Appendix B- Ground Motion Spectra

For a few of the substation sites listed in the database, site recordings were available. When possible, ground motions from these recordings were included in the database. For the sites where instrumental recordings were not available, ground motion spectra based on event specific attenuation relations modified with residuals at nearby sites (Somerville and Smith, 1999) or based on the work of Abrahamson and Silva (1997) were used as the best estimate of ground motion at the site.

The spectra (5% damping) generated by Somerville and Smith and used in this study are listed in Table B.1. Spectra can be viewed in Adobe Acrobat by clicking on the links for each substation.

 Table B.1 List of Ground Motion Spectra in Appendix B
Substation Owner North Latitude West Latitude Strong Motion Record at Site Source of Spectrum
Coalinga Earthquake
SS#12
PG&E
36.140
120.125
No
Abrahamson and Silva, 1997 attenuation
Landers Earthquake
SS#5
SCE
34.87
116.85
Yes
recording
Loma Prieta Earthquake
SS#24
PG&E
37.225
121.741
No
event specific attenuation, Somerville and Smith
SS#25
PG&E
37.328
122.077
No
event specific attenuation, Somerville and Smith
SS#26
PG&E
36.810
121.755
No
event specific attenuation, Somerville and Smith
SS#28
PG&E
37.501
121.986
No
event specific attenuation, Somerville and Smith
SS#39
PG&E
37.583
122.318
No
event specific attenuation, Somerville and Smith
Morgan Hill Earthquake
SS#20
PG&E
Not Available
.
.
.
SS#21
PG&E
37.053
121.022
No
Abrahamson and Silva, 1997 attenuation
SS#24
PG&E
37.225
121.741
No
Abrahamson and Silva, 1997 attenuation
North Palm Springs Earthquake
SS#7
SCE
33.93
116.58
Yes
recording
Northridge Earthquake
SS#3
LADWP
34.586
118.656
No
event specific attenuation, Somerville and Smith
SS#31
SCE
34.44
118.58
Yes
recording
SS#34A
LADWP
34.176
118.360
Yes
recording
SS#34
LADWP
34.281
118.479
Yes
recording
SS#35
LADWP
Not Available
.
Yes
recording
SS#36
LADWP
34.229
118.545
No
event specific attenuation, Somerville and Smith
SS#37
LADWP
Not Available
.
.
.
SS#38
LADWP
34.178
118.543
No
event specific attenuation, Somerville and Smith
SS#41
SCE
34.42
118.58
No
event specific attenuation, Somerville and Smith
SS#47
LADWP
34.312
118.481
Yes
recording
SS#44
LADWP
34.311
118.490
Yes
recording
SS#45
SCE
34.49
118.12
Yes
event specific attenuation, Somerville and Smith
Point Mugu Earthquake
SS#40
SCE
34.30
119.18
Yes
Abrahamson and Silva, 1997 attenuation
San Fernando Earthquake
SS#1
SCE
33.77
118.10
No
event specific attenuation, Somerville and Smith
SS#8
SCE
34.16
118.18
No
event specific attenuation, Somerville and Smith
SS#18
SCE
33.98
118.15
No
event specific attenuation, Somerville and Smith
SS#19
SCE
33.88
118.18
No
event specific attenuation, Somerville and Smith
SS#23
SCE
34.04
118.10
No
event specific attenuation, Somerville and Smith
SS#41
SCE
34.42
118.58
No
event specific attenuation, Somerville and Smith
SS#45
SCE
34.49
118.12
No
event specific attenuation, Somerville and Smith
Santa Barbara Earthquake
SS#13
SCE
34.47
119.89
Yes
recording
Sierra Madre Earthquake
SS#14
SCE
34.151
118.088
No
Abrahamson and Silva, 1997 attenuation
Tejon Ranch Earthquake
SS#9
SCE
Not Available
.
Yes
recording
Whittier Narrows Earthquake
SS#1
SCE
33.77
118.10
No
event specific attenuation, Somerville and Smith
SS#4
SCE
33.93
118.11
No
event specific attenuation, Somerville and Smith
SS#6
SCE
33.85
118.10
No
event specific attenuation, Somerville and Smith
SS#8
SCE
34.16
118.18
No
event specific attenuation, Somerville and Smith
SS#10
SCE
33.89
118.37
No
event specific attenuation, Somerville and Smith
SS#15
SCE
34.22
118.19
No
event specific attenuation, Somerville and Smith
SS#16
SCE
33.82
118.22
No
event specific attenuation, Somerville and Smith
SS#17
SCE
33.87
118.37
No
event specific attenuation, Somerville and Smith
SS#19
SCE
33.88
118.18
Yes
event specific attenuation, Somerville and Smith
SS#22
SCE
34.172
118.347
No
event specific attenuation, Somerville and Smith
SS#23
SCE
34.04
118.10
No
event specific attenuation, Somerville and Smith
SS#27
SCE
33.953
118.042
No
event specific attenuation, Somerville and Smith
SS#29
SCE
34.044
118.128
No
event specific attenuation, Somerville and Smith
SS#30
SCE
33.95
117.92
Yes
recording
SS#32
SCE
33.936
118.067
No
event specific attenuation, Somerville and Smith
SS#42
SCE
33.983
118.111
No
event specific attenuation, Somerville and Smith
SS#43
SCE
33.942
118.139
No
event specific attenuation, Somerville and Smith
SS#46
SCE
34.01
117.95
No
event specific attenuation, Somerville and Smith
Whittier Narrows Aftershock
SS#1
SCE
33.77
118.10
No
event specific attenuation, Somerville and Smith
SS#2
SCE
34.141
118.025
No
event specific attenuation, Somerville and Smith
SS#4
SCE
33.93
118.11
No
event specific attenuation, Somerville and Smith
SS#6
SCE
33.85
118.10
No
event specific attenuation, Somerville and Smith
SS#8
SCE
34.16
118.18
No
event specific attenuation, Somerville and Smith
SS#11
SCE
33.894
118.264
No
event specific attenuation, Somerville and Smith
SS#15
SCE
34.22
118.19
No
event specific attenuation, Somerville and Smith
SS#23
SCE
34.04
118.10
No
event specific attenuation, Somerville and Smith
SS#33
SCE
34.05
118.161
No
event specific attenuation, Somerville and Smith

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