Optical Logging for Dust and Microbes in Boreholes in Glacial Ice

Summary

This data set contains high-resolution logs of dust and microbes measured at the Siple Dome A borehole in Antarctica. The data were obtained using a newly developed optical borehole logger, which fits into a fluid-filled borehole in glacial ice. It can detect dust and microbes in ice out to several meters from the borehole, and measure optical properties of those particles. The data set contains information on depth and optical signal. Data are available via FTP in data file format (.dat).

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.

Bay, R. C. 2009. Optical Logging for Dust and Microbes in Boreholes in Glacial Ice. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N59P2ZKB.

Overview Table

Category	Description
Data format	Generic data file format (.dat)
Spatial coverage and resolution	Southernmost Latitude: 81° 39.53' S Northernmost Latitude: 81° 39.53' S Westernmost Longitude: 148° 48.72' W Easternmost Longitude: 148° 48.72' W
Temporal coverage and resolution	Two Antarctic field seasons, 2000-2001 and 2001-2002.
Tools for accessing data	Spreadsheet software.
File naming convention	DustLog_SDMA.dat Backscatter_SDMA.dat
File size	The data set is 4750 KB.
Parameter(s)	Depth (meters, corrected) Signal (arbitrary units)
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. Ryan Bay
Physics Department
University of California-Berkeley
Berkeley, CA 94704

Technical Contact

Acknowledgements

This research was supported by NSF OPP grant 0125794.

2. Detailed Data Description

Format

Data are in generic data file format (.dat).

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/bay_nsidc_0403/ directory. The data set consists of two data files, DustLog_SDMA.dat, and Backscatter_SDMA.dat, and a readme file, 00README.txt.

File Size

The data set is 4750 KB total.

Spatial Coverage

Data were obtained at the Siple Dome A borehole in Antarctica.

Southernmost Latitude: 81° 39.53' S
Northernmost Latitude: 81° 39.53' S
Westernmost Longitude: 148° 48.72' W
Easternmost Longitude: 148° 48.72' W

Temporal Coverage

Data were collected during two Antarctic field seasons, from 2000 to 2001 and 2001 to 2002.

Parameter or Variable

This data set includes raw data from dust logging of the Siple Dome A borehole. Parameters include measurement depth and signal. These data can be used to identify dust and other particles in the ice surrounding the borehole. Data were taken in the Siple Dome A borehole in 2000-01 and 2001-02. The Dust Logger measures the amount of light beamed into the horizon which exits the borehole and returns. Backscatter data from a second instrument with lower resolution are included in the file, Backscatter_SDMA.dat.

Sample Data Record

Depth (meters)	Signal (arb units)
54.904	0.134

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The data set is approximately 4700 KB.

Software and Tools

Data are accessible using spreadsheet software.

Related Data Collections

• WAISCORES: Deep Ice Coring in West Antarctica (NSIDC-0120)
• Physical and Structural Properties of the Siple Dome Ice Cores (NSIDC-0128)

4. Data Acquisition and Processing

Theory of Measurements

Data were taken in the Siple Dome A borehole during two Antarctic field seasons in 2000-2001 and 2001-2002. The dust logger is an optical instrument which detects dust particles and air bubbles by shining a light against the borehole walls and recording the fraction of light that scatters back into the borehole. The logger was lowered into an ice core borehole, which was kept open with an insoluble antifreeze matched to the ice density. Detailed description of the instrument is avilable in Bay, et al., 2001. See references below.

5. References and Related Publications

Bay, R. C., P. B. Price, G. D. Clow, and A. J. Gow. 2001. Climate logging with a new rapid optical technique at Siple Dome. Geophys. Res. Lett. 28(24), p. 4635-4638 .

Bay, R. C., N. E. Bramall, P. B. Price, G. D. Clow, R. L. Hawley, R. Udisti, and E. Castellano. 2006. Globally synchronous ice core volcanic tracers and abrupt cooling during the last glacial period. J. Geophys. Res. 111 (D11108) doi:10.1029/2005JD006306.

Table 1 lists related documents that are available on the NSIDC Web site.

Table 1. Related Documents

Document	Description	URL
WAISCORES	Related project Web site	http://nsidc.org/data/waiscores/data.html
Antarctic Glaciological Data Center	Data center	http://nsidc.org/agdc/

6. Document Information

Acronyms

The acronyms used in this document are listed in Table 2.

Table 2. Acronyms and Abbreviations

Acronym	Description
.DAT	Data file extension
FTP	File Transfer Protocol
NSIDC	National Snow and Ice Data Center
URL	Uniform Resource Locator

Document Creation Date

10 July, 2009

Document URL

http://nsidc.org/data/docs/agdc/nsidc0403_bay/index.html