The biggest ice shelf of the Antarctic, Larsen C, is thinning from above and below and could soon collapse, with major consequences for global sea levels. A team of scientists from the British Antarctic Survey (BAS) and led by Dr Paul Holland analysed the condition of the Larsen C ice shelf, which is the largest ice shelf on the Antarctic peninsula, and found out that it is thinning due to warmer ocean and air temperatures that are causing losses of ice from both above and below. Indeed, researchers used satellite radar imagery taken between 1998 and 2012, and discovered that throughout this timespan Larsen C lost 4 metres of thickness. Being Larsen C more than twice the size of Wales, its collapse – which, according to Dr Holland’s team, could happen within decades – could contribute significantly to sea level rise. Scientists recently warned that the collapse of ice shelves in the Antarctica could add metres to the global sea levels, and Professor David Vaughan, who is director of science at the BAS, stated that the collapse of Larsen C alone could lead to a few centimetres of sea level rise, and therefore poses a serious threat on coastal communities around the world. The study was published in May in the journal Cryosphere, and is of particular interest as it reveals that, even though losses are significant both from above and below, the main driver is ice loss from below; in fact, the shelf is floating on increasingly warm ocean currents, and this is causing a loss of around 28 centimetres of ice a year from below. The ice shelf is also thinning from above, as the layer of snow on top is becoming more compact due to warmer air, which is melting the snow and filling into air pockets; more specifically, it is estimated that this is contributing another 3.7 centimetres a year to the thinning of the ice shelf. Dr Vaughan stressed the importance of the finding that oceanic warming is the major driver of the melting of the ice, and said that “if, as this piece of work is beginning to indicate, the oceans have a role in the Antarctic Peninsula as well then actually we have to start thinking about ice shelves around the rest of the Antarctic on those same time scales of several decades”. The gLAWcal Team POREEN project Wednesday, 13 May 2015 (Source: Guardian)