简易烈度计记录的噪声水平评价:以泸定 M_s6. 8 级地震为例

In China's earthquake early warning and intensity rapid reporting system, intensity meters are widely utilized. The spectral characteristics of intensity meters are primarily calibrated in testing laboratories. However, in destructive earthquakes, there is lack of necessary research and analysis on the response characteristics of intensity meters. The 2022 Luding, Sichuan M_s6. 8 earthquake was taken as a case study, the comparison between MEMS records and strong-motion records were conducted in terms of the noise level, signal-to-noise ratio ( SNR), optimal value of high-pass filter cutoff frequency (f_HP ) and effective period range ( T_max ). The noise effect of MEMS records was evaluated finally. The following conclusions are drawn: ( 1 ) Covering the entire frequency domain, the SNR of the MEMS records is lower by an order of magnitude on average than that of the strong-motion records, indicating that the dynamic range of the MEMS sensor is approximately 20 dB lower than that of the conventional accelerometer. (2) The optimal value of f_HP for the MEMS records has larger variability than that for the strong-motion records, standing out especially in the vertical component. (3) The optimal value of f_HP for MEMS records is larger, resulting in a smaller T_max in response spectra than that for the traditional strong-motion records, which is about 1-2 seconds shorter in the horizontal component and about 3 seconds shorter in the vertical component. The results will contribute to the rational application of MEMS records, serving correlated research in seismology and earthquake engineering.