Numerical simulation of spatial-temporal evolution characteristics of subsurface fluid based on strong body seismogenic model

Using finite element technique of the plane-strain problem in solid-liquid two-phase medium, we studied the characteristics of “field precursors” and “focus precursors” of subsurface fluid and their spatial-temporal evolution in case of dip-slip earthquake. The results show that: (1) the change of ground fluid is slow and the anomaly is not prominent in the early period which is of elastic accumulation and non-linear; (2) dilatancy emerges and anomaly focus mainly in the source region in the moderate period which is hardening and of local dilatancy. In the period the focus precursors emerge earlier than the field precursors; (3) anomalies spread continuously in the source area and new regions with big anomaly emerge out of the source region in the middle-short period which is of large-scale dilatancy.