New Tsunami Threat For Japan

A geological fault discovered beneath the sea near Japan poses the threat of generating giant waves, a new study reports.

Such waves, called tsunami, could pose a threat to densely populated coastal cities in southwestern Japan.

Researchers led by Jin-Oh Park of the Japan Marine Science and Technology Center in Yokohama discovered the fault using a seismic reflection profile, developed by measuring vibrations from the surface that are reflected back by deep rock formations.

Their findings are reported in Friday's issue of the journal Science.

They suggest the newly found branching fault may have contributed to the powerful Tonankai earthquake in 1944.

The fault is located in an area where the Philippine Sea plate is sinking below the Eurasian plate. Movement of the plates deep within the Earth can travel up the fault where it has the potential to trigger earthquakes and could generate a tsunami, the researchers say.