Continuous GPS (static) Data from the Ross Ice Shelf, Antarctica

Summary

In October 2005, three geodetic GPS receivers were deployed on the Ross Ice Shelf near the ice front to observe short-term fluctuations in ice-shelf velocity associated with tidal forcing and other phenomena. Two stations were placed on either side of a large rift that is expected to eventually create the next iceberg to calve from the Ross Ice Shelf (called "Nascent Iceberg"). One station was established at a location near station R13, occupied in 1979 during the RIGGS project (Thomas et al., 1984), to determine if the near-ice-front part of the Ross Ice Shelf has significantly changed its long-term flow since the late 1970s. Data are available in comma-delimited ASCII format and Matlab native mat files. Data are available via FTP.

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.

MacAyeal, Douglas, Brunt Kelly and Matthew King. 2008. Continuous GPS (static) data from the Ross Ice Shelf, Antarctica. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N57W694M.

Overview Table

Category	Description
Data format	comma-delimited ASCII format, Matlab native mat files
Spatial coverage and resolution	Southernmost Latitude:78 South Northernmost Latitude: 78 South Westernmost Longitude: 178 West Easternmost Longitude: 178 West
Temporal coverage and resolution	5-second sample rate, standard geodetic GPS resolution 29 October to 21 November 2005
File naming convention	NASC.enu - Nascent Iceberg easting, northing and up NASS.enu - Nascent Iceberg Station "south" easting, northing and up R13A.enu - Station R13 easting, northing and up NASC.llh - Nascent Iceberg latitude, longitude and height above reference ellipsoid NASS.llh - Nascent Iceberg Station "south" latitude, longitude and height above reference ellipsoid R13A.llh - Station R13 latitude, longitude and height above reference ellipsoid
File size	Approximately 80 Megabytes (MB)
Parameter(s)	geodetic time, latitude, longitude, elevation, easting, northing, estimate of 1-sigma error on each geodetic parameter
Procedures for obtaining data	Available via FTP

Contacts and Acknowledgments
Detailed Data Description
Data Access and Tools
Data Acquisition and Processing
References and Related Publications
Document Information

1. Contacts and Acknowledgments

Investigator(s)

Douglas MacAyeal
Department of Geophysical Sciences
University of Chicago
5734 S. Ellis Ave.
HGS 413
Chicago, Illinois 60637 USA

Kelly Brunt
Scripps Institution of Oceanography
University of California San Diego
La Jolla, California 92093 USA

Matthew King
Department of Civil Engineering and Earth Sciences
University of Newcastle
Newcastle upon Tyne
NE1 7RU UK

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 National Science Foundation (NSF) Office of Polar Programs (OPP) grant 0229546 awarded to D. MacAyeal.

2. Detailed Data Description

Format

Comma Delimited ASCII and Matlab native MAT file

File Naming Convention

Files are named according to the following convention

NASC.enu
NASS.enu
R13A.enu
NASC.llh
NASS.llh
R13A.llh

where:

File Naming Convention
Variable	Description
NASC	Nascent Iceberg
NASS	Nascent Iceberg Station "south"
R13A	station R13
enu	easting, northing and up
llh	latitude, longitude and height above reference ellipsoid

File Size

Approximately 80 Megabytes

Spatial Coverage

Southernmost Latitude: 78 South
Northernmost Latitude: 78 South
Westernmost Longitude: 178 West
Easternmost Longitude: 178 West

Spatial Resolution

10 centimeter vertical, 5 centimeter horizontal

Temporal Coverage

29 October 2005 to 21 November 2005

Temporal Resolution

15-sec sample rate, standard geodetic GPS resolution

Parameter or Variable

Parameters include: geodetic time, latitude, longitude, elevation, easting, northing, estimate of 1-sigma error on each geodetic parameter

Sample Data Record

Coordinate Time Series are provided in two formats:

