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Overview:
Students will use the National Geographic Forces of Nature website to learn about volcanoes and plate tectonics, then read an online feature about volcanic hot spots. They will refer to a map of the Galápagos Islands to predict the age and volcanic activity of various islands. They will brainstorm what the islands might look like today, read descriptions of each island, and try to correctly match the descriptions with the islands’ names. The class will predict how each island might change over time. Finally, students will create brochures informing visitors to the Galápagos Islands about how the islands were formed and why they differ geologically from each other.
These lesson plans were developed for the National Geographic Channel film, Galápagos.
Connections to the Curriculum:
Geography, geology, Earth science
Connections to the National Geography Standards:
Standard 7: "The physical processes that shape patterns of Earth's surface"
Time:
Three hours. (It will take four hours if you show students the video.)
Materials Required:
- Computer with Internet access
- A wall map of the world (optional)
- Copies of a map of the Galápagos Islands
- Copies of the student handout: Name That Island! (PDF, Adobe Reader required)
- National Geographic Channel Galápagos DVD (optional)
Objectives:
Students will
- review volcanoes and plate tectonics on a National Geographic online feature;
- read about and discuss volcanic hot spots;
- locate volcanoes on a map of the Galápagos Islands;
- predict the age and volcanic activity of various islands in the Galápagos chain;
- brainstorm what four of the Galápagos Islands might look like;
- match the four islands with written descriptions;
- predict how each of these islands might change over time; and
- create brochures to inform visitors to the Galápagos about how the islands were created and why they look different from each other.
Geographic Skills:
Acquiring Geographic Information
Answering Geographic Questions
Analyzing Geographic Information
S u g g e s t e d P r o c e d u r e
Opening:
Ask students where they think volcanoes erupt: on land or in the ocean. If they say "both," they are correct. Ask if they can think of any volcanoes in United States. They may have heard of Mount St. Helens, in Washington State, on the North American landmass, or of the Hawaiian Islands, in the Pacific Ocean. Students will learn about a volcanic island chain called the Galápagos Islands, which was created in much the same way as the Hawaiian Islands.
Have students look at photographs of the Galápagos Islands on the National Geographic Channel Galápagos micro-site. Explain that this island chain is part of the South American country of Ecuador. If you have a world map in the classroom, ask a student volunteer to point out South America and to locate Ecuador. Can he or she find the Galápagos Islands? (They lie along the equator about 600 miles [965.6 kilometers] west of Ecuador.)
As an option, you may have students find the Galápagos Islands on the National Geographic MapMachine.
Development:
In a brief class discussion, ask students to describe what they know about plate tectonics and the relationship between the Earth's plates and volcanoes.
Have students go online to National Geographic: Forces of Nature and select "Volcanoes." Ask them to read "What Is a Volcano?" Students should then click the numeral "2" (in the yellow bar) and read "Where Do Volcanoes Occur?" Click "Next." The map will show Earth's plate boundaries and volcano locations.
Ask students to locate South America on this map. Have them find an area of volcanoes off the northwest coast of South America. This is the location of the Galápagos Islands. Have students continue to step 3 ("How Do Volcanoes Form?"). Click on the second volcano from the left, and read about volcanoes that form over hot spots.
Tell the class that the Galápagos Islands were formed when the Nazca plate moved over a hot spot, under the surface of the Earth. (To see a map that labels Earth's plates, students can go to this U.S. Geological Survey page).
To learn about hot spots, have students read NOAA: Ocean Explorer—What Is a Hot Spot?. After they have read this page, discuss the answer to the question "How is a volcano formed over a hot spot?" to make sure they understand the basic concept of hot spots. As an option, you may ask them to write a short paragraph answering this question.
Have students scroll down the NOAA Web page to see a diagram of the Hawaiian Islands, which were formed over a hot spot. Small white arrows that represent the direction in which the plate is moving point toward the upper left. Which island is farthest from the hot spot: the oldest island or the youngest island? On which island would students expect to see a volcano erupting today: the oldest island or the youngest island? Students should understand that as an island moves away from a hot spot, its volcanoes become dormant because they are no longer directly over the area where the Earth's magma (molten rock material) rises to the surface.
Have students focus on the Galápagos Islands map. Explain that the Nazca plate is slowly moving toward the southeast about one or two inches (25.4 or 50.8 millimeters) every year. Explain to the students that active volcanoes can be found on Fernandina Island and Isabela Island, thus confirming their close proximity to the hotspot that formed the Galápagos Islands. Ask them to draw arrows pointing southeast to show the direction of the plate's movement relative to the hotspot.
As a class, ask students to answer the following questions and explain their reasoning. What islands are the youngest (answer: northwesternmost, because they are closest to the hotspot) and the oldest (answer: southeasternmost, because they are farthest from the hotspot) in the chain?
Write "Older Volcanic Island" and “Newer Volcanic Island" on the board. Have a class discussion about some of the basic differences between an older and a younger volcanic island. You may wish to have students conduct some of their own research and report back. Be sure to cover the following points, which are general characteristics of volcanic islands based on their age:
- A younger volcanic island will be more volcanically active, and may contain evidence of recent eruptions. Older volcanoes are less active or may be dormant.
- Younger volcanic islands, which have been more recently formed, tend to have fresher volcanic flows with built-up, sharper-edged rocks. Older volcanoes have been more affected by erosion, which reduces elevation.
- Volcanic rock erodes into soil; therefore, older islands may have deeper soil.
- The deeper soil of older islands supports more dense vegetation, which in turn can support more wildlife.
Distribute the Name That Island! ( PDF) handout and ask students to read the descriptions. Have them try to correctly match the island names with their descriptions, based on their understanding of the islands' age and volcanic activity. ( answers: Island 1. Isabela; Island 2: Española [about 3.5 million years old]; Island 3: Fernandina [about 700,000 years old]; Island 4. Santa Cruz). This may be done individually, in pairs, or in small groups. They can also read about these islands at the National Geographic Channel Galápagos micro-site.
As a class, discuss their responses.
(Optional) Show students the first hour of the National Geographic Channel Galápagos DVD. They should pay particular attention to the description of how the islands were formed and the differences between Fernandina, Isabela, Santa Cruz, and Española. How do these islands differ in terms of their vegetation and animal species? In what way does the age of each island relate to its animal and plant life? (Their answers should be similar to the information on the handout, which contains descriptions taken from the program.)
Closing:
Review what students have learned by posing these questions: How were the Galápagos Islands formed? What are some differences between the oldest and youngest islands?
Ask students to predict how each of the four islands they have focused on might change over time. For example, Española is now about 3.5 million years old. In a little less than two million years, Fernandina will be that old. Considering what students know about what Española is like today, what do they think Fernandina might be like at that time?
Suggested Student Assessment:
Ask students to imagine that they work for a tour company that takes visitors to the Galápagos Islands. Many visitors are curious about how the islands were formed and why they look different from each other today. Have students make brochures that could be given to visitors as they arrive on their tour boat. Brochures should include the following:
- a description of how the Galápagos Islands were formed; this should be at least one paragraph
- an illustration or map showing the process by which the Galápagos Islands were formed
- a description and comparison of the islands of Fernandina, Isabela, Santa Cruz, and Española (at least one paragraph each). Students can find more information about each island online at the International Galápagos Tour Operators Association: Info for Travelers.
Assessment rubric:
Rank each task 1-5 points:
Extending the Lesson:
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