Variations in the intensity of the global seismic process in the 20th and the beginning of 21st centuries     

A. I. Lutikov  E. A. Rogozhin 《Izvestiya Physics of the Solid Earth》2014,50(4):484-500

The variations in the intensity of the global seismic process during the 20th and beginning of the 21st centuries are analyzed. It is established that the evolution of the global seismic process is marked by a trend of a certain quasi-periodicity in the release of seismic energy. The analysis of the lithospheric seismicity during 113 years has shown that this time interval accommodated three periods of seismic activation separated by two periods of relative seismic quiescence. The global seismicity of the Earth is strongly dominated by the contributions of the earthquakes in the Pacific seismic belt. A considerable effect is also provided by the northeastern margin of the Indian Ocean. The horizontal displacements of the lithospheric plates are probably responsible for the accumulation of stresses in the potential sources of the earthquakes at the interplate contacts and in the orogenic areas inside the continents. The revealed clustering of the earthquakes with M ≥ 8.3 in the narrow time intervals is probably due to the fact that the strongest seismic event that occurs at the beginning of each activation is a trigger which simultaneously causes the relaxation of a few dozen mature potential sources within 10–15 years. This interval of seismic activation is followed by a relatively quiet period of 30–35 years, when the energy for the next activation is accumulated in a series of high-magnitude sources.  相似文献   

Seismic monitoring of source zones of strong earthquakes     

A. I. Lutikov 《Izvestiya Physics of the Solid Earth》2008,44(3):181-192

A rational choice of the scalar seismic moment and ordering index is proposed that can be advantageously used for the monitoring of source zones of strong earthquakes in order to predict the development of a seismic situation. These parameters are the main characteristics of seismotectonic deformation. The ordering index characterizes a regular change in time of chaotization and ordering phases of the seismic process related to the occurrence of strong aftershocks. Using the December 5, 1997, Kronotskii (M _w = 7.8) and December 26, 2004, Sumatra (M _w = 9.0) earthquakes as an example, temporal variations of the studies parameters in the aftershock zones of these earthquakes are analyzed in detail.  相似文献