| Data Tables, Images, and Other Entities: |
| Data Table: | Units_and_Column_Descriptions
View Table Metadata
|
|
Short Name: | glstkht |
| Online Distribution Info: |
| Schema Name: | http://www.mcmlter.org/queries/glacier_results.jsp |
| Description: |
|
You can build your own query for to retrieve Glacier Stake Height Replications for all glaciers using the URL
http://www.mcmlter.org/queries/glacier_results.jsp and the described parameters below, or you can just
visit the URL http://www.mcmlter.org/queries/glacier_queries.jsp and simply use the online form to build your
own glacier query for all the availabe glaciers and parameters (ie. average stake height, stake height, snow depth,
snow and ice mass changes, snow density, mass balance summary). Using the form is the easiest method.
|
|
Here is an example to query for Glacier Stake Height Replications from December 1998 to
January 2000 on Taylor Glacier:
http://www.mcmlter.org/queries/glacier_results.jsp?begDate=12/01/1998&endDate=01/01/2000&metStation=TAY&dataType=GLSTKHT
|
|
variable (dataType) abbreviations for glacier data:
|
AVGLSTK (Average Stake Height)
GLSNDPT (Snow Depths)
GLSTKHT (Stake Heights)
MSCHNG (Snow and Ice Mass Changes)
SNWDNS (Snow Densities)
WEQ (Mass Balance Summary)
|
|
| begDate: |
|
| Desired begin date for the data, use format MM/DD/YYYY |
|
| endDate: |
|
| Desired End Date for the data query |
|
| metStation: |
|
| This is the shorthand code for the name of the glacier, as follows: Canada=CAN, Commonwealth=COM, Howard=HOW, Hughes=HUGH,
Suess=SUES, Taylor=TAY |
|
| dataType: |
|
| variable abbreviation for the parameter of interest, such as snow and ice mass changes, or mass balance summaries.
For a list of the used abbreviations, see the abbreviation section above |
|
|
| Data Set Owner(s): |
|
Individual: | Andrew Fountain |
|
Address: |
| Department of Geology, |
| 17 Cramer Hall, |
| 1721 SW Broadway, |
| Portland State University , |
| Portland, OR 97207-0751
USA |
|
|
Phone:
|
|
|
Email Address:
|
|
|
| Metadata Provider(s): |
|
Organization: | McMurdo Dry Valleys LTER |
|
Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
|
|
Phone:
|
|
|
Phone:
|
|
|
Email Address:
|
|
|
| Associated Party: |
|
Individual: | Hassan Basagic |
|
Address: |
| Department of Geology, |
| Portland State University , |
| Portland, OR 97207-0751
USA |
|
|
Email Address:
|
|
|
|
Role:
|
|
| Abstract: |
| |
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 includes stake
height and snow depth measurements to the surface of six glaciers in Taylor Valley,
McMurdo Dry Valleys, Antarctica. Monitoring the changes in these measurements over time
provides a record of mass balance, and aids in determining the role of glaciers in the polar
hydrologic cycle.
|
|
| Keywords: |
|
|
- glacier
(theme)
- Antarctica
(theme)
- McMurdo Dry Valleys
(theme)
- dry valleys
(theme)
- mass balance
(theme)
- stake height
(theme)
|
| Additional Information: |
| |
| A Note about measurement timing |
The goal of each summer season is to take measurements in early spring (Oct/Nov) and
late summer (late January). This provides a measure of seasonal winter/summer changes of glacier mass.
In some circumstances we have the opportunity or need to measure the glaciers in mid-season (Dec).
View the dates the measurements were made at the following URL: http://www.mcmlter.org/data/glaciers/timing/stkdates.pdf
|
| A Note about the SURFACE variable |
The surface is either snow or ice. Sometimes a thin layer of snow (~a few crystals thick) is referred to as
trace or dusting.
|
| A Note about Stake names |
A stake with an H or V indicates a stake along the ice cliff that forms the boundary of the
glacier terminus. An H is a horizontal stake placed into the vertical wall of the glacier terminus, and V
is a stake placed into the ice apron at the base of the ice cliff. The vertical stakes were installed to
support the horizontal stakes and provide a nearby measure of ablation for a surface with a much
different slope.
|
| Additional Notes |
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 so that the
data can be corrected or qualified. Thus, these data may be modified
and future data will be appended.
|
|
| License and Usage Rights: |
| |
| MCM LTER data may be used freely with the following restrictions: |
The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions.
