Understanding the atmospheric response to seismic sources: the 2020 Mw4.9 Kiruna minequake, Sweden
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.