%0 Journal Article %J Limnology and Oceanography Letters %D 2022 %T Barotropic seiches in a perennially ice-covered lake, East Antarctica %A Castendyk, Devin %A Hilary A. Dugan %A Gallagher, Hugh A. %A Pujara, Nimish %A Peter T. Doran %A John C. Priscu %A W. Berry Lyons %X

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.

%B Limnology and Oceanography Letters %V 7 %P 26 - 33 %8 02/2022 %G eng %U https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.10226 %N 1 %! Limnol Oceanogr Letters %R 10.1002/lol2.10226 %0 Journal Article %J mSystems %D 2022 %T Elevational constraints on the composition and genomic attributes of microbial communities in Antarctic soils %A Dragone, Nicholas B. %A Henley, Jessica B. %A Holland-Moritz, Hannah %A Melisa A. Diaz %A Hogg, Ian D. %A W. Berry Lyons %A Diana H. Wall %A Byron Adams %A Noah Fierer %E Mackelprang, Rachel %K Antarctica %K microbial ecology %K soil microbiology %K soils %X

The 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.

%B mSystems %V 7 %P e01330-21 %8 01/2022 %G eng %U https://journals.asm.org/doi/full/10.1128/msystems.01330-21 %N 1 %R 10.1128/msystems.01330-21 %0 Journal Article %J Global Change Biology %D 2022 %T Response of Antarctic soil fauna to climate‐driven changes since the Last Glacial Maximum %A Franco, André L. C. %A Byron Adams %A Melisa A. Diaz %A Lemoine, Nathan P. %A Dragone, Nicholas B. %A Noah Fierer %A W. Berry Lyons %A Hogg, Ian D. %A Diana H. Wall %K biodiversity %K climate change %K glacial retreat %K nematodes %K Shackleton Glacier %K soil invertebrates %X

Understanding 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.

%B Global Change Biology %V 28 %8 01/2022 %G eng %U https://onlinelibrary.wiley.com/doi/10.1111/gcb.15940 %N 2 %R 10.1111/gcb.15940 %0 Book Section %B Hydrogeology, Chemical Weathering, and Soil Formation %D 2021 %T Chemical weathering in the McMurdo Dry Valleys, Antarctica %A W. Berry Lyons %A Leslie, Deborah L. %A Michael N. Gooseff %E Hunt, Allen %E Egli, Markus %E Faybishenko, Boris %K aluminosilicate weathering %K CaCO3 dissolution/precipitation %K chemical weathering %K hyporheic zone %K McMurdo Dry Valleys %X

While 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.

%B Hydrogeology, Chemical Weathering, and Soil Formation %S Geophysical Monograph Series %I John Wiley & Sons, Inc. %C Hoboken, NJ %P 205-216 %G eng %U https://agupubs.onlinelibrary.wiley.com/doi/10.1002/9781119563952.ch11 %& 11 %R 10.1002/9781119563952.ch11 %0 Journal Article %J Journal of Geophysical Research: Biogeosciences %D 2021 %T Exploring the boundaries of microbial habitability in soil %A Dragone, Nicholas B. %A Melisa A. Diaz %A Hogg, Ian D. %A W. Berry Lyons %A W. Andrew Jackson %A Diana H. Wall %A Adams, Byron J. %A Noah Fierer %K Antarctica %K astrobiology %K bacteria %K extremophiles %K fungi %K soils %X

Microbes 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.

%B Journal of Geophysical Research: Biogeosciences %V 126 %8 06/2021 %G eng %U https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JG006052 %N 6 %! J Geophys Res Biogeosci %R 10.1029/2020JG006052 %0 Journal Article %J Biogeosciences %D 2021 %T Geochemical zones and environmental gradients for soils from the central Transantarctic Mountains, Antarctica %A Melisa A. Diaz %A Christopher B. Gardner %A Welch, Susan A. %A W. Andrew Jackson %A Adams, Byron J. %A Diana H. Wall %A Hogg, Ian D. %A Noah Fierer %A W. Berry Lyons %X

Previous 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.

%B Biogeosciences %V 18 %P 1629 - 1644 %8 03/2021 %G eng %U https://bg.copernicus.org/articles/18/1629/2021/ %N 5 %! Biogeosciences %R 10.5194/bg-18-1629-2021 %0 Journal Article %J GSA Bulletin %D 2021 %T Geochemistry of contrasting stream types, Taylor Valley, Antarctica %A Harmon, Russell S. %A Leslie, Deborah L. %A W. Berry Lyons %A Kathleen A. Welch %A Diane M. McKnight %X

The 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.

%B GSA Bulletin %V 133 %P 425-448 %8 01/2021 %G eng %U https://pubs.geoscienceworld.org/gsa/gsabulletin/article/133/1-2/425/587799/Geochemistry-of-contrasting-stream-types-Taylor %N 1/2 %R 10.1130/B35479.1 %0 Thesis %B School of Earth Sciences %D 2020 %T Analysis of acid-leachable barium, copper, iron, lead, & zinc concentrations in Taylor Valley, Antarctic stream sediments %A Piergallini, Brianna %A W. Berry Lyons %K acid-leachable metal %K Antarctica %K geochemistry %K McMurdo Dry Valleys %K polar sediments %K sedimentation rate %X

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.

%B School of Earth Sciences %I The Ohio State University %C Columbus, OH %V B.S. %8 05/2020 %G eng %U http://hdl.handle.net/1811/91772 %9 bachelors %0 Journal Article %J Proceedings of the National Academy of Sciences %D 2020 %T Genetic diversity of soil invertebrates corroborates timing estimates for past collapses of the West Antarctic Ice Sheet %A Gemma E. Collins %A Hogg, Ian D. %A Convey, Peter %A Sancho, Leopoldo G. %A Cowan, Don A. %A W. Berry Lyons %A Byron Adams %A Diana H. Wall %A Allan Green, T. G. %K climate change %K microarthropods %K molecular clock %K phylogeography %K terrestrial biodiversity %X

During 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.

%B Proceedings of the National Academy of Sciences %8 08/2020 %G eng %U https://www.pnas.org/content/early/2020/08/19/2007925117 %R 10.1073/pnas.2007925117 %0 Journal Article %J Earth and Planetary Science Letters %D 2020 %T Geochemistry of aeolian material from the McMurdo Dry Valleys, Antarctica: Insights into Southern Hemisphere dust sources %A Melisa A. Diaz %A Welch, Susan A. %A Sheets, J. M. %A Kathleen A. Welch %A Khan, Alia L. %A Byron Adams %A Diane M. McKnight %A Craig S Cary %A W. Berry Lyons %K aeolian material %K Antarctica %K major oxides %K mineralogy %K rare earth elements %K trace elements %X

In 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.

%B Earth and Planetary Science Letters %V 547 %8 10/2020 %G eng %U https://www.sciencedirect.com/science/article/pii/S0012821X20304040 %R 10.1016/j.epsl.2020.116460 %0 Journal Article %J Frontiers in Earth Science %D 2020 %T Silicon isotopes reveal a non-glacial source of silicon to Crescent Stream, McMurdo Dry Valleys, Antarctica %A Hirst, Catherine %A Opfergelt, Sophie %A François Gaspard %A Hendry, Katharine R. %A Hatton, Jade E. %A Sue Welch %A Diane M. McKnight %A W. Berry Lyons %X

In 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.

%B Frontiers in Earth Science %V 8 %8 06/2020 %G eng %U https://www.frontiersin.org/articles/10.3389/feart.2020.00229/full %R 10.3389/feart.2020.00229 %0 Journal Article %J Frontiers in Earth Science %D 2020 %T Silicon isotopic composition of dry and wet-based glaciers in Antarctica %A Hatton, Jade E. %A Hendry, Katharine R. %A Hirst, Catherine %A Opfergelt, Sophie %A Henkel, Susann %A Silva-Busso, Adrián %A Welch, Susan A. %A Wadham, Jemma L. %A W. Berry Lyons %A Bagshaw, Elizabeth %A Staubwasser, Michael %A Diane M. McKnight %X

Glaciers 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.

%B Frontiers in Earth Science %V 8 %8 07/2020 %G eng %U https://www.frontiersin.org/articles/10.3389/feart.2020.00286/full %R 10.3389/feart.2020.00286 %0 Journal Article %J E3S Web of Conferences %D 2019 %T Diurnal chemistry of two contrasting stream types, Taylor Valley, McMurdo Dry Valley Region, Antarctica %A Harmon, Mark E. %A Leslie, D.L. %A W. Berry Lyons %A Kathleen A. Welch %A Diane M. McKnight %E Chudaev, O. %E Kharaka, Y. %E Harmon, R.S. %E Millot, R. %E Shouakar-Stash, O. %X

Numerous 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.

%B E3S Web of Conferences %V 98 %8 06/2019 %G eng %U https://www.e3s-conferences.org/articles/e3sconf/abs/2019/24/e3sconf_wri-162018_01020/e3sconf_wri-162018_01020.html %R 10.1051/e3sconf/20199801020 %0 Journal Article %J Journal of Geophysical Research: Biogeosciences %D 2019 %T The Geochemistry of Englacial Brine From Taylor Glacier, Antarctica %A W. Berry Lyons %A Jill A. Mikucki %A German, Laura A. %A Kathleen A. Welch %A Sue Welch %A Christopher B. Gardner %A Tulaczyk, Slawek M. %A Pettit, Erin C. %A Kowalski, Julia %A Dachwald, Bernd %X

Blood 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.

%B Journal of Geophysical Research: Biogeosciences %V 124 %8 03/2019 %G eng %U https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JG004411 %N 3 %R 10.1029/2018JG004411 %0 Journal Article %J Applied Geochemistry %D 2019 %T The geochemistry of glacial deposits in Taylor Valley, Antarctica: Comparison to upper continental crustal abundances %A Carolyn Dowling %A Sue Welch %A W. Berry Lyons %K Antarctica %K geochemistry %K glacial deposits %K polar dry-based glaciers %K Taylor Valley %X

Wet-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.

