Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy

This data set contains optical brightness and depth data from the Siple Dome borehole in Antarctica, as well as layer depths derived from the brightness log. These data can provide insight into firn compaction and vertical motion of the ice sheet.

Contacts and Acknowledgments
Detailed Data Description
Data Access and Tools
Data Acquisition and Processing
References and Related Publications
Document Information

Citing These Data

The following example shows how to cite the use of this data set in a publication.

Waddington, Edwin, Robert Hawley, Richard Alley, and Ken Taylor. 2012. Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy, Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5DB7ZRZ.

Overview

Sensor	Camera
Spatial Coverage	Siple Dome, Antarctica Latitude: 81.66°S Longitude: 148.82° W
Spatial Resolution	5 mm depth
Temporal Coverage	2000-12-15 to 2001-11-15, Austral summer only
Temporal Resolution	Single Measurement
Parameters	Annual Layer Depth Optical Firn Brightness
Data Format	ASCII text (.txt)
Metadata Access	View Metadata Record
Data Access	FTP

1. Contacts and Acknowledgments

Investigators Name and Title

Dr. Edwin D. Waddington
University of Washington
Department of Earth and Space Sciences
Seattle, Washington 98195-1310
USA

Dr. Robert L. Hawley
Dartmouth College
Earth Sciences, HB 6105
Hanover, New Hampshire 13755
USA

Dr. Richard B. Alley
Department of Geosciences
517 Deike Building
University Park, Pennsylvania 16802
USA

Dr. Ken C. Taylor
Desert Research Institute
Department of Geosciences
Nevada System of Higher Education
2215 Raggio Parkway
Reno, Nevada 89512
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 supported by the National Science Foundation (NSF) Office of Polar Programs (OPP) grant number 0087521.

2. Detailed Data Description

Format

The data set is provided as two ASCII text (.txt) files.

File and Directory Structure

The data set consists of two data files, layers.txt and BOS.txt. Data are on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0515_waddington_V01/ folder.

File Size

Two data files are 12 KB to 467 KB.

Volume

The entire data set is approximately 480 KB.

Spatial Coverage

Siple Dome, Antarctica
Latitude: 81.66°S
Longitude: 148.82° W

Spatial Resolution

5 mm depth

Temporal Coverage

15 December 2000 to 15 November 2010, Austral summer only

Temporal Resolution

Single measurement

Parameter or Variable

This data set provides annual layer depths and firn optical brightness, as measured by Borehole Optical Stratigraphy (BOS). These data include both the optical brightness versus depth record from Siple Dome, and also the layer depths derived from the brightness log. The brightness log is a record of firn reflectivity, and peaks in brightness are interpreted to be fine-grained high-density winter snow, as part of the "wind slab depth-hoar couplet." For more details see Hawley, et. al., 2003.

Parameter Description

The data set consists of two files. Layer picks are provided as one single column in the layers.txt file. The file BOS.txt provides depth and brightness measurements made using Borehole Optical Stratigraphy (BOS), a method described in detail in Hawley, et. al., 2003.

**Table 1.** Parameter Description for the BOS.txt file
Parameter	Description
Depth	Depth in meters
Intensity	Optical brightness, measured using the BOS method.

3. Data Access and Tools

Data Access

Data are available via FTP.

Software and Tools

Data are readable using standard spreadsheet software.

4. Data Acquisition and Processing

Data Acquisition Methods

Data were collected using Borehole Optical Stratigraphy (BOS). BOS uses a downward looking video camera and post-processing software to create a log of brightness versus depth. The active light source on the camera returns from the borehole walls to the camera, which views the walls with a wide angle lens. Brightness is calculated by averaging the pixel values of an annulus of pixels around the borehole wall. For a detailed description of techniques, see Hawley, et. al., 2003 and Hawley, et. al., 2011.

5. References and Related Publications

Hawley, R.L., E.D. Waddington, R.B. Alley, and K.C. Taylor. 2003. Annual Layers in Polar Firn Detected by Borehole Optical Stratigraphy. Geophysical Research Letters 30(15), doi:10.1029/2003GL017675.

Hawley, R.L., E.D. Waddington. 2011. In-Situ Measurements of Firn Compaction Profiles Using Borehole Optical Stratigraphy. Journal of Glaciology, 57(202), 289-294.

Related Data Collections

Borehole Optical Stratigraphy Modeling, Antarctica

Related Web Sites

Antarctic Glaciological Data Center at NSIDC

6. Document Information

Acronyms and Abbreviations

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

**Table 2.** Acronyms and Abbreviations
Acronym	Description
AGDC	Antarctic Glaciological Data Center
BOS	Borehole Optical Stratigraphy
FTP	File Transfer Protocol
NSF	National Science Foundation
NSIDC	National Snow and Ice Data Center
URL	Uniform Resource Locator

Document Creation Date

April 4, 2012

Document URL

http://nsidc.org/data/docs/agdc/nsidc0515-waddington/index.html

Service Interruption

National Snow and Ice Data Center