Lesson Two
Vesuvius Erupts Enduring Understanding There are different types of volcanic eruptions.
Essential Question How did Mount Vesuvius erupt in A.D. 79?
What Students Will Learn Vesuvius erupted violently in A.D. 79 in what is now called a Plinian eruption.
What Students Will Do • Chart four different types of volcanic eruptions. • Observe a demonstration of a Plinian Eruption.
Materials For Each Student • “Types of Volcanic Eruptions” (page 45), one copy for each student For the Teacher • Books and images of volcanos and eruptions • Computers, IPad, or Chromebooks for videos • Make a transparency of “Ash Layers”
Background Information Different types of volcanoes erupt differently. When volcanoes erupt they “give off a vast range of products from steam and gas to molten lava, ash, pumice, and boulders, all of which are ultimately derived from magma, the molten material that rises from beneath the Earth’s crust” (Scarth 2009). Vesuvius is a stratovolcano, which are usually tall, mountainous volcanoes whose steep sides have been formed over time by repeated deposits of ash, lapilli,
SUBJECTS: science, social studies, language arts CCSS and NGSS: R.7, SL.2 and ESS3.B Natural Resources, ADQP, AID, CEDS SKILLS: • Bloom’s Taxonomy: Evaluation, Analysis, Application, Comprehension • Facets of Understanding: Explanation, Application, Perspective DURATION: 45-60 minutes CLASS SIZE: Any lava, and pyroclastic flows. Other types of volcanoes, such as the shield, cinder cone, and lava dome volcanoes, produce very different types of eruptions. In an oversimplified model volcanic eruptions can be grouped under four main categories: mild, moderate, vigorous, and violent. The eruption of Mount Vesuvius in A.D. 79 is one of the most famous because it destroyed, buried, and immortalized the towns of Pompeii and Herculaneum and Roman villas in Campania. They were entombed for over seventeen hundred years, until archaeologists slowly began to reveal their secrets to the world. “Thus, the eruption destroyed –and preserved –the most famous archaeological sites in the world, and they, in turn have helped make Vesuvius the most famous of all volcanoes” (Scarth 2009). How can we learn about the eruption of Vesuvius in A.D. 79? Scientific studies of the eruption provide information about the phases of the eruption supported by layers of ash that show evidence of pyroclastic flows.
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By analyzing how thick the layers are, what type of volcanic material they contain, and how the deposits were distributed, geologists have been able to reconstruct the different phases of the eruption. The first phase of the eruption was characterized by a widespread dispersal of pumice from a high eruptive column, that rose to the height of almost 20 miles. During this phase, white and gray pumice dispersed to the southeast of the volcano, traveling a distance of 43 miles. The second phase of the eruption was characterized by the collapse of the column and pyroclastic flows and surges. This phase caused major damage and extensive loss of life within 6 to 10 miles of the volcano. The surges can be detected as layers of thin ash then thick, massive layers indicate pyroclastic flows. The third phase consists of a deposit of lapilli. With the final phase as a succession of layers composed of pebbles and sand. At the Villa Oplontis the total deposit of ash, surges, flows, lapilli, and pebbles constitute a depth of 30 feet. Vesuvius’ eruption in A.D. 79 was named a Plinian eruption, since Pliny was the first to document its shape and characteristics. Plinian eruptions are characterized by the pine-tree-shaped clouds that form above the volcano’s crater, as well as the wide variety of hazardous materials ejected by the volcano, such as ash, poisonous gases, and lapilli.
