Chapter 3 Cones, Eruptions, and Pyroclasts

Chapter 3 focuses on Cones, Eruptions, and Pyroclasts, looking at products of volcanic eruptions and hotspot volcanoes.

Lessons included in this chapter:

#7 Lava Flows and Pyroclasts

#8 Volcanic Cones and Eruptions

#9 Hotspot Volcanoes - Hawaii and Yellowstone.

Resources for Teachers can be found under the Chapter #3 Copymaster.

Select from the options on the right to proceed.

Lava Flows and Pyroclasts Lesson #7

Lava is melted rock that has reached the Earth's surface through a volcano's main vent or through side vents and fissures.

Some volcanoes produce little or no lava. Some volcanoes eject pyroclasts, which are fragmented or broken rock. The word pyroclastic comes from a Greek word that means "Rock broken by fire".

When volcanoes do produce lava flows they are classified as either Pahoehoe or Aa. The lava is identical in both pahoehoe and aa lava flows, the difference comes from the amount of lava erupted and the speed of cooling. Pahoehoe lava flows are produced from a small amount of lava that moves slowly, while aa flows usually are associated with a large volume of lava that moves swiftly. Aa flows are generally 6-15 feet thick and pahoehoe flows are usually 1-3 feet thick.

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If the lava is very hot and has a low viscosity (runny with a low gas and silica content) the lava flow is called Pahoehoe. If, on the other hand, the lava has a high viscosity (thick and pasty with a high gas and silica content) it is called Aa.

Silica is a white or colorless crystal that is present in sand and quartz. It is one of the most abundant compounds in the Earth's crust.

 

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The photograph shows a pahoehoe flow on the left and an aa flow on the right.

 

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Pahoehoe (Pa-Hoy-Hoy) lava flows are very hot, thin and runny. When it cools is has a smooth to ropey texture because of the low silica content which makes it cool quickly.

Pahoehoe flows creep along generally at less than 3 feet per minute but some flows have been measured at over 20 miles per hour. The terms pahoehoe and aa are from the native Hawaiian language and are now used by geologists the world over.

 

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This pahoehoe flow is advancing on the skeleton of a large mammal perhaps a horse or a cow. The lava will engulf the animal and may fossilize the remains!!

Notice how the flow advances in globs of lava. These globs of lava are called lobes.

 

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Aa lava flows are formed when the lava is produced in a manner that allows it to cool quickly. When a fire fountain shoots the lava high into the air it cools somewhat before it can flow after landing on the surface. Aa lava also forms when there is a huge amount of lava produced or a steep slope moves the lava at high speeds. These high speeds put the lava in greater contact with the air, which makes it cool more quickly.

Notice the rough and fragmented upper surface of the photo at the left. Would you like to walk barefoot on this after it cools?

 

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A pahoehoe lava flow produced the lava tube in the picture above.

A lava tube forms when the lava on the outer surface of the flow cools much faster than the inside of the flow. The outside becomes cooled hardened lava rock while the inside stays molten and also keeps flowing. If something happens to stop the flowing lava there will be nothing to fill the void and a tube is the result.

 

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No, this is not a North Dakota blizzard. This photo is showing the ash fall from Mt. Pinatubo's (Phillipines) eruption in 1992. Many inches of ash fell and the U.S. Naval and Air Force bases near the mountain were closed because of the eruption.

When Mt. St. Helens erupted in 1980 the ash cloud rose to an altitude of over 50,000 feet, that is almost 10 miles high! The mountain kept spewing ash for another nine hours on May 18th. The ash deposits were many inches deep in many cities in Washington. This ash choked humans and animals. People were forced to wear gas masks so they could go outside of their homes.

Pyroclasts are particles that are ejected during a volcanic eruption. They range in size from very small particles called dust to ash (1/10 of an inch) to lapilli ("little stones" 1/10 of an inch to 2 inches ) to the largest of the pyroclasts, blocks and bombs (2 inches to many feet in diameter).

Volcanic Ash is any very fine grained material erupted from a volcano that is less than 1/10 of an inch (2 millimeters) in diameter. This is very fine material and was given the name ash because it resembles ashes from the burning of wood or coal.

Volcanic ash is rock that has been exploded and shattered by steam inside the volcano. Ash and lava flows build stratovolcanoes into mountains with repeated eruptions.

 

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Pyroclastic flows are spinning mixtures of pyroclasts (small pieces of obsidian, ash, pumice, and cinders) and very hot gases. They flow down the side of the volcano at speeds up to 100 miles per hour and at temperatures sometimes over 700 degrees Fahrenheit!! With temperatures that high pyroclastic flows kill everything it their path.

