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  • The Dynamic Land Cover Dataset Version 2 is a suite of land cover information products from Geoscience Australia (GA). These information products deliver International Standards Organisation (ISO) compliant land cover maps across the Australian landmass. The datasets provide a consistent series of maps that show how Australian land cover is changing over time. The current version consists of 14 maps each based on 2 years of MODIS data. The 14 maps cover the period from January 2001 - December 2015. The Dynamic Land Cover Dataset uses a standard land cover classification to show the change in behaviour of land cover across Australia. The DLCD includes data for every 250m by 250m area on the ground, for the period 2001 to 2015. The DLDC provides a basis for reporting on change and trends in vegetation cover and extent. Information about land cover dynamics is essential to understanding and addressing a range of national challenges such as drought, salinity, water availability and ecosystem health. The current release of the second version DLCDv2.1 presents land cover information for every 250m by 250m area of the country for each of the two year intervals listed in the table below. It consists of maps based on 2 years of MODIS EVI time-series data. The date ranges for each of the map series are: • January 2001-December 2002 • January 2002-December 2003 • January 2003-December 2004 • January 2004-December 2005 • January 2005-December 2006 • January 2006-December 2007 • January 2007-December 2008 • January 2008-December 2009 • January 2009-December 2010 • January 2010-December 2011 • January 2011-December 2012 • January 2012-December 2013 • January 2013-December 2014 • January 2014-December 2015 DLCD can be used as an input for a wide range of environmental modelling applications, including: • Climate • Wind and water erosion risk • Evapotranspiration • Carbon dynamics • Land surface processes In conjunction with other data sources, the DLCD can be used to identify emerging patterns of land cover change and provide a spatial and historical context within which to interpret change. The land cover classification scheme used conforms to the 2007 International Standards Organisation (ISO) land cover standard (19144-2). The dataset shows Australian land covers clustered into 22 classes. These reflect the structural character of vegetation, ranging from cultivated and managed land covers (crops and pastures) to natural land covers such as trees and grasslands.

  • Eonomic Fairways Explorer video presentation for PDAC 2015. The purpose of this video demonstration is to show the Proof of Concept (PoC) of the Economic Fairways Explorer application, which enables users to perform "what if" economic modelling and scenarios using GIS data. The Economic Fairways Explorer application is based upon the CIAP framework.

  • Mount Isa mineralized province has brought renewed interest of exploration in the greenfield regions in finding base metal (Pb-Zn-Ag) deposits which is often being hosted on black Urquhart shale which is electrically conductive medium. The new study is focused on understanding the structural framework which is favourable for mineralization; for example, the pathways for mineralized fluid, zone(s) of highly conductive region suggesting either conductive sulphide mineralization or the presence of the favourable host for mineralization. This prompts magnetotelluric investigations with frequency range 10-4 103 Hz for broadband and 10 20x103 Hz for audio magnetotelluric investigations. Higher frequency allows investigating relatively shallow and highly resolvable structure; on the other hand, lower frequency allows investigating structure seated deep below the horizontal surface. The new zone of investigations which is an upside down L-shaped region at the southwest corner of the Mount Isa region is designated as Mount Isa extension. The broadband magnetotelluric data are acquired in a regular rectangular grid fashion in, so as to help in building a 3D electrical conductivity image of the subsurface. In the current study we focus on analysing and modelling magnetotelluric data at a rectangular zone which is at the western end of the L-shaped region. We designate this zone as West Bloc and conduct detailed data driven analysis and modelling of MT data. We conduct dimensionality analysis and direction (or strike) analysis using phase ellipse and Mohr circle methods. In addition, we also conduct imaging in a vertical plane using apparent resistivity and phase pseudosections for both the transverse electric (TE) and the transverse magnetic (TM) modes of measured fields. We conduct inverse modelling on apparent resistivity and phase data. We initially make 1D Occam inversion in every MT sites. Using 1D Occam inversion results in every MT sites along a profile we create 2D resistivity section by stitching those results by appropriate gridding methods. We then conduct 2D inversion using ModEM software and generate several sections along profiles. We compare inverted 2D sections with the stitched sections. We then conduct 3D inversion using ModEM software and build 3D image of resistivity variation. In our every inversion run either 1D or 2D or 3D our starting model remains a half space. We observe, although there is a general agreement in stitched 2D sections with the 2D sections generated by 2D and 3D inverse modelling that the modelling results differ substantially. We conclude such observation is consistent with the following fact: 1) the conductivity structure in the study area is not purely 1D, 2D or 3D rather a hybrid one and 2) the half space starting model for higher dimension inversion scheme is too coarse to overcome the issues of local minima of optimization. Therefore, most pragmatic approach is to build a prior model using a lower dimension inversion scheme before any higher order inversion run. We would implement the foretold strategy of inverse modelling in future exercise.

