Assess the importance of plate tectonic theory in helping to understand the nature and causes of volcanic activity Flashcards
1
Q
What is happening to plates along oceanic ridges?
A
They are moving apart
2
Q
What is sea floor spreading (oceanic ridges?)
A
Plates move apart, new crust carried away from ridge
3
Q
What are volcanoes like along oceanic ridges?
A
Fairly gentle sides
Low viscosity
Frequent but gentle eruptions
4
Q
The deeper the oceanic plate descends what happens?
A
The hotter the surroundings become
5
Q
What happens at constructive margins?
A
Brittle first fractures as sections of it move apart
6
Q
How are rift valleys formed?
A
Areas of crust drop down between parallel faults
7
Q
What happens through thinning crust?
A
Magma forces its way to the surface to form volcanoes - mt nyiragongo
