UPPER LIMIT OF SEISMIC SIGNALS FROM GRAVITATIONAL WAVES

Abstract

The effect of surface seismic disturbances induced by cosmic gravitational radiation is considered. A brief review of previous results is included. A spherically symmetric homogeneous isotropic Earth model with a four-component adaptive seismic array on the Earth's surface is used for calculations in the frequency range ~0.01-0.1 Hz. Digital seismic data obtained by the TERRAscope network during a six-month period were used to evaluate the upper intensity limit of gravitational radiation bursts, hup = (1.0 ± 0.1) × 10-14, in terms of a dimensionless spatial-metric variation amplitude. An equivalent hup conversion of hup to the spectral intensity of the gravitational radiation flux density Ig yielded an upper bound for the upper limit: Ig <1.6 × 108 erg/(s.cm2 Hz). It is concluded that, if seismoacoustic waves are really excited by gravitational wave bursts, their amplitudes at the frequency fg = 0.05 Hz are bound to be below 1.4 × 10-8 cm.