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Ocean Waves UPSC |Oceanography | Physical Geography

Table of Contents:

  • Movement of Ocean Water
  • Ocean waves 
  • Formation of Ocean waves
  • Wave Motions
  • Characteristics of Ocean waves
  • How are ocean waves formed? Distinguish between a wave of oscillation and a wave of translation. (UPSC 2019)
  • What are the factors affecting the height of the waves? ( NCERT)
  • What are the factors affecting the height of the waves? ( NCERT)

Movement of Ocean Water:

Ocean water moves in two ways namely horizontal movement and Vertical movement.

Horizontal movement of ocean water includes Ocean Waves and Ocean Currents.

Vertical movement of ocean water includes Tides, Upwelling, and Downwelling.

In this article, we will discuss the Ocean waves only.

Ocean Waves:

Ocean waves result from the wind transferring energy to the water's surface. Waves are actually energy, it is not the water that moves across the ocean surface. The energy that moves over the ocean water is known as ocean waves. Water particles only travel in a small circle as the wave passes.

Ocean waves can vary in size and strength and play a crucial role in Earth's climate and ecosystems.

Ocean Waves

Formation of Wave:

Ocean waves form primarily due to the transfer of energy from the wind to the surface of the water. 

The following are simplified explanations of the process of the formation of ocean waves:

Wind Generation: 
It starts with the wind blowing across the ocean's surface. The friction between the moving air and the water creates small ripples called capillary waves.

Wind Energy Transfer: 
As the wind continues to blow, it imparts more energy to these capillary waves. Some of them grow in size and become wind-generated waves.

Wave Growth: 
These wind-generated waves grow as more energy is transferred from the wind to the water. The size and strength of the waves depend on factors like wind speed, duration, and the distance over which the wind blows.

Transformation and Propagation: 
Once formed, these waves can travel across vast distances, carrying the energy of the wind with them. They can be influenced by factors like the ocean's depth, bottom contours, and interference from other wave systems.

From the above, we can say winds are the main energy source of waves. Winds create friction on the ocean surface and it causes movement of water with wind direction. 

Wave motion:

Wave makes water molecules move vertically and horizontally.

The wave of Oscillation:

  • When a wave passes, water molecules follow the circular motion. The circular or elliptical motion of water molecules is called wave Oscillation.
  • Waves are the transfer of energy through a medium or space without the net transfer of matter. This means that the particles of the medium oscillate or vibrate as the wave passes through, but they don't move with the wave.

The wave of translation:

  • Wave also makes water molecules move forward in the direction of winds. The horizontal movement of the water is called the wave of translation.

Ocean Waves motion

Characteristics of waves:

The following are important characteristics of waves:

Amplitude: The amplitude of a wave represents its maximum displacement from its equilibrium position. In a transverse wave (like ocean waves or light waves), it's the height of the wave crest or the depth of the trough. In a longitudinal wave (like sound waves), it's the maximum compression or rarefaction of the medium.

Wavelength: Wavelength is the distance between two consecutive points that are in phase, such as two wave crests or two troughs.

Frequency: Frequency is the number of complete cycles (oscillations) a wave undergoes in one second and is measured in Hertz (Hz). 

Wave Speed: The speed at which a wave propagates through a medium is determined by its frequency and wavelength. 

Winds provide energy to the wave; winds cause waves to travel in the ocean and energy is released on the shoreline.
Wave generally does not affect the ocean bottom water.
The largest wave is found in the open ocean and wave continues to grow larger as they move and absorb energy from the winds.
Waves may travel thousands of km before breaking onshore.

How are ocean waves formed? Distinguish between a wave of oscillation and a wave of translation. (UPSC 2019)


Ocean waves are primarily formed by the transfer of energy from the wind to the surface of the ocean. The process involves the movement of water particles in circular orbits as the energy is transmitted. These circular motions result in the up-and-down movement of surface waves. 

Here's a simplified explanation of how ocean waves are formed:

Formation of Ocean Waves:

Wind Generation: 
It begins with the wind blowing across the surface of the ocean, creating friction between the moving air and the water.

Energy Transfer: 
This friction transfers kinetic energy from the wind to the water's surface, causing small ripples or capillary waves to form.

Wave Growth: 
If the wind continues to blow, these small ripples grow in size and become wind-generated waves. The size and strength of these waves depend on factors such as wind speed, duration, and the distance the wind has traveled across the water, known as the fetch.

Fully Developed Sea: 
Over time, wind-generated waves can reach a maximum size for the given wind conditions, creating a state known as a "fully developed sea."

