(Article of periodic en Anglais - 1982)

Document title

Assessing the global meltwater spike

Authors(s) and Affiliation(s)



L. V. Worthington (1968, Meteorological Monographs 8, 6367) hypothesized that a low-salinity lid covered the entire world ocean. By deconcolving isotopic curves from the western equatorial Pacific and equatorial Atlantic, W. H. Berger, R. F. Johnson, and J. S. Killingley (1977, Nature London 269, 661-663) and W. H. Berger (1978, Deep-Sea Research 25, 473-480) reconstructed "meltwater spikes" similar to those actually observed in the Gulf of Mexico and thus apparently confirmed the Worthington hypothesis. It is shown that this conclusion is unwarranted. The primary flaw in the reconstructed meltwater spikes is that the mixing intensity used in the deconvolution operation is overestimated. As a result, structure recorded in the mixed isotopic record becomes exaggerated in the attempt to restore the original unmixed record. This structure can be attributed to variable ice-volume decay during deglaciation, effects of differential solution on planktonic foraminifera, temporal changes in abundance of the foraminifera carrying the isotopic signal, and analytical error. An alternative geographic view to the global low-salinity lid is offered: a map showing portions of the ocean potentially affected by increased deglacial meltwater at middle and high latitudes and by increased precipitation-induced runoff at low and middle latitudes.


Article of periodic

published at : Quaternary research New York

Editor :

Millesime : 1982, vol. 17, no2 [pp. 148-172]

Bibliographic references : 98 réf.



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