At 14:44 on September 18, 2022, a magnitude 6.9 earthquake occurred in Hualien County, Taiwan Province, my country, with a depth of 10 kilometers. Netizens in Fujian and Guangdong expressed a strong sense of tremor. According to the data that can be found, this earthquake was the largest earthquake in Hualien County, Taiwan Province in the past 10 years, causing the collapse of many buildings in Hualien County.
No casualties were found at present. According to statistics, the average annual earthquake in Hualien area in Taiwan is more than 6,000, and 400 earthquakes have obvious tremors, almost every few days. So, why do Hualien have frequent earthquakes? Hualien is located in the eastern part of Taiwan Province, in a narrow valley between mountains and seas, and on the Milun fault at the junction of the Eurasian plate and the Philippine Sea plate. For a long time, the Philippines and the Asia-European sectors have squeezed and collided, and the subduction zone is below the Asia-European sector.
forms fault displacement, causing frequent geological activities. According to the opinions of Taiwan earthquake expert Chen Guochang, the 6.5-magnitude earthquake on September 17 and the 6.9-magnitude earthquake on September 18 are in the same earthquake zone. The 6.9-magnitude earthquake on the 18th is theoretically an main earthquake because the crust energy is imbalanced after the 6.5-magnitude earthquake on the 17th. After the main earthquake explodes, the basic equilibrium can be reached. After that, the energy released by the crust should show a decreasing trend. Therefore, there will be constant aftershocks in the Hualien area in the future. Will it affect the mainland?
According to relevant information, the last two Hualien earthquakes were thrust-type ruptures on the eastern fault zone of Hualien Long Valley. As the name suggests, it is an earthquake that occurs on the sections of the two plates under the interaction of two plates, which is a thrust-type earthquake. Dr. Allen, a famous geological expert in Australia, once said, "The largest earthquakes on the earth are almost all thrust-type earthquakes." For example, the magnitude 9.1 earthquake in Sumatra that broke out in 2004 caused more than 100,000 casualties and triggered a tsunami, which indirectly caused more than 200,000 casualties, which can be called a geological disaster.
and the magnitude 9 earthquake that broke out in Japan in 2011 caused the tsunami to affect countries around the Pacific Ocean and caused leakage at the Fukushima nuclear power plant in Japan. The earthquake indirectly killed more than 13,000 people and disappeared more than 14,000 people. Thrust-type earthquakes mainly occur at the extinction border at the plate junction, such as the Himalayas earthquake zone in my country, , Taiwan earthquake zone, etc.
. According to the description of Taiwan earthquake experts, the focal mechanism of Taiwan this time is consistent with the characteristics of the fault thrust type rupture in the eastern Hualien Long Valley. Although the earthquake felt obvious along the eastern coast of my country, Hualien was located in the eastern part of Taiwan Province, so it had little impact on the mainland. However, experts remind that due to frequent geological activities in the Pacific and Asia-European plates recently, areas in seismic zones and fault zones should take precautions and drills.
