As the climate continues to warm, the Thwaites Glacier, often labeled the Doomsday Glacier, is undergoing rapid changes. It discharges billions of tons of ice into the ocean each year, accounting for about four percent of the annual rise in global sea level. The most accelerated melting occurs where the glacier meets the seafloor. This contact point has retreated roughly fourteen kilometers since the late 1990s, exposing a larger portion of ice to relatively warm ocean waters and intensifying the melt from below.
Scientists warn that a complete collapse of Thwaites could push sea levels higher by more than seventy centimeters, increasing the risk of flooding in coastal cities around the world. The ice shelf itself could disintegrate sooner than some earlier projections suggested.
To gain a clearer understanding of the glacier’s dynamics, a collaborative team from the United States and the United Kingdom conducted an intensive field investigation. The researchers drilled a six hundred meter borehole into the ice using a hot water system and deployed a suite of instruments to monitor changes over a five day period. This hands on effort brought fresh data on how the glacier interacts with the adjacent ocean.
A torpedo like robot named Icefin was deployed to reach once inaccessible zones. The remotely operated vehicle captured high resolution imagery and collected measurements on water temperature, salinity, and ocean currents, offering a rare window into the under ice environment. The capability to maneuver close to the seafloor allowed researchers to study dynamic regions that are typically hidden from view.
Experts described the mission as a breakthrough in observing the Subantarctic interface where ice and ocean meet. One lead author noted that the data revealed a nuanced and complex picture of the processes at work. Additional analyses from the research team emphasized the value of integrating under ice observations with satellite and shipboard measurements to build a more complete understanding of glacier behavior.
Findings indicate that melting underneath the flatter portions of the ice shelf proceeded at a slower pace than anticipated, even as the glacier was retreating. The measured melt rates ranged from approximately two to five point four meters per year, which is lower than some prior estimates. This slower melt at depth contrasts with the rapid retreat observed at other parts of the glacier and near the edge where it meets warmer waters.
The slowdown appears to be linked to a layer of colder, fresher water at the base of the glacier. This distinct water mass forms a barrier between the ocean and the ice shelf, reducing heat transfer and dampening melt in certain regions. Yet surface and near surface forces continue to drive ongoing retreat, signaling that the glacier remains in a precarious balance and vulnerable to shifts in ocean temperatures and circulation patterns.
Despite indications of localized stability in some zones, the overall trajectory of Thwaites remains destabilized. The researchers stressed that continued monitoring is essential to understand how evolving ocean conditions may influence future change. The study underscores the importance of combining direct measurements with remote sensing to capture the full range of processes shaping the glacier and its contribution to sea level rise.