Fig. 3: Change in the number of strong pair-wise correlation coefficients with time, as well as volume flux into each Western Galápagos volcano.

a Number of strong positive correlations between each pair of time series determined using windowed correlation analysis (“Methods”). The correlation coefficient is calculated between each pair of volcanoes (Supplementary Fig. S10), and the number of values that are >0.9 are counted. The count for each window is plotted at the centre of the window (5 months), the size of which is annotated by the horizontal black bar. b Number of strong negative correlations between each pair of time series, determined using windowed correlation analysis (“Methods”). The correlation coefficient is calculated between each pair of volcanoes (Supplementary Fig. S10), and the number of values that are <−0.9 are counted. Source data are provided as a Source Data file. c Estimates of volume flux for each unrest period, either from published analysis or estimated here. d Volume change with time at each Western Galápagos volcano for a sill source. The spatial coordinates (X, Y, and Z values) of a sill are determined for each volcano and then held constant, while the variables that control volume change (length, width, and opening) are allowed to vary. The width of each bar corresponds to the length of the period modelled, as does the horizontal black line, while different colours represent each volcano. Periods of significant unrest (e.g., eruptions) have been masked out (vertical grey bars) for the corresponding volcano (e.g., Sierra Negra 2018). In the Galápagos, eruptions typically comprise multiple sources at different levels in the crust that cannot be accurately modelled by a single, fixed source.