Some Deep-Water Sound-Transmission Paths South of Cyprus

Deep-water sound-transmission paths extending in range through two convergent zones in the Mediterranean Sea south of Cyprus have been recorded by a new method that permits high-resolution nearly continuous observation of travel-time difference from a rapidly moving sound source as a function of elapsed time. Striking confirmation of some travel-time relations discussed by previous authors are presented. The paths near Cyprus differ from those in the Atlantic because the Mediterranean skip distance is about twenty miles and the axis of the deep-sound channel is only about 1000 ft deep. A number of additional features of the bottom reflected path are clearly indicated. The details of the refracted path indicate scattering that blurs the refracted caustic and permits reception of weak refracted arrivals at lesser ranges and travel times than predicted by simple ray computations.