![]() Perihelion: It is the position where the earth is closest to the sun (around January 3 rd). Tidal ranges will be much less than the average during this period. During this period, unusually high and low tide occur.Īpogee: When the moon’s orbit is farthest from the earth, it is called as apogee. Perigee: When the moon’s orbit is closest to the earth, it is called as perigee. They also occur twice in a month- during the first quarter moon and the last quarter moon. The tides during this period will be lower than the normal which are called as the neap tides. Thus, the gravitational forces of the sun and the moon tend to counteract one another. Neap Tides: Normally after seven days of a spring tide, the sun and the moon become at a right angle to each other with respect to the earth. They occur twice in a month-one on the full moon (Poornima) and the other on the new moon (Amavasya).Ģ. Spring Tides: When the sun, the moon, and the earth are in a straight line, the height of the tide will be higher than normal. Tides based on the sun, the moon, and the earth’s positionsġ. They generally occur along the west coast of North America.ī. Mixed Tide: Tides having variations in heights are known as mixed tides.Diurnal Tides: Only one high tide and one low tide each day.Semi-diurnal Tide: They are the most common tidal pattern, featuring two high tides and two low tides each day.It is the period between high tide and low tide during which water flows away from the shore. Ebb Tide is the receding or outgoing tide. ![]() It is thus the time period between a low tide and a high tide (i.e., the rising time).A flow tide or a flood tide is a rising tide or incoming tide which results in a high tide.The regular interval between two high or two low tides is 12 hours 25 minutes.When the tide is channeled between islands or into bays and estuaries, they are termed as Tidal Currents.The highest tides in the world occur in the Bay of Fundi in Canada.Sun’s gravitational pull and the centrifugal force due to the rotation of earth are the other forces which act along with the moon’s gravitational pull.The moon’s gravitational pull to a great extent is the major cause of the occurrence of tides (the moon’s gravitational attraction is more effective on the earth than that of the sun).Note: The water movements which are caused by the meteorological effects like the said above are called as surges and they are not regular like tides.They are a vertical movement of waters and are different from movements of ocean water caused by meteorological effects like the winds and atmospheric pressure changes.Tide are the periodical rise and fall of the sea levels, once or twice a day, caused by the combined effects of the gravitational forces exerted by the sun, the moon and the rotation of the earth.A wave has two major parts: the raised part is called as the crest while the low-point is called as the trough.In a wave, the movement of each water particle is in a circular manner.This energy for the waves is provided by the wind.They are actually the energy, not the water as such, which moves across the ocean surface.Waves are a kind of horizontal movements of the ocean water.Waves are nothing but the oscillatory movements that result in the rise and fall of water surface.Waves and the ocean currents are horizontal movements of ocean waters while the tide is a kind of vertical movement of the ocean water. The major movements of the ocean waters can be classified into three. Movements of ocean water are also affected by external forces like the sun, moon and the winds. There are different types of movements of ocean water under the influence of different physical characteristics like temperature, salinity, density, etc. You all know that the ocean water is never still. Movements of ocean water: The classification Factors influencing the origin and nature of ocean currents.Tides based on the sun, the moon, and the earth’s positions Movements of ocean water: The classification.
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