Zusammenfassung der Ressource
Plate tectonics
- Replaced idea of
continental drift
- 1950s and 1960s
- 7 large sections
called plates
- A few smaller sections
called plates
- Convection currents
- Caused by the intense
heat in the mantle
- Causes the plates to move
- Plate boundaries
- Where two
plates meet
- Slow movement of the
plates
- Forms volcanoes and
new mountains
- Makes earthquakes
and tsunamis
- Constructive plate
boundary
- Where two plates are moving
apart (diverging)
- New crust is made
- Hot magma from the mantle
rises to fill the gap
- Creates new mountains
under the sea
- Mid oceanic ridge
- When new magma continues
to build up above the ocean
- New volcanic
island are made
- Destructive plate
boundary
- Two plates move together
(continental and oceanic)
- Denser continental plate is forced
down (subducted) underneath the
less dense oceanic crust
- creates an ocean trench and
causes the material to melt as
it is dragged down
- The magma rises
through cracks as a very
violent volcano
- Earthquakes
- Conservative plate boundary
- Plates meet and
slide past eachother
- No crust is
destroyed or
added
- Sliding movement is not
smooth and immense friction
builds up
- Eventually one plate suddenly jerks past the
other causing shockwaves and an earthquake
on the surface
- Faults are found here due to the plates
moving in different directions
- Collision plate boundary
- Two continential plates
bump into eachother
- Both plates are
continental so they buckle
and fold
- Pushes up the land
to create fold
mountains