Why was Myanmar quake felt in Bangkok, and how safe is S'pore?

Simply Science

- Zhaki Abdullah

On March 28, Myanmar was hit by one of its worst earthquakes in a century, with more than 3,000 left dead after a 7.7-magnitude earthquake hit the Sagaing region of the South-east Asian nation.

Tremors were felt as far as Hanoi in Vietnam, more than 2,000km away. Tremors were also felt in Bangkok, more than 1,000km from the epicentre, where a skyscraper that was under construction collapsed as a result.

Simply Science looks at what caused the earthquake, and just how safe Singapore is from the impact of such natural disasters.

Earthquakes typically occur in fault zones, where tectonic plates—large sections of rock making the earth's crust and upper mantle—collide or slide against one another.

Myanmar lies at the convergence of four tectonic plates—the Eurasian plate, the Indian plate, the Sunda plate and the Burma microplate.

Experts have attributed the earthquake to a strike-slip of the Sagaing fault, where the Indian and Sunda plates moved horizontally along each other.

The Sagaing fault is a major fault, or crack in the rock, running about 1,400km from Myanmar's north to its south.

As to why the tremors were felt in Bangkok, Associate Professor Wei Shengji from the Asian School of the Environment at NTU, said the size of the event resulted in the generation of strong seismic waves that could travel long distances.

This was amplified by the Bangkok basin, otherwise known as the Chao Phraya delta, whose soft soils resulted in the earthquake being more dangerous.

Buildings have a natural frequency of vibration, determined by factors such as height, materials and construction.