Earth and Space Science: Plate Tectonics

Earth and Space Science

• Plate Tectonics Theory: Proposes the Earth's lithosphere is composed of plates.
• Evidence Supporting Plate Tectonics:
  • Fossil distribution: Similar fossils found in different locations.
  • Earthquake and volcano locations: Clustered at plate boundaries.
  • Geological Features: Activities occur along boundaries.
  • Spreading seafloor: Molten material causes plates to move apart.
• Plate Boundaries: These are locations where plate interactions cause geological activity.
• Convergent Boundaries: Plates move toward each other.
  • Types include fold mountains, deep-sea trenches and volcanic mountains.
  • Resulting movement is destructive.
    • Continental-Continental: Neither plate sinks.
    • Continental-Oceanic and Oceanic-Oceanic: Denser oceanic plate sinks.
• Divergent Boundaries: Plates move away from each other.
  • Types include mid-ocean ridges and rift valleys
  • Resulting movement is constructive.
• Transform Boundaries: Plates slide past each other.
  • Types include major earthquakes.
  • Resulting movement is conservative.
• Volcanoes:
  • Types (Structure):
    • Cinder Cone (e.g., Taal) – Piles of lava
    • Composite/Stratovolcano (e.g., Mayon) – Alternating layers of lava and ash.
    • Shield (e.g., Mauna Kea) – Outpourings of lava
  • Types (Activity):
    • Active – Erupted within last 10,000 years.
    • Potentially-Active – Young looking, no recent eruption records
    • Inactive – Not erupted in last 10,000 years.
• Volcanic Eruptions: Magma's temperature, viscosity, silica content, amount of dissolved gases are factors that affect eruptions.
  • Types: Phreatic, Phreatomagmatic, Strombolian, Vulcanian, Plinian
• Volcanic Hazards: Lava flows, tephra falls, pyroclastic density currents (PDCs).
• Energy from Volcanoes: Hot water from volcanic activity can be converted to steam to generate electricity.
• Climate Factors: Latitude, altitude, distance from sea, topography regulate climate.
• Climate Phenomena: Global Warming, El Niño, La Niña.
• Indicators of Climate Change: Rising temperatures, sea levels, melting ice caps.
• Practical Ways to Mitigate Climate Change: Reduce, reuse, recycle, eat vegetables, save energy.
• Stars and Constellations:
  • Stars are massive balls of gas (Hydrogen and Helium).
• Movement of Stars: Earth's rotation and revolution affect star visibility.
• Beliefs and Practices about Constellations: Astrology and Indigenous practices like using constellations for navigation.
• Galaxies: Composed of Hydrogen, Helium, oxygen and Carbon.
  • Types: Spiral, Elliptical and Irregular.
  • Components: Disk, bulge.