Natural hazards such as floods, dam breaks, storm surges and tsunamis impact communities around the world every year. To reduce the impact, accurate modelling is required to predict where water will go, and at what speed, before the event has taken place.

This report comprises three parts, authored as indicated: Part I: Geoscience Australia. Cechet B. and Sanabria A. Part II: Bureau of Meteorology and JDH Consulting. Kepert J. and Holmes J. Part III: Cyclone Testing Station, James Cook University. Ginger J. and Henderson D

Australia boasts arguably the richest Quaternary faulting record in all of the world's stable continental region (SCR) crust. Significant variation in Quaternary fault scarp length, vertical displacement, relation to other faults and to topography, justifies the division of the continent according to fault character. Six onshore 'neotectonic domains' are recognised. Each domain relates to a distinct underlying crustal type and architecture, which can be broadly assigned to the classes: cratonic, non-cratonic and extended. In general, as has previously been recognised, higher activity is associated with extended crust than with non-extended crust. Application of this domains model permits greater confidence in identifying analogous systems elsewhere in the world. A common characteristic across Australia appears to be the temporal clustering of large earthquakes - periods of earthquake activity comprising a finite number of large events are separated by much longer periods of seismic quiescence. In several instances there is evidence for deforming regions at scales of several hundred kilometres switching on and off over the last several million years. What is not clear from the limited available paleoseismic data is whether successive active periods are comparable in terms of slip, number of events, magnitude of events, etc. Irrespective, this apparent bimodal recurrence behaviour poses problems for probabilistic seismic hazard assessment (PSHA) in that it implies that large earthquake recurrence is not random (i.e. Poissonian). The points critical to understanding the hazard posed by SCR faults, and modelling this hazard probabilistically, become: 1) is the fault in question in the midst of an active period, or in a quiescent period; 2) how many large events might constitute an active period, and how many ruptures has the fault generated so far in its current active period (should it be in one); and 3) what is the mean recurrence interval in an active period, and what is the variability around this mean? This data might be, with caution, incorporated statistically into PSHAs. Keywords: intraplate, neotectonics, palaeoseismology, temporal clustering

One of the important inputs to a probabilistic seismic hazard assessment is the expected rate at which earthquakes within the study region. The rate of earthquakes is a function of the rate at which the crust is being deformed, mostly by tectonic stresses. This paper will present two contrasting methods of estimating the strain rate at the scale of the Australian continent. The first method is based on statistically analysing the recently updated national earthquake catalogue, while the second uses a geodynamic model of the Australian plate and the forces that act upon it. For the first method, we show a couple of examples of the strain rates predicted across Australia using different statistical techniques. However no matter what method is used, the measurable seismic strain rates are typically in the range of 10-16s-1 to around 10-18s-1 depending on location. By contrast, the geodynamic model predicts a much more uniform strain rate of around 10-17s-1 across the continent. The level of uniformity of the true distribution of long term strain rate in Australia is likely to be somewhere between these two extremes. Neither estimate is consistent with the Australian plate being completely rigid and free from internal deformation (i.e. a strain rate of exactly zero). This paper will also give an overview of how this kind of work affects the national earthquake hazard map and how future high precision geodetic estimates of strain rate should help to reduce the uncertainty in this important parameter for probabilistic seismic hazard assessments.

The recent review into natural disasters endorsed by the Council of Australian Governments recommends that Australia work towards the development of a world class national framework for natural disaster management. Currently, there is no nationally consistent tool that provides information about the social aspects (vulnerability, capacity, recovery) of Australian communities to natural hazards. Such information is essential in gaining a holistic picture of risk from natural hazards and would greatly assist decision makers responsible for and administering funding under the recommended natural disaster arrangements endorsed by the Council of Australian Governments (COAG). The Risk Research Group at Geoscience Australia is developing rigorous risk assessments and tools to assist Federal and State Government decision makers better mitigate the risks from natural hazards. Social research, when combined with a physical model of natural hazards, can contribute to the development of comprehensive risk assessments for use by government decision makers. It can also be used to assist government decision makers gain an insight into the factors shaping long-term community recovery. The COAG Review recognises the need for evidence based risk assessments to be undertaken for Australia communities, as well as recognising the need for a greater understanding of long term recovery within communities. This paper will provide an example of a national framework that draws on social datasets and vulnerability research to ptovide an insight into some of the key factors influencing long-term community recovery. The framework is adapted to address Recommendation 43 of the COAG review, which recognises the need for government to support long-term community recovery in order to develop sustainable communities. The role of social research in developing this recommendation demonstrates that by understanding our governance system and current policy developmnet, natural disaster research can significantly contribute to the Australian Government's management of natural disasters.

