日本信浓川地震带超压热水系的喷溢作用与地震活动  

The Expulsion Activities of Geopressured Hydrothermal System and the Occurrence of Eearthquakes in the Shinanogawa Seismic Belt in Japan

作　　者：徐辉龙[1] 孙金龙[2] 丘学林[2] 赵明辉[2] 

机构地区：[1]中国地质大学(武汉)资源学院,武汉430074 [2]中国科学院边缘海地质重点实验室中国科学院南海海洋研究所

出　　处：《华南地震》2006年第1期106-117,共12页South China Journal of Seismology

基　　金：国家自然科学基金项目(40476025);中国科学院知识创新工程重要方向项目课题(KZCX3-SW-234-4);广东省科技计划项目(2004B33201002)

摘　　要：信浓川地震带位于日本大地沟北部,地壳运动十分强烈,区内地震主要沿信浓川流域发生,并密集成带,大地构造上处于日本海板块向本州板块俯冲的边界线上。该地震带大多数地震为中强震,且均为浅源地震,地震发生伴随着明显的地下水前兆异常,震中区有强烈的超压热水系的喷溢活动。震中区地下水的温度、电导率以及主要地球化学成分呈线性异常分布,并与地震强弱或地震断裂规模有关,地震断层的规模控制了超压热水系喷溢活动的强度和规模。地震发生与超压热水系喷溢活动有着密切的成生关系,超压热水系喷溢活动使断层发生活动所需应力条件降低,诱发地震发生,同时断层活动为超压热水系向上喷溢提供通道。The Shinanogawa seismic belt, Honshu Island, Japan, extends along the S Okhotsk Plate. A geopressured hydrothermal which is developed in the Northern Fossa Magna, hinano River bounding the Eurasian Plate and the system is widely distributed in the Northern Fossa Magna region. Many destructive earthquakes are related to the activity of this geopressured hydrothermal system in the Shinanogawa seismic belt. The expulsion of geopressured hydrothermal system and rising from depth along an active fault triggered the occurrence of an earthquake and opened the fault as a pathway. The anomalous areas in temperature, electrical conductivity and Cl- concentration of groundwater trend northeast as a linear distribution and convincingly demonstrate the presence of a buried active fault at the epicentral area of the destructive earthquake in the Shinanogawa seismic belt. The distribution of the major axis of the anomalous area in groundwater temperature shows an extremely positive relation with the magnitude of earthquake. It means that the distribution of the anomalous area in groundwater temperature may indicate the scale of earthquake fault. The linearly anomalous areas in groundwater temperature resulting from the percolation of geopressured hydrothermal system and having no historical destructive earthquake are of the predicted areas of future destructive earthquakes. Four potential earthquake areas are proposed and discussed based on the re-examinations of the active faults and seismicity in the Shinanogawa seismic belt.

关 键 词：活动断层 日本大地沟 信浓川地震带 超压热水系 喷溢活动 地震 

分 类 号：P315.723[天文地球—地震学]