Manhattan-Sized Iceberg a Threat to Shipping Lanes, Being Tracked

A team of international researchers received an emergency grant to track an enormous iceberg, equal in size to Manhattan, which is making its way to the sea after calving from the Pine Island Glacier.

A massive Antarctic iceberg, almost 270 square miles in size, the size of Manhattan or Singapore, separated itself from the Pine Island Glacier on July 8, 2013. After calving from the Antarctic glacier it was floating in the Amundsen Sea and was listed as the fastest flowing glacier in the Western Antarctic as it maintained a constant speed of 4 kilometers.

At the rate at which it was floating, the researchers feared that it could become a maritime hazard.

To prevent this hazard from happening, the Natural Environment Research Council (NERC) has granted an emergency fund to researchers at the University of Southampton to help in tracking the icy giant that could be a possible threat to the shipping lanes in the Southern Ocean.

"The primary reason to monitor the iceberg is that it's very large. An iceberg that size could survive for a year or longer and it could drift a long way north in that time and end up in the vicinity of world shipping lanes in the Southern Ocean," Dr Robert Marsh from Ocean and Earth Science at the University of Southampton, an investigator on the project, said in a press statement.

Dr Marsh further states that the Antarctic Peninsula is an active region and there is a high possibility for the ships to cross the path of this huge flowing iceberg.

It was the space agency NASA that had initially identified the crack in the glacier tongue on October 14, 2011. At that point of time the emerging crack was just 24 kilometers long with a width of 50 meters. On May 11, 2012, a 30 square kilometer iceberg was seen that was enclosed by another massive icy giant. Since then this natural event has been monitored by scientists from Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research with the help of TerraSAR-X, an earth observation satellite from the German Space Agency (DLR).  The changes occurring in the icy giant have been documented in several  images and using this data the scientists are solving the secrecy of 'calving' (set loose).

Globally, on an average of every two years such massive icebergs break off of glaciers. But this is the first time that researchers are tracking and predicting the path of the iceberg.

The result they obtain will be used in the future to accurately model the path of large icebergs, which might be a common occurrence in the future due to the rising temperatures that trigger glacier calving. Apart from this, the ocean currents get affected by the large amount of freshwater that is released from the iceberg.

"If the iceberg stays around the Antarctic coast, it will melt slowly and will eventually add a lot of freshwater that stays in that coastal current, altering the density and affecting the speed of the current. Similarly, if it moves north it will melt faster but it could alter the overturning rates of the current as it may create a cap of freshwater above the denser seawater," says Professor Grant Bigg of the University of Sheffield, principal investigator on the grant.

Bigg clarifies that even though the glacier is not massive enough to trigger a large scale impact, it definitely could have an effect. Especially, if such glacier calving events become common, the amount of freshwater amassing can have a long lasting drastic effect.