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Overview
Students use ice cream glaciers and hot wax lava flows to simulate the interaction of glaciers and lava flows.
Learner Objectives:
Students will: ● (^) Recognize that the volcano and its glaciers co-exist as a dynamic system ● (^) Identify the types of interactions and energy transformations, that occur between glaciers and hot volcanic rocks ● (^) Identify some types of geologic features at Mount Rainier that are a product of glacier-volcano interactions
Setting: classroom
Timeframe: 50 minutes for demonstration
and discussion. For student groups, add 20–30 minutes for next day observations and discussions
Materials:
● (^) Graphic “Glaciers on Mount Rainier” ● (^) Graphic “Columbia Crest Summit” ● (^) Graphic “Glacier-Volcano Interactions” ● (^) Graphic “Maximum Extent of Glaciers on Mount Rainier During the Ice Ages” ● (^) Graphic “How Lava Ridges are Made”
Grade Level: 6– 10
Fire and Ice
Activity last modified: September 5, 2014
● (^) Graphic “Glacier Scratches (Striations) on Lava Rock at Mount Rainier” ● (^) Graphic “Volcanic Rocks of Modern Mount Rainier” ● (^) Graphic “Lava flows—Experimental and Real World Comparisons” ● (^) Stove or other heat source ● (^) Candy thermometer ● (^) Double-boiler pot ● (^) Disposable stirrer (pencil, paint stirrer, stick ● (^) Camera (optional) Ingredients required for each model: ● (^) metal cookie tray with sides (1/2 inch high minimum) ● (^) cereal bowl ● (^) wax paper ● (^) masking tape ● (^) modeling clay (8 oz per model group; black illustrates solidified lava well) ● (^) ice cream (1 quart; vanilla illustrates glacier ice well) ● (^) ice cream scoop ● (^) household wax (one pound; used for canning, candle making; also called “Home Canning Wax,” or “Paraffin”) ● (^) crayons (four different colors (quality crayons work best; do not use water soluble crayons) ● (^) scissors to cut clay strips—for use with soft clay only (optional)
U.S. Department of the Interior U.S. Geological Survey General Information Product 19
Living with a Volcano in Your Backyard-
An Educator's Guide with Emphasis on Mount Rainier Prepared in collaboration with the National Park Service
NATIONALSERVICEPARK
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Vocabulary: Erosion, glacier, ice ages, lahar, lava, lava flows, pyroclastic flow, striations, vent, volcano, volcanic eruptions
Skills: Interpret, infer, demonstrate, explain, predict, visualize
Benchmarks:
See benchmarks in Introduction.
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Ice-age glaciers envelop Mount Rainier
To understand the extent to which hot volcanic rocks have interacted with surrounding glaciers, we need to put on our “glacier glasses” and envision landscapes largely buried by ice. During ice ages that occurred repeatedly between approximately 1.8 million and 11,000 years ago, large ice sheets covered northern Europe and much of Canada and the northern United States, including the Puget Sound area. Mountain ranges in the western United States, including the Cascades were mantled by extensive glaciers. Some of the glaciers on Mount Rainier were hundreds of meters (1,000 feet or more) thick on the flanks of the volcano and almost 1,000 meters (3,000 feet) thick in valleys at the base of the cone. Mountain glaciers coalesced and flowed for 100 kilometers (60 miles). Glacier ice covered the locations of the present day communities of Ashford, Alder, Greenwater, and Carbonado. Around 15,000 years ago, these enormous glaciers began to thin and recede into existing valleys. Their descendents cover much of Mount Rainier today. View the extents of glaciers then and now in the graphic “ Maximum Extent of Glaciers on Mount Rainier During the Ice Ages .”
Mount Rainier erupted repeatedly while buried by ice-age glaciers
Mount Rainier erupted repeatedly during past ice ages. The co-existence of volcanic and glacial processes led to a variety of interactions that shaped the mountain in a unique way. The origins of these features can be understood only when the interactions of the glaciers and volcanic forces are recognized.