%B Applied Geochemistry %8 05/2019 %G eng %U https://www.sciencedirect.com/science/article/pii/S0883292719301246 %! Applied Geochemistry %R 10.1016/j.apgeochem.2019.05.006 %0 Journal Article %J Journal of Geophysical Research: Biogeosciences %D 2019 %T The hydroecology of an ephemeral wetland in the McMurdo Dry Valleys, Antarctica %A Wlostowski, Adam %A Schulte, Nicholas O. %A Byron Adams %A Ball, Becky %A Rhea M.M. Esposito %A Michael N. Gooseff %A W. Berry Lyons %A Uffe N. Nielsen %A Ross A. Virginia %A Diana H. Wall %A Kathleen A. Welch %A Diane M. McKnight %K Antarctica %K desert hydrology %K diatom biodiversity %K hyporheic interactions %K wetlands %X

The 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.

%B Journal of Geophysical Research: Biogeosciences %8 11/2019 %G eng %U https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JG005153 %R 10.1029/2019JG005153 %0 Journal Article %J Journal of Geophysical Research: Earth Surface %D 2018 %T Aeolian material transport and its role in landscape connectivity in the McMurdo Dry Valleys, Antarctica %A Melisa A. Diaz %A Byron Adams %A Kathleen A. Welch %A Sue Welch %A Opiyo, Stephen O. %A Khan, Alia L. %A Diane M. McKnight %A Craig S Cary %A W. Berry Lyons %X

Arid 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.

%B Journal of Geophysical Research: Earth Surface %V 123 %P 3323 - 3337 %8 12/2018 %G eng %U https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2017JF004589 %N 12 %! J. Geophys. Res. Earth Surf. %R 10.1029/2017JF004589 %0 Journal Article %J Geology %D 2018 %T Barium and barite dynamics in Antarctic streams %A Saelens, Elsa D. %A Christopher B. Gardner %A Kathleen A. Welch %A Sue Welch %A W. Berry Lyons %X

Most 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.

%B Geology %V 46 %P 811 - 814 %8 08/2018 %G eng %U https://pubs.geoscienceworld.org/gsa/geology/article/545184/Barium-and-barite-dynamics-in-Antarctic-streams %N 9 %R 10.1130/G45048.1 %0 Journal Article %J Geoderma %D 2018 %T Biogeochemical weathering of soil apatite grains in the McMurdo Dry Valleys, Antarctica %A Heindel, Ruth C %A W. Berry Lyons %A Sue Welch %A Spickard, Angela M %A Ross A. Virginia %X

The 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.

%B Geoderma %V 320 %P 136-145 %8 01/2018 %G eng %U https://www.sciencedirect.com/science/article/pii/S0016706117320694 %! Geoderma %R 10.1016/j.geoderma.2018.01.027 %0 Journal Article %J Frontiers in Earth Science %D 2018 %T Dissolved Trace and Minor Elements in Cryoconite Holes and Supraglacial Streams, Canada Glacier, Antarctica %A Sarah Fortner %A W. Berry Lyons %K Antarctica %K cryoconite holes %K glacier melt chemistry %K supraglacial streams %K trace elements %X

 

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.

 

%B Frontiers in Earth Science %V 6 %8 04/2018 %G eng %U http://journal.frontiersin.org/article/10.3389/feart.2018.00031/full %! Front. Earth Sci. %R 10.3389/feart.2018.00031 %0 Journal Article %J Scientific Reports %D 2018 %T Drivers of solar radiation variability in the McMurdo Dry Valleys, Antarctica %A Maciek K. Obryk %A Andrew G Fountain %A Peter T. Doran %A W. Berry Lyons %A Eastman, R. %X

 

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.

 

%B Scientific Reports %V 8 %8 03/2018 %G eng %U http://www.nature.com/articles/s41598-018-23390-7.pdf %! Sci Rep %R 10.1038/s41598-018-23390-7 %0 Journal Article %J Journal of Geophysical Research: Biogeosciences %D 2018 %T Fe and Nutrients in Coastal Antarctic Streams: Implications for Primary Production in the Ross Sea %A Sydney A. Olund %A W. Berry Lyons %A Sue Welch %A Kathleen A. Welch %X

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.

%B Journal of Geophysical Research: Biogeosciences %V 123 %P 3507 - 3522 %8 12/2018 %G eng %U https://agupubs.pericles-prod.literatumonline.com/doi/full/10.1029/2017JG004352 %N 12 %! J. Geophys. Res. Biogeosci. %R 10.1029/2017JG004352 %0 Journal Article %J Elementa: Science of the Anthropocene %D 2018 %T The impact of fossil fuel burning related to scientific activities in the McMurdo Dry Valleys, Antarctica: Revisited %A W. Berry Lyons %A Saelens, Elsa D. %A Kathleen A. Welch %K carbon dynamics %K emissions %K fossil fuels %K helicopter %K management %K McMurdo Dry Valleys %K nitrogen %K science activites %X

 

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.

 

%B Elementa: Science of the Anthropocene %V 6 %8 04/2018 %G eng %U https://www.elementascience.org/article/10.1525/elementa.288/ %! Elem Sci Anth %R 10.1525/elementa.288 %0 Journal Article %J Journal of Geophysical Research: Atmospheres %D 2018 %T Near-surface refractory black carbon observations in the atmosphere and snow in the McMurdo Dry Valleys, Antarctica and potential impacts of foehn winds %A Khan, Alia L. %A McMeeking, Gavin %A Schwarz, Joshua P. %A Xian, Peng %A Kathleen A. Welch %A W. Berry Lyons %A Diane M. McKnight %X

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. 

 

%B Journal of Geophysical Research: Atmospheres %V 123 %P 2877 - 2887 %8 01/2018 %G eng %U http://doi.wiley.com/10.1002/2017JD027696 %N 5 %! J. Geophys. Res. Atmos. %R 10.1002/2017JD027696 %0 Journal Article %J Polar Biology %D 2018 %T Stable C and N isotope ratios reveal soil food web structure and identify the nematode Eudorylaimus antarcticus as an omnivore–predator in Taylor Valley, Antarctica %A Shaw, E. Ashley %A Byron Adams %A John E. Barrett %A W. Berry Lyons %A Ross A. Virginia %A Diana H. Wall %X

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.

%B Polar Biology %V 41 %P 1013–1018 %8 05/2018 %G eng %U http://link.springer.com/10.1007/s00300-017-2243-8 %N 5 %! Polar Biol %R 10.1007/s00300-017-2243-8 %0 Journal Article %J Geophysical Research Letters %D 2018 %T Transit times and rapid chemical equilibrium explain chemostasis in glacial meltwater streams in the McMurdo Dry Valleys, Antarctica %A Wlostowski, Adam %A Michael N. Gooseff %A Diane M. McKnight %A W. Berry Lyons %X

Fluid  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.

%B Geophysical Research Letters %V 45 %P 13322 - 13331 %8 12/2018 %G eng %U https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL080369 %N 24 %! Geophys. Res. Lett. %R 10.1029/2018GL080369 %0 Journal Article %J Geophysical Research Letters %D 2017 %T Ca isotopic geochemistry of an Antarctic aquatic system %A W. Berry Lyons %A Bullen, T %A Kathleen A. Welch %X

The 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. 

%B Geophysical Research Letters %V 44 %P 882 - 891 %8 01/2017 %G eng %U http://onlinelibrary.wiley.com/doi/10.1002/2016GL071169/full %N 2 %! Geophys. Res. Lett. %R 10.1002/2016GL071169 %0 Thesis %B School of Earth Sciences %D 2017 %T Comparing the Weathering Environment of Permian and Modern Antarctic Proglacial Lake Sediments: Mineralogical and Geochemical Study %A Brewster, Shelby A. %E W. Berry Lyons %X

The 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.

%B School of Earth Sciences %I The Ohio State University %C Columbus, OH %V B.S. %G eng %U http://hdl.handle.net/1811/80763 %9 bachelors %0 Journal Article %J Nature Ecology & Evolution %D 2017 %T Decadal ecosystem response to an anomalous melt season in a polar desert in Antarctica %A Michael N. Gooseff %A John E. Barrett %A Byron Adams %A Peter T. Doran %A Andrew G Fountain %A W. Berry Lyons %A Diane M. McKnight %A John C. Priscu %A Eric R. Sokol %A Cristina D. Takacs-Vesbach %A Martijn L. Vandegehuchte %A Ross A. Virginia %A Diana H. Wall %B Nature Ecology & Evolution %V 1 %P 1334-1338 %8 09/2017 %G eng %U https://www.nature.com/articles/s41559-017-0253-0 %N 9 %! Nat Ecol Evol %R 10.1038/s41559-017-0253-0 %0 Thesis %B Earth Sciences %D 2017 %T Fe and Nutrients in Coastal Antarctic Streams: Implications for Marine Primary Production in the Ross Sea %A Sydney A. Olund %E W. Berry Lyons %X

The 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.

The behavior and potential colloidal/nanoparticulate speciation of the Fe in these streams was investigated through analysis of three physiochemical forms of Fe - environmentally active Fe (acid-soluble/no filtration), filterable Fe (filtered through 0.4 μm), and dissolved Fe (filtered through 0.2 μm). It has been suggested that the dissolved fraction is mainly nanoparticulate and represents a more bioavailable form of Fe, as compared with colloids and particles. Overall, the combined average annual flux from two MDV streams is approximately 240 moles fFe yr-1, which is consistent with previously predicted values. The dissolved fraction of Fe (<0.2 μm) was between 18% and 27% percent of the fFe, meaning the fFe pool is mostly colloidal. While the Fe flux from these streams is several orders of magnitude less than aeolian and iceberg sources, terrestrial streams are expected to become a more significant source of Fe to the Ross Sea. As the Antarctic climate warms, ice-free regions similar to the MDV should increase in extent and glacier melt. This study questions how, and in what quantities, Fe is solubilized and transported from the landscape into the SO to better inform predictions of Fe fluxes following continued warming.
%B Earth Sciences %I Ohio State University %V M.S. %G eng %U http://rave.ohiolink.edu/etdc/view?acc_num=osu1492697894343546 %9 masters %0 Thesis %B School of Earth Sciences %D 2017 %T The geochemistry of minor cations within Antarctic stream water: Determining the role of the hyporheic zone %A Saelens, Elsa D. %E W. Berry Lyons %B School of Earth Sciences %I The Ohio State University %C Columbus, OH %V B.A. %G eng %U http://library.ohio-state.edu/record=b8218699~S7 %9 bachelors %0 Thesis %B Earth Sciences %D 2017 %T Spatial and Temporal Geochemical Characterization of Aeolian Material from the McMurdo Dry Valleys, Antarctica %A Melisa A. Diaz %E W. Berry Lyons %X

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.

