These volcanoes are named after an eruption in Mount Pelee in the Caribbean that killed 30,000 people. When a volcano erupts, magma bursts out. Dust, gas, steam and hot rock shoot into the sky. Streams of magma called lava come to the surface and pour from the top of the volcano and down its sides. Sometimes the eruption is so loud it sounds like an explosion.
Hot magma cools as it rises to the top.
Some of it becomes solid on the way up. The solid pieces are blasted out in the eruption. The smaller pieces about the size of marbles are known as volcanic ash and the larger ones are called volcanic bombs . Volcanic bombs can be as big and as heavy as trucks. The very small particles are called volcanic dust.