Global Hazards

Question 1

What is a destructive plate margin? For an oceanic and continental plate

Answer 1

• An oceanic and continental plate move toward each other
• The oceanic plate is forced beneath (subduction)
• The plate sinks forming magma
• Magma escapes through a composite volcano

Question 2

What is a destructive plate margin? For two continental plates (collision margin)

Answer 2

• The two continental plates move towards each other
• Neither can sink so the land buckles
• This forms fold mountains
• This is a collision margin earthquakes can occur here

Question 3

What is a constructive plate margin?

Answer 3

• The plates move away from each other
• Magma rises up to form a shield volcano
• The movement of plates over the mantle can cause earthquakes

Question 4

What is a conservative plate margin?

Answer 4

• The plates move side by side at different speeds
• Friction occurs causing the plates to become stuck
• Pressure builds up as the plates try to move
• When released it sends out large amounts of energy causing an earthquake

Question 5

What are the atmospheric circulation cells in order from equator to poles

Answer 5

Hadley
Ferrell
Polar

Question 6

What does temperate climate experience

Answer 6

• air rises frequent rainfall

Question 7

What does a polar climate experience

Answer 7

Cold air sinking, icy

Question 8

What does a desert climate experience

Answer 8

Dry air sinking, high temps

Question 9

What’s high pressure

Answer 9

• cold air sinking, clear conditions

Question 10

What is low pressure

Answer 10

• hot moist air rising, stormy weather

Question 11

What are two examples of extreme weather

Answer 11

• high wind due to mountains
• high temps along the equators

Question 12

What’s the location of droughts

Answer 12

• anywhere but mainly located around tropics of cancer and Capricorn

Question 13

What happens during an El Niño year

Answer 13

• warm water pushed east by trade winds
• low pressure, warm air rises causing floods in South America
• high pressure, cool air sinking causing drought in Australia

Question 14

What happens during a La Niña year

Answer 14

-pool of warm water pushed west
- high pressure, cool sinking air causes drought in South America
-low pressure, warm rising air causing flooding is Australia

Question 15

Where are tropical storms mainly located

Answer 15

-the tropics of cancer and Capricorn

Question 16

How do tropical storms form

Answer 16

• 27° water, low pressure causes thunderstorm, sucks in trade winds
• Coriolis effect causing the spin
• begins to spin faster than 74 mph
• in the eye cool air sinks causing clear conditions
• loses energy source once it hits land

Question 17

What’s the structure of the earth

Answer 17

Crust- large tectonic plates
Mantle- liquid rock moving the plates
Inner/outer cores

Question 18

How do convection currents move the plates

Answer 18

-Liquid magma heats up becoming less dense and rises
-along the top magma cools starting to sink
-convection currents
-creates drag causing tectonic plates to move

Question 19

What’s a shield volcano

Answer 19

Gently sloping
Found at hotspots and constructive margins
Gentle eruptions

Question 20

What’s a composite volcano

Answer 20

Layers of ash and lava
Found at destructive margins
Violent eruptions

Question 21

What’s a hotspot

Answer 21

Magma rises breaking through the surface
Active volcanoes can occur here

Question 22

How are earthquakes caused

Answer 22

Plates become locked, friction, once plates move energy released as seismic waves

Question 23

What’s a shallow focus earthquake

Answer 23

• seismic waves spread and damage large areas but are small

Question 24

What’s a deep focus earthquake

Answer 24

• occur in destructive margins
  -localised damage as seismic waves travel vertically

Question 25

What are ways to mitigate a tectonic hazard

Answer 25

Monitoring- seismometers to detect, evacuate

Preparation- good communication systems, locate, help

Building design- shatterproof windows, don’t hurt people