Methane Measurements from the GISP2 and Siple Dome Ice Cores

Summary

This data set contains methane measurements made in trapped air in the holocene sections of two ice cores: the Siple Dome ice core in Antarctica, and the Greenland Ice Sheet Project 2 (GISP2) ice core in Greenland. The measurements were made at Oregon State University between 2007 and 2009. Measurements were made relative to the NOAA04 methane concentration scale using a working standard internally calibrated to NOAA certified air standards. Concentrations are corrected for gravitational fractionation and solubility effects in the melt-refreeze extraction. Data are available via FTP in Microsoft Excel (.xls) format.

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.

Brook, Edward J. 2009. Methane Measurements from the GISP2 and Siple Dome Ice Cores. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N58P5XFZ.

Overview Table

Category	Description
Data format	Microsoft Excel (.xls) spreadsheet
Spatial coverage and resolution	Siple Dome: Southernmost Latitude: 81.65°S Northernmost Latitude: 81.65°S Westernmost Longitude: 148.81°W Easternmost Longitude: 148.81°W GISP2: Southernmost Latitude: 73.58°N Northernmost Latitude: 73.58°N Westernmost Longitude: 38.4°W Easternmost Longitude: 38.4°W
Temporal coverage and resolution	Measurements were made betwen 2007 and 2009. The age range of the samples is 0 to 11.7 thousand years (ka) for GISP2 and 0 to 10.9 ka for Siple Dome.
File naming convention	Brook_Holocene_CH4.xls
File size	44 KB
Parameter(s)	Depth Methane Concentration Gas Age
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. Edward Brook
Department of Geosciences
104 Wilkinson Hall
Oregon State University
Corvallis, OR 97330
USA

Technical Contact

Acknowledgements

This research was supported by National Science Foundation (NSF) Office of Polar Programs (OPP) grant number 0520523.

2. Detailed Data Description

Format

Data are in Microsoft Excel (.xls) format.

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/brook_nsidc_0440/ directory. Within this directory, there is one data file, and one readme file in text format (.txt).

File Naming Convention

The data file, Brook_Holocene_CH4.xls, contains methane data from the Holocene portion of the GISP2 and Siple Dome ice cores.

File Size

The data set is a total of 44 KB.

Spatial Coverage

The file contains data from the Siple Dome ice core, drilled in Antarctica, and the GISP2 ice core, from Greenland. The geographic locations of the two ice cores are listed below:

Siple Dome:
Southernmost Latitude: 81.65°S
Northernmost Latitude: 81.65°S
Westernmost Longitude: 148.81°W
Easternmost Longitude: 148.81°W

GISP2:
Southernmost Latitude: 73.58°N
Northernmost Latitude: 73.58°N
Westernmost Longitude: 38.4°W
Easternmost Longitude: 38.4°W

Temporal Coverage

Measurements were made between 2007 and 2009. The age range of the samples is 0 to 11.7 thousand years (ka) for GISP2 and 0 to 10.9 ka for Siple Dome.

Parameter or Variable

Measurement depths range from 55.7 to 598.39 meters below the surface (mbs) for the Siple Dome ice core, and 95.98 to 1695.35 mbs for the GISP2 ice core.

Parameter Description

The measurements contain depth in meters below surface, gas age in thousands of years (ka), and methane concentration, in parts per billion (ppb).

Sample Data Record

GISP2 Ice Core			Siple Dome Ice Core
Mid Depth Below Surface (m)	Methane Concentration (ppb)	Meese/Sowers Gas Age (ka)	Mid Depth Below Surface (m)	Methane Concentration (ppb)	Gas Age (ka) (Brook et al., 2005)
95.98	910.7	0.03	55.7	1015.9	0.08059
99.24	894.0	0.05	60.35	865.1	0.11929

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The total volume of the data set is 44 KB.

Software and Tools

Data are accessible using spreadsheet software.

Related Data Collections

• Siple Dome Methane Record
• Siple Dome Core Date from Measurement of the d18O of Paleoatmospheric O2
• GISP2 (B and D Core) Methane Concentrations
• GISP2 (D Core) Methane Concentration Data

4. Data Acquisition and Processing

Theory of Measurements

Measurements were made relative to the NOAA04 methane concentration scale using a working standard internally clailbrated to NOAA certified air standards. Concentrations are corrected for gravitational fractionation and solubility effects in the melt-refreeze extraction. The time scale used was the GISP2: Mees/Sowers Time Scale. The method of construction of the Siple Dome time scale provided here is described in Brook et al., 2005.

5. References and Related Publications

Brook, E., J. W. C. White, A. Schilla, M. Bender, B. A. Barnett, J. Severinghaus, K. C. Taylor, R. B. Alley and E.J . Steig. 2005. Timing of millennial-scale climate change at Siple Dome, West Antarctica, during the last glacial period, Quaternary Science Reviews 24, 1333-1343. doi:10.1016/j.quascirev.2005.02.002

The following related documents are available:

Table 1. Related Documents

Document	Description	URL
Antarctic Glaciological Data Center	Data center Web site	http://nsidc.org/agdc/

6. Document Information

Acronyms

The following acronyms are used in this document.

Table 2. Acronyms and Abbreviations

Acronym	Description
FTP	File Transfer Protocol
KA	Thousands of Years
MBS	Meters Below Surface
NSIDC	National Snow and Ice Data Center
PPB	Parts Per Billion
URL	Uniform Resource Locator
XLS	Microsoft Excel File Extension

Document Creation Date

8 December 2009

Document URL

http://nsidc.org/data/docs/agdc/nsidc0440_brook/index.html