gravitational tides

Gravitational tides are the rise and fall of sea levels caused by the gravitational pull of the Moon and the Sun on Earth. As these celestial bodies move, their gravity pulls water towards them, creating bulges or "high tides" in the ocean. When the Earth rotates, these bulges shift, leading to "low tides" as the water recedes. The shape of the coastline and local features also affect how tides behave. Tides occur regularly, roughly every six hours, and are influenced by the positions of the Moon and Sun, as well as the Earth's rotation and topography.