Michael N. GooseffAndrew G. Fountain 2015-07-25 tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/1e2dbc08f9793a2ff5590a4429610832 https://mcm.lternet.edu/content/glacier-stake-locations-mcmurdo-dry-valleys-antarctica-1993-2023-ongoing As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor mass balance and meltwater flow from the Taylor Valley glaciers. This data set contains global positioning system (GPS) measurements of stakes on glaciers. The measurements include both low-quality estimates (+/- 100m) from hand-held GPS units and high precision measurements (+/- 2 cm) using Trimble (4000 SSE) geodetic receivers. The purpose of these measurements was to obtain rough stake locations for use in relocating stakes in the future and precise stake locations for use in calculating stake displacement. The measurements are made relative to the WGS84 ellipsoid. 1993-11-07 2023-01-25 ground condition In 2015, Inigo San Gil moved these data to the Drupal Ecological Information Management System, thus modernizing a bit the way data is managed and distributed.------Data for the original stake locations was submitted by Andrew G. Fountain to the data manager in August, 1997. The column showing "file name" identifies the original file containing that record. These are ascii text files and can be found in the McMurdo LTER data manager's home directory on INSTAAR's Unix system.Once submitted to INSTAAR, the data manager used Microsoft Excel and Access software to produce files that were in more of a relational mode. The resulting files are represented in the "glstkloc.dat" file (ascii text, comma delimited format), and "glstkloc.txt" file (MS-DOS text format).Initially, there was no date associated with each record in the data file. However, due to constant movement of ice on glaciers, the stake locations required subsequent measurements during the 1996-97 field season. When this occurred, a field for date was added to this file. Dates from the initial GPS measurements were acquired from the raw data files submitted by Andrew Fountain. If uncertain about what date to use, confirmation was made with Karen Lewis.Upon verifying altitude corrections for the gps locations with Bjorn Johns of UNAVCO (in March, 1998), Karen Lewis discovered that all of the ellipsoidal heights to sea level obtained by precise GPS measurements were too short by 55.24 meters. Denise Steigerwald therefore adjusted the elevations for these stakes by adding 55.24 meters.In April, 2000, Denise Steigerwald added fields for dataset code and glstkid. Dataset code would allow the data to be linked to the metadata in a relational database. Glstkid is a code that ties stake records to points on a GIS base map being developed by Michael Prentice at the University of New Hampshire. In addition, Denise:Removed records associated with "B" (replacement) stakes. Coordinates for these stakes match those provided for the original stakes. Data sets containing replacement stake records had their stake values divided into 'stake' and 'stk replcmnt' fields, thus allowing the 'stake' fields to be linked between the locations file and the data files.Converted all latitudes and longitudes from degrees-minutes-seconds to degrees in decimal format. This would allow them to be stored in numeric format rather than as text. As needed Located in the Miers Valley, this glacier became object of the MCMLTER program study in 2015. 163.732166290280 163.582477569580 -78.097276633989 -78.118713184740 The Canada Glacier a small glacier flowing south-east into the northern side of Taylor Valley.  The glacier receives less than 10 cm of snowfall annually. Its seasonal melting feeds Lake Hoare to the west and Lake Fryxell to the east. 163.057708740234 162.894287109375 -77.598403930664 -77.632133483887 The Commonwealth glacier flows in a southeasterly direction and enters the northern side of Taylor Valley immediately west of Mount Coleman. Named by the British Antarctic Expedition for the Commonwealth of Australia in the early 1900s.   163.373565673828 163.197784423828 -77.545059204102 -77.589111328125 286m 286m meter Howard is a small alpine glacier just west of Crescent Glacier, flowing into Taylor Valley on the north from the Kukri Hills. Geologist T.L. Pewe studied and named it for Arthur D. Howard, 163.147994995117 163.036087036133 -77.662025451660 -77.687744140625 717m 717m 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.   162.280426025391 161.683044433594 -77.721229553223 -77.769035339355 Hughes Glacier is a small alpine glacier flowing toward Lake Bonney in Taylor Valley from the Kukri Hills on the south. Named for Professor McKenny Hughes. 162.581527709961 162.437667846680 -77.727073669434 -77.749969482422 The Suess Glacier is between the Canada Glacier and Lacroix Glacier, flowing south into Taylor Valley. Scott named after the early nineties British Antarctic Expedition for Professor Eduard Suess. 162.744598388672 162.647781372070 -77.633750915527 -77.651824951172 1 000m 1 000m meter [term:vocabulary] None <cntperp> <cntper>McMurdo Dry Valleys LTER Information Manager</cntper> </cntperp> <cntemail>im@mcmlter.org</cntemail> Name: Anna T. Wright Role: field technician Name: Renée F. Brown Role: data manager Name: Anna J. Bergstrom Role: former field crew Name: Adam Wlostowski Role: former field crew Name: Thomas Nylen Role: former field crew Name: Hassan Basagic Role: former field crew Name: Inigo San Gil Role: former data manager Name: Chris Gardner Role: former data manager Name: Denise Steigerwald Role: former data manager Not Applicable Not Applicable Field and/or Lab Methods  Handheld measurements were acquired using either a NAVPRO 5000 or GARMIN 45 GPS unit. Latitude and longitude accuracy are about +/- 100m. The handheld units did not provide adequately accurate elevations, so elevation was acquired from the 1971 map of the valley. There was no special procedure in acquiring the data or exact location relative to the stake.   