Science

• Crust


  The outermost layer of the Earth
• Kinds of crust


  • Oceanic crust
  • Continental crust
• Mantle


  The layer below the crust, with an upper semi-molten part and a lower molten part, containing a deformable region called the asthenosphere
• Core


  The innermost layer of the Earth, consisting mostly of iron and nickel, divided into an outer molten layer and an inner solid layer
• Moho


  The boundary between the Earth's crust and mantle, discovered by seismic wave analysis
• Continental drift theory


  The theory that the continents were once joined in a single landmass called Pangaea, which then broke apart and drifted
• Seafloor spreading theory


  The theory that the mid-ocean ridge is formed by molten rock flowing from a crack in the Earth's crust, pushing the ocean floor apart as it hardens
• Plate tectonics theory


  The theory that the Earth's crust is made up of large rigid plates that float on the mantle and move relative to each other, creating surface features like mountains and trenches
• 7 major tectonic plates

  • African Plate
  • Antarctic Plate
  • Eurasian Plate
  • Indo-Australian Plate
  • Pacific Plate
  • South American Plate
  • North American Plate
• 14 minor tectonic plates

  • Amurian Plate
  • Arabian Plate
  • Burma Plate
  • Caribbean Plate
  • Caroline Plate
  • Cocos Plate
  • Nazca Plate
  • Okhotsk Plate
  • Philippine Sea Plate
  • Scotia Plate
  • Somali plate
  • Sunda Plate
  • Yangtze Plate
  • New Hebrides Plate
• Some tectonic plates are moving towards each other, others are moving apart, and a few are sliding past each other, creating surface features like mountains and trenches
• Plates with continents move relatively slowly, about 2 cm per year, while those without continents move faster, about 12 cm per year
• Crust


  The outermost layer of the Earth
• Kinds of crust


  • Oceanic crust
  • Continental crust
• Mantle


  The layer below the crust, with an upper semi-molten part and a lower molten part due to high temperature, containing a deformable region called the asthenosphere
• Core


  The innermost layer of the Earth, consisting mostly of iron and nickel
• Layers of the core

  • Outer core
  • Inner core
• Outer core


  Molten due to intense heat
• Inner core


  Solid due to extremely high pressure offsetting the melting process from intense heat
• Moho


  The boundary between the Earth's crust and mantle, discovered by Andrija Mohorovicic through the study of seismic waves
• Earthquakes and other explosive activities near the Earth's surface can cause seismic waves
• Continental drift theory


  Proposed by Alfred Wegener, suggesting that continents were once joined in a single landmass called Pangaea which later broke apart and drifted
• Wegener spent the rest of his life searching for evidence to prove his continental drift theory but died in 1930 without convincingly explaining what caused the continents to move
• Seafloor spreading theory


  Molten rock flowing from a crack in the Earth's crust forms mountains, pushing the ocean floor apart
• Plate tectonics theory


  Describes the large-scale motion of the Earth's surface, building on continental drift and seafloor spreading concepts
• 7 major tectonic plates

  • African Plate
  • Antarctic Plate
  • Eurasian Plate
  • Indo-Australian Plate
  • Pacific Plate
  • South American Plate
  • North American Plate
• 14 minor tectonic plates

  • Amurian Plate
  • Arabian Plate
  • Burma Plate
  • Caribbean Plate
  • Caroline Plate
  • Cocos Plate
  • Nazca Plate
  • Okhotsk Plate
  • Philippine Sea Plate
  • Scotia Plate
  • Somali plate
  • Sunda Plate
  • Yangtze Plate
  • New Hebrides Plate
• Some tectonic plates are moving towards each other, others are moving apart, and a few are sliding past each other, creating many of the Earth's surface features like mountains and deep-sea trenches
• Plates with continents move relatively slow, about 2 cm per year, while those without continents move faster, about 12 cm per year