Fig. 1: The moment rate and statistics of episodic tremor and slip (ETS) in 2021 and the evolution of slow slip event (SSE).
From: Secondary acceleration of slip fronts driven by slow slip event coalescence in subduction zones
a Moment rate history (blue curve), and daily near-field (within 50 km) and total number of tremors (red and yellow histograms, respectively) during the whole ETS. The vertical dash lines indicate the coalescence time of SSEs. The gray shaded area is used to distinguish the two SSEs. The two black triangles at the top of the x-axis indicate the two peak values of the moment for the SSE2. The three purple triangles at the down of the x-axis indicate the three increases of the tremors for the SSE2. b Spatio-temporal evolution of SSE2. Daily slip rate contoured in color maps. The orange contour lines indicate the cumulative slip area every 3.5 mm of SSE1. The black dots represent the corresponding daily tremor locations from the Pacific Northwest Seismic Network (PNSN) catalog (https://pnsn.org). The black dashed lines indicate depths at 20 km interval40.
