Tell your class that for the next few days they will be learning about volcanoes. Explain that, unlike many other geological processes, volcanic eruptions are sudden and dramatic rather than slow and steady.  Give your students some examples of catastrophic volcanic eruptions, such as:

• Mount Tambora, Indonesia: erupted in 1815 and killed approximately 92,000 people
• Mount Pinatuba, the Philippines: erupted June 1991 after being dormant for 635 years
• Mount St. Helens, Washington, USA: erupted violently in May 1980. Ask students if they know anything about these or other volcanic eruptions in history (Accept all answers).

Tell students that they are going to see a demonstration of a volcano.Place the model “volcano” in a central location in the classroom. Ask the students if they have ever seen a demonstration like this before.(Many of them are likely to have seen this demonstration when they were younger.)Ask the students to predict what you will do to make the volcano “erupt.”(Accept all answers.)Ask them to pay careful attention to the sights, sounds, and smells of the “eruption” and to record detailed observations in their notebooks.

Demonstrate the eruption with the materials prepared prior to the lesson.Slowly pour the vinegar solution into the “volcano.” It will not erupt like a real volcano, but should bubble violently over the top of the jar.Give students a few minutes to record their observations. Ask the students to explain why the volcano “erupted." (Chemical reaction of the vinegar solution and baking soda.) Ask if they think this demonstration accurately simulated the look, feel, and smell of an erupting volcano, as well as the processes that cause real volcanoes to erupt.(No – a real volcano would produce heat, the lava would be bright, it might smell smoky or like sulfur. The processes would also be MUCH different – instead of a chemical reaction from adding an external solution, real volcanoes erupt because of internal processes in the Earth.)

Tell students they will now watch a video segment of an actual volcanic eruption. Provide students with a focus for media interacion by asking them to observe the characteristics of the eruption and record their observations in their notebooks, alongside or below their observations about the simulated volcano. Play the A Land Born in Fire QuickTime Video. When the segment is finished, give students a few minutes to finish writing their observations.

Lead the class in a discussion contrasting the two eruptions, based on the observations they recorded in their notebooks. Some questions to ask are:

• What differences did you observe between the simulated volcano and the actual volcano in the video?(Simulation had bubbles instead of lava; there was no heat or pressure involved in the simulation; no blast; consistency of lava was different; lava flow in the simulated volcano did not cool and harden to form surface features; etc.)
• Based on what you observed from the video, what do you think you might see, hear, and smell near a real erupting volcano? (Flowing lava, spewing ash, rumbling, landslides, falling rocks, smoke, ground and buildings shaking)
• What are some of the consequences of volcanic eruptions? How might an eruption change the area surrounding the volcano? (Lava cools and creates new surface features, changes landscape, starts fires, etc.)
• What can scientists tell from the lava at different eruption sites? (Temperature based on color and brightness, how and when the lava was formed, some information about patterns of eruption)

Tell students that, as they saw in the video segment, volcanoes occur when magma, which is molten rock beneath the Earth’s surface, erupts through openings in the crust. Once the magma has reached the surface, it is called lava. Open the Virtual Volcano interactive Web site and display on a screen for the class. Click “Enter” to enter the site, and then click the “Inside a volcano” link on the left side navigation menu. Walk students through the different features of the volcano.

Explain that while the basic process by which volcanoes erupt is the same for all volcanoes, not all volcanoes are the same. Divide the class into pairs or groups, with each pair/group at their own computer. Direct pairs/groups to the Virtual Volcano Web site and ask them to click on the "Volcano types” link in the left side navigation menu. Ask students to read about the three types of volcanoes listed: Stratovolcano, Cinder Cone, and Shield. Give students a focus for media interacion by asking them to note the distinguishing features of each type of volcano, including how they are formed, what they look like, and examples. Distribute the Volcano Types Organizer for students to record their observations. Give students 5-10 minutes to complete the activity. When students have finished, check for comprehension by asking students to share their answers with the class.

Ask students, based on the information they now have about volcano types, what factors they think might contribute to creating different types of volcanoes and eruptions?(Lava consistency/viscosity, lava cooling, force of eruption, location) Ask students to click on the “Build your own volcano and watch it erupt” link, and visit that section of the Web site on the class computer as well. Point out that the viscosity and gas levels of magma contribute greatly to the type of volcano that will be formed.

Tell students you would now like them to complete the activity and build their own volcanoes. Give students a focus for media interaction by asking them to try and create at least one of each type of volcano by adjusting the viscosity and gas settings. Students should record the settings and type of eruption that results on their organizers. Tell students that there is also a fourth type of volcano that can be created; if they find it, they should fill in its information on the Volcano Types organizer. Give students 5-10 minutes to complete the activity.

When students have finished, check for comprehension by reviewing the new answers on the organizer. Ask students how they created the different volcano types. Ask if anyone found the fourth type of volcano, and what it is (Lava dome). Review the information about lava domes.

Ask students to name the three different types of plate boundaries (convergent, divergent, transform). If students need a primer or refresher on plate boundaries, ask them to visit the Plates & Boundaries section of Dynamic Earth and read the information on the first page.

