Record 748-Foot Core Drilled in Antarctica Offers Clues to Future Sea-Level Rise

An international team of scientists has successfully drilled and recovered a record-breaking 228-meter (748-foot) sediment core from beneath the West Antarctic Ice Sheet (WAIS), providing an unprecedented look into Earth’s climate history. This geological archive, extracted from under 523 meters (1,716 feet) of ice, is expected to yield critical data for understanding how the massive ice sheet will respond to a warming planet and what it means for future global sea levels.

A Record-Breaking Glimpse into the Past

The achievement, part of the SWAIS2C project (“Sensitivity of the West Antarctic Ice Sheet to 2°C Warming”), shatters previous records for similar under-ice cores, which were less than 10 meters (33 feet) long. The team, which includes specialists from Binghamton University, State University of New York, and Victoria University of Wellington in New Zealand, conducted the operation at the Crary Ice Rise, a critical location on the edge of the Ross Ice Shelf. This area acts as a pinning point, slowing the flow of ice from the continent into the ocean.

First Clues from the Deep

Preliminary analysis suggests the core contains a continuous climate record spanning the last 23 million years. This includes periods when global average temperatures were significantly more than 2°C higher than pre-industrial levels. Scientists discovered a wide range of deposits, from fine-grained silts to gravel with large stones. Crucially, the presence of shell fragments and the remains of light-dependent marine organisms indicates that the region was once an open ocean. This finding supports the long-held hypothesis that the Ross Ice Shelf and parts of the WAIS have collapsed in the past during warmer climates.

“This archive will give us important information about how the West Antarctic Ice Sheet and the Ross Ice Shelf will likely respond to temperatures exceeding 2°C,” stated co-chief scientist Hugh Horgan from Victoria University of Wellington.

Why the West Antarctic Ice Sheet Matters

The stability of the WAIS is a critical question for climate scientists and coastal communities worldwide. It is considered a potential tipping point in the climate system because much of its base rests on bedrock far below sea level, making it highly vulnerable to warming ocean waters. Satellite observations confirm that the ice sheet is already losing mass at an accelerating rate. If the WAIS were to melt completely, it holds enough ice to raise global sea levels by an estimated 4 to 5 meters (13 to 16 feet), which would have devastating consequences for coastal cities around the globe.

A Triumph of Polar Engineering

Securing the core was a monumental logistical challenge that succeeded on the third attempt. The 29-person international team of scientists, engineers, and polar specialists operated from a remote camp over 700 kilometers (435 miles) from the nearest permanent research station. To reach the seabed, the team first had to use a hot-water drill to melt a hole through the 523-meter-thick ice before lowering more than 1,300 meters (4,265 feet) of drilling equipment into the borehole.

What’s Next for the Climate Archive?

The recovered sediment cores are now being transported from Antarctica to be distributed to laboratories in the 10 collaborating nations for detailed analysis. Researchers will study the physical, chemical, and biological properties of the sediment layers to reconstruct a detailed history of environmental changes. This data will be used to test and improve the accuracy of climate and ice sheet models, ultimately providing clearer projections of future sea-level rise and helping policymakers prepare for the impacts of a warmer world.