Black Saw

Sierra Negra is the name given to an extensive shield volcano on the southeastern tip of Isabela Island in the Galapagos archipelago, Ecuador. It rises to a height of 1124 meters above sea level. It joins with the volcano of Cerro Azul to the west and to the north with that of Alcedo. It is one of the most active volcanoes in Galapagos with the most recent eruption in June 2018.

The surface of Sierra Negra and its neighboring volcanoes are covered by young lavas, adding difficulty for the exact knowledge of their formation. An estimate based on volume (588 km3) and the types of eruptions suggest that Sierra Negra is about 535,000 years old.