Abstract: By using the Hugoniot curve as a Riemann invariant in a nonconservative velocity pressure model, a new system is settled, which can be put under a conservative form system looking like the Euler equations. The usual mass density is replaced by a new strain variable. This system is applied to modelize the propagation of a seismic wave from the bottom of the ocean to the surface. A sharp front shock is observed, which is eroded by the gravity and friction effects during the propagation, and will provoke a tsunami wave or not, according to these effects on its amplitude.