expelled at great speed in a turbulent mass. volcano: burning mountain, comes from the name of the Roman god, Vulcan, god of fire and the blacksmith of the gods. Misconception Alert! Pyroclastic vs. Lava Flow One type of volcanic hazard that most people think of first is lava flow, which is the flow of hot molten rock.Yet a lava flow is one of the least deadly of all of the volcanic processes. This is partly because lava flows do not move very fast, only traveling a few miles per hour. There is another type of flow that comes from a volcanic eruption that is much more dangerous than a lava flow, and that is a pyroclastic flow. A pyroclastic flow is a dense collection of fragments and gases from a volcanic eruption that flows down the slope of a volcano. Whereas a lava flow is something that might inch towards you giving you time to flee, a pyroclastic flow is something that races down the side of a volcano, leaving little time to react. The high speeds at which a pyroclastic flow travels, which can be more than 100 miles per hour, make this volcanic hazard very dangerous. And, not only are pyroclastic flows dangerous because of their speeds, but also because they are very hot (1,000 degrees Celsius, 1839 degrees Fahrenheit) and contain toxic gases. http://study.com/academy/lesson/volcanichazards-definition-types-prevention.html#
Preparing to Teach 1. Set up volcanic eruption stations with images, books, and an ipad/computer/chromebook of eruptions. 2. Prepare to share Background Information. 3. Post Enduring Understanding and Essential Questions. 4. Post Word Bank words. 5. Gather examples of lapilli and pumice.
Word Bank cross-section: diagram of layers of soil and rocks. geyser: a natural hot spring that throws out a spray of steam and water from time to time. lapilli: “little stones” a small stony particle ejected from a volcano. pumice: a very light and porous volcanic rock. pyroclastic flow: huge, glowing clouds of scorching hot gas and volcanic fragments, ranging in size from dust, ash, and pumice to large rocks which are
Uncovering Prior Knowledge How did Mount Vesuvius erupt in A.D. 79? Inform students that this question will guide their learning. Indicate Word Bank words and inform students that they will use these words as tools and define them during the lesson. 1. Ask students: What do you know about volcanoes and volcanic eruptions? Uncover misconceptions to address later in the lesson. 2. Pass around lapilli or pumice. Engage student’s senses by asking them: • How does the lapilli feel (weight, texture)? How does the pumice feel?
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• What does it smell like? • What color is it? What does it look like? • What surprised you as you looked at the lapilli and then felt it? 3. Are there any volcanoes in your state/nearby? What volcano erupted most recently in the U.S.?
Discovering New Knowledge 1. Students will complete a chart on the four different types of volcanic eruptions. 2. Group students (2-3) to explore the four different types of volcanic explosions in stations. While looking at the videos they can write fill out the worksheet “Types of Volcanic Eruptions”. 3. Jigsaw the stations: Send 2 groups to each station (5 minutes to gather the information about their specific type of eruption, then 3 minutes to share what they have learned with everyone at that station to make sure they have all have the information.) • Station 1: Mild Eruptions-Yellowstone National Park https://www.youtube. com/watch?v=USCvVndukjA • Station 2: Moderate Eruptions- Big Island https://www.youtube.com/watch?v=_ hyE2NO7HnU • Station 3: Vigorous- Santiaguito Volcano https://www.youtube.com/ watch?v=gZrZdevFREc (MUTE) • Station 4: Violent- Mount St. Helens https:// www.youtube.com/watch?v=UK--hvgP2uY https://youtu.be/xP2dreOI8gI?t=3m 4. After the groups finish watching the videos and filling out the worksheet, bring them back together to report to each other (or have students rotate through all of the stations). One person from each station (one from station 1,2,3 and, 4) becomes a group of four. They have a conversation about their knowledge of one type of volcanic eruption. Each person has a turn. 5. Review each eruption type using the guided notes on page 44. 6. Use the “Misconception Alert: Pyroclastic vs. Lava Flow” to lead a brief discussion on the difference between the two. 7. Ask students to predict which type of eruption the A.D. 79 Mount Vesuvius eruption was. 8. Demonstrate a Plinian eruption telling students
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this is how Mount Vesuvius erupted, but do not tell students which type of eruption it is. a. Watch a video of a pyroclastic flow: http:// www.discovery.com/tv-shows/discoverypresents/videos/ultimate-guide-tovolcanoes-pyroclastic-flow/ 10. Tell students to make observations as they watch the eruption. After watching the demonstration, ask students to describe the eruption and indicate which type of eruption it is (violent). Tell students this is how Mount Vesuvius erupted in A.D. 79. Check for understanding that students are not including lava in their description. 11. Next, use the Background Information to introduce the volcano Vesuvius. (Display a map of the volcano). Tell students: Now that we have learned about different types of volcanos, we are going to focus on the famous volcano that destroyed Pompeii. Share Background Information. 12. Ask students: Why do you think it is called a Plinian eruption? Vesuvius’ eruption in A.D. 79 was named a Plinian eruption, since Pliny was the first to document its shape and characteristics. Plinian eruptions are characterized by the umbrella pine-shaped clouds that form above the volcano’s crater. This pine is different than pine trees in the United States. Display picture of an umbrella pine (see below).
