on-going monitoring of the source of this material is merited.
10acarbon dynamics10aemissions10afossil fuels10ahelicopter10amanagement10aMcMurdo Dry Valleys10anitrogen10ascience activites1 aLyons, Berry1 aSaelens, Elsa, D.1 aWelch, Kathleen, A. uhttps://www.elementascience.org/article/10.1525/elementa.288/04038nas a2200205 4500008004100000245015700041210006900198260001200267300001600279490000800295520333900303100001903642700002103661700002403682700001503706700002403721700001703745700002403762856004603786 2018 eng d00aNear-surface refractory black carbon observations in the atmosphere and snow in the McMurdo Dry Valleys, Antarctica and potential impacts of foehn winds0 aNearsurface refractory black carbon observations in the atmosphe c01/2018 a2877 - 28870 v1233 a
Measurements of light absorbing particles in the boundary layer of the high southern latitudes are scarce, particularly in the McMurdo Dry Valleys (MDV), Antarctica. During the 2013 - 2014 austral summer near-surface boundary layer refractory black carbon (rBC) aerosols were measured in air by a single particle soot photometer (SP2) at multiple locations in the MDV. Near-continuous rBC atmospheric measurements were collected at Lake Hoare Camp (LH) over two months and for several hours at more remote locations away from established field camps. We investigated periods dominated by both up and down-valley winds to explore the causes of differences in rBC concentrations and size distributions. Snow samples were also collected in a 1m pit on a glacier near the camp. The range of concentrations rBC in snow were 0.3 – 1.2 ± 0.3 μg-rBC/L-H2O, and total organic carbon were 0.3 – 1.4 ± 0.3 mg/L. The rBC concentrations measured in this snow pit are not sufficient to reduce surface albedo, however, there is potential for accumulation of rBC on snow and ice surfaces at low elevation throughout the MDV which were not measured as part of this study. At LH, the average background rBC mass aerosol concentrations was 1.3 ng/m3. rBC aerosol mass concentrations were slightly lower, 0.09 – 1.3 ng/m3, at the most remote sites in the MDV. Concentration spikes as high as 200 ng/m3 were observed at LH, associated with local activities. During a foehn wind event, the average rBC mass concentration increased to 30-50 ng m-3. Here we show the rBC increase could be due to resuspension of locally produced BC from generators, rocket toilets, and helicopters, which may remain on the soil surface until redistributed during high wind events. Quantification of local production and long-range atmospheric transport of rBC to the MDV is necessary for understanding the impacts of this species on regional climate.
1 aKhan, Alia, L.1 aMcMeeking, Gavin1 aSchwarz, Joshua, P.1 aXian, Peng1 aWelch, Kathleen, A.1 aLyons, Berry1 aMcKnight, Diane, M. uhttp://doi.wiley.com/10.1002/2017JD02769602332nas a2200193 4500008004100000245017900041210006900220260001200289300001600301490000700317520164300324100001701967700001701984700002202001700001702023700002302040700002002063856005502083 2018 eng d00aStable C and N isotope ratios reveal soil food web structure and identify the nematode Eudorylaimus antarcticus as an omnivore–predator in Taylor Valley, Antarctica0 aStable C and N isotope ratios reveal soil food web structure and c05/2018 a1013–10180 v413 a
Soil food webs of the McMurdo Dry Valleys, Antarctica are simple. These include primary trophic levels of mosses, algae, cyanobacteria, bacteria, archaea, and fungi, and their protozoan and metazoan consumers (including relatively few species of nematodes, tardigrades, rotifers, and microarthropods). These biota are patchily distributed across the landscape, with greatest faunal biodiversity associated with wet soil. Understanding trophic structure is critical to studies of biotic interactions and distribution; yet, McMurdo Dry Valley soil food web structure has been inferred from limited laboratory culturing and micro- scopic observations. To address this, we measured stable isotope natural abundance ratios of C (13C/12C) and N (15N/14N) for di erent metazoan taxa (using whole body biomass) to determine soil food web structure in Taylor Valley, Antarctica. Nitrogen isotopes were most useful in di erentiating trophic levels because they fractionated predictably at higher trophic levels. Using 15N/14N, we found that three trophic levels were present in wet soil habitats. While cyanobacterial mats were the primary trophic level, the nematode Plectus murrayi, tardigrade Acutuncus antarcticus, and rotifers composed a secondary trophic level of grazers. Eudorylaimus antarcticus had a 15N/14N ratio that was 2–4‰ higher than that of grazers, indicating that this species is the sole member of a tertiary trophic level. Understanding the trophic positions of soil fauna is critical to predictions of current and future species interactions and their distributions for the McMurdo Dry Valleys, Antarctica.
1 aShaw, Ashley1 aAdams, Byron1 aBarrett, John, E.1 aLyons, Berry1 aVirginia, Ross, A.1 aWall, Diana, H. uhttp://link.springer.com/10.1007/s00300-017-2243-801835nas a2200169 4500008004100000245013700041210006900178260001200247300001800259490000700277520122000284100002101504700002501525700002401550700001701574856007401591 2018 eng d00aTransit times and rapid chemical equilibrium explain chemostasis in glacial meltwater streams in the McMurdo Dry Valleys, Antarctica0 aTransit times and rapid chemical equilibrium explain chemostasis c12/2018 a13322 - 133310 v453 aFluid transit time is understood to be an important control on the shape of concentration-discharge (C-q) relationships, yet empirical evidence supporting this linkage is limited. We investigated C-q relationships for weathering-derived solutes across seven Antarctic glacial meltwate streams. We hypothesized that (H1) solute fluxes in McMurdo Dry Valley streams are reaction limited so that C-q relationships are characterized by dilution and that (H2) transit time explains between-stream variability in the degree of C-q dilution. Results show that C-q relationships are chemostatic because solute equilibrium times are shorter than stream corridor fluid transit times. Between-stream variability in the efficiency of solute production is positively correlated with transit time, suggesting that transit time is an important control on the solute export regime. These results provide empirical evidence for the controls on weathering-derived C-q relationships and have important implications for Antarctic ecosystems and solute export regimes of watersheds worldwide.
1 aWlostowski, Adam1 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aLyons, Berry uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL08036902937nas a2200157 4500008004100000245006000041210006000101260001200161300001400173490000700187520246500194100001702659700001402676700002402690856006502714 2017 eng d00aCa isotopic geochemistry of an Antarctic aquatic system0 aCa isotopic geochemistry of an Antarctic aquatic system c01/2017 a882 - 8910 v443 aThe McMurdo Dry Valleys, Antarctica, are a polar desert ecosystem. The hydrologic system of the dry valleys is linked to climate with ephemeral streams that flow from glacial melt during the austral summer. Past climate variations have strongly influenced the closed-basin, chemically stratified lakes on the valley floor. Results of previous work point to important roles for both in-stream processes (e.g., mineral weathering, precipitation and dissolution of salts) and in-lake processes (e.g., mixing with paleo-seawater and calcite precipitation) in determining the geochemistry of these lakes. These processes have a significant influence on calcium (Ca) biogeochemistry in this aquatic ecosystem, and thus variations in Ca stable isotope compositions of the waters can aid in validating the importance of these processes. We have analyzed the Ca stable isotope compositions of streams and lakes in the McMurdo Dry Valleys. The results validate the important roles of weathering of aluminosilicate minerals and/or CaCO3 in the hyporheic zone of the streams, and mixing of lake surface water with paleo-seawater and precipitation of Ca-salts during cryo-concentration events to form the deep lake waters. The lakes in the McMurdo Dry Valleys evolved following different geochemical pathways, evidenced by their unique, nonsystematic Ca isotope signatures.
1 aLyons, Berry1 aBullen, T1 aWelch, Kathleen, A. uhttp://onlinelibrary.wiley.com/doi/10.1002/2016GL071169/full02219nas a2200133 4500008004100000245013600041210006900177260004400246490000900290520170700299100002502006700001702031856003702048 2017 eng d00aComparing the Weathering Environment of Permian and Modern Antarctic Proglacial Lake Sediments: Mineralogical and Geochemical Study0 aComparing the Weathering Environment of Permian and Modern Antar aColumbus, OHbThe Ohio State University0 vB.S.3 aThe Antarctic continent has been in a polar to subpolar position since the Permian period. Although it has experienced milder climates over this time period as evidenced by corals in the fossil record, Antarctica did undergo extensive glaciation during the Permian. This is based on the abundance of Permian tillites (sedimentary rocks derived from glacier tills) found in the Transantarctic Mountains. In this research, I have compared Permian age proglacial lake sediments that are associated with tilites to modern proglacial lake siltstones and mudstones from Antarctica. This was done to determine the climate, especially the amount of glacier melt that occurred when these Permian sediments were deposited. The modern lake sediments are deposited in perennially ice-covered lakes by ephemeral streams that only flow 6 to 12 weeks a year. The geochemical analyses of the Permian samples and the modern sediments from Lake Hoare in the McMurdo Dry Valleys suggest that the Permian samples are more highly chemically weathered than the modern sediments. The mineralogy of Lake Hoare sediments contain more primary minerals than chemical weathering produced minerals in the Pagoda Formation rocks, thus supporting the geochemical analysis that the Pagoda Formation minerals have been more weathered. All these data suggest that the Permian lake samples were deposited in a warmer, more hydrogeologically active environment than were the modern lake sediments. These data support previously published sedimentological and paleontological data that the Pagoda samples were deposited under more temperate or warm-based proglacial conditions than what is observed in the McMurdo Dry Valleys today.
1 aBrewster, Shelby, A.1 aLyons, Berry uhttp://hdl.handle.net/1811/8076300851nas a2200265 4500008004100000245009100041210006900132260001200201300001400213490000600227100002500233700002200258700001700280700002100297700002400318700001700342700002400359700002100383700002000404700003300424700003100457700002300488700002000511856005400531 2017 eng d00aDecadal ecosystem response to an anomalous melt season in a polar desert in Antarctica0 aDecadal ecosystem response to an anomalous melt season in a pola c09/2017 a1334-13380 v11 aGooseff, Michael, N.1 aBarrett, John, E.1 aAdams, Byron1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aSokol, Eric, R.1 aTakacs-Vesbach, Cristina, D.1 aVandegehuchte, Martijn, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://www.nature.com/articles/s41559-017-0253-002715nas a2200133 4500008004100000245011000041210006900151260002600220490000900246520222000255100002202475700001702497856006702514 2017 eng d00aFe and Nutrients in Coastal Antarctic Streams: Implications for Marine Primary Production in the Ross Sea0 aFe and Nutrients in Coastal Antarctic Streams Implications for M bOhio State University0 vM.S.3 aThe Southern Ocean (SO) has been an area of much biogeochemical interest due to the role of Fe limitation for primary production. Primary production is associated with increased carbon sequestration, making it important to characterize and quantify the fluxes of Fe and other nutrients to the ocean. Water samples were collected in the McMurdo Dry Valleys, Antarctica (MDV) from four subaerial streams flowing into the Ross Sea. They were analyzed for macronutrients (N, P, Si) and Fe to determine the potential impact of terrestrial water input on the biogeochemistry of coastal oceanic waters. Our stream data yield an average filterable composition of N3P1 Si100Fe0.8, which is substantially different from the planktonic composition as demonstrated by empirical measurements, and suggests that these streams are a potential source of Fe and P, relative to N and Si, to coastal phytoplankton communities.
Aeolian processes play an important role in the transport of both geological and biological materials globally, on the biogeochemistry of ecosystems, and in landscape evolution. As the largest ice free area on the Antarctic continent (approximately 4800 km2), the McMurdo Dry Valleys (MDV) are potentially a major source of aeolian material for Antarctica, but information on the spatial and temporal variability of this material is needed to understand its soluble and bulk geochemistry, deposition and source, and hence influence on ecosystem dynamics. 53 samples of aeolian material from Alatna Valley, Victoria Valley, Miers Valley, and Taylor Valley (Taylor Glacier, East Lake Bonney, F6 (Lake Fryxell), and Explorer’s Cove) were collected at five heights (5, 10, 20, 50, 100 cm) above the surface seasonally for 2013 through 2015. The sediment was analyzed for soluble solids, total and organic carbon, minerology, and bulk chemistry. Of the soluble component, the major anions varied between Cl- and HCO3-, and the major cation was Na+ for all sites. Soluble N:P ratios in the aeolian material reflect nutrient limitations seen in MDV soils, where younger, coastal soils are N-limited, while older, up valley soils are P-limited. Material from East Lake Bonney was P-limited in the winter samples, but N-limited in the full year samples, suggesting different sources of material based on season. Analysis of soluble salts in aeolian material in Taylor Valley compared to published soil literature demonstrates a primarily down valley transport of materials from Taylor Glacier towards the coast. The bulk chemistry suggests that the aeolian material is highly unweathered (CIA values less than 60 %), but scanning electron microscope images show alteration for some individual sediment grains. The mineralogy was reflective of local rocks, specifically the McMurdo Volcanics, Ferrar Dolerite, Beacon Sandstone and granite, but variations in major oxide percentages and rare earth element signatures could not be explained by mixing lines between these four rock types. This potentially suggests that there may be an additional, and possibly distant, source of aeolian material to the MDV that is not accounted for. This work provides the first fully elevated spatial and temporal analysis of the geochemistry of aeolian material from the Dry Valleys, and contributes to a better understanding of sediment provenance and how aeolian deposition may affect surface biological communities.
