Island Hot Spots

7.1 Volcanoes
7.2 Volcanoes at Plate Boundaries
7.3 Volcanic Hot Spots

Are Volcanoes Unique to Earth?

• Fact Check: No, volcanoes are found on other planets, too.

• Example: Olympus Mons on Mars, the largest volcano in the solar system.

• Comparison: Olympus Mons is three times the height of Mt. Everest, with gentle slopes.

What is a Volcano

• Definition: A volcano is a vent for magma to escape, including lava, ash, and gases.

• Variety in Structure:

  • Large cones

  • Broad shields

  • Small cones and fractured domes

Volcano Stages: Active, Dormant, or Extinct?

• Stages Explained:

  • Active: Erupting or likely to erupt soon.

  • Dormant: Currently inactive but erupted recently.

  • Extinct: No eruption in recent history, unlikely to erupt again.

Multiple Choice

When a volcano is not currently active but able to become active in the future is called ___________________

• extinct

• fault

• hot spot

• dormant

Where Are Volcanoes Found?

• Location Types:

  • Along plate boundaries (convergent and divergent)

  • At hotspots within tectonic plates

• Pacific Ocean Basin: Example of volcanic diversity (East Pacific Rise, island arcs, Hawaii).

Volcanoes and Plate Boundaries

• Convergent Boundaries: Subducting plates create volcanic arcs.

• Divergent Boundaries: Lower pressure allows mantle melting, creating fissures.

Multiple Choice

Volcanic belts form along _____.

• the boundaries of Earth’s plates

• North American mountain ranges

• islands in the Pacific Ocean

• the middle of Earth’s plates

Hotspots and Intraplate Volcanoes

• Hotspots: Fixed zones where mantle plumes create volcanic chains.

• Examples:

  • Hawaii: Hotspot volcanoes forming islands.

  • Continental Hotspots: Rare, massive eruptions (e.g., Yellowstone).

Summary

• Volcanoes are found across Earth and other planets.

• Types depend on location and formation processes.

• Volcanoes can be classified by activity stages and location (boundaries or hotspots).