Iceberg could disrupt ocean currents worldwide

Posted by Emma Woollacott

The calving of a massive Antarctic iceberg is expected to affect ocean circulation worldwide, causing colder winters the other side of the world.

The 2,500 square kilometer Mertz Glacier Tongue, south of Australia,  broke off two weeks ago after another 97km-long iceberg collided with it.

While the calving hasn't been shown to be caused by climate change, it's expected to lead to some.

The Antarctic Climate & Ecosystems (ACE) Cooperative Research Centre warns that the position of the two icebergs is likely to cause drastic changes to ocean currents worldwide.

The reason is that, each winter, an area of ice called the Mertz Glacier Polynya is formed immediately northwest of the Mertz Glacier Tongue and in the neighboring coastal bays.

Strong off-shore winds across this area lead to the growth of large amounts of sea ice each year. This is crucial to the formation of very salty, dense shelf water - a major ingredient of the world ocean circulation. 

A drop in production of this water could lead to colder winters in the North Atlantic for years to come, says ACE. It will also have important implications for the marine biology of the region.