1 aDiaz, Melisa, A.1 aLyons, Berry uhttp://rave.ohiolink.edu/etdc/view?acc_num=osu150046821614772503797nas a2200157 4500008004100000245012100041210007100162260001200233300001600245490000700261520325100268100001703519700002403536700001703560856006203577 2017 eng d00aA temporal stable isotopic (δ18O, δD, d-excess) comparison in glacier meltwater streams, Taylor Valley, Antarctica0 atemporal stable isotopic δ18O δD dexcess comparison in glacier m c08/2017 a3069 - 30830 v313 aIn this paper, we describe the importance of hyporheic dynamics within Andersen Creek and Von Guerard Stream, Taylor Valley, Antarctica, from the 2010–2011 melt season using natural tracers. Water collection started at flow onset and continued, with weekly hyporheic‐zone sampling. The water δ18O and δD values were isotopically lighter in the beginning and heavier later in the season. D‐excess measurements were used as an indicator of mixing because an evaporative signature was evident and distinguishable between 2 primary end‐members (glacier meltwater and hyporheic zone). Hyporheic‐zone influence on the channel water was variable with a strong control on streamwater chemistry, except at highest discharges. This work supports previous research indicating that Von Guerard Stream has a large, widespread hyporheic zone that varies in size with time and discharge. Andersen Creek, with a smaller hyporheic zone, displayed hyporheic‐zone solute interaction through the influence from subsurface hypersaline flow. Overall, the evolution of Taylor Valley hyporheic‐zone hydrology is described seasonally. In mid‐December, the hyporheic zone is a dynamic system exchanging with the glacier meltwater in the channel, and with diminishing flow in January, the hyporheic zone drains back into the channel flow also impacting stream chemistry. This work adds new information on the role of hyporheic zone–stream interaction in these glacier meltwater streams.
1 aLeslie, D.L.1 aWelch, Kathleen, A.1 aLyons, Berry uhttp://onlinelibrary.wiley.com/doi/10.1002/hyp.11245/full00939nas a2200217 4500008004100000022001400041245011900055210006900174260001200243100001600255700002000271700002200291700002100313700002500334700002000359700002400379700001700403700002200420700002400442856025500466 2016 eng d a0722-406000aEvidence for dispersal and habitat controls on pond diatom communities from the McMurdo Sound Region of Antarctica0 aEvidence for dispersal and habitat controls on pond diatom commu c02/20161 aSakaeva, A.1 aSokol, Eric, R.1 aKohler, Tyler, J.1 aStanish, Lee, F.1 aSpaulding, Sarah, A.1 aHowkins, Adrian1 aWelch, Kathleen, A.1 aLyons, Berry1 aBarrett, John, E.1 aMcKnight, Diane, M. uhttp://link.springer.com/10.1007/s00300-016-1901-6http://link.springer.com/content/pdf/10.1007/s00300-016-1901-6http://link.springer.com/content/pdf/10.1007/s00300-016-1901-6.pdfhttp://link.springer.com/article/10.1007/s00300-016-1901-6/fulltext.html00639nas a2200205 4500008004100000245007600041210006900117260001200186300001300198490000700211100001700218700002500235700001700260700002400277700001700301700002500318700002100343700001700364856005200381 2016 eng d00aHydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica0 aHydrological Controls on Ecosystem Dynamics in Lake Fryxell Anta c07/2016 ae01590380 v111 aHerbei, Radu1 aRytel, Alexander, L.1 aLyons, Berry1 aMcKnight, Diane, M.1 aJaros, Chris1 aGooseff, Michael, N.1 aPriscu, John, C.1 aHewitt, Judi uhttp://dx.plos.org/10.1371/journal.pone.015903802242nas a2200181 4500008004100000245012300041210006900164260001200233300001400245490000700259520163300266100002101899700002501920700002401945700001701969700001701986856005702003 2016 eng d00aPatterns of hydrologic connectivity in the McMurdo dry valleys, Antarctica: a synthesis of 20 years of hydrologic data0 aPatterns of hydrologic connectivity in the McMurdo dry valleys A c04/2016 a2958-29750 v303 aStreams in the McMurdo Dry Valleys (MDVs) of Antarctica moderate an important hydrologic and biogeochemical connection between upland alpine glaciers, valley-bottom soils, and lowland closed-basin lakes. Moreover, MDV streams are simple but dynamic systems ideal for studying interacting hydrologic and ecological dynamics. This work synthesizes 20 years of hydrologic data, collected as part of the MDVs Long-Term Ecological Research project, to assess spatial and temporal dynamics of hydrologic connectivity between glaciers, streams, and lakes. Long-term records of stream discharge (Q), specific electrical conductance (EC), and water temperature (T) from 18 streams were analysed in order to quantify the magnitude, duration, and frequency of hydrologic connections over daily, annual, and inter-annual timescales. At a daily timescale, we observe predictable diurnal variations in Q, EC, and T. At an annual timescale, we observe longer streams to be more intermittent, warmer, and have higher median EC values, compared to shorter streams. Longer streams also behave chemostatically with respect to EC, whereas shorter streams are more strongly characterized by dilution. Inter-annually, we observe significant variability in annual runoff volumes, likely because of climatic variability over the 20 record years considered. Hydrologic connections at all timescales are vital to stream ecosystem structure and function. This synthesis of hydrologic connectivity in the MDVs provides a useful end-member template for assessing hydrologic connectivity in more structurally complex temperate watersheds.
1 aWlostowski, Adam1 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aJaros, Chris1 aLyons, Berry uhttp://onlinelibrary.wiley.com/doi/10.1002/hyp.1081801836nas a2200193 4500008004100000245013000041210006900171260001200240300001600252490000700268520116600275100002501441700002401466700002001490700002401510700002401534700001701558856006701575 2016 eng d00aStream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica0 aStream biogeochemical and suspended sediment responses to permaf c03/2016 a1723 - 17320 v133 aStream channels in the McMurdo Dry Valleys are characteristically wide, incised, and stable. At typical flows, streams occupy a fraction of the oversized channels, providing habitat for algal mats. In January 2012, we discovered substantial channel erosion and subsurface thermomechanical erosion undercutting banks of the Crescent Stream. We sampled stream water along the impacted reach and compared concentrations of solutes to the long-term data from this stream ( ∼ 20 years of monitoring). Thermokarst-impacted stream water demonstrated higher electrical conductivity, and concentrations of chloride, sulfate, sodium, and nitrate than the long-term medians. These results suggest that this mode of lateral permafrost degradation may substantially impact stream solute loads and potentially fertilize stream and lake ecosystems. The potential for sediment to scour or bury stream algal mats is yet to be determined, though it may offset impacts of associated increased nutrient loads to streams.
1 aGooseff, Michael, N.1 aVan Horn, David, J.1 aSudman, Zachary1 aMcKnight, Diane, M.1 aWelch, Kathleen, A.1 aLyons, Berry uhttp://www.biogeosciences.net/13/1723/2016/bg-13-1723-2016.pdf03321nas a2200205 4500008004100000022001400041245008600055210006900141260001200210300001600222490000700238520262100245100001702866700002302883700002402906700002502930700001502955700002402970856012102994 2015 eng d a0091-761300aAntarctic streams as a potential source of iron for the Southern Ocean: Figure 1.0 aAntarctic streams as a potential source of iron for the Southern c11/2016 a1003 - 10060 v433 aDue to iron’s role in oceanic primary production, there has been great interest in quantifying the importance of Fe in regions where concentrations are very low and macronutrients, nitrate and phosphate, are available. Measurements of filterable (i.e., <0.4 μm) Fe concentrations in streams from Taylor Valley, McMurdo Dry Valleys, Antarctica, suggest that coastal-zone stream Fe input to the Southern Ocean could potentially play an important role in primary production in nearshore regions. Filterable Fe (fFe) data from streams in the McMurdo Dry Valleys were used to represent glacier meltwater that flows through ice-free landscape with the potential of transporting Fe to the Antarctic coastal zone. Estimates of potential fFe flux to the Antarctic Peninsula region using our mean fFe concentration of 10.6 µg L–1 combined with an estimate of ice-free area for the Antarctic Peninsula result in an fFe flux of 1.2 × 107 g yr–1. Although small compared to iceberg and aeolian Fe fluxes, future stream input to the Southern Ocean could increase due to glacier retreat and
1 aLyons, Berry1 aDailey, Kelsey, R.1 aWelch, Kathleen, A.1 aDeuerling, Kelly, M.1 aWelch, Sue1 aMcKnight, Diane, M. uhttp://geology.gsapubs.org/lookup/doi/10.1130/G36989.1http://geology.geoscienceworld.org/lookup/doi/10.1130/G36989.103075nas a2200157 4500008004100000024003700041245014500078210006900223260003500292300000700327490002500334520248000359100002402839700001702863856003702880 2015 eng d ahttp://hdl.handle.net/1811/6888700aChemical Weathering and Mineralogy of McMurdo Dry Valley Streams: Examining the Controls of Current and Future Ephemeral Stream Geochemistry0 aChemical Weathering and Mineralogy of McMurdo Dry Valley Streams aOhio State Universityc05/2015 a380 vUndergraduate Theses3 aThe McMurdo Dry Valleys form the largest ice-free region in Antarctica and are the coldest, driest deserts in the world. But, for approximately 6-12 weeks per year in the austral summer, continuous sunlight and near-freezing temperatures create meltwater streams that descend from the surrounding alpine glaciers. These ephemeral streams are a distinctive feature in the barren dry valley landscape and are important sources of nutrients and solutes from the weathering of streambed and hyporheic zone materials. This setting has been a US National Science Foundation funded Long-Term Ecological Research (LTER) project since 1993. A major goal of the McMurdo LTER is to understand how liquid water, the primary limiting condition for life in Antarctica, is affected by climate variability. The McMurdo Dry Valleys are extremely climate-sensitive and even seemingly small variations in temperature can have a drastic effect on hydrological activity. The McMurdo LTER program has been successful in collecting and analyzing a large amount of stream data pertaining to weathering products but, a more comprehensive analysis and interpretation of the data have yet to be undertaken. Assessment of current and future stream geochemistry is critical to predict the impact of increased water flow due to glacier melt and increasing temperature which could greatly influence the ecological function and biologic diversity in the McMurdo Dry Valleys. Surface sediments were collected at multiple locations from ephemeral streams and analyzed using a scanning electron microscope and x-ray diffraction to determine sediment mineralogy and evidence of chemical weathering. Geochemical reactions were modeled using previously collected stream water data and the USGS PHREEQC software for the speciation calculations and the assessment of the solubility controlling solid phases. Chemical weathering was apparent through visible mineral alteration and the formation of secondary weathering products. Modeling results indicate that stream geochemistry will not significantly be affected by increased water temperature in the future. These results suggest stream geochemistry and chemical weathering may instead be controlled primarily through hydrologic exchange in the hyporheic zone.
1 aScheuermann, Jordan1 aLyons, Berry uhttp://hdl.handle.net/1811/6888708594nas a2200241 4500008004100000022001300041245020300054210006900257260001200326300001400338490000800352520755800360100001907918700002407937700002007961700002407981700002308005700002308028700001708051700002708068700002708095856023008122 2015 eng d a0009254100aComparison of arsenic and molybdenum geochemistry in meromictic lakes of the McMurdo Dry Valleys, Antarctica: Implications for oxyanion-forming trace element behavior in permanently stratified lakes0 aComparison of arsenic and molybdenum geochemistry in meromictic c05/2015 a110 - 1250 v4043 aWater samples were collected for arsenic (As) and molybdenum (Mo) analysis from different depths in Lakes Hoare and Fryxell, both of which are located in the Taylor Valley within the McMurdo Dry Valleys of Antarctica. Sampling depths within each lake were chosen to capture variations in As and Mo concentrations and As speciation in the oxic mixolimnia and anoxic monimolimnia of these meromictic lakes. Arsenic concentrations ranged from 0.67 nmol kg− 1 to 3.54 nmol kg− 1 in Lake Hoare and from 1.69 nmol kg− 1 to 17.5 nmol kg− 1 in Lake Fryxell. Molybdenum concentrations varied between 5.05 nmol kg− 1 and 43 nmol kg− 1 in Lake Hoare, and between 3.52 nmol kg− 1 and 25.5 nmol kg− 1 in Lake Fryxell. Concentrations of As and Mo generally increased with depth in the mixolimnion of each lake, consistent with uptake near the ice–water interface by organic particles and/or Fe/Mn oxides/oxyhydroxides, followed by gravitational settling and regeneration/remineralization at depth in the vicinity of the redoxcline. Arsenic concentrations either remained constant (Hoare) or increased with depth (Fryxell) in the anoxic monimolimnia, whereas Mo exhibited dramatic decreases in concentrations across the redoxcline in both lakes. Geochemical modeling predicts that As and Mo occur as thioanions in the anoxic bottom waters of Lakes Hoare and Fryxell, and further that the contrasting behavior of both trace elements reflects the respective reactivity of their thioanions towards Fe-sulfide minerals such as mackinawite (FeS) and/or pyrite (FeS2). More specifically, the geochemical model suggests that Fe-sulfide mineral precipitation in the anoxic monimolimnia of both lakes regulates dissolved sulfide concentrations at levels that are too low for As-sulfide minerals (e.g., orpiment, realgar) to precipitate, whereas mackinawite and/or pyrite react(s) with particle reactive thiomolybdate anions, possibly forming an Fe–Mo–S mineral that precipitates and, hence, leads to Mo removal from solution.
