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Flashcards in Hotspots Deck (10)
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1

Example of where one is?

Hawaii

2

What are hotpots?

Stationary localised sources of heat - thermal plumes.

3

How did Hawaiian seamounts form?

From Pacific plate moving over stationary hotspot in mantle.

4

So what is the process occurring over hotspot?

They produce persistent sources of magma which melts overriding Pacific plate.
Magma which is denser rises up through mantle and erupts onto crust forming active seamount.

5

What happens over time to seamount?

Countless eruptions occur causing seamount to emerge above sea level forming island volcano.

6

What does sea floor spreading do to volcano island?

It moves volcano beyond hotspot cutting off magma supply.
One island becomes extinct another volcano forms.
Leaves Long Trail of island volcanos along Pacific floor.

7

What is the lava produced from hotspot ?

Mainly balsatic.

8

Nature of balsatic lava ?

Low viscous
Low silica content
Not explosive
More frequent
Lower on VEI scale

9

What type of volcanoes present in Hawaii?

Shield volcanoes.

10

Characteristics of shield volcanoes?

Basaltic rock forming gently sloping cones of layers of less viscous lava.
Gentle
Predictable.