Researchers warning that Antarctica’s remote Wilkes Subglacial Basin harbors enough ice to raise global sea levels by up to four meters are calling for urgent international expeditions to study the unstable region before climate thresholds trigger runaway glacial retreat.
For decades, scientific concern regarding melting Antarctic ice has focused primarily on the West Antarctic Ice Sheet and its fragile, marine-based glaciers. Researchers argued that East Antarctica, anchored by a much colder and thicker ice sheet resting largely on dry land, would remain secure under short-term global warming scenarios. A new study led by Professor Matt King from the University of Tasmania, challenges that long-held assumption, identifying deep marine basins in the east that share the vulnerabilities of their western counterparts.
The Wilkes Subglacial Basin Structure and Hidden Risks
Stretching roughly 870 miles, or 1,400 kilometers, along the inland side of the Transantarctic Mountains within Australian territory, the Wilkes Subglacial Basin is a massive depression in the bedrock entirely hidden beneath a thick layer of ice. Much of the basin consists of an ice sheet sitting on bedrock that is deeper than 2,000 meters below sea level, and scientists have had to rely on radar and satellite observations to collect data on the vast basin.
Such a configuration leaves it prone to marine ice sheet instability, meaning that once a certain threshold is crossed, the retreat of coastal glaciers speeds up dramatically. When this melting reaches a tipping point, the ice sheet can quickly become unstable, according to Victoria University ice sheet modeller Nick Golledge.
“The Wilkes Subglacial Basin is arguably the last unexplored place in Antarctica,” Matt King, a professor at the University of Tasmania and lead author of the study, said in a statement.
Matt King, professor at the University of Tasmania and lead author of the study
Containing immense volumes of frozen water, the region holds enough ice to elevate worldwide ocean levels by 3 to 4 meters, or up to 10 to 13 feet, should complete melting occur. King noted that melting Antarctic ice can disrupt the entire global climate system. To evaluate the stability of the basin, the investigators integrated climate, oceanographic, and geological data alongside sophisticated ice sheet simulations.
Observed Changes at Cook Glacier and Past Pliocene Warnings
Signs of environmental stress are already being observed. Showing an accelerated rate of thinning since the 1990s, the basin’s primary outlet, the Cook Glacier, presently discharges approximately 40 billion tonnes, or 44 billion tons, of ice annually into the surrounding ocean, as reported by the study’s authors.
Geological data from past warm epochs provide stark context for these modern observations. Although exact projections regarding temperature impacts on Antarctica remain uncertain, researchers point out that during the mid-Pliocene—a geological timeframe spanning 3.3 million to 3 million years ago—temperatures exceeded pre-industrial levels by 2 to 3.5 degrees Celsius, while sea levels surpassed modern heights by 6 to 23 meters.
The limited evidence we do have highlights the risk of rapid change as temperatures rise.
“The limited evidence we do have highlights the risk of rapid change as temperatures rise,” said study co-author Professor Nancy Bertler, a climate scientist at Earth Sciences New Zealand and Te Herenga Waka—Victoria University of Wellington.
Nancy Bertler, climate scientist at Earth Sciences New Zealand and Victoria University of Wellington
International Expeditions Planned to Close Observation Gaps
Despite the high stakes, direct observations of the basin remain sparse. No ship has ever been within 150 kilometers of the Cook Glacier terminus, and researchers needed multiple icebreakers to be in the same area—an effort that could take five to 10 years to co-ordinate. There is no in-situ seabed mapping data of the sea floor, and information about the oceanic conditions that could drive future melting remains very limited.
Reaching the basin overland is similarly difficult because the Transantarctic Mountains stand between it and both New Zealand’s Scott Base and the US McMurdo Station. Requiring three summers of effort after two failed attempts had to be abandoned, the expedition team set up camp on the ice at a distance of 1,100 kilometers from the closest permanent station.
To bridge these critical data gaps, the international scientific community is rallying behind coordinated multi-year programs. On October 1, the Korea Polar Research Institute reported the publication of a joint study involving 39 specialists hailing from 13 nations, which included Principal Researcher Lee Wonsang.
According to the Korea Polar Research Institute, while East Antarctica has traditionally been viewed as relatively stable in contrast to the rapidly evolving West Antarctic sector, this investigation offers compelling reasons to rethink that assumption, and the institute added that it will actively join international collaborative efforts to eliminate observational blind spots in Antarctica during the upcoming fifth International Polar Year.
“The evidence points to a clear need to find out more about how this region will change as the climate warms,” says Professor Rob McKay, director of Victoria University’s Antarctic Research Centre.
Professor Rob McKay, director of Victoria University’s Antarctic Research Centre