2. Waves Wave- disturbance caused by the movement of energy from a source through a medium (solid, liquid, gas) –As the energy travels, the medium moves in specific ways In ocean waves, the energy is moving through the water, but the water is not moving

3. Parts of a Wave Crest = highest part of the wave Trough = lowest part of the wave. Wave height = vertical distance between the trough and the crest. Wavelength = the distance between troughs or crests. Period = the time a wave takes to go by any given point.

13. Deep Water, Transitional Water and Shallow Water Waves Characteristics of a wave mostly depend on the depth of the water they are in. –Deep water waves are in water that is deeper than about ½ its wavelength –Transitional waves travel through water that is between 1/20 and ½ of their wavelength. –Shallow water waves are waves in water shallower than 1/20 their wave length

23. Wind Waves Wind waves are waves caused by wind blowing across the water –The faster and the longer the wind blows, the bigger the waves get. –The greater the fetch, the distance over which the wind blows unimpeded, the bigger the waves get.

28. Wave Refraction Wave Refraction occurs when a wave line approaches the shore at an angle. –The line does not break simultaneously. The part is shallower water breaks first and then the deeper parts break. So the waves ‘bend’, and can bend as much as 90°

32. Wave Diffraction Wave Diffraction is the propagation of a wave around an obstacle –Wave crests excite the water at the gap which generates new waves.

35. Internal Waves Internal Waves are subsurface waves that can form between layers of different densities –They can be 30 m high with wavelengths over 0.8 km –They move very slowly because the difference in density is small –May be important in mixing nutrients and can be quite powerful.

39. Storm Surge Storm Surges –Technically not a wave because it is only a crest –Low pressure in the atmosphere causes water to dome, which can be as high as 9 m –Can have devastating consequences because they are often combined with high wind waves

43. Seiche Seiches –Like the water in a bath tub, confined bodies of water will rock back and forth sometimes due to atmospheric conditions or seismic activity

45. Tsunami Tsunami- Japanese term meaning ‘harbor wave’ –Shallow water waves caused by the rapid displacement of ocean water by landslides, icebergs, volcanic eruptions or earthquakes –They have wavelengths up to 200 km and are therefore never in shallow water –Move at about 212 m/sec or 470 miles/hour –Very low steepness and a very long period (5 to 20 minutes) –Incredibly Destructive »>200,000 people died on Dec 26, 2004