A hypothesis on seismogenic process in a hard interacalary strata in the crust and promoting earthquakes by fluids for intraplate strong earthquake

Based on the up-to-date studies on relationship between crust fluids and strong erathquake activities both home and abroad, several aspects of search and illustrations were conducted and a hypothesis on seismogenic process in a hard intercalary strata in the crust and promoting earthquakes by a fluids (SPH-PEF) was presented. The points of the hypothesis are that there are two (upper and lower) fluid activity systems and a hard intercalary strata between them in the crust. The hard intercalary strata is the one in which geostress is accumulated and earthquake is developed. When the stress is cumulated to the yield strength at some places, the micro-crack (dilatancy) stages will begin and earthquake source entity will be formed. The fluids of lower fluid system are absorbed to source entity by suctionpumps, and results in the two correspondence synchronous mechanics processes, the enhancement of shear force and the weakness of resistance to shear stress, and finally leads to the equality between the shear force and the resistance to shear stress, and the occurrence of earthquake.