Climate change is often claimed for large environmental events, but a giant piece of ice that broke off a glacier may have been caused by something else.
The massive piece of the Pine Island glacier, which is the "longest and fastest flowing" in Antarctica, broke off and is now floating in the Amundsen Sea, an Alfred-Wegener-Institute press release reported.
Scientists noticed a crack in the glacier around October of 2011. "As a result of these cracks, one giant iceberg broke away from the glacier tongue. It measures [450 square miles] and is therefore almost as large as the city of Hamburg," Prof. Angelika Humbert, ice researcher at the Alfred Wegener Institute said.
Glaciers often crack and break (called calving), but this piece is especially large.
"Glaciers are constantly in motion. They have their very own flow dynamics. Their ice is exposed to permanent tensions and the calving of icebergs is still largely unresearched ," ice modeler Angelika Humbert said.
The team of German researchers used TerraSAR-X satellite data to create computer simulations of the glacier's flow and compared them with reality. As far as the team could tell, the giant crack was not caused by climate change.
"The creation of cracks in the shelf ice and the development of new icebergs are natural processes," Humbert said.
The fact that the glacier is the fastest flowing in the region (it has a flow speed of about two miles per year) climate change has little to do with it. The flow speed is believed to be caused by altered wind directions over the Amundsen Sea.
"The wind now brings warm sea water beneath the shelf ice. Over time, this process means that the shelf ice melts from below, primarily at the so-called grounding line, the critical transition to the land ice", Humbert said.
If the glacier speeds up even more, it could mean trouble for the Western Antarctic ice shelf.
"The Western Antarctic land ice is on land which is deeper than sea level. Its "bed" tends towards the land. The danger therefore exists that these large ice masses will become unstable and will start to slide," said Humbert.
The newly formed glacier will "act as a plug" to keep back the rest of the ice sheet, which contributes to rising sea levels as it melts, LiveScience reported.
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