Explore how gravity and the moon affect tides. Find out how tides are useful to man.

• 1.

  If you have ever spent time at the beach, you probably noticed that the water rises slowly on the shore for six hours, then slowly recedes, or falls back, for another six hours. These movements happen twice a day and are called tides.

• 2.

  Tides are caused by the pull of the moon when it is directly overhead. That gravity is actually pulling the water toward the moon. In doing so, it causes the water to rise on the surface of the earth.

• 3.

  Why then, you may wonder, do we have high tides when the sun is out as well? What is actually happening is that the moon's gravity is pulling the water on the opposite side of the earth—the side that is having night while you are having day. That same gravity is pulling the earth away from the water on the side where you are standing.

• 4.

  At the shore, tides may rise from 6 to 8 feet, but in the middle of the ocean, the rise is much less and barely noticed.

• 5.

  Tides are useful to man. They keep harbors and seaports clean by carrying waste material' from the land out to sea, where it sinks to the bottom. Tides also make harbor entrances deep enough for fishing vessels and ocean liners to sail through.

• 6.

  In small groups, use Crayola® Model Magic® to create a relief sculpture based on what you have learned about tides. Use a large piece of plywood, thick foamcore, or thick cardboard as a base for your piece.

• 7.

  Find a clean area on the floor to work. Knead modeling compound thoroughly for best adherence. To create new colors, knead 2 primary colors until well mixed.

• 8.

  Press modeling compound firmly onto board. Use a rolling pin to roll out large flat areas. Push your thumbs and fingers into soft modeling compound after it is laid onto the board for interesting textures.

• 9.

  Model Magic that is fresh from the pack will stick to itself. Dried pieces can be glued together. After piece is completely dry, it may be displayed on a wall for all to see!

Standards

• LA: Read and comprehend informational texts, including history/social studies, science, and technical texts, at the high end of the grade level text complexity band independently and proficiently.
• LA: Engage effectively in a range of collaborative discussions (one-on-one, in groups, and teacher led) with diverse partners on grade level topics and texts, building on others’ ideas and expressing their own clearly.
• LA: Write informative/explanatory texts to examine a topic and convey ideas and information clearly.
• LA: Adapt speech to a variety of contexts and tasks, demonstrating command of formal English when indicated or appropriate.
• LA: Report on a topic or text, tell a story, or recount an experience with appropriate facts and relevant, descriptive details, speaking clearly at an understandable pace.
• SCI: Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation.
• SCI: Analyze and interpret data from maps to describe patterns of Earth’s features.
• VA: Intentionally take advantage of the qualities and characteristics of art media, techniques, and processes to enhance communication of experiences and ideas.
• VA: Use visual structures of art to communicate ideas.
• VA: Integrate visual, spatial, and temporal concepts with content to communicate intended meaning in artworks.

Adaptations

• Possible classroom resources include: Oceans: Looking at Beaches and Coral Reefs, Tides and Currents, Sea Mammals and Fish, Seaweeds and Other Ocean Wonders by Adrienne Mason; MOON AND TIDES, INSIDE SCIENCE READERS (Inside Science: Earth and Space Science) by Rob Lang
• Students work in small groups to develop a calendar sculpture for each month of the year. Post calendars in a timeline-like format. Students trace actual tidal events by researching daily news reports on tides.
• How do tides effect weather issues? Students consider a projected weather event such as a hurricane. How do tidal patterns influence the hurricane's impact on land and human upgrades to the land? Students research specific weather events that have documented influence from high or low tides.