Comparison of polarity and moment tensor inversion methods for source analysis of acoustic emission data

Seismic moment tensors of acoustic emissions recorded during laboratory rock deformation experiments: sensitivity to attenuation and anisotropy

“…Graham et al (2010) further compared the moment tensor inversion with the polarity methods developed by Zang et al (1998) and found a concurrent set of results from both methods, similar to what was recently observed by Charalampidou et al (2015). However, moment tensor inversion provides more detailed information about the fracture process in the source.…”

“…They display source mechanisms similar to natural earthquakes (Ohtsu 1991;Lockner 1993;Graham et al 2010;Kwiatek et al 2011;Aker et al 2014) but their size is different. AEs are much smaller and radiate much higher frequencies (e.g.…”

Rupture Cascades in a Discrete Element Model of a Porous Sedimentary Rock

“…Starting from the level of single particles of porous granular media, rupture cascades and scaling laws both emerge spontaneously in the competition between realistic structural disorder and the interactions and correlations that arise from external dynamic loading and internal stress redistribution. Our approach quantitatively reproduces the observed scaling laws of crackling noise remarkably well without tuning [9,10,20], including those of parameters such as burst energy and duration not available to lattice-based models.In the model, cylindrical samples are constructed by sedimenting spherical particles in a container. Figure 1(a) illustrates that particles fall one by one on the top of the growing particle layer and dissipate their kinetic energy by colliding with other particles and also with the container wall.…”

“…Such failure is often preceded by detectable changes in mechanical properties (stress and strain) and in geophysical signals (elastic wave velocity, electrical conductivity, and acoustic emissions) measured remotely at the sample boundary [9]. In particular, acoustic emissions result from sources of internal damage due to sudden local dislocations in the form of tensile or shear microcracks whose origin time, location, orientation, duration, and magnitude can all be inferred from the radiated wave train [10]. Typically, only a very small proportion of the microcracks revealed by destructive thin sectioning after the test result in detectable acoustic emissions [11].…”

HybridMT: A MATLAB/Shell Environment Package for Seismic Moment Tensor Inversion and Refinement

“…The resolved MTs are typically decomposed into volumetric and deviatoric components, using various decomposition schemes allowing for an understanding of the detailed physical kinematic source processes, regardless of the type of seismicity and event magnitude. The MT inversion has been applied to resolve the displacements in the source for large and small natural earthquakes (Vavryčuk et al, 2008;Scognamiglio et al, 2010;, induced microseismicity (Ross et al, 1996;Panza and Saraò, 2000;Šílený and Milev, 2006;Cesca et al, 2013;Guilhem et al, 2014;Johnson, 2014a,b), as well as for acoustic emission activity measured in situ (Manthei et al, 2001;Collins et al, 2002) or in laboratory experiments on rocks samples (Sellers et al, 2003;Thompson et al, 2009;Graham et al, 2010;Charalampidou et al, 2011;Kwiatek, Goebel, and Dresen, 2014). The analysis of seismic MTs sheds light on numerous issues of earthquake physics, such as rupture dynamics (McGarr and Fletcher, 2003;McGarr et al, 2010), fault complexity (McLaskey and Glaser, 2011;McGarr, 2012), the role of pore pressure in seismogenic processes (Fischer and Guest, 2011), and damage-related radiation of seismic energy (Ben-Zion and Ampuero, 2009;Castro and Ben-Zion, 2013, among others).…”