- Open the lesson by asking students what, if anything, they already know about volcanoes. (Answers will vary, may include knowledge about mountains, lava, explosions.)
- Explain to students that a volcano is an opening in the earth’s surface, which allows liquid rock, ash, and gases to escape from inside the earth. Tell students that when these materials come out of a volcano, often unexpectedly and at high speeds, it is called an eruption.
- Distribute the Volcanic Vocabulary organizer (PDF) (RTF), and tell students that you are going to discuss what makes volcanoes erupt. Give students a visual aid by drawing a simple picture of a volcano in the board, or projecting one on the screen. (A simple cross-section of a volcano can be found here: http://www.kidcyber.com.au/IMAGES/volcanoXjup1.jpg.) As you review the vocabulary terms, point them out on the image of the volcano.
- Explain that the solid ground that we stand on is called the Earth’s crust, and underneath the crust is a layer called the mantle, which is made up of liquid, or molten, rock called magma. Volcanoes erupt when the magma escapes through the crust. Explain that when it is underground the molten rock is called magma, when it is above ground it is called lava. Write the definitions of crust, mantle, magma, and lava on the chart paper or chalkboard/whiteboard, and label them on your volcano image (if they are not labeled already). Ask students to fill in the definitions on their organizer. Answers can be found on the Volcanic Vocabulary Terms and Definitions Answer Key (PDF) (RTF).
- How does the magma escape from the crust? Divide the class into groups of 3 or 4 students. Tell students that they are going to create a model of Earth using a boiled egg. Before distributing eggs to the group, demonstrate what they will be doing. Take a medium-boiled egg and roll it gently on a paper towel, so that the shell cracks but does not break off. Distribute 1 egg and paper towels to each group. Ask each group to roll their egg gently on a paper towel to crack the shell. Explain that the broken eggshell is like Earth’s crust – it is not one solid piece, instead it is broken up into smaller chunks called plates. Write the definition of plates on the chart paper or chalkboard/whiteboard, and ask students to fill in the definition on their organizer.
- Ask each group to GENTLY squeeze their egg. They should see some movement in the pieces of the eggshell. Explain that the Earth’s plates are in motion – they float on top of the liquid mantle. Now ask students to squeeze the egg harder. They should notice some material oozing out of the cracks. (For this part of the activity, it’s all right if the students make a mess!) Explain that on Earth, sometimes when the plates move magma escapes from between the cracks, and causes a volcanic eruption.
- Have students clean up and wash their hands if necessary.
Learning Activity 1:
- Ask students if they know where Hawaii is located. If they say yes, ask one of them to point it out on a map for the class; if they don’t know, point it out for them. (A world map is recommended for this activity rather than a U.S. map, to accurately reflect Hawaii’s location.) Tell students that while Hawaii is often thought of as an island paradise, it is also home to some of the most active volcanoes on Earth.
- Tell students that they are going to watch a video clip about a volcano in Hawaii. FRAME the clip by explaining that the Kilauea volcano has been erupting ever since 1983, and it is an attraction for both tourists and scientists studying its activity. Give students a FOCUS by asking them to look and listen for three characteristics of volcanoes – how they look, sound, act, etc. PLAY the “Volcanic Views” clip. FOLLOW UP by asking students to share their answers with the class. (Answers may include: smoky, loud, tall, hot, produce a lot of lava, etc.) (Access the video segments for this lesson at the Video Segments Page.)
- Review the new vocabulary terms from the clip. As in the introductory activity, write them on chart paper or the chalkboard/whiteboard as you define them, and ask students to fill in the definitions on their organizers.
- Vent: the opening through which volcanic material comes out
- Crater: a large hole formed by an explosion or collapse of a volcanic vent
- Lava Lake: pool of molten lava contained inside a vent or crater4.Explain that the volcanoes on Hawaii are different than many of the volcanoes around the world, since they do not occur at the cracks, or boundaries, between the plates. Hawaii’s volcanic activity is due to a hotspot.
