Feeds

Geneva devastated by monster tsunami, millions at risk

News just in from 563 AD

  • alert
  • submit to reddit

High performance access to file storage

Geologists have found the culprit behind a huge tsunami that devastated the site of the Swiss city of Geneva in 563 AD and say a similar wave could be in the city's future.

"Out of its banks it devastated villages with very old men and herds, it even destroyed many holy places with their priests and rose with fury over the bridge at Geneva, mills and men, and went into the city of Geneva, there are many people slain," wrote contemporary chronicler (and later local saint) Marius Aventicensis of the original wave.

Both Aventicensis and the Frankish historian Saint Gregory of Tours wrote about the event, describing how the local Mount Tauredunum collapsed, causing the wave, but the scientific community had been split on exactly how it occurred. One school of thought felt the rocks created a dam, which later burst, while another postulated the landslide itself caused the monster wave.

A paper published in Nature Geoscience appears to have found the answer on the bottom of Lake Geneva, and turns out neither theory is totally correct. But the suggested cause is not good news for the million or so people who live surrounding the lake today.

"It’s certainly happened before and I think we can expect that it will probably happen again sometime," says geologist Guy Simpson, from the University of Geneva, one of the researchers behind the project.

The researchers used seismic testing of the lake bed and discovered a fan-shaped deposit across the floor of the lake, averaging five meters thick and covering 50 square kilometers. It emanates from the western tip of the water body where the Rhone river enters the lake, near the location of the ex-Mount Tauredunum.

By taking sediment cores, the team found it was composed of turbidite, which is formed when sediment is disturbed, typically by earthquakes and landslides. The cores have been dated to between 381 and 612 AD, making them highly likely to be linked to the event.

The team suggests the turbidite was formed from a layer of silt that was deposited by the Rhone as it enters Lake Geneva, and is still being deposited today. Over the passage of time, the silt builds up into a broad delta of mud that forms into canyons as material falls into the deeper part of the lake.

Lake Geneva tsunami

The tsunami as it happened (click to enlarge)

For whatever reason, most likely an earthquake, a large chunk of the mountain slid into the lake near or on top of this silt and caused the entire structure to slide onto the lake floor. The displacement triggered a tsunami that rushed around the arc of the lake, washing over the site of the current city of Lausanne with a wave 13 meters high and drenching Geneva with eight meters of watery destruction.

Lest property prices start crashing in the area, "will probably happen again sometime," in geological terms, is likely to be a very long-term bet. But there have been plenty of examples of similar tsunamis in the past and geologists are have been warning for years about one event that could wash away the entire US Eastern seaboard.

When the Cumbre Vieja volcanic mountain on the Canary Islands last erupted in 1949, a local geologist found it had cracked, with the western face (estimated to be made up of 500 cubic kilometers of rock) sliding down two meters towards the Atlantic Ocean. The islands are very volcanically active and the last eruption occurred in 1971.

In a worst-case scenario, the entire side of the volcano could slide into the sea. That amount of rock hitting the ocean would generate a kilometer-tall tsunami that would still be 50 meters high when it hit the US coastline, with the wave fanning out to disrupt Western Europe as well.

Sleep tight. ®

High performance access to file storage

More from The Register

next story
Fancy joining Reg hack on quid-a-day challenge?
Recruiting now for charity starvation diet
Red-faced LOHAN team 'fesses up in blown SPEARS fuse fiasco
Standing in the corner, big pointy 'D' hats
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
Opportunity selfie: Martian winds have given the spunky ol' rover a spring cleaning
Power levels up 70 per cent as the rover keeps on truckin'
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
New FEMTO-MOON sighted BIRTHING from Saturn's RING
Icy 'Peggy' looks to be leaving the outer rings
prev story

Whitepapers

Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.