Tsunamis are caused by abrupt disturbances that displace a large mass of seawater. The most common and impactful triggers are:
- Undersea earthquakes: sudden vertical movement of the seabed at fault zones (especially near subduction zones) lifts or drops water, initiating tsunami waves that radiate outward.
- Undersea landslides: large amounts of sediment or rock sliding down continental slopes or into the ocean can shove water and generate waves.
- Volcanic activity: explosive eruptions, collapses of volcanic edifices, or caldera collapses can displace water and trigger tsunamis.
- Meteorite or asteroid impacts: a large object striking the ocean can displace seawater violently, producing tsunami waves.
- Other contributing factors: rapid changes to the sea surface from glacier calving, or complex interactions where multiple events occur in quick succession, can amplify tsunami generation.
Key context:
- The most frequent and globally destructive tsunamis are generated by earthquakes, particularly near plate boundaries where one plate dives beneath another (subduction zones). This is often summarized as “earthquakes are the primary cause, with landslides and volcanic activity as important secondary causes.”
- Tsunami energy travels across ocean basins and is shaped by seafloor topography and coastal shelf geometry, so the same deep-water disturbance can produce different wave heights when it approaches shore.
If you’d like, I can tailor this to a specific region or time frame (for example, the Pacific “Ring of Fire” and recent major events) and provide a concise, cited summary.
