Not located on the Ring of Fire, is Vietnam safe from earthquakes?

earthquake - Photo 1.

Earthquake epicenters around the world - Screenshot

After the 7.7 magnitude earthquake in Myanmar caused tremors in Hanoi and Ho Chi Minh City, many people also asked questions about the risk and possibility of an earthquake occurring in Vietnam.

Sharing about this issue, Associate Professor Dr. Nguyen Hong Phuong - Chairman of the Scientific Council of the Institute of Geophysics, Vietnam Academy of Science and Technology - said that strong earthquakes are concentrated along the fire rings.

There are three largest rings of fire on the planet: the Pacific, Mediterranean - Himalayan and extending along the seamounts from the Arctic Ocean through the Atlantic Ocean to the south.

“Vietnam is not located on the Ring of Fire, so we are safe. There are no destructive earthquakes like the one in Sumatra - Andaman in 2004 (9.3 magnitude) that took the lives of about 300,000 people or a strong earthquake like the one in Myanmar recently,” said Mr. Phuong.

However, Vietnam is still susceptible to strong earthquakes because our country has many fault systems tens to hundreds of kilometers long and deep faults, so earthquakes still occur.

Mr. Phuong said that according to recorded data, earthquakes in the South of our country are much weaker than earthquakes in the North.

The reason is that the sources of earthquakes in the North are very deep fault zones, named after rivers and spread across the North such as the Da River fault, the Red River fault, the Chay River fault, the Lo River fault, and the Ma River fault. These are the sources of strong earthquakes, especially in the Northwest region.

"The two strongest earthquakes in Vietnam's history were recorded in Tuan Giao (Dien Bien province) in 1983 and Dien Bien in 1985 with magnitudes of 6.8 and 6.7 respectively, which proves that the earthquakes were relatively strong.

"If a 6.8 magnitude earthquake like the one in Tuan Giao happened in Hanoi, what would happen? That's why we have to study which faults are likely to generate earthquakes to have preventive and response solutions to minimize damage," said Mr. Phuong.

Earthquake - Photo 2.

Rocks rolled down from the mountain onto a house in Hoa Binh due to the impact of a 4.0-magnitude earthquake that occurred on the morning of March 25, 2024 in My Duc district, Hanoi - Photo: H.KHOI

Dr. Nguyen Xuan Anh, director of the Earthquake Information and Tsunami Warning Center (Institute of Earth Sciences), once said that research by the Institute of Geophysics (now the Institute of Earth Sciences) showed that the two strongest earthquakes in Vietnam in Dien Bien and Tuan Giao caused surface vibrations near the epicenter (surface vibration intensity) of level 8 and level 9 on the MSK-64 scale.

"In our studies, we estimate that in the future, the Northwest region may still experience earthquakes of similar magnitude and ground vibrations occurring in the epicenter areas may be at level 8 or 9," said Mr. Xuan Anh.

According to Mr. Xuan Anh, earthquakes have a surface vibration intensity of level 8 and level 9, people can easily feel the shaking and fear.

The two previous earthquakes in Dien Bien and Tuan Giao did not cause much damage because at that time, there were not many buildings and surrounding areas built yet.

"If an earthquake with a surface vibration intensity of level 8 or level 9 occurs, construction works in the Northeastern and Northwestern provinces, although earthquake-resistant, can still be damaged and the impact level is relatively severe," said Mr. Xuan Anh, adding that a surface vibration intensity of level 9 can completely damage houses, the ground can crack 10cm wide, and level 8 will destroy houses.

A 6-7 magnitude earthquake releases energy equivalent to 37 atomic bombs.

According to Mr. Phuong, earthquakes of magnitude 4-5 (magnitude M) correspond to surface vibration intensity of level 4-5 on the MSK-64 scale, releasing energy equivalent to 3/100 of the atomic bomb dropped on Hiroshima (Japan) or 15 tons of TNT.

"This is what is happening in Kon Plong (Kon Tum), the biggest earthquake here was 5 magnitude (July 28, 2024)" - Mr. Phuong said.

If the earthquake is 5-6 magnitude, the surface vibration intensity is 6-7, equivalent to an atomic bomb.

"In Tuan Giao and Dien Bien, there were earthquakes of magnitude 6.8 and 6.7, equivalent to a surface vibration intensity of level 8-9, releasing energy equivalent to 37 atomic bombs" - Mr. Phuong shared.

According to Mr. Phuong, earthquakes of magnitude 7 or higher are often catastrophic. For example, the magnitude 9.3 earthquake in Sumatra - Andaman caused a tsunami that killed 300,000 people, this earthquake released energy equivalent to 36,700 atomic bombs or 475,000,000 tons of TNT.