Overview of the precursors and dynamics of the 2012-13 basaltic fissure eruption of Tolbachik Volcano, Kamchatka, Russia

摘要: Abstract We present a broad overview of the 2012–13 flank fissure eruption Plosky Tolbachik Volcano in central Kamchatka Peninsula. The lasted more than nine months and produced approximately 0.55 km3 DRE (volume recalculated to density 2.8 g/cm3) basaltic trachyandesite magma. is one most voluminous historical eruptions mafic magma at subduction related volcanoes globally, it second largest Kamchatka. was preceded by five elevated seismicity ground inflation, both which peaked day before commenced on 27 November 2012. batch high-Al ascended from depths 5–10 km; its apical part contained 54–55 wt.% SiO2, main body 52–53 wt.% SiO2. started opening 6 km-long radial southwestern slope volcano that fed multi-vent phreatomagmatic magmatic explosive activity, as well intensive effusion lava with an initial discharge > 440 m3/s. After 10 days continued only lower fissure, where effusive activity Hawaiian–Strombolian type occurred pond crater growing scoria cone. rate for month long, effusion-dominated gradually declined 140 18 m3/s formed compound field total area ~ 36 km2; evolved high-discharge channel-fed 'a'a lavas dominantly low-discharge tube-fed pahoehoe lavas. On 23 August, ceased intra-crater drained. Weak Strombolian-type explosions several days bottom until end around 5 September 2013. Based array new data collected during this eruption, we develop model storage transport system links zones two genetically types (high-Al high-Mg basalts) clusters local seismicity. explains why precursory dynamics drastically different those previous 1975–76.