Geography year 7 Flashcards
(37 cards)
What are the 4 different sorts of plate boundaries?
Collision, conservatives, destructive, constructive
Collision
When two plates of the same weight and size crash together. They form a mountain
Conservative
Two plates slides past each other. They scrape and it creates huge earthquakes.
Destructive
When an oceanic crust crashes into an continental crust. The oceanic crust gets pushed down because of its weight.
Constructive
When two plates move apart
Volcanoes
When there is a gap in the earth’s crust and magma gets out. They happen in constructive and destructive plate boundaries
Earthquakes
Vibrations in the earth’s crust. Happens in all PB. The biggest occur in conservative and destructive because there is loads of friction
Active volcano
Can erupt any day soon
Dormant volcano
Sleeping. A volcano that has not erupted recently but can erupt again.
Extinct volcano
Dead. Unlikely to ever erupt again.
Pyroclastic flow
Boiling hot gas rushing down the side of a volcano
Lava
Boiling hot molten/melted rock
Volcanic bomb
Lumps of boiling hardened lava
Ash and gases
Tiny particles of dust or gas
Oceanic crust
Under the sea. Thin but heavy
Continental crust
Thick but light. Under a continent
Focus
Where the earthquake’s starts underground
Epicenter
The point on the surface which is directly above the focus
Aftershock
Smaller earthquakes which happen after the main one
Plate boundaries
Where two plate tectonics meet
Convention currents
The heat from the core makes the magma from the mantle move in a circular way. They push the plates around.
Seismic waves
The energy of the earthquake traveling out in all directions.
Measuring earthquakes
Earthquakes are usually measured on the Richter scale using a seismograph and by using the mercalli scale.
Richter scale
A logarithmic scale so a ‘6’ on the TS is ‘10’ times larger then a ‘5’ and ‘100’ times larger then a ‘4’.
