Estimating Ice Discharge at Greenland's Three Largest Outlet Glaciers Using Local Bedrock Uplift

Rapid changes in ice discharge from Greenland outlet glaciers.

Using satellite-derived surface elevation and velocity data, we found major short-term variations in recent ice discharge and mass loss at two of Greenland's largest outlet glaciers. Their combined rate of mass loss doubled in less than a year in 2004 and then decreased in 2006 to near the previous rates, likely as a result of fast re-equilibration of calving-front geometry after retreat. Total...

Radar Measurements of Ice Sheet Thickness of Outlet Glaciers in Greenland

We have conducted airborne measurements over the Greenland ice sheet from the NASA P-3B aircraft using a 150MHz coherent radar depth sounder to obtain extensive ice sheet thickness measurements. Simultaneous measurements of ice sheet elevation were also made using a laser altimeter. In outlet glacier areas along the ice sheet margin, the ice surface is characterized by a very rough, crevassed s...

Origin of stratified basal ice in outlet glaciers of Vatnajökull and Öræfajökull, Iceland

During the period 2000–2005, we collected samples of englacial ice, vent water, frazil/anchor ice and stratified basal ice from warm-based outlet glaciers of Vatnajökull and Öræfajökull, Iceland, and analysed them for H, O and D. Results of H analyses show that the stratified basal ice contains H from atmospheric thermonuclear testing and is younger than the englacial ice. Results of the O and ...

Subglacial discharge at tidewater glaciers revealed by seismic tremor

Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems. However, our present inability to track subglacial discharge and its variability significantly hinders our understanding of these processes. Here ...

Discharge, discharge variability, and the bedrock channel profile