Hitting the Ice Sheets Where It Hurts
"Several large tidewater outlet glaciers of the Greenland and Antarctic ice sheets now
appear to exhibit a nearly universal signature of recent increased discharge to the ocean.
That this increase is occurring in the Northern and Southern hemispheres suggests a common cause.
The culprit may be additional heat delivered by subsurface waters melting the submarine bases of
these glaciers. This scenario would explain the observations and at the same time provide evidence
that warmer subsurface waters are reaching the Earth's polar latitudes. Moreover, it indicates that
the ocean plays a more critical role than the atmosphere in determining near-term glaciological
contributions to changes in sea level."
"Oceanic low blows. Schematic representing warm intermediatedepth water breaching a submarine
sill and sinking in a water cavity beneath the ice shelf to access the grounding line of
an outlet glacier."
"A recent assessment of changes in speed and mass balance around Greenland identifies these three
large glaciers as among the most active recently, with accelerations up to 210% (12). The activity on
Kangerdlugssuaq and Helheim glaciers has been confirmed by analysis of optical imagery on slightly different
time intervals (13). Smaller glaciers along the southeast and southwest Greenland coasts are also
by Robert Bindschadler
24 March 2006