Abstract. Despite the occurrence of several large earthquakes during the last decade,
Chile continues to have a great tsunamigenic potential. This arises as a
consequence of the large amount of strain accumulated along a subduction zone
that runs parallel to its long coast, and a distance from the trench to the
coast of no more than 100 km. These conditions make it difficult to
implement real-time tsunami forecasting. Chile issues local tsunami warnings
based on preliminary estimations of the hypocenter location and magnitude of
the seismic sources, combined with a database of pre-computed tsunami
scenarios. Finite fault modeling, however, does not provide an estimation of
the slip distribution before the first tsunami wave arrival, so all
pre-computed tsunami scenarios assume a uniform slip distribution. We
implemented a processing scheme that minimizes this time gap by assuming an
elliptical slip distribution, thereby not having to wait for the more time-consuming finite fault model computations.We then solve the linear shallow
water equations to obtain a rapid estimation of the run-up distribution in the
near field. Our results show that, at a certain water depth, our linear
method captures most of the complexity of the run-up heights in terms of shape
and amplitude when compared with a fully nonlinear tsunami model. In
addition, we can estimate the run-up distribution in quasi-real-time as soon
as the results of seismic finite fault modeling become available.
Bayesian near-field tsunami forecasting with uncertainty estimates
