How the Moon Affects the Ocean

Rotations

• The Earth rotates around the sun, while spinning constantly like a top, causing the yearly seasons, as well as 24-hour days. Similarly, the moon does the same thing around the Earth. It rotates completely around the Earth about every 27 days. The gravity of the moon constantly pulls at everything on the Earth, but only the ocean water -- which moves freely when compared to material objects -- shows signs of this gravity. Tides occur throughout the ocean and have been integrated into human culture as a natural part of life.

High Tides and Low Tides

• The tug of the moon doesn't remain constant, even on the scale of one day. Each day, there are a total of two high and low tides. The reason behind this is the Earth's spin. As the planet rotates, a different side will of the Earth will face the moon throughout the day; the moon, on the other hand, will be in relatively the same position during the day. The water will "pull" with the gravity of the moon. The side of the Earth facing the moon, as well as the opposite side, will be experiencing high tide while the adjacent sides of the Earth will be experiencing low tide.

Spring Tides

• Although the name might imply it, spring tides have nothing to do with the season of spring; instead, they represent a type of tide that occurs year-round. Like the moon, the sun also exerts a force on the tides, although it is only 46 percent the strength of the moon's force. During new moons and full moons (when the moon is directly in line with the sun), the gravity of the two combine, creating tides that are 20 percent higher or 20 percent lower than usual.

Neap Tides

• As the forces can combine, they can also cancel each other out. During neap tides, the moon lines up around the Earth in its quarter-phase position. This alignment causes a right angle between the sun and the moon, which causes the tides to be exceptionally mellow.