Figure 1. Diagram of the characteristics of an ocean wave. The wave height (H) is the distance from the crest of the wave to its trough. Wavelength (L) is the distance between subsequent crests (in this case, A and B), while period (T) is the time it takes for subsequent crests to pass the same point. The majority of wind-driven waves have periods of less than 20 seconds and wavelengths of several hundred meters. Tsunamis can have periods upwards of an hour and wavelengths of several kilometers.
Last updated on October 6, 2005