Volcanoes Flashcards
lava flow
masses of magma and solid black rock
lava
magma when it erupts into the Earth’s surface. It’s fluid as water
vent
opening in the Earth’s crust that magma and gasses erupt in the atmosphere
magma
molten rock that has not reached the Earth’s surface
magma chamber
a reservoir of magma beneath a volcano in the Earth’s crust
hot spot
a plume of hot material that has risen from the mantle
volcano
an opening in the Earth’s crust from which lava, ash and gas erupts and creates a landform
viscosity
lava’s resistance to flow
pahoehoe
smooth, rope-like appearance that cools slowly; solid basaltic lava
a’a lava
lava that has rough edges; it has a pokey appearance and cools quickly
pillow lava
lava that looks like clouds
lahar
fast-moving mud flow
pyroclastic material
solid rock fragments ejected during a volcanic eruption
pyroclastic flow
dense, super-heated cloud of gas that moves rapidly downhill after a volcanic eruption
cinder cone
small volcano, very explosive, cone shape
composite
they have tall peaks and spread out; they have alternating layers of lava
shield
broad-based, largest volcano
batholiths
big dome of igneous rock
laccoliths
little dome of igneous rock
caldera
collapsed volcano, large crater-shaped basin, looks like a lake
tephra
they can be large, dense rocks or light rocks carried upward from an explosion or from gasses
volcanic neck
a column of solid fed lava; it’s in the volcanic vent
lava plateau
lava pouring from a crack or fissure in the volcano
fissure
fracture or crack in a volcano’s surface which lava flows from
volcanic pipe
a vertical feature through which magma passes to reach the vent
dike
narrow vertical cuts across older rock
sill
a horizontal layer in older rock
