Intraplate Seamounts of the Northwest Sector of the Pacific Ocean

Abstract

A method is proposed for identifying seamounts in the northwest sector of the Pacific based on the following criteria: a closed, close to isometric contour of the isobaths at the base of a structure, its quasi-conical shape, and angles of slope exceeding 5° within the limits of the closed contour. A catalog of the mountains has been compiled, consisting of 1995 objects and their quantitative characteristics. The catalog data were statistically processed, and the following was calculated: the correlation between the number of seamounts from the radius of their base and volume, the distribution of the number of mountains, and the total volume within the study area. It is shown that seamounts are characterized as multiscale, and they are located very unevenly: areas with and without their accumulation are distinguished, and the composition of volcanic rocks is typically isotopically and geochemically heterogeneous. It is concluded that currently there is no single geodynamic model that can explain the revealed phenomena in their entirety. At the same time, the data suggest that the nature of some magma chambers that feed intraplate volcanoes is caused by transformation of energy in the lithosphere as a nonlinear open system.