The earthquake in My Duc district that caused the inner city of Hanoi to shake on the morning of March 25 was due to the activity of the Red River fault zone, according to experts from the Institute of Geophysics.
According to the Earthquake Information and Tsunami Warning Center (Institute of Geophysics), at 8:05 a.m. in My Duc district, a 4-magnitude earthquake occurred, with a depth of about 16 km, causing many people in the inner city of Hanoi to feel it. Shake for 3-5 seconds. Natural disaster risk level is 0.
Share with VnExpress, Associate Professor, Dr. Nguyen Hong Phuong, seismologist at the Institute of Geophysics, determined that the initial cause was a tectonic earthquake, caused by a natural fault zone (a geological phenomenon related to tectonic processes). created in the Earth's crust. Normally, faults often occur in places with unstable geological conditions).
A residential camera in Dong Tam commune, My Duc district, recorded an earthquake at 8:5 a.m. on March 25. Video: Nguyen Son
According to Associate Professor Phuong, the earthquake in My Duc occurred because it was located only about 1,8 km from the Red River fault zone - the source of the earthquake, running across the boundary of Hanoi City. This is a fault extending more than 1.000 km originating from Yunnan (China) running down to Northern Vietnam, extending to Vinh Phuc.
This fault is in a dormant period and this era lasts for several thousand years, according to expert forecasts. Therefore, along this fault zone, only medium or small earthquakes arise.
In Vietnam, up to now, only about 30 small earthquakes have been recorded with a magnitude of about 3 to 4 degrees. "According to the moment magnitude scale, these earthquakes do not exceed 6 degrees, so they do not cause house collapse or human damage," Mr. Phuong emphasized.
The earthquake occurred in My Duc district, about 50 km from Hanoi center. Graphics: Hoang Khanh
Associate Professor Phuong added that the earthquake in My Duc is different from the type of stimulated earthquake that happened in Kon Plong district, Kon Tum province. Earthquakes are stimulated by human impacts on the environment, specifically in hydroelectric areas where the reservoir layer is pressed down, causing stimulated earthquakes. The earthquake in Hanoi occurred on the Red River fault zone, due to nature causing deep cracks on the Earth's surface, which are likened to "a throat to release energy from underground, expressed in the form of earthquake, called tectonic earthquake.
Because it is not very active, tectonic earthquakes in My Duc are not dangerous. But he advised people to still be vigilant. Currently, the Institute of Geophysics is monitoring aftershocks after the earthquake.
Dr. Nguyen Xuan Anh, Director of the Institute of Geophysics, explains the law of earthquakes caused by seismogenic faults in the Red River - Lo River - Chay River fault zone, showing that it usually takes hundreds of years, or five to seven hundred years. Last year, a strong earthquake occurred. It is necessary to study the Red River fault segment to assess earthquake danger in more detail. The Hanoi area needs to conduct an earthquake risk assessment.
He also proposed setting up a number of monitoring devices in high-rise buildings in the city to quantitatively assess the level of shaking caused by earthquakes.
Experts said that it is very difficult to predict exactly when an earthquake will occur. Even in Japan, scientists do not know whether it will happen tomorrow or not. However, scientists can predict the magnitude of the earthquake in that area, or what the maximum level will be. "Therefore, people need to follow official information to respond promptly," Associate Professor Phuong said.
As Quynh
