Common natural sources of ionizing radiation on the ocean bottom consist of the elements potassium, thorium, uranium, and decay products of the last two. Only gamma rays from these sources are of concern to us; naturally occurring alpha and beta particles will not penetrate the cable structure into the fibers to cause damage. The gamma energies will be up to 2.62 MeV. Shielding is not feasible except for very short runs.
© 1985 Optical Society of AmericaPDF Article