Index 497
static friction, 359–60
static time correction, 145
station corrections, 424
steady state friction, 361
stereographic projection, faults, 223–8
stereonet, 223
Stevenson, D., 174n9
stick-slip earthquakes, 359–64
stishovite, 205, 208
strain
infinitesimal strain theory, 49
recording of, 404
seismic strain rate tensor, 341
strain energy, 52, 61–2
strain tensor, 38, 47–8
see also stress
strainmeters, 404, 406
Streckheisen seismometers, 404
strength, of lithosphere, 357–9
strength envelope, 357
stress
constitutive equations, 38, 48–51
deviatoric stresses, 45–6
earthquake stress drop, 269–73
elastic moduli, 49–50
field, 45–7, 345
maximum stress difference, 356
normal stress, 40, 42, 350–1, 353, 357
in oceanic lithosphere, 328–31
principal stresses, 42–3
and rock fracture, 350–4
shear stresses, 40, 43–5, 350–1
stress drop, 269–73
stress and strain tensor, 50, 177–8
stress tensor, 38, 39–42, 350
stress–strain curve, 349
viscous relaxation of, 355–6
yield stress, 349
see also strain
strike angle, 218
strike-slip fault, 45, 218, 225–7, 236, 244, 254–5,
269, 298–9, 328
string waves
calculation, 466–9
harmonic waves, 31–2, 35–6
normal modes, 36–8
reflection and transmission, 32–5
theory, 29–31
strong-motion sensors, 404, 406
STS-1 seismometer, 404
STS-2 seismometer, 404
subduction zones, 198, 286, 307–25
earthquakes, 307–8, 309–10
interplate trench earthquakes, 321–5
subduction slab earthquakes, 312–21
thermal models, 308–12
summation convention, 449
superadiabatic gradient, 201, 209
superposition, 34, 219, 377
surface force, 39
surface wave magnitude, 264
surface waves, 3, 86–93
anisotropy, 182
dispersion, 87, 93–100, 433
focal mechanisms, 235–9
geometry, 87
Lg waves, 197–8
mantle waves, 251
mode equivalence, 106–7, 109
radiation amplitudes, 236–7
waveform modeling, 235–9
see also Rayleigh wave, Love wave, tsunami
swarm, earthquake, 326, 328
sweep signals, 149–52
symmetric matrix, 458
Synthetic Aperture Radar interferometry (InSAR),
252–4
synthetic seismogram calculation, 466–9
synthetic seismograms, 111, 229
synthetic waveforms see waveform modeling
systematic errors, 391–2, 397
systematic bias, 392–3
t*, 196
take-off angle, 222
tangential motion, spheroidal modes, 110
tangential traction, 43–4, 116
Tango, Japan, earthquake (1927), 254, 256
Tangshan, China, earthquake (1976), 12,
26
tau function, 121, 138, 159
tau-p method, 137–40
tectosphere, 170
temperature
in the earth, 202–4
measuring variations, 186
tensional stress, 40, 51
tensional (T) axis, 221, 227–8
tensor
invariants, 43, 457
stress, 38–9
strain, 38, 47–8
Tericiera Rift, 326
tesseral hermonics, 104
thermal boundary layer, 170, 204, 287
thermal diffusivity, 300, 309
thermal isostasy, 301n3
thermal lithosphere, 304
thermal models, subduction, 308–12
thrust earthquakes, 321–3, 340
moment tensor, 250
thrust fault, 45, 218, 225–7, 236, 244, 328,
336
Tibet, 336–7
tides, solid earth, 373, 400
Tien Shan mountain belt, 336
time series analysis, 369
time-dependent behavior, 349–50, 355
time-frequency domain equivalence, 229, 235,
373–4
Tokyo earthquake (1923), 12, 18–19, 407
tomography, 99, 425
attenuation, 198–9
cross-borehole, 433
nonlinear, 433
whole-mantle, 433–4
see also travel time tomography
Tonga arc, 311
Tonga subduction zone, 199, 320
toroidal modes, 104
torsional modes, 104–6
total reflection, 33
total internal reflection, 67
traction vector, 39
