A Greenlandic fisherman died in a tsunami in 1952. Did climate change kill him?

In 1952, a landslide along the coast of Greenland triggered a tsunami that killed a local fisherman and injured several others. The tragedy went largely uninvestigated at the time.

Today, however, a new study is shedding light on the disaster. Earlier this month, a team of researchers published a study that found that the landslide was likely caused by permafrost degradation that was induced by Arctic warming. The finding marks the earliest known warming-induced landslide-tsunami in the Arctic—and suggests that global warming and climate change turned deadly earlier than previously thought.

“The findings definitely surprised me,” said Kristian Svennevig, a geologist at the Geological Survey of Denmark and Greenland (GEUS) and the lead author of the study. “To see such a clear indication of permafrost degradation already occurring 70 years ago was not something that we were expecting.”

The study—which was published in Science of The Total Environment, a peer-reviewed scientific journal—shows that the landslide deposit was covered by so-called molards, which are formed when blocks of permafrost cemented landslide material degrade into distinctive cones after the landslide. Molards, the researchers explain, are a clear indication that the slope material that failed was permafrozen.

The study also found that the landslide’s surface of rupture was deep enough within the permafrozen slope to insulate it from natural seasonal temperature fluctuations. Only several years of prior Arctic warming could have reached so deep into the slope, the researchers concluded. In fact, the Arctic had at the time already experienced anomalies of up to +1.7°C since the start of the century.

The research team conducted the study through a mix of on-site field research and historical record analysis.

This included the use of photographic datasets from sources like US Navy records, the Danish National Cadaster and GEUS archives. The team also reviewed the few records of press coverage of the disaster from Greenlandic radio and print media outlets.

Moreover, the team interviewed a local resident who was seven years old at the time of the tsunami. The resident, who recounted the tsunami waves hitting his town, is believed to be the last living eyewitness of the disaster.

(Footage of the 1952 landslide six months after it happened. The clip shows molards in the making as blocks of permafrost melt. Credit: GEUS)

The study stresses that it is impossible to say for certain what exactly triggered the 1952 landslide. But the researchers note that their findings show that permafrost degradation was the major precondition to the disaster and suggest that this is likely due to global warming in the Arctic.

Today, the Arctic continues to warm at alarming rates, with temperatures rising in the region twice as fast as the rest of the planet, according to the US National Oceanic and Atmospheric Administration (NOAA). Arctic warming, NOAA reported in its latest Arctic report card, has caused the Greenland Ice Sheet to lose ice for 25 consecutive years.

“We may expect an increase in catastrophic landslides in the Arctic,” Svennevig stated. “Maybe we are already experiencing just that—starting with the 1952 landslide.”

Indeed, several other major landslides have been recorded in the Arctic in recent decades. In 2021, for instance, a significant landslide occurred roughly 7km south-east of the 1952 landslide site. The landslide did not cause a tsunami, but researchers determined that the landslide was caused by a similar pattern of permafrost degradation due to warming.

Researchers note that the study of landslides in Greenland and throughout the Arctic remains limited. Experts also maintain that further analysis of past landslides can help people today better understand the impact of rising temperatures worldwide.

“I think as we look back on previous events with our current understanding of a century plus of warming, we might find more of these early warnings of climate change,” Svennevig stated, adding that further study in the area could contribute to the complex task of predicting when and where future landslides will occur.

The study of the fatal 1952 landslide comes as the world continues to be on the brink of several climate crisis tipping points. These junctures entail changes to significant parts of the global climate system that become inevitable and self-perpetuating regardless of efforts to mitigate warming.

Such tipping points, as one major study published in Science recently noted, include the collapse of the Greenland ice sheets and widespread permafrost thaw. "These changes may lead to abrupt, irreversible, and dangerous impacts with serious implications for humanity,” the study concluded.