【摘要】 选取唐山地区2008～2018年震相数据,利用单台多震和达法和多台多震和达法分别计算波速比,结合研究区内的地震活动对波速比的变化特征进行研究。结果显示,多台多震和达法得到的波速比结果较为稳定,而单台多震和达法得到的结果变化幅度大,显示更多细节;唐山地区M_L≥4.5地震发生前单台波速比存在不同程度的异常,异常台站的方位与地震具有一定的对应性。更多还原

【Abstract】 We select the seismic phase reports of Tangshan region by Hebei digital seismic network from 2008 to 2018 and calculate the wave velocity ratio by multi station-multi earthquake method and single station-multi earthquake method. We then analyze the characteristics of wave velocity ratio change combined with seismic activity. The results show that using the velocity ratio by multi station-multi earthquake method is more stable, but the results by the single station-multi earthquake method show more detail, and low value anomaly appears in varying degrees before M_L≥4.5 earthquakes in the Tangshan region. The locations of abnormal stations correspond to earthquakes, to some extent.更多还原