%B Earth Sciences %I Ohio State University %V M.S. %G eng %U http://rave.ohiolink.edu/etdc/view?acc_num=osu1500468216147725 %9 masters %0 Journal Article %J Hydrological Processes %D 2017 %T A temporal stable isotopic (δ18O, δD, d-excess) comparison in glacier meltwater streams, Taylor Valley, Antarctica %A Leslie, D.L. %A Kathleen A. Welch %A W. Berry Lyons %X

In this paper, we describe the importance of hyporheic dynamics within Andersen Creek and Von Guerard Stream, Taylor Valley, Antarctica, from the 20102011 melt season using natural tracers. Water collection started at flow onset and continued, with weekly hyporheiczone sampling. The water δ18O and δD values were isotopically lighter in the beginning and heavier later in the season. Dexcess measurements were used as an indicator of mixing because an evaporative signature was evident and distinguishable between 2 primary endmembers (glacier meltwater and hyporheic zone). Hyporheiczone 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 hyporheiczone solute interaction through the influence from subsurface hypersaline flow. Overall, the evolution of Taylor Valley hyporheiczone hydrology is described seasonally. In midDecember, 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 zonestream interaction in these glacier meltwater streams. 

%B Hydrological Processes %V 31 %P 3069 - 3083 %8 08/2017 %G eng %U http://onlinelibrary.wiley.com/doi/10.1002/hyp.11245/full %N 17 %! Hydrological Processes %R 10.1002/hyp.v31.1710.1002/hyp.11245 %0 Journal Article %J Polar Biology %D 2016 %T Evidence for dispersal and habitat controls on pond diatom communities from the McMurdo Sound Region of Antarctica %A Sakaeva, A. %A Eric R. Sokol %A Tyler J. Kohler %A Lee F. Stanish %A Sarah A. Spaulding %A Howkins, Adrian %A Kathleen A. Welch %A W. Berry Lyons %A John E. Barrett %A Diane M. McKnight %B Polar Biology %8 02/2016 %G eng %U http://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.html %! Polar Biol %R 10.1007/s00300-016-1901-6 %0 Journal Article %J PLOS ONE %D 2016 %T Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica %A Herbei, Radu %A Rytel, Alexander L. %A W. Berry Lyons %A Diane M. McKnight %A Chris Jaros %A Michael N. Gooseff %A John C. Priscu %E Hewitt, Judi %B PLOS ONE %V 11 %P e0159038 %8 07/2016 %G eng %U http://dx.plos.org/10.1371/journal.pone.0159038 %N 7 %! PLoS ONE %R 10.1371/journal.pone.015903810.1371 %0 Journal Article %J Hydrological Processes %D 2016 %T Patterns of hydrologic connectivity in the McMurdo dry valleys, Antarctica: a synthesis of 20 years of hydrologic data %A Wlostowski, Adam %A Michael N. Gooseff %A Diane M. McKnight %A Chris Jaros %A W. Berry Lyons %X

Streams 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. 

%B Hydrological Processes %V 30 %P 2958-2975 %8 04/2016 %G eng %U http://onlinelibrary.wiley.com/doi/10.1002/hyp.10818 %N 17 %! Hydrol. Process. %& 2958 %R 10.1002/hyp.10818 %0 Journal Article %J Biogeosciences %D 2016 %T Stream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica %A Michael N. Gooseff %A David J. Van Horn %A Sudman, Zachary %A Diane M. McKnight %A Kathleen A. Welch %A W. Berry Lyons %X

 Stream 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.

%B Biogeosciences %V 13 %P 1723 - 1732 %8 03/2016 %G eng %U http://www.biogeosciences.net/13/1723/2016/bg-13-1723-2016.pdf %N 6 %! Biogeosciences %R 10.5194/bg-13-1723-2016 %0 Journal Article %J Geology %D 2015 %T Antarctic streams as a potential source of iron for the Southern Ocean: Figure 1. %A W. Berry Lyons %A Dailey, Kelsey R. %A Kathleen A. Welch %A Deuerling, Kelly M. %A Sue Welch %A Diane M. McKnight %X

Due 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 

%B Geology %V 43 %P 1003 - 1006 %8 11/2016 %G eng %U http://geology.gsapubs.org/lookup/doi/10.1130/G36989.1http://geology.geoscienceworld.org/lookup/doi/10.1130/G36989.1 %N 11 %! Geology %& 1003 %R 10.1130/G36989.1 %0 Thesis %B School of Earth Sciences %D 2015 %T Chemical Weathering and Mineralogy of McMurdo Dry Valley Streams: Examining the Controls of Current and Future Ephemeral Stream Geochemistry %A Scheuermann, Jordan %A W. Berry Lyons %X

The 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.

%B School of Earth Sciences %C Ohio State University %V Undergraduate Theses %P 38 %8 05/2015 %G eng %U http://hdl.handle.net/1811/68887 %9 bachelors %0 Journal Article %J Chemical Geology %D 2015 %T Comparison of arsenic and molybdenum geochemistry in meromictic lakes of the McMurdo Dry Valleys, Antarctica: Implications for oxyanion-forming trace element behavior in permanently stratified lakes %A Yang, Ningfang %A Kathleen A. Welch %A Mohajerin, T. Jade %A Telfeyan, Katherine %A Chevis, Darren A. %A Grimm, Deborah A. %A W. Berry Lyons %A White, Christopher D. %A Johannesson, Karen H. %X

Water 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.

%B Chemical Geology %V 404 %P 110 - 125 %8 05/2015 %G eng %U http://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/plain %! Chemical Geology %& 110 %R 10.1016/j.chemgeo.2015.03.029 %0 Journal Article %J Antarctic Science %D 2015 %T Experimental formation of pore fluids in McMurdo Dry Valleys soils %A Joseph S. Levy %A Andrew G Fountain %A W. Berry Lyons %A Kathleen A. Welch %X

The 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.

%B Antarctic Science %V 27 %P 163 - 171 %8 04/2015 %G eng %U http://www.journals.cambridge.org/abstract_S0954102014000479 %N 02 %! Antarctic Science %R 10.1017/S0954102014000479 %0 Journal Article %J Artic, Antarctic and Alpine Research %D 2015 %T Patterns and processes of salt efflorescences in the McMurdo region, Antarctica %A Bisson, K. M. %A Kathleen A. Welch %A Sue Welch %A Sheets, J. M. %A W. Berry Lyons %A Joseph S. Levy %A Andrew G Fountain %X

Evaporite 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.

%B Artic, Antarctic and Alpine Research %G eng %U http://aaarjournal.org/doi/abs/10.1657/AAAR0014-024 %0 Journal Article %J Water Resources Research %D 2015 %T Potential for real-time understanding of coupled hydrologic and biogeochemical processes in stream ecosystems: Future integration of telemetered data with process models for glacial meltwater streams %A Diane M. McKnight %A Cozzetto, K %A Cullis, James D.S. %A Michael N. Gooseff %A Chris Jaros %A Koch, J. %A W. Berry Lyons %A Neupauer, R. M. %A Wlostowski, Adam %B Water Resources Research %V 51 %P 6725 - 6738 %8 08/2015 %G eng %U http://doi.wiley.com/10.1002/2015WR017618http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F2015WR017618 %N 8 %! Water Resour. Res. %R 10.1002/2015WR017618 %0 Journal Article %J Antarctic Science %D 2015 %T A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond %A Kennicutt, M.C. %A Steven L. Chown %A Cassano, J.J. %A Liggett, D. %A Lloyd S. Peck %A Massom, R. %A Rintoul, S.R. %A Storey, J. %A Vaughan, D.G. %A Wilson, T.J. %A Allison, I. %A Ayton, J. %A Badhe, R. %A Baeseman, J. %A Barrett, P.J. %A Elanor R. Bell %A Bertler, N. %A Bo, S. %A Brandt, A. %A David Bromwich %A Craig S Cary %A Clark, M.S. %A Peter Convey %A Costa, E.S. %A Cowan, D. %A Deconto, R. %A Dunbar, R. %A Elfring, C. %A Escutia, C. %A Francis, J. %A Fricker, H.A. %A Fukuchi, M. %A Gilbert, N. %A Gutt, J. %A Havermans, C. %A Hik, D. %A Hosie, G. %A Jones, C. %A Kim, Y.D. %A Le Maho, Y. %A Lee, S.H. %A Leppe, M. %A Leitchenkov, G. %A Li, X. %A Lipenkov, V. %A Lochte, K. %A López-Martínez, J. %A üdecke, C. %A W. Berry Lyons %A Marenssi, S. %A Miller, H. %A Morozova, P. %A Naish, T. %A Nayak, S. %A Ravindra, R. %A Retamales, J. %A Ricci, C.A. %A Rogan-Finnemore, M. %A Ropert-Coudert, Y. %A Samah, A.A. %A Sanson, L. %A Scambos, T. %A I.R. Schloss %A Shiraishi, K. %A Siegert, M.J. %A Simões, J.C. %A Storey, B. %A Sparrow, M.D. %A Diana H. Wall %A Walsh, J.C. %A Wilson, G. %A Winther, J.G. %A J.C. Xavier %A Yang, H. %A Sutherland, W.J. %X

Antarctic 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

%B Antarctic Science %V 27 %P 3 - 18 %8 Jan-02-2015 %G eng %U http://www.journals.cambridge.org/abstract_S0954102014000674 %N 01 %! Antarctic Science %R 10.1017/S0954102014000674 %0 Journal Article %J Chemical Geology %D 2014 %T Boron isotopic geochemistry of the McMurdo Dry Valley lakes, Antarctica %A Leslie, D.L. %A W. Berry Lyons %A Warner, Nathaniel %A Vengosh, Avner %A Olesik, J %A Kathleen A. Welch %A Deuerling, Kelly %X

 

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.

