Dispersion of Rayleigh waves originating in the Mid-Atlantic Ridge

Abstract

Dispersion curves, plotted for earthquakes originating in ten designated Mid-Atlantic Ridge areas and recorded at five standard stations, were compared with model, oceanic dispersion curves derived by Dorman, Oliver, and Santo for determinations of oceanic structural variations, and for the influence of the Mid-Atlantic Ridge on the dispersion of Rayleigh-waves. The observed curves indicate, in general, that the model shear velocities should be higher for the Atlantic crustal layer. Trinidad dispersion curves do not demonstrate oceanic dispersive characteristics and, with gravity anomalies, imply a regional crustal and sedimentary layer thickening between the Trinidad station and the Ridge. Group velocity and ridge-path percentage comparisons suggest little influence of the Mid-Atlantic Ridge on the dispersion of Rayleigh-waves.