  • Flyer to promote interest in Earth science

  • Pockmarks have been observed around the world's ocean and lake beds for decades. They indicate shallow and/or deep sub-surface fluid seepage, and may occur in isolation or in groups. Dense fields of pockmarks were identified in three areas (510 km2) mapped using multibeam sonar in the Oceanic Shoals Commonwealth Marine Reserve, located in the tropical Timor Sea on the Australian continental shelf. The pockmarks occur in flat, barren, silty plains (~105 m water depth) which surround extensive carbonate banks and terraces (~40-75 m water depth). The banks hosted rich communities of benthic organisms including sponge gardens and corals. A distinctive feature of many of the pockmarks in this area is a linear scour mark that extends up to 200 m from pockmark depressions. Previous numerical and flume tank simulations have shown that scouring of pockmarks occurs in the direction of the dominant near-seabed flow. These geomorphic features may therefore serve as a proxy for local-scale bottom currents, which may in turn provide information on sediment processes influencing biodiversity patterns in the region. In this presentation, we: 1) provide information on the methods used to characterise and count the scoured and non-scoured depressions (i.e. an automated method involving ArcGIS spatial analyst tools); (2) draw on other datasets to provide information on why the pockmarks developed (e.g. multibeam backscatter and geochemical variables); and 3) investigate their potential as an environmental proxy (oceanographic) for benthic habitat studies.

  • A comprehensive assessment of the performance of predictive models is needed as they have been increasingly employed to generate spatial predictions for environmental management. This study clarified the definition of variance explained (VECV) for predictive models and revealed the relationships between commonly used predictive accuracy measures and VECV that is independent of unit/scale and data variation and unifies these measures. We quantified the relationships between these measures and data variation, further assessed the accuracy of predictive methods in environmental sciences and classified the predictive models based on VECV. This study provides a tool to directly compare the accuracy of predictive models for data with different unit/scale and variation, and establishes a cross-disciplinary context and benchmark for assessing predictive models in environmental sciences and other disciplines.

  • Although marine reserves are becoming increasingly important as anthropogenic impacts on the marine environment continue to increase, we have little baseline information for most marine environments. In this study, we focus on the Oceanic Shoals Commonwealth Marine Reserve (CMR) in northern Australia, particularly the carbonate banks and terraces of the Sahul Shelf and Van Diemen Rise which have been designated a Key Ecological Feature (KEF). We use a species-level inventory compiled from three marine surveys to the CMR to address several questions relevant to marine management: 1) Are carbonate banks and other raised geomorphic features associated with biodiversity hotspots? 2) Are there environmental or biogeographic variables that can help explain local and regional differences in community structure? 3) How do sponge communities differ between individual raised geomorphic features? Approximately 750 sponge specimens were collected in the Oceanic Shoals CMR and assigned to 348 species, of which only 18% included taxonomically described species. Between the eastern and western CMR, there was no difference between sponge species richness or assemblages on raised geomorphic features. Within individual raised geomorphic features, sponge assemblages were significantly different (ANOSIM: Global R = 0.328, p < 0.001), but species richness was not. There were no environmental factors related to sponge species richness, although sponge assemblages were weakly but significantly related to several environmental variables (mean depth, mean backscatter, mean slope). These patterns of sponge diversity are considered in the context of marine reserve management in order to explore how such information may help support the future management of this region.