A characteristic of Australian stable continental region (SCR) faults appears to be the temporal clustering of surface rupturing earthquakes. With the possible exception of active faults in the Flinders Ranges and Mt Lofty Ranges regions of South Australia, active periods of earthquake activity comprising a finite number of events are separated by much longer periods of seismic quiescence. This behaviour poses particular problems for seismic hazard assessment in that it implies that recurrence of large earthquake events is not random (Poisson) as is implicitly assumed in most seismic hazard assessment methods. We present a model that helps to conceptualise the points critical to understanding the hazard posed by intraplate faults and in modelling this hazard probabilistically. Specifically, we look to identify whether the SCR fault in question is about to enter an active period, is in the midst of an active period, or is in a quiescent period. In relation to this issue it becomes important to know how many previous ruptures the fault has generated in its current active period (should it be in one), and specifically, if a fault is in an active period, what is the <i>average</i> recurrence interval and what is the variability around this average. This <i>average</i> could be incorporated statistically into probabilistic seismic hazard assessments.

A review of the methods employed to collect 'buildings specific field data' following the impact of Severe Tropical Cyclone Larry (March 2006) resulted in a plan to build a vehicular mounted rapid data inventory collection system to compliment post disaster surveys. The system assists to overcome the issues related to restricted access, poor weather and difficult working conditions. The ability to quickly collect comprehensive information which is highly critical for both damage assessment and vulnerability model validation reduces assessment errors caused by rapid clearing of debris and repairs following the disaster, along with the use of tarpaulins, which often obscure the level of damage viewed from the street. The Rapid Inventory Collection System (RICS) consists of four 5 Megapixel Gigabit Ethernet digital cameras operating at approximatly four frames per second. The high-resolution cameras, enclosed within all weather housings, are attached to an extendable aluminium tripod with either suction cup or magnetic 'feet' which can be attached to a 4WD dual cab roof or tray. The cameras stream images which are captured via a five port Gigabit Ethernet switch supporting jumbo frames to reduce the CPU load required to handle incoming data to a Quad Core processor Laptop. The images are compressed in jpeg format 'on-the-fly' and displayed in a Graphical User Interface (GUI) along with GPS location, bearing and speed. An additional display window shows the street-directory (UBD) roadmap and a GPS tracklog. Hot keys for instant damage assessment marking location and damage levels have been programed into the GUI. All images are time synchronised and stored in a geo-referenced database for spatial analysis to estimate the damage.

In plate boundary regions moderate to large earthquakes are often sufficiently frequent that robust estimates of fundamental seismic parameters such as the recurrence intervals of large earthquakes and maximum credible earthquake (Mmax) can be made. The same is not true for the Stable Continental Regions (SCRs) of the world. Large earthquakes are so infrequent that the data distributions upon which recurrence and Mmax estimates are based are heavily skewed towards magnitudes below Mw 5.0, and so require significant extrapolation up to magnitudes for which damaging ground-shaking might be expected. The rarity of validating evidence from palaeo-surface rupturing earthquakes limits the confidence with which extrapolated statistical parameters may be applied. Herein we present an earthquake catalogue containing, 150 palaeo-earthquakes, from 60 palaeo-earthquake features, based upon a >100 ka record of palaeo-earthquakes recorded in the Precambrian Shield of southwest Western Australia. From this data we show that Mmax for non-extended-SRC is well constrained at M7.22 and M7.65 for extended-SCR. In non-extended-SRC the earthquakes are likely episodic with periods of quiescence of 10-100ka in between active phases. The largest earthquakes are likely to occur on pre-existing faults. We expect these results might apply to most areas of non-extended-SCR worldwide.

A series of storm deposits at Curacoa Island, a steep bedrock island in the Palm Group, north Queensland, record the passage of cyclonic events. Storm ridge accretion occurs when cyclonic waves and surge combine to transport coarse sediment, mostly broken coral, onto the shore and deposit it above normal tidal levels. Narrow fringing reefs at Curacoa act as a rapidly replenished sediment source, augmented by lithic gravel transported longshore. Beachface, stormberm, ridge platform and washover deposits can accrete during a single event. A series of storm ridges were examined via stratigraphic pits and trenches on two traverses; deposits from 22 events were identified and their ages were determined with multiple, accordant radiocarbon dates from corals within each deposit. About 15% of the dates were older than accordant group ages and indicated reworked specimens. Accordant group ages were combined and converted to calibrated radiocarbon ages. Ridge ages increase uniformly with distance from the oldest ridge indicating uniform depositional processes over the last 5000 years. A time series of storm deposit ages indicates that cyclone frequency was statistically constant over the last 5000 years. This evidence is despitesuggestions of 1oC warmer sea surface temperatures in the region about 5000 years ago (Gagan et al., 1998) which may have promoted cyclonic frequency. warmer .

This dataset is a spatial representation of the Geoscience Australia Earthquake Database. The dataset contains recorded magnitudes for earthquakes on and near Australia. Local events of magnitude 4 and above and regional events of magnitude 6 and above are displayed.