Waves
What is a wave?
A wave is the transmission of energy through matter. Ocean waves are caused primarily by wind although earthquakes, submarine landslides, volcanoes, and tidal motions contribute to waves as well. Ocean waves move the individual water particle in a circular motion as they pass. Look at the image to the left. As the energy moves through the water, the boat goes up and forward, down and back...but remains in the same place. This means that ocean waves are transverse waves since the motion of the wave is perpendicular to the motion of the water.
What creates waves?
Waves are created by "disturbing forces". These include wind, gravity, and seismic activity. "Restoring forces" are those that resist the creation of waves. These include gravity, the Coriolis Effect and surface tension. The interaction between disturbing and restorative forces give waves their characteristics.
Characteristics of wind-generated waves:
Size: Determined by 3 factors:
Wave energy also varies seasonally. Winter waves are generally stronger and will move sand away from the beach due to winter storms. Summer waves are more gentle and less energetic. They move find sand onto the beach.
Pictures Below: The left hand side is the "winter" beach that has had a period of big waves that have removed most of the fine sand, leaving only rocks. The right hand side is of the same beach shown in the previous picture but after a period of small waves for several months. This is the typical "summer beach" piled high with fine sand. Under all the sand is the layer of rocks you saw in the previous picture.
We will learn about parts of a wave in class.
A wave is the transmission of energy through matter. Ocean waves are caused primarily by wind although earthquakes, submarine landslides, volcanoes, and tidal motions contribute to waves as well. Ocean waves move the individual water particle in a circular motion as they pass. Look at the image to the left. As the energy moves through the water, the boat goes up and forward, down and back...but remains in the same place. This means that ocean waves are transverse waves since the motion of the wave is perpendicular to the motion of the water.
What creates waves?
Waves are created by "disturbing forces". These include wind, gravity, and seismic activity. "Restoring forces" are those that resist the creation of waves. These include gravity, the Coriolis Effect and surface tension. The interaction between disturbing and restorative forces give waves their characteristics.
Characteristics of wind-generated waves:
Size: Determined by 3 factors:
- Duration; the longer the wind blows=the bigger the wave
- Velocity; the stronger the wind=the bigger the wave
- Fetch; the longer the distance the wind is in contact with the water=the bigger the wave
Wave energy also varies seasonally. Winter waves are generally stronger and will move sand away from the beach due to winter storms. Summer waves are more gentle and less energetic. They move find sand onto the beach.
Pictures Below: The left hand side is the "winter" beach that has had a period of big waves that have removed most of the fine sand, leaving only rocks. The right hand side is of the same beach shown in the previous picture but after a period of small waves for several months. This is the typical "summer beach" piled high with fine sand. Under all the sand is the layer of rocks you saw in the previous picture.
We will learn about parts of a wave in class.
Types of Waves:
Swells are waves that form in the open ocean and over time develop the same wavelength. These swells can travel thousands of miles.
Breakers are waves we see coming into shore. Approximately 8000 waves a day hit our beaches. As the open ocean waves come closer to shore, the seafloor becomes shallower. The friction of the ocean floor slows the bottom of the wave down while the top is still going at full speed. Eventually, the crest topples over.
Swells are waves that form in the open ocean and over time develop the same wavelength. These swells can travel thousands of miles.
Breakers are waves we see coming into shore. Approximately 8000 waves a day hit our beaches. As the open ocean waves come closer to shore, the seafloor becomes shallower. The friction of the ocean floor slows the bottom of the wave down while the top is still going at full speed. Eventually, the crest topples over.
Development of Waves: