Volcanoes, Earthquakes, and Mountain Ranges

Main Topics

• Description of Earth's features
• Relationship between volcanoes, earthquakes, and mountain ranges
• Earth's layers and crust
• Plate tectonics
• Geographical regions and their tectonic activity
• Summary and key concepts

Earth's Features and Formation

• Earth is described as having various features like mountains and volcanoes.
• These features are connected through plate tectonics.

Earth's Layers

• Earth is composed of four layers:
  • Crust: The outermost layer.
  • Mantle: Located below the crust.
  • Outer Core
  • Inner Core
• Earth's crust is divided into two types:
  • Continental Crust: Thick, forms the continents, 30-50 km deep.
  • Oceanic Crust: Thinner, forms ocean floors, 5-10 km deep, made of denser rocks.

Lithosphere and Tectonic Plates

• The lithosphere includes the crust and the upper mantle.
• It is divided into tectonic plates, which are large and small pieces of the Earth's surface.
• Plates move slowly due to heat currents in the mantle.
• Types of plate movements:
  • Apart: Can lead to earthquakes.
  • Collide: Can create mountains.
  • Subduction: One plate dives under another forming volcanoes.

Tectonic Activity and Geographical Features

• Volcanoes, earthquakes, and mountain ranges often occur in the same locations.
• Plate movements cause different geological events:
  • Earthquakes can occur on land or underwater.
  • Volcanoes form through subduction.
  • Mountain Ranges form when plates collide.

The Pacific Ring of Fire

• A major tectonic region encircling the Pacific Ocean.
• Known for frequent earthquakes and volcanic activity.

Tectonic Plates Affecting the Philippines

• Philippine Sea Plate: East of the Philippines, causes earthquakes and volcanic activity.
• Eurasian Plate: Northwest, interacts with Philippine Sea Plate.
• Pacific Plate: Further east, influences Philippine tectonic activity.
• Sunda Plate: Southwest, affects southern Philippines.

Key Concepts

• Plate Tectonics Theory: Earth's crust is made of moving plates causing geological features.
• Continental Plates: Thicker, less dense.
• Oceanic Plates: Thinner, denser.
• Earthquakes, volcanoes, and mountains are aligned with plate boundaries.
• Geologic activities like earthquakes and volcanism help define tectonic plates' boundaries.

Conclusion

• Understanding of plate tectonics is crucial to explaining Earth's geological features.
• Next topic to explore: Plate boundaries.