 

 

%B Chemical Geology %V 386 %P 152 - 164 %8 10/2014 %G eng %U http://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/plain %! Chemical Geology %& 152 %R 10.1016/j.chemgeo.2014.08.016 %0 Journal Article %J Antarctic Science %D 2014 %T The effects of high meltwater on the limnology of Lake Fryxell and Lake Hoare, Taylor Valley, Antarctica, as shown by dissolved gas, tritium and chlorofluorocarbons %A Carolyn Dowling %A Robert J. Poreda %A W. Berry Lyons %X

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.

%B Antarctic Science %V 26 %P 331 - 340 %8 Jan-08-2014 %G eng %U http://www.journals.cambridge.org/abstract_S095410201300062X %N 04 %! Antarctic Science %R 10.1017/S095410201300062X %0 Thesis %B Earth Sciences %D 2014 %T Elemental Cycling in a Flow-Through Lake in the McMurdo Dry Valleys, Antarctica: Lake Miers %A Alexandria Corinne Fair %A W. Berry Lyons %E Anne E. Carey %E Yu-Ping Chin %X

The 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.

%B Earth Sciences %I Ohio State University %C Columbus %V Master Thesis %P 122 %8 06/2014 %G eng %U https://etd.ohiolink.edu/!etd.send_file?accession=osu1413291502&disposition=inline %9 masters %0 Journal Article %J Limnology and Oceanography %D 2014 %T Radiocarbon abundance and reservoir effects in lakes of the McMurdo Dry Valleys, Antarctica %A Peter T. Doran %A Kenig, Fabien %A Lawson Knoepfle %A Jill A. Mikucki %A W. Berry Lyons %B Limnology and Oceanography %V 59 %P 811-826 %8 05/2014 %G eng %N 3 %& 811 %0 Journal Article %J Ecological Monographs %D 2014 %T The spatial structure of Antarctic biodiversity %A Peter Convey %A Steven L. Chown %A Clarke, Andrew %A Barnes, David K. A. %A Bokhorst, Stef %A Vonda Cummings %A Hugh W. Ducklow %A Francesco Frati %A Green, T. G. Allan %A Shulamit Gordon %A Griffiths, Huw J. %A Clive Howard-Williams %A Huiskes, Ad H. L. %A Johanna Laybourn-Parry %A W. Berry Lyons %A McMinn, Andrew %A Morley, Simon A. %A Lloyd S. Peck %A Quesada, Antonio %A Robinson, Sharon A. %A Schiaparelli, Stefano %A Diana H. Wall %X

Patterns 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.

 

%B Ecological Monographs %V 84 %P 203 - 244 %8 05/2014 %G eng %U http://www.esajournals.org/doi/abs/10.1890/12-2216.1 %N 2 %! Ecological Monographs %R 10.1890/12-2216.1 %0 Thesis %B Geological Sciences %D 2013 %T The application of stable isotopes, δ11B, δ18O, and δD, in geochemical and hydrological investigations %A Leslie, D.L. %A W. Berry Lyons %K Antarctica %K boron isotopes %K hyporheic zone %K McMurdo Dry Valleys %K Ohio precipitation source %K oxygen-18 and deuterium isotopes %K saline lake %X

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.

%B Geological Sciences %I Ohio State University %C Columbus, OH %V Ph.D. %G eng %U http://rave.ohiolink.edu/etdc/view?acc_num=osu1386000037 %9 doctoral %0 Journal Article %J Applied Geochemistry %D 2013 %T The carbon stable isotope biogeochemistry of streams, Taylor Valley, Antarctica %A W. Berry Lyons %A Leslie, D.L. %A Harmon, R.S. %A Klaus Neumann %A Kathleen A. Welch %A Bisson, K. M. %A Diane M. McKnight %B Applied Geochemistry %V 32 %P 26 - 36 %8 05/2013 %G eng %R 10.1016/j.apgeochem.2012.08.019 %0 Journal Article %J Arctic, Antarctic, and Alpine Research %D 2013 %T Do Cryoconite Holes have the Potential to be Significant Sources of C, N, and P to Downstream Depauperate Ecosystems of Taylor Valley, Antarctica? %A Bagshaw, Elizabeth %A Martyn Tranter %A Andrew G Fountain %A Kathleen A. Welch %A Hassan J. Basagic %A W. Berry Lyons %B Arctic, Antarctic, and Alpine Research %V 45 %P 440 - 454 %8 11/2013 %G eng %N 4 %R 10.1657/1938-4246-45.4.440 %0 Journal Article %J Geological Society of America Bulletin %D 2013 %T Garwood Valley, Antarctica: A new record of Last Glacial Maximum to Holocene glaciofluvial processes in the McMurdo Dry Valleys %A Joseph S. Levy %A Andrew G Fountain %A O'Connor, J. E. %A Kathleen A. Welch %A W. Berry Lyons %B Geological Society of America Bulletin %V 125 %P 1484 - 1502 %8 09/2013 %G eng %U http://bulletin.geoscienceworld.org/content/early/2013/06/07/B30783.1.abstract %N 9-10 %R 10.1130/B30783.1 %0 Journal Article %J Eos, Transactions American Geophysical Union %D 2013 %T Understanding Terrestrial Ecosystem Response to Antarctic Climate Change %A Joseph S. Levy %A W. Berry Lyons %A Byron Adams %B Eos, Transactions American Geophysical Union %V 94 %P 33 - 33 %8 01/2013 %G eng %U http://onlinelibrary.wiley.com/doi/10.1002/2013EO030009/abstract %N 3 %R 10.1002/2013EO030009 %0 Journal Article %J Antarctic Science %D 2013 %T Water track modification of soil ecosystems in the Lake Hoare basin, Taylor Valley, Antarctica %A Joseph S. Levy %A Andrew G Fountain %A Michael N. Gooseff %A John E. Barrett %A Robert Vantreese %A Kathleen A. Welch %A W. Berry Lyons %A Uffe N. Nielsen %A Diana H. Wall %B Antarctic Science %P 1 - 10 %G eng %R 10.1017/S095410201300045X %0 Journal Article %J Antarctic Science %D 2012 %T The geochemistry of upland ponds, Taylor Valley, Antarctica %A W. Berry Lyons %A Kathleen A. Welch %A Christopher B. Gardner %A Chris Jaros %A Daryl L. Moorhead %A Knoepfle, J %A Peter T. Doran %B Antarctic Science %V 24 %P 3 - 14 %8 2/2012 %G eng %U http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8483351 %N 01 %R 10.1017/S0954102011000617 %0 Journal Article %J Geophysical Research Letters %D 2012 %T Hypersaline “wet patches” in Taylor Valley, Antarctica %A Joseph S. Levy %A Andrew G Fountain %A Kathleen A. Welch %A W. Berry Lyons %B Geophysical Research Letters %V 39 %8 03/2012 %G eng %N 5 %R 10.1029/2012GL050898 %0 Journal Article %J Geochimica et Cosmochimica Acta %D 2012 %T Perchlorate and chlorate biogeochemistry in ice-covered lakes of the McMurdo Dry Valleys, Antarctica %A W. Andrew Jackson %A Alfonso F. Davila %A Nubia Estrada %A W. Berry Lyons %A John D. Coates %A John C. Priscu %B Geochimica et Cosmochimica Acta %V 98 %P 19 - 30 %8 12/2012 %G eng %U http://www.sciencedirect.com/science/article/pii/S001670371200511X %R 10.1016/j.gca.2012.09.014 %0 Web Page %D 2012 %T Taylor’s ‘missing’ lake: Integrating history into LTER research in the McMurdo Dry Valley %A Khan, A %A Howkins, Adrian %A W. Berry Lyons %I LTER News %C Albuquerque %V 2013 %G eng %U http://news.lternet.edu/Article2568.html %0 Journal Article %J Geography Compass %D 2011 %T Hydrological Connectivity of the Landscape of the McMurdo Dry Valleys, Antarctica %A Michael N. Gooseff %A Diane M. McKnight %A Peter T. Doran %A Andrew G Fountain %A W. Berry Lyons %B Geography Compass %V 5 %P 666 - 681 %8 09/2011 %G eng %U http://onlinelibrary.wiley.com/doi/10.1111/j.1749-8198.2011.00445.x %N 9 %R 10.1111/j.1749-8198.2011.00445.x %0 Journal Article %J Antarctic Science %D 2011 %T Long-term ecosystem networks to record change: an international imperative %A Diana H. Wall %A W. Berry Lyons %A Steven L. Chown %A Peter Convey %A Clive Howard-Williams %A Quesada, Antonio %A Warwick F. Vincent %B Antarctic Science %V 23 %P 209 %8 06/2011 %G eng %U http://www.journals.cambridge.org/abstract_S0954102011000319 %N 03 %! Antarctic Science %R 10.1017/S0954102011000319 %0 Journal Article %J Geological Society of America Bulletin %D 2011 %T Water tracks and permafrost in Taylor Valley, Antarctica: Extensive and shallow groundwater connectivity in a cold desert ecosystem %A Joseph S. Levy %A Andrew G Fountain %A Michael N. Gooseff %A Kathleen A. Welch %A W. Berry Lyons %B Geological Society of America Bulletin %V 123 %P 2295-2311 %8 11/2011 %G eng %U http://bulletin.geoscienceworld.org/content/123/11-12/2295.short %N 11-12 %R 10.1130/B30436.1 %0 Thesis %B Geological Sciences %D 2010 %T Aeolian sediments of the McMurdo Dry Valleys, Antarctica %A Deuerling, Kelly M. %A W. Berry Lyons %K aeolian transport %K Antarctica %K dust %K experimental leaching %K geochemistry %K McMurdo Dry Valleys %K sediment provenance %K weathering %X

The 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.

