The linearized equations of motion for the case of one-dimensional flow are solved as a sequence of approximations for the modes of oscillation of a fluid in an enclosed basin by using Galerkin's method from the calculus of variations.
Clarke, D. J.. 1968. "Seiche motions for one-dimensional flow." Journal of Marine Research 26, (3). https://elischolar.library.yale.edu/journal_of_marine_research/1128