4. Explain that hotspots occur when magma pushes through the middle of a plate, not in the cracks between plates, as if a hole was poked through the shell of an uncooked egg and liquid oozed out. (Demonstrate on an uncooked egg for the class, if desired.) Write hotspot on a piece of chart paper or the chalkboard/whiteboard, along with its definition, and ask students to fill in the definition on their organizers.
Learning Activity 2:
- Ask your students if they think that volcanoes can change the way the Earth looks. (Yes.) Based on what they already know about volcanoes, what might cause the changes? (Lava, ash, explosions.) Explain that when the hot lava stops flowing and cools, it can create rocks or new land that looks very different from the original landscape, and that volcanic activity is responsible for shaping much of how the earth looks today.
- Tell students that they are going to see a video demonstrating how lava has affected the land in Hawaii. FRAME the clip by telling students that the lava flows from Kilauea and other volcanoes have been making changes to Hawaii’s landscape for thousands of years. (Access the video segments for this lesson at the Video Segments Page.) Distribute the Lava Landscapes Organizer (PDF) (RTF) to each student. Ask one of your students to read the first question on the organizer aloud: “Is lava a force of destruction or creation?” Provide a FOCUS for watching the clip by asking your students to consider this question as they watch the clip. PLAY the “Lava Landscapes” clip. FOLLOW UP by asking for student responses to the focus question. (Answer: lava is both destructive and creative.) Go through questions 2 – 4 on the Lava Landscapes organizer and answering them as a class. Replay the clip if necessary.
- Ask students what, if anything, can stop the flow of lava? (Answers may vary.) Tell students that in Hawaii, the flow of lava can be stopped by the ocean.
- FRAME the next clip by telling students that even though lava is cooled by the ocean, there is still some activity once the lava makes contact with the water. Give students a FOCUS by asking them to think about what lava does once it meets the water that it does not do on land. Play the “Steamy Seas” Clip. (Access the video segments for this lesson at the Video Segments Page.) FOLLOW UP by asking students for their responses. (Cause explosions, create steam.) Go through the remaining questions on the Lava Landscapes organizer and answer them as a class. Replay the clip if necessary.
- Remind students that even though they only saw videos of a volcano in Hawaii, there are more volcanoes in Hawaii and all over the world. Ask students if they know of any other places in the world where there are volcanoes, and to indicate where those volcanoes are on a world map with either pushpins or small sticky notes. (Accept all answers.)
- Project the Decade Volcano Map on a screen for the class. Explain to your students that these volcanoes have been chosen for study because of their activity, and the fact that they are close to populated areas. By being designated as Decade Volcanoes, scientists and the public can work together to be prepared for a potential eruption.
- Look at the map together as a class. Ask students the following questions, and click on the volcano that they choose as an answer. View the picture of the chosen volcano and invite student comments. As you review each volcano, ask a student to mark it on the world map with a pushpin or sticky note.
- Which volcanoes are on or near the Pacific Ocean? (Avachinsky-Koryaksky, Mt. Unzen, Sakurajima, Taal, Merapi, Ulawun, Mt. Ranier, Colima, Santa Maria, Galeras) Since there are many volcanoes, choose 2 or 3 to click on and look at.
- Which volcano on this map is located in Hawaii? (Mauna Loa)
- Which volcanoes are located in Europe?. (Vesuvius, Mt. Etna, Santorini)
- Which volcano is located in Africa? (Nyiragongo)
- Which volcanoes are located in the United States? (Mt. Rainier, Mauna Loa)
4. Point out to students that the majority of volcanoes on the map are on or near the coasts of the Pacific Ocean. Project the WorldAtlas.com Ring of Fire map onto a screen for the whole class. Explain that more than half of the world’s active volcanoes are in this “ring” that circles the Pacific Ocean. Explain that this has to do with the boundaries, or spaces, between continental plates. As students should remember from the egg demonstration, when the plates push up against each other or move away from each other, sometimes lava will come up to the surface and through the cracks between plates. Ask students if they can name some of the countries that contain volcanoes in the Ring of Fire. (Answers can include: U.S., Canada, Indonesia, Japan, Mexico, Philippines, Russia, New Zealand, Chile, Mariana Islands, Tonga.) Ask students to mark these countries with pushpins or sticky notes on the world map.