Carusone, O & Hudyma, M 2017, 'Variations in apparent stress and energy index as indicators of stress and yielding around excavations', in M Hudyma & Y Potvin (eds), UMT 2017: Proceedings of the First International Conference on Underground Mining Technology, Australian Centre for Geomechanics, Perth, pp. 205-218, https://doi.org/10.36487/ACG_rep/1710_16_Carusone (https://papers.acg.uwa.edu.au/p/1710_16_Carusone/) Abstract: Analysis of source parameters of microseismic events provides useful information about the rock mass response to mining. Energy index and apparent stress are source parameters that quantify relative coseismic stress adjustment. Trends in these parameters might show how mining-induced stresses change in the initial hours after a blast. Analysis of events following production blasts in a deep open stoping operation suggests that the rock mass undergoes a rapid stress increase immediately after the blast, followed by some degree of more gradual yielding. These responses vary between different stope blasts and spatially around a stope. These results may also vary with local conditions such as rock mass properties and stoping geometry. Keywords: seismic monitoring, rock mass response