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Difficulty: EasyOceans, Coastal Processes, and Coastal Landforms

Arrange the following stages of wave transformation in chronological order, from open water generation to its final arrival at the shoreline.

  1. 1Wind friction across the open ocean surface generates deep-water waves.
  2. 2The wave base makes contact with the rising seabed, causing friction that slows the wave bottom.
  3. 3The wave height increases and the crest becomes increasingly steep and unstable.
  4. 4The unstable wave crest breaks forward, releasing energy as swash up the beach.

Answer

The correct sequence of wave movement is: initial wind generation in open water, followed by seabed friction in shallow water, followed by wave steepening, and concluding with wave breaking and swash movement up the shore.
Waves originate in open water through wind action. Upon entering shallow nearshore areas, friction with the seabed retards the base of the wave. The crest continues at high speed, steepening until it loses structural stability and breaks in the surf zone, driving swash up the beach slope.

Step-by-Step Solution

1
Identify the origin of marine wave energy.
Deep-water waves are formed far offshore by wind blowing over fetch area.
Wave creation must precede any coastal interaction.
2
Determine the impact of shallow water on wave motion.
As water depth becomes less than half the wavelength, wave base drags along the sea bottom.
Shoaling causes bottom friction which decreases wave velocity at the bottom.
3
Analyze structural change in wave profile.
Wave height increases, wavelength decreases, and crest steepens.
Top of wave moves faster than bottom due to bottom drag.
4
Pinpoint the final shoreline process.
Wave collapses forward in surf zone into swash.
Excessive steepness causes instability, breaking wave energy onto the beach slope.

Key Concept

Wave Shoaling and Breaking Mechanics
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Topics

Oceans, Coastal Processes, and Coastal Landforms

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