normal traction, 44
tangential traction, 44
transfer function, 377, 379
transform faults, 286
continental, 334
spreading centers, 298, 305–7
transition zone, 162–3, 171
and deep earthquakes, 317
mineralogy, 205
velocities and density, 203
transmission coefficients
P–SV waves, 79–84
SH waves, 76–8
string waves, 33
transverse component, 57
transverse isotropy, 178–9, 208
transverse waves, 57
travel time curves
AK135, 162
earthquake location, 422–4
IASP91, 162–4
inversion, 161–2
Jeffreys–Bullen, 162
PREM, 202–3
travel time equation
dipping layer, 125
direct arrival, 120
head wave, 121
layered structure, 123
reflected wave, 121
in spherical earth, 159
travel time tables, 162–4
travel time tomography
examples, 430–4
inverse problem, 426–30
subduction zones, 311
theory, 424–6
travel times
intercept-slowness formulation, 137–40
low-velocity zone, 160–1
reflected waves, 134–7
refracted waves, 121–2
residuals, 420
seismic waves, 60–1, 119–20
spherical earth, 157–9
triplication, 160, 171
upper mantle, 171
trenches, 288
see also subduction zones
triple vector dipole, 245
triplication, 160
core, 168
upper mantle, 171
Truckee earthquake (1966), 267
tsunamis, 19–20, 241, 271
dispersion, 99–101
real-time warnings, 26
seismic sources, 241, 271
two-station method, phase velocity, 97–8
ultra-low-velocity zone (ULVZ), 174, 208
uncertainty principle, 7, 382
uniaxial tension, 51
uniformitarianism, 341n4
United States
Advanced National Seismic System (ANSS),
410
earthquake forecasting, 21
earthquake hazard map, 15, 21
earthquake risk, 13–14
National Earthquake Hazards Reduction
Program, 25
National Seismographic Network (NSN),
408
regional networks, 410
upper mantle see mantle
static friction, 359–60
static time correction, 145
station corrections, 424
steady state friction, 361
stereographic projection, faults, 223–8
stereonet, 223
Stevenson, D., 174n9
stick-slip earthquakes, 359–64
stishovite, 205, 208
strain
infinitesimal strain theory, 49
recording of, 404
seismic strain rate tensor, 341
strain energy, 52, 61–2
strain tensor, 38, 47–8
see also stress
strainmeters, 404, 406
Streckheisen seismometers, 404
strength, of lithosphere, 357–9
strength envelope, 357
stress
constitutive equations, 38, 48–51
deviatoric stresses, 45–6
earthquake stress drop, 269–73
elastic moduli, 49–50
field, 45–7, 345
maximum stress difference, 356
normal stress, 40, 42, 350–1, 353, 357
in oceanic lithosphere, 328–31
principal stresses, 42–3
and rock fracture, 350–4
shear stresses, 40, 43–5, 350–1
stress drop, 269–73
stress and strain tensor, 50, 177–8
stress tensor, 38, 39–42, 350
stress–strain curve, 349
viscous relaxation of, 355–6
yield stress, 349
see also strain
strike angle, 218
strike-slip fault, 45, 218, 225–7, 236, 244, 254–5,
269, 298–9, 328
string waves
calculation, 466–9
harmonic waves, 31–2, 35–6
normal modes, 36–8
reflection and transmission, 32–5
theory, 29–31
strong-motion sensors, 404, 406
STS-1 seismometer, 404
STS-2 seismometer, 404
subduction zones, 198, 286, 307–25
earthquakes, 307–8, 309–10
interplate trench earthquakes, 321–5
subduction slab earthquakes, 312–21
thermal models, 308–12
summation convention, 449
superadiabatic gradient, 201, 209
superposition, 34, 219, 377
surface force, 39
surface wave magnitude, 264
surface waves, 3, 86–93
anisotropy, 182
dispersion, 87, 93–100, 433
focal mechanisms, 235–9
geometry, 87
