This data set is an Antarctic radar-based subglacial lake classification collection, which focuses on the radar reflection properties of each given lake.
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Antarctic Subglacial Lake Classification Inventory, Version 1
|Spatial Resolution:||Not Specified|
|Temporal Resolution:||Not specified|
|Platform(s)||FIELD INVESTIGATION, FIELD SURVEYS|
|Sensor(s):||IMAGING RADAR SYSTEMS, RADAR|
|Data Contributor(s):||Donald Blankenship, John Holt, Sasha Carter|
|Metadata XML:||View Metadata Record|
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.Blankenship, D. D., S. P. Carter, J. W. Holt, D. L. Morse, M. E. Peters, and D. A. Young. 2009. Antarctic Subglacial Lake Classification Inventory, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5CN71VX. [Date Accessed].
Detailed Data Description
This data set is an Antarctic radar-based subglacial lake classification collection, which focuses on the radar reflection properties of each given lake. The Subglacial lakes are separated into four categories specified by radar reflection properties. Additional information includes: latitude, longitude, length (in kilometers), hydro-potential (in meters), bed elevation (in meters above WGS84), and ice thickness (in meters).
The data set is in Microsoft Excel (
.xls) format viewable with spreadsheet software. A coverage map is available in TIF format.
Data are available on the FTP site in the
ftp://sidads.colorado.edu/pub/DATASETS/AGDC/blankenship_nsidc_0336/ directory. The directory contains four files: an Excel spreadsheet,
lake_detect.xls, a Tagged Image File Format (TIF) image, a readme file, and a supplementary Portable Document Format (PDF) file.
Within the lake_detect.xls file, there are 12 sheets defined by lake type and location. For more information on the lake defining algorithms, please see the article Radar-Based Subglacial Lake Classification in Antarctica on the Geochemistry, Geophysics, Geosystems Web site. A PDF of the article is also available via FTP.
The 12 sheets within the Excel file are named according to their lake type and region. The following table describes the naming system for sheets within the lake_detect.xlsfile
Example laketype.xls sheet names:
|definite||brighter than surroundings by at least 2 dB, specular across at least 5% of its extent, maintains a reflection coefficient of -10 dB or greater across at least 5% of its extent|
|dim||specular and brighter than surroundings, but lack the absolute reflectivity of definite lakes; estimated reflection coefficient falls well below -10 dB|
|fuzzy||high absolute and relative reflection coefficients, but not specular|
|indistinct||specular, but not brighter than surroundings.|
|WLK||Wilkes Basin-Dome C|
|LVS||Lake Vostok Region|
|PPT||Mercer Ice Stream-South Pole|
Excel File, 68 KB; TIF image file 7.1 MB
Parameters include location of lakes as geographic coordinates, lake length, hydro-potential, bed elevation in meters above WGS84, and ice thickness. The Wilkes Basin-Dome C (WLK) spreadsheet also includes the lake number from the Siegert, et al inventory in 2005.
The following table describes the columns in the data files:
|Latitude/Longitude||Lake location in geographic coordinates|
|Length||Lake length in kilometers|
|Hydro-potential||Hydraulic potential, also called hydraulic head, is the sum of the elevation of the water body and the fluid pressure. In this case hydraulic head is equal to the elevation plus ice thickness multiplied by density contrast of ice relative to water or 0.917h_ice + z_bed.|
|Bed Elevation||Bed elevation, measured as meters above World Geodetic System 84 (WGS84), a standard coordinate frame for the Earth|
|Ice Thickness||Ice thickness above the lake feature, measured in meters, ±standard error|
|Number||If applicable, inventory number from Siegert et al., 2005|
|Notes||Investigator's notes, generally related to lake location|
The following example shows sample data from the
definite_WLK spreadsheet in the
(m above WGS84)
Ice Thickness (m)
Number (from Siegert et al 2005 Inventory)
|Concordia got broken up into two overlapping lakes|
Software and Tools
Data are accessible using standard spreadsheet software.
The data set is approximately 60KB. Supplementary files are approximately 11MB.
Data Acquisition and Processing
The Antarctic Subglacial Lake Classification Inventory lists the locations and categories of lakes in East Antarctica. For more information on data processing, please see the article Radar-Based Subglacial Lake Classification in Antarctica on the Geochemistry, Geophysics, Geosystems Web site. A PDF of the article is also available via FTP.
This data set was developed using laser and radar altimetry measurements, as well as measurements of gravitational and magnetic fields.
A lake detection algorithm was used to identify and categorize four major "lake" types using digital ice-penetrating radar data. For details on the algorithm, please see the article Radar-Based Subglacial Lake Classification in Antarctica on the Geochemistry, Geophysics, Geosystems Web site.
References and Related Publications
Contacts and Acknowledgments
Donald D. Blankenship
University of Texas Institute for Geophysics
John A. and Katherine G. Jackson School of Geosciences,
The University of Texas at Austin
Sasha P. Carter
Scripps Institution of Oceanography, UCSD
9500 Gilman Drive
La Jolla CA, 92093
Mail Code: 0225
John W. Holt
University of Texas Institute for Geophysics
John A. and Katherine G. Jackson School of Geosciences
University of Texas at Austin
This research was funded by the National Science Foundation under Cooperative Agreement OPP 91-19379 and OPP 93-19379, as well as NSF grant OPP 99-11617.
Document Creation Date
6 February 2009