Earths Layers
What are the four layers of the Earth from the centre to the surface?
Answer: Inner core, outer core, mantle, crust.
Name the three types of plate boundaries.
Answer: Convergent, divergent and transform.
What is the name of the melted rock beneath the Earth's surface?
Answer: Magma.
What is an earthquake?
Answer: A sudden movement of the Earth's crust.
What is the most common cause of a tsunami?
Answer: An underwater earthquake.
Which layer of the Earth do we live on?
Answer: The crust.
At which plate boundary do plates move towards each other?
Answer: Convergent.
What is the opening at the top of a volcano called?
Answer: Crater.
What are the waves that travel through the Earth during an earthquake called?
Answer: Seismic waves.
Name two other causes of a tsunami.
Answer: Underwater volcanic eruptions and underwater landslides.
Which layer is made of hot, semi-molten rock that helps move the tectonic plates?
Answer: The mantle.
At which plate boundary do plates move away from each other?
Answer: Divergent.
What is the large underground store of magma called?
Answer: Magma chamber.
What is the point inside the Earth where an earthquake begins?
Answer: The focus.
Why do tsunami waves become much taller near the coast?
Answer: They slow down in shallow water, causing the waves to increase in height.
Which layer is the coolest layer of the Earth?
Answer: The crust.
At which plate boundary do plates slide past one another?
Answer: Transform.
What process causes one plate to sink beneath another?
Answer: Subduction.
What is the point directly above the focus on the Earth's surface called?
Answer: The epicentre.
Name two effects of a tsunami.
Answer: Any two:
What process in the mantle causes tectonic plates to move?
Answer: Convection currents.
An oceanic plate collides with a continental plate. Which plate sinks and why?
Answer: The oceanic plate sinks because it is denser.
Explain how a volcano forms.
Answer: Plates collide → the oceanic plate subducts → it melts → magma rises → a volcano forms.
Why does Australia have earthquakes but no active volcanoes?
Answer: Australia is in the middle of the Australian Plate, so there are no major plate boundaries to create volcanoes. However, stress builds up within the plate, causing earthquakes.
Explain how a tsunami forms.
Answer: An underwater earthquake, volcanic eruption or landslide suddenly displaces a large volume of water. Waves travel across the ocean and become much taller as they reach shallow water, causing flooding when they reach the coast.