USGS National-Strong Motion Program
Preliminary Corrected Peak Ground Acceleration and Velocity and Pseudo-Spectral Acceleration Values for
September 28, 2004, Parkfield, CA Earthquake (posted 09/28/2004; updated 07/20/2005)
Mw 6.0, 09/28/2004, 17:15 UTC, 09/28/2004, 10:15 AM PDT, 35.815 N, 120.374 W, 7.9 km depth, Regional Network ID# nc51147892
Sta Inst Inst State: City; Recorder Location Owner Lat Lon Dist Az Ch Sensor Orient PGA PGV PSA at:
Code type S/N     deg deg km deg No type deg cm/s/s cm/s 0.3 s 1.0 s 3.0 s
GFU GEOS 7 CA: Parkfield; Gold Hill USGS 35.8331 -120.3464 3.2 51 1 GEOS UP -116 -2.1 7.1 1.8 0.57
                  2 GEOS 360 136 -5.7 13.8 3.0 1.04
                  3 GEOS 90 -168 6.0 15.0 3.7 0.57
EFU GEOS 17 CA: Parkfield; Eades USGS 35.8942 -120.4212 9.8 334 1 GEOS UP -192 7.4 18.5 9.7 0.99
                  2 GEOS 360 -384 -25.8 46.1 39.8 3.22
                  3 GEOS 90 312 -26.7 37.5 37.3 4.21
PHOB RF130 9266 CA: Hog Canyon NCSN 35.8666 -120.4796 11.1 301 1 RF130 360 251 -19.5 38.6 18.0 2.77
                  2 RF130 90 269 -22.6 57.8 33.6 3.64
                  3 RF130 UP 171 -9.2 38.6 8.0 1.00
UPSAR01 RT72-04 13 CA: Parkfield; UPSAR 01 USGS 35.8212 -120.5072 11.6 275 1 FBA-2g UP 88 5.5 18.9 6.1 0.52
                  2 FBA-2g 360 -134 10.5 38.1 16.7 1.33
                  3 FBA-2g 90 180 -15.3 72.8 16.7 1.67
UPSAR02 RT72-04 14 CA: Parkfield; UPSAR 02 USGS 35.8221 -120.5064 11.6 275 1 FBA-2g UP -86 3.7 13.9 7.3 0.52
                  2 FBA-2g 360 -170 -15.8 32.4 17.0 1.42
                  3 FBA-2g 90 300 -18.0 69.9 14.8 1.69
UPSAR03 RT72-04 15 CA: Parkfield; UPSAR 03 USGS 35.8214 -120.5052 11.6 275 1 FBA-2g UP 105 -4.5 20.7 9.1 0.54
                  2 FBA-2g 360 -145 10.4 36.3 13.7 1.39
                  3 FBA-2g 90 248 -17.3 42.2 10.5 1.36
UPSAR04 RT72-04   CA: Parkfield; UPSAR 04 USGS     11.6 275   never installed
UPSAR05 RT72-04 17 CA: Parkfield; UPSAR 05 USGS 35.8238 -120.5033 11.6 275 1 FBA-2g UP -181 -6.2 28.1 9.5 0.56
                  2 FBA-2g 360 -235 17.3 49.0 16.1 1.66
                  3 FBA-2g 90 -360 -22.9 73.8 24.1 1.46
UPSAR06 RT72-04 18 CA: Parkfield; UPSAR 06 USGS 35.8239 -120.5031 11.6 275 1 FBA-2g UP 110 -5.2 20.7 8.9 0.54
                  2 FBA-2g 360 -222 -13.2 66.9 16.3 1.58
                  3 FBA-2g 90 241 -17.0 96.0 20.0 1.61
UPSAR07 RT72-04 19 CA: Parkfield; UPSAR 07 USGS 35.8238 -120.5028 11.6 275 1 FBA-2g UP 187 5.9 34.3 8.5 0.54
