A probabilistic tsunami hazard assessement (PTHA) was developed for the island of Tongatapu, All modelled tsunamis were initiated by hypothetical thrust earthquakes on the nearby Kermadec-Tonga subduction zone. We provide raster outputs containing the inundation depth with an estimated 10% and 2% chance of being exceeded in 50 years, as well as the code used to perform the analysis [both available here: https://github.com/GeoscienceAustralia/ptha/tree/master/misc/probabilistic_inundation_tonga2020].

University of Newcastle researchers captured media attention in 2017 with the release of a study modelling tsunami risk for the city of Sydney. The study considered a range of scenarios from minor disruptions through to rare, one-in-5000-year disasters. It’s possible the study made headlines in part for the novelty factor. This is not to say Australians are flippant about tsunamis; as a nation, we have grieved the traumatic impact of tsunamis in our region. We just don’t think it will happen to us. However, the science says otherwise. The historical and prehistorical record indicates that tsunamis have affected Australia in the past and could do so again. To Australia’s north and east lie thousands of kilometres of tectonic plate boundaries, where undersea earthquakes could generate tsunamis that reach Australia in a matter of hours. Given half the Australian population lives within 10 kilometres of a coastline – not to mention the scores of interstate and international visitors to our beaches – it’s imperative we take tsunami planning seriously. That’s why the Australian Institute for Disaster Resilience (AIDR) partnered with the Australian Tsunami Advisory Group (ATAG) to revise and refresh national guidance for tsunami emergency planning in Australia. ATAG is the leading national group for tsunami capability development, bringing together the expertise of policymakers, scientists and emergency services practitioners from around Australia. The review produced the Tsunami Emergency Planning in Australia Handbook, an authoritative resource for emergency managers, local and state governments, port authorities and commercial operators in coastal areas. Replacing its 2010 predecessor, Manual 46: Tsunami Emergency Planning in Australia, the handbook was published on 5 November 2018 to mark the United Nations World Tsunami Awareness Day. In clear, accessible language, the handbook outlines the causes and characteristics of tsunamis, separating fact from fiction and highlighting key terms. It introduces planners to both ‘Marine Threat’ and ‘Land Inundation Threat’ – key categories in the tsunami warnings framework – and explores the corresponding planning considerations for coastal communities as well as more transitory ‘maritime’ communities – including fishers, boaters and swimmers. Maritime communities also encompass a range of commercial and government activities, including offshore oil and gas enterprises, military exercises and tourism. The handbook steps users through the responsibilities, processes and warning types that comprise the Australian Tsunami Warning System that was established by the Australian Government after the 2004 Indian Ocean tsunami. ATAG has actively contributed to the management of tsunami risk by promoting research, knowledge management and education. In 2018, ATAG also partnered with AIDR to develop the Tsunami hazard modelling guidelines that represent the most up-to-date view of tsunami hazard nationally. A key companion to the revised handbook, the guidelines present a principles-based approach to developing tsunami hazard information for different purposes; from emergency management to infrastructure development and insurance. The guidelines don’t dictate the use of a particular software; they ask questions to support cooperative approaches between scientists and end users. As for the handbook, stakeholder consultation was key to the development of the Tsunami hazard modelling guidelines. Geoscience Australia, an ATAG member, led the process in partnership with public and private sector representatives and with Commonwealth funding support through Emergency Management Australia. The guidelines emerged from a community-driven development process that engaged different end users and recognised the impact of a range of factors on modelling approaches and decisions (such as the use case and available data). A workshop held in Canberra in 2017 was a key step, bringing together tsunami modelling experts from government, industry and academia. The handbook and companion guidelines are complimented by the Probabilistic Tsunami Hazard Assessment from Geoscience Australia. This resource informs local tsunami inundation modelling, which feeds into evacuation planning and community safety. The Tsunami handbook is also supported by Tsunami: The Ultimate Guide – an online learning resource developed collaboratively by ATAG and led by Surf Life Saving Australia. The guide raises tsunami awareness through the education of school-aged children and achieved a highly commended award in the 2014 Resilient Australia Awards. The Tsunami Emergency Planning in Australia Handbook and the suite of companion resources is part of the Australian Disaster Resilience Handbook Collection. The Handbook Collection represents nationally agreed principles on a range of salient disaster resilience themes; supporting organisations across sectors to adopt best-practice approaches aligned to national policy.

Indonesia is one of the most disaster prone countries in the world due to its hazard profile and high population exposure. Despite its risk profile, disaster management has not traditionally been informed by best available information. Since 2008, the Australian and Indonesian governments have partnered to increase the use of science and technology in Indonesia to support decision making in disaster management. Our partnership has concentrated on strengthening the evidence base for informed disaster management by improving: - hazard information for earthquake, tsunami, volcano and flood - spatial data for exposure (population, building, roads and infrastructure) - decision support tools such as InaSAFE that assist disaster managers to combine hazard and exposure data to inform disaster response and management. We have worked alongside technical and disaster management agencies, universities, non-government organisations and the private sector to develop Indonesian capacity to manage disasters and institutionalise best-practices. Partnerships have facilitated science-to-policy and science-to-programming outcomes in disaster management that help people prepare for, respond to and recover from crises. Ten years is a good time for a partnership to form, blossom and deliver effective and sustainable changes. The achievements over this time are too many to list in entirety. Science and Technology for Disaster Management merely scratches the surface to highlight the most significant achievements. There is a tendency in doing so to focus on achievements over the last three years. In most cases the achievements of this later period of the program have only been possible because they have built on and extended the achievements of the former seven years. Science and Technology for Disaster Management demonstrates how our collaboration has increased the use of science and technology in Indonesian disaster management by developing new knowledge and enhancing capacity, both within the scientists and within policy and decision makers. In doing so, tangible policies have been developed and implemented and practices have changed. The program has helped to strengthen relationships between agencies within Indonesia and also between Indonesia and Australia in the areas of disaster management and science more broadly. New relationships manifest as distinct government-to-government collaborations and strong peer-to-peer links.

