GREENLAND GLACIERS ARE SPEEDING UP
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation (melting and sublimation) over many years, often centuries. Crevasses, seracs, and other distinguishing features of a glacier are due to its flow. Another consequence of glacier flow is the transport of rock and debris abraded from its substrate and resultant landforms like cirques and moraines. Glaciers form on land, often elevated, and are distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
Greenland’s ice sheet is on the move, with new images showing its glaciers moving 30 percent faster than they were a decade ago.
We encourage you to read the full article by checking the site’s url at the end of this blog.
The heavily crevassed ice on this small Greenland outlet glacier cascades down to the fjord water (bottom right), which is filled with icebergs and small bits of ice.
CREDIT: Ian Joughin and Science / AAAS
Greenland and Antarctica … glaciers are shrinking and the water contained in them is moving into the oceans, adding to the already rising sea level. A glacier’s velocity is a measure of how fast the ice on the surface of the sheet is flowing … The faster the flow, the more water and ice mass is lost from the glacier.
“You can think of the Greenland ice sheet as a really large lake that has hundreds of those little outlet streams that are acting like conveyor belts to move ice from the middle of the ice sheet, where it’s getting added by precipitation, to the edges,” study researcher Twila Moon, a graduate student at the University of Washington, told LiveScience…
researchers analyzed satellite images of the Greenland glaciers taken between 2000 and 2010. These annual images were put through a computer program to detect how quickly the ice is moving. In general, the glacial flow has sped up by 30 percent over the 10 years, Moon said … The glaciers that drop off into the sea are flowing the fastest, Moon said, up to 7 miles (11 kilometers) per year and their speeds are accelerating. “The areas where the ice sheet loses the most ice are also the areas we are seeing the biggest changes,” Moon said…
“A lot of the drive behind current Greenland ice sheet and Antarctica studies is to ask, ‘What sea-level rise can we expect?'” Moon said. “Both of these areas hold vast amounts of ice and the potential for very large sea-level rises. We need to understand what’s happening on them to see what potential scenario will be realized.”
Jennifer Welsh, LiveScience Staff Writer, May 03,2012