Heinrich event

Figure 5. An example of the use of concentrations to assess changes in sediment mass accumulation taken from McManus et al. (1998). The upper panel shows the measured °Thxs, calculated from measured °Th concentrations by correction for detrital °Th, and for the effects of age using 5 0 stratigraphy (see Appendix). Because the supply of °Th to the sediment is a constant, low °Th represent times of rapid sediment mass accumulation. The calculated mass flux is shown in the lower panel. Dramatic increases in mass flux are observed during all but one of the Heinrich events, shown by the gray bands.

Thomson J, Higgs NC, Clayton T (1995) A geochemical criterion for the recognition of Heinrich events and estimation of their depositional fluxes by the ( °Thexcess)° profiling method. Earth Planet Sci Lett 135 41-56... 

These are called Heinrich events after the marine scientist who discovered them in 1988 (see Chapter 13.5.4). 

NADW flows southward the ongoing oxidation of organic matter results in a progressive C-depletion down to less than 0.4%c in the Southern Ocean. Reductions in observed in many cores from the North-Atlantic (Samtheim et al. 2001 Elliot et al. 2002) have been interpreted as meltwater input to the surface ocean (Heinrich events), which caused changes in deep water circulation. 

Data on the planktonic foraminifer Neogloboquadrina pachyderma from the northeastern region of the Atlantic Ocean (west of Ireland) enabled retrieval of SST and the tracing of Heinrich events associated with iceberg kicks. 

Oerlemans J. (1993) Evaluating the role of cUmate cooUng in iceberg production and Heinrich events. Nature 364, 783-786. 

Francois R. and Bacon M. P. (1994) Heinrich events in the North Atlantic radiochemical evidence. Deep-Sea Res. 141, 315-334. 

Figure 9 High resolution alkenone temperature estimates obtained by Cacho et al. (2002) from the Mediterranean Sea in relation to oscillations in temperature recorded by in Greenland ice cores. Important millennial events (Younger Dryas = YD, H = Heinrich Event, D/0 = Dansgaard/Oeschger Event) line up between the records to the...

Bard E., Rostek F., Turon J.-L., and Gendreau S. (2000) Hydrological impact of Heinrich events in the subtropical northeast Atlantic. Science 289, 1321-1324. 

Rosell-Mele A., Maslin M. A., Maxwell J. R., and Schaeffer P. (1997) Biomarker evidence for Heinrich events. Geochim. Cosmochim. Acta 61, 1671-1678. 

K/Ar ages of Heinrich Event Detritus Nd—Sr—Pb Isotopes in Terrigenous Sediments... 

Broecker W. S., Bond G. C., Klas M., Clark E., and McManus J. (1992) Origin of the Northern Atlantic s Heinrich events. 

Grousset E. E., Pujol C., Labeyrie L., Auffret G., and Boelaert A. (2000) Were the North Atlantic Heinrich events triggered by the behavior of the European ice sheets Geology 28(2), 123-126. 

Gwiazda R. H., Hemming S. R., and Broecker W. S. (1996a) Provenance of icebergs during Heinrich event 3 and the contrast to their sources during other Heinrich episodes. Paleoceanography 11(4), 371—378. 

Hesse R. and Khodabakhsh S. (1998) Depositional facies of late Pleistocene Heinrich events in the Labrador Sea. Geology 26(2), 103-106. 

Kirby M. E. and Andrews J. T. (1999) Mid-Wisconsin Laurentide ice sheet growth and decay implications for Heinrich events 3 and 4. Paleoceanography 14(2), 211 —223. 

Blunier T., Stocker T. F., Chappellaz J., and Raynaud D. (1999) Phase lag of Antarctic and Greenland temperature in the last glacial and link between CO2 variations and Heinrich events. In Reconstructing ocean history A window into the future Proceedings of the Sixth International Conference on Paleoceanograpky) (eds. F. Abrantes and A. Mix). Kluwer Academic/Plenum, New York,pp. 121-138. 

Records of the percent ice-rafted detritus (% iRD) in cores from the North Atiantic. Heinrich events i-5 are iabeied on the graphs, aithough ionger cores indicate that there are more. The map shows a suite of cores in which these events are observed only two representative curves of the data are shown here. Modified from Hemming (2004). 

The first five Heinrich events have been dated at calendar ages of 12, 16.5, 23, 29 and 40 ly BP. They coincide with cold intervals in between some of the D/0 cycles. It is somewhat counterintuitive that armadas of icebergs would appear during cold intervals however, the... 

Hemming, S.R, (2004) Heinrich Events massive late Pleistocene detritus layers of the North Atlantic and their global climate imprint. Rev. Geophys. 42, 1-43. 

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