GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 3.3 ______ ___ GNGTS 2023 Fig 2. (a) Δ CFS for tremors along the Cascadia subduction zone as a function of epicentral latitude. We highlight four fault segments which show elevated mean tidal stress values for the occurrence of tremors: the northernmost and southernmost patches of the subduction zone and two intermediate areas approximately located at 44.5° and 46° N (red lines in the map and dashed red lines in panels a, b and c). (b) Spatial coefficient of variation for tremors along the ETS zone. Two minima are observed in correspondence of the maxima of the average Δ CFS plotted in (a). (c) Coefficient of variation of tremor time series between 2009 and 2021 as a function of latitude (data from PNSN and EPS catalogs, 2009 − 2021, respectively available at http://pnsn.org) . Two minima are observed in correspondence of the maxima of the average Δ CFS plotted in (a) and the minima points of the spatial coefficient of variation. (d) Map of tremors along the Cascadia ETS zone. Black points represent regular earthquakes, their size is proportional to the magnitude. After Zaccagnino et al., 2022b.