Measurements of acoustic wave propagation beneath the seafloor provide critical data for understanding the physical properties of marine sediments and crustal rock. Such information can be used to examine the composition and alteration of such material. Historically, most studies investigating the acoustic properties have used either seismic or laboratory techniques. Although useful, such data is often inaccurate for extrapolating to significant depth in the sea-floor. With the advent of sonic logging in the Ocean Drilling Program, some high-resolution acoustic data has become available. Because of the complexity of lithology, structure, geometry and available equipment, most measurements have only been able to determine compressional wave variations. The present project would adapt and modify for use on the JOIDES Resolution available industry equipment for measuring shear wave velocities and waveforms. This in situ data can be combined with routinely measured compressional velocities to completely characterize the acoustic properties of drilled sediments. The principal investigator is a promising young scientist who is fully qualified to undertake the proposed project. This award represents his first NSF research support.
