Earthquake seismology

Cover......Page 1
Editor-in-Chief......Page 2
Volume Editors......Page 3
Preface......Page 4
4.01 Comprehensive Overview......Page 7
Introduction......Page 8
Earthquake Size......Page 9
Transcurrent plate boundaries......Page 13
Divergent plate boundaries......Page 15
Convergent plate boundaries......Page 20
Intraplate earthquakes......Page 21
The Largest and Deadliest Earthquakes......Page 23
Earthquake Size Distribution......Page 25
Point-Source Parameters......Page 27
Moment-Tensor Representation......Page 30
Kinematic source models......Page 31
Slip Behavior......Page 33
Brittle Failure......Page 34
Creep......Page 35
Aseismic Transients and Tremor......Page 38
Friction......Page 39
Energy Budget......Page 41
Hydrological processes......Page 42
Melting......Page 44
Fault-Zone Structure......Page 45
Borehole Observations, Fault-Zone Drilling,
and Seismicity in Mines......Page 46
State of Stress......Page 47
Earthquake Nucleation and Short-Term Earthquake Prediction......Page 49
Earthquake Forecasting......Page 50
Static Stress Triggering......Page 51
Dynamic Triggering......Page 52
Temporal Distribution of Earthquakes......Page 54
Strong Motion Prediction......Page 55
Solid Earth-Atmospheric Coupling......Page 56
Earthquake Risk Mitigation......Page 57
References......Page 59
Relevant Websites......Page 64
Introduction......Page 65
Seismic Radiation from a Point Source......Page 66
The Near Field of a Point Force......Page 67
Energy Flow from Point Force Sources......Page 68
The Green Tensor for a Point Force......Page 69
Moment Tensor Sources......Page 70
Radiation from a Point Moment Tensor Source......Page 71
A More General View of Moment Tensors......Page 72
Moment Tensor Equivalent of a Fault......Page 73
Eigenvalues and Eigenvectors of the Moment Tensor......Page 74
Seismic Radiation from Moment-Tensor Sources in the Spectral Domain......Page 75
More Realistic Radiation Model......Page 76
The Kinematic Dislocation Model......Page 77
Haskell’s model......Page 78
The Circular Fault Model......Page 79
The Kinematic Circular Source Model of Sato and Hirasawa......Page 80
Generalization of Kinematic Models and the Isochrone Method......Page 81
Crack Models of Seismic Sources......Page 82
Rupture Front Mechanics......Page 83
Stress and Velocity Intensity......Page 84
The static circular crack......Page 85
Conclusions......Page 86
References......Page 87
nomenclature......Page 89
Introduction......Page 90
Singular Crack Models......Page 91
Planar Breakdown Zone Models......Page 92
The Governing Equations......Page 94
Exact Solutions for Quasistatic Two-Dimensional Planar Cracks......Page 95
Dynamic Effects......Page 99
Fracture Energy......Page 101
Coupling between Elastodynamics and Shear Heating......Page 104
References......Page 108
Rate- and State-Dependent Friction......Page 113
Stability of Slip......Page 115
Depth Dependence of Constitutive Parameters......Page 117
Creep Events and Silent Earthquakes......Page 118
Earthquake Afterslip......Page 120
Numerical Simulations of Spontaneous Earthquake Nucleation......Page 121
Earthquake Rate Formulation......Page 122
Aftershock-rate equations......Page 124
Foreshocks......Page 126
Earthquake Triggering......Page 127
Stress Changes Estimated from Earthquake Rates......Page 130
Conclusions and Future Directions......Page 131
References......Page 132
nomenclature......Page 136
Normal Stress Reduction or Loss of Contact from Normal Interface Vibrations......Page 137
Dynamic Normal Stress Reduction from Elastic or Permeability Mismatch......Page 138
Acoustic Fluidization......Page 139
Elastohydrodynamic Lubrication......Page 140
Thermal Pressurization of Pore Fluid......Page 141

'Flash’ Heating/Melting at Asperity Contacts......Page 142
Interfacial Lubrication by Friction Melt......Page 145
Interfacial Lubrication by Thixotropic Silica Gel......Page 148
Implications of Low Dynamic Friction for Earthquake Stress Drops and for Orientations and Magnitudes of Tectonic Stress......Page 150
