Fig. 2: The evolution of secondary ruptures.
a Normalized differentiation \(\overline{{\partial }_{t}A\left(x,t\right)}\) reveals numerous sequenced ruptures occurring in the 3 ms following the initial rupture. b The first 1 ms of (a). Vertical dashed lines labeled by integers denote sequential ruptures as they pass the slip measurement location. c, d The detailed evolution of the contact area (blue line) and the slip (red line) in (a, b), respectively. The light purple backgrounds denote the temporal windows over which the labeled ruptures continued to propagate within the interface. \(\delta {u}_{i}\) and \(\delta {A}_{i}\) denote the slip and contact area drop precipitated by ith rupture. The slip measured at the X position denoted in (a) (red mark) and (b) (white dashed line). The slopes of the black lines in (b) denote the local rupture velocities as ruptures cross the measurement section. e Three typical (i = 1, 4, 9) slip profiles (red) are compared to LEFM predictions (black). i = 1 is sub-Rayleigh, while i = 4 is supershear. The i = 9 rupture is supershear until the yellow line, it then transitions to sub-Rayleigh. Black and green curves are LEFM predictions within the supershear and sub-Rayleigh ranges, respectively.
