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Slide A

Still Wondering...

Why do earthquakes get deeper in the Andes mountains in a line pattern, but are more spread out and shallow in the Himalayas?

Why are there a lot of volcanoes in the Andes mountains and very few in the Himalayas?

Himalayas

Andes

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Revisit Case Locations

Slide B

Is there information on any of these cards that help explain volcanoes?

Presence of Volcanoes

Other hot stuff

Review Case Site Cards to determine if any information is available to answer our questions. Display slide B. In groups, ask students to quickly revisit the case site locations to find any additional information that could help answer these two questions. In particular, have students make a table in their science notebooks and list the sites that have these features:

Presence of Volcanoes: Andes, Japan, Aleutians, Mexico, Iceland, Mid-Atlantic Ridge

Presence of other hot stuff: Mid-Atlantic Ridge (black smoker, thermal vents), Iceland (hot springs, geysers), Baikal (thermal vents)

Students might also have additional questions arise which they should record into their notebooks.

When they have their tables ready, ask students to share what they noticed looking across all the case sites. Record student ideas on a t-chart on the board or chart paper. Then ask students which of these things they have figured out. Say, Ok, so let’s review. We know in some places plates are colliding and in other places they are spreading away from one another. Let’s add arrows to represent these movements.

Have a discussion to review what was figured out in the last lesson, and what they still can’t fully explain. Part of this discussion is reviewing what is known, but should also make visible some key features at the case locations that still have lingering questions.

Use this discussion to motivate students to want to know more about how volcanoes form in different places. Students should have some ideas from Lessons 6 and 8, and this lesson will build upon those ideas, with a particular emphasis on volcanoes where plates are colliding.

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Obtain Information from Videos and Animations

Slide C

In your notebook: As you watch the videos and animations, record noticings and wonderings in you science notebook.

What I notice

What I wonder

Watch Video #1.

Watch a Series of Animations.

Present information that scientists have put forth to explain volcanoes. Tell students, Scientists have been studying the plates and volcanoes for awhile now, and they have developed some ideas for how mountains and volcanoes form in different ways. We are going to watch and read about this and see if this is consistent with some of the data we have seen so far. Display slide C.

Create a Notice and Wonder chart to track initial noticings and questions. Ask students to create a Notice and Wonder chart in their science notebooks. It will be used for three sources of information, so it will need a third column to track the sources. Tell students they will first watch a dramatic video, then you will show them an animation by a scientist, and then finally they will do a short reading. They should track their noticings and wonderings across these sources of information.✱

Play the first video. Navigate to the dramatic video. Tell students that this is a dramatic version of what scientists think causes some volcanoes to form in some places and remind them that the speed of movement on the video is the course of millions of years (reference Lesson 7 if needed). Consider playing the two-minute video twice to give students time to notice new things in the video. Then pause to let students write their ideas. This first resource should take about five minutes to watch once or twice and write.

Play the animations. Navigate to the animations. Orient students to the animation. There are four options at the top: Continental Rift Volcanism (African Rift Valley, Baikal Rift Valley), Continental Volcanic Arc (Andes, Mexico), Hotspot Volcanoes (Hawai’i - this is not included in this unit), and Island Arc volcanism (Japan, Aleutians). Do not play the Continental Rift Volcanism or Hotspot Volcanoes for this activity.

Begin with the “Continental Volcanic Arc” button. Ask students what they noticed about the different plates on the animation and which locations this might help explain. Students should notice a continent and an ocean - which is the same as the Andes mountains and Mexico. Have students watch the animation one or two times closely.

Then move to the “Volcanic-island-arc” button. Ask students what they notice is different about this animation (e.g., there are two ocean plates). Ask students if they know which location this helps us explain (e.g., Japan, Aleutians). Students might also say Iceland and the Azores, but when the animation plays, the movement of the plates in the animation is toward one another, which rules out Iceland and the Azores, since plates are moving away from one another in those sites. Allow students to watch the animation one or two times and track noticings and wonderings.

Total time to play animations and write on their Notice and Wonder chart is about five minutes.

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Why do volcanoes form in some places?

Slide D

Close Reading

Identify the question(s) you are trying to answer in the reading.
Read once for understanding to see what the reading is about.
Read a second time to highlight a few key ideas that help answer the questions posed in the reading.
Using key ideas from the reading, draw and write new ideas on the diagram at the end.
Track noticings and wonderings into your science notebook.

Use the strategies below as you read the text.

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Building Understanding: Volcano Formation

Slide E

Draw visual representations of what you think is happening.
Write words to explain how volcanoes form.
Cite evidence from the video, animations, and the reading.
Note areas where the group agrees and disagrees.
Be ready to share with the class.

In your groups, draw and write your shared ideas for “Why do volcanoes form in some places?”

In groups, students write and draw new ideas to answer the question, Why do volcanoes form in some places? They can pull information from the video, animations, and readings to draw and write their ideas in small groups of two to four students. Display slide E to guide their work in groups. Tell students they should be ready to share their new ideas with the whole class.