1 aYang, Ningfang1 aWelch, Kathleen, A.1 aMohajerin, Jade1 aTelfeyan, Katherine1 aChevis, Darren, A.1 aGrimm, Deborah, A.1 aLyons, Berry1 aWhite, Christopher, D.1 aJohannesson, Karen, H. uhttp://linkinghub.elsevier.com/retrieve/pii/S0009254115001874http://api.elsevier.com/content/article/PII:S0009254115001874?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S0009254115001874?httpAccept=text/plain01522nas a2200181 4500008004100000022001400041245007100055210006900126260001200195300001400207490000700221520096100228100002101189700002401210700001701234700002401251856006501275 2015 eng d a0954-102000aExperimental formation of pore fluids in McMurdo Dry Valleys soils0 aExperimental formation of pore fluids in McMurdo Dry Valleys soi c04/2015 a163 - 1710 v273 aThe aim of the study was to determine if soil salt deliquescence and brine hydration can occur under laboratory conditions using natural McMurdo Dry Valleys soils. The experiment was a laboratory analogue for the formation of isolated patches of hypersaline, damp soil, referred to as ‘wet patches’. Soils were oven dried and then hydrated in one of two humidity chambers: one at 100% relative humidity and the second at 75% relative humidity. Soil hydration is highly variable, and over the course of 20 days of hydration, ranged from increases in water content by mass from 0–16% for 122 soil samples from Taylor Valley. The rate and absolute amount of soil hydration correlates well with the soluble salt content of the soils but not with grain size distribution. This suggests that the formation of bulk pore waters in these soils is a consequence of salt deliquescence and hydration of the brine from atmospheric water vapour.
1 aLevy, Joseph, S.1 aFountain, Andrew, G1 aLyons, Berry1 aWelch, Kathleen, A. uhttp://www.journals.cambridge.org/abstract_S095410201400047906572nas a2200169 4500008004100000245008400041210006900125520601300194100001906207700002406226700001506250700001906265700001706284700002106301700002406322856005606346 2015 eng d00aPatterns and processes of salt efflorescences in the McMurdo region, Antarctica0 aPatterns and processes of salt efflorescences in the McMurdo reg3 aEvaporite salts are abundant around the McMurdo region, Antarctica (~78°S) due to very low precipitation, low relative humidity, and limited overland flow. Hygroscopic salts in the McMurdo Dry Valleys (MDVs) are preferentially formed in locations where liquid water is present in the austral summer, including along ephemeral streams, ice-covered lake boundaries, or shallow groundwater tracks. In this study, we collected salts from the Miers, Garwood, and Taylor Valleys on the Antarctic continent, as well as around McMurdo Station on Ross Island in close proximity to water sources with the goal of understanding salt geochemistry in relationship to the hydrology of the area. Halite is ubiquitous; sodium is the major cation (ranging from 70%–90% of cations by meq kg−1 sediment) and chloride is the major anion (>50%) in nearly all samples. However, a wide variety of salt phases and morphologies are tentatively identified through scanning electron microscopy (SEM) and X-ray diffraction (XRD) work. We present new data that identifies trona (Na3(CO3)(HCO3)·2H2O), tentative gaylussite (Na2Ca(CO3)2·5H2O), and tentative glauberite (Na2Ca(SO4)2) in the MDV, of which the later one has not been documented previously. Our work allows for the evaluation of processes that influence brine evolution on a local scale, consequently informing assumptions underlying large-scale processes (such as paleoclimate) in the MDV. Hydrological modeling conducted in FREZCHEM and PHREEQC suggests that a model based on aerosol deposition alone in low elevations on the valley floor inadequately characterizes salt distributions found on the surfaces of the soil because it does not account for other hydrologic inputs/outputs. Implications for the salt distributions include their use as tracers for paleolake levels, geochemical tracers of ephemeral water tracks or “wet patches” in the soil, indicators of chemical weathering products, and potential delineators of ecological communities.
1 aBisson, K., M.1 aWelch, Kathleen, A.1 aWelch, Sue1 aSheets, J., M.1 aLyons, Berry1 aLevy, Joseph, S.1 aFountain, Andrew, G uhttp://aaarjournal.org/doi/abs/10.1657/AAAR0014-02400864nas a2200217 4500008004100000245020400041210006900245260001200314300001600326490000700342100002400349700001600373700002400389700002500413700001700438700001300455700001700468700002100485700002100506856011900527 2015 eng d00aPotential for real-time understanding of coupled hydrologic and biogeochemical processes in stream ecosystems: Future integration of telemetered data with process models for glacial meltwater streams0 aPotential for realtime understanding of coupled hydrologic and b c08/2015 a6725 - 67380 v511 aMcKnight, Diane, M.1 aCozzetto, K1 aCullis, James, D.S.1 aGooseff, Michael, N.1 aJaros, Chris1 aKoch, J.1 aLyons, Berry1 aNeupauer, R., M.1 aWlostowski, Adam uhttp://doi.wiley.com/10.1002/2015WR017618http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F2015WR01761804591nas a2201033 4500008004100000022001400041245009100055210006900146260001600215300001100231490000700242520199300249100002002242700002202262700001802284700001602302700002002318700001502338700001802353700001502371700001802386700001702404700001602421700001402437700001402451700001702465700001802482700002102500700001602521700001102537700001502548700002002563700001902583700001602602700001802618700001602636700001402652700001602666700001502682700001602697700001602713700001602729700001802745700001602763700001602779700001302795700001802808700001202826700001402838700001402852700001402866700001602880700001402896700001402910700002002924700001102944700001702955700001502972700002502987700001603012700001703028700001703045700001503062700001703077700001403094700001403108700001703122700001803139700001603157700002403173700002303197700001603220700001503236700001603251700001803267700001803285700001803303700001803321700001503339700001803354700002003372700001603392700001503408700001803423700001703441700001303458700002103471856006503492 2015 eng d a0954-102000aA roadmap for Antarctic and Southern Ocean science for the next two decades and beyond0 aroadmap for Antarctic and Southern Ocean science for the next tw cJan-02-2015 a3 - 180 v273 aAntarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone
1 aKennicutt, M.C.1 aChown, Steven, L.1 aCassano, J.J.1 aLiggett, D.1 aPeck, Lloyd, S.1 aMassom, R.1 aRintoul, S.R.1 aStorey, J.1 aVaughan, D.G.1 aWilson, T.J.1 aAllison, I.1 aAyton, J.1 aBadhe, R.1 aBaeseman, J.1 aBarrett, P.J.1 aBell, Elanor, R.1 aBertler, N.1 aBo, S.1 aBrandt, A.1 aBromwich, David1 aCary, Craig, S1 aClark, M.S.1 aConvey, Peter1 aCosta, E.S.1 aCowan, D.1 aDeconto, R.1 aDunbar, R.1 aElfring, C.1 aEscutia, C.1 aFrancis, J.1 aFricker, H.A.1 aFukuchi, M.1 aGilbert, N.1 aGutt, J.1 aHavermans, C.1 aHik, D.1 aHosie, G.1 aJones, C.1 aKim, Y.D.1 aLe Maho, Y.1 aLee, S.H.1 aLeppe, M.1 aLeitchenkov, G.1 aLi, X.1 aLipenkov, V.1 aLochte, K.1 aLópez-Martínez, J.1 aüdecke, C.1 aLyons, Berry1 aMarenssi, S.1 aMiller, H.1 aMorozova, P.1 aNaish, T.1 aNayak, S.1 aRavindra, R.1 aRetamales, J.1 aRicci, C.A.1 aRogan-Finnemore, M.1 aRopert-Coudert, Y.1 aSamah, A.A.1 aSanson, L.1 aScambos, T.1 aSchloss, I.R.1 aShiraishi, K.1 aSiegert, M.J.1 aSimões, J.C.1 aStorey, B.1 aSparrow, M.D.1 aWall, Diana, H.1 aWalsh, J.C.1 aWilson, G.1 aWinther, J.G.1 aXavier, J.C.1 aYang, H.1 aSutherland, W.J. uhttp://www.journals.cambridge.org/abstract_S095410201400067404850nas a2200217 4500008004100000022001300041245007600054210006900130260001200199300001400211490000800225520403500233100001704268700001704285700002204302700001904324700001404343700002404357700002104381856023004402 2014 eng d a0009254100aBoron isotopic geochemistry of the McMurdo Dry Valley lakes, Antarctica0 aBoron isotopic geochemistry of the McMurdo Dry Valley lakes Anta c10/2014 a152 - 1640 v3863 a
The geochemistry of boron was investigated in the ice-covered lakes and glacier meltwater streams within Taylor and Wright Valley of the McMurdo Dry Valleys (MCM), Antarctica, in order to achieve a greater understanding of the source of boron to these aquatic systems and how in-lake processes control boron concentration. Selected lake depths (surface and bottom water) and streams were analyzed for boron geochemistry. Boron stable isotope values in these waters span the range of + 12.3‰ to + 51.4‰, which corresponds to the variations from glacier meltwater streams to the hypolimnion of a highly evaporated hypersaline lake. The data demonstrate that the major sources of B to the aquatic system are via terrestrial chemical weathering of aluminosilicates within the stream channels, and a marine source, either currently being introduced by marine-derived aerosols or in the form of ancient seawater. Lakes Fryxell, Hoare, and upper waters of Lake Joyce, which experience more terrestrial influence of aluminosilicate chemical weathering via glacial meltwater streams, display a mixture of these two major sources, while the source of B in the bottom waters of Lake Joyce appears to be primarily of marine origin. Lakes Bonney and Vanda and the Blood Falls brine have a marine-like source whose δ11B values have become more positive by mineral precipitation and/or adsorption. Don Juan Pond displays a terrestrial aluminosilicate influence of a marine-like source. These hypersaline lake waters from Antarctica are similar in δ11B to other hypersaline lake waters globally, suggesting that similar processes control their B geochemistry.
1 aLeslie, D.L.1 aLyons, Berry1 aWarner, Nathaniel1 aVengosh, Avner1 aOlesik, J1 aWelch, Kathleen, A.1 aDeuerling, Kelly uhttp://linkinghub.elsevier.com/retrieve/pii/S000925411400391Xhttp://api.elsevier.com/content/article/PII:S000925411400391X?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S000925411400391X?httpAccept=text/plain02515nas a2200169 4500008004100000022001400041245016900055210006900224260001600293300001400309490000700323520188900330100002102219700002302240700001702263856006502280 2014 eng d a0954-102000aThe effects of high meltwater on the limnology of Lake Fryxell and Lake Hoare, Taylor Valley, Antarctica, as shown by dissolved gas, tritium and chlorofluorocarbons0 aeffects of high meltwater on the limnology of Lake Fryxell and L cJan-08-2014 a331 - 3400 v263 a
Small changes in the availability of liquid water can have profound effects on the water levels, aqueous chemistry and biogeochemical dynamics of the closed-basin, perennially ice-covered lakes of the McMurdo Dry Valleys, Antarctica. We have compiled the published and unpublished data on dissolved gas, tritium and chlorofluorocarbons (CFCs) for Lake Fryxell and Lake Hoare to determine the effects of a high meltwater year (2001–02 summer) on the lakes. The dissolved gas, tritium and CFC data indicate that the pulse of freshwater that flowed onto the surfaces of the lakes did not mix extensively with the upper water column. At the bottom of Lake Hoare, the measurable CFC and lower dissolved gas values suggest that the recent meltwater may have mixed with bottom waters. The probable mechanism for this transportation is weak density currents with c. 0.1–1.5% surface water being transported downwards in Lake Hoare. This deep water input, while not constant, may have a significant effect on the chemistry of the bottom waters in Lake Hoare over time. In Lake Fryxell, the tritium and CFC data indicate that the recent meltwater did not significantly affect the bottom water chemistry; therefore, weak density currents may not be present in Lake Fryxell.
