Lecture Notes: Earth as a System

Introduction to Earth as a System

• Earth can be viewed as a complex system.
• System: A set of interacting or interdependent components.

Biotic and Abiotic Factors

• Biotic Factors:
  • Derived from 'bio' meaning life.
  • Living factors in a system.
  • Example: Gut bacteria in human intestines.
  • Antibiotics combat harmful biotic factors (e.g., bad bacteria).
• Abiotic Factors:
  • 'A' prefix means not, thus abiotic means non-living.
  • Non-living factors in a system.
  • Examples: Soil, air pressure, water pressure, temperature.

Earth’s Major Spheres

• Earth's system is often broken down into major components referred to as spheres.
  • Earth itself is a sphere.

The Atmosphere

• Encompasses all the air around Earth.
• About 60 miles thick.
• Consists of the gases surrounding Earth.

The Biosphere

• Made up of all living organisms on Earth.
• Organisms mostly reside on or near the Earth’s surface.

The Hydrosphere

• Includes all water on and below Earth’s surface.
• Comprises oceans, seas, lakes, rivers, precipitation, and icebergs.

The Geosphere

• Composed of all non-water, non-gas, and non-living components.
• Includes rock, continents, ocean floor, and Earth's interior.

Conclusion

• Understanding Earth as a system involves recognizing the interaction between its biotic and abiotic factors.
• The four spheres represent the major interacting components of Earth’s system.