Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-09T06:00:50.996Z Has data issue: false hasContentIssue false

Edge waves on a gently sloping beach

Published online by Cambridge University Press:  26 April 2006

John Miles
Affiliation:
Institute of Geophysics and Planetary Physics, University of California, San Diego, La Jolla, CA 92093, USA

Abstract

Edge waves of frequency ω and longshore wavenumber k in water of depth h(y) = h1Hy/h1), 0 [les ] y < ∞, are calculated through an asymptotic expansion in σ/kh1 on the assumptions that σ [Lt ] 1 and kh1 = O(1). Approximations to the free-surface displacement in an inner domain that includes the singular point at h = 0 and the turning point near gh ≈ ω2/K2 and to the eigenvalue λ ≡ ω2gh are obtained for the complete set of modes on the assumption that h(y) is analytic. A uniformly valid approximation for the free-surface displacement and a variational approximation to Λ are obtained for the dominant mode. The results are compared with the shallow-water approximations of Ball (1967) for a slope that decays exponentially from σ to 0 as h increases from 0 to h1 and of Minzoni (1976) for a uniform slope that joins h = 0 to a flat bottom at h = h1 and with the geometrical-optics approximation of Shen, Meyer & Keller (1968).

Type
Research Article
Copyright
© 1989 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ball, F. K.: 1967 Edge waves in an ocean of finite depth. Deep-Sea Res. 14, 7988.Google Scholar
Buchholz, H.: 1953 Die Konfluente Hypergeometrische Funktion, p. 143. Springer.
Keller, J. B.: 1958 Surface waves on water of non-uniform depth. J. Fluid Mech. 4, 607614.Google Scholar
Keller, J. B.: 1961 Tsunamis – Water waves produced by earthquakes. Tsunami Hydrodynamics Conference (IUGG Monograph no. 24).Google Scholar
Miles, J. W.: 1985 Surface waves in basins of variable depth. J. Fluid Mech. 152, 379389.Google Scholar
Minzoni, A. A.: 1976 Nonlinear edge waves and shallow-water theory. J. Fluid Mech. 74, 369374.Google Scholar
Shen, M. C., Meyer, R. E. & Keller, J. B., 1968 Spectra of water waves in channels and around islands. Phys. Fluids 11, 22892304.Google Scholar
Shen, M. C. & Keller, J. B., 1975 Uniform ray theory of surface, internal and acoustic wave propagation in a rotating ocean or atmosphere. SIAM J. Appl. Maths 28, 857875.Google Scholar
Stokes, G. G.: 1846 Report on recent research in hydrodynamics. Brit. Ass. Rep. Part 1; Mathematical and Physical Papers (1880), vol. 1, pp. 167187. Cambridge University Press.
Ursell, F.: 1952 Edge waves on a sloping beach. Proc. R. Soc. Lond. A 214, 7997.Google Scholar