Reference:
A. Turquet, Q. Brissaud, et al. Understanding the atmospheric response to seismic sources: the 2020 Mw4.9 Kiruna minequake, Sweden. Geophysical Research Letters (in review, 2023)
A minequake of magnitude Mw4.9 occurred on 18 May 2020 early in the morning at the LKAB underground iron ore mine in Kiruna, Sweden. This is the largest mining-induced earthquake in Scandinavia. It generated acoustic signals observed at three infrasound arrays at 9.3 (KRIS, Sweden), 155 (IS37, Norway), and 286 km (ARCI, Norway) distance. Using regional seismic data, we performed a moment-tensor inversion highlighting that this event was dominated by a shallow-depth collapse in agreement with in-mine seismic station data. This was further confirmed by full waveform modelling within a coupled Earth-atmosphere model at local and regional distances using full moment tensor sources. Discrepancies between epicentral location from regional seismic inversion and simulated acoustic data indicate that local pressure records can help further constraining a seismic event location. Numerical simulations demonstrate a potential of using local and regional infrasound data to constrain focal mechanism and depth. Below, is the preprint in pdf format: