PhD in Numerical modelling of tsunamis

Find Løvholt defended his thesis "Numerical modelling of tsunami generation and propagation" for the degree of Ph.D. (philosophiae doctor) at the University of Oslo, Friday, April 25, 2009. See the official announcement from the Department of Mathematics.

The incident in Southeast Asia on 2nd Christmas Day 2004 showed that tsunamis can cause great harm and that damage can strike far from the area where the wave is generated. The simplest tsunami models assume that the travelling wave speed is independent of wavelength.

Such a model is used to calculate the tsunami on 2nd Christmas Day, and the results show good correspondence with observations of the wave. Simulations of potential future tsunamis on the coast of Thailand are also conducted, and these are used by Thai authorities for the assessment of future risk.

The thesis has revealed that more advanced tsunami models that take into account that the wave speed varies with the wave length can be unfortunate when the seabed is steep, and give unreliable results in such fjords. The study shows that caution must be shown when such models are used. In the thesis, significant efforts has been made to organize and calculate the criteria for when unstable results can occur, also as a tool for model selection for subsequent simulations.

A possible tsunami from the La Cumbre Vieja volcano on La Palma in the Canary Islands has been disputed because of its potential devastation. In this thesis improved models have been used for simulations of the generation and propagation of waves across the Atlantic for the worst possible scenario on La Palma. The propagation of the waves is examined in more detail than what was done in earlier work, and shows smaller waves than the previous devastating predictions. A new computer model was developed specifically for the propagation of such waves over long distances.

Find Løvholt is employed by NGI. The work is conducted at NGI through the International Center for Geohazards (ICG), which is one of The Research Council of Norway's centres of excellence, and in association with the Department of Mathematics at the University of Oslo. The candidate has also worked in collaboration with Simula Research Laboratory, NORSAR and the Department of Physics, University of Oslo,