Geography: Hazardous Earth - 11/5/2026

What does air at the equator do? (Global Circulation)

Equator air is warm, rises, low pressure

What does cool air do? (Global Circulation)

Cool air falls, is high pressure

What air is able to hold less moisture? (Global Circulation)

Rising, warm, low pressure air at the equator ; this means there is more precipitation at the equator

What are Ice Cores? (Natural Climate Change)

Ice cores: cylinders of ice up to 500,000 years old

What are 3 natural causes of climate change? (Natural Climate Change)

Milankovich cycles — The Earth’s orbit changing ~ once every 100,000 yrs

Sun energy radiated changes over 11 yrs

Volcanic eruptions — pump ash into atmosphere - cooling effect

Large asteroid collisions — cause cooling - materials block sun ; can cause fires - release CO₂ —> greenhouse gas effect

Ocean Currents — can cause cooling/warming - in UK we have warm & wet climate due to warm Atlantic currents

What is the main CO₂ anthropogenic production? (Humans & Climate Change)

Industry ; transport ; energy production ; farming

What are 3(/6) statistics to prove anthropogenic climate change? (Humans & Climate Change)

Global temps rising - in 2024 avg global temp was 1.5ºC above the avg pre-industrial

Atmospheric CO₂ lvls rising with global temps

Oceans warmed ~0.06ºC per decade in 1980’s vs 0.27ºC in 2020’s

Sea lvl rose ~14cm in 20^th century

Artic sea ice covers 13% less sea each decade

Extreme weather events more frequent - heat extremes 5x more common than a century ago

What are 4(/8) possible consequences of global warming? (Humans & Climate Change)

Biodiversity loss - land & ocean

More frequent & longer lasting droughts

More frequent & heavier rain —> more floods

Loss of glaciers —> water supply issues in areas

Changes in farming - could affect food supplies

Spread of pests & disease

More frequent & stronger hurricanes —> more destruction

Sea-level rises —> coastal flooding

What are the regional names of trpopical cyclones? (Tropical Cyclones)

Atlantic & NE Pacific: Hurricane

NW Pacific: Typhoon

Indian Ocean & S Pacific: Cyclone

How do trpoical cyclones form? (Tropical Cyclones)

1. Seawater above 26.5ºC - occur in tropics, usually in summer - late-autumn

2. Low pressure, moist, warm air (with low wind shear [diff directions]) rises through atmosphere

3. Coriolis effect causes air to spiral and drags strong winds

4. Form cylinder of rising air surrounding an eye (of descending, high pressure air)

What scale categorises tropical cyclones and by what factors does it use to do so? (Tropical Cyclones)

Saffir-Simpson scale categorises tropical cyclones into 5 categories

This is done using the tropical cyclones’ max wind speed, pressure, storm surge and damage

Roughly, how many deaths, damage and storm surge caused by Hurricane Katrina 2005? (Tropical Cyclones)

Over $100 billion damages

Almost 2000 deaths

Storm surge over 8 meters

What are 3 secondary impacts of tropical cyclones? (Tropical Cyclones)

Storm surges

Coastal flooding

Landslides

What 3 factors can make countries more/less vulnerable to tropical cyclones? (Tropical Cyclones)

Physical - low-lying coastal areas

Social - poor areas (poor people often live in high density, poor quality housing in low-lying areas)

Economic - rich, developed countries have better tech

What were the 3 main reasons Hurricane Katrina killed almost 2000 people? (Tropical Cyclones)

• Old levee system

• Pumping stations flooded & failed to work

• Poor evacuation procedure:

- Highways jammed

- Public transport not used

- Shelters did not have enough food

What are 4 improvements since 2005 Hurricane Katrina? (Tropical Cyclones)

• All New Orleans levees made higher & stronger

• All floodwater pumping stations made flood-proof

• Largest storm barrier in the world built

• Improved search & rescue teams

This cost $14 billion.

What were the 3 main reasons Typhoon Haiyan 2013 killed over 6000 people? (Tropical Cyclones)

• General lack of preparation

• Insufficient emergency food & shelter

• No infrastructure to send aid - largely had to wait for international aid

What are 3 improvements since 2013 typhoon Haiyan? (Tropical Cyclones)

• Rebuilt homes & infrastructure better and stronger “Build Back Better“

• Disaster risk maps

• Warning systems

What are the 4 basic parts of the Earth’s composition - and what are they composed of? (Tectonics)

Crust + [lithospheric mantle] } Lithosphere

Mantle { Lithospheric mantle, asthenosphere, Mesosphere

Outer Core

Inner Core

Which crust is denser? (Tectonics)

The oceanic crust is denser than continental crust

Think same amount of material just more condensed

What are the three main plate boundaries? (Tectonics)

Convergent: 2 plates colliding (one flows underneath the other - subduction) Earthquakes & Volcanoes

Divergent: 2 plates moving away from each other due to convection currents pulling them apart

Conservative: 2 plates sliding past each other Earthquakes

What are hotspots? (Tectonics)

Hotspots: points on the Earth’s crust with high heat flow (linked to increased volcanic activity)

Can create island chains

What are 3(/5) features of shield volcanoes? (Tectonics)

1. Found on constructive plate boundaries/hotspots

2. Formed by eruptions of non-viscous lava which flows a long way before solidifying

3. Gently sloping sides & wide base

4. Basaltic magma - very hot with low silica & gas content

5. Frequent, non-violent eruptions

What are 3(/5) features of composite volcanoes? (Tectonics)

1. Found on destructive plate boundaries

2. Formed by eruptions of viscous, sticky lava & ash that do not flow far

3. Steep, sloping sides & narrow base

4. Made of layers of lava & ash

5. Andesitic magma (less hot ; contains lots of silica & gas)

6. Infrequent, violent eruptions

What is the epicentre & focus? (Tectonics)

Epicentre: the point directly above the focus - on the surface

Focus: Central point of the earthquake - deep under the surface

What caused the Japan Tōhoku earthquake 2011? (Tectonics)

• Pacific tectonic plate subducting plate carrying Japan

• 9.0 magnitude

• Occurred in clay with shallow focus meaning the ground vibrated more causing more destruction

What preparation did Japan use for the 2011 Tōhoku earthquake? (Tectonics)

“Predict, prepare, protect”

Strict building codes - strong framework in skyscrapers

Regular drills

Advanced early warning system

What were the primary & secondary impacts of the Japan Tōhoku 2011 earthquake? (Tectonics)

Primary:

• Over 18,000 dead/missing

• catastrophic destruction of coastal cities by tsunami waves

• Widespread infrastructure failure

Secondary:

• Fukushima nuclear meltdown

• Widespread homelessness & displacement

• Economic devastation £35 billion

What plate boundary does Haiti sit on? (Tectonics)

Conservative

What preparation did Haiti use for the 2010 Port-au-Prince earthquake? (Tectonics)

Largely unprepared due to poverty (70% less than $2 a day), weak governance & lack of seismic building codes

What were the primary & secondary impacts of the Haiti Port-au-Prince 2010 earthquake? (Tectonics)

Primary:

Roughly 300,000 deaths + 300,000 injuries

Almost 300,000 buildings destroyed (mostly houses)

Secondary:

Cholera outbreak infecting over 800,000 people

Over 1.5 million homeless

What were the short & long term responses to the Haiti Port-au-Prince 2010 earthquake? (Tectonics)

Short-term:

Immediate search & rescue

Emergency aid

Deployment of medical units

[All hampered due to damaged infrastructure]

Long-term:

New homes built to high standard

Rebuilt the port

Over 1 million still lived in temporary housing 1 year post-earthquake