Seismic risks of Karoo fracking require monitoring – scientists
Publish date: 09 January 2018
Issue Number: 538
Diary: Legalbrief Environmental
The SA Government is looking into fracking to reduce the country’s huge reliance on coal for energy, write Andrzej Kijko, director of the Natural Hazard Centre, University of Pretoria, and Surina Esterhuyse, a lecturer at the Centre for Environmental Management, University of the Free State, in an analysis on The Conversation site. ‘A few studies have been done for government on the potential for shale gas in the country. These include a report on the technical readiness for a shale gas industry, a strategic environmental assessment on shale gas and a multi-authored academic book on hydraulic fracturing in the Karoo. Government must now integrate this information into policy and develop regulations for the fracking industry,’ they note. ‘Our research set out to look at the link between earthquakes and fracking,’ they explain. ‘It formed part of the vulnerability mapping for fracking in SA. Seismic hazards in SA are not high by international norms. But there could be significant damage to infrastructure if seismicity increases,’ they write. ‘Both extraction and underground injection of fluids have been shown to cause earthquakes,’ they state. ‘The effect of fracking on the local seismic region can be measured by analysing the seismicity before, during, and after the fracking process,’ they explain. ‘But there is little knowledge on geological information for the Karoo region where fracking has been proposed. This means that potentially dangerous faults in the region may go undetected. It’s important to get more geological and tectonic information as well as data about the degree and depths of the proposed fracking process in the region. This could tell us what seismic effect to expect as a result of fracking,’ they argue. ‘We must monitor local seismic activity before fracking starts to create a baseline for the specific site and surrounding areas. Seismic monitoring before exploration will aid in identifying the location of faults and the stress field nature in areas where it is currently unknown. This, linked with seismic monitoring during and after fracking, can help scientists perform reliable risk assessments to assist with proper regulation,’ conclude Kijko and Esterhuyse.