New research shows Antarctica's Larsen C Ice Shelf is thinning on both the top and bottom.
The ice shelf neighbored Larsen A and B, which collapsed in 1995 and 2002, respectively, the British Antarctic Survey reported. The new finding could help scientists predict how Antarctic ice will contribute to future sea level rise.
To make their findings, the researchers looked at satellite data and eight radar surveys taken between 1998 and 2012. The data showed the Larsen C Ice Shelf lost about 13 feet of ice during this period.
"What's exciting about this study is we now know that two different processes are causing Larsen C to thin and become less stable. Air is being lost from the top layer of snow (called the firn), which is becoming more compacted-probably because of increased melting by a warmer atmosphere. We know also that Larsen C is losing ice, probably from warmer ocean currents or changing ice flow," said lead author, Paul Holland from British Antarctic Survey (BAS). "If this vast ice shelf-which is over two and a half times the size of Wales and 10 times bigger than Larsen B - was to collapse, it would allow the tributary glaciers behind it to flow faster into the sea. This would then contribute to sea-level rise."
The researchers predicted the ice shelf could collapse within the century, and found an ominous crack is forming in the ice that could cause it to retreat back further than it has in the past. The ice shelf also appears to be becoming detached from the Bawden Ice Rise at its northern edge.
"When Larsen A and B were lost, the glaciers behind them accelerated and they are now contributing a significant fraction of the sea-level rise from the whole of Antarctica. Larsen C is bigger and if it were to be lost in the next few decades then it would actually add to the projections of sea-level rise by 2100," said Professor David Vaughan, glaciologist and Director of Science at BAS.
The researchers expect sea level rise to exceed about 20 inches by 2100, which could be a huge problem for cities built at low elevations or on coasts.
The findinds were published in a recent edition of the journal The Cryosphere.
