2017-2018 USAP Field Season
New constraints on post-glacial rebound and Holocene environmental history along the northern Antarctic Peninsula from raised beaches
Dr. Alexander R Simms
University of California Santa Barbara
Supporting Stations: ARSV Laurence M. Gould
An indication of accelerated ice loss across Antarctica is the increase in the rate that land is rising across the Antarctic Peninsula, as measured by GPS observations. However, GPS data are limited to the last two decades. Researchers hope to determine how recent observations of uplift compare to the average long-term uplift rate across the peninsula. The team will determine uplift rates over the past 5,000 years by reconstructing past sea levels through use of ground-penetrating radar. The radar data will unveil beach structure including ancient shorelines that can be used to understand further how sea-level rise and past climate changes are recorded in beach deposits. These new records will: (1) help determine natural variability of the Antarctic Ice Sheet and relative sea level; (2) provide new insight about uplift and the structure of Earth's interior; and (3) help refine methods used to determine the age of geologic deposits.
Field Season Overview
Researchers will sample and conduct elevation and ground-penetrating radar (GPR) surveys of raised beaches at two sites in the Antarctic Peninsula, Livingston and Joinville Islands, in order to determine their age and to reconstruct past sea levels and climate based on their character. In the 2017-18 season a team of four science team members and one ASC field camp manager will deploy to Joinville Island for approximately twelve days. Fieldwork will occur within the Firth of Tay on the southern side of Joinville Island in mid-February to early March. As a contingency plan, if weather conditions do not allow access to Joinville Island in the 2017-18 season (determined prior to starting the cruise), the science team will travel to Livingston Island and will attempt to access Joinville Island in the 2018-19 season. Team will deploy to and retrieved from the field site via small boats. Once deployed at field site, the team will conduct all of their fieldwork from a tent-based field camp. The equipment needed at each site includes camping gear (i.e. sleep and kitchen tents, stove, water, food, fuel, etc.), a small generator to recharge GPS and GPR equipment, and 20 wooden rock boxes to transport collected beach material for later analysis. The optically stimulated luminescence (OSL) dating determines the last exposure of mineral grains to sunlight. Each day in the field, two people will collect GPR and/or OSL samples, one person will be responsible for cobble roundness measurements and/or GPS surveying, and one person will be responsible for IRD identification. The science team anticipates collecting four approximately 300 m long GPR profiles aligned orthogonally to the coast at Joinville Island and four approximately 800 m long GPR profiles on Livingston Island. They also anticipate collecting a total of 96 OSL samples on each island. The GPR will be from the PI’s university. Each box will be filled with ~30-40 lbs of rock. The GPS will be on loan from UNAVCO.
Deploying Team Members