格尔木地震台阵勘址数据分析与台阵布局设计

为了增强西部地区的地震监测能力, 中国拟在格尔木地区建立一个小孔径地震台阵。 本文对台阵勘址数据进行了噪声与信号的相关性分析, 得到地震监测的最佳台间距。 结果表明, 对于近震和区域震的监测, 该台阵子台间距最好小于500 m, 对于远震的监测, 台站组合间距应为1500～2000 m。 最后将勘址布设的台阵作为初选台阵进行了台阵响应计算, 计算显示, 台阵响应的主瓣在NW-ES方向较窄, 表明对来自该方向事件的慢度分辨率较高; 由于呈“L”型分布, 该初选台阵确定某些方向地震的方位角较好, 但检测其他方向事件的方位角精度不高, 这可以通过台阵校正进行改善; 台阵响应中出现的多处侧瓣是由于子台间距较大造成的。

Site Survey and Design of the Golmud Seismic Array

A small aperture seismic array will be built in western China to increase earthquake monitoring ability of the northwest region of China. The correlation values of noises and signals recorded by the test array were calculated in the paper to find the best inter-sensor distance to monitor earthquakes. The research results implied that the inter-sensor distance of each two neighbor stations shouldn’t be longer than 500 m to fulfill the monitoring demand of regional events, the distances of station pairs should be 1500~2000 m to monitor the teleseismic events. At last, considering the survey array as the primary array to calculate the array response, the result was a narrow main lobe in the Northwest-Southeast direction, which showed that the narrow main lobe gave a higher slowness resolution for the event coming from this direction. Because of the L shape distribution, the array had a low resolution on azimuth, but could be improved by the correction appointing to a specific area. The appearance of many side lobes is due to the bigger inter-sensor distances of the test array.