NewScientist’s Adam Popescu (15 July 2017) reports on a tsunami off the coast of Greenland – and its motivating force:
… it was a surprise when a magnitude 4.1 “quake” struck Nuugaatsiaq, a tiny island off Greenland’s west coast on 17 June. It triggered a tsunami that smashed homes, leaving at least four people dead. But what residents – and seismic equipment – initially labelled as a quake may be nothing of the sort.
“Everyone was fooled by the collapse of a mountain,” says Martin Luethi, a glaciologist at the University of Zurich, who has been studying Greenland’s glaciers since 1995. “The tsunami wasn’t triggered by an earthquake.”
Luethi thinks the culprit was a landslide at nearby Karrat fjord. As the falling mountain hit the ocean, it created enough seismic noise to dupe sensors and generate the waves that inundated Nuugaatsiaq. He blames melting ice for destabilising the rock below.
And why did the mountain collapse?
“Ice cannot hold a mountain together if the ice flows,” says Luethi. “Melting and freezing cycles mean rocks are getting destroyed. There’s so much unstable rock in Greenland and they have no earthquakes to shake it down.”
This triggers a memory from years ago about some study done on evidence of a huge tsunami, thought to be triggered by an underwater landslide.
Looks like climate change is going to be triggering all sorts of interesting – if horrifying – mysteries to explore. Just like there may be more Lyme disease.
