Estimation of the Spatial Variability of Transmission Losses at Low Frequency inShallow Water Using Multichannel Seismic Reflection Data. (Reannouncement with New Availability Information)

摘要

Spectral studies of commercial marine multichannel reflection profiling datademonstrate their utility for providing estimates of the degree of spatial variability in low-frequency ( < 100-Hz) transmission characteristics that is present in contrasting shallow water environments. The excellent spatial sampling provided by these readily available datasets allow them to resolve approx. 10-dB changes in returned energy levels occurring over distances of as little as a few hundred meters. At frequencies below the cutoff frequency, when the wave field is no longer dominated by water-borne energy. These small scale variabilities in transmission losses cannot be straightforwardly predicted from routinely collected mapping data (e.g., reflection profiles and velocity analyses of precritical reflections). Existing commercial marine multichannel reflection profiling datasets constitute an important resource for the mapping of changes in propagation characteristics in shallow water.