Climate Change Causing Tsunamis? What’s Next?!

How a Rockslide in Greenland Set Off a 650-foot Tsunami

It was late spring 2018, and they invited us to a friend’s wedding in Spain.

Traveling in early summer can be quite expensive, but we found an interesting way to make it to Europe from the United States: spending a day in Iceland. Why not?

So we added some warm clothes in our packs to enjoy the quick Iceland layover and planned our day there. What should we do? We found out there was a hike we could do around a glacier. An Icelandic glacier? Count me in!

I have been to many glaciers before but had forgotten something about the noise. Wherever you were, no matter what, you could hear this cringy noise from moving ice masses. It was as if the mountains were alive and speaking to one another. It helped us better understand the dynamism of the Earth’s surface, which we usually only learn about from books.

I remember having this conversation with Silvia about how, if glaciers were powerful enough to create such a noisy background, they sure could be powerful enough to modify the Earth’s surface, as we know they did, and even more. But little did we know glaciers would soon show another unexpected superpower.

In September 2023, an unusual event in East Greenland caught the attention of scientists worldwide. Unlike anything typically seen, seismic signals were detected for nine continuous days. What initially appeared as a mystery soon unfolded into a fascinating study about how climate change increasingly reshaped Earth’s most remote regions.

A rockslide triggered by glacier melting collapsed into Dickson Fjord, creating a massive 650-foot (200-meter) tsunami that reverberated through the Earth and sparked an international scientific effort to uncover the cause.

To crack the case, scientists from around the world joined forces. The team, led by Dr. Kristian Svennevig from the Geological Survey of Denmark and Greenland, included 68 experts across different fields, from seismology to satellite imagery analysis.

They compiled global seismic data, field observations, high-resolution satellite images, and computer simulations to piece together the sequence of events. Tell me scientists aren’t detectives of nature!

This collaborative approach enabled the team to track the source of the seismic signal to the exact spot where the rockslide had occurred. By simulating how the landslide interacted with the fjord, they identified the tsunami and its subsequent “sloshing” effect, known as a seiche, as the root of the prolonged seismic activity.

So, what did they find?

The research revealed that the rockslide, a 25-million-cubic-meter avalanche of rock and ice, fell into Dickson Fjord, creating a tsunami that initially reached heights of 200 meters.

The water then sloshed back and forth within the confines of the fjord for nine days, producing a rare type of seismic signal that was picked up by monitoring stations around the globe. This phenomenon, called a seiche, typically occurs when water oscillates in a closed or semi-enclosed basin. In this case, the fjord’s shape and the immense energy from the landslide kept the waves moving for an extended period.

The researchers used supercomputers to simulate these movements and validate their findings. As seismologist Dr. Alice Gabriel from UC San Diego’s Scripps Institution of Oceanography pointed out, “It was a big challenge to do an accurate computer simulation of such a long-lasting, sloshing tsunami.”

However, their model closely matched the real-world observations, providing key insights into how the event unfolded and why the seismic signal persisted for so long.

However, what’s particularly significant is that this wasn’t just a one-off event. Climate change played a direct role in setting the stage for the landslide. Oh, climate change, the usual suspect!

Melting glaciers at the base of the mountain destabilized the landscape, making the rockslide — and the resulting tsunami — inevitable. This connection highlights how warming temperatures in polar regions are increasingly leading to large, destructive landslides, as confirmed by other events, like the 2017 Karrat Fjord landslide in western Greenland, which caused fatalities.

Arctic tsunamis threaten coastal landscapes and communities – survey of Karrat Isfjord 2017 tsunami effects in Nuugaatsiaq, western Greenland

On the 17 June 2017, a massive landslide which mobilized 35–58 million m3 of material and triggered a tsunami entered the Karrat Isfjord in western Greenland.

You may be asking, why is this important?

This study underscores the complex interplay between climate change and geological hazards. As the world’s glaciers retreat, landscapes that have been stable for millennia are becoming vulnerable to landslides and similar events.

Further, these hazards pose risks not only to the environment but also to human infrastructure, as seen by the destruction of $200,000 worth of facilities at an unoccupied research station on Ella Island. Indeed, climate change may cost us lots of economic resources!

The scientists behind the study emphasize the importance of monitoring these remote areas. With more frequent landslides expected in the future, early detection systems and better preparedness could help minimize damage and, in some cases, save lives.

The study’s lead author, Dr. Svennevig, remarked, “When we set out on this scientific adventure, everybody was puzzled and no one had the faintest idea what caused this signal.” The answer came only through international collaboration and diverse scientific tools. Collaboration and technology at its finest.

But this research goes beyond just understanding one event. It opens the door to a broader examination of how climate change might trigger similar phenomena elsewhere. Dr. Gabriel highlighted this by saying, “Climate change is shifting what is typical on Earth, and it can set unusual events into motion.”

Looking back through seismic records, scientists may now be able to spot other, previously misunderstood signals, which could reveal more about how Earth’s changing climate is influencing geophysical processes in ways we’ve only begun to understand. See the video below if you want to have a quick glimpse inside the moving glacier.

The rockslide-generated tsunami in Greenland is a loud reminder that the effects of climate change are wide-reaching. With glaciers melting and landscapes destabilizing, similar events are likely to become more frequent, making it all the more important to study these phenomena and prepare for what lies ahead.

This groundbreaking research solved the mystery of the nine-day seismic signal and provided critical insights into the hidden forces at play in our changing world. Forces that have always been in plain sight but are now ready to show their true power. The Earth’s power.