郯庐断裂带的活断层分段与潜在震源区的划分

Active Fault Segmentation and the Identification of Potential Seismic Zones along the Tanlu Fault

近年来我们在一些工程地震工作中,认为活断层分段在潜在震源区判定中具有举足轻重的作用。一个科学的、有依据的潜在震源区当能客观地反映构造活动特性和地震活动参数。活断层分段,应给出潜在震源区的边界条件及某些参数。应强调活断展与障碍构造的演化和发育,强调活断层自身的风格和特点:如不同的构造类型;断裂几何学、力学和运动学特点,活动量和活动速率;活动时代;横断层的存在及历史强震和古地震的活动等等。以郯庐断裂为例,在实际工作中,把断层进行四级划分可达到和满足潜在震源区的需要,并具有重要意义。

In recent years,based upon some research work of earthquake engineering, we think that active fault segmentation plays an important role in assessing the potential seismic zones. Now,in the compiling of seismic zoning map of China and the working out the outline of earthquake engineering and seismic microzonation by SSB,the method of estimating of seismic risk is used,The most advantage is combining the long-term earthquake prediction and probabilistric method. In the early stage of estimating seismic risk, dividing the potential seismic zone is one of the important work. A reasonable potential seismic zone with enough evidences should reflect the tectonic activity and parameters of seismic activity. Active fault segmentation should supply the boundary conditions of the potential seismic zone and some parameters. Therefore, we should emphasize the evolution and development of barrier structure and emphasize characters of active faults,such as the structural patterns,the characteristics of faults in geometry, mechanics and kinematics, quantities and rates of movement, active stages, existence of transverse faults, historical strong earthquakes and paleoearthquake, ect. For example,the Tanlu fault, in practical working, was divided into four segments. This would be meat the need of dividing potential seismic zone and would be very important.