The tides having variations in height are known as:

The correct answer is Mixed tide.

Key Points

• The tides having variations in height are known as Mixed tide.
• The periodical rise and fall of the sea level, once or twice a day, mainly due to the attraction of the sun and the moon, is called a tide.
• The moon’s gravitational pull to a great extent and to a lesser extent the sun’s gravitational pull, are the major causes for the occurrence of tides.
• Another factor is centrifugal force which acts opposite to gravitational pull of earth.

Additional Information Diurnal tide

• There is only one high tide and one low tide during each day.
• The successive high and low tides are approximately of the same height.

Semi- diurnal tide

• The most common tidal pattern, featuring two high tides and two low tides each day .
• The successive high or low tides are approximately of the same height.

Spring tide

• The position of both the sun and the moon in relation to the earth has direct bearing on tide height.
• When the sun, the moon and the earth are in a straight line, the height of the tide will be higher.
• These are called spring tides and they occur twice a month, one on full moon period and another during new moon period.