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Advanced Microstructural Characterization of Polar Ice Cores
Entry ID: baker_0738975


Summary
Abstract: This award supports a project to use advanced microscopic and spectroscopic techniques to explore critical questions about microstructure in ice cores, in particular the microstructural locations of impurities, complete grain orientations, and microstructures associated with specific stress regimes or imposed strain.

Purpose: This work complements the visual stratigraphy, electrical conductivity measurement, and precise, detailed measurements of the soluble ion and gas contents that are performed by other researchers. Visual stratigraphy, ECM, ion chromatography and stable isotope analysis of ice cores contribute immensely to our understanding of paleoclimate and, to our ability to predict future climate change. We use primarily scanning electron microscope techniques – imaging, energy dispersive spectroscopy, and electron backscatter diffraction – and micro computed X-ray tomography to provide specific information on the microstructural location of impurities, the effect of impurities on physical properties of ice, the effects of stress and strain on microstructure, c- and a-axis fabric at selected depths, and the densification of snow and firn. This information will allow paleoclimatologists to better interpret ice core data and other scientists to understand and model the physical and mechanical properties of natural ice sheets.

Related URL
Link: VIEW PROFESSIONAL HOME PAGE
Description: Research Interests

Mechanical behavior; phase tranformations; electron microscopy; x-ray topography; x-ray diffraction; ice; magnetic materials; intermetallic compounds; high temperature materials; nanoparticles for magnetic hyperthermia


Data Set Citation
Dataset Originator/Creator: Rachel Obbard
Dataset Title: Mean and median grain area and grain perimeter from 7 depths of Siple Dome (SDMA) between 640 m and 790 m.
Dataset Release Date: September 21, 2012
Dataset Release Place: 14 Engineering Drive Hanover, NH. 03755 USA
Dataset Publisher: Thayer School, Dartmouth College
Version: 1.0

Dataset Originator/Creator: Rachel Obbard
Dataset Title: Grain size and approximate age for 14 samples from Upper Fremont Glacier, WY
Dataset Release Date: September 21, 2012
Dataset Release Place: 14 Engineering Drive Hanover, NH. 03755 USA
Dataset Publisher: Thayer School, Dartmouth College
Version: 1.0

Dataset Originator/Creator: Rachel Obbard
Dataset Title: Structure Log for Upper Fremont Glacier, WY
Dataset Release Date: September 21, 2012
Dataset Release Place: 14 Engineering Drive Hanover, NH. 03755 USA
Dataset Publisher: Thayer School, Dartmouth College
Version: 1.0

Dataset Originator/Creator: Rachel Obbard
Dataset Title: a{0001} and c{11-20} axis pole figures for 9 depths of the Upper Fremont Glacier, WY (core 98-4).
Dataset Release Date: September 21, 2012
Dataset Release Place: 14 Engineering Drive Hanover, NH. 03755 USA
Dataset Publisher: Thayer School, Dartmouth College
Version: 1.0

Dataset Originator/Creator: Rachel Obbard
Dataset Title: a{0001} and c{11-20} axis pole figures for 5 depths of the Siple Dome (SDMA) core between 640m and 790m and misorientation angle distribution for the same grains.
Dataset Release Date: September 21, 2012
Dataset Release Place: 14 Engineering Drive Hanover, NH. 03755 USA
Dataset Publisher: Thayer School, Dartmouth College
Version: 1.0

Dataset Originator/Creator: Rachel Obbard
Dataset Title: Pore size and distribution in 55 firn samples from Siple Dome (SDMA), Antarctica
Dataset Release Date: September 21, 2012
Dataset Release Place: 14 Engineering Drive Hanover, NH. 03755 USA
Dataset Publisher: Thayer School, Dartmouth College
Version: 1.0


Temporal Coverage
Start Date: 2009-09-01
Stop Date: 2011-03-01

Start Date: 2009-01-01
Stop Date: 2009-06-01

Start Date: 2006-06-01
Stop Date: 2009-01-01

Start Date: 2010-02-01
Stop Date: 2010-03-01

Start Date: 2008-01-01
Stop Date: 2009-06-01

Start Date: 2009-07-01
Stop Date: 2011-12-31


Location Keywords
GEOGRAPHIC REGION > POLAR
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > ARCTIC


