B6/B5 (potential includes: pyrophyllite, alunite, well-ordered kaolinite) Blue is low content, Red is high content Useful for mapping: (1) different clay-type stratigraphic horizons; (2) lithology-overprinting hydrothermal alteration, e.g. high sulphidation, "advanced argillic" alteration comprising pyrophyllite, alunite, kaolinite/dickite; and (3) well-ordered kaolinite (warmer colours) versus poorly-ordered kaolinite (cooler colours) which can be used for mapping in situ versus transported materials, respectively.

<div>Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia, in partnership with state and Northern Territory governments. EFTF program (2016-2024) aims to drive industry investment in resource exploration in frontier regions of northern Australia by providing new precompetitive data and information about energy, mineral and groundwater resource potential. In order to address this overarching objective of EFTF program, Geoscience Australia led a key element of the Australian Government’s commitment to achieve net zero by 2050 is the adoption of hydrogen (H2) energy. The key benefit of using H2 is that it is a clean fuel, emitting only water vapour and heat when combusted. The recent discovery of a 98% pure geologic H2 gas field in Mali has captured the imagination of explorers and the search is now on for new natural H2 gas accumulations across the world. Australia is considered one of the most prospective locations for sub-surface natural H2 due to our ancient geology and presence of potentially suitable H2 traps. A review of occurrences of natural (or geologic) H2 found high concentrations of H2 gas present in central western, New South Wales (NSW). This project, in collaboration with the Geological Survey of NSW, builds on that early work and presents the results identifying new occurrences of natural H2 through soil gas surveys in various locations across central and far west, NSW. Funded through the EFTF Strategic Innovation Reserve Fund (SIRF), FrontierSI was commissioned to identify circular to sub-circular morphologies, sometimes called Fairy Circles, across parts of far west, NSW as potential locations for naturally occurring hydrogen gas deposits. This report briefly introduces hydrogen gas exploration, and its importance to Australia's future energy mix, outlines the methods used to identify circular morphologies, the results, discussion, and recommendations for future work. Specifically, currently available literature was reviewed that describes the observable features believed to be related to natural hydrogen seeps, the previous methods used as well as the variety of datasets previously explored. The aim was to utilise open-source data and earth observation datasets where possible, and work towards an automated detection method. The Digital Earth Australia (DEA) Water Observation dataset was found to include many of the known hydrogen related features in Western Australia and was used as a foundation for creating an identification methodology. A modified version of the water observation layer was used along with other datasets including vegetation cover, which was applied to help refine and remove features that did not meet the set criteria for naturally occurring hydrogen deposits. This resulted in the production of two datasets over the two areas of interest, identified by Geoscience Australia at the beginning of the project, and used by their teams for site selection.

The high frequency (10 min) and resolution (~2km) of Himawari-8 data provides an enormous opportunity for the monitoring and investigation of highly dynamic oceanographic phenomena. This presentation aims to demonstrate the value of himawari-8 SST data for studies of the Bonney Coast upwelling, East Australian Current (EAC) and Madden-Julian Oscillation (MJO) diurnal SST (dSST) variations. During the 2016–17 summer, we identified three distinct upwelling events along the Bonney Coast. Each event surpassed its predecessor in area of influence, minimum temperature and duration. The EAC’s mapped between July 2015 and Sept 2017 showed clear seasonal and intra-seasonal variations. During summer, the EAC and its extension frequently encroached into the coastal areas of northern NSW and eastern Tasmania. A composite analysis based on MJO phases during the summer seasons of 2015–16 and 2016–17 showed that the dSST typically peaked during phases 2 and 3 off the northwest shelf, prior to the onset of the active phases of MJO (phase 4). The analysis indicated that dSST is negatively correlated with the surface wind speed but positively correlated with short-wave latent heat flux. In future, these monitoring and analytical capabilities can be effectively implemented in Geoscience Australia’s Digital Earth Australia platform. Abstract submitted/presented to 2019 Australian Marine science Association AMSA Conference (https://www.amsa.asn.au/2019-fremantle)

