deep-seated processes upper mantle advection-polymorphic hypothesis deep processes oceans velocity models адвекційно-поліморфна гіпотеза Earth’s crust Kamchatka P-wave velocity PT-parameters Tethys a complex of geological and geophysical methods advective-polymorphic hypothesis boundary of recent activation zone continents continuum mechanics crust degassing density and geoelectric models of the upper mantle energy sources filling of «white spots» formation and transfer of fluids geological hydrogen geological theory heat flow of the Earth hydrogen degassing magma sources mantle and core of the Earth mantle gravity anomaly