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Global Change Master Directory (GCMD)
Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines
Entry ID: NSF-ANT09-44475


Summary
Abstract: Intellectual Merit: The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica's inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed <2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time.
Broader Impact: The proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences.

Related URL
Link: View Related Information
Description: Original data submitted.


Link: View Related Information
Description: NSF Award Abstract #0944475

Geographic Coverage
 N: -84.1 S: -87.4  E: 161.2  W: -149.7

Data Set Citation
Version: Not provided


Temporal Coverage
Start Date: 2010-06-01
Stop Date: 2014-05-31


Location Keywords
CONTINENT > ANTARCTICA
VERTICAL LOCATION > LAND SURFACE
GEOGRAPHIC REGION > POLAR


Science Keywords
SOLID EARTH >ROCKS/MINERALS/CRYSTALS >AGE DETERMINATIONS    [Definition]
PALEOCLIMATE >LAND RECORDS >GLACIATION    [Definition]
LAND SURFACE >GEOMORPHIC LANDFORMS/PROCESSES >GLACIAL PROCESSES    [Definition]


Project
NSF/PLR >Division of Polar Programs, National Science Foundation    [Information]


Data Set Progress
COMPLETE


Data Center
United States Antarctic Program Data Center    [Information]
Data Center URL: http://www.usap-dc.org/

Data Center Personnel
Name: ROBERT A. ARKO
Email: info at usap-data.org
Contact Address:
Lamont-Doherty Earth Observatory
61 Route 9W
City: Palisades
Province or State: NY
Postal Code: 10964
Country: USA


Personnel
MICHAEL KAPLAN
Role: INVESTIGATOR
Email: mkaplan at ldeo.columbia.edu
Contact Address:
Lamont-Doherty Earth Observatory
City: Palisades
Province or State: NY
Postal Code: 10964
Country: US


Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2014-07-17
Last DIF Revision Date: 2018-11-12



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