Improvements in the continuous seismic profiler

The continuous seismic profiling system used at the Woods Hole Oceanographic Institution now has (1) an electrical spark sound source which has a maximum stored energy of 100,000 joules and can produce a variety of acoustic pulses with peak pressures of up to 134 db above 1dyne/cm2, at a repetition period of 10 sec, and which has a conversion efficiency (stored electrical energy to sound energy radiated) of 10 percent, (2) a streamlined and uniformly neutrally buoyant line‐hydrophone array with a band‐pass of 20 to 1,000 cps, and (3) a matched‐filter detector that measures the correlation between the reflected signal and the waveform incident on the sea floor in the same frequency range as the reflection. A source whose sonic output can be varied readily makes possible tailoring the resolution of the system for the best display of features of the oceanic crust of varying vertical size. A large reduction in the self‐noise of the detector is achieved through the use of streamlined, stable‐towing, line‐hydro...