What Affects Tides?

The tide is the movement of the Earth's bodies of water. Tides are mostly seen in the ocean, but also occur in smaller bodies of water like bays and large lakes. Tides occur in cycles: high tide occurs when the water is at its highest point and low tide occurs when the water has receded. Scientists and oceanographers can determine when a tide will occur based on factors that impact its movement.

Gravity

Gravity, first described by Sir Isaac Newton in 1687, is the naturally occurring circumstance where objects are attracted to each other in direct proportion to their mass. The masses and gravitational pull of the sun, the moon and the Earth all interact and cause the occurrence of tides on the Earth's surface. Although the sun is the largest celestial body, its large mass is a counterbalance to the proximity of the moon to the Earth.

Moon

The moon is the most powerful force that impacts the occurrence and timing of tides. As the Earth revolves on its tilted axis, the moon revolves around the Earth, taking appropriately 28 days. Because the distance from the Earth to the moon is relatively short, the moon's gravitational pull exerts a strong magnet on objects on the Earth. The fluidity of the ocean means that the water will draw closer to the moon when the Earth is tilted toward the moon and recede when the Earth is tilted away.

Weather Pattern

Weather patterns like wind and rain also affect tides. If the wind is blowing strongly toward the shore, it will help to push the waves higher and increase the level of the tide. Conversely, the winds can push the water back from the shore, making the low tides even lower. Rain occurs during a low pressure system. This atmospheric pressure increases the height of the tide while high pressure systems decrease the level of the tides.

Shoreline Shape

The shape of the shore or coastline also impacts the tide, more specifically the tidal range, which is the difference between the peak of the high tide and the nadir of the low tide. A funnel shaped coast increases the degree of the tide while narrow shaped shorelines or shallow water decreases the magnitude of a tide.