Williams et al. (2009) report on new multibeam sonar bathymetry and underwater video data collected from submarine canyons and seamounts on Australia's southeast continental margin to 'investigate the degree to which geomorphic features act as surrogates for benthic megafaunal biodiversity' (p. 214). The authors describe what they view as deficiencies in the design of the Marine Protected Areas (MPAs) in the southeast region of Australia, in which geomorphology information was employed as a surrogate to infer regional-scale patterns of benthic biodiversity. This comment is designed to support and underscore the importance of evaluating MPA designs and the validity of using abiotic surrogates such as geomorphology to infer biodiversity patterns, and seeks to clarify some of the discrepancies in geomorphic terminologies and approaches used between the original study and the Williams et al. (2009) evaluation. It is our opinion that the MPA design criteria used by the Australian Government are incorrectly reported by Williams et al. (2009). In particular, we emphasise the necessity for consistent terminology and approaches when undertaking comparative analyses of geomorphic features. We show that the MPA selection criteria used by the Australian Government addressed the issues of false homogeneity described by Williams et al. (2009), but that final placement of MPAs was based on additional stakeholder considerations. Finally, we argue that although the Williams et al. (2009) study provides valuable information on biological distributions within seamounts and canyons, the hypothesis that geomorphic features (particularly seamounts and submarine canyons) are surrogates for benthic biodiversity is not tested explicitly by their study.

This preliminary report will provide a geochemical and ionic characterisation of groundwater, to determine baseline conditions and, if possible, to distinguish between different aquifers in the Laura basin. The groundwater quality data will be compared against the water quality guidelines for aquatic ecosystem protection, drinking water use, primary industries, use by industry, recreation and aesthetics, and cultural and spiritual values to assess the environmental values of groundwater and the treatment that may be required prior to reuse or discharge.

Geoscience Australia has been acquiring deep crustal reflection seismic transects throughout Australia since the 1960s. The results of these surveys have motivated major interpretations of important geological regions, contributed to the development of continental-scale geodynamic models and improved understanding about large-scale controls on mineral systems. Under the Onshore Energy Security Program, Geoscience Australia has acquired, processed and interpreted over 5000 km of new seismic reflection data. These transects are targeted over geological terrains in all mainland states which have potential for hydrocarbons, uranium and geothermal energy systems. The first project was undertaken in the Mt Isa and Georgetown regions of North Queensland. Interpretations of these results have identified several features of interest to mineral and energy explorers: a previously unknown basin with possible hydrocarbon and geothermal potential; a favourable setting for iron oxide uranium-copper-gold deposits; and, a favourable structural setting for orogenic gold deposits under basin cover. Other geophysical data were used to map these features in 3D, particularly into areas under cover. Seismic imaging of the full thickness of the crust provides essential, fundamental data to economic geologists about why major deposits occur where they do and reduces risk for companies considering expensive exploration programs under cover.

Tropical Cyclone (TC) Yasi crossed Queensland's Cassowary Coast during the night of 2nd and 3rd of February, 2011. The cyclone was forecast to be a severe storm with wind gusts expected to exceed the design gust wind speeds for houses set out in AS4055, BoM (2011). Following the passage of the cyclone, it was evident that significant damage to the region's building stock had occurred. Geoscience Australia (GA), together with collaborators from the National Institute of Water and Atmospheric Research, New Zealand (NIWA), Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) and Maddocks & Associates, undertook a survey of damage to the region's buildings caused by severe wind and storm surge. This paper reports on the survey.

Deep seismic reflection data across the Western Lachlan Orogen of southeast Australia have provided important insights into crustal-scale fluid pathways and possible source rocks across one of the world's richest orogenic gold provinces. The profiles span three of Victoria's most productive structural zones: the Stawell, Bendigo and Melbourne zones. Zone-scale variations in the age and style of gold deposits are reflected by changes in crustal structure and composition as revealed by the seismic data. The Stawell and Bendigo structural zones can be broadly divided into a lower region of interlayered meta-volcanic and meta-sedimentary rocks and an upper region of meta-sedimentary rocks. First-order faults appear to have accommodated large scale crustal thickening down to the lower crust. The bilateral distribution of gold production in the Stawell and Bendigo zones is related to the V-shaped crustal-scale geometry of the two zones in cross-section. Major first-order faults, like the east dipping Moyston Fault and a set of west dipping listric faults, were major fluid conduits during the most important gold event at 440 Ma. These first-order faults converge in the mid and lower crust in a region beneath the western Bendigo Zone where mafic volcanic rocks are identified as a likely common source of metamorphic fluids and gold during the main 440 Ma mineralizing event.

