Get Data

Data Set ID:
NSIDC-0123

Siple Dome Core Date from Measurement of the d18O of Paleoatmospheric Oxygen, Version 1

This data set is part of the West Antarctic Ice Sheet Cores (WAISCORES) project, an NSF-funded project to understand the influence of the West Antarctic ice sheet on climate and sea level change. WAISCORES researchers acquired and analyzed ice core samples from the Siple Dome, in the Siple Coast region, West Antarctica. This data set includes a timescale record for the Siple Dome ice core.

Geographic Coverage

Spatial Coverage:
  • N: -81, S: -81, E: -149, W: -149

Spatial Resolution: Not Specified
Temporal Coverage:
  • 1 January 1996 to 31 December 1999
Temporal Resolution: Not specified
Parameter(s):
  • Glaciers/Ice Sheets > Glacier Thickness/Ice Sheet Thickness
  • Snow/Ice > Ice Depth/Thickness
  • Glaciers/Ice Sheets > Ice Sheets
  • Ice Core Records > Isotopes
  • Snow/Ice > Snow Depth
  • Snow/Ice > Snow/Ice Chemistry
  • Snow/Ice > Snow Stratigraphy
Platform(s) GROUND STATIONS, GROUND-BASED OBSERVATIONS, LABORATORY
Sensor(s): CORING DEVICES
Data Format(s):
  • Microsoft Excel
  • Microsoft Word
Version: V1
Data Contributor(s): Michael Bender, James White

Data Citation

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Bender, M. 2003. Siple Dome Core Date from Measurement of the d18O of Paleoatmospheric Oxygen, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5TX3C95. [Date Accessed].

Back to Top

Collapse All / Open All

Detailed Data Description

This data set is part of the West Antarctic Ice Sheet Cores (WAISCORES) project, an NSF-funded project to understand the influence of the West Antarctic ice sheet on climate and sea level change. WAISCORES researchers acquired and analyzed ice core samples from the Siple Dome, in the Siple Coast region, West Antarctica. This data set includes a timescale record for the Siple Dome ice core.  This chronology is derived by measuring the delta oxygen-18 of paleoatmospheric oxygen (δ18Oatm) then correlating those measurements to the Greenland Ice Sheet Project 2 (GISP2) record by adjusting the Siple Dome timescale so that its curve of δ18Oatm coincided with that of GISP2. The replicate samples were measured at 1 to 1.5 kiloyear (kyr) resolution for the length of the core. Because of core relaxation and cracking at the surface associated with gas loss and a small fractionation of O isotopes associated with loss of O2, the δ18Oatm timescale and accuracy of the constraints of the Siple Dome control depths are subject to limited error.

Format

Data are available as Microsoft Excel (.xls) and Word (.doc) files.

Background color on
File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/waiscores/bender/ directory. Table 1 lists the files in this directory:

Table 1. Files in the /AGDC/waiscores/bender/ directory
File Name Description
d18Oatm.xls
d18Oatm2.xls
Analytical data for paleoatmospheric oxygen, gas and ice age data, and constrained timescale of ice core chronology
d18Oatm.doc Graphical representation of time series records, in kiloyears (kyr), for Siple Dome, constrained with Vostok and GISP2 measurements, including:
  • Stable isotope ratio of paleoatmospheric oxygen (δ18Oatm) in per mil (‰)
  • Deuterium ratio of ice (δDice) in per mil (‰)
  • Stable isotope ratio of oxygen in ice(δ18Oice) in per mil (‰)
Background color on
File Naming Convention

The file names for the Microsoft Excel data files are d18Oatm.xls and d18Oatm2.xls. The file name for the Microsoft Word data file is d18Oatm.

Background color on
File Size

The data set contains three files ranging in size from 52 KB to 235 KB.

Background color on
Spatial Coverage

Ice core data were collected at the Siple Dome site in the Siple Coast region of Antarctica.

Southernmost Latitude: 81°S
Northernmost Latitude: 81°S
Westernmost Longitude: 149°W
Easternmost Longitude: 149°W

Background color on
Temporal Coverage

Data were obtained during three Antarctic field seasons in 1996 to 1999.

