Bond event

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 the Holocene, mainly based on petrologic tracers of drift ice in the North Atlantic. However, more recent work at a single site suggested that the 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, after the publication of the Greenland Ice Core Chronology 2005 (GICC05) for the North Greenland Ice Core Project 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 with most aridification events in the Middle East for the past 55,000 years (both Heinrich and Bond events).

List

Most Bond events do not have a clear climate signal; some correspond to periods of cooling, but others are coincident with aridification in some regions. Gaps between events have been estimated to be 1,000–1,500 years, with Bond event # 4 as an outlying data point.