The Thwaites Glacier in the Antarctic is in danger of collapsing, and the results could be devastating. Thwaites releases billions of tonnes of what was frozen ice into the ocean each year, but why it was melting so fast was a mystery to scientists.
However, a team of British and American scientists have mapped the cavities beneath the glacier and have come to some shocking conclusions.
The cavities were much bigger than expected – some half the size of the Grand Canyon – which allowing warmer water to gnaw away at the underside of the glacier, causing it to melt from the bottom as well as the top.
The British Antarctic Survey (BAS) and used all the weapons in their arsenal, including a ship, a plane and most importantly a submarine to map the bottom of the glacier to the bottom of the ocean floor, which was much deeper than expected.
The new study, which was published in The Cryosphere journal, will allow scientists to better predict how sea levels will inevitably rise in the future.
Lead author Dr Tom Jordan, an aero-geophysicist at BAS, who led the airborne survey, said: “It was fantastic to be able to map the channels and cavity system hidden beneath the ice shelf; they are deeper than expected – some are more than 800 metres deep.
“They form the critical link between the ocean and the glacier.
“The offshore channels, along with the adjacent cavity system, are very likely to be the route by which warm ocean water passes underneath the ice shelf up to the grounding line, where the ice meets the bed.”
Lead author, Dr Kelly Hogan, a marine geophysicist at BAS who was part of the team who surveyed the ocean floor, said: “We found the coastal sea floor, which is incredibly rugged, is a really good analogue for the bed beneath the present-day Thwaites Glacier both in terms of its shape and rock type.