'Unique geography puts city in peril

While the probability of another earthquake hitting Thailand in the near future is very low, many parts of the country including Bangkok - are at high risk of experiencing shocks from tremors which originate from nearby fault lines, a seismologist warned.

- AEKARACH SATTABURUTH

Speaking at the Bangkok Post Knowledge Forum, which was held with the theme "After the Quake", Professor Pennung Warnitchai from the Asian Institute of Technology said Bangkok has unique geographical features which render it vulnerable to the effects of distant quakes.

The city, he said, is built on a foundation of soft soil that amplifies seismic waves, so even though Bangkok isn't built directly over a fault line, the city and its residents-especially those living in high-rise buildings -can sometimes feel the effects of earthquakes whose epicentres are located far away. The earthquake that was felt in Bangkok on March 28, for instance, was caused by a slip along the Sagaing Fault, which is located deep in Myanmar, he said.

"The city sits on soft soil in a basinlike terrain, which slows down seismic waves and amplifies them. This creates long-period ground motion that especially affects tall buildings," Prof Pennung said.