Annales Geophysicae
Annales Geophysicae
ANGEO
Articles | Volume 22, issue 5
Articles | Volume 22, issue 5
https://doi.org/10.5194/angeo-22-1585-2004
© Author(s) 2004. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-22-1585-2004
© Author(s) 2004. This work is distributed under
the Creative Commons Attribution 3.0 License.
Articles | Volume 22, issue 5
08 Apr 2004
 | 08 Apr 2004

Pre-earthquake ionospheric anomalies registered by continuous GPS TEC measurements

J. Y. Liu, Y. J. Chuo, S. J. Shan, Y. B. Tsai, Y. I. Chen, S. A. Pulinets, and S. B. Yu

Abstract. In this paper we examine pre-earthquake ionospheric anomalies by the total electron content (TEC) derived from a ground-based receiver of the Global Positioning System (GPS). A 15-day running median of the TEC and the associated inter-quartile range (IQR) are utilized as a reference for identifying abnormal signals during all of the 20M≥6.0 earthquakes in the Taiwan area from September 1999 to December 2002. Results show that the pre-earthquake ionospheric anomalies appear during 18:00–22:00LT (LT=UT+8h) within 5 days prior to 16 of the 20M≥6.0 earthquakes. This success rate of 80% (=16/20%) suggests that the GPS TEC is useful to register pre-earthquake ionospheric anomalies appearing before large earthquakes.

Key words. Ionosphere (ionospheric disturbances; ionosphere-atmosphere interactions)

How to cite. Liu, J. Y., Chuo, Y. J., Shan, S. J., Tsai, Y. B., Chen, Y. I., Pulinets, S. A., and Yu, S. B.: Pre-earthquake ionospheric anomalies registered by continuous GPS TEC measurements, Ann. Geophys., 22, 1585–1593, https://doi.org/10.5194/angeo-22-1585-2004, 2004.