How Does the Moon Affect the Ocean Tides on Earth?

The moon plays a major role in the low tides and high tides in the oceans on Earth because the Earth and Moon are attracted to each other gravitationally. Gravity and the gravitational pull are the foundation of how the Earth, the Sun and the Moon continue to orbit each other and allow human life to continue on Earth.

While you are sitting at home, or standing still, the Earth, along with everything in our Solar System, is constantly on the move in Space. The earth-moon system has a center of gravity, called the Barycenter. This is a point located inside the earth and moves in a way that it is always in line with the earth's center and the moon's center where the Earth's mass is much larger than the moon's mass.

The moon's gravity starts to pull on the oceans that are located right below the moon, and the moon's gravity is a little weaker on the other side of the earth. At the same time, the earth is orbiting the Barycenter causing a high tide effect on two opposite sides of the earth at once, then there are two low tide areas at roughly 90 degree angles to the high tides. This is how low tide starts at one time and high tide starts later before repeating itself over and over again every day.

The word "tides" is a term used to define the alternating rise and fall in sea level with respect to the land, produced by the gravitational attraction of the moon and the sun. You may also notice on a smaller scale tides in large lakes as well as in the atmosphere and in the Earth's crust. Additional factors that are not from the Solar System play a role in the tides on Earth and the role the Moon plays in making them rise and fall. The coastline, local depth of the water, ocean-floor topography, and other hydrographic and meteorological influences play a role in altering the range, interval between high and low water, and times of arrival of the tides.

The Sun also plays a role in the tides on Earth, but it is to a lesser degree due to its greater distance from the Earth. It takes the Sun a full 25 days to spin completely around. The Earth takes 24 hours to rotate, and the Moon takes 27 1/2 days to completely rotate around the Earth. But it takes an additional 2 days for the moon to come back to the same place in the sky that it was 29 1/2 days before. As the Earth orbits the Sun, the Moon orbits the Earth.

The data collected from the moon to the ocean tides helps Scientists, Meteorologists and everyone who enjoys the oceans and ocean related activities such as fishing, boating and surfing know whether it is safe to go into the water and what the weather for the day will be.

Sources:

NOAA