Hotspots

Question 1

Example of where one is?

Answer 1

Hawaii

Question 2

What are hotpots?

Answer 2

Stationary localised sources of heat - thermal plumes.

Question 3

How did Hawaiian seamounts form?

Answer 3

From Pacific plate moving over stationary hotspot in mantle.

Question 4

So what is the process occurring over hotspot?

Answer 4

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.

Question 5

What happens over time to seamount?

Answer 5

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

Question 6

What does sea floor spreading do to volcano island?

Answer 6

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.

Question 7

What is the lava produced from hotspot ?

Answer 7

Mainly balsatic.

Question 8

Nature of balsatic lava ?

Answer 8

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

Question 9

What type of volcanoes present in Hawaii?

Answer 9

Shield volcanoes.

Question 10

Characteristics of shield volcanoes?

Answer 10

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