Volcano 1
What is molten rock that is under the earth's surface?
magma
Magma and pyroclastic material erupt through a volcano's ________.
vent
rapidly moving clouds of tephra mixed with hot, suffocating gasses
pyroclastic flow
What is the most active volcanic region?
What is the Ring of Fire
What is magma called when it is on the earth's crust?
At what two boundaries do volcanoes primarily form?
Convergent & Divergent Boundaries
What is created when two oceanic plates diverge?
mid-ocean ridge
The ring of fire has many convergent boundaries where the oceanic plate dives below the continental plate. This is called _______________.
subduction
A fast-flowing mudslide created by volcanic steam, melted glaciers, and sediments.
Lahar
What kind of rock is formed when lava cools and hardens?
igneous rock
Pyroclastic ash layered on the ground is called _______.
tephra
Name and describe the 3 classifications of volcanoes based on activity.
Active - has erupted in recent human history
Dormant - not active; not eroded
Extinct - not active; eroded
Name the 3 types of volcanic emissions and provide an example.
Liquid - lava
Solid - pyroclastic material (ash, cinder, bomb)
Gas - toxic gases and steam
Name the 3 types of volcanoes.
Shield, Cinder Cone, Composite or Stratovolcano
Name 3 types of magma
Basaltic: upper mantel melts
Andesitic: determined by same silica content (50-60%)as andesitic rock
Rhyolitic: molten material mixes with continental crust
4 types of Plutons: describe them
Batholiths: largest: body of igneous rock formed beneath the Earth's surface by the intrusion and solidification of magma
Laccoliths: igneous rock, typically lens-shaped, that has been intruded between rock strata causing uplift in the shape of a dome.
Sills: cuts parallel to preexisting rocks
Dikes: cuts across preexisting rocks
Yellowstone is filled with geysers, hot springs, and fumaroles. It is the result of a collapsed super volcano forming a caldera. Would this be considered active, dormant, or extinct?
Active
What type of volcano and activity is Paricutin in Mexico?
cinder cone; active
What type of volcano and activity is Mauna Kea on the Big Island of Hawaii?
shield volcano; dormant
What type of volcano and activity is Mt. Rainier?
Composite volcano; active
Volcanoes that are inactive, but have NOT eroded are considered to be _____________.
dormant
Describe 3 characteristics of a cinder cone.
Emits pyroclastic material (ash, cinder, bombs)
Explosive
Steep sides
Smaller size
Name 3 characteristics that describe a composite volcano.
Alternating layers of lava and tephra
Medium size and slope
Most common type of volcano
Name three characteristics that describe a shield volcano.
Emits relatively quiet flows of lava
Largest Volcano
Slopes are more gradual
Describe the difference between a crater and a caldera.
A crater is smaller and typically caused by a single explosion that blows outward.
A caldera is massive and is the result of a volcano collapsing inward.