                  2 FBA-2g 360 368 -16.8 56.8 19.1 1.60
                  3 FBA-2g 90 -319 18.5 70.8 21.5 1.66
UPSAR08 RT72-04 20 CA: Parkfield; UPSAR 08 USGS 35.8248 -120.5011 11.6 275 1 FBA-2g UP -132 -5.3 34.2 5.8 0.61
                  2 FBA-2g 360 -181 -14.0 35.7 21.0 1.64
                  3 FBA-2g 90 252 -15.9 59.6 14.4 1.57
UPSAR09 RT72-04 21 CA: Parkfield; UPSAR 09 USGS 35.8260 -120.5007 11.6 275 1 FBA-2g UP 133 -8.9 37.0 6.3 0.62
                  2 FBA-2g 360 -200 17.5 30.9 28.6 2.01
                  3 FBA-2g 90 275 -22.2 62.0 26.9 1.91
UPSAR10 RT72-04 22 CA: Parkfield; UPSAR 10 * USGS 35.8276 -120.5002 11.6 275 1 FBA-2g UP -171 6.6 28.8 7.0 0.63
                  2 FBA-2g 360 271 -20.6 44.3 24.8 1.67
                  3 FBA-2g 90 -305 -23.8 49.2 26.1 1.54
UPSAR11 RT72-04 47 CA: Parkfield; UPSAR 11 USGS 35.8258 -120.5020 11.6 275 1 FBA-2g UP 233 -9.1 53.0 6.2 0.53
                  2 FBA-2g 360 350 -20.0 73.6 21.4 1.77
                  3 FBA-2g 90 -456 -27.2 102.0 25.2 1.59
UPSAR12 RT72-04 50 CA: Parkfield; UPSAR 12 USGS 35.8269 -120.5039 11.6 275 1 FBA-2g UP 112 -8.1 28.0 6.9 0.53
                  2 FBA-2g 360 -241 19.9 58.5 17.5 1.80
                  3 FBA-2g 90 221 -16.0 70.2 16.8 1.70
UPSAR13 RT72-04 49 CA: Parkfield; UPSAR 13 USGS 35.8274 -120.5045 11.6 275 1 FBA-2g UP 161 -8.0 22.5 9.1 0.51
                  2 FBA-2g 360 -226 17.4 49.4 25.9 1.93
                  3 FBA-2g 90 -289 -19.3 59.4 19.5 1.90
UPSAR14 RT72-04   CA: Parkfield; UPSAR 14 USGS 35.8271 -120.5053 11.6 275   offline due to electrical problems
WFU GEOS 12 CA: Parkfield; Work Ranch USGS 35.8145 -120.5111 12.4 270 1 GEOS UP 167 4.4 12.4 3.6 0.33
                  2 GEOS 360 183 5.6 14.8 5.3 0.81
                  3 GEOS 90 335 9.9 23.4 3.9 0.83
DFU GEOS 77 CA: Parkfield; Donna Lee USGS 35.9392 -120.4245 14.5 342 4 GEOS UP 171 9.0 20.3 4.4 0.83
                  5 GEOS 360 366 -13.9 42.3 10.2 1.54
                  6 GEOS 90 289 -15.1 31.4 12.7 2.35
FFU GEOS 34 CA: Parkfield; Froelich USGS 35.9111 -120.4855 14.7 317 4 GEOS UP -215 -6.6 14.1 10.5 1.09
                  5 GEOS 360 373 -11.1 23.5 15.4 2.59
                  6 GEOS 90 448 -17.5 54.2 9.8 1.76
JFU GEOS 8 CA: Parkfield; Joaquin Canyon USGS 35.9397 -120.4319 14.8 339 1 GEOS UP -301 9.6 55.9 4.9 0.68
                  2 GEOS 21 -609 25.5 122.0 18.3 1.90
                  3 GEOS 111 487 -30.3 73.9 21.3 3.72
