Project Scope.

Overall mass loss of the Greenland Ice Sheet is increasing over time, but the specific outlet glaciers that contribute to this mass loss exhibit heterogeneous response to climate change. Some glaciers are not retreating, while neighboring glaciers are. In addition, recent observations in Alaska suggest that sedimentation at outlet glacier termini might build topography at rates of several meters per year, exceeding the topographic change associated with rebound-induced uplift, which is thought to be important to constrain future mass loss of the ice sheets. Thus, sedimentation at grounding lines of outlet glaciers may be an important process that builds topography possibly contributing to the diverse response of glaciers to climate change and may buffer some amount of sea level rise from ice sheets.

This project aims to quantify the rates of processes contributing to sediment build-up at the termini of outlet glaciers (producing moraines). Our observations will:

1. determine the processes contributing to sediment mass-balance within moraines at active outlet glacier termini

2. determine rates of sedimentation for each process from in situ field observations

3. link processes to drivers (ice sheet, climate, geometric etc)

Our observations will form the basis for parameterizations of ice sheet sedimentation that, when coupled to ice sheet models provide a more realistic depiction of glacier variability over time.