There were two pyroclastic flows from Mt. St. Helens main eruption in 1980. The first flow was called the "stone wind" and it annihilated everything in its path. Huge trees over one hundred feet tall were snappped and splintered like twigs. Temperatures of over 700 degrees ate up all the oxygen in the area. All animal life in its path was destroyed in seconds including 57 humans. Later in the day another pyroclastic flow piled pumice and ash in thick deposits for many miles around the mountain.

The photo above is a pyroclastic flow down the north flank of Mt. St. Helens.

 

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Pumice is a very light colored, frothy volcanic rock. Pumice is formed from lava that is full of gas. The lava is ejected and shot through the air during an eruption. As the lava hurtles through the air it cools and the gases escape leaving the rock full of holes.

Pumice is so light that it actually floats on water. Huge pumice blocks have been seen floating on the ocean after large eruptions. Some lava blocks are large enough to carry small animals.

Pumice is ground up and used today in soaps, abrasive cleansers, and also in polishes.

 

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Bombs and blocks are the largest of the pyroclasts.

Blocks are angular chunks of rock that has been ejected from a volcano during an eruption.

The photo above is of a geologist studying pumice blocks from the May 18, 1980 eruption of Mt. St. Helens.

 

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A bomb is formed as lava hurtles through the air, cooling and forming a hardened lava rock. A bomb's shape is usually more rounded or streamlined. Notice the teardrop shape of the bombs.

 

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Obsidian is a very shiny natural volcanic glass. When obsidian breaks it fractures with a distinct conchoidal fracture. Notice in the photo to the left how it fractures. Obsidian is produced when lava cools very quickly. The lava cools so quickly tht no crystals can form.

When people make glass they melt silica rocks like sand and quartz then cool it rapidly by placing it in water. Obsidian is produced in nature in a similar way.

Obsidian is usually black or a very dark green, but it can also be found in an almost clear form.

Ancient people throughout the world have used obsidian for arrowheads, knives, spearheads, and cutting tools of all kinds. Today, obsidian is used as a scapel by doctors in very sensitive eye operations.

 

Write the answers to the following questions in complete sentences on a piece of paper. Use the page titles located directly under the questions to move your way through the lesson to locate the answers. When you have finished the questions click on the Earth icon to return to the start of the lesson.

1. Describe pahoehoe and aa lava flows.

2. What is a pyroclast and how do they form?

3. Write a definiton for the following;

- High viscosity

- Low viscosity

Volcanic Cones and Eruptions Lesson #8

cones1

 

The photo above is of Mt. St. Helens today. This once beautiful mountain was changed dramatically on May 18, 1980. The eruption that occurred was a Plinian eruption, which is the most violent eruption classification.

As you learned in the last lesson, different magmas have varying amounts of silica and gas that cause the lava to either be thick and pasty or thin and runny. The thickness and thinness of the magma will determine how a volcano will erupt and what kind of a cone will form.

Volcanoes will erupt for two reasons

1. The magma deep under the crust is less dense than the surrounding rock causing it to rise.

2. As the magma approaches the surface of the Earth the gas that is in the magma will come bubbling out because the pressure surrounding the magma will decrease nearer the surface.

 

Have you ever had a can of soda pop explode all over the room? This "eruption" of pop is caused by the same scientific principle that causes a volcano to erupt violently. When you open the pop can the pressure is released so quickly that the gas that is dissolved in the pop comes rushing out along with some of the pop.

 

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Volcanoes are classified by the eruption type and by the volcanic cone shape.

There are three basic cone shapes and six eruption types. The three cone shapes are cinder cones, shield cones, and composite cones or stratovolcanoes.

 

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The six eruption types are in order from least explosive to the most explosive; Icelandic, Hawaiian, Strombolian, Vulcanian, Pelean, and Plinian.

Notice how, as the eruptions become more violent, the cone shapes become more steeply constructed.

 

You will read about these volcanic types in more depth later in the lesson.

 

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Icelandic, flood, or fissure eruptions are all terms for volcanic eruptions that flood the surface of the Earth with massive amounts of very hot, very thin, runny lava. The lava comes out of the ground through long cracks in the surface called fissures. Some of these fissures can be up to 15 miles long.

The type of cone produced from icelandic eruptions is a shield cone. Shield cones are very low and very broad shaped volcanoes. These volcanoes erupt many times over the same area forming huge, and thick lava plateaus.

The Deccan Plateau of India was formed this way and covers 100,000 square miles (A little smaller than the state of Montana). The Columbia Plateau of the western United States is the largest lava plateau in the world. It covers almost 100,000 square miles and is almost a mile thick in places.

The photo above is of Krafla Volcano on the island of Iceland.

