Tides

Definition

Tides are the periodic rise and fall of sea levels caused by the gravitational forces exerted by the Moon and the Sun, along with Earth's rotation. These movements create a cycle of high and low tides that typically occur twice daily.

5 Must Know Facts For Your Next Test

1. The primary force driving tides is the gravitational pull of the Moon, with the Sun also contributing to a lesser extent.
2. Spring tides, which are higher than average, occur during full and new moons when the Earth, Moon, and Sun are aligned.
3. Neap tides, which are lower than average, happen during the first and third quarters of the moon when the gravitational forces of the Moon and Sun are perpendicular.
4. The difference in height between consecutive high and low tides is known as tidal range.
5. Coastal geography can significantly amplify or diminish tidal effects due to local topography and bathymetry.

Review Questions

• What celestial bodies primarily influence Earth's tides?
• How do spring tides differ from neap tides in terms of their occurrence and effect?
• What term describes the difference in water level between high tide and low tide?

Related terms

Gravitational Force: The attractive force acting between any two masses; it decreases with distance but never completely disappears.

Spring Tide: A tide just after a new or full moon when there is the greatest difference between high and low water levels.

Neap Tide: A tide just after the first or third quarters of the moon when there is least difference between high and low water levels.