6: Volcanoes

Question 1

How does mantle rock melt?

Answer 1

Increase in temperature, decrease in pressure or addition of water which greater lowers MP

Question 2

Dry melts

Answer 2

Occur at divergent boundaries due to decrease in pressure

Question 3

What is a shield volcano?

Answer 3

Very long and wide volcano made of basalt. Formed from repeated effusion of low-viscus magma from multiple vents

Question 4

Composite volcano

Answer 4

High height vs width. Formed from fragmentation of wet basalic magma

Question 5

Composite volcano

Answer 5

High height vs width. Formed from fragmentation of wet basaltic magma

Question 6

Central feature of basaltic flow

Answer 6

Very slow moving, no explosion

Question 7

stratovolcanic eruptions

Answer 7

explosive, higher silica content, much more viscous. Sometimes formed a caldera

Question 8

What is volatile fluxing?

Answer 8

Slab gets pulled down into mantle, as it re-crystallising, then looses water. This water vapour hits mantle wedge and melts mantle, becomes buoyant rises to the crust as a volcanic chain

Question 9

What’s apyroclastic flow

Answer 9

Incandescent volcanic ash and dust eruption; blocks the sun therefore cools the earth

Question 10

How would you warm up the earth?

Answer 10

Basaltic volcano eruption (effusive) emitting CO2 into the air

Question 11

Effusive vs Explosive

Answer 11

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