The mechanisms of seismic risk in different regions have some similarilties.Seismic risk can be described with some indices of seismicity which similarity reflects the difference of seismic risk.

• 不同地区地震危险性的产生机制具有相似性，地震危险性可由若干地震活动性指标(要素)加以描述，因此，这些指标特性的相似性反映了地震危险性大小的差异。