Ocean Waves: Parts, Motion & Breakers | Grade 6-8 Earth Science General Information: This slideshow introduces wave vocabulary (wave, crest, trough, wavelength, wave height, frequency, amplitude) and explains that most ocean waves are caused by wind. It shows how water particles move in circular orbits that diminish with depth and describes what happens as waves approach shore: wavelength decreases, height increases, and the crest outruns the base to form breakers. Estimated Content:Number of s