Which agents drive erosion of surface soil and rock?

• A. Sunlight
• B. Ice, water, and wind
• C. Earthquakes only
• D. Chemical reactions

Answer: (B)

Erosion is the process that removes and transports surface soil and rock by natural forces. The primary drivers are moving agents that physically carry material away: water in streams, rivers, rain, and coastal waves; wind that picks up and deposits fine particles; and ice, especially glaciers, that grind, pluck, and transport rock as they advance and retreat. These forces continually reshape landscapes by eroding surfaces and redistributing sediment.

Sunlight contributes to weathering by heating and causing expansion and contraction, but it doesn’t transport material, so it isn’t an erosion agent. Earthquakes can trigger landslides and rapid sediment movement, but they’re episodic events rather than ongoing carriers of erosion. Chemical reactions break down minerals but don’t move material themselves, so they’re a separate process from erosion.