Frozen white molasses

From the air, Greenland’s ice sheet looked like white molasses oozing
down the mountainside and into the sea. Researchers are investigating Greenland’s glacial lakes, which form atop the
ice sheet each spring and summer as returning sunlight melts ice and
snow. They have found that as lake grow larger, large cracks can open
up at their bases, allowing the lake water to drain in a dramatic surge
all
the way to the bedrock at the bottom of glaciers. The water lubricates the
base of the glacier, like grease on a railroad track,
allowing glaciers to flow faster toward the coast and discharge more
ice
to the ocean.

(Photo by Chris Linder, Woods Hole Oceanographic Institution)