Radar Studies of Internal Stratigraphy and Bed Topography along the US ITASE-II Traverse, Antarctica

Summary

This data set contains ice penetrating radar data from the US-International Trans-Antarctic Science Expedition (ITASE) Traverse, from Taylor Dome to South Pole recorded by the St. Olaf College deep radar system. Parameters include latitude, longitude, distance along profile (m), ice thickness pick (m), surface elevation (m), and bed echo power (relative units) from the approximately 1800 km traverse recorded during the 2006-2007 and 2007-2008 Antarctic field seasons (austral summer). The traverse has been broken into three segments, which are shown on three maps provided with the data. A sample radar profile covering approximately 120 km of the traverse near Titan Dome is also provided.

Data are available via FTP as ASCII text files (.txt). Profile location maps and sample profile sections are available as Joint Photographic Experts Group (.jpg) image files.

Citing These Data

The following example shows how to cite the use of this data set in a publication. For more information, see our Use and Copyright Web page.

The following example shows how to cite the use of this data set in a publication. List the principal investigators, year of data set release, data set title, publisher: NSIDC, and digital media.

Jacobel, R. 2010. Radar Studies of Internal Stratigraphy and Bed Topography along the US ITASE-II Traverse, Antarctica. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5G73BMS.

Overview Table

Category	Description
Data format	ACSII text files (.txt), Joint Photographic Experts Group (.jpg) image files, binary data (available via DVD, on request)
Spatial coverage and resolution	Southernmost Latitude: 90°S Northernmost Latitude: 78°S Westernmost Longitude: 130°E Easternmost Longitude: 160°E
Temporal coverage and resolution	Two Antarctic field seasons in austral summers of 2006-2007 and 2007-2008
File naming convention	STOC_US_ITASE_Deep_Radar_Site_064_072.txt
File size	Files in this data set range in size from 700 KB to 17 MB
Parameter(s)	Latitude Longitude Distance along Profile (km) Depth (m) Thickness (m) Bed Echo Power (relative units) Surface Elevation (m)
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)

Dr. Robert Jacobel
Department of Physics
St. Olaf College
1520 St. Olaf Ave.
Northfield, MN 55057

Technical Contact

Acknowledgements

This research was supported by National Science Foundation (NSF) Office of Polar Programs (OPP) grant 0337567.

2. Detailed Data Description

Format

Data are available as ASCII text files (.txt). Example profiles and location maps are available as image files in Joint Photographic Experts Group (.jpg).

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/jacobel_nsidc_0475/ directory.

File Naming Convention

Files are named according to the following convention:

STOC_US_ITASE_Deep_Radar_Site_XXX_XXX.txt

• Where: XXX corresponds to the profile segments in the location maps. The specific location (latitude and longitude) of each profile section is described in its corresponding data file.
  

Example: The file, STOC_US_ITASE_Deep_Radar_Site_064_072.txt contains data from the profile segment 064 to 072.

Files contain ice penetrating radar data from the US-ITASE Traverse fromTaylor Dome to South Pole, recorded by the St. Olaf College deep radar system. 

File Size

Files in this data set range in size from 700 KB to 17 MB.

Spatial Coverage

Data were collected along the US-ITASE II route in Antarctica.

Southernmost Latitude: 90°S
Northernmost Latitude: 78°S
Westernmost Longitude: 130°E
Easternmost Longitude: 160°E

Spatial Coverage Maps

These maps show traverse locations for the US-ITASE traverse route conducted in 2006-2007 and 2007-2008. The ice core locations indicate the two-digit year of the start of that traverse, and the site number.

 

Temporal Coverage

Data in this collection were obtained during the 2006-2007 and 2007-2008 Antarctic field seasons.

Parameter or Variable

 

Table 1. Parameters in the Profile Data Files

Parameter	Description
Latitude/Longitude	Location of radar measurement
Distance	Distance along profile (km)
Bed Depth	Ice sheet depth, or thickness (m)
Bed Echo Power	Power contained in bed echo wavelet (relative units). For more information see Jacobel, et al., 2010.
Elevation	Surface elevation (m)

 

Sample Data Record

The following example shows sample data from the STOC_US_ITASE_DEEP_RADAR_Site_064-071.txt file.

Latitude	Longitude	Distance	Bed Depth	Layer Depth	Elevation
8.0266686e+001	1.4441099e+002	4.7565250e+002	2.3144550e+003	2.2020676e+003	8.0764291e+004

Sample Data Image

Figure 4. Sample radar profile covering approximately 120 km of the traverse near Titan Dome

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The total volume of the data set is approximately 46 MB.

Software and Tools

Data are accessible using standard spreadsheet software.

