This report is being provided to the Fire and Emergency Services Authority
(FESA) as part of the Collaborative Research Agreement (CRA) 
with Geoscience Australia (GA).
FESA has recognised the potential vulnerability of the Western Australia
coastline to tsunami originating from earthquakes on
the Sunda Arc subduction zone. 
There is historic evidence of tsunami affecting the 
Western Australia coastline, \cite{CB:ausgeo}, 
and FESA has sought to assess
the relative risk of its urban and regional communities to the tsunami
threat and develop detailed response plans for a range of plausible events.

This report describes the modelling methodology and initial results
for a specific tsunami-genic event as it impacts the Onslow township
and its surrounds. In particular, maximum inundation maps are shown
and discussed 
for the event occurring at mean sea level as well as 
highest and lowest astronomical tide. The inundation results allow
estimation of the number of houses inundated and collapsed, as well as
the numbers of persons affected. The Onslow township has approximately
350 residential structures and a population of around 800.
For this specific event at high tide, approximately
100 houses are inundated with two of those collapsing. Approximately
15-20\% of the population will sustain injuries, including fatalities.

Future studies
will present a series of scenarios for a range of return periods to 
assist FESA in developing appropriate plans for a range of event impacts.
This will also allow an assessment of the relative tsunami risk 
to communities along the NW Shelf of WA. 
This report and the decision support tool are the 
June 2006 deliverables of the Collaborative Research Agreement,
Tsunami Impact Modelling for WA, between FESA and GA.

