Fresh Water Causes Antarctic Seas to Rise Faster

Monday 08th Sep 2014 by theWeather Club

Glacial meltwater is a key factor in the sea level rise in Antarctica (Image from Wikimedia Commons)

Sea levels around Antarctica are rising faster than anywhere else in the Southern Ocean, and researchers now think they have the answer: Glacial meltwater.

Roughly 350 billion tonnes of freshwater entering the ocean around Antarctica - from melting Antarctic ice sheets and floating ice shelves - are causing sea levels to rise much higher and faster than the global average. The global average rise in sea level over the past 19 years has been approximately 6cm, whilst around Antarctic it is 2 cm higher.

The work - published in Nature Geoscience - involved examining sea levels using satellite imagery covering a million square kilometres, as well as ship-based measurements of sea water, which confirmed the reduction in ocean salinity. According to Craig Rye, an oceanographer at University of Southampton, fresh-water is less dense than salt water, therefore in regions with excess, accumulated freshwater there are localised increases in sea level. Computer model simulations of the effect of melting glaciers were also explored, and were found to support their theory.

The research was carried out by University of Southampton in close collaboration with researchers at the National Oceanography Centre and the British Antarctic Survey.