The precise GPS measurements were acquired with help of UNAVCO. (See photos and further  descriptions below). Measurements were made using a Trimble 4000 SSE receiver. A base station was set up prior to measurements in the field. The  baseline between the measurements and basestation did not exceed 15 km. The measurements were collected as rapid static surveys.   For the precise measurements, the GPS antenna was mounted on top of a 2 meter  tall rangepole. The rangepole was placed next to the each ablation stake on the down-glacier side of the stake, and the tip of the rangepole was placed on the  board used for mass balance measurements at that stake to insure that the measured elevation was relative to the same surface used in the mass balance  measurements. This system resulted in the rangepole sitting 2-3 cm away from the  down-glacier side of the ablation stake. Repeatibility of placement was  ascertained to be about +/- 2 cm based on repeat measurements. The rangepole was  always vertical, as indicated by a level-bubble.   At each stake, data were collected for 10 - 20 minutes, sufficient to keep the horizontal precision of the GPS results within 2 cm. Accuracy of the resulting measurements are estimated to be 5 cm in the horizontal and vertical,  after accounting for set-up error.   During the 1995/96 season, the position of all the ablation stakes on four different glaciers were measured using rapid-static GPS. A re-measurement in the 1996/97 season provided displacements and velocities.    Instrumentation:NAVPRO 5000 GARMIN 45 GPS unit. Trimble 4000 SSE receiver  Handheld measurements were acquired using either a NAVPRO 5000 or GARMIN 45 GPS unit. Latitude and longitude accuracy are about +/- 100m. The handheld units did not provide adequately accurate elevations, so elevation was acquired from the 1971 map of the valley. There was no special procedure in acquiring the data or exact location relative to the stake. The precise GPS measurements were acquired with help of UNAVCO. (See photos and further  descriptions below). Measurements were made using a Trimble 4000 SSE receiver. A base station was set up prior to measurements in the field. The  baseline between the measurements and basestation did not exceed 15 km. The measurements were collected as rapid static surveys. For the precise measurements, the GPS antenna was mounted on top of a 2 meter  tall rangepole. The rangepole was placed next to the each ablation stake on the down-glacier side of the stake, and the tip of the rangepole was placed on the  board used for mass balance measurements at that stake to insure that the measured elevation was relative to the same surface used in the mass balance  measurements. This system resulted in the rangepole sitting 2-3 cm away from the  down-glacier side of the ablation stake. Repeatibility of placement was  ascertained to be about +/- 2 cm based on repeat measurements. The rangepole was  always vertical, as indicated by a level-bubble. At each stake, data were collected for 10 - 20 minutes, sufficient to keep the horizontal precision of the GPS results within 2 cm. Accuracy of the resulting measurements are estimated to be 5 cm in the horizontal and vertical,  after accounting for set-up error. During the 1995/96 season, the position of all the ablation stakes on four different glaciers were measured using rapid-static GPS. A re-measurement in the 1996/97 season provided displacements and velocities.   unknown GLSTKLOC Glacier stake locations DATASET CODE Code representing stake heights location dataset The data provider Code representing stake heights location dataset Glacier - Stake ID Code formed with the Glacier, Stake and Date of measurement, used for legacy GIS mapping. The data provider Code formed with the Glacier, Stake and Date of measurement, used for legacy GIS mapping. Glacier Name Name of glacier where measurement was made The data provider Name of glacier where measurement was made Stake number Unique number for each stake on glacier The data provider Unique number for each stake on glacier DATE_TIME Date of data measurement. The data provider calendar date/time MM/DD/YYYY gregorian calendar Latitude Sample Latitude The data provider degree Longitude Sample Longitude The data provider degree Elevation Elevation of sample site - from map. The data provider meter Comments Comments about the overall data or STAKE COORDINATES The data provider Comments about the overall data or STAKE COORDINATES FILE_NAME Name of file in which data was submitted The data provider Name of file in which data was submitted McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-glac-locations-20250311.csv None 2015-07-25 2015-07-25 Biological Data Profile of the Content Standards for Digital Geospatial Metadata devised by the Federal Geographic Data Committee. Drupal Ecological information Management Systems, version D7, Biological Data Profile module