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Earthquakes and Volcanoes Lesson 3
Types of Magma and Eruptions
ESOL adaptations in italics
ESOL revisions are underlined
Rationale: Tectonic activity in Earth’s crust results in seismic events all over the world,
including the western United States. By learning about seismic events such as
earthquakes, tsunamis, volcanoes, and their underlying causes, students become more
informed of the impacts that these events may have on their lives in the present and
future.
This lesson builds on the previous lesson, which highlighted tectonic activity as the
underlying cause of volcanoes. Content on this lesson may also build upon students’ prior
knowledge of and experience with volcanoes. The point of this lesson is to link students’
prior knowledge of plate tectonics and general volcano formation to new knowledge
about the types of magma released at eruption points and the varying eruptions that
different types of magma can cause. Students will participate in demonstrations, reading,
and discussion in order to visualize and process this new content. Watching and
participating in demos will ideally increase student interest and allow visual learners to
“see” the difference between magmas of different viscosities. This visualization will help
students to comprehend and explain why different magmas result in different types of
volcanic eruptions. Reading and discussion in addition to demos will hopefully help
students process the material more deeply, as they are reading, seeing, and speaking
about the content. Discussion also facilitates peer to peer learning experiences, which can
often be more meaningful than teacher-student experiences.
Lesson Objective:
• Students will be able to identify the differences in viscosity between various
magmas and predict which type of eruption each will cause.
o Student-friendly version: I can identify different types of magma and
predict which types of eruptions they will cause.
• Students will be able to discuss the differences between magmas and explain why
they result in different types of eruptions.
o Student-friendly version: I can use adjectives to discuss the differences
between different magmas and use words like “because”, “therefore”,
“however”, and “whereas” to explain why they cause different types of
eruptions.
• Key vocabulary: viscosity, basaltic magma, granitic magma, andesitic magma,
tephra
Lesson Assessment:
• Peer to peer discussion: students will read p.341-343 in the textbook and discuss
answers to the following questions with a partner: “Some eruptions are quiet and
some are violent. What causes this difference? Compare and contrast the different
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types of lava. Which types are more viscous?” The teacher will provide the class
with possible sentence frames and sentence starters to help all students practice
writing answers in complete sentences. Frames will include “Quiet eruptions are
caused by ________, but/however/whereas violent/loud eruptions are caused
by_____” and “_____lava is ______” and “____eruptions are caused by ______
because _____”. Pairs will record their answers. The teacher will circulate to
listen in on student discussion and make clarifications. Formative assessment.
Not graded.
• Class discussion: After peer discussion, the teacher will pose questions to the
class as a whole to probe student understanding. She will ask students to elaborate
on their answers when necessary. She will ask students whether they agree or
disagree with their peers’ responses and why to gauge collective understanding
and reasoning. Formative assessment. Not graded.
• Students who are limited in English may rely on the bilingual academic aid in the
classroom to translate/interpret questions and directions. The teacher will
challenge these students to practice their speaking skills in both small group and
class-wide discussion.
Standards:
• MS-ESS2-2: Construct an explanation based on evidence for how geosciences
processes have changed Earth at varying time and spatial scales.
• Related Crosscutting concepts
o Cause and effect relationships may be used to predict phenomena in
natural or designed systems. (MS-ESS3-1),(MS-ESS3-4)
Time: one class period (49 min.)
Materials:
• Lesson objectives and needed materials (pencils & paper) written on the board
• Lesson topic written on week outline board
• Sentence starters and reading/writing activity directions written on board
• Clear cup halfway filled with water
• Clear cup halfway filled with molasses
• Clear cup halfway filled with natural peanut butter
• Plastic straws (3)
• Bottle of Sprite
• Plastic bin
• Teacher’s science spiral
• Printout of vocabulary words and definitions (3)
• Images of divergent plate boundary volcanoes, subduction zone volcanoes, hot
spot
Beginning of Lesson (5-7 min)
At the beginning of class, the teacher will announce that class has begun and that
everyone should be in their assigned seats with voices off. Students who are not
immediately ready will be called out by name.
• The teacher will direct attention to the week outline board and remind students
that the day’s topic is types of magma and eruptions. She will direct student
attention to the objectives on the board and inform them of the activity for the
day.
• The teacher will inform students that they are going to quickly review the
previous day’s lesson before moving on. She will display images of volcanoes
forming at divergent plate boundaries, subduction zones, and hot spots
consecutively. With each new image, she will ask students to describe what is
happening in the picture and why this tectonic activity results in volcanoes. The
teacher will instruct students to pair-share for 30 seconds and then call on
students at random share their thoughts with the class. She will also ask
volunteers to add/corroborate what the called-on student has already said.