  • The Vlaming Sub-basin is an elongated, north-south trending Mesozoic depocentre in the Perth Basin, Western Australia containing up to 14 km of sediments. A number of potential plays at different stratigraphic levels were identified by the previous exploration. Although potential plays were described for the Early Cretaceous Gage Sandstone overlain by the South Perth Shale seal, they were not successfully explored in any detail. The exploration primarily focused on structural traps in the syn-rift succession due to the assumption that all hydrocarbons were generated prior to or at the time of the breakup. Petroleum systems modelling undertaken in 2007 concluded that some source rocks in the sub-basin reached maturity after the deposition of the South Perth Shale seal, therefore making plays in the post-breakup Gage reservoir prospective. Deposited as a lowstand component of the deltaic South Perth Supersequence, the Gage Lowstand Fan (previously referred to as the Gage Sandstone) infilled paleotopographic lows of the Valanginian breakup unconformity. Characteristics of the reservoir-seal pair were derived from sequence-stratigraphic analysis and seismic facies mapping by integrating 2D seismic interpretation, well log analysis and new biostratigraphic data. Palaeogeographic reconstructions for the South Perth Supersequence reveal a series of regressions and transgressions that infill the paleodepressions. The Gage reservoir is a sand-rich submarine fan system and ranges from canyon-confined inner fan deposits to middle fan deposits on a basin plain. Sand sheets in the distal middle fan and stacked channelized sands in the inner fan may provide an extensive reservoir of good to excellent quality. Characteristics of the South Perth Shale seal vary greatly across the basin and may account for some dry wells. A re-evaluation of the regional seal determined the extent of the pro-delta shale facies within the South Perth Supersequence, which provides an effective seal for the underlying Gage reservoir. 3D geological modelling provided a better understanding of the reservoir heterogeneity. Flow path analysis identified multiple stratigraphic closures at the top of the Gage reservoir, with the most favourable located in the Rottnest Trough.

  • The distribution of volcanic-hosted massive sulphide deposits through time is episodic, involving relatively short time intervals of apparent high productivity and long intervals of low productivity. This distribution is principally related to the geodynamic evolution of the Earth. The vast majority of these deposits is associated with the assembly of supercontinents and form along convergent margins, generally in back-arc basins or rifted arcs. This contrasts with the distribution of black smoker deposits, which presently form along both convergent margins, particularly in the western Pacific, and divergent margins at mid-ocean ridges. However, the latter environment is rarely preserved deep into the geological past. There also appear to be systematic patterns in a number of other features of volcanic-hosted massive deposits through time. Deposits hosted by mafic-dominated successions are dominant in Archean to Proterozoic rocks, whereas deposits hosted by felsic-dominated successions are most common in Phanerozoic rocks. Geochemical characteristics of felsic rocks within the host successions and ore lead and sulphur isotope data of the ores have also changed with time. This suggests changes in the process of subduction and/or changes in the characteristics of the over-riding plate with time, consistent with isotopic and geologic evidence for greater reworking of pre-existing crust during the Phanerozoic. Other secular changes that are reflected in characteristics of volcanic-hosted massive sulphide deposits include the redox state and salinity of coeval oceans. As an example, both the abundance of sulphate minerals and sulphur isotope patterns reflect the development of periods of anoxic conditions over time, with major intervals of anoxia, reflected by a virtual lack or low abundance of sulphate minerals in volcanic-hosted massive sulphide deposits in the Mesoarchean to the Paleoproterozoic, and shorter intervals since.

  • A fully four-dimensional (3D x time) open source (BSD-3), object-oriented biophysical dispersal model was developed to simulate the movement of marine larvae over semi-continuous surfaces. The model is capable of handling massive numbers of simulated larvae, can accommodate diverse life history patterns and distributions of characteristics, and saves point-level information to a relational database management system. The model was used to study Australia's northwest marine region, with attention given to connectivity patterns among Australia's north-western Commonwealth Marine Reserves (CMRs). This work was supported by the Marine Biodiversity Hub through the Australian Government's National Environmental Research Program (NERP).