Subsidence or Uplift:
- During an earthquake, the sudden movement of tectonic plates along a fault line can cause vertical displacement of the Earth's crust beneath the ocean. If a significant portion of the seafloor abruptly drops (subsides) or rises (uplifts), it can displace a large volume of water, generating a tsunami.
Undersea Landslides:
- Major earthquakes can trigger massive underwater landslides, especially in areas with steep underwater slopes or canyons. These landslides can displace water and initiate tsunami waves.
Seafloor Deformation:
- The ground shaking and seismic energy released by an earthquake can cause deformation and disruption of the seafloor topography. Such disturbances can disturb the equilibrium of the water column, leading to the formation of tsunamis.
The characteristics of the resulting tsunami depend on several factors, including the magnitude of the earthquake, the extent and nature of seafloor displacement, and the underwater topography of the region.
Once generated, a tsunami propagates as a series of waves that travel across the ocean at high speeds, often exceeding 500 kilometers per hour (300 miles per hour) in deep waters. As these waves approach the coastline, they encounter shallower water and slow down, causing the wave height to increase. This height increase, combined with the immense energy carried by the waves, leads to the destructive impact of tsunamis on coastal areas.
