1A Hazardous Earth Flashcards
What are two ways in which heat at the equator can be re-distributed around the world?
- Air currents
- Ocean currents
Atmospheric Pressure
The “Weight” of the air and the force this exerts on the ground. Pressure has a big impact on the climatic features of an area.
What is climate change and 3 natural causes
Climate change refers to how the average climatic conditions of the planet vary over time.
Natural causes:
- Eccentricity
- Axial tilt
- Precession
- Solar variation
- Volcanism
- Surface impact
Evidence for natural climate change
- Ice cores
- Tree rings
- Historical sources
What is the greenhouse effect?
When greenhouse gasses trap heat that is radiated from the surface which would otherwise have been lost to space.
4 human activities that produce greenhouse gasses
- Energy
- Industry
- Transport
- Farming
Possible consequences of climate change
- Rising sea levels cause costal flooding
- Stronger and more frequent tropical cyclones cause greater destruction
- Pests and diseases more widespread
- Food supplies potentially affected by changes in farming practices
- Water supply problems caused by loss of glaciers
- Longer and more frequent droughts
- More frequent and heavier precipitation causes more flooding
- Biodiversity lost in the oceans and on land
What are tropical cyclones?
They are large-scale, rotating storms that form over the oceans in tropical areas. Depending on where in the world they form, they are also known as hurricanes, cyclones or typhoons. They can be devastating if they move over land
What is the structure of a tropical cyclone like?
- Above is a dense canopy or covering of cirrus cloud, caused by the massive uplift of warm, moist air into the atmosphere.
- At the centre are swirling bands of rain, high banks of cloud that can stretch out 1000km from the cyclone centre and which produce heavy rain and strong winds.
- At the centre is the eye, and around that is the eye wall. This thick bank of cloud rises 15km into the atmosphere. The eye wall has the heaviest rain and the strongest winds.
- the eye has no wind and clear skies, it is where air is falling back down to earths surface- a zone of high pressure. It is often the first sign on satellite images that a tropical cyclone has formed.
How are tropical cyclones formed?
Formed in tropical areas. High temperatures cause air to rise away from the ocean surface. The rising air causes thunderstorms. Sometimes these storms group together, creating a strong flow of warm, rapidly rising air, which turn produces an area of extreme low pressure at the centre of these converging storms.
However, these conditions must be present:
Moist warm air, warmer then 26.5 Celsius
At the time of year when ocean water is its warmest
Winds must be converging at the ocean surface, causing the air to rise
Factors affecting tropical cyclone intensity
Land and ocean
Solar radiation
Environmental vertical wind shear
Ambient humidity
3 main reasons of dissipation of tropical cyclones
- When it reaches land it looses energy because it has lost its fuel source - the warm water
- When it moves into areas of colder water (Below 26.5)
- When it runs into other weather systems where winds are blowing in different directions
What physical hazards do tropical cyclones bring?
High winds
Intense rainfall
Storm surges
Costal flooding
Landslides
Physical v Social v Economic vulnerability to tropical cyclones
- Physical: Weak buildings, coastal areas, or flood-prone regions.
- Social: Poor, elderly, or isolated people struggle more.
- Economic: Poorer countries and people can’t afford to prepare or recover easily.
4 ways of preparing for tropical cyclones
Atmospheric pressure
Modelling
Satellite tracking and radar
Communicating information
Main differences on how people prepared for hurricane Katrina vs typhoon Haiyan
The main differences are:
1. Resources: The U.S. had better resources but mismanaged them. The Philippines had fewer resources and weaker infrastructure.
2. Government: Katrina had poor coordination; Haiyan’s government lacked capacity to prepare fully.
3. Awareness: Katrina’s risks were known but some couldn’t evacuate; Haiyan’s risks weren’t well understood.
4. Impact: Katrina exposed inequality; Haiyan was worsened by widespread poverty.
Main differences on how people responded to hurricane Katrina vs typhoon Haiyan
Here’s an even simpler version:
- Preparedness:
• Katrina: The U.S. was not ready.
• Haiyan: The Philippines tried to prepare but couldn’t stop the damage. - Government Response:
• Katrina: The U.S. took too long to help.
• Haiyan: The Philippines acted fast, but needed more help. - International Help:
• Katrina: The U.S. didn’t need much help.
• Haiyan: The world gave lots of help. - Communication:
• Katrina: Slow communication delayed help.
• Haiyan: Social media helped spread the news fast. - Displacement:
• Katrina: Many people were displaced for a long time.
• Haiyan: Millions were displaced, and it took years to recover. - Military:
• Katrina: U.S. military helped late.
• Haiyan: Military responded quickly, with help from others. - Social Impact:
• Katrina: Poor people suffered the most.
• Haiyan: Rural areas struggled, but the country came together. - Media:
• Katrina: Media showed the U.S. government’s failures.
• Haiyan: Social media quickly raised awareness. - Recovery:
• Katrina: Recovery was slow.
• Haiyan: Recovery was also slow, but lots of help came.
