Rocks, eruptions and canyon projects

Scientists cannot say the exact day a volcano will erupt, but they can see warning signs. Before an eruption, magma moves under the ground. It causes many small earthquakes. The ground may swell, like a slowly filling balloon. The gases that come out may change, and the ground and water nearby may get hotter. Scientists monitor these signs all the time with instruments that sense shaking, tilting, heat and gas, and with pictures from satellites. When the signs get stronger, they warn the authorities. People can then evacuate along planned routes, carry an emergency kit with water, food, a torch and masks for ash, and listen to the official messages. Preparing early, and following the plan, keeps people safe.