VFU GEOS 63 CA: Parkfield; Vineyard Canyon USGS 35.9225 -120.5342 18.8 310 4 GEOS UP 145 6.3 23.4 8.8 1.51
                  5 GEOS 360 256 22.4 71.6 17.7 3.57
                  6 GEOS 90 184 -16.9 40.7 30.6 2.63
KFU GEOS 54 CA: Parkfield; Jack Canyon USGS 35.7125 -120.2025 19.2 126 1 GEOS UP -159 4.4 9.9 2.5 0.38
                  2 GEOS 360 -167 10.7 23.4 7.4 0.73
                  3 GEOS 90 -144 -6.1 18.7 7.2 0.51
MFU GEOS 6 CA: Parkfield; Middle Mountain USGS 35.9576 -120.4956 19.3 325 1 GEOS UP -108 8.4 33.6 7.3 1.60
                  2 GEOS 360 -402 29.4 108.0 16.1 6.19
                  3 GEOS 90 181 -26.0 50.5 22.4 6.90
RFU GEOS 52 CA: Parkfield; Red Hills USGS 35.6244 -120.2535 23.8 153 4 GEOS UP 53 1.7 5.2 2.9 0.23
                  5 GEOS 360 -47 -3.1 9.3 3.8 0.27
                  6 GEOS 90 -45 1.8 6.0 1.6 0.11
SFU GEOS 99 CA: Parkfield; Stockdale Mtn USGS 35.9730 -120.5786 25.5 314 1 GEOS 180 bad sensor      
                  2 GEOS 180 -229 6.8 26.6 3.8 0.60
                  3 GEOS 270 -347 8.1 27.3 4.4 0.79
1747 Etna 1406 CA: Coalinga; Fire Station 39 USGS 36.137 -120.363 35.7 2 1 FBA-2g 360 -44 5.9 11.3 8.5 2.30
                  2 FBA-2g UP -27 -3.9 6.7 5.3 1.04
                  3 FBA-2g 90 -78 6.0 13.0 10.6 2.51
1083 Etna 1429 CA: San Luis Obispo; Rec Center USGS 35.285 -120.661 64.3 204 1 FBA-2g 360 -10 0.9 3.6 1.2 0.08
                  2 FBA-2g UP 5 0.4 1.6 0.6 0.06
                  3 FBA-2g 90 -13 1.2 2.3 1.4 0.15
1748 K2 722 CA: Fresno; NSMP USGS office USGS 36.744 -119.728 118.3 29 1 FBA-2g 360 -3 0.3 1.0 0.3 0.22
                  2 FBA-2g UP -5 0.2 1.4 0.2 0.03
                  3 FBA-2g 90 -5 -0.4 1.4 0.7 0.29
1840 Etna 4022 CA: Fresno; VA Medical Center USGS 36.773 -119.781 118.9 26 1 EpiSen 90 7 -0.5 1.3 0.7 0.19
                  2 EpiSen 360 -5 0.4 1.3 0.5 0.15
                  3 EpiSen UP -4 -0.2 1.0 0.2 0.05
1575 Etna 1404 CA: Hollister; City Hall Annex USGS 36.851 -121.402 147.4 322 1 FBA-2g 360 -11 3.2 1.8 3.7 1.98
                  2 FBA-2g UP -6 -1.7 0.9 1.8 0.98
                  3 FBA-2g 90 14 3.2 2.5 5.7 1.79
1797 K2 1854 CA:Hollister; Airport building USGS 36.891 -121.404 151.0 323 1 EpiSen 90 -9 3.4 1.4 1.9 2.26
                  2 EpiSen 360 -10 2.8 1.6 2.2 2.20
                  3 EpiSen UP 5 1.5 0.7 1.1 0.66
* UPSAR10 PGA is suspect due to high-amplitude, high frequency (~40Hz) unknown noise at 6.85 s after P-onset near time of record peak amplitude