The Mechanism of Induced Seismicity

Vol. t59. 2002 J damaged zone on the rock mass. Collins el al. examine the benefits of employing small-scale microseismic and acoustic emission systems to investigate the temporal fracture mechanics of microcrack formation associated with a tunnel sealing experiment at the Underground Research Laboratory nuclear waste test site in Canada. They associate microseismic events with clusters of acoustic emissions and outline that both types of sources are generally characterized by deviatoric failure components. Using the same experimental setup, Hazzard el al. employed a bonded particle model to simulate shear microfraclures induced by the lunnel excavation. Comparing Ihe modeling results with information provided by the moniloring of microseismicity and acoustic emissions, the authors identify similarities in both the presence of foreshocks associated with macro-slip events, and the pallerns of energy release during loading. Hildyard and Young allempt to model the seismic wave interaction with fractured rock surrounding underground openings, through exper iments such as a rockbursl simulation, in situ events generating acoustic emissions, and laboratory fractures. Their results highlight that realistic wave modeling around openings requires the presence of a stress-dependent fracture stiffness coupling the surfaces of the fracture. Ultrasonic attenuation tomography and enhanced velocity tomography were studied by D~bski and Young for an earlier laboratory experiment of thennally induced fractures in granite.

Inhalt
Seasonal Seismicity of Northern California Before the Great 1906 Earthquake.- Post-seismic Effects of an M 7.2 Earthquake and Microseismicity in an Abandoned, Flooded, Deep Mine.- Microseismicity Induced by Heavy Rainfall Around Flooded Vertical Ore Veins.- Moment Tensor Inversion of Regional Phases: Application to a Mine Collapse.- Source Time Function of Seismic Events at Rudna Copper Mine, Poland.- Reliability of Seismic Moment Tensor Inversions for Induced Microseismicity at Kidd Mine, Ontario.- Effect of the Rock Properties on Mining-induced Seismicity Around the Ventersdorp Contact Reef, Witwatersrand Basin, South Africa.- The Assessment of Damage Around Critical Engineering Structures Using Induced Seismicitiy and Ultrasonic Techniques.- High-resolution Mechanics of a Microearthquake Sequence.- Simulation of Unstable Fault Slip in Granite Using a Bonded-particle Model.- Modelling Seismic Waves Around Underground Openings in Fractured Rock.- Tomographic Imaging of Thermally Induced Fractures in Granite Using Bayesian Inversion.- A Simple Analogue Experiment to Account for Power-law and Exponential Decays of Earthquake Sequences.- Induced Microearthquake Patterns in Hydrocarbon and Geothermal Reservoirs: Six Case Studies.- Seismological Studies of a Fluid Injection in Sedimentary Rocks, East Texas.- Production-induced Normal Faulting in the Valhall and Ekofisk Oil Fields.- An Application of Induced Seismicity Data Analysis for Detection of Spatial Structures and Temporal Regimes of Deformation Processes in Hydrocarbon Fields.- Application of Kalman Filtering Techniques for Microseismic Event Detection.- Near-surface Microearthquakes at The Geysers Geothermal Field, California.- Determination of Stress State from Focal Mechanisms of Microseismic Events Induced During Hydraulic Injection at the Hijiori Hot Dry Rock Site.- Detailed Fracture System of the Soultz-sous-Forêts HDR Field Evaluated Using Microseismic Multiplet Analysis.- Evaluation of Subsurface Structure at Soultz Hot Dry Rock Site by the AE Reflection Method in Time-frequency Domain.- Using Automated, High-precision Repicking to Improve Delineation of Microseismic Structures at the Soultz Geothermal Reservoir.- Reservoir-induced Seismicity in Brazil.