The World and Tectonics Flashcards
(33 cards)
what is TNC
Trans-National corperation
what is globalisation
when businesses and organisations develop international influence or start to operate on an international scale
what are HIC, MIC, LIC
high income countries, medium income countries and low income countries
What is the earths crust
crust is the layer that we live on. it is a thin skin of rock around the earth
why do TNCs source their products from different countries
because they can produce them for much cheaper rates in low income countries and make more money for themselves
what is pangea
the idea that all continents were joined together as one large landmass called pangea. Throughout millions of years the landmass split up to make the continents that we have now.
what is continental drift
the idea that continents are slowly shifting positions and moving called continental drift.
name some evidence for continental drift
there are similar patterns of rocks on different continents- they couldve been close together or joined.
there are similar fossils found on different continents- these regions were close together or joined
some continents look like they would fit together as a jigsaw
what are tectonic plates
large plates that cover the earths surface made up of the earths crust
what are the edges of tectonic plates called
plate boundaries
why do tectonic plates move
there are convection currents below the plate in the hot lave. these convection currents drive plates in the directions they are going in and can cause plates to move together or apart
what happens at a constructive plate boundary
At a constructive plate boundary two plates move apart. As they move apart magma rises up to fill the gap making a volcano. However since the magma can escape easily at the surface, the volcano wont erupt with much force. Earthquakes can also occur at these boundaries
what happens at a destructive plate boundary
At a destructive plate boundary a continental plate and an oceanic plate meet. The oceanic plate descends under the continental plate because it is denser. As it descends it starts to melt due to the heat from friction caused by the movement of the two plates against eachother.
The melted plate is now hot, liquid rock - magma. The magma rises through gaps in the continental rock. If it reaches the surface the magma will form a volcano. Because of the friction, volcanoes are very powerful at destructive plate boundaries
are volcanos more powerful at constructive or destructive plate boundaries and why
at destructive boundaries because there is so much friction from the two plates moving against eachother which forces the magma up. volcanoes which are at constructive plate boundaries are much less powerful because the magma can just rise and bubble through the gap made from plates moving apart.
what happens at collision plate boundaries
collision boundaries occur when two plates that have similar densities move together eg a continental plate and a continental plate. This causes the material between them to buckle and rise up forming fold mountains. Fold mountains are made by the two plates colliding at the same force causing them to crumble and are forced upwards.
what happens at conservative/transverse plate boundaries
at transverse plate boundaries two plates dont directly collide but slide past eachother along a fault (weakness). It doesnt matter what direction the plates are going in because they still slide past eachother. There is friction between the plates but no where near as much as on destructive plate boundaries. There isnt any volcanoes at these boundaries but earthquakes do occur.
what is the inner core
the centre of the earth. its solid due to the large amount of pressure
what is the mantle
the layer of molten rock between the core and the crust
what is magma
the molten rock / hot liquid rock in the mantle
what are convection currents
currents that drive the plates created by the heat from the core
what causes an earthquakes
earthquakes are caused by masses of rock shifting below earths surface. they move due to convection currents and the plates grind against eachother along fault lines. when plates cant move past eachother anymore due to faults, it blocks the plates motion which builds up lots of stress until the fault gives way and releases an earthquake.
where do earthquakes occur
along plate boundaries on the surface, on plate margins
how are earthquakes measured
on a seismograph and the magnitude measured on the richter scale
how does the richter scale work
each level is 30 times more powerful than the previous level