Analysis of the time spread of bottom interacting signals from an abyssal plain environment

Measured and simulated signals from explosive sources are compared to determine some of the features of the time spread introduced by bottom interaction in an area having 200 m of sediment cover. Two types of time spreading are observed: (1) a short-duration (0.5 s) primarily low-frequency continuation of the measured signal beyond the termination of the simulated signal. The short-duration time spread is made up of a sequence of spikes and could be caused by interaction with layers in the upper part of the sediment. Scattering from the basalt beneath the sediment is consistent with the features of the long-duration time spread.