two tectonic plates slide past each other underwater, causing a large movement of water
large ocean waves form
.
large ocean waves move in all directions away from the shifting plates
.
large ocean waves slow down and increase in height as they reach the coast
Explanation:
Tsunamis are initiated underwater and usually happen as a result of underwater earthquakes which can be initiated when tectonic plates slide past each other.
This causes a large movement of water such that large waves form and move away in al directions from the source. As these waves approach the shore they slow down speed but this only increases their height such that when they make landfall the effect could be devastating.
