Importance of tides

Importance of tides

Introduction

There are different types of natural phenomena occurring in the ocean, like ocean currents, tsunamis, breaking waves, etc. Tides are also a natural phenomenon. The gravitational pull of the moon and the sun causes the ocean water to rise and fall, this phenomenon is called tide.  The importance of tides is immense in human life and other areas. Below is a discussion of the importance of tides.

About 71% of the earth’s surface is covered by water and the other 29% consists of continents and islands. The effect of gravitational force on water is much higher than on land. Therefore, tides mainly occur in water bodies.

Tides are long waves that move across the ocean which is one large body of water. It is free to move all over the earth. On the other hand, the water of rivers, and lakes do not cover a sufficient area. So the water of lakes and rivers cannot be transferred significantly by the force of gravity like the ocean. Therefore most of the time tides occur in the ocean. Mainly tides are the changes in the level of the ocean water at a certain place (2) & (4).

Tides and their types

Definition of tide

Due to the gravitational force of the moon and the sun, the centrifugal force of the earth, and the earth’s rotation, the seawater swells in one place at regular intervals and then goes down in another place. This swelling and falling of the seawater together are called tide (5).

Some interesting facts about tides

  • Due to the gravitational force of the moon, the seawater swells up and down at regular intervals. This is known as tides.
  • This phenomenon occurs due to the centrifugal force of the earth and the gravitational force of the moon and the sun.
  • It causes tidal waves in the ocean.
  • Tides occur depending on the shoreline.
  • This type of phenomenon depends on the rising and falling of the water level.
  • Depending on the concentration of seawater, salinity, etc. the seed of water changes, and tides are created.
  • Due to the gravitational pull of the moon and the sun, the seawater regularly swells. This is known as high tide. And the sea level goes down regularly. This is called low tide.
  • There are tides every 12 hours.
  • The position of the earth, moon, and sun is mainly responsible for this.
  • In all parts of the ocean, the effect of tides is greater in the rainy season than in the summer or winter.
  • The intensity of the tide is not the same all year round (1) & (2).

Types of tide

Tide is the rise and fall of ocean water due to the gravitational pull of the sun and the moon and the centrifugal force of the earth. There are different types of tides.

Based on the position of the moon, sun, and earth, there are four types of tides

1. Primary tide

The moon rotates around the earth. During this rotation, the moon is most attracted to the part of the earth that is closest to the moon. Due to this attraction, water comes from all around and swells towards the moon and the tide is created. This type of tide is known as the primary tide. The primary tide is also called the lunar tide because it is created by the attraction of the moon.

2. Secondary tide

During the primary tide, the centrifugal force is stronger than the gravitational force of the moon on the opposite side of the earth. As a result, the water in the opposite place also swells, that is, the tide is created. This is called secondary tide.

3. Spring tide

  • The tidal wave that is created by the gravitational pull of the sun and moon on the date of the new moon and the full moon is called the spring tide.
  • In a lunar month, it occurs twice.
  • It is also known by the name of ‘King Tide.’
  • A Spring tide occurs on a full moon or new moon days.
  • In spring tides, the difference between high tides and low tides is greatest.

Spring Tides are the result of the sun and moon working together to exert more pull on the earth’s oceans.

  • The influence of spring tide on human life is greater than the neap tide.
  • These types of tides are strong tides. Because it is created by the combined attraction of the moon and the sun.

4. Neap tide

  • On the date of bright fortnight and dark fortnight, the sun and the moon are perpendicular to the earth. This causes the moon and the sun to attract the earth from opposite directions. As a result, the low tide that is created is called the neap tide.
  • When the sun and the moon are at right angles with respect to the earth, Neap tides or low tides are formed.
  • It occurs seven days after the spring tide.
  • Neap Tides occur on quarter moon days.
  • In Neap Tides, the difference between high tides and low tides is the least.

Neap tides are the result of the moon and Sun working against each other.

  • The effects of neap tide on human life are less.
  • A neap tide is a weak tide (3) & (5).

According to the frequency definition of tides

1. Semi-Diurnal Tides

  • A semi-diurnal tide consists of two phases of equal high water and two phases of low equal water per day.
  • When the moon is directly above the equator, there is a tendency for semi-diurnal tides.
  • Semi-Diurnal tides are found along the Atlantic coast of the United States.

2. Diurnal Tides

  • Diurnal tide consists of one phase of high water and one phase of low water per day.
  • This tide occurs when the moon is farthest from the equator.
  • These tides occur daily on the coast of the Gulf of Mexico.

3. Mixed Tides

  • Mixed tides are like semi-diurnal tides.
  • There are two phases of high water and two phases of low water every day.
  • Mixed tides occur when the moon is too far north or too far south of the equator (3) & (5).

Advantages of tides

  1. The tide will always flow and move, which means it is a source of energy that we can use renewable.
  2. Large ships can come into the river at high tide.
  3. Many marine fish move into the river during high tide.
  4. As a result of the tide, the river bed becomes deep.
  5. Ports and rivers are often ice-free in tidal saltwater.
  6. The tidal wave clears the river waste (5).

Disadvantages of tides

  • When saltwater enters the river at high tide, the river water becomes salty, which makes farming difficult.
  • If the current in the river is low, silt accumulates in the river when tidal water enters.
  • High tides often cause floods. As a result, cultivation and houses are damaged along the river banks.
  • If there is a flood in the river due to high tide, there is a possibility of the boat sinking and death.
  • Tidal water often collects silt from rivers and stores it in inland rivers. As a result, the depth of the river decreases.
  • Through the tide the freshwater of the river becomes salty. Saltwater cannot be used for drinking, industry, and other purposes (1) & (3).

Importance of tides

  • Tides change the topography of the earth.
  • Creeks and inlet formation are caused by tides.
  • The tides help to create low floodplains of rivers. Flood plains are very fertile.
  • They bring saltwater to the shore and their constant movement prevents the port from freezing.
  • As a result of tides, sea fish enter the river and increase the number of fish in the river.
  • Tidal water is used in salt production.
  • The river water rises during the tide and ships can easily navigate the river.
  • Tidal wave clears the river waste.
  • As a result of the tide, the estuary of the river is silt free.
  • During tide, water enters the river and increases the width and depth of the river.
  • The tides help to remove pollutants and carry out the nutrients necessary for the survival of marine plants and animals.
  • Tide helps the ships to arrive at the harbor more easily.
  • Every 24 hours, there are two high tides and two low tides. Tidal forecasting, as well as the rapid movement of water during flow and outflow, will provide a renewable energy source for the coastal community. Hydropower plants can use the flow of water like a river (4) & (5).

Q&A

1. Why are the tides important?

Tides are important because of the following

  • Tides are responsible for the change in the topography of the earth.
  • Creeks and inlet formation are due to tides.
  • The tides create low floodplains of rivers that are very fertile.
  • They prevent the port from freezing by bringing saltwater.
  • As a result of tides, sea fish enter the river and increase the number of fish in the river.
  • Tidal water is used in salt production (4).

2. How are tides helpful to humans?

Some of the significant effects of tides on human life are

  • It helps in navigation.
  • Prevents the port from freezing.
  • The number of fish in the river increased due to low tides.
  • Used in salt production.
  • Clears the river waste.
  • Tide helps the ships to arrive at the harbor more easily (5).

Written By: Manisha Bharati