Tsunamis in lakes pose a growing threat

Lake Tsunamis are on the rise - Newsreel
More than a year after tsunamis hit Japan, the devastation was visible. Now tsunamis on lakes are on the rise. | Photo: Artway Pics (iStock)

In recent years the world has witnessed some terrifying tsunamis as undersea earthquakes sent mountains of rushing water inland.

But that only happens in the sea – right? Apparently not.

The Seismological Society of America (SSA) is now warning of the rise of lake tsunamis as climate change takes a tighter grip on the planet.

In an article published this week by the SSA, geologist Bretwood Higman of the Ground Truth Alaska organisation said lake tsunamis were increasingly common, particularly in areas with mountain glaciers.

He said so far most of the lake tsunamis were in remote locations but it may be only a matter of time before one would swamp a populated area.

The water surges are triggered by landslides into small bodies of water.

At the SSA Annual Meeting, Dr Higman said it was becoming increasingly important to assess sites in populated areas for the  possibility of lake tsunamis.

“There are some cases where there are dramatic and very distinctive precursory seismic signals that precede a catastrophic landslide, sometimes by as much as days,” he said. “If we could get to the point where we understood these and knew how to detect them, they could be really useful.”

Dr Higman described the tsunamis as an “an emerging, climate-linked hazard.”

“Higher temperatures melt the glaciers that buttress the walls of the valley that cradles the shrinking glacier,” the SSA article said.

“Without the glacier in place to hold them up, the valley walls are more prone to landslide, either into an existing body of water or a new lake created by the glacier melt.

“This is something that historically has been a pretty rare event, but in the last few years there have been a really surprising number of these.”

The full article is on the SSA website.