活动断层与地球物理方法

Active Fault and Geophysical Methods

活动断层是诱发地震的主要原因 ,也是破坏城市建筑设施的主要因素。对活动断层进行探测并评价其危害性具有重要意义。在论述活动断层的特征及探测阶段的基础上 ,结合实例探讨了利用地球物理方法探测第四纪覆盖下的活动断层。实践表明 ,重磁方法和直流联合剖面法能直观地确定断层的地表位置 ;高密度电法、电磁法、浅层地震、地质雷达、井间层析成像、放射性方法等能提供断层的形态特征、近地表的活动规律 ,还能为活动断层的分段性研究提供依据。这对我国即将开展的大城市活动断层探测和评价工作具有指导作用。

Active fault is one of the main causes for breakout of earthquake and one of the main factors for destruction of buildings in cities. Therefore, the active fault detecting and its jeopardize evaluating are very important. On the basis of the discussion on characters and detection phases of active fault, some cases on active fault detection by geophysical methods are shown in this paper. The facts demonstrate that the gravity, magnetic and resistivity profile methods can indicate the position of the fault; the high--density resistivity profile, EM, shallow seismic, GPR, CT imaging and radioactivity methods can provide the profile characters of the fault and the information for its activity, and subsection study. This is important for coming projects of active fault detection and evaluation in metropolis of China.