An earthquake of magnitude 5. 1 occurred in Songyuan, Jilin. What are the causes of frequent earthquakes in Songyuan in recent years?

There have been many earthquakes of different scales in Songyuan City, Jilin Province in recent years. The reason is that Songnen Plain is not the main seismic zone, but a continental fault zone, which is much more stable than the volcanic seismic zone around the Pacific Ocean, but slightly more active than other inland areas. Geologically, Songyuan belongs to the earthquake-prone zone. The northeast section of Fuyu-Zhaodong fault zone is a small hidden fault zone, which passes through Songyuan City and is named Fuyu North Fault. Therefore, the crust in this area is active and earthquakes are frequent. Songyuan is located in atypical basin topography, on the Tan-Lu seismic belt (the longest seismic belt in China, 2400 kilometers long). In the east of this seismic belt, the Pacific plate tends to squeeze westward, and in the west, the Eurasian plate tends to escape eastward. Therefore, Matsubara was attacked from both sides, so the earthquake continued. Historically, many major earthquakes in China occurred on this fault zone, such as Haicheng earthquake, and most of them were dextral strike-slip type.

Up to now, the largest earthquake in Songyuan history is M = 5.8, which occurred at16: 04 on October 23rd. But there are countless microseisms, large and small. 20 165438 2007+654381October 2216: 08, the border between Gan 'an County and Qianguoerluosi Mongolian Autonomous County, Songyuan City, Jilin Province (44.7 degrees north latitude, 124. 1 degree east longitude Shallow earthquakes has happened many times before.