Question

List any three uses of high tides.

Answer 1

Answer:

Strong tides help in the building of lower flood plains of rivers. These are very fertile. Since the debris is swept away by tides, they help to keep the harbours clean. In cold countries, tides bring in salt water to the shore and their continuous movement prevents the harbour from becoming ice bound.

Tides

The rhythmic rise and fall of water twice in a day is called a tide.

High Tide: This occurs when water covers much of the shore by rising to its highest level.

Low Tide: There is a low tide when water falls to its lowest level and recedes from the shore.

Tides are caused by the strong gravitational pull exerted by the sun and the moon on the earth’s surface. The rise and fall of water due to tides is used for generating electricity in some places. The water of the earth closer to the moon gets pulled under the moon’s gravitational force and causes a high tide.

Types of Tides

spring tide

Spring Tides: During the full moon and new moon days, the sun, the earth and the moon are in the same line and the tides are the highest. These tides are called spring tides.

neap tide

Neap Tide: When the moon is in its first and third quarters, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of the sun and the earth. This results in low tides; called neap tides.

Advantages of High Tide:

They help in navigation. They raise the water level close to the shores and help the ships to arrive at the harbor more easily.

They help in fishing. More fish come closer to the shore during high tides. This helps the fishermen to have a good catch and earn more.

Ocean Current

They are streams of water flowing continuously on the ocean’s surface in definite directions. They influence the temperature conditions of the area. They may be warm or cold.

Warm Current: They originate near the equator and move towards the poles. The Gulf Stream is a warm current. They bring warm temperature over land surface.

Cold Current: They carry water from polar or higher latitudes to tropical or lower latitudes. For example; the Labrador Ocean Current. They result in cold temperature over the land surface.

There is about a seven-day interval between springs and neaps.

Spring tide: Sun and Moon on the same side (0°)

Neap tide: Sun and Moon at 90°

Spring tide: Sun and Moon at opposite sides (180°)

Neap tide: Sun and Moon at 270°

Spring tide: Sun and Moon at the same side (cycle restarts)