Chapter 8 Section 1 Why Volcanoes Form Flashcards
What is the ring of fire?
The concentration of volcanoes surrounding the Pacific ocean along the Pacific plate boundaries is called the ring of fire
Where are most volcanoes located?
Directly on tectonic plate boundaries.
What is a volcano?
A vent or fissure in earths surface through which magma and gases are expelled.
What is magma?
Liquid rock produced under earths surface. Igneous rocks formed from magma.
Where does most volcanic activity on earth occur?
At mid-Ocean ridges at divergent plate boundary.
What Are hotspots?
Volcanically active places that are not located at tectonic plate boundaries. hotspots are directly above mantle plumes.
How do hotspot volcanoes differ from other volcanoes?
They are less common, and they can produce multiple ructions is the crust moves over a stationary mantle plume.
How does adding fluid to hot rocks cause magma to form?
When fluids after the half melting rock the melting temperature of the rock decreases and magma forms.
What three factors cause magma to form?
When the temperature of rock increases, when the pressure on the rock decreases, or when water lowers the melting temperature of the rock
