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This is a Feb. 2017 image of the Larsen C ice shelf in Antarctica made available by the Antarctic Survey on Wednesday July 12, 2017. Photo: British Antarctic Survey via AP

The six-month wait is over: a gigantic 5,800-square-kilometer Antarctic ice shelf monitored by scientists finally broke away this week.

The Larsen C Ice Shelf completely calved off the Antarctic Peninsula sometime between Monday and today, and was detected by a NASA satellite using thermal infrared imaging.

Larsen C was already floating in the ocean before it broke off so it has no immediate impact on sea level, according to scientists with the United Kingdom-based Project MIDAS.

But the freed iceberg now weighs 1 trillion tons, and has twice the volume of Lake Erie, according to the scientists.

“We have been anticipating this event for months, and have been surprised how long it took for the rift to break through the final few kilometers of ice,” said Adrian Luckman, lead MIDAS investigator. “The iceberg is one of the largest recorded and its future progress is difficult to predict.”

Its fate could follow two previous ice shelves on the peninsula. Larsen A collapsed in 1995 and Larsen B suddenly broke off and disintegrated in 2002.

If Larsen C melts, it could allow glaciers to flow off the land quicker, but at a still relatively-modest rate.

The rift cannot be explicitly linked to anthropogenic global warming, explained Martin O’Leary, a glaciologist at Swansea University who is another member of the MIDAS project.

“Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position,” said O’Leary, in a MIDAS statement. “This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that that rest of the shelf is becoming unstable.”

The British Antarctic Survey contends that man-driven changes in the world’s climate is causing the rapid thinning of most of the polar ice.

“There is little doubt that climate change is causing ice shelves to disappear in some parts of Antarctica at the moment,” said David Vaughan, a glaciologist who is also the Survey’s director of science. “We see no obvious signal that climate warming is causing the whole of Antarctica to break up. However, around the Antarctic Peninsula, where we saw several decades of warming through the latter half of the 20th century, we have seen these ice shelves collapsing and ice loss increasing.”

Indeed, NASA scientists announced this week that they had established evidence that warming events in the Arctic, on the opposite pole, were becoming more frequent.
 

Laboratory Equipment Managing Editor Lauren Scrudato contributed to this report.

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