Climate change caused a landslide last year that shook the earth for nine days

Key Points
  • A landslide in Greenland last year caused the earth to shake for nine days.
  • A year later, researchers attributed the earthquake to rising temperatures caused by climate change.
  • “Landslides are increasing due to climate change,” scientist Amelie Meyer told SBS News.
Last year, a major landslide in an uninhabited part of Greenland caused a mega-tsunami.
An estimated 25 million cubic meters of rock and ice flowed into Dicksonfjord, creating waves that initially reached heights of 200 meters, while the average wave height was around 110 meters.
But what followed was considerably more powerful: it caused the Earth to shake for nine days.

Researchers were initially baffled by what caused the seismic event. A year later, scientists say they can now explain what happened.

A seismic hum

In September 2023, seismometers around the world began detecting a 10.88 millihertz seismic signal originating from eastern Greenland.

It reportedly appeared every 90 seconds for nine days.
The research started with the Danish army and was expanded to include experts from 15 different countries.
As reported this week in the scientific journal Science, a team of 68 scientists from 40 different institutions worldwide has identified the source of the seismic hum.

The September mega-tsunami wave lodged in the narrow fjord (about 38 km long and 3 km wide) and echoed back and forth for days.

Elevation map with legend and coordinates.

The avalanche of rocks and ice crashed into the fjord at speeds of over 100 miles per hour, causing a mega-tsunami that lurched back and forth for days. Credit: Science

The sloshing motion generated so much energy that it created vibrations that were observable worldwide.

“The physics behind this event is simple: the ice melts and can no longer support the overlying rock,” Hrvoje Tkalčić, head of geophysics at the Australian National University, told SBS News.
“The rock falls into a fjord, creating a tsunami and seiche (a standing wave that lasts for nine days), which we can detect using seismometers,” he said.

Although this is a rarity, this may not be the last event of its kind.

‘Landslides are increasing’

Scientists in the journal attribute climate change-induced temperature increases to major landslides in the polar regions.
Just 25 days after the initial event, another landslide occurred, further eroding the gorge.

“Landslides are common and are increasing due to climate change,” said Amelie Meyer, a senior scientist at the University of Tasmania.

A thin layer of soil with solid ice underneath.

According to Dr. Meyers, climate change is degrading permafrost and thinning glaciers, making landslides more frequent and severe. Source: Getty / Galen Rowell

“As temperatures rise, the elevation at which you have permafrost (frozen ground) also rises. Those areas are then exposed to temperatures above freezing at certain times of the year,” Meyer told SBS News.

“The ground is no longer held together by the cold. It’s not so much the melting, but the rocks breaking down.”
According to Meyer, the increased frequency and severity of these events should serve as a warning to people who enjoy outdoor activities in such areas.
“More and more accidents are happening on passages that used to be safe.

“There are times in the summer when you would avoid these areas, but climate change means many people are unsafe all year round.”

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *