Resonance oscillations of the Soufrière Hills Volcano (Montserrat, W.I.) magmatic system induced by forced magma flow from the reservoir into the upper plumbing dike

摘要: Abstract Short-period deformation cycles are a common phenomenon at active volcanoes and often attributed to the instability of magma flow in upper plumbing system caused by fluctuations viscosity related cooling, degassing, crystallization. Here we present 20-min periodic oscillations ground based on high-precision continuous borehole strain data that were associated with 2003 massive dome-collapse Soufriere Hills Volcano, Montserrat (West Indies). These high-frequency lasted ~ 80 min preceded 4-hour episode rapid expansion shallow reservoir. Strain amplitude ratios indicate deformational changes generated pressure variations reservoir – reversed polarity adjacent dike. The unusually short period cannot be explained thermally induced properties. We investigate underlying mechanism via numerical model forced through reservoir-dike accounting for time-dependent dilation/contraction dike due viscous response surrounding host rock. Our results suggest cyclic modulated dynamical interplay between chamber incapacity narrow take up fast enough volumes supplied allow us place first order constraints crustal rocks consequently its fractional melt content. Hence, time crustal-scale situ measurements rheological properties mush zones magmatic systems.