AEES member Brian Gaull made a submission to the WA Government as part of their enquiry into fracking. View the full submission here, and read the introduction below.
Recordings of earthquakes over the last century have shown that mining is just one of many industrial activities that can induce large enough events to cause significant damage and death. Filling of water reservoirs behind dams, extraction of oil and gas, and geothermal energy production are examples of other industrial activities that have shown to induce earthquakes in various parts of the world.
In Western Australia, there is some historical evidence of induced seismicity following the establishment of mines and dams (see for eg Kalgoorlie Gold Mine, the Ord-River Dam). However, in the main, it has not been well documented, due to the fact that instrumentation was not installed prior to the commencement of the construction of production infrastructure. Clearly, this is critical gap, in terms of making definitive statements about whether there was a significant increase in the background seismicity that could have been attributed to operations.
Mundaring Geophysical Observatory (MGO) was the administrative centre for WesternAustralia’s state branch of Geoscience Australia’s seismic network until April, 2000. From its inception in 1959, there has been an ongoing recording of natural earthquakes and mining activities in the state. Administration of the state seismograph network was then handed over to Geoscience Australia’s headquarters in Canberra.
To properly consider the potential threat from induced earthquakes from the extraction of natural gas or oil from the Western Australian sedimentary basins, a short history of what causes the natural earthquakes in the state and a brief survey of current data collection in international aggregations and in particular areas and contexts in WA will be surveyed here for context.