By Thomas Springer
Updated Mar 24, 2022
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Tides are the rhythmic rise and fall of the ocean’s surface, driven by the gravitational pull of the Moon and the Sun. The Moon’s proximity gives it a stronger influence, but the Sun’s mass and the relative positions of both bodies create the timing and magnitude of each tide.
The Moon’s gravity pulls ocean water toward the side of Earth it faces, creating a bulge. On the opposite side, Earth is pulled slightly away from the water, forming a second bulge. High tides occur where the bulges are located, while low tides happen midway between them. Every point on Earth experiences roughly two high and two low tides each day.
Spring tides arise when the Sun, Earth, and Moon align—during full or new Moon phases. In this configuration, the gravitational forces of the Sun and Moon reinforce each other, producing the strongest high and low tides. The term “spring” refers to the sudden, powerful rise and fall of the water, not the season.
When the Moon is at its first or third quarter, the Sun, Earth, and Moon form a right angle. Their gravitational pulls counteract one another, resulting in weaker high and low tides. These are called neap tides, the period of minimal tidal range.
Occasionally, spring tides become even more pronounced during proxigean (or perigean) spring tides. This occurs a few times a year when the Moon is at its closest point to Earth (perigee) while also being new or full. The Moon’s proximity amplifies its pull, leading to record-high and record-low tides.
For detailed tide charts and scientific explanations, consult the NOAA or NASA tide resources.
