Retrieving Seismic Source Characteristics Using Seismic and Infrasound Data: The 2020 ML 4.1 Kiruna Minequake, Sweden

• Published in: Geophysical Research Letters
• Main Authors: Antoine Turquet, Quentin Brissaud, Celso Alvizuri, Sven Peter Näsholm, Alexis Le Pichon, Johan Kero
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2024
• Subjects: infrasound; earthquake; seismo‐acoustic; source inversion; simulations; Geophysics. Cosmic physics; QC801-809; Kiruna
• Online Access: https://doi.org/10.1029/2024GL109276; https://doaj.org/article/70b81d338ea047b085e4a8158d4b3728

Abstract A minequake of magnitude ML 4.1 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. We perform full‐waveform focal mechanism inversion based on regional seismic data and local infrasound data. These independently highlight that this event was dominated by a shallow‐depth collapse in agreement with in‐mine seismic station data. However, regional infrasound data cannot inform the inversion process without an accurate model of atmospheric winds and temperatures. Yet, our numerical simulations demonstrate a potential of using local and regional infrasound data to constrain an event's focal mechanism and depth.