The Science and Mechanics of a Tsunami

Tsunamis are long-period gravity waves generated by disturbances capable of transferring substantial energy into the ocean. Although major submarine earthquakes are responsible for many of history’s most destructive tsunamis, landslides, volcanic eruptions, and atmospheric disturbances can also produce catastrophic coastal flooding. This article investigates the physical mechanisms governing tsunami generation, propagation, shoaling, run-up, and inundation, examining how geological sources interact with ocean bathymetry, coastal geography, infrastructure, and human behavior. Historical and contemporary events, including the 1755 Lisbon earthquake, 1883 Krakatau eruption, 1958 Lituya Bay megatsunami, 1960 Chilean earthquake, 2004 Indian Ocean tsunami, 2011 Tōhoku disaster, 2018 Anak Krakatau collapse, and 2022 Hunga Tonga–Hunga Haʻapai eruption, demonstrate the diversity of tsunami sources and consequences. Particular attention is given to scientific forecasting, warning-system limitations, traditional knowledge, the Philippines, and rising sea levels. Future tsunami risk will depend not only on geological events but also on decisions concerning coastal development, scientific monitoring, infrastructure resilience, and evacuation preparedness.