Spatio‐temporal analysis of stress diffusion in a mining‐induced seismicity system

The spatio‐temporal correlation of micro‐earthquakes occuring in a mining‐induced seismic system (Creighton mine, Ontario, Canada) is investigated. It is shown that, when considering only the after‐events correlated to a main event, i.e., not accounting for the uncorrelated regime of ‘background’ activity, the spatial distribution of these after‐events occuring at t after the main event change with t. This change takes the form of an expanding pattern, characterized by a typical scale Lc( t) varying as Lc( t) ∼ tH, H being estimated to 0.18. This diffusion exponent is found to increase when considering only a subset of the most energetic events as mainshocks. We interpret this result as the indication of a stress (sub‐)diffusion mechanism, involving propagation on the heterogeneous fractal fault network.