Moon causes tides in ocean

The moon is responsible for high and low tides. The tidal force is caused by the moon's gravitational pull. The tidal force causes Earth—and its water—to bulge out on the sides closest to and farthest from the moon. These water bulges are high tides.

Every day, your region of the Earth passes through both of these bulges as the Earth rotates. A high tide occurs when you are in one of the bulges. A low tide occurs when you are not in one of the bulges. This cycle of two high tides and two low tides occurs most days along most of the world's coastlines.

However, when the moon's gravity pulls on the water in the oceans, someone is bound to notice. Water moves much more easily than air, and it wants to bulge in the direction of the moon. This is referred to as the tidal force.

The water on the moon's side always wants to bulge out toward the moon due to tidal force. This bulge is referred to as a high tide. A high tide may occur as your part of the Earth rotates into this bulge of water.

The Sun, like the moon, causes tides, though they are much smaller. When the earth, moon, and Sun align, as they do at full and new moons, the lunar and solar tides reinforce each other, resulting in more extreme tides known as spring tides. When the lunar and solar tides oppose each other, the result is unusually small tides known as neap tides. Because there is a new moon or a full moon every two weeks, large spring tides occur about every two weeks.