Sesimic Risk assessment of Active Fault Systems in Japan using Release Rate of Seismic Moments

提出了利用地震矩释放率平均速率进行地震危险性评价的方法。减轻内陆大地震引起的地震灾害。这些内陆地震是由活动断层系统的运动产生的。将危险性评价方法应用于日本中部的主要活动断裂系统和中部地区西部的两个活动断裂系统。用该方法对1995年兵古县-南部M=7.2级地震的地震危险性进行了重新评价。结果表明，该方法能较好地估计地震危险性。主要研究结果如下：1。根据各组成活动断层的平均滑动率和历史地震震级估算鹤川-伊势湾构造线的地震矩释放率。另一方面，通过历史文献和实地调查，对伊势湾周边地区代代相传的沉岛传说进行了验证。还有人指出，最近一次发生在伊势湾的地震是1586年的天正地震。利用矩释放率和从最近一次事件到现在的经过时间，可以评价构造线的地震危险性。根据活动断层的分布和历史地震资料，将中部地区西部的大原湖—w .山山湖和岩国—喀山湖两个活动断层系统定义为活动断层与地质断层的连接带。地震矩释放率也可用于评价活动断裂系统的地震危险性。1997年山口根-北部M=6.1级地震可能是由大原湖-山山断裂带中部的运动引起的。3 .将野外调查与现有的微震活动性和重力资料相结合，明确了活动断裂系统的三维几何形状，由断层几何形状估计的地震矩释放率与由断层滑动率和地震震级计算的地震矩释放率基本一致。危险性评价方法正确地评价了兵古肯-南部地震是由高月-六子-浅路构造线运动引起的。少

The method of seismic risk evaluation with the use of the average rate of seismic moment-release rates has been developed. to mitigate seismic hazards induced by large inland earthquakes. These inland earthquakes are generated by the movement of active fault systems. The risk evaluation method was applied to major active faults systems in central Japan and two active faults systems in the western Chugoku district. The seismic risk of the 1995 M=7.2 Hyogo-ken-nanbu earthquake was also re-evaluated by the method. It was found that the seismic risk was significantly estimated by the method. The main result is as follows ;1. The seismic moment-release rate of the Tsurugawan-Isewan tectonic line was estimated from average slip-rates of constituent active faults and magnitude of historical earthquakes. On the other hand, legeneds of submerged islands, which have been passed from generation to generation in the regions around Ise bay, were checked by historical documents and field survey. II … More was pointed out that the latest earthquake which occurred in Ise Bay was the 1586 Tensho earthquake. With use of the moment-release rate and elapsed time from the latest event to the present, the seismic risk of the tectonic line can be evaluated.2. The two active fault systems, Lake Ohara - W.Yauneyama and Iwakuni - Kamine in the western Chugoku district were defined as zones linking active and geologic faults based on distributions of active faults and historical earthquakes. The seismic risk of the active fault systems can be also evaluated from the seismic moment-release rate. It was probable that the 1997 M=6.1 Yamaguchi-ken-hokubu earthquake was caused by the movement of central part of the Lake Ohara - W.Yauneyama fault system.3. Three-dimensional geometry of active fault systems was clarified by the combination of field surveys with available microseismicity and gravity data The seismic moment-release rate which was estimated from the fault geometry is in consistent with those which was calculated from fault slip-rates and earthquake magnitude.4. It was properly evaluated by the risk assessment method that the Hyogo-ken-nanbu earthquake was generated by the movement Of the Takatsuki - Rokko - Awaji tectonic line. Less