What causes the tides?

Tides are the periodic rise and fall of sea levels, and they are caused by a combination of factors, including the gravitational forces of the moon and the sun, the rotation of the Earth, and the shape of the ocean basins.

The moon is the primary cause of tides because it is closer to the Earth and has a stronger gravitational pull than the sun. As the Earth rotates, the moon's gravity causes a bulge of water on the side of the Earth facing the moon, creating a high tide. On the opposite side of the Earth, there is also a high tide because the moon's gravity pulls the Earth away from the water, creating a bulge. The areas between the high tides experience low tides.

The sun also affects tides, but its influence is less than that of the moon because it is farther away from the Earth. During a full moon or a new moon, the gravitational forces of the sun and the moon combine, resulting in the highest tides, called spring tides. During the first and third quarters of the moon, the gravitational forces of the sun and the moon work against each other, resulting in the lowest tides, called neap tides.

Other factors that can affect tides include the shape of the ocean basins, the depth of the water, and the weather conditions.