Traveling ionospheric tsunami disturbances of GPS total electron content induced by the 2018 Mw 7.5 Sulawesi Indonesia earthquake

It has been known that tsunami waves can trigger atmospheric disturbances, which is termed traveling atmospheric tsunami disturbances (TATDs) near the sea surface, then travel upward into the ionosphere and significantly disturb the electron density within it, which is called traveling ionospheric tsunami disturbances (TITDs). In this paper, TITDs in the total electron content (TEC) induced by tsunami waves of the 28 September 2018 Mw 7.5 Sulawesi Indonesia earthquake are detected by of seven ground-based receivers of the global positioning system (GPS) in the South Asia, Oceanic, Pacific areas. Both the circle method and the beam forming technique have been applied examining 20+ identified TITD signatures to locate the TATD origin and the averaged TITD horizontal propagation speed. It is found that the origin is about 100 km North of the epicenter and the horizontal speed is of about 187 m/s.