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Probabilistic Relationships between Ground‐Motion Parameters and Modified Mercalli Intensity in California

Bulletin of the Seismological Society of America

By:
, ,
DOI: 10.1785/0120110156

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Abstract

We use a database of approximately 200,000 modified Mercalli intensity (MMI) observations of California earthquakes collected from USGS "Did You Feel It?" (DYFI) reports, along with a comparable number of peak ground-motion amplitudes from California seismic networks, to develop probabilistic relationships between MMI and peak ground velocity (PGV), peak ground acceleration (PGA), and 0.3-s, 1-s, and 3-s 5% damped pseudospectral acceleration (PSA). After associating each ground-motion observation with an MMI computed from all the DYFI responses within 2 km of the observation, we derived a joint probability distribution between MMI and ground motion. We then derived reversible relationships between MMI and each ground-motion parameter by using a total least squares regression to fit a bilinear function to the median of the stacked probability distributions. Among the relationships, the fit to peak ground velocity has the smallest errors, though linear combinations of PGA and PGV give nominally better results. We also find that magnitude and distance terms reduce the overall residuals and are justifiable on an information theoretic basis. For intensities MMI≥5, our results are in close agreement with the relations of Wald, Quitoriano, Heaton, and Kanamori (1999); for lower intensities, our results fall midway between Wald, Quitoriano, Heaton, and Kanamori (1999) and those of Atkinson and Kaka (2007). The earthquakes in the study ranged in magnitude from 3.0 to 7.3, and the distances ranged from less than a kilometer to about 400 km from the source.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Probabilistic Relationships between Ground‐Motion Parameters and Modified Mercalli Intensity in California
Series title:
Bulletin of the Seismological Society of America
DOI:
10.1785/0120110156
Volume
102
Issue:
1
Year Published:
2012
Language:
English
Publisher:
Seismological Society of America
Publisher location:
El Cerrito, CA
Contributing office(s):
Geologic Hazards Science Center
Description:
18 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
204
Last page:
221
Number of Pages:
18
Country:
United States
State:
California
Additional Online Files(Y/N):
N