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What Causes High Tides?

Many people will be familiar with high tides and low tides -- the ebb and flow of the sea. If you were to visit the beach for the day, you would need to check the times of high and low tide to make sure you are not disappointed when you arrive. Much of the sandy shore could be underwater if you time your visit wrong. Tides are caused by the gravitational pull of the moon, but there are also other influences that can cause high and low tides.

Lunar Tides
- The gravitational pull of the Moon is the main force behind high tides. As the Moon revolves around the Earth, its gravity pulls on the oceans on the Earth's surface, causing them to bulge. This bulge causes the high tide.
Spring Tides
- High tides are higher when the Sun and Moon align during the times of full Moon and new Moon. The two bodies together cause a greater gravitational pull, and this higher tide is known as spring tide.
Solar Tides
- The Sun also has a similar gravitational effect on the oceans as the Moon does, but because the Sun is farther away, the effect is about half that of a Lunar tide.
Neap Tides
- There are times when the difference between high tides and low tides are very small. This happens when the Moon is at a right angle to the sun during its first or last quarter, and the gravitational pull of the Moon and the Sun cancel each other out.

Nature