Lesson Plan - Get It!
What do you see happening to the water when you go to the beach? Does it seem to sneak in, closer and closer, then sneak back out again? Why?
If you have ever been to the beach, you probably noticed the movement of the water.
The waves of the ocean crash on the beach, then they get pulled back out to sea, only to come crashing down on the beach once again.
Think about a time when you were sitting on the beach. If you stay at the beach for hours, you may notice that the waves are getting closer to where your beach chairs are or the water is getting further away. The sea rises and falls with the tides.
Do you want to see the tides in action? Great! You will watch a time lapse video that shows how the tides come in and go out. Watch the The Hopewell Rocks - OFFICIAL Time Lapse Video of 45.6 Foot Tide by Kevin Snair (silent video, below):
You saw how high the tides got in the video. The tides rose up forty-five feet! Some tide cycles can cause the water to rise over fifty feet while others only rise three feet. The tides depend on where you are located on Earth. Did you know the tides are caused by the movement of the moon and the sun? Read on to find out more.
The moon and the sun exert a gravitational pull on the Earth. Just like gravity keeps you from floating away from Earth, gravity affects the tides. The placement of the Earth, the sun, and the moon cause different types of tides.
(If you need a review on how the Earth and moon move around the sun, check out The Moon series of Related Lessons in the right-hand sidebar.)
Spring tides, which are the highest tides, are caused when the Earth, sun, and moon are all lined up in a row. These tides occur every two weeks during the new moon and the full moon. Below you can see how the Earth, sun, and moon would line up during a spring tide:
Neap tides are smaller tides. They form when the Earth, sun, and the moon form a right angle. When these tides happen, the water is pulled in two different directions. This type of tide usually occurs when there is a quarter moon or three-quarter moon. With the help of your parent or teacher, point to where the moon is during spring tides and where the moon is during neap tides (below):
Image by KVDP and converted by Surachit, via Wikimedia Commons is in the public domain.
The gravitational pull from the moon and the sun causes the tides. The rising and falling of ocean waters can affect animals that live in certain areas around the ocean.
In the Got It? section, you will learn about tide pools. Before moving on to the Got It? section, tell your parent or teacher what the two types of tide are and how they are caused.