1 aDowling, Carolyn1 aPoreda, Robert, J.1 aLyons, Berry uhttp://www.journals.cambridge.org/abstract_S095410201300062X03450nas a2200169 4500008004100000245009600041210006900137260004500206300000800251490001800259520283100277100003003108700001703138700002003155700001803175856008703193 2014 eng d00aElemental Cycling in a Flow-Through Lake in the McMurdo Dry Valleys, Antarctica: Lake Miers0 aElemental Cycling in a FlowThrough Lake in the McMurdo Dry Valle aColumbusbOhio State Universityc06/2014 a1220 vMaster Thesis3 aThe ice-free area in Antarctica known as the McMurdo Dry Valleys has been monitored biologically, meteorologically, hydrologically, and geochemically continuously since the onset of the MCM-LTER in 1993. This area contains a functioning ecosystem living in an extremely delicate environment. Only a few degrees of difference in air temperature can effect on the hydrologic system, making it a prime area to study ongoing climate change. The unique hydrology of Lake Miers, i.e. its flowthrough nature, makes it an ideal candidate to study the mass balance of a McMurdo Dry Valley lake because both input and output concentrations can be analyzed. This study seeks to understand the physical and geochemical hydrology of Lake Miers relative to other MCMDV lakes. Samples were collected from the two inflowing streams, the outflowing stream, and the lake itself at 11 depths to analyze a suite of major cations (Li+ , Na+ , K+ , Mg+ , Ca2+), major anions (Cl- , Br- , F- , SO4 2- , ΣCO2), nutrients (NO2 - , NO3 - , NH4 + , PO4 3- , Si), trace elements (Mo, Rb, Sr, Ba, U, V, Cu, As), water isotopes (δD, δ 18O), and dissolved organic carbon (DOC). The lake acts as a sink for all constituents analyzed, but by amounts varying from ~10% (DOC, NH4 + , and NO2 - ) to PO4 3- at nearly 100%, indicating this lake may be P-limited. Cl- , a typically conservative element, was only 79% retained, which could be due to the late season sample collection, hyperheic zone influences, or other factors. The hyperheic zone’s role in lake and stream iii geochemistry was analyzed with a 24-hour sampling event. The positive relationships between stream flow and solute concentrations indicate that the delta in Miers Valley plays a role in controlling stream geochemistry and future work could help to explain this relationship. Lake depth profiles of trace elements U, V, Cu, and As decrease relative to Cl in the deepest part of the lake, while non-reducing trace elements show increases with depth. SO4 2- and dissolved O2 lake depth profiles decrease from 53 μM and 22.3 mg/L to 18 μM and 1.8 mg/L, respectively, at depth, indicating that the lake bottom is under reducing and near anoxic conditions. Lake depth profiles show that, while the “biological pump” may be a factor controlling lake chemistry, it is masked by the stronger signal of diffusion from the lake bottom sediments and requires future work to understand fully. The “age” of Lake Miers was calculated with a diffusion model to be 84 years, which agrees with other estimates of 100-300 years. The diffusion of solutes from the lake bottom and the redox conditions at depth are two major processes controlling the geochemistry of Lake Miers, and future work can help determine their extent and relationship with other processes.
1 aFair, Alexandria, Corinne1 aLyons, Berry1 aCarey, Anne, E.1 aChin, Yu-Ping uhttps://etd.ohiolink.edu/!etd.send_file?accession=osu1413291502&disposition=inline00623nas a2200169 4500008004100000245009600041210006900137260001200206300001200218490000700230100002100237700001800258700002100276700002200297700001700319856011700336 2014 eng d00aRadiocarbon abundance and reservoir effects in lakes of the McMurdo Dry Valleys, Antarctica0 aRadiocarbon abundance and reservoir effects in lakes of the McMu c05/2014 a811-8260 v591 aDoran, Peter, T.1 aKenig, Fabien1 aKnoepfle, Lawson1 aMikucki, Jill, A.1 aLyons, Berry uhttps://mcm.lternet.edu/content/radiocarbon-abundance-and-reservoir-effects-lakes-mcmurdo-dry-valleys-antarctica03560nas a2200397 4500008004100000022001400041245005200055210004800107260001200155300001400167490000700181520243500188100001802623700002202641700001902663700002502682700001902707700002002726700002202746700002102768700002402789700002102813700002302834700002702857700002302884700002802907700001702935700001902952700002202971700002002993700002103013700002503034700002603059700002003085856005703105 2014 eng d a0012-961500aThe spatial structure of Antarctic biodiversity0 aspatial structure of Antarctic biodiversity c05/2014 a203 - 2440 v843 aPatterns of environmental spatial structure lie at the heart of the most fundamental and familiar patterns of diversity on Earth. Antarctica contains some of the strongest environmental gradients on the planet and therefore provides an ideal study ground to test hypotheses on the relevance of environmental variability for biodiversity. To answer the pivotal question, “How does spatial variation in physical and biological environmental properties across the Antarctic drive biodiversity?” we have synthesized current knowledge on environmental variability across terrestrial, freshwater, and marine Antarctic biomes and related this to the observed biotic patterns. The most important physical driver of Antarctic terrestrial communities is the availability of liquid water, itself driven by solar irradiance intensity. Patterns of biota distribution are further strongly influenced by the historical development of any given location or region, and by geographical barriers. In freshwater ecosystems, free water is also crucial, with further important influences from salinity, nutrient availability, oxygenation, and characteristics of ice cover and extent. In the marine biome there does not appear to be one major driving force, with the exception of the oceanographic boundary of the Polar Front. At smaller spatial scales, ice cover, ice scour, and salinity gradients are clearly important determinants of diversity at habitat and community level. Stochastic and extreme events remain an important driving force in all environments, particularly in the context of local extinction and colonization or recolonization, as well as that of temporal environmental variability. Our synthesis demonstrates that the Antarctic continent and surrounding oceans provide an ideal study ground to develop new biogeographical models, including life history and physiological traits, and to address questions regarding biological responses to environmental variability and change.
My dissertation research utilizes stable isotopes as tracers of water and solute sources to study specific geochemical (solute origin) and hydrological (glacier meltwater source across a season comparing water contributions from hyporheic zone and/or glacier melt and residence time of precipitation within a managed water supply) problems within McMurdo Dry Valleys (MCM), Antarctica, and Central Ohio, USA. In Chapter II, δ11B isotopic and dissolved B measurements are used to infer the origin of B within MCM aquatic system. Boron stable isotopic values span the range of +12.3‰ to +51.4‰, varying from glacier meltwater streams to the hypolimnion of a highly evaporated hypersaline lake. These data demonstrate that the major sources of B are chemical weathering of alumniosilicates within the stream channels, and a marine source, either currently introduced by marine-derived aerosols or from ancient seawater. In-lake processes create a more positive δ11B through adsorption or mineral precipitation. The glacier meltwater streams, Lakes Fryxell, Hoare, and upper waters of Lake Joyce display a mixture of these two sources, with Lake Joyce bottom waters primarily of marine origin. Lakes Bonney and Vanda and Blood Falls brine are interpreted as having a marine-like source changed by in-lake processes to result in a more positive δ11B, while Don Juan Pond displays a more terrestrial influence. In Chapter III, δ18O and δD are used to trace water source variation via hyporheic zone or glacier melt within two MCM streams over an entire melt season. The isotopic variation of these streams was more negative at the beginning of the season and more positive later. D-excess measurements were used to infer mixing between hyporheic storage and glacier meltwater. It was supported that Von Guerard Stream has a large, widespread hyporheic zone that changes with time and discharge amounts. The chemistry of Andersen Creek also displayed hyporheic zone influence at certain times of the year. This work adds important new information on the role of hyperheic zone-stream interactions, and supports the short term, more physically based, descriptions of hyporheic dynamics explained in the past decade. Chapter IV describes water flow and travel time within a human managed watershed-reservoir system by measuring the δ18O and δD of the precipitation source to the reservoirs and finally to the distribution system, the tap. Generally, the tap waters experienced little lag time in the managed system, having a residence time of about two months. Tap and reservoir waters preserved the precipitation signal with the reservoir morphology acting as an important control. These water supply reservoirs functioned more like a river system with a faster throughput of water and larger variations in chemical parameters. Other water supply reservoirs have a greater capacity with a larger amount of water supply usage through a more lacustrine environment, which displays more constant solute concentrations and longer flow-through times. This work provides a basic understanding of a regional water supply system in central Ohio, reservoir isotopic dynamics, and Ohio precipitation sources.
10aAntarctica10aboron isotopes10ahyporheic zone10aMcMurdo Dry Valleys10aOhio precipitation source10aoxygen-18 and deuterium isotopes10asaline lake1 aLeslie, D.L.1 aLyons, Berry u http://rave.ohiolink.edu/etdc/view?acc_num=osu138600003700663nas a2200193 4500008004100000245008400041210006900125260001200194300001200206490000700218100001700225700001700242700001700259700001900276700002400295700001900319700002400338856010700362 2013 eng d00aThe carbon stable isotope biogeochemistry of streams, Taylor Valley, Antarctica0 acarbon stable isotope biogeochemistry of streams Taylor Valley A c05/2013 a26 - 360 v321 aLyons, Berry1 aLeslie, D.L.1 aHarmon, R.S.1 aNeumann, Klaus1 aWelch, Kathleen, A.1 aBisson, K., M.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/carbon-stable-isotope-biogeochemistry-streams-taylor-valley-antarctica00735nas a2200181 4500008004100000245015100041210006900192260001200261300001400273490000700287100002300294700002000317700002400337700002400361700002400385700001700409856012700426 2013 eng d00aDo Cryoconite Holes have the Potential to be Significant Sources of C, N, and P to Downstream Depauperate Ecosystems of Taylor Valley, Antarctica?0 aDo Cryoconite Holes have the Potential to be Significant Sources c11/2013 a440 - 4540 v451 aBagshaw, Elizabeth1 aTranter, Martyn1 aFountain, Andrew, G1 aWelch, Kathleen, A.1 aBasagic, Hassan, J.1 aLyons, Berry uhttps://mcm.lternet.edu/content/do-cryoconite-holes-have-potential-be-significant-sources-c-n-and-p-downstream-depauperate00638nas a2200169 4500008004100000245013200041210006900173260001200242300001600254490000800270100002100278700002400299700002100323700002400344700001700368856008300385 2013 eng d00aGarwood Valley, Antarctica: A new record of Last Glacial Maximum to Holocene glaciofluvial processes in the McMurdo Dry Valleys0 aGarwood Valley Antarctica A new record of Last Glacial Maximum t c09/2013 a1484 - 15020 v1251 aLevy, Joseph, S.1 aFountain, Andrew, G1 aO'Connor, J., E.1 aWelch, Kathleen, A.1 aLyons, Berry uhttp://bulletin.geoscienceworld.org/content/early/2013/06/07/B30783.1.abstract00488nas a2200145 4500008004100000245007700041210006900118260001200187300001200199490000700211100002100218700001700239700001700256856006900273 2013 eng d00aUnderstanding Terrestrial Ecosystem Response to Antarctic Climate Change0 aUnderstanding Terrestrial Ecosystem Response to Antarctic Climat c01/2013 a33 - 330 v941 aLevy, Joseph, S.1 aLyons, Berry1 aAdams, Byron uhttp://onlinelibrary.wiley.com/doi/10.1002/2013EO030009/abstract00730nas a2200193 4500008004100000245009900041210006900140300001100209100002100220700002400241700002500265700002200290700002200312700002400334700001700358700002200375700002000397856011900417 2013 eng d00aWater track modification of soil ecosystems in the Lake Hoare basin, Taylor Valley, Antarctica0 aWater track modification of soil ecosystems in the Lake Hoare ba a1 - 101 aLevy, Joseph, S.1 aFountain, Andrew, G1 aGooseff, Michael, N.1 aBarrett, John, E.1 aVantreese, Robert1 aWelch, Kathleen, A.1 aLyons, Berry1 aNielsen, Uffe, N.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/water-track-modification-soil-ecosystems-lake-hoare-basin-taylor-valley-antarctica00619nas a2200193 4500008004100000245006400041210005800105260001100163300001100174490000700185100001700192700002400209700002900233700001700262700002400279700001600303700002100319856008500340 2012 eng d00aThe geochemistry of upland ponds, Taylor Valley, Antarctica0 ageochemistry of upland ponds Taylor Valley Antarctica c2/2012 a3 - 140 v241 aLyons, Berry1 aWelch, Kathleen, A.1 aGardner, Christopher, B.1 aJaros, Chris1 aMoorhead, Daryl, L.1 aKnoepfle, J1 aDoran, Peter, T. uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=848335100514nas a2200145 4500008004100000245006300041210005600104260001200160490000700172100002100179700002400200700002400224700001700248856010300265 2012 eng d00aHypersaline “wet patches” in Taylor Valley, Antarctica0 aHypersaline wet patches in Taylor Valley Antarctica c03/20120 v391 aLevy, Joseph, S.1 aFountain, Andrew, G1 aWelch, Kathleen, A.1 aLyons, Berry uhttps://mcm.lternet.edu/content/hypersaline-%E2%80%9Cwet-patches%E2%80%9D-taylor-valley-antarctica00621nas a2200181 4500008004100000245010500041210006900146260001200215300001200227490000700239100002000246700002400266700001900290700001700309700002100326700002100347856007100368 2012 eng d00aPerchlorate and chlorate biogeochemistry in ice-covered lakes of the McMurdo Dry Valleys, Antarctica0 aPerchlorate and chlorate biogeochemistry in icecovered lakes of c12/2012 a19 - 300 v981 aJackson, Andrew1 aDavila, Alfonso, F.1 aEstrada, Nubia1 aLyons, Berry1 aCoates, John, D.1 aPriscu, John, C. uhttp://www.sciencedirect.com/science/article/pii/S001670371200511X00474nas a2200133 4500008004100000245010000041210006900141260002700210490000900237100001200246700002000258700001700278856004500295 2012 eng d00aTaylor’s ‘missing’ lake: Integrating history into LTER research in the McMurdo Dry Valley0 aTaylor s missing lake Integrating history into LTER research in aAlbuquerquebLTER News0 v20131 aKhan, A1 aHowkins, Adrian1 aLyons, Berry uhttp://news.lternet.edu/Article2568.html00581nas a2200169 4500008004100000245008600041210006900127260001200196300001400208490000600222100002500228700002400253700002100277700002400298700001700322856007200339 2011 eng d00aHydrological Connectivity of the Landscape of the McMurdo Dry Valleys, Antarctica0 aHydrological Connectivity of the Landscape of the McMurdo Dry Va c09/2011 a666 - 6810 v51 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1749-8198.2011.00445.x00651nas a2200205 4500008004100000022001400041245007900055210006900134260001200203300000800215490000700223100002000230700001700250700002200267700001800289700002700307700002100334700002500355856006500380 2011 eng d a0954-102000aLong-term ecosystem networks to record change: an international imperative0 aLongterm ecosystem networks to record change an international im c06/2011 a2090 v231 aWall, Diana, H.1 aLyons, Berry1 aChown, Steven, L.1 aConvey, Peter1 aHoward-Williams, Clive1 aQuesada, Antonio1 aVincent, Warwick, F. uhttp://www.journals.cambridge.org/abstract_S095410201100031900630nas a2200169 4500008004100000245013600041210006900177260001200246300001400258490000800272100002100280700002400301700002500325700002400350700001700374856006900391 2011 eng d00aWater tracks and permafrost in Taylor Valley, Antarctica: Extensive and shallow groundwater connectivity in a cold desert ecosystem0 aWater tracks and permafrost in Taylor Valley Antarctica Extensiv c11/2011 a2295-23110 v1231 aLevy, Joseph, S.1 aFountain, Andrew, G1 aGooseff, Michael, N.1 aWelch, Kathleen, A.1 aLyons, Berry uhttp://bulletin.geoscienceworld.org/content/123/11-12/2295.short05611nas a2200229 4500008004100000245006100041210006000102260004000162490000900202520491500211653002205126653001505148653000905163653002605172653001705198653002405215653002405239653001505263100002505278700001705303856006105320 2010 eng d00aAeolian sediments of the McMurdo Dry Valleys, Antarctica0 aAeolian sediments of the McMurdo Dry Valleys Antarctica aColumbus, OHbOhio State University0 vM.S.3 aThe role of dust has become a topic of increasing interest in the interface between climate and geological/ecological sciences. Dust emitted from major sources, the majority of which are desert regions in the Northern Hemisphere, is transported via suspension in global wind systems and incorporated into the biogeochemical cycles of the ecosystems where it is ultimately deposited. While emissions within the McMurdo Dry Valleys (MDV) region of Antarctica are small compared to other source regions, the redistribution of new, reactive material by wind may be important to sustaining life in the ecosystem.
