[imagesource:flickr]
Scientists say that a massive landslide in a Greenland fjord triggered a wave that “shook the Earth” and caused a 200-metre high wave that bounced around a narrow fjord for nine days.
The event took place last September and was picked up by sensors all over the world, leading scientists to investigate where it had come from.
A multinational team of scientists and the Danish Navy conducted a detective operation that produced the investigation’s findings, which are published in the journal Science. Once again, climate change has been found to have triggered the collapse, and these events are becoming more frequent.
“When colleagues first spotted this signal last year, it looked nothing like an earthquake. We called it an ‘unidentified seismic object’,” recalled Dr Stephen Hicks from UCL, one of the scientists involved.
“It kept appearing – every 90 seconds for nine days.”
Following the weird signals, scientists from all across the world began discussing the event on an online chat platform, while at the same time, their colleagues in Greenland received reports of a tsunami that happened in a remote fjord.
The source of the signal was identified as Dickson Fjord in East Greenland by researchers using seismic data. They then gathered satellite images and photographs of the fjord that were taken by the Danish Navy soon before the signal emerged.
Eventually, the researchers calculated that a 200-meter-high “mega-tsunami” was created when 25 million cubic meters of rock—the volume of 25 Empire State Buildings—slammed into the ocean.
The sediment that the enormous wave threw upwards created an imprint on the glacier that can be seen in the “after” photos taken at the spot.
[image: Soren Rysgaard/Danish Army]
While tsunamis usually dissipate within hours in the open ocean, this wave was trapped and due to the complex fjord systems, the wave just kept on bouncing back and forth between the glaciers in what must have been a breathtaking sight. One almost wishes an Instagrammer was on location to capture it, although it would likely not have ended well for them.
“We’ve never seen such a large scale movement of water over such a long period.”
After studying the event, scientists believe the landslide was caused by rising temperatures in Greenland, which have melted the glacier at the base of the mountain. Even more disturbing is their consensus that this phenomenon is likely to repeat itself.
“We are witnessing a rise in giant, tsunami-causing landslides, particularly in Greenland.”
Though the Dickson Fjord event alone may not definitively confirm the trend, its sheer, unprecedented scale highlights an urgent need for deeper investigation the scientists conclude.
[source:bbc]