What is under Puerto Rico?

Under Puerto Rico is the Puerto Rico trench. The Puerto Rico Trench is a deep oceanic trench in the Atlantic Ocean north of the island of Puerto Rico. It is the deepest point in the Atlantic Ocean, with a depth of 8,605 metres (28,225 feet). The trench is about 175 kilometres (109 miles) long and 65 kilometres (40 miles) wide, and is part of the Cayman Trench, a larger geologic feature that extends from Cuba to the Cayman Islands to Puerto Rico. The trench is the result of the collision of the North American and Caribbean tectonic plates, which caused the sea floor to buckle and form the deep trench.