Ionospheric perturbations in plasma parameters before global strong earthquakes |
| |
Authors: | Jing Liu Jianping Huang Xuemin Zhang |
| |
Institution: | 1. Institute of Earthquake Science, China Earthquake Administration, Beijing 100036, China;2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;3. University of Chinese Academy of Sciences, Beijing 100049, China |
| |
Abstract: | Based on the electron density (Ne) and temperature (Te) data from DEMETER, the ionospheric perturbations before 82 Ms ? 7.0 earthquakes (EQs) during 2005–2010 were studied, using moving median and space difference methods within 10 days before and 2 days after these events in local nighttime. It was found that the plasma parameters disturbances appeared before 49 EQs, in which more disturbances were detected before shallow-focus earthquakes than deep ones, and there was little difference between continental and oceanic ones, both exceeding 1/2 percentage. For the disturbed time, more perturbations were seen in 1, 3, 5, 6, 8 days before EQs and 1 day after EQs. For the spatial distribution, the anomalies before EQs were not just above the epicenters, but shifted equatorward with several degrees to almost twenty degrees. Most of the abnormities were positive ones, which demonstrate that Ne increases before EQs at the altitude of 670 km of DEMETER. Perturbations of Ne were more than that of Te, which illustrates that Ne is much more sensitive to seismic activity than Te. |
| |
Keywords: | Ionospheric perturbations Abnormities of EQs DEMETER satellite |
本文献已被 ScienceDirect 等数据库收录! |
|