Volcano 1
What is molten rock that is under the earth's surface?
magma
Magma and pyroclastic material erupt through a volcano's ________.
vent
75% of Earth's active volcanoes are located along the ________.
Ring of Fire
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?
What is lava?
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 Zone
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 and describe 3 extrusive volcanic features
Volcanic cones
hot springs
geyser
fumaroles
(listen to descriptions)
Mount Tambora in Indonesia erupted in 1815 and sent ash around the globe making for a cooler year. What VEI was this? How much pyroclastic material did it give off?
Volcanic Explosivity Index (VEI) 7. It gave off more than 100 cubic km of pyroclastic material.
Yellowstone is filled with geysers, hot springs, and fumaroles. It is the result of a collapsed supervolcano 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 is Mt Pelee in Martinique ?
Composite volcano; active
Volcanoes that have not erupted in a long time but are expected to erupt again in the future are referred to as _____________.
dormant
Describe 3 characteristics of a cinder cone.
Emits pyroclastic material (ash, cinder, bombs)
Explosive
Steep sides
Name 3 characteristics that describe a composite volcano.
Alternating layers of lava and tephra
Steep slope
Made of Acid lava
Name three characteristics that describe a shield volcano.
Emits relatively quiet flows of lava (basic 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.