Washington: Data from the GPS stations has indicated that an unusually hot melting season in 2010 accelerated ice loss in southern Greenland by 100 billion tons – and large portions of the island’s bedrock rose an additional quarter of an inch in response.
The finding was concluded from a network of nearly 50 GPS stations planted along the Greenland coast to measure the bedrock’s natural response to the ever-diminishing weight of ice above it.
Every year as the Greenland Ice Sheet melts, the rocky coast rises, explained Michael Bevis, Ohio Eminent Scholar in Geodynamics and professor in the School of Earth Sciences at Ohio State University.
Some GPS stations around Greenland routinely detect uplift of 15 mm (0.59 inches) or more, year after year. But a temperature spike in 2010 lifted the bedrock a detectably higher amount over a short five-month period – as high as 20 mm (0.79 inches) in some locations.
“Pulses of extra melting and uplift imply that we’ll experience pulses of extra sea level rise. The process is not really a steady process,” Bevis said at the American Geophysical Union meeting in San Francisco.
Greenland GPS Network (GNET) measurements indicate that as that ice melted away, the bedrock beneath it rose. The amount of uplift differed from station to station, depending on how close the station was to regions where ice loss was greatest.
Southern Greenland stations that were very close to zones of heavy ice loss rose as much as 20 mm (about 0.79 inches) over the five months.
Even stations that were located far away typically rose at least 5 mm (0.2 inches) during the course of the 2010 melting season. But stations in the North of Greenland barely moved at all.