Title: Mapping the Spatial Extent of Basal Frozen-on Ice in Northern Greenland

Abstract: The Greenland ice sheet covers 80% of Greenland and is the largest ice sheet in the northern hemisphere. Multi-Channel Coherent Depth Sounder (MCoRDS) developed at the Center for Remote Sensing of Ice Sheets (CReSIS) has provided extensive radar data from Greenland spanning 1995 – 2011, most recently as part of NASA Operation IceBridge. In a comprehensive review of this dataset, we have identified near-bed ice packages that are distinct from surrounding ice. These features are unstratified, distinguishable from the bed, and exhibit spatial continuity between the flight lines. We geolocate the spatial extent of the features and demonstrate that they are widespread in northern Greenland. They are morphologically similar to the accreted ice packages discovered in East Antarctica during the Antarctic Gamburtsev Province (AGAP) project, which were interpreted as frozen-on ice packages. The interactions at the ice-bed interface determine the large-scale behavior of ice sheets. Frozen-on ice packages may influence the rheology and the known dynamics of this interface and that of the overlying ice sheet. The extent of the observed ice packages indicates that these processes are common throughout the Greenland ice sheet. Mapping their distribution enhances our understanding of the Greenland ice sheet and highlights the importance of incorporating these processes into ice sheet models.

Funding: Operation IceBridge is a NASA project. LDEO’s contribution to IceBridge is supported by NASA contract no. NNG10HP20C.

Output: Presented as a poster (#C41E-0450 ) at the 2011 American Geophysical Union Annual Meeting.

We’re mapping the spatial extent of subglacial features under the Greenland ice sheet using airborne geophysics collected from NASA Operation IceBridge and other missions to better understand the dynamics of the ice sheet. Click to download a higher resolution of the poster.