%B Geological Sciences %I Ohio State University %C Columbus, OH %V M.S. %G eng %U http://rave.ohiolink.edu/etdc/view?acc_num=osu1290524862 %9 masters %0 Book Section %B Life in Antarctic Deserts and other Cold Dry Environments %D 2010 %T Antarctic McMurdo Dry Valley stream ecosystems as analog to fluvial systems on Mars %A Michael N. Gooseff %A Diane M. McKnight %A Carr, M. H. %A Baeseman, J. %E Peter T. Doran %E W. Berry Lyons %E Diane M. McKnight %B Life in Antarctic Deserts and other Cold Dry Environments %I Cambridge University Press %C Cambridge %P 139 - 159 %@ 9780521889193 %G eng %R 10.1017/CBO9780511712258.005 %0 Journal Article %J Global Biogeochemical Cycles %D 2010 %T Biogeochemical weathering under ice: Size matters %A Wadham, J. L. %A Martyn Tranter %A Skidmore, M %A Hodson, A. J. %A John C. Priscu %A W. Berry Lyons %A Sharp, M. %A Wynn, P. %A Margaret S. Jackson %B Global Biogeochemical Cycles %V 24 %8 2010 %G eng %N 3 %R 10.1029/2009GB003688 %0 Book %B Astrobiological Analogs %D 2010 %T Life in Antarctic Deserts and Other Cold Environments %A Peter T. Doran %A W. Berry Lyons %A Diane M. McKnight %E Diane M. McKnight %E Michael N. Gooseff %E Cristina D. Takacs-Vesbach %E Jill A. Mikucki %E Martyn Tranter %E Sun, Henry J %K Planetary Science %B Astrobiological Analogs %I Cambridge University Press. %C Cambridge %V 5 %P 307 %@ 9780511712258 %G eng %U http://ebooks.cambridge.org/ebook.jsf?bid=CBO9780511712258 %R 10.1017/CBO9780511712258 %0 Journal Article %J Ecological Modelling %D 2010 %T Physiochemical properties influencing biomass abundance and primary production in Lake Hoare, Antarctica %A Herbei, Radu %A W. Berry Lyons %A Johanna Laybourn-Parry %A Christopher B. Gardner %A John C. Priscu %A Diane M. McKnight %B Ecological Modelling %G eng %R LTER %0 Book Section %B Life in Antarctic Deserts and other Cold Dry Environments %D 2010 %T Saline lakes and ponds in the McMurdo Dry Valleys: ecological analogs to martian paleolake environments %A Jill A. Mikucki %A W. Berry Lyons %A Ian Hawes %A Brian D. Lanoil %A Peter T. Doran %B Life in Antarctic Deserts and other Cold Dry Environments %I Cambridge University Press %C Cambridge %P 160 - 194 %@ 9780521889193 %G eng %U http://ebooks.cambridge.org/chapter.jsf?bid=CBO9780511712258&cid=CBO9780511712258A013 %R 10.1017/CBO9780511712258.006 %0 Journal Article %J Antarctic Science %D 2010 %T Spatial variations in the geochemistry of glacial meltwater streams in the Taylor Valley, Antarctica %A Kathleen A. Welch %A W. Berry Lyons %A Whisner, Carla %A Christopher B. Gardner %A Michael N. Gooseff %A Diane M. McKnight %A John C. Priscu %B Antarctic Science %V 22 %P 662 - 672 %8 12/2010 %G eng %U http://www.montana.edu/lkbonney/DOCS/Publications/WelchEtAl2010Geochemistry.pdf %N 06 %R 10.1017/S0954102010000702 %0 Thesis %D 2009 %T The Minor Alkaline Earth Element and Alkali Metal Behavior in Closed-basin Lakes %A Witherow, R %Y W. Berry Lyons %I The Ohio State University %G eng %9 doctoral %R LTER %0 Journal Article %J Hydrobiologia %D 2009 %T Particulate organic and dissolved inorganic carbon stable isotopic compositions in Taylor Valley lakes, Antarctica: the effect of legacy %A Knoepfle, J %A Peter T. Doran %A Kenig, Fabien %A W. Berry Lyons %A Galchenko, V %B Hydrobiologia %V 632 %P 139-156 %G eng %R LTER %0 Journal Article %J Aquatic Geochemistry %D 2009 %T The saline lakes of the McMurdo Dry Valleys, Antarctica, %A William J. Green %A W. Berry Lyons %B Aquatic Geochemistry %P 321-348 %G eng %N 15 %R LTER %0 Journal Article %J Review of Geophysics %D 2009 %T State of the Antarctic and the Southern Ocean climate system, %A Paul A. Mayewski %A David Bromwich %A Campbell, H %A Hamilton, G %A W. Berry Lyons %A Maasch, K %A Aoki, S %A Xiao, C %A van Ommen, T %A Meredith, M %A Summerhayes, C %A Turner, J %A Worby, A %A John E. Barrett %A Casassa, G %A Bertler, N %A T Bracegirdle %B Review of Geophysics %V 47 %G eng %R LTER %0 Book Section %B Polar Lakes and Rivers: Limnology of Arctic and Antarctic Aquatic Ecosystems %D 2008 %T Biogeochemical processes in high-latitude lakes and rivers %A W. Berry Lyons %A Finlay, J %E Warwick F. Vincent %E Johanna Laybourn-Parry %B Polar Lakes and Rivers: Limnology of Arctic and Antarctic Aquatic Ecosystems %I Oxford University Press %C Oxford %G eng %R LTER %0 Thesis %D 2008 %T The geochemistry of glacier snow and melt: The Oregon Cascades and Taylor Valley, Antarctica. %A Sarah Fortner %Y W. Berry Lyons %I The Ohio State University %V Ph.D. %G eng %9 doctoral %R LTER %0 Journal Article %J Environmental Science and Technology %D 2008 %T Mercury Deposition in a Polar Desert Ecosystem %A Witherow, R %A W. Berry Lyons %B Environmental Science and Technology %V 42 %P 4710-4716 %G eng %R LTER %0 Journal Article %J Limnology and Oceanography %D 2008 %T Supersaturated N2O in a perennially ice-covered Antarctic lake: Molecular and stable isotopic evidence for a biogeochemical relict. %A John C. Priscu %A Brent C. Christner %A John E. Dore %A Marian B. Westley %A Brian N. Popp %A Karen L. Casciotti %A W. Berry Lyons %B Limnology and Oceanography %V 53 %P 2439-2450 %G eng %U http://brent.xner.net/pdf/Priscu_etal2008_ELB-N2O.pdf %N 6 %R LTER %0 Journal Article %J Journal of Geophysical Research %D 2007 %T The biogeochemical evolution of cryoconite holes on glaciers in Taylor Valley, Antarctica %A Bagshaw, Elizabeth %A Martyn Tranter %A Andrew G Fountain %A Kathleen A. Welch %A Hassan J. Basagic %A W. Berry Lyons %B Journal of Geophysical Research %V 113 %P G04S35 %G eng %R LTER %0 Journal Article %J Journal of Geophysical Research %D 2007 %T Biogeochemical stoichiometry of Antarctic Dry Valley ecosystems %A John E. Barrett %A Ross A. Virginia %A W. Berry Lyons %A Diane M. McKnight %A John C. Priscu %A Andrew G Fountain %A Diana H. Wall %A Daryl L. Moorhead %A Peter T. Doran %K Biggie %X

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.

