Test: Movements of Ocean Water - UPSC MCQ

The current of Indian Ocean is the west wind drift.Its a cold current,which bring cold water into warm water areas.

There are two main driving forces for ocean currents, surface wind and the (horizontal) gradients in temperature and salinity.

The most common tidal pattern, featuring two high tides and two low tides each day is called Semi-diurnal tide.

Wave crest and trough refers to key features of a wave. Understanding these terms can help clarify how waves function:

• The crest is the highest point of a wave.
• The trough is the lowest point of a wave.

These two points are essential for measuring:

• Wave size: The distance between the crest and trough determines the wave's amplitude, indicating its energy.
• Wave length: The distance between successive crests or troughs.
• Wave speed: The rate at which the wave travels through a medium.

By focusing on the crest and trough, one can better understand wave behaviour in various contexts, such as in oceans or sound waves.

Wave amplitude refers to a specific characteristic of waves.

• Height of the wave: This is the distance from the rest position to the peak of the wave.
• Half of the wave height: Amplitude is defined as half the height of the wave, measured from the rest position to the crest.
• Not the breadth: Amplitude does not relate to the width of the wave.
• Not a time interval: It does not represent the time between successive waves.

In summary, the wave amplitude is half the height of the wave, specifically from the equilibrium position to the crest or trough.

The current of Atlantic ocean is Gulf current.It is warm current which bring warm water into cold water areas.

A is the correct option.The term “knot”, in reference to currents, is defined as one nautical mile per hour and is used to measure speed.Surfers usually use knots for wave speeds (or sometimes miles per hour.) To convert to knots or nautical miles per hour simply multiply by 2. So a 10 second period wave will have a deep water speed of 30 knots.

Water particles only travel in a small circle as a wave passes. Wind causes waves to travel in the ocean and the energy is released on shorelines.

The Great Barrier Reef is a site of remarkable variety and beauty on the north-east coast of Australia. It contains the world’s largest collection of coral reefs, with 400 types of coral, 1,500 species of fish and 4,000 types of molluscs. It also holds great scientific interest as the habitat of species such as the dugong (‘sea cow’) and the large green turtle, which are threatened with extinction.

Salinity and density of water, direction and shape of the coast and gravitational force are the factors that decide the origin and movement of currents.