June 27, 2011 Stronger ocean currents beneath West Antarctica's
Pine Island Glacier Ice Shelf are eroding the ice from below,
speeding the melting of the glacier as a whole, according to a
new study in Nature Geoscience. A growing cavity beneath the ice
shelf has allowed more warm water to melt the ice, the
researchers say -- a process that feeds back into the ongoing
rise in global sea levels. The glacier is currently sliding into
the sea at a clip of four kilometers (2.5 miles) a year, while
its ice shelf is melting at about 80 cubic kilometers a year --
50 percent faster than it was in the early 1990s -- the paper
estimates. "More warm water from the deep ocean is entering the
cavity beneath the ice shelf, and it is warmest where the ice is
thickest," said study's lead author, Stan Jacobs, an
oceanographer at Columbia University's Lamont-Doherty Earth
Observatory. In 2009, Jacobs and an international team of
scientists sailed to the Amundsen Sea aboard the icebreaking
ship Nathaniel B. Palmer to study the