The December tsunami responsible for killing 283,000 people in Indonesia and coastal Asia could have been even worse, Colorado researchers reported today.
The giant waves, which hit with the force of a bomb several million times bigger than the one dropped on Hiroshima, were triggered by an 800-mile- long earthquake off the coast of Indonesia.
While it moved explosively fast at times, the quake slowed and ceased making deadly waves as it moved northward, said Roger Bilham, a geologist at the University of Colorado.
That may have saved some lives in India, Myanmar and Thailand, where at least 16,000 people died.
“It would have been much bigger, far more devastating,” Bilham said.
Bilham’s study was one of several published today in the journal Science revealing new details about two earthquakes off the coast of Indonesia.
The December quake registered a magnitude of 9.3 and triggered a second in March, registering 8.7.
No place on Earth was unaffected – everywhere moved up or down half an inch or more.
“There are a lot of unusual things about this quake, besides the fact that it was huge,” said Stuart Sipkin, a geologist with the National Earthquake Information Center in Golden and co-author of one of the earthquake reports.
Since a magnitude-9.2 earthquake flattened Prince William Sound, Alaska, in 1964, scientists have wired the world with seismometers, geographic positioning systems and other monitoring devices, Sipkin said.
That meant that, this time, they could capture strikingly detailed information about where the earthquakes started, how they propagated along the fault and how they shifted pressures underground.
Earthquakes still elude prediction, said David Wald, also with the National Earthquake Information Center and co-author of one of the Science papers. But when the March quake occurred just south of the original one, tossing small tsunami waves onto Sumatra, scientists realized just how quickly one area of faulting can create stress in another.
“That was cause and effect,” Wald said. “And now we are a bit concerned about what’s going to happen to the next segment. … We do know it has had big earthquakes in the past, and that’s bad news.”
It could also be bad news for the Indonesian island of Sumatra, because the two recent earthquakes may have put greater stress on a fault that runs below the island, Wald said.
Staff writer Katy Human can be reached at 303-820-1910 or khuman@denverpost.com.