AMSL 101 Lecture Notes - Tufting, Rethra, Masone
Document Summary
Nearly all active volcanoes are located in one of three plate tectonic settings: subduction zones at convergent plate boundaries example: volcanoes lining the trenches of the pacific ocean, forming the pacific ring of fire , rifting and sea floor spreading at divergent plate boundaries example: volcanic eruptions at mid ocean ridges, and in some rift zones on the continents, like the east african rift valley, hot spots example: the hawaiian islands and the galapagos islands. Increasing its temperature o: decreasing its pressure, adding water (to lower the melting temperature), magmas that are generated deep within the earth begin to rise because they are less dense than the surrounding solid rock, as they rise they may encounter a depth (or pressure) where the dissolved gas no longer can be held in solution in the magma, and the gas begins to form a separate phase (makes bubbles) and will continue to grow in size as pressure is reduced.
