Fig. 5. Order parameter θ as a function of time for the five events analyzed.

The figure represents the behavior of the ratio $\mathrm{\theta }={\mathit{T}}_{\mathrm{l}}^{†}/{\mathit{T}}_{\mathrm{u}}^{†}$ characterizing the order/disorder of the effective connectivity matrix as a function of time (note a point missing in the Brazilian data set because of a data blackout between days 10 and 11). For each data set, two or three matrices T^† are plotted, considering one or two times before and one after the main event (signaled with a red vertical bar). A clear transition from a hierarchical directed to a distributed symmetrical scenario is observed for events (A), (B), (C), and (D). The Google data set, depicted in (E), behaves differently by not showing the same evidence of transition effects.