On March 28, a 7.9 - magnitude earthquake struck Myanmar, causing significant casualties and property losses. Why was this earthquake so destructive? Has the Earth entered an earthquake - active period? What are the misunderstandings in post - earthquake self - rescue? Experts in the emergency management field provided detailed explanations.
Why was this earthquake so destructive? Experts from the China Earthquake Networks Center analyzed that this earthquake occurred in the Myanmar Arc region. Since the Cenozoic era, the intense collision between the Indian Plate and the Eurasian Plate has led to large - scale shortening of the lithosphere and the formation of the Himalayan orogenic belt. The Myanmar Arc region is located at the eastern tectonic junction of the Himalayan orogenic belt, with strong crustal tectonic deformation and high seismic activity. A series of north - south - trending tectonic units and faults have formed, making it one of the most seismically active areas on the Himalayan seismic belt. Statistics show that since 1900, there have been 10 earthquakes of magnitude 7 or above within a 300 - kilometer radius of the epicenter of this earthquake, with the largest being an 8.0 - magnitude earthquake in Myanmar on May 23, 1912. It is understood that this earthquake is the largest - magnitude earthquake globally this year. A specially - invited expert from the Institute of Geophysics, China Earthquake Administration, believes that this was a typical shallow - focus earthquake inside the crust. Its rupture surface might have reached the ground surface, causing strong ground shaking. The area near this fault zone is where the population in Myanmar is relatively concentrated. The earthquake caused a large number of buildings to collapse, posing a severe challenge to emergency rescue efforts.
Has the Earth entered an earthquake - active period? Why are there differences in magnitude data? Since the beginning of this year, there have been 17 earthquakes of magnitude 6 or above globally. With recent earthquakes occurring in many places, does this mean that the Earth has entered an active seismic period? An expert said that the overall global seismic activity this year is lower than in previous years. Based on the current situation, it's hard to say that the Earth is in an earthquake - active stage after this earthquake. For the same earthquake, the China Earthquake Networks Center usually releases two pieces of information: 'automatically determined' and 'officially determined'. There are slight differences in the time, location, and magnitude of the earthquake between the two. The first 'automatically determined' result is a set of reference 'three elements' (the time of the earthquake, the epicenter, and the magnitude) quickly calculated by a computer through reading and analyzing data monitored by seismic instruments. The second 'officially determined' result is the 'precise answer' finally obtained by scientists through a series of operations such as manual calculations. Therefore, there will be slight differences between the two pieces of information. In addition, in the same earthquake, the magnitudes given by different institutions may vary. Industry insiders said that there are many influencing factors behind this. The main reason is the use of different magnitude scales, such as surface - wave magnitude, body - wave magnitude, and moment magnitude. 'Different magnitude scales are like different rulers, and the measured magnitudes will have deviations.'
How to self - rescue after an earthquake? 'Earthquakes are characterized by instantaneous occurrence, strong destructiveness, and serious secondary disasters. Mastering self - rescue skills is crucial.' An expert reminded everyone to keep in mind the principle of 'taking shelter nearby during the earthquake and evacuating quickly after the earthquake'. When indoors, quickly judge your location and the shaking situation. Take shelter nearby in a small - compartment room such as a bathroom, close to water but away from fire, and protect your head and neck. Don't stand by the window or on the balcony to avoid being injured by falling objects. If you are in a classroom or library, stay away from bookshelves and take shelter under a desk, holding the desk legs tightly with your hands. Leave the room only after the shaking stops and it is confirmed that it is safe outdoors. Don't take the elevator, jump out of the building, or break the window to escape. Choose to walk downstairs. When outdoors, go to an open area as soon as possible. Stay away from tall buildings, avoid buildings that may collapse or large objects that are likely to fall, such as buildings, glass curtain walls, overpasses, pedestrian overpasses, high chimneys, and billboards. Keep away from dams, steep cliffs, and factories or facilities storing flammable, explosive, or dangerous chemicals. If you are buried, stay calm and conserve your energy. You can send out a distress signal by knocking on stones. Strengthen drills at ordinary times, learn more about earthquake - proof and disaster - avoidance knowledge, and jointly improve the ability to prevent and reduce disasters.
In addition, experts also reminded of some misunderstandings in earthquake escape and avoidance. Misunderstanding 1: Immediately flee outdoors regardless of the actual situation after an earthquake. If the indoor shelter conditions and building quality are good, indoor shelter should be the first choice. Earthquakes occur instantaneously. When people enter or leave a building, the probability of being injured by falling objects is relatively high. Roof tiles, billboards, glass walls, etc. also have the risk of collapse. If people living on high floors all flee outside at the same time, it is easy to cause chaos and unnecessary trouble. Misunderstanding 2: Hide in furniture such as wardrobes. Although a large wardrobe is sturdy, its center of gravity is too high and it is easy to tip over. Once a person gets into the wardrobe, their vision will be blocked and their limbs will be restricted. This not only misses the chance of escape but also makes it difficult to be rescued. Misunderstanding 3: Lying on the ground or waiting for rescue in a lying position can save energy. Lying or lying prone during an earthquake is very dangerous. This will increase the planar area of the body, and the probability of being hit by debris and other objects is greater than when standing. Lying down also makes it difficult for the body to move flexibly. The best posture is to protect your head with your hands and lie on your side in a curled position (to protect the spine).