USGS National-Strong Motion Program
Preliminary Corrected Peak Ground Acceleration and Velocity and Pseudo-Spectral Acceleration Values for
April 22, 2003, Hydesville, California Earthquake (posted 04/23/2003; updated 09/15/2003)
ML 3.9, 04/22/2003, 10:46 UTC, 04/22/2003, 03:46 AM PDT, 40.588 N, 124.087 W, 27.8 km depth
Sta	Inst	Inst	State: City; Recorder Location	Owner	Lat	Lon	Dist	Az	Ch	Sensor	Orient	PGA	PGV	PSA at:
No	type	S/N			deg	deg	km	deg	No	type	deg	cm/s/s	cm/s	0.3 s	1.0 s	3.0 s
1746	Etna	2011	CA: Fortuna; Fire Station	USGS	40.589	-124.128	3.5	272	1	EpiSen	90	139.8	4.2	12.30	0.654	0.0818
									2	EpiSen	360	83.6	-2.1	5.40	0.312	0.0244
									3	EpiSen	UP	16.8	0.3	0.69	0.091	0.0045
1586	Etna	1993	CA: Loleta; Fire Station	USGS	40.644	-124.221	12.9	299	1	EpiSen	90	14.0	0.3	0.82	0.205	0.0184
									2	EpiSen	360	22.2	-0.8	2.47	0.287	0.0273
									3	EpiSen	UP	-27.5	0.5	0.94	0.089	0.0085
1023	Etna	1990	CA: Ferndale; Fire Station	USGS	40.576	-124.263	15.0	265	1	EpiSen	90	-25.9	0.9	3.36	0.436	0.0296
									2	EpiSen	360	-30.2	-0.7	5.52	0.340	0.0236
									3	EpiSen	UP	15.8	0.4	2.49	0.204	0.0099
1582	Etna	2020	CA: Eureka; College of Redwoods	USGS	40.699	-124.200	15.6	322	1	EpiSen	90	-86.8	1.7	3.49	0.538	0.0363
									2	EpiSen	360	-41.2	1.4	4.07	0.774	0.0525
									3	EpiSen	UP	-19.6	-0.5	1.94	0.238	0.0165
1581	Etna	2021	CA: Eureka; South Bay School	USGS	40.735	-124.207	19.2	328	1	EpiSen	270	-32.1	-1.1	2.11	0.405	0.0307
									2	EpiSen	180	37.7	-1.8	5.03	0.748	0.0512
									3	EpiSen	UP	-7.6	-0.3	2.37	0.174	0.0095
1584	Etna	2003	CA: Ferndale; Bunker Hill FAA	USGS	40.498	-124.295	20.3	241	1	EpiSen	90	9.5	-0.3	1.21	0.149	0.0100
									2	EpiSen	360	7.8	-0.2	0.86	0.214	0.0136
									3	EpiSen	UP	12.2	-0.2	0.62	0.036	0.0044
1725	Etna	2039	CA: Ferndale; Centerville B&B	USGS	40.544	-124.354	23.1	258	1	EpiSen	90	6.3	0.2	1.28	0.157	0.0097
									2	EpiSen	360	7.0	-0.2	1.64	0.173	0.0111
									3	EpiSen	UP	-8.2	0.2	0.55	0.120	0.0059
1580	Etna	2023	CA: Arcata; Humboldt State Univ	USGS	40.874	-124.075	31.8	2	1	EpiSen	90	6.7	0.2	0.33	0.044	0.0046
									2	EpiSen	360	6.6	0.2	0.31	0.042	0.0052
									3	EpiSen	UP	-2.3	0.1	0.11	0.023	0.0022