Was Grand Banks event of 1929 a slump spreading in two directions?

Abstract

This paper describes a kinematic model of tsunami generated by submarine slides and slumps spreading in two orthogonal directions. This model is a generalization of our previously studied models spreading in one direction. We show that focusing and amplification of tsunami amplitudes can occur in an arbitrary direction, determined by the velocities of spreading. This kinematic model is used to interpret the asymmetric distribution of observed tsunami amplitudes following the Grand Banks earthquake—slump of 1929.