Disasters Flashcards
(21 cards)
Which type of plates form destructive plate margins?
Oceanic and continental plates
Which plate is more dense an oceanic plate or continental plate?
Oceanic plate
How is a volcano formed by a destructive plate boundrary?
The oceanic plate subducts under the contential plate, and then the oceanic plate melts into magma which rises to make a volcano.
Which type of plates form a constructive plate margin?
Two oceanic plates.
How does a constructive plate margin form volcanoes.
The magma rises from beneath the surface as the two plates above it split apart.
What does MMS stand for?
Moment Magnitude Scale.
How do you measure earthquakes?
Moment magnitude scale
Can collision plate boundries cause earthquakes AND volcanoes?
No
What is the name of the point where the earthquake orignates?
The focus
What is the name of the point directly above the point where the earthquake started?
Epicentre
What are the waves released by an earthquake called?
Seismic waves
What are the four plate margins?
Conservative, Constructive, Destructive, Collision
What is ridge push?
When ridges formed by constructive plate boundaries push the two oceanic tectonic plates apart
What is slab pull?
When the subducting plate in destructive plate margins pushes the rest of the tectonic plate downwards due to gravity
What is the problem with the convection currents theory
The plates were moving faster than the convection currents they were floating on.
How do destructive plate boundaries cause earthquakes?
The oceanic plate is subducted underneath the surface as it is more dense, the oceanic plate then proceeds to catch on the contential crust and it builds up pressure until the plate releases which causes an earthquake
Which volcanoes have a dip in the middle?
Cinder cone volcanoes
Which type of volcanoes are the tallest?
Composite volcanoes
Which volcano is known as low profile?
Shield Volcano
What are 3 hazards that volcanoes form?
(any three of) Pyroclastic flow Lahar Ash clouds Volcanic bombs Lava flow
What is pyroclastic flow and what hazards does it cause?
Superheated, fast moving rocks. Can easily destroy houses or cars and kill people, if the rocks land on them.