Conclusions......Page 151
References......Page 152
Introduction......Page 158
Early Experimental Studies......Page 159
Simulating tectonic loading......Page 161
Simulating the nucleation process......Page 162
Choosing appropriate model materials and diagnostics......Page 163
Supershear and Sub-Rayleigh to Supershear Transition in Homogeneous Fault Systems......Page 165
Purely Sub-Rayleigh and Purely Supershear Earthquake Ruptures......Page 166
The Experimental Visualization of the Sub-Rayleigh to Supershear Earthquake Rupture Transition......Page 168
A Theoretical Model for the Sub-Rayleigh to Supershear Transition......Page 169
Directionality of Ruptures along Faults Separating Weakly Dissimilar Materials: Supershear and Generalized Rayleigh Wave Speed Ruptures......Page 172
Two Types of Ruptures along Inhomogeneous Fault Systems......Page 173
Experimental Setup......Page 175
Experimental Results......Page 176
Comparison of the Experimental Results to Early Numerical and Theoretical Studies......Page 178
The Parkfield Earthquake Discussion in the Context of Experiments and of Recent Numerical Studies......Page 179
Discussion of the Historic, North Anatolian Fault Earthquake Sequenc
e in View of the Experimental Results......Page 180
Observing Crack-Like, Pulse-Like,
Wrinkle-Like and Mixed Rupture Modes in the Laboratory......Page 182
Experimental Investigation of Dynamic Rupture Modes......Page 184
Specimen configuration and loading......Page 185
Visualizing Pulse-Like and Crack-Like Ruptures in the Laboratory......Page 186
Wrinkle-Like Opening Pulses along Interfaces in Homogeneous Systems......Page 190
Discussion......Page 192
References......Page 194
nomenclature......Page 198
Introduction......Page 199
Data Preparation......Page 201
Parametrization of slip distribution......Page 203
Example of linear expression: multi-time-window method......Page 205
Example of nonlinear expression......Page 206
Calculation of Synthetic Data......Page 207
Best Estimate......Page 209
Constraints and Regularization......Page 210
Comparison in the Frequency Domain......Page 212
Example of Slip Model: The 1999 Chi-Chi Earthquake......Page 214
Characteristics of Slip Models......Page 216
Implication of Slip Models for Fault Dynamics......Page 218
Dynamic Modeling and Slip Models......Page 219
Scaling of Earthquake Heterogeneity......Page 220
Discussion and Conclusion......Page 221
References......Page 222
Relevant Websites......Page 228
Introduction......Page 229
Stress Interactions between Faults in a Homogeneous Elastic Half-Space......Page 230
Coulomb Failure......Page 231
2-D Case: Coulomb Stress on a Plane of Specified Orientation......Page 232
2-D Case: Change of Coulomb Stress on Optimally Orientated Faults......Page 233
3-D Case: Strike-Slip and Dip-Slip Conditions......Page 234
Sensitivity to the Main-Shock Focal Mechanism......Page 235
Coulomb Stress Changes and Aftershocks......Page 237
Coulomb Stress Changes Preceding the Landers Rupture......Page 238
Stress Changes Following the Landers Rupture but before the Big Bear Earthquake......Page 239
Stress Changes Caused by the Landers, Big Bear,
and Joshua Tree Ruptures......Page 240
Interactions between Large Earthquakes: Western Turkey and the Aegean......Page 241
Is It Better to Calculate Stress Transfer to Known Faults?......Page 243
Introducing Time into the Failure Criterion......Page 245
Rate- and State-Dependent Friction Equations......Page 246
Elastic Half-Space Loading Models......Page 247
Inhomogeneous Lithospheric Models - The Effects of Voids or Fissures......Page 249
Interactions between Volcanic Eruptions and Earthquakes......Page 250
Fluid Movement in Nonvolcanic Regions......Page 251
The Distribution of Small Events before Large Earthquakes......Page 252
Dynamic Triggering......Page 255
Conclusions......Page 256
References......Page 257
Relevant Website......Page 259
4.09 Dynamic Triggering......Page 260
nomenclature......Page 261
Seismic waves and dynamic stress triggering......Page 262
