利用粘滞模型研究华北地区中强地震的趋势特征

A Study on the Characteristics of the Mid-strong Earthquake Trend in North China by Using the Viscoelastic Model

通过对华北地震区块体以及板块运动的分析研究,建立粘滞模型对华北块体深部地壳及上地幔的力学特征进行研究,在给定的边界条件下解出华北地震区的应力松弛周期为56年。通过对华北地震区1900年以来MS≥6.0级地震的周期和蠕变曲线的分析,得出了和粘滞模型一致的结果。据此判断华北地震区在2022年之前处于平静期,在此期间将有多次5级左右地震发生的可能,印尼巨震的发生使边界条件发生显著变化,可能导致平静期缩短。

Based on the analysis of the neighboring block and tectonic plate in the North China earthquake zone, we establish a viscoelastic model to research the mechanical characteristics of the crust and the upper mantle in deep of the North China earthquake zone. Under the limited boundary condition, we find the stress relaxation period is 56 years. By analyzing the periods and the creep curve of the earthquakes （Ms≥6.0） since 1900, we obtain the same results as that by the viscoelastic model. According to this, we estimate that the North China earthquake zone will be in the quiescent period before 2022, and several earthquakes with about Ms=6 may occur in this period. The great earthquake in Indonesia has obviously changed the boundary condition. It may shorten the quiescent period.