LabsBy The Nation Published on March 29, 2011
After Burma, quakes rocked Thailand too


Earthquakes that were felt in the North and Bangkok last Thursday actually occurred with epicentres in Thailand, but were mistaken, by both the public and initially by local seismologists, as taking place in Burma, or as aftershocks, a senior meteorological official said yesterday.


The quakes in Burma took place roughly one hour earlier, and the tremors felt widely in Thailand had epicentres within Thailand, said deputy Meteo-rology Department spokesman Adisorn Fungkhajorn.


The Thailand-based quakes occurred on the following fault lines, at the following locations and times, with various magnitudes on the Richter scale: at 9.17pm, a quake of magnitude 4 occurred on the Pua fault lines in Nan's Wieng Sa district; at 10.09pm a 3-magnitude quake occurred on the Mae Chan fault in Chiang Rai's Chiang Saen; and at 10.15pm a further quake of magnitude 3.4 occurred on the Mae Chan fault lines in Mae Sai.

"They were triggered by the earthquakes in Burma, and a study of the subsequent quakes or aftershocks is underway, and whether there will be more quakes coming in Thailand. An advisory will be issued to the public soon," said Adisorn, who is the chief meteorological official in the North.

He said there were two previous earthquakes in Thailand in recent weeks. On February 23 a quake of magnitude 2.0 occurred on the Mae Chan fault lines in Chiang Rai's Phan district, and on March 1, there was a 3.2 magnitude quake on the same Mae Chan fault lines, but in Chiang Mai's Chaiya Prakan district.


The government has called a meeting on Thursday of key agencies involved in meteorological and other scientific affairs, along with agencies having civil-defence duties and responsibility for safety and rescue operations, to work out long-standing precautions and measures to cope with possible future earthquakes.

PM's Office Minister Satit Wongnongtaey, who will chair the meeting as the director of an ad-hoc flood-relief centre, said a new office to specifically handle earthquake affairs was not needed. He repeated assurances from relevant agencies that no dams in Thailand were affected by last Thursday's quakes.

On the agenda for Thursday's meeting will be the enforcement of existing quake-safety regulations, quick compensation payments to quake victims, a nationwide survey of safety features and the ability of all high-rise buildings to cope with an earthquake, quick and effective early warnings, and the need, in case of a big quake, to survey possible damage sustained by high-rise buildings in Bangkok or by major dams, especially hydropower dams in the North and the West, which are located near geophysical fault lines.


Asian Institute of Technology seismologist Penneung Wanichchai said he had not yet checked information in yesterday's report. However, earthquakes in the northern region, especially on the Mae Chan and Pua fault lines, occurred often because the faults were still active.