What Causes Waves?

1
What Causes Waves?

• Wind
• Submarine disturbance
• Gravitational attraction of sun and moon

2
Wind Generation of Waves

• Wind velocity
• Wind duration
• Fetch (distance over which wind blows)
• Simply put, wave size increases as all these
  factors increase.

3
Wave Motions

• Forward movement of the wave form.
• Orbital motion of water particles beneath the
  wave.
• It is wave energy, NOT water molecules, that
  moves across the sea surface.

4
Deep Water Waves

• Waves do NOT interact with the seafloor.
• Orbits of the water molecules are circular.

5
Shallow Water Waves

• Waves DO interact with the seafloor.
• Orbits of the water molecules become elliptical.

6
Rogue Waves?

• Constructive wave interference - wave buildup

7
Rogue Waves
http//bit.ly/cs1I9b
http//bit.ly/9XWFZu
http//bit.ly/dmFsI7
8
Shallow Waves Affected by Bottom

• In shallow water, the sea bottom transforms the
  waves properties. This leads to wave refraction
  and waves collapse forming surf (breakers).

9
Transformation of Shallow-water Waves
10
Motion of Water Particles Beneath Waves
11
Wave Videos Reflection off a sea wall
http//www.youtube.com/watch?vPevRZAxDxZw Big
wave at beach http//www.weather.com/blog/weathe
r/8_21326.html https//www.youtube.com/watch?vQdo
TdG_VNV4featureplayer_embeddedat131 Tacoma
narrows bridge http//video.search.yahoo.com/sea
rch/video_yltA2KLqIGXaSdPEn0AIxT7w8QF?ptacoman
arrowsbridgeb21tnr20