01931nas a2200229 4500008004100000245010800041210006900149260001200218490000700230520115400237100002101391700001701412700001701429700002401446700002401470700001601494700001601510700001701526700001501543700002301558856012001581 2019 eng d00aDiurnal chemistry of two contrasting stream types, Taylor Valley, McMurdo Dry Valley Region, Antarctica0 aDiurnal chemistry of two contrasting stream types Taylor Valley  c06/20190 v983 a

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.

1 aHarmon, Mark, E.1 aLeslie, D.L.1 aLyons, Berry1 aWelch, Kathleen, A.1 aMcKnight, Diane, M.1 aChudaev, O.1 aKharaka, Y.1 aHarmon, R.S.1 aMillot, R.1 aShouakar-Stash, O. uhttps://www.e3s-conferences.org/articles/e3sconf/abs/2019/24/e3sconf_wri-162018_01020/e3sconf_wri-162018_01020.html03797nas a2200157 4500008004100000245012100041210007100162260001200233300001600245490000700261520325100268100001703519700002403536700001703560856006203577 2017 eng d00aA temporal stable isotopic (δ18O, δD, d-excess) comparison in glacier meltwater streams, Taylor Valley, Antarctica0 atemporal stable isotopic δ18O δD dexcess comparison in glacier m c08/2017 a3069 - 30830 v313 a

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. 

1 aLeslie, D.L.1 aWelch, Kathleen, A.1 aLyons, Berry uhttp://onlinelibrary.wiley.com/doi/10.1002/hyp.11245/full04850nas a2200217 4500008004100000022001300041245007600054210006900130260001200199300001400211490000800225520403500233100001704268700001704285700002204302700001904324700001404343700002404357700002104381856023004402 2014 eng d a0009254100aBoron isotopic geochemistry of the McMurdo Dry Valley lakes, Antarctica0 aBoron isotopic geochemistry of the McMurdo Dry Valley lakes Anta c10/2014 a152 - 1640 v3863 a

 

The geochemistry of boron was investigated in the ice-covered lakes and glacier meltwater streams within Taylor and Wright Valley of the McMurdo Dry Valleys (MCM), Antarctica, in order to achieve a greater understanding of the source of boron to these aquatic systems and how in-lake processes control boron concentration. Selected lake depths (surface and bottom water) and streams were analyzed for boron geochemistry. Boron stable isotope values in these waters span the range of + 12.3‰ to + 51.4‰, which corresponds to the variations from glacier meltwater streams to the hypolimnion of a highly evaporated hypersaline lake. The data demonstrate that the major sources of B to the aquatic system are via terrestrial chemical weathering of aluminosilicates within the stream channels, and a marine source, either currently being introduced by marine-derived aerosols or in the form of ancient seawater. Lakes Fryxell, Hoare, and upper waters of Lake Joyce, which experience more terrestrial influence of aluminosilicate chemical weathering via glacial meltwater streams, display a mixture of these two major sources, while the source of B in the bottom waters of Lake Joyce appears to be primarily of marine origin. Lakes Bonney and Vanda and the Blood Falls brine have a marine-like source whose δ11B values have become more positive by mineral precipitation and/or adsorption. Don Juan Pond displays a terrestrial aluminosilicate influence of a marine-like source. These hypersaline lake waters from Antarctica are similar in δ11B to other hypersaline lake waters globally, suggesting that similar processes control their B geochemistry.

