0 comments
A major landslide in Greenland triggered a massive tsunami, generating seismic vibrations never seen before. These vibrations reverberated across the Earth for nine days, underscoring the alarming effects of climate change on the region’s geological stability.
Last September, scientists worldwide detected a seismic signal that lasted for nine days leading them to label it as an ‘unidentified seismic object’. Following this, they were prompted to perform an international investigation to unravel the unique nature of the signal.
A study published in early September concluded that a massive landslide in Dickson Fjord, Greenland triggered a tsunami approximately 200 meters high, which was the origin of the signal detected as far as Antarctica.
According to the scientists behind the study, the landslide involved a mountain peak that collapsed due to the thinning of the glacier at its base – a process accelerated by climate change. As such, an estimated 25 million cubic meters of rock and ice plunged into the Fjord causing the signal.
Further data analysis suggests that the rock-ice avalanche may have contributed to a submarine landslide that was forced into deeper waters due to a destabilized underwater slope.
Danish and Greenlandic authorities simultaneously received reports of a significant tsunami, at the unoccupied Nanok station and a research base on Ella Island which suffered damage. Due to the landslide hitting the waterway at nearly a 90-degree angle, the waves ricocheted back and forth for nine days, a phenomenon known as a seiche by scientists.
Evidence from satellite imagery has also suggested that there were four previous instances of smaller landslides from the same area. As shocking as this geological event was, however, it’s not the first occurrence of this magnitude.
In fact, on June 17, 2017, a huge landslide occurred in Karrat Fjord, Greenland, resulting in a massive tsunami that devastated the fishing village of Nuugaatsiaq. The landslide involved millions of cubic meters of rock collapsing into the Fjord, generating waves that reached heights of up to 100 meters.
This event was so powerful that it initially registered as a magnitude 4.1 earthquake due to the seismic energy released. Authorities have since classified the region as a dangerous area, as geological studies indicated instability in the surrounding cliffs.
The urgency that comes with such events is natural and geological but is heavily influenced by climate change. Arctic regions are experiencing the fastest global warming, and similar, though less seismically intense events, have occurred in western Greenland, Alaska, Canada, Norway, and Chile.
Alice Gabriel, one of the study’s authors, noted that Earth is currently a complex system and that climate change is disrupting the planet’s ‘sensitive balance quite violently’.
Glaciers provide structural support to the mountain slopes they rest upon. As such, when they continue to melt due to rising temperatures, the stability of mountain slopes is compromised. The thinning of glaciers can then lead to sudden failures of rock slopes that they essentially prop up.
This phenomenon is further exacerbated by the erosion of permafrost, which weakens the structural integrity of these slopes. In many mountainous regions, permafrost acts as a stabilizing layer that binds soil and rock together which is also affected by the rise in global temperature.
The interaction between melting glaciers, increased precipitation from climate change, and geological instability can create a feedback loop that heightens the risk of natural disasters in vulnerable regions. The recent Greenland landslide that triggered a tsunami serves as a stark example of this phenomenon.
Moreover, communities located near glaciated regions face heightened risks from landslides and associated tsunamis. This was evident in the 2017 Nuugaatsiaq event, where 11 houses were destroyed, and 4 people were presumed dead.
Professor Anne Mangeney, one of the experts involved in the recent study, voiced her concern about such events, stating, ‘The vibrations from this travelled from Greenland to Antarctica in less than an hour. This shows how climate change is affecting the entire world in just a matter of hours’.
The events in Greenland have tested our ability to respond to climate emergencies and highlighted our lack of preparedness for larger-scale occurrences.
It underscores the fact that, while we can’t control Earth’s natural systems, we do influence them. From climate emergency action plans to international collaboration, considerable efforts are needed to mitigate these risks and prepare for future events like this.
