How are volcanoes formed?
Volcanoes are really big mountains that build taller and taller, after a while, they might erupt. This means that the molten rock in the bottom of the volcano, magma, comes from within the earth and erupts onto the surface. It will come up through the earth’s surface through, the easiest gap in the earths surface. The volcano might be explosive and produce ashes and lava. The explosions are usually first because there are lots of gases inside the magma. When you have a bottle of soda pop, you do not see any bubbles of gas, but when you open it, bubbles form almost instantly. Once the gas bubbles have all escaped, the soda is flat. Once the magma is flat, a lava flow comes out. Most of the volcanoes from around the Pacific Ocean are composite, which means that there are layers of ashes and lava. Most volcanoes are 10,000 to 100,000 years old — it takes time for them to grow big.