A SEISMOGRAPH FOR RECORDING WEAK EARTHQUAKES

Abstract

A highly sensitive seismograph is now used at the Kamchatkan seismic stations to record weak earthquakes as an extra channel. The seismometer has a free period Ts = 0.2 s, damping factor Ds = 0.4, and sensitivity S = 100 s/m at a load of kΩ. This channel increases magnification by 1.5-2 orders. This lowers the cutoff magnitude of complete reporting by 2-3 scale units compared to the commonly used short period instruments.