Figure 3: Stick–slip event properties.
From: Laboratory observations of slow earthquakes and the spectrum of tectonic fault slip modes
(a) The friction rate parameter (b−a) transitions from velocity strengthening to velocity weakening at ∼5–7 mm displacement. (b) Data from 29 experiments showing effective friction stiffness k′= k/σn′ as a function of shear displacement for stable sliding (black dots) and stick–slip events (red dots). The heavy black line defines the evolution of kc′ based on the distinction between stable sliding and stick–slip. (c) Data for unstable slip events shown in b are colour coded by peak slip velocity and shown as a function of shear displacement. Stick–slip is slowest for κ∼1. The 40–50 mm interval marked by the grey box denotes data used to compile stick–slip properties. (d) Stick–slip event velocity and (e) duration as a function of normalized critical stiffness κ =k/kc. Black dots show data from events in the displacement interval 40–50 mm for eight experiments; red dots show mean values ±1 s.d. for each experiment.
