Tsunamigenic

Tsunamigenic refers to anything that can generate a tsunami. The term derives from tsunami and the suffix -genic meaning producing. In practice, tsunamigenic sources are events that displace seawater, most commonly earthquakes of the seafloor, but also submarine landslides, volcanic eruptions, or, far less commonly, meteorological phenomena or asteroid impacts.

Most tsunamigenic tsunamis originate from undersea earthquakes, especially those involving sudden vertical movement of the sea floor at subduction zones. Volcanic eruptions, particularly explosive eruptions that involve submarine or island edifices, and massive submarine landslides can also produce tsunamis. Other rare sources include meteorite impacts and large-scale atmospheric disturbances that couple with the ocean surface (meteotsunamis).

In deep water, tsunamis have long wavelengths (often hundreds of kilometers) and travel rapidly, up to about 700–800 km/h depending on depth. Their wave heights are typically small offshore, but amplification near coastlines can produce significant run-up. Run-up height, inundation, and damage depend on seabed displacement, bathymetry, coastal topography, and tide and wave direction.

Detection and warning systems use seismic data and ocean-bottom pressure sensors to detect tsunamis and issue alerts. Early warning times range from minutes to hours for distant sources, whereas near-field tsunamis may give little warning. Preparedness and risk mitigation rely on planning, education, and evacuation procedures.

See also: tsunami, tsunami warning system, DART (Deep-ocean Assessment and Reporting of Tsunamis).