Details

Rocas Atoll. This photograph, acquired on 21 November 2019, was taken by an astronaut onboard the International Space Station (ISS), shows the only atoll in the South Atlantic Ocean. Rocas Atoll is part of the Fernando de Noronha archipelago, located approximately 260 kilometers (160 miles) off the northeastern coast of Brazil. This image clearly captures the defining boundary between the outer algal ridge, the open ocean, and the sandy bottom closer to the atoll’s center.
An atoll is usually a circular or oval-shaped reef structure with a lagoon in the center. These structures typically form around a volcanic island that has subsided while the coral continues to grow upward.
This photograph, acquired on November 21, 2019, was taken by an astronaut onboard the International Space Station (ISS), shows the only atoll in the South Atlantic Ocean. Rocas Atoll is part of the Fernando de Noronha archipelago, located approximately 260 kilometers (160 miles) off the northeastern coast of Brazil. This image clearly captures the defining boundary between the outer algal ridge, the open ocean, and the sandy bottom closer to the atoll’s center.
An atoll is usually a circular or oval-shaped reef structure with a lagoon in the center. These structures typically form around a volcanic island that has subsided while the coral continues to grow upward. Photo courtesy of NASA.