%B Journal of Geophysical Research %V 112 %P G01010+12 %8 02/2007 %G eng %R 10.1029/2005JG000141 %0 Journal Article %J Geophysical Research Letters %D 2007 %T Organic carbon in Antarctic precipitation %A W. Berry Lyons %A Kathleen A. Welch %A Doggett, J %B Geophysical Research Letters %V 34 %G eng %R LTER %0 Journal Article %J Geomorphology %D 2007 %T Reactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: A long-term geomorphological experiment %A Diane M. McKnight %A Cathy M. Tate %A Edmund D. Andrews %A Dev K. Niyogi %A Cozzetto, K %A Kathleen A. Welch %A W. Berry Lyons %A D. G. Capone %B Geomorphology %V 89 %P 186-204 %8 09/2007 %G eng %N 1-2 %R 10.1016/j.geomorph.2006.07.025 %0 Journal Article %J Geological Society of America Bulletin %D 2007 %T Solute and isotope geochemistry of subsurface ice melt seeps in Taylor Valley, Antarctica %A Harris, K %A Anne E. Carey %A Kathleen A. Welch %A W. Berry Lyons %A Andrew G Fountain %K Climate Response %B Geological Society of America Bulletin %V 119 %P 548-555 %8 01/2007 %G eng %U http://gsabulletin.gsapubs.org/content/119/5-6/548.short %N 5-6 %R 10.1130/B25913.1 %0 Conference Proceedings %B Antarctica; A keystone in a changing world--online proceedings for the tenth international symposium %D 2007 %T Trends in discharge and flow season timing of the Onyx River, Wright Valley, Antarctica since 1969 %A Michael N. Gooseff %A Diane M. McKnight %A Peter T. Doran %A W. Berry Lyons %E Alan Cooper %E Carol Raymond %E ISAES Editorial Team %B Antarctica; A keystone in a changing world--online proceedings for the tenth international symposium %I U.S. Geological Survey Open-File Report 2007-1047 %G eng %R LTER %0 Journal Article %J Antarctic Science %D 2006 %T The aeolian flux of calcium, chloride and nitrate to the McMurdo Dry Valleys landscape: Evidence from snow pit analysis %A Witherow, R %A Bertler, N %A Kathleen A. Welch %A W. Berry Lyons %A Paul A. Mayewski %A Sneed, S %A Thomas H. Nylen %A Handley, M %A Andrew G Fountain %B Antarctic Science %V 18 %P 497-505 %G eng %R LTER %0 Book Section %B Trends in Antarctic Terrestrial and Limnetic Ecosystems: Antarctica as a Global Indicator %D 2006 %T Antarctic lake systems and climate change %A W. Berry Lyons %A Johanna Laybourn-Parry %A Kathleen A. Welch %A John C. Priscu %E D.M. Bergstrom %E Peter Convey %E A.H.L. Huiskes %B Trends in Antarctic Terrestrial and Limnetic Ecosystems: Antarctica as a Global Indicator %I S %C Dordrecht, The Netherlands %G eng %R LTER %0 Journal Article %J Antarctic Science. %D 2006 %T Measuring ecosystem response in a rapidly changing environment: the Latitudinal Gradient Project %A Clive Howard-Williams %A Peterson, D %A W. Berry Lyons %A Cattaneo-Vietti, R %A Shulamit Gordon %B Antarctic Science. %V 10 %G eng %N 4 %R LTER %0 Book Section %B Paleoenvironmental Record and Applications of Calcretes and Palustrine Carbonates %D 2006 %T Pedogenic carbonate distribution within glacial till in Taylor Valley, Southern Victoria Land, Antarctica %A Foley, K %A W. Berry Lyons %A John E. Barrett %A Ross A. Virginia %B Paleoenvironmental Record and Applications of Calcretes and Palustrine Carbonates %I Geological Society of America %P 89-103 %G eng %R 10.1130/2006.2416(06) %0 Thesis %D 2006 %T A Qualitative Approach to Understanding the Rate of Weathering, Taylor Valley, Antarctica %A Miller, E %Y W. Berry Lyons %I The Ohio State University %G eng %9 bachelors %R LTER %0 Journal Article %J Arctic, Antarctic, and Alpine Research %D 2006 %T A stable isotopic investigation of a polar desert hydrologic system, McMurdo Dry Valleys, Antarctica %A Michael N. Gooseff %A W. Berry Lyons %A Diane M. McKnight %A Bruce H. Vaughn %A Andrew G Fountain %A Carolyn Dowling %B Arctic, Antarctic, and Alpine Research %V 38 %P 60-71 %8 02/2006 %G eng %N 1 %R 10.1657/1523-0430(2006)038[0060:ASIIOA]2.0.CO;2 %0 Journal Article %J Soil Biology and Biochemistry %D 2006 %T Terrestrial ecosystem processes of Victoria Land, Antarctica %A John E. Barrett %A Johnson N. Nkem %A Sletten, R %A Steltzer, H %A Diana H. Wall %A Wallenstein, M %A Ross A. Virginia %A D. W. Hopkins %A Aislabie, J %A Bargagli, R %A Bockheim, J %A Campbell, I %A W. Berry Lyons %A Daryl L. Moorhead %B Soil Biology and Biochemistry %V 38 %P 3019-3034 %G eng %R LTER %0 Journal Article %J Annals of Glaciology %D 2005 %T The chemical composition of runoff from Canada Glacier, Antarctica: implications for glacier hydrology during a cool summer %A Martyn Tranter %A Andrew G Fountain %A W. Berry Lyons %A Thomas H. Nylen %A Kathleen A. Welch %B Annals of Glaciology %V 40 %P 15-19 %G eng %R LTER %0 Journal Article %J Geophysical Research Letters %D 2005 %T Comment on ``El Niño suppresses Antarctic warming'' by N. Bertler et al. %A Peter T. Doran %A Gary D. Clow %A Christian H. Fritsen %A Christopher P. McKay %A Andrew N. Parsons %A John C. Priscu %A W. Berry Lyons %A Walsh, J %A Andrew G Fountain %A Diane M. McKnight %A Daryl L. Moorhead %A Ross A. Virginia %A Diana H. Wall %K Tropical meteorology %B Geophysical Research Letters %V 32 %P L07706 %G eng %N 7 %R 10.1029/2004GL021716 %0 Journal Article %J Geochimica et Cosmochimica Acta %D 2005 %T Dating water and solute additions to ice-covered Antarctic lakes %A W. Berry Lyons %A Carolyn Dowling %A Kathleen A. Welch %A Snyder, G %A Robert J. Poreda %A Peter T. Doran %A Andrew G Fountain %B Geochimica et Cosmochimica Acta %V 69 %P A720 %G eng %M LTER63392 %0 Journal Article %J Aquatic Geochemistry %D 2005 %T The Geochemistry of Supraglacial Streams of Canada Glacier, Taylor Valley (Antarctica), and their Evolution into Proglacial Waters %A Sarah Fortner %A Martyn Tranter %A Andrew G Fountain %A W. Berry Lyons %A Kathleen A. Welch %B Aquatic Geochemistry %V 11 %P 391-412 %G eng %M LTER63390 %0 Journal Article %J Annals of Glaciology %D 2005 %T Groundwater seeps in Taylor Valley Antarctica: An example of a subsurface melt event %A W. Berry Lyons %A Kathleen A. Welch %A Anne E. Carey %A Diana H. Wall %A Ross A. Virginia %A Andrew G Fountain %A Peter T. Doran %A Csatho, B %A Tremper, C %B Annals of Glaciology %V 40 %P 200-206 %G eng %R LTER %0 Journal Article %J Geochimica et Cosmochimica Acta %D 2005 %T Halogen geochemistry of the McMurdo Dry Valleys Lakes, Antarctica: clues to the origin of solutes and lake evolution %A W. Berry Lyons %A Kathleen A. Welch %A Snyder, G %A Olesik, J %A Graham, E %A G. M. Marion %A Robert J. Poreda %B Geochimica et Cosmochimica Acta %V 69 %P 305-323 %G eng %M LTER63393 %0 Thesis %B Geological Sciences %D 2005 %T Mathematical Modeling of a Hydrocarbon Spill on the Ice Cover of Lake Fryxell, Antarctica %A Marinko Karnovic %A Anne E. Carey %A Scott E. Bair %A van der Veen, Cornelis %Y W. Berry Lyons %X

Numerous 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.

