Heinrich events
Armadas of icebergs break off North America and dump rock across the Atlantic floor.
- When
- —
- Duration
- 44 thousand years
- Known to
- ± 3 thousand years
- Era
- Late Pleistocene, Quaternary
Six times during the last glacial, the Laurentide ice sheet discharges vast fleets of icebergs into the North Atlantic, leaving layers of ice-rafted debris in deep-sea cores far from any coast. The freshwater released disrupts overturning circulation and cools the North Atlantic region sharply, with effects reaching the tropics and the monsoons. They are the clearest evidence that ice sheets can collapse partially and abruptly on their own, not only in response to warming.