When lava meets ice
During times of extensive glaciation, lava poured repeatedly from the summit vent of Mount Rainier and encountered glaciers. In the contest between lava flows, rock, and ice, glaciers at first appear to be less durable. In theory, a lava flow can melt about ten times its volume of ice, though it rarely does so. We commonly think of lava flows as bullish, relentless, and unstoppable. However, observations at ice-clad volcanoes around the world prove that glaciers can survive the onslaught of heat from lava flows. In some situations, glaciers can exert some control over the movement of lava flows, and as such are the architects of Mount Rainier. Consider these mechanisms.
◆ (^) Lava flows tumble and disintegrate on steep slopes : Lava that flows over steep slopes often breaks apart and plunges onto the glacier, where it cools as rock debris. Sometimes the fragmenting lava flow forms a turbulent avalanche of scorching hot rock and gas called a pyroclastic flow , which can sweep across the snow and ice. Incorporation of snow and ice into the pyroclastic flow can cause the flow to transform into a volcanic mudflow (lahar). Lahar layers are found in river valleys that extend from Mount Rainier.
◆ (^) Ice-age glaciers act as physical and thermal barriers to lava flows : An advancing lava flow melts downward through thick ice until it contacts bedrock, where it chills and hardens, confined within the glacier. After the eruption, glacier ice often flows across the hardened lava flow. By this mechanism, Mount Rainier gains volume, and retains its glacier cover. Some of these lava flows, now partially eroded, are visible as ledges on the flanks of Mount Rainier.
◆ (^) Thin ice and ice-free regions allow lava flows to travel far : Lava encounters less resistance in the thin ice and ice-free ridges between thick valley glaciers. The lava flow’s outer skin cools and hardens, while the interior of the flow remains fluid and travels many kilometers (miles) from the base of the volcano. Over time, successive stacks of elongated lava flows have built ridges—from the bottom up—in a pattern that radiates from the cone of Mount Rainier. Paradise Ridge, Mazama Ridge, Rampart Ridge, and Emerald Ridge are some examples of this phenomenon. This interaction is depicted in the graphic “ How Lava Ridges are Made .” The phenomenon can happen only when glaciers envelop Mount Rainier, such as during an ice age.
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Fire and Ice (^) - continued...
Procedure
Fire and Ice
Students use ice cream glaciers and hot wax to simulate the interaction of ice-age glaciers and lava flows. They observe results and relate this to actual processes and features at Mount Rainier.
What to do Before Class Begins:
1. Decide whether you will conduct this activity as a demonstration or with student groups. Student groups will require multiple amounts of items listed in “ Materials ,” and additional time for setup. Students build their model, and then make repeated trips to the source of the molten wax on a stove top or hot plate. 2. A demonstration can be accomplished in less time, but will require you to assemble the wax papered tray and volcano model, and to break crayons and melt the wax prior to the beginning of class. If conducting the demonstration with several classes, consider constructing ice age glaciers with the first class and adding one or more layers of wax “lava” with each successive class, followed by examination of the model the next day. 3. Decide whether to assign students with homework that investigates glaciers, ice ages, and glacier-ice interactions (Procedure Part I number 2) prior to performing the activity. 4. As you prepare for post-activity discussion, keep in mind that no two completed volcanoes models will be alike. On these models, both ice cream glaciers and the older clay lava flows can influence the route of young wax lava flows. Students might observe that successive pourings of wax cause “stacking” of lava flows, as produced at Mount Rainier during the ice ages. Remind students that they should make general observations about melting of ice cream glaciers, the size, shape and overlapping nature of lava flow layers, and any interactions of wax lava flows with the tray rim. Be prepared for a variety of results.
Fire and Ice
Part I: Preparing Students for the Activity
1. Display the graphic “ Glaciers on Mount Rainier ” and point out that the glaciers are large; they show crevasses and are visible in white. Small discontinuous white areas are snow or ice patches. These do not flow and are not considered glaciers.
