Mona passage
Coordinates: 18°30′N 68°0′W / 18.500°N 68.000°W
The Mona Passage is a strait that separates the islands of Hispaniola and Puerto Rico. The Mona Passage connects the Atlantic Ocean to the Caribbean Sea, and is an important shipping route between the Atlantic and the Panama Canal.
The 80 mi (130 km) stretch of sea between the four islands is one of the most difficult passages in the Caribbean. It is fraught with variable tidal currents created by the large islands on either side of it, and by sand banks that extend out for many miles from both coasts.
There are three islands in the Mona Passage:
The Passage was also the site of a devastating earthquake and resulting tsunami that hit western Puerto Rico in 1918. It is the site of frequent small earthquakes. The passage is underlain by a seismically active rift zone that overprints an older partly eroded tilted-block structure. Desecheo Island sits on the Desecheo ridge, a narrow east–west ridge that extends west from the northwest corner of Puerto Rico. The ridge forms the southern boundary of the 4000 m deep Mona rift which extends toward the north to the strike slip fault zones which bound Puerto Rico and Hispanola. The east face of the rift has a sharp relief of 3 km and is controlled by the N - S trending Mona Rift Fault. The epicenter of the 1918 earthquake was located along the east or southeast edge of the Mona Rift.
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