Tsunamis and tsunami hazards in Central America

A tsunami catalogue for Central America is compiled containing 49 tsunamis for the period 1539-1996, thirty seven of them are in the Pacific and twelv e in the Caribbean. The number of known tsunamis increased dramatically aft er the middle of the nineteenth century, since 43 events occurred between 1 850 and 1996. This is probably a consequence of the lack of population livi ng near the coast in earlier times. The preliminary regionalization of the earthquakes sources related to repor ted tsunamis shows that, in the Pacific, most events were generated by the Cocos-Caribbean Subduction Zone (CO-CA). At the Caribbean side, 5 events ar e related with the North American-Caribbean Plate Boundary (NA-CA) and 7 wi th the North Panama Deformed Belt (NPDB). There are ten local tsunamis with a specific damage report, seven in the Pa cific and the rest in the Caribbean. The total number of casualties due to local tsunamis is less than 455 but this number could be higher. The damage s reported range from coastal and ship damage to destruction of small towns , and there does not exist a quantification of them. A preliminary empirical estimation of tsunami hazard indicates that 43% of the large earthquakes (Ms greater than or equal to 7.0) along the Pacific C oast of Central America and 100% along the Caribbean, generate tsunamis. On the Pacific, the Guatemala-Nicaragua coastal segment has a 32% probability of generating tsunamis after large earthquakes while the probability is 67 % for the Costa Rica-Panama segment. Sixty population centers on the Pacifi c Coast and 44 on the Caribbean are exposed to the impact of tsunamis. This estimation also suggests that areas with higher tsunami potential in the P acific are the coasts from Nicaragua to Guatemala and Central Costa Rica; o n the Caribbean side, Golfo de Honduras Zone and the coasts of Panama and C osta Pica have major hazard. Earthquakes of magnitude larger than 7 with ep icenters offshore or onshore (close to the coastline) could trigger tsunami s that would impact those zones.