US International Trans Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping

Documentation  |  Derived Images

Data Set Summary

Snow accumulation rates typically show high variability over short distances. This data set contains accumulation rates using ground-penetrating radar (GPR) to detect isochronal layers in the firn in West Antarctica. These layers were then dated using results from ice core analyses. These data show that accumulation rates along this profile have decreased in recent decades. The radar profile extends between two ice core sites taken along one of the US ITASE traverse routes.

Data are available via FTP in both ASCII and Excel formats.

Citing These Data

Spikes, V.B., G.S. Hamilton, S.A. Arcone, S. Kaspari, and P.A. Mayewski. 2005. US International Trans Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping. Boulder, CO, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5GH9FV6.

Overview Table

Category	Description
Parameter(s)	Snow accumulation rates
Spatial coverage	US ITASE traverse routes, West Antarctica
Temporal coverage	Data were collected in December 2000.
Data format	Tab-delimited ASCII file and Excel file
File size	ITASE_accumulation_004_005.txt: 1.1 MB ITASE_accumulation_004_005.xls: 2.0 MB
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

Vandy B. Spikes, Gordon S. Hamilton, Paul A. Mayewski, and Susan Kaspari
Climate Change Institute
Department of Earth Sciences
University of Maine
Orono, ME, USA

Steven A. Arcone
U.S. Army ERDC, Cold Regions Research and Engineering Laboratory
Hanover, NH, USA

Technical Contact

Acknowledgements

This research was supported by:

• Distribution of Snow Accumulation and Mass Balance across the West Antarctic Ice Sheet. Principle Investigator: Vandy Blue Spikes, University of Maine. NASA Fellowship Award Number ESS/01-0000-0097.

• High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet. Principle Investigator: Steven A. Arcone, U.S. Army Cold Regions Research and Engineering Laboratory. National Science Foundation OPP award #0088035

• Mass Balance and Accumulation Rate Along US ITASE Routes. Principle Investigator: Gordon S. Hamilton, University of Maine. National Science Foundation OPP award #0196441

• US ITASE Glaciochemistry. Principle Investigator: Paul A. Mayewski, University of Maine. National Science Foundation OPP award #0096299

• US ITASE SMO: A Collaborative Program of Research from South Pole to Northern Victoria Land. Pinciple Investigator: Paul A. Mayewski, University of Maine. National Science Foundation OPP award #0229573

2. Detailed Data Description

Format

Data are available as a tab-delimited ASCII file and an Excel spreadsheet.

File Size

ITASE_accumulation_004_005.txt: 1.1MB
ITASE_accumulation_004_005.xls: 2.0MB

Study Area Location Map:

The below map shows the location of the study area. The dashed lines are ITASE traverse routes. The solid line represents the section of the traverse between ice core sites 00-4 and 00-5, the GPR transect. The figure and caption are taken from Spikes et al. (2004).

Location maps and ice core data. a) Continent-scale map of Antarctica. b) Portion of West Antarctica (boxed region in a) showing some of the US ITASE traverse routes (white lines). Red circles indicate where ice cores were collected. The solid white line represents the transect along which the radar profile was collected between 00-4 and 00-5. The white arrow indicates the direction of travel during data acquisition. The shaded relief map was generated from a digital elevation model (Liu et al. 1999), which was also used to estimate ice flow directions at 00-4 and 00-5 (black arrows). c) Ice core density and chemistry (nssSO42-) profiles for 00-4 (blue) and 00-5 (red).

See Absolute Earth™ - Antarctic Snow Accumulation to download an interactive map of Antarctica that shows ice core locations. Absolute Earth™ is a proprietary line of Global Information Systems used to gather, process, store, manipulate, interpret, visualize, and disseminate any georeferenced data. Absolute Earth products are intended to make geographically-based information available to all people, regardless of background or skill level. These extremely flexible products merge advanced web applications with desktop software, network databases, and Earth visualization technologies.

Spatial Coverage

The distance along the transect is 100 km.

Core Site 00-4 Location:	78.0832°S	120.082°W
Core Site 00-5 Location:	77.6832°S	123.993°W

Temporal Coverage

Data were collected in December 2000.

Sample Data Record - GPS Coordinates and GPR-derived Accumulation Rates

Traces were measured from core 00-4 to 00-5. Time is given in seconds for the day tied to GMT. Distance is in km along the track. Accumulation rates are presented as water equivalent (m/year). The years represent either a horizon age (for example, 1966, which is the amount of accumulation that occurred between 1966 and 2000) or the amount of accumulation between two horizons (for example, 1941-1966).

Trace#	Time(sec)	Longitude	Latitude	X(km)	Y(km)	Elevation(m)	Distance(km)	1966(m/a)	1941(m/a)	1893(m/a)	1848(m/a)	1815(m/a)	1941-1966	1893-1941	1848-1893	1815-1848
1	85265.7	-120.0821281	-78.08317476	-1124.287	-651.258	1697.19	0.04	0.18671053	0.19447709	0.19273349	0.19189462	0.19329594	0.20535027	0.19055399	0.18988135	0.19979295
2	85270.3	-120.0822793	-78.08315856	-1124.287	-651.262	1697.19	0.05	0.1867103	0.19447698	0.19273351	0.19189469	0.19329601	0.20535033	0.19055417	0.18988153	0.19979305
3	85275	-120.0824306	-78.08314236	-1124.286	-651.265	1697.19	0.05	0.18671364	0.19447698	0.19273351	0.19189469	0.19329601	0.20534566	0.19055417	0.18988153	0.19979305
4	85279.7	-120.0825818	-78.08312616	-1124.286	-651.269	1697.18	0.06	0.18675183	0.19447688	0.19273353	0.19189476	0.19329609	0.20529195	0.19055434	0.1898817	0.19979316

3. Data Access and Tools

Data Access

Data are available via FTP.

4. Data Acquisition and Processing

Data were acquired using ground-penetrating radar (GPR). The isochronal layers in the firn were dated using results from ice core analyses.

5. References and Related Publications

Liu, Hongxing, Kenneth C. Jezek, Biyan Li. 1999. Development of Antarctic digital elevation model by integrating cartographic and remotely sensed data: A geographic information system based approach. Journal of Geophysical Research 104 (B10): 23199-23214.

Spikes, V.B., G.S. Hamilton, S.A. Arcone, S. Kaspari, and P.A. Mayewski. 2004. Variability in accumulation rates from GPR profiling on the West Antarctic Plateau. Annals of Glaciology 39.

6. Document Information

Document Creation Date

March 2005

Document URL

http://nsidc.org/data/docs/agdc/nsidc0269_spikes/index.html