Final answer:
Cotidal lines are used to mark points where high tide occurs simultaneously and help determine the phase of the tide at specific ocean locations. These lines take into account the twice-daily tides influenced by the gravitational pull of the Moon and the Sun, and the effect local topography and bathymetry have on tide ranges.
Step-by-step explanation:
Cotidal lines are lines on a map that connect points where high tide occurs simultaneously. They are essential for understanding the phase of the tide at a particular location in the ocean, as they illustrate the predicted times at which high and low tide will occur across different areas. The tides are the result of the gravitational pull of the Moon and Sun on the Earth's oceans, combined with the rotation of Earth.
Anyone living near the coast may notice the regular rising and falling of sea level known as the tides, which happen approximately twice daily. These tides are directly linked to the Moon's gravitational pull and are influenced by the local topography, or the shape of the coastline, and the bathymetry, or depth profile of the ocean floor. In some places, such as the Bay of Fundy, the range of the tide can be exceptionally large, reaching up to 16.3 meters.
By observing the intertidal zone, you can identify the area that is above water at low tide and submerged at high tide. Variations in tide can be extreme, and tide tables must be computed for each coastal location because of the complexities introduced by Earth's rotation, land masses, ocean depth, and other factors affecting ocean tides.