A Theoretical Model of Primary Frequency Microseisms

Abstract

A comprehensive mechanism for making quantitative estimates of the seismic response associated with quasi‐monochromatic system of pressure waves in shallow water is proposed. Based on generalized linear wave theory, it applies to low‐frequency components in the microseism spectrum. A model of pressure response function is derived by considering the agitated surface of open sea with wave trains converging towards the shore‐line from scattered sources. As expected, this favours low‐frequency swell and is able to isolate energy associated with a specified frequency component. Lastly, an expression for the local energy balance in the seismic wave guide is deduced and the computed results from this theory is tabulated with those from recent measurements. Broadly speaking the two are sufficiently in agreement except at very low frequency range of the spectrum. Copyright © 1972, Wiley Blackwell. All rights reserved