Myanmar, Bangkok Earthquake: The science behind the 7.7 magnitude tremor & its devastating impact

Myanmar has been ravaged by shock after shock in the form of powerful earthquakes for two consecutive days now.

On Friday a massive quake of magnitude 7.7 struck Myanmar, with its epicentre in Mandalay, caused widespread damage in both Myanmar and Thailand, the worst-hit countries. It was followed by two aftershocks - one recorded 6.9 magnitude and the other reached 5 magnitude on the Richter Scale.

While the death toll was still rising and crossed 1,000 on Saturday, the country was hit with another 4.3 mangnitude quake, the impact of which is still to be accessed in the aftermath of the first disaster.


The tremors of the 7.7M were felt as far away as Bangkok, prompting panic and the collapse of buildings, including a high-rise in Thailand that killed at least nine people. The Myanmar government has also confirmed three deaths from the tragedy so far.

But what caused this massive earthquake?

The science of earthquakes

An earthquake happens when there is a sudden release of energy beneath the Earth's surface due to the movement of tectonic plates.

Earth's outer shell, the lithosphere, is broken into large plates that "float" on the semi-molten mantle below.

These plates move slowly, and their interactions—whether they push against each other, pull apart, or slide past each other—cause stress to accumulate. When this stress is too great, it is released in the form of seismic waves, causing the ground to shake.

Myanmar’s earthquake trigger

The primary reason behind the earthquake is Myanmar's location along the Sagaing Fault, a major tectonic boundary between the Indian Plate and the Burma microplate.

This fault spans about 1,200 kilometres across Myanmar and is highly active, causing much of the region's seismic activity. The Sagaing Fault is a right-lateral transform fault, meaning the two landmasses on either side of it move horizontally past one another.

The plates along the Sagaing Fault move at a rate of between 11 mm to 18 mm per year. While this might seem like a small amount, the continuous movement over time leads to a significant accumulation of stress.

When the built-up energy is released, it results in powerful earthquakes. This constant shifting makes the region vulnerable to seismic events, as seen in the recent quake.

Myanmar’s seismic history

Myanmar is no stranger to earthquakes, particularly along the above mentioned Fault. However, this fault has been responsible for few significant seismic events that include two earthquakes of 8 magnitude and 7.8 magnitude in 1946, a 6.8 magnitude quake in 2012, and Friday's one, among some others.

According to Reuters, the USGS Earthquake Hazards Program reported on Friday that fatalities from the recent earthquake in Myanmar could range from 10,000 to 100,000 people, with economic losses potentially reaching up to 70% of the country's GDP.

These projections are based on historical earthquake data and factors such as Myanmar’s size, location, and overall preparedness for seismic activity, the report noted.

As the Sagaing region, which is close to the densely populated Mandalay, is not accustomed to large seismic events, infrastructure in the area was not designed to withstand such strong quakes, making the potential damage much more severe.

These events echo the region's vulnerability to future quakes and stresses the need for better preparedness and infrastructure to withstand seismic activity.

To mitigate the damage, authorities must focus on strengthening building codes, improving disaster management, and enhancing early warning systems to protect both residents and infrastructure.