USAP-DC

This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth's climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area.

Person	Role
Hall, Brenda	Investigator and contact
Denton, George	Co-Investigator

Antarctic Glaciology

Award # 0944150

USAP-0944150_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	Marshall Valley U-Series Data	ASCII	exists
USAP-DC	Marshall Valley Radiocarbon Data	ASCII	exists
USAP-DC	Royal Society Range Headland Moraine Belt Radiocarbon Data	Excel	exists
USAP-DC	Salmon Valley Radiocarbon Data	Excel	exists

1. Heath, S., Hall, B., Denton, G., Henderson, G., and Hendy, C., 2022. Ice-sheet expansion from the Ross Sea into McMurdo Sound, Antarctica, during the last two glaciations. Quaternary Science Reviews 278, 107379.
2. Hall, B., Denton, G., Heath, S., Henderson, G., Jackson, M., Koffman, T., Mattas, L., Miles, M., and Walther, T., 2019. Extent and age of Ross Sea drifts during the last two glaciations, McMurdo Sound, Antarctica. Interdisciplinary Antarctic Earth Sciences Meeting, Julian, CA.
3. Jackson, M.S., Hall, B.L., and Denton, G.H., 2018. Asynchronous behavior of the Antarctic Ice Sheet and local glaciers during and since Termination 1, Salmon Valley, Antarctica. Earth and Planetary Science Letters 482,396-406.
4. Hall, B., Denton, G., Heath, S., Jackson, M., and Koffman, T., 2015. Accumulation and marine forcing of ice dynamics in the western Ross Sea during the last deglaciation. Nature Geoscience 8, 625-629.
5. Anderson, J.B., Conway, H., Bart, P.J., Kirshner, A.E., Greenwood, S.L., McKay, R.M., Hall, B.L., Ackert, R.P., Licht, K., Jakobsson, M., Stone, J.O., 2014. Ross Sea paleodrainage and deglacial history during and since the LGM. Quaternary Science Reviews 100, 31-54.
6. Golledge, N., Levy, R., McKay, R.M., Fogwill, C.J., White, D.A., Graham, A.G.C., Smith, J.A., Hillenbrand, C-D., Licht, K.J., Denton, G.H., Ackert, R.P., Jr., Maas, S.M., Hall, B.L., 2013. Glaciology and geological signature of the Last Glacial Maximum Antarctic ice sheet. Quaternary Science Reviews, 78, 225-247.
7. Hall, B., Denton, G., Stone, J., and Conway, H., 2013. History of the grounded ice sheet in the Ross Sea sector of Antarctica during the last glacial maximum and the last termination. Geological Society of London, doi 10.1144/SP381.5.
8. Hall, B., Denton, G., Heath, S., Jackson, M., and Koffman, T., 2015. Timing of the last glacial maximum and deglaciation in the Ross Sea. 22nd Annual WAIS Meeting, Loveland, CO.
9. Jackson, M., Hall, B., and Denton, G., 2012. History of the Ross Sea ice sheet in Salmon Valley during the last glaciation. 19th Annual West Antarctic Ice Sheet Meeting, Pack Forest Park, Washington.
10. Allard, S., Hall, B., and Denton, G., 2011. History of the Ross Sea ice sheet based on glacial and lake records from Marshall Valley, Antarctica. 18th West Antarctic Ice Sheet Annual Meeting, Loveland, CO.
11. Hall, B., 2011. History of the Antarctic Ice Sheet in the Ross Sea sector at and since the last glacial maximum. 11th International Symposium on Antarctic Earth Sciences, Edinburgh, Scotland, July 2011
12. Koffman, T., Hall, B., and Denton, G., 2011. New radiocarbon dates from glacial deposits in Miers Valley constrain the past behavior of the Antarctic Ice Sheet. 18th Annual West Antarctic Ice Sheet meeting, Loveland, CO.