Meyer, S, Durham, C & Falmagne, V 2024, 'Advanced seismological analysis of a complex seismic event at LaRonde mine', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 355-372, https://doi.org/10.36487/ACG_repo/2465_18
(https://papers.acg.uwa.edu.au/p/2465_18_Meyer/)
Abstract: The LaRonde mine has been in continuous operation since 1988, with mining undertaken from near surface to a current depth of 3,260 m, and reserves and resources extending deeper. Over the past decade mininginduced seismicity at great depths has become a significant challenge at LaRonde. Strategic and tactical control measures have been successfully implemented to manage seismic risks and promote a safe working environment. As mining progresses ever deeper, the enhanced analysis of seismic data can support a more comprehensive understanding of the increased dynamic responses of rock masses and structural behaviours subject to varying stresses and deformations induced by mining. This advanced understanding is needed to continue to improve the mine design, optimise ground support schemes and plan the ore extraction sequence, thereby contributing to the management of seismic risk.
In August 2023 the mine experienced a significant seismic event around the 317–320 levels of the East mine. Bulking and excavation damage were observed in multiple locations, some away from the initially processed event location. An advanced seismic analysis was undertaken to help understand and explain the processes and observations associated with the event. Seismic data from a regional network on the surface was combined with that from the in-mine system to improve seismic source parameter estimates. The recorded waveforms contain multiple phases, indicating a complex event driven by more than a single failure mechanism occurring over an extended volume. A finite source inversion was undertaken to provide a more realistic description of the source process, how it is distributed in space and how it evolved in time. The findings illustrate that large seismic events in mines need to be considered as regions of deformation where the failure mechanisms can vary and that traditional approaches, such as a point source approximation and peak ground velocity-focused analyses, are inadequate for such scenarios.

Keywords: seismicity, rockburst, moment tensor, finite source inversion, mining-induced seismicity