[ad_1]
April 25 of this year is the fifth anniversary of the 8.1 magnitude earthquake in Nepal. Researcher Jiang Changsheng from the China Earthquake Administration Institute of Geophysics explained that,Earth scientists have worked hard for five years and have now revealed that the Nepal 8.1 strong earthquake is a rare extremely low angle push earthquake and the seismic rupture surface is extremely complex.
The 8.1 magnitude earthquake five years ago was the largest earthquake in Nepal since the strong earthquake of 1934. It caused the attention of earth scientists worldwide and carried out a great deal of scientific research.
Jiang Changsheng referred to the image of scientific research progress as the scientists’ “breakup case” process. He believes that although there are still many scientific questions to be answered in the 8.1 earthquake process in Nepal and the evolution of disasters, reviewing the progress of scientific research in the last five years Five mysteries of the “killer” of the earthquake.
——This is a rare very low angle push earthquake. Nepal’s 8.1 magnitude earthquake occurred in the Himalayan main thrust fault (MHT) at a depth of approximately 18 kilometers underground, its special feature being that the tilt angle is only 7 degrees, which is almost equivalent to the fault parallel to the surface.
——The breaking surface of this earthquake is extremely complex and controls the scale of the breaking of the earthquake. The Nepal magnitude 8.1 earthquake gradually broke from west to east on the smooth northbound contact surface (5 ° immersion). The irregularity of the subduction failure plane may be related to the local tear during the Indian plate subduction process, and at the same time, a rupture formed. The irregular slowdown in propagation limits the scale of the earthquake rupture to the east.
——There is a preliminary scientific response to the risk of a subsequent earthquake that caused social unrest. In the six months after the earthquake in Nepal, there was no apparent seismic slide in the rupture area, the possibility of continued strong aftershocks and large earthquakes such as the overthrow of the domino is almost non-existent. The follow-up course still needs time to take the test.
—— Many new understandings have been made about the earthquake damage to the project. The earthquake caused severe damage to Nepal’s hydroelectric facilities, damaging approximately 20% of hydroelectric capacity, mainly due to the earthquake that caused landslides caused by the steep side walls of the river valley. Research on earthquake damage to cultural heritage buildings in the Kathmandu Valley shows that 69.2% of the brick wood structure and 81.2% of the masonry structure were severely damaged and collapsed.
——Space observation of the earth plays an important role in this earthquake investigation. Because satellite remote sensing data can make high-precision, large-scale observations in space, in this Nepal earthquake, it played a major role in deformation of related blocks, fault tectonic activities, and disaster identification.
Jiang Changsheng noted that under the influence of various factors, such as the environment and tectonic conditions of pregnancy, the occurrence and evolution of major earthquakes have their own special characteristics and scientific mysteries to solve. After the 8.1 magnitude earthquake in Nepal, the process of “solving the case” and the scientific knowledge acquired by scientists can only be “a glimpse of the leopard”. Solving these problems through intensive and in-depth scientific research will be an effective way for humans to continually challenge and overcome natural disasters.
On April 25, 2015, a magnitude 8.1 earthquake in Nepal killed nearly 9,000 people, injured more than 22,000 people and collapsed nearly 500,000 buildings, until 2,900 cultural and historical sites were damaged.
