Volcanoes and earthquakes! Flashcards
Where are volcanoes usually formed?
Volcanoes are usually formed at the plate boundaries where magma from the mantle rises up through cracks in the Earth’s.
What happens when magma comes to Earth’s surface?
At the Earth’s surface, magma erupts to form lava flows and ash deposits.
What is the difference between lava and magma?
Magma is the name for liquid rock when it is underground. Lava is the name for liquid rock when it is on the surface.
What does this lava and ash do?
The lava and ash harden as they cool to form new rocks. So each time the volcano erupts, it gets bigger.
When is a volcano eruption violent?
Sometimes, if the magma is really thick, and contains dissolved gas, pressure builds up and the eruption is violent.Gases and rock shoot up the opening.
What can violent eruptions cause?
Violent eruptions can cause earthquakes and avalanches-and tsunamis if the volcano is close to the sea.
What does active volcano mean?
Some volcanoes are active and may erupt at any time.
What does dormant/inactive volcanoes mean?
Some volcanoes are inactive or dormant, which means they have not erupted for a very long time.
What does extinct volcanoes mean?
Other volcanoes are extinct, which means they will not erupt again.
