The water temperatures on the West Antarctic shelf are rising. The reason for this is predominantly warm water from greater depths, which as a result of global change now increasingly reaches the shallow shelf. There it has the potential to accelerate the glacier melt from below and trigger the sliding of big glaciers.
The Antarctic ice sheet is a giant water reservoir. The ice cap on the southern continent is on average 2, meters thick and contains about 70 percent of the world's fresh water. If this ice mass were to melt completely, it could raise the global sea level by 60 meters. Therefore scientists carefully observe changes in the Antarctic. In the renowned international journal Science, researchers from Germany, the UK, the US and Japan are now publishing data according to which water temperatures, in particular on the shallow shelf seas of West Antarctica, are rising.
The elevated temperatures have accelerated the melting and sliding of these glaciers in recent decades and there are no indications that this trend is changing,"says the lead author of the study, Dr. For their study, he and his colleagues of the University of East Anglia, the California Institute of Technology and the University of Hokkaido Japan evaluated all oceanographic data from the waters around Antarctica from to that were available in public databases.
These data show that five decades ago, the water masses in the West Antarctic shelf seas were already warmer than in other parts of Antarctica, for example, in the Weddell Sea. However, the temperature difference is not constant. Around Antarctica in greater depth along the continental slope water masses with temperatures from 0.
These temperatures are very warm for Antarctic conditions. And they are significant shallower than 50 years ago," says Schmidtko. Especially in the Amundsen Sea and Bellingshausen Sea they now increasingly spill onto the shelf and warm the shelf.
