The excitation of tsunami by low-frequency non-stationary point and distributed centres of expansion

The elevation of the Free surface of a liquid relative to the bottom is cal culated for a layer of incompressible heavy liquid with a thickness of 4 km located over an elastic half-space with a point or distributed centre of e xpansion acting on it at a depth of 40 km, the intensity of which undergoes stationary transient oscillations. The dependence of this elevation on the period of the source is investigated in the case when the period is greate r than 2 minutes but less than 40 minutes. It is established that observabl e tsunamis are only excited by low frequency oscillations of the source. (C ) 2001 Elsevier Science Ltd. All rights reserved.