%B Geological Sciences %I The Ohio State University %C Columbus %V M.S. %P 114 %8 06/2005 %G eng %9 masters %0 Thesis %D 2005 %T Mercury Concentrations in Snow and the Modern Mercury Flux to Taylor Valley, Antarctica %A Witherow, R %Y W. Berry Lyons %I The Ohio State University %V M.S. %G eng %9 masters %R LTER %0 Thesis %D 2005 %T Pedogenic Carbonate Distribution within Glacial Till in Taylor Valley, Southern Victoria Land, Antarctica %A Foley, K %Y W. Berry Lyons %I The Ohio State University %V M.S. %G eng %9 masters %R LTER %0 Journal Article %J Ice and Climate News %D 2005 %T Perturbation of hydrochemical conditions in natural microcosms entombed within Antarctic ice %A Martyn Tranter %A Andrew G Fountain %A Christian H. Fritsen %A W. Berry Lyons %A John C. Priscu %A Stratham, P %A Kathleen A. Welch %B Ice and Climate News %V 6 %P 22-23 %G eng %M LTER63398 %0 Journal Article %J Annals of Glaciology %D 2004 %T The Carbon Isotopic Composition of Dissolved Inorganic Carbon in Perennially Ice-Covered Antarctica Lakes: Searching for a Biogenic Signature. %A Klaus Neumann %A W. Berry Lyons %A John C. Priscu %A David J. DesMarais %A Kathleen A. Welch %B Annals of Glaciology %V 39 %G eng %M LTER63377 %0 Journal Article %J Polar Biology %D 2004 %T The distribution of microplankton in the McMurdo dry valley lakes, Antarctica: Response to ecosystem legacy or present-day climate controls? %A Emily C. Roberts %A John C. Priscu %A Craig F. Wolf %A W. Berry Lyons %A Johanna Laybourn-Parry %B Polar Biology %V 27 %P 238-249 %G eng %R LTER %0 Journal Article %J Hydrological Processes %D 2004 %T Extreme hydrochemical conditions in natural microcosms entombed within Antarctic ice. %A Martyn Tranter %A Andrew G Fountain %A Christian H. Fritsen %A W. Berry Lyons %A John C. Priscu %A Stathan, P %A Kathleen A. Welch %B Hydrological Processes %V 18 %P 379-387 %G eng %M LTER49874 %0 Journal Article %J Aquatic Geochemistry %D 2004 %T Geomicrobiology of Blood Fall: An iron-rich saline discharge at the terminus of the Taylor Glacier, Antarctica %A Jill A. Mikucki %A Christine M. Foreman %A Sattler, B %A W. Berry Lyons %A John C. Priscu %B Aquatic Geochemistry %V 10 %P 199-200 %G eng %M LTER63375 %0 Book Section %B Long-Term Environmental Change in Arctic and Antarctic Lakes %D 2004 %T Paleolimnology of extreme cold terrestrial and extraterrestrial environments. %A Peter T. Doran %A John C. Priscu %A W. Berry Lyons %A Powell, R %A Robert J. Poreda %A Dale T. Andersen %Y Pienitz, R %Y Douglas, Marianne S. V. %Y J.P. Smol %B Long-Term Environmental Change in Arctic and Antarctic Lakes %I Kluwer Academic Publishers %C Dordrecht, The Netherlands %P 475-507 %@ 978-1-4020-2125-1 %G eng %0 Book Section %B Long-term environmental change in Arctic and Antarctic lakes %D 2004 %T Paleolimnology of Ice-covered Environments %A Peter T. Doran %A John C. Priscu %A W. Berry Lyons %A Powell, R %A Robert J. Poreda %E Pienitz, R %E Douglas, Marianne S. V. %E John Smol %B Long-term environmental change in Arctic and Antarctic lakes %I Kluwer Academic Publishers %P 475-507 %G eng %M LTER63363 %0 Journal Article %J The International Journal of Astrobiology %D 2003 %T Biochemistry of Si in the McMurdo Dry Valley lakes, Antarctica %A Pugh, H %A Kathleen A. Welch %A W. Berry Lyons %A John C. Priscu %A Diane M. McKnight %B The International Journal of Astrobiology %V 1 %P 737-749 %G eng %M LTER49866 %0 Book Section %B Climate Variability and Ecosystem Response at Long-Term Ecological Research Sites %D 2003 %T Century to millennial scale climate change and ecosystem response in Taylor Valley, Antarctica %A Andrew G Fountain %A W. Berry Lyons %E D. Greenland %E D. G. Goodin %E R. C. Smith %K Climate Response %B Climate Variability and Ecosystem Response at Long-Term Ecological Research Sites %S Long-Term Ecological Research Network %I Oxford University Press %C New York City %P 319-340 %@ 0195150597 %G eng %M LTER49864 %0 Book Section %B Antarctic Ecosystems: Models for Wider Ecological Understanding %D 2003 %T Chemistry and lake dynamics of the Taylor Valley lakes, Antarctica: The importance of long-term monitoring. %A Kathleen A. Welch %A Klaus Neumann %A W. Berry Lyons %A Diane M. McKnight %E Clive Howard-Williams %E W. Davidson %E P. Broady %B Antarctic Ecosystems: Models for Wider Ecological Understanding %I Caxton Press %G eng %M LTER49862 %0 Thesis %D 2003 %T Phosphorus in Taylor Valley, Antarctica: the connection between landscape age and nutrient limitation in aquatic ecosystem components %A Gudding, J %Y W. Berry Lyons %I The Ohio State University %V M.S. %G eng %9 masters %R LTER %0 Journal Article %J Aquatic Geochemistry %D 2003 %T Strontium isotopic signatures of the streams and lakes of Taylor Valley, southern Victoria Land, Antarctica: chemical weathering in a polar climate %A W. Berry Lyons %A C. A. Nezat %A Benson, L %A Bullen, T %A Graham, E %A Kidd, J %A Kathleen A. Welch %A Thomas, J %B Aquatic Geochemistry %V 8 %P 875-895 %G eng %M LTER49869 %0 Journal Article %J Hydrological Processes %D 2003 %T Surface glaciochemistry of Taylor Valley, southern Victoria Land, Antarctica and its relationship to stream chemistry. %A W. Berry Lyons %A Kathleen A. Welch %A Andrew G Fountain %A Gayle L. Dana %A Bruce H. Vaughn %A Diane M. McKnight %B Hydrological Processes %V 17 %P 115-130 %G eng %M LTER49868 %0 Journal Article %J Nature %D 2002 %T Antarctic climate cooling and terrestrial ecosystem response %A Peter T. Doran %A John C. Priscu %A W. Berry Lyons %A John E. Walsh %A Andrew G Fountain %A Diane M. McKnight %A Daryl L. Moorhead %A Ross A. Virginia %A Diana H. Wall %A Gary D. Clow %A Christian H. Fritsen %A Christopher P. McKay %A Andrew N. Parsons %K Climate Response %B Nature %V 415 %P 517-520 %8 01/2002 %G eng %N 6871 %9 Journal %R 10.1038/nature710 %0 Thesis %D 2002 %T The biogeochemistry of Si in the McMurdo Dry Valley Lakes %A Pugh, H %Y W. Berry Lyons %I The Ohio State University %V B.S. %G eng %9 bachelors %R LTER %0 Thesis %D 2002 %T The chemical evolution of Canada Glacier melt: supraglacial and proglacial waters in Taylor Valley, Antarctica %A Tegt, S %Y W. Berry Lyons %I The Ohio State University %V M.S. %G eng %9 masters %R LTER %0 Journal Article %J Nature %D 2002 %T Recent Temperature Trends in the Antarctic %A John E. Walsh %A Gary D. Clow %A Christian H. Fritsen %A Christopher P. McKay %A Andrew N. Parsons %A Peter T. Doran %A John C. Priscu %A W. Berry Lyons %A Andrew G Fountain %A Diane M. McKnight %A Daryl L. Moorhead %A Ross A. Virginia %A Diana H. Wall %B Nature %V 418 %P 291-292 %G eng %M LTER49851 %0 Journal Article %J Arctic, Antarctic, and Alpine Research %D 2002 %T Snow patch influence on soil biogeochemical processes and invertebrate distribution in the McMurdo Dry Valleys, Antarctica %A Michael N. Gooseff %A John E. Barrett %A Peter T. Doran %A Andrew G Fountain %A W. Berry Lyons %A Andrew N. Parsons %A Porazinska, D %A Ross A. Virginia %A Diana H. Wall %K Biggie %B Arctic, Antarctic, and Alpine Research %V 35 %P 91-99 %8 02/2003 %G eng %U http://instaar.metapress.com/content/r086455ju7213711/ %N 1 %9 Journal %M LTER49857 %R 10.1657/1523-0430(2003)035[0091:SPIOSB]2.0.CO;2 %0 Journal Article %J Journal of Geophysical Research %D 2002 %T Valley floor climate observations from the McMurdo Dry Valleys, Antarctica, 1986-2000 %A Peter T. Doran %A Christopher P. McKay %A Gary D. Clow %A Gayle L. Dana %A Andrew G Fountain %A Thomas H. Nylen %A W. Berry Lyons %K Biggie %X

Climate 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.

