Most of these tsunamis were associated with underwater, or what are called submarine earthquakes, although the Caribbean Sea region has all of the potential tsunami-generating sources: submarine earthquakes, subaerial or submarine landslides and volcano activity.
They are also trying to understand the role that deep seas trenches play in earthquakes - these cracks in the sea floor are formed at the boundary of two tectonic plates and some believe the push and pull taking place deep underwater could be the cause of major earthquakes, such as the 2011 quake that resulted in such devastation in Japan.