Nabro Caldera #

Nabro Caldera
Image courtesy of NASA., under PD
A photo taken from the International Space Station shows the horseshoe-shaped Nabro caldera in Eritrea, near the border with Ethiopia, just days before it exploded volcanically.

The structure stretched 8 km (5 mi) in diameter and opened to the southwest. Two smaller calderas lay within the larger one. Gullies and channels scarred the outer flanks, signs of many years of runoff.

The inner edge of the caldera had steep cliffs, some as high as 400 m (1,300 ft).