Subject Area(s): Physical Science
Associated Unit: none
Lesson Title: How far does a lava flow go?
Header Insert Image 1 here, right justified to wrap
Image # 1
ADA Description: lava flow with volcano in background
Caption: none
Image file name: volcano_ lava_flow
Source/Rights: Copyright © 1.bp.blogspot.com/.../s400/volcano-lavaflow.jpg
Grade Level 6-9
Lesson # __ of __
Lesson Dependency: none
Time Required: 20 minutes
Summary:
This lesson teaches about volcanoes, magma, and lava flows. The lesson covers lava
composition, factors that affect flow, and risk to human settlements.
Engineering Connection (or possible technological application)
This lesson has relevance to chemical engineering by teaching the properties of liquid
movement. Understanding what increases and decreases liquid flow can aid in the design
of structures that use liquids to do work, as well as ones that control or contain them.
This lesson is also directly relevant to the field of geochemical engineering, where
engineers use science to solve environmental and civil engineering problems. Engineers
work on ways to halt or divert lava flows in order to protect human structures. For
instance, R.D. Schuiling recently suggested that limestone walls could be built that
rapidly cool lava (making it more viscous) and thus slowing the flow enough to salvage
human settlements.
Engineering Category, if applicable: (1)
Level of Inquiry:
See associated activity
Keywords: flow, fluid, lava, liquid, movement, slope, surface area, viscosity, volume
Educational Standard
1) CA State Standards (1998) addressed:
Earth Science (grades 9-12)
Dynamic Earth Processes:
e. Students know there are two kinds of volcanoes: one kind with violent eruptions
producing steep slopes and the other kind with voluminous lava flows producing gentle
slopes.
Investigation & Experimentation (grades 9-12)
1a. Select and use appropriate tools and technology (such as computer-linked probes,
spreadsheets, and graphing calculators) to perform tests, collect data, analyze
relationships, and display data.
2) National Standards addressed:
Science as Inquiry Standards (grades 9-12):
Abilities necessary to do scientific inquiry, understanding scientific inquiry
Physical Science Standards (grades 5-8):
Properties and changes of properties in matter
Pre-Requisite Knowledge
Pre-requisite knowledge includes a mathematical understanding of surface area, an
understanding of the liquid phase, and background lessons on earth science (e.g., earth’s
layers, plate tectonics, and volcanoes)
Learning Objectives
After this lesson, students should be able to:
 Understand how the properties of liquid movement are relevant to the phenomena of
lava flows and how this can affect human civilization, and understand how fluid
properties are important in science and engineering.
Introduction / Motivation
Volcanoes can be hazardous geological features. This is because they contain
large amounts of hot molten rock mixed with dissolved gases that are very close to the
surface (teacher can show or sketch a picture on the board showing magma beneath a
volcano). Does anyone know what the molten rock mixture is called? (Answer: magma).
What can happen to this magma when it moves close to the surface and the gases start to
bubble out? (Answer; it can erupt). Once magma reaches the surface, it is called lava.
Lava can leave volcanoes in violent bursts. This is called an explosive eruption (show a
picture or depict on diagram on board). It can also leave through river-like streams. This
is called an effusive eruption (show a picture or depict on board). When lava flows
effusively, there are different aspects that can make it move fast or slowly and also affect
how much area the lava covers.
For instance, the amount the compound, silica (SiO2) found in magma will make
it move more slowly. The ability for a fluid to move fast or slow is termed its viscosity.
In other words, viscosity is a fluid’s resistance to flow. This means that more viscous
fluids do no flow as easily as less viscous ones. Who can think of some fluids that are
viscous? (Example answers: honey, glue, oil, sour cream, motor oil). How about some
fluids that are not very viscous? (Example answers: water, juice, milk, coffee, gasoline,
alcohol). Viscosity is an important property of fluids that has many applications in our
lives. For instance, suppose you were an engineer that was designing a glue factory.
Would you have to know the viscosity of glue in order to design machine that fills glue
bottles?
Now getting back to lava flow, another aspect that can affect the spread of lava is
the shape of the volcano that it is coming out of. Volcanoes can be tall and thin or they
can be short and wide. In other words, they may have different slopes. Some are steep
and some are not. These different landscapes affect how a liquid flows over it.
