Fig. 4: Seismicity changes versus time relative to SST times.
From: Effects of episodic slow slip on seismicity and stress near a subduction-zone megathrust
a Cumulative numbers of seismicity deeper than 25 km in the three regions shown as solid lines (blue: Region A, pink: Region B and green: Region C) assuming that the lower limit of analysis magnitude, Mc, is 0.7. Note that increased seismicity rates appear to occur ~2–4 weeks before SST times. b Cumulative numbers of seismicity in the combined region assuming different levels of completeness (Mc = 0.5, 0.7, 1.0). Increased seismicity rates appear to occur approximately from 2 weeks before to a week after SST times. c b-values versus Mc for the combined region. Blue and red dots indicate b-values for events that occurred in 2-month time windows before and after SST times, respectively. Note the decrease in b-values for most values of Mc. An assumed Mc of 0.7 is the preferred value. d b-value time variation of in-slab events for the combined region using 1-month moving windows. Red, green, and blue dots indicate the estimated b-values using Mc of 0.5, 0.7, and 1.0, respectively. Note high b-values peak 6 weeks before SST times. e Magnitude of events of in-slab events for the combined region. f Cumulative numbers of seismicity in the interplate event cluster in the region updip of the SST zone indicated by orange dots in Fig. 2a, b. In (a, b, f), dashed reference lines show the pre-SST trend.
