A Broadband Accelerometer for Studying High Frequency Noise Produced by the Earth

This article considers a physical and mathematical model of an accelerometer for recording ultrasmall surface vibrations (10–10–10–11 m) in the frequency range of tens of hertz that operates on the basis of the S-mode of bending vibrations. The simulation results made it possible not only to compare the basic design characteristics with the experimental parameters of the available prototype of the accelerometer but also to study the change in the properties of the accelerometer with changing mechanical and electrical parameters of the structure. The ability to turn on a sequential series of bimorphic elements makes it possible to increase the sensitivity at the converter output to 10 V s2/m in the working frequency band of 10–100 Hz, which is more than an order of magnitude higher than the sensitivity of the currently available broadband systems based on piezoceramic transducers. The resonance frequency of the accelerometer is 520 Hz, while the transverse sensitivity is 1% or less. The methodology and features of the experimental recording of seismic noise by an accelerometer at the Nachiki seismic station in Kamchatka are described. The efficiency of using the registration system for observing tidal effects in seismic noise is shown.