GEOSC 040 Lecture Notes - Lecture 20: Wind Wave, Orbit
Document Summary
Speed of shallow water waves depends on water depths. White caps observed in strongly wind driven seas. 3 main factors in wave generation by wind. Wind strength: average or persistent wind velocity. Wind duration: time that wind blows in one general direction. Fetch: distance over which wind blows uninterrupted. Most waves have a period between 1 and 10 seconds. Constructive interference: waves interact to build crests or troughs higher or deeper than those of the original waves. Destructive interference: means that waves cancel one another out. Such interactions produce characteristic patterns or beats every fourth, fifth, sixh wave is larger than the other waves in the group: surfers learn how to capitalize on these patterns. Steepness of a wave flank does not exceed about 120 degrees. A rule of thumb: h/l is a ratio of 1/7. A wave with l=156 m in our example above can have h<22m. The package of waves moves slower than individual waves.
