Fundamentals of Earth Processes

Fundamentals of the Earth and its Processes

• Earth is the only planet in the Solar System that supports life.
• It is a terrestrial planet, primarily made of rocks, and is the third planet from the sun.
• The atmosphere contains free oxygen, and liquid water covers approximately 71% of its surface, mainly in oceans.
• Earth has a diameter of about 8,000 miles (13,000 km) and is shaped like a sphere due to gravitational forces.

Earth's History

• Divided into four eons: Hadean, Archean, Proterozoic, and Phanerozoic, each marked by significant geological and biological developments.

Hadean (4,540-4,000 Million Years Ago)

• Formed from cosmic debris, with no life and extreme temperatures.
• Characterized by frequent volcanic eruptions and a nebular atmosphere.

Archean (4,000-2,500 Million Years Ago)

• Marked by the emergence of prokaryotic unicellular life.
• Presence of some landmasses and an atmosphere rich in greenhouse gases.

Proterozoic (2,500-541 Million Years Ago)

• Known as "early life," featuring the rise of eukaryotic multicellular organisms.
• Experienced periods known as "Snow Ball Earth" when global temperatures dropped significantly.

Phanerozoic (541 Million Years Ago - Present)

• Characterized by complex life forms and the existence of modern oceans.
• Evolution of modern plants, animals, and humans occurred, along with the formation and separation of the supercontinent Pangaea.

Pangaea, Laurasia, and Gondwanaland

• Pangaea: A supercontinent that included nearly all of Earth's landmasses.
• Laurasia: Composed of current areas like North America, Europe, and Asia.
• Gondwanaland: Included the landmasses of Africa, South America, Australia, Antarctica, and the Indian subcontinent.

Layers of the Earth

• Crust: The outermost layer composed of solid rocks and minerals.
• Mantle: The thick, mostly solid layer beneath the crust, divided into five parts: Lithosphere, Asthenosphere, Transition Zone, Lower Mantle, and D" (D Prime).
• Core: The innermost layer, extremely hot and dense, primarily made of iron and nickel.

Hydrosphere and Water Cycle

• The hydrosphere encompasses all water on, under, and above Earth's surface.
• The water cycle involves continuous movement of water through:
  • Evaporation: Liquid water changes to gas.
  • Condensation: Water vapor becomes liquid.
  • Precipitation: Water falls back to Earth in liquid or frozen form.
  • Infiltration: Water absorbs into the ground.
  • Runoff: Water that flows over the ground surface into water bodies.

Atmosphere Layers

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere
• Exosphere

Ecology Basics

• Focuses on interactions between organisms and their environment, emerging from Greek words meaning 'household' and 'study.'
• Ecologists study ecosystems across land and water environments.

Biotic and Abiotic Components

• Biotic: Living components, including plants, animals, bacteria.
• Abiotic: Non-living factors, including sunlight, soil, temperature.

Levels of Organization in Ecology

• Organism: An individual living entity.
• Population: A group of the same species in an area.
• Community: Multiple species populations in a region.
• Ecosystem: Interaction of biotic and abiotic elements.
• Biosphere: Contains all ecosystems, supporting life.

Habitat and Niche

• Habitat: The physical environment where a population lives.
• Niche: The role and resources required for a species' survival, growth, and reproduction.

Interspecific Interactions

• Competition: Organisms competing for resources.
• Predation: One organism kills and consumes another (predator-prey dynamics).
• Symbiosis: Long-term interactions between species, with types including:
  • Mutualism: Both species benefit.
  • Commensalism: One benefits, other is neither helped nor harmed.
  • Parasitism: One benefits at the expense of another.

Energy Flow in Ecosystems

• The sun is the ultimate energy source for the biosphere.
• Plants convert light energy through photosynthesis, while consumers derive energy by eating other organisms.

Major Roles of Organisms in Ecosystems

• Producers (Autotrophs): Create organic molecules from inorganic substances using photosynthesis or chemosynthesis.
• Consumers (Heterotrophs): Obtain energy by consuming other organisms; include herbivores, carnivores, omnivores, and scavengers.

Plants Trivia

• During the day, plants absorb carbon dioxide and release oxygen.
• At night, they take in oxygen and expel carbon dioxide.