New data for 2014 concerning the retreat of the calving front of the Jakobshavn glacier, Greenland, on the NASA Earth Observatory site.
The paper presents results concerning the detection of widespread ice-covered valleys that extend significantly deeper below sea level and farther inland than previously thought. This has potential implications for ice dynamics and how Greenland might contribute to sea level rise in the future, through the ocean thermal forcing. The paper can be found here. Here's the title, authors and abstract:
Deeply incised submarine glacial valleys beneath the Greenland ice sheet
M. Morlighem, E. Rignot, J. Mouginot, H. Seroussi and E. Larour
Abstract. The bed topography beneath the Greenland ice sheet controls the flow of ice and its discharge into the ocean. Outlet glaciers move through a set of narrow valleys whose detailed geometry is poorly known, especially along the southern coasts1–3. As a result, the contribution of the Greenland ice sheet and its glaciers to sea-level change in the coming century is uncertain4. Here, we combine sparse ice-thickness data derived from airborne radar soundings with satellite derived high-resolution ice motion data through a mass conservation optimization scheme5.We infer ice thickness and bed topography along the entire periphery of the Greenland ice sheet at an unprecedented level of spatial detail and precision. We detect widespread ice-covered valleys that extend significantly deeper below sea level and farther inland than previously thought. Our findings imply that the outlet glaciers of Greenland, and the ice sheet as a whole, are probably more vulnerable to ocean thermal forcing and peripheral thinning than inferred previously from existing numerical ice-sheet models.
I am re-posting an interesting message from Mauri Pelto on the Zachariae Isstrom ice loss. The original message is below ....
Dear Glacier Colleagues:
Petermann has got lots of attention this summer but the losses in area of Zachariae Isstrom and the open water currently at its front are worth noting. Below is a link to a post on the glacier with numerous Landsat images, this is meant only as a visual update not a substitute for the detailed research that has been conducted and will continue on this important outlet glacier.