The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models’ weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning. Appeared online in Front. Earth Sci., 05 March 2021.

This report describes the 2018 Probabilistic Tsunami Hazard Assessment for Australia (henceforth PTHA18). The PTHA18 estimates the frequency with which tsunamis of any given size occur in deep waters around the Australian coastline. To do this it simulates hundreds of thousands of possible tsunami scenarios from key earthquake sources in the Pacific and Indian Oceans, and models the frequency with which these occur. To justify the PTHA18 methodologies a significant fraction of the report is devoted to testing the tsunami scenarios against historical observations, and comparing the modelled earthquake rates against alternative estimates. Although these test provide significant justification for the PTHA18 results, there remain large uncertainties in “how often” tsunamis occur at many sites. This is due to fundamental limitations in present-day scientific knowledge of how often large earthquakes occur.

Many mapped faults in the south-eastern highlands of New South Wales and Victoria are associated with apparently youthful topographic ranges, suggesting that active faulting may have played a role in shaping the modern landscape. This has been demonstrated to be the case for the Lake George Fault, ~25 km east of Canberra. The age of fluvial gravels displaced across the fault indicates that relief generation of approximately 250 m has occurred in the last ca. 4 Myr. This data implies a large average slip rate by stable continental region standards (~90 m/Myr assuming a 45 degree dipping fault), and begs the question of whether other faults associated with relief in the region support comparable activity rates. Preliminary results on the age of strath terraces on the Murrumbidgee River proximal to the Murrumbidgee Fault are consistent with tens of metres of fault activity in the last ca. 200 kyr. Further south, significant thicknesses of river gravels are over-thrust by basement rocks across the Tawonga Fault and Khancoban-Yellow Bog Fault. While these sediments remain undated, prominent knick-points in the longitudinal profiles of streams crossing these faults suggest Quaternary activity commensurate with that on the Lake George Fault. More than a dozen nearby faults with similar relief are uncharacterised. Recent seismic hazard assessments for large infrastructure projects concluded that the extant paleoseismic information is insufficient to meaningfully characterise the hazard relating to regional faults in the south-eastern highlands, despite the potential for large earthquakes alluded to above. While fault locations and extents remain inconsistent across scales of geologic mapping, and active fault lengths and slip rates remain largely unquantified, the same conclusion may be drawn for other scales of seismic hazard assessment.

Tropical cyclone return period wind hazard layers developed using the Tropical Cyclone Risk Model. The hazard layers are derived from a catalogue of synthetic tropical cyclone events representing 10000 years of activity. Annual maxima are evaluated from the catalogue and used to fit a generalised extreme value distribution at each grid point.

Tsunamis are unpredictable and infrequent but potentially large impact natural disasters. To prepare, mitigate and prevent losses from tsunamis, probabilistic hazard and risk analysis methods have been developed and have proved useful. However, large gaps and uncertainties still exist and many steps in the assessment methods lack information, theoretical foundation, or commonly accepted methods. Moreover, applied methods have very different levels of maturity, from already advanced probabilistic tsunami hazard analysis for earthquake sources, to less mature probabilistic risk analysis. In this review we give an overview of the current state of probabilistic tsunami hazard and risk analysis. Identifying research gaps, we offer suggestions for future research directions. An extensive literature list allows for branching into diverse aspects of this scientific approach. Appeared online in Front. Earth Sci., 29 April 2021

The Geological Survey of Canada's 5th Generation seismic hazard model for Canada forms the basis for the seismic design provisions of the 2015 National Building Code of Canada (NBCC). We deaggregate the seismic hazard results for selected cities to help understand the relative contributions of the earthquake sources in terms of distance and magnitude. Deaggregation for a range of probabilities and spectral accelerations (Sa) from 0.2 to 10.0 seconds is performed to examine in detail the hazard for two of Canada's largest urban centres at highest risk, Vancouver in the west and Montréal in the east. A summary table of deaggregated seismic hazard is provided for other selected Canadian cities, for Sa(0.2), Sa(2.0) and peak ground acceleration (PGA) at a probability of exceedence of 2%/50 years. In most cases, as the probability decreases, the hazard sources closer to the site dominate. Larger, more distant earthquakes contribute more significantly to hazard for longer periods than shorter periods. The deaggregations allow better-informed choices of scenario events and for the selection of representative time histories for engineering design.

This document describes a structure for exchanging information to assist discovery and retrieval/transfer of flood information, including GIS flood mapping data. The draft class model represents metadata, data and summary information that supports the goals of the National Flood Risk Information Project (NFRIP) to improve the quality, consistency and accessibility of flood information. This document describes the data model that will be used to create an application schema.