Tsunami inundation hazards from global earthquake sources: Towards high-resolution, large area maps with quantified uncertainties

Australia's coastline is exposed to tsunamis generated by large subduction earthquakes in the Indian and Pacific Oceans. While recent events had limited impacts in Australia, future earthquakes could in-principle direct much larger waves to our coast. With only a few hours between earthquake detection and tsunami arrival, prior planning is necessary to guide the emergency response. To this end we need an understanding of tsunami hazards: which coastal areas might be inundated, how deep, and how likely? This talk will discuss recent progress in tsunami inundation hazard assessment at Geoscience Australia. We adopt a probabilistic approach to the problem, which involves modelling hypothetical earthquake-tsunamis from major Indian and Pacific Ocean sources, their effects onshore, and their (uncertain) chance of occurrence. To illuminate the science underlying this we will consider: 1. How well tsunami models can simulate historical tsunamis; 2. Representations of hypothetical tsunamis and their natural variability; 3. New techniques to compute onshore hazards while accounting for uncertain earthquake frequencies.