By Ralph Jennings, Reuters
TAIPEI, Taiwan — Taiwan will be spared from devastating earthquakes over the next five to 10 years because a recent chain of smaller tremors has eased the geologic pressure that causes big ones, Taiwan’s top seismological authority said.
A series of small to mid-sized quakes following a deadly 7.3 quake in September 1999 have reduced so much tension along a portion of the Circum-Pacific Seismic Fault east of the island that it will take years to build back up, said Kuo Kai-wen, the Central Weather Bureau Seismology Centre’s director.
“In future years, Taiwan is going to be pretty safe, and I’ve got my evidence. I’ve been thinking about it,” Kuo told Reuters. “Taiwan is in a period of geologic energy-release safety.”
Among the recent seismic activity, a 6.6 earthquake shook Taiwan in the wee hours of Sept. 7, and a 6.9 quake jolted the island a day after Christmas last year. Both damaged undersea Internet cables and raised fears of a bigger one on the way.
A 7.1 temblor in 2004, too deep and too far offshore to cause major damage, also helped ease geologic pressure as it rocked Taipei, he said.
Buildings on the island are designed to withstand quakes of less than a magnitude 7, Kuo said
Taiwan was “calm” from 1973 to 1999, Kuo said, and pressure buildup over those years led to the 1999 earthquake, which released energy equal to 80 atomic bombs.
Smaller quakes should release energy equivalent to 11 atomic bombs per year to be safe, he said, and Taiwan is on track.
But the Indian Ocean south of Indonesia can expect more quakes exceeding a magnitude 7 because pressure built up steadily over the whole 20th century, he said. Since 2000, six such quakes have hit the area, including a 9.15 quake that set off a tsunami and killed more than 200,000 people on Dec. 26, 2004.
Seismologists, however, generally say there is no reliable way of predicting earthquakes.