The model of the Uzon-Geizernaya volcano-tectonic depression and Kikhpinych volcano, Kamchatka, from the joint analysis of microseismic sounding data and local geodynamic activity

Abstract

The model of the magmatic system beneath the Uzon-Geizernaya volcano-tectonic depression and adjacent Kikhpinych volcano in Kamchatka is constructed to a depth of 30 km based on the microseismic sounding data. For doing this, measurements of the natural microseismic field by the Guralp CMG-6TD portable broadband seismometer were carried out at 60 points along three profiles with a total length of about 28 km. The revealed structural heterogeneities were interpreted in the common context with the previous geological, geological-morphological, and petrological results. The area of a shallow crystallized magmatic reservoir is identified and spatially localized below the depression. The zones of the presumed concentration of the basaltic melts probably responsible for the local geodynamic activation of the region during the past 15 years are revealed as the peripheral magmatic chamber of the Kikhpinych volcano at a depth of 5–12 km and a deeper (15–20 km) magma storage. The geometry of the identified deep structures is consistent with the local microseismicity and the model of the contemporary magmatic intrusion into the upper crustal layers, which is based on the data of satellite interferometry.