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plate margins and tectonic plates - Coggle Diagram
plate margins and tectonic plates
earth's structure
inner core = 5,500 temp
outer core is liquid
mantle made up of magma
there are conservation currents in the mantle which move, carrying the plate above
crust is thin layer between 0-60km
the crust is broken into oceanic and continental
tectonic plates
1) crust is broken into plates
2) heat rising and falling inside the mantle create convection currents
3) the convection currents move the plates floating on the mantle
4) where the convection currents diverge near the earth crust, plate move apart
5) where the convection currents converge, plate move towards each other
hotspots
hotspot = stationary magma beep in the earth that create volcanoes on the surface
magma comes to the surface through cracks in the rocks with great heat and low pressure
can be link to plate margins or may just a crustal plate
destructive plates margin
oceanic plate and constructive plate move towards each other
collision process called subduction
oceanic plate in denser than constructive
oceanic plate is under constructive when they collide
when oceanic plate sinks under it melts and become magma
magma escapes through the pressure cracks in a rock and comes up though a volcano
subduction can cause volcanic activity and/or earthquakes
many of these margins are around the pacific plate where it subducts under the eurasian plate near japan
constructive plate margin
plates move away from each other
when the plates part magma rises up to make a new crust in the form of a shield volcano or a fissure volcano
this movement can also cause earthquakes
volcanoes and earthquakes
conservative plate margins
plates move past each other causing friction and get stuck
plates are still trying to move so pressure and stress builds up in the crust
when the pressure is suddenly released, causing an earthquake
can be very destructive as the focus is close to the earth surface
no volcanoes only earthquake
collision zones
Collision zones form when two continental plates move towards each other and collide.
The land between the plates is forced upwards to form fold mountains, eg The Alps and Himalayas.