On March 28, 2025, a powerful 7.7-magnitude earthquake struck near Mandalay, Myanmar, causing significant destruction and loss of life.
Although Bangkok, the capital city of Thailand, is located approximately 1,000 kilometers from Myanmar Earthquake were still felt across the city, especially within mid to high rise structures. These vibrations led to notable structural impacts such as cracking and swaying of tall buildings.
Why it happened?
Thailand is surrounded by several regional seismic sources.
Among them, the three major faults with the potential to generate large-magnitude earthquakes, up to approximately magnitude 8, are the Sagaing Fault, the Kanchanaburi Fault, and the Andaman Fault. These faults, pose a significant seismic risk to Thailand and particularly to Chiang Mai and Bangkok.
Similar to the effects observed in Mexico City during the 1985 Michoacán earthquake, Bangkok remains at risk of damaging seismic ground motions despite its distance from active faults.
This is primarily due to the presence of soft surficial soil deposits, which can amplify earthquake ground motions by approximately 3 to 4 times (Pennung W, et al., 2000).
Spectral acceleration analysis, which examines how buildings respond to different vibration periods, shows that structures between 10 and 50 stories tall tend to experience stronger shaking.
It is largely due to the amplification effects caused by the soft soil conditions in the Bangkok basin. However, the seismic forces recorded during the recent earthquake in the Bangkok area were lower than those specified in Thailand’s seismic design standards (Zone 5, DPT 1301/1302-61).
This serves as a reminder that even distant earthquakes can pose serious risks, prompting a need for stronger seismic resilience in Bangkok’s urban landscape.
