The Tides

The tides are the daily rising and falling of water levels in the oceans and connected bodies of water as a result of the Earth rotating within a field of gravity from both the Sun and the Moon. The pull of gravity from the Sun and the Moon are strong enough to pull on and deform large bodies of water. If we consider that the earth would normally have a round or spherical layer of water, the effect of gravity pulls that sphere into an oval. The animations below greatly exaggerate this effect on the water layer shown in light blue.

Spring Tides

Spring tides are the largest of the tides and are created when the Sun and the Moon are aligned. The force of gravity from the Sun works with the Moon and cause water to collect as shown in the animation above. Imagine the red dot on the Earth represents your location. When the red dot is near a thicker layer of water, you would be at high tide, and when the dot is near a thinner layer of water, you would be at low tide. During spring tides, the tidal range (the difference in height between high and low tide) is the largest.

This alignment of the Earth and Moon is also considered a spring tide because the Earth and Moon are still aligned.

Neap Tides

When the Sun and the Moon are at right angles to each other, they create neap tides. The tidal range of neap tides is smaller than that of spring tides. It should be pointed out that the Moon has a larger effect on the tides than the Sun. This is not because the Moon has a greater force of gravity. In fact, at the surface of the Earth, the Sun's force of gravity is about 170 times stronger than the Moon's force of gravity. What helps make the Moon more effective is that the Moon is closer so there is a larger difference between the amount it pulls on the closer portion of the water and the amount it pulls on the farther portion. It also has more of a gravitational "pinch" since the moon's gravity is pulling the water on the western half of the Earth toward the East and the eastern half to the West.