Climate determinism or Geomagnetic determinism?
Gallet, Y.; Genevey, A.; Le Goff, M.; Fluteau, F.; Courtillot, V.
AA(Institut de Physique du Globe de Paris, 4 Place Jussieu, Paris, 75005 France ; email@example.com), AB(Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions 14 quai Francois Mitterrand, Paris, 75001 France ; firstname.lastname@example.org), AC(Institut de Physique du Globe de Paris, 4 Place Jussieu, Paris, 75005 France ; email@example.com), AD(Institut de Physique du Globe de Paris, 4 Place Jussieu, Paris, 75005 France ; firstname.lastname@example.org), AE(Institut de Physique du Globe de Paris, 4 Place Jussieu, Paris, 75005 France ; email@example.com)
American Geophysical Union, Fall Meeting 2006, abstract #GP51A-0940
1503 Archeomagnetism, 1521 Paleointensity, 1605 Abrupt/rapid climate change (4901, 8408), 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
(c) 2006: American Geophysical Union
A number of episodes of sharp geomagnetic field variations (in both intensity and direction), lasting on the order of a century, have been identified in archeomagnetic records from Western Eurasia and have been called "archeomagnetic jerks". These seem to correlate well with multi-decadal cooling episodes detected in the North Atlantic Ocean and Western Europe, suggesting a causal link between both phenomena. A possible mechanism could be a geomagnetic modulation of the cosmic ray flux that would control the nucleation rate of clouds. We wish to underline the remarkable coincidence between archeomagnetic jerks, cooling events in Western Europe and drought periods in tropical and sub-tropical regions of the northern hemisphere. The latter two can be interpreted in terms of global teleconnections among regional climates. It has been suggested that these climatic variations had caused major changes in the history of ancient civilizations, such as in Mesopotamia, which were critically dependent on water supply and particularly vulnerable to lower rainfall amounts. This is one of the foundations of "climate determinism". Our studies, which suggest a geomagnetic origin for at least some of the inferred climatic events, lead us to propose the idea of a geomagnetic determinism in the history of humanity.
Possible impact of the Earths magnetic field on the history
of ancient civilizations
Yves Gallet a,⁎, Agnès Genevey b, Maxime Le Goff a, Frédéric Fluteau a,c,
Safar Ali Eshraghi d
a Equipe de Paléomagnétisme, Institut de Physique du Globe de Paris, 4 place Jussieu, 75252 Paris cedex 05, France
b Centre de Recherche et de Restauration des Musées de France, UMR CNRS 171, Palais du Louvre, Porte des Lions,
14 quai François Mitterrand, 75001 Paris, France
c UFR des Sciences Physiques de la Terre, Université Denis Diderot Paris 7, 2 Place Jussieu, 75251 Paris cedex 05, France
d Geological Survey of Iran, Azadi sq., Meraj blvd., PO Box 13185-1494 Tehran, Iran
Received 30 November 2005; received in revised form 3 April 2006; accepted 3 April 2006
Available online 19 May 2006
Editor: R.D. van der Hilst
We report new archeointensity results from Iranian and Syrian archeological excavations dated from the second millennium BC.
These high-temperature magnetization data were obtained using a laboratory-built triaxial vibrating sample magnetometer.
Together with our previously published archeointensity results from Mesopotamia, we constructed a rather detailed geomagnetic field intensity variation curve for this region from 3000 BC to 0 BC. Four potential geomagnetic events (“archeomagnetic jerks”), marked by strong intensity increases, are observed and appear to be synchronous with cooling episodes in the North Atlantic.
This temporal coincidence strengthens the recent suggestion that the geomagnetic field influences climate change over multi-decadal time scales, possibly through the modulation of cosmic ray flux interacting with the atmosphere. Moreover, the cooling periods in the North Atlantic coincide with episodes of enhanced aridity in the Middle East, when abrupt societal changes occurred in the eastern Mediterranean and Mesopotamia.
Although the coincidences discussed in this paper must be considered with caution, they lead to the possibility that the geomagnetic field impacted the history of ancient civilizations through climatically driven environmental changes, triggering economic, social and political instability.
© 2006 Elsevier B.V. All rights reserved.
The Mayans: Climate Determinism or Geomagnetic Determinism?
Equipe de Paléomagnétisme, Institut de Physique du Globe de Paris, France
Centre de Recherche et de Restauration des Musées de France, Palais du Louvre, France
Climatic variations since the end of the last ice age have been large enough to influence the fate of ancient civilizations, and deciphering the exact role of climate in the history of old societies is an active and challenging domain of research. This potential influence, which serves as the foundation of ‘climate determinism,’ can be viewed as the response of natural-resource-dependent, agriculture-based communities to climatically driven environmental changes. In some cases, these could have provoked major damage in economic and social organization of the societies, thus paving the way for political disintegration.
Published 13 March 2007.
Index Terms: 1503 Geomagnetism and Paleomagnetism: Archeomagnetism; 1616 Global Change: Climate variability (1635, 3305, 3309, 4215, 4513).