Transitions between explosive and effusive phases during the cataclysmic 2010 eruption of Merapi volcano, Java, Indonesia

• DOI: 10.1007/s00445-016-1046-z
• Publication Date: 2016-07-18T02:39:10Z
• Authors: Katie Preece; Ralf Gertisser; Jenni Barclay; Sylvain J. Charbo...; Jean-Christophe K...; Richard A. Herd
• Keywords: Pumice; Scoria; Effusive eruption; Lateral eruption; Magma chamber; Dense-rock equivalent; Strombolian eruption; Phreatic eruption; Silicic; Dome (geology)

Transitions between explosive and effusive activity are commonly observed during dome-forming eruptions may be linked to factors such as magma influx, ascent rate degassing. However, the interplay these is complex resulting eruptive behaviour often unpredictable. This paper focuses on driving forces behind well-documented 2010 eruption of Merapi, volcano's largest since 1872. Time-controlled samples were collected from deposits, stage style activity. These include scoria pumice initial explosions, dense scoriaceous dome formed via activity, well deposited subplinian column collapse. Quantitative textural analysis groundmass feldspar microlites, including measurements areal number density, mean microlite size, crystal aspect ratio, crystallinity size distribution analysis, reveal that shallow pre- syn-eruptive magmatic processes acted govern changing eruption. High-An (up ∼80 mol% An) microlites early erupted was likely preceded by an influx hotter or more mafic magma. in driven primarily dynamics conduit, with degassing crystallisation acting feedback mechanisms, cycles Explosivity enhanced presence a 'plug' cooled within plumbing system, which hinder degassing, leading overpressure prior