High‐fidelity paleointensity determination from historic volcanoes in Japan
High‐fidelity paleointensity determination from historic volcanoes in Japan
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DOI：
10.1029/2012jb009368
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发表时间：
2012-08
影响因子：
--
通讯作者：
Yongjae Yu
中科院分区：
文献类型：
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作者：
Yongjae Yu
[1]提供高精度的古地磁强度估计是识别古地磁场时间波动的关键。尽管日本有丰富的古地震烈度数据，但只有十几个数据符合现代标准，并进行了系统的蚀变检查。高保真度的古强度估计获得了从山收集的历史安山质熔岩。阿索（Ojodake，公元前700年），山雾岛（Iwoyama，AD 1768; Ohachi，AD 1235），and Mt.樱岛（安英，公元1779年; Nabeyama，公元764 - 766年）。在过去的4000年里，日本的地磁场强度变化与全球模型（ARCH3k.1，CALS 3k.3，CALS 3k.4，CALS 7k.2和CALS 10k.1b）的预测明显不同。在日本编制的高保真Thellier数据集显示，在公元前590 - 765年和公元1330 - 1435年有两个明显的高强度，在公元前700年有一个低强度。这些具有异常高/低强度的时间间隔与从欧洲古地磁数据中识别出的四个潜在的古地磁急动中的三个几乎相同，这意味着古地磁急动具有全球性（或至少是北方半球）特征。为了改善全球模式预测的区域地磁场变化的代表性差，在东亚地区需要更多的高保真古强度测定。
[1] Providing high-fidelity paleointensity estimates is pivotal to identify temporal fluctuation of ancient geomagnetic field. Despite abundance of available paleointensity data in Japan, only dozen of them satisfy modern standards with systematic alteration checks. High-fidelity paleointensity estimates were obtained from historic andesitic lavas collected from Mt. Aso (Ojodake, ≈700 BC), Mt. Kirishima (Iwoyama, AD 1768; Ohachi, AD 1235), and Mt. Sakurajima (An-ei, AD 1779; Nabeyama, AD 764–766). Variation of geomagnetic field intensity is distinctively different from the prediction of global models (ARCH3k.1, CALS3k.3, CALS3k.4, CALS7k.2, and CALS10k.1b) for the past 4000 years in Japan. The compilation of high-fidelity Thellier data set in Japan showed two obvious high intensities at AD 590–765 and AD 1330–1435 and one low intensity at ≈700 BC. These time intervals with anomalous high/low intensities are nearly identical to three of the four potential archeomagnetic jerks recognized from the European archeomagnetic data, implying that the archeomagnetic jerks were global (or at least northern hemispheric) features. To improve the poor representation of regional geomagnetic field variation with respect to the global model prediction, more high-fidelity paleointensity determinations are required in East Asia.