A new peer-reviewed study has identified 245 previously undetected glacial earthquakes near the ocean-facing edge of Thwaites Glacier — Antarctica's so-called Doomsday Glacier — clustered in a period between 2018 and 2020 that coincided with the glacier's ice tongue flowing faster toward the sea. [1] The research, published in Geophysical Research Letters and written up by geophysicist Thanh-Son Pham for The Conversation, is the first substantial evidence that this specific kind of seismic activity, long documented in Greenland, also occurs at meaningful scale in Antarctica. [1]
Glacial earthquakes happen when tall, thin icebergs break off a glacier's edge, capsize in the water, and collide violently with the parent ice mass, sending seismic waves that can travel thousands of kilometers. [1] They produce almost no high-frequency waves, the signal typically used to detect and locate conventional earthquakes, which is why they went largely undocumented in Antarctica despite decades of routine seismic monitoring elsewhere on the continent. [1] Pham's study used seismic stations positioned in Antarctica itself, rather than relying on the global monitoring network that had failed to catch smaller Antarctic events, and turned up more than 360 total glacier-related seismic events between 2010 and 2023 — most not previously included in any earthquake catalogue. [1]
Two-thirds of those events, 245 of the 362 total, clustered near the marine edge of Thwaites, and most are likely genuine glacial earthquakes caused by capsizing icebergs. [1] The pattern that stands out is not seasonal. Greenland's glacial earthquakes vary with the calendar, spiking in late summer as warm air temperatures drive melt — but Thwaites's most prolific earthquake period instead lined up with a documented acceleration in the glacier's ice-tongue speed toward the ocean, independently confirmed by satellite observations. [1] Pham's own language about what caused that speed-up is careful rather than conclusive: the acceleration "could have been caused by ocean conditions, the effect of which is not yet well understood." [1]
A second cluster of seismic events turned up near Pine Island Glacier, roughly 60 to 80 kilometers from open water — too far inland to be explained by capsizing icebergs, and, in Pham's own assessment, "puzzling" events that "remain" for follow-up research to explain. [1] That unresolved cluster is a useful check on how far the Thwaites findings should be read: the study documents a genuine, previously invisible signal, but it does not yet fully explain even its own second-largest data cluster, let alone settle the broader question of how fast the glacier as a whole is destabilizing.
That caution matters because of what Thwaites represents on paper. A full collapse of the glacier would raise global sea levels by roughly three meters, and the glacier has drawn its "Doomsday" nickname from research suggesting it could disintegrate rapidly rather than melt gradually. [1] ScienceDaily's headline on the syndicated piece leads with the earthquake discovery inside that framing, which risks flattening a study built around words like "hints" and "not yet well understood" into a more certain signal of imminent collapse than the underlying research claims. Pham's own framing of what comes next is explanatory rather than alarmist: the findings, he writes, could help resolve "current large uncertainty in the projected sea-level rise over the next couple of centuries" — a research agenda, not a countdown. [1]
-- DARA OSEI, London