Fault-zone Properties and Earthquake Rupture Dynamics

by Fukuyama

• ISBN13: 9780123744524
• ISBN10: 0123744520
• Format: Hardcover
• Copyright: 2009-03-23
• Publisher: Elsevier Science

Summary

The dynamics of the earthquake rupture process are closely related to fault zone properties which the authors have intensively investigated by various observations in the field as well as by laboratory experiments. These include geological investigation of the active and fossil faults, physical and chemical features obtained by the laboratory experiments, as well as the seismological estimation from seismic waveforms. Earthquake dynamic rupture can now be modeled using numerical simulations on the basis of field and laboratory observations, which should be very useful for understanding earthquake rupture dynamics. Features: * First overview of new and improved techniques in the study of earthquake faulting * Broad coverage * Full color Benefits: * A must-have for all geophysicists who work on earthquake dynamics * Single resource for all aspects of earthquake dynamics (from lab measurements to seismological observations to numerical modelling) * Bridges the disciplines of seismology, structural geology and rock mechanics * Helps readers to understand and interpret graphs and maps Also has potential use as a supplementary resource for upper division and graduate geophysics courses.

Table of Contents

Preface	p. xi
Foreword	p. xiii
List of Contributors	p. xv
Introduction: Fault-Zone Properties and Earthquake Rupture Dynamics	p. 1
Geometry and Slip Distribution of Coseismic Surface Ruptures Produced by the 2001 Kunlun, Northern Tibet, Earthquake	p. 15
Introduction	p. 16
Tectonic Setting	p. 18
Deformation Characteristics of the 2001 Coseismic Surface Rupture	p. 19
Geometric Distribution and Deformational Structure	p. 19
Coseismic Slip Distribution	p. 24
Measurement Method of Strike-Slip Offset	p. 24
Field Observations	p. 26
Analysis of High-Resolution Remote Sensing Images	p. 28
Seismic Inversion Results	p. 29
Discussion	p. 30
Relationship between the Coseismic Surface Rupture and Preexisting Fault	p. 30
Coseismic Strike-Slip Displacement	p. 31
Conclusions	p. 33
Aseismic-Seismic Transition and Fluid Regime along Subduction Plate Boundaries and a Fossil Example from the Northern Apennines of Italy	p. 37
Introduction	p. 38
Deformation and Seismogenesis at Accretionary and Erosive Subduction Margins	p. 40
Seismogenic Zone: Definition	p. 42
Slow Slip Events and Seismic Tremors	p. 46
Seismically Produced Structures	p. 48
The Up-Dip Limit of Seismogenesis in a Fossil Erosive Subduction Channel	p. 52
Subduction Channel Architecture	p. 53
Subduction Channel Internal Structure: A Low-Friction Plate Boundary	p. 55
Disussion and Comparison between Erosive and Accretionary Seismogenic Zones	p. 58
Conclusions and Future Perspective	p. 59
Fault Zone Structure and Deformation Processes along an Exhumed Low-Angle Normal Fault: Implications for Seismic Behavior	p. 69
Introduction	p. 70
Regional Setting	p. 71
Fault Zone Architecture	p. 73
Geometry and Kinematics	p. 73
Fault Rock Distribution and Microstructures	p. 75
Discussion	p. 78
Fault Rock Evolution	p. 78
The Mechancial Paradox of Low-Angle Normal Faults	p. 79
A Slip Model for Low-Angle Normal Faults (Evidences That ZF Was Active as LANF)	p. 80
Conclusions	p. 82
Pseudotachylytes and Earthquake Source Mechanics	p. 87
Introduction	p. 87
Pseudotachylytes	p. 89
Mesoscale Geometry of Pseudotachylyte	p. 90
Microstructures and Geochemistry in Pseudotachlytes	p. 91
Temperature Estimate of Frictional Melts	p. 93
Distribution of Tectonic Pseudotachylytes	p. 94
Production of Pseudotachylytes	p. 95
The Role of Water	p. 99
A Natural Laboratory of an Exhumed Seismogenic Source	p. 100
Rupture Dynamics	p. 104
Transient Stress Pattern	p. 104
Examples of Transient Stress Markers Observed	p. 105
