A data-model comparison on the glacial thinning history of Byrd Glacier, Antarctica
Dr Jamey Stutz1, Dr Shaun Eaves1,2, Ms Claudia Moore1,2, Dr. Klaus Wilcken3, Dr. Kevin Norton2, Dr Dan Lowry4
1Antarctic Research Centre, Te Herenga Waka – Victoria University Of Wellington, , New Zealand, 2School of Geography, Environment and Earth Sciences, Te Herenga Waka – Victoria University of Wellington, , New Zealand , 3Australian Nuclear Science and Technology Organisation, , Australia, 4GNS Science, Lower Hutt, New Zealand
Response of marine based sectors of the Antarctic Ice Sheet (AIS) to projected warming remains a significant uncertainty in sea level rise projections. The aim of this project is to provide understanding of past mechanisms and feedbacks of ice sheet change, and to reduce uncertainty in projections of future change. We extend the satellite record of ice sheet change by targeting strategic locations around the margins of the Ross Ice Shelf, which is responsible for buttressing large sectors of the marine-based West AIS. At these locations, glacial sediments deposited on nunataks adjacent to dynamic ice margins record the transient evolution of ice thickness throughout the Holocene period. Here, we focus on the Byrd Glacier, which drains 10% of the East AIS by area and contributes ~20% of the total mass of the Ross Ice Shelf. At Lonewolf Nunataks along the upper Byrd Glacier, our cosmogenic surface exposure ages constrain (i) past rates of ice thinning; (ii) total magnitudes of ice elevation change; and (iii) the absolute timing of ice discharge and thinning events in these sensitive regions. In this presentation, we will review the existing knowledge of Transantarctic Mountain outlet glaciers and present new data from our 2019-20 season along the upper Byrd Glaciers. Comparing our data to recent regional-scale ice sheet model simulations of the last deglaciation, we observe a distinct time lag between modelled thinning and our data-constrained thinning history. Our new data-model comparison will inform high-resolution, sector-scale numerical glacier model experiments, in which we seek to determine drivers of ice sheet thinning and retreat.
Jamey is a glacial geologist, primarily working in Antarctica. He uses cosmogenic nuclides extracted from glacial debris to reconstruct past glacier thickness. Jamey comes from The Ohio State University where he completed his masters before coming to New Zealand to complete his PhD and continues working at the Antarctic Research Centre.