Tsunami is the oceanic gravity waves produced by mass displacements in large shallow offshore thrust earthquakes. The January 1, 2024 \(M_\textrm{W}\) 7.5 Noto Peninsula earthquake excited a tsunami to spread across the East Sea (Sea of Japan), arriving at the east coast of the Korean Peninsula. The influence of oceanic gravity waves on the coastal medium is investigated. The mass loading by tsunami induces ground tilting, producing transient long-period ground motions to be polarized in coastline-perpendicular directions. The tsunami-induced ground motions are well recorded in inland seismometers nearby the coast. The wavetrain durations and spectral contents of the tsunami-induced seismic signals in seismometers share with those of the tsunami waves in tide gauges, suggesting the same source of energy. The amplitudes of tsunami-induced ground motions are proportional to the tsunami heights, being modulated by the distance from the coast and medium properties. The discriminative tsunami-induced ground motions produce dynamic stress changes that are effective at shallow depths, reaching 0.81 kPa on the coast. A large runup height may induce dynamic stress changes effective to depths.
