张北近场资料处理及震源区地震分布三维图像

Data Processing of Nearfield Earthquake Records in Zhangbei Earthquake Region and 3-D Image of Earthquake Distribution in Focal Region

简要介绍张北近场地震资料处理软件平台的主要功能 ,提出了计算机自动查找近场地震事件的快速有效方法 ,解决了小震、微震的快速查找 .提出了利用密集的震源区精确地震定位结果获得该区地震分布三维图像的方法 ,可以反映震源区活动构造的三维形态 .获得了张北震源区地震分布的三维图像 ,它展现了该区域现今活动断裂分布的三维构造格局 .该震源区周围存在五条断裂 ,北东和北西向的四条断裂围成的“棱形”边界包围了震中区 .北东向的 (1)和北西向的 (2 )及北北西向的 (3)三条断裂交汇于单晶河附近 ,地震分布最密集的区域位于该三条断裂的交汇处附近 .该区域的地震主要是由这三条断裂的活动所造成 .

Major functions of software platform for near field earthquack rocords of Zhangbei are introduced briefly. A fast and effective method is proposed to search small earthquakes and microseisms. Another method is proposed to get a 3-D earthquake distribution image using dense and high precise hypocenter position data. Based on this image, we can get 3-D distribution of active faults in earthquake region. We have obtained 3-D image of earthquake distribution in Zhangbei earthquake region. The 3-D structure of active faults have been revealed. In the earthquakes region, there are five faults: two NE-trending faults, two NW-trending faults and one NNW-trending fault. The NE-trending faults and NW-trending faults form a 'rhomb' encircleing the hypocenter region. Three faults of NE-trending①, Nw-trending② and Nww-trending③ intersect near Danjinghe, the most dense of region earthquake distribution. According to the image obtained we can deduced earthquake occurred due to the recent activity of these three faults.