snyder_halogenchem English utf8 dataset McMurdo Dry Valleys LTER http://mcmlter.org/ 2014-11-04 ISO 19115-2 Geographic Information - North American Profile Metadata - Data with Biological Extensions ISO 19115-2:2009(E) Halogen chemistry and isotopic composition in McMurdo lake waters and pore fluids 2014-11-04 publication Glen Snyder Rice http://www.rice.edu/ (713) 348-4054 Earth Science-MS 126 Houston TX 77251 US gsnyder@rice.edu pointOfContact documentDigital 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. Name: Chris Gardner Role: data manager Name: Inigo San Gil Role: data manager completed McMurdo Dry Valleys LTER http://mcmlter.org/ unknown 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) inorganic nutrients theme LTER Core Areas English 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 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): 25.2 163.259582519531 163.048782348633 -77.622711181641 -77.597076416016 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): 4.9 161.662445068359 161.608886718750 -77.726486206055 -77.715972900391 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): 160 161.691970825195 161.391906738281 -77.542304992676 -77.518882751465 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.   162.280426025391 161.683044433594 -77.769035339355 -77.721229553223 ground condition 2005-12-09 2006-01-07 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.             https://mcm.lternet.edu/sites/default/files/data/ANCILLARY_SNYDER_HALOGENCHEM_0.csv ANCILLARY_SNYDER_HALOCHEM eng; US McMurdo Dry Valleys LTER ANCILLARY_SNYDER_HALOCHEM Data Source Definition : units and column description Record Delimiter : \n Number of Header Lines : 26 Number of Footer Lines : 1 Orientation : Column Quote Character : "Field Delimiter : , false DATASET_CODE Table Identifier LOCATION_NAME Name of lake where measurement was made LOCATION_TYPE Sample type description and/or location SAMPLE_ID Sample identification code LATITUDE Sample Latitude LONGITUDE Sample Longitude DATE_TIME Date sample was collected Date Time Format: mm/dd/yyyy DEPTH (m) Stream, pond, or lake depth. In the case of ice-covered lakes, depth is in meters below the upper ice surface. alk (meq/L) Alkalinity in milliequivalents per liter I (umol/kg) Total dissolved iodine in micromoles per kilogram Br (umol/kg) Total dissolved bromine in micromoles per kilogram Cl (mM) Dissolved chloride in millimoles per liter 129I/I(E-15) Molar ratio of I-129 to total iodine (10^-15) +/-129I/I(E-15) 1-sigma error in molar ratios of I-129/I-127 (10^-15) 129I(at/uL) Concentration of I-129 in atoms per microliter +/-129I(at/uL) 1-sigma error for I-129 concentration 36Cl/Cl(E-15) Molar ratio of Cl-36 to Cl-37 (10^-15) +/-36Cl/Cl(E-15) 1-sigma error in molar ratios of Cl-36/Cl-37 (10^-15) 36Cl(at/uL) Concentration of Cl-36 in atoms per microliter +/-36Cl/Cl(at/uL) 1-sigma error for 36Cl concentration DEPTH MASL Depth referred to the Sea level. Distance below Mean Average Sea water level reference from which sample was drawn DBF https://mcm.lternet.edu/sites/default/files/data/ANCILLARY_SNYDER_HALOGENCHEM_0.csv dataset  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.              Metadata Access Constraints: none Metadata Use Constraints: none annually McMurdo Dry Valleys LTER http://mcmlter.org/ pointOfContact