Bilinearity in the Gutenberg-Richter Relation Based on M-L for Magnitudes Above and Below 2, From Systematic Magnitude Assessments in Parkfield (California)

Staudenmaier, Nadine, Tormann, Thessa, Edwards, Benjamin ORCID: 0000-0001-5648-8015, Deichmann, Nicholas and Wiemer, Stefan (2018) Bilinearity in the Gutenberg-Richter Relation Based on M-L for Magnitudes Above and Below 2, From Systematic Magnitude Assessments in Parkfield (California). GEOPHYSICAL RESEARCH LETTERS, 45 (14). pp. 6887-6897.

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Abstract

Several studies have shown that local magnitude, M L, and moment magnitude, M , scale differently for small earthquakes (M < ~2) than for moderate to large earthquakes. Consequently, frequency‐magnitude relations based on one or the other magnitude type cannot obey a power law with a single exponent over the entire magnitude range. Since this has serious consequences for seismic hazard assessments, it is important to establish for which magnitude type the assumption of a constant exponent is valid and for which it is not. Based on independently determined M , M L and duration magnitude, M d, estimates for 5,304 events near Parkfield, we confirm the theoretically expected difference in scaling between the magnitude types, and we show that the frequency‐magnitude distribution based on M and M d follows a Gutenberg‐Richter relation with a constant slope, whereas for M L it is bilinear. Thus, seismic hazard estimates based on M L of small earthquakes are likely to overestimate the occurrence probability of large earthquakes.

Item Type:	Article
Uncontrolled Keywords:	magnitude scaling, Gutenberg-Richter bilinearity, earthquake scaling
Depositing User:	Symplectic Admin
Date Deposited:	13 Sep 2018 10:59
Last Modified:	19 Jan 2023 01:17
DOI:	10.1029/2018GL078316
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3026235