Distinct body wave phenomena caused by mantle structure : detection, observations and interpretations

Abstract

This thesis intends to advance our understanding of secondary broad band body wave arrivals caused by mantle structure, the wave propagation phenomena behind them, and the corresponding constraints on Earth structure. These items are intimately related to each other and their understanding promises to increase the constraints and resolution of the fine structure of the Earth. The research of this thesis is presented in four chapters and comprises evidence of steeply reflected and focused arrivals from the D" region, a new coherency measure and stacking technique to detect weak but coherent signals, and the observation and explanation of non-geometrical PP and SS precursors caused by amplitude and phase fluctuations in the wave field.