The interaction of the dry, warm foehn winds and the cool, moist coastal breezes “recycles” soil particles throughout the landscape. The bulk of sediment movement occurs during foehn events in the winter that redistribute material throughout the MDV. To understand the source and transfer of this material samples were collected early in the austral summer (November 2008) prior to the initiation of extensive ice melt from glacial and lake surfaces, aeolian landforms, and elevated sediment traps. These were preserved and processed for grain size distribution and major element composition at the sand and silt particle sizes. Major elemental oxide analysis indicated that the silt and sand size particles are of different composition: SiO2 values for silt range from 50 to 59% by weight and for sand range from 59 to 74%. When compared to the elemental oxide composition four rock types present in the MDV, the composition of the silt indicates a mixing influenced mostly by the igneous rock types (Ferrar Dolerite and McMurdo Volcanic basanite) and sand a mixing influenced largely by the sedimentary rocks (Beacon Sandstone and the metasedimentary Basement Complex). This could imply a local source of the aeolian material that is corroborated by low CIA values at both particle sizes (44-57%) indicating low degrees of chemical weathering. In addition, comparison of 87Sr/86Sr and 143Nd/144Nd to values published for the major MDV rock types and ice core dust to values analyzed in 3 silt size glacier sample and one bulk glacier sample also indicates a local source of sediments and that it is not likely to be transferred inland.
During the melt season, the aeolian material is actively solubilized where it interacts with water, releasing solutes and vital bioavailable nutrients throughout the aquatic system. Differences in the chemistry of supra- and proglacial streams as well as lake surface waters may be derived from the deposition and dissolution of these aeolian sediments. To simulate these conditions, a two-step leaching method using deionized water to represent glacial melt in field conditions was employed and leachates analyzed for major ion and nutrient constituents. Leachates represent a small degree (<0.7%) of dissolution of major elements, and are solubilized to a greater extent from samples closer to the coast or with increased silt content. The composition of the leachates reflects the dissolution of the major salts found in the MDV. Leach 1 (cold water) indicates that Na- and Cl-bearing salt phases are dissolved to a greater extent than seen in Leach 2 (freeze-thaw). Conversely, Leach 2 compositions indicate that carbonate mineral dissolution and Mg-bearing silicate weathering are proceeding to a greater extent than in Leach 1.
Inorganic N:P ratios follow the same patterns of nutrient limitations based on the Redfield Ratio found by Priscu (1995) in the terminal lakes of the Taylor Valley: N-limited in the Fryxell and Hoare basins (east) and P-limited in the Bonney basin (west). This is also consistent with the age of the tills in the area, as found by Gudding (2003). The concentration of soluble Fe in the leachates is about the same as soluble inorganic P, and thus is not a limiting nutrient in the leachates. Comparison of total dissolved N and P to their inorganic counterparts reveals increased organic nutrients in the glacier and lake leachates that may indicate the influence of biota. Nutrient fluxes based on known sediment fluxes from elevated sediment traps deployed throughout the MDV and the composition of these leachates range from 0.34-330 g a-1 for N, 0.02-8.3 g a-1 for P, and 0.03-8.6 g a-1 for Fe. These are at least two orders of magnitude less than calculated loads from streams to the lakes in the Taylor Valley and, thus, should be considered underestimations or minima.
This work provides the first investigation into the composition and source of aeolian transported materials in the MDV, as well of what is potentially solubilized from it during the austral summer melt season. In addition, it will contribute to the understanding of the interplay between aeolian and aquatic processes in the MDV and further the understanding of this unique ecosystem.
Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10–106 years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates.
10aBiggie1 aBarrett, John, E.1 aVirginia, Ross, A.1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aFountain, Andrew, G1 aWall, Diana, H.1 aMoorhead, Daryl, L.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/biogeochemical-stoichiometry-antarctic-dry-valley-ecosystems00393nas a2200121 4500008004100000245004600041210004600087490000700133100001700140700002400157700001500181856007500196 2007 eng d00aOrganic carbon in Antarctic precipitation0 aOrganic carbon in Antarctic precipitation0 v341 aLyons, Berry1 aWelch, Kathleen, A.1 aDoggett, J uhttps://mcm.lternet.edu/content/organic-carbon-antarctic-precipitation00763nas a2200205 4500008004100000245013200041210006900173260001200242300001200254490000700266100002400273700002000297700002400317700002000341700001600361700002400377700001700401700001900418856012000437 2007 eng d00aReactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: A long-term geomorphological experiment0 aReactivation of a cryptobiotic stream ecosystem in the McMurdo D c09/2007 a186-2040 v891 aMcKnight, Diane, M.1 aTate, Cathy, M.1 aAndrews, Edmund, D.1 aNiyogi, Dev, K.1 aCozzetto, K1 aWelch, Kathleen, A.1 aLyons, Berry1 aCapone, D., G. uhttps://mcm.lternet.edu/content/reactivation-cryptobiotic-stream-ecosystem-mcmurdo-dry-valleys-antarctica-long-term00599nas a2200181 4500008004100000245009400041210006900135260001200204300001200216490000800228653002100236100001400257700002000271700002400291700001700315700002400332856006100356 2007 eng d00aSolute and isotope geochemistry of subsurface ice melt seeps in Taylor Valley, Antarctica0 aSolute and isotope geochemistry of subsurface ice melt seeps in c01/2007 a548-5550 v11910aClimate Response1 aHarris, K1 aCarey, Anne, E.1 aWelch, Kathleen, A.1 aLyons, Berry1 aFountain, Andrew, G uhttp://gsabulletin.gsapubs.org/content/119/5-6/548.short00704nas a2200169 4500008004100000245010300041210006900144260005400213100002500267700002400292700002100316700001700337700001700354700001900371700002700390856011700417 2007 eng d00aTrends in discharge and flow season timing of the Onyx River, Wright Valley, Antarctica since 19690 aTrends in discharge and flow season timing of the Onyx River Wri bU.S. Geological Survey Open-File Report 2007-10471 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aDoran, Peter, T.1 aLyons, Berry1 aCooper, Alan1 aRaymond, Carol1 aTeam, ISAES, Editorial uhttps://mcm.lternet.edu/content/trends-discharge-and-flow-season-timing-onyx-river-wright-valley-antarctica-196900754nas a2200205 4500008004100000245012400041210006900165300001200234490000700246100001600253700001500269700002400284700001700308700002300325700001300348700002200361700001500383700002400398856012600422 2006 eng d00aThe aeolian flux of calcium, chloride and nitrate to the McMurdo Dry Valleys landscape: Evidence from snow pit analysis0 aaeolian flux of calcium chloride and nitrate to the McMurdo Dry a497-5050 v181 aWitherow, R1 aBertler, N1 aWelch, Kathleen, A.1 aLyons, Berry1 aMayewski, Paul, A.1 aSneed, S1 aNylen, Thomas, H.1 aHandley, M1 aFountain, Andrew, G uhttps://mcm.lternet.edu/content/aeolian-flux-calcium-chloride-and-nitrate-mcmurdo-dry-valleys-landscape-evidence-snow-pit00563nas a2200169 4500008004100000245004600041210004600087260003400133100001700167700002800184700002400212700002100236700002000257700001800277700002000295856007800315 2006 eng d00aAntarctic lake systems and climate change0 aAntarctic lake systems and climate change aDordrecht, The NetherlandsbS1 aLyons, Berry1 aLaybourn-Parry, Johanna1 aWelch, Kathleen, A.1 aPriscu, John, C.1 aBergstrom, D.M.1 aConvey, Peter1 aHuiskes, A.H.L. uhttps://mcm.lternet.edu/content/antarctic-lake-systems-and-climate-change00592nas a2200145 4500008004100000245010200041210006900143490000700212100002700219700001600246700001700262700002300279700002100302856012300323 2006 eng d00aMeasuring ecosystem response in a rapidly changing environment: the Latitudinal Gradient Project0 aMeasuring ecosystem response in a rapidly changing environment t0 v101 aHoward-Williams, Clive1 aPeterson, D1 aLyons, Berry1 aCattaneo-Vietti, R1 aGordon, Shulamit uhttps://mcm.lternet.edu/content/measuring-ecosystem-response-rapidly-changing-environment-latitudinal-gradient-project00612nas a2200145 4500008004100000245011000041210006900151260003400220300001100254100001300265700001700278700002200295700002300317856012600340 2006 eng d00aPedogenic carbonate distribution within glacial till in Taylor Valley, Southern Victoria Land, Antarctica0 aPedogenic carbonate distribution within glacial till in Taylor V bGeological Society of America a89-1031 aFoley, K1 aLyons, Berry1 aBarrett, John, E.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/pedogenic-carbonate-distribution-within-glacial-till-taylor-valley-southern-victoria-land00487nas a2200109 4500008004100000245009400041210006900135260003000204100001400234700001700248856011200265 2006 eng d00aA Qualitative Approach to Understanding the Rate of Weathering, Taylor Valley, Antarctica0 aQualitative Approach to Understanding the Rate of Weathering Tay bThe Ohio State University1 aMiller, E1 aLyons, Berry uhttps://mcm.lternet.edu/content/qualitative-approach-understanding-rate-weathering-taylor-valley-antarctica00687nas a2200181 4500008004100000245010500041210006900146260001200215300001000227490000700237100002500244700001700269700002400286700002200310700002400332700002100356856012800377 2006 eng d00aA stable isotopic investigation of a polar desert hydrologic system, McMurdo Dry Valleys, Antarctica0 astable isotopic investigation of a polar desert hydrologic syste c02/2006 a60-710 v381 aGooseff, Michael, N.1 aLyons, Berry1 aMcKnight, Diane, M.1 aVaughn, Bruce, H.1 aFountain, Andrew, G1 aDowling, Carolyn uhttps://mcm.lternet.edu/content/stable-isotopic-investigation-polar-desert-hydrologic-system-mcmurdo-dry-valleys-antarctica00812nas a2200265 4500008004100000245006500041210006400106300001400170490000700184100002200191700002200213700001500235700001600250700002000266700001900286700002300305700002000328700001600348700001600364700001600380700001600396700001700412700002400429856009300453 2006 eng d00aTerrestrial ecosystem processes of Victoria Land, Antarctica0 aTerrestrial ecosystem processes of Victoria Land Antarctica a3019-30340 v381 aBarrett, John, E.1 aNkem, Johnson, N.1 aSletten, R1 aSteltzer, H1 aWall, Diana, H.1 aWallenstein, M1 aVirginia, Ross, A.1 aHopkins, D., W.1 aAislabie, J1 aBargagli, R1 aBockheim, J1 aCampbell, I1 aLyons, Berry1 aMoorhead, Daryl, L. uhttps://mcm.lternet.edu/content/terrestrial-ecosystem-processes-victoria-land-antarctica00648nas a2200157 4500008004100000245012800041210006900169300001000238490000700248100002000255700002400275700001700299700002200316700002400338856012800362 2005 eng d00aThe chemical composition of runoff from Canada Glacier, Antarctica: implications for glacier hydrology during a cool summer0 achemical composition of runoff from Canada Glacier Antarctica im a15-190 v401 aTranter, Martyn1 aFountain, Andrew, G1 aLyons, Berry1 aNylen, Thomas, H.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/chemical-composition-runoff-canada-glacier-antarctica-implications-glacier-hydrology-during00884nas a2200265 4500008004100000245007800041210007000119300001100189490000700200653002500207100002100232700001900253700002700272700002700299700002400326700002100350700001700371700001300388700002400401700002400425700002400449700002300473700002000496856010200516 2005 eng d00aComment on ``El Niño suppresses Antarctic warming'' by N. Bertler et al.0 aComment on El Niño suppresses Antarctic warming by N Bertler et aL077060 v3210aTropical meteorology1 aDoran, Peter, T.