Hundreds of Glacial Earthquakes Detected at Antarctica’s ‘Doomsday’ Glacier

A new seismic analysis of Antarctica has revealed more than 360 previously undocumented glacial earthquakes at the vulnerable Thwaites and Pine Island glaciers between 2010 and 2023, raising fresh questions about ice-sheet stability and future sea-level rise, according to research soon to be published in Geophysical Research Letters.

By Staff Reporter | Updated: 13 December 2025

New Signals Beneath Antarctica’s Ice

Glacial earthquakes, a special type of seismic event generated when tall, thin icebergs break off and capsize at a glacier’s ocean front, have long been documented in Greenland but remained elusive in Antarctica. In the new study, a researcher reports evidence for hundreds of such low-frequency quakes around Antarctica’s Amundsen Sea sector, with a strong concentration at Thwaites Glacier, often referred to as the “Doomsday Glacier” because of its potential to drive rapid global sea-level rise if it collapses.

The events were detected using seismic stations based on the Antarctic continent, rather than the global monitoring networks that had previously missed these smaller-magnitude quakes. The findings suggest that interactions between warming oceans and Antarctica’s ice shelves may be producing more dynamic and frequent iceberg calving than recognized by traditional earthquake catalogs.


What Are Glacial Earthquakes?

Glacial earthquakes were first identified in the early 2000s in Greenland, when seismologists noticed unusual, long-period seismic signals originating from major outlet glaciers. According to the U.S. Geological Survey and subsequent peer-reviewed studies, these events occur when large icebergs detach from a glacier’s terminus and topple or capsize, slamming back against the “mother” glacier and the ocean water.

Unlike typical tectonic earthquakes, which generate a wide spectrum of seismic waves including high-frequency components, glacial earthquakes are dominated by long-period, low-frequency motions. These signals can travel thousands of kilometers through the Earth’s crust but are harder to pinpoint with standard detection techniques that rely heavily on high-frequency energy.

Researchers say this frequency difference is one reason glacial earthquakes went largely unnoticed for decades, despite continuous monitoring for earthquakes, volcanic activity and nuclear tests. Only when scientists re-examined seismic records with new analytical approaches did the distinctive signature of glacial quakes stand out.

“These events are powerful but sneaky,” explained glaciologist Meredith Nettles of Columbia University in earlier work on Greenland glacial quakes. “They move a lot of ice, but their frequency content makes them easy to miss with tools designed for tectonic earthquakes.”

Lessons From Greenland’s Glacial Quakes

Most glacial earthquakes documented to date have been associated with major Greenland outlet glaciers such as Jakobshavn Isbræ, Helheim and Kangerdlugssuaq, according to studies published over the past two decades in journals including Science and Nature. These events can reach magnitudes comparable to those of underground nuclear tests carried out by North Korea, making them detectable by high-quality, continuously operating seismic networks worldwide.

In Greenland, glacial earthquakes show a clear seasonal pattern. They occur more frequently in late summer, when warmer air and ocean temperatures enhance surface melt and undercut ice fronts, promoting calving. Multiple research groups have reported that these events have become more common since the 1990s, a trend many scientists link to amplified Arctic warming.

Climate scientists caution that the link between glacial earthquakes and long-term ice loss is complex. While more frequent calving events can indicate destabilizing ice fronts, some calving is a natural part of glacier dynamics. Still, the growing catalog of Greenland events has become an important indicator of how fast large outlet glaciers are changing in a warming climate.

The new Antarctic study extends this line of inquiry to the southern hemisphere, where comparable records have been sparse.


Elusive Evidence in Antarctica

Antarctica holds the largest single mass of ice on Earth, yet direct confirmation of glacial earthquakes driven by capsizing icebergs has been comparatively rare. Earlier attempts to find such events primarily relied on the global seismic monitoring network, the same system used to track powerful tectonic earthquakes and nuclear tests.

If Antarctic glacial earthquakes are generally smaller than the largest Greenland events, they may fall below the detection threshold of those distant global stations. That limitation, scientists argue, could explain why the continent’s glacial seismicity has appeared relatively quiet in earlier analyses.

In the new research, the author instead turned to seismic instruments deployed within Antarctica itself, including stations on or near the ice sheet in West Antarctica. By systematically searching low-frequency data recorded between 2010 and 2023, the study identified more than 360 glacier-related seismic events that are largely absent from standard earthquake catalogs maintained by global agencies.

