Ice-penetrating radar surveys and high-resolution satellite data have revealed a previously unknown system of interconnected subglacial basins beneath East Antarctica — a discovery that glaciologists say fundamentally changes how scientists model the continent's ice sheet dynamics and may require substantial revisions to long-term sea level rise projections that underpin global climate planning and coastal infrastructure design.
One System Where Scientists Saw Many
The research, drawing on data from NASA's ice-penetrating radar instruments and the European Space Agency's CryoSat-2 altimetry satellite, found that several subglacial features previously treated as separate geological structures are actually components of a single continuous fan-shaped basin network extending more than 400 kilometers beneath the East Antarctic Ice Sheet.
The discovery matters because the standard model of subglacial hydrology — the science of how water flows beneath Antarctic ice — treats these features as discrete, independently draining systems. When they are connected, meltwater can move between them in ways that existing models do not account for, potentially accelerating the transfer of geothermal heat from the continent's base to the ice above and lubricating large-scale ice sheet movement toward the coast.
"What we thought were independent lakes and channels are actually communicating with each other," said a glaciologist at the University of Colorado's Institute of Arctic and Alpine Research who contributed to the analysis. "That changes the entire hydrological picture for this sector of Antarctica in ways we are still working through."
East Antarctica's Overlooked Risk
Most public discussion of Antarctic vulnerability has focused on West Antarctica, where the Thwaites and Pine Island glaciers have been retreating rapidly enough to generate their own dedicated international research consortiums. East Antarctica is roughly ten times larger than West Antarctica by ice volume, but it has long been considered more stable — a slower-moving factor in sea level calculations that some models project to contribute positively through increased snowfall accumulation in a warmer atmosphere.
The new basin discovery complicates that assessment. The interconnected subglacial system lies beneath a sector of East Antarctica where the underlying bedrock dips below sea level — a configuration that makes the ice above it potentially susceptible to Marine Ice Sheet Instability, the same feedback mechanism driving concern about Thwaites. Once warm ocean water finds a pathway beneath ice resting on below-sea-level bedrock, the retreat can become self-sustaining in ways that are difficult to halt through any currently available intervention.
Researchers are careful to note that the new findings do not indicate East Antarctic collapse is imminent or even likely on timescales relevant to living humans. The basin system is currently frozen and draining slowly. But its connectivity means the system's behavior under sustained warming conditions is considerably less predictable than earlier models assumed — a finding with significant implications for the upper range of sea level rise projections.
Implications for Sea Level Science
The Intergovernmental Panel on Climate Change's Sixth Assessment Report, released in 2021, used sea level projections that relied heavily on ice sheet models built from subglacial mapping data now understood to be incomplete for this region. Researchers involved in the current discovery say their findings will be incorporated into the next generation of Antarctic ice sheet models informing the IPCC's Seventh Assessment, expected around 2028.
In Boulder, Colorado, National Snow and Ice Data Center researchers working on sea level budget assessments said the new mapping data will require recalibration of at least three regional ice drainage models currently in operational use by federal and international agencies. The adjustment is expected to widen uncertainty ranges in near-term sea level projections rather than definitively shift central estimates — a distinction that matters enormously for coastal planners trying to design for specific water level scenarios in cities like Miami, Charleston, and New Orleans.
"More uncertainty is not what planners want to hear, but it's the honest scientific answer right now," said a researcher at the National Snow and Ice Data Center. "We've found something that tells us our previous confidence was built on incomplete information. That is science working correctly, even when the news is inconvenient."
How the Discovery Was Made
The research team built its findings on a combination of airborne radar surveys conducted over multiple Antarctic field seasons and systematic reanalysis of archived satellite data stretching back nearly two decades. The technical challenge — imaging geological structures buried under more than two kilometers of ice — required cross-referencing data from multiple instruments and field campaigns before the connected nature of the basin system became clear.
Researchers said the finding highlights the compounding value of long-term observational archives, which allowed comparison of ice surface velocity measurements taken years apart to infer subglacial activity that no single field campaign could have detected. NASA's Operation IceBridge and its successor airborne survey programs are credited with providing the radar data quality that made the discovery technically achievable — a result that would have been impossible with the resolution available even a decade ago.
A follow-on field campaign to deploy ground-based seismic sensors directly above the newly identified basin network is being planned for the 2027-2028 Antarctic research season, pending funding approval from the National Science Foundation. That campaign is expected to provide the first direct measurements of water movement within the system — data that will determine whether the connectivity identified by radar is actively influencing ice dynamics today.