Asian tsunami 'could return at any time'
Friday, 23 Mar 2007 08:03
The Indian Ocean tsunami claimed more than 250,000 lives
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Scientists have "no way of knowing" when the next earthquake with the magnitude of that which caused the Boxing Day 2004 Asian tsunami could strike, a leading geologist has warned.
At least 225,000 people died following the December 26th tsunami, with people from countries more than 1,000 miles away in the Indian Ocean affected.
And Robert McCaffrey, professor of earth and environmental sciences at the New York-based Rensselaer Polytechnic Institute says that the 9.2 (M9) level quake that caused the tsunami could feasibly happen at any time.
He uses his article in the latest edition of the Science journal to advocate improvements in early warning systems.
M9 earthquakes occur when one tectonic plate gradually slips under another at a boundary known as a subduction, with the resulting friction, cracking and lifting of the plates creating seismic activity.
The scientific consensus, according to Professor McCaffrey, is that such events occur between every 200 and 1,000 years, but he dismisses this as "narrow understanding" of a "lethal" area of geology.
"Seismologists have long tried to determine which subduction boundaries are more likely than others to break," he writes.
"Yet, the great earthquake of 2004 ruptured a segment that was thought to be among the least likely to go," adding that all tectonic plates should be considered "locked, loaded, and dangerous".
He goes on to say that on December 26th three years ago "Earth gave us a stark reminder of the important difference between improbability and impossibility".
"Our understanding of where and when the next great earthquake will happen is in its infancy at best. We have not had enough time to decipher M9 behaviour," he added.
"We can never forget what happened [in 2004].
"Now is the time to use the knowledge that we have gained and work to save lives should another M9 hit tomorrow or hundreds of years from now. Many didn't know about tsunamis before the quake; we must make sure that now they never fail to remember their destructive force," Professor McCaffrey concludes.