13. Hand out “Ash Layers” to each student or project it on the board. How many main phases of the eruption were there? What evidence is there in the cross-section? Assist students with defining cross-section. Share Background Information with students on the phases.
Reflecting on New Knowledge 1. Ask students: How do volcanos erupt differently? On the board or poster board write the 4 types of volcanic eruptions (Hydrothermal, Hawaiian, Vulcanian, and Plinian). 2. Have students write an observation on a post-it note and place it under the appropriate type. Ask students: How did Mount Vesuvius erupt in A.D. 79? Then read the observation notes under the Plinian Eruption. 3. Project USGS image of Volcano hazards. Ask students: How do the giant eruptions in the Yellowstone National Park region compare to other large historic eruptions? https://www. google.com/url?hl=en&q=https://volcanoes. usgs.gov/vsc/images/image_mngr/0-99/ img5_547w_350h.jpg&source=gmail&ust= 1467236724828000&usg=AFQjCNGRXiHFNhhvIzjf80fJgXzysssqg
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Notes
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Mild/ Geyser Eruption
Moderate/ Hawaiian Eruption
Hydrothermal, geysers, hot springs, mud pots
1969 Eruption of Mauna Uu, a vent of Kilauea Volcano in Hawaii. Photo by D.A. Swanson, USGS, August 22, 1969. Explosive molten lava with very hot magma
Old Faithful geyser of Yellowstone National Park. Photo from iStockphoto/Zuki
Vigorous/Vulcanian Eruption
Violent/ Plinian Eruption
Vulcano in the Aeolian Islands. Photo by Jessica Ball, March 15, 2009. Santiaguito in Guatemala. Vigorous, hydrovolcanic, hydromagmatic. Dust, ash, cinders, ejected with blocks of rock, no lava but large quantities of gas. Named for the Italian island of Vulcano (Aeolian islands) thought to be the vent/chimney above the forge of the Roman smith god Vulcan. ]44[
Mount St. Helens. Photo by Austin Post, USGS, May 18, 1980 Pyroclastic flows. Lots of gas! Vicious, cool magma, gas blasts out with enormous force. Explosions shatter the magma in dust and ash. Scorching, glowing clouds of ash and fumes that race down the sides. Pumice.
Name: _______________________________________________________ Date: ______________________ Period: _________
Types of Volcanic Eruptions
VIOLENT
VIGOROUS
MODERATE
MILD
Eruption
Example (Name and Location)
Draw a picture
Description (indicate if there is lava or no lava)
Geyser
Hawaiian
Vulcanian
Plinian
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Ash Layers Timeline of the Eruption of Vesuvius in AD 79 Date and Time Day 1, 11-12 pm Day 1, 12 pm Day 1, 12 pmDay 2, 4 am Day 2, 4-6 am
Description Fine ash fell to the east of Vesuvius Column of hot gas and pumice exploded from the volcano, climbing to a height of 10-20 miles then spreading out. Pumice and Rock fragments begin to fall at a rate of 6 inches per hour. The column of hot gas and pumice began to collapse, flows and surges of hot ash and gases swept down. First Surge Second Surge Third Surge Three more phases
Day 2, 4-6 am Day 2, 5-7 am Day 2, 6:30 am Day 2, 7:30 – 8 am Table: Berry, Joanne. 2007. The Complete Pompeii. New York: Thames & Hudson, pp. 25
Sigurdsson, Haraldur, Stanford Cashdollar and Stephen R. J. Sparks. ‘The Eruption of Vesuvius in AD 79: Reconstruction from Historical and Volcanological Evidence. American Journal of Archaeology, Vol. 86, No. 1 (Jan. 1982), pp. 39-51. Boston, MA: Archaeological Institute of America.
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