SUBMARINE VOLCANO 8.10 (KURIL ISLAND ARC)

Abstract

The submarine volcano 8.10, part of the South Iturup group of underwater volcanoes of the Kuril island arc (KIA), was studied using a proven technology of quantitative interpretation of hydromagnetic survey materials in combination with echo sounding, continuous seismoacoustic profiling, and analysis of petromagnetic properties and chemical composition of dredged rocks. The technology makes it possible to interpret directly from the original data without resorting to the procedure of their preliminary restoration in the nodes of a regular network. As a result of the performed studies, it was established that dredged andesite-basalts and andesites are representatives of different lava flows that have a single magmatic source, but differing in the conditions and dynamics of crystallization. The main carrier of the natural residual magnetization of basaltic andesites is titanomagnetite with low Ti content, and that for andesites is magnetite. In the volcanic edifice, supply channels and peripheral magma chambers are distinguished. The submarine Volcano 8.10, as well as the other KIA volcanoes studied, formed during geomagnetic inversions. The presence of hydroacoustic anomalies at the top of the volcano indicates that the manifestations of underwater gas-hydrothermal activity in the southern part of the KIA are more significant than was thought until recently.