Dynamic Fault Strength	p. 110
Field Estimates	p. 111
Experimental Results	p. 113
Theoretical Estimates	p. 116
Discussions and Conclusions	p. 120
A New Approach to the Study of Exhumed Pseudotachylyte-Bearing Faults	p. 123
The Critical Slip Distance for Seismic and Aseismic Fault Zones of Finite Width	p. 135
Introduction	p. 136
Friction Laws and the Transition from Static to Kinetic Friction	p. 139
Contact Model for the Critical Slip Distance of Solid Surfaces and Shear Zones	p. 140
Model for a Shear Zone of Finite Thickness	p. 143
Results	p. 146
Implications for Scaling of the Dynamic Slip Weakening Distance	p. 151
Discussion	p. 154
Scaling of Slip Weakening Distance with Final Slip during Dynamic Earthquake Rupture	p. 163
Introduction	p. 164
Rupture History from Kinematic Source Models	p. 167
Inferring Traction, Evolution	p. 169
Measuring Dc' from Peak Slip Velocity	p. 172
Measuring Dc from Inferred Traction Evolution Curves	p. 174
Scaling between Dc and Final Slip	p. 179
Discussion and Concluding Remarks	p. 180
Rupture Dynamics on Bimaterial Faults and Nonlinear Off-Fault Damage	p. 187
Introduction	p. 187
Formation of Damage Zone due to Dynamic Fault Growth	p. 191
Inference about Orientation and Distribution of Secondary Fractures	p. 191
Modeling of Generation of Tensile Microfractures	p. 193
Modeling of Dynamic Generation of Mesoscopic Shear Branches	p. 195
Effects of Damage on Earthquake Rupture in a Poroelastic Medium	p. 196
Rheology of Damage Zone	p. 197
Fault Growth on a Bimaterial Interface	p. 199
Field Observation of Faults	p. 199
Quasi-Static Features of In-Plane Tensile Crack	p. 199
Theoretical and Numerical Studies of Dynamic Fault Slip	p. 199
Regularization of an Ill-Posed Problem	p. 205
Poroelastic Bimaterial Effects on Fault Slip	p. 206
How Much Are Earthquake Ruptures Influenced by Bimaterial Effects?	p. 207
Macroscopic Parameter Affected by the Existence of Fault at Bimaterial Interface	p. 209
Concluding Remarks	p. 209
Boundary Integral Equation Method for Earthquake Rupture Dynamics	p. 217
Introduction	p. 217
Basic Equations	p. 218
General Description	p. 218
Planar Fault of Two-Dimensional Nature	p. 221
Three-and Two-Dimensional Green's Functions	p. 223
Planar Fault of Three-Dimensional Nature	p. 225
Regularization	p. 226
Hypersingularities in the Integration Kernels	p. 226
Planar Two-Dimensional Antiplane Fault	p. 227
Planar Three-Dimensional Fault	p. 228
Planar Two-Dimensional In-Plane Fault	p. 231
Isolating the Instantaneous Response Term	p. 232
Spatiotemporal Discretization	p. 233
Boundary Elements and Time Steps	p. 233
Discretizing the Equations	p. 234
Implicit Time-Marching Scheme	p. 237
Courant-Friedrichs-Lewy Condition and the Explicit Time-Marching Scheme	p. 237
Evaluating Discrete Integration Kernals	p. 239
Planar Two-Dimensional Antiplane Fault	p. 239
Planar Two-Dimensional In-Plane Fault	p. 243
Planar Three-Dimensional Fault	p. 245
Interface with the Two-Dimensional Theory	p. 247
Dealing with Nonplanar Faults	p. 248
Overview	p. 248
Evaluating Discrete Intergration Kernels	p. 250
Inventory of Available Stress Response Functions	p. 252
Linear Fault Element in a Two-Dimensional Medium	p. 252
Rectangular Fault Element in a Three-Dimensional Medium	p. 253
Triangular Fault Element in a Three-Dimensional Medium	p. 254
Numerical Modeling Studies in the Literature	p. 254
Numerical Stability	p. 255
Related Topics	p. 256
Fracture Criterion	p. 256
Formulation in the Fourier and Laplace Domains	p. 257
Displacement Discontinuity BIEM	p. 258
Fault Opening	p. 258
Faults in a Half-Space	p. 260
Galerkin Method	p. 262
Conclusion	p. 263
Dynamic Rupture Propagation of the 1995 Kobe, Japan, Earthquake	p. 269
Introduction	p. 269
Computation Method	p. 272
Fault Model	p. 273
Computation Results	p. 275
Discussion and Conclusion	p. 277
List of Abbreviations	p. 285
Index	p. 289
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