Extensive recession of Cordillera Darwin glaciers in southernmost South America during Heinrich Stadial 1

The geographic expression and phasing of events during the last termination are important for isolating mechanisms that caused Earth to emerge from the last ice age. Heinrich Stadial 1 (HS1; 14,600–18,000 yr BP) is a key because of the central role that its far-field effects had on the last termination in the Southern Hemisphere. Here, we present new data from Cordillera Darwin that show rapid glacier recession in southern South America during HS1. This retreat was coeval with ice recession elsewhere in South America and New Zealand, with increased upwelling in the Southern Ocean, with warming of SSTs offshore of Chile, and with a rise in atmospheric CO2. Together, these data indicate a coherent and rapid response to the effects of HS1 in the middle and high latitudes of the Southern Hemisphere.

► Basal radiocarbon ages from bogs in central Cordillera Darwin are as old as 17 ka. ► Rapid collapse of Cordillera Darwin ice occurred during Heinrich Stadial 1. ► This collapse likely was driven by southward shifting oceanic and atmospheric fronts.