The end of the last ice age saw a rapid melting of glaciers which lead to the raising of sea levels. This rise stabilized some 6000 years ago. The situation stabilized for the rest of the millennia until now. Over the past century the sea level in the US has risen by 25 to 30 centimeter. However even this figure is disputed with some environmentalist quipping that the rise in the last century has been more than what it was in the last 1000 years.
The warming of the globe has been precipitated by increasing green house gasses leading to melting glaciers and causing the ocean water to expand because of warming. Both increase the levels of the oceans. Core samples and tide gauge measurements and recently measurements with GPS have indicated that the GMSL or Global Mean Sea Level has risen by 4 to 8 inches. The yearly rate of rise has been 3.2 mm which is twice the rate in the preceding 80 years. Burning fossil fuels and human activities have released an enormous amount of greenhouse gases into the atmosphere. 80% of this additional heat is absorbed by the oceans.
A recent study has revealed that the rise of sea levels in the Antarctica has been higher than the Global Mean Sea Level rise. The study was done under the aegis of University of Southampton and the findings were published in the journal Nature Geoscience.
The study authors wrote“On the basis of the model simulations, we conclude that this sea-level rise is almost entirely related to steric adjustment, rather than changes in local ocean mass, with a halosteric rise in the upper ocean and thermosteric contributions at depth. We conclude that accelerating discharge from the Antarctic Ice Sheet has had a pronounced and widespread impact on the adjacent sub polar seas over the past two decades.”
The study involved the study of satellite images of the coast of Antarctica for the last 19 years. The sea level in the region rose by 8 cm which happens to be the 2cm more than the global average of 6 cm. This meant that each year 350 gigatons of fresh water into the oceans around Antarctica. The freshwater influx in the region is 2 mm more than the average of the Southern Ocean. The freshwater comes from Antarctic ice sheet and floating ice shelves and it is leading to a reduction in the salinity of the oceans.