Tides of Ocean – Geography – UGC NET – Notes

Tides are the rise and fall of seawater caused by the sun and moon’s gravitational influences. Tides are primarily formed by the earth’s and moon’s centrifugal and centripetal forces. 

Formation of Tides

• The gravitational pull exerted on the Earth by the Sun and the Moon causes tides to form.
• The gravitational pull exerted on the Earth by the Sun and the Moon causes tides to form.
• The Sun’s gravitational pull is significantly greater than the Moon’s, and this difference is crucial in the formation of tides.
• Tides are classified as either high or low, depending on the size and position of the Sun and Moon.

Types of Tides

Based on Frequency

Types of Tides Based on Frequency

Semi-Diurnal Tides:

• Each day, a semi-diurnal tidal cycle has two almost equal high tides and two low tides.
• The time between high and low tides is around 12 hours and 25 minutes.
• The Indian Ocean is home to the most Semi-Diurnal Tides.
• The following are some of the most common coasts where semidiurnal tides occur: Eastern African Coast and Bay of Bengal.

Diurnal Tides:

• It amounts to four times per day.
• The sun produces two tides, while the moon produces two.
• The tide of Spring It’s a very high tide brought on by the Sun’s complementary role in relation to the moon.
• In a gravitational system, syzygy is the almost straight-line alignment of three celestial bodies (such as the sun, moon, and earth during a solar or lunar eclipse).
• There are two types of syzygy namely
• Conjunction: When the moon and the sun are on the same side, it is called a conjunction.
• Opposition: When the moon and the sun are on opposite sides of the sky. The magnitude of the tide will be the same in both of these situations.

Syzygy- where sun, moon & earth forms a straight line