Lecture Notes: Tectonic Plates and Earth's Structure

Introduction

• Concept of Movement: Constant movement occurs, even in sleep, due to tectonic plates.
• Tectonic Plates: Essential to understanding geology.

Earth's Compositional Layers

• Three Major Layers:
  • Crust: Thin layer.
  • Mantle: Thick layer beneath the crust.
  • Core: Divided into:
    • Solid Metallic Inner Core
    • Molten Outer Core

Structure of a Tectonic Plate

• Composition:
  • Crust and Uppermost Mantle: Form the rigid lithosphere.
• Thickness: Up to a few hundred kilometers.
• Movement: Plates ride above the asthenosphere, which flows slowly due to molten minerals.

Plate Movement

• Lithosphere:
  • A shell around Earth, broken into plates.
• Tectonic Activity:
  • Movement of plates causes earthquakes, volcanoes, and mountain belts.

Identifying Plate Boundaries

• Earthquake Distribution:
  • Use earthquake locations to map plate boundaries.
  • Example: 1600+ earthquakes of magnitude 5+ in one year.
• Mapping Exercise:
  • Start with a blank world map.
  • Example locations: Atlantic and Pacific Oceans.

Major Tectonic Plates

• Key Plates:
  • Pacific Plate
  • North American Plate
  • South American Plate
  • African Plate
  • Antarctica Plate
  • Eurasian Plate
  • Indian-Australian Plate
  • Nazca Plate

Smaller Plates

• Cocos Plate
• Caribbean Plate
• Scotia Plate
• Philippine Plate
• Arabian Plate

Conclusion

• Confidence Check: Evaluate ability to complete map-related tasks.
• Next Steps: Practice creating plate boundary maps.