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Extension of Gutenberg‐Richter distribution to MW −1.3, no lower limit in sight

January 1, 2009

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.

Publication Year 2009
Title Extension of Gutenberg‐Richter distribution to MW −1.3, no lower limit in sight
DOI 10.1029/2009GL038080
Authors Margaret S. Boettcher, Arthur F. McGarr, Malcolm J. S. Johnston
Publication Type Article
Publication Subtype Journal Article
Series Title Geophysical Research Letters
Index ID 70045032
Record Source USGS Publications Warehouse
USGS Organization Earthquake Science Center