Lecture Notes: Wave Trains and Water Waves

Wave Trains

Definition: A wave train is a set of waves moving together across the ocean.
Energy Transfer: Energy is transferred between waves, with the leading wave dying out to create a new wave at the back.
- E.g., Wave 1 dies out, transferring energy to create Wave 5.
Wave Motion: As waves move from left to right:
- Wave 1 creates Wave 5
- Wave 2 creates Wave 6
- Wave 3 creates Wave 7
Group Speed:
- The speed of the wave train is half the speed of an individual wave.
- Understanding this is crucial for assignments and exams.
Assignment: Watch "Waves Across the Pacific" by Walter Monk and complete the accompanying worksheet.

Wave Base: The wave base is equal to half the wavelength.
- Determines whether a wave is a deep or shallow water wave.
Deep Water Waves:
- Wave base does not touch the ocean floor.
- Occur in deeper water where wavelength is constant.
Shallow Water Waves:
- Wave base interacts with the ocean floor.
- Results in slowing wave speed and shortened wavelength as it approaches the shore.
- Wave height increases until breaking.
- Analogy: Cars slowing down at a red light, getting closer together.

Swami's, Downtown Encinitas:
- Stormy conditions with mixed wave periods, wavelengths, and speeds.
- All waves are shallow water waves due to wave base touching the sea floor.
Pleasure Point, Santa Cruz:
- Clearer conditions with distinct deep and shallow water waves.
- Out at sea: Deep water waves with longer wavelengths and faster speeds.
- Nearshore: Shallow water waves with shorter wavelengths and slower speeds.

Wave Period: Time between wave crests at a fixed point.
- Remains constant between deep and shallow water waves.
Wave Characteristics Transition:
- Wavelength: Shortens in shallower water.
- Wave Speed: Decreases in shallower water.
- Wave Height: Increases until breaking as it approaches the shore.

Distinction: Difference between deep and shallow water waves is based on wave base touching the ocean floor.
Exam and Assignment Reminder: Be familiar with these concepts for tests and assignments.

Feel free to ask questions for further clarification on any topic.