straitstimes.asia1.com
OCT 9 1999
THE NEXT BIG ONE
BEIJING -- China could be hit any time by a massive earthquake similar to that which devastated Taiwan last month.
The biggest threat hangs over a densely populated zone in the country's north-west, according to a French seismologist.
"Most of Chinese territory is under the threat of earthquakes with magnitudes greater than 8 on the Richter scale," said Professor Paul Tapponnier of the Paris-based Institute of Earth Physics in a recent interview in Beijing.
Prof Tapponnier, who is taking part in a Sino-French seismological and geological research project begun 20 years ago, said the area of greatest risk lay near the north-western Chinese city of Lanzhou that has two million inhabitants.
"We are studying in particular a 200-km segment of the Haiyuan fault, which lies around 100 km from Lanzhou, and which has not shifted since the 13th century," he said.
Pressure had been building up underground for some time, as the Indian continental plate burrowed into its Chinese neighbour, throwing up the Himalayas like a bulldozer, he explained.
"We are expecting a sudden shift of 12 m of this segment along with an earthquake which could happen at any time," he said.
It was another 1,000-km- section of this fault that caused a tremor measuring 8.5 on the Richter scale which killed between 200,000 and 300,000 people in Lanzhou in 1920.
The Haiyuan fault crosses Gansu province.
Large tremors have also rocked western, north-east and south-west China, giving the country a world record number of earthquake victims.
China has been hit by 15 temblors measuring over 8 on the Richter scale in this century. The last of these -- measured at 7.8 by the Chinese but 8.2 by the Americans -- razed the northern industrial city of Tangshan, 200 km east of Beijing, on July 28, 1976.
The official death toll was 242,000 and about 164,000 people were badly injured.
Prof Tapponnier said China's seismological movement was unique: the movement was towards the heart of the continent, not at the meeting place of tectonic plates like in Taiwan's case.
"Continental China is buckling under the action of the collision between India and Asia which began 50 million years ago, with India acting both like a bulldozer and a snow plough, pushing China and South-east Asia eastwards," he explained.
The result of this continental collision is six major fault lines on a par with the San Andreas fault in North America, which move between 10 and 12 mm every year.--AFP
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