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SW Iceland shell growth chronology. (bottom, left axis) Individual detrended growth series (gray lines) and Master Shell Growth Chronology (MSC; black line) represented as shell growth indices (SGI), (middle; right axis) number of individual shell growth series included in the MSC, and (top, left axis) expressed population signal (EPS; solid line) and 0.85 EPS threshold (dashed line; see text). The shaded region prior to 1791 shows where the chronology contains fewer than 3 shells.