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N.1 aPriscu, John, C.1 aLyons, Berry1 aWalsh, J1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/comment-el-ni%C3%B1o-suppresses-antarctic-warming-n-bertler-et-al00618nas a2200181 4500008004100000245006900041210006800110300000900178490000700187100001700194700002100211700002400232700001400256700002300270700002100293700002400314856009800338 2005 eng d00aDating water and solute additions to ice-covered Antarctic lakes0 aDating water and solute additions to icecovered Antarctic lakes aA7200 v691 aLyons, Berry1 aDowling, Carolyn1 aWelch, Kathleen, A.1 aSnyder, G1 aPoreda, Robert, J.1 aDoran, Peter, T.1 aFountain, Andrew, G uhttps://mcm.lternet.edu/content/dating-water-and-solute-additions-ice-covered-antarctic-lakes00646nas a2200157 4500008004100000245013500041210006900176300001200245490000700257100001900264700002000283700002400303700001700327700002400344856012000368 2005 eng d00aThe Geochemistry of Supraglacial Streams of Canada Glacier, Taylor Valley (Antarctica), and their Evolution into Proglacial Waters0 aGeochemistry of Supraglacial Streams of Canada Glacier Taylor Va a391-4120 v111 aFortner, Sarah1 aTranter, Martyn1 aFountain, Andrew, G1 aLyons, Berry1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/geochemistry-supraglacial-streams-canada-glacier-taylor-valley-antarctica-and-their00711nas a2200205 4500008004100000245008900041210006900130300001200199490000700211100001700218700002400235700002000259700002000279700002300299700002400322700002100346700001400367700001500381856010900396 2005 eng d00aGroundwater seeps in Taylor Valley Antarctica: An example of a subsurface melt event0 aGroundwater seeps in Taylor Valley Antarctica An example of a su a200-2060 v401 aLyons, Berry1 aWelch, Kathleen, A.1 aCarey, Anne, E.1 aWall, Diana, H.1 aVirginia, Ross, A.1 aFountain, Andrew, G1 aDoran, Peter, T.1 aCsatho, B1 aTremper, C uhttps://mcm.lternet.edu/content/groundwater-seeps-taylor-valley-antarctica-example-subsurface-melt-event00681nas a2200181 4500008004100000245012100041210006900162300001200231490000700243100001700250700002400267700001400291700001400305700001400319700001900333700002300352856012400375 2005 eng d00aHalogen geochemistry of the McMurdo Dry Valleys Lakes, Antarctica: clues to the origin of solutes and lake evolution0 aHalogen geochemistry of the McMurdo Dry Valleys Lakes Antarctica a305-3230 v691 aLyons, Berry1 aWelch, Kathleen, A.1 aSnyder, G1 aOlesik, J1 aGraham, E1 aMarion, G., M.1 aPoreda, Robert, J. uhttps://mcm.lternet.edu/content/halogen-geochemistry-mcmurdo-dry-valleys-lakes-antarctica-clues-origin-solutes-and-lake02329nas a2200181 4500008004100000245009400041210006900135260004900204300000800253490000900261520166100270100002201931700001701953700002001970700002001990700002702010856011002037 2005 eng d00aMathematical Modeling of a Hydrocarbon Spill on the Ice Cover of Lake Fryxell, Antarctica0 aMathematical Modeling of a Hydrocarbon Spill on the Ice Cover of aColumbusbThe Ohio State Universityc06/2005 a1140 vM.S.3 aNumerous perennially ice-covered lakes exist in the McMurdo Dry Valleys region of Antarctica. Ice cover melting on these lakes and meltwater infiltration are important processes affecting the ecology of these lakes. The three lakes in Taylor Valley, Lakes Bonney, Fryxell and Hoare, have been investigated since 1993 as part of the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) site. A Bell 212 helicopter flying in support of the National Science Foundation's Antarctic Research Program crashed on the frozen surface of Lake Fryxell on January 17, 2003. This resulted in the release of approximately 731 Liters (193 gallons) of diesel fuel and amounts of engine oil and hydraulic fluid. Two physically based models are developed that simulate heat, meltwater flow and solute transport. The first is a transient, one-dimensional, thermodynamic model, which can predict the temperature distribution in the ice cover, melting rate at the surface and at the bottom of ice cover, and ice thickness. The second model simulates unsaturated flow and solute transport and is used to estimate water content distribution and solute transport through the ice cover. The validation of heat transport model was accomplished by comparing model results with the original measurements of ice temperature at various depth in Lake Fryxell. Because of lack of the field data, validation of the unsaturated flow and solute transport model couldn't been accomplished, instead of model validation, programming code has been verified by comparing results with results generated by the HYDRUS 1D software, developed by U.S. Salinity Laboratory, USDA.
1 aKarnovic, Marinko1 aLyons, Berry1 aCarey, Anne, E.1 aBair, Scott, E.1 avan der Veen, Cornelis uhttps://mcm.lternet.edu/content/mathematical-modeling-hydrocarbon-spill-ice-cover-lake-fryxell-antarctica00509nas a2200121 4500008004100000245009200041210006900133260003000202490000900232100001600241700001700257856011300274 2005 eng d00aMercury Concentrations in Snow and the Modern Mercury Flux to Taylor Valley, Antarctica0 aMercury Concentrations in Snow and the Modern Mercury Flux to Ta bThe Ohio State University0 vM.S.1 aWitherow, R1 aLyons, Berry uhttps://mcm.lternet.edu/content/mercury-concentrations-snow-and-modern-mercury-flux-taylor-valley-antarctica00539nas a2200121 4500008004100000245011000041210006900151260003000220490000900250100001300259700001700272856012800289 2005 eng d00aPedogenic Carbonate Distribution within Glacial Till in Taylor Valley, Southern Victoria Land, Antarctica0 aPedogenic Carbonate Distribution within Glacial Till in Taylor V bThe Ohio State University0 vM.S.1 aFoley, K1 aLyons, Berry uhttps://mcm.lternet.edu/content/pedogenic-carbonate-distribution-within-glacial-till-taylor-valley-southern-victoria-land-000677nas a2200181 4500008004100000245009700041210006900138300001000207490000600217100002000223700002400243700002700267700001700294700002100311700001600332700002400348856012300372 2005 eng d00aPerturbation of hydrochemical conditions in natural microcosms entombed within Antarctic ice0 aPerturbation of hydrochemical conditions in natural microcosms e a22-230 v61 aTranter, Martyn1 aFountain, Andrew, G1 aFritsen, Christian, H.1 aLyons, Berry1 aPriscu, John, C.1 aStratham, P1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/perturbation-hydrochemical-conditions-natural-microcosms-entombed-within-antarctic-ice00642nas a2200145 4500008004100000245014700041210006900188490000700257100001900264700001700283700002100300700002500321700002400346856012600370 2004 eng d00aThe Carbon Isotopic Composition of Dissolved Inorganic Carbon in Perennially Ice-Covered Antarctica Lakes: Searching for a Biogenic Signature.0 aCarbon Isotopic Composition of Dissolved Inorganic Carbon in Per0 v391 aNeumann, Klaus1 aLyons, Berry1 aPriscu, John, C.1 aDesMarais, David, J.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/carbon-isotopic-composition-dissolved-inorganic-carbon-perennially-ice-covered-antarctica00670nas a2200157 4500008004100000245014600041210006900187300001200256490000700268100002300275700002100298700002000319700001700339700002800356856012800384 2004 eng d00aThe distribution of microplankton in the McMurdo dry valley lakes, Antarctica: Response to ecosystem legacy or present-day climate controls?0 adistribution of microplankton in the McMurdo dry valley lakes An a238-2490 v271 aRoberts, Emily, C.1 aPriscu, John, C.1 aWolf, Craig, F.1 aLyons, Berry1 aLaybourn-Parry, Johanna uhttps://mcm.lternet.edu/content/distribution-microplankton-mcmurdo-dry-valley-lakes-antarctica-response-ecosystem-legacy-or00667nas a2200181 4500008004100000245009000041210006900131300001200200490000700212100002000219700002400239700002700263700001700290700002100307700001500328700002400343856011800367 2004 eng d00aExtreme hydrochemical conditions in natural microcosms entombed within Antarctic ice.0 aExtreme hydrochemical conditions in natural microcosms entombed a379-3870 v181 aTranter, Martyn1 aFountain, Andrew, G1 aFritsen, Christian, H.1 aLyons, Berry1 aPriscu, John, C.1 aStathan, P1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/extreme-hydrochemical-conditions-natural-microcosms-entombed-within-antarctic-ice00629nas a2200157 4500008004100000245011500041210006900156300001200225490000700237100002200244700002700266700001500293700001700308700002100325856012500346 2004 eng d00aGeomicrobiology of Blood Fall: An iron-rich saline discharge at the terminus of the Taylor Glacier, Antarctica0 aGeomicrobiology of Blood Fall An ironrich saline discharge at th a199-2000 v101 aMikucki, Jill, A.1 aForeman, Christine, M.1 aSattler, B1 aLyons, Berry1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/geomicrobiology-blood-fall-iron-rich-saline-discharge-terminus-taylor-glacier-antarctica00791nas a2200217 4500008004100000020002200041245008200063210006900145260005900214300001200273100002100285700002100306700001700327700001400344700002300358700002300381700001500404700002900419700001500448856011000463 2004 eng d a978-1-4020-2125-100aPaleolimnology of extreme cold terrestrial and extraterrestrial environments.0 aPaleolimnology of extreme cold terrestrial and extraterrestrial aDordrecht, The NetherlandsbKluwer Academic Publishers a475-5071 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aPowell, R1 aPoreda, Robert, J.1 aAndersen, Dale, T.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, J.P. uhttps://mcm.lternet.edu/content/paleolimnology-extreme-cold-terrestrial-and-extraterrestrial-environments00602nas a2200193 4500008004100000245004700041210004600088260003100134300001200165100002100177700002100198700001700219700001400236700002300250700001500273700002900288700001500317856007600332 2004 eng d00aPaleolimnology of Ice-covered Environments0 aPaleolimnology of Icecovered Environments bKluwer Academic Publishers a475-5071 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aPowell, R1 aPoreda, Robert, J.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, John uhttps://mcm.lternet.edu/content/paleolimnology-ice-covered-environments00536nas a2200157 4500008004100000245006700041210006600108300001200174490000600186100001200192700002400204700001700228700002100245700002400266856008800290 2003 eng d00aBiochemistry of Si in the McMurdo Dry Valley lakes, Antarctica0 aBiochemistry of Si in the McMurdo Dry Valley lakes Antarctica a737-7490 v11 aPugh, H1 aWelch, Kathleen, A.1 aLyons, Berry1 aPriscu, John, C.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/biochemistry-si-mcmurdo-dry-valley-lakes-antarctica00702nas a2200181 4500008004100000020001500041245009900056210006900155260004300224300001200267653002100279100002400300700001700324700001800341700001900359700001800378856012400396 2003 eng d a019515059700aCentury to millennial scale climate change and ecosystem response in Taylor Valley, Antarctica0 aCentury to millennial scale climate change and ecosystem respons aNew York CitybOxford University Press a319-34010aClimate Response1 aFountain, Andrew, G1 aLyons, Berry1 aGreenland, D.1 aGoodin, D., G.1 aSmith, R., C. uhttps://mcm.lternet.edu/content/century-millennial-scale-climate-change-and-ecosystem-response-taylor-valley-antarctica00679nas a2200169 4500008004100000245011200041210006900153260001700222100002400239700001900263700001700282700002400299700002700323700001700350700001500367856012700382 2003 eng d00aChemistry and lake dynamics of the Taylor Valley lakes, Antarctica: The importance of long-term monitoring.0 aChemistry and lake dynamics of the Taylor Valley lakes Antarctic bCaxton Press1 aWelch, Kathleen, A.1 aNeumann, Klaus1 aLyons, Berry1 aMcKnight, Diane, M.1 aHoward-Williams, Clive1 aDavidson, W.1 aBroady, P. uhttps://mcm.lternet.edu/content/chemistry-and-lake-dynamics-taylor-valley-lakes-antarctica-importance-long-term-monitoring00570nas a2200121 4500008004100000245013800041210006900179260003000248490000900278100001500287700001700302856012900319 2003 eng d00aPhosphorus in Taylor Valley, Antarctica: the connection between landscape age and nutrient limitation in aquatic ecosystem components0 aPhosphorus in Taylor Valley Antarctica the connection between la bThe Ohio State University0 vM.S.1 aGudding, J1 aLyons, Berry uhttps://mcm.lternet.edu/content/phosphorus-taylor-valley-antarctica-connection-between-landscape-age-and-nutrient-limitation00722nas a2200193 4500008004100000245015200041210006900193300001200262490000600274100001700280700001800297700001400315700001400329700001400343700001200357700002400369700001400393856012100407 2003 eng d00aStrontium isotopic signatures of the streams and lakes of Taylor Valley, southern Victoria Land, Antarctica: chemical weathering in a polar climate0 aStrontium isotopic signatures of the streams and lakes of Taylor a875-8950 v81 aLyons, Berry1 aNezat, C., A.1 aBenson, L1 aBullen, T1 aGraham, E1 aKidd, J1 aWelch, Kathleen, A.1 aThomas, J uhttps://mcm.lternet.edu/content/strontium-isotopic-signatures-streams-and-lakes-taylor-valley-southern-victoria-land00682nas a2200169 4500008004100000245012300041210006900164300001200233490000700245100001700252700002400269700002400293700002000317700002200337700002400359856012900383 2003 eng d00aSurface glaciochemistry of Taylor Valley, southern Victoria Land, Antarctica and its relationship to stream chemistry.0 aSurface glaciochemistry of Taylor Valley southern Victoria Land a115-1300 v171 aLyons, Berry1 aWelch, Kathleen, A.1 aFountain, Andrew, G1 aDana, Gayle, L.1 aVaughn, Bruce, H.