Relationship between tsunami velocity, wave length, and water depth.

This is one of the slides from Larry Braile's PowerPoint presentation.

Tsunami wave propagation characteristics – note that as water depth becomes smaller, waves slow down, become shorter wavelength, and have larger amplitude.


Larry asks: When the water is 10 m deep, what is the separation of the waves in minutes?

Here's my answer:  The formula relating the period (T) with velocity (V) and wavelenght (L) is:

T = L / V

for 10m depth, T = 10.6/36 = 0.29 hours (about 18 minutes)

From a trough, the water would rise for 9 minutes and then fall for 9 minutes to the next trough.

The velocity is given by the squareroot of (water depth X the acceleration of gravity)

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