This Geoscience Australia Record documents the scientific analysis undertaken, and results obtained from geodetic monitoring during the Camden Environmental Monitoring Project (CEMP); a collaborative project undertaken with the New South Wales Department of Planning, Industry and Environment. The aim of the CEMP was to determine the environmental impacts, if any, of active coal seam gas extraction projects in New South Wales. Geodetic monitoring, using satellite radar interferometry (InSAR) and Global Positioning System (GPS) measurements, was used to specifically assess if subsidence (downward vertical land movement) is occurring at the Camden Gas Project; at the time the State’s only actively producing coal seam gas project. To address this question, Geoscience Australia undertook a comprehensive InSAR analysis using data sets from three orbiting radar satellites (ALOS, Envisat and Radarsat-2) covering two periods of time (2006 to 2010, and 2015 to 2019). The outputs of this InSAR analysis are vertical and horizontal ground surface displacement and velocity map products, together with a quantification of the uncertainty of these measurements. Furthermore, a new network of 20 ground geodetic monitoring sites was established in May and June 2016 for the purpose of validating measurements made using InSAR. GPS data was collected at these monitoring sites between July 2016 and June 2019 and processed to obtain 3-dimensional ground surface displacement and velocity measurements. From the analysis of independent InSAR and GPS data sets undertaken during the CEMP, we conclude that no measurable subsidence (i.e. a land movement velocity not greater than 10 mm/yr) has occurred as a result of coal seam gas production in the Camden Gas Project during the time periods of monitoring. However, decimetre-scale horizontal and vertical surface movements have occurred in the Southern Coalfields at the locations of subsurface longwall coal mines. Comparison of the measurements made by InSAR and GPS across the 20-site geodetic monitoring network shows that the two independent geodetic techniques agree within 10 millimetres, even when decimetre-scale movement is occurring. This demonstrates the potential for utilising InSAR for accurate remote monitoring of ground surface movements (including subsidence) at large scales and in the absence of sufficient ground geodetic monitoring infrastructure. The conclusions drawn and the measurements made in this work are specific to the area covered by the CEMP geodetic monitoring project, and are therefore not applicable to other resource extraction activities in other areas because of operational and geological differences from site to site. However, the methods described herein would be applicable to monitoring other resource extraction activities.

The Australian Government is investing in a world first analysis platform for satellite imagery and other Earth observations. From sustainably managing the environment to developing resources and optimising our agricultural potential, Australia must overcome a number of challenges to meet the needs of our growing population. Digital Earth Australia (DEA) will deliver a unique capability to process, interrogate, and present Earth observation satellite data in response to these issues. It will track changes across Australia in unprecedented detail, identifying soil and coastal erosion, crop growth, water quality, and changes to cities and regions. DEA will build on the globally recognised innovation, the Australian Geoscience Data Cube1; which was the winner of the 2016 Content Platform of the Year at the Geospatial World Leadership Awards and was developed as a partnership between GA, CSIRO and the National Collaborative Research Infrastructure Strategy (NCRIS) supported National Computational Infrastructure (NCI).

<p>A methane (CH4) and carbon dioxide (CO2) release experiment was held from April – June 2015 at the Ginninderra Controlled Release Facility in Canberra, Australia. The experiment provided an opportunity to compare different emission quantification techniques against a simulated CH4 and CO2 point source release, where the actual release rates were unknown to the participants. This dataset contains quality controlled 5 minute averaged CH4 concentration and meteorlogical data from 21 May to 12 June for 4 Eddy Covariance towers, 1 scanning Boreal laser, 2 scanning FTIR instruments and 2 Picarro towers. <p>This dataset accompanies the article: Cartwright, L., Zammit-Mangion, A., Bhatia, S., Schroder, I., Phillips, F., Coates, T., Neghandhi, K., Naylor, T., Kennedy, M., Zegelin, S., Wokker, N., Deutscher, N. and Feitz, A. (2019) Bayesian atmospheric tomography for detection and estimation of methane sources: Application to data from the Ginninderra 2015 release experiment, Atmospheric Measurement Techniques (submitted) <p>Dataset citation: <p>Feitz, A., Schroder, I., Phillips, F., Coates, T., Neghandhi, K., Bhatia, S., Naylor, T., Kennedy, M,. Zegelin, S., Wokker, N., Deutscher, N.M., Cartwright, L. and Zammit-Mangion, A. (2019) The 2015 Ginninderra CH4 and CO2 release experiment: Fixed and scanning sensor dataset, Geoscience Australia, DOI: http://dx.doi.org/10.26186/5cb7f14abd710