Amplitude-distance relation for 20-second Rayleigh waves

Abstract

Abstract Amplitude measurements on Rayleigh waves near a period of 20 sec were extracted from an 8-month data base for nine stations of the High-Gain Long-Period network. Application of an appropriate statistical model resulted in station, event, and distance terms; the distance terms defined a relation significantly different from the standard distance-dependent correction for Ms estimation. The apparent Q for 20-sec Rayleigh waves implied by this new data is roughly 700, in contrast to the 350 implied by the standard correction.