IASPEI - Picture Gallery

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS002 Poster presentation 1788
The potential use of coastal tide gauge data in the Australian Tsunami
Warning System
Mr. Stewart Allen
Bureau of Meteorology Research Centre Australian Bureau of Meteorology IASPEI
Diana Greenslade
The Australian Bureau of Meteorology (the Bureau), in conjunction with Geoscience Australia is currently
developing an operational tsunami warning system. One planned component of this warning system is
to run a numerical tsunami model in real-time, initialised with seismic information and assimilating sealevel
data. DART buoys are typically located offshore in deep water and provide an ideal data stream
that can be assimilated into a tsunami propagation model. The Bureau is currently also expanding and
enhancing its coastal tide gauge network. These tide gauges provide another data stream that can be
used for model verification and could potentially also be used for data assimilation. Tide gauges are
almost always in enclosed harbours, bays or ports and the variability seen in tide gauge records of
tsunamis will contain variability due to the tsunami interacting with the local small-scale topography,
e.g. shoaling, seiching, reflections, diffraction, refraction, wave-breaking etc. These effects are not
represented in the relatively coarse resolution of a tsunami propagation model. The relationship
between the signal of a tsunami at a tide gauge and the offshore wave is strongly dependent on
location and determining the relationship between the two is a challenge. There is therefore a need to
analyse the tide gauge signal and location to determine what, if any, characteristics of a tsunami can be
extracted from the observed signal and used for model verification and/or assimilation. In this
presentation, initial results from an analysis of some existing Australian tide gauge data will be
presented.
Keywords: tsunami, tideguage, modelling