Near noon on April 25, large tectonic plates below the Earth's surface moved and created an impact equivalent to 20 atomic bombs, ripping the ground in Katmandu, Nepal.
The tremor occurred as expected , 81 years after a strong earthquake with similar magnitude in this area. According to the Nepal Earthquake Research Technology Association, in the 1255 records, this place used to occur a strong earthquake of level 8 every 75 years.
Many buildings and monuments in Nepal were destroyed after the earthquake on April 25.(Photo: Reuters)
The cause of earthquakes is the frequent movement of cracks running along the southern border of Nepal, where the Indian subcontinent collides with Eurasian tectonic plates 40-50 million years ago. "The collision between them is a typical example for geological activity, " said geophysicist Lung S. Chan, a Hong Kong expert. The Indian tectonic plate is shifting its northward direction to Asia at a rate of 5 cm per year. According to Chan, geologically, this speed is very fast.
Describe the structure of tectonic plates and faults.(Photo: USGS / WSJ)
The repulsive effect of tectonic plates produces friction, creating pressure and energy until the crust cracks. According to Hongfeng Yang expert, in the case of Nepal, tectonic plates move forward about two meters. After an earthquake, tectonic plates continue to move. Chan describes the energy quake, "like when you open the lid of a boiling water bottle, the energy is released, but after we cover the bottle, the process of energy accumulation begins."
Times of India quoted an expert as saying the force generated by the 7.8 Richter earthquake swept across Kathmandu was equivalent to 20 thermonuclear bombs , each of which had greater destructive power than the bomb that destroyed Hiroshima, Japan. Copy, many times.
The US Geological Survey believes that earthquakes in Nepal are relatively shallow, with a tendency to cause more damage and aftershocks than the earthquake impact deep below the Earth's surface.
Nepal is an area prone to devastating earthquakes, not only because of its enormous strength from tectonic collisions, but also due to faults below the surface of the country. A common fracture creates space when the ground is separated. Meanwhile, Nepal is on a thrust fault, where a tectonic plate will push itself up on another plate.
The most obvious proof of this is the Himalayas. The fault lines run along the 2,250 km, the continuous collision between the tectonic plates of India and Eurasia makes the peaks continue to rise a few centimeters per year.
Serious earthquakes in Nepal seem to happen by law , but predicting what will happen is not easy. Past records and today's measurements of tectonic plate motion indicate that, if pressure builds up in this area in a consistent manner, earthquakes with heavy destructive power will occur come out every 40-50 years.
According to experts, the complexity of the impact on the fracture is the reason why researchers cannot accurately predict the average earthquake that an area will have to go through in a century.