Extended Data Fig. 1: The stress intensity factor K of an arrested rupture is determined by strain gage measurements.
From: How frictional ruptures and earthquakes nucleate and evolve
a. Strain gage measurements (symbols) of the measured stress changes, Δσxx, excited by a rupture that arrested at point xarrest, as a function of x − xarrest. Fitted LEFM predictions (see Eq. (6)) (lines) compare well with the strain gage measurements, when K is the sole fitting parameter. Shown are 3 different events, each with a different value of varr, the rupture velocity immediately prior to rupture arrest at imposed barriers. b. The initial ‘pre-stress’ data, \({\sigma }_{xy}^{pre}\), measured at the nucleation site in a single sequence of 30 induced nucleation events. Red symbols are events in which the previous arrested rupture triggered a nucleation event. In these cases \({\sigma }_{xy}^{pre} \sim 0\). Blue symbols denote \({\sigma }_{xy}^{pre}\) for events in which the previous arrested rupture did not trigger a nucleation event. These finite pre-stresses need to be accounted for to correctly determine the shear stress, τ, at the nucleation site.
