In strain softening earthquake models, the single variable R = Kf/Ks measures the nearness to earthquake instability; Kf and Ks are stiffnesses of the fault zone and elastic surroundings. Instability occurs when increasing R reaches unity. For a simple two-dimensional antiplane model, R is a function of dε/dU and H, where ε is shear strain at the ground surface, and U is remote displacement observed at a distance, H, from the fault. R is independent of the fault zone constitutive law, crustal rigidity, and shear stress magnitude.

First Page Preview

First page PDF preview
You do not currently have access to this article.