Australia’s Probabilistic Tsunami Hazard Assessment – a valuable tool and a Sendai good practice
Coinciding with World Tsunami Awareness Day on 5 November, Geoscience Australia, the Australian government’s national geoscience agency, released its new Probabilistic Tsunami Hazard Assessment (PTHA). A huge undertaking, this new assessment is the first update in ten years - making it a valuable tool for informing Australia’s evidence-based infrastructure resilience planning and risk mitigation strategies, as well as disaster management and evacuation plans.
While not typically in the news for suffering from tsunami disasters, there have been more than 50 recorded incidents of tsunamis affecting the Australian coast since European settlement started. The PTHA18 highlights that the northwest coast in Western Australia is more likely than the east or southwest coast to experience a tsunami due to its proximity to the Indonesia tectonic plate boundary, which has a long, seismically active fault line.
For this update, Geoscience Australia collected earthquake data from across the world, thus increasing the accuracy and quality of the assessment. Moreover, the 2018 PTHA reflects advances in the understanding of how frequently large earthquakes occur and the uncertainties in these frequencies. It also provides data for many more sites than before, making it easier for researchers to use the data in local studies, including for major Australian offshore islands and territories.
Disaster risk reduction specialists from across the world will also benefit from this assessment, and countries can work together to understand the threat in their regions. The Australian PTHA18 can be used to understand how often tsunamis could occur and how big they could be in their area of interest, and importantly, which source zones are more likely to generate a tsunami that could impact their location. Moreover, the PTHA18 data can also be used by countries in the Indian Ocean and South West Pacific Oceans.
Under the Sendai Framework for Disaster Risk Reduction, the number one priority for action is “understanding disaster risk.” This new assessment is exactly the type of work needed to transform risk information into knowledge that can be used by government officials, business owners, and civil society organizations, to plan and develop disaster risk reduction strategies that build resilience into existing and new physical structures. Furthermore, by making the assessment available online to the world, Australia is helping to bridge the technical knowledge gap by ensuring equal access to quality information.
To access the 2018 PTHA, visit Geoscience Australia’s website through the link on this page, where you will also find two other national hazard assessments: The 2018 National Seismic Hazard Assessment, and the 2018 Tropical Cyclone Hazard Assessment, which was released on 1 November 2018.