gsca English utf8 dataset McMurdo Dry Valleys LTER http://mcmlter.org/ 2014-11-12 ISO 19115-2 Geographic Information - North American Profile Metadata - Data with Biological Extensions ISO 19115-2:2009(E) Chlorophyll-a Concentrations for Soil Biota Distribution Experiment 2014-11-12 publication Diana Wall Colorado State University http://www.colostate.edu Johnson Hall 107 Fort Collins CO 80523 US Diana.Wall@colostate.edu http://wp.natsci.colostate.edu/walllab/ pointOfContact documentDigital  Investigation of the variation in soil biota and soil properties across the McMurdo Dry Valleys was part of the McMurdo Dry Valleys Long Term Ecological Research (LTER) project. Chlorophyll-a concentrations from soil samples collected for organism extraction and identification  was determined. Chlorophyll-a samples were gathered on the following dates:    * December 12 and 22, 1994,  * January 9, 1995,  * November 8, 1995,  * December 7, 1995, and  * January 12, 1998.    Name: Ross A. Virginia Role: associated researcher Name: Andy Parsons Role: field crew Name: Denise Steigerwald Role: data manager Name: Inigo San Gil Role: data manager completed McMurdo Dry Valleys LTER http://mcmlter.org/ unknown IN 2016, metadata was completed to enhance preservation, (San Gil)    This file was created by Mark St. John at Colorado State University in Oct-1998, using raw data from the Excel workbooks '9412gsca.raw', '9511gsca.raw', and '9801gsca.raw'. The file format was suggested by the LTER data manager, to conform with the relational database structure. On 30-Oct-1998, the file was submitted to Denise Steigerwald, the MCM LTER data manager, located at INSTAAR, University of Colorado.              Upon arrival at INSTAAR, the data manager combined the 3 data files, removed columns for latitude and longitude, and updated the location names to match those provided in the "soil measurement locations" file (from which latitude and longitude can be found). The resulting file was reformatted to present in ascii, comma delimited text and MS-DOS text (table layout) on the MCM LTER web site. Both of these files are linked to this web page above.   population dynamics theme LTER Core Areas English Located in middle of Beacon Valley. Ceased ops in 2012ID: BENM 160.656900000000 160.656900000000 -77.828000000000 -77.828000000000 Moss Sample 130 @ Cape Crozier 169.200103759766 169.200103759766 -77.456802368164 -77.456802368164 The Cape Royds Pond 1 is an ice free pond in the Ross Island Code : CR1 Area: 1,792 Temperature: 6.3 celsius 166.163772583008 166.163772583008 -77.552818298340 -77.552818298340 Soil biota distribution: Wright Valley Labyrinth (Dais) at dais 160.718994140625 160.718994140625 -77.550697326660 -77.550697326660 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 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 Lake Vida is a hypersaline lake in Victoria Valley, the northernmost of the large McMurdo Dry Valleys, on the continent of Antarctica. It is isolated under year-round ice cover, and is considerably more saline than seawater. Lake Vida is one of the largest lakes in the McMurdo Dry Valley region and is a closed-basin endorheic lake. The permanent surface ice on the lake is the thickest non-glacial ice on earth, reaching a depth of at least 21 metres or 69 ft. The ice at depth is saturated with brine that is seven times as saline as seawater. The high salinity allows the brine to remain liquid at an average yearly water temperature of 13 degrees Celsius or 9 farenheit. Hydrology: Lake Vida has at least three named inflows: Victoria River, Kite Stream, and Dune Creek. Victoria River passes through the Vida Basin into Victoria Valley, Victoria Land as ephemeral glacial meltwater from the Upper Victoria Glacier, draining from Victoria Upper Lake. Geology: In the vicinity of Lake Vida, a variety of geological features are noted, the most significant being glaciers, lakes, valleys, ridges, and summits. There are approximately 25 named glaciers within a 25 kilometres radius with the nearest being Upper Victoria Glacier, Packard Glacier, Clark Glacier, and Clio Glacier. Valley: Victoria 161.930999755859 161.930999755859 -77.388298034668 -77.388298034668 The Nussbaum Riegel Pond is in the Taylor Valley in between the Bonney and Chad Basins.  