Explain to students that the movement of the continental and oceanic plates form “zones of volcanism.” The first zone of volcanism occurs at convergent boundaries. Project the Slip, Slide, Collide section of the Dynamic Earth interactive for the whole class. Display the first picture on the Convergent Boundary page. Explain to students that a “subduction zone” is formed when a thinner oceanic plate collides with a thicker, sturdier continental plate. The oceanic crust is then pulled under the continental crust. This process is called subduction. As the oceanic crust is forced deeper into the earth, high heat and pressure melt the rock and form magma. Scroll to the bottom picture and explain that a Convergent Boundary zone of volcanism can also occur when two continental plates collide. Click through to the next page, which focuses on Divergent Boundaries. Play the animation of diverging plates, and explain that as plates move away from each other, volcanoes form from the magma that flows into the rift area. Explain that there is a third zone of volcanism that does not occur at a plate boundary. Hotspots, or intraplate volcanism, occur when a stationary plume of magma breaks through a tectonic plate to form a volcano.

Tell students that this movement of plates and the subsequent volcanic activity often leads to new surface features on the Earth. For example, without the action of volcanoes, many mountains and islands would not exist. Explain that hotspots are responsible for creating many island chains around the globe. Ask students if they can think of an example of this kind of island chain (Hawaii). Tell students that there are several hotspot island chains around the world, and point out examples on a world map (Tahiti, Galapagos, Easter, Pitcairn). Explain that these island chains are created when a plate moves over a hotspot, and volcanoes are formed in a line that follows the plate’s movement.

Tell students that they’ll be watching two video segments about hotspot island formation in Hawaii. Distribute the Hawaiian Islands Organizer to students. Provide students with a focus for media interacion by asking them to look for the factors that contribute to the formation of the new island. Play How to Build an Island from Scratch QuickTime Video and Creating an Island Paradise QuickTime Video segments. Give students a few minutes to record their answers. Replay the segments, if necessary. Check for comprehension by reviewing answers with the class.

Tell students that many of the world’s volcanoes are located around the edge of the Pacific Ocean, where many plate boundaries are located, and this region is sometimes called the “Ring of Fire." Ask students to locate the Ring of Fire on a world map.

Display Plate Tectonics Map on a large screen to the entire class, or print copies and distribute to each student. Ask students to name the countries in the Ring of Fire.(U.S., Canada, Indonesia, Japan, Mexico, Philippines, Russia, New Zealand, Chile, Mariana Islands, Tonga). Ask students to point out the plate boundaries at which volcanoes most frequently occur, based on the active volcanoes shown on the map (Eurasian, Indo-Australian, North American, Cocos, Nazca, Pacific, Arabian, African, South American, Antarctic). Students may refer to page 5 of the Earth Science Reference Tables for the names of the plates.

Ask students, based on the occurrence of volcanoes on the map, at which type of boundary volcanoes most frequently occur. (At convergent boundaries.) Ask students to point out any volcanoes on the map that occur at other boundaries or zones of volcanism. (Many at the Divergent boundary of the Arabian and Indo-Australian plates, hotspots in the middle of the Pacific plate, on the North American Plate, on the Arabian Plate, on the Nazca plate.  There is also a hotspot on the Mid-Atlantic Ridge, at the boundary of the North American and Eurasian Plates.) Students may once again refer to the Earth Science Reference Tables for the types of boundaries between the plates, if necessary.

Instruct students to go to the Earth’s Plates interactive. Divide the class into groups of 3 – 4 students and assign one case study to each group (there will most likely be doubles among the groups). Distribute the Case Study Organizer to each student. Provide students with a focus for media interacion by asking students to read the information in their case study and use the information given as well as their knowledge of zones of volcanism to locate their volcano on the map. Ask students to record the details of their case study on the Case Study Organizer. Give students 5-10 minutes to complete the activity. Review answers with the class. As each group presents its findings, encourage other groups to fill in all information for the other Case Studies on their organizer. If desired, the groups can learn more information about the other volcanoes on the map by clicking on the “Read About all the Volcanoes” link, and completing the organizer for the remaining four volcanoes on the list.

By this time students should be familiar with many causes and effects of volcanic eruptions. Explain that while scientists are working on ways to predict volcanic eruptions, they are not always entirely accurate. Tell the class that they will be looking at a Web site interactive from the U.S. Geological Survey that uses data from eruptive episodes of Mt. St. Helens to demonstrate methods of predicting eruptions. Go to the Predicting Volcanic Eruptions Web site and choose the appropriate screen size for your computer.

Go to the “Ground Deformation” section of the interactive by clicking the link on the left menu bar. Give students a focus for media interacion by asking them to notice the three factors considered by USGS scientists in predicting volcanic eruptions. Read or call on students to read each of the three paragraphs on the first page of the Ground Deformation section. Once the paragraphs have been read, check for comprehension by asking students to name the three factors. (New faults or thrust faults, ground tilt, and earthquakes). If desired, roll over the pictures to give students more information and a better understanding of the factors leading up to eruption.

Divide the class into pairs or groups, with each pair or group using their own computer. Distribute the Predicting Volcanic Eruptions Organizer to each student. Instruct pairs/groups to read and watch the animations on the remaining pages of the Ground Deformation section. Provide students with a focus for media interacion by asking them to observe how the data found is analyzed by scientists. Students can record their answers on the organizer. Give pairs/groups 10-15 minutes to complete the interactive and fill in their answers.Review answers with the class.

Tell the pairs/groups that they will now have the chance to analyze the data surrounding volcanic eruptions themselves. Direct students to click on the “Exercise” link in the left toolbar. Give students a focus for media interacion by asking them to carefully read and review the information presented on pages 1-3, and then use that information to make predictions and choose their actions on pages 4-6.

For a related homework assignment, students can visit either the Kilauea or Mt. St. Helens section of the interactive and view the data surrounding the eruptions. Students can use this information to write a short (1-2 page) paper describing the factors that indicated that these volcanoes were going to erupt.