Correlated petrology and seismicity indicate rapid magma accumulation prior to eruption of Kizimen volcano, Kamchatka

Abstract

The increase in number and intensity of earthquakes during a pre-eruptive crisis is the main basis of seismic volcano monitoring. However, a strong understanding of how these seismic signals relate to magmatic processes in the magma plumbing systems prior to volcanic eruptions is crucial for these efforts. Here we compare the characteristics of a seismo-volcanic crisis prior to the 2010–2013 explosive-extrusive eruption of Kizimen volcano, Kamchatka with the timescales of processes in the magma plumbing system. These timescales are inferred from the numerical modelling of iron-magnesium intracrystalline interdiffusion in 88 zoned orthopyroxene crystals from dacites and silica-rich andesites collected after the eruption. We find that the eruptible magmas were assembled rapidly during a magma mixing process beginning around 1.5 years before the eruption, which is well correlated with the onset of the seismic crisis. We conclude that the observed seismic re-activation marked the onset of magma mixing and led to destabilization of the reservoir, followed by the eruption.

Sulfur‐rich mafic magma injection into the felsic magma chamber beneath Asama volcano, central Japan: Records in olivine‐hosted melt inclusions from the Itabana and Tenmei eruptions

“…The injection of new mafic magma often marks the beginning of a new phase of volcanic unrest (Sparks & Cashman, 2017). Timing between injection of new mafic magma and eruption is highly variable but has been estimated for some eruptions (Ostorero et al, 2022). The addition of new magma will lead to magma hybridization and therefore partly or completely obliterate the contribution of the original basaltic injection (Auer et al, 2018).…”

“…The injection of new mafic magma often marks the beginning of a new phase of volcanic unrest (Sparks & Cashman, 2017). Timing between injection of new mafic magma and eruption is highly variable but has been estimated for some eruptions (Ostorero et al, 2022).…”

The role of mixing and crystallization in the differentiation of magmatic systems

“…This process could have led to slow effusion of magma in dome complexes from Mount Dutton 28 and the hot ma c recharge at Quizapu volcano (Chile) in AD 1846-1847 which produced an andesite-dacite mingled lava ow without an explosive component, due to syn-eruptive magma degassing following the recharge 89 . Ma c injections into felsic magma reservoirs can also lead to endmembers hybridization without triggering an eruption, for example for Kizimen volcano 30,31 and…”

“…We use a natural dacite from the 2010-2013 eruption of Kizimen volcano (Kamchatka) (Fig. 1c) (the sample coordinates are speci ed in another study 31 ) and a synthetic basalt end-member (Supplementary Table 1; Supplementary Note). A basalt was synthesized (Supplementary Note) because no natural ma c samples were found on the eld after the 2010 Kizimen eruption; either because no ma c samples were emitted on the surface during the eruption or because only a small quantity was emitted and was missed during the sampling.…”

“…The basaltic composition corresponds to a basaltic enclave in a lava ow of Kizimen 92 (Supplementary Table 1; Supplementary Note). The dacitic sample is porphyritic and consists of ~ 29% of crystals (plagioclase, amphiboles, orthopyroxenes, Fe-Ti oxides and some resorbed olivines and quartz) 31 . Powders from each of the two end-members were melted and homogenized for 4 h inside a high-temperature furnace (Nabertherm® HT 04/17) at ambient pressure at the Department of Physics and Geology (University of Perugia) at 1500°C in Pt 80 Rh 20 crucibles (same method as previous studies 16, 40,93 ).…”