Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 46601 ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Analysis of ionospheric parameters above active seismic regions Analysis of ionospheric parameters above active seismic regions Patil Vivek Patil Vivek Atulkar Roshni Atulkar Roshni Purohit P K Purohit P K National Institute of Technical Teachers' Training and Research ru National Institute of Technical Teachers' Training and Research ru National Institute of Technical Teachers' Training and Research ru National Institute of Technical Teachers' Training and Research ru National Institute of Technical Teachers' Training and Research ru National Institute of Technical Teachers' Training and Research ru 16 1 1 7 29 10 2021 https://rjes.ru/en/nauka/article/46601/view

The aim of this paper is to examine the anomalous variations of the critical frequency ($f_oF2$), total electron content (TEC), and $f_oE_s$ parameters before earthquake occurred on 1 April 2014 near Iquique Chile ($M=8.2$) and event on 25 October 2013 in Japan ($M=7.1$). Using the bound method we analyzed the variations of $f_oF2$, TEC, $f_oE_s$ and $N_mF2$ parameters. The anomalous variations in $f_oF2$, TEC, $f_oE_s$ and $N_mF2$ parameters observed 1 day, 15 days, 4 days and 1 day prior to Chile event and anomalous variations in $f_oF2$, TEC and $f_oE_s$ observed 3 days, 3 days and 2 days prior to earthquake event of Japan.

The aim of this paper is to examine the anomalous variations of the critical frequency ($f_oF2$), total electron content (TEC), and $f_oE_s$ parameters before earthquake occurred on 1 April 2014 near Iquique Chile ($M=8.2$) and event on 25 October 2013 in Japan ($M=7.1$). Using the bound method we analyzed the variations of $f_oF2$, TEC, $f_oE_s$ and $N_mF2$ parameters. The anomalous variations in $f_oF2$, TEC, $f_oE_s$ and $N_mF2$ parameters observed 1 day, 15 days, 4 days and 1 day prior to Chile event and anomalous variations in $f_oF2$, TEC and $f_oE_s$ observed 3 days, 3 days and 2 days prior to earthquake event of Japan.

 $f_oF2$ TEC $f_oE_s$ $N_mF2$ earthquake ionospheric precursors bound method $f_oF2$ TEC $f_oE_s$ $N_mF2$ earthquake ionospheric precursors bound method

