Abstract
With twelve years of seismic data from TauTona Gold Mine, South Africa, we show that mining-induced earthquakes follow the Gutenberg-Richter relation with no scale break down to the completeness level of the catalog, at moment magnitude MW −1.3. Events recorded during relatively quiet hours in 2006 indicate that catalog detection limitations, not earthquake source physics, controlled the previously reported minimum magnitude in this mine. Within the Natural Earthquake Laboratory in South African Mines (NELSAM) experiment's dense seismic array, earthquakes that exhibit shear failure at magnitudes as small as MW −3.9 are observed, but we find no evidence that MW −3.9 represents the minimum magnitude. In contrast to previous work, our results imply small nucleation zones and that earthquake processes in the mine can readily be scaled to those in either laboratory experiments or natural faults.
Department
Center for Coastal and Ocean Mapping
Publication Date
5-2009
Volume
36, issue 10
Journal Title
Geophysical Research Letters
Publisher Place
Washington DC, USA
Rights
Copyright 2009 by the American Geophysical Union.
Publisher
American Geophysical Union Publications
Digital Object Identifier (DOI)
10.1029/2009GL038080
Document Type
Journal Article
Recommended Citation
Boettcher, M. S., A. McGarr, and M. Johnston (2009), Extension of Gutenberg-Richter distribution to MW −1.3, no lower limit in sight, Geophys. Res. Lett., 36, L10307, doi:10.1029/2009GL038080.