Marum, Volcanic crater in Malampa, Vanuatu

Marum is a volcanic crater in Malampa province featuring steep slopes and multiple geological structures within its caldera. The interior shows a complex system of deep basins and rock formations shaped by continuous volcanic processes.

The crater has remained continuously active since recorded history, with numerous eruptions reshaping the surrounding area. This ongoing geological activity has profoundly influenced the development of the landscape over centuries.

The crater lies in Malampa province on Ambrym, where the indigenous population lives close to the active vents. Sulphur dioxide emissions from Marum and Benbow produce acid rain that contaminates the rainwater and drilled wells the islanders rely on for drinking water; by the end of 2008 only one water supply station was still working in the west of the island.

Visiting requires professional guides and permits, as conditions and accessibility change based on weather and volcanic activity. Check local conditions before planning your visit to understand current access possibilities.

Marum is one of the craters of Ambrym whose activity has been continuous since 1996. Between October and December 2009 it released 15,000 tonnes of sulphur dioxide, and the plume was tracked 800 km to the north-west. On 19 July 2011 gases including SO2 rose 3 km and travelled 185 km.