Fast and furious: crustal CO2 release at Merapi volcano, Indonesia

Abstract

Volcanoes located over carbonate-rich sedimentary rocks often emit large volumes of CO2 and have strong records of explosive activity. Examples include Vesuvius and the Colli Albani volcanic field in Italy; Popocatepetl in Mexico; and Merapi in Indonesia, all of which display petrological and/or gas-chemical evidence for magma-carbonate interaction. Merapi is one of the most active volcanoes in Java (Fig. 1), and represents a serious hazard by being located less than 30 km from Yogyakarta, the largest city in Central Java with a population of about 3.5 million. In this article, we discuss the outcome of recently-published experimental results demonstrating that CO2 can be released through a magma-carbonate interaction more rapidly than had been previously expected. As carbonate rocks are considered to be an important source of the volcanic CO2 at Merapi, and because they are also a potential influence on eruption dynamics, understanding the timescales of crustal CO2 degassing is important in improving eruption forecasting at carbonate-hosted volcanoes.