Record-Breaking Drill Retrieves Longest Antarctic Ice Core

The 228-meter sediment core provides a 23-million-year climate history to predict the future of the West Antarctic Ice Sheet.

Published on Feb. 21, 2026

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An international research team has recovered a record-breaking 228-meter-long sediment core from beneath the West Antarctic Ice Sheet, providing a geological time capsule spanning 23 million years. The core offers critical insights into how the West Antarctic Ice Sheet and Ross Ice Shelf have responded to past periods of global warming, which could help predict how they will react to modern climate change.

Why it matters

The West Antarctic Ice Sheet is a global floodgate - if it completely melts, sea levels could rise by 4-5 meters, submerging major coastal cities. This new sediment core provides the first direct evidence of how the ice sheet's margins have shifted during ancient warm periods, filling a crucial gap in climate models that previously relied on peripheral data.

The details

The sediment core was extracted in three-meter segments, revealing a diverse geological timeline reflected in the changing composition of the seabed. The layers transitioned from fine-grained muds to firm gravels containing large rocks, indicating shifts between periods of quiet deep-water deposition and more turbulent glacial activity. The presence of light-dependent marine fossils and shell fragments within the sediment also proves that this now-frozen region was once an ice-free open ocean.

  • The record-breaking 228-meter sediment core was recovered in 2026.
  • The sediment core captures a geological record spanning approximately 23 million years.

The players

Huw Horgan

Co-chief scientist of the SWAIS2C project, which led the drilling expedition.

Molly Patterson

Professor of Geology at Binghamton University, USA, and member of the SWAIS2C research team.

SWAIS2C project

An international research team that conducted the record-breaking sediment core drilling expedition in Antarctica.

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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 are 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, Co-chief scientist of the SWAIS2C project (interestingengineering.com)

“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, Professor of Geology at Binghamton University, USA (interestingengineering.com)

What’s next

The SWAIS2C team is now focused on pinpointing the exact timing and environmental triggers of past ice sheet collapses in the region to determine how close the West Antarctic Ice Sheet is to a similar retreat today.

The takeaway

This record-breaking sediment core provides the first direct evidence of how the West Antarctic Ice Sheet has responded to past periods of global warming, filling a crucial gap in climate models and offering critical insights into the future of this vulnerable region as the planet continues to warm.