Large Geomagnetic Field Anomalies Revealed in Bronze to Iron Age Archeomagnetic Data from Tel Megiddo and Tel Hazor, Israel
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UC San Diego UC San Diego Previously Published Works Title Large geomagnetic field anomalies revealed in Bronze to Iron Age archeomagnetic data from Tel Megiddo and Tel Hazor, Israel Permalink https://escholarship.org/uc/item/6qq4n62v Authors Shaar, Ron Tauxe, Lisa Ron, Hagai et al. Publication Date 2016-05-15 DOI 10.1016/j.epsl.2016.02.038 Peer reviewed eScholarship.org Powered by the California Digital Library University of California JID:EPSL AID:13725 /SCO [m5G; v1.173; Prn:2/03/2016; 15:35] P.1(1-13) Earth and Planetary Science Letters ••• (••••) •••–••• 1Q1 Contents lists available at ScienceDirect 67 2 68 3 69 4 Earth and Planetary Science Letters 70 5 71 6 72 7 www.elsevier.com/locate/epsl 73 8 74 9 75 10 76 11 77 12 Large geomagnetic field anomalies revealed in Bronze to Iron Age 78 13 archeomagnetic data from Tel Megiddo and Tel Hazor, Israel 79 14 80 ∗ 15Q2 Ron Shaar a,b, , Lisa Tauxe b, Hagai Ron a, Amotz Agnon a, Yael Ebert a, Sharon Zuckerman c, 81 16 d 82 17 Israel Finkelstein 83 18 a 84 The Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel b 19 Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0220, USA 85 c 20 The Institute of Archaeology, The Hebrew University of Jerusalem Jerusalem 91905, Israel 86 d 21 The Department of Archaeology and Ancient Near Eastern Civilizations, Tel Aviv University, Tel Aviv 6997801, Israel 87 22 88 23 a r t i c l e i n f o a b s t r a c t 89 24 90 25 91 Article history: Geomagnetic field measurements from the past few centuries show heightened secular variation activity 26 92 Received 13 October 2015 in the southern hemisphere associated with the south Atlantic anomaly (SAA). It is uncertain whether 27 Received in revised form 2 February 2016 93 geomagnetic anomalies at a similar scale have existed in the past owing to limited coverage and 28 Accepted 17 February 2016 94 uncertainties in the paleomagnetic database. Here we provide new evidence from archaeological sources 29 Available online xxxx 95 in the Levant suggesting a large positive northern hemisphere anomaly, similar in magnitude to the SAA Editor: B. Buffett 30 during the 9th–8th centuries BCE, called “Levantine Iron Age anomaly”. We also report an additional 96 31 Keywords: geomagnetic spike in the 8th century. The new dataset comprises 73 high precision paleointensity 97 32 paleointensity estimates from ca. 3000 BCE to 732 BCE, and five directional measurements between the 14th and 98 33 archaeomagnetism the 9th centuries BCE. Well-dated pottery and cooking ovens were collected from twenty archaeological 99 geomagnetic anomaly 34 strata in two large contemporaneous stratigraphical mounds (tells) in Israel: Tel Megiddo and Tel Hazor. 100 geomagnetic spikes 35 The new data are combined with previously published data and interpreted automatically using the 101 geomagnetic secular variations PmagPy Thellier GUI program. The Tel Megiddo and Tel Hazor data sets demonstrate excellent internal 36 102 consistency and remarkable agreement with published data from Mesopotamia (Syria). The data illustrate 37 103 the evolution of an extreme geomagnetic high that culminated in at least two spikes between the 11th 38 104 and the 8th centuries BCE (Iron Age in the Levant). The paleomagnetic directional data of the 9th century 39 ◦ 105 BCE show positive inclination anomalies, and deviations of up to 22 from the averaged geocentric axial 40 dipole (GAD) direction. From comparison of the Levantine archaeomagnetic data with IGRF model for 106 41 2015 we infer the “Levantine Iron Age anomaly” between the 10th and the 8th centuries BCE is a local 107 42 positive anomaly. The eastward extent of the anomaly is currently unknown. 108 43 © 2016 Elsevier B.V. All rights reserved. 109 44 110 45 111 46 112 47 113 48 1. Introduction SV is used to decipher the role that geomagnetism may play 114 49 in controlling climate (Gallet et al., 2005, 2006; Courtillot et 115 50 The geomagnetic field has changed constantly throughout al., 2007; Wanner et al., 2008; Knudsen and Riisager, 2009; 116 51 Earth’s history, from large-scale global events such as reversals Ertepinar et al., 2012); in geochronology, SV helps constrain 117 52 and excursions to short temporal and spatial scale changes known chronologies for archaeological dating (Ben-Yosef et al., 2008b; 118 53 as secular variation (SV). SV is among the least well constrained Lodge and Holme, 2009; Ben-Yosef et al., 2010; Pavon-Carrasco 119 54 of the geomagnetic phenomena. Yet, it is of key interest for a et al., 2011). 