On the use of finite fault solution for tsunami generation problems

Denys Dutykh (1) , Dimitrios Mitsotakis (2) , Xavier Gardeil (1)

1 LAMA - Laboratoire de Mathématiques
2 LM-Orsay - Laboratoire de Mathématiques d'Orsay

The present study is devoted to the tsunami wave generation problem. The main goal of this work is two-fold. First of all, we propose a simple and computationally inexpensive model for the description of the sea bed displacement during an underwater earthquake, based on the finite fault solution for the slip distribution under some assumptions on the rupturing process dynamics. Once the bottom motion is reconstructed, we study waves induced on the free surface of the ocean. For this purpose we consider three different models approximating the Euler equations of the water wave theory. Namely, we deal with linearized Euler equations (also known as Cauchy-Poisson problem), a Boussinesq system and a weakly nonlinear model. An intercomparison of these approaches is performed. All developments in this study are illustrated on the real world example of the July 17, 2006 Java event.

Mots clés: water waves; tsunami waves; co-seismic displacements; moving bottom; tsunami generation

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]; Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Physique Atmosphérique et Océanique [physics.ao-ph]; Analyse numérique [math.NA]; Dynamique des Fluides [physics.flu-dyn]; Physique Numérique [physics.comp-ph]; Océan, Atmosphère; Océanographie

Denys Dutykh, Dimitrios Mitsotakis, Xavier Gardeil. On the use of finite fault solution for tsunami generation problems. 2010. ⟨hal-00509384v1⟩