Higher modes of seismic surface waves: Propagation in Eurasia

Abstract Second Love and second Rayleigh modes are found to propagate in Eurasia across many different structures; the continent is divided into regions where these higher modes have the same dispersion characteristics. The condition for constructive interference breaks down only when the second modes cross areas of rapid change at oceanic-continental boundaries and under some mountain ranges. There are many paths in Eurasia where the second Love and Rayleigh modes have the same dispersion, and along these paths the two wave trains have a constant phase relationship, suggesting that the modes have some form of elastic linkage.