120 55 number of research fields: In geophysical research SV is used to Recent SV data from the first two millennia BCE from Euro- 121 56 study geodynamo processes, outer core properties, and lower man- Asian archaeological sources have revealed intriguing anomalies. 122 57 tle heterogeneities (Jackson et al., 2000; Jackson and Finlay, 2007; Ben-Yosef et al. (2009) and Shaar et al. (2011) reported high field 123 intensity fluctuations in the southern Levant (Israel and Jordan) 58 Korte and Holme, 2010); in climatic and environmental research 124 59 during the 10th and the 9th century BCE that they referred to 125 60 as “geomagnetic spikes”. The “spikes” are the extreme climax of 126 a high field maximum (>160 ZAm2) in the Levant that appears 61 * Corresponding author at: The Institute of Earth Sciences, The Hebrew University 127 62 of Jerusalem, Jerusalem 91904, Israel. Tel.: +972 2 6584248. in close approximation to other unusually high paleointensity val- 128 63 E-mail address: [email protected] (R. Shaar). ues seen in Turkey (Ertepinar et al., 2012)and Georgia (Shaar et 129 64 130 http://dx.doi.org/10.1016/j.epsl.2016.02.038 65 131 0012-821X/© 2016 Elsevier B.V. All rights reserved. 66 132 JID:EPSL AID:13725 /SCO [m5G; v1.173; Prn:2/03/2016; 15:35] P.2(1-13) 2 R. Shaar et al. / Earth and Planetary Science Letters ••• (••••) •••–••• 1 al., 2013), and to other local maxima with lower values seen, for 67 2 example, in France (Herve et al., 2013), and SE Asia (Hong et al., 68 3 2013). Thus, at least at a continental scale, the high-field episode 69 4 is likely associated with a complicated field structure (Genevey 70 5 et al., 2008; Kovacheva et al., 2009; Korte and Constable, 2011; 71 6 Tema and Kondopoulou, 2011; Tema et al., 2012; Kovacheva et al., 72 7 2014), suggesting a complex global deviation from a simple dipole 73 8 configuration (de Groot et al., 2013, 2015) that calls for further in- 74 9 vestigation. 75 10 After establishing the observation of a high field maximum in 76 11 the Levant during the 10th to 9th centuries, it is now paramount 77 12 to investigate its evolution through time. Also, it is of particular 78 13 interest to investigate whether the Levant high field episode is a 79 14 local anomaly (e.g. de Groot et al., 2015) or a global dipole feature 80 15 (e.g. Hong et al., 2013). Addressing these issues is the main target 81 16 of this research. 82 17 To accomplish the abovementioned objectives we investigate 83 18 two key archaeological mounds (tells) in Israel: Tel Megiddo (also 84 19 known as Armageddon of Revelations) and Tel Hazor. These two 85 20 contemporaneous sites were of the most important settlements 86 21 during the Bronze and Iron Age in the Levant, well known in 87 22 biblical, Egyptian, and Mesopotamian texts. Owing to intense ar- 88 23 chaeological explorations of the sites over the past decades their 89 24 chronologies are precisely dated, and hence, the sites provide in- 90 25 valuable well-dated archaeological material for high-resolution ar- 91 26 chaeomagnetic investigation. 92 27 The rationale for this work is as follows. First, we explore and 93 28 test the robustness of our absolute paleointensity methodology by: 94 29 95 a) deploying a recently published automatic interpretation tech- Fig. 1. Location map. Tel-Megiddo and Tel-Hazor (this study) are marked with stars. 30 nique (Shaar an Tauxe, 2013; Shaar et al., 2015), and b) cross- Sites with measurement data uploaded to the MagIC database (colored symbols in 96 Fig. 5) are shown in colored squares. Other sites from Syria are shown in gray circles 31 checking the two independent contemporaneous archaeomagnetic 97 (open squares in Fig. 5). (For interpretation of the references to color in this figure 32 datasets. Second, we aim to deliver a comprehensive, and the most Q4 98 legend, the reader is referred to the web version of this article.) 33 complete to date, description of paleointensity variations during 99 34 the Bronze and Iron Age in the Levant by combining the overall 100 records (Finkelstein and Piasetzky, 2010; Regev et al., 2014; Toffolo 35 published data. Finally, we compare the anomalies observed in the 101 et al., 2014). Most significant are several destruction layers, dated 36 archaeomagnetic data with today’s IGRF field in order to seek sim- 102 by a large number of radiocarbon ages, which make the back- 37 ilar patterns between the SAA and the local Levantine high. 103 38 bone of the Megiddo chronology (Finkelstein and Piasetzky, 2009; 104 Regev et al., 2014). At least one destruction layer is also securely 39 2. Methods 105 40 dated historically – the one caused by the Assyrian king Tiglath- 106 Pileser III in 732 BCE. The Early Bronze Age settlement was excep- 41 2.1.