When you shook up the can, you created pressure. When you opened the can, you released the pressure. You might live in a part of the world where an active volcano is nearby. In many parts of the world, you may be able to see an old volcano. Volcanoes are shaped from the building up of layers of ash and lava.
Old volcanoes come in three basic shapes.
These volcanoes now have a short and fat shape. Volcanoes that had very thick lava are shaped like pointed cones. The lava ran slowly down their sides. Some of these volcanoes look like mountains with their tops cut off. Hot water springs are often found near volcanoes.