Tsunamis, or tidal waves, result from an imbalance in ocean waters generated by abrupt disturbances on the marine floor from volcanic eruptions, underwater landslides, meteorite impacts or earthquakes, usually of magnitude 7 or higher (TT, Jan. 7, 2005).
Since 1539, 49 tidal waves have been documented in Central America, only nine of which have caused significant destruction, killing a total 455 people. The Pacific coast has been the hardest hit, weathering 37 big waves, while 12 have hit the Caribbean.
Guatemala and Nicaragua are at the highest risk for tidal waves, though 15 small tidal waves created by earthquakes have struck Costa Rican shores, five on the Caribbean coast and 10 on the Pacific.
The most destructive wave demolished Villa Golfo Dulce in the southern Pacific zone in 1854, and was caused by a strong quake. The 1992 Nicaragua tsunami lapped Costa Rica’s northern Pacific coast, but caused little damage there, mostly to boats and bridges.