Evidence for Dynamic Triggering......Page 263
Widespread Evidence for Remote Dynamic Triggering in Western North America......Page 264
The MW=7.3 Landers earthquake of 28 June 1992......Page 265
The MW=7.1 Hector Mine earthquake of 16 October 1999......Page 266
The MW=7.9 Denali Fault earthquake of 3 November 2002......Page 267
Instrumental evidence from around the globe......Page 268
Triggering by solid Earth tides......Page 271
Crustal triggering......Page 272
Triggered Onsets and Delay Times......Page 274
Repeat Triggering and Recharge Times......Page 275
Dynamically Triggered Deformation......Page 278
Coulomb failure under dynamic stresses......Page 279
Subcritical crack growth......Page 282
Hydrous fluid transport: changes in permeability and pore pressure......Page 283
Magmatic fluids......Page 284
Challenges in Detecting Triggered Seismicity......Page 285
Challenges in Determining the Triggering Processes......Page 286
Conclusions......Page 287
References......Page 291
Hydrologic Response to Stress......Page 295
Poroelastic flow and deformation......Page 296
Permanent deformation......Page 297
Poroelastic deformation and fluid flow......Page 298
Liquefaction......Page 299
Water-level oscillations......Page 301
Persistent and delayed postseismic changes in water level in the near and intermediate field......Page 302
Near-field response of unconsolidated materials......Page 303
Streamflow......Page 307
Mud Volcanoes......Page 312
Geysers......Page 313
Feedback between Earthquakes and Hydrology......Page 314
Hydrologic Precursors......Page 315
References......Page 317
Introduction......Page 323
Deep Earthquake Source Properties......Page 324
Gutenberg-Richter statistics......Page 325
Isolated giant earthquakes......Page 326
Aftershock Occurrence......Page 327
Long-range triggering......Page 328
Duration of rupture......Page 329
Spatial pattern of rupture, rupture velocity,
and stress drop......Page 331
The M 8.2 1994 Bolivian earthquake......Page 334
Dehydration Embrittlement......Page 335
Anticrack Faulting in a Metastable Phase......Page 336
Thermal Shear Instability......Page 338
Thermal parameter......Page 339
Stresses and Fault Plane Solutions......Page 340
Focal mechanisms and reactivated faults......Page 341
Double Seismic Zones......Page 342
Outboard Earthquakes and Recumbent Slabs......Page 344
Viability of the Three Main Physical Mechanisms......Page 346
Notable Points and Speculations......Page 347
References......Page 349
Relevant Website......Page 352
4.12 Volcanology 101 for Seismologists......Page 353
Glossary......Page 354
Introduction to Volcanic Systems......Page 355
Melt......Page 356
Degassing......Page 357
Gas budgets......Page 358
Viscosity, Density,
and Volatile Content......Page 360
Drivers of One-Way Magma Ascent......Page 362
Drivers of Convective Magma Ascent with Return Flow......Page 363
Magma Mixing - Conditions, Evidence,
Effects......Page 364
Geospeedometers of Magma Ascent, Convection,
and Mixing......Page 365
Self-sealing in hydrothermal systems......Page 366
Volcanic Unrest......Page 367
Seismicity......Page 368
Ground Deformation......Page 370
Other Changes - Gravity, Magnetic, Electrical, Thermal,
Hydrologic......Page 371
Regional earthquakes......Page 372
Explosive versus Effusive Eruptions: Fragmentation of Magma......Page 373
Measures of Magnitude, Intensity (Volume DRE, Mass Discharge Rate, 
VEI)......Page 375
Lava flows and lava domes......Page 376
Eruption Forecasts......Page 377
Successes and false alarms......Page 378
Concentrated Sediment-Water Flows (Lahars)......Page 379
Risk Mitigation......Page 380
Future Directions......Page 381
References......Page 383
Introduction......Page 391
Signals Observed by Short-Period Seismometers......Page 392
Broadband Signals......Page 393
Description of Volcanic Seismic Sources......Page 395
Equivalent Forces of General Seismic Sources......Page 396
The Seismic Moment Tensor......Page 397
The Single Force......Page 398
