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) Cation, Anion Concentrations Along Lake Sediment/Water Interface 2014-11-04 publication Peter Doran Louisiana State University http://lsu.edu pdoran@lsu.edu https://www.lsu.edu/science/geology/people/faculty/doran.php pointOfContact documentDigital As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic aqueous geochemical sampling program has been undertaken. A series of water samples have been collected and analyzed for major ion chemistry by ion chromatography. The concentrations of ions cover a wide range of total dissolved solids from fresh to hypersaline lake waters. This dataset shows concentrations of lithium, sodium, potassium, magnesium, calcium, iron, chlorine, bromine, and SO4 found along the sediment/water interface of Taylor Valley lakes. Name: Kathleen A. Welch Role: associated researcher Name: Chris Gardner Role: data manager Name: Inigo San Gil Role: data manager completed McMurdo Dry Valleys LTER http://mcmlter.org/ unknown Data and Metadata was moved to DEIMS by Inigo on 2015.Data sets were submitted to the data manager by Kathy Welch at the University of Alabama. The raw data files listed under 'file name' are the names of the original files submitted, which are stored in the /data1/data/lakes/lakechem/ directory on INSTAAR's Unix system. These files are ascii text files. Upon arrival at INSTAAR, the data manager added variables for lake, date, and location description. Kathy Welch could specify which season and lake the samples were drawn from. However, more specific locations, sample dates, and description of sampling methods will need to be updated by Peter Doran.The file was imported into Microsoft Access version 2.0 on INSTAAR's Unix system, and can currently be found there. The file was then exported in ascii, comma delimited text and MS-DOS text (table layout) to present on the MCM LTER web site. Both of these files are linked to this web page above. inorganic nutrients theme LTER Core Areas English Lake Bonney is a saline lake with permanent ice cover at the western end of Taylor Valley in the McMurdo Dry Valleys of Victoria Land, Antarctica. It is 7 kilometres or 4.3 mi long and up to 900 metres or 3,000 ft wide. A narrow channel only 50 metres or 160 ft wide. Lake Bonney at Narrows separates the lake into East Lake Bonney 3.32 square kilometres or 1.28 sq mi and West Lake Bonney, 0.99 square kilometres or 0.38 sq mi. The west lobe is flanked by Taylor glacier. Valley: Taylor Distance to Sea : 25 Maximum Length (km): 4.8 Maximum Width (km): 0.9 Maximum Depth (m): 37 Surface Area (km^2): 3.32 Ice Thickness Average Surface (m): 3 - 4.5 Volume (m^3 * 10^6): 54.7 162.536209106445 162.353210449219 -77.724441528320 -77.697700500488 Lake Hoare occupies a narrower portion of the Taylor Valley, dammed by the Canada Glacier. It would drain almost completely without this dam. There are a number of islands which may be related to an old terminal of Canada Glacier. The lake is fed primarily from direct runoff from the glacier, as well as meltwater streams. (Lake level rose ~1.5 m between 1972 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 : 15 Maximum Length (km): 4.2 Maximum Width (km): 1 Maximum Depth (m): 34 Surface Area (km^2): 1.94 Ice Thickness Average Surface (m): 3.1 - 5.5 Volume (m^3 * 10^6): 17.5 162.935836791992 162.784423828125 -77.639259338379 -77.623085021973 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 Bonney is a saline lake with permanent ice cover at the western end of Taylor Valley in the McMurdo Dry Valleys of Victoria Land, Antarctica. It is 7 kilometres or 4.3 mi long and up to 900 metres or 3,000 ft wide. A narrow channel only 50 metres or 160 ft wide. Lake Bonney at Narrows separates the lake into East Lake Bonney 3.32 square kilometres or 1.28 sq mi and West Lake Bonney, 0.99 square kilometres or 0.38 sq mi. Valley: Taylor Distance to Sea : 28 Maximum Length (km): 2.6 Maximum Width (km): 0.9 Maximum Depth (m): 40 Surface Area (km^2): 0.99 Ice Thickness Average Surface (m): 2.8-4.5 Volume (m^3 * 10^6): 10.1 162.354934692383 162.269104003906 -77.727287292480 -77.714805603027 ground condition 1996-01-01 1998-12-31 Data contained in these files has been subjected to quality control standards imposed by the investigator. The user of this data should be aware that, while efforts have been taken to ensure that these data are of the highest quality, there is no guarantee of perfection for the data contained herein and the possibility of errors exists. If you encounter questionable data, please contact the MCM LTER data manager corrected or qualified. Thus, these data may be modified and future data will be appended. https://mcm.lternet.edu/sites/default/files/lksdmtch.csv