High and low tides are caused by the moon. The moon's gravitational pull generates something called the tidal force. The tidal force causes Earth—and its water—to bulge out on the side closest to the moon and the side farthest from the moon. These bulges of water are high tides.
The oceans' levels change daily across the globe. We know them as tidal changes. But what causes this constant shift in sea level and why is it more dramatic is some places than others?
The gravitational forces of the Moon and the Sun create tides. Other factors include the Earth’s rotation, the Moon’s orbit, the presence of continents on Earth, variations in water depth, and the inertia of the water.
What Causes Tides in the Ocean? Tides are the rhythmic rise and fall of sea levels, a phenomenon primarily caused by the gravitational forces exerted by the Moon and the Sun on the Earth, as well as the Earth’s own rotation.
Earth tides, which raise and lower the bottom of the ocean, and the tide's own gravitational self attraction are both significant and further complicate the ocean's response to tidal forces.
As a result, the moon’s gravitational pull causes the oceans to bulge on both the side of Earth closest to the moon and the side furthest from it, creating tides. The moon’s ability to raise tides on the Earth is an example of a tidal force. The moon exerts a tidal force on the whole planet.
Ocean tides are the regular rise and fall of sea levels caused primarily by the gravitational pull of the moon and, to a lesser extent, the sun. Most coastlines experience two high tides and two low tides roughly every 24 hours and 50 minutes, a period known as a lunar day.
What is the Cause of Ocean Tides? Ocean tides are primarily caused by the gravitational pull of the Moon and, to a lesser extent, the Sun on Earth’s oceans.
A plain-language guide to why the sea rises and falls twice a day: how the Moon's gravity pulls the ocean into bulges, why high tide arrives later each day, and what spring and neap tides really are.