On September 16th, 2023, scientists all over the world observed unusual seismic signals on the earthquake sensors. 

Usually, seismic waves of earthquakes last from a few seconds to hours and have high frequencies. The signal that scientists observed was quite different, lasting over nine days and vibrating at a single frequency. 

We now know that the vibrations resulted from the collapse of a mountain peak after the glacier underneath it started melting. The collapsing mountain created a huge landslide and mega-tsunami, with waves as tall as 200 meters!

The Discovery

Since this is the first time in recorded history that an event like this happened, it took  68 scientists from 15 countries to decipher its cause!

Using large amounts of seismic data, field measurements, and satellite imagery, paired with computer-generated simulations of tsunami waves, scientists could finally piece this puzzle together.

Scientists traced the waves back to the Dickson fjord (a large body of water located between steep walls of rock) in Greenland. The melting glacier and collapsing mountain led to an estimated 25 million cubic meters of rock and ice being discharged into the fjord.

However, because of the angle between the direction of the landslide and the flow of the fjord, a lot of the landslide’s energy stayed inside the fjord. This resulted in water sloshing around inside the fjord in a phenomenon known as a seiche, and waves resonating for an extended period, thus the 9-day-long vibrations that were recorded. Miraculously, nobody was hurt during this event, but a research center and a few archaeological sites were destroyed, resulting in a loss of about $200,000.

Looking Ahead

The discovery is also a reminder of the silent damage climate change can cause all over the planet simultaneously.

Glaciers and ice are important for regulating our planet's temperature because their white surfaces reflect the sun's rays into space. This phenomenon, known as Albedo Effect, is described in an earlier article here. The melting of glaciers will cause our planet to warm up at an accelerated rate. And the current rise in temperatures tells us that this may have been the first time, but is not the last.

The one positive outcome has been the high accuracy of the tsunami modeling which shows us the merits and bright future of current technology. 

Sources: Washington Post, Guardian, NatoGeo, Arstechnica