Amazing Volcanoes: Dynamic Earth Revealed
Amazing Volcanoes: Dynamic Earth Revealed
1
minute
00
second
Lesson duration is: 10 minItems in this lesson
Amazing Volcanoes: Dynamic Earth Revealed
1
minute
00
second
What do you already know about volcanoes?
Learning Objective
At the end of the lesson you will be able to describe how volcanoes form, explain different types of volcanoes, and discuss the impact of volcanic eruptions on Earth and beyond.
Review: What Will You Remember?
Can you explain how volcanoes form, describe their types, and discuss their effects on Earth and beyond?
What Is a Volcano?
A volcano is an opening in a planet’s crust, allowing hot lava, ash, and gases to escape from below the surface.
Where Do Volcanoes Form?
Most volcanoes are found along the edges of tectonic plates, especially where they are moving apart or together. Many are under the sea at mid-ocean ridges.
Divergent vs. Convergent Boundaries
Divergent (Spreading)
One plate slides under another. Melting creates magma that can form chains of volcanoes, like in the Pacific 'Ring of Fire'.
Convergent (Colliding)
Plates move apart. Magma rises to form new crust, creating volcanoes mostly under the sea like at the Mid-Atlantic Ridge.
Hotspots and Rifts
Hotspots are areas where magma rises in the middle of a plate, forming volcanoes like in Hawaii. Rifting within continents can also create volcanoes, as seen in East Africa.
What Does a Volcano Look Like?
Volcanoes come in many shapes—not just steep cones! Their features depend on erupting materials and the way they erupt.
Different Types of Volcanoes
Stratovolcanoes & Domes
Shield & Cinder Cones
Shield: Wide, gentle slopes, slow lines of lava (Hawaii). Cinder Cones: Small, steep, built from loose material, short-lived eruptions.
Stratovolcano: Tall, steep, layers of lava and ash, explosive (Fuji). Domes: Steep sides, slow lava, can form within other volcano craters.
Earth’s Tectonic Plates
Earth’s surface is made of large plates. These plates move slowly, creating most volcanic activity at their boundaries.
Other Volcanic Features
There are also fissure vents (long cracks), cryptodomes (bulges), mud volcanoes, submarine, and subglacial volcanoes.
Supervolcanoes
Supervolcanoes erupt huge volumes of ash, changing climate for years. Examples include Yellowstone (USA) and Lake Toba (Indonesia).
Volcanic Eruptions and Climate
Giant eruptions eject ash and gases, blocking sunlight and sometimes cooling the planet temporarily.
Volcanoes Beyond Earth
Other planets and moons have volcanoes too! For example, Mercury and some moons of Jupiter and Saturn feature volcanic activity.
Key Terms: Volcanology
Volcanology is the study of volcanoes. The word 'volcano' comes from Vulcan, the Roman god of fire.
Write down 3 things you learned in this lesson.
Write down 2 things you want to know more about.
Ask 1 question about something you haven't quite understood yet.
