Mathematics in the Service of Tsunami Research


Since the tsunami in Japan last March, Prof. Jörn Behrens from the KlimaCampus has had plenty to do. Along with his working group "Numeric Methods in Geosciences", he has been developing computer simulations for tsunamis, among other things.

Since the SIAM conference (Society for Industrial and Applied Mathematics) in California last March, results from Prof. Jörn Behrens´ research have been in great demand. Just a few days earlier, the catastrophic tsunami had hit Japan, pushing tsunami research into the focus of the scientific world.

There already exist a few different approaches to predicting such catastrophes, but each of them comes with numerous “uncertainties.” In his research, Prof. Behrens focuses on the question of how these uncertainties can be better calculated into the process of predicting tsunamis. If they can be described mathematically, then the predictive systems will be much more precise. This would make it possible for governments to react more quickly to developing tsunamis and other natural catastrophes. A piece of simulation software based on Behrens’ ideas has been in use as part of the Indonesian early warning system since the end of 2009. It was developed in large part using German funds.

A second focus of his research is the development of more exact tsunami simulations. With the help of adaptive models, which are based on numerical methods that adjust over time, he and his group are portraying interactions between small- and large-scale processes. "The adaptive grid adjusts itself to local conditions and takes both small waves near the coast and larger waves in the open ocean into consideration. At the same time, it has a relatively short calculation period and uses little memory despite having a high density of data", the mathematician explained.

At the request of the renowned American Society for Industrial and Applied Mathematics, Behrens wrote an article on the state of tsunami research together with Randy LeVeque, a colleague from Seattle (in Washington state) – with surprisingly positive feedback to date. The article was even published on the front page of the SIAM News, the newspaper published by the mathematics network. The article can also be accessed online.

Prof. Behrens´ success has also brought additional responsibilities with it: in summer 2012, he and his international colleagues will organize the Gene Golub SIAM Summer School in Monterey, California. "It is an honor for us, because the summer school is very well known. For two weeks, we will work very intensively with 50 selected doctoral students from a number of countries", said Behrens.
What will the future bring? The simulations developed by Behrens and his working group could be used on other natural catastrophes in the future. The models could also potentially be modified for use in the prediction of storm tides or hurricanes.