Single ship large offset seismic profiling using a surface towed radio telemetry array (strata)

The precise measurement of the seismic velocities of the shallow crust in the deep (>3 km) ocean requires source-receiver offsets (5-10 km) that are typically larger than that available from conventional multichannel hydrophone arrays (i.e. 2.4 - 3.6 km). Almost all our knowledge of the seismic structure of the deep ocean crust has been provided by experiments carried out at discrete locations, using sonobuoys or ocean bottom instruments. The result is that the available spatial sampling is too poor to reliably define possible systematic trends in the evolution of crustal velocities. This has stimulated our development and evaluation of a prototype surface towed radio telemetry array (STRATA) that can be towed at ranges up to 8 km astern of a research vessel underway, thus allowing the continuous estimation of velocities of the shallow basaltic basement (Figure 1).