Deriba Caldera, a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, is a geologically young volcanic structure located at the top of the Marra Mountains of western Sudan. This image was taken by Expedition 18 from aboard the International Space Station. The Marra Mountains are part of a large geologic feature known as the Darfur Dome. The Deriba Caldera was formed by explosive eruption of the Jebel Marra volcano approximately 3,500 years ago. Image Credit: NASA
