High Tides & Moon Phases

Gravitational pulls affect the ocean tides.
••• tide clock image by Leslie Batchelder from Fotolia.com

The gravitational forces of the moon, Earth and sun affect the ocean tides. Each day, four different tides occur—two high tides and two low tides. During a full or new moon, when the Earth, moon and sun align, spring tides form, creating higher and lower than normal tides. During the first- and third-quarter moon phases, when the moon and sun are at right angles to the Earth, neap tides occur, creating low and high tides with minimal difference in heights.

Lunar Tides

According to The Astronomer Cafe, the moon’s gravity does not directly cause the tides. As the moon pulls upward, the Earth is pulling downward—with the moon having a slight advantage. The sun also provides a gravitational pull, although much less than the moon. This gravitational pull, known as “tractive” force, causes the tides.

Rotation

The moon revolves around the Earth, never in the same place at the same time. Thus, the high and low tides change by 50 minutes each day. The Earth rotates on an axis, and the moon makes one complete rotation in our sky every 25 hours (not to be confused with the 27-day orbit around the Earth), causing two tidal peaks and two tidal troughs every day, with a 12-hour separation between the two tides.

Spring Tides

The combined gravitational pull of the moon (at new or full moon phase) and the sun creates higher high tides and lower low tides, known as spring high tides. Spring tides do not have anything to do with the season spring. According to the Astronomer Cafe, spring tides are approximately the same height whether at a new or full moon since the tidal bulges occur on opposite sides of the Earth—the side toward the moon (or sun) and the side away from the moon (or sun). The distance of the tides is not equitable because of the varying gravitation pulls between the sun and earth, and the moon and earth.

Proxigean Tides

Proxigean spring tides occur approximately once every 1.5 years. These rare high tides occur when the moon is between the Earth and sun (new moon) and at its closest to the Earth (called proxigee).

Neap Tides

During the first quarter or last quarter phase of the moon, when the sun and moon are perpendicular (at right angles) to each other in relation to the Earth, the tidal gravitational pulls interfere with each other, producing weaker tides, known as neap tides. Neap tides exhibit little difference between high and low tides.

Related Articles

The Difference Between Spring & Neap Tides
The Difference Between Low Tides & High Tides
When is the Moon's Pull on Earth the Strongest?
What Tide Corresponds With a Solar Eclipse?
Explanation of the Tides and Moon
The Effects of the Moon Phases on Ocean Tides
What Are the Causes of the 4 Seasons on Earth?
Facts About High & Low Tides
What Are Diurnal Tides?
What Kind of Tides Occur When the Moon & Sun Are at...
What Are the Two Motions of the Earth?
Relationship Between Moon Phases & Tides
How Is the Moon Positioned When There Is a High Tide?
The Movement of the Sun & Moon in the Sky
The Explanation of Phases of the Moon
How Does the Moon Affect Earth's Seasons?
Moon Phases & How the Seasons Change
How Does the Earth's Revolution Affect Its Seasons?
Five Phases of the Moon
How Many Earth Days Equals One Year on Venus?