GLOBAL HAZARDS

• How does the global circulation system work ?

  The sun heats up air in the Earth's atmosphere. The temperature of the Earth's atmosphere depends on the latitude(how far away it is from the equator). As the equator is closets to the sun, the air is warm and the air at the North and South Pole is cold.
• What is a a Hadley Cell ?

  Largest cell which extends from the equator to between 30degrees and 40degrees north and south.
• What is a Ferrel Cell ?

  Th middle cell which generally occurs from the edge of the Hadley to between 60degrees and 70degrees.
• What are Polar Cells ?

  The smallest and weakest cell which extends from the edge of the Ferrel cell to the Poles at 90degrees.
• What are the factors affecting temperature ?

  Latitude, altitude, proximity to water bodies, ocean currents, prevailing winds, Albedo effect.
• What is the hottest place on Earth ?

  Lut Desert in Iran is the hottest place on Earth at 70.7 degrees celcius. There is intense sunshine and surfaces absorb heat.
• What is the coldest place on Earth ?

  Antarctica is the coldest place on Earth with the temperatures dropping to -82.9 degrees celcius. Sun rays are less intense in Polar regions.
• What are the types of winds ?

  Trade winds, Katabatic winds, and Jet Streams.
• What are trade winds ?

  Winds that blow from high pressure belts to low pressure belts.
• what is the earths core in the middle split into

  inner metallic core (solid), outer core (liquid). hottest part of the earth
• molten surrounds the core and consists of semi molten rock
• The crust is the very thin outer layer floating on semi - solid mantle and is the layer we live on
• The crust is broken into large pieces called tectonic plates. There are two types of crust called continental and oceanic crust
• continental crust is thicker and less dense
• oceanic crust is thinner and more dense
• asthenosphere


  upper layer of the earths mantle
• lithosphere 


  outer part of the earth, consisting of crust and upper mantle
• Convection Currents in the Mantle

  Radioactive decay in the Earth's mantle and crust generates heat. The lower part of the asthenosphere heats up, becomes less dense and rises. The magma in the asthenosphere becomes less cooler as it gets further away from the Earth's core. It becomes more dense and sinks
• Destructive Plate Margins


  The oceanic plate slides beneath the continental plate which is called the subduction zone. The rocks catch against each other as the plates are not smooth surfaces. Pressure builds up along the plates until they can not take the stress. The plates slide past each other which can cause them to move and therefore the ground shakes (earthquakes).
• Constructive Plate Margins


  The plates separates. The convection current diverges which causes a gap between the plates. Magma rises up to fill this gap.