Survey of the shallow structure on the northeast end of Wenchuan earthquake fault zone by artificial seismic
汶川地震断裂带东北端浅部结构的人工地震探测

Fault zone is sensitive to the post-seismic stress state. We can get the fault healing process by monitoring the fault zone seismic velocity temporal variation. In order to get the shallow structure at the northeast end of Wenchuan earthquake fault zone, we carried out a shallow structure survey by artificial seismic sources. The strong shallow reflector and complex structure produced a complicated wave field and low signal to noise ratio data. Based on separated surface, reflection and refraction waves by f-k transform, we imaged the subsurface structure by refraction common middle point imaging, surface wave velocity inversion, and reflection wave stack imaging. An integrated interpretation was done combing the three imagine data and the shallow faults and velocity distribution were given. This work is helpful to post-seismic emergency monitoring of earthquake fault zone.