Related Data Collections

• Antarctic Glaciological Data Center (AGDC)
  
• Ice Thickness and Internal Layer Depth Along the 2001 and 2002 US ITASE Traverses

4. Data Acquisition and Processing

Theory of Measurements

Researchers conducted ground-based ice-penetrating radar surveys along the US-ITASE traverse from Taylor Dome to South Pole to depict bedrock topography, internal stratigraphy and to derive information about basal conditions (wet vs. dry) based on differences in the radar reflectivity. This research was part of the larger ITASE multidisciplinary study, of which the primary aim is the collection and interpretation of a continental-wide array of environmental parameters assembled through the coordinated efforts of scientists from several nations. The primary planned product of this cooperative endeavor is the description and understanding of environmental change in Antarctica over approximately the last 200 years.

Sensor or Instrument Description

Researchers used a 3 MHz radio echo-sounding system to transmit and receive radio waves through as much as three kilometers of ice. For more information, visit the St. Olaf College Radar Program Web site.

Data Acquisition Methods

The system and operator were towed by a snow machine, housed in a small shelter built on a wooden Komatik sled. Power for the receiver, and for battery chargers, was provided either by a solar-powered battery system, or a small gas-powered generator mounted on the back of the sled. The transmitter batteries were recharged by the solar panels or generator. The shelter was also equipped with a GPS receiver to locate the data points.

The transmitter was towed 100 m or more behind the receiver sled. The transmitter and its battery sat in a small sled, protected from the elements by the sled's nylon cover. The antennas for the transmitter and receiver were housed in strong rubber hoses and tied to the tow ropes to keep the antennas as straight and parallel as possible.

5. References and Related Publications

Jacobel, R. W., K. E. Lapo, J. R. Stamp, B. W. Youngblood, B. C. Welch and J. L. Bamber. 2010. A Comparison of Basal Reflectivity and Ice Velocity in East Antarctica. The Cryosphere, 4, 447–452, doi:10.5194/tc-4-447-2010.

Arcone, S. A., R. W. Jacobel and G. S. Hamilton. 2010. Unconformable Stratigraphy in East Antarctica, Part I: Influence of Bed Topography, Ice Flow and Metamorphism on Antidunal Accumulation in Firn. Journal of Glaciology. Submitted.

Arcone, S. A., R. W. Jacobel and G. S. Hamilton. 2010. Unconformable Stratigraphy in East Antarctica, Part II: Low Frequency GPR Profiles of Englacial Bedding Sequences and Metamorphic Layers. Journal of Glaciology. Submitted.

Arcone, S. A. and R. W. Jacobel. 2008. Megapackets and Megapseudosynclines Profiled With GPR East of the Megadunes Region, East Antarctica. EOS Transactions, American Geophysical Union, 89(53), C31B-048.

Lapo, K. E., J. R. Stamp, B. W. Youngblood, B. C. Welch and R. W. Jacobel. 2010.Using Radar-Derived Measurements of Basal Reflectivity to Locate Antarctic Subglacial Lakes. EOS Transactions, American Geophysical Union, 91(52), Abstract C21A-0505.

Jacobel, R. W., S. A. Arcone, B. C. Welch, B. W. Youngblood, J. L. Olson, J. R. Stamp, and J. M. Werner. 2009. Ice Attenuation and Basal Conditions from Radar Observations Along the US-ITASE Traverse in East Antarctica. Geophysical Research Abstracts, 11, 02577.

Jacobel, R. W., S. A. Arcone, B. C. Welch, B. W. Youngblood, J. L. Olson, J. R. Stamp and J. M. Werner. 2008. Accumulation Patterns and Basal Conditions from Radar Observations Along the US- ITASE Traverse in East Antarctica. EOS Transactions, American Geophysical Union, 89(53), C31B-0486.

Welch, B. C., R. W. Jacobel, and S. A. Arcone. 2009. First Results from Radar Profiles Collected Along the US-ITASE Traverse from Taylor Dome to South Pole (2006-2008 ). Annals of Glaciology, 50(51), 10.

The following related documents are available

Table 2. Related Documents

Document	Description	URL
Antarctic Glaciological Data Center (AGDC)	Product Web site	http://nsidc.org/agdc/
St. Olaf College Center for Geophysical Studies of Ice and Climate	Investigator program Web site	http://www.stolaf.edu/other/cegsic/

6. Document Information

Acronyms

The following acronyms are used in this document.

Table 3. Acronyms and Abbreviations

Acronym	Description
FTP	File Transfer Protocol
US-ITASE	United States - International Trans-Antarctic Science Expedition
NSIDC	National Snow and Ice Data Center
URL	Uniform Resource Locator

Document Creation Date

15 October 2010

Document URL

http://nsidc.org/data/docs/agdc/nsidc0475_jacobel/index.html