Mona Canyon (Spanish: Cañón de la Mona), also known as the Mona Rift, is an 87-mile-long (140 km) submarine canyon located in the Mona Passage, between the islands of Hispaniola (particularly the Dominican Republic) and Puerto Rico, with steep walls measuring between 1.25 and 2.17 miles (2.01 and 3.49 km) in height from bottom to top.
The Mona Canyon stretches from the Desecheo Island platform, specifically the Desecheo Ridge, in the south to the Puerto Rico Trench, which contains some of the deepest points in the Atlantic Ocean, in the north.
[3] The Mona submarine canyon geomorphology is highly complex yet unexplored.
The complex seafloor is the result of oceanographic and tectonic forces that are actively forming and reshaping the landscape of the region.
The canyon is located in an intricate and irregular tectonic region at the boundary between the Caribbean and North American plates, where the east–west transversing subduction Septentrional Fault ends in an approximately 1,000-meter-deep (3,300 ft) hole west of the landform.