Steep terrain affects optical satellite images through both irradiance and BRDF effects. To obtain corrected land surface reflectance and detect land surface change through time series analysis over rugged surfaces, it is necessary to remove or reduce the topographic effects. In this paper, a physical based BRDF and atmospheric correction model for both flat and sloping surfaces in conjunction with the 1-second SRTM (Shuttle Radar Topographic Mission) derived DSM product was applied to conduct BRDF, atmospheric and terrain correction. The model was applied to 8 Landsat scenes covering different seasons and terrain types in eastern Australia. Initial visual assessment showed that the algorithm removed much of the topographic effect and detected deep shadows in all 8 images. Indirect validation based on the change in correlation between the data and terrain slope showed that the correlation coefficient between the surface reflectance factor and the cosine of the incident (sun) angle reduced dramatically after the topographic correction algorithm was applied. The correlation coefficient typically reduced from 0.80 to 0.02 in areas of significant relief. The terrain corrected surface reflectance can also provide suitable input data for multi-temporal land cover classification in areas of high relief based on spectral signatures and spectral albedo, while the products based only on BRDF and atmospheric correction cannot. To ensure stability of the terrain corrected reflectance products when expert intervention in the processing workflow needs to be minimal, the paper also shows the need for additional constraints and calibration the correction algorithm. For example, to avoid overcorrection, the algorithm currently applies an angle threshold to both the BRDF model and the direct irradiance. Above all, the accuracy and effectiveness of the product is shown to depend particularly on the quality of the DSM data, its co-registration with the Landsat data and its spatial resolution.

The GPS and Galileo systems will transmit triple frequency signals which will be available freely to the GNSS user community. This provides an opportunity for users to form optimal linear combinations which have low noise, are free from ionospheric errors, have increased wavelength and have enhanced integer ambiguity resolution capability. This paper presents optimised linear combinations for GPS and Galileo which address these factors. Based on the theoretical development, the optimal combination is free from first order ionospheric effects and has less noise than any of the other dual frequency ionosphere free combinations. The optimal combination was validated using authentic triple frequency data from the recently launched Block IIF GPS satellite, PRN 25. It is shown that the noise in the optimal combination is lower than the L1/L2 and L2/L5 dual frequency ionosphere free combinations and at the same level as the L1/L5 combination. The optimal linear combination is ideal for undifferenced Precise Point Positioning (PPP) which requires an ionosphere free, low noise combination that does not necessarily have integer coefficients. However, the combination coefficients can be simply rounded to integer values to enhance integer ambiguity resolution and this gives similar results to studies elsewhere.

Geoscience Australia has completed a regional study of the greenhouse gas storage prospectivity for the Petrel Sub-basin (Bonaparte Basin), offshore Northern Territory. The Bonaparte Basin is a mature petroleum exploration province and well placed for possible CO2 storage. Former greenhouse gas acreage release areas, as well as the recommendation of the Carbon Storage Taskforce provided the impetus for the collection of pre-competitive data and a regional geological study. In 2009, the Taskforce had identified large, low risk storage capacity within the Mesozoic formations of the Petrel Sub-basin. Data acquisition was designed to cover an area of low seismic coverage and to better define potential traps and seal integrity. A total of 4091 km of high resolution, 2D seismic data was acquired in early 2012 and is currently available through pre-competitive data through Geoscience Australia. Also, a marine environment survey, which comprised collection of biophysical data, as well as seabed and shallow surface geophysical data, was completed. These data sets provide a baseline for future monitoring, as well as assistance in understanding uncertainty in leakage pathways. These datasets have been integrated and interpreted in a 3D visualisation and modelling environment where different geological scenarios could be tested. A basic geological model encompassing stratigraphic horizons and structure was constructed and then populated using well data as well as extrapolation methods such as facies modelling. This geological and reservoir engineering project has assessed prospective plays for CO2 injectivity and migration using the predicted CO2 sources available in the region. The findings of this study adds to the knowledge of Australia's offshore basins and supports both government and industry for future CO2 storage exploration in the Bonaparte Basin, as well as the carbon capture and storage industry in general. WABS

We present the first detection of the Galactic aberration in 8-GHz astrometric observations of extragalactic radio sources by geodetic VLBI. We analyzed the full geodetic VLBI observational data base to derive source proper motion and we fitted dipolar and quadrupolar vector spherical harmonics coefficients to the velocity field. Our results are in good agreement with theoretical prediction and constitute the first observation of this very tiny effect

For the first time in Australia, active present-day hydrocarbon seepage has been imaged on the tropical carbonate Yampi Shelf, in 50 and 90 m water depth. Seepage features consist of gas plumes in the water column associated with specific seabed features, such as clusters of reflective blocks, hard-grounds, pockmark fields and mounds. Seepage activity and intensity appear to vary with changes in pressure related to macro-tidal cycles. The seabed features coincide with sub-surface features such as areas of seismic signal attenuation under high amplitude reflectors, seismic discontinuities and bright spots. Hydrocarbon migration-seepage pathways appear to be controlled by the reactivation of pre-existing fractures and dykes within the basement. The types of seabed features and their preservation on a tropical carbonate shelf are strongly influenced by the coarse bioclastic nature of sediments and the high energy of macro-tidal currents and storm reworking.