摘要
发生在城市范围内的直下型大地震可能产生巨大的灾害 ,包括高的振动破坏和强的断裂地表错动。因此 ,城市范围内的直下型活动断裂和隐伏活动断裂探测及地震危险性和危害性评价是十分重要的。立足于城市环境复杂、污染重、干扰强的特点 ,文中介绍了城市活动断裂探测的主要方法 ,包括地质地貌、地球化学和地球物理方面的多种探测方法。在地质地貌方法中 ,最新断裂活动面的断错地质地貌制图及针对断裂新活动和古地震研究的钻探和槽探具有特别重要的意义 ,年轻地质体和地貌面年龄测定是一项关键技术 ;地球化学探查 ,尤其是多种气体测项在隐伏断裂初步定位中起到先锋作用 ;在各种地球物理探测中 ,浅层地震勘探起着关键作用 ,而在探查活动断裂深部背景和孕震可能性时 ,各种深地震探测方法是十分重要的。在城市活动断裂探测这一新的工作中 ,必须更多地强调和更好地做到地质地貌、地球化学和地球物理探测的结合 ,做到多种探测手段和勘探方法的综合运用 ,这样才能做好断裂定位、断裂活动性判定及分析断裂孕震条件工作。
Large earthquake that occurs in the urban area may cause tremendous disaster, involving damages generated by strong ground shaking and surface rupturing along the seismogenic active fault Therefore, it is very important to survey and prospect the active faults and concealed active faults, and to assess their seismic hazards in the urban areas Considering these problems that most of the urban areas facing high noisy and shaking disturbance, heavy pollution and complicated surroundings, here some main methods for surveying and prospecting the active faults are introduced including geological and geomorphologic mapping as well as geochemical and geophysical prospecting methods Geological and geomorphic mapping for latest faulting traces, and drilling and trenching for study of recent activity of the faults and paleoseismology are very important, while the age dating to the young geologic body and geomorphologic surfaces is a key technique Geochemical prospecting, especially surveying by use of multiple geogases, is often used in the first step to locate a possible concealed active fault Shallow seismic prospecting method will play main role among various geophysical exploration methods Various kinds of deep seismic prospecting methods are strongly recommended to detect the deep tectonic settings of active faults which may likely induce future destructive earthquakes Nevertheless, in this new task for active fault detection in the urban areas, we must emphasize and rely on the comprehensive utilization of various kinds of techniques and methods from geology, geomorphology, geochemistry and geophysics, so that we can locate active faults, and better assess the activity of the faults and their capability to generate destructive earthquake
出处
《地学前缘》
EI
CAS
CSCD
2003年第1期93-104,共12页
Earth Science Frontiers
基金
国家发展计划委员会高新技术项目 ( 2 0 0 1977)
