A quake measuring 5.1 on the open-ended Richter scale struck Chiayi County in southern Taiwan yesterday with no immediate damage reported, the Central Weather Bureau (CWB) said.

The CWB said the earthquake, which took place at 5:26 pm, struck 15.9 kilometers southeast of Chiayi City seismic station at a depth of 14.3 kilometers.

"The quake has nothing to do with the magnitude 6.4 quake that hit southern Taiwan last week," the CWB said.

That earthquake, which rocked Jiasian in Kaohsiung County, was the strongest temblor to hit the southern part of the island in over a century.

No casualties were reported, but the quake temporarily knocked out power in some areas and disrupted the island's high-speed railway, which had yet to be restored to normal as of yesterday.

A seismologist said in Taipei on Sunday that he and his colleagues are investigating a suspected fault that could have been responsible for last week's powerful earthquake that injured 96 people.

The 6.4-magnitude quake rocked the south of the island March 4, derailing a carriage on a high-speed train, toppling farm houses and momentarily cutting off electricity to more than half a million homes.

The tremor - the biggest ever to hit the Kaohsiung area in a century - immediately sparked concern and prompted scientists to review the existing geological records for the area.

Kuo Kai-wen, the head of the official Seismology Centre, told AFP that the subsequent aftershock records indicated that "there may be a blind or an unidentified faultline in the area."

A blind fault means a thrust fault that is "buried" under the uppermost layers of rock in the earth's crust.

The relevant data collected by the center will be used for the investigation currently being done by experts from the Central Geological Survey, the National Central University and the island's top academic body, Academia Sinica, Kuo said.

China Daily/Agencies

(HK Edition 03/09/2010 page4)