The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications.
A copy of any resultant publications should be sent to the McMurdo data manager and principal investigator.
The end-user follow the guidelines set forth in the LTER Network Data Access Policy, Data Access Requirements, and General Data Use Agreement found at http://www.mcmlter.org/data_guidelines.htm
|
|
| Geographic Coverage: |
|
Geographic Description: | Data was collected from the Canada, Commonwealth, Howard, Hughes, Suess and
Taylor glaciers, located in the Taylor Valley of Antarctica. Specific latitudes, longitudes, and elevations of the
stakes from which information was gathered can be found in the glacier stake locations file.
|
|
Bounding Coordinates:
|
| West: | 162 degrees
|
| East: | 163.6 degrees
|
| North: | -77.2 degrees
|
| South: | -77.8 degrees
|
|
Mimimum Altitude: | 0 meter |
|
Maximum Altitude: | 2000 meter |
|
| Temporal Coverage: |
|
Begin:
|
|
|
End:
|
|
|
|
| Maintenance: |
|
Description:
|
Data for the original stake height and snow depth measurements, as well as the averages and standard deviations 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 on the PC in the McMurdo LTER data manager's
office at INSTAAR.
Once submitted to INSTAAR, the data manager used Microsoft Excel and Access software to produce files that were in more
of a relational mode. Information was assigned to different files according to type of data it dealt with. Separate files were generated for:
* stake height replications,
* snow depth replications, and
* averages/standard deviations calculated from stake height and snow depth replications.
In March, 2000, Thomas Nylen submitted data from the 1997-98, 1998-99 and 1999-2000 seasons. Instead of lumping all of the stake
height and snow depth values for each glacier under one file, they were separated into files for each glacier. Metadata fields were also
updated at this time.
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 divided the 'stake' field to 'stake' and 'stk replcmnt' values. The 'stake' value is an ID for a stake in a given location
over time, while the 'stk replcmnt' value shows whether the stake is the original (A), the first replacement stake installed (B), the second
stake installed (C), and so forth. (Melting on the glacier over time makes installation of replacement stakes necessary.) Since the
replacement value is only relevant for the stake heights and snow depths datasets, division of the 'stake' value into separate fields
made it more straightforward for grouping data across different datasets (eg. stake heights and snow densities).
|
|
|
Frequency:
| |
| Contact: |
|
Organization: | McMurdo Dry Valleys LTER |
|
Position: | Data Manager |
|
Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
|
|
Phone:
|
|
|
Email Address:
|
|
|
| Publisher: |
|
Organization: | McMurdo Dry Valleys LTER |
|
Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
|
|
Phone:
|
|
|
| Methods Info: |
| Step 1: |
|
|
Description:
|
|
Stakes were drilled into the snow and ice. Measurements are taken from the top of the
stake to a round board that sits on the surface. The board, about 25 cm in diameter, is needed to
average the surface height over a larger area because local roughness, especially on ice surfaces,
can overwhelm the change in height since the last measurement. Roughness typically results from
an "ablation well" around the stake, caused by enhanced solar absorption and subsequent longwave
radiation from the stake. Measurements against the stake became meaningless. Methodology
evolved to taking 4 replicated measurements at each stake. Height to the surface was then calculated
from the sum of the distance from the top of the stake to the board, the board thickness, and subtracting
the depression of the board into the snow.
If snow covered the ice surface, the snow depth was also measured. Procedures evolved to acquiring
4 - 8 replications around each stake. Typically, the final value of snow depth was the average of all
measurements. In some cases, values were discarded because measurements were taken in hidden
holes in the ice surface. Snow depth is important to record because the ice surface could have ablated
prior to a snowfall. Therefore, to assess the mass balance at that stake, both ice surface change and
snow depth is required.
|
|
|
|