Low Crustal Fluid Reservoirs in Ultramafic Cumulates of Kamchatka

Based on published geophysical and petrological data, lower crustal fluid reservoirs have been proposed below the Klyuchevskoy Volcano, expressed as a low Vp/Vs anomaly. A high Vp/Vs anomaly under the proposed fluid reservoir is interpreted as a zone of magma accumulation. The localization of fluids in these reservoirs in the ductile lower crust can vary from isolated inclusions to filling of microfractures over a time scale of several months. Using a simplified poroelastic model, it is shown that the transition in the topology of pore space filled with fluid or melt can provide the observed changes in Vp/Vs in the anomalies of high and low values at a melt content of several vol