ERTH 110 Lecture Notes - Lecture 13: Oceanic Crust, Silicate Minerals, Rhyolite
Document Summary
Introduction to volcanism: 1,500 active volcanoes on earth, 400 erupted in the last century, most activity concentrated along major plate boundaries. Impact risks depend on: type of volcano, population density in surrounding area. At plate boundaries, magma is created: magma is molten, rock, lava is (cid:373)ag(cid:373)a o(cid:374) the earth"s surface, volcanoes form around a volcanic vent. Not all volcanoes are the same: different processes in formation, depends on tectonic settings. Volcanic origin: the location of volcanic mountains on earth is a function of plate tectonics and hot-spot activity. Volcanic activity occurs in 3 settings: along subduction boundaries at continental-oceanic plate convergence (mt. Hot spot: hot spots, volcanic centers resulting from hot materials from deep in the mantle perhaps near the mantle core boundary, molten materials move up through mantle overlying plates. Hot spot locations: found under both continental and oceanic crust, continental: yellowstone national park, oceanic: hawaiian- emperor chain, plates move over hot spots creating a chain of island volcanoes.
