title: Six centuries of geomagnetic intensity variations recorded by royal Judean stamped jar handles.
abstract: Earth's magnetic field, one of the most enigmatic physical phenomena of the planet, is constantly changing on various time scales, from decades to millennia and longer. The reconstruction of geomagnetic field behavior in periods predating direct observations with modern instrumentation is based on geological and archaeological materials and has the twin challenges of (i) the accuracy of ancient paleomagnetic estimates and (ii) the dating of the archaeological material. Here we address the latter by using a set of storage jar handles (fired clay) stamped by royal seals as part of the ancient administrative system in Judah (Jerusalem and its vicinity). The typology of the stamp impressions, which corresponds to changes in the political entities ruling this area, provides excellent age constraints for the firing event of these artifacts. Together with rigorous paleomagnetic experimental procedures, this study yielded an unparalleled record of the geomagnetic field intensity during the eighth to second centuries BCE. The new record constitutes a substantial advance in our knowledge of past geomagnetic field variations in the southern Levant. Although it demonstrates a relatively stable and gradually declining field during the sixth to second centuries BCE, the new record provides further support for a short interval of extreme high values during the late eighth century BCE. The rate of change during this "geomagnetic spike" [defined as virtual axial dipole moment > 160 ZAm2(1021Am2)] is further constrained by the new data, which indicate an extremely rapid weakening of the field (losing ∼27% of its strength overca.30 y).
authors.affiliation: Department of Archaeology and Ancient Near Eastern Cultures, Tel Aviv University, Tel Aviv 69978, Israel; ltauxe@ucsd.edu ebenyose@post.tau.ac.il.|Institute of Archaeology, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Erez
authors.initials: E
authors.lastname: Ben-Yosef
authors.affiliation: Department of Archaeology and Ancient Near Eastern Cultures, Tel Aviv University, Tel Aviv 69978, Israel.|Institute of Archaeology, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Millman
authors.affiliation: The Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Ron
authors.initials: R
authors.lastname: Shaar
authors.affiliation: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0220 ltauxe@ucsd.edu ebenyose@post.tau.ac.il.
authors.forename: Lisa
authors.identifier: 0000-0002-4837-8200
authors.initials: L
authors.lastname: Tauxe
authors.affiliation: Department of Archaeology and Ancient Near Eastern Cultures, Tel Aviv University, Tel Aviv 69978, Israel.|Institute of Archaeology, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Oded
authors.initials: O
authors.lastname: Lipschits
keywords: archaeointensity; archaeomagnetic spikes; archaeomagnetism; levantine archaeomagnetic curve; paleosecular variation