%B Journal of Geophysical Research %V 107 %P 4772-4784 %8 12/2002 %G eng %N 4772 %9 Journal %M LTER49856 %R 10.1029/2001JD002045 %0 Journal Article %J Water Resources Research %D 2002 %T Weathering reactions and hyporheic exchange controls on stream water chemistry in a glacial meltwater stream in the McMurdo Dry Valleys %A Michael N. Gooseff %A Diane M. McKnight %A W. Berry Lyons %A Blum, A %K Biggie %B Water Resources Research %V 38 %P 1279-1296 %8 12/2002 %G eng %U http://www.agu.org/pubs/crossref/2002/2001WR000834.shtml %N 12 %9 Journal %M LTER49852 %R 10.1029/2001WR000834 %0 Journal Article %J GSA Bulletin %D 2001 %T Chemical weathering in streams of a polar desert (Taylor Valley, Antarctica). %A C. A. Nezat %A W. Berry Lyons %A Kathleen A. Welch %B GSA Bulletin %V 113 %P 1401-1408 %G eng %M LTER49835 %0 Journal Article %J Biogeochemistry %D 2001 %T CO2 concentrations in perennially ice-covered lakes of Taylor Valley, Antarctica %A Klaus Neumann %A W. Berry Lyons %A John C. Priscu %A Donahoe, R %B Biogeochemistry %V 56 %P 27-50 %G eng %M LTER49556 %0 Journal Article %J Polar Geography %D 2001 %T The McMurdo Dry Valleys Long-Term Ecological Research Program: new understanding of the biogeochemistry of the Dry Valley lakes: a review. %A W. Berry Lyons %A Kathleen A. Welch %A John C. Priscu %A Johanna Laybourn-Parry %A Daryl L. Moorhead %A Diane M. McKnight %A Peter T. Doran %A Martyn Tranter %B Polar Geography %V 25 %P 202-217 %G eng %M LTER49832 %0 Book Section %B Climate Variability and Ecosystem Response at Long Term Ecological Research Sites %D 2000 %T Climate and hydrologic variations and implications for lake and stream ecological response in the McMurdo Dry Valleys, Antarctica %A Kathleen A. Welch %A W. Berry Lyons %A Diane M. McKnight %A Chris Jaros %A Andrew G Fountain %A Thomas H. Nylen %A Peter T. Doran %A Clive Howard-Williams %E D. Greenland %E D. G. Goodin %E R. C. Smith %B Climate Variability and Ecosystem Response at Long Term Ecological Research Sites %I Oxford University Press %P 174-195 %G eng %M LTER49813 %0 Journal Article %J Environmental Science and Technology %D 2000 %T Fossil fuel burning in Taylor Valley, southern Victoria Land, Antarctica: estimating the role of scientific activities on carbon and nitrogen reservoirs and fluxes %A W. Berry Lyons %A C. A. Nezat %A Kathleen A. Welch %A Kottmeier, S %A Peter T. Doran %B Environmental Science and Technology %V 34 %P 1659-1662 %G eng %M LTER49545 %0 Journal Article %J Freshwater Biology %D 2000 %T The importance of landscape position and legacy: The evolution of the Taylor Valley Lake District, Antarctica. %A W. Berry Lyons %A Andrew G Fountain %A Peter T. Doran %A John C. Priscu %A Klaus Neumann %A Kathleen A. Welch %B Freshwater Biology %V 43 %P 355-367 %G eng %M LTER49553 %0 Thesis %D 1999 %T Carbon dynamics in lakes and streams of Taylor Valley, Antarctica %A Klaus Neumann %Y W. Berry Lyons %I University of Alabama, Tuscaloosa %V Ph.D. %G eng %9 doctoral %R LTER %0 Journal Article %J Geochimica et Cosmochimica Acta %D 1999 %T Chlorine-36 in the waters of the McMurdo Dry Valley lakes, southern Victoria Land, Antarctica: revisited %A W. Berry Lyons %A Kathleen A. Welch %A Pankaj Sharma %B Geochimica et Cosmochimica Acta %V 62 %P 185-191 %G eng %N 2 %M LTER12888 %0 Journal Article %J Palaeography, Palaeoclimatology, Palaeoecology %D 1999 %T Dating quaternary lacustrine sediments in the McMurdo Dry Valleys Antarctica %A Peter T. Doran %A G. W. Berger %A W. Berry Lyons %A Robert A. Wharton Jr. %A M. L. Davisson %A J. Southon %A J. E. Dibb %K sediments %B Palaeography, Palaeoclimatology, Palaeoecology %V 147 %P 223-239 %8 03/1999 %G eng %N 3 %9 Journal %M LTER12822 %R 10.1016/S0031-0182(98)00159-X %0 Journal Article %J Science %D 1999 %T Geomicrobiology of sub-glacial ice above Vostok Station %A John C. Priscu %A Edward E. Adams %A W. Berry Lyons %A Mary A. Voytek %A David W. Mogk %A Robert L. Brown %A Christopher P. McKay %A Cristina D. Takacs-Vesbach %A Kathleen A. Welch %A Craig F. Wolf %A Julie D. Kirshtein %A Recep Avci %B Science %V 286 %P 2141-2144 %G eng %N 5447 %R 10.1126/science.286.5447.2141 %0 Journal Article %J Geology %D 1999 %T History of McMurdo Dry Valley Lakes, Antarctica, from stable chlorine isotope data %A W. Berry Lyons %A Frape, S %A Kathleen A. Welch %B Geology %V 27 %G eng %N 527-530 %R LTER %0 Journal Article %J Geophysical Research Letters %D 1999 %T Mercury in aquatic systems in Antarctica %A W. Berry Lyons %A Kathleen A. Welch %A Jean-Claude Bonzongo %B Geophysical Research Letters %V 26 %P 2235-2238 %G eng %N 15 %M LTER12887 %0 Journal Article %J BioScience %D 1999 %T Physical controls on the Taylor Valley Ecosystem, Antarctica %A Andrew G Fountain %A W. Berry Lyons %A Melody B. Burkins %A Gayle L. Dana %A Peter T. Doran %A Karen J. Lewis %A Diane M. McKnight %A Daryl L. Moorhead %A Andrew N. Parsons %A John C. Priscu %A Diana H. Wall %A Robert A. Wharton Jr. %A Ross A. Virginia %K Water availability %B BioScience %V 49 %P 961-972 %8 12/1999 %G eng %N 12 %9 Journal %M LTER12832 %0 Thesis %D 1998 %T Chemical Weathering in Taylor Valley, Antarctica: Quantity and Quality %A C. A. Nezat %Y W. Berry Lyons %I University of Alabama, Tuscaloosa %V Ph.D. %G eng %9 doctoral %R LTER %0 Journal Article %J Limnol. Oceanogr. %D 1998 %T Evidence of deep circulation in two perennially ice-covered Antarctic lakes %A Scott W. Tyler %A Peter G. Cook %A Anya Z. Butt %A James M. Thomas %A Peter T. Doran %A W. Berry Lyons %B Limnol. Oceanogr. %V 43 %P 625-635 %G eng %N 4 %M LTER12968 %0 Book Section %B Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica %D 1998 %T Geochemical Linkages Among Glaciers, Streams, and Lakes Within the Taylor Valley, Antarctica %A W. Berry Lyons %A Kathleen A. Welch %A Klaus Neumann %A Jeffrey K. Toxey %A Robyn McArthur %A Changela Williams %A Diane M. McKnight %A Daryl L. Moorhead %Y John C. Priscu %B Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica %V 72 %P 77-92 %G eng %M LTER12885 %0 Journal Article %J Annals of Glaciology %D 1998 %T Inorganic carbon-isotope distribution and budget in the Lake Hoare and Lake Fryxell basins, Taylor Valley, Antarctica %A Klaus Neumann %A W. Berry Lyons %A D.J. Des Marais %B Annals of Glaciology %V 27 %P 685-690 %G eng %M LTER12911 %0 Journal Article %J Antarctic Science %D 1998 %T A late holocene dessication of Lake Hoare and Lake Fryxell, McMurdo Dry Valleys, Antarctica %A W. Berry Lyons %A Scott W. Tyler %A Robert A. Wharton Jr. %A Diane M. McKnight %A Bruce H. Vaughn %B Antarctic Science %V 10 %P 247-256 %G eng %N 3 %M LTER12883 %0 Journal Article %J Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28) %D 1998 %T McMurdo Dry Valleys LTER: Density-driven mixing in Lake Hoare? %A W. Berry Lyons %A Kathleen A. Welch %A Scott W. Tyler %A Pankaj Sharma %B Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28) %V 31 %P 205 %G eng %N 2 %M LTER12884 %0 Book Section %B Ecosystem Processes in Antarctic Ice-free Landscapes %D 1997 %T The abundance of planktonic virus-like particles in Antarctic lakes %A Kepner, R.L. %A Robert A. Wharton Jr. %A Galchenko, V %Y W. Berry Lyons %Y Clive Howard-Williams %Y Ian Hawes %B Ecosystem Processes in Antarctic Ice-free Landscapes %I Balkema Press %C Rotterdam %P 241-250 %G eng %M LTER12864 %0 Book Section %B Ecosystem Processes in Antarctic Ice-free Landscapes %D 1997 %T Carbon dynamics of aquatic microbial mats in the Antarctic dry valleys: A modelling synthesis %A Daryl L. Moorhead %A W. Shane Davis %A Robert A. Wharton Jr. %Y W. Berry Lyons %Y Clive Howard-Williams %Y Ian Hawes %B Ecosystem Processes in Antarctic Ice-free Landscapes %I Balkema Press, Rotterdam %P 181-196 %G eng %M LTER12903 %0 Book Section %B Ecosystem Processes in Antarctic Ice-free Landscapes %D 1997 %T Chemical weathering rates and reactions in the Lake Fryxell Basin, Taylor Valley : Comparison to temperate river basins %A W. Berry Lyons %A Kathleen A. Welch %A C. A. Nezat %A K. Crick %A Jeffrey K. Toxey %A J.A. Mastrine %A Diane M. McKnight %Y W. Berry Lyons %Y Clive Howard-Williams %Y Ian Hawes %B Ecosystem Processes in Antarctic Ice-free Landscapes %I Balkema Press, Rotterdam %P 147-154 %G eng %M LTER12882 %0 Book Section %B Ecosystem Processes in Antarctic Ice-free Landscapes %D 1997 %T Climate history of the McMurdo Dry Valleys since the last glacial maximum: A synthesis %A W. Berry Lyons %A Louis R. Bartek %A Paul A. Mayewski %A Peter T. Doran %Y W. Berry Lyons %Y Clive Howard-Williams %Y Ian Hawes %B Ecosystem Processes in Antarctic Ice-free Landscapes %I Balkema Press, Rotterdam %P 155-162 %G eng %M LTER12881 %0 Book Section %B Plasma Source Mass Spectrometry: Developments and Applications %D 1997 %T Determination of rare earth elements in Antarctic lakes and streams of varying ionic strengths %A Graham, E %A Ramsey, L. A. %A W. Berry Lyons %A Kathleen A. Welch %B Plasma Source Mass Spectrometry: Developments and Applications %I Royal Society of Chemistry %C London %P 253-262 %G eng %M LTER12845 %0 Journal Article %J Geochimica et Cosmochimica Acta %D 1997 %T Lithium in waters of a polar desert %A W. Berry Lyons %A Kathleen A. Welch %B Geochimica et Cosmochimica Acta %V 61 %P 4309-4319 %G eng %N 20 %M LTER12880 %0 Book Section %B Ecosystem Processes in Antarctic Ice-free Landscapes %D 1997 %T The microbial loop in Antarctic lakes %A Johanna Laybourn-Parry %Y W. Berry Lyons %Y Clive Howard-Williams %Y Ian Hawes %B Ecosystem Processes in Antarctic Ice-free Landscapes %I Balkema Press %C Rotterdam %P 231-240 %G eng %M LTER12870 %0 Book Section %B Ecosystem Processes in Antarctic Ice-free Landscapes %D 1997 %T Sources and sinks of nutrients in a polar desert stream, the Onyx River, Antarctica %A Clive Howard-Williams %A Ian Hawes %A Anne-Maree Schwarz %A Julie A. Hall %Y W. Berry Lyons %Y Clive Howard-Williams %Y Ian Hawes %B Ecosystem Processes in Antarctic Ice-free Landscapes %I Balkema Press %C Rotterdam %P 155-170 %G eng %M LTER12857 %0 Book Section %B Ecosystem Processes in Antarctic Ice-free Landscapes %D 1997 %T Species composition and primary production of algal communities in Dry Valley streams in Antarctica: Examination of the functional role of biodiversity %A Dev K. Niyogi %A Cathy M. Tate %A Diane M. McKnight %A John H. Duff %A Alexander S. Alger %Y W. Berry Lyons %Y Clive Howard-Williams %Y Ian Hawes %B Ecosystem Processes in Antarctic Ice-free Landscapes %I Balkema Press, Rotterdam %P 171-179 %G eng %M LTER12913 %0 Journal Article %J Journal of Chromatography A %D 1996 %T Determination of major element chemistry in terrestrial waters from Antarctica by ion chromatography %A Kathleen A. Welch %A W. Berry Lyons %A Graham, E %A Klaus Neumann %A James M. Thomas %A D. Mikesell %B Journal of Chromatography A %V 739 %P 257-263 %G eng %M LTER12983 %0 Journal Article %J Antarctic Journal of the U.S. %D 1995 %T McMurdo LTER: Comparative limnology of the Taylor Valley lakes: The major solutes %A Kathleen A. Welch %A W. Berry Lyons %B Antarctic Journal of the U.S. %V 30 %P 292-293 %G eng %N 5 %M LTER12982 %0 Journal Article %J Antarctic Journal of the U.S. %D 1994 %T McMurdo LTER: Inorganic geochemical studies with special reference to calcium carbonate dynamics %A Kathleen A. Welch %A W. Berry Lyons %A John C. Priscu %A R. L. Edwards %A Diane M. McKnight %A Harold R. House %A Robert A. Wharton Jr. %B Antarctic Journal of the U.S. %V 29 %P 237-239 %G eng %N 5 %M LTER12981 %0 Journal Article %J Journal of Paleolimnology %D 1994 %T Paleolimnology of the McMurdo Dry Valleys, Antarctica %A Peter T. Doran %A Robert A. Wharton Jr. %A W. Berry Lyons %B Journal of Paleolimnology %V 10 %P 85-114 %G eng %N 2 %M LTER12815 %R 10.1007/BF00682507 %0 Journal Article %D 1993 %T The geochemical evolution of terrestrial waters in the antarctic: the role of rock-water interactions, in Physical and Biogeochemical Processes in Antarctic Lakes %A W. Berry Lyons %A Paul A. Mayewski %V 59 %P 135-143 %G eng %M LTER12879 %0 Journal Article %J Chemical Geology %D 1993 %T Stable isotopic biogeochemistry of carbon and nitrogen in a perennially ice-covered Antarctic lake %A Robert A. Wharton Jr. %A W. Berry Lyons %A D.J. Des Marais %B Chemical Geology %V 107 %P 159-172 %G eng %M LTER12984