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/surface-glaciochemistry-taylor-valley-southern-victoria-land-antarctica-and-its-relationship00890nas a2200277 4500008004100000245006500041210006500106260001200171300001200183490000800195653002100203100002100224700002100245700001700266700002000283700002400303700002400327700002400351700002300375700002000398700001900418700002700437700002700464700002400491856009700515 2002 eng d00aAntarctic climate cooling and terrestrial ecosystem response0 aAntarctic climate cooling and terrestrial ecosystem response c01/2002 a517-5200 v41510aClimate Response1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aWalsh, John, E.1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N. uhttps://mcm.lternet.edu/content/antarctic-climate-cooling-and-terrestrial-ecosystem-response00431nas a2200121 4500008004100000245006200041210005800103260003000161490000900191100001200200700001700212856008000229 2002 eng d00aThe biogeochemistry of Si in the McMurdo Dry Valley Lakes0 abiogeochemistry of Si in the McMurdo Dry Valley Lakes bThe Ohio State University0 vB.S.1 aPugh, H1 aLyons, Berry uhttps://mcm.lternet.edu/content/biogeochemistry-si-mcmurdo-dry-valley-lakes00539nas a2200121 4500008004100000245011500041210006900156260003000225490000900255100001200264700001700276856012400293 2002 eng d00aThe chemical evolution of Canada Glacier melt: supraglacial and proglacial waters in Taylor Valley, Antarctica0 achemical evolution of Canada Glacier melt supraglacial and progl bThe Ohio State University0 vM.S.1 aTegt, S1 aLyons, Berry uhttps://mcm.lternet.edu/content/chemical-evolution-canada-glacier-melt-supraglacial-and-proglacial-waters-taylor-valley00772nas a2200253 4500008004100000245004700041210004700088300001200135490000800147100002000155700001900175700002700194700002700221700002400248700002100272700002100293700001700314700002400331700002400355700002400379700002300403700002000426856007200446 2002 eng d00aRecent Temperature Trends in the Antarctic0 aRecent Temperature Trends in the Antarctic a291-2920 v4181 aWalsh, John, E.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N.1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/recent-temperature-trends-antarctic00760nas a2200229 4500008004100000245012700041210006900168260001200237300001000249490000700259653001100266100002500277700002200302700002100324700002400345700001700369700002400386700001800410700002300428700002000451856005900471 2002 eng d00aSnow patch influence on soil biogeochemical processes and invertebrate distribution in the McMurdo Dry Valleys, Antarctica0 aSnow patch influence on soil biogeochemical processes and invert c02/2003 a91-990 v3510aBiggie1 aGooseff, Michael, N.1 aBarrett, John, E.1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry1 aParsons, Andrew, N.1 aPorazinska, D1 aVirginia, Ross, A.1 aWall, Diana, H. uhttp://instaar.metapress.com/content/r086455ju7213711/03551nas a2200217 4500008004100000245009000041210006900131260001200200300001400212490000800226520282700234653001103061100002103072700002703093700001903120700002003139700002403159700002203183700001703205856011103222 2002 eng d00aValley floor climate observations from the McMurdo Dry Valleys, Antarctica, 1986-20000 aValley floor climate observations from the McMurdo Dry Valleys A c12/2002 a4772-47840 v1073 aClimate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from −14.8°C to −30.0°C, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site-to-site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the nonsummer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r2 = 0.992) of increasing potential temperature with distance from the coast (0.09°C km−1). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites.
10aBiggie1 aDoran, Peter, T.1 aMcKay, Christopher, P.1 aClow, Gary, D.1 aDana, Gayle, L.1 aFountain, Andrew, G1 aNylen, Thomas, H.1 aLyons, Berry uhttps://mcm.lternet.edu/content/valley-floor-climate-observations-mcmurdo-dry-valleys-antarctica-1986-200000603nas a2200169 4500008004100000245014000041210006900181260001200250300001400262490000700276653001100283100002500294700002400319700001700343700001200360856006100372 2002 eng d00aWeathering reactions and hyporheic exchange controls on stream water chemistry in a glacial meltwater stream in the McMurdo Dry Valleys0 aWeathering reactions and hyporheic exchange controls on stream w c12/2002 a1279-12960 v3810aBiggie1 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aLyons, Berry1 aBlum, A uhttp://www.agu.org/pubs/crossref/2002/2001WR000834.shtml00510nas a2200133 4500008004100000245008300041210006900124300001400193490000800207100001800215700001700233700002400250856010200274 2001 eng d00aChemical weathering in streams of a polar desert (Taylor Valley, Antarctica).0 aChemical weathering in streams of a polar desert Taylor Valley A a1401-14080 v1131 aNezat, C., A.1 aLyons, Berry1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/chemical-weathering-streams-polar-desert-taylor-valley-antarctica00540nas a2200145 4500008004100000245008500041210006900126300001000195490000700205100001900212700001700231700002100248700001500269856011000284 2001 eng d00aCO2 concentrations in perennially ice-covered lakes of Taylor Valley, Antarctica0 aCO2 concentrations in perennially icecovered lakes of Taylor Val a27-500 v561 aNeumann, Klaus1 aLyons, Berry1 aPriscu, John, C.1 aDonahoe, R uhttps://mcm.lternet.edu/content/co2-concentrations-perennially-ice-covered-lakes-taylor-valley-antarctica00774nas a2200193 4500008004100000245014400041210006900185300001200254490000700266100001700273700002400290700002100314700002800335700002400363700002400387700002100411700002000432856012800452 2001 eng d00aThe McMurdo Dry Valleys Long-Term Ecological Research Program: new understanding of the biogeochemistry of the Dry Valley lakes: a review.0 aMcMurdo Dry Valleys LongTerm Ecological Research Program new und a202-2170 v251 aLyons, Berry1 aWelch, Kathleen, A.1 aPriscu, John, C.1 aLaybourn-Parry, Johanna1 aMoorhead, Daryl, L.1 aMcKnight, Diane, M.1 aDoran, Peter, T.1 aTranter, Martyn uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-long-term-ecological-research-program-new-understanding-biogeochemistry00868nas a2200229 4500008004100000245013400041210006900175260002800244300001200272100002400284700001700308700002400325700001700349700002400366700002200390700002100412700002700433700001800460700001900478700001800497856012300515 2000 eng d00aClimate and hydrologic variations and implications for lake and stream ecological response in the McMurdo Dry Valleys, Antarctica0 aClimate and hydrologic variations and implications for lake and bOxford University Press a174-1951 aWelch, Kathleen, A.1 aLyons, Berry1 aMcKnight, Diane, M.1 aJaros, Chris1 aFountain, Andrew, G1 aNylen, Thomas, H.1 aDoran, Peter, T.1 aHoward-Williams, Clive1 aGreenland, D.1 aGoodin, D., G.1 aSmith, R., C. uhttps://mcm.lternet.edu/content/climate-and-hydrologic-variations-and-implications-lake-and-stream-ecological-response00674nas a2200157 4500008004100000245016800041210006900209300001400278490000700292100001700299700001800316700002400334700001700358700002100375856012000396 2000 eng d00aFossil fuel burning in Taylor Valley, southern Victoria Land, Antarctica: estimating the role of scientific activities on carbon and nitrogen reservoirs and fluxes0 aFossil fuel burning in Taylor Valley southern Victoria Land Anta a1659-16620 v341 aLyons, Berry1 aNezat, C., A.1 aWelch, Kathleen, A.1 aKottmeier, S1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/fossil-fuel-burning-taylor-valley-southern-victoria-land-antarctica-estimating-role00667nas a2200169 4500008004100000245011600041210006900157300001200226490000700238100001700245700002400262700002100286700002100307700001900328700002400347856012600371 2000 eng d00aThe importance of landscape position and legacy: The evolution of the Taylor Valley Lake District, Antarctica.0 aimportance of landscape position and legacy The evolution of the a355-3670 v431 aLyons, Berry1 aFountain, Andrew, G1 aDoran, Peter, T.1 aPriscu, John, C.1 aNeumann, Klaus1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/importance-landscape-position-and-legacy-evolution-taylor-valley-lake-district-antarctica00481nas a2200121 4500008004100000245007000041210006900111260003800180490001000218100001900228700001700247856009500264 1999 eng d00aCarbon dynamics in lakes and streams of Taylor Valley, Antarctica0 aCarbon dynamics in lakes and streams of Taylor Valley Antarctica bUniversity of Alabama, Tuscaloosa0 vPh.D.1 aNeumann, Klaus1 aLyons, Berry uhttps://mcm.lternet.edu/content/carbon-dynamics-lakes-and-streams-taylor-valley-antarctica00557nas a2200133 4500008004100000245011000041210006900151300001200220490000700232100001700239700002400256700001900280856012400299 1999 eng d00aChlorine-36 in the waters of the McMurdo Dry Valley lakes, southern Victoria Land, Antarctica: revisited0 aChlorine36 in the waters of the McMurdo Dry Valley lakes souther a185-1910 v621 aLyons, Berry1 aWelch, Kathleen, A.1 aSharma, Pankaj uhttps://mcm.lternet.edu/content/chlorine-36-waters-mcmurdo-dry-valley-lakes-southern-victoria-land-antarctica-revisited00684nas a2200205 4500008004100000245008100041210006900122260001200191300001200203490000800215653001400223100002100237700001900258700001700277700002400294700002100318700001600339700001700355856010600372 1999 eng d00aDating quaternary lacustrine sediments in the McMurdo Dry Valleys Antarctica0 aDating quaternary lacustrine sediments in the McMurdo Dry Valley c03/1999 a223-2390 v14710asediments1 aDoran, Peter, T.1 aBerger, G., W.1 aLyons, Berry1 aWharton, Robert, A.1 aDavisson, M., L.1 aSouthon, J.1 aDibb, J., E. uhttps://mcm.lternet.edu/content/dating-quaternary-lacustrine-sediments-mcmurdo-dry-valleys-antarctica00781nas a2200241 4500008004100000245006000041210005900101300001400160490000800174100002100182700002200203700001700225700002100242700002000263700002200283700002700305700003300332700002400365700002000389700002500409700001600434856008900450 1999 eng d00aGeomicrobiology of sub-glacial ice above Vostok Station0 aGeomicrobiology of subglacial ice above Vostok Station a2141-21440 v2861 aPriscu, John, C.1 aAdams, Edward, E.1 aLyons, Berry1 aVoytek, Mary, A.1 aMogk, David, W.1 aBrown, Robert, L.1 aMcKay, Christopher, P.1 aTakacs-Vesbach, Cristina, D.1 aWelch, Kathleen, A.1 aWolf, Craig, F.1 aKirshtein, Julie, D.1 aAvci, Recep uhttps://mcm.lternet.edu/content/geomicrobiology-sub-glacial-ice-above-vostok-station00489nas a2200121 4500008004100000245008700041210006900128490000700197100001700204700001300221700002400234856010900258 1999 eng d00aHistory of McMurdo Dry Valley Lakes, Antarctica, from stable chlorine isotope data0 aHistory of McMurdo Dry Valley Lakes Antarctica from stable chlor0 v271 aLyons, Berry1 aFrape, S1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/history-mcmurdo-dry-valley-lakes-antarctica-stable-chlorine-isotope-data00424nas a2200133 4500008004100000245004500041210004500086300001400131490000700145100001700152700002400169700002600193856007100219 1999 eng d00aMercury in aquatic systems in Antarctica0 aMercury in aquatic systems in Antarctica a2235-22380 v261 aLyons, Berry1 aWelch, Kathleen, A.1 aBonzongo, Jean-Claude uhttps://mcm.lternet.edu/content/mercury-aquatic-systems-antarctica00878nas a2200277 4500008004100000245006500041210006400106260001200170300001200182490000700194653002300201100002400224700001700248700002400265700002000289700002100309700002100330700002400351700002400375700002400399700002100423700002000444700002400464700002300488856008900511 1999 eng d00aPhysical controls on the Taylor Valley Ecosystem, Antarctica0 aPhysical controls on the Taylor Valley Ecosystem Antarctica c12/1999 a961-9720 v4910aWater availability1 aFountain, Andrew, G1 aLyons, Berry1 aBurkins, Melody, B.1 aDana, Gayle, L.1 aDoran, Peter, T.1 aLewis, Karen, J.1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aParsons, Andrew, N.1 aPriscu, John, C.1 aWall, Diana, H.1 aWharton, Robert, A.