Long waves on oceanic ridges

A ridge in an ocean of uniform depth acts as a waveguide for long waves. A uniform rectangular ridge is used as a simple model, and it is shown that in this case an infinite number of modes of propagation along the ridge are possible. Actual dispersion curves are given for numerical examples based on the Mid-Atlantic Ridge. In the case of a ridge of general shape, a simple variational technique is suggested as a means of achieving numerical solutions. Two numerical examples of these techniques are given. The effect of the Earth’s rotation is considered at the end of the paper, and it is shown that in the numerical examples in this paper, this effect is very small.