HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Gregor, N. J. Articles by Youngs, R. R. Search for Related Content GeoRef GeoRef Citation

Ground-Motion Attenuation Relationships for Cascadia Subduction Zone Megathrust Earthquakes Based on a Stochastic Finite-Fault Model

Pacific Engineering and Analysis
311 Pomona Avenue
El Cerrito, CA 94530
(N.J.G., W.J.S.)
URS Corporation
500 12th Street, Suite 200
Oakland, CA 94607
(I.G.W.)
Geomatrix Consultants
2101 Webster Street
Oakland, CA 94612
(R.R.Y.)

Manuscript received 25 February 2002.

The number of strong ground motion recordings available for regression analysis in developing empirical attenuation relationships has rapidly grown in the last 10 years. However, the dearth of strong-motion data from the Cascadia subduction zone has limited this development of relationships for the Cascadia subduction zone megathrust, which can be used in the calculation of design spectra for engineered structures. A stochastic finite-fault ground-motion model has been used to simulate ground motions for moment magnitude (M) 8.0, 8.5, and 9.0 megathrust earthquakes along the Cascadia subduction zone for both rock-and soil-site conditions. The stochastic finite-fault model was validated against the 1985 M 8.0 Michoacan, Mexico, and the 1985 M 8.0 Valpariso, Chile, earthquakes. These two subduction zone megathrust earthquakes were recorded at several rock sites located near the fault rupture. For the Cascadia megathrust earthquakes, three different rupture geometries were used to model the M 8.0, 8.5, and 9.0 events. The geometries only differ in their respective fault lengths. A fault dip of 9° to the east with a rupture width of 90 km was selected to represent average properties of the Cascadia subduction zone geometry. A regional crustal damping and velocity model was used with the stochastic finite-fault model simulations. Ground motions were computed for 16 site locations. The parametric uncertainties associated with the variation in source, path, and site effects were included in the development of the ground motions. A functional form was fit to the ground-motion model simulations to develop region-specific attenuation relationships for the Cascadia megathrust rupture zone for both rock and soil site conditions. The total uncertainty was based on a combination of the modeling and parametric uncertainties (sigmas). These newly developed attenuation relationships for Cascadia subduction zone megathrust earthquakes can be used in both the probabilistic and deterministic seismic-hazard studies for engineering design for the Pacific Northwest.

This article has been cited by other articles:

				Empirical Ground-Motion Relations for Subduction-Zone Earthquakes and Their Application to Cascadia and Other Regions Bulletin of the Seismological Society of America, August 1, 2003; 93(4): 1703 - 1729.

				K. W. Campbell Prediction of Strong Ground Motion Using the Hybrid Empirical Method and Its Use in the Development of Ground-Motion (Attenuation) Relations in Eastern North America Bulletin of the Seismological Society of America, June 1, 2003; 93(3): 1012 - 1033. [Abstract] [Full Text] [PDF]