 

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Hawaiian eruptions are similar to Icelandic eruptions because both eruption types have many fissures bringing the lava to the surface. Both types of eruptions are known for their beautiful fire fountains like the one shown above. The lava that flows from both types of eruptions is very hot, thin, and runny which allows for fast flowing lava flows.

The main difference lies in the fact that most Hawaiian eruptions have the greatest quantity of lava pouring out of the main vent at the volcano's summit, not along side fissures. These summit eruptions build the cone steeper and higher. The volcano above was formed from Hawaiian eruptions.

 

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Shield cones were named by Icelandic people because the cone's shape reminded them of a warriors shield layed down. Shield cones form from hot, runny lava that is erupted from the the volcano through its summit and the many side vents and fissures throughout the volcano's flanks (Sides). Shield cones are low, very broad, and gently sloping volcanoes. The volcano pictured above is Mauna Kea, which is located on the big island of Hawaii.

Mauna Loa, which is also on the big island, is the largest volcano on Earth and the tallest mountain in the world if measured from the floor of the ocean where it was formed. Mauna Loa is 13,677 feet above sea level but over 17,000 feet of mountain lies under the water. This volcanic mountain is over 30,000 feet tall from sea floor to the summit. Maua Loa started to form above the Hawaiian hot spot about one million years ago and broke the surface of the ocean about 500,000 years ago. 

 

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Strombolian and Vulcanian eruptions are more explosive than Icelandic and Hawaiian eruptions.

Strombolian eruptions are named for the volcanic island off of the coast of Italy. Stromboli has erupted over many centuries almost constantly. Stromboli has been named the "Lighthouse of the Mediterranean" because it erupts every 20 minutes or so.

Strombolian eruptions are short lived explosive eruptions that shoot very thick and pasty lava into the air along with bursts of steam and gas.

Strombolian eruptions usually produce little or no lava. Because of this the cones that are produced by this type of eruption is a very steep sided cone called a cinder cone.

The photo shows a strombolian eruption taking place from a cinder cone.

 

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Cinder cones get their name from the material that forms them, cinders. Cinder cones are the simplest volcanic formation. They form from explosions of red, hot magma cinders and ash. These cinders and ash settle around the main vent and build a steep sided cone. Very little lava is erupted from a cinder cone. Cinder cones very rarely rise to more than 1,000 feet above the surrounding landscape. Cinder cones are known for their very violent, explosive, exciting eruptions. Paricutin in Mexico and Mt. Vesuvius in Italy are famous cinder cones.

 

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Vulcanian eruptions are more violent and explosive than strombolian eruptions. Vulcanian eruptions are named after the island of Vulcano off the coast of Italy. This is the same island that gave us the name "Volcano". Vulcanian eruptions contain high dark clouds of steam, ash, and gas. The ash plume builds a cauliflower shaped head and a thinner more treetrunk-like base. When the volcano quits erupting ash and gases it then ejects thick pasty lava. Vulcanian eruptions usually build a steep sided cone that is more symetrical than a cinder cone. This more symetrical cone is called a strovolcano.

Vulcanian eruptions will send an ash plume to a height of 2 -9 miles. The photo to the left is of Katla volcano in Iceland which erupted in 1918.

 

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Stratovolcanoes or composite cones are formed from a combination of eruptions. First the volcano will have an explosive eruption that ejects huge amounts of steam, gas and ash. This will be followed by the ejection of lava. A large stratovolcano will be built with many layers of ash and lava.

Stratovolcanoes are the most common type of volcanic cone. There are many famous stratovolcanoes in the world. Mt. St. Helens and Rainier in Washington, Mt. Fuji in Japan, Mt. Pinatubo in the Philippines, and Mt. Etna in Sicily are all examples of stratovolcanoes.

The photo above is of the volcano Mayon, which is in the Philippines.

 

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Pelean and Plinian eruptions are the most dangerous and explosive of the eruption types. Pelean eruptions are named for the catastophic eruption on the island of Martinique in the Carribean Sea in 1902. The eruption and the pyroclastic flow that followed killed 29,000 people almost instantly. "Glowing clouds" of gas and ash flew down the mountain at over 70 miles per hour. The cloud was so full of ash that it was heavier than air and hugged the ground as it approached the coast. The temperatures were probably around 700 degress F. which would annihalate everything in its path.

The only person to survive was a prisoner that was sentenced to death. The only reason he survived was that he was imprisoned in a very thick walled cell and the only door faced away from the explosion.

A Plinian eruption is the most explosive of the eruption types. Mt. St. Helens eruption was a plinian eruption. Plinian eruptions are characterized by a very high ash cloud that rise upwards to 50,000 feet (almost 10 miles) high. Very deadly pyroclastic flows are also part of plinian eruptions.

