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Trapped Gas Composition and Chronology of the Vostok Ice Core

Summary

This data set includes a time scale for the Vostok ice core, retrieved from Vostok Station on the East Antarctic Plateau. This chronology is derived by orbitally tuning to molecular oxygen to nitrogen (O2/N2) ratios in occluded air for depths deeper than 1550 m (greater than 112,000 years old), and by gas correlation to the Greenland Ice Sheet Project 2 (GISP2) chronology for the ice core section that is shallower than 1422 m (less than 102,000 years old). Because of poor gas preservation in air bubbles in shallower depths, investigators could only constrain the Vostok chronology for the section deeper than 1550 m by O2/N2. Thus for the shallower section of the core, they synchronized the Vostok delta oxygen-18 (δ18O) and methane (CH4) measurements to those of the GISP2 to obtain the chronology (see Bender, et al. 2006). Note, CH4 data are not included in this data set.

Investigators analyzed the O2/N2 and the δ18O record ratios for approximately the past 115,000 to 400,000 years in the Vostok ice core. They combined new measurements for O2/N2 and δ18O with data from Bender (2002) and Petit, et al. (1999), respectively.

Data are in Microsoft Excel format and are available via FTP.

Citing These Data

We kindly request that you cite the use of this data set in a publication using the following citation example. 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 media format.

Bender, M., and M. Suwa. 2007. Trapped gas composition and chronology of the Vostok ice core. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5P26W12.

Overview Table

Category Description
Data format Microsoft Excel
Spatial coverage and resolution Southernmost Latitude: 72.4667° S
Northernmost Latitude: 72.4667° S
Westernmost Longitude: 106.8000° W
Easternmost Longitude: 106.8000° W

Maximum depth: 3400 m
Temporal coverage and resolution Data collection: September 2003 through June 2006
Data coverage: 115,000 to 400,000 years before present (ybp)
File naming convention Suwa_2007_VostokO2N2chronology.xls
File size Approximately 281 KB
Parameters Depth, ice age, gas age, O2/N2, δ18O of paleoatmospheric O218Oatm)
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

Michael Bender
Department of Geosciences
Princeton University
M48 Guyot Hall
Princeton, NJ 08544 USA

Makoto Suwa
Department of Geosciences
Princeton University
Guyot Hall  
Princeton, NJ 08544 USA

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 funded by the National Science Foundation (NSF) Office of Polar Programs (OPP) grant 0230260 awarded to Michael Bender.

2. Detailed Data Description

File Structure

The following table shows the parameters represented in each of the three groups of data, along with their units of measurement. For the O2/N2 and δ18O data, investigators combined new measurements with data from Bender (2002) and Petit, et al. (1999), respectively.

Variable Unit of measurement
Depth Meters (m)
Ice age Thousands of years (ka)
Gas age Thousands of years (ka)
Variable Unit of measurement
Depth Meters (m)
O2/N2 Per mil, one part per thousand (‰)
Ice age Thousands of years (ka)
Variable Unit of measurement
Depth Meters (m)
δ18Oatm Per mil, one part per thousand (‰)
Gas age Thousands of years (ka)

File Naming Convention

The file name for the Microsoft Excel data file is Suwa_2007_VostokO2N2chronology.xls.

File Size

The data file is approximately 281 KB.

Spatial Coverage

Investigators took samples from the Vostok ice, retrieved from Vostok Station on the East Antarctic Plateau.

Southernmost Latitude: 72.4667° S
Northernmost Latitude: 72.4667° S
Westernmost Longitude: 106.8000° W
Easternmost Longitude: 106.8000° W

Spatial Resolution

The maximum depth of the samples taken from the Vostok ice core was 3400 m.

Temporal Coverage

Investigators analyzed Vostok ice core samples from September 2003 through June 2006.

Parameter or Variable

Investigators recorded depth, ice age, gas age, O2/N2, and δ18O of paleoatmospheric O218Oatm). Data cover a time period of approximately 115,000 years to 400,000 years before present (ybp).

3. Data Access and Tools

Data Access

Data are available via FTP.

Related Data Collections

4. Data Acquisition and Processing

Data Acquisition Methods

Investigators used a double melt refreeze method to extract air trapped in bubbles and clathrate hydrates in an ice sample. The O2/N2, δ15N of N2, and δ18O of O2 values were determined using a Finnegan Delta Plus mass spectrometer.

Investigators combined their data with results from previous studies. They combined new measurements for O2/N2 and δ18O with data from Bender (2002) and Petit, et al. (1999), respectively.

Processing Steps

Investigators corrected all δ18O and O2/N2 values reported within this data set for gravitational enrichment by subtracting 2 x δ15N of N2 and 4 x δ15N of N2 of the same sample, respectively.

5. References and Related Publications

Bender, M. L. 2002. Orbital tuning chronology for the Vostok climate record supported by trapped gas composition. Earth and Planetary Science Letters 204(1), 275-289.

Petit, J. J., J. Jouzel, D. Raynaud, N. I. Barkov, J.-M. Barnola, I. Basile, M. Bender, et al. 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, 429-436.

Suwa, M. 2007. Chronologies for ice cores constrained by their gas records and their implications for climate history for the past 400,000 years. PhD thesis, Princeton University, Princeton, NJ.

Suwa, M., and M. Bender. In press. Chronology of the Vostok ice core constrained by O2/N2 ratios of occluded air, and its implication for the Vostok climate records. Quaternary Science Reviews.

6. Document Information

Acronyms and Abbreviations

The following acronyms and abbreviations are used in this document.

δ18Oatm delta 18O of paleoatmospheric O2
FTP File Transfer Protocol
GISP2 Greenland Ice Sheet Project 2
ka One thousand years
NSF National Science Foundation
NSIDC National Snow and Ice Data Center
OPP Office of Polar Programs
Per mil, one part per thousand
URL Uniform Resource Locator
ybp Years before present

Document Creation Date

July 2007

Document URL

http://nsidc.org/data/docs/agdc/nsidc0311_bender/index.html