Project Sponsor : NASA (Cryospheric Science Research Announcement, ROSES-2020)
Start Date : 08/01/2023
Faculty Investigator : Dr. Brian Gunter
Project Status : In progress
Glacial Isostatic Adjustment (GIA), specifically so the post-glacial rebound component, describes the response of the solid earth to variable ice loading. Using satellite gravimetry from GRACE and GRACE-FO, altimetry from ICESat-2 and others, as well as additional surface process models, we empirically estimate the present-day uplift of the bedrock beneath the Antarctic Ice Sheet (AIS).
Characterizing the Antarctic GIA signal is critical to understanding the impacts of climate change. Ice mass change calculations require removing the GIA field from total mass changes, a result that allows for the determination of AIS contribution to present and future sea-level rise. Current GIA modeling efforts can be classified into two fields: forward modeling, which uses ice sheet histories developed from paleo data and physics-based ice sheet modeling to estimate uplift; and inverse modeling, which optimally estimates the modern uplift using an observation-based approach. As ice sheet histories and modeling efforts contain significant error, the resolution of GIA is the largest source of uncertainty within the determination of ice sheet mass change. Using our empirical inversion and associated algorithms, we are able to produce optimal estimates of present-day rates of solid earth uplift.
Working in tandem with the Earth Surface Evolution Group at the University of Wisconsin-Madison, these fields are used as part of a model that uses paleo constraints to calculate relative sea level histories.
Upcoming work will focus on developing improved processing algorithms for input data and the inversion, as well as the incorporation of other Antarctic data sources.