AQA - GCSE Geography - Tectonic Hazards

NATURAL HAZARD

an extreme event that causes loss of life, damage to property or severe disruption to human activities

INNER CORE

-solid iron and nickel

-5500C

OUTER CORE

liquid iron and nickel

MANTLE

semi-molten rock (magma)

CRUST

thin layer of solid rock

PLATE MARGIN

where two or more plates meet

CONSTRUCTIVE MARGINS

-plates pull apart

-creates volcanoes, as it allows magma to reach the surface and erupt through faults.

CONSTRUCTIVE MARGIN EXAMPLE

mid-Atlantic ridge

DESTRUCTIVE MARGINS

-plates move together, oceanic sub-ducts under continental crust

-friction causes Earthquakes

-melting plate causes Volcanic activity

DESTRUCTIVE MARGIN EXAMPLE

Pacific plate subducting under Eurasian plate

CONSERVATIVE MARGINS

-plates move alongside each other at different speeds

-edges stick together, energy builds up, one jolts forward, friction causes Earthquakes

CONSERVATIVE MARGIN EXAMPLE

San Andreas Fault

COLLISION MARGINS

-continental crusts move together and collide, creating a fold (mountain)

COLLISION MARGIN EXAMPLE

Himalayas and the Alps

HOT SPOT

places where the mantle is very close to the surface

EPICENTRE

directly above the focus, on the surface

RICHTER SCALE

measures the amount of energy given off by an earthquake

PRIMARY EFFECTS

occurs straight away when a hazard happens

SECONDARY EFFECTS

occurs later on, bringing more problems to the affected

PYROCLASTIC FLOW

torrent of hot ash, rock, gases and steam, moving at up to 450 mph

LAHAR

60mph mudslide of melted snow and volcanic ash

COMPOSITE VOLCANOES

cone-shaped volcano made up of many layers

SHIELD VOLCANOES

large-sized, low-lying volcano, formed from fluid magma flows

ACTIVE VOLCANOES

erupted recently

DORMANT VOLCANOES

erupted in the last 2000 years

EXTINCT VOLCANOES

not erupted in many thousands of years

TSUNAMI

large wave caused by an Earthquake, Volcano or Coastal landslide

CONVECTION CURRENTS

the movement of circulating magma, causing the Earth's plates to move

WHY ARE NATURAL HAZARDS WORSE IN LICs?

-poorer houses and infrastructure

-poorer healthcare

-less money for protection methods

WHY DO PEOPLE STILL LIVE IN HIGH-RISK AREAS?

-settled

-confidence in ability to 'fix' things

-attitude "it won't happen to me"

-fertile soil, valuable minerals, geothermal energy and tourism opportunities

HOW CAN YOU PREDICT VOLCANIC ACTIVITY?

-mini Earthquakes

-escaping gases

-change in volcanic shape

HOW CAN WE PROTECT AGAINST NATURAL HAZARDS?

-reinforce infrastructure to withhold the weight of ash and shaking of Earthquakes

-firebreaks to reduce the spread of fire

HOW CAN WE PREPARE FOR NATURAL HAZARDS?

-trained emergency services

-taught how to react

-receive emergency or longer-term aid

FOCUS

where an Earthquake originates below the surface

SEISMOGRAM

measures the shaking of an Earthquake

SEISMIC WAVES

shock waves of energy, travels through the rock to the surface

WHY DO THE LARGEST EARTHQUAKES DON'T ALWAYS RESULT IN THE MOST DEATHS?

-HIC vs LIC: LICs are less prepared

-population could be higher where the smaller Earthquakes are

-quality of infrastructure

Japan - GENERAL FACTS

-HIC

-11th March, 2011

-9.0 Richter Scale

-Earthquake occurred at sea

Japan - PRIMARY EFFECTS

-15, 894 deaths (most from tsunami)

- 6156 injured

-800,00 affected

-127,000 homes destroyed

-25bn tonnes debris

Japan - SECONDARY EFFECTS

-Nuclear reactor failure caused radiation contamination of land

-several coastal towns destroyed by tsunami waves

-£181bn long term rebuilding plan (£133 bn initial cost)

Haiti - GENERAL FACTS

-LIC

-12 th January

-7.0 Richter Scale

-Earthquake originated near Capital Port-au-Prince

-shallow Earthquake

Haiti- PRIMARY EFFECTS

-220,000 deaths

-20,000 injured

-3.5 million affected

-electricity, water, sanitation and communications affected

-Buildings 'pancaked' due to poor building standards

Haiti- SECONDARY EFFECTS

-landslides and avalanches blocked roads and hampered relief attempts

-Cholera and typhoid outbreaks

- Looting and civil unrest

-no tsunami

HIC

High Income Country

LIC

Low Income Country

NEE

Newly Emerging Economy

Iceland volcano

Strato Volcano (composite cone)r

Erupted May 2010

Iceland volcano Effects

£1.7bn lost income from stock exchange

Sulphur Dioxide caused acid rain

Airlines lost £130 million per day

Localised flooding

Land covered in ash calling crops