Science: Volcanoes: Types, Formation, and Eruptions
Learning how volcanoes form, what types exist, and how they erupt
Science: Volcanoes: Types, Formation, and Eruptions
Learning how volcanoes form, what types exist, and how they erupt
Earth Science - Grade 4-5
- 1
What is a volcano?
Think about what comes out of a volcano during an eruption.
A volcano is an opening in Earth's crust where melted rock, gases, and ash can rise to the surface. - 2
Name the three main types of volcanoes often studied in elementary science.
The three main types of volcanoes are shield volcanoes, composite volcanoes, and cinder cone volcanoes. - 3
Describe one feature of a shield volcano.
Think about the shape of a shield lying on the ground.
A shield volcano has broad, gently sloping sides because its lava flows easily and spreads out over large areas. - 4
Describe one feature of a composite volcano.
A composite volcano is tall and steep-sided, and it forms from many layers of lava, ash, and other volcanic material. - 5
Describe one feature of a cinder cone volcano.
Think about loose rock pieces building up into a cone shape.
A cinder cone volcano is usually small, steep, and made from bits of cooled lava and ash that pile up around the vent. - 6
How does magma become lava?
Magma becomes lava when it reaches Earth's surface during a volcanic eruption. - 7
Where do many volcanoes form on Earth?
Think about places where Earth's large crust pieces meet.
Many volcanoes form near the edges of tectonic plates, where plates move apart, collide, or slide past one another. - 8
Explain how pressure inside Earth can cause a volcano to erupt.
Pressure builds when magma and gases collect below Earth's surface. When the pressure becomes too great, the magma and gases force their way out through a volcano. - 9
List two materials that can come out of a volcano during an eruption.
Think about liquids, tiny particles, and gases.
Two materials that can come out of a volcano are lava and ash. Gases and rock fragments can also be released. - 10
Why are some volcanic eruptions quiet while others are explosive?
Some eruptions are quiet because the lava is thin and flows easily, allowing gases to escape. Other eruptions are explosive because the magma is thicker and traps gases until pressure builds up. - 11
A volcano has wide, gentle slopes and lava that flows easily. What type of volcano is it most likely to be?
Match the description to the volcano type with broad sides.
It is most likely a shield volcano because shield volcanoes have gentle slopes and are formed by flowing lava. - 12
How can volcanic eruptions change Earth's surface?
Volcanic eruptions can change Earth's surface by building new land, covering areas with lava or ash, and forming mountains, islands, or new rock layers.