Application of the Fast Marching Method to the Reconstruction of Greenland Ice Sheet Retreat Across the Early Holocene Period

As the Greenland Ice Sheet retreats, it has become an increasingly large contributor to global sea level rise. As such, it has become important to study the geologic past of Greenland to understand the projected acceleration of mass loss, and where the ice sheet is heading in the future. In this research, we utilize the PaleoGrIS database, which contains 12 contours at 500-1000 year intervals, ranging between 14,000 years ago and 6,500 years ago. The contours were constructed by a team at the University of Sheffield using geochronological methods, mainly terrestrial cosmogenic nuclide surface exposure and radiocarbon dating. These methods allowed them to develop full contours of the Greenland Ice Sheet with varying degrees of uncertainty. Using the contours provided by the PaleoGrIS version 1.0 database, we have applied the fast marching method to better understand how the ice sheet has retreated spatially and temporally across the Early Holocene Period. The fast marching method is a numerical technique used to model the evolution of boundaries and interfaces. Thus, it provides us with a method to describe the velocity and extent between each contour. An increased understanding of the temporal and spatial patterns between each contour enables us to improve the quantification of uncertainty on the Greenland Ice Sheet.