According to the pre-publication summary shared with media outlets, the events cluster in two main regions: the termini of Thwaites Glacier and Pine Island Glacier, both major fast-flowing outlets of the West Antarctic Ice Sheet.


Focus on the ‘Doomsday Glacier’

Thwaites Glacier, located in the Amundsen Sea sector of West Antarctica, has drawn intense scientific and public attention over the past decade. Multiple studies, including work by the International Thwaites Glacier Collaboration (ITGC), project that a full collapse of Thwaites and its upstream catchment could raise global sea levels by around 3 meters over centuries. Researchers warn that parts of the glacier rest on ground that slopes downward inland, a configuration that can, under certain conditions, promote rapid retreat.

In the new seismic analysis, most of the identified Antarctic glacial earthquakes originate near the ocean-facing end of Thwaites Glacier, where its ice shelf meets warming waters. The events are interpreted as signals of large icebergs calving and capsizing, with their collisions generating the distinctive long-period seismic waves that travel across the continent and beyond.

Satellite observations over the same period have shown increasing fracturing and retreat at Thwaites’ ice front. The emerging seismic record adds another layer of evidence that the glacier’s terminus is highly dynamic, even if many individual events are too small to be detected by the global network.

Scientists emphasize that the presence of glacial earthquakes alone does not prove an imminent catastrophic collapse. Instead, the quakes provide a detailed, time-stamped record of iceberg calving that can be combined with satellite imagery, ocean measurements and ice-flow models to refine projections of future change.


Pine Island Glacier: A Second Hotspot

The study’s second cluster of Antarctic glacial earthquakes lies at Pine Island Glacier, another major West Antarctic outlet roughly east of Thwaites. Pine Island and Thwaites together have been described in scientific literature as the largest individual contributors to sea-level rise from Antarctica in recent decades.

Pine Island’s ice shelf has experienced repeated episodes of thinning and calving, documented by satellite missions from NASA and the European Space Agency. Large rifts and fractures have periodically led to the release of massive tabular icebergs, some extending tens of kilometers.

The new seismic detections indicate that certain Pine Island calving episodes are also accompanied by glacial earthquakes. Researchers say that each recorded event represents a discrete, energetic interaction between collapsing ice and the surrounding ocean, offering clues about the mechanical processes at play at the ice front.

Comparing the timing and magnitude of glacial earthquakes at Pine Island and Thwaites may help scientists understand how local ocean conditions, bedrock topography and ice-shelf geometry influence calving behavior across the Amundsen Sea region.


Many glaciologists view glacial earthquakes as potential indicators of how rapidly large outlet glaciers are responding to climate change, particularly to warming oceans that erode ice shelves from below. In Greenland, the observed increase in glacial quake frequency has been widely interpreted as consistent with accelerated calving in a warming Arctic.

For Antarctica, the picture is still emerging. The new analysis suggests that low-frequency calving-related seismicity has been ongoing at Thwaites and Pine Island for at least a decade, but without a long-term Antarctic catalog, it remains difficult to determine whether these events are becoming more frequent or energetic over time.

Some scientists argue that identifying hundreds of previously unrecorded events underscores how incomplete earlier assessments of Antarctic ice dynamics have been. They contend that more comprehensive monitoring could reveal stronger links between ocean warming, ice-shelf thinning and seismic activity.

Others urge caution, noting that calving is an inherent part of glacier behavior and that short observational records can be misleading. They emphasize the need to integrate glacial earthquake data with multi-decade satellite archives, airborne surveys and numerical models before drawing firm conclusions about trends.

“These findings are an important puzzle piece, but they are not the whole picture,” said a polar scientist not involved in the study, speaking to science media. “We need to know whether this level of seismic activity is new or simply newly observed.”

How Researchers Detected the Hidden Quakes

The new study relies on analysis of low-frequency seismic data from instruments deployed across West Antarctica. Because glacial earthquakes lack the high-frequency energy used in standard earthquake-location algorithms, the researcher applied specialized techniques that focus on long-period surface waves and correlate signals between multiple stations.

According to a summary provided ahead of peer-reviewed publication, the methodology involved searching continuous records from 2010 to 2023 for events with the spectral and temporal characteristics of known Greenland glacial earthquakes. Candidate events were then cross-checked against satellite imagery to confirm the presence of contemporaneous calving episodes where possible.

The approach builds on earlier work in the northern hemisphere but adapts it to the unique geometry and station coverage of Antarctica. By using regional data rather than distant global stations, the analysis could identify smaller events and better constrain their locations near specific glacier fronts.

