On 11 October 1918 , the western coast of Puerto Rico was hit by a major earthquake which caused a tsunami . The 1918 earthquake was caused by an old left-lateral strike-slip fault near the Mona Passage . In 1953 , Santo Domingo , Dominican Republic , was affected by the Santo Domingo earthquake . The actual subduction zone ( Puerto Rico Trench ) has not ruptured in over 200 years , which is a major concern to geophysicists , as they believe it may be due for a major event
major earthquake
1918 San Fermín earthquake
Puerto Rico Trench