Precursory activity and evolution of the 2011 eruption of Shinmoe-dake in Kirishima volcano—insights from ash samples

Ballistic ejecta and eruption condition of the vulcanian explosion of Shinmoedake volcano, Kyushu, Japan on 1 February, 2011

“…This is also supported by the facts that most of the historical explosive activities in the Shinmoedake volcano is characterized by phreatic and phreatomagmatic eruptions (Imura and Kobayashi, 2001). Even for vulcanian explosions at the later stage of the 2011 event, magma-water interaction is suggested based on a microscopic analysis of ash particles (Suzuki et al, 2013b). However, this idea is questionable for the 1 February vulcanian explosion because it is likely that the shallow hydrothermal system had been mostly dried up during the subplinian and dome-building stages in January.…”

The 2011 eruptive activity of Shinmoedake volcano, Kirishimayama, Kyushu, Japan—Overview of activity and Volcanic Alert Level of the Japan Meteorological Agency—

“…The amplitude of volcanic tremor and infrasonic wave for this event were similar to those of phreatic eruption events in 2008 and 2010 (Table 1). However, according to Geshi et al (2011) and Suzuki et al (2013), the ash of this eruption event contained pumiceous particles about 10% in volume. Therefore, it is considered that this eruption was phreatomagmatic and new magma had reached to a shallow level under the Shinmoedake crater.…”

Volume change of the magma reservoir relating to the 2011 Kirishima Shinmoe-dake eruption—Charging, discharging and recharging process inferred from GPS measurements

“…Prior to the 2011 eruption, phreatic explosions occurred in August 2008, andMarch, April, May, June, andJuly, 2010. A series of magmatic eruptions started on January 19, 2011, with a phreatomagmatic eruption with a trace of juvenile magma (Suzuki et al, 2013b). This was the first major eruption since the 1716-1717 eruption that evolved from a phreatic to a magmatic eruption (Imura and Kobayashi, 1991).…”