Format: NASC.enu

YYYY	DDDD	E (m)	N (m)	U (m)	sigmaE	sigmaN	sigmaU
2005	308.021181	0.0000000	0.0000000	0.0000000	0.0151979	0.0122770	0.0211774
2005	308.021354	-0.0005261	0.0009654	0.0002030	0.0150979	0.0121783	0.0210778
2005	308.021528	-0.0015257	0.0013512	-0.0017596	0.0150978	0.0119737	0.0207815
2005	308.021701	-0.0035775	0.0036679	-0.0033163	0.0150978	0.0119588	0.0205870
2005	308.021875	-0.0036775	0.0038711	-0.0042955	0.0150978	0.0119514	0.0204898
2005	308.022049	-0.0058030	0.0056184	-0.0080156	0.0150978	0.0119441	0.0203926
2005	308.022222	-0.0071025	0.0062022	-0.0109584	0.0150978	0.0119295	0.0201982
2005	308.022396	-0.0087020	0.0061611	-0.0109670	0.0149978	0.0119221	0.0201010
2005	308.022569	-0.0053769	0.0058848	-0.0140907	0.0150978	0.0119150	0.0200038
2005	308.022743	-0.0026041	0.0075522	-0.0168058	0.0150978	0.0119150	0.0200038

Format: .NASC.llh

YYYY	DDD	lat (dec deg)	lon (dec deg)	ell. hgt (m)	lon (W dec deg)	sigmaN(m)	sigmaE(m)	sigma h (m)
2005	308.021181	-78.127361074	181.503503932	-11.1666	-178.496496068	0.0122770	0.0151979	0.0211774
2005	308.021354	-78.127361065	181.503503908	-11.1664	-178.496496092	0.0121783	0.0150979	0.0210778
2005	308.021528	-78.127361062	181.503503867	-11.1684	-178.496496133	0.0119737	0.0150978	0.0207815
2005	308.021701	-78.127361041	181.503503774	-11.1699	-178.496496226	0.0119588	0.0150978	0.0205870
2005	308.021875	-78.127361039	181.503503773	-11.1709	-178.496496227	0.0119514	0.0150978	0.0204898
2005	308.022049	-78.127361024	181.503503681	-11.1746	-178.496496319	0.0119441	0.0150978	0.0203926
2005	308.022222	-78.127361018	181.503503621	-11.1776	-178.496496379	0.0119295	0.0150978	0.0201982
2005	308.022396	-78.127361019	181.503503555	-11.1776	-178.496496445	0.0119221	0.0149978	0.0201010
2005	308.022569	-78.127361021	181.503503699	-11.1807	-178.496496301	0.0119150	0.0150978	0.0200038
2005	308.022743	-78.127361006	181.503503817	-11.1834	-178.496496183	0.0119150	0.0150978	0.0200038

Error Sources

Day 308 is offset to the east due to an antenna move

Days 322 and 323 are suspect - their time series is anomolous and the Tropospheric estimates for those days are also offset

3. Data Access and Tools

Data Access

Available via FTP

Volume

Approximately 80 Megabytes (MB)

Related Data Collections

4. Data Acquisition and Processing

Sensor or Instrument Description

Trimble R7 model GPS receivers with standard (discus style) antennas

Data Acquisition Methods

Trimble R7 model GPS receivers with standard (discus style) antennas were deployed on standard survey tripods buried in the snow (receiver was buried beneath the tripod) during November 2005. A solar panel was mounted on a post nearby and was used to charge a single 12-v battery through a charge controller. Power was applied continuously. Data were given to Dr. Matt King of the University of Newcastle to process (see data header).

5. References and Related Publications

Brunt, K. M., 2008. Tidal Motion of the Ross Ice Shelf and its Interaction with the Siple Coast Ice Streams, Antarctica. (PhD dissertation, University of Chicago, Chicago, IL, USA, 202 pages).

Table X. Related Documents Document Description URL

6. Document Information

Acronyms

The following acronyms are used in this document.

Acronyms and Abbreviations
Acronym	Description
FTP	File Transfer Protocol
NSIDC	National Snow and Ice Data Center
mat	Matlab native format
MB	megabytes
GPS	Global Positioning System
sigmaE	assigned error estimates of easting
sigmaN	assigned error estimates of northing
sigmaU	assigned error estimates of up
sigma h	assigned error estimates of height
enu	easting, northing and up
llh	latitude, longitude and height above reference ellipsoid
URL	Uniform Resource Locator

Document Creation Date

October 2008

Document URL

http://nsidc.org/data/docs/agdc/nsidc0347_macayeal/index.html

Service Interruption

National Snow and Ice Data Center