Pine Island glacier in Antarctica just lost enough ice to cover Manhattan 5 times more

A huge iceberg about five times the size of Manhattan has been detached from the Pine Island Glacier of Antarctica yesterday (October 29), just one month after the first appearance of a crack , according to the satellite images.

"I was a little surprised," said Stef Lhermitte, assistant professor in the Department of Geoscience and Remote Sensing at the Delft University of Technology in the Netherlands.

Since he spotted the crack in early October, Lhermitte had guessed that icebergs would take weeks or months to undo, "but that turned out to be rather fast," he told Reuters. Live Science. [Photo Gallery: Antarctica’s Pine Island Glacier Cracks]

At 115 square miles (300 square kilometers), the huge amount of ice that has detached from the ice floe is even larger than the mass that broke up last year said Lhermitte.

However, the newborn iceberg did not stay together for long. In the space of one day, it was split into smaller pieces, the largest piece measuring about 226 km2 (87 square miles) before breaking even more, said Lhermitte.

The largest iceberg was large enough to receive a name, but it is not known yet if this will happen, since it has been around for so little time. But if it bears the same name, it will likely be called B-46 by the US National Ice Center, Lhermitte said.

Lhermitte first noticed the crack that led to this giant calving event, while watching a satellite image of October 3. Lhermitte said he received a satellite image of the Pine Island Glacier every day in his inbox. "And suddenly, I saw something that I had not seen the day before," he told Live Science at the time.

But after consulting the images of Sentinel-1, a satellite managed by the European Space Agency, Lhermitte discovered that the crack had appeared the last week of September, between September 25 and 30. By compiling together satellite images, Lhermitte does a GIF showing how fast the iceberg has come off the ice floe.

Even more dramatic is a time-lapse from 1972 to 2018, showing how the pack ice has declined over the years. It is natural for ice patches to grow and shrink over time, as this time frame shows. But in 2015, the ice cap dropped significantly, and then continued to retreat to the present day without showing growth, Lhermitte said.

For years, the ice sheet touched a shallow point at the bottom of the ocean, called an anchor point, which could have prevented it from regressing too far back, said Lhermitte. . "After 2015, he lost the connection with this anchor point, which could explain retirement in 2015 and 2017," said Lhermitte. "And now this [ice shelf break] is about 5 kilometers [3.1 miles] more inland. "

In addition, the Pine Island Glacier seems to empty icebergs more frequently than before. At the beginning of the year 2000, glaciers created icebergs about every six years. The calving took place in 2001, 2007 and 2013. But since 2013, they were four: in 2013, 2015, 2017 and 2018, said Lhermitte.

"The retreat we are seeing now is outside of what we observed [in modern times]Said Lhermitte. And this is worrying because ice trays are essential structural elements for glaciers; they slow down the flow of ice in the ocean, much like the dirt from an obstructed drain impedes the flow of water, he said.

Comparison of the Pine Island Glacier's Calving Front in 2018 and Historical Data from 1973 to 2011 by @JoeMacGregor shows how many PIG fell from the 1973-2013 range. pic.twitter.com/ifxmk85hMo

– Stef Lhermitte (@StefLhermitte) October 30, 2018

It's unclear exactly why Pine Island Glacier is boring icebergs more often than before. Deep, warm seawater melts the pack ice. "It depends on the climate, but the fact that the wind conditions change," explains Lhermitte, "is the cause of the heat of this hot water." "It is very difficult to say that it is a climate change because we still do not know how it all works."

Originally posted on Live Science.