 

 

1 aLeslie, D.L.1 aLyons, Berry1 aWarner, Nathaniel1 aVengosh, Avner1 aOlesik, J1 aWelch, Kathleen, A.1 aDeuerling, Kelly uhttp://linkinghub.elsevier.com/retrieve/pii/S000925411400391Xhttp://api.elsevier.com/content/article/PII:S000925411400391X?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S000925411400391X?httpAccept=text/plain03970nas a2200217 4500008004100000245011000041210007200151260004000223490001000263520322300273653001503496653001903511653001903530653002403549653003003573653003703603653001603640100001703656700001703673856006203690 2013 eng d00aThe application of stable isotopes, δ11B, δ18O, and δD, in geochemical and hydrological investigations0 aapplication of stable isotopes δ11B δ18O and δD in geochemical a aColumbus, OHbOhio State University0 vPh.D.3 a

My dissertation research utilizes stable isotopes as tracers of water and solute sources to study specific geochemical (solute origin) and hydrological (glacier meltwater source across a season comparing water contributions from hyporheic zone and/or glacier melt and residence time of precipitation within a managed water supply) problems within McMurdo Dry Valleys (MCM), Antarctica, and Central Ohio, USA. In Chapter II, δ11B isotopic and dissolved B measurements are used to infer the origin of B within MCM aquatic system. Boron stable isotopic values span the range of +12.3‰ to +51.4‰, varying from glacier meltwater streams to the hypolimnion of a highly evaporated hypersaline lake. These data demonstrate that the major sources of B are chemical weathering of alumniosilicates within the stream channels, and a marine source, either currently introduced by marine-derived aerosols or from ancient seawater. In-lake processes create a more positive δ11B through adsorption or mineral precipitation. The glacier meltwater streams, Lakes Fryxell, Hoare, and upper waters of Lake Joyce display a mixture of these two sources, with Lake Joyce bottom waters primarily of marine origin. Lakes Bonney and Vanda and Blood Falls brine are interpreted as having a marine-like source changed by in-lake processes to result in a more positive δ11B, while Don Juan Pond displays a more terrestrial influence. In Chapter III, δ18O and δD are used to trace water source variation via hyporheic zone or glacier melt within two MCM streams over an entire melt season. The isotopic variation of these streams was more negative at the beginning of the season and more positive later. D-excess measurements were used to infer mixing between hyporheic storage and glacier meltwater. It was supported that Von Guerard Stream has a large, widespread hyporheic zone that changes with time and discharge amounts. The chemistry of Andersen Creek also displayed hyporheic zone influence at certain times of the year. This work adds important new information on the role of hyperheic zone-stream interactions, and supports the short term, more physically based, descriptions of hyporheic dynamics explained in the past decade. Chapter IV describes water flow and travel time within a human managed watershed-reservoir system by measuring the δ18O and δD of the precipitation source to the reservoirs and finally to the distribution system, the tap. Generally, the tap waters experienced little lag time in the managed system, having a residence time of about two months. Tap and reservoir waters preserved the precipitation signal with the reservoir morphology acting as an important control. These water supply reservoirs functioned more like a river system with a faster throughput of water and larger variations in chemical parameters. Other water supply reservoirs have a greater capacity with a larger amount of water supply usage through a more lacustrine environment, which displays more constant solute concentrations and longer flow-through times. This work provides a basic understanding of a regional water supply system in central Ohio, reservoir isotopic dynamics, and Ohio precipitation sources.

10aAntarctica10aboron isotopes10ahyporheic zone10aMcMurdo Dry Valleys10aOhio precipitation source10aoxygen-18 and deuterium isotopes10asaline lake1 aLeslie, D.L.1 aLyons, Berry u http://rave.ohiolink.edu/etdc/view?acc_num=osu138600003700663nas a2200193 4500008004100000245008400041210006900125260001200194300001200206490000700218100001700225700001700242700001700259700001900276700002400295700001900319700002400338856010700362 2013 eng d00aThe carbon stable isotope biogeochemistry of streams, Taylor Valley, Antarctica0 acarbon stable isotope biogeochemistry of streams Taylor Valley A c05/2013 a26 - 360 v321 aLyons, Berry1 aLeslie, D.L.1 aHarmon, R.S.1 aNeumann, Klaus1 aWelch, Kathleen, A.1 aBisson, K., M.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/carbon-stable-isotope-biogeochemistry-streams-taylor-valley-antarctica