Tsunamis are caused by violent seafloor movement associated with earthquakes, landslides, lava entering the sea, seamount collapse, or meteorite impact. The most common cause is earthquakes. See the percentages on the right for the geological events that cause tsunamis.Note that 72% of tsunamis are generated by earthquakes. A disturbance that displaces a large water mass from its equilibrium position can cause a tsunami.ee the percentages on the right for the geological events that cause tsunamis. Note that 72% of tsunamis are generated by earthquakes. A disturbance that displaces a large water mass from its equilibrium position can cause a tsunami.