Gilligan’s and Other Islands

Subject: Geography

Grade(s): 4-6

Coney Island, Treasure Island, Gilligan’s Island: While these may be some of the most imaginative islands ever created in the world, there are also hundreds of fascinating real islands in the world — from the island continent of Australia to the island nation of Great Britain to the island state of Hawaii. In this lesson, students are introduced to the subject of islands around the world and discover two main ways in which islands developed over millions of years. They then create a presentation about six specific islands of the world.

Students will:
· Understand the definition of an island.
· Learn at least two different ways in which islands are formed.
· Understand an archipelago
· Discover how plant and animal species develop on an island.

National Geography Standards
Standard 4:
The physical and human characteristics of places.
Standard 7: The physical processes that shape the patterns of earth’s surfaces.

Materials Needed
· Gillian’s and Other Islands Challenge Cards from WorldTeasers: World Culture & Geography
· Map of Great Britain, Europe, and Ireland
· Map of southeastern coast of Africa

Getting Started
Begin by asking students if they can think of one thing that Australia, Great Britain, and Hawaii all have common geographically. (They are all three completely surrounded by water.) Ask students what we call an area of land, such as Australia or Hawaii, that is completely surrounded by water. (An island.) Ask students if they can name any other islands (e.g., Martha’s Vineyard, Puerto Rico, Greenland). Has anyone ever visited an island? If so, what was it like? Give students a chance to tell what they know about islands. Then, tell students that in this lesson they will learn about some of the many different islands of the world and will also learn two different ways in which islands are formed.

Show students a map of Great Britain and Europe. Ask a volunteer to locate and point out the country of Great Britain. Is Great Britain an island? (Yes.) Where is it located? (Between the country of Ireland and mainland Europe.)

Tell students that at one time — thousands of years ago — Great Britain was joined to both Ireland and what is now northeastern France in Europe. Then ask student what they think might have happened. How do they think Great Britain became an island? Write their answers on the chalkboard. Tell students that the island of Great Britain was formed when sea levels rose, separating a section of land (now known as known as Great Britain) from the mainland. This happened when the heavy weight of glacial ice caused part of the earth’s crust to sink. Geologists call this isostatic depression.

Isostatic depression is one way in which islands have been created over millions of years. Can students think of another way? Show students a map of African and Madagascar. Ask a volunteer to point to the island nation of Madagascar. Tell students that Madagascar is the 4th largest island in the world. It used to be connected to the continent of Africa. Explain that over the years, erosion caused one part of the land to break off from the continent of Africa, forming the island of Madagascar.

Tell students that Great Britain and Madagascar are two examples of continental islands. Can they think of other island nations that are examples of continental islands? (Sicily off Europe; Greenland off North America; Barbados and Trinidad off South America.)

A second type of islands is called oceanic islands or volcanic islands. These islands develop as a result of the activity of undersea volcanoes. For example, an undersea volcano erupts and over time layers of lava eventually emerge above the surface of the ocean. Iceland is the largest volcanic island in the world. Can students think of other volcanic islands? (The Hawaiian Islands) Tell students that the Hawaiian Islands is also an example of an archipelago — a chain or cluster of islands.

Divide the class into six groups to research and report back to the class on one particular island of the world and how it was formed. For their reports, be sure each group includes: Name of Island, Location, Size, Type of Island, How It Was Formed. A list of islands of the world grouped by oceans and continents can be found at
(Or distribute at random one of the six WorldTeaser Challenge Cards titled Gilligan’s and Other Islands, which challenge students with a fascinating fact about each of six different islands: Bermuda, Aruba, Cyprus, Howland Island, Jersey, and Puerto Rico. Have student groups research the formation of these six islands.)

Based on what they have learned, ask students if they think new islands will be formed on earth in the future? Why or why not? Tell students that, in fact, the newest island to form on earth actually developed only about 45 years ago. The island is called Surtsey. Assign a group of students to research Surtsey, including type of island (oceanic island), when it first emerged (1963), and when plants and animals first appeared on the island.

Extension: Island Vocabulary
Have students write a brief definition of each of thee words associated with islands.
coral reef,
plate tectonics
sea level

Discussion Questions
What are some of the ways that plants and animals may have gotten to new islands? Are those ways different for oceanic or volcanic islands as opposed to continental islands? (Yes, generally species on continentals were already there when the island separated from the mainland. Species on oceanic islands got there through wind or rain or the ocean’s currents.) Suppose that a piece of the state of Washington broke off and became an island. What kind of plants and animals might you expect to find on that island? What if a piece of Maine broke off and became an island. What kind of plants and animals do you think you would find there?

Next Week: Idioms

Source: WorldTeasers: World Culture and Geography — An educational game designed to help upper elementary grade students supersize their global knowledge with fascinating, intriguing, and amusing trivia about countries and their culture. Grades 4 +. Available at

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