【摘要】 对2010年4月14日玉树7.1级地震前3个月青海区域地震台网记录的无地震记录和无仪器故障的连续数字化观测资料进行FFT频谱分析,确定优势频率为0.03 Hz。通过Butterworth滤波器提取50.2~0.4 Hz的波形资料,运用亮度函数SSA扫描方法对提取资料进行扫描计算,亮度函数空间分布表明青海境内东昆仑地震断裂带内存在周期为30 s的辐射源,并对其呈现的时空特征做了初步的分析。结果显示,玉树7.1级地震前,由于受到青藏块体向北运动的影响,随着时间的推移辐射源有沿东昆仑地震断裂带由西向东逐步向玉树7.1级地震震中运动的现象。更多还原

【Abstract】 The spectra analysis of the continues digital observation data with no earthquake recording and no instrument fault is done by FFT method in Qinghai Regional Seismic Network in three months before MS7.1 earthquake on Apr.14,2010,and the predominance frequency of it is confirmed to 0.03 Hz.In the instrument working bandwidth,the waveforms in frequency of 0.2 ~ 0.4 Hz was extracted by Butterworth filter,and the extracted data was calculated by SSA continuous scanning waveforms with brightness function.The spatial distribution of brightness function showed that there exited a radiant source in the period of 30 s in the East Kunlun Fault Belt,and the temporal and spatial characteristic of the radiant source was primarily analyzed.The results showed that influenced by the northward movement of Qinghai Tibet Block,the radiant source gradually moved to the epicenter of Yushu MS7.1 earthquake from west to East with time along the East Kun Lun seismic fracture zone before the Yushu MS7.1 earthquake.更多还原