Abstract
A total of 1503 events for a 2-month period associated with am N 2.6 rockburst is investigated for possible space-time correlations between low magnitude (−1.1 to −0.4)b values and several estimates of stress (static stress drop, apparent stress, and dynamic stress). Spatial variations of decreasingb values were found to be well correlated with increasing stress release estimates for time intervals prior to the rockburst and following the aftershock sequence. The strongest correlation tob value was with the dynamic stress drop, having correlation coefficients of 0.87 and 0.79 for the two intervals, respectively. The rockburst was found to actually occur at the intersection of the spatial coordinates corresponding to the largest gradient inb value. Based on these correlations, we conclude that the low magnitude seismicity is an indicator of the stress state within the rock mass, and can be used to study and forecast stress patterns in the vicinity of an impending major event. Time variations, however, did not show the same clear correlations and these are discussed in terms of departure from steady state conditions. Regardless, our results favour the use ofb values in a spatial, context rather than in a time analysis approach, and we consider thatb values provide valuable information regarding the changing stress conditions within the seismogenic volume.
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References
Brune, J. N. (1970),Tectonic Stress and the Spectra of Seismic Shear Waves from Earthquakes, J. Geophys. Res.75, 4997–5009. Correction in J. Geophys. Res.76, 5002, 1971.
Falls, S. (1986),A Study of Seismic Properties of Rock Samples from Falconbridge, Strathcona Mine, Internal Res. Report, Queen's University, Kingston, Canada #RP001NSERC, 25 pp.
Gendzwill, D. J., andPrugger, A. F.,Algorithms for micro-earthquake locations. InProc. 4th Symp. on Acoustic Emissions and Microseismicity (Pennsylvania State University University Park 1985), pp. 601–615.
Hanks, T. C., andKanamori, H. (1979),A Moment Magnitude Scale, J. Geophys. Res.84, 2348–2350.
Kanamori, H.,The nature of seismicity patterns before large earthquakes. InEarthquake Prediction: An International Review (eds. Simpson, D. W., Richards, P. G.) (Maurice Ewing Series, vol. 4, AGU, Washington D.C. 1981), pp. 1–19.
Madariaga, R. (1976),Dynamics of an Expanding Circular Fault, Bull. Seismol. Soc. Am.66, 639–666.
McGarr, A. (1991),Observations Constraining Near-source Ground Motion Estimated from Locally Recorded Seismograms, J. Geophys. Res.96, 16495–16508.
Nuttli, O. N. (1973),Seismic Wave Attenuation and Magnitude Relations for Eastern North America, J. Geophys. Res.78, 876–885.
Scholz, C. H., andAviles, C. A.,The fractal geometry of fault and faulting. InEarthquake Source Mechanics (eds. Das, S., Boatwright, J., and Scholz C. H.) (Maurice Ewing Ser., vol. 37, AGU, Washington D.C. 1986), pp. 147–155.
Snoke, J. A. (1987),Stable Determination of (Brune) Stress Drops, Bull. Seismol. Soc. Am.77, 530–538.
Thurber, C. H. (1985),Nonlinear Earthquake Location: Theory and Examples, Bull. Seismol. Soc. Am.75, 779–790.
Trifu, C-I., Urbancic, T. I., andYoung, R. P. (1993),Non-similar Frequency-magnitude Distribution for M<1 Seismicity, Geophys. Res. Lett., in press.
Trifu, C-I., andRadulian, M. (1991),The Frequency-magnitude Distribution of Earthquakes in the Vrancea Region: Relevance for a Discrete Model, J. Geophys. Res.96, 4601–4611.
Urbancic, T. I., Young, R. P., Bird, S. C., andBawden, W.,Microseismic source parameters and their use in characterizing rock mass behaviour: Considerations from Strathcona mine. InProc. 94th AGM (Canadian Institute of Mining, Montreal, Canada 1992), pp. 36–47.
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Urbancic, T.I., Trifu, CI., Long, J.M. et al. Space-time correlations ofb values with stress release. PAGEOPH 139, 449–462 (1992). https://doi.org/10.1007/BF00879946
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DOI: https://doi.org/10.1007/BF00879946