Antarctica may have been discovered exactly 200 years ago but the icy landmass is yet to reveal all of its secrets. A team of scientists from the International Thwaites Glacier Collaboration (ITGC) travelled to Antarctica to study its seabed groundling line.
The grounding line marks the point where the Antarctic glacier rests on the ocean seabed and floats over the water.
Scientists are studying this critical part of the Antarctic continent to better understand how it contributes to global sea levels rising.
Britney Schmidt from the Georgia Institute of Technology said: “Visiting the grounding line is one of the reasons work like this is important because we can drive right up to it and actually measure where it is.
“It’s the first time anyone has done that or has ever even seen the grounding zone of a major glacier under the water, and that’s the place where the greatest degree of melting and destabilisation can occur.”
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However, visiting the glacier’s grounding line is not as simple as it may at first seem.
The researches first had to drill deep into the Thwaites Glacier to lower their robot to the seabed.
The feat was achieved with a hot-water drill that melted a 1,953ft-deep (590m) access hole into the glacier.
The researchers could then lower their underwater robot, the Icefin, all the way down under the Antarctic.
According to Dr Schmidt, the robot swam nearly 10 miles during a series of consecutive trips to chart the grounding line.
She said: “Icefin swam over 15 km (9.3 miles) round trip during five missions.
“This included two passes up to the grounding zone, including one where we got as close as we physically could to the place where the seafloor meets the ice.
It’s the first time anyone has done that
Britney Schmidt, Georgia Institute of Technology
“We saw amazing ice interactions driven by sediments at the line and from the rapid melting from warm ocean water.”
The Thwaites Glacier accounts for about four percent of the global sea-level rise.
Researchers fear the glacier’s grounding line could reach a tipping point in its foundation, triggering a massive collapse of the glacier.
Should the Florida-sized mass of ice crash into the oceans, sea levels could rise by another 25 inches (63.5cm).
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Keith Nicholls, an oceanographer from the British Antarctic Survey, said: “We know that warmer ocean waters are eroding many of West Antarctica’s glaciers, but we’re particularly concerned about Thwaites.
“This new data will provide a new perspective of the processes taking place, so we can predict future change with more certainty.”
On top of the seabed study, the Thwaites researchers drilled into the Antarctic glacier to collect ice core samples.
The samples were taken from depths between 985ft and 2,300ft (300m and 700m).
The researchers also took sediment samples from the seafloor under the glacier and carried out seismic and radar measurements.
The results of their surveys are expected to fuel studies and research around the globe in the coming months and years.
According to the ITGC, the amount of ice water flowing into the oceans from Thwaites has nearly doubled in the last 30 years.
Dr Schmidt said: “While Greenland’s contribution to sea level has already reached an alarming rate, Antarctica is just now picking up its contributions to sea level.
“It has the largest body of ice on Earth and will contribute more and more of sea-level rise over the next 100 years and beyond.
“It’s a massive source of uncertainty in the climate system.”
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