Record-Breaking Sediment Core May Help Predict Antarctic Ice Loss

An international research team has recovered the longest sediment core ever drilled from beneath an ice sheet, providing crucial insights into past climate changes.

Published on Feb. 23, 2026

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An international research team has recovered the longest sediment core ever drilled from beneath an ice sheet in West Antarctica. The 228-meter core preserves evidence of climate changes spanning millions of years and will help improve predictions of how the West Antarctic Ice Sheet may respond to ongoing global warming. The core was drilled at Crary Ice Rise, on the margin of the West Antarctic Ice Sheet, and provides direct evidence of how the ice-sheet margin behaved during earlier warm intervals in Earth's history.

Why it matters

If the West Antarctic Ice Sheet were to melt completely, global sea level would rise by four to five meters. The new sediment core will give researchers critical insights about how the West Antarctic Ice Sheet and Ross Ice Shelf are likely to respond to temperatures above 2°C above pre-industrial levels, which is a key threshold for climate change impacts.

The details

The researchers recovered the sediment core at a drilling site located around 700 kilometers from the nearest support station. The core contains a striking variety of sediment types, from fine-grained muds to firmer gravels with larger rocks, indicating the region experienced past periods of open ocean when there was partial or complete retreat of the Ross Ice Shelf and potential collapse of the West Antarctic Ice Sheet. Determining the timing of these past ice retreats and the environmental factors that drove the changes is a central focus of the research team.

  • The researchers drilled through 523 meters of ice at Crary Ice Rise to extract the 228-meter sediment core.
  • The sediment core is estimated to preserve a record of climate changes spanning the past 23 million years.

The players

SWAIS2C

An international research project called the Sensitivity of the West Antarctic Ice Sheet to 2°C, which is focused on understanding how the West Antarctic Ice Sheet may respond to further global warming.

Huw Horgan

SWAIS2C Co-Chief Scientist and researcher at Te Herenga Waka – Victoria University of Wellington, ETH Zurich and WSL.

Molly Patterson

SWAIS2C Co-Chief Scientist and Professor of Geology at Binghamton University, USA.

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What they’re saying

“This record will give us critical insights about how the West Antarctic Ice Sheet and Ross Ice Shelf is likely to respond to temperatures above 2°C. Initial indications are that the layers of sediment in the core span the past 23 million years, including time periods when Earth's global average temperatures were significantly higher than 2°C above pre-industrial.”

— Huw Horgan, SWAIS2C Co-Chief Scientist

“We saw a lot of variability. Some of the sediment was typical of deposits that occur under an ice sheet like we have at Crary Ice Rise today. But we also saw material that's more typical of an open ocean, an ice shelf floating over ocean, or an ice-shelf margin with icebergs calving off.”

— Molly Patterson, SWAIS2C Co-Chief Scientist

What’s next

The SWAIS2C team will now refine and confirm the age of the sediment core records through further analysis, with the goal of determining when past periods of ice retreat occurred and what environmental factors drove those changes.

The takeaway

The recovery of this record-breaking sediment core from beneath the West Antarctic Ice Sheet is a significant scientific and technical achievement that will provide crucial insights into how the region's ice may respond to future global warming, helping to improve predictions of sea level rise.