兰州台阵响应函数及不同方位小地震事件FK分析结果

The Array Response Function of Lanzhou Seismic Array and Results of FK Analysis for Small Earthquakes in Different Azimuths

摘要:

计算了兰州台阵不同频率的台阵响应函数,对台阵附近不同方位的4个小震进行了FK分析。结果显示兰州台阵2 Hz以下的台阵响应函数在原点附近呈现出对称的单主峰图样,而高于2Hz时台阵响应函数出现较多旁瓣,表明该台阵对于2 Hz以下的信号具有较好的分辨能力。小震的FK分析结果表明,根据甘肃省地震局地震目录和IASP91速度模型计算得到P波方位角和慢度与FK分析的结果总体上比较一致,但也存在一定差别,这种差别可能由所使用的理论模型和当地模型有差别以及未做台阵校正所引起。

Abstract:

The array response function of Lanzhou seismic array is calculated in different frequencies.Four small earthquakes in different azimuths are analyzed with FK method.The results indicate that there is a main peak in the image of FK analysis in frequency smaller than 2 Hz,and many side slobes correspond with higher frequencies,which indicate that the array has good ability to resolve the signals with frequency less than 2 Hz.The results of FK method for 4 small earthquakes indicate that the azimuth and slowness estimated by FK analysis are mainly consistent with the results calculated by seismic catalog referring IASP91 velocity model,but there is difference between both results.The difference maybe caused by difference between the velocity structure beneath the array and the IASP91 model,as well as no application of array correction.