Earth and Its System Quiz

Earth's Characteristics

• Third planet from the sun and classified as a terrestrial planet.
• Known as the "blue planet" due to extensive water coverage (global ocean).
• Unique in its ability to support life.
• Oblate spheroid shape, slightly flattened.

Earth's Interior Structure

• Crust: Thin solid outer layer divided into continental and oceanic crust.

  • Continental Crust:
    • Approximately 35 km thick, may exceed 70 km in mountains.
    • Composed mainly of granodiorite.
  • Oceanic Crust:
    • Roughly 7 km thick, primarily made of basalt.

• Mantle:

  • Constitutes over 82% of Earth's volume, extends to nearly 2,900 km deep.
  • Dominated by peridotite, richer in magnesium and iron.
  • Divided into upper and lower mantle with lithosphere and asthenosphere layers.

• Lithosphere:

  • Rigid outer layer comprising crust and upper mantle.
  • Relatively cool and stable.

• Asthenosphere:

  • Below lithosphere, characterized by a small amount of melting.
  • Allows tectonic plate movement.

• Lower Mantle:

  • Very hot and flows gradually; strengthens with depth due to pressure.

• Core:

  • Central region composed of an iron-nickel alloy.
  • Divided into outer (liquid) and inner (solid) core.

Earth's Gravity

• Constant gravitational acceleration at Earth's surface is 9.8 m/s².

Earth as a System

• Systems encompass individuals, populations, communities, and ecosystems.
  • Individual: Single species member.
  • Population: Group of the same species in a specific area.
  • Community: Different species interacting in a common area.
  • Ecosystem: Community interactions with abiotic environmental factors.

Earth's Four Spheres

• Hydrosphere:

  • Contains all water, circulates within oceans, continents, glaciers, and atmosphere.
  • Oceans hold 71% of Earth's waters, consisting of 97.5% of all water.

• Atmosphere:

  • Gaseous envelope above Earth's surface, includes multiple layers: troposphere, stratosphere, mesosphere, thermosphere, exosphere.

• Geosphere:

  • Comprises solid Earth, including the core, mantle, and crust.

• Biosphere:

  • Thin layer supporting all life forms on land, in water, and in air.

Earth's Energy Budget

• Internal Source:

  • Heated by radioactive decay and gravitational contraction, providing energy through convection.

• External Source:

  • Solar energy is primary external energy source, sustaining life and warming Earth's surface and atmosphere.

Biotic Groups

• Autotrophs (Producers):

  • Organisms that produce their own food; includes plants, algae, certain bacteria, and phytoplankton.

• Heterotrophs (Consumers):

  • Organisms that cannot produce their own food; includes animals, fungi, most protozoa, and many bacteria.