ENVS 3000 Lecture Notes - Lecture 7: Lava Lake, Pacific Plate, Volcano
Document Summary
Magma that has emerged from a volcano onto earth"s surface. Set 7 ring of fire contains most of the world"s active volcanoes; in the pacific ocean, an area corresponding to subduction zones on the border of the pacific plate. Viscosity describes a liquid"s resistance to flow, with a high viscosity indicating a high resistance to flow. Hot magma=less viscous (determined by silica content and lava temperature) Low silica in magma so it has nonexplosive eruptions. Formed by collapse of the summit (highest part) of the volcano, in which a lava lake may form and from which lava may flow during an eruption. Formed above hot spots located below the lithospheric plates. Pyroclastic debris includes all types of volcanic debris that are explosively ejected from a volcano vents openings at top of the volcano where magma comes out of. More viscous than shield, but has an intermediate amount of silica in it.
