Overview
This lecture explains the differences between composite, shield, and cinder cone volcanoes, focusing on their structure, eruption style, and notable examples.
Composite Volcanoes
- Composite volcanoes have multiple vents and internal channels for magma movement.
- Their eruptions are violent, with lava sometimes breaking through the volcano's sides.
- They can reach great heights due to the large amount of erupted material.
- Notable examples include Mount St. Helens (USA) and Mount Fuji (Japan).
Shield Volcanoes
- Shield volcanoes have a wide, rounded appearance resembling a warrior's shield.
- Their shape is formed by thin, runny lava that flows easily during eruptions.
- Eruptions are generally slow and non-explosive, with gradual buildup over time.
- The Hawaiian Islands consist of shield volcanoes.
Cinder Cone Volcanoes
- Cinder cone volcanoes erupt by ejecting ash and lava from a single vent at the top.
- Debris from eruptions cools and accumulates around the vent, forming a cone shape.
- These volcanoes are usually not higher than 1,000 feet.
Key Terms & Definitions
- Composite Volcano — Tall, steep volcano built from multiple layers of lava and ash, with several vents and violent eruptions.
- Shield Volcano — Broad, rounded volcano created by runny lava flows that build up slowly over time.
- Cinder Cone Volcano — Small, steep volcano formed by accumulation of ash and lava fragments around a single vent.
Action Items / Next Steps
- Review the characteristics and examples of each volcano type.
- Prepare to compare and contrast these volcanoes for upcoming assignments or exams.