One-dimensional shear-wave velocity (VS ) profiles are presented at 50 strong motion sites in New South Wales and Victoria, Australia. The VS profiles are estimated with the spectral analysis of surface waves (SASW) method. The SASW method is a noninvasive method that indirectly estimates the VS at depth from variations in the Rayleigh wave phase velocity at the surface.

Tsunami hazard assessments are often derived using computational approaches that model the occurrence rates of a suite of hypothetical earthquake-tsunami scenarios. While uniform slip earthquake models are often used, recent studies have emphasized that spatially non-uniform earthquake slip substantially affects tsunamis, with wave heights and run-up varying by a factor of three or more due to slip heterogeneities alone (i.e. assuming fixed ‘bulk rupture parameters’ such as the earthquake magnitude, rupture plane geometry, location, and shear modulus). As a result, stochastic slip models are increasingly being used for directly simulating slip variability in hazard assessments. Irrespective of how the tsunami scenarios are generated, the statistical properties of the modelled tsunami need to well approximate the statistical properties of real tsunami with the same bulk rupture parameters. For example, ideally a future real tsunami will have a 50% chance of having a peak wave height below the median corresponding synthetic peak wave height; a 90% chance of being below the 90th percentile; and so on. Testing is required to determine whether any model has performance comparable to this ideal case. The literature suggests large differences in the statistical properties of stochastic slip models, implying not all will give a good representation of real tsunami variability. However, by comparing model scenarios against a suite of historic tsunami observations, we can statistically test whether key properties of real tsunami have the same distribution as their corresponding synthetic scenarios. We would recommend that such tests become standard in the validation of tsunami hazard scenario generation methods, to reduce the chance of using an inappropriate model which could significantly bias a hazard assessment. The current study evaluates the statistical performance of earthquake-tsunami scenarios which form part of the updated Australian Probabilistic Tsunami Hazard Assessment, currently being developed by Geoscience Australia. The model scenarios are compared with deep-ocean DART buoy wave time-series for 15 recent tsunamis, each recorded at between 1 and 28 sites. No event specific calibration is applied to the models. We evaluate three different earthquake-tsunami scenario generation methods (fixed-size uniform slip; variable-size uniform-slip; variable-size stochastic-slip) in terms of how well they model the statistical properties of wave heights, and discuss the capacity of each method to generate wave time-series which match historical events. We find that some events cannot be well modelled using our fixed-size uniform-slip scenarios, while it is usually possible to match observations reasonably well with a variable-size uniform-slip event, or a variable-size stochastic-slip event. Both of the latter produce families of solutions which usually envelope the observed DART buoy tsunami wave heights, although quantiles of the variable-size uniform-slip events appear to have some downward bias, while quantiles of the variable-size stochastic-slip events seem more consistent with observations.

Using the new release of the local wind multipliers software (V.3.1) (<a href="https://pid.geoscience.gov.au/dataset/ga/145699">eCat 145699</a>) and an appropriate source of classified terrain data, local wind multipliers on a national scale for the whole continent of Australia at (approximately) 25-metre resolution were calculated. This product is a necessary component for calculating local wind speeds from scenarios and guiding impact assessment of severe wind hazards for both federal and state-wide Emergency Services in Australia.

The Australian Flood Studies Database is available on line by Geoscience Australia. The database provides metadata on Australian flood studies and information on flood risk with a digital version where available. The purpose of the document is to guide new users in data entry and uploading of flood studies to a level acceptable for inclusion in the database.

Severe TC Vance was one of the most intense cyclones to impact mainland Australia. The observed damage to buildings could be explained in terms of structural performance of those buildings. Combining the structural vulnerability of housing with an estimate of the maximum wind gusts, we can explore the possible impacts that a repeat of Vance would cause in Exmouth, and compare the outcomes with what occurred in 1999. The analysis of the impacts of TC Vance on present-day Exmouth shows that very few houses would be completely destroyed. Not surprisingly, older houses (pre-1980’s construction era, excluding the US Navy block houses) would dominate those destroyed, and most likely the timber-framed style houses, many of which were substantially damaged in TC Vance. Published in the Australian Journal of Emergency Management July 2019 edition

The 6th Generation Seismic Hazard Model of Canada (CanadaSHM6) provides the basis for seismic design values proposed by Natural Resources Canada for the 2020 edition of the National Building Code of Canada (NBCC 2020). This Open File includes OpenQuake compatible source model files that will generate seismic hazard values as currently being proposed. Once NBCC 2020 is finalized, this report will be superseded by a subsequent Open File, to document the final model used to generate seismic hazard values using CanadaSHM6 for NBCC 2020.

