An improved method for seismic moment tensor inversion of acoustic emissions through assessment of sensor coupling and sensitivity to incidence angle

Published on Jan 1, 2014in International Journal of Rock Mechanics and Mining Sciences4.151
· DOI :10.1016/J.IJRMMS.2013.11.005
Grzegorz Kwiatek23
Estimated H-index: 23
Elli-Maria Christodoulos Charalampidou8
Estimated H-index: 8
+ 1 AuthorsSergei Stanchits24
Estimated H-index: 24
1. IntroductionAE analysis is frequently used in laboratory experiments asa method to describe the spatio-temporal evolution of damage.Furthermore, characterization of the AE sources provides insightinto the micromechanical processes involved in the initiation andcoalescence of cracks in rock samples [1]. AE source mechanismanalysis provides additional information on the orientation andmechanisms of individual cracks during nucleation and formationof a fracture [2]. Simple techniques estimating the faultingmechanisms are based on average polarities [3] using dilatationaland compressional first P-wave motions. This allows separatingrecorded AEs into tensile, shear and compaction sources. Themoment tensor (MT) represents a measure of the deformation inthe seismic source [4]. It is commonly used to provide informationon fault plane parameters (strike, dip and rake of the fault). Thedecomposition of the MT allows estimating the ratio of the volu-metric and non-volumetric strain in the seismic source e.g. [5]. TheMT inversion carries information on non-double couple (NDC) anddouble-couple (DC) components in earthquake sources, providinginformation onprocesses involved influid-induced seismicity[6–10]and mining-induced seismicity [11–13]. Collins et al. [14] investi-gated the source mechanisms of seismic events related to fracturingof tunnel walls. Sixteen AE sensors (frequency band 40–400 kHz)were used to calculate seismic MTs of extremely small seismicevents (M
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