1. Band ratio: (B6+B8)/B7 Blue is low content, Red is high content (potentially includes: chlorite, epidote, jarosite, nontronite, gibbsite, gypsum, opal-chalcedony) Useful for mapping: (1) jarosite (acid conditions) - in combination with ferric oxide content (high); (2) gypsum/gibbsite - in combination with ferric oxide content (low); (3) magnesite - in combination with ferric oxide content (low) and MgOH content (moderate-high) (4) chlorite (e.g. propyllitic alteration) - in combination with Ferrous in MgOH (high); and (5) epidote (calc-silicate alteration) - in combination with Ferrous in MgOH (low).

1. Band ratio: B4/B3 Blue is low abundance, Red is high abundance (1) Exposed iron ore (hematite-goethite). Use in combination with the "Opaques index" to help separate/map dark (a) surface lags (e.g. maghemite gravels) which can be misidentified in visible and false colour imagery; and (b) magnetite in BIF and/or bedded iron ore; and (3) Acid conditions: combine with FeOH Group content to help map jarosite which will have high values in both products. Mapping hematite versus goethite mapping is NOT easily achieved as ASTER's spectral bands were not designed to capture diagnostic iron oxide spectral behaviour. However, some information on visible colour relating in part to differences in hematite and/or goethite content can be obtained using a ratio of B2/B1 especially when this is masked using a B4/B3 to locate those pixels with sufficient iro oxide content.

1. Band ratio: B1/B4 Blue is low abundance, Red is high abundance (potentially includes carbon black (e.g. ash), magnetite, Mn oxides, and sulphides in unoxidised envornments Useful for mapping: (1) magnetite-bearing rocks (e.g. BIF); (2) maghemite gravels; (3) manganese oxides; (4) graphitic shales. Note 1: (1) and (4) above can be evidence for "reduced" rocks when interpreting REDOX gradients. Combine with AlOH group Content (high values) and Composition (high values) products, to find evidence for any invading "oxidised" hydrothermal fluids which may have interacted with reduced rocks evident in the Opaques index product.

Band ratio: B3/B2 Blue is low content Red is high content Use this image to help interpret the amount of "obscuring/complicating" green vegetation cover.

1. Band ratio: B13/B10 Blue is low silica content Red is high silica content (potentially includes Si-rich minerals, such as quartz, feldspars, Al-clays) Geoscience Applications: Broadly equates to the silica content though the intensity (depth) of this reststrahlen feature is also affected by particle size <250 micron. Useful product for mapping: (1) colluvial/alluvial materials; (2) silica-rich (quartz) sediments (e.g. quartzites); (3) silification and silcretes; and (4) quartz veins. Use in combination with quartz index, which is often correlated with the Silica index.

1. Band ratio: B5/B4 Blue is low ferrous iron content in carbonate and MgOH minerals like talc and tremolite. Red is high ferrous iron content in carbonate and MgOH minerals like chlorite and actinolite. Useful for mapping: (1) un-oxidised "parent rocks" - i.e. mapping exposed parent rock materials (warm colours) in transported cover; (2) talc/tremolite (Mg-rich - cool colours) versus actinolite (Fe-rich - warm colours); (3) ferrous-bearing carbonates (warm colours) potentially associated with metasomatic "alteration"; (4) calcite/dolomite which are ferrous iron-poor (cool colours); and (5) epidote, which is ferrous iron poor (cool colours) - in combination with FeOH content product (high).

<p>This dataset measures the mean decadal warming rates of the sea surface temperature (SST) in 58 Australian Marine Parks (with the exception of the Heard Island and McDonald Islands Marine Park) over the past 25 years (1992 to 2016). They are derived from the Sea Surface Temperature Atlas of the Australian Regional Seas (SSTAARS). The field of “trend_d” represents the linear SST trend for March 1992 to December 2016. The unit of the warming rates is Celsius degree/per decade. <p>This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.