Activation of Seismo-Acoustic Events after Large-Scale Blasting at an Iron Ore Body of the Kursk Magnetic Anomaly

Abstract

The authors analyze weak seismic activity at the Korobkovo iron ore deposit in the area of the Kursk Magnetic Anomaly. A sensing system in use enabled recording seismic events with a magnitude from –2.5 to –1.4 induced by a large-scale blast. Localization of hypocenteres was accurate to \(\sim50\) m. The most of origins of the recorded events occurred in the neighborhood of a faulting zone across the zone of mining, and at the interface of bed series. The values of a seismic moment of the events are within of two orders of magnitude \(10^{5}{-}10^{7}\) N\(\,\cdot\,\)m at an angular origin frequency of 70–600 Hz. The estimated seismic energy ranges from 0.0006 to 1 J. The reduced seismic energy values from \(2\cdot10^{-9}\) to \(2\cdot10^{-7}\) J/(N\(\,\cdot\,\)m) and the low velocities allow categorizing the recorded events as slow earthquakes.