[M-IS10] Interdisciplinary studies on pre-earthquake processes

[MIS10-11] Spatial analyses of the M7.1 earthquake precursors observed by FORMOSAT-7/COSMIC-2 on 14 November 2019

★Invited Papers

*FU-YUAN CHANG¹、YUN-CHENG WEN¹ (1.National Central University)

キーワード：FORMOSAT-7/COSMIC-2 (F7/C2), Earthquake, Special analysis

FORMOSAT-7/COSMIC-2 (F7/C2), with the mission orbit of 550 km altitude, 24-deg inclination, and a period of 97 minutes, was launched on 25 June 2019. Tri-GNSS Radio occultation System (TGRS), Ion Velocity Meter (IVM), and RF beacon onboard F7/C2 six small satellites allow scientists to observe the plasma structure and dynamics in the mid-latitude, low-latitude, and equatorial ionosphere in detail. F7/C2 TGRS is a next version and advanced generation mission payload of GOX (Gps Occultation eXperiment) onboard FORMOSAT-3/COSMIC (F3/C), which sounds ionospheric electron density profiles, while F7/C2 IVM provides in situ observations of ion density, ion temperature, and ion velocity at the satellite altitude. F7/C2 observations and the total electron content (TEC) of the global ionosphere map (GIM) are used to study SIPs of a M7.1 earthquake northwest of Kota Ternate, Indonesia on 14 November 2019. It is found over the epicenter area that the GIM TEC and F7/C2 IVM ion density significantly increases 19-20 days before the earthquake. The special analysis shows that the anomalous TEC and ion density frequently and persistently appear specifically over the epicenter area, which confirms SIPs of the plasma quantities associated the earthquake have been observed. The increase in the upward ion velocity suggests that an eastward electric fields 0.34-0.64 mV/m generated 19-20 days before the earthquake are essential.