Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 Earthquake
A large number of various precursors have been reported since the Wenchuan <i>M</i><sub>S</sub> 8.0 earthquake (EQ) took place on 12 May 2008 in China. In this work, previous investigations of both ground-based electromagnetic (EM) parameters and spatial ionospheric parameter...
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doaj-fb5b21ea0b644ff5b07fc527c8146c572020-11-25T00:47:47ZengMDPI AGAtmosphere2073-44332019-06-0110735510.3390/atmos10070355atmos10070355Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 EarthquakeMei Li0Jun Lu1Xuemin Zhang2Xuhui Shen3China Earthquake Networks Center, China Earthquake Administration, Beijing 100045, ChinaChina Earthquake Networks Center, China Earthquake Administration, Beijing 100045, ChinaThe Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, ChinaThe Institute of Crustal Dynamics, China Earthquake Administration, Beijing 100085, ChinaA large number of various precursors have been reported since the Wenchuan <i>M</i><sub>S</sub> 8.0 earthquake (EQ) took place on 12 May 2008 in China. In this work, previous investigations of both ground-based electromagnetic (EM) parameters and spatial ionospheric parameters were first examined. The statistical results showed that various anomalies presented different time-scale variations but tended to be characterized by a common feature − reaching their climax on 9 May, three days before the Wenchuan event, which indicates a lithosphere−atmosphere−ionosphere (LAI) electromagnetic coupling. Second, the fluctuations on 9 May based on the observational ground-based ultra low frequency (ULF) electrical field at the Gaobeidian (GBD) station and the direct current/ultra low frequency (DC−ULF) geomagnetic vertical Z field at the Chengdu (CD) station were comparably analyzed with those of ionospheric disturbances reported previously. The results showed that distinct electromagnetic changes, geomagnetic “double low-point” phenomena, and ionospheric disturbances above both sides of the Earth started in turn, respectively, but reached their climax simultaneously within dozens of hours on 9 May. This evolutionary process increases the probability that electromagnetic energy propagates from the epicentral area, via the atmosphere and ionosphere, to the equatorial plane, and through this plane finally to its magnetically conjugated area in the opposite hemisphere, causing electromagnetic disturbances on the Earth’s surface, in the atmosphere, and in the ionosphere and its conjugate point, in that order.https://www.mdpi.com/2073-4433/10/7/355Wenchuan earthquakeground-based electromagnetic variationsionospheric disturbanceslithosphere-atmosphere-ionosphere electromagnetic coupling process |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Mei Li Jun Lu Xuemin Zhang Xuhui Shen |
spellingShingle |
Mei Li Jun Lu Xuemin Zhang Xuhui Shen Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 Earthquake Atmosphere Wenchuan earthquake ground-based electromagnetic variations ionospheric disturbances lithosphere-atmosphere-ionosphere electromagnetic coupling process |
author_facet |
Mei Li Jun Lu Xuemin Zhang Xuhui Shen |
author_sort |
Mei Li |
title |
Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 Earthquake |
title_short |
Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 Earthquake |
title_full |
Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 Earthquake |
title_fullStr |
Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 Earthquake |
title_full_unstemmed |
Indications of Ground-based Electromagnetic Observations to A Possible Lithosphere–Atmosphere–Ionosphere Electromagnetic Coupling before the 12 May 2008 Wenchuan <i>M</i><sub>S</sub> 8.0 Earthquake |
title_sort |
indications of ground-based electromagnetic observations to a possible lithosphere–atmosphere–ionosphere electromagnetic coupling before the 12 may 2008 wenchuan <i>m</i><sub>s</sub> 8.0 earthquake |
publisher |
MDPI AG |
series |
Atmosphere |
issn |
2073-4433 |
publishDate |
2019-06-01 |
description |
A large number of various precursors have been reported since the Wenchuan <i>M</i><sub>S</sub> 8.0 earthquake (EQ) took place on 12 May 2008 in China. In this work, previous investigations of both ground-based electromagnetic (EM) parameters and spatial ionospheric parameters were first examined. The statistical results showed that various anomalies presented different time-scale variations but tended to be characterized by a common feature − reaching their climax on 9 May, three days before the Wenchuan event, which indicates a lithosphere−atmosphere−ionosphere (LAI) electromagnetic coupling. Second, the fluctuations on 9 May based on the observational ground-based ultra low frequency (ULF) electrical field at the Gaobeidian (GBD) station and the direct current/ultra low frequency (DC−ULF) geomagnetic vertical Z field at the Chengdu (CD) station were comparably analyzed with those of ionospheric disturbances reported previously. The results showed that distinct electromagnetic changes, geomagnetic “double low-point” phenomena, and ionospheric disturbances above both sides of the Earth started in turn, respectively, but reached their climax simultaneously within dozens of hours on 9 May. This evolutionary process increases the probability that electromagnetic energy propagates from the epicentral area, via the atmosphere and ionosphere, to the equatorial plane, and through this plane finally to its magnetically conjugated area in the opposite hemisphere, causing electromagnetic disturbances on the Earth’s surface, in the atmosphere, and in the ionosphere and its conjugate point, in that order. |
topic |
Wenchuan earthquake ground-based electromagnetic variations ionospheric disturbances lithosphere-atmosphere-ionosphere electromagnetic coupling process |
url |
https://www.mdpi.com/2073-4433/10/7/355 |
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