Tectonics - EQ1

Question 1

At what boundaries are volcanoes mostly found?

Answer 1

Oceanic - Continental convergent
Oceanic - Oceanic divergent plate boundaries

Question 2

What percentage of active volcanoes are found along the Ring Of Fire?

Answer 2

75%.

Question 3

Name the statistics for earthquakes along the Ring Of Fire

Answer 3

80% of the world’s largest earthquakes.
90% of the world’s total earthquakes.

Question 4

Name the 5 steps of a volcanic eruption

Answer 4

1. Subduction of a tectonic plate
2. Heat + pressure creates magma (molten rock).
3. This plate has a lower density than the surroundings and so rises.
4. Pressure + gas content build up in the magma chamber.
5. Blockage is cleared with an eruption e.g Pinatubo 1991

Question 5

What is the example of a volcanic eruption?

Answer 5

Pinatubo, Philippines-1991.

Question 6

Name the 4 steps of an earthquake

Answer 6

1. Plates move towards or slide past each other.
2. Builds up tectonic strain.
3. Pressure exceeds friction.
4. Leads to a fracture- energy released as seismic waves=earthquake e.g Chile 2010, 8.8 magnitude.

Question 7

Name the example of an earthquake

Answer 7

Chile 2010 - 8.8 magnitude.

Question 8

Name 3 different types of plate boundaries

Answer 8

1. Divergent
2. Convergent
3. Conservative

Question 9

At which plate boundaries do lower magnitude earthquakes take place and why?

Answer 9

Divergent- less tectonic strain (usually between 3.0-5.0 magnitude e.g Iceland)

Question 10

What are the 2 different plate combinations at a divergent boundary?

Answer 10

Oceanic - Oceanic
Continental- Continental

Question 11

What happens at divergent plate boundaries?

Answer 11

New crust forms - earthquakes are formed by crustal stretching.

Question 12

Name an example of an O-O divergent plate boundary

Answer 12

Mid-Atlantic Ridge.

Question 13

Name an example of a C-C plate boundary

Answer 13

Rift valley between Nubian and Somalian plates.

Question 14

What are the 2 possible plate combinations at convergent boundaries?

Answer 14

Oceanic - Continental
Continental - Continental

Question 15

What are the 3 hazards situated at O-C convergent plate boundaries?

Answer 15

Earthquakes
Volcanoes
Tsunamis

Question 16

Name an example of a location of an O-C convergent plate boundary

Answer 16

Ring Of Fire.

Question 17

What are possible at C-C convergent plate boundaries?

Answer 17

Only earthquakes.

Question 18

Name an example of a C-C convergent plate boundary

Answer 18

Indian and Eurasian plate - Fold mountains of the Himalayas.

Question 19

Name an example of an earthquake at a C-C convergent plate boundary

Answer 19

Nepal 2015 - 7.8 magnitude.

Question 20

Name the 2 possible combinations at conservative plate boundaries

Answer 20

Oceanic - Oceanic
Continental - Continental

Question 21

What are possible at O-O conservative plate boundaries?

Answer 21

High magnitude earthquakes.
Possibly Tsunamis.

Question 22

What are possible at C-C conservative plate boundaries?

Answer 22

Only high magnitude earthquakes.

Question 23

Name an example of a C-C conservative plate boundary

Answer 23

San Andreas Fault - Pacific and North American plate.

Question 24

Describe what happens to cause intra-plate earthquakes

Answer 24

1. Pressure from all sides on the tectonic plate.
2. Causes a reactivation of ancient rifts + faults.
3. A fracture can occurs.
4. Arguably more risky as perception of risk is lower - due to lower frequencies, therefore population are less prepared.

e.g Gujarat 2001 - 7.7 magnitude (20k deaths)

Question 25

Name an example of an intra-plate earthquake

Answer 25

Gujarat 2001 - 7.7 magnitude (20k deaths).

Question 26

Describe what happens to form intra-plate volcanoes

Answer 26

1. A stationary mantle plume breaks through the thin oceanic crust to form a volcano and new crust forms.
2. The oceanic plate is constantly moving and creates a volcanic island chain.

e.g Hawaiian Islands and eruption of Mount Kilauea in 2018.

Question 27

Name an example of a volcanic island chain and a volcanic eruption

Answer 27

Hawaiian Islands.
Mount Kilauea in 2018.