The influence of microseismic perturbations on a cold damped electrometer

Abstract

It is proved that the excess fluctuation of an electrometer above the electrical and mechanical Brownian movements found in a former investigation was due to microseismic movements of the soil. A theory is developed of the influence of mechanical perturbations on a cold damped 1) electrometer. This theory predicts a characteristic connection between the course of the excess fluctuation with the damping and the Fourier spectrum of the microseismic movement; this connection was checked experimentally. A further proof is the fact, that the Fourier spectrum of the microseismic movement deduced from the spectrum of a recording of the fluctuation of our electrometer is in agreement with a Fourier analysis of a seismogram.