Get Data


Data can be downloaded through a Web browser or command line via FTP. When using a Web browser, the FTP link first directs you to an Optional Registration Form that if filled out, will allow you to receive notifications about updates or processing changes related to that specific data set. After completing the Optional Registration Form, the FTP directory becomes available. For additional help downloading data through an FTP client, go to the How to access data using an FTP client support page.


Data Set ID:

US ITASE Stable Isotope Data, Antarctica, Version 1

This data set includes stable isotope measurements from snow pits, firn, and ice cores collected by the the US component of the International Trans-Antarctic Scientific Expedition ( ITASE). The ITASE program aims to collect and interpret a continental-wide array of environmental parameters assembled through the coordinated efforts of scientists from several nations.

These data were collected between 1999 and 2007. The data have been compiled into single files for each sampling site, though in some cases a file contains data from more than one ice core or snow pit. Each file in the data set includes deuterium/hydrogen (δD) and/or 18-oxygen/16-oxygen (δ18O) ratios, depths, and in some cases ice age or other information. Further details regarding the data are provided in each data file. Data are available via FTP in ASCII text format (.txt). Data were collected during five Antarctic field seasons from 1999 to 2007. Data from 1999 to 2002 are currently available. Data from 2003 to 2007 will be added in the future.

Geographic Coverage

Spatial Coverage:
  • N: -65, S: -90, E: -88, W: -130

Spatial Resolution: Not Specified
Temporal Coverage:
  • 1 January 1999 to 31 December 2007
Temporal Resolution: Not specified
  • Ice Core Records
  • Snow/Ice > Ice Depth/Thickness
  • Ice Core Records > Isotopes
  • Snow/Ice > Snow Depth
Sensor(s): AMS, PALMS
Data Format(s):
  • ASCII Text
Version: V1
Data Contributor(s): Eric Steig

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.

Steig, E. J. 2009. US ITASE Stable Isotope Data, Antarctica, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: [Date Accessed].

Back to Top

Collapse All / Open All

Detailed Data Description


Data are ASCII text format (.txt)

Background color on
File and Directory Structure

Data are available on the FTP site in the directory. Within this directory, there are currently 15 ASCII text files containing data collected in 1999 to 2002. Additional data files for 2003 to 2007 will be added in the future.

Background color on
File Naming Convention

Files are named according to the following convention and as described in Table 1. Additional information on the ice cores and snow pits is provided in the heading of each data file.



Table 1. File Naming Convention
Variable Description
ITASE Project name
YYYY 4-digit year of data collection
N Site number
EXT File extension

Example: ITASE_1999_1.txt: Contains data from the ITASE expedition collected in 1999.

Background color on
File Size

File size ranges between 26 KB and 170 KB.

Background color on

The total volume of the data set will be approximately 4 MB, when all data files are available.

Background color on
Spatial Coverage

Southernmost Latitude: 90° S
Northernmost Latitude: 65° S
Westernmost Longitude: 130° W
Easternmost Longitude: 85° W

Location Map

itase core and route map
Figure 1. Map of ITASE Traverse Routes and Ice Core Locations
Image courtesy US ITASE Program

Background color on
Temporal Coverage

Data were collected during five Antarctic field seasons from 1999 to 2007. Data from 1999 to 2002 are currently available. Data from 2003 to 2007 will be added in the future.

Temporal Resolution

Weekly to annual

Background color on
Parameter or Variable

Parameters include oxygen and deuterium isotope ratios, and in some case ice age. Each data file contains additional details on the specific measurements and parameters in the file.

Parameter Description

Table 2. Parameter Description
Parameter Description
Depth Top and bottom sample depth, in meters
Age Sample age at top and bottom of sample, in calendar year
d180 Stable oxygen ratio (18-oxygen/16-oxygen), in parts per million
delD Deuterium ratio, in parts per million
dxs Deuterium excess, in parts per million
Sample number Sample identification number

Sample Data Record

Example: ITASE_2000_1.txt

Depth Top (m) Depth Bottom (m) Age Top (calendar year) Age Bottom d18O (per mil) delD (per mil) dxs (per mil) Sample Number
0 0.02 2001 2000.97 -29.83 -239.02 -0.36 ITASE2000C1_p442
Background color on

Software and Tools

Data are accessible using spreadsheet software.

Quality Assessment

Percent Isotope ratios are normalized on the V-SWOW / SLAP scale; precision is better than 0.1 per mill for d18O and better than 1 per mill for and delD.

Background color on

Data Acquisition and Processing

Stable isotope concentrations (δ18O and δD) were analyzed by mass spectrometry, using CO2 equilibration and Cr reduction, in a laboratory at the University of Washington. For more information, see Steig, et al. 2005, and Schneider, et al., 2005, and the additional references cited below.

Background color on

References and Related Publications

Contacts and Acknowledgments

Dr. Eric J. Steig
University of Washington
Department of Earth and Space Sciences
70 Johnson Hall City: Seattle Province or State: WA Postal Code:
Seattle, Washington 98195


This research was supported by NSF OPP grants 0440414 and 0196105.

Document Information

Document Creation Date

18 September 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