Recall the sources of information from the previous class. Ask one or two students to recall the sources of information they used in the previous class to answer the question, “Why do volcanoes form in some places?” Students should remember consulting several sources: a video, two animations, and a reading.

Facilitate a Building Understandings Discussion.✱ Using a chart labeled “Why do volcanoes form in some places?” to anchor the discussion, begin to ask students for their ideas and track them onto the chart. It might be helpful to replicate the cross-section diagram at the end of the handout, although students will have additional ideas beyond the continental-ocean collision represented in that diagram.

Elicit ideas from different groups and ask for students to volunteer to draw or write an idea on the shared classroom chart. Press students to cite evidence from one of the sources to help support the thinking from their group. Here are some sample questions and possible ways to follow-up with students.

Tell students that the class will revisit this chart later, but right now they will look for more evidence to support this theory. Ask students, Have you seen any other evidence that could help support this theory of volcano formation?

Students may or may not say something about how the heavier plate going back down into the mantle matches the pattern of earthquakes at the Andes and in Japan. Students will have studied these cross-sections in the context of earthquake patterns, but may not connect this as a source of evidence for why volcanoes form. If they do not, it is OK for you to offer that noticing to the students.

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More evidence?

Slide F

Does this pattern tell us anything?

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Using Seismic Explorer to observe earthquake depth

Slide G

https://tinyurl.com/SEVersion4

Revisit the “Volcanoes” and “Other Hot Stuff” table from Day 1. Ask students to turn in their notebook to the table from Day 1 where they visited the case site locations and tracked which ones had volcanoes and which ones had other hot features. Ask students to circle the places where two plates are colliding and one is possibly sinking below the other.

Then tell students they will use Seismic Explorer one more time to see if the earthquake data matched their thinking about places that a) have volcanoes and b) we think a plate might be sinking below another plate there.

In groups, explore Seismic Explorer using the cross-section tool. Students will have used the cross-section tool in Lesson 4, but quickly remind them of how it is used again. Display slide G. Then open Seismic Explorer, Version 4. While projecting the main screen, negotiate with students an interesting area to demonstrate the cross section tool:

Display the relief map as the “Map Type.”
Zoom into one case site on the map.
Run the default earthquake mapping tool (1980-2019, magnitudes 0-10, earthquake data). Ask students to articulate what the tool is showing. This should be familiar from previous lessons.
Then, click “Draw Cross Section” and click and drag to specify the area you will examine in cross section. Explain to students that we will be able to look at the depth of the earthquakes that have occurred in the area selected.
Finally, click “Open 3D Model.” Ask students to articulate what the tool is showing. Listen for answers such as:

This shows a side view, or cross sectional view, of the area we selected.
It’s similar to the models we constructed of Earth’s crustal plates.
In this way, we can see the same earthquakes we saw from a bird’s-eye view, but can now also see their depths.

Students investigate site locations. Hand out Volcanoes and Earthquakes: Case Site Analysis. Groups should visit each site location where volcanoes exist and two plates are colliding and one might be sinking. Then groups will record evidence from Seismic Explorer onto the handout.✱ Encourage students to study the earthquake depth patterns and see if it serves as evidence for how scientists think volcanoes forms.✱

When students have completed their analysis of the cross-section data in Seismic Explorer, ask them to answer the following question on their handout, “How does studying earthquake activity data help us understand why volcanoes form in some places and not in others?” If time allows, ask a student or two to share their thinking. Listen for ideas about:

Earthquakes happen when plates bump into each other, so for earthquakes to happen that deep, it must mean one is going under the other.
The pattern shows that earthquakes get deeper in a line and that matches what scientists think about a plate going under another plate.

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Consensus Discussion

Slide H

The goal of this discussion is to develop a model together to explain why volcanoes form in some places. Our discussion is guided by these questions:

What question are we trying to answer?
What information and data do we have?
What do we all seem to agree on?
What do we disagree on?
What are some new ideas that we may want to consider?

Facilitate a Consensus Discussion.✱ Display slide H and talk through the norms on the slide. Then, ask students to create a three-column Progress Tracker in their science notebooks. Likewise, display the previous chart labeled “Why do volcanoes form in some places?” at the front of the room. Ask students to write in the question we have been trying to answer: Why do volcanoes form in some places?

Ask students to recollect the sources of information and data we have worked with as a class to answer this question. These sources include: a video, animations, a reading, and earthquake data.

Elicit ideas from students what we figured out as a class. Ask students to share words and pictures, and let students come to the chart to draw and write their ideas. These ideas might include:

One plate is heavier than another plate.
One plate sinking below another plate.
The sinking plate is melting and causing magma and gas to push through the crust to the surface (underneath the lighter plate above).
Cracks and openings in thin parts of the plate also allow magma to push through forming volcanoes and/or new crust.
Earthquakes get deeper as one crust sinks under another crust.

Allow time for students to not only draw and write on the shared Progress Tracker, but also on the one in their notebooks.

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Himalayas and Andes

Slide I

Exit Ticket

How are the Himalayas mountains and the Andes mountains similar? How are they different?