structure of the earth

• Biosphere is the layer of the Earth that supports life and contains all the world's ecosystems
• Ecosystems are communities of organisms living together with their physical environment
• Biotic refers to all living organisms within an ecosystem (e.g. plants and animals)
• Abiotic refers to all non-living organisms within an ecosystem (e.g. rocks)
• Each abiotic and biotic component of an ecosystem is closely related and affects each other
• Types of ecosystems:

  • Marine ecosystems: most common on Earth, covering 75% of the Earth's surface
  • Freshwater ecosystems: rarest, covering only 1.8% of the Earth's surface
  • Terrestrial ecosystems: cover the remainder of Earth and are incredibly diverse
• Terrestrial ecosystems can be grouped into biomes based largely on climate:

  • Tropical rainforests
  • Savannas
  • Deserts
  • Coniferous forests
  • Deciduous forests
  • Tundra
• Hydrosphere is the total amount of water found on the surface of the planet, underground, and in the air
• The Earth's hydrosphere can be in solid form (ice), liquid, or gas (vapour)
• Solid water exists as glaciers, ice sheets, ice caps, and icebergs (cryosphere)
• Liquid water exists on the surface as oceans, lakes, rivers, and below ground as groundwater
• Gaseous water is visible as clouds and fog
• Water moves through the hydrosphere in a cycle known as the hydrological cycle
• Atmosphere is an invisible layer of gases surrounding the Earth, held in place by gravity
• Nitrogen and oxygen make up 99% of the gases in the atmosphere
• Water vapour and dust are also present in the atmosphere
• The atmosphere acts as a filter, keeping out most ultraviolet radiation while letting in the sun's warming rays
• The atmosphere consists of 5 layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere
• Geosphere includes the Earth's interior, rocks, minerals, landforms, and processes that shape the Earth's surface
• The geosphere consists of 4 main layers: Inner Core, Outer Core, Mantle, and Crust
• Processes such as metamorphism, melting, solidification, weathering, erosion, deposition, and burial shape the geosphere
• Layers of the geosphere:

  • Mantle: largest layer containing semi-molten rock called magma
  • Outer Core: similar characteristics to the Inner Core, located 2880km to 5180km from the Earth's surface
  • Inner Core: hottest layer, located 5180km to 6400km from the Earth's surface
  • Crust: solid and thinnest layer, broken into Oceanic and Continental Plates