Geography Topic 1 Flashcards
What is the Lithosphere?
The uppermost layer of the earth. It includes the top of the mantle and the crust. It is cool and brittle.
What are tectonic plate?
The earth’s surface is broken up into large pieces.
What is the mantle?
The middle layer of the earth, between the crust and core and its 2900 km thick.
What is the Asthenosphere?
Part of the earth’s mantle. It is hot, semi-molten layer that lies beneath the tectonic plates.
What is the core?
The solid centre of the earth. However, the outer core maybe liquid not solid
Facts about the Inner Core
♡ 1220 km
♡ 6000°C
♡ Made from solid nickel and iron
Facts about the Outer Core
♡ 2200km
♡ 4400 °C
♡ Made from liquid nickel and iron
Facts about the Mantle
♡ 2900 km thick
♡ Properties of a solid but can flow very slowly
♡ 4000 °C
Facts about the crust
♡0-100 km thick
♡ made up of igneous, metamorphic and sedimentary rocks
♡ thin and rocky
♡ 200°C and 400°C
Facts about continental crust
♡ Thick granite
♡ 10-50 miles (30-50km)
♡ less dense
♡ floats high on the mantle
Facts about oceanic crust
♡ Basalt rock ♡ Very thin ♡ denser ♡ 1-3 miles (6-8km) ♡ Basalt is the same rock is in the mantle
What is Radioactive Decay?
Some elements are naturally unstable and radioactive (eg.Uranium). Atoms of these elements release particles from the nuclei and give off heat.
How do volcanoes from?
- Heat source from the core
- Convection currents also happen in the inner core
- Heat moves towards the surface in plumes
- Heated rock from the mantle rises
- The magma cools down and sinks back down the be reheated
- semi-molten rocks spread out carrying the plate
What is this tectonic hazards?
Divergent
What is this tectonic hazards?——>
Collision
What is this tectonic hazards?<====>(rubbing against each other)
Conservative
What is this tectonic hazards?——-<==>—— (one going under the other)
Convergent
What two types of crust are included in a divergent?
- Oceanic
2. Oceanic
What two types of crust are included in a convergent?
- Oceanic
2. Continental
What two types of crust are included in a collision?
- Continental
2. Continental
What two types of crust are included in a conservative?
- Continental
2. Continental
What is a hot spot volcano?
A place in the centre of a plate where magma rises. This causes the lithosphere to melt and magma pushes through the crust to form volcanoes.
Magma=
Underground
Lava=
Erupted out of volcanoes (above ground)
Earthquake
- Movement of the tectonic plates
- Concentrated along fault lines (fractures in earth’s crust)
- Friction builds up along plate boundaries as they move against each other until finally the energy is released
- This energy is sent out in seismic waves
What is the focus?
The point inside the crust where the pressure is released
What are seismic waves?
The earthquakes’s energy being released
What is the epicentre?
The point on the earth’s surface above the focus.
What is a seismometer?
It measures and records seismic waves.
Tsunami?
- Destructive/ convergent plate movement causes earthquake
- Sea above earthquake forced upwards
- Sea movement causes tsunami
- Seismic waves spread quickly outwards
- Waves crashes onto shore devastation low lying area
What does LEDC stand for?
Less economically developed country
What does MEDC stand for?
More economically developed country
Dark surfaces?(land)
Absorbs sunlight which is converted to heat. It heats up quickly in summer= low pressure (rising air)
Sea?
Takes longer to absorb heat, but also longer to cool. In summer, air over it Reaganism cooler and denser, forming areas of high pressure.
What is the definition of atmospheric circulation?
The movement of air around the earth to try and balance the temperature.
