Tech & Science

Scientists Have Drilled 7,000 Feet Into West Antarctic Ice Sheet to Find Out When it Last Disappeared

Scientists working in West Antarctica have drilled deep down into the ice, eventually reaching the sediment below at a depth of over 1.3 miles—or 7,000 feet. The team, with the British Antarctic Survey (BAS), reached the depth of 2,152 meters after 63 hours of continuous drilling at the Rutford Ice Stream—a large, fast flowing glacier that delivers ice into the ocean.

This is the deepest hole ever drilled using hot water—the previous deepest hole in Antarctica was 3,900 feet by a team from Caltech, while another group went 5,300 feet into the ice in Western Greenland.

The findings should help researchers better understand how the region will react to rising global temperatures—and to what extent melting will cause sea levels to rise.

The BAS team drilled down using hot water until they reached the sediment deep beneath the surface of the ice. They were then able to feed instruments down the borehole to take measurements like the water pressure, ice temperature and deformation. These readings should help them better understand the conditions at these depths, which will help scientists predict how the region will react to climate change in the future.

Keith Makinson, a physical oceanographer at the BAS, told Newsweek: “Rutford Ice Stream is a fast—one meter per day—flowing glacier 18 miles wide and over 1.2 miles deep, draining West Antarctica. It has been studied for almost 40 years. Ice streams drain the majority of ice from Antarctica so understanding how easily they slide over the ground beneath them into the ocean is critical to efforts attempting to predict changing sea level."

He said the biggest challenge when it comes to drilling in these remote regions is the freezing temperature—around minus 30 degrees Celsius. This means the 30cm hole they drilled would constantly refreeze. “There is a limited time window of about 24 hours where the hole is large enough to deploy instruments,” Makinson said. “After two or three days the hole has fully refrozen. This makes the round the clock drilling and science work very time pressured.”

West Antarctica has been covered in ice for millions of years—a period of cooling around 34 million years ago caused the continent to freeze over, producing the landscape we see today. However, climate change is causing the West Antarctic Ice Sheet to destabilize, placing it at risk of collapse. Should this happen, scientists estimate sea levels could rise by between two and three meters.

The West Antarctic Ice Sheet mostly sits on ground that is well below sea level—at some points over 8,000 feet deep. If it becomes unstable, it could quickly melt and flow into the ocean. By understanding what happened to the ice sheet during periods of warming in the past, scientists hope to predict sea level rise in the future—and this is what data from the latest drilling expedition should tell them.

“We will find how long ago the ice sheet last disappeared completely, and how water and soft sediments underneath it helped the ice move fast on its journey to eventually melting in the sea,” Makinson said.

Antarctica drilling camp The British Antarctic Survey camp where the drilling took place. British Antarctic Survey

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