2. Instruct students to hypothesize about ways that the volcano and the glaciers influence one another. (You might wish to assign this as homework on the day previous to the volcano model.) Diagram their answers on the classroom whiteboard. Refer to the “ Teacher Background ,” and to the graphics “ Columbia Crest Summit ,” “ Glacier-Volcano Interaction ,” and “ Glacier Scratches (Striations) on Lava Rock at Mount Rainier .”
3. Display the graphic “Maximum Extent of Glaciers on Mount Rainier During the Ice Ages ” which illustrates the maximum extent of glaciation during the ice ages and today. Tell students that the volcano model in the activity represents glaciation during the last ice age; some older ice ages had even more extensive glaciers.
Part II: Setup of the Volcano and Glacier Model
1. Begin preparation of the volcano model by covering a tray and cereal bowl with wax paper.
Use masking tape to hold paper in place. Less surface area exposed to hot wax means reduced time spent on messy cleanup.
2. Turn bowl upside down on the tray as a volcano model.
The inverted bowl will represent the existing volcano that formed previously by the accumulation of volcanic rocks. Newer lava flows made of wax will be poured over the top of it.
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6. Color the wax lava with crayons.
Remove the paper wrappers from 5 or 6 different colored non-water soluble crayons and break each crayon into fingernail-sized pieces. Melt one colored crayon for each pouring of a wax lava flow, starting with the crayon lightest in color, and progressing to darker colors with each new lava flow (example: clear, orange, red, purple, black). With this method, you need melt only one pot of wax to obtain multiple colors of lava flows. There is no need to subdivide the melted wax into separate containers.
Part III: Fire And Ice Simulation
1. To be sure that students understand the volcano model, ask them the following questions: a. What does the bowl represent? b. What do the clay strips represent? c. What do the areas of ice cream represent? d. What does the wax represent? e. Describe the appearance of the landscape beneath the glaciers. 2. Ask students to hypothesize about what happens when hot lava and glacier ice interact. What will happen to the glaciers? To the lava flows? 3. Add half of a colored crayon to the melting wax.
Point out to students that each colored wax batch represent a new series of lava flows. Slowly pour approximately one-fifth of the melted colored wax over the summit area and upper slopes of the volcano model. Allow the wax to cool and solidify for a number of minutes. In the meantime, add the next color crayon to the wax in the pot and allow several minutes for melting. This also provides valuable time for student observations and discussion of glacier-lava flow interactions.
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4. Instruct student to observe where the lava travels faster.
Where does the wax lava travel the farthest? Where does the wax lava pool? Do students observe melting of the ice cream glaciers? How does the lava interact with the walls of the tray?
5. Repeat the pouring of wax lava flows and student observations until all wax has been poured.
Use cooling times for discussion of energy transformation that occur when hot lava meets glacier ice.
6. Instruct students to make additional observations and to relate them to an actual volcano.
For example, students might note that melting of the ice cream represents melting of glaciers; wax lava flows travel fastest on steep slopes and they form pools and solidify at the base of the volcano; wax lava solidifies against tray walls as real lava flows would pool against valley walls. Students might note that wax lava flows that travel off the volcanic cone, and over glaciers are thin and breakable.
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Fire and Ice (^) - continued...
Extensions
◆ (^) Instruct students to conduct research projects about glacier-volcano interactions. Students can visit Web sites listed on the Internet Resources List to identify landscape features that are products of glacier-volcano interactions at Cascade volcanoes, Iceland, and elsewhere.
◆ (^) Engage the class in a discussion of energy transformations using these concepts: As the blocks of lava begin to avalanche down the mountainside, the lava begins to accelerate. If you’ve ever tried to carry a large block up a mountain, you know that it takes a lot of energy! Once you drop that block down the mountain side and it begins to roll, the energy that it took to lift it up the mountain is converted into kinetic energy—the energy of motion.
◆ (^) Engage the class in a discussion of heat transfer between lava and glacier ice along the following concepts: Many lava flows that issue from steep-sided volcanoes break up into blocks and rubble that avalanche down the slope and mix with snow and ice. The melting of snow and ice by this process has the potential to create lahars that travel great distances beyond the slope of the mountain and threaten nearby communities.
