Lesson 2 Quick Changes to Earth’s landscape – We learned that flooding can be considered both a slow and rapid change to Earth’s surface depending on the amount of snowmelt or precipitation. Flash floods may result from heavy rainfall and can sweep away crops, rocks, soil, and plants. We learned that volcanic eruptions can happen quickly. The sudden eruption of a volcano can be violent, resulting in gas, molten rock, ash, and bits of rock spewing into the air. A volcano can also produce the slow release of lava resulting in landforms. We learned that geophysicists study changes to Earth’s surface.