Volcanoes and Earthquakes Flashcards
Why do earthquakes and volcanoes happen roughly in the same places?
Because they are found in the same zones of activity.
What is the ‘Ring of Fire’?
A ‘belt’ of volcanoes all the way round the edge of the Pacific Ocean.
What does Earth consist of?
The core = the extremely hot centre of the earth. Surrounding the core is the mantle (layer of molten rock). On top of the mantle is the crust, the outer shell of the earth.
What are ‘plates’?
Plates are the broken sections of the Earth’s crust.
What is a ‘plate boundary’?
The place where two plates meet.
Are the plates static or do they move?
They move very slowly and this movement at the plate boundaries can cause earthquakes and volcanic eruptions.
Explain why a volcanic eruption and an earthquake happen?
When two plates rub together, the friction between them makes the rock melt. The liquid rock rises upwards and erupt on the surface as a volcano. The movement of the plates scraping together makes the ground shake and sets off earthquakes.
What is magma?
Liquid rock
What are volcanoes?
Volcanoes are openings (vents) in the ground where magma from deep inside the earth forces its way to the surface.
In which shape does the magma come out of the earth in a volcano?
Magma may appear as flows of molten lava, volcanic bombs, fragments of rock or ash and dust.
What 3 states can a volcano be in?
Active, dormant, extinct.
When is a volcano active?
If it has erupted recently and is likely to erupt again.
When is a volcano dormant?
If it hasn’t erupted in the last 2000 years.
When is a volcano extinct.
When there is no activity.
What blows out of a volcano?
Steam, gas, dust, ash.
What is a volcanic bomb?
Lumps of molten rock that solidify as they fall.
What is a secondary cone?
It forms like a branch of the main vent.
What the store of molten rock underneath a volcano called?
A magma chamber.
What 3 types of volcanoes are there depending on the type of lava?
Ash and two types of lava volcanoes (thick lava and runny lava).
Who do people live in volcanic areas?
Ash and lava turn into rich fertile soil. Good for farming.
What are the effects of an eruption on people?
It can kill them, they might have to move, it can destroy their homes and livelihood. It can bury villages.
How can you divert lava?
With a series of small explosions.
What is a natural hazard?
Things like earthquakes, floods, droughts and volcanic eruptions.
What is Europe’s most active volcano?
Mount Etna in Sicily.
