Relation between the characteristics of strong earthquake activities in Chinese mainland and the Wenchuan earthquake

Abstract

This paper studies the relations between the great Wenchuan earthquake and the active-quiet periodic characteristics of strong earthquakes, the rhythmic feature of great earthquakes, and the grouped spatial distribution of M S8.0 earthquakes in Chinese mainland. We also studied the relation between the Wenchuan earthquake and the stepwise migration characteristics of M S≥7.0 earthquakes on the North-South seismic belt, the features of the energy releasing acceleration in the active crustal blocks related to the Wenchuan earthquake and the relation between the Wenchuan earthquake and the so called second-arc fault zone. The results can be summarized as follows: the occurrence of the Wenchuan earthquake was consistent with the active-quiet periodic characteristics of strong earthquakes; its occurrence is consistent with the features of grouped occurrence of M S8.0 earthquakes and follows the 25 years rhythm (each circulation experiences the same time) of great earthquakes; the Wenchuan M S8.0 earthquake follows the well known stepwise migration feature of strong earthquakes on the North-South seismic belt; the location where the Wenchuan M S8.0 earthquake took place has an obvious consistency with the temporal and spatial characteristic of grouped activity of M S≥7.0 strong earthquakes on the second-arc fault zone; the second-arc fault zone is not only the lower boundary for earthquakes with more than 30 km focal depth, but also looks like a lower boundary for deep substance movement; and there are obvious seismic accelerations nearby the Qaidam and Qiangtang active crustal blocks (the northern and southern neighbors of the Bayan Har active block, respectively), which agrees with the GPS observation data. © 2009 Seismological Society of China and Springer Berlin Heidelberg.