Implications of felt area-magnitude relations for earthquake scaling and the average frequency of perceptible ground motion

Arthur Frankel

doi:10.1785/bssa0840020462

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Implications of felt area-magnitude relations for earthquake scaling and the average frequency of perceptible ground motion

Arthur Frankel

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Abstract

Observed relations between felt area and moment magnitude M for stable continental regions ( SCR ) and California earthquakes can be explained by a simple model with geometrical spreading, attenuation ( Q −1 ), and earthquake stress drops that remain constant from M 4 to 8. Differences in the slopes of the observed felt area- M relations between SCR and California earthquakes are consistent with differences in Q between these tectonic settings. Fitting the felt area- M data to the model yields an estimate of f/Q , where f is the average frequency of minimum perceptible ground motion. Using fits to the data and instrumentally derived values of Q , I find that f is between about 2 and 4 Hz. I present an estimate of the spectral acceleration level associated with the lower limit of perceptibility.

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Arthur Frankel. 1994. Implications of felt area-magnitude relations for earthquake scaling and the average frequency of perceptible ground motion. https://doi.org/10.1785/bssa0840020462

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