The convergent boundaries appear at places where two or more tectonic plates collide, move towards one another, and one or more of them are subducting bellow the other plate/s.
Because of the subduction that takes place, a lot of adjustments are happening in the crust, and that results in very common earthquake activity. The underwater earthquakes are the ones that can cause a tsunami, as they affect the water, as was the case with the devastating tsunami in 2004 in the Indian Ocean.