Waveform Analysis of Volcanic Seismic Sources......Page 399
Slow Waves in Solid/Fluid Composite......Page 400
Resonating Sources: A Crack......Page 402
Other Resonating Sources......Page 403
Flow-Induced Oscillation......Page 404
Broadband Seismometry......Page 406
Array Analysis......Page 407
Models for Volcanic Seismic Signals......Page 408
Aso......Page 409
Kilauea......Page 410
Miyake......Page 411
Stromboli......Page 413
Explosion Quakes......Page 414
Concluding Remarks......Page 416
References......Page 417
Relevant Website......Page 422
4.14 Interaction of Solid Earth, Atmosphere, and Ionosphere......Page 423
Glossary......Page 424
Cause......Page 426
Turbulence......Page 427
Discovery......Page 428
Excitation mechanism......Page 429
Microseisms......Page 430
Source location......Page 431
The correlation technique in diffuse wavefield......Page 432
Historical Context......Page 433
Wave propagation in the atmosphere......Page 434
Frequency-wavelength domains of interest......Page 435
Surface observation: seismometer, microbarograph,
hydrophones......Page 436
High-altitude observation: ionosondes, Doppler sounding, transmission (GPS),
in situ......Page 437
Seismic waves......Page 438
Tsunami waves......Page 439
Direct atmospheric waves......Page 440
The Case of the Great Sumatra-Andaman Earthquake......Page 441
Conclusion......Page 442
References......Page 443
Seismic and Aseismic Slip at Plate Boundaries......Page 447
Afterslip......Page 450
Interseismic Slip Events......Page 451
EAS and Seismic Tremor......Page 454
Cascadia......Page 459
Southwest Japan......Page 460
Mexico......Page 462
Alaska......Page 463
San Andreas Fault......Page 464
EAS and Seismicity......Page 466
Mechanics of EAS......Page 468
Recurrence of EAS......Page 469
Acknowledgments......Page 470
References......Page 471
Introduction......Page 475
Aspects of Global Seismicity......Page 476
Recent Discoveries and Future Directions......Page 480
References......Page 483
4.17 Tsunamis......Page 484
The 2004 Indian Ocean Tsunami......Page 485
1960 Chilean tsunami......Page 487
1896 Sanriku tsunami......Page 488
1700 Cascadia tsunami......Page 489
Deep ocean measurements......Page 490
Post-tsunami surveys......Page 491
Study of Historical Documents......Page 492
Tsunami magnitude Mt......Page 493
Fault parameters and ocean-bottom deformation......Page 494
Tsunamigenic and tsunami earthquakes......Page 495
Tsunamis from Landslides......Page 496
Modeling landslide tsunamis......Page 497
Volcanic tsunamis due to landslides......Page 498
Ray-Theoretical Approach......Page 499
Basic Equations for Tsunami Propagation......Page 500
Numerical Computations......Page 501
Tsunami Warning and Hazard Reduction Systems......Page 502
Far-Field Tsunami Warning Systems......Page 503
Local Tsunami Warning Systems......Page 504
Long-Term and Probabilistic Forecast......Page 505
Tsunami Hazard Maps and Public Awareness......Page 506
References......Page 507
Relevant Websites......Page 512
4.18 Physical Processes That Control Strong Ground Motion......Page 513
What Is Strong Ground Motion?......Page 514
Amplitude of Strong Motion......Page 515
Representation Theorem......Page 517
Empirical Green’s Functions......Page 518
Synthetic Green’s Functions......Page 519
Inversions for Slip Models......Page 521
Fourier Amplitude Spectrum of the Seismic Source......Page 522
Scaling of Source Parameters......Page 523
Amplification due to the Decrease in Shear Velocity......Page 525
Refraction of Body Waves Toward Vertical Incidence......Page 527
Reflection and Transmission across Interfaces......Page 528
Resonance in Flat-Layered Low-Velocity Layers at the Surface......Page 529
Effect of Basin Edges on Incoming Body Waves......Page 530
Long Linear Valleys Acting as Waveguides......Page 531
Scattering......Page 532
Correlation and Coherency......Page 534
Effect of Topography......Page 535
Q......Page 537
Nonlinearity......Page 539
Pulse Duration and Directivity......Page 542
Predicting Ground Motion Synthetic Seismograms......Page 544
