This data set includes basal shear distributions inferred from surface observations - surface ice velocities (Joughin et al., 2010, Rignot et al., 2011), bed and surface elevations (Fretwell et al., 2013) under ten selected locations in Greenland and Antarctica. In Greenland, the locations were: 79° North and Zachariae Glaciers, Jakobshan Isbrae, North East Greenland Ice Stream, Petermann Glacier. The Antarctica locations were Bindschadler Ice Stream, Lambert Ice Stream, MacAyeal Ice Stream, Pine Island Glacier, Thwaites Glacier, and an unnamed location around ~40° E 84° S.
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Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers, 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): | VISUAL OBSERVATIONS |
Data Format(s): |
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Version: | V1 |
Data Contributor(s): | Olga Sergienko |
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.
Sergienko, O. 2015. Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5XS5SBW. [Date Accessed].Literature Citation
As a condition of using these data, we request that you acknowledge the author(s) of this data set by referencing the following peer-reviewed publication.
Sergienko, O. and R. C. Hindmarsh. 2013. Regular Patterns in Frictional Resistance of Ice-Stream Beds Seen by Surface Data Inversion, Science. 342. 11086-1089. http://dx.doi.org/10.1126/science.1243903.
Sergienko, O., T. T. Creyts, and R. C. Hindmarsh. 2014. Similarity of organized patterns in driving and basal stresses of Antarctic and Greenland ice sheets beneath extensive areas of basal sliding, Geophysical Research Letters. 41. 3925–3932. http://dx.doi.org/10.1002/2014GL059976
Detailed Data Description
This data set includes basal shear distributions inferred from surface observations - surface ice velocities (Jougin et al, 2010, Rignot et al, 2011), bed and surface elevations (Fretwell et al, 2013) under ten selected locations in Greenland and Antarctica. In Greenland, the locations were: 79° North and Zachariae Glaciers, Jakobshan Isbrae, North East Greenland Ice Stream, Petermann Glacier. The Antarctica locations were Bindschadler Ice Stream, Lambert Ice Stream, MacAyeal Ice Stream, Pine Island Glacier, Thwaites Glacier, and an unnamed location around ~40° E 84° S. Figure 1 shows the driving stress (kPa) of Antarctica and Greenland. Rectangles outline areas where inversion for basal traction were preformed. See Table 1 for the specific ice stream or glacier outlined. (Sergienko 2014)

Rectangle | Ice Stream/Glacier Name |
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Antarctica | |
B | Bindschadler Ice Stream |
M | MacAyeal Ice Stream |
E | Unnamed location at 40° E, 84° S |
L | Lambert Ice Stream |
Greenland | |
P | Petermann Glacier |
J | Jakobshavn Isbræ |
NZ | 79° North and Zachariæ glaciers |
N | North-East Greenland Ice Stream (NEGIS) |
The detailed description of the inversion procedure and discussion of the results are provided in Sergienko and Hindmarsh (2013) for Pine Island and Thwaites Glaciers (Antarctica) and Sergienko, Creyts and Hindmarsh (2014) for all other locations. The inversion procedure utilized a full-Stokes, three-dimensional finite-element model of variable horizontal resolutions (1/6 to 1/3 of the local ice thickness) using irregular domains (Sergienko and Hindmarsh 2013, Sergienko et al. 2014). Tikhonov regularizations have been utilized in all inversions.
Data are in MATrix LABoratory (MATLAB) (.mat) and Network Common Data Form (netCDF) (.nc) formats.
Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0626_sergienko/
directory. Within this directory, there is one .zip file, NSF0934534.zip
. Within the .zip file, there are two folders, Antarctica
and Greenland
. The Antarctica folder contains 12 files and the Greenland folder contains 8 files.
There are two files for each location: .mat and .nc. See Figure 2 for a listing of the files.

Data are in rectangular arrays. Table 2 describes the arrays.
Variable | Description |
---|---|
X | Easting coordinate (m) |
Y | Northing coordinate (m) |
Taub | Basal shear stress (kPa) |
File size ranges from 111 KB to 4,827 KB.
The data set is ~20 MB.
The data represents multiple glaciers and ice streams at the following locations:
Greenland: 84° N 20° W to 60° N 75° W
Antarctica: 75° S 60° E to 90° S 150° W
Spatial Resolution
Spatial resolution is 500 m.
Projection and Grid Description
Data sets are on polar stereogarphic projections described by Fretwell et al. (2013) for Antarctic locations and Bamber et al. (2013) for Greenland locations.
Data were collected from 01 June 2009 to 31 July 2013.
Basal Shear Stress
Sample Data Record
Refer to Figures 3 and 4 for examples of the data.


Software and Tools
In order to view the netCDF files, you can download a free tool from NASA: Panoply netCDF, HDF, and GRIB Data Viewer.
The MATLAB files can be accessed using MATLAB.
Data Acquisition and Processing
Basal shear distributions under ten selected locations in Greenland (79° North and Zacharia Glaciers, Jakobshan Isbrae, North East Greenland Ice Stream, Petermann Glacier) and Antarctica (Bindschadler Ice Stream, Lambert Ice Stream, MacAyeal Ice Stream, Pine Island Glacier, Thwaites Glacier, Unnamed location around ~40° E 84° S) were inferred from surface observations - surface ice velocities (Jougin et al. 2010, Rignot et al. 2011), and bed and surface elevations (Fretwell et al. 2013, Bamber et al. 2013).
Processing Steps
The inversion procedure utilized a full-Stokes, three-dimensional finite-element model of variable horizontal resolutions (1/6 to 1/3 of the local ice thickness) using irregular domains (Sergienko and Hindmarsh (2013), Sergienko, Creyts, and Hindmarsh (2014)). Tikhonov regularizations have been utilized in all inversions. The detailed description of the inversion procedure and discussion of the results are provided in Sergienko and Hindmarsh (2013) for Pine Island and Thwaites Glaciers (Antarctica) and Sergienko, Creyts. (2014) for all other locations.
For this data set, inversion outputs were bi-linearly interpolated (with interp2 Matlab command) on a rectangular, 500 m resolution grid. Values outside the study domains are NaN in the Matlab format files (.mat) and -9999 in the Network Common Data Form (.nc) files.
References and Related Publications
Contacts and Acknowledgments
Olga Sergienko
Princeton University
Atmospheric and Oceanic Science
GFDL, 201 Forrestal Rd, Office 347
Princeton, NJ 08544 USA
This research was funded by National Science Foundation (NSF) grant number 034534.
Document Information
Document Creation Date
15 June 2015
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