b'Geophysics in the surveysNewsGeological Survey of Victoria: Onshore conventional gas industry in Victoria restarts and new 3D models availableOnshore conventional gas industrygravity and gravity gradiometry surveyagainst these new gravity data using in Victoria restarts (Full Spectrum Falcon) over the on- anda 3D forward modelling and inversion near-shore Otway Basin (Figure 1, Carterapproach (Figure 2, McLean etal., 2021). The restart of Victorias onshoreetal., 2019). See Preview 201 for location. The geometries of geological bodies conventional gas industry commencedThe 3D geometries of geologicaland structures were constrained using on 1 July 2021. The restart follows threestructures were tested quantitativelya variety of datasets including density years of detailed scientific investigations by the Victorian Gas Program (VGP) to scientifically understand the potential for new onshore conventional gas discoveries and the risks, benefits and impacts of allowing the industry to continue.The results indicate that there are likely to be commercially feasible onshore conventional gas resources yet to be discovered in the Otway and Gippsland basins (see Preview 205 for locations). Regional environmental studies undertaken by the programme showed that developing these gas resources would not compromise the states groundwater supplies or agricultural sector.The programmes geoscientific investigations concluded in early 2020 and nearly 70 VGP technical reports are available from Earth Resources Publications at www.earthresources.vic.gov.au/geology-exploration/maps-reports-data and throughFigure 1.Map showing Full Spectrum Falcon terrain corrected (1.80 g/cc) vertical gravity results (gD) from the Otway Basin Airborne Gravity Survey.the programmes webpages www.earthresources.vic.gov.au/projects/victorian-gas-program. A couple of examples are provided below:New 3D geological framework models for Otway and Gippsland basinsNew regional 3D geological framework models have been built for the Otway (Romine etal., 2020) and Gippsland (Powell etal., 2020) basins using existing seismic and well data held by the Geological Survey of Victoria (GSV). A new velocity model was subsequently developed for the Otway Basin (Dunne & Boyd, 2020), extending the depth converted 3D geological framework model to the west and south across the Penola Trough and to the base of the continental slope.3D modelling of Otway Basin airborne gravity data incorporates basement structures and the MohoAs part of the VGP, the Geological SurveyFigure 2.Discretised basement and basin model showing all geological units with forward model, of Victoria (GSV) conducted an airborneobserved and residual gravity response below.AUGUST 2021 PREVIEW 28'