uid=MCM,o=EDI,dc=edirepository,dc=org all public read snyder_halogenchem Glen Snyder

Earth Science-MS 126 Houston TX 77251 US

(713) 348-4054 gsnyder@rice.edu McMurdo Dry Valleys LTER http://mcmlter.org/ Chris Gardner gardner.177@osu.edu https://orcid.org/0000-0003-0400-3754 data manager Inigo San Gil

Department of Biology, MSC03 2020 University of New Mexico Albuquerque NM 87131 US

(505) 277-2625 (505) 277-2541 isangil@lternet.edu data manager 2014-01-01 English

As part of a collaborative investigation between researchers at Rice University, Arkansas State University, University of Rochester, and Ohio State University, lakes of the McMurdo Dry Valleys were sampled at discreet depth intervals during the 2005-2006 field season.  Sample splits were subsequently analyzed for chemical and isotopic composition of both gases and dissolved  ions, as well as dissolved organic carbon. In addition, cryogenic salts were sampled in the surrounding lake shores in order to determine the salt sources. Gravity cores were also obtained and the pore waters were collected by centrifuging the wet sediment.   Presented  in this file are the dissolved halogens :chloride, bromide, and total iodine in lake waters and pore waters. The isotopic composition of I-129 and Cl-36 are also presented for these same samples, as are the molar ratios of I-129/I-127, and Cl-36/Cl-37.   Alkalinity was also determined in order to subsequently investigate the relationship between the oxidation of organic matter and the release of iodine into the lake waters.

isotopes lakes limnology LTER Controlled Vocabulary alkalinity chemistry Cl-36 halogen I-129 lake limnology Station Keywords inorganic nutrients LTER Core Areas This material is based upon work supported by the National Science Foundation under Grant No.0440686   Citations:   Snyder, GT, Hubbard, A., Muramatsu, Y., Lu, H.-L. (2008) Radiogenic Halogen Isotopes in Cold Places: Deep Seeps or Recent Salt Dissolution? , GSA Annual meeting, Houston, Abstract 330-12.   Dowling, C., Leslie, D., Poreda, R., Darrah, T., Lyons, W.B., Snyder, G. (2007) Preliminary interpretations of the groundwater flow system of Wright Valley, Antarctica using stable isotopes and noble gas, GSA Denver Annual Meeting, October, 2007, abstract 177-1.    Snyder, G T,  Dowling, C B, Poreda, R J  (2007) Redox controls on solute transfer between shallow sediments and bottom-waters: Chemical and isotopic evidence from two Antarctic Dry Valley Lakes, Eos Trans. AGU, 88(52), Fall Meet. Suppl.H14-D-07.   Lyons, WB, Dowling, C., Welch, KA, Snyder, G., Poreda, RJ, Doran, PT, Fountain, A. (2005) Dating water and solute additions in ice-covered Antarctic lakes, Goldschmidt Conference, Moscow, Idaho, Geochimica et Cosmochimica Acta 69 (2),305-323   Lyons, WB,  K.A. Welch, KA, Snyder, G,  Olesik, J, Graham, EY,  Marion, GM,  Poreda, RJ (2005). Halogen geochemistry of the McMurdo Dry Valleys lakes, Antarctica: Clues to the origin of solutes and lake evolution and age. Geochimica et Cosmochimica Acta, 69, 305-323.            

This data package is released under the Creative Commons Attribution 4.0 International License (CC BY 4.0; http://creativecommons.org/licenses/by/4.0/), which allows consumers (hereinafter referred to as “Data Users”) to freely reuse, redistribute, transform, or build on this work (even commercially) so long as appropriate credit is provided. Accordingly, Data Users are required to properly cite this data package in any publications or in the metadata of any derived products that result from its use (in whole or in part). A recommended citation is provided on the summary metadata page associated with this data package in the McMurdo Dry Valleys LTER Data Catalog (https://mcmlter.org/data), and a generic citation may be found on the summary metadata page in the repository where this data package was obtained. When these data contribute significantly to the contents of a publication, Data Users must also acknowledge that data were provided by the NSF-supported McMurdo Dry Valleys Long Term Ecological Research program (OPP-2224760). This data package has been released in the spirit of open scientific collaboration. Hence, Data Users are strongly encouraged to consider consultation, collaboration, and/or co-authorship (as appropriate) with the data package creator(s). Data Users should be aware these data may be actively used by others for ongoing research; thus, coordination may be necessary to prevent duplicate publication. Data Users should also recognize that misinterpretation of data may occur if they are used outside the context of the original study. Hence, Data Users are urged to contact the data package creator(s) if they have any questions regarding methodology or results. While substantial efforts are made to ensure the accuracy of this data package (with all its components), complete accuracy cannot be guaranteed. Periodic updates to this data package may occur, and it is the responsibility of Data Users to check for new versions. This data package is made available “as is” and comes with no warranty of accuracy or fitness for use. The creator(s) of this data package and the repository where these data were obtained shall not be liable for any damages resulting from misinterpretation, use, or misuse of these data. Finally, as a professional courtesy, we kindly request Data Users notify the primary contact referenced in the metadata when these data are used in the production of any derivative work or publication. Notification should include an explanation of how the data were used, along with a digital copy of the derived product(s). Thank you.

