The Queen Charlotte Fault (QCF) off western Canada is the northern equivalent to the San Andreas Pacific - America boundary. Geomorphology and surface processes associated with the QCF system have been revealed in unprecedented detail by recent seabed mapping surveys. The QCF bisects the continental shelf of British Columbia forming a fault-valley that is visible in multibeam sonar bathymetry data. The occurrence of the fault within a valley, and its association with what appear to be graben structures, suggest the fault may exhibit minor rifting (extension) as well as strike-slip motions in the region offshore from Haida Gwaii (Queen Charlotte Islands). Fault-valley formation, slumping and stranding of submarine canyon thalwegs are geomorphic expressions of QCF tectonism, illustrating the general applications of multibeam technology to marine geophysical research.

Models of seabed sediment mobilisation by waves and currents over Australia's continental shelf environment are used to examine whether disturbance regimes exist in the context of the intermediate disturbance hypothesis (IDH). Our study shows that it is feasible to model the frequency and magnitude of seabed disturbance in relation to the dominant energy source (wave-dominated shelf, tide-dominated shelf or tropical cyclone dominated shelf). Areas are mapped where the recurrence interval of disturbance events is comparable to the rate of ecological succession, which meets criteria defined for a disturbance regime. We focus our attention on high-energy, patch-clearing events defined as exceeding the Shields (bed shear stress) parameter value of 0.25. Using known rates of ecological succession for different substrate types (gravel, sand, mud), predictions are made of the spatial distribution of a dimensionless ecological disturbance index (ED), given as: ED = FA (ES/RI), where ES is the ecological succession rate for different substrates, RI is the recurrence interval of disturbance events and FA is the fraction of the frame of reference (surface area) disturbed. Maps for the Australian continental shelf show small patches of ED-seafloor distributed around the continent, on both the inner and outer shelf. The patterns are different for wave-dominated (patches on the outer shelf trending parallel to the coast), tide-dominated (patches crossing the middle-shelf trending normal to the coast) and cyclone-dominated (large oval-shaped patches crossing all depths). Only a small portion of the shelf (perhaps ~10%) is characterised by a disturbance regime as defined here. To our knowledge, this is the first time such an analysis has been attempted for any continental shelf on the earth.

We present a probabilistic tectonic hazard analysis of a site in the Otway Basin,Victoria, Australia, as part of the CO2CRC Otway Project for CO2 storage risk. The study involves estimating the likelihood of future strong earthquake shaking and associated fault displacements from natural tectonic processes that could adversely impact the storage process at the site. Three datasets are used to quantify the tectonic hazards at the site: (1) active faults; (2) historical seismicity, and; (3) GPS surface velocities. Our analysis of GPS data reveals strain rates at the limit of detectability and not significantly different from zero. Consequently, we do not develop a GPS-based source model for this Otway Basin model. We construct logic trees to capture epistemic uncertainty in both the fault and seismicity source parameters, and in the ground motion prediction. A new feature for seismic hazard modelling in Australia, and rarely dealt with in low-seismicity regions elsewhere, is the treatment of fault episodicity (long-term activity versus inactivity) in the Otway model. Seismic hazard curves for the combined (fault and distributed seismicity) source model show that hazard is generally low, with peak ground acceleration estimates of less than 0.1g at annual probabilities of 10-3-10-4/yr. The annual probability for tectonic displacements of greater than or equal to 1m at the site is even lower, in the vicinity of 10-8-10-9/yr. The low hazard is consistent with the intraplate tectonic setting of the region, and unlikely to pose a significant hazard for CO2 containment and infrastructure.

An igneous zircon reference material (OG1) was characterised for U-Pb isotopes by ID-TIMS, and utilised to evaluate SIMS (SHRIMP) instrumental mass fractionation (IMF) of radiogenic Pb isotopes (207Pb*/206Pb*). The TIMS 207Pb*/206Pb* reference value for OG1 was 0.29907 ± 0.00011 (95% confidence limit), 3465.4 ± 0.6 Ma. The high 207Pb* (~ 30 -g g-1), negligible common Pb, and isotopic homogeneity permitted precise (± 1-2) 207Pb*/206Pb* measurements within the analytical sessions. External reproducibility of mean 207Pb*/206Pb* ratios between sessions was demonstrated for one instrument, yielding a mean IMF of +0.87 ± 0.49. The mean 207Pb*/206Pb* ratios between instruments were dispersed beyond uncertainties, with session IMF values from +3.6 ± 1.7- to -2.4 ± 1.3, and a grand mean IMF value (twenty-six sessions) of +0.70 ± 0.52, indicating a tendency towards elevated 207Pb*/206Pb*. The specific causes of variability in IMF are unclear, but generally reflect subtle differences in analytical conditions. The common practice in SIMS of assuming that IMF for Pb+ is insignificant could result in systematic age biases and underestimated uncertainties, of critical importance for precise correlation of Precambrian events. Nevertheless, a zircon RM such as OG1 can be readily incorporated into routine dating to improve 207Pb*/206Pb* accuracy and external reproducibility.

