The Australian Bureau of Meteorology (BoM) have been recording peak gust wind speed observations in the Australian region for over 70 years. The current wind loading code and the performance of our infrastructure is based primarily on the Dines anemometer interpretation of the peak gust wind speed. Australian building codes through the Australia/New Zealand Wind Actions Standard [1] as well as the wind engineering community in general rely to a significant extent on these peak gust wind speed observations. In the mid-1980's the Australian Bureau of Meteorology (BoM) commenced a program to replace the aging pressure tube Dines anemometer with the Synchrotac and Almos cup anemometers. Only six Dines anemometers remain in operation, mainly as backup or for high-speed measurement. During the anemometer replacement procedure, many localities had more than one type of anemometer operating, recording extreme events. The passage of Cyclone Vance through Exmouth in 1999 saw Dines and Almos anemometers, separated by 25 metres, recording peak gusts of 144 and 122 knots respectively [2]. A weak cyclone that passed through Townsville in April 2000 recorded a peak gust of 70 knots on the Dines and 59 knots on the Almos anemometer [3]. These systematic differences raise concerns about the consistency and utility of the peak gust wind speed database.

In Global ShakeMap (GSM) applications where access to real-time ground-motion data - which constrains the shaking - is often limited, we must rapidly estimate the shaking distribution in the earthquake source region using solely predictive techniques. Current ShakeMap practice is to first calculate instrumental ground motions using a Ground-Motion Prediction Equation (GMPE). These instrumental ground motions are subsequently converted to macroseismic intensities, which are employed to evaluate human exposure to potentially fatal levels of ground-shaking in PAGER (Prompt Assessment of Global Earthquakes for Response). Here, we use the combined dataset of global instrumental and macroseismic intensity ground motion data gathered for the Atlas of ShakeMaps (Allen et al., this meeting) for evaluating the GSM approach. Several commonly used GMPEs are evaluated for active tectonic crust, subduction zones, and stable continental regions. Using our preferred instrumental GMPE, we subsequently evaluate peak motion to intensity conversion equations. Finally, we evaluate several intensity prediction equations against the ShakeMap Atlas dataset. This review has led us to recommend several fundamental changes to current GSM practice, particularly in the prediction of active crustal ground motions. We also recommend that macroseismic intensities should be predicted using conversion equations that consider earthquake magnitude and distance to rupture, in addition to peak ground motions. Though not exhaustive, this review provides a comprehensive analysis of GMPEs and macroseismic intensity prediction techniques in different tectonic regimes against a large dataset of global ground motion data. The primary purpose of this study is to evaluate these techniques with a view of improving current practices in rapid ground motion prediction for the GSM and PAGER systems.

In addition to the devastating 1989 Newcastle earthquake, at least four other earthquakes of magnitude 5 or greater have occurred in the surrounding Hunter region since European settlement in 1804. Some of these earthquakes caused damage in areas that, at the time, were sparsely populated. Similar events, were they to occur today in populated areas, would certainly cause significant damage. The frequency with which these events have occurred in the Hunter region suggests that earthquakes pose a genuine threat to the communities there. This study presents the most comprehensive and advanced earthquake risk assessment undertaken for any Australian city to date. It has focused on the economic losses caused by damage to buildings from earthquake ground shaking, and not on the impacts from other, secondary hazards such as soil liquefaction and surface faulting. The study has adopted a probabilistic approach that makes allowances for the variability that is inherent in natural processes as well as the uncertainty in our knowledge. The results from this project will assist decision-makers involved in local and state government, policy development, the insurance industry, engineers, architects, and the building and finance industries to manage potential damage and loss of life from earthquakes in Newcastle and Lake Macquarie. The results also have implications for the earthquake risk facing larger Australian cities such as Sydney, Melbourne and Adelaide. This is due to a number of factors, including similarities between the earthquake hazard in Newcastle and Lake Macquarie and other parts of Australia, and similarities between the urban environments, particularly the composition of the building stock.

Poster describing the FIRE-DST project (GA contribution) focising on the developments in 2011/12 FY with respect to the Bushfire Risk Assessment Framework (BRAF) and the computational framework.

A study of the consistency of gust wind speed records from two types of recording instruments has been undertaken. The study examined Bureau of Meteorology's (BoM) wind speed records in order to establish the existence of bias between coincident records obtained by the old pressure-tube Dines anemometer and the records obtained by the new Synchrotac and Almos cup anemometers. This study was an important step towards assessing the quality and consistency of gust wind speed records that form the basis of the Australian Standards/NZ Standards for design of residential building (AS/NZS 1170.2:2002 and AS 4055:2006). The Building Code of Australia (BCA) regulates that buildings in Australia must meet the specifications described in the two standards. BoM has been recording peak gust wind speed observations in the Australian region for over 70 years. The Australia/New Zealand Wind Actions Standard as well as the wind engineering community in general rely on these peak gust wind speed observations to determine design loads on buildings and infrastructure. In the mid-1980s BoM commenced a program to replace the aging Dines anemometer with cup anemometer. During the anemometer replacement procedure, many localities had both anemometers recording extreme events. This allowed us to compare severe wind recordings of both instruments to assess the consistency of the recordings. The results show that the Dines anemometer provides higher severe gust wind speeds than the 3 cup anemometer when the same wind gust is considered. The bias varies with the wind speed and ranges from 5 to 17%. This paper presents the methodology and main outcomes from the assessment of coincident measurements of gust wind speed.

