High paleointensities for the Canary Islands constrain the Levant geomagnetic high
High paleointensities for the Canary Islands constrain the Levant geomagnetic high
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DOI：
10.1016/j.epsl.2015.03.020
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发表时间：
2015-06
影响因子：
5.3
通讯作者：
L. Groot;Annemarieke Béguin;M. Kosters;E. Rijsingen;E. Struijk;A. Biggin;E. Hurst;C. Langereis;M. Dekkers
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文献类型：
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作者：
L. Groot;Annemarieke Béguin;M. Kosters;E. Rijsingen;E. Struijk;A. Biggin;E. Hurst;C. Langereis;M. Dekkers
由于缺乏地磁场区域变化的全矢量记录，目前对黎凡特强度高等神秘地磁特征的理解面临挑战。在这里，我们应用最近提出的多方法paleointensity的方法，一套19个熔岩从加那利群岛之间的公元前4000年和公元1909年。我们的新记录揭示了高古地磁强度（VADMs >120 ZAm 2）与公元前1000年地中海东部地磁强度峰值相吻合。此外，我们的数据表明，这种地磁现象以每世纪6.7-12°的速度向西移动。除了IZZI-Thellier法、微波-Thellier法和多样品法外，校正后的伪Thellier法是多方法古强度法的重要组成部分。这种相对古强度方法的校准是来自一套夏威夷熔岩，它是改进的加那利群岛冷却单位的结果。然而，从居里温度非常低（<150 °C）的样品得到的伪Thellier结果不能可靠地转换为绝对古强度估计。多方法的paleointensity方法产生了一个可靠的估计为60%的流量采样-一个异常高的成功率的paleointensity研究涉及熔岩。
Understanding the behavior of enigmatic geomagnetic traits such as the Levant intensity high is currently challenged by a lack of full vector records of regional variations in the geomagnetic field. Here we apply the recently proposed multi-method paleointensity approach to a suite of 19 lavas from the Canary Islands dating between ∼4000 BC and 1909 AD. Our new record reveals high paleointensities (VADMs >120 ZAm2) coinciding with and shortly after the peak in geomagnetic intensity in the Levant at ∼1000 BC. Furthermore our data suggests a westward movement of this geomagnetic phenomenon at a rate of 6.7–12° per century. In addition to IZZI-Thellier, microwave-Thellier and the multi-specimen method, the calibrated pseudo-Thellier method is an important part of the multi-method paleointensity approach. The calibration of this relative paleointensity method was derived from a suite of Hawaiian lavas; it is improved with the results of the Canarian cooling units. Pseudo-Thellier results from samples with very low Curie temperature (<150 °C), however, cannot be reliably converted to absolute paleointensity estimates. The multi-method paleointensity approach yielded a reliable estimate for ∼60% of the flows sampled – an unusually high success rate for a paleointensity study involving lavas.