Name ___________________ Date _____ Class ____ _

Physical Geography of East Asia and Southeast Asia

DiHerentiated Instruction

The Ring of Fire Volcanoes are not randomly distributed over Earth's surface. Most

are concentrated on the edges of continents, along island chains, or beneath the sea. More than half of the world's active volcanoes above sea level encircle the Pacific Ocean. They form a so-called "Ring of Fire." Geologists have developed a theory-called plate tectonics-to explain the locations of volcanoes. Each continent sits on one or more large bases called tectonic plates. As these plates move, the continents atop them move, an effect called continental drift. The rate of movement varies from just under 1 inch (2.3 em) to 7 inches (17 em) per year. That is too slow for people to notice, but over millions of years, this movement can have dramatic effects.

The movements of Earth's plates have shaped the surface of Earth. Sometimes the plates pull away from each other, and sometimes they collide. When continental plates collide, they push with tremendous force. This causes the land to rise and form mountains. Collisions of continental and oceanic plates produce a different result. The thinner ocean plate slides underneath the thicker continental plate. Earthquakes and volcanoes are common in areas where the collision of ocean and continental plates makes Earth's crust unstable.

Directions: On a separate sheet of paper, answer the following questions.

1. Identifying Name the tectonic plates of the Pacific Ring of Fire.

2. Explaining How does the theory of plate tectonics explain the formation of the Ring of Fire?

I]

KEY A Volcanoes

--- Plate boundary

Tectonic Plate Boundaries

-* Pacific Plate

A

,

" ,

Antarctic Plate 5

t~ , -' ,

41

_ .. ~, !eaching Strategies f~r Differ~nt Learning Styles

The following activities are ways the basic lesson can be modified to accommodate students' different learning styles.

English Learners (EL)

Have students name two types of geologic activity that occur as a result of plate tectonics [volcanic activity and earthquakes]. They should also identify and list any words in the article that they do not understand, and then look up the words in a dictionary and record the definitions.

Verbal/Linguistic; Intra personal Ask students to write a two- to three-page

report about Anak Krakatau: what it is, how it was formed, and what is happening there now.

Logical/Mathematical

The island of Java is almost entirely of volcanic origin. It has numerous volcanoes, 20 of which have been active in recent histori­cal times. Ask students to compile a table of Java's volcanoes; for each, they should list its name, elevation, and date of last eruption.

Kinesthetic

Ask students to create a model demonstrat­ing the moving plates in Earth's crust, and draw diagrams explaining plate movements and changes. Allow students to display their models in class.

Visual/Spatial

Subduction occurs when one tectonic plate is forced underneath another. Within the ocean, large trenches are formed through subduction. Trenches are the deepest parts of the seafloor, and many of the world's largest trenches are located along the Ring of Fire. Ask students to add the locations of at least five Pacific trenches to the map on the previ­ous page. Students also should indicate the maximum depth of each trench.

Advanced Learners

Ask students to expand on the informa­tion in the article by exploring some aspect of

42

the geology of the Ring of Fire. For example, students might discuss the various types of plate boundaries and their actions/results, or explain differences between plate-boundary and intraplate volcanoes.

Verbal/Linguistic; Interpersonal

The Ring of Fire got its name because it is a circular (ring-shaped) area where many fiery volcanoes are located. Ask students to pair with a classmate and spend five minutes gen­erating as many other colorful names for the region as they can, based on the information in the article. Have students share their names with the class.

Auditory/Musical; Visual/Spatial

The June 1991 eruption of Mount Pinatubo on the island of Luzon in the Philippines came after 500 years of dormancy. It produced one of the largest and most violent eruptions of the 1900s. Ask students to research the events surrounding the eruption. Then have them create a song or piece of art commemorating the event.

Logical/Mathematical Ask students to use library or Internet

resources to create a map of the Ring of Fire, indicating the locations of major volcanic eruptions and major earthquake activity over the past three decades. Students also should prepare brief reports comparing and contrast­ing the locations of volcanoes and earthquakes, and how these two phenomena might be related.

Below Grade Level

Students can represent many ideas in a concise manner by using the One-Sentence Summary strategy. Ask students to study the article and map closely, finding the main ideas. Then ask them to write a one-sentence summary of the information, in 25 words or less, based on the following model: The Ring of Fire was formed ...