Sixth Grade
Worksheets
Tides
Fishermen make their living from the sea, and information about tides can be important in their jobs. In many places, they can find out when the day's high tides and low tides will occur by looking them up in a tide table.
Tides affect other jobs, too, from beach rental businesses to the US Navy.
But tides are mysterious forces, and they are not easy to predict. Tides tables are made only after observing conditions in a coastal area for a long period of time. These observations must take into account many variables because tides have many causes.
The main cause of tides is the moon. The moon's gravity pulls on the earth and causes tides. The moon pulls up a bulge of water in the ocean on the side of the earth facing the moon. Because of the force caused by the earth's rotation, there will also be a bulge in the ocean on the opposite side of the earth. As these bulges in the ocean move to shore, they result in high tides.
In areas of the earth near the equator, such as on islands in the Caribbean Sea, the tides are fairly small. In other areas farther north or south, the tides may be much larger. In the Bay of Fundy in Nova Scotia, high tides may rise up to fifty feet.
