A new study has revealed that the risk of destructive tsunamis is in places such as Kingston, Istanbul, and Los Angeles.
Geologists studying the Haiti earthquake have said that like Haiti's capital, these cities too lie near the coast. They are near an active geologic feature called a strike-slip fault where two tectonic plates slide past each other like two hands rubbing against each other.
AdvertisementThis latest research has suggested even a moderate earthquake on a strike-slip fault can generate tsunamis through submarine landslides, raising the overall tsunami risk in these places.
"The scary part about that is you do not need a large earthquake to trigger a large tsunami," Matt Hornbach of the University of Texas said.
"Organizations that issue tsunami warnings usually look for large earthquakes on thrust faults. Now we see you don't necessarily need those things. A moderate earthquake on a strike-slip fault can still be cause for alarm," said Hornbach.
Within minutes after the magnitude 7 Haiti earthquake, a series of tsunami waves, some as high as 9 feet (3 meters), crashed into parts of the shoreline.
A few weeks later, a team of scientists from the U.S. and Haiti conducted geological field surveys of sites on and offshore near the quake's epicenter.
The scientists determined the tsunamis were generated primarily by weak sediment at the shore that collapsed and slid along the seafloor, displacing the overlying water.
Combined with newly discovered evidence of historic tsunamis, the survey revealed a third of all tsunamis in the area are generated in this way.
"We found that tsunamis around Haiti are about 10 times more likely to be generated in this way than we would have expected," said Hornbach.
The findings were published in the journal Nature Geoscience.
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