Characteristics of Active Volcanoes in Sumatra, Indonesia: From Perspective Seismicity, Magma Chemical Composition and Eruption History

¹ Doctoral Program of Physics, Department of Physics, Mathematics and Natural Sciences Faculty, Gadjah Mada University, Indonesia
² Geophysical Laboratory, Department of Physics, Mathematics and Natural Sciences Faculty, Universitas Gadjah Mada, Indonesia
³ Geophysics Study Program, Department of Physics, Mathematics and Natural Sciences Faculty, University of Bengkulu, Indonesia

^* Corresponding author: ws@ugm.ac.id

Abstract

The characteristics of active volcanoes in Sumatra have been summarized based on the analysis of the relationship between seismicity, morphology, magma chemical composition, and eruption history. The level of volcano activity is linked to how partial melting depth, continuity distribution of hypocentre beneath each volcano to the trench line (magma dyke), visual activity seen on craters, chemical magma content, and reoccurrence of eruption analysis. The analysis result showed the current status of the volcano is inverted linear with partial melting depth. The scatter point of the hypocentre beneath the alert and warning volcano is continued to the trench line, but normal volcano status is discontinued. It was similar to volcanic activity seen in craters. It may relate to the quantity and activity of magma flow in dyke. According to reoccurrence analysis, Mt. Krakatau, Mt. Marapi, and Mt. Kerinci are highly vulnerable because they have the shortest accumulated eruption interval. However, all of active volcanoes have the potential for repeated massive eruptions, like what happened to Sinabung. Mix eruption is their eruption because magma types tend to be basaltic and andesitic. Only on Mt. Dempo is detected rhyolitic (SiO₂ more than 65%).