The effective depth of a Pekeris ocean waveguide, including shear wave effects

Weston’s [J. Acoust. Soc. Am. 32, 647–654 (1960)] concept of the effective depth of a Pekeris-type shallow water waveguide has been extended to admit seabeds that support shear waves. The amended effective depth formula leads to estimates of normal mode phase speeds that are surprisingly accurate, without numerical iteration. Results for six hypothetical, though realistic, bottom types are compared with an ‘‘exact’’ normal mode model that includes shear wave effects and another normal mode model that does not.