WASHINGTON (AP) — Nearly all of Greenland’s massive ice sheet suddenly
started melting a bit this month, a freak event that surprised scientists.
Even Greenland’s coldest and highest place, Summit station, showed melting.
Ice core records show that last happened in 1889 and occurs about once every
Three satellites show what NASA calls unprecedented melting of the ice sheet
that blankets the island, starting on July 8 and lasting four days. Most of
the thick ice remains. While some ice usually melts during the summer, what
was unusual was that the melting happened in a flash and over a widespread
"You literally had this wave of warm air wash over the Greenland ice sheet
and melt it,” NASA ice scientist Tom Wagner said Tuesday.
The ice melt area went from 40 percent of the ice sheet to 97 percent in
four days, according to NASA. Until now, the most extensive melt seen by
satellites in the past three decades was about 55 percent.
Wagner said researchers don’t know how much of Greenland’s ice melted, but
it seems to be freezing again. “When we see melt in places that we haven’t
seen before, at least in a long period of time, it makes you sit up and ask
what’s happening?” NASA chief scientist Waleed Abdalati said. It’s a big
signal, the meaning of which we’re going to sort out for years to come.”
About the same time, a giant iceberg broke off from the Petermann Glacier in
northern Greenland. And the National Snow and Ice Data Center on Tuesday
announced that the area filled with Arctic sea ice continues near a record
Wagner and other scientists said because this Greenland-wide melting has
happened before they can’t yet determine if this is a natural rare event or
one triggered by man-made global warming. But they do know that the edges of
Greenland’s ice sheets have already been thinning because of climate change.
Summer in Greenland has been freakishly warm so far. That’s because of
frequent high pressure systems that have parked over the island, bringing
warm clear weather that melts ice and snow, explained University of Georgia
climatologist Thomas Mote.
He and others say it’s similar to the high pressure systems that have parked
over the American Midwest bringing record-breaking warmth and drought.
Ohio State University ice scientist Jason Box, who returned Tuesday from a
three-week visit, said he ditched his cold weather gear for the cotton pants
that he normally dons in Nevada. “It was sunny and warm and all the locals
were talking about how sunny it was,” Box said after getting off a plane.
“Beyond T-shirt weather.”