Abstract
The eruption of Makaturing volcano in Mindanao, Philippines circa 1765 displaced the local Maranao-speaking Iranun people, who relocated as far as the west coast of Borneo, significantly impacting the history of Southeast Asia. Deprived of their former way of life, the Iranun sea raiders roamed the seas of neighbouring coasts from New Guinea and the Moluccas to mainland Southeast Asia. Their exploits had the immediate effects of severely disrupting traditional trade routes and striking great fear into coastal populations across Southeast Asia. No record of the eruption exists in global eruption catalogues. Historical accounts provide limited spatial information about the characteristics of the eruption, with pyroclastic density currents “littering the landscape and harbour with tons of stones and huge boulders” (deposits > 2 m thick) and ash deposited 40 leagues (230 km) to the southwest of the volcano in the Sulu archipelago. We use a numerical ash dispersal model to reconstruct the eruption dynamics, duration and impacts, as well as to constrain the time of year of the eruption. The direction of ash dispersal and reported deposit characteristics suggest that the eruption happened towards the end of the year and was relatively low magnitude, reinforcing the importance of context in the assessment of eruption consequences.
