Bond event

Bond events are North Atlantic ice rafting events that are tentatively linked to climate fluctuations in the Holocene. Eight such events have been identified. Bond events were previously believed to exhibit a roughly c. 1,500-year cycle, but the primary period of variability is now put at c. 1,000 years.

Gerard C. Bond of the Lamont–Doherty Earth Observatory at Columbia University was the lead author of the 1997 paper that postulated the theory of 1470-year climate cycles in the Late Pleistocene and Holocene, mainly based on petrologic tracers of drift ice in the North Atlantic. However, more recent work at a single site suggested that these tracers did not provide sufficient support for 1,500-year intervals of climate change, and suggested that the reported c. 1,500 ± 500-year period was a statistical artifact.

Furthermore, following publication of the Greenland Ice Core Chronology 2005 (GICC05) for the North GRIP ice core, it became clear that Dansgaard–Oeschger events also show no such pattern. The North Atlantic ice-rafting events happen to correlate with episodes of lowered lake levels in the Mid-Atlantic region of the United States, the weakest events of the Asian monsoon for at least the past 9,000 years, and also correlate with most aridification events in the Middle East for the past 55,000 years (both Heinrich and Bond events).