Middle of Lesson (40 min)
• The teacher will ask volunteers to help pass back vocabulary and notes from the
previous lesson. While papers are being passed back, the teacher will ask students
if they’ve ever experienced being near to a volcano. If students are not sure, she
will list volcanoes nearby, such as the Three Sisters, Broken Top, Mt. Hood,
Crater Lake, Shasta, Mt. Bachelor, Lava Butte, Three Fingered Jack, Black Butte.
She may also list famous volcanoes in Mexico:
http://upload.wikimedia.org/wikipedia/commons/a/ae/Map_mexico_volcanoes.gif
• Before moving into the demos, the teacher will inform the class that there will be
new vocabulary in this lesson and will ask students to write down vocabulary
words. These may be written on a new sheet or added to the sheet that was just
passed back from the previous lesson.
• The teacher will write down each vocabulary word and its definition in her
science spiral and display it on the document camera as she writes. Students will
copy words and definitions on their own papers. She will read the definition aloud
as she writes. Students who are not able to keep up with her writing pace may
copy from extra printouts of the vocabulary definitions.
• Next, the teacher will inform the class that volcanic eruptions are controlled by
two factors: the amount of water vapor and other gasses trapped in the magma,
and the viscosity of the magma. She will demo the results of gas buildup using the
bottle of Sprite, noting that the CO2 in the drink is dissolved in the liquid and
isn’t visible. When the bottle is initially opened, there is a soft hiss, but no liquid
comes out. This simulates a quiet eruption. When she closes the bottle and shakes
it, more gas is released from the liquid, which builds up pressure. When she opens
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the bottle again (over the plastic bin) liquid escapes along with the gas, simulating
an explosive eruption.
• The second controlling factor is magma viscosity. The teacher will ask a student
to read the definition of viscosity to the class. To demonstrate the comparative
viscosity of different magmas, she will invite students up to try to blow bubbles
(representing gas) in the water, molasses, and peanut butter in each cup. Water,
molasses, and peanut butter represent basaltic, andesitic, and granitic magma
consecutively. As each material is demoed, the teacher will ask a student from the
audience to read out the definition of each type of magma. More viscous material
results in “messier” eruptions.
• After demos, the teacher will instruct students to pair up and read through
pages341-343 in the textbook and discuss and write down the answers to the
assessment questions. This should take about 15 min.
• After 15 min. the teacher will ask students to move back to their assigned seats
and lead the class-wide discussion
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End of Lesson (2 min)
• The teacher will ask students to make sure their names are on the pair-share
answer sheets and to pass them to the front of the room.
• When the room is clean and students are seated quietly in their assigned seats,
they will be dismissed.
Potential Problems: I’m hoping that the demos will be engaging for the class, but I will need to
be strategic about who I pick to participate in these activities. “Showboaters” could be tempted to
derail the learning if they are getting attention from the entire class at once. Also, I’m estimating
15 minutes for reading and pair share. This could be too much time or too little depending on the
ability level and focus of the students in each class.
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Reflection: I struggled with putting the objectives for this lesson into student-friendly
terms. As they are written in the lesson, they are cumbersome and intimidating – especially when
written in big letters on a whiteboard. I modified them the morning of the lesson to be more
concise and used bullet points to make them less visually daunting. After all of these changes, I
wound up running out of time for the written portion of the lesson. In the future, I would shorten
the demo/discussion portion of the lesson and make sure to provide adequate time for writing.
This was the day of the viscosity disaster. I should have known not to include words like
“thick, sticky, blow, puff, hard” all in the same lesson with a bunch of middle school students.
Sometimes I’m far more naïve than they are. I did the viscosity demo with a volunteer during the
morning block. I didn’t realize my mistake until after I’d started the demo. About half of the
class was trying not to die of laughter, but I didn’t want to clue the oblivious half of the room
(including the ELLs, who did not catch the double meaning) in to the opportunity for innuendo,
so I struggled through. Mr. K was very amused. I gave my helper the opportunity to step down
halfway through the demo, but she elected to stay up in front of the class and finish the demo. I
apologized to her later for the awkward, ill-thought-out lesson.
I modified the demo for the afternoon class to try to remove any innuendo opportunities.
Instead of blowing bubbles in the different liquids, I showed that more viscous liquids flow more
slowly. This was slightly better, but the natural peanut butter looked like vomit under the doc
cam, which led to a whole different set of jokes. On the up side, a lot of students remembered
throughout the week that granitic magma is thick… “like peanut butter”.
In retrospect, I did not need to take time to demo viscosity. I think in the future I should stick
with written definitions that emphasize differences in thickness and stay away from stickiness,
visuals, and blowing through straws – for my own sanity if nothing else. The exploding soda
demo went very well.