Mountains wear down and coastlines retreat. Erosion is the process that removes soil, rock, and dissolved material and transports it elsewhere. Water, wind, ice, and gravity are the main agents.

Rivers cut valleys and carry sediment to the sea. Glaciers scrape bedrock and deposit moraines. Wind strips topsoil from bare fields and sculpts sandstone into arches. Human activities such as deforestation and intensive farming often accelerate erosion rates far beyond natural background levels.

The material removed becomes the sediment that builds deltas, beaches, and floodplains. Controlling erosion protects agricultural land and water quality. Geologists read erosional landforms to reconstruct past climates and tectonic events. The process is slow in human terms yet relentless on geologic timescales.

• Removal and transport of surface material
• Driven by water, wind, ice, and gravity
• Shapes valleys, coasts, and deserts
• Can be accelerated by human activity