Hundreds of Iceberg Earthquakes Are Shaking Antarctica’s ‘Doomsday Glacier’

New seismic evidence reveals growing instability at the edge of one of Earth’s most dangerous glaciers.

Glacial earthquakes are rattling one of Antarctica’s most fragile ice formations, raising new questions about the stability of the so-called Doomsday Glacier and its potential impact on global sea levels.

A new scientific analysis has identified hundreds of previously undocumented glacial earthquakes occurring near the ocean-facing edge of the Thwaites Glacier between 2010 and 2023, suggesting the glacier may be undergoing significant structural stress.

2021 Findings Put Thwaites Glacier on the Global Radar

According to scientific reports published in 2021, researchers warned that Antarctica’s Thwaites Glacier — often called the “Doomsday Glacier” — was already approaching a critical threshold. Studies showed that warming ocean waters were eroding the glacier from below, accelerating ice flow and increasing fracture rates. Covering an area roughly the size of Florida or the United Kingdom, Thwaites alone was estimated to account for about 4 percent of annual global sea-level rise. Scientists cautioned that a full collapse could raise sea levels by several feet, placing millions of people in low-lying coastal cities at severe flood risk. Researchers also noted that the glacier’s flow speed had doubled over the previous three decades, and that its destabilization could potentially trigger wider ice loss across West Antarctica, amplifying sea-level rise even further.

What Are Glacial Earthquakes?

Unlike traditional earthquakes caused by tectonic plate movement, glacial earthquakes originate in icy polar regions. They occur when massive icebergs break away from glaciers and overturn in the ocean, violently colliding with the glacier itself.

This collision generates powerful ground vibrations that can travel thousands of kilometers. However, these events are unusual because they do not produce high-frequency seismic waves, making them difficult to detect using conventional global earthquake monitoring systems.

Because of this unique seismic signature, glacial earthquakes were only recognized by scientists within the past two decades.

Why Antarctica Has Been a Mystery Until Now

While glacial earthquakes have been widely observed near Greenland’s ice sheet, Antarctica has long lacked clear evidence of similar activity. Scientists believe this is partly because Antarctic glacial earthquakes tend to be weaker in magnitude, allowing them to evade detection by global seismic networks.

To overcome this limitation, researchers analyzed data from seismic stations located directly on the Antarctic continent, rather than relying solely on international monitoring systems.

The result was the identification of more than 360 glacier-related seismic events, most of which are not yet included in official earthquake catalogs.

Instruments installed by the International Thwaites Glacier Collaboration to track seismic activity, ice flow, and ocean-driven melting beneath the glacier.

The Doomsday Glacier Under Stress

Approximately two-thirds of the detected events occurred near the marine terminus of the Thwaites Glacier, often referred to as the Doomsday Glacier due to its enormous potential impact on sea levels.

If Thwaites were to collapse entirely, scientists estimate it could raise global sea levels by up to 3 meters (10 feet). Even more concerning is evidence suggesting the glacier could destabilize rapidly under certain conditions.

The most intense cluster of glacial earthquakes occurred between 2018 and 2020, coinciding with a period when satellite data confirmed a significant acceleration of the glacier’s ice tongue toward the sea.

Ocean Conditions May Be the Key Driver

Unlike Greenland’s glacial earthquakes, which peak during warmer summer months, the Antarctic events do not appear to follow seasonal temperature patterns.

Instead, researchers believe ocean conditions beneath the glacier may be playing a more dominant role. Changes in ocean temperature or circulation could weaken the ice tongue from below, triggering increased iceberg calving and seismic activity.

This ocean-driven mechanism remains poorly understood and is now a priority for future research.

A Second Cluster Raises New Questions

Another group of seismic detections was found near the Pine Island Glacier, one of Antarctica’s largest contributors to sea-level rise. However, these events occurred far inland, making iceberg capsizing an unlikely explanation.

Scientists say these anomalies remain unexplained and warrant further investigation to determine their origin.

Why These Findings Matter

The discovery of widespread glacial earthquakes at Thwaites offers scientists a new tool for monitoring the glacier’s stability in real time. Understanding how ice, ocean water, and solid ground interact at the glacier’s edge could significantly improve projections of future sea-level rise.

Reducing uncertainty in these models is critical, as current estimates vary widely when forecasting global sea levels over the next several centuries.

What Comes Next

Researchers plan to expand seismic monitoring across Antarctica and combine it with satellite observations and ocean data. By doing so, they hope to clarify how rapidly the Doomsday Glacier could destabilize—and what that would mean for coastal communities worldwide.