Assessment
Use the questions in the “ Fire and Ice Simulation ” to assess students’ thinking as it progresses through recognition that glaciers influence the landscape on a volcano. Note how students’ understanding develops from general observations of the volcano model to recognition of the processes that shape an actual ice-covered volcano. As the activity progresses, students should recognize that the volcano and glaciers co-exist as a dynamic system and that many geologic and hydrologic features on the volcano are the results of glacier-volcano interactions. Students should begin to think more globally, and recognize that glaciers can influence the shape of glacier-clad volcanoes worldwide. To further assess their understanding, instruct students to write a summary paragraph about glacier-volcano interactions.
References
Crandell, D.R., and Miller, R.D., 1974, Quaternary stratigraphy and extent of glaciation in the Mount Rainier region, Washington: U.S. Geological Survey Professional Paper 847, 59 p.
Driedger, C.L., 1986, A visitors guide to Mount Rainier glaciers: Pacific Northwest National Parks and Forests Association, 80 p.
Driedger, C.L., and Kennard, P.M., 1986, Ice volumes on the Cascade volcanoes: Mount Rainier, Mount Hood, Three Sisters, and Mount Shasta: U.S. Geological Survey Professional Paper 1365, 28 p.
Driedger, C.L., 1993, Glaciers on Mount Rainier, U.S. Geological Survey Fact Sheet, Open-File Report 92–474, 2 p.
Lescinsky, D.T., and Sisson, T.W., 1998, Ridge-forming, ice-bounded lava flows at Mount Rainier, Washington: Geology, v. 26, pp. 351–354.
Lescinsky, D.T., and Fink, J.H., 2000, Lava and ice interaction at stratovolcanoes: use of characteristic features to determine past glacial extents and future volcanic hazards: Journal of Geophysical Research, v.105, 23, pp. 711–23,726.
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Refer to Internet Resources Page for a list of resources available as a supplement to this activity.
Photo Credits
1. Glaciers on Mount Rainier, Photo by Carolyn Driedger, USGS. 2. Columbia Crest summit, Photo by Donal Mullineaux, USGS. 3. Glacier-volcano interactions, Photo by Carolyn Driedger, USGS. 4. Glacier scratches (striations) on lava rock at Mount Rainier, Photo by Carolyn Driedger, USGS. 5. Lava Flows—Experimental and real world comparisons, Photo by Carolyn Driedger, USGS.
Living with a Volcano in Your Backyard–An Educator's Guide: U. S. Geological Survey GIP 19
Columb ia Cre st Summit
The history of glaciers and volcanic processes has been intertwined since the construction of the present mountain began about 500,000 years ago.
Photo by Donal Mullineaux, USGS
Living with a Volcano in Your Backyard–An Educator's Guide: U. S. Geological Survey GIP 19
Glacier Volcano Interactions
Volcano Provides:
◆ Extensive high-altitude slopes
◆ Rugged topography
Glacier Provides:
◆ Control over the behavior of lava flows
◆ Water for formation of lahars and debris flows
◆ Mechanical erosion of volcano
Photo by Carolyn Driedger, USGS
Living with a Volcano in Your Backyard–An Educator's Guide: U. S. Geological Survey GIP 19
How Lava Ridg e s are Made
Ice Age glaciation on Mount Rainier ―
Ice-age glaciers buried much of Mount Rainier.
Some rock ridges remained exposed.
Eruption of lava during ice ages ―
Some lava flows disintegrated as pyroclastic flows.
Others melted holes in the glacier, but later were
buried by flowing ice.
This lava flow met little resistence on the rock ridge,
and flowed a great distance. It cooled and hardened.
Lava ridges and glaciers today ―
Glaciers melted at the end of the ice
age. Stack of lava flows remain as ridges.
Living with a Volcano in Your Backyard–An Educator's Guide: U. S. Geological Survey GIP 19
Glacier Scratche s (Striations ) on Lava Rock At Mount Rainier
Photo by Carolyn Driedger, USGS
