TY JOUR TI Gravity Waves Driven by Tsunami after the Kamchatka Earthquake on July 29, 2025 KW Tsunamigenic earthquake KW atmospheric gravity wave KW total electron content variations KW Hawaiian Islands KW Kamchatka megathrust earthquake JO Russian Journal of Earth Sciences AU Ryabova, S.A. AU Shalimov, S.L. PY 2026 IS 26 PB Geophysical Center of the Russian Academy of Sciences