Collaborative Research: Plestocene East Antarctic Ice Sheet History as Recorded in Sediment Provence and Chronology of High-Elevation TAM Moraines

Lead PI: Michael Kaplan , Dr. Gisela Winckler

Unit Affiliation: Geochemistry, Lamont-Doherty Earth Observatory (LDEO)

June 2010 - May 2014
Inactive
Antarctica
Project Type: Research

DESCRIPTION: 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.

OUTCOMES: Found that the sites contain pre-LGM landforms. Also found that the moraine ages increase towards the back of the moraine sequence (towards the headwall) and away from the EAIS at both Howe and Achernar glaciers. Samples do not show a complex history of burial and re-exposure.

SPONSOR:

National Science Foundation (NSF)

FUNDED AMOUNT:

$202,884

EXTERNAL COLLABORATORS:

IUPUI

WEBSITE:

https://www.nsf.gov/awardsearch/showAward?AWD_ID=0944475&HistoricalAwards=false

PUBLICATIONS:

Kaplan, M.R. and Licht, K.J. and Winckler, G. and Schaefer, J.M. and Bader, N. and Mathieson, C. and Roberts, M. and Kassab, C.M. and Schwartz, R. and Graly, J.A.. "Middle to Late Pleistocene stability of the central East Antarctic Ice Sheet at the head of Law Glacier," Geology, 2017. doi:10.1130/G39189.1 Citation details

Bader, Nicole A. and Licht, Kathy J. and Kaplan, Michael R. and Kassab, Christine and Winckler, Gisela. "East Antarctic ice sheet stability recorded in a high-elevation ice-cored moraine," Quaternary Science Reviews, v.159, 2017. doi:10.1016/j.quascirev.2016.12.005 Citation details

Bromley, Gordon R.M. and Winckler, Gisela and Schaefer, Joerg M. and Kaplan, Michael R. and Licht, Kathy J. and Hall, Brenda L.. "Pyroxene separation by HF leaching and its impact on helium surface-exposure dating," Quaternary Geochronology, v.23, 2014. doi:10.1016/j.quageo.2014.04.003 Citation details

Graly, Joseph A. and Licht, Kathy J. and Druschel, Gregory K. and Kaplan, Michael R.. "Polar desert chronologies through quantitative measurements of salt accumulation," Geology, 2018. doi:10.1130/G39650.1 Citation details

KEYWORDS

ocean and climate physics climate change transantarctic mountains cosmogenic dating till composition moraines paleoclimate east antarctic ice sheet