The National Exposure Information System (NEXIS) is a unique modelling capability designed by Geoscience Australia (GA) to provide comprehensive and nationally-consistent exposure information in response to the 2003 COAG commitment to cost-effective, evidence-based disaster mitigation. Since its inception, NEXIS has continually evolved to fill known information gaps by improving statistical methodologies and integrating the best publically-available data. In addition to Residential, Commercial and Industrial building exposure information, NEXIS has recently expanded to include exposure information about agricultural assets providing a wider understanding of how communities can be affected by a potential event. GA's collaboration with the Attorney General's Department (AGD) has involved the consolidation of location-based data to deliver consistent map and exposure information products. The complex information requirements emphasised the importance of having all relevant building, demographic, economic, agriculture and infrastructure information in NEXIS available in a clear and unified Exposure Report to aid decision-makers. The Exposure Report includes a situational map of the hazard footprint to provide geographic context and a listing of detailed exposure information consisting of estimates for number and potential cost of impacted buildings by use, agricultural commodities and cost, the number and social vulnerability of the affected population, and the number and lengths of infrastructure assets and institutions. Developed within an FME workbench, the tool accepts hazard footprints and other report specifics as input before providing an HTML link to the final output in approximately 5 minutes. The consolidation of data and streamlining of exposure information into a simple and uniform document has greatly assisted the AGD in timely evidence-based decision-making during the 2014-15 summer season.

In June 2012 Geoscience Australia was commissioned by Commonwealth Scientific and Industrial Research Organisation (CSIRO) to undertake detailed wind hazard assessments for 14 Pacific Island countries and East Timor as part of the Pacific-Australia Climate Change Science and Adaptation Planning (PACCSAP) program. PACCSAP program follows on from work Geoscience Australia did for the Pacific Climate Change Science Program (PCCSP) looking at CMIP3 generation of climate models. The objective of this study is to improve scientific knowledge by examining past climate trends and variability to provide regional and national climate projections. This document presents results from current and future climate projections of severe wind hazard from tropical cyclones for the 15 PACCSAP partner countries describing the data and methods used for the analysis. The severe wind hazard was estimated for current (1981 to 2000) and future (2081 to 2100) climate scenarios. Tropical-cyclone like vortices from climate simulations conducted by CSIRO using six Coupled Model Intercomparison Project phase 5 (CMIP5) models (BCC-CSM1.1, NorESM1-M, CSIRO-Mk3.6, IPSL-CM5A, MRI-CGM3 and GFDL-ESM2M) as well as the International Best Track Archive for Climate Stewardship were used as input to the Geoscience Australia's Tropical Cyclone Risk Model to generate return period wind speeds for the 15 PACCSAP partner countries. The Tropical Cyclone Risk Model is a statistical-parametric model of tropical cyclone behaviour, enabling users to generate synthetic records of tropical cyclones representing many thousands of years of activity. The 500-year return period wind speed is analysed and discussed into more details in this report, since it is used as a benchmark for the design loads on residential buildings. Results indicate that there is not a consistent spatial trend for the changes in 500-year cyclonic wind speed return period when CMIP5 models are compared individually. BCC-CSM1M and IPSL-CM5A presented an increase in the annual TC frequency for East Timor, northern hemisphere and southern hemisphere. On the other hand, NorESM1M showed a decrease in the annual TC frequency for the same areas. The other three models showed a mixed of increase and decrease in their annual TC frequency. When CMIP5 models were analysed by partner county capitals for the 500-year cyclonic wind speed return period, IPSL-CM5A and GFDL-ESM2M models presented an increase in the cyclonic wind speed intensity for almost all capitals analysed with exception of Funafuti (GFDL-ESM2M), which presented a decrease of 0.7% and Honiara (IPSL-CM5A) with a decrease of 1.6%. The tropical cyclone annual frequency ensemble mean indicates an increase in the tropical cyclone frequency within all three regions considered in this study. When looking at individual capitals, a slight increase in the 500-year return period cyclonic wind speed ensemble mean varying between 0.8% (Port Vila) to 9.1% (Majuro) is noticed. A decline around 2.4% on average in the 500-year return period cyclonic wind speed ensemble mean is observed in Dili, Suva, Nukualofa and Ngerulmud. The ensemble spatial relative change did not show any particular consistency for the 500-year cyclonic wind speed. Areas where Marshall Islands and Niue are located presented an increase in the 500-year cyclonic wind speed while a decrease is observed in areas around South of Vanuatu, East of Solomon Islands, South of Fiji and some areas in Tonga. The information from the evaluation of severe wind hazard from tropical cyclones, together with other PACCSAP program outputs, will be used to build partner country capacity to effectively adapt and plan for the future and overcome challenges from climate change.

A selection of images and short animations explaining key aspects of the 2004 Indian Ocean/ Sumatra tsunami, revised and issued for release to the media and other interested organisations on the tenth anniversary of the disaster. This selection updates existing resources previously released by Geoscience Australia.

Summary XML files complying with the Australian Flood Study Data Model including one file for each Jurisdiction and on All-in-one file.