Relationship of the Vp/Vs Parameter with the State of the Magmatic Substance and Activity of the Northern Group of Volcanoes in Kamchatka

Research reveals that the ratio of seismic P- and S-wave velocities (Vp/Vs) varies significantly with volcanic activity and magmatic conditions in Kamchatka's Northern Group of Volcanoes (NGV). Low Vp/Vs values, indicative of melt presence or temperature changes, were observed beneath Klyuchevskoi at 8–10 km depth and Plosky Tolbachik at 3–5 km. This suggests dynamic interactions between magmatic chambers, crustal/mantle inputs, and fluid-gas components. Unlike prior assumptions, the study identifies a 'neutral layer' as the primary feeding source for these volcanoes, challenging the notion that Klyuchevskoi's peripheral chamber is the sole supplier. The findings highlight spatial-temporal Vp/Vs variations tied to volcanic activity phases, offering new insights into magma composition and subduction zone dynamics in Kamchatka.

Slavina, L. B., Kuchai, M. S., Likhodeev, D. V., & Senyukov, S. L. (2019). Relationship of the Vp/Vs Parameter with the State of the Magmatic Substance and Activity of the Northern Group of Volcanoes in Kamchatka. Izvestiya, Atmospheric and Oceanic Physics, 55(8), 816–839. https://doi.org/10.1134/s0001433819080097