This data set contains temperature-depth profile measurements taken in 22 boreholes drilled on the West Antarctic Ice Sheet, which exhibit two distinctly different thermal states of basal ice: a warm state and a relatively colder state. The data are available in ASCII Text Format (.txt) and Portable Document Format (PDF) via FTP.
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Temperature of the West Antarctic Ice Sheet, Version 1
Geographic Coverage
Spatial Coverage: |
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Spatial Resolution: |
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Temporal Coverage: |
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Temporal Resolution: | Not specified |
Parameter(s): |
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Platform(s) | GROUND-BASED OBSERVATIONS |
Sensor(s): | THERMISTORS |
Data Format(s): |
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Version: | V1 |
Data Contributor(s): | Hermann Engelhardt |
Metadata XML: | View Metadata Record |
Data Citation
As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.
Engelhardt, H. 2013. Temperature of the West Antarctic Ice Sheet, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5PN93J8. [Date Accessed].This data set contains temperature-depth profile measurements taken in 22 boreholes drilled on the West Antarctic Ice Sheet, which exhibit two distinctly different thermal states of basal ice: a warm state and a relatively colder state. The data are available via FTP in ASCII Text Format (.txt
) and Portable Document Format (.pdf
).
Detailed Data Description
This data set contains temperature-depth profile measurements taken in 22 boreholes drilled on the West Antarctic Ice Sheet, which exhibit two distinctly different thermal states of basal ice: a warm state and a relatively colder state. The warm state shows on Siple Dome and on Whillans Ice Stream. A relatively colder state, found at the Unicorn, the Kamb Ice Stream, and the Bindschadler Ice Stream has basal temperature gradients greater than 50 K km-1. A large block of cold ice stranded and frozen to the bed at the Unicorn, and simultaneously a much warmer ice existing only a few kilometers across the Dragon, and shear margin in fast moving Alley Ice Stream poses a paradox. The relatively cold ice at the Unicorn must have come from a source different from the present Whillans Ice Stream catchment area. It is hypothesized that the Unicorn paradox was created by a super-surge. Also, the stagnant Siple Ice Stream, many relict shear margins, cold patches of ice at the Crary Ice Rise, and ice rafts embedded in the Ross Ice Shelf, all point to a major event triggered either by an internal instability or by a subareal volcanic eruption. Most of these features appeared to have been formed about 500 years ago. Subsequent freeze-on of a 10-20 m thick basal layer of debris-laden ice and water loss had the effect of a slow-down of the ice streams, and in the case of the Kamb Ice Stream an almost complete stoppage.
The following tables give specific information for each borehole file such as location, ice thickness, ice surface velocity, and the date the borehole was drilled.
Note: In the following tables, the year listed in the file name doesn't always match the year listed in the column titled Date Drilled. For example, the T-AIS/WIS-1992-6.txt file name has a date drilled of 17 January, 1993. A field season always runs from November to February; thus, the drilling season for this site started in November 1992, but this specific borehole was actually drilled on 17 January, 1993. Thus, the Date Drilled doesn't always match the date in the file name.
