Activity Summary
Students use volcanic ash data to look for the supply of a potential supervolcanic eruption that happened within the western U . s . States.

Learning Objectives
Students can:

describe a few of the characteristics of the supervolcanic eruption.

better know how additional data might help support or refute a hypothesis.

• copy from the “CSI: Ashfall Fossil Beds” student handout (PDF or HTML )
• pencil or pen

• copy from the “Volcanic Identification” student handout (PDF or HTML )
• copy from the “Volcano Suspects: Location” student handout (PDF or HTML )
• copy from the “Volcano Suspects: Description” student handout (PDF or HTML )
• copy from the “Volcano Suspects: Ash Composition” student handout (PDF or HTML )
• use of print and Internet U.S. map sources

Background
Supervolcanic eruptions are very large eruptions that leave a minimum of 1,000 cubic kilometers of magma and pyroclastic material (a warm, dry, fast-moving combination of ash, pumice, rock fragments, and gas). These eruptions could destroy almost all existence inside a radius of countless kilometers in the site and may bury areas as a long way away as 1,500 kilometers in meters of ash. Large-scale explosive eruptions of the type produce calderas, large depressions created through the collapse from the summit or flanks of the volcano.

Volcanic ash includes rock, mineral, and glass fragments smaller sized than two millimeters across. Ash is created through the catastrophic stop by pressure on magma introduced about through the volcanic eruption (splitting up of volcanic edifice leads to atmospheric pressure inside volcano). This will cause gases within the magma to grow strongly, fragmenting the magma into small pieces, which instantly solidify on ejection in to the atmosphere (lower temperature when compared with magmatic temperatures).

Ash from the particular volcano features its own unique characteristics, similar to an individual’s fingerprints. These traits include chemical composition, and also the shape and size of crystals and glass shards. They may be used to determine not just the specific volcano that created the ash, however the particular eruption from that volcano too.

The options, combined with the chronilogical age of the ash, help scientists find out the supply of material. Volcanic rocks are usually split into four fundamental types&#8212basalt, andesite, dacite, and rhyolite&#8212according towards the average power of major compounds within the rock. These compounds include plastic dioxide (SiO2 ), titanium dioxide (TiO2 ), aluminum oxide (Al2 O3 ), iron oxide (FeO or Fe2 O3 ), manganese oxide (MnO), magnesium oxide (MgO), calcium oxide (CaO), sodium oxide (Na2 O), potassium oxide (K2 O), and phosphorous pentaoxide (P2 O5 ).

In 1971, Michael Voorheis, a paleontologist in the College of Nebraska Condition Museum, designed a startling discovery in a farm in northeastern Nebraska. He uncovered the bones of 200 fossilized rhinos, along with the prehistoric skeletons of camels, lizards, horses, and turtles. They were wiped out countless years back by suffocating levels of volcanic ash (the website later grew to become referred to as Ashfall). But there aren’t any volcanoes in Nebraska, nor had there have you been. Actually, there aren’t any volcanoes within the continental U . s . States east of Colorado.

Where did the ash originate from?

Scientists learned that the ash originated from an very explosive eruption roughly ten million years back. By analyzing and evaluating ash samples in the Ashfall site to individuals created by volcano eruptions of the identical age, the scientists could find out the supply of the eruption because the Bruneau-Jarbridge volcano in southwestern Idaho, some 1,500 kilometers away.

Within this activity, students uses real volcanic data to recognize the likely supply of volcanic ash present in a place of Nebraska.

caldera: Large depression created by collapse from the ground following an explosive volcanic eruption of a big body of stored magma.

pyroclastic flow: Hot, dry, fast-moving combination of ash, pumice, rock fragments, and gas from the volcano.

supervolcano: A volcano which has created a very large explosive eruption relating to the ejection of immeasureable ash in to the atmosphere, causing formation of the giant caldera.

tephra: The overall term now utilized by volcanologists for airborne volcanic ejecta associated with a size.

Brainstorm using the class concerning the possible kinds of information they should identify a resource of volcanic ash. (Age an example is generally a vital identifying characteristic however, because supervolcanic explosions are extremely rare, knowing age the ash sample allows students to instantly find out the source. It is therefore not incorporated like a characteristic within this activity.)

Organize students into teams and distribute copies from the “CSI: Ashfall Fossil Beds” and “Volcanic Identification” student handouts.

Ask students to make use of the data around the “Volcanic Identification” handout to recognize the kind of ash in the Nebraska site and the kind of eruption and volcano that may have created it.

Show students they’re supplied with three teams of data, individually. (You might want to emphasize students this is actual real volcanic data.) For every data set, they’ll be requested to evaluate the data and&#8212 according to that data&#8212eliminate “suspect” volcanoes they believe least fit the profile for that Ashfall event. Additionally they is going to be requested to rate how certain they’re of the conclusions. Explain that they’ll review their conclusions again when all of the data have been in.

Distribute the 3 data handouts within the following order, getting students complete each one of these before beginning the following:

Volcano Suspects: Location
Volcano Suspects: Description
Volcano Suspects: Ash Composition

After students complete each handout within the order given above, ask them to mark their “Volcano Suspects Table” on their own primary “CSI: Ashfall Fossil Beds” handout using the volcano or volcanoes they think is or would be the least likely suspect(s) in line with the data, and rate their level of confidence within their answer.

