In-depth seismo-acoustic analysis of mining-induced Mw 4.9 Kiruna earthquake

Abstract:

The mining operations in Kiruna, Sweden caused an earthquake Mw 4.9 in 18 May 2020 early morning. According to Swedish media, the mine was immediately evacuated afterwards because of the risk of aftershocks. This event is the largest magnitude mining-induced earthquake that has ever taken place in Scandinavia and produced signals recorded by three infrasound arrays at distances of 7 km (KIR, Sweden), 155 km (IS37, Norway) and 286 km (ARCI, Norway). Our study investigates seismo-acoustic characteristic features of this event recorded in near and far-field. We focus particularly on how the signal propagated in the atmosphere and in the earth. We provide a detailed comparison between the observed and predicted wave front characteristics at the arrays. We also conduct a comparison of amplitude corrected for propagation effect versus magnitude and ground shaking amplitude. These results show that infrasound records up to ~300 km from a shallow moderate-magnitude earthquake can provide ground shaking information as well as local amplification caused by topographic and geological features.