Earth's Subsystems Quiz

Earth's Subsystems

Atmosphere

• Consists of a thin layer of gases encasing the lithosphere.
• Composed of 78% nitrogen, 21% oxygen, 0.9% argon, and trace gases.
• Facilitates heat redistribution on Earth's surface through atmospheric circulation.
• Engages in a continuous exchange of heat and moisture with the hydrosphere via the hydrologic cycle.

Lithosphere

• Refers to the solid outer layer of the Earth, commonly known as the crust.
• Comprises both continental and oceanic crust alongside various internal layers.
• Encompasses rocks from the crust and upper mantle, contributing to Earth's geology.

Biosphere

• Represents all life forms on Earth, spanning various ecosystems.
• Ranges from soil and rainforests to mangroves, coral reefs, and oceanic depths.
• Photosynthetic organisms form the base of the food chain, utilizing CO2 and releasing oxygen.
• Acts as a CO2 sink, integral to the carbon cycle and reliant on sunlight for energy.

Hydrosphere

• Covers approximately 70% of Earth with liquid water, predominantly in oceans.
• Only 3% of Earth's water is fresh; two-thirds exists as ice and one-third in streams, lakes, and groundwater.
• Oceans serve as significant CO2 sinks through direct atmospheric exchange and rock weathering.
• Ocean circulation plays a critical role in heat absorption and redistribution on Earth's surface.

Origin of Systems Approach to Earth Study

• Friedrich Wilhelm Heinrich Alexander von Humboldt advocated for a holistic understanding of the universe, including Earth's systems.
• The term "biosphere" was popularized by Russian-Ukrainian scientist Vladimir Vernadsky, positing life as a geological force.
• Gaia Hypothesis, conceived in the 1970s by James Lovelock and Lynn Margulis, proposes that the biosphere self-regulates, influencing its physical and chemical environment.