Caldera-forming eruptions and characteristics of caldera volcanoes in the Sunda Arc, Indonesia

Abstract

Historical documents that describe caldera-forming eruptions in Indonesia are reviewed to identify precursory events that occurred immediately before caldera-forming eruptions, and to determine the characteristics of the eruptive history before caldera-forming eruptions. The review revealed that small-to intermediate-scale eruptions occurred several months before climactic eruptions. The distribution of eruption sites or fumarole sites expanded by several kilometers during the precursor period. The long-term eruption rate remained high for around ky, although the following changes have occurred in the past ,-, years: a decrease in the long-term eruption rate, an increase in explosive eruption events, and the migration or restriction of the distribution of eruption sites on volcano flanks. Larger pre-caldera volcano edifices tend to result in larger calderas. Finally , the range of caldera morphologies is discussed. Abstract