TideLab

Ocean & Celestial Gravitational Mechanics

0° (New Moon)
0° New 90° 1st Qtr 180° Full 270° 3rd Qtr
12:00 (Noon)
00:00 06:00 12:00 18:00 24:00
Spring Tide
Lunar Dist: 1.00x
Equatorial Tidal Bulge Mechanics
Click canvas to reposition Observer Pin
Sun Pull: 46% (Fixed Right 0°)
Moon Pull: 100%
Synergy: Constructive
+3m
-3m
Observer Sea Level High Water Slack
+2.18m (+7.15 ft)
Tidal Range 4.36 m
Tide Trend Peak Slack
Synchronized 24-Hour Tide Curve Semi-Diurnal Cycle

Why is there an Antipodal (Far-Side) Bulge?

Tides are caused by differential gravity, not direct pull alone. The sublunar ocean experiences stronger gravitational attraction than Earth's solid center, accelerating toward the Moon. Conversely, Earth's center is pulled more strongly toward the Moon than the far-side ocean. This gravitational gradient stretches the ocean into a dual-sided prolate ellipsoid.

Spring vs. Neap Synergy (Syzygy vs. Quadrature)

When the Sun, Earth, and Moon align at Syzygy (New & Full Moons), solar and lunar tidal forces reinforce constructively, creating elevated Spring Tides. At Quadrature (90° First & Third Quarters), the Sun's bulge partially offsets the Moon's bulge, resulting in dampened Neap Tides.