T-AIS/WIS-1988-1.txt
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Location
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S 83° 29’ 58”, W 138° 25’ 26” |
Ice Thickness
|
1035 m |
Ice Surface Velocity
|
443 m/a |
Date Drilled
|
1 December 1988 |
T-AIS/WIS-1989-3,4.txt
|
|
---|---|
Location
|
S 83° 29’ 10”, W 138° 31’ 15” |
Ice Thickness
|
1057 m |
Ice Surface Velocity
|
443 m/a |
Date Drilled
|
18 December 1989 |
T-AIS/WIS-1991-1.txt
|
|
---|---|
Location
|
S 83° 29’ 00”, W 138° 25’ 36” |
Ice Thickness
|
1055 m |
Ice Surface Velocity
|
438 m/a |
Date Drilled
|
17 December 1991 |
T-AIS/WIS-1992-2,6.txt
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---|---|
Location
|
S 83° 29’ 05”, W 138° 27’ 29” |
Ice Thickness
|
1052 m |
Ice Surface Velocity
|
424 m/a |
Date Drilled
|
12 December 1992 |
T-AIS/WIS-1992-6.txt
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Location
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S 83° 32’ 17”, W 138° 27’ 29” |
Ice Thickness
|
1057 m |
Ice Surface Velocity
|
not measured |
Date Drilled
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17 January 1993 |
T-AIS/WIS-1995-4,7.txt
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Location
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S 83° 27’ 43”, W 138° 56’ 47” |
Ice Thickness
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1026 m |
Ice Surface Velocity
|
not measured |
Date Drilled
|
4 January 1996 |
T-BIS-1998-4.txt
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Location
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S 81° 04’ 25”, W 140° 00’ 19” |
Ice Thickness
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1086 m |
Ice Surface Velocity
|
365 m/a |
Date Drilled
|
23 January 1999 |
T-ER-1996-12.txt
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---|---|
Location
|
S 82° 40’ 36”, W 135° 49’ 31” |
Ice Thickness
|
1124 m |
Ice Surface Velocity
|
10.9 m/a |
Date Drilled
|
10 January 1997 |
T-KIS-1996-2.txt
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---|---|
Location
|
S 82° 26’ 42”, W 135° 58’ 36° |
Ice Thickness
|
1189 m |
Ice Surface Velocity
|
14 m/a |
Date Drilled
|
26 November 1996 |
T-KIS-2000-1,2.txt
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---|---|
Location
|
S 82° 22’ 00”, W 136° 24’ 00” |
Ice Thickness
|
949.4 m |
Ice Surface Velocity
|
3 m/a |
Date Drilled
|
18 December 2000 |
T-KIS-2000-6.txt
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Location
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S 82° 25’ 57”, W 136° 24’ 08” |
Ice Thickness
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1191.8 m |
Ice Surface Velocity
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12 m/a |
Date Drilled
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13 January 2001 |
T-KIS-2000-9.txt
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Location
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S 82° 23’ 59”, W 136° 24’ 16” |
Ice Thickness
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1033.5 m |
Ice Surface Velocity
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6 m/a |
Date Drilled
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14 January 2001 |
T-RR-1997-42.txt
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Location
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S 81° 35’ 47”, W 148° 41’ 38” |
Ice Thickness
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955 m |
Ice Surface Velocity
|
not measured |
Date Drilled
|
8 January 1998 |
T-SD-1997-1.txt
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Location
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S 81° 39’ 30”, W 148° 48’ 30” |
Ice Thickness
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1004.6 m |
Ice Surface Velocity
|
not measured |
Date Drilled
|
29 November 1997 |
T-UC-1993-9.txt
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Location
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S 83° 34’ 24”, W 138° 08’ 58” |
Ice Thickness
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908.4 m |
Ice Surface Velocity
|
2.8 m/a |
Date Drilled
|
22 December 1993 |
T-UC-1993-11.txt
|
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---|---|
Location
|
S 83° 34’ 56”, W 138° 08’ 45” |
Ice Thickness
|
910.6 m |
Ice Surface Velocity
|
2 m/a |
Date Drilled
|
30 December 1993 |
T-UC-1993-14.txt
|
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Location
|
S 83° 40’ 45”, W 138° 22’ 18” |
Ice Thickness
|
1091.6 m |
Ice Surface Velocity
|
1.6 m/a |
Date Drilled
|
9 January 1994 |
T-UC-1993-16.txt
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Location
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S 83° 36’ 39”, W 138° 02’ 31” |
Ice Thickness
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962.3 m |
Ice Surface Velocity
|
0.5 m/a |
Date Drilled
|
19 January 1994 |
Data are provided in ASCII Text Format (.txt
) and Portable Document Format (.pdf
).
Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0537_engelhardt_V01/ directory
. Within this directory, there are 18 text files and 2 PDFs. The text files contain two columns of data. The first column contains temperature data in degree Celsius, and the second column contains height above the bottom of the ice data in meters. Refer to Figure 2. The two PDFs contain temperature plots. Refer to Figures 3 and 4.
T-AIS/WIS-1988-1.txt
T-AIS/WIS-1989-3,4.txt
T-AIS/WIS-1991-1.txt
T-AIS/WIS-1992-2.txt
T-AIS/WIS-1992-6.txt
T-AIS/WIS-1995-4,7.txt
T-BIS-1998-4,5.txt
T-ER-1996-12.txt
T-KIS-1996-2.txt
T-KIS-2000-1,2.txt
T-KIS-2000-6.txt
T-KIS-2000-9.txt
T-RR-1997-42.txt
T-SD-1997-1.txt
T-UC-1993-9.txt
T-UC-1993-11.txt
T-UC-1993-14.txt
T-UC-1993-16.txt
T-cold.pdf
T-warm.pdf
This section explains the file naming convention used for this product with an example.
Example File Name: T-AIS/WIS-1991-1.txt
T-LL-YYYY-N.txt
Refer to Table 1 for the valid values for the file name variables listed above.
Where:
Variable
|
Description
|
---|---|
T |
Stands for Temperature |
LL |
Location of drill site. Refer to Table 2 for a listing of the drill site locations. Note: The location AIS/WIS refers to one location. AIS is a branch of the Whillans Ice Stream (WIS). |
YYYY |
Corresponds to the borehole drilling season, not necessarily the exact year it was drilled. |
N |
The number of the borehole. Note: When there are two borehole numbers listed, that means there are two boreholes next to each other at the same drill site, and the data of the two boreholes are merged. |
.
txt |
ASCII Text File |
Variable
|
Drill Site Location
|
---|---|
AIS |
Alley Ice Stream |
BIS |
Bindschadler Ice Stream |
ER |
Engelhardt Ridge |
KIS |
Kamb Ice Stream |
RR |
Raymond Ridge |
SD |
Siple Dome |
UC |
Unicorn1 |
WIS |
Whillans Ice Stream |
1The Unicorn is an island with slow moving ice between Alley Ice Stream (AIS) and Van der Veen Ice Stream (VIS), the two branches of Whillan Ice Stream (WIS). |
This data set is 58 KB in size.
Southernmost Latitude: 83° 40’ 45”
Northernmost Latitude: 81° 04’ 25”
Westernmost Longitude: 148° 48’ 30”
Easternmost Longitude: 135° 49’ 31”
Spatial Resolution
0.05°C
Data set temporal coverage is from 1988 to 2001.
Ice Temperature
West Antarctic Ice Sheet
Sample Data Record
The text files for this data set contain two columns of data. The first column contains temperature data in degree Celsius, and the second column contains data about the height above the bottom of the ice in meters. Figure 2 is a sample data record of data file T-AIS/WIS-1992-2.txt.
The PDF files for this data set contain a cold temperature plot and a warm temperature plot courtesy of Engelhardt 2004b. Refer to Figures 3 and 4.



Software and Tools
These data files can be viewed with any text editor.
Data Acquisition and Processing
The temperature measurements were taken in boreholes drilled on the West Antarctic Ice Sheet. Strings of temperature-calibrated thermistors were inserted into the water filled boreholes and left to freeze. The thermistors were encased in pressure tight tubings to prevent them from being altered by the high pressure in the refreezing process. The resistances of the thermistors were re measured over several years as the temperature equilibrated with the surrounding ice. The corresponding temperatures are known to better than 0.05° C.
References and Related Publications
Contacts and Acknowledgments
Dr. Hermann Engelhardt
University of Maryland
Center of Environmental Sciences
Appalachian Laboratory
301 Braddock Road
Frostburg, MD 21532-2307
E-mail: engel@caltech.edu
Telephone: 301 689 3405
This research was supported by NSF OPP Grant Numbers 8519083 and 9615420.
Document Information
DOCUMENT CREATION DATE
April 2013
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