Strong Motion Information

The Pacific Northwest Seismograph Network

PNW EARTHQUAKE INFORMATION

Strong Motion Information

Magnitude: 5.1
Date and time: 1999/07/03 01:43 UTC
Latitude: 47.0740, Longitude: -123.4637
Hypocentral Depth: 40.65 km

NOTE: The above values may have been changed since this document was written

[ Station Map ] [ Values ] [ Parameter Definitions ] [ Station Locations ] [ Station Photographs ]

Maps

Seattle area map with strong-motion station locations and peak accelerations from each component of each station.
Western Washington map with broadband station locations and peak accelerations from each component of each station.

Strong Motion Parameters

Strong Motion Parameters for each component of each station
STA	COMP	Dist (km)	PGA (%g)	Dur_rel (sec)	AI (sec)	SI(5%) (cm)	PGV (cm/sec)	F_d (Hz)	BW (Hz)
UPS	ELZ	77	0.5097	82.9	0.1150	2.2266	0.6310	1.2	0.1
UPS	ELN	77	0.4998	63.2	0.1620	3.1364	0.6751	1.2	0.1
UPS	ELE	77	0.7997	57.4	0.2186	4.3333	1.0178	1.3	0.1
TBPA	ELZ	86	0.7393	90.3	0.2607	3.9120	0.6482	1.1	0.1
TBPA	ELN	86	1.0056	100.1	0.7818	6.6996	1.2763	1.2	0.1
TBPA	ELE	86	1.7798	103.9	0.7886	8.0247	1.8142	1.2	0.1
QAW	ELZ	104	0.9164	49.1	0.1303	2.5064	0.5368	0.4	0.1
QAW	ELN	104	0.5664	56.6	0.1711	2.7771	0.6418	1.9	0.1
QAW	ELE	104	0.5844	61.9	0.1502	2.6939	0.8185	1.1	0.1
MPL	ELZ	106	0.3012	49.0	0.0258	1.0740	0.2970	1.1	0.1
MPL	ELN	106	0.4995	40.4	0.0583	1.5257	0.4524	3.5	0.1
MPL	ELE	106	0.5281	42.5	0.0556	1.5725	0.3750	1.4	0.1
SPW	HHZ	106	0.3132	54.2	0.0283	0.9488	0.3378	2.5	0.1
SPW	HHN	106	0.6118	42.9	0.0630	1.4467	0.4234	2.3	0.2
SPW	HHE	106	0.5031	44.5	0.0863	2.0786	0.5443	1.6	0.1
SPW	ELZ	106	0.3473	55.9	0.0282	0.9771	0.3464	2.5	0.1
SPW	ELN	106	0.6535	42.8	0.0719	1.5401	0.4512	2.3	0.2
SPW	ELE	106	0.4975	44.5	0.0865	2.0693	0.5622	1.6	0.1
SEA	ELZ	109	0.2333	89.0	0.0298	1.4297	0.3252	1.1	0.1
SEA	ELN	109	0.4451	69.0	0.0719	2.8418	0.7139	0.4	0.1
SEA	ELE	109	0.5314	74.0	0.0772	3.1340	0.8046	0.4	0.3
NOWS	ELZ	114	0.2792	138.8	0.0485	1.3725	0.4416	2.3	0.1
NOWS	ELN	114	0.5646	78.1	0.1302	2.8706	0.6536	2.2	0.1
NOWS	ELE	114	0.5706	69.0	0.1208	2.8043	0.6418	2.1	0.1
RAW	ELZ	120	0.2089	46.2	0.0158	0.5855	0.1510	3.6	0.1
RAW	ELN	120	0.3470	42.4	0.0311	0.9696	0.2249	3.6	0.3
RAW	ELE	120	0.2903	43.6	0.0316	1.0954	0.2481	1.4	0.3
ELW	HHZ	129	0.1384	47.3	0.0072	0.4265	0.1195	1.3	0.1
ELW	HHN	129	0.2395	48.8	0.0130	0.6514	0.1380	1.2	0.1
ELW	HHE	129	0.2834	49.1	0.0142	0.5966	0.1794	1.6	0.2
ELW	ELZ	129	0.1406	47.9	0.0074	0.4364	0.1316	1.3	0.1
ELW	ELN	129	0.1894	48.5	0.0138	0.6785	0.1550	1.2	0.1
ELW	ELE	129	0.2093	49.2	0.0140	0.6013	0.1746	1.6	0.2
LON	BHZ	131	0.1368	37.7	0.0049	0.3502	0.1265	1.9	0.3
LON	BHN	131	0.1625	34.1	0.0061	0.4560	0.1603	2.1	0.4
LON	BHE	131	0.1560	38.6	0.0067	0.4879	0.1423	1.7	0.1
MBPA	ELZ	150	0.1638	198.8	0.0118	0.2267	0.0650	29.7	0.1
MBPA	ELN	150	0.5157	38.9	0.0308	0.4376	0.1950	3.6	0.1
MBPA	ELE	150	0.3869	36.9	0.0267	0.2899	0.1190	6.7	0.1
TTW	BHZ	151	0.2443	36.9	0.0117	0.3833	0.1377	3.6	0.1
TTW	BHN	151	0.3917	37.5	0.0318	0.5794	0.1897	2.6	0.2
TTW	BHE	151	0.3637	39.5	0.0332	0.7065	0.2021	2.6	0.1
ERW	HHZ	166	0.0640	58.6	0.0009	0.1844	0.0390	2.4	0.2
ERW	HHN	166	0.0847	46.4	0.0015	0.1864	0.0535	4.1	0.1
ERW	HHE	166	0.0830	47.0	0.0016	0.2465	0.0760	2.5	0.1
ERW	ELZ	166	0.0638	53.9	0.0009	0.1863	0.0382	1.1	0.2
ERW	ELN	166	0.0885	46.1	0.0017	0.1968	0.0513	4.1	0.1
ERW	ELE	166	0.0846	46.9	0.0016	0.2482	0.0725	2.5	0.1
RBO	ELN	184	0.2062	53.5	0.0147	0.6290	0.1177	1.7	0.5
RBO	ELZ	184	0.1701	57.7	0.0081	0.4741	0.0963	1.7	0.5
RBO	ELE	184	0.2274	50.9	0.0293	0.9162	0.1638	1.5	0.2
LTY	BHZ	213	0.0231	55.1	0.0001	0.0570	0.0150	1.5	0.3
LTY	BHN	213	0.0163	54.1	0.0001	0.0632	0.0158	3.0	0.1
LTY	BHE	213	0.0237	51.2	0.0002	0.0750	0.0168	1.9	0.1

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 Locations

Here is a table showing station coordinates and sensor information.

Station Photographs

ELW - Echo Lake Power Switching Station, near North Bend.
LON - Longmire Springs, Mount Rainier National Park (CREST station).
SBES - Silver Beach Elementary School, Bellingham.
SEA - Seismic Pier at the University of Washington, Seattle.
SP2 - Seward Park, Seattle.
UPS - University of Puget Sound, Tacoma.

Last modified Fri Jan 5 14:08:40 PST 2001

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

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PNW EARTHQUAKE INFORMATION