A UK team of climate scientists has discovered a rift in the Antarctic rock as deep as the Grand Canyon, which they believe is increasing the rate ice melt from the continent. With the recent news that an iceberg twice the size of Manhattan has broken away from Greenland, it seems that both of the planet’s ice caps may be in significant trouble.
The Antarctic chasm, known as the Ferrigno rift, was discovering using ice-penetrating radar and was revealed to be about 1.5km (1 mile) deep. The team believe that the sheer depth of the canyon is bringing warmer sea water into the ice sheet, which is speeding up the rate of melting.
Describing their discovery in the journal Nature, the team, led by Dr Bingham from the University of Aberdeen, said: “What we found is that lying beneath the ice there is a large valley, parts of which are approximately a mile deeper than the surrounding landscape. If you stripped away all of the ice here today, you’d see a feature every bit as dramatic as the huge rift valleys you see in Africa and in size as significant as the Grand Canyon. This is at odds with the flat ice surface that we were driving across – without these measurements we would never have known that it was there.
“What’s particularly important is that this spectacular valley aligns perfectly with the recordings of ice-surface lowering and ice loss that we have witnessed with satellite observations over this area for the last 20 years.”
The team also discovered that present-day ice loss is greater here than in other parts of Antarctica, where some glaciers are shrinking by more than a metre per year. The study was conducted in partnership with the British Antarctic Survey. Co-author Dr Fausto Feraccioli from the organization said: “The newly discovered Ferrigno Rift is part of a huge and yet poorly understood rift system that lies beneath the West Antarctic Ice Sheet. What this study shows is that this ancient rift basin, and the others discovered under the ice that connect to the warming ocean can influence contemporary ice flow and may exacerbate ice losses by steering coastal changes further inland.”
Ice loss from West Antarctica is believed to contribute about 10% to global sea level rise, but it is still unknown how the planet’s ice sheets are responding to the rising temperatures. What is known that if either the Arctic or Antarctic ice sheets were to completely melt, then the sea levels would rise by several metres.