Volcanic Hazards A-Level Terms Flashcards
What are the primary volcanic hazards? (5 hazards)
Pyroclastic flows, tephra, nuée ardente, ash fallout and volcanic gases.
What are the secondary volcanic hazards? (4 hazards)
Lahars, volcanic landslides, tsunamis and acid rain.
What is a pyroclastic flow?
A mixture of hot rock. lava, ash and gases rising rapidly from a volcanic eruption.
What is a tephra?
Rock fragments ejected during volcanic erruptions.
What is a nuée ardente?
(“Glowing cloud”)
A type of pyroclastic flow. A dense, rapidly moving cloud of hot gases, ashes and lava fragments.
What is a lahar?
Destructive mudflow caused by a volcanic eruption.
What is a tsunami?
A large wave triggered by seismic activity.
What is acid rain?
When volcanoes erupt sulphurous gases, causing acidic rainwater.
What does the term intraplate mean?
Meaning in the middle of a plate; away from the plate margins.
What are subduction zones?
Where thin, dense oceanic crust is forced beneath the thicker, less dense continental crust at a destructive plate boundary.
What is a shield volcano?
A volcano with gently sloping sides and fluid, basaltic lava.
What is a caldera?
A large volcanic crater
formed by a highly explosive eruption where the volcano summit is removed.
What are hotspots?
Where mantle plumes rise up from areas of thin crust.
