Drowned beach off the Nicoya Peninsula
in Costa Rica
During the interseismic cycle (between large earthquakes),
subduction of the Cocos plate beneath the Caribbean plate offshore
Costa Rica causes the land surface near the plate boundary to be
dragged down with the downgoing plate. This vertical deformation
is purely elastic, i.e., the land will rebound after the next large
earthquake occurs there. This pattern of slow subsidence between
large earthquakes and fast uplift following a large earthquake exists
at most strongly coupled subduction zone boundaries around the world.
Contributed by Susan Schwartz |
