The structure of the Earth Flashcards
What are the 5 different parts of the Earth?
(staring from the outside)
Crust 🠯 Upper mantle 🠯 Lower mantle 🠯 Outer core 🠯 Inner core
How thick is the crust in km?
35 to 70km
How thick is the upper mantle in km?
720km
How thick is the lower mantle in km?
2,171km
How thick is the mantle in km?
2,900km
How thick is the outer core in km?
2,300km
How thick is the inner core in km?
1,200km
What are the 2 types of tectonic plates?
Continental and oceanic
What is the crust made of?
Solid rock
What is the mantle made of?
Semi-molten magma
How much volume of the Earth does the mantle take up?
80%
Is the lower mantle made of softer rock compared to the upper mantle?
Yes
What state is the outer core in?
Liquid state
What metals is the core mainly made from?
Iron and nickel
Is the core dense?
Yes
How hot is the inner core?
5500°C
How much does the inner core grow each year?
1mm
Why do tectonic plates move?
Because of convection currents
What are convection currents formed by?
Heat rising in the mantle, losing heat and therefore sinking, then rising again. This steadily drags plates apart over time.
What is a destructive plate boundary?
A destructive plate boundary is when a continental and an oceanic plate push towards each other
What happens at a destructive plate boundary?
As they collide, the denser, heavier oceanic plate is forced underneath the continental plate. This is known as subduction. The oceanic plate melts to form magma. The magma’s pressure builds up and it escapes through weaknesses in the rock and rises through a composite volcano.
What is formed at a destructive plate boundary?
Subduction zones and ocean trenches are formed at a destructive plate boundary.
What is a constructive plate boundary?
A constructive plate boundary is when the plates move away from each other.
What happens at a constructive plate boundary?
The magma from the mantle rises up to create a new crust and can also create shield volcanoes.
What is formed at a constructive plate boundary?
A new crust, shield volcanoes, and ocean ridges
What is a conservative plate boundary?
A conservative plate boundary is when the plates slide past each other in opposite directions or in the same directions but different speeds.
What happens at a conservative plate boundary?
The plates attempt to move but due to friction they become stuck, however the plates are still trying to move so pressure increases. When it is released, the energy can cause earthquakes.
