Tides. Tidal forces

Tides are periodic fluctuations in sea level that occur as a result of the gravitational pull of the Moon and the Sun on the Earth. These gravitational forces generate a bulge in the surface of the ocean, creating the high and low tides seen along coastlines.

The interaction between the Moon, the Earth and the Sun is the main factor influencing the formation of tides. The Moon has a dominant influence due to its proximity to the Earth. The Moon’s gravity pulls water toward itself, creating a bulge on the side of the Earth facing the Moon, resulting in a high tide known as a high tide. On the opposite side of the Earth, there is also a bulge due to the centrifugal force generated by the Earth’s rotational motion, resulting in another high tide called the ebb tide.

The Sun also contributes to the tides, although its influence is about half that of the Moon due to its greater distance. During new and full moons, when the Moon, the Earth and the Sun are aligned, their gravitational forces add up and produce the most intense tides known as neap tides. On the other hand, during the waxing and waning quarters, when the Moon and the Sun form a right angle, their forces are offset and weaker tides known as neap tides are generated.

In addition to gravitational pull, other factors such as the topography of the seafloor, the shape of coastlines, and the depth of the oceans can affect tidal characteristics in specific regions. For example, narrow estuarine or channel inlets can amplify tides, generating higher tides known as amplifying tides.

Tides have diverse applications and consequences. In navigation, knowledge of tides is crucial to avoid groundings and to determine the optimal times to enter or leave harbors. In power generation, tides are used in tidal power plants to produce electricity from the movement of water. In addition, tides influence coastal ecosystems and marine species distribution by affecting nutrient availability and exposure of intertidal areas.