Study of the 2013 Lushan M = 7.0 earthquake coseismic ionospheric disturbances
P. Chen1,2, J. J. Chen3, W. Q. Yao1, and B. Zhang11College of Geomatics, Xi'an University of Science and Technology, Xi'an 710054, China 2State Key Laboratory of Geodesy and Earth's Dynamics, Wuhan 430077, China 3School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China
Received: 10 Sep 2013 – Accepted for review: 18 Sep 2013 – Discussion started: 16 Oct 2013
Abstract. On 20 April 2013, an earthquake of M =7.0 occurred in Lushan, Sichuan province, China. This paper investigates the coseismic ionospheric anomalies using GPS (Global Positioning System) data from 23 reference stations in Sichuan province that are a part of the Crustal Movement Observation Network of China (CMONOC). The recorded results show that a clear ionospheric anomaly occurred within 15 min after the earthquake near the epicenter, and the occurrence time of the anomalies recorded by various stations is related to the distance from the epicenter. The maximum anomaly is 0.25 TECu, with a 2 min duration and the distance of the recording station to the epicenter is 83 km. Acoustic waves generated by the crustal vertical movement during the earthquake propagate up to the height of the ionosphere lead to the ionospheric anomaly, and the propagation speed of the acoustic wave is calculated as 0.72 ± 0.04 km s-1 based on the propagation time and propagation distance, consistent with the average speed of sound waves within a 0–450 km atmospheric height.
Chen, P., Chen, J. J., Yao, W. Q., and Zhang, B.: Study of the 2013 Lushan M = 7.0 earthquake coseismic ionospheric disturbances, Nat. Hazards Earth Syst. Sci. Discuss., 1, 5643-5662, doi:10.5194/nhessd-1-5643-2013, 2013.