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Data Set ID:
NSIDC-0110

Tephra in Siple and Taylor Dome Ice Cores, Version 1

This data set consists of electron microprobe geochemical analyses of glass shards sampled from Siple Dome and Taylor Dome ice cores during the 1999-2000 field season. Geochemical data are in tab-delimited ASCII and Excel formats. Backscattered electron images of tephra samples are in TIFF format. Data are available via ftp.

Geographic Coverage

Spatial Coverage:
  • N: -81, S: -81, E: -148, W: -148

  • N: -77.8, S: -77.8, E: 158.71, W: 158.71

Spatial Resolution: Not Specified
Temporal Coverage:
  • 1 January 1999 to 31 December 2000
Temporal Resolution: Not specified
Parameter(s):
  • Ice Core Records > Volcanic Deposits
Platform(s) GROUND-BASED OBSERVATIONS
Sensor(s): CORING DEVICES, ELECTRON MICROPROBES
Data Format(s):
  • TIFF
  • Microsoft Excel
  • ASCII Text
Version: V1
Data Contributor(s): Nelia Dunbar

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.

Dunbar, N. 2002. Tephra in Siple and Taylor Dome Ice Cores, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N50P0WXF. [Date Accessed].

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Detailed Data Description

Format and File Sizes

Geochemical analyses are in tab-delimited ASCII and Excel formats.

  • "sipleA_tephra.txt" (ASCII file, 5 KB)
  • "sipleA_tephra.xls" (Excel file, 37 KB)
  • "sipleA*.tif" (TIFF files of backscattered electron images, 139 KB to 890 KB)

Geochemical analyses have following data fields:

  • Depth of samples (m). If the sample name contains "filter" then depth is given in the "Top depth in core" column.
  • Number of geochemical analyses per sample
  • Mean and standard deviation of geochemical composition in percentage weight (normalized to 100 percent)

Note: the number next to the sample name (for example, "sipleA 34.4-34.7") indicates the sample depth in meters.

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Spatial Coverage

Tephra samples were collected from Siple Dome (81° S, 148° W) and Taylor Dome (77° 48' S, 158° 43' E).

Study Area Location Map

Siple and Taylor Domes, Antarctica

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Temporal Coverage

Cores were taken during the 1999-2000 field season.

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Parameter or Variable

Data consist of electron microprobe analyses of glass shards where compositionally-consistent samples were present. The following variables are reported:

  • Depth of samples (m). If the sample name contains "filter" then depth is given in the "Top depth in core" column.
  • Number of geochemical analyses per sample
  • Mean and standard deviation of geochemical composition in percentage weight (normalized to 100 percent)
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Software and Tools

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Data Acquisition and Processing

Electron microprobe analyses and backscatter electron images were processed with a Cameca SX-100 microprobe. Geochemical quantities are reported in percentage weight and normalized to 100 percent. Na2O is normalized to the value obtained by neutron activation analysis. Analytical precision, based on replicate analyses of standard reference materials of similar composition to the unknowns, is as follows (in percentage weight):

SiO2±0.47
TiO2±0.03
FeO±0.06
MnO±0.06
MgO±0.07
CaO±0.02
Na2O±0.55
K2O±0.27
P2O5±0.02
Cl±0.07

Preprocessing for electron microprobe analysis was conducted by irradiating neutron activation samples at the University of Missouri Research Reactor. Separated samples were analyzed at the New Mexico Institute of Mining and Technology. Irradiation lasted approximately 40 hours at a flux of 2.5 x 1013N cm-2 s-1. Analytical errors, based on replicate analysis of samples, to 1σ, are as follows:

Major elements (percentage weight):

FeO ± 0.01
Na2O ± 0.04

Trace elements (ppm):

Sc±0.04
Cr±12
Co±0.13
Ni±1
Zn±1
As±0.7
Br±0.07
Rb±0.8
Sr±0.7
Sb±0.1
Cs±1.4
Ba±10
La±1.8
Ce±1.4
Nd±0.7
Sm±0.07
Eu±0.14
Tb±0.02
Yb±0.07
Lu±0.01
Hf±0.12
Ta±0.04
Ta±0.04
W±0.05
U±0.02
Th±1

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References and Related Publications

Contacts and Acknowledgments

Nelia W. Dunbar
New Mexico Institute of Mining and Technology
E&ES Department
Socorro, NM 87801 USA

Acknowledgements: 

This research was supported by NSF grant OPP-9615167 ("Volcanic Record from the Siple and Taylor Dome Ice Cores, Antarctica").

Document Information

DOCUMENT CREATION DATE

June 2002

No technical references available for this data set.
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