Surface Elevation and Ice Thickness, Western Marie Byrd Land, Antarctica

Summary

This data set provides surface elevation and ice thickness data for a portion of the Marie Byrd Land sector of West Antarctica, including the Ford Ranges, the Sulzberger Ice Shelf, much of the Edward VII Peninsula, and the Shirase Coast region of the eastern Ross Ice Shelf. The radar data were collected by the University of Texas Istitute for Geophysics (UTIG) Support Office for Aerogeophysical Research (SOAR). The investigators used radar sounding and laser altimetry from a Twin Otter aircraft flying at varying altitudes, at least 300 m above the surface, at an air speed of about 130 knots. Surveys were accomplished with 64 flights in December 1998 and January 1999.

Data are available via FTP in ASCII text (.txt) format.

Citing These Data

Luyendyk, B. and Wilson, D. 2003. Surface Elevation and Ice Thickness, Western Marie Byrd Land, Antarctica Boulder, CO: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5BZ63ZH.

Overview Table

Category Description
Data format Data are provided in ASCII text format (.txt). Two images in .jpg format are also provided.
Spatial coverage and resolution Southernmost Latitude: -80°S
Northernmost Latitude: -71°S
Westernmos Longitude: -157°W
Easternmost Longitude: -136°W
Temporal coverage 25 through 27 December 1998.
File size Data files range from 4 MB to 7 MB. Image files are 189 KB and 196 KB.
Parameter(s) Ice sheet thickness and elevation.
Procedures for obtaining data Data are available via FTP.

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

1. Contacts and Acknowledgments

Investigator(s) Name and Title

Bruce. P. Luyendyk
Dept. of Geological Sciences
University of California Santa Barbara
Santa Barbara, CA 93106-9630

Douglas. S. Wilson
Dept. of Geological Sciences
University of California Santa Barbara
Santa Barbara, CA 93106-9630

7/26/10 Add additional contact?

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

Acknowledgements

This research was supported by NSF OPP grant 0338151. 7/22/10 add additional grant number? emailed J. Holt (UTIG)

2. Detailed Data Description

These data were acquired during an aerial survey of the western Marie Byrd Land region of Antarctica, which was flown in December 1998 by the University of Texas Istitute for Geophysics (UTIG) Support Office for Aerogeophysical Research (SOAR). The study measured surface and base ice elevations by radar and strength of magnetic and gravity fields. The coverage area measured approximately 460 by 360 km, and included the Shirase Coast of the eastern Ross Ice Shelf, much of the Edward VII Peninsula, the Sulzberger Ice Shelf, and the Ford Ranges. Track spacing was either 5.3 or 10.6 km over most of the area. The 60 Mhz radar system usually provided good images of the base of the ice for thicknesses less than 1 km but rarely imaged thicknesses greater than 1.5 km. Data formats for all observations include files for original flight profiles and grids of edited data at 1.06 km node spacing.

Format

Data are provided in ASCII text format. Two images in JPG format are also provided.

File Size

Data files range from 4 MB to 7 MB. Image files are 189 KB and 196 KB.

Spatial Coverage

Southernmost Latitude: -80°S
Northernmost Latitude: -71°S
Westernmos Longitude: -157°W
°W

Spatial Coverage Map

Map of Antarctica

Temporal Coverage

Data were collected from 25 through 27 December 1998.

Parameter or Variable

Parameter Description

Ice sheet thickness and elevation.

The following table describes the column headings for the surface elevation files "srfelev.txt" and "srfelev.xls".

Latitude Longitude Surface Elev. Flight Elev. Year Julian Day Seconds Flight Profile
Degrees north Degrees east Elevation in meters above the WGS84 ellipsoid Elevation in meters above the WGS84 ellipsoid Year Day of the year Seconds from the start of day (midnight) Flight number Profile number

The following table describes the column headings for the ice thickness files "icethick.txt" and "icethick.xls".

Latitude Longitude Ice Thick Year Julian Day Seconds Flight Profile
Degrees north Degrees east Ice thickness in meters Year Day of the year Seconds from the start of day (midnight) Flight number Profile number

Sample Data Record

The following sample is taken from the surface elevation data, "srfelev.txt".

-79.782348 -142.66064 266.6 1140.5 1998 358 9661.59 RTZ8/32 Wy-Y11a
-79.782288 -142.66121 267.2 1140.5 1998 358 9661.78 RTZ8/32 Wy-Y11a
-79.782229 -142.66179 267.6 1140.5 1998 358 9661.97 RTZ8/32 Wy-Y11a
-79.782154 -142.66252 267.9 1140.5 1998 358 9662.22 RTZ8/32 Wy-Y11a

The following is a small version of the suface elevation map "WMB_srf_elev.jpg."

The next sample is taken from the ice thickness data, "icethick.txt".

-79.782348 -142.66064 1073.3 1998 358 9661.59 RTZ8/32 Wy-Y11a
-79.782288 -142.66121 1071.6 1998 358 9661.78 RTZ8/32 Wy-Y11a
-79.782229 -142.66179 1058.5 1998 358 9661.97 RTZ8/32 Wy-Y11a
-79.782154 -142.66252 1040.7 1998 358 9662.22 RTZ8/32 Wy-Y11a

The following is a small version of the ice thickness map "WMB_bed_elev.jpg."

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

Total volume is 22.5 MB.

Related Data Collections

4. Data Acquisition and Processing

Theory of Measurements

Sensor or Instrument Description

Radar sounding and laser altimetry instruments.

Data Source

Data was acquired by sensors mounted on a Twin Otter aircraft.

Processing Steps

Determining gravity anomalies required corrections for aircraft acceleration aircraft, measured by differential carrier-phase GPS navigation, filtering to remove wavelengths less than 10 km (which are commonly contaminated by aircraft motion), and editing of occasional spikes. The gravity anomalies allow estimation of bed topography under floating ice and under ice too thick for radar imaging. Magnetic anomaly reduction includes a correction for daily variation as measured at the base camp.

5. References and Related Publications

Luyendyk, B.P., D.S. Wilson, and C.S. Siddoway. 2003. Eastern margin of the Ross Sea Rift in western Marie Byrd Land, Antarctica: Crustal structure and tectonic development. Geochem. Geophys. Geosyst. 4(10), 1090, doi:10.1029/2002GC000462.

6. Document Information

Acronyms and Abbreviations

The following acronyms and abbreviations are used in this document.

AGDC Antarctic Glaciological Data Center
FTP File Transfer Protocol
NSF National Science Foundation
SOAR Support Office for Aerogeophysical Research
UTIG University of Texas Institute for Geophysics

Document Creation Date

December 2003

Document URL

http://nsidc.org/data/docs/agdc/nsidc0119_luyendyk/index.html