An Ice-covered, oval pond.Code: NRP Area: 6,133 Temperature: 3.1 celsius 162.814727783203 162.814727783203 -77.684379577637 -77.684379577637 ground condition 1994-12-12 1998-01-12 https://mcm.lternet.edu/sites/default/files/gsca.csv gsca eng; US McMurdo Dry Valleys LTER gsca Data Source Definition : This ancillary dataset is not too large. You can download the associated comma delimited file and interpret the columns as defined in the detailed metadata provided here. Record Delimiter : \n Number of Header Lines : 1 Number of Footer Lines : 0 Orientation : Column Quote Character : "Field Delimiter : , false LOCATION Name of area where measurement was made DATE_TIME Date on which sample was gathered Date Time Format: mm/dd/yy SAMPLE # Sample ID CHL-A (uG/G SOIL) Chlorophyll a concentration found in soil COMMENTS Helpful hints about the sample FILE NAME Name of file in which data was stored DBF https://mcm.lternet.edu/sites/default/files/gsca.csv dataset  At each site 10-25 soil samples were taken for chlorophyll a analysis as follows:  Sampling bags were prepared with one sterile 'Whirlpak' bag and clean plastic scoop per sample.  The location of the sampling was recorded each year so that areas were not re-sampled.  Soil was collected to 1 cm depth with the plastic spoon, excluding rocks with a diameter >5 mm.  About 4 teaspoons of soil were placed into thevial, keeping the vial out of the light in a closed hand.  The soil samples were stored in a light-tight bag, in a cooler for transportation.  On return to the laboratory (within 8 hours of sampling), the soils were stored at +5 degrees C until further processing.   Extraction of chlorophyll from the soil. All procedures were carried out in the dark or very low irradiance to avoid degradation of the chlorophyll.  The soil samples were mixed thoroughly in the vials, and a sample of approximately 5 g was weighed out into a 50 mL plastic centrifuge tube with a screw-top cap. 10 mL of a 50:50 DMSO/90% acetone solution was added to each sample and they were mixed thoroughly on a bench-top Vortex mixer for about 5 seconds.  The vials were placed in a -4 degrees C constant temperature room, in the dark, and left for 12-18 hours.   Determination of chlorophyll-a concentration.  This was determined fluorometrically using a Turner model 111 fluorometer.  A calibration using a known concentration of chlorophyll was carried out prior to sample analysis. The machine was blanked using a 50:50 DMSO/90% acetone solution.  Each vial was mixed thoroughly, then centrifuged for 5 minutes at about 1800 RPM.  A sample of approximately 4 mL of the DMSO/acetone solution was taken from the top of the sample with a pipette, being careful not to get any soil particles in the solution.  The sample was placed in a cuvette, into the fluorometer and the fluorescence was recorded.  This was done fairly quickly in order to prevent light from breaking down the chlorophyll.  This measurement is called Fo, the initial fluorescence.  After taking this reading, 0.1 mL of 1N HCl was added directly to the cuvette and the cuvette was gently agitated.  After 20 seconds, the fluorescence was re-measured.  (During this step, the acid converts the chlorophyll to phaeophytin by releasing a magnesium ion in an acidic environment).  This measurement is called Fa, the fluorescence after acidification.  The solution was discarded into a waste container, and the cuvette rinsed 3 times with DMSO/90% acetone solution before proceeding with the next sample.     Calculation of chlorophyll concentration.  The calibration curve that was constructed for the fluorometer had the following equation:  [chlorophyll (microg/L) = (Fo-Fa)-0.4254)/2.2385].  The Fo and Fa figures were put in to this equation to calculate chlorophyll concentration.  Subsequently, this figure was divided by 1000 to convert to microg/mL.  Next, this is multiplied by 10 as the soil was extracted in 10mL of DMSO/90% acetone.  Finally, this is divided by the fresh weight of the soil in g to give the concentration in microg chlorophyll per g fresh weight of soil.  If the extract was diluted prior to reading on the fluorometer, the dilution factor (noted in the comments column) was applied at the end of the equation.   Metadata Access Constraints: none Metadata Use Constraints: none annually McMurdo Dry Valleys LTER http://mcmlter.org/ pointOfContact