Geography

• Magma vs. Lava


  Magma is molten rock beneath the surface, while lava is magma that has been erupted onto the surface, having cooled and solidified.
• Plate Tectonics


  The Earth's surface is broken into large, rigid plates that fit together like a jigsaw puzzle, and are in constant motion.
• Volcano


  A vent or fissure in the Earth's surface through which magma and gases escape, forming different types such as Shield, Stratovolcano, and Caldera.