The moon's gravitational force pulls water towards it, creating a high tide on the surface of the ocean closest to the moon. Also, the centrifugal force created by the Earth and moon orbiting around a central point creates a similar bulge on the opposite side, creating a second high tide.
Ordinarily, the Earth's gravitational field pulls down on the liquid on the planet's surface. The moon's own gravity partially offsets this effect, resulting in slightly lower gravity on the side of the Earth facing the moon. This change in the gravitational field is not strong enough to affect most solid objects, but the water molecules in the oceans and other large bodies are susceptible to the change, creating a bulge in the surface of the water that follows the moon around the Earth. Water on the opposite side of the planet is not affected by this gravitational pull, since the Earth's mass is in the way. This water is affected by the centrifugal force of the planetary spin, pushing it outwards.
The sun also has a small effect on the Earth's tides. When the moon and sun line up, the tides created are higher than those that occur when the moon's gravity is working perpendicular to the sun's own pull. In addition, the moon's variable distance from the Earth during its orbit can also have an effect on the height of tidal variations.Learn More
Tides form when the gravitational forces of the moon and sun act on the Earth as it spins around its axis. Tides are the rise and fall of the sea level in reference to land. For example, spring tides are the result of the alignment of the sun, moon and Earth that typically occurs during new and full moons.Full Answer >
According to Science and the Sea, lunar tides are the most common tides and are caused by the Moon's gravity. Although the Sun's gravity is stronger, it is farther from the Earth than the Moon, which is why lunar tides are more than two times stronger than solar tides.Full Answer >
The basic lunar cycle of a body of water consists of two high tides and two low tides, which occur every 24 hours and 50 minutes. The basic cycle of solar tides is 24 hours.Full Answer >
Low tides and high tides occur as a result of gravitational forces between the moon and Earth. There is a gravitational force exerted on every object on the planet by the moon. The effect of the gravitational force is more apparent on bodies of water than it is on land.Full Answer >