海洋地质与第四纪地质

郯庐断裂带的地震活动主要集中于中部的下辽河-莱州湾段和潍坊-嘉山段,各段在活断层和地震活动方面存在不同的表现。1668年地震发生于潍坊-嘉山段的中部,是全新世断层活动的结果。该地震产生了惨重的人口损失和建筑物破坏,其地震灾害具有典型性。未来应注意渤海地区地震的群集型活动以及安丘地区和新沂一泗洪地区的强震活动。还应注意在新的经济条件下新的地震灾害内容和新的灾害类型。

Earthquakes are the most serious geological hazard. The generation of earthquakes is closely related to active faults. The activities of faults can cause the occurrence of earthquakes. A large earthquake can lead to great hazards. Based on the geological investigations in the past few years and the analysis of historical records,this paper discusses the relationship between the active faults in Tanlu fault zone and the 1668 Tancheng earthquake (8.5), meanwhile mainly discusses the hazards produced by the 1668 Tancheng earthquake. Tanlu fault zone is a large deep fault zone in eastern China continent with strike of NNE. It is also a strong seismic zone which has a great effect on eastern China. According to the different behaviors of active faults and seismicities,Tanlu fault zone can be divided into four segments , which are Hegang-Tieling segment, Xialiaohe-Laizhquwan segment,Weifang-Jiashan segment and Jiashan-Guangji segment. The seismicities along Tanlu fault zone are concentrated in Xialiaohe-Laizhouwan segment and Weifang-- Jiashan segment. However, the seismisities in the two segments belong to different seismic models. Xialiaohe-Laizhouwan segment has a feature of grouping activity of strong earthquakes,while Weifang-Jiashan segment has a feature that the seismicities are controlled by the fault segmentation and recurrence of strong earthquakes in the same site with the same recurrence interval. The 1668 Tancheng earthquake occurred in the middle section of Weifang-Jiashan segment,which was the result of the activity of Holocene faults and produced a 130-km-long seismic fault. This earthquake is the largest earthquake in eastern China continent, which caused great injuries and deaths, serious destruction of many kinds of buildings and complex ground deformation. The seismic hazards are typical. In the future, for Xialiaohe-Laizhouwan segment, we consider that a series of strong and medium-strong earthquakes would concentratively occur in the coming active periods,while for Weifang-Jiashan segment,we consider the recurrence of strong earthquakes according to the recurrence intervals,especially in Anqiu and Xinyi-Sihong areas because these two areas are close to the recurrence intervals,to which we should pay great attention. In addition,we should also consider the new seismic hazard types and new seismic hazard contents under the new economic conditions.