14.1 Flashcards
Volcanism
describes all the processes associated with the discharge of magma, hot fluids, and gasses
Only 5 percent of magma erupts far from plate boundaries
2 Major Belts
Circum, Medeterranian
subduction zones
form where oceanic crust descends into the mantle
circum belt
aka pacific belt
aka the pacific ring of fire
area of volcanoes that encircles the majority of the pacific plate
meditteranian belt
area of active volcanoes associated with the boundaries between eurasian, african, and arabian plates
_________________ move apart at a _______________
tectonic plate, divergent plate boundary
how much of earth’s volcanic eruptions are underwater
2/3
also typically not explosive
forms pillow lava
hot spot
unusually hot area in earth’s mantle where high temp plumes of magma rise toward the surface
most hot spots occur where
where columns of solid, hot material from the deep mantle, called mantle plumes rise and reach the crust
flood basalt
huge amounts of lava that erupts from fissures
fissure
long crack in earth’s crust
conduit
tube like structure that allows lava to reach the surface
vent
opening in earth’s crust through which lava erupts and flows out onto the surface
crater
bowl shaped depression that forms around the central vent at the summit of a volcano
caldera
large crater that can form when the summit or side of a volcano collapses into the magma chamber during or after an eruption