Lg waves, 197–8
mantle waves, 251
mode equivalence, 106–7, 109
radiation amplitudes, 236–7
waveform modeling, 235–9
see also Rayleigh wave, Love wave, tsunami
swarm, earthquake, 326, 328
sweep signals, 149–52
symmetric matrix, 458
Synthetic Aperture Radar interferometry (InSAR),
252–4
synthetic seismogram calculation, 466–9
synthetic seismograms, 111, 229
synthetic waveforms see waveform modeling
systematic errors, 391–2, 397
systematic bias, 392–3
t*, 196
take-off angle, 222
tangential motion, spheroidal modes, 110
tangential traction, 43–4, 116
Tango, Japan, earthquake (1927), 254, 256
Tangshan, China, earthquake (1976), 12,
26
tau function, 121, 138, 159
tau-p method, 137–40
tectosphere, 170
temperature
in the earth, 202–4
measuring variations, 186
tensional stress, 40, 51
tensional (T) axis, 221, 227–8
tensor
invariants, 43, 457
stress, 38–9
strain, 38, 47–8
Tericiera Rift, 326
tesseral hermonics, 104
thermal boundary layer, 170, 204, 287
thermal diffusivity, 300, 309
thermal isostasy, 301n3
thermal lithosphere, 304
thermal models, subduction, 308–12
thrust earthquakes, 321–3, 340
moment tensor, 250
thrust fault, 45, 218, 225–7, 236, 244, 328,
336
Tibet, 336–7
tides, solid earth, 373, 400
Tien Shan mountain belt, 336
time series analysis, 369
time-dependent behavior, 349–50, 355
time-frequency domain equivalence, 229, 235,
373–4
Tokyo earthquake (1923), 12, 18–19, 407
tomography, 99, 425
attenuation, 198–9
cross-borehole, 433
nonlinear, 433
whole-mantle, 433–4
see also travel time tomography
Tonga arc, 311
Tonga subduction zone, 199, 320
toroidal modes, 104
torsional modes, 104–6
total reflection, 33
total internal reflection, 67
traction vector, 39
normal traction, 44
tangential traction, 44
transfer function, 377, 379
transform faults, 286
continental, 334
spreading centers, 298, 305–7
transition zone, 162–3, 171
and deep earthquakes, 317
mineralogy, 205
velocities and density, 203
transmission coefficients
P–SV waves, 79–84
SH waves, 76–8
string waves, 33
transverse component, 57
transverse isotropy, 178–9, 208
transverse waves, 57
travel time curves
AK135, 162
earthquake location, 422–4
IASP91, 162–4
inversion, 161–2
Jeffreys–Bullen, 162
PREM, 202–3
travel time equation
dipping layer, 125
direct arrival, 120
head wave, 121
layered structure, 123
reflected wave, 121
in spherical earth, 159
travel time tables, 162–4
travel time tomography
examples, 430–4
inverse problem, 426–30
subduction zones, 311
theory, 424–6
travel times
intercept-slowness formulation, 137–40
low-velocity zone, 160–1
reflected waves, 134–7
refracted waves, 121–2
residuals, 420
seismic waves, 60–1, 119–20
spherical earth, 157–9
triplication, 160, 171
upper mantle, 171
trenches, 288
see also subduction zones
triple vector dipole, 245
triplication, 160
core, 168
upper mantle, 171
Truckee earthquake (1966), 267
tsunamis, 19–20, 241, 271
dispersion, 99–101
real-time warnings, 26
seismic sources, 241, 271
two-station method, phase velocity, 97–8
ultra-low-velocity zone (ULVZ), 174, 208
uncertainty principle, 7, 382
uniaxial tension, 51
uniformitarianism, 341n4
United States
Advanced National Seismic System (ANSS),
410
earthquake forecasting, 21
earthquake hazard map, 15, 21
earthquake risk, 13–14
National Earthquake Hazards Reduction
Program, 25
National Seismographic Network (NSN),
408
regional networks, 410
upper mantle see mantle