Chapter 11: Volcanoes Flashcards
Refers to the motion of molten rocks that has reached the earth’s surface and moved down the slope of volcanic vents
lava/lava flow
Difference between lava and magma?
location
Where are volcanoes formed? name all 3
convergent plate boundaries, divergent plate boundaries, and hotspots
What causes the tectonic plates to move?
convection currents
Why are there many volcanoes along the pacific ring of fire?
moving of tectonic plates
What are active volcanoes?
exhibit volcanic activity within the last 10,000 years
What are Dormant Volcanoes?
shows no historical record in the past 10,000 years however may have the potential to erupt
They can move toward each other, drift away from each other, or override each other with the heavier tectonic plate sinking to the mantle and the lighter plate rising above it in a process called _____?
subduction
semi-molten rock
magma
elongated fracture or crack on earth’s crust from which lava erupts
fissure
passageway through which magma travels to reach earth’s surface
conduit
opening where the volcanic materials are released
vent
bowl-shaped depression at the top of the volcano where the vent is located
crater
sides of a volcano
flank
underground compartment where the magma is stored
magma chamber/magma reservoir
Formed by highly viscous or think, slow-moving lava. Also termed as composite volcano, it has steep upper slopes. They are the most dangerous type of volcano, most of them are in the pacific ring of fire.
stratovolcano
Formed by loose and fluid lava that flows over each other. They are usually low and broad, resembling a warrior’s armored _____ or a gigantic blob.
shield volcano
Also known as scoria cone, is formed by fluid lava that is ejected because of high pressure that builds up in the magma chamber. Volcanic eruptions are short-lived and appear like a wild fountain show.
cinder cone volcano
pulverized rocks, minerals, volcanic glass
ash
avalanche of hot volcanic ash
ash flow
horizontal crack with solidified or cooled magma
sill
vertical crack with solidified or cooled magma
dyke
This is also called mudflow or flow of volcanic debris. They can be classified into two
types: primary or hot ____ associated directly with the eruption, and secondary or cold ____
flow because of heavy rainfall.
Lahar
These are hot bursts of trapped gases that push their way through solid barriers and
rapidly into the atmosphere.
Blasts
This refers to a mound of lava that grows inside the crater, called a cryptodome.
If it grows outside the volcano, it is called an exodome.
Dome growth
This refers to glowing hot material that moves down the slope of an erupting
volcano and comes in contact with the surface.
Pyroclastic flow
These are volcanic materials of gases, ash, rock fragments, and water
Pyroclastic surges
These may consist of combinations of pumice, scoria (basalt), thick rock
fragments, and crystals with tephra particle sizes ranging from 2 mm in diameter (ash) to
more than 64 mm in diameter (blocks).
Tephra falls
They are series of sea waves caused by the displacement of large volumes of
water because of an underwater earthquake or volcanic eruption.
Tsunami
Types of eruption:
least violent type, with highly fluid or runny lava flowing out of several vents
Hawaiian
Types of eruption:
Is violent. featuring continuous ejection of magma and gas. It results in the formation of volcanic bombs and cinder cones
Strombolian
Types of eruption:
A thick, viscous magma flows around the vent as solid lava and dust are ejected
Vulcanian
Types of eruption:
Is the most violent and explosive type of eruption. Cause by the buildup of viscous magma and dissolved gas. this type is accompanied by fast-flowing pyroclastic debris and lahars.
Plinian
