Lesson 1 Flashcards
What are the layers that make up the Earth’s structure?
- Crust
- Mantle
- Outer Core
- Inner Core
The Earth’s structure is made up of four main layers.
What is the outermost layer of the Earth called?
Crust
The crust is where we live and consists of solid land and oceans.
What is the thickness range of the Earth’s crust?
5 km to 30 km
The crust is thinnest beneath oceans and thickest beneath continents.
What is the layer beneath the Earth’s crust?
Mantle
The mantle is the thickest layer of the Earth.
What is the mantle composed of?
Slow-moving, semi-molten rock
The mantle is denser than the crust.
What causes earthquakes?
Movement of tectonic plates on the mantle
The tectonic plates float on the mantle and their movement is responsible for earthquakes.
What occurs when magma breaks through gaps in the Earth’s crust?
Volcanic activity
This is a result of volcanic eruptions.
What is the core of the Earth primarily composed of?
Iron
The core is very hot and consists mostly of iron.
What are the two sections of the Earth’s core?
- Outer Core
- Inner Core
The outer core is molten liquid iron, while the inner core is solid iron.
What is the state of the outer core?
Molten liquid iron
The outer core’s movement produces the Earth’s magnetic field.
Why is the inner core solid?
Due to high pressure
The pressure is so great that particles are squeezed together despite high temperatures.
What is the thin layer of gases surrounding the Earth called?
Atmosphere
The atmosphere is held in place by Earth’s gravitational pull.
What is the name of the state change from a solid to a liquid?
Melting
This process is also referred to as fusion.
What does the word ‘molten’ mean?
In a liquid state due to heat
Molten refers to materials that have melted.
Which part of the Earth’s atmosphere is closest to the surface?
Troposphere
The troposphere is where most weather occurs.