Stochastic simulations......Page 545
Empirical Green’s functions......Page 546
Synthetic Green’s functions with kinematic and dynamic sources......Page 547
Ground Motion Prediction Equations......Page 548
Future Directions for GMPEs......Page 551
Conclusions......Page 553
References......Page 554
Relevant Websites......Page 565
Paleoseismology and the Significance of Paleoearthquakes......Page 566
Recognition of tectonic deformation......Page 567
Application of geochronology......Page 568
Chronologies of Paleoearthquakes......Page 569
Surface ruptures......Page 571
Regional coseismic deformation......Page 572
Ground shaking and secondary effects......Page 574
Slip rates......Page 575
Slip per event......Page 576
Models......Page 577
Characteristic Earthquakes......Page 578
Time Predictable and Recurrence Models......Page 580
Rupture Patterns......Page 581
Uncertainty in Paleoseismic Data......Page 582
Applications and Future Directions......Page 583
References......Page 584
Frequency-Magnitude Relation and the Historical Observation Window......Page 589
Effects of Tectonics on Sites of Human Occupation, Resonant Effects,
and Vulnerability of Tells......Page 591
Communication Issues between Disciplines......Page 592
Earthquake Traces in Archeological Sites......Page 593
Elevated or submerged coastal land surfaces......Page 594
Collapsed walls with preferential axes of destruction......Page 595
Aligned fallen columns......Page 596
Slipped keystones......Page 597
Skeletons of Trapped Humans and Domestic Animals......Page 598
Fire......Page 599
Informing Archeological Methods with a Seismology Perspective......Page 600
Forensic Anthropology......Page 601
Benefits to Seismology......Page 602
References......Page 603
Introduction......Page 605
Forecasting Earthquakes at Different Spatial and Temporal Scales......Page 606
Global Seismic Hazard......Page 607
Earthquake fatalities since 1900......Page 609
Concentrations of risk......Page 611
The San Francisco Bay Area......Page 612
Future losses......Page 614
The
'Holy Grail’ of Seismology: Earthquake Prediction......Page 616
Long-Term Mitigation: Earthquake-Resistant Buildings......Page 617
Strong-motion observations......Page 618
Strong-motion simulations......Page 619
New seismic resistant designs......Page 621
The rich and the poor......Page 622
The new and the old......Page 623
Short-Term Mitigation: Real-Time Earthquake Information......Page 624
ShakeMap......Page 625
Rapid finite source modeling......Page 626
Applications of ShakeMap......Page 628
S-waves versus P-waves......Page 630
Warning around the world......Page 633
ElarmS in California......Page 634
Warning times......Page 637
Future development......Page 638
Benefits and costs......Page 639
Conclusion......Page 640
References......Page 641
Introduction - Why Drill to Study Earthquakes?......Page 646
Fault-Zone Permeability......Page 648
Chemical Effects of Fluids on Fault-Zone Rheology......Page 649
Frictional Strength of Faults......Page 650
Weak Plate-Bounding Faults......Page 651
Near-Field Observations of Earthquake Nucleation and Propagation......Page 654
Fault-Zone Drilling Projects......Page 655
San Andreas Fault Observatory at Depth......Page 656
Nojiima Fault......Page 658
Chelungpu Fault......Page 659
Gulf of Corinth......Page 660
NELSAM......Page 664
NanTroSeize......Page 665
Summary......Page 666
References......Page 667
nomenclature......Page 672
Glossary......Page 673
GR Frequency-Magnitude Scaling......Page 674
Baringth’s Law......Page 676
Omori’s Law......Page 677
Accelerated Moment Release......Page 680
Recurrence Times......Page 682
Interoccurrence Times......Page 683
Deterministic Chaos......Page 684
Criticality and Self-Organized Criticality......Page 685
Cellular Automata Models......Page 686
Numerical Simulations......Page 688
Damage Mechanics Models......Page 689
Overview......Page 691
Earthquake Forecasting (Prediction)......Page 692
References......Page 693
Relevant Website......Page 697