The Fire and Emergency Services Authority (FESA) of Western Australia  and 
associated volunteers respond to a wide range of emergencies 
as well as undertaking search and rescue operations on land and 
water\footnote{http://www.fesa.wa.gov.au/internet/}. 
FESA helps the West Australian 
community prepare, prevent (where possible) and respond safely to disasters.
FESA also aims to reduce injury, loss of life and destruction of property in 
Western Australian communities through proactive measures. 
These measures involve understanding the relative risk
of the disaster so that resources can be directed to appropriate areas
and corresponding evacuation plans put in place.  

The key role of the Risk Research Group at Geoscience Australian 
is to develop knowledge on the risk from natural and 
human-caused hazards for input to policy and operational decision making on 
the mitigation of risk to Australian communities. The Group achieves 
this through the development of computational methods, models and decision 
support tools that assess the hazard, vulnerability and risk posed by hazard
events. To develop an understanding of the tsunami risk, GA has developed
decision support tools, consisting of inundation
maps overlaid on aerial photography of the region 
detailing critical infrastructure as well as damage modelling estimates. 

This report is the first in a series of tsunami assessments 
of the North West Shelf. The scenario used for this study has
an unknown return period, but is considered a plausible event (see
Section \ref{sec:methodology}). 
Subsequent assessments will use refined hazard models with
associate return periods. A suite of assessments will be
made for Onslow and other localities, as advised by FESA.

Onslow has a population of around 800 and
is part of the Shire of Ashburton in the Pilbara region of 
Western Autralia\footnote{http://www.pdc.wa.gov.au/region/political.htm}. 
Onslow supports
a variety of industries, including oil, gas, mining, cattle, 
fishing and tourism.

The modelling technique to simulate the 
impact ashore is discussed in Section \ref{sec:methodology} and data inputs
discussed in Section \ref{sec:data}. 
The inundation results are presented and discussed in Section \ref{sec:results} 
and the impact modelling results outlined in Section \ref{sec:impact}.
A summary of the results detailing issues
regarding underlying data and further model development, are discussed 
in Section \ref{sec:summary}.

