Study On Microseismic Monitoring And Active Fault In The Bohai Strait Area

Bohai Strait is a major national project,with large scale,large investment,large benefits,the impact of large,high risk characteristics,the project site is particularly important.Active fault is a significant factor in the selection of major projects,Coastal and Marine major projects need to find the location of active faults distributed in coastal waters and the relevant laws of nature and intensity of activities,so that the project to avoid possible active faults.Therefore,the identification of active faults in the Bohai Strait activity patterns is the key to the Bohai Strait Tunnel project siting.The fault of sea area activity is located at the seabed and is covered by seawater.The conventional method of fault investigation of land area activity generally does not work,which makes the research of fault in sea area increase the difficulty.The active faults are slippery and creep by sliding.The fault creep activity changes the fault stress field,resulting in strain deformation.Through the stress and strain observation,the creep activity of the fault can be studied.Earthquake is one of the main manifestations of viscous slip fault activity.Through microseismic monitoring,it can study the viscous slip activity of fault.Microseismic monitoring technology is not affected by seawater,and the method is simple,can obtain a large number of microseismic data in the short term,and then more comprehensive access to geological structure information,so microseismic monitoring technology is an important means to study the activity of viscous fault.At present,the study of active faults in the Bohai Strait area is low.In recent years,scientists have mainly used the Method of sound wave detection to study the active faults in the Bohai Strait area,and lacked a comprehensive study on the activities of the active faults in the area,and lacked of understanding of the activities of the active faults in the area.This paper analyzes the distribution and activity of active faults in the Bohai Strait by using microseismic monitoring technology combined with comprehensive research methods of land area,sea area and island geological survey.On the basis of previous studies,the modern activity of the active faults in the Bohai Strait area has been further understood.The monitoring results show that: Fengyidian fault through the Penglai City Economic Development Zone extension into the sea,the current activity is strong,the fracture may be associated with the Penglai-Weihai fault was "T" shape intersect,the structure of the intersecting site activity.The Tuoji Island North fault is now possible move.Near the village of Zhu Pan has a Holocene fault with NW direction is still active.The current activity of the Changdao's faults is weak.