Marine physical and geochemical data can be valuable in predicting the potential distributions and assemblages of marine species, acting as surrogate measures of biodiversity. The results of surrogacy analysis can also be useful for identifying ecological processes that link physical environmental attributes to the distribution of seabed biota. This paper reports the results of a surrogacy study in Jervis Bay, a shallow-water, sandy marine embayment in south-eastern Australia. A wide range of high-resolution co-located physical and biological data were employed, including multibeam bathymetry and backscatter data and their derivatives, parameters that describe seabed sediment and water column physical characteristics, seabed exposure, and infauna species. The study applied three decision tree models and a robust model selection process. The results show that the model performance for three diversity indices and seven out of eight infauna species range from acceptable to good. Important surrogates for infauna diversity and species distributions within the mapped area are broad-scale habitat type, seabed exposure, sediment nutrient status, and seabed rugosity and heterogeneity. The results demonstrate that abiotic environmental parameters of a sandy embayment can be used to effectively predict infauna species distributions and biodiversity patterns. International Journal of Geographical Information Science

An integrated analysis of both airborne and field short-wave infrared hyperspectral measurements was used in conjunction with conventional field mapping techniques to map hydrothermal alteration in the central portion of the Mount Painter Inlier in the Flinders Ranges, South Australia. The airborne hyperspectral data show the spatial distribution of spectrally distinct minerals occurring as primary minerals and as weathering and alteration products. Field spectral measurements, taken with a portable infrared mineral analyzer spectrometer and supported by thin-section analyses, were used to verify the mineral maps and enhance the level of information obtainable from the airborne data. Hydrothermal alteration zones were identified and mapped separately from the background weathering signals. A main zone of alteration, coinciding with the Paralana Fault zone, was recognized, and found to contain kaolinite, muscovite, biotite, and K-feldspar. A small spectral variation associated with a ring-like feature around Mount Painter was tentatively determined to be halloysite and interpreted to represent a separate hydrothermal fluid and fluid source, and probably a separate system. The older parts of the alteration system are tentatively dated as Permo-Carboniferous. The remote sensing of alteration at Mount Painter confirms that hyperspectral imaging techniques can produce accurate mineralogical maps with significant details that can be used to identify and map hydrothermal activity. Application of hyperspectral surveys such as that conducted at Mount Painter would be likely to provide similar detail about putative hydrothermal deposits on Mars.

Tropical cyclones present a significant hazard to countries situated in the warm tropical waters of the western Pacific. These severe storms are the most costly and the most common natural disaster to affect this region (World Bank, 2006). The hazards posed by these severe storms include the extreme winds, storm surge inundation, salt water intrusion into ground water supplies, and flooding and landslides caused by the intense rainfall. Despite the high vulnerability of the islands in this region, there have been relatively few previous studies attempting to quantify the hazard from tropical cyclones in this region (i.e. Shorten et al. 2003, Shorten et al. 2005, Terry 2007). Understanding this hazard is also vital for informing climate change adaptation options. This study aims to address the limited understanding of the extreme wind hazard in this region. The wind hazard from tropical cyclones is evaluated for the current climate and projections were made to assess how this hazard may change in the future. The analysis is performed using a combination of historical tracks and downscaled climate models with Geoscience Australia's Tropical Cyclone Risk Model. The work was funded as part of the Pacific Climate Change Science Program (PCCSP), which forms the science component of the International Climate Change Adaptation Initiative (ICCAI), an Australian government initiative designed to meet high priority climate change adaptation needs of vulnerable countries in our region. This study assesses the wind hazard for the fifteen PCCSP partner countries which include 14 islands located in the West Pacific as well as East Timor.

Abstract. Severe wind is one of the major natural hazards in Australia. The component contributors to economic loss in Australia with regards to severe wind are tropical cyclones, thunderstorms and sub-tropical (synoptic) storms. Geoscience Australia's Risk and Impact Analysis Group (RIAG) is developing mathematical models to study a number of natural hazards including wind hazard. This paper discusses wind hazard under current and future climate using RIAG's synoptic wind hazard model. This model can be used in non-cyclonic regions of Australia (Region A in the Australian-New Zealand Wind Loading Standard; AS/NZS 1170.2:2002) where the wind hazard is dominated by synoptic and thunderstorm gust winds.

A symposium was held at the University of Wales, Swansea in July 2007 to honour the career and achievements of Professor Michael Collins. The symposium was organised by Michael's former postgraduate students as a tribute to his contributions over the past 30 years as a scientist, teacher, mentor and friend. About 30 of the 50+ Ph.D. and M.Sc. students that Michael has supervised over the years were fortunate to attend the symposium, which offered the opportunity for all of us to learn about the many different subjects and projects that Michael supervised and to renew our friendships with the Collins family, as well as the extended, academic Collins 'family'.

Annular to crescent-shaped low back scatter SAR slicks over carbonate reefs and shoals in the Timor Sea with slick `feathering', and within the coral spawning period for the region, are interpreted to be caused by a coral spawn event. In contrast, ocean current data and detailed swath bathymetry of the sea floor to the southeast of the coral spawn slicks suggest that elongate repeating slicks in this area are related to current flow over submarine channels. Assessment of these slicks in association with ancillary data, such as bathymetry, current velocities, weather and timing of scene capture allow a more robust interpretation of their origins. Through differentiating coral spawn and bathymetric slicks from oil and other biological slicks in shallow carbonate systems, such as the Timor Sea, petroleum and environmental assessments for these areas can be improved.