Science 5.8 Flashcards
(18 cards)
What is a volcano?
An opening in earth’s crust, though which magma from the mantle rises to the surface
How many active volcanoes are on earth’s surface?
Approximately 1500 (not counting those found underwater)
Where can you find most volcanoes?
Edges of the Pacific Ocean
What do we call the area around the Pacific Ocean where there are a lot of volcanoes?
Ring of Fire
What do you call a spot in the middle of a tectonic plate where volcanoes can form?
Hot spots
What islands were formed in a hot spot?
Hawaiian islands
What is a magma chamber?
The reservoir underneath the volcano that holds magma
What causes explosions in volcanoes?
Gases
What do you call the spot on top of the magma chamber?
The vent
What happens to make a volcano errupt?
The pressure gets too high and the top of the vent explodes
What is a secondary vent?
Another smaller hole where the magma comes out
What do you call magma once it flows out of the volcano?
Lava
What do you call the hill that is formed by the cooling lava after a volcano errupts?
The cone
When a volcano erupts, what is expelled from the vents?
Lava
Ash
Gas
What are the 2 main types of volcano?
Shield
Stratovolcanoes
What is a shield volcano?
They look like shields, they are large and have gentle slopes
The lava is thin so it flows easily
What is a stratovolcanoe?
They create high mountains with steep slopes
Lava is thicker and flows more slowly
Which type of volcano is more violent?
Stratovolcanoe
