Here is a short photo post illustrating the melting of Greenland's ice sheets. The speed and scale of the melt moving far more quickly then predicted, with startling changes over the past number of years.
Greenland ice sheet, 1992 vs. 2002 (via BBC):
Greenland ice sheet, 2005 (via Union of Concerned Scientists):
According to scientists, glacial surface meltwater is a factor in ice sheet collapse. As water melts at the surface, it flows downward through the ice through crevaces and moulins where it breaks up ice pacs from the inside and lubricates the surface between glacial undersides and rock.
A river flowing over the glacial surface into a large moulin (via Nasa).
A glacial surface lake 4.5 Miles South of Swiss Camp, inland from Disko Bay in West Greenland (via Greenpeace).
Aerial view of a meltwater pond (via The Flight Academy).