Science Keywords
CRYOSPHERE >GLACIERS/ICE SHEETS    [Definition]
CRYOSPHERE >SNOW/ICE    [Definition]
PALEOCLIMATE >ICE CORE RECORDS    [Definition]


ISO Topic Category
CLIMATOLOGY/METEOROLOGY/ATMOSPHERE


Platform
LABORATORY    [Information]


Instrument
SCANNING ELECTRON MICROSCOPES    [Information]
Spectrometers    [Information]
MICROSCOPES    [Information]


Keywords
ice cores
microstructure
impurities
grain orientations


Data Set Progress
COMPLETE


Originating Center
Thayer School of Engineering, Dartmouth College


Data Center
NSIDC Antarctic Glaciological Data Center    [Information]
Data Center URL: http://nsidc.org/agdc/

Data Center Personnel
Name: NSIDC AGDC USER SERVICES
Phone: +1 (303) 492-6199
Fax: +1 (303) 492-2468
Email: nsidc at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA


National Snow and Ice Data Center    [Information]
Data Center URL: http://nsidc.org

Data Center Personnel
Name: NSIDC USER SERVICES
Phone: +1 (303) 492-6199
Fax: +1 (303) 492-2468
Email: nsidc at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA


Personnel
IAN BAKER
Role: INVESTIGATOR
Phone: 603-646-2184
Fax: 603-646-9024
Email: Ian.Baker at Dartmouth.edu
Contact Address:
Thayer School of Engineering
Dartmouth College
8000 Cummings Hall
City: Hanover
Province or State: NH
Postal Code: 03755-8000
Country: USA


RACHEL WYNDHAM OBBARD
Role: INVESTIGATOR
Phone: 603-646-9613
Fax: 603-646-9024
Email: rachel.w.obbard at dartmouth.edu
Contact Address:
Thayer School of Engineering
Dartmouth College
8000 Cummings Hall
City: Hanover
Province or State: NH
Postal Code: 03755
Country: USA


Publications/References
Li, X; Iliescu, D; Baker, I. "On the effects of temperature on the strength of H2SO4-doped ice single crystals," JOURNAL OF GLACIOLOGY, v.55, 2009, p. 481-484. View record at Web of Science

Obbard, RW; Troderman, G; Baker, I. "Imaging brine and air inclusions in sea ice using micro-X-ray computed tomography," JOURNAL OF GLACIOLOGY, v.55, 2009, p. 1113-1115. View record at Web of Science

R.W. Obbard, I. Baker, D. Prior. "A scanning electron microscope technique for identifying the mineralogy of dust in ice cores," Journal of Glaciology, v.57, 2011, p. 511.

Rasband, W.S. 2006. ImageJ program. Bethesda, MA, National Institutes of Health. Retzlaff, R. and C.R. Bentley.

R.W. Obbard, K.E. Sieg, I. Baker, D. Meese (2011a) Microstructural evolution in the fine-grained region of the Siple Dome ice core. Journal of Glaciology, 57(206):1046-1056.

R.W. Obbard, T. Cassano, K. Aho, G. Troderman, I. Baker (2011b) Using borehole logging to orient an ice core from the Upper Fremont Glacier, Wyoming. Journal of Glaciology, 57(205):0840-846.

Olsen, L.M., G. Major, K. Shein, J. Scialdone, R. Vogel, S. Leicester, H. Weir, S. Ritz, T. Stevens, M. Meaux, C.Solomon, R. Bilodeau, M. Holland, T. Northcutt, R. A. Restrepo, 2007 .

Morin, R.H., G.E. Descamps and L.D. Cecil. 2000. Characterizing englacial structure from analysis of acoustic televiewer logs,Upper Fremont Glacier, Wyoming. In Proceedings of the Seventh Logging, 24–26 October 2000, Golden, Colorado. Houston, TX,International Symposium on Mineral and GeoTechnical Society of Petrophysicists & Well Log Analysts. Minerals and Geotechnical Logging Society, 235–243.

Lomonaco, R.; Albert, M.; Baker, I. (2011) Microstructural evolution of fine-grained layers through the firn column at Summit, Greenland. Journal of Glaciology 57(204): 755-762

Creation and Review Dates
DIF Creation Date: 2012-09-04
Last DIF Revision Date: 2016-01-27



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