Page 233 - Global Tectonics

(a)
GARLOCK FAULT Mojave
Dry lakes N

SAN
Desert

ANDREAS
Line 1
Central FAULT
SAN
Santa 6.7b
Clarita Valley San ZONE
Transverse
Santa Susana
Mts GABRIEL
SSF
Gabriel
SF FAULT
MHF Ranges
6.7a NHF SMFZ 5.8 Mts
San Fernando
VF
Valley RF
Santa Monica Mts San Gabriel SMFZ
HF Valley
MCF SMoF Los
Santa Angeles 5.9 Puente
Monica NEWPORT – INGLEWOOD Hills WHITTIER FAULT 34˚N
Los Angeles Basin

Peninsular

California
Area Pacific Ocean FAULT 6.3 Ranges
of map 118˚W
km
0 10 20 30 40 50 60 70
San San
Puente Sierra San Andreas
(b) Hills Whittier Madre Gabriel Gabriel Mojave
Mts
Fault Fault Fault Fault Fault Desert
0 2 5 5 0
3 4 6 5.95 5.0 5
6.05 6.1 6.3 6.15
5.9
Depth (km) 10 6.1 ? 5.9 ? 5.8 5.9 5.8 6.3 wide-angle 10
5
6.8
Mojave
San Gabriel
20
Line 1 6.7 bright reflective zone 6.7 reflections V.E. 1:1 20
Reflector discontinuity 6.3
6.5
100
0 10 20 30 40 50 60 70 80 90 6.3 110 120 130
30 7.8 7.8 M 7.8 30
Distance (km)
M

Figure 8.8 (a) Shaded relief map and (b) seismic profile of the Central Transverse Ranges, southern California showing
faults (thin black lines, dotted where buried), shotpoints (gray circles), seismographs (thick black line), and epicenters
of earthquakes greater than M = 5.8 since 1933 (images provided by G. Fuis and modified from Fuis et al., 2003, with

permission from the Geological Society of America). Focal mechanisms with attached magnitudes: 6.7a, Northridge
(Hauksson et al., 1995); 6.7b, San Fernando (Heaton, 1982); 5.9, Whittier Narrows (Hauksson et al., 1988); 5.8, Sierra
Madre (Hauksson, 1994); 6.3, Long Beach (Hauksson, 1987). HF, Hollywood Fault; MCF, Malibu Coast Fault; MHF,
Mission Hills Fault; NHF, Northridge Hills Fault; RF, Raymond Fault; SF, San Fernando surface breaks; SSF, Santa Susana
Fault; SmoF, Santa Monica Fault; SMFZ, Sierra Madre Fault Zone; VF, Verdugo Fault. In (b) gray area represents
−1
−1
refraction coverage, thin black lines represent velocity contours or boundaries; contour interval 0.5 km s to 5.5 km s
−1
and arbitrary above 5.5 km s . Large numbers on either side of the San Andreas Fault are average basement velocities.