Evolution of the stress field in southern California and triggering of moderate‐size earthquakes: A 200‐year perspective

Abstract

Abstract. Changes in stress in southern California are modeled from 1812 to 2025 using as input (1) stress drops associated with six large (7.0 < M < 7.5) to great (M > 7.5) earthquakes through 1995 and (2) stress buildup associated with major faults with slip rates > 3 mm/yr as constrained by geodetic, paleoseismic, and seismic measurements. Evolution of stress and the triggering of moderate to large earthquakes are treated in a tensoffal rather than a scalar manner. We present snapshots of the cumulative Coulomb failure function (ACFF) as a function of time for faults of various strike, dip, and rake throughout southern California. We take ACFF to be zero everywhere just prior to the great shock of 1812. We find that about 95% of those well-located M > 6 earthquakes whose mechanisms involve either strike-slip or reverse faulting are consistent with the Coulomb stress evolutionary model; that is, they occurred in areas of positive ACFF.

Earthquake Doublet Sequences: Evidence of Static Triggering in the Strong Convergent Zones of Taiwan

“…Such a good consistency between the increased delta CFF patterns and the subsequent earthquakes, including the 2 nd largest earthquake and most aftershocks, indicates that the earthquakes that followed were likely triggered by the static stress generated by the 1 st largest earthquake. This result is similar to previous findings with respect to static stress triggering (e.g., King et al 1994;Stein et al 1994;Deng and Sykes 1997;Gomberg et al 1998;Stein 1999;Ammon et al 2008), rather than from dynamic triggering (Freed 2005). Alternatively, the triggering of 2 nd largest earthquake might be a result of rupture propagation beyond fault discontinuities (Kase and Kuge 2001;Duan and Oglesby 2006;Kase and Day 2006).…”

Stress evolution in southern California and triggering of moderate‐, small‐, and micro‐size earthquakes

“…Rupture models for these events are listed in Table A2 and will be described below on a region-by-region basis. The detailed rupture models for the original six earthquakes of M > 7 are not repeated since they are described by Deng and Sykes [1997]. In this paper, we use M w for moment magnitude.…”

Earthquake Triggering Effect Scenarios During the 2014 Sequence in Cephalonia and 2015 Earthquake in Lefkada Broader Areas, Ionian Sea, Greece

“…For the friction coefficient a common value of μ΄ =0 .4 was selected (Nalbant et al, 1998;Papadimitriou, 2002) since many authors have supported that the results are not very sensitive to the changes of μ΄ (e.g. Deng and Sykes, 1997a;1997b;King et al, 1994;Stein et al, 1997).…”