Earth Science Fundamentals

Earth's Structure

• The Earth is composed of three main layers:
  1. Crust: outermost solid layer, ranging in thickness from 5-70 km
  2. Mantle: thick, viscous layer beneath the crust, divided into upper and lower mantle
  3. Core: innermost layer, composed of a solid inner core and a liquid outer core

Plate Tectonics

• The Earth's lithosphere (outer layer) is broken into several large plates that move relative to each other
• Plate movement is responsible for:
  • Earthquakes
  • Volcanic activity
  • Mountain building
  • Sea-floor spreading

Earth's Systems

• Hydrosphere: all the Earth's water, including oceans, lakes, rivers, and groundwater
• Atmosphere: the layer of gases surrounding the Earth
• Geosphere: the solid, rocky part of the Earth
• Biosphere: the region of the Earth where living organisms exist

Weathering and Erosion

• Weathering: the breakdown of rocks into smaller particles, through:
  • Mechanical weathering (e.g. freeze-thaw cycles)
  • Chemical weathering (e.g. oxidation, dissolution)
• Erosion: the transportation of weathered particles away from their source, through:
  • Water (e.g. rivers, ocean currents)
  • Wind
  • Ice (e.g. glaciers)

Earth's Processes

• Rock Cycle: the continuous process of rock formation, transformation, and destruction
• Water Cycle: the movement of water between the Earth's systems, including:
  • Evaporation
  • Condensation
  • Precipitation
  • Runoff

Earth's Resources

• Renewable resources: resources that can be replenished naturally, such as:
  • Solar energy
  • Wind energy
  • Water
• Non-renewable resources: resources that cannot be replenished naturally, such as:
  • Fossil fuels (e.g. coal, oil, gas)
  • Minerals (e.g. iron, copper)