https://mcm.lternet.edu/content/halogen-chemistry-and-isotopic-composition-mcmurdo-lake-waters-and-pore-fluids Don Juan Pond is located in the west end of the Wright Valley. It is wedged between the Asgard Range and the Dias. On the west end there is a small tributary and a feature that has been described as a rock glacier. Don Juan Pond is a shallow (i.e. flat bottom) hyper-saline pond. The salinity is high enough that it doesn't freeze even in winter. Therefore, unlike other lakes and ponds in the dry valleys, it has no ice cover. It has been described as a groundwater discharge zone. The dominant ions in solution are calcium and chloride. The area around Don Juan Pond is covered with sodium chloride and calcium chloride salts that have been precipitated as the water evaporated. Area and volume of Don Juan Pond varies over time. According to the USGS topo map published in 1977, the area was approximately 0.25 sq. km. However, in recent years the size of the pond has shrunk considerably. The pond has changed over the past 5 years although this is mostly anecdotal. The maximum depth in 93-94 was described as "a foot deep." In Jan 97, it was approximately 10cm deep; in Dec 98 the pond was almost dry everywhere except for an area 10's of sq meters. Most of the water that was left was restricted to depressions around large boulders in the pond. Valley: Wright Distance to Sea : 60 Maximum Length (km): 0.75 Maximum Width (km): 0.35 Maximum Depth (m): 0.1 161.190994262695 161.190994262695 -77.561897277832 -77.561897277832 200 200 meter The Lake Fryxell basin is formed by a moraine depression in a wider portion of the Taylor Valley. It has a number of moraine islands and shallower areas, as well as several relatively well developed deltas. The lake is fed by at least 10 meltwater streams with a total drainage catchment of 230 km2. The lake is dammed to the southwest by the Canada Glacier and is topographically closed. It is perennially ice covered; during summer months, an ice-free moat generally forms around much of the lake margin. Lake levels have risen ~2 m between 1971 and 1996. There are no surface outflows; the only known water loss is through ice ablation (evaporation, sublimation and physical scouring). Valley: Taylor Distance to Sea : 9 Maximum Length (km): 5.8 Maximum Width (km): 2.1 Maximum Depth (m): 20 Surface Area (km^2): 7.08 Ice Thickness Average Surface (m): 3.3 - 4.5 Volume (m^3 * 10^6): 25.2 163.048782348633 163.259582519531 -77.597076416016 -77.622711181641 18 18 meter Lake Joyce lies in the Pearse Valley against the Taylor Glacier. Valley: Pearse Distance to Sea : 44 Maximum Length (km): 1 Maximum Width (km): 1 Maximum Depth (m): 35 Surface Area (km^2): 0.83 Ice Thickness Average Surface (m): 3.9 - 5.6 Volume (m^3 * 10^6): 4.9 161.608886718750 161.662445068359 -77.715972900391 -77.726486206055 301 301 meter Lake Vanda is located in the Wright Valley, adjacent to the Taylor Valley. It is fed primarily by the Onyx River, which has its origin at Lake Brownworth, and ultimately at the Lower Wright Glacier located ~27 km east of the lake. The lake has no outflow. Valley: Wright Distance to Sea : 47 Maximum Length (km): 8 Maximum Width (km): 2 Maximum Depth (m): 75 Surface Area (km^2): 5.2 Ice Thickness Average Surface (m): 2.8 - 4.2 Volume (m^3 * 10^6): 160 161.391906738281 161.691970825195 -77.518882751465 -77.542304992676 143 143 meter The Taylor Glacier is an Antarctic glacier about 54 kilometres (34 mi) long, flowing from the plateau of Victoria Land into the western end of Taylor Valley, north of the Kukri Hills, south of the Asgard Range. The middle part of the glacier is bounded on the south by Beacon Valley.Scott (early nineties British Antarctic expedition) named the glacier for Griffith Taylor, geologist and leader of the Western Journey Party of the British Antarctic expedition.Like other glaciers in the McMurdo Dry Valleys, Taylor Glacier is “cold-based,” meaning its bottom is frozen to the ground below.   161.683044433594 162.280426025391 -77.721229553223 -77.769035339355 2005-12-09 2006-01-07 This dataset was created Sept 30, 2008 by MCM-LTER information manager (Chris Gardner) after email discussion with PI Glen Snyder. In 2016 metadata wsas completed (San Gil) McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER

