Ionospheric total electron content disturbance associated with May 12, 2008, Wenchuan earthquake

• Published in: Geodesy and Geodynamics Vol. 6; no. 2; pp. 126 - 134
• Main Authors: Li, Jianyong, Meng, Guojie, You, Xinzhao, Zhang, Rui, Shi, Hongbo, Han, Yufei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2015; KeAi Communications Co., Ltd
• Subjects: COSMIC; Crustal Movement Observation Network of China (CMONOC); f0F2; Global ionospheric map (GIM); Global positioning system (GPS); Ionospheric disturbance; Total electron content (TEC); Wenchuan earthquake; 全球定位系统; 大地震; 异常信号; 总电子含量; 汶川; 电子密度分布; 电离层扰动; 等离子体频率; Crustal Movement Observation Network of China (CMONOC); Wenchuan earthquake; COSMIC; Ionospheric disturbance; Global ionospheric map (GIM); Global positioning system (GPS); Total electron content (TEC); f0F2
• ISSN: 1674-9847; 2589-0573; 2589-0573
• DOI: 10.1016/j.geog.2015.01.003

Possible ionospheric disturbances relating to the May 12, 2008, MsS.0 Wenchuan earthquake were identified by Global Positioning System （GPS）-derived total electron content （TEC）, ion- osonde observations, the global ionospheric map （GIM）, and electron density profiles detected by the Constellation Observation System for Meteorology Ionosphere and Climate （COSMIC）. We applied a statistical test to detect anomalous TEC signals and found that a unique enhancement in TEC, recorded at 16 GPS stations, appeared on May 9, 2008. The critical fre- quency at F2 peak （foF2）, observed by the Chinese ionosondes, and maximal plasma frequency, derived from COSMIC data, revealed a characteristic similar to GPS TEC variations. The GIM showed that the anomalous variations of May 9 were located southeast of the epicenter. Using GPS data from 13 stations near the epicenter, we analyzed the TEC variations of satellite orbit traces during 04：00-11：00 UT. We found that TEC decreased to the east and increased to the southeast of the epicenter during this period. Results showed that the abnormal disturbance on May 9 was probably an ionosphenc precursor of the Wenchuan earthquake of May 12, 2008.