Study: Mountain 'tsunami' once hit Geneva

GENEVA, Switzerland, Nov. 1 (UPI) -- Nearly 1,500 years ago a massive flood inundated Geneva, Switzerland, and researchers say the unlikely-sounding culprit was a tsunami-like wave in the Alps.

Far from any ocean, the massive wave was probably caused by a huge landslide into the Rhone River near where it flows into the eastern end of Lake Geneva, Swiss researchers say.

Analysis of a massive sediment deposit at the bottom of the lake's easternmost corner shows the material once sat above the lake and had slid all at once into the river, sending a giant wave down the length of the 225-square-mile lake toward Geneva at the western end, the researchers said.

They estimate the landslide caused a wave 9- to 26 feet high, National Geographic reported.

Mills, houses, cattle and even entire churches were swept away, scientists said.

While there's little indication a repeat of a Geneva "tsunami" is imminent, the new study found evidence of several large flooding events in Geneva since the last glacier retreated, researchers said.

"If this has happened five to six times since the last glaciation, there's reason to believe it could happen again in the future," University of Geneva geologist Guy Simpson said.

"A three-meter [ten-foot] wave that hit Geneva today would be a scary wave."