Abstract: Based on the research and the division of the active tectonic blocks and their boundaries in Chinese mainland, the feature of the large earthquake activities in the 24 boundaries between the 6 grade Ⅰactive tectonic block regions and the 22 grade Ⅱ active tectonic blocks are studied. The seismicity levels on the active tectonic block boundaries are discussed considering the large earthquake frequency and the released strain energy in unit distance and time. And then, the theoretic maximal magnitude and the recurrence period of each boundary are calculated from the G-R relation. By comparing with the actual earthquake records, it is found that the intensities of the earthquake deduced from the seismic activity parameter (a/b) in the main active boundaries in Chinese mainland are consistent with that of the nature earthquakes. Meanwhile, an inverse relation is found between the recurrence period of large earthquake and the tectonic motion rate on the boundaries. These results show that the a, b value of each boundary obtained in this paper is valuable. In addition, the present seismic activities and hazards of these boundaries are also probed into with the historical data and their elapsed time on each boundary based on the hypothesis that the large earthquakes satisfy Poisson distribution.

Key words: active tectonic block, active tectonic boundary, large earthquake activity, seismic activity parameter a and b value

摘要： 在中国大陆及周边活动地块与活动地块边界带研究和划分的基础上,研究了中国陆区6个Ⅰ级活动地块区和22个Ⅱ级活动地块之间的共计24个活动边界带上的强震活动特征。从各边界带上强震活动的频次和单位时间、单位长度的地震应变能释放出发,讨论了各活动地块边界带的强震总体活动水平;并从震级频度关系出发,计算了各带的理论最大震级与复发周期。通过与实际地震记录对比发现,由中国大陆各主要活动地块边界带的地震活动参数(a/b)所推算的强震活动强度与实际地震活动强度总体上具有较好的一致性,强震复发期与构造活动速率则呈明显的反向变化关系,这也表明本研究给出的各边界带的a,b值具有一定的参考意义。文中还利用历史强震资料以及各带强震活动的离逝时间,基于泊松分布,探讨了各活动边界带的现今地震活动水平及其危险程度。

关键词: 活动地块, 活动边界带, 强震活动, 地震活动参数a,b值