challenge of natural hazards

Question 1

what are natural hazards?

Answer 1

physical events that have the potential to do damage to humans and the environment. e.g. volcanoes

Question 2

what affects hazard risks?

Answer 2

population growth, climate change, deforestation, wealth

Question 3

what are the two sections in the crust?

Answer 3

oceanic crust= thin + dense + young
continental crust= thicker + less dense + old

Question 4

what is a constructive plate boundary?

Answer 4

when two plates move apart and magma rises and cools to create new crust and potential volcanic activity. e.g. Mid-Atlantic ridge

Question 5

what is a destructive plate boundary?

Answer 5

when oceanic plate and continental plate meet and the oceanic plate sinks beneath continental crust. Pressure is released causing earthquakes and magma rises through continental crust. e.g. Ring Of Fire

Question 6

what is a conservative plate boundary?

Answer 6

when two plates move past each other in different directions and speeds. Plates jam causing pressure and earthquakes. e.g. San Andreas Fault

Question 7

primary effects of earthquakes

Answer 7

buildings destroyed
people killed/injured
pipes + electricity damaged

Question 8

secondary effects of earthquakes

Answer 8

business reduced due to money spent on repairs
fires due to broken gas pipes
lack of clean water due to broken water pipes
traffic= less emergency services

Question 9

why do people live on earthquake prone zones?

Answer 9

-poverty (inertia)
-tourism=money
-family links
-ignorance or arrogance

Question 10

primary effects of volcanoes

Answer 10

-environment, buildings, homes destroyed
-people & animals killed by debris, lava, pyroclastic flows
-water contamination

Question 11

secondary effects of volcanoes

Answer 11

-fertile land
-tourism increases
-emergency aid struggle to arrive
-diseases spread

Question 12

why do people live in earthquake prone zones?

Answer 12

-resources
-poverty
-fertile soil (agriculture)
-tourism
-geothermal power

Question 13

methods to predict volcano

Answer 13

-seismometers
-GPS satellites= measures increase in ground temperature
-sulfur dioxide= if released magma is close to surface
-ground deformation

Question 14

methods to plan for volcanoes

Answer 14

-hazard maps= people know the danger zones and safe areas if eruptions occur so evacuation is quick

Question 15

immediate responses to volcanoes

Answer 15

-evacuation
-extinguish fires
-send aid
-shelters
-provide food and water

Question 16

long-term responses to volcanoes

Answer 16

-repair buildings
-improve monitoring
-restore water and gas supplies

Question 17

what is global atmospheric circulation

Answer 17

-at the equator, air is heated causing it to rise= creates a low pressure belt→ cools and condenses to form clouds+rain
-at 30° north and south of equator, cool air sinks=creates high pressure belt→ cloudless skies+low rainfall
-cool air reaches ground and moves as surface air back to equator or poles
-surface winds blowing back to the equator are known as trade winds→ blow from SE in Southern hemisphere and NE in Northern hemisphere.→ at equator, they meet and are heated
-Surface winds blowing to the Poles= westerlies
-At 60° N& S of hemisphere, warmer surface winds meet colder air. warmer air = less dense = forced to rise → creates low pressure + rain.

Question 18

what are tropical storms?

Answer 18

intense low pressure weather systems with heavy rain and strong winds that must reach a level of 74mph that spiral around the centre.

Question 19

how do tropical storms form?

Answer 19

1)when the sea temp is 27°c or higher and the wind sheer is low.
2)warm,moist air rises and condenses creating low pressure increasing surface winds.
3)they move towards the west and the earth’s rotation deflects paths of the winds causing it to spin.
4)it loses strength when they move on land

Question 20

primary effects of tropical storm hazards

Answer 20

-hurricane force winds=over 74mph
→ break windows,rip tiles,create debris
-heavy rain → flooding, damage land, drowning
-storm surge= low pressure area beneath tropical storm enables a bulge of water to form → up to 10m above tide, flooding, damage buildings, soil becomes saline

Question 21

secondary effects of tropical storm hazards

Answer 21

-landslides= the movement of a mass of rock, debris, or earth down a slope due to saturated soil.
-large waves= erodes coastline, damage buildings, sink boats.

Question 22

primary effects of tropical storm impacts

Answer 22

-deaths/injuries
-buildings destroyed/damages
-electric supplies cut off

Question 23

secondary effects of tropical storm impacts

Answer 23

-homelessness
-contaminated water
-road/railways blocked by debris= difficult to provide aid.

Question 24

what is mitigation?

Answer 24

action of reducing the severity of something or trying to stop a situation altogether

Question 25

what is adaptation?

Answer 25

action of changing to cope with a situation

Question 26

long-term planning of tropical storms (responses)

Answer 26

-land using zone
-emergency services and army practice
-evacuation plans- centralised & family
→ all adaptations
-flood defences- mangroves,rivers & sea
→mitigation

Question 27

short-term planning of tropical storms (responses)

Answer 27

-board up windows
-remove loose objects
-evacuate
-turn off gas & electricity
→ adaptations