Wilkes Subglacial Basin: Antarctica’s Hidden Threat to Global Sea Levels

The Wilkes Subglacial Basin in East Antarctica sits atop a bedrock situated up to 2,000 meters below sea level, where a complete melt of its massive ice sheet would drive global ocean levels up by three to four meters, slate.fr reported. While surface conditions across the 1,400-kilometer by 400-kilometer region look unchanging, the underlying topography and warming ocean water create conditions for potential long-term instability. More than a century ago, Australian geologist Sir Douglas Mawson led a sledge expedition covering hundreds of kilometers of ice to reach this remote region of East Antarctica, which had to turn back following the tragic death of one of its members. Another Australian, Cecil Madigan, led a separate group across the sea ice to the same region before also turning back. These intrepid explorers never actually set foot on an ice sheet that could prove crucial for our future. To this day, no one is known to have traveled there.

Warm Ocean Temperatures Threaten East Antarctic Ice Sheets

East Antarctic ice sheets are increasingly vulnerable to shifting environmental conditions, as past warm periods show significant shrinkage when global temperatures were 2 to 3 degrees Celsius higher than pre-industrial levels. Today, ocean temperatures just off the East Antarctic coast hover around minus 1.8 degrees Celsius, keeping the thick ice stable against the basin edges. However, minor increases in water temperatures or changes in ocean currents could accelerate melting along the basin boundary. Torrents of meltwater would likely disrupt ocean currents at the base of the oceanic circulation, triggering major upheavals for marine life and the wider climate.

Bedrock geometry inside the Wilkes Subglacial Basin deepens inward away from the ocean. As coastal ice retreats along this downward slope, warm water will reach deeper sections of the ice sheet. This dynamic turns ice withdrawal into a self-sustaining process that resists natural stabilization.

Historical Analogues in Past Climates

During the Pliocene epoch three million years ago, global temperatures matched the 2 to 3 degree Celsius warming trajectory projected for the end of the twenty-first century. Past ice sheet melting during that period pushed ice margins hundreds of kilometers inland and raised global sea levels between 6 and 23 meters. Marine sediment cores from the period indicate profound physical transformations across the Antarctic continent.

Radar Aircraft Map Wilkes Subglacial Basin Bedrock

Most existing data regarding the Wilkes Subglacial Basin comes from radar-equipped aircraft capable of penetrating thick ice to map sub-surface bedrock topography.