2. Waves

3. Anatomy of wave – Wave- transmission of energy through matter – Longitudinal wave- matter oscillates in same direction of energy transmission – Transverse wave- matter oscillates perpendicular to direction of energy transmission – Orbital wave- matter oscillates in a circular path as energy passes (ocean waves!)

5. Anatomy of wave – H:L - ration of wave height to wave length – Speed = wavelength/ period

6. Wave causes – Disturbing force- cause waves – Restoring force- resist waves

7. Wave characteristics – Deepwater waves – occur in water that is deeper than half their wavelength; bottom does not affect the wave – Transitional waves- occur when depth is between ½ and 1/20 the wavelength – Shallow water waves- occur when depth is less than 1/20 the wavelength; bottom affects wave

8. Wave size affected by: – Wind speed – Wind duration – Fetch- surface area over which wind blows

9. Surf and breaking waves – Why do waves break? Transitional waves slow down because of bottom; shortens wavelength causing wave height to increase When wave’s H:L ratio passes 1:7, the crest is moving faster than trough; causes wave to break with the crest toppling forward

10. Types of Breakers – Spilling Breaker- top of wave tumbles and slides down front of wave; gently sloped beaches – Plunging breaker- curled on top; moderately steep beaches – Surging Breaker- surges unbroken (destructive), steep wall- like beaches

11. Wave interactions – Refraction- bending of waves as they approach shore – Diffraction- when waves pass an obstacle, energy shifts forming a new wave pattern – Reflection- wave bounces back when hits obstacle http://www.tectonics.caltech.edu/outreach/a nimations/tsunami_youtube.html http://www.tectonics.caltech.edu/outreach/a nimations/tsunami_youtube.html

12. Destructive waves – Storm surge- forms when high winds push water against the shore – Tsunami- results from sudden displacement of water caused by landslide, falling iceberg, volcanic eruption or earthquake Always shallow water waves because wavelength is so long that no ocean is deep enough for them to be deepwater waves Do not destroy ships because wavelength is so long that ships rise and fall without noticing