Features and processes

Question 1

The global pattern of plates and plate boundaries

Answer 1

Since used for military purposed revealed invaluable data

Maps produced from seismic data showed that most earthquakes were concentrated around narrow bands

Question 2

What are 3 types of plate boundary

Answer 2

Divergent (constructive)
Convergent (destructive)
Conservative

Question 3

Facts on Divergent boundaries

Answer 3

Plates are moving apart and magma is rising through the asthenosphere and forcing its way to the surface
Mainly occurs at MOR
Mountain chains

Question 4

Transform faults

Answer 4

MOR are not continuous, they are broken into segments by transform faults
No volcanic activity
Earthquakes can occur

Question 5

What are pillow lavas

Answer 5

Eruption of magma along divergent boundaries occurs mainly underwater
Magma erupting directly onto the sea bed is cooled rapidly forming rounded moulds called pillow lava’s

Question 6

What are black smokers

Answer 6

MOR sea water seeps into rifts and is superheated
Rises to the surface and causes chemical changes in the basaltic rocks
Superheated jets of water sometimes emerge containing metal sulphides

Question 7

What are underwater rift valleys

Answer 7

Found along MOR
As magma rises to the surface the overlying rocks are forced up into a dome
Rigid lithosphere is placed under great stress and fractures along parallel faults

Question 8

Oceanic - continental plate margins

Answer 8

Oceanic plates are denser so forced under continental plates when they converge
This is subduction
Forms a trench

Question 9

Oceanic - Oceanic

Answer 9

The denser one will subduct
Creating a trench
Forms chain of volcanic islands

Question 10

Continental - Continental

Answer 10

Little subduction occurs

Question 11

Conservative plate margins

Answer 11

Slide past each other
No volcanic activity
Earthquakes can occur