Did the huge Greenland glacier break apart because of global warming? Maybe not.

An ice island about twice the size of Manhattan broke away from Greenland's Petermann Glacier last week, but the calving was likely caused by ocean currents, not global warming.

Greenland's Petermann Glacier ice shelf has given birth to a large iceberg, a July 21 satellite image shows.

NASA

July 26, 2012

Petermann glacier, a 70 km (43 mile) long tongue of ice that flows into the Arctic Ocean in northwest Greenland, recently calved an “ice island” approximately 130 square kilometers (50 sq. miles) — about twice the area of Manhattan.

The image above, acquired by NASA’s Terra satellite, shows the ice island as it drifts toward the ocean five days after breaking off the main glacier.

And if you want an idea of what a slab of ice this large looks like up close, here’s a video taken by researchers on approach to a smaller chunk of the 2011 island:

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Petermann glacier has been known for birthing massive ice islands; previously in August 2010 an even larger island broke away from the glacier, measuring 251 square kilometers (97 sq. miles). That slab of ice eventually drifted into the northern Atlantic and was even visible from the Space Station a year later!

 Read: Manhattan-Sized Ice Island Seen From Space

Although some of Greenland’s glaciers have been observed to be quickening their seaward pace as a result of global warming, this particular calving event — which occurred along a crack that appeared in 2001 satellite imagery — isn’t thought to be a direct result of climate but rather of ocean currents and isn’t expected to have any significant effect on the rate of Greenland’s ice loss as a whole. Still, satellite observation of such events provides valuable data for researchers monitoring the processes that are involved with rapidly accelerating Arctic ice loss.

Jason Major is a graphic artist from Rhode Island now living and working in Dallas, Texas. He writes about astronomy and space exploration on his blog Lights In The Dark, on Universe Today and also on Discovery News.

This story originally appeared in Universe Today.

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