Automative approaches for capturing localised tsunami response -
Application to the French coastlines
Abstract
Local bathymetry and onshore features can have a substantial effect on
the spatial variability of impact from an incoming tsunami. In a warning
context, being able to provide localised tsunami forecasts at strategic
locations would therefore mitigate the damage posed. Despite the recent
advancements in computing powers and the development of highly efficient
tsunami codes, capturing this local variability can oftentimes be
unfeasible in a warning setting. Traditional high resolution simulations
which can capture these localised effects are often too costly to run
‘on-the-fly’. Alternative approaches which capture the localised
response to an incoming tsunami, which are based upon utilising the
maximum wave heights from a computationally cheap regional forecast, are
developed here. These alternative approaches are envisaged to aid in a
warning centre’s ability at providing extremely rapid localised
forecasts. The approaches focus upon two different methods: transfer
functions and machine learning techniques. The transfer functions are
based upon recent extensions to the established Green’s Law. The
extended versions introduce site specific amplification parameters, with
the aim of capturing the neglected localised effects. An automative
approach which optimises for these site specific parameters is outlined
and the performance of these transfer functions is explored. A machine
learning model is also trained and utilised to predict the localised
tsunami hazard. Its performance is compared to the extended Green’s Law
approach for several sites along the French coast. These developed
methods showcase promising techniques that a tsunami warning centre
could utilise to provide high resolution warnings.