QA INTERNATIONAL / SCIENCE SOURCE / SCIENCE PHOTO LIBRARY QA INTERNATIONAL / SCIENCE SOURCE / SCIENCE PHOTO LIBRARY
The wind blows on the ocean and puts its surface in motion a steady up-and-down movement in the water called waves. If the wind blows harder, more water is moved, and the waves become larger. As popular as they may be with surfers and swimmers, waves can sometimes become a threat. A steady wind blowing at a speed of just 17 miles per hour (27 km/h) can whip up 6-foot (2-m) waves that are a danger to boats. In the middle of the ocean, sailors often face walls of water that are even higher. With the wind blowing for two days at 70 miles per hour (113 km/h), waves may be nearly 50 feet (15 m) high as tall as a five-story building!.
Model release not required. Property release not required.