Variation of Proportionality Between Stress Drop and Slip, With Implications for Megathrust Earthquakes

Abstract Earthquake stress drop Δ σ is related to fault slip via , where μ D and L c denote shear modulus, average slip, dimension. C controlled by the system geometry, characterizes effective stiffness of system, commonly assumed be a constant near 1. We use 3D elastostatic models systematically investigate how burial depth, dip angle, direction. find that decreases with smaller depth value for shallow‐dipping surface‐rupturing roughly one‐fifth deeply buried case. Our results help explain apparent magnitude‐dependent drops megathrust earthquakes in Thingbaijam et al. (2017), https://doi.org/10.1785/0120150291 . There may also implications depth‐ magnitude‐dependence other source parameters, reducing uncertainties seismic tsunami hazard assessments earthquakes.