Abstract:

 Aftershocks triggered by an earthquake were located at different positions as shown by a large number of seismic parameters. Before the earthquake these positions can be looked as some units that are independent, discontinuous each other, and under elastic deformation. The author named them strain quanta. In combination with previous research findings, the author set up an earthquake model, and the Wenchuan earthquake in China that took place on May 12th, 2008 is interpreted with the model as follows: The strain quanta, which were formed in Longmenshan fault zone, hindered the movements of Longmenshan fault, and then brought about slip deficit. That made the velocityfield change in Longmenshan fault zone measured before the earthquake very unconspicuous. At 14:28 on May 12, 2008, one of the strain quanta reached its maximum energy storage in the first place, so it released its energy and made the surrounding crustal stress redistributed. The stress redistribution reduced the maximum energy storage of other strain quanta and made them release their energy in advance, and then caused the Ms 8.0 earthquake and subsequently many aftershocks. Moreover, we can make use of the observation of the velocity field change among the faults in the same plate to predict earthquakes. The smallest change of speed field of the fault will be measured out if many elastic strain quanta are formed along it; the elastic strain quanta are the source of the future earthquakes; and the fault is the potential earthquake fault.

Key words: earthquake, Wenchuan of China, slip deficit, Longmenshan fault, strain quanta