AFP, Paris :
With a wave runup of nearly 200 metres, the tsunami that ripped through an Alaskan fjord in 2015 was one of the largest ever documented. But with no-one killed, it almost went unnoticed.
It was triggered by a massive rockfall caused by melting of the Tyndall Glacier, which experts say has given them the clearest picture to date of landslide-generated tsunamis.
With global warming causing glaciers to shrink at an unprecedented rate, there is an increased risk of tidal waves triggered by the collapse of rocky slopes weakened as ice retreats, a study in Scientific Reports said Thursday.
“As glaciers thin around the world, they are modifying their landscapes dramatically. In the case of Taan Fjord, the result was a massive tsunami,” said Dr Dan Shugar, assistant professor of Geoscience at the University of Washington Tacoma and co-author of the report.
“The tsunami was triggered by a massive landslide in October 2015 that occurred above a glacier that had retreated dramatically in the late 20th century,” he told AFP. The tsunami generated a wave runup, the maximum vertical extent of wave uprush on a beach, of 193 metres (633 feet).
Glacial ice supports and undercuts steep slopes so when the ice melts, the underlying bedrock is left exposed and unstable, increasing the likelihood of rockfalls and landslides.
“We need to better understand the risk posed by these steep slopes in a changing climate,” Shugar said.
The study provides a benchmark for modelling landslide and tsunami hazards, the authors said.
“Our results call attention to an indirect effect of climate change that is increasing the frequency and magnitude of natural hazards near glaciated mountains.”
With a wave runup of nearly 200 metres, the tsunami that ripped through an Alaskan fjord in 2015 was one of the largest ever documented. But with no-one killed, it almost went unnoticed.
It was triggered by a massive rockfall caused by melting of the Tyndall Glacier, which experts say has given them the clearest picture to date of landslide-generated tsunamis.
With global warming causing glaciers to shrink at an unprecedented rate, there is an increased risk of tidal waves triggered by the collapse of rocky slopes weakened as ice retreats, a study in Scientific Reports said Thursday.
“As glaciers thin around the world, they are modifying their landscapes dramatically. In the case of Taan Fjord, the result was a massive tsunami,” said Dr Dan Shugar, assistant professor of Geoscience at the University of Washington Tacoma and co-author of the report.
“The tsunami was triggered by a massive landslide in October 2015 that occurred above a glacier that had retreated dramatically in the late 20th century,” he told AFP. The tsunami generated a wave runup, the maximum vertical extent of wave uprush on a beach, of 193 metres (633 feet).
Glacial ice supports and undercuts steep slopes so when the ice melts, the underlying bedrock is left exposed and unstable, increasing the likelihood of rockfalls and landslides.
“We need to better understand the risk posed by these steep slopes in a changing climate,” Shugar said.
The study provides a benchmark for modelling landslide and tsunami hazards, the authors said.
“Our results call attention to an indirect effect of climate change that is increasing the frequency and magnitude of natural hazards near glaciated mountains.”