The author reports that more than 360 distinct glacial seismic events were identified, the majority of them at Thwaites and Pine Island glaciers. Many do not appear in global catalogs maintained by agencies such as the International Seismological Centre, highlighting a gap between local and global monitoring capabilities.

Independent experts note that full validation will require broader community scrutiny once the detailed methods and datasets are available in the forthcoming Geophysical Research Letters article.


Implications for Sea-Level Projections

Understanding how and when glaciers lose ice to the ocean is central to improving projections of future sea-level rise. Thwaites and Pine Island glaciers together drain a significant portion of the West Antarctic Ice Sheet, which contains enough ice to raise global sea levels by several meters if it were to collapse over long timescales.

Glacial earthquakes provide a near-real-time record of large calving events, complementing satellite observations that may only capture snapshots every few days or weeks. Researchers say integrating seismic data into ice-flow and ocean models could refine estimates of how quickly ice fronts are retreating and how sensitive they are to changes in ocean temperature and circulation.

Some modeling studies have suggested that once certain grounding lines in West Antarctica retreat past critical thresholds, further retreat could become self-sustaining, a process known as marine ice-sheet instability. While the new seismic results do not directly confirm such a tipping point, they document active ice–ocean interactions at key outlet glaciers that are central to those concerns.

Policymakers and coastal planners rely on assessments from bodies such as the Intergovernmental Panel on Climate Change, which incorporate a range of potential Antarctic contributions to sea-level rise. As the observational basis expands to include glacial earthquakes, experts expect future assessments to incorporate this additional line of evidence.


Scientific Debate and Remaining Uncertainties

The discovery of hundreds of Antarctic glacial earthquakes has prompted a range of reactions within the polar science community. Many researchers welcome the findings as a significant advance in understanding the dynamics of Thwaites and Pine Island glaciers, while also emphasizing the preliminary nature of the results.

Supporters of the new approach argue that glacial seismicity has been systematically undercounted in Antarctica and that incorporating these data will lead to more realistic representations of calving in predictive models. They note that seismic networks are relatively inexpensive compared with satellite missions and can operate year-round in darkness and bad weather.

Others raise questions about how consistently glacial earthquakes can be interpreted as indicators of destabilization. Some point out that glaciers may undergo periods of intense calving even under relatively stable climate conditions, and that factors such as local geometry or subglacial hydrology can play major roles.

There is also discussion over how to communicate findings about the “Doomsday Glacier” to the public. While the term has helped draw attention to the vulnerability of Thwaites, several scientists caution that it can be misleading if it suggests a sudden, global catastrophe is imminent, rather than a process unfolding over decades to centuries.

As the full study becomes available, researchers are expected to compare its event catalog with independent datasets, including ice-penetrating radar, GPS measurements and high-resolution satellite time series, to test interpretations of individual quakes and broader trends.


  • Thwaites Glacier alone could contribute around 3 meters to global sea levels if it were to collapse fully over long timescales, according to multiple modeling studies.
  • Pine Island and Thwaites glaciers are currently among the fastest-changing sectors of the West Antarctic Ice Sheet.
  • Glacial earthquakes are dominated by low-frequency seismic waves and can be missed by standard earthquake detection methods.
  • In Greenland, glacial earthquakes are most common in late summer and have increased in frequency since the 1990s, coinciding with rapid regional warming.
  • The new Antarctic study identified more than 360 glacial seismic events from 2010 to 2023, primarily at Thwaites and Pine Island.

What the New Findings Mean

The identification of hundreds of glacial earthquakes at Antarctica’s Thwaites and Pine Island glaciers provides a new window into how rapidly these vulnerable ice fronts are changing. By revealing a previously hidden pattern of calving-related seismicity, the study adds to a growing body of evidence that key sectors of the West Antarctic Ice Sheet are highly dynamic and closely coupled to the ocean.

Scientists emphasize that the results should be viewed as an additional observational tool rather than a definitive forecast of sea-level rise. The long-term stability of Thwaites and Pine Island will depend on a combination of factors, including future greenhouse gas emissions, ocean circulation changes, ice-shelf buttressing and bedrock topography.

As the full analysis is scrutinized and integrated with other datasets, glacial earthquakes are likely to become a standard part of how researchers monitor polar ice. For coastal communities and decision-makers, the findings underscore the importance of continued observation of Antarctica’s ice sheet, which will remain a major factor in global sea-level projections for decades to come.


Image Placement Suggestions

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