What mostly causes waves?

• A. Tides
• B. Earthquakes
• C. Tsunamis
• D. Wind friction

Answer: (D)

Waves on the ocean are mainly generated when wind blows over the water and drags on the surface. This friction transfers energy from the moving air into the water, creating ripples that grow into waves. The size of these wind-driven waves depends on how strong the wind is, how long it blows, and how far the wind travels across the water (fetch).

Tides come from the gravitational pull of the Moon and Sun, causing slow, large-scale bulges in the oceans—quite different from the everyday waves you see. Tsunamis result from rapid vertical displacement of water due to earthquakes or landslides, which is also a different phenomenon. So, the everyday cause of most waves is wind friction on the water surface.