Temporal Resolution

Data was analyzed at 1,000 to 1,500 years (1–1.5 kyr) before present (ybp) resolution

Background color on
Parameter or Variable

Parameters for ice core chronology analysis include the top depth in meters (m), the delta deuterium ratio (δD) of ice core samples as provided by James White, the delta oxygen-18 ratio of paleoatmospheric oxygen (δ18Oatm) in parts per trillion (ppt), the gas age and ice age in kiloannum (ka), and the linearly interpolated gas age and ice age in kiloyears (kyr).

Sample Data Record

Below is a sample record of the ice core chronology analysis data from d18Oatm2.xls. The ice core chronology analysis is separated into six sample records: deuterium analysis from James White, gas and ice age versus depth chronology, paleoatmospheric delta oxygen-18 ratio analysis, linearly interpolated gas chronology, and ice core timescale. The ice core timescale is separated into deuterium (δD) versus ice age and paleoatmospheric delta oxygen-18 (δ18Oatm) versus gas age for plotting. Only the first four data records are shown for each sample record.

Deuterium Analysis from James White

top depth, m d D
382.234 -218.8
382.794 -217.4
393.832 -210.5
394.332 -226.0

Gas and Ice Age versus Depth Chronology

top depth, m Gas Age
ka
Ice Age
ka
382.234 6.1 6.7
382.794 6.1 6.7
393.832 6.3 6.9
394.332 6.3 6.9

Paleoatmospheric Delta Oxygen-18 Ratio Analysis

Ice depth of gas sample
top depth, m
18Oatm-a, ppt 18Oatm-b, ppt means of reps
18Oatm, ppt
59.575 0.04 0.06 0.05
119.339 -0.11 -0.01 -0.06
179.459 0.03 -0.01 0.01
239.502 0.00 0.02 0.01

Linearly Interpolated Gas Chronology

Gas Age
control pt.
(kyr)
Gas Age
linear interp.
(kyr)
Ice Age
(kyr)
1.0 1.6
1.9 2.5
... ... ...
69.5 69.5 70.1
71.0 71.6

Ice Core Timescale (dD vs. Ice Age)

Siple_ice_age Siple_dD
6.7 -218.8
6.7 -217.4
6.9 -210.5
6.9 -226.0

Ice Core Timescale (d18Oatm vs. Gas Age)

Ice depth of gas sample
top depth, m
Siple_gas_depth
Gas Age
linear interp.
Siple_gas_ageSIPLE_D18OATM
mean
d 18Oatm, ppt
Siple_18Oatm
59.575 1.0 0.05
119.339 1.9 -0.06
179.459 2.9 0.01
239.502 3.8 0.01
Background color on
Error Sources

Gas loss due to core relaxation and cracking at the surface and a small fractionation of O isotopes associated with loss of O2 both contribute to the error in the δ18Oatmtimescale and accuracy of the constraints of the Siple Dome control depths.

Background color on

Software and Tools

Data are accessible using standard spreadsheet and word processing document software.

Volume

The total volume of the data set is 528 KB.

Background color on

Data Acquisition and Processing

Analysis of ice core samples followed the sample processing methods described in Brook et al., 2005, to obtain measurements of the oxygen isotope ratio of paleoatmospheric O2 (δ18Oatm) and the deuterium isotope ratio. Samples were then calculated for gas age and ice age to obtain the gas chronology and subjected to linear interpolation to constrain the timescale to correlate with the GISP2 record. The experimental effort involved measuring the δ18O of O2, δ15N of N2, and the O2/N2 ratio in replicate samples, at 1 to 1.5 kyr resolution for the length of the core. For more information on data acquisition methods, see the researchers' notes in the Major Findings and the References and Related Publications listed below.

Background color on

References and Related Publications

Contacts and Acknowledgments

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

Dr. James White
INSTAAR
450 UCB
University of Colorado
Boulder, CO 80309
USA

Document Information

Document Creation Date

28 December 2009

No technical references available for this data set.
No FAQs or How Tos available for this data set.

Access complete Knowledge Base

Questions? Please contact:
NSIDC User Services
Phone: 1 303 492-6199
Email: nsidc@nsidc.org