The following are differences between a "wave of oscillation" and a "wave of translation":

Wave of Oscillation:
A wave of oscillation is a type of wave where the particles of water move back and forth about their equilibrium positions.
In the case of ocean waves, the water particles near the surface move in circular orbits as the wave passes through. They don't travel with the wave but oscillate in place.
The energy of the wave is transmitted through these oscillations of water particles.

Wave of Translation:
A wave of translation is a type of wave where energy is transferred through the medium with the propagation of a disturbance.

In ocean waves, the wave itself moves across the surface of the ocean, transporting energy horizontally.

While water particles do move in these waves, they don't travel long distances with the wave. Instead, they move in relatively small orbits as the wave passes beneath them.

In summary, ocean waves are formed by the wind's transfer of energy to the water surface, causing the circular oscillation of water particles. These waves are classified as both waves of oscillation (for the particle motion) and waves of translation (for the energy propagation).


What are the factors affecting the height of the waves?

( Chapter 5: Water, Class 7- Our Environment ( GEOGRAPHY), SOCIAL SCIENCE)


The height of ocean waves, also known as wave height or wave amplitude, is influenced by several factors:

Wind Speed and Duration:
 The most significant factor in wave height is wind. Stronger winds blowing for a longer duration over a larger area create larger waves. Faster winds transfer more energy to the water's surface, causing waves to grow in height.

Wind Fetch: 
Fetch refers to the uninterrupted distance over which the wind blows across the water. A longer fetch allows waves to build up to greater heights. For example, ocean waves typically have a longer fetch than waves on a small lake, resulting in larger ocean waves.

Wind Consistency: 
Consistent winds in one direction create waves that are more organized and have a steady height. Inconsistent or shifting winds can lead to choppy, irregular waves.

Water Depth: 
Water depth affects the behavior of waves. In shallow water, waves tend to slow down, increase in height, and become steeper (this is why waves often break near the shore). In deep water, waves typically have a lower height.

Ocean Currents: 
Ocean currents can influence wave height. When waves encounter opposing currents, they can become steeper and higher. Conversely, when waves move in the same direction as the current, they may be smaller.

Storms and Weather Patterns: 
Storm systems and weather patterns can generate exceptionally large waves, especially when low-pressure systems interact with strong winds. These are often referred to as storm surges or storm waves.

Underwater Topography: 
The shape of the ocean floor can influence wave height. For example, when waves encounter a shallow, underwater feature like a reef or sandbar, they can become larger and break as they reach shallower depths.

Tidal Effects: 
Tides can affect wave height. During high tide, waves may appear higher because there is less distance between the water's surface and the ocean floor.

Geographic Location: 
The location of a body of water can influence the type and size of waves. Different regions have different prevailing wind patterns and oceanographic conditions that affect wave height.


Which factors affect the movement of ocean water?

( Chapter 5: Water, Class 7- Our Environment ( GEOGRAPHY), SOCIAL SCIENCE)


The movement of ocean water is influenced by a combination of many factors, both on a large scale and at regional levels. 

Here are some of the primary factors that affect the movement of ocean water:

Wind is one of the most significant factors driving ocean currents. The friction between the wind and the ocean's surface transfers energy to the water, creating surface currents. Prevailing wind patterns, such as the Trade Winds and Westerlies, play a crucial role in shaping ocean currents.

Coriolis Effect: 
The Coriolis force is generated as a result of the Earth's rotation and causes ocean currents to veer to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This effect influences the direction of ocean currents.

Temperature and Density: 
Variations in water temperature and salinity (saltiness) affect water density. Cold, dense water tends to sink, while warm, less dense water rises. This movement drives the vertical circulation of ocean water, known as thermohaline circulation or the "ocean conveyor belt."

Continental Topography: 
The shape and location of continents and ocean basins influence the direction and flow of ocean currents. For example, currents can be funneled through narrow passages and around landmasses, creating unique patterns.

Ocean Floor Features: 
Ocean submarine ridges, seamounts, and trenches on the ocean floor can redirect and channel ocean currents. These features can also influence upwelling and downwelling.

Tides are caused by the gravitational pull of the Moon and the Sun. They create alternating rises and falls in sea level, which can result in the movement of water in and out of coastal areas.

Earth's Rotation: 
The rotation of the Earth affects the movement of ocean water. In addition to the Coriolis Effect, it causes the ocean's surface to bulge slightly around the equator, leading to the creation of equatorial currents.

Atmospheric Pressure: 
Differences in atmospheric pressure can affect ocean currents. Low-pressure systems can result in the piling up of water, leading to storm surges and changes in sea level.

Earth's Gravitational Pull: 
The Earth's gravitational pull creates a slight bulge in the ocean's surface, which is responsible for the twice-daily rise and fall of tides.

These factors are responsible for the ocean water motion.

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