Japan Faces Tidal Wave Threat

BBC ^ | 8-15-2002

[blam]

Thursday, 15 August, 2002, 18:18 GMT 19:18 UK

Japan faces tidal wave threat

Seismic reflection imaging revealed the fault Image © Science

Scientists in Japan have discovered a fault in the seabed off the country's coast with the potential to unleash a giant "tsunami" tidal wave.

Any tsunami could hit the mainland with only a few minutes' warning

Bill McGuire Benfield Greig Hazard Research Centre The newly-detected fault lies off the south-eastern coast of Japan and may have been responsible for the magnitude 8.1 earthquake which struck the country in 1944, they say.

Jin-Oh Park and his colleagues at Jamstec, the Japan Marine Science and Technology Center, say that an earthquake along the fault would threaten cities along the Japanese coast.

The fault is close enough to the Japanese coast for there to be only minutes between a substantial earthquake along it and the tsunami reaching land.

Uncharted sea bed

The fault, which lies close to where the Philippine Sea plate is sinking beneath the Eurasian plate, is only dozens of kilometres away from land.

"Any tsunami would hit the mainland with only a few minutes' warning," explained Bill McGuire, director of the UK's Benfield Greig Hazard Research Centre.

The fault is off Japan's south-eastern coast

"Most people in Japan live along the coast and evacuating them in only a few minutes would be impossible," he said.

"It's an additional tsunami risk in a country that has many of them," he added.

The newly-discovered fault was uncovered by seismic reflection imaging.

Submarine faults are difficult to find and much of the ocean floor is still poorly understood.

Faults may never protrude above the ocean floor or may be covered in sediment.

History of disaster

Jin-Oh Park and his colleagues believe that the fault they have found may have been responsible not just for a magnitude 8.1 quake in 1944, but a nearby magnitude 8.3 quake two years later.

Very large earthquakes tend to occur every 100 to 200 years along faults of the kind now discovered, they explain.

Details of the fault's discovery appear in the journal Science

[First_Salute]

Is this an essay question?

[Frank_Discussion]

Science question: I thought tsunamis gained destructive power as the wace gained water mass on the way to land? Wouldn't a tsunami that that hits in only a few minutes be relatively benign? Y'know, kind of like pulling a punch, it may hit fast but not hard.

[ken5050]

Where's the obligatory para blaming this on the US bombs dropped on Hiroshima and Nagasaki?

[Frank_Discussion]

wace = wave

[Tacis]

Hey, isn't that near where Godzilla is from?

[First_Salute]

Lex Luthar?

[TightSqueeze]

Any tsunami could hit the mainland with only a few minutes' warning

With uncertainty of this scale and magnitude, I suggest eating dessert first.

[Frank_Discussion]

Good advice for any occasion! :-)

[Loyalist]

Where's the obligatory para blaming this on the US bombs dropped on Hiroshima and Nagasaki?

Just below the obligatory para blaming any natural disaster, or even a sunny day in the mid-70's with a soft, pleasant breeze, on global warming.