Tsunamis are one of the most destructive natural hazards causing heavy human losses. They can be generated by submarine earthquakes and/or volcanic eruptions and landslides, and it is almost impossible to forecast their impact. Despite different methods currently used to monitor tsunami propagation in both near field (500 km away the source) and far field (up to 500km from the source), like seafloor pressure sensors, DART and tide gauges, the monitoring of tsunamis remains very challenging. It is known that tsunami propagation generates internal gravity waves that can be detected in the ionosphere within 20-60 minutes after they are generated at the ocean surface [1, 2]. By using measurements of total electron content (TEC) from GNSS-receivers, one can detect co- tsunamic ionospheric disturbances (TTIDs), and estimate tsunami parameters based on analysis of TTIDs’characteristics. However, many phenomena, as coming from the earth and as coming from space generate gravity waves and may be confused with a tsunami signal. More particularly, the solar terminator, characterized by the day/night transition, is a very important element to consider for TTIDs detection because of its regularity of occurrence. The 29 July 2025, a Mw8.8 earthquake occurred off the eastern coast of the Kamchatka peninsula and generated a tsunami that propagated across the Pacific Ocean. This is the largest earthquake since the March 2011 Tohoku-Oki event, providing a unique opportunity to identify, within TEC time series, the key parameters required to distinguish TTIDs from solar terminator effects, and to study and characterize the associated tsunami signal. We present a detailed analysis of thespatio-temporal parameters of TTID in the Hawaii region. [1] C. O. Hines, Can. J. Phys. 38, 1441 (1960). [2] J. Hong, H. Kil, W. K. Lee, Y. S. Kwak, B. K. Choi, and L. J. Paxton, Geophys. Res. Lett. 49, e2022GL099163 (2022).