A digital liquefaction susceptibility map for the HAZUS earthquake loss estimation of the San Juan metropolitan area, Puerto Rico

Puerto Rico is part of a seismically active region. Earthquakes of low to moderate intensity regularly affect Puerto Rico and the surrounding region (McCann, 1985). Historical records document that earthquakes caused extensive damage in Puerto Rico in 1670, 1787, and 1918. The intensities of these three earthquakes may have been capable of inducing land-deformation processes, such as liquefaction. Liquefaction occurs when a saturated soil loses its cohesive properties owing to excess pore-water pressure generated by and accumulated during strong earthquake ground shaking. Areas vulnerable to liquefaction are particularly vulnerable to extensive property damage during earthquakes. The earthquakes of 1670 and 1918 possibly caused liquefaction in the coastal zone of western Puerto Rico (Moya and McCann, 1994).