Precise date for the Laacher See eruption synchronizes the Younger Dryas

The Laacher See eruption (LSE) in Germany ranks among Europe’s largest volcanic events of the Upper Pleistocene 1 , 2 . Although tephra deposits of the LSE represent an important isochron for the synchronization of proxy archives at the Late Glacial to Early Holocene transition 3 , uncertainty in the age of the eruption has prevailed 4 . Here we present dendrochronological and radiocarbon measurements of subfossil trees that were buried by pyroclastic deposits that firmly date the LSE to 13,006 ± 9 calibrated years before present ( bp ; taken as ad 1950), which is more than a century earlier than previously accepted. The revised age of the LSE necessarily shifts the chronology of European varved lakes 5 , 6 relative to the Greenland ice core record, thereby dating the onset of the Younger Dryas to 12,807 ± 12 calibrated years bp , which is around 130 years earlier than thought. Our results synchronize the onset of the Younger Dryas across the North Atlantic–European sector, preclude a direct link between the LSE and Greenland Stadial-1 cooling 7 , and suggest a large-scale common mechanism of a weakened Atlantic Meridional Overturning Circulation under warming conditions 8 – 10 .