lksdmtch eng; US McMurdo Dry Valleys LTER lksdmtch Record Delimiter : \r\n Number of Header Lines : 1 Number of Footer Lines : 0 Orientation : Column Quote Character : "Field Delimiter : , false Sample Name Sample Name Lake Lake where data was gathered Season Season; Date range when sample was collected depth (m) Depth from which sample was gathered Location Description Details about the sampling location Li (mg/L) mass concentrations Li (mM) millimolar concentration Na (mg/L) mass concentrations Na (mM) millimolar concentration K (mg/L) mass concentrations K (mM) millimolar concentration Mg (mg/L) mass concentrations Mg (mM) millimolar concentration Ca (mg/L) mass concentrations Ca (mM) millimolar concentration F (mg/L) mass concentrations F (mM) millimolar concentration Cl (mg/L) mass concentrations Cl (mM) millimolar concentration Br (mg/L) mass concentrations Br (mM) millimolar concentration SO4 (mg/L) mass concentrations SO4 (mM) millimolar concentration File Name Original file name before entered into database DBF https://mcm.lternet.edu/sites/default/files/lksdmtch.csv dataset Dedicated sampling equipment for each lake has been important for maintaining the integrity of the samples. For example, the range of Cl- concentration in the investigated lakes varies by more than three orders of magnitude. This carryover between samples becomes a potential problem. Carryover can also be a potential problem during analysis, and therefore analytical blanks are run to monitor this. The initial sample processing was carried out in field laboratories. A 100-ml sample aliquot was filtered for each anion and cation sample. All samples were filtered through 0.4-microm Nucleopore filters, usually within 12h of collection. The cation samples were filtered into acid-washed polyethylene bottles which had been rinsed with DI water, while the anion samples were filtered into DI-washed bottles. The cation samples were acidified by adding 0.5% (v/v) of concentrated HCl. Quality control was maintained by carefully rinsing all filtration apparatus with DI between samples and by processing filtration blanks which were later run as samples. The majority of water chemistry samples were returned to the Crary Laboratory, McMurdo Station, Antarctica, for analysis. Some of the samples were returned to the laboratory at the University of Alabama for analysis owing to time constraints during the field season. DX-300 ion chromatographic system was used for the major ion analyses. The system included a gradient pump module, high-pressure injection valve with a 25-microm sample loop, a Dionex conductivity detector (CDM-3) advanced computer interface and automated sampler. The timed events and data collection were controlled by the Dionex AI-450 chromatography software for Windows. The same ion chromatographic system was used but was switched back and forth between anion and cation configurations. For the anions, a Dionex Ionpac AS4A-SC analytical column (250x4mm I.D.) and AG4A-SC guard column (50x4mm I.D.) and AG4A-SC guard column (50x4mm I.D.) were used along with an Anion Self-Regenerating Suppressor-1. The eluent was 1.8 mM Na2CO3-1.7 mM NaHCO3. The gradient pump flow-rate was 2 ml/min and the background conductivity was ca. 16 uS. For the cations, the Dionex Ionpac CS12 analytical column (250x4mm I.D.) and CG12 guard column (50x4mm I.D) were used with a Cation Self-Regenerating Suppressor-1. The eluent was 0.020 M methanesulfonic acid. The eluent flow-rate was 1.0 ml/min and the background conductivity was ca. 200-250 nS. The stock standard solutions used for a typical batch of samples from the lakes are specified below: CATION CONCENTRATION (mg/L) ANION CONCENTRATION (mg/L) Na+ 100 Cl- 100 K+ 20 SO4(2-) 100 Mg(2+) 50 F- 10 Ca(2+) 50 Br- 2 Li+ 1 Appropriate dilutions of the stock standards were used to prepare a range of standards for calibration. Owing to the high salt concentrations in many of the samples, dilutions were made before the samples were run. Dilutions ranged from 1:2 for Lake Hoare surface water up to 1:6000 for the Lake Bonney deep water. The samples were diluted by serial dilution, using plastic microbeakers and adjustable pipettors. Replicate and duplicate samples were run daily. Usually, each sample was injected twice and samples from each batch were run in duplicates to check the precision of the dilutions. In almost every case, the relative standard deviation of the duplicates was less than 1%, even with dilutions of 1:6000. In addition, analytical blanks and filtration blanks were analyzed to check the quality control. Metadata Access Constraints: none Metadata Use Constraints: none annually McMurdo Dry Valleys LTER http://mcmlter.org/ pointOfContact