Bond event
Bond events are North Atlantic climate fluctuations occurring every ≈1,470 ± 500 years throughout the Holocene. Eight such events have been identified, primarily from fluctuations in ice-rafted debris. Bond events may be the interglacial relatives of the glacial Dansgaard–Oeschger events, with a magnitude of perhaps 15–20% of the glacial-interglacial temperature change.
Gerard C. Bond of the Lamont-Doherty Earth Observatory at Columbia University, was the lead author of the paper published in 1997 that postulated the theory of 1,470-year climate cycles in the Holocene, mainly based on petrologic tracers of drift ice in the North Atlantic.[1][2]
The existence of climatic changes, possibly on a quasi-1,500 year cycle, is well established for the last glacial period from ice cores. Less well established is the continuation of these cycles into the holocene. Bond et al. (1997) argue for a cyclicity close to 1470 ± 500 years in the North Atlantic region, and that their results imply a variation in Holocene climate in this region. In their view, many if not most of the Dansgaard–Oeschger events of the last ice age, conform to a 1,500-year pattern, as do some climate events of later eras, like the Little Ice Age, the 8.2 kiloyear event, and the start of the Younger Dryas.
The North Atlantic ice-rafting events happen to correlate with most weak events of the Asian monsoon over the past 9,000 years,[3][4] as well as with most aridification events in the Middle East.[5] Also, there is widespread evidence that a ≈1,500 yr climate oscillation caused changes in vegetation communities across all of North America.[6]
For reasons that are unclear, the only Holocene Bond event that has a clear temperature signal in the Greenland ice cores is the 8.2 kyr event.
The hypothesis holds that the 1,500-year cycle displays nonlinear behavior and stochastic resonance; not every instance of the pattern is a significant climate event, though some rise to major prominence in environmental history.[7] Causes and determining factors of the cycle are under study; researchers have focused attention on variations in solar output, and "reorganizations of atmospheric circulation."[7] Bond events may also be correlated with the 1800 year lunar tidal cycle. [8]
[edit] List of Bond events
Most Bond events do not have a clear climate signal; some correspond to periods of cooling, others are coincident with aridification in some regions.
- ≈1,400 BP (Bond event 1)
- ≈2,800 BP (Bond event 2) — correlates with an early 1st millennium BC drought in the Eastern Mediterranean, possibly triggering the collapse of Late Bronze Age cultures.[9][10]
- ≈4,200 BP (Bond event 3) — correlates also with the collapse of the Akkadian Empire and the end of the Egyptian Old Kingdom.[11][12]
- ≈5,900 BP (Bond event 4)
- ≈8,100 BP (Bond event 5)
- ≈9,400 BP (Bond event 6) — correlates with the Erdalen event of glacier activity in Norway,[13] as well as with a cold event in China.[14]
- ≈10,300 BP (Bond event 7)
- ≈11,100 BP (Bond event 8) — coincides with the transition from the Younger Dryas to the boreal.[15]
[edit] See also
[edit] References
- ^ Bond, G.; et al. (1997). "A Pervasive Millennial-Scale Cycle in North Atlantic Holocene and Glacial Climates". Science 278 (5341): 1257–1266. doi:10.1126/science.278.5341.1257. http://rivernet.ncsu.edu/courselocker/PaleoClimate/Bond%20et%20al.,%201997%20Millenial%20Scale%20Holocene%20Change.pdf.
- ^ Bond, G.; et al. (2001). "Persistent Solar Influence on North Atlantic Climate During the Holocene". Science 294 (5549): 2130–2136. doi:10.1126/science.1065680. PMID 11739949.
- ^ Gupta, Anil K.; Anderson, David M.; Overpeck, Jonathan T. (2003). "Abrupt changes in the Asian southwest monsoon during the Holocene and their links to the North Atlantic Ocean". Nature 421 (6921): 354–357. doi:10.1038/nature01340. PMID 12540924.
- ^ Yongjin Wang; et al. (2005). "The Holocene Asian Monsoon: Links to Solar Changes and North Atlantic Climate". Science 308 (5723): 854–857. doi:10.1126/science.1106296. PMID 15879216.
- ^ Parker, Adrian G. et al (2006). "A record of Holocene climate change from lake geochemical analyses in southeastern Arabia". Quaternary Research 66 (3): 465–476. Bibcode 2006QuRes..66..465P. doi:10.1016/j.yqres.2006.07.001.
- ^ Viau, André E.; et al. (2002). "Widespread evidence of 1,500 yr climate variability in North America during the past 14 000 yr". Geology 30 (5): 455–458. doi:10.1130/0091-7613(2002)030<0455:WEOYCV>2.0.CO;2.
- ^ a b Cox, John D. (2005). Climate Crash: Abrupt Climate Change and What It Means for Our Future. Washington DC: Joseph Henry Press. pp. 150–155. ISBN 0309093120.
- ^ Keeling, Charles; Whorf, TP (2000). "The 1,800-Year Oceanic Tidal Cycle: A Possible Cause of Rapid Climate Change". Proceedings of the National Academy of Sciences of the United States of America 97 (8): 3814–3819. doi:10.1073/pnas.070047197. JSTOR 122066. PMC 18099. PMID 10725399. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=18099.
- ^ Kaniewski, D.; et al. (2008). "Middle East coastal ecosystem response to middle-to-late Holocene abrupt climate changes". PNAS 105 (37): 13941–13946. doi:10.1073/pnas.0803533105.
- ^ Kaniewski, D.; et al. (2010). "Late second–early first millennium BC abrupt climate changes in coastal Syria and their possible significance for the history of the Eastern Mediterranean". Quaternary Research 74 (2): 207–215. doi:10.1016/j.yqres.2010.07.010.
- ^ Gibbons, Ann (1993). "How the Akkadian Empire Was Hung Out to Dry". Science 261 (5124): 985. Bibcode 1993Sci...261..985G. doi:10.1126/science.261.5124.985. PMID 17739611.
- ^ Stanley, Jean-Daniel; et al. (2003). "Nile flow failure at the end of the Old Kingdom, Egypt: Strontium isotopic and petrologic evidence". Geoarchaeology 18 (3): 395–402. doi:10.1002/gea.10065.
- ^ Dahl, Svein Olaf; et al. (2002). "Timing, equilibrium-line altitudes and climatic implications of two early-Holocene glacier readvances during the Erdalen Event at Jostedalsbreen, western Norway". The Holocene 12 (1): 17–25. doi:10.1191/0959683602hl516rp.
- ^ Zhou Jing; Wang Sumin; Yang Guishan; Xiao Haifeng (2007). "Younger Dryas Event and Cold Events in Early-Mid Holocene: Record from the sediment of Erhai Lake". Advances in Climate Change Research 3 (Suppl.): 1673–1719. http://www.climatechange.cn/qikan/manage/wenzhang/08.pdf.
- ^ Allen, Harriet D. (2003). "Response of past and present Mediterranean ecosystems to environmental change". Progress in Physical Geography 27 (3): 359–377. doi:10.1191/0309133303pp387ra.
