USAP-DC

Glacier ice loss from Antarctica has the potential to lead to a significant rise in global sea level. One line of evidence for accelerated glacier ice loss has been an increase in the rate at which the land has been rising across the Antarctic Peninsula as measured by GPS receivers. However, GPS observations of uplift are limited to the last two decades. One goal of this study is to determine how these newly observed rates of uplift compare to average rates of uplift across the Antarctic Peninsula over a longer time interval. Researchers reconstructed past sea levels using the age and elevation of ancient beaches now stranded above sea level on the low-lying coastal hills of the Antarctica Peninsula and determined the rate of uplift over the last 5,000 years. The researchers analyzed the structure of the beaches using ground-penetrating radar and the characteristics of beach sediments to understand how sea-level rise and past climate changes are recorded in beach deposits. We found that unlike most views of how sea level changed across Antarctica over the last 5,000 years, its history is complex with periods of increasing rates of sea-level fall as well as short periods of potential sea-level rise. We attribute these oscillations in the nature of sea-level change across the Antarctic Peninsula to changes in the ice sheet over the last 5,000 years. These changes in sea level also suggest our understanding of the Earth structure beneath the Antarctic Peninsula need to be revised. The beach deposits themselves also record periods of climate change as reflected in the size and shape of their cobbles. This project has lead to the training of five graduate students, three undergraduate students, and outreach talks to k-12 schools in three communities.

Person	Role
Simms, Alexander	Investigator and contact
Theilen, Brittany	Researcher
Gernant, Cameron	Researcher
DeWitt, Regina	Co-Investigator

Antarctic Earth Sciences

Award # 1644197

USAP-1644197_1

Deployment	Type
Alexander Simms	field camp

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	Granulometry of Joinville and Livingston Island beaches	Not Provided	exists
USAP-DC	Electron Microprobe Analysis of feldspar separates from rock and sediment OSL samples from Joinville and Livingston Island Beaches	Not Provided	exists
USAP-DC	OSL data - Joinville and Livingston Islands - Raw data	Not Provided	exists
USAP-DC	Joinville and Livingston Islands - rock and sediment OSL ages	Not Provided	exists
USAP-DC	Ground Penetrating Radar Profiles from Beaches on Joinville Island, Antarctic Peninsula	None	exists
USAP-DC	Ground-Penetrating Radar data from Livingston Island in the Antarctic Peninsula	None	exists
USAP-DC	Radiocarbon Ages from Beaches on Joinville Island, Antarctic Peninsula	None	exists

1. Zurbuchen, J. and Simms, A.R., 2019. Late Holocene ice-mass changes recorded in a relative sea-level record from Joinville Island, Antarctica. Geology, v. 47, p. 1064-1068. (doi:10.1130/G46649.1)
2. Simms, A.R., Whitehouse, P.L., Simkins, L.M., Nield, G., DeWitt, R., and Bentley, M.J., 2018. Late Holocene relative sea level near Palmer Station, northern Antarctic Peninsula, strongly controlled by late Holocene ice-mass changes. Quaternary Science Reviews, v. 199, p. 49-59 (doi:10.1016/j.quascirev.2018.09.017)
3. Simms, A.R., Bentley, M.J., Simkins, L.M., Zurbuchen, J., Reynolds, L.C., DeWitt, R., and Thomas, E.R., 2021. Evidence for a "Little Ice Age" glacial advance within the Antarctic Peninsula - Examples from glacially-overrun raised beaches. Quaternary Science Reviews, v. 271, p. 107195. (doi:10.1016/j.quascirev.2021.107195)