tectonic plates

Question 1

what is a destructive plate margin?

Answer 1

-two plates are moving towards eachother
-where an oceanic plate meets a continental plate,the denser oceanic plate is sub-ducted and destroyed creating gas-rich magma

Question 2

what is a constructive plate margin?

Answer 2

-two plates move away from eachother.
-magma rises from the mantle to fill the gap and cools,creating new crust

Question 3

what is a conservative plate margin?

Answer 3

-two plates moving sideways past each other or moving in the same direction at different speeds

Question 4

Where do volcanos occur?

Answer 4

At destructive and constructive plate margins

Question 5

What happens at destructive plate margins?

Answer 5

The denser oceanic plate moves down into the mantle where it melts.
A pool of magma forms which then rises through cracks in the crust called vents.
The magma erupts, forming a volcano.

Question 6

What happens at constructive plate margins?

Answer 6

The magma rises up into the gap created by the plates moving apart, forming a volcano.
Some volcanos also form over parts of the mantle that are really hot. Called hotspots.

Question 7

What happens when a volcano erupts?

Answer 7

It emits lava and gasses.
Some volcanos emit a lot of ash, which can cover land, block out the sun and form pyroclastic flows.

Question 8

Where do earthquakes occur?

Answer 8

At destructive, constructive and conservative plate margins.

Question 9

How are earthquakes caused in destructive plate margins?

Answer 9

Tension builds when one plate gets stuck as it moves past the other.

Question 10

How are earthquakes caused in constructive plate margins?

Answer 10

Tension builds along cracks in the plates as they move away from each other.

Question 11

How are earthquakes caused in conservative plate margins?

Answer 11

Tension builds up when plates that are grinding past each other get stuck.

Question 12

How are earthquakes measured?

Answer 12

Using the moment magnitude scale.

Question 13

What does the moment magnitude scale do?

Answer 13

Measures the amount of energy released by an earthquake.

Question 14

What are the primary effects of the New Zealand earthquake 2016?

Answer 14

-2 people died and over 50 were injured
-tens of thousands of homes were damaged and some were destroyed
-60 people needed emergency housing
-the total cost of the damage was around 8.5 billion
-over 200km of road and over 190km of rail line were destroyed
-communications, water, sewage and power supplies were cut off

Question 15

What were the secondary effects of the New Zealand earthquake 2016?

Answer 15

-the earthquake triggered up to 100,000 landslides which blocked major road and rail routes
-a major landslide blocked the river leading to flooding and evacuation of 10 farms
-the earthquake generated a tsunami with waves of around 5m, leaving debris up to 250m inland

Question 16

What were the primary effects of the Nepal earthquake 2015?

Answer 16

-around 9000 people died and more than 22,000 were injured
-an estimated 800,000 buildings were damaged or destroyed
-4 million people were left homeless
-the cost of damage was over 5 billion
-roads and bridges were destroyed
-water tanks and pipes were destroyed, leaving 2 million people without access to clean water and sanitation

Question 17

What were the secondary effects of the Nepal earthquake 2015?

Answer 17

-triggered avalanches on Mount Everest which killed 18 people
-many mountain roads were blocked by landslides,preventing emergency aid from reaching remote areas
-a lack of clean water caused outbreaks typhus which killed at least 13 people

Question 18

What were New Zealand’s immediate responses to the earthquake?

Answer 18

-a tsunami warning was issued quickly and residents and coastal areas were told to move to higher grounds
-people were housed in emergency shelters and community centres
-power was restored to most places within a few hours. Temporary water supplies were set up
-200 of the most vulnerable people were evacuated by helicopter within first 24 hours
-international warships were sent to kaikoura with supplies like food, medicine and portable toilets

Question 19

What were New Zealand’s long term responses to the earthquake?

Answer 19

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