CANADA... BRITISH COLUMBIA LANDSLIDE TRIGGERED METRE TALL LAKE TSUNAMI

By Chandrayee Roy Choudhury, Canada

A massive landslide on B.C.'s remote central coast in 2020 triggered a lake tsunami over 100 metres tall, according to a new paper published by researchers from the University of Northern British Columbia.



Described as a rare "hazard cascade," the tsunami then sent a vast torrent of water or "outburst flood" into Elliot Creek, uprooting trees, soil and rock as it surged down the valley. The slurry was in turn propelled into the Southgate River and then Bute Inlet, leaving a devastated landscape in its wake.

"Imagine a landslide with a mass equal to all of the automobiles in Canada, travelling with a velocity of about 140 kilometres an hour when it runs into a large lake," said lead author Marten Geertsema, adjunct professor of ecosystem science at UNBC. 



"The landslide displaced enough water to cause a tsunami with a wave height that exceeded 100 metres. This drained most of the lake water which then travelled down a 10-kilometre-long channel causing widespread channel erosion and loss of salmon habitat." 



According to the study, the torrent destroyed 8.5 kilometres of salmon spawning ground and sent a plume of sediment and organic matter 60 kilometres into Bute Inlet.