Some examples of destructive forces include erosion by water or wind, volcanic activity, earthquakes, the impact of glaciers and even animals' degradation of the environment. Silt and soil deposition, as well as volcanic lava flows, are examples of constructive forces.
A constructive force increases geological diversity by creating new mountains and land formations in the Earth’s crust. Destructive forces wear away geological features.
The Hawaiian Islands were forged by constructive forces of underwater volcanoes that deposited enough lava to form new land. Atolls were islands created by the deposition of coral skeletons. Water can be a constructive force as it floods plains, causing small creeks that create curvy paths called meanders. Silt deposition in a river can form a delta. Animals that travel in herds, like deer, leave paths in the woods; this is considered a constructive force because these paths can be used by others.
Rocks in large streams and rivers are smoothed by water’s destructive force of erosion. Oxbow ponds are formed when water erosion creates a more direct path for a river, leaving a remnant water reservoir.
Weathering of statues and buildings are caused by wind erosion. Water seeping into cracks in asphalt, then freezing in the winter causing large bumps in the road, illustrates the destructive force of ice.