%A Hiroshi Asanuma
%A Hyuma Nozaki
%A Hiroaki Niitsuma
%A D. Wyborn
%O Geothermal Resources Council 2005 Annual Meeting, September 25-28, 2005, Reno, Nevada
%J Geothermal Resources Council Transactions
%T Interpretation of microseismic events with larger magnitude collected at Cooper Basin, Australia
%X The authors analyzed the spatial and temporal distribution of the microseismic events with larger moment magnitude observed during a hydraulic stimulation at the Australian HFR site in the Cooper Basin. The seismic traces of the large events were saturated and we could not directly estimate the moment magnitude from the trace. Accordingly we estimated the moment magnitude from a combination of the duration time and the local magnitude of smaller unsaturated events. There was no clear relationship between the magnitude of the events so determined and the hydraulic records. Indeed some of the big events occurred even after shut-in. We have found that some of the big events brought very clear extension of the seismic cloud into previously seismically silent zones suggesting that some kind of hydraulic barrier was broken by the big events. The authors currently consider that the microseismic events at this site mainly originate from a slip of asperities in existing fractures. Control and prediction of the big events at this site requires further study.
%N 0193-
%K Microseimicity, HDR, HWR, EGS, stimulation, Cooper Basin, Australia,
%P 87-92
%V 29
%D 2005
%I Geothermal Resources Council
%L epos1775