the earthquake in Haiti was caused by
tectonic plates moving horizontally in opposite directions along a strike-slip
fault with little vertical deformation. as we will show in
this simplified example. For a tsunami to be generated the
earthquake must have significant vertical change at the seafloor.this rarely happens with strike-slip faults. To see how tsunamis are formed, let’s look at a subduction zone with locked plates…sometimes
referred to as “locked and loading”. Here we see the leading edge of
the overlying plate is locked to the underlying plate by immense
friction . The arrow marks the original location of the continental plate.
They can hold together for tens to hundreds of years before the overcome friction and rebound, vertically displacing a great wall of water known as a tsunami .