Today you will be experimenting with how volume, viscosity and slope affect the
surface area that a liquid covers. You will pretend that the liquid soap you are given is
molten hot lava (but you can touch it, or course!). Some groups will experiment with
viscosity and will use salt and water to investigate this property. The other groups will
investigate the affect of slope using different sized sticks. For all groups, your lava will
flow over a transparency with 1cm squares printed on it (your volcano). You will record
the surface area that your lava covers by pouring it onto the graph transparency
(demonstrate this by using an overhead projector) and then counting the squares. Partial
squares should be added up to wholes using your best guesses (demonstrate using
overhead).
Lesson Background & Concepts for Teachers
Word
magma
lava
viscosity
effusive
slope
Definition
melted rock and dissolved gasses
magma that has reached the earth’s surface
a liquid’s resistance to flow
flowing , e.g., lava that flows
steepness, incline
Associated Activities
For GK-12 lessons, please list the activities associated with this lesson, by title.
**For each activity, please attach a filled-out Activity Template.
Activity # 1 Title: How Far Does a Lava Flow Go: investigating the effects of volume,
viscosity, and slope on surface area of liquids.
Lesson Closure
(Note: to be discussed after associated activity)
Now that you have experimented with your lava (soap), who can tell me how
volume affects the surface area that a lava flow will cover? (Answer: greater volume,
more area). How about how viscosity affects the surface area that a lava flow will cover?
(Answer: the more viscous the lava, the less area it will cover). Who can tell me how
slope affects the surface area that a lava flow will cover? (Answer: the steeper the slope,
the more surface area it will cover). What other properties do you think affect lava flow?
(Potential answers: temperature: higher temp results in lower viscosity, how much stuff is
in the way blocking the lava, the substrate that lava is flowing across: smooth vs. rough).
Bring back the question that I asked you before the experiment, do you think that
all volcanoes have the same risk to human settlements? (Answer: students should realize
that risk to human settlements may depend on how much lava there is, how fast the lava
flows (its viscosity), the slope of the volcano, and other potential factors). It turns out
that some volcanoes are a lot more dangerous than others. One famous example of a
dangerous volcano is Mount Nyiragongo in the Democratic Republic of Congo. Its lava
has very low viscosity because of its low silica content. Mount Nyiragogo also has very
steep slopes. The factors together enable the lava to travel up to 60 mph! The volcano’s
close proximity to a city also makes it especially dangerous. By contrast, Mt Kilauea a
much less steep volcano with more viscous lava so even though it is very active, it poses
less threat to humans.
In the second part of the activity, each group “became” a group of geochemical
engineers with the goal brainstorming ways to save human structures from lava flows. I
would like one person from each group to share one possibility you came up with to stop
or divert lava flows (Possible answers: spraying lava with cold water, building a walls,
digging ditches to divert flow, decreasing the slope of the substrate, cooling the ambient
air, adding things to increase viscosity….they can be creative here!).
Lastly, can anyone tell me why knowing the properties of liquid movement might
be important to know in the world today? (Possible answers: designing dams, boat
motors, turbines, understanding water currents in the ocean, in industry (creating liquid
products), studying the earth’s mantle and liquids in space).
Assessment
See associated activity
Lesson Extension Activities
Additional Multimedia Support
Lava flow video clips:
http://www.volcanovideo.com/p8vidclp.htm
http://dsc.discovery.com/convergence/pompeii/videogallery/videogallery.html
References
Smith, Michael, Southard, John B., Eisenkraft, Arthur, Freebury, Gary, Ritter, Robert,
Demery, Ruta. Integrated Coordinated Science for the 21st Century. Armonk, NY: It’s
About Time, 2004.
Schuiling, R.D. "How to stop or slow down lava flows" Int. J. Global Environmental
Issues 8 (2008): 282-285
Allard, P, Baxter, P, Halbwachs,M, Kasareka, M, Komorowski, JC, & Joron JL. "The
most destructive effusive eruption in modern history: Nyiragongo 2003". Geophysical
Research Abstracts 5 (2003): 11970.
Onpedia. Accessed on April 15, 2009. http://www.onpedia.com/encyclopedia/MountNyiragongo
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Owner
UCLA SEE-LA GK-12 Program, University of California, Los Angeles.
Contributors
Developers: Brittany Enzmann and Marschal Fazio. This lesson was developed as part of
the UCLA Science and Engineering of the Environment of Los Angeles (SEE-LA GK12) program and has been classroom tested in several 9th grade Integrated Coordinates
Science classes at University High School in Los Angeles.
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