| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Article |
U.S. Geological Survey
University of Washington
Seattle,
Washington 98195
(T.L.P., C.S.W.)
U.S. Geological Survey
345 Middlefield Road
Menlo Park,
California 94025
(T.M.B.)
Department of Geophysics
University of
Washington
Seattle, Washington 98195
(K.C.C., R.S.C.)
Department of Geological Sciences
University of Texas
El
Paso, Texas 79968
(C.M.S., K.C.M.)
College of Ocean and Atmospheric Sciences
Oregon State
University
Corvallis, Oregon 97331
(A.M.T.)
Recordings of the 1999 Mw 7.6 Chi-Chi (Taiwan) earthquake, two local earthquakes, and five blasts show seismic-wave amplification over a large sedimentary basin in the U.S. Pacific Northwest. For weak ground motions from the Chi-Chi earthquake, the Seattle basin amplified 0.2- to 0.8-Hz waves by factors of 8 to 16 relative to bedrock sites west of the basin. The amplification and peak frequency change during the Chi-Chi coda: the initial S-wave arrivals (0–30 sec) had maximum amplifications of 12 at 0.5–0.8 Hz, whereas later arrivals (35–65 sec) reached amplifications of 16 at 0.3–0.5 Hz. Analysis of local events in the 1.0- to 10.0-Hz frequency range show fourfold amplifications for 1.0-Hz weak ground motion over the Seattle basin. Amplifications decrease as frequencies increase above 1.0 Hz, with frequencies above 7 Hz showing lower amplitudes over the basin than at bedrock sites. Modeling shows that resonance in low-impedance deposits forming the upper 550 m of the basin beneath our profile could cause most of the observed amplification, and the larger amplification at later arrival times suggests surface waves also play a substantial role. These results emphasize the importance of shallow deposits in determining ground motions over large basins.
This article has been cited by other articles:
|
|
 |
|
  A. Barberopoulou A Seiche Hazard Study for Lake Union, Seattle, Washington Bulletin of the Seismological Society of America, August 1, 2008; 98(4): 1837 - 1848. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Snelson, T. M. Brocher, K. C. Miller, T. L. Pratt, and A. M. Trehu Seismic Amplification within the Seattle Basin, Washington State: Insights from SHIPS Seismic Tomography Experiments Bulletin of the Seismological Society of America, October 1, 2007; 97(5): 1432 - 1448. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. L. Pratt, M. E. Templeton, R. Frost, and A. P. Shafer Variations in Short-period Geophone Responses in Temporary Seismic Arrays Seismological Research Letters, May 1, 2006; 77(3): 377 - 388. [Full Text] [PDF]
|
|
|
|
|
|
A. Barberopoulou, A. Qamar, T. L. Pratt, and W. P. Steele Long-Period Effects of the Denali Earthquake on Water Bodies in the Puget Lowland: Observations and Modeling Bulletin of the Seismological Society of America, April 1, 2006; 96(2): 519 - 535. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Pratt and T. M. Brocher Site Response and Attenuation in the Puget Lowland, Washington State Bulletin of the Seismological Society of America, April 1, 2006; 96(2): 536 - 552. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Li, W. S. D. Wilcock, T. L. Pratt, C. M. Snelson, and T. M. Brocher Seismic Attenuation Structure of the Seattle Basin, Washington State, from Explosive-Source Refraction Data Bulletin of the Seismological Society of America, April 1, 2006; 96(2): 553 - 571. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. M. Brocher A Regional View of Urban Sedimentary Basins in Northern California Based on Oil Industry Compressional-Wave Velocity and Density Logs Bulletin of the Seismological Society of America, December 1, 2005; 95(6): 2093 - 2114. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. L. Jemberie and C. A. Langston Site Amplification, Scattering, and Intrinsic Attenuation in the Mississippi Embayment from Coda Waves Bulletin of the Seismological Society of America, October 1, 2005; 95(5): 1716 - 1730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Validation of a 3D Velocity Model of the Puget Sound Region Based on Modeling Ground Motion from the 28 February 2001 Nisqually Earthquake Bulletin of the Seismological Society of America, October 1, 2004; 94(5): 1670 - 1689.
|
|
|
|
|
|
An Efficient Finite-Difference Method for Simulating 3D Seismic Response of Localized Basin Structures Bulletin of the Seismological Society of America, October 1, 2004; 94(5): 1690 - 1705.
|
|
|
|
|
|
Interpretation of the Seattle Uplift, Washington, as a Passive-Roof Duplex Bulletin of the Seismological Society of America, August 1, 2004; 94(4): 1379 - 1401.
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
