volcanoes
100

How are volcanoes formed

Volcanoes are formed when magma from within the Earth's upper mantle works its way to the surface

200

What are the 4 types of volcanoes

cinder cones, composite volcanoes, shield volcanoes, and lava domes.

300

What is the difference between a volcano and a caldera?

A caldera is a massive crater-like bowl that forms after a volcanic eruption and/or the collapse of a volcano. A volcano is a vent or fissure which contains a magma chamber and can erupt with lava or volcanic gasses through the surface of the earth.

400

how long does a volcano eruption last

Most eruptions last hours but some continue for weeks and months.

500

what is crater and calderas 

a volcanic crater i an opeing or depression at the top of a volcano