The features of precursors of crustal deformation and gravity before some strong earthquakes in North China have been analyzed. The results show that, before strong earthquakes, a close tectonics-dependent dynamic pro...The features of precursors of crustal deformation and gravity before some strong earthquakes in North China have been analyzed. The results show that, before strong earthquakes, a close tectonics-dependent dynamic process should exist in large areas and the media in the epicentral area should change their state. With these results as a basis, an improved combination-hardening model has been put forward. When the adjusting element moves, the tectonic movements is intensified in large areas and the density of deep media on both sides of faults will be changed. In the stress concentration element, there will be a media hardening process due to the continuous accumulation of energy. It is such a mechanism that results in the various steps of precursors.展开更多
基金This project is one of the research achievements of the "Ninth Five-Year Plan" under No. 95-04, CSB, China.
文摘The features of precursors of crustal deformation and gravity before some strong earthquakes in North China have been analyzed. The results show that, before strong earthquakes, a close tectonics-dependent dynamic process should exist in large areas and the media in the epicentral area should change their state. With these results as a basis, an improved combination-hardening model has been put forward. When the adjusting element moves, the tectonic movements is intensified in large areas and the density of deep media on both sides of faults will be changed. In the stress concentration element, there will be a media hardening process due to the continuous accumulation of energy. It is such a mechanism that results in the various steps of precursors.
