Gigantic Chunk of Iceberg Eight Times the Size of Manhattan Breaks off from Antarctica’s Pine Island Glacier

A massive ice shelf that is eight times the size of Manhattan separated itself from the Pine Island Glacier in the Antarctica on July 8, 2013. The gigantic ice shelf is currently floating in the Amundsen Sea in the form of a very large iceberg.

It was on October 14, 2011 that a group of scientist from the American Space Agency NASA identified the first crack in the glacier tongue. The then emerging crack was some 24 kilometers long and 50 meters wide.  The second crack was noticed on May 11, 2012. It produced a 30 square kilometer  iceberg that was enclosed by another bigger iceberg.

"As a result of these cracks, one giant iceberg broke away from the glacier tongue. It measures 720 square kilometres and is therefore almost as large as the city of Hamburg",  Prof. Angelika Humbert, ice researcher at the Alfred Wegener Institute, said in a press release.

Since then a team of scientists from Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research , have been following the cracks with the help of TerraSAR-X, an earth observation satellite from the German Space Agency. They have documented the changes in several single images and this data is believed to solve the secrecy of 'calving'.

In order to get a deep understanding of the physical processes involved in glacier movements and also to observe the progress of the two cracks spotted earlier, the team worked with the high resolution radar images of the DLR earth observation satellite TerraSAR-X. With this they managed to approximately measure the width of the cracks and measure the speed at which the ice was flowing.

 "Above the large crack, the glacier last flowed at a speed of twelve metres per day", said Dr. Dana Floricioiu from DLR. And Nina Wilkens, PhD graduate in Prof. Humbert's team.  "Using the images we have been able to follow how the larger crack on the Pine Island glacier extended initially to a length of 28 kilometres. Shortly before the "birth" of the iceberg, the gap then widened bit by bit so that it measured around 540 metres at its widest point."

The team used the data provided by TerraSAR-X satellite in computer simulation by which they can model the mechanism of the ice masses when they break and flow. These simulation results were compared with current satellite data.

According to Humbert, the Pine Island glacier, which flows from Hudson Mountains to Amundsen, is the fastest flowing glacier in Western Antarctic and flows at the speed of 4 kilometers per year. This speed is not affected by the rising air temperature but the wind directions.

A faster flow of the Pine Island glacier for the Western Antarctic ice shelf would lead to serious consequences.