Post-Visit Activity: Tropical Belt GRADE LEVEL K-3rd; California Content Standards for K, 1st and 3rd SUBJECTS Earth Sciences, Physical Sciences, History-Social Sciences DURATION Preparation: 10 minutes Activity: 45 minutes SETTING Classroom

Students will: 1. locate the equator, Tropic of Cancer and Tropic of Capricorn on a map and globe of the world 2. identify and color the locations of tropical rainforests on a world map

Materials

world maps (one map per student) transparency (one per class) transparency markers crayons (one set per student) hole puncher (one per class) yarn (one ball per class) scissors (one per student) inflatable globe (one per class)

Vocabulary

™ equator: an imaginary circle around the middle of the Earth that divides the planet into two equal halves—the Northern Hemisphere and the Southern Hemisphere ™ latitude: gives the location of a place on Earth north or south of the equator. Latitude measured in degrees (marked with °) ranging from 0° at the Equator (low latitude) to 90° at the poles (90° N for the North Pole or 90° S for the South Pole; high latitude). ™ Tropic of Cancer: latitude 23°5' north of the equator and the most northerly latitude at which the sun can shine directly overhead ™ Tropic of Capricorn: latitude 23°5' south of the equator and the most southerly latitude at which the sun can shine directly overhead

Teacher Background

The tropics are the geographic regions of the world centered on the equator. They are located in the equatorial region between the Tropic of Cancer (23°27’N) and the Tropic of Capricorn (23°27’S). They have high temperatures throughout the whole year. A typical daytime temperature in tropical rain forests at anytime during the year is 29°C (85°F). These consistently high temperatures occur because the tropics receive more direct radiation and more consistent radiation from the sun than the temperate regions further north and south. They do not tilt dramatically toward or away from the sun during any season, as compared to the temperate regions farther north and south. There is at most a 5°C (9°F) difference in temperature between the seasons in the tropics.

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Tropical Belt

The word “rain forest” connotes the fact that these are the some of the world’s wettest ecosystems. Tropical rain forests around the world have high humidity, about 88% during the wet season and about 77% in the dry season. They receive approximately 60 to 80 inches (152.4 to 203.2 centimeters) of rainfall per year although the exact rainfall varies for different years and different rain forests. South America’s tropical rain forests, for example, receive between 200 and 300 centimeters (80 and 120 inches) of rainfall in a typical year. In comparison, San Francisco receives only about 56 centimeters (22 inches) of rain per year.

Activity

Introduction ™ Prior to class, fill the inflatable globe with air and use it as a model of the earth. ™ Point out the equator to the students. Point out San Francisco. ™ Discuss how to describe where the equator lies on the globe (e.g., in the middle of the earth). ™ Write on the board students’ own verbal descriptions of where the equator is.

Procedure 1. Pass out a world map and crayons to each student. 2. Use the transparency on the overhead to guide the students through the activity and to model each action. 3. Instruct students to use a blue crayon to color in the oceans on their maps (advanced students could write down the oceans’ names: Atlantic, Pacific, Indian, Arctic, and Southern). 4. Instruct students to color the landmasses yellow (advanced students could write the names of the seven major continents: North America, South America, Europe, Africa, Asia, Australia, and Antarctica). 5. Instruct students to take a green marker/crayon and color in the rain forests of the world (these areas are striped on the maps provided). 6. Ask students to touch the middle of their maps to indicate the equator. 7. Walk around to check for accuracy. 8. Introduce the equator and have students trace the equator with a red marker/crayon and label it. 9. After the maps are colored and labeled, tell the students that they need to trace two other special lines to complete their maps. These two lines should be drawn using an orange crayon. Starting from the top of the map, the first line will mark where the tropical rain forests start appearing on the map (Tropic of Cancer) and the second line will mark where the rain forests end at the bottom of the map (Tropic of Capricorn). 10. Introduce these special lines as the “Tropic of Cancer” and the “Tropic of Capricorn.” 11. After tracing these two lines, students will use scissors and cut a straight line along the Tropic of Cancer and the Tropic of Capricorn. The end result will be a wide strip of the map that can be used to make a Tropical Belt. 12. Punch a hole at each end and tie the ends together with yarn. The students can wear the belt in class to remind themselves that rain forests are found near the equator or midsection of the Earth.

Wrap-Up

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Discuss the following questions: ™ Where is the middle of the Earth? (have students point to the equator) ™ There is an imaginary circle around the Earth called the equator. What does the equator run through? (continents and oceans) ™ Why are the tropical rain forests found near the equator? (Because that is where the sun’s energy is focused) ™ Can we see the equator if we could look at the Earth through space? (no, this is an invisible line that humans have named, but we can see the rain forests from space)

Extensions

Use a flashlight to focus light on the equator (middle section of the globe). Ask students to spin the globe in their hands to simulate rotation. Students can also tilt the Earth to demonstrate seasonal changes and make note of how these changes do not change the amount of ultraviolet radiation that strikes the equator.

References

Kricher, J.C. (1997) A Neotropical Companion: An introduction to the animals, plants, and ecosystems of the new world tropics. Princeton, NJ: Princeton University Press.

Prance, G.T., & Lovejoy, T.E. (Eds.). (1985). Key environments: Amazonia. Oxford: Pergamon Press.

Primack, R. & Corlett, R. (2005). Tropical Rain Forests: An ecological and biogeographical comparison. Malden, MA: Blackwell Publishing.

Correlated California State Content Standards

Kindergarten History- Social Science K.4 Students compare and contrast the locations of people, places, and environments and describe their characteristics.

Grade One History- Social Science 1.2 Locate on maps and globes their local community, California, the United States, the seven continents, and the four oceans.

Grade Three Physical Science 1a. Students know energy comes from the Sun to Earth in the form of light.

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