In the end students have finished the 3 handouts and completed their “Volcano Suspects Table,” keep these things identify their primary suspect and answer the questions for auction on their “CSI: Ashfall Fossil Beds” handout. Lead a category discussion about which volcano was the primary suspect and why. Did students’ opinions change because they got more data? Why or why don’t you? Which data were best? That have been least relevant?

Being an extension, ask students to analyze and set of the eruptions from the different “suspect” volcanoes. When did the main eruptions occur each and every site? What evolved as the result of individuals eruptions? Should students stress about residing in a place where supervolcanic eruptions may have happened? Why or why don’t you?

Kind of ash at Ashfall:felsic, since the ash includes a silica content in excess of 65 %

Kind of eruption probably to possess produced Ashfall:highly explosive

Kind of volcano form probably to possess produced Ashfall:caldera or dome volcano

Volcano Suspects: Location

Which volcano is situated nearest towards the Ashfall site? Yellowstone

Which volcanoes are farthest away? Mount St. Helens, Lassen, Crater Lake, and Lengthy Valley

Volcano Suspects: Description

The eruptive volume matches the explosiveness of the volcano. Which volcano had probably the most explosive eruption? Which volcano had minimal explosive eruption? Yellowstone had probably the most explosive eruption Mount St. Helens had minimal.

Does there appear to become a relationship between how big a volcano’s crater/caldera as well as an eruption’s explosiveness? Why or why don’t you? Yes, more explosive volcanoes appear to possess bigger calderas due to the more effective eruptions they’ve created.

Volcano Suspects: Ash Composition

For every suspect volcano, can you characterize the magma that created the ash sample as mafic, intermediate, or felsic? Why? All of the given samples match felsic eruptions according to their silica content.

Which ash appears to become most similar in composition towards the Ashfall sample? The Bruneau-Jarbridge ash is most similar in composition.

CSI: Ashfall Fossil Beds

Student solutions will be different but should indicate the next:

Location: most-distant volcanoes (Mount St. Helens, Lassen Peak) least likely

Description:stratovolcanoes (Mount St. Helens, Lassen) and fewer explosive volcanoes (Crater Lake, Mount St. Helens, Lassen) least likely

Ash Composition: individuals with greatly differing levels of silica, aluminum, sodium, and potassium in the Ashfall site (Mount St. Helens, Crater Lake, Lassen Peak, Lengthy Valley&#8212and to some lesser extent, Valles Caldera, and La Garita) least likely

Sample Volcano Suspects Table

CSI: Ashfall Fossil Beds Student Handout Questions

The majority of the listed “suspect” volcanoes have calderas, that are large depressions created through the collapse from the summit or flanks of the volcano throughout a large-scale, highly explosive eruption. Why would a caldera-developing eruption function as the probably supply of the ash present in Nebraska? Caldera-developing eruptions are felsic eruptions and would produce massive levels of ash that may achieve an excellent distance in the supply of the eruption.

Probably the most explosive volcanoes have magma with an excellent silica (SiO2 ) content. According to these details, which from the suspect volcanoes is probably to possess had probably the most explosive eruption? Yellowstone and La Garita

Which volcano do you consider was probably the most likely supply of the eruption that wiped out the creatures in Nebraska? Why? Bruneau-Jarbridge, since the ash is extremely similar in composition. Although the caldera isn’t the nearest, it were built with a very explosive eruption that may have created enough ash to achieve Nebraska.

NOVA&#8212Mystery from the Megavolcano
world wide web.pbs.org/nova/megavolcano
Uncover exactly what a supervolcano eruption might mean today, discover what training could be learned in the Toba eruption, begin to see the impact Toba had 75,000 years back, and explore a roadmap of supereruptions all over the world.

Ashfall Fossil Beds Condition Historic Park
ashfall.unl.edu
Features details about the Ashfall Fossil Beds along with the background and geology from the area.

Smithsonian Institution: Global Volcanism Program
world wide web.volcano.si.edu
Describes volcanoes all over the world and eruptions which have happened in the past 10,000 years.

Volcanoes and Earthquakes
by Susanna Van Rose. Dorling Kindersley, 2004.
Explains how volcanoes and earthquakes occur.

Volcanoes
by Robert and Barbara Decker. W.H. Freeman and Company, 1997.
Provides more information concerning the geology of volcanoes.

The “Investigating Evaporation” activity aligns using the following National Science Education Standards (see books.nap.edu/html/nses ).

Grades 5-8
Science Standard D
Earth and Space Science
Structure of the world system

Science Standard F
Science in Personal and Social Perspectives
Natural hazards

Grades 9-12
Science Standard D
Earth and Space Science
The foundation and evolution of the world system

Science Standard F
Science in Personal and Social Perspectives
Natural and human-caused hazards

Classroom Activity Author

Margy Kuntz has written and edited educational materials in excess of two decades. She’s authored numerous educational supplements, basal text materials, and trade books on science, math, and computers.