Glaciers Quicken Pace to Sea
Posted: Fri Sep 24, 2004 10:03 am
A number of huge glaciers in the West Antarctic are sliding into the ocean at an accelerating rate and raising sea levels, according to new data.
The new study, published Thursday in the journal Science, found that six glaciers flowing into the Amundsen Sea have quickened their march into the ocean over the past 15 years, and the pace has accelerated recently. The fastest of these, the Pine Island Glacier, is ripping along at a six-yards-a-day pace -- 25 percent faster than it was moving in the 1970s -- making it one of the fastest-moving glaciers on Earth.
Pine Island Glacier and its neighbour Thwaites Glacier are very active glaciers that together drain one third of the West Antarctic Ice Sheet. A collaboration with scientists at University College London that involved the use of ranging altimeters in satellites had shown that the Pine Island Glacier/Thwaites Glacier drainage basin was shrinking. The drainage basin is so far from any research station that the region is inaccessible to field parties, so for further studies, satellites are crucial.
In collaboration with US colleagues at NASA/JPL, BAS scientists have applied radar interferometry techniques to observations from European Space Agency satellites to study this region. The observations show that Pine Island Glacier accelerated around 10% per year from 1992 to 2000, while its neighbour Thwaites Glacier flowed normally. Importantly, the pattern and rate of change observed suggested that the glacier's acceleration was caused by increased lubrication at the bed of the glacier, rather than by the retreat of a (now non-existent) buttressing ice shelf. Such information is vital for assessing the future size of the West Antarctic Ice Sheet and the impact on sea level worldwide.
Attached files
The new study, published Thursday in the journal Science, found that six glaciers flowing into the Amundsen Sea have quickened their march into the ocean over the past 15 years, and the pace has accelerated recently. The fastest of these, the Pine Island Glacier, is ripping along at a six-yards-a-day pace -- 25 percent faster than it was moving in the 1970s -- making it one of the fastest-moving glaciers on Earth.
Pine Island Glacier and its neighbour Thwaites Glacier are very active glaciers that together drain one third of the West Antarctic Ice Sheet. A collaboration with scientists at University College London that involved the use of ranging altimeters in satellites had shown that the Pine Island Glacier/Thwaites Glacier drainage basin was shrinking. The drainage basin is so far from any research station that the region is inaccessible to field parties, so for further studies, satellites are crucial.
In collaboration with US colleagues at NASA/JPL, BAS scientists have applied radar interferometry techniques to observations from European Space Agency satellites to study this region. The observations show that Pine Island Glacier accelerated around 10% per year from 1992 to 2000, while its neighbour Thwaites Glacier flowed normally. Importantly, the pattern and rate of change observed suggested that the glacier's acceleration was caused by increased lubrication at the bed of the glacier, rather than by the retreat of a (now non-existent) buttressing ice shelf. Such information is vital for assessing the future size of the West Antarctic Ice Sheet and the impact on sea level worldwide.
Attached files