Nutrients (NH4 - NO3 - NO2 - PO4) English utf8 dataset McMurdo Dry Valleys LTER Information Manager im@mcmlter.org pointOfContact 2014-11-04 ISO 19115-2 Geographic Information - North American Profile Metadata - Data with Biological Extensions ISO 19115-2:2009(E) Nitrogen and phosphorus concentrations in discrete water column samples collected from lakes in the McMurdo Dry Valleys, Antarctica (1993-2020, ongoing) 2014-11-04 publication John Priscu Montana State University http://www.montana.edu/ jpriscu@montana.edu pointOfContact documentDigital An important part of the McMurdo Long Term Ecological Research (LTER) project is identifying patterns and movements of nutrients in perennial ice-covered lakes. This dataset addresses this core area of research and quantifies macronutrient concentrations (NH4+, NO3-, NO2, SRP) found at specific depths in McMurdo Dry Valley lakes. Name: Kathleen A. Welch Role: lab technician Name: Renée F. Brown Role: data manager Name: Amy Chiuchiolo Role: former field crew Name: Inigo San Gil Role: former data manager completed McMurdo Dry Valleys LTER Information Manager im@mcmlter.org pointOfContact unknown Data and metadata were improved for compliance with mandates and standards for LTER during 2014.     Data and metadata were offered through the DEIMS system since 2015 (San Gil)    Data from this table was submitted to INSTAAR by John Priscu's team at Montana State University. The raw data files listed under 'file name' are the names of the original files submitted. The 1993/94 and 1994/95 datasets are Microsoft Excel version 6.0 files, and the 1995/96, 1996/97 and 1997/98 datasets are ascii text files. Upon arrival at INSTAAR, the data manager fine-tuned the location codes and limno runs to match those provided in the "locations, dates, codes for lake chemistry, biology samples" file. The file was imported into Microsoft Access 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. Information for the metadata was obtained from the Metanut9697.rtf and Metanut9798.rtf files. The files were called up using Microsoft Word version 6.0. Text from these files was used to create this page in html format. inorganic nutrients theme LTER Core Areas English 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 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 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 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 Miers lies in the Miers Valley. Valley: Miers Distance to Sea : 20 Maximum Length (km): 1.5 Maximum Width (km): 0.7 Maximum Depth (m): 21 Surface Area (km^2): 1.3 Ice Thickness Average Surface (m): 3.4 - 6 Volume (m^3 * 10^6): 2.9 163.886840820313 163.812332153320 -78.101478576660 -78.094047546387 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 A lake with an area of 1 square mile which occupies the north portion of Pyramid Trough, Scott Coast. Named by New Zealand Geographic Board (NZGB) (1994) in association with Pyramid Trough. 162.823226928711 162.718856811523 -77.442016601563 -77.417655944824 ground condition 1993-10-27 2020-01-11 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/data/mcmlter-lake-nutrients-20220317.csv LIMNO_NUTRIENTS eng; US McMurdo Dry Valleys LTER LIMNO_NUTRIENTS Data Source Definition : Details about the nutrients lake data container: column definitions, units and codes used, etc. Record Delimiter : \n Number of Header Lines : 1 Number of Footer Lines : 1 Orientation : Column Quote Character : "Field Delimiter : , false DATASET_CODE Code to designate the table name LIMNO_RUN Code for lake's sampling location and date LOCATION NAME Name of lake where measurement was made LOCATION_CODE Code for site where measurement was made DATE_TIME Date on which sample was gathered Date Time Format: MM/DD/YYYY Depth (m) Distance below the piezometric water level from which sample was drawn NH4 (uM) Ammonia concentration found using Lachat NH4(MCM)(uM) Ammonia concentration found using manual methods NH4 Comments Helpful hints about the NH4 sample SRP (uM) Soluble reactive phosphorus found using Lachat SRP(MCM)(uM) Soluble reactive phosphorus found using manual methods SRP Comments Helpful hints about the SRP sample NO2 (uM) Nitrite concentration found using Lachat NO2(MCM)(uM) Nitrite concentration found using manual methods NO2 Comments Helpful hints about the NO2 sample NO3 (uM) Nitrate concentration found using Lachat NO3(MCM)(uM) Nitrate concentration found using manual methods NO3 Comments Helpful hints about the NO3 sample File Name Name of file in which data was submitted Sample Comments notes about the sample 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/mcmlter-lake-nutrients-20220317.csv dataset Lake water samples are collected at specific depths with a five-liter Niskin bottle during normal LTER limnological sampling.  Sub-samples for nutrient analysis are decanted into a 1 L amber Nalgene bottle.  One 100 mL sub-sample is taken from the one-liter amber Nalgene bottle.  The sample is filtered through a combusted (475 degree centigrades for 4 hours) and acidified (the acidification step began with the 2008-2009 season) Whatman 25 mm GF/F using a bell jar apparatus. The filter is used for chlorophyll-a analysis.  The filtrate is collected in a 125 mL acid washed Nalgene bottle and stored at -20 degrees centigrades until analysis  at the Crary Analytical Lab.  Nutrient assays are performed with a Lachat Quickchem AE Autoanalyzer using standard methods.  Ammonia is analyzed using the phenol hypochlorite method.  Nitrite is determined by diazotization with sulfanilamide  and NED. Nitrate is determined by reducing nitrate to nitrite by passing a sample through a copperized cadmium column and analyzing for nitrite, which yields nitrate + nitrite (N+N) concentration. The nitrate concentration is determined by subtracting the nitrite concentration from the N+N concentration.  Soluble  Reactive Phosphorus is determined using ammonium molybdate methods.  Lakes Fryxell, Miers and Hoare are analyzed with a Lachat Quickchem Autoanalyzer.  East and West Lobes of Lake Bonney are analyzed manually (spectrophotometrically) using a 5cm cuvette.   Methods and Notes for 2011-2012 season samples: Samples from the 2011-2012 season were analyzed by Skalar San++ CFA at The Ohio State University. Ammonia was analyzed using a salicylate method. Nitrite was determined by diazotization with sulfanilamide and NED. Nitrate was determined by reducing nitrate to nitrite by passing a sample through a copperized cadmium column and analyzing for nitrite, which yields nitrate + nitrite (N+N) concentration. The nitrate concentration was determined by subtracting the nitrite concentration from the N+N concentration. Soluble Reactive Phosphorus was determined using ammonium molybdate methods. Lakes Miers, Fryxell and Hoare were analyzed with a Skalar CFA instrument. East and West Lobes of Lake Bonney were analyzed manually (spectrophotometrically) using a 10cm cuvette. Method Detection Limit (MDL) and dilutions are listed in the data file for each sample. All values were reported with 2 decimal places for informational purposes; 1 decimal place is significant for N analytes, except for values over 100, for which no decimal places are significant; 2 decimal places are significant for P, except for values over 10, for which 1 decimal place is significant.   Metadata Access Constraints: none Metadata Use Constraints: none annually McMurdo Dry Valleys LTER http://mcmlter.org/ pointOfContact