Why Thai authorities could not issue an earthquake warning

Rescue personnel walk near a building that collapsed in Bangkok, Thailand, on March 28, after a strong earthquake struck central Myanmar on the same day.PHOTO: REUTERS

BANGKOK – Following the 7.7-magnitude earthquake that struck Mandalay, Myanmar on March 28, many areas in Thailand – including the northern and central regions, as well as Bangkok – experienced tremors.

The incident sparked widespread criticism about why the relevant authorities did not issue a prior warning.

Veerachart Wiwekkawin, a senior geologist and earthquake expert at the Department of Mineral Resources, said that the cause of the earthquake was the Sagaing Fault, which stretches from Mandalay to Yangon.

READ: ‘Mass casualty’ after magnitude 7.7 quake strikes Myanmar, Thailand

The fault is relatively far from Thailand, yet many areas in northern and central Thailand, including Bangkok, were able to feel the tremors.

The reason the seismic waves reached Bangkok, he said, is due to geological factors that allowed the earthquake waves to propagate further.

The low frequency of the waves made it easier for tall buildings in Bangkok to resonate with the tremors, which made the shaking more noticeable. Therefore, it is not surprising that people in tall buildings felt the tremors from this earthquake.

Mr Veerachart explained that aftershocks are smaller than the main earthquake and gradually decrease in intensity, until they disappear completely.

READ: State of emergency declared in Bangkok after quake – Thai PM

It is unlikely that the population in Thailand would be significantly impacted, and the situation is relatively safe, he added.

When asked about the reason for the lack of prior warning, Mr Veerachart explained that it is impossible to predict exactly when or where an earthquake will occur.

However, once an earthquake has happened, authorities can send out notifications to inform people about the impact and possible aftershocks, which could continue for another two to three weeks.

Meanwhile, the Thai Meteorological Department has said that earthquakes remain a natural disaster that cannot be predicted. Effective earthquake prevention and mitigation require accurate ground vibration data from a monitoring system that meets international standards.

The department said that ground acceleration monitoring stations, crustal movement measurement stations, and sea level measurement stations have been installed across Thailand.

These stations continuously monitor and provide information related to earthquake hazards 24 hours a day. They also issue warnings for areas at risk in the event of a major earthquake in the sea. Upon detecting anomalies, the system can immediately send alerts to relevant authorities.

To prevent and mitigate earthquake hazards, the public is encouraged to stay informed about natural disaster news, so they can be better prepared to evacuate in time, the department added.

Map: STRAITS TIMES GRAPHICS Source: US GEOLOGICAL SURVEY