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/physical-controls-taylor-valley-ecosystem-antarctica00492nas a2200121 4500008004100000245007500041210006900116260003800185490001000223100001800233700001700251856010200268 1998 eng d00aChemical Weathering in Taylor Valley, Antarctica: Quantity and Quality0 aChemical Weathering in Taylor Valley Antarctica Quantity and Qua bUniversity of Alabama, Tuscaloosa0 vPh.D.1 aNezat, C., A.1 aLyons, Berry uhttps://mcm.lternet.edu/content/chemical-weathering-taylor-valley-antarctica-quantity-and-quality00605nas a2200169 4500008004100000245008000041210006900121300001200190490000700202100002100209700002000230700001900250700002200269700002100291700001700312856010600329 1998 eng d00aEvidence of deep circulation in two perennially ice-covered Antarctic lakes0 aEvidence of deep circulation in two perennially icecovered Antar a625-6350 v431 aTyler, Scott, W.1 aCook, Peter, G.1 aButt, Anya, Z.1 aThomas, James, M.1 aDoran, Peter, T.1 aLyons, Berry uhttps://mcm.lternet.edu/content/evidence-deep-circulation-two-perennially-ice-covered-antarctic-lakes00747nas a2200205 4500008004100000245009700041210006900138300001000207490000700217100001700224700002400241700001900265700002300284700002000307700002300327700002400350700002400374700002100398856012200419 1998 eng d00aGeochemical Linkages Among Glaciers, Streams, and Lakes Within the Taylor Valley, Antarctica0 aGeochemical Linkages Among Glaciers Streams and Lakes Within the a77-920 v721 aLyons, Berry1 aWelch, Kathleen, A.1 aNeumann, Klaus1 aToxey, Jeffrey, K.1 aMcArthur, Robyn1 aWilliams, Changela1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/geochemical-linkages-among-glaciers-streams-and-lakes-within-taylor-valley-antarctica00570nas a2200133 4500008004100000245012200041210006900163300001200232490000700244100001900251700001700270700002200287856012700309 1998 eng d00aInorganic carbon-isotope distribution and budget in the Lake Hoare and Lake Fryxell basins, Taylor Valley, Antarctica0 aInorganic carbonisotope distribution and budget in the Lake Hoar a685-6900 v271 aNeumann, Klaus1 aLyons, Berry1 aMarais, D.J., Des uhttps://mcm.lternet.edu/content/inorganic-carbon-isotope-distribution-and-budget-lake-hoare-and-lake-fryxell-basins-taylor00612nas a2200157 4500008004100000245009600041210006900137300001200206490000700218100001700225700002100242700002400263700002400287700002200311856012100333 1998 eng d00aA late holocene dessication of Lake Hoare and Lake Fryxell, McMurdo Dry Valleys, Antarctica0 alate holocene dessication of Lake Hoare and Lake Fryxell McMurdo a247-2560 v101 aLyons, Berry1 aTyler, Scott, W.1 aWharton, Robert, A.1 aMcKnight, Diane, M.1 aVaughn, Bruce, H. uhttps://mcm.lternet.edu/content/late-holocene-dessication-lake-hoare-and-lake-fryxell-mcmurdo-dry-valleys-antarctica00509nas a2200145 4500008004100000245006800041210006400109300000800173490000700181100001700188700002400205700002100229700001900250856009400269 1998 eng d00aMcMurdo Dry Valleys LTER: Density-driven mixing in Lake Hoare?0 aMcMurdo Dry Valleys LTER Densitydriven mixing in Lake Hoare a2050 v311 aLyons, Berry1 aWelch, Kathleen, A.1 aTyler, Scott, W.1 aSharma, Pankaj uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-lter-density-driven-mixing-lake-hoare00597nas a2200169 4500008004100000245007200041210006700113260002900180300001200209100001700221700002400238700001700262700001700279700002700296700001500323856008900338 1997 eng d00aThe abundance of planktonic virus-like particles in Antarctic lakes0 aabundance of planktonic viruslike particles in Antarctic lakes aRotterdambBalkema Press a241-2501 aKepner, R.L.1 aWharton, Robert, A.1 aGalchenko, V1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/abundance-planktonic-virus-particles-antarctic-lakes00661nas a2200169 4500008004100000245009900041210006900140260002900209300001200238100002400250700001700274700002400291700001700315700002700332700001500359856011700374 1997 eng d00aCarbon dynamics of aquatic microbial mats in the Antarctic dry valleys: A modelling synthesis0 aCarbon dynamics of aquatic microbial mats in the Antarctic dry v bBalkema Press, Rotterdam a181-1961 aMoorhead, Daryl, L.1 aDavis, Shane1 aWharton, Robert, A.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/carbon-dynamics-aquatic-microbial-mats-antarctic-dry-valleys-modelling-synthesis00811nas a2200217 4500008004100000245012400041210006900165260002900234300001200263100001700275700002400292700001800316700001400334700002300348700001900371700002400390700001700414700002700431700001500458856012000473 1997 eng d00aChemical weathering rates and reactions in the Lake Fryxell Basin, Taylor Valley : Comparison to temperate river basins0 aChemical weathering rates and reactions in the Lake Fryxell Basi bBalkema Press, Rotterdam a147-1541 aLyons, Berry1 aWelch, Kathleen, A.1 aNezat, C., A.1 aCrick, K.1 aToxey, Jeffrey, K.1 aMastrine, J.A.1 aMcKnight, Diane, M.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/chemical-weathering-rates-and-reactions-lake-fryxell-basin-taylor-valley-comparison00670nas a2200181 4500008004100000245009200041210006900133260002900202300001200231100001700243700002200260700002300282700002100305700001700326700002700343700001500370856010300385 1997 eng d00aClimate history of the McMurdo Dry Valleys since the last glacial maximum: A synthesis0 aClimate history of the McMurdo Dry Valleys since the last glacia bBalkema Press, Rotterdam a155-1621 aLyons, Berry1 aBartek, Louis, R.1 aMayewski, Paul, A.1 aDoran, Peter, T.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/climate-history-mcmurdo-dry-valleys-last-glacial-maximum-synthesis00602nas a2200145 4500008004100000245009900041210006900140260003900209300001200248100001400260700001900274700001700293700002400310856012200334 1997 eng d00aDetermination of rare earth elements in Antarctic lakes and streams of varying ionic strengths0 aDetermination of rare earth elements in Antarctic lakes and stre aLondonbRoyal Society of Chemistry a253-2621 aGraham, E1 aRamsey, L., A.1 aLyons, Berry1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/determination-rare-earth-elements-antarctic-lakes-and-streams-varying-ionic-strengths00369nas a2200121 4500008004100000245004000041210004000081300001400121490000700135100001700142700002400159856006400183 1997 eng d00aLithium in waters of a polar desert0 aLithium in waters of a polar desert a4309-43190 v611 aLyons, Berry1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/lithium-waters-polar-desert00462nas a2200145 4500008004100000245004200041210003800083260002900121300001200150100002800162700001700190700002700207700001500234856006700249 1997 eng d00aThe microbial loop in Antarctic lakes0 amicrobial loop in Antarctic lakes aRotterdambBalkema Press a231-2401 aLaybourn-Parry, Johanna1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/microbial-loop-antarctic-lakes00672nas a2200181 4500008004100000245008800041210006900129260002900198300001200227100002700239700001500266700002400281700002000305700001700325700002700342700001500369856010600384 1997 eng d00aSources and sinks of nutrients in a polar desert stream, the Onyx River, Antarctica0 aSources and sinks of nutrients in a polar desert stream the Onyx aRotterdambBalkema Press a155-1701 aHoward-Williams, Clive1 aHawes, Ian1 aSchwarz, Anne-Maree1 aHall, Julie, A.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/sources-and-sinks-nutrients-polar-desert-stream-onyx-river-antarctica00795nas a2200193 4500008004100000245015600041210006900197260002900266300001200295100002000307700002000327700002400347700001900371700002500390700001700415700002700432700001500459856012700474 1997 eng d00aSpecies composition and primary production of algal communities in Dry Valley streams in Antarctica: Examination of the functional role of biodiversity0 aSpecies composition and primary production of algal communities bBalkema Press, Rotterdam a171-1791 aNiyogi, Dev, K.1 aTate, Cathy, M.1 aMcKnight, Diane, M.1 aDuff, John, H.1 aAlger, Alexander, S.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/species-composition-and-primary-production-algal-communities-dry-valley-streams-antarctica00641nas a2200169 4500008004100000245010500041210006900146300001200215490000800227100002400235700001700259700001400276700001900290700002200309700001700331856012300348 1996 eng d00aDetermination of major element chemistry in terrestrial waters from Antarctica by ion chromatography0 aDetermination of major element chemistry in terrestrial waters f a257-2630 v7391 aWelch, Kathleen, A.1 aLyons, Berry1 aGraham, E1 aNeumann, Klaus1 aThomas, James, M.1 aMikesell, D. uhttps://mcm.lternet.edu/content/determination-major-element-chemistry-terrestrial-waters-antarctica-ion-chromatography00483nas a2200121 4500008004100000245008600041210006900127300001200196490000700208100002400215700001700239856010500256 1995 eng d00aMcMurdo LTER: Comparative limnology of the Taylor Valley lakes: The major solutes0 aMcMurdo LTER Comparative limnology of the Taylor Valley lakes Th a292-2930 v301 aWelch, Kathleen, A.1 aLyons, Berry uhttps://mcm.lternet.edu/content/mcmurdo-lter-comparative-limnology-taylor-valley-lakes-major-solutes00688nas a2200181 4500008004100000245010100041210006900142300001200211490000700223100002400230700001700254700002100271700002000292700002400312700002200336700002400358856012400382 1994 eng d00aMcMurdo LTER: Inorganic geochemical studies with special reference to calcium carbonate dynamics0 aMcMurdo LTER Inorganic geochemical studies with special referenc a237-2390 v291 aWelch, Kathleen, A.1 aLyons, Berry1 aPriscu, John, C.1 aEdwards, R., L.1 aMcKnight, Diane, M.1 aHouse, Harold, R.1 aWharton, Robert, A. uhttps://mcm.lternet.edu/content/mcmurdo-lter-inorganic-geochemical-studies-special-reference-calcium-carbonate-dynamics00452nas a2200133 4500008004100000245005800041210005700099300001100156490000700167100002100174700002400195700001700219856008200236 1994 eng d00aPaleolimnology of the McMurdo Dry Valleys, Antarctica0 aPaleolimnology of the McMurdo Dry Valleys Antarctica a85-1140 v101 aDoran, Peter, T.1 aWharton, Robert, A.1 aLyons, Berry uhttps://mcm.lternet.edu/content/paleolimnology-mcmurdo-dry-valleys-antarctica00588nas a2200121 4500008004100000245016800041210006900209300001200278490000700290100001700297700002300314856012900337 1993 eng d00aThe geochemical evolution of terrestrial waters in the antarctic: the role of rock-water interactions, in Physical and Biogeochemical Processes in Antarctic Lakes0 ageochemical evolution of terrestrial waters in the antarctic the a135-1430 v591 aLyons, Berry1 aMayewski, Paul, A. uhttps://mcm.lternet.edu/content/geochemical-evolution-terrestrial-waters-antarctic-role-rock-water-interactions-physical-and00557nas a2200133 4500008004100000245010300041210006900144300001200213490000800225100002400233700001700257700002200274856012700296 1993 eng d00aStable isotopic biogeochemistry of carbon and nitrogen in a perennially ice-covered Antarctic lake0 aStable isotopic biogeochemistry of carbon and nitrogen in a pere a159-1720 v1071 aWharton, Robert, A.1 aLyons, Berry1 aMarais, D.J., Des uhttps://mcm.lternet.edu/content/stable-isotopic-biogeochemistry-carbon-and-nitrogen-perennially-ice-covered-antarctic-lake