Abstract: The 1830 Cixian, Hebei province, M 7(1/2) earthquake is a strong sequence with high activity and long duration In recent years, a large amount of small shocks have been recorded in the region of Cixian county by the Handan remote sensing seismological network The 3 dimensional spatial distribution of focuses and focal mechanism of these small shocks are analyzed It is suggested that the focal fault of the 1830 Cixain earthquake is a fault with NWW strike and left lateral strike slip This result is in agreement with the isoseismal and surface rupture belt of the Cixain earthquake Therefore, it is feasible to outline spatial orientation and motion mode of the focal fault of historical great earthquakes from characteristics of swarms of current small shocks which occurred in the historical seismic region by combining method of seismology and geology

Key words: Historical earthquake, Focal mechanism, Focal fault

摘要： 1830年磁县7(1/2)级地震是一个活动水平高、持续时间长的强震序列。近年来邯郸遥测地震台网记录到沿磁县地震极震区方向发生的大量小地震。根据对这些小地震的震源位置、震源机制的三维空间分布的分析,认为磁县地震的震源断层是NWW向近于直立的左旋走滑断层,它和磁县地震的等震线、地表破裂带特征相符合。这个例子说明在地震学和地震地质学相结合的基础上,有可能由历史大地震区内现今小地震的群体特征,推测历史大地震的震源断层空间取向及其运动方式。

关键词: 历史地震, 震源机制, 震源断层