Tides: How do they occur?

Are you wondering how tides occur? High tides and low tides occur because of the moon. The gravitational pull of the moon gives rise to the tidal force. This force generates bulges in the water bodies on the earth, and these bulges are commonly known as tides. With the earth’s rotation, every region of the planet witnesses the bulges every day. 

What are Tides? 

Tides are long waves that move across the oceans. They take place because of the gravitational force of the moon, and slightly of the sun, on the earth. When the highest point of the wave, also known as the crest, reaches the coast, it is called a high tide. Similarly, when the lowest point, also known as a trough, reaches the coast, it is called a low tide. 

The high moon-facing tides are formed because of the powerful gravitational pull on the side of the earth. Thus, it is the moon’s gravitational force that pulls the ocean towards itself, causing a high tide.  

On the other hand, the bulge on the far side of the earth occurs because of inertia. Since the moon’s gravitational pull is weaker, the inertia overpowers, causing the ocean to bulge out. 

As the earth continues to rotate, different parts of it face the moon. It causes the cycles of tides to take place across the planet. 

Types of Tides

Tides get to a maximum height and fall to the minimum height twice every month. There are two types of tides – Spring tides and Neap tides.

• Spring Tides: When the difference between high and low tides is the highest, they are called spring tides. Spring tides can be witnessed after the full moon and new moon. They take place when the sun, moon, and earth are all in a line. It happens because the solar tides and lunar tides line up together to reinforce one another, leading to a bigger total tide

• Neap Tides: When the difference between high and low tides is the lowest, they are known as neap tides. Neap tides can be witnessed when the sun, earth, and moon form a right angle. It takes place when the moon is either in the first quarter or third. In this case, the lunar high tide comes in contact with the solar low tide, causing a total low tide

The continuous movement of the earth, sun, and moon makes it possible for the spring tides to happen every 36 to 48 hours after the full or new moon. It always takes place at the same time for a given location.  

The Importance of Tides for Human Life

Every natural phenomenon takes place for a reason and impacts human life. Some benefits of tides are: 

• Fishing: Tides influence sea creatures. Tides impact the reproductive activities of marine life, such as ocean plants and fishes, ultimately coming to the aid of humans

• Navigation: Tides play a vital role in navigation. They help the ships reach the harbour safely since the high tides raise the water level closer to the shore

• Weather: Tides are influential in stirring the ocean water that ultimately creates better habitable climatic conditions and balances the temperature on the planets

• Tidal energy: One of the most significant importance of tides is producing tidal energy. Two high tides and two low tides occur every day, causing a speedy water movement during the inflow and outflow. This movement provides an excellent source of renewable energy to the people living near coastlines

• Tidal zone foods: There are several sea creatures such as crabs, seaweed, mussels, and snails that inhabit the tidal area. Without tidal movement, these oceanic creatures would die, leading to reduced food resources. Therefore, tidal waves are essential for abundant seafood

What Is a Tidal Bore?

A tidal bore takes place along a coast where a river flows into a sea or an ocean. It is a strong tide that pushes the river against the current. 

A tidal bore can be recognized as a surge, an immediate change in depth. When the channel becomes deeper, it is seen as a positive surge. Conversely, when a channel becomes shallower, it is seen as a negative surge.

Tidal bores do not occur on all coasts. The river must be shallow and have a narrow outlet towards the sea for a tidal bore to occur. The point of contact between the river and the sea, called the estuary, must be flat and wide.  

Besides, the bore is where the colour of the river changes from blue or green to brown. Tidal bores can also tear the vegetation from its roots. Therefore, recreational sports such as river surfing and kayaking can be dangerous around this area. 

Tidal bores affect the river mouth’s ecology as well. Animals can get hit by the leading edge of the tidal wave and might lose their lives in the rush of the silty water. Thus, tidal bores also possess a risk for the animals, the onlookers, and the ships around. 

In conclusion:- 

Tides are very long waves that travel across oceans. They are caused by the gravitational forces of the moon and, to a lesser extent, the sun on the earth. High tide is caused by gravity pulling the ocean towards the moon. The bulge on the Earth’s far side is caused by inertia.