The Effects of the Moon Phases on Ocean Tides

The Effects of the Moon Phases on Ocean Tides
••• johnnorth/iStock/GettyImages

Ocean tides are caused by the complex interplay of three astronomical bodies: the Sun, the Earth and the Moon. Both the Sun and the Moon exert a gravitational pull on the Earth's water. The resulting force of the Moon's gravity creates two tidal bulges on opposite sides of the Earth. Depending on the relative position of the Sun, the tidal bulges will change slightly as the Moon experiences its phases.

Full Moon and New Moon

At both full moon and new moon, tides are at their most drastic. High tides are very high, and low tides are very low. At full moon, the Moon and Sun are in a straight line on opposite sides of the Earth. Their gravitational forces combine to create larger tidal bulges. At new moon, the Moon and Sun are in a straight line on the same side of the Earth. In this case, their gravitational forces still combine to create large tidal bulges. These situations are called spring tides.

Quarter Moons

At quarter moons, the Earth's tides are at their least drastic. When the Moon is at a quarter phase, it forms a right angle with the Sun (with the Earth at the vertex). The gravitational forces from each body act at perpendicular angles, diminishing the overall tidal bulge. The Moon is still exerting a stronger gravitational force than the Sun, so there is still a net tidal bulge. However, this bulge is at its smallest. These situations are called neap tides.

Waxing Gibbous and Waning Crescent

During the waxing gibbous and waning crescent phases, the Moon is approaching its full and new phases, respectively. Because of this, the resulting tidal bulges will increase in size until they reach their maximum during the spring tides.

Waning Gibbous and Waxing Crescent

During the waning gibbous and waxing crescent phases, the Moon is on its way to the quarter phases. Because of this, the tidal bulge will decrease until it reaches its minimum at the neap tides.

Related Articles

What Tide Corresponds With a Solar Eclipse?
High Tides & Moon Phases
The Difference Between Spring & Neap Tides
Relationship Between Moon Phases & Tides
The Difference Between Low Tides & High Tides
When is the Moon's Pull on Earth the Strongest?
What Kind of Tides Occur When the Moon & Sun Are at...
What Are Diurnal Tides?
Facts About High & Low Tides
Explanation of the Tides and Moon
Relationship Between Gravity & the Mass of the Planets...
What Are the Causes of the 4 Seasons on Earth?
Definition of Phases of the Moon
What Causes Tides in the Ocean?
What Are the Eight Phases of the Moon in Order?
Chances of a Solar Eclipse
How Is the Moon Positioned When There Is a High Tide?
Five Phases of the Moon
How Are a Solar & Lunar Eclipse Alike?
How Much Time Is One Day on Mars?