3.1 The termination of the Younger Dryas….
It has been proposed that the Younger Dryas period/GS-1 was initiated by a cosmic impact, for which there is indirect and debated evidence in a large number of sites in the NH surrounding the North Atlantic region (Kennett et al., 2015). A very significant Platinum (Pt) spike has been identified in the GISP2 ice core (Petaev et al., 2013) and at several North American sites (Moore et al., 2017) that potentially originate from the same impact event. The Pt spike occurs about 45 years after the volcanic quadruplet, i.e. after the Greenland cooling has initiated but before it has reached its minimum (Fig. S1b). The hypothesis of the YD initiation by a cosmic impact is currently debated (Holliday et al., 2020).