The Great Sumatra-Andaman Earthquake and Indian Ocean Tsunami of 2004 came as a surprise to most of the earth science community. Few were aware of the potential for the subduction zone off Sumatra to generate giant (Mw>= 8.5) earthquakes, or that such an earthquake might generate a large tsunami. In retrospect, important indicators that such an event might occur appear to have not been well appreciated: (1) the tectonic environment of Sumatra was typical of those in which giant earthquakes occur; (2) GPS campaigns, as well as paleogeodetic studies indicated extensive locking of the interplate contact; (3) giant earthquakes were known to have occurred historically. While it is now widely recognised that the risk of another giant earthquake is high off central Sumatra, just east of the 2004 earthquake, there seems to be relatively little concern about the subduction zone to the north, in the northern Bay of Bengal along the coast of Myanmar. It is shown here that similar indicators suggest the potential for giant earthquake activity is high: (1) the tectonic environment is similar to other subduction zones that experience giant megathrust earthquakes; (2) stress and crustal strain observations indicate the seismogenic zone is locked; and, (3) historical earthquake activity indicates that giant tsunamigenic earthquakes have occurred in the past. These are all consistent with active subduction in the Myanmar subduction zone, and it is hypothesized here that the seismogenic zone there extends beneath the Bengal Fan. The results suggest that giant earthquakes do occur off the coast of Myanmar, and that a very large and vulnerable population is thereby exposed to a significant earthquake and tsunami hazard.

INFORMING NATURAL HAZARD RISK MITIGATION THROUGH A RELIABLE DEFINITION OF EXPOSURE Krishna Nadimpalli, Mark Edwards, Mark Dunford Risk & Impact Analysis Group, Geoscience Australia GPO Box 378, Canberra, ACT 2601, Australia, krishna.nadimpalli@ga.gov.au Fundamental to any risk assessment is an understanding of the infrastructure and people exposed to the hazard under consideration. In Australia there is presently no nationally consistent exposure database that can provide this information. The need to better understand risk was recognised in the report on natural disaster relief and mitigation arrangements made to the Council of Australian Governments (COAG) in 2003. The report included a recommendation to develop and implement a five-year national program of systematic and rigorous disaster risk assessments. In response to this Geoscience Australia (GA) is undertaking a series of national risk assessments for a range of natural hazards. This work is being underpinned by a parallel development of a national definition of community exposure called the National Exposure Information System (NEXIS). The NEXIS aims to provide nationally consistent and best available exposure information at the building level. The building types considered are residential, business (commercial and industrial), and ancillary (educational, government, community, religious, etc.). NEXIS requires detailed spatial analysis and integration of available demographic, structural and statistical data. Fundamentally, this system is being developed from several national spatial datasets as a generic approach with several assumptions made to derive meaningful information. NEXIS is underpinning scenarios and risk assessments for various hazards. Included are earthquakes, cyclones, severe synoptic wind, tsunami, flood and technogenic critical infrastructure failure. The NEXIS architecture is completed and the system currently provides residential exposure information nationally. The prototype for business exposure is well developed and a national definition of business exposure will be generated by June 2008. Ancillary buildings and various critical infrastructure sector exposures will be incorporated into the future. While the present approach is largely generic, more specific building and socio-economic information will be incorporated as new datasets or sources of information become available. Opportunities also exist for NEXIS to be integrated with early warning and alert systems to provide real time assessments of damage or to forecast the impact for a range of hazards. This paper describes the methodologies used by NEXIS and how these will be advanced in the future to provide a more complete and specific definition of exposure to inform severe hazard risk assessment, risk mitigation and post event response.

FIRE NOTE 4 page article for the BCRC/AFAC information series.

Australian building codes through the Australia/New Zealand Wind Actions Standard as well as the wind engineering community in general rely to a significant extent on the peak wind gust speed observations collected over more than 60 years by the Bureau of Meteorology (BoM). The current wind loading code and the performance of our infrastructure (residential, commercial, industrial and critical infrastructure) is based primarily on the Dines anemometer interpretation of the peak gust wind speed. In the early 1990's BoM commenced a program to replace the aging pressure tube Dynes anemometer with the Synchrotac and Almos cup anemometers. As of October 2008 only six Dynes anemometers remain in operation.

The impacts of climate change, including sea level rise and the increased frequency of storm surge events, will adversely affect infrastructure in a significant number of Australian coastal communities. In order to quantify this risk, Geoscience Australia in collaboration with the Department of Climate Change and Energy Efficiency, have undertaken a first-pass national assessment which has identified the extent and value of infrastructure that are potentially vulnerable to impacts of climate change. We have utilised the best available national scale information to assess the vulnerability of Australia's coastal zone to the impacts of climate change. In addition to assessing coastal vulnerability assuming the current population, we also examined the changes in exposure under a range of future population scenarios provided by the Australian Bureau of Statistics. Continuation of the current trend for significant development in the coastal zone increases the number and value of residential buildings potentially vulnerable by 2100. We found that over 270,000 residential buildings are potentially vulnerable to the combined impacts of inundation and recession by 2100. This equates to a replacement value of approximately AUD$72 billion. Nearly 250,000 residential buildings were found to be potentially vulnerable to inundation only, which equates to AUD$64 billion. Queensland and New South Wales have the largest vulnerability (considering both value and number of buildings affected). Nationally, approximately 33,000 km of road and 1,500 km of rail infrastructure are potentially at risk by 2100. These results are influencing policy and adaptation planning decisions made by federal, state and local government.