Is an unusual large enhancement of ionospheric electron density linked with the 2008 great Wenchuan earthquake
Is an unusual large enhancement of ionospheric electron density linked with the 2008 great Wenchuan earthquake
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DOI：
10.1029/2008ja013613
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发表时间：
2008-11
影响因子：
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通讯作者：
B. Zhao;Min Wang;T. Yu;W. Wan;J. Lei;Libo Liu;B. Ning
中科院分区：
文献类型：
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作者：
B. Zhao;Min Wang;T. Yu;W. Wan;J. Lei;Libo Liu;B. Ning
[1]2008年5月12日6时28分，中国西南部汶川县（31.0°N，103.4°E）发生Ms = 8.0的大地震。在武汉（30.5°N，114.4°E）和厦门（24.4°N，123.9°E），电离层F2峰的最大电子密度（NmF 2）在下午-日落时段出现异常的大幅度增强。5月9日（Kp ≤ 2）地磁平静日，即震前3天，这两个台站的平均值比5月1-12日的中值增加约2倍，而日本的山川（31.2°N，130.6°E）和冲绳（26.7°N，128.2°E）的平均值增加则不明显。结合中国58个GPS接收机网的观测资料和全球电离层图，分析了电离层总电子含量的变化，揭示了电离层电子含量长期增强的区域在东经90° ~ 130 °之间。我们的研究结果表明，这种异常增强最有可能是一个地震电离层签名。
[1] On 12 May 2008 at 0628 UT a major earthquake Ms = 8.0 struck Wenchuan County (31.0°N, 103.4°E) in southwest China. The maximum ionospheric electron density at F2 peak (NmF2) recorded an unusual large enhancement during the afternoon-sunset sector by the Chinese ionosondes over Wuhan (30.5°N, 114.4°E) and Xiamen (24.4°N, 123.9°E), which are close to the earthquake epicenter. An averaged increase at these two stations is about 2 times on a geomagnetic quiet day, 9 May (Kp ≤ 2), 3 days prior to the earthquake, relative to the median value of 1–12 May, whereas the increase was much less significant over Yamagawa (31.2°N, 130.6°E) and Okinawa (26.7°N, 128.2°E) in Japan. Combining the data from the network of 58 global positioning system receivers around China and the global ionospheric map, the variations of the total electron content reveal the region where enhancement persisted for a long period to be within longitudes 90°–130°E. Our results suggest that this abnormal enhancement is most possibly a seismo-ionospheric signature.