Swiss‑led team retrieves longest‑ever Antarctic drill core

Researchers recover the longest drill core to date in Antarctica Keystone-SDA

A Swiss‑led research team has extracted a 228‑metre drill core from beneath the Antarctic ice sheet. This is the longest ever recovered from sediments below any ice sheet.

+ Get the most important news from Switzerland in your inbox

According to the federal technology institute ETH Zurich, the drill core will help scientists better predict how global warming could affect future sea levels. The team aims to use it to pinpoint the temperatures at which the Antarctic ice sheet begins to melt.

The 29‑member team, drawn from ten countries and co‑led by ETH Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), spent ten weeks in a remote camp on the Ross Ice Shelf, some 700 kilometres from the nearest research station.

Earlier drilling attempts failed

To reach the hard‑to‑access sediments, the team first melted a shaft through 523 metres of ice. They then drilled a further 228 metres into the seabed beneath West Antarctica.

+ Predicting the climate of the future with 1.2 million-year-old iceExternal link

This is by far the longest core ever drilled beneath an ice sheet. The previous deepest was under ten metres. ETH Zurich says two earlier attempts to extract a core of this length had failed.

The drill core is seen as a climate archive, preserving evidence of environmental conditions from the distant past. According to ETH Zurich, early analyses indicate that the sediment layers could date back as far as 23 million years. That span includes periods when global average temperatures were significantly higher than they are today.

When will the ice melt?

If the West Antarctic ice sheet were to melt completely, global sea levels would rise by four to five metres, according to current estimates. The Ross Ice Shelf plays a crucial role in holding that ice in place, acting like a giant doorstop that keeps the glaciers behind it stable. If it were to disappear, the West Antarctic ice could flow freely into the ocean.

+ Why the Swiss are leading efforts to track melting glaciersExternal link

The researchers now want to understand the conditions that caused the ice sheet to become unstable in the past. A central question is whether a rise of two degrees above pre‑industrial temperatures would be enough to trigger a retreat.

The drill core was kept chilled on site before being flown to Scott Base in New Zealand. It will then be shipped on to mainland New Zealand, where detailed laboratory analyses are due to begin. The project is known as SWAIS2C (Sensitivity of the West Antarctic Ice Sheet to 2°C).

Translated from German by AI/sp

How we work

We select the most relevant news for an international audience and use automatic translation tools to translate them into English. A journalist then reviews the translation for clarity and accuracy before publication.  

Providing you with automatically translated news gives us the time to write more in-depth articles. The news stories we select have been written and carefully fact-checked by an external editorial team from news agencies such as Bloomberg or Keystone.

If you have any questions about how we work, write to us at [e-mail]