Geography

• Tropical Storm-Typhoon Haiyan


  November 2013
• Tropical Storm


  • Category 5 (strongest) - Wind speeds over 170 mph, torrential rain, and 15m high storm surge
• Storm surge


  Tropical storms have very low air pressure, this causes the sea level to rise. These high seas (3-8m higher than normal) flood huge areas of land.
• Global atmospheric circulation is the world's system of winds, which transport heat from equator to poles. It is the main factor determining global weather and climate patterns.
• Global atmospheric circulation


  • Warm air rises low pressure
  • Cold air sinks-high pressure
  • Air moves from areas of high pressure to areas of low pressure
• Global atmospheric circulation patterns

  • Equator (0°): Hot and rainy (humid - tropical rainforests)
  • 30° N and S: Hot and dry (arid - deserts)
  • Poles (90° N and S): Cold and dry
• The winds are bent due to the earth's spin. In the southern hemisphere, winds are bent to the left. In the northern hemisphere, winds are bent to the right.
• The air moves in three types of cells: Hadley, Ferrel and Polar.
• The number of floods in the UK has increased since the 1960s, showing that the UK's weather is becoming more extreme.
• Extreme weather


  Weather that is significantly different to normal patterns
• In China, the city of Haicheng was evacuated following strange animal behaviour. Days later a 7.3 magnitude earthquake struck. It is estimated it saved 150,000 lives.
• Tropical storm


  A storm with wind speeds of over 74mph and torrential rain.
• Tropical storm structure


  Tropical storms are circular in shape and usually lasts 7-14 days
• Primary vs secondary impacts

  Worse in HICs - More infrastructure to be damaged and businesses disrupted. Worse in LICs - Poorer building quality, more collapses - higher deaths and injuries.
• Tropical storm


  A storm with wind speeds of over 74mph and torrential rain. Known as hurricanes, typhoons and cyclones
• Tropical storm


  • Circular in shape
  • Usually lasts 7-14 days
• Formation of tropical storms

  1. The sun heats the sea/ocean

  2. Warm, moist air evaporates and rises

  3. More air rushes in to replace the air that has just evaporated

  4. As the air rises it condenses to form thick clouds

  5. The earth's rotation causes the clouds to spin, forming the tropical storm's distinctive spinning shape

  6. Cold air sinks in the centre of the storm forming the eye of the storm

  7. It moves in the prevailing wind direction (east to west)

  8. It reaches land and loses energy as its energy source (warm water) is gone. Friction of the land also reduces its energy
• Structure of a tropical storm

  • Eye - centre of the storm, cold air sinks, no clouds or wind, calm conditions
  • Up to 400 miles across
  • On either side of the eye is the eyewall - a tall bank of cloud. Here are very strong winds, heavy rain, thunder & lightning
• Tropical storms are measured on the Saffir-Simpson scale
• Conditions needed to form a tropical storm

  • Ocean temperature of 27°C or higher
  • Latitude between 5-20° north and south of the equator (enough spin here to create spiral shape)
• As temperature increases


  More of the world's oceans will be 27°C or higher, meaning more places will have tropical storms
• As temperature increases


  Tropical storms become stronger, with more category 4 and 5 storms
• Storm surge


  A tropical storm impact
• Methods to predict tropical storms

  • Satellite imagery
  • Previous tropical storm data and computer models
• Methods to plan for tropical storms

  • Evacuation routes and practice drills
  • Warning systems
  • Emergency kits
  • Building regulations - new homes in low-risk areas, buildings designed to withstand storms, flood defences
• LICS do not always have the technology to accurately predict storm paths
• If tropical storm predictions are inaccurate, the consequences can be large
• Practice drills and emergency kits help people in both HICs and LICS prepare, resulting in less panic and preventing additional deaths
• Building regulations are weaker in LICS
• HIC responses to tropical storms are more effective and quicker due to the country's resources, while LIC responses are slower and rely on international aid
• Primary impacts are worse in LICS due to building collapse leading to most of the primary and secondary effects, while primary effects are better in HICS due to better building quality
• The 2011 Japan tropical storm is unique because the tsunami caused the most damage, not the shaking
• The main types of weathering are physical, chemical, and biological.
• Chemical weathering involves the breakdown of minerals through reactions with water or air.
• Physical weathering is the breaking down of rocks into smaller pieces without changing their composition.
• Chemical weathering occurs when water reacts with minerals in rock, causing them to dissolve or change form.
• Biological weathering occurs when plants grow into rocks and break them apart over time.
• Biological weathering refers to the breakdown of rocks by living organisms such as plants and animals.
• Physical weathering involves breaking rocks into smaller pieces without changing their composition.
• Physical weathering includes processes such as frost wedging, thermal expansion/contraction, and abrasion by wind-blown sand.