Why do Tides Rise and Fall?

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Tides are regular movements of the oceans. The water in the ocean is held close to the Earth by gravity. The Moon and Sun also have some pull on the Earth. The Moon's gravity affects water in the oceans. The sea is pulled slightly towards the Moon, causing a bulge or high tide. When the Sun's gravity and the Moon's gravity pull in the same direction, their combined force causes a very high or spring tide. When the Sun and Moon pull against each other at right angles, a very low or neap tide occurs. The Moon is travelling around the Earth and at the same time, the Earth is also spinning on its axis, so most places have two high and two low tides about every 24 hours. During a high tide, the water flows as far inland as it can, while during a low tide, the water is pushed away.

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