One of the largest-ever tsunamis happened this summer. And we now know it was caused by a huge landslide.
Many of you might not even have heard about it, but it was a truly scary tsunami, mounting to heights of 100 metres at its peak.
It happened along the coast of Greenland, striking the remote settlement of Nuugaatsiaq, where it left four people dead.
The raw footage of the event is terrifying:
Just imagine the devastation that would cause in a heavily-populated area.
By now, everyone living on an ocean coast is aware of the possibility of a deadly tsunami. But although we usually associate them with seismic activity, this one was a bit different: scientists now say it was caused by a massive landslide plunging into the sea. And that landslide was in turn triggered by ice melts.
That’s not good news for the people of Greenland, many of whom live in coastal areas on a land mass that can expect to see more and more such catastrophic erosion in the coming years as climate change accelerates, melting down the ice that holds Greenland’s coastal hills together.
Tsunamis like this one, caused by shifting matter, can be incredibly dangerous. They’re called megatsunamis, and there have been several deadly ones in recent memory.
One of the worst megatsunamis happened in Italy back in 1963, again as the result of a landslide.
But the worst one of all time was far, far bigger, towering at about 5 km in height — although that one happened millions of years before humans existed, as the result of the impact that likely wiped out the dinosaurs:
To get a sense of just how big the Greenland tsunami was compared to other well-known incidents, consider that the famous Japanese tsunami of 2011 — which damaged the Fukushima nuclear plant — was only 40 metres at peak height.
This year’s Greenland tsunami was more than twice as tall.
But it’s still not the record-holder for tsunami height in recent decades. That title goes to the 1958 tsunami in Alaska, which reached the mind-blowing height of 500 metres:
Sadly, as the Earth’s coastal population density continues to rise, we can probably expect more tsunamis with high death tolls in our lifetimes. But thanks to improvements in early warning systems, the chances of timely evacuation are getting better.
That said, if we ever have another asteroid causing a 5 km tall tsunami on Earth, all bets are off.