An asymptotic method based upon ray theory is developed for the study of surface waves on a viscous fluid of variable depth. An asymptotic solution involving a phase function and an amplitude function is constructed. Uniform asymptotic expansions at and away from caustics and shorelines are obtained. To illustrate the method, an example concerning the spreading of a bore over a sloping beach is considered.

1.
J. B.
Keller
,
J. Fluid Mech.
4
,
607
(
1958
).
2.
M. C.
Shen
,
R. E.
Meyer
, and
J. B.
Keller
,
Phys. Fluids
11
,
2289
(
1968
).
3.
J. B.
Keller
and
V. C.
Mow
,
J. Fluid Mech.
38
,
365
(
1969
).
4.
W. D.
McKee
,
Proc. Cambridge Philos. Soc.
73
,
205
(
1973
).
5.
D.
Hector
,
J.
Cohen
, and
N.
Bleistein
,
Stud. Appl. Math.
51
,
121
(
1972
).
6.
M. C.
Shen
and
J. B.
Keller
,
SIAM J. Appl. Math.
28
,
857
(
1975
).
7.
M. C.
Shen
and
J. B.
Keller
,
Phys. Fluids
16
,
1565
(
1973
).
8.
J. K.
Cohen
and
R. M.
Lewis
,
J. Inst. Math. Its Appl.
3
,
266
(
1967
).
9.
D.
Ludwig
,
SIAM Rev.
17
,
605
(
1975
).
10.
R.
Voronka
and
J. B.
Keller
,
Math. Biosci.
25
,
331
(
1975
).
11.
M. C.
Shen
and
S. M.
Shih
,
Phys. Fluids
17
,
280
(
1974
).
12.
D.
Ludwig
,
Commun. Pure Appl. Math.
19
,
215
(
1966
).
13.
R. M. Lewis and J. B. Keller, New York University Report No. EM‐194 (1964).
14.
A. Erdelyi, Asymptotic Expansions (Dover, New York, 1956).
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