The Pacific Northwest Seismograph Network PNW EARTHQUAKE INFORMATION Strong Motion Information

Magnitude	Date	Latitude	Longitude	Depth
2.8	2003/04/28 22:25 UTC	45.1155	-122.4277	14.31

Contents

Maps

Shake Map Instrumental Intensity, peak accelerations, peak velocities.

Strong Motion Parameters

Strong Motion Parameters for each component of each station

STA	COMP	Dist (km)	PGA (%g)	PGV (cm/sec)
COLT	ENE	6	0.7370	0.1500
COLT	ENN	6	0.6671	0.1450
COLT	ENZ	6	0.4888	0.1051
PERL	ENE	36	0.0284	0.0108
PERL	ENN	36	0.0204	0.0086
PERL	ENZ	36	0.0206	0.0049
MRIN	ENE	41	0.0482	0.0130
MRIN	ENN	41	0.0432	0.0166
MRIN	ENZ	41	0.0338	0.0092
EYES	ENE	55	0.0181	0.0096
EYES	ENN	55	0.0181	0.0055
EYES	ENZ	55	0.0150	0.0056
HUBA	ENE	60	0.0372	0.0157
HUBA	ENN	60	0.0379	0.0131
HUBA	ENZ	60	0.0295	0.0172
ROSS	ENE	63	0.0404	0.0444
ROSS	ENN	63	0.0467	0.0716
ROSS	ENZ	63	0.0428	0.0389
COR	BHE	91	0.0021	0.0010
COR	BHN	91	0.0017	0.0006
COR	BHZ	91	0.0014	0.0006
HEBO	BHE	105	0.0355	0.0074
HEBO	BHN	105	0.0142	0.0035
HEBO	BHZ	105	0.0041	0.0014
HEBO	SNE	105	0.0411	0.0078
HEBO	SNN	105	0.0207	0.0036
HEBO	SNZ	105	0.0052	0.0018
EUO	BHE	131	0.0028	0.0008
EUO	BHN	131	0.0025	0.0008
EUO	BHZ	131	0.0030	0.0009
EUO	SNE	131	0.0030	0.0007
EUO	SNN	131	0.0031	0.0007
EUO	SNZ	131	0.0029	0.0010
ALVY	ENE	133	0.0021	0.0029
ALVY	ENN	133	0.0022	0.0029
ALVY	ENZ	133	0.0025	0.0046
LANE	ENE	134	0.0025	0.0029
LANE	ENN	134	0.0030	0.0041
LANE	ENZ	134	0.0031	0.0038
PIN	BHE	191	0.0016	0.0007
PIN	BHN	191	0.0011	0.0006
PIN	BHZ	191	0.0006	0.0004
PIN	SNE	191	0.0017	0.0010
PIN	SNN	191	0.0013	0.0007
PIN	SNZ	191	0.0007	0.0005
TAKO	BHE	202	0.0025	0.0009
TAKO	BHN	202	0.0023	0.0010
TAKO	BHZ	202	0.0018	0.0006
TAKO	SNE	202	0.0029	0.0012
TAKO	SNN	202	0.0031	0.0014
TAKO	SNZ	202	0.0019	0.0007

Parameter Definitions

• STA - The 3 or 4 letter station designation.
• COMP - Component flag. Each station has a tri-axial accelerometer for measuring motions in the vertical (Z), north-south (N) , and east-west (E) directions. The "EL" part of the component indicates that the data are from an accelerometer with a high sample rate (here 100 samples per second). A "BH" or "HH" indicates that the data are from a broadband velocity sensor. (The "HH" components usually have a 100 sps sample rate and the "BH" components are usually 40 or 50 sps).
• Dist - Surface distance from the earthquake epicenter to the recording station.
• PGA - Peak ground acceleration. The peak value from a single component (no vector sums). Values are expressed in percent g (acceleration due to gravity, 32 ft/sec/sec or 9.81 m/sec/sec).
• PGV - Peak ground velocity; determined by integrating the acceleration time-series using the trapezoidal rule.

Station Information

List showing station coordinates and sensor information.
Station Maps

The information presented in this document is preliminary. It will be modified after additional analysis of the accelerograms.

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