Antselevich, M. G. The influence of Tashkent earthquake on the Earth's magnetic field and the ionosphere // Tashkent Earthquake 26 April 1966 - Tashkent: FAN Publ.., 1971. - p. 187. Antselevich, M. G. The influence of Tashkent earthquake on the Earth's magnetic field and the ionosphere // Tashkent Earthquake 26 April 1966 - Tashkent: FAN Publ.., 1971. - p. 187. Chuo, Y. J., Chen, Y. I., Liu, J. Y., Pulinets, S. A. Ionospheric $f_oF2$ Variations prior to strong earthquakes in Taiwan area, // Adv. Space Res., 2001. - v. 27 - no. 6-7 - p. 1305. Chuo, Y. J., Chen, Y. I., Liu, J. Y., Pulinets, S. A. Ionospheric $f_oF2$ Variations prior to strong earthquakes in Taiwan area, // Adv. Space Res., 2001. - v. 27 - no. 6-7 - p. 1305. Chauhan, V., Singh, O. P., Pandey, U., Singh, B., Arora, B. R., Rawat, G., Pathan, B. M., Sinha, A. K., Sharma, A. K., Patil, A. V. A Search for precursors of earthquakes from multi-station ULF observations and TEC measurements in India, // Indian J. Radio and Space Sci., 2012. - v. 41 - p. 543. Chauhan, V., Singh, O. P., Pandey, U., Singh, B., Arora, B. R., Rawat, G., Pathan, B. M., Sinha, A. K., Sharma, A. K., Patil, A. V. A Search for precursors of earthquakes from multi-station ULF observations and TEC measurements in India, // Indian J. Radio and Space Sci., 2012. - v. 41 - p. 543. Dabas, R. S., Rupesh, M. Das, Sharma, Kavita, Pillai, K. G. M. Ionospheric pre-cursors observed over low latitudes during some of the recent major earthquakes, // J. Atm. and Sol.-Terr. Phys., 2007. - v. 69 - p. 1813. Dabas, R. S., Rupesh, M. Das, Sharma, Kavita, Pillai, K. G. M. Ionospheric pre-cursors observed over low latitudes during some of the recent major earthquakes, // J. Atm. and Sol.-Terr. Phys., 2007. - v. 69 - p. 1813. Datchenko, E. A., Ulomov, V. I., Chernyshova, C. P. Electron density anomalies as the possible precursor of Tashkent earthquake, // Dokl. Uzbek. Acad. Sci., 1972. - v. 69 - no. 12 - p. 30. Datchenko, E. A., Ulomov, V. I., Chernyshova, C. P. Electron density anomalies as the possible precursor of Tashkent earthquake, // Dokl. Uzbek. Acad. Sci., 1972. - v. 69 - no. 12 - p. 30. Dobrovolsky, I. R., Zubko, S. I., Mayachkin, V. I. Estimation of the size of earthquake preparation zones, // Pure and Appl. Geophys., 1979. - v. 117 - no. 5 - p. 1025. Dobrovolsky, I. R., Zubko, S. I., Mayachkin, V. I. Estimation of the size of earthquake preparation zones, // Pure and Appl. Geophys., 1979. - v. 117 - no. 5 - p. 1025. Gokhberg, M. B., Pilipino, V. A., Pokhotelov, O. A. Seismic Precursors in the ionosphere, // Izvestiya Earth Phys., 1983. - v. 19 - p. 762. Gokhberg, M. B., Pilipino, V. A., Pokhotelov, O. A. Seismic Precursors in the ionosphere, // Izvestiya Earth Phys., 1983. - v. 19 - p. 762. Liu, J. Y., Chuo, Y. J., Shan, S. J., Tsai, Y. B., Pulinets, S. A., Yu, S. B. Pre-earthquake Ionospheric anomalies monitored by GPS TEC, // Ann. Geophys., 2004. - v. 22 - p. 1585. Liu, J. Y., Chuo, Y. J., Shan, S. J., Tsai, Y. B., Pulinets, S. A., Yu, S. B. Pre-earthquake Ionospheric anomalies monitored by GPS TEC, // Ann. Geophys., 2004. - v. 22 - p. 1585. Plotkin, V. V. GPS detection of ionospheric perturbation before the 13 February 2001 El Salvador earthquake, // Nat. Hazards and Earth Syst. Sci., 2003. - v. 3 - p. 249. Plotkin, V. V. GPS detection of ionospheric perturbation before the 13 February 2001 El Salvador earthquake, // Nat. Hazards and Earth Syst. Sci., 2003. - v. 3 - p. 249. Pulinets, S. A., Boyarchuk, K. A. Ionospheric Precursors of Earthquakes - Berlin: Springer., 2004. - 315 pp. Pulinets, S. A., Boyarchuk, K. A. Ionospheric Precursors of Earthquakes - Berlin: Springer., 2004. - 315 pp. Xu, T., Wu, J., Zhao, Z., Liu, Y., He, S., Li, J., Wu, Z., Hu, Y. Monitoring ionospheric variations before earthquakes using the vertical and oblique sounding network over China, // Nat. Hazards Earth Syst. Sci., 2011. - v. 11 - p. 1083. Xu, T., Wu, J., Zhao, Z., Liu, Y., He, S., Li, J., Wu, Z., Hu, Y. Monitoring ionospheric variations before earthquakes using the vertical and oblique sounding network over China, // Nat. Hazards Earth Syst. Sci., 2011. - v. 11 - p. 1083.