Tides are primarily caused by the gravitational pull of the Moon and the Sun on Earth's oceans, with the Moon's influence being stronger due to its closer proximity.

This creates two tidal bulges: one on the side of Earth facing the Moon where the pull is strongest, and another on the opposite side where inertia allows water to lag behind.

As Earth rotates daily, coastal areas experience alternating high and low tides roughly every 12 hours.

Gravitational Forces Explained

Imagine Earth as a water balloon squeezed by invisible hands—the Moon's gravity tugs hardest on the near side, piling up ocean water into a bulge, while the far side bulges due to centrifugal force from the Earth-Moon orbital dance.

The Sun adds its own pull, about half as strong as the Moon's because it's much farther away, but their combined effects create spring tides during full and new moons when aligned.

When the Sun and Moon are at right angles (quarter moons), their pulls partially cancel, leading to weaker neap tides.

Types of Tides

Tide Type| When It Occurs| Description| Tidal Range
---|---|---|---
Spring Tide| New or full moon| Moon and Sun aligned; maximum gravitational pull| Highest highs and lowest lows 13
Neap Tide| Quarter moons| Moon and Sun at 90°; pulls partially oppose| Smallest range 1
King Tide| Spring tide + perigee (Moon closest)| Extreme highs/lows, often seasonal| Up to 20% higher 34

Other Influencing Factors

  • Earth's Rotation and Shape : Continents block water flow, amplifying tides in bays like the Bay of Fundy (up to 50+ ft).
  • Ocean Depth and Inertia : Shallow seas respond more dramatically; water resists quick changes.
  • Moon's Orbit : Elliptical path causes monthly variations—higher tides at perigee.

Fun fact: Even land "tides" rise/fall a foot or so daily, but we don't notice amid the ocean drama.

Recent Context (2026)

As of January 2026, king tides have made headlines along U.S. coasts due to perigean spring alignments, exacerbating coastal erosion amid ongoing sea level rise discussions—no major new theories, but forums buzz about climate- tide interactions.

TL;DR : Moon's gravity bulges oceans toward and away from it; Sun modulates; Earth spins through the bulges twice daily.

Information gathered from public forums or data available on the internet and portrayed here.