Antarctic coastal waters 'rising faster'
Near-shore waters went up by about 2mm per year more than the general trend for the Southern Ocean as a whole in the period between 1992 and 2011. Scientists say the melting of glaciers and the thinning of ice shelves are dumping 350 billion tonnes of additional water into the sea annually. This influx is warming and freshening the ocean, pushing up its surface.
"Freshwater is less dense than salt water and so in regions where an excess of freshwater has accumulated we expect a localised rise in sea level," explained Dr Craig Rye from the University of Southampton, UK, and lead author on the new journal paper. Globally, sea levels are going up, in part because of the contribution of the world's diminishing ice fields. This is well known.
But the Nature Geoscience report is the first to show the direct consequences to sea surface height (SSH) around Antarctica itself. While the satellite data record indicates there has been a general upward trend in SSH in the Southern Ocean south of 50 degrees of up to 2.4mm per year, those satellites also indicate a more rapid rise in waters sitting on the continental shelf.