Abstract:Based on the continuous observation data of 8 sets of VP broadband vertical pendulum tiltmeters in Hebei province, the paper analyzes reflecting-earthquake characteristics, reflecting-earthquake ability and time-frequency characteristics, and discusses the reflecting-earthquake efficiency of broadband vertical pendulum tiltmeters in Hebei province. The results show that: 1) The reflecting-earthquake capacity of broadband vertical pendulum tiltmeter in Hebei area is directly proportional to the magnitude, inversely proportional to the focal depth (except Chongli station), and has little correlation with the epicentral distance. 2) All instruments can record relatively complete teleseismic seismic waves, and the starting time of P wave and S wave can be seen clearly from the waveform diagram. 3) The time-frequency analysis shows that the instrument can record relatively complete surface wave signals, but due to the limitation of sampling rate, the body wave (P and S wave) signals are not fully recorded, and the signals above 0.5 Hz cannot be recorded. 4) Due to the modification of instrument parameters by the manufacturer, Chongli station has obvious difference in signal response ability in high-frequency part from other station instruments, and can record more high-frequency signals. However, the reflecting-earthquake efficiency of shallow source earthquakes is contrary to that of other instruments. Therefore, the modification results of instrument parameters need to be further verified.
MA Wugang. Analysis of Reflecting Earthquake Efficiency and Time Frequency Characteristics of the VP Broadband Vertical Pendulum Tiltmeters in Hebei Province[J]. jgg, 2022, 42(6): 643-649.