Developing and exploiting a unique seismic dataset from South African gold mines for source characterization and wave propagation

Abstract

In this project, the authors are developing and exploiting a unique seismic dataset to address the characteristics of small seismic events and the associated seismic signals observed at local (<200 km) and regional (<2000 km) distances. The dataset is being developed using mining-induced events from three deep gold mines in South Africa recorded on in-mine networks (<1 km) composed of tens of high-frequency sensors, a network of four broadband stations installed as part of this project at the surface around the mines (1–10 km), and a network of existing broadband seismic stations at local/regional distances (50–1000 km) from the mines. After a year of seismic monitoring of mine activity (2007), over 10,000 events in the range –3.4 < ML < 4.4 have been catalogued and recorded by the in-mine networks. Events with positive magnitudes are generally well recorded by the surface-mine stations, while magnitudes of 3.0 and larger are seen at regional distances (up to ~600 km) in high-pass filtered recordings