title: A landform sub-circular depression study in western NSW
Creators: name: C., Boreham
name: C., Fisk
name: C., Boreham
name: K., Czado
name: E., Black
name: M., Seehaber
name: G., Kennedy
name: F., Yuan
Publisher: name: Commonwealth of Australia (Geoscience Australia)
Year: 2024
Subjects: subject: EFTF – Exploring for the Future
subject: Strategic Innovation Reserve Fund (SIRF)
subject: Natural hydrogen
subject: Gas seepage
subject: Remote Sensing
subject: Sub-circular depressions
subject: EARTH SCIENCES
subject: Published_External

description: 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.