Deputy CGS Director Chiang Chung-jung told the media that the center in 2003 studied the activity of Datun Mountain, which is a group of volcanic peaks, in an attempt to determine whether the volcano was active or dormant.

It was found that although there was a magma chamber in the base of the mountain, there was almost no seismic activity there, which means that the volcano's most recent eruption may have been its last before it enters the state where it could be classified as dormant, Chiang said.

Although Datun Mountain might not be a dormant volcano based on the finding that it might still have a magma supply, the lack of siesmic movement prompted the center to conclude that it is almost dormant, Chiang reiterated.

He agreed that it was a big breakthrough for researchers from Academia Sinica to determine recently that Datun last erupted some 5,000 years ago, instead of 200,000 years ago, as was previously thought.

After a 10-month analysis of the surface materials formed from volcanic ash and mudflow residues, the Academia Sinica scholars and two Russian professors concluded that Datun Mountain was an active volcano. The scholars said that according to international classification, an active volcano is one that has erupted within the last 12,000 years. A dormant volcano is one that is not classified as active but could feasibly erupt again.

A previous study had stated that the last eruption of Datun Mountain occurred 200,000 years ago and classified it as a dormant volcano.

On concerns that Datun Mountain has now been reclassified as an active volcano that could threaten the lives of the six million people in the greater Taipei area, Chiang said that the possibility of the mountain erupting again is "extremely low." "Besides, volcanic eruptions can be predicted, " he said, urging that there is no need for people to panic over the matter.

(By Deborah Kuo)