 Waters were sampled by first drilling through the ice and then lowering a Go-Flo bottle to the indicated depths. Retrieved samples were then spit into separate containers for analysis. Following the sampling of water, a shallow gravity corer with plastic lining was  attached to steel cable  and lowered through the ice hole and down to the lake bottom. The corer was dropped the final 3 meters. Core recovery ranged from only a few centimeters to 25 centimeters. Once recovered, the sediments were stoppered and transported vertically to Crary Laboratory at McMurdo station. Sediment was separated along several intervals of each core and sediment and pore waters were separated by centrifugation.     Chloride was determined through ion chromatography according to methods described in Welch, K.A., Lyons, W.B., Graham, E., Neumann, K., Thomas, J.M., and D. Mikesell. 1996. Determination of major element chemistry in terrestrial waters from Antarctica by ion chromatography. Journal of Chromatography A 739: 257-263. Kathy Welch carried out the chloride determinations at the Crary Laboratory, McMurdo Station.   Alkalinity was determined by titration of samples with hydrochloric acid at Crary Laboratory, McMurdo Station. The methods  used for alkalinity determinations are described in  Gieskes, J.M., Gamo, T.,Brumsack, H.,1991. Chemical Methods for Intersitital water analysis aboard JOIDES Resolution, ODP Tech. Note 15, Texas AandM University, 60 pp.    Samples were diluted then analyzed for I-127 and Br-79 using ICP-MS. Replicate analyses were carried out at the ICP-MS facility of Cin-Ty Lee at Rice University, as well as the ICP-MS facility of Yasuyuki Muramatsu at  Gakushuin University, Tokyo. Methods for analysis are described in: Schnetger, B., and Muramatsu, Y., Determination of the halogens, with special reference to iodine, in geological and biological samples using pyrohydrolysis for preparation of inductively coupled plasma mass spectrometry and ion chromatography for measurement, Analyst, 121:1627-1631.   Chloride was extracted from the samples as purified AgCl. Likewise, iodine was extracted as purified AgI using methods described in Snyder, GT and  Fabryka-Martin, JT  (2007). 129-I and 36-Cl in dilute hydrocarbon waters: Marine-cosmogenic, in situ, and anthropogenic sources. In: G.T. Snyder and J.E. Moran (Eds.), special issue: "The halogens and their isotopes in marine and terrestrial aqueous systems", Applied Geochemistry, 22 , 692-704. The purified chloride and iodide targets were sent to PRIME Laboratory at Purdue University for AMS (accelerator mass spectrometry)  analysis of Cl-36 and I-129.             

ANCILLARY_SNYDER_HALOCHEM units and column description ANCILLARY_SNYDER_HALOGENCHEM.csv 11504 26 1 \n column , " https://mcm.lternet.edu/sites/default/files/data/ANCILLARY_SNYDER_HALOGENCHEM_0.csv DATASET_CODE DATASET_CODE Table Identifier string Table Identifier LOCATION_NAME Location Name Name of lake where measurement was made string Name of lake where measurement was made LOCATION_TYPE LOCATION_TYPE Sample type description and/or location string Sample type description and/or location SAMPLE_ID SAMPLE_ID Sample identification code string Sample identification code LATITUDE LATITUDE Sample Latitude degree real Null None given LONGITUDE LONGITUDE Sample Longitude degree real Null None given DATE_TIME DATE_TIME Date sample was collected date mm/dd/yyyy DEPTH (m) Depth Stream, pond, or lake depth. In the case of ice-covered lakes, depth is in meters below the upper ice surface. meter real Null None given alk (meq/L) alk (meq/L) Alkalinity in milliequivalents per liter meq/L real 0.49 62.17 NULL None given I (umol/kg) I (umol/kg) Total dissolved iodine in micromoles per kilogram umol/kg real 0.004 8.109 NULL None given Br (umol/kg) Br (umol/kg) Total dissolved bromine in micromoles per kilogram umol/kg real 0.267 5041.977 NULL None given Cl (mM) Cl (mM) Dissolved chloride in millimoles per liter mM real 0.16 18178.8 NULL None given 129I/I(E-15) 129I/I(E-15) Molar ratio of I-129 to total iodine (10^-15) dimensionless real 445 2163 NULL None given +/-129I/I(E-15) +/-129I/I(E-15) 1-sigma error in molar ratios of I-129/I-127 (10^-15) dimensionless real 44.86 612.65 NULL None given 129I(at/uL) 129I(at/uL) Concentration of I-129 in atoms per microliter at/uL real 0.0416 0.823 NULL None given +/-129I(at/uL) +/-129I(at/uL) 1-sigma error for I-129 concentration dimensionless real 0.2290 0.0032 NULL None given 36Cl/Cl(E-15) 36Cl/Cl(E-15) Molar ratio of Cl-36 to Cl-37 (10^-15) dimensionless real 0.93 6.36 NULL None given +/-36Cl/Cl(E-15) +/-36Cl/Cl(E-15) 1-sigma error in molar ratios of Cl-36/Cl-37 (10^-15) dimensionless real 0.93 17.95 NULL None given 36Cl(at/uL) 36Cl(at/uL) Concentration of Cl-36 in atoms per microliter at/uL real 0.0 1.0 NULL None given +/-36Cl/Cl(at/uL) +/-36Cl/Cl(at/uL) 1-sigma error for 36Cl concentration dimensionless real 0.0 1.0 NULL None given DEPTH MASL DEPTH MASL Depth referred to the Sea level. Distance below Mean Average Sea water level reference from which sample was drawn meter 1 real