Mt. Vesuvius, which erupted in 79 A.D. in Italy, was a classic Plinian eruption. Very hot ash falls killed thousands of people in the city of Pompei. Ash falls as high as 17 feet buried the city. Plinian eruptions were named for Pliny the Elder of Rome who died in one of the many eruptions of Vesuvius.

The photo on the left side of this card shows Mt. St. Helens in its plinian eruption on May 18, 1980. The ash cloud rose to a height of over 50,000 feet.

 

Write your answers to the questions on a sheet of paper. When you finish the lesson click on the "Earth" icon so that the next pair of students will be transported to the start of this lesson.

Click on the page titles located directly under the questions to maneuver your way through the lesson to find the answers for the following questions.

1. Name the six eruption types and the three cone shapes.

2. Describe how a: Shield cone form Cinder cone forms Stratovolcano forms

3. Draw diagrams to represent the six eruption types.

 

Hotspot Volcanoes - Hawaii and Yellowstone Lesson #9

This lesson was adapted and modified from Dr. Stephen Mattox's, "A Guide to The Geology of Hawaii Volcanoes National Park".

 

Do you remember that there are three ways that volcanoes can form? They form at subduction zones, mid-ocean ridges and at something called a hot spot. In this lesson you will learn about what causes hot spots to produce volcanoes.

 

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What do you notice about the lines of island groups in the Pacific Ocean?

 

A geologist in the 1960's, by the name of Tuzo Wilson, noticed that there were straight lines of submarine volcanoes and volcanic islands in the Pacific.

 

These linear chains of volcanoes ran in parallel lines to each other. (See white lines on the map)

 

The active volcanoes in these chains are all located in the southeast corner and are the last island in that group.

 

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The oldest islands were the northern most islands in the group. Coincidence???

 

What Tuzo Wilson decided was that the Pacific plate was moving over three hot spots. The Hawaii-Emperor Seamounts, Tuamotu, and the Austral groups of islands each formed over a different hot spot.

About 43 million years ago the Pacific plate shifted its path to a more northwesterly direction. All the island groups changed course at the same time!!

He also concluded that all the islands in the Emperor Seamount- Hawaiian chain all formed over the same hot spot that is currently under the big island of Hawaii today.

 

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A hot spot occurs because of the intense heat of the outer core. This heat radiates through the mantle bringing hot solid rock upward to the hot spot. These areas of rising solid rock are called mantle plumes. Because of lower pressure in the upper region of the mantle the rock begins to melt. This forms magma which rises inch by inch until it reaches the surface forming a volcano.

In 1971 W. Jason Morgan added to the hot spot theory. When the rising solid rock (mantle plume) reaches the plates it splits and spreads horizontally. This split or flow causes the plates to drift.

Morgan proposed that there are 20 different hot spots in the world. Most hot spots are located at mid-ocean ridges, but there are a few located in the middle of plates, like Hawaii and Yellowstone.

 

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This is a map of the Hawaiian Islands today. They didn't always look like this. 4.6 million years ago there was only one island in this group. As the Pacific plate moved slowly northwesterly it produced the Hawaiian Islands, one at a time. Today the big island of Hawaii sits over the same hot spot that produced the other islands.

 

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The first Hawaiian Island to form over the hot spot was Kauai. It began to break the surface of the Pacific Ocean about 4.6 million years ago.

 

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As the Pacific plate moved westward another island formed. That island was Oahu. The capital and largest city of Hawaii, Honolulu, is located on this extinct volcanic island.

 

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The islands of Oahu, Molokai, Lanai, and Maui share the same volcanic base. They all formed from separate volcanoes that were connected by huge lava flows. These volcanic islands also formed from the same hot spot.

 

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Today the Big Island of Hawaii sits over the hot spot and has the only active volcanoes in that island group. Konala, Hualaiai, Mauna Kea, Mauna Loa and Kilauea volcanoes have built the island over the last 500,000 years. Mauna Loa volcano is the largest volcano on Earth. It is over 30,000 feet tall from the seafloor where it was born to the summit, which is 13,684 feet above sea level.

 

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This is a caldera.

A caldera is a large bowl-shaped crater that is formed by the collapse of a volcanic cone after an eruption.

 

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The animation shows the steps in the formation of a caldera.

The volcano usually shows signs of erupting by producing earthquakes as the magma rises in the volcano.

When you shake a can of soda pop and then open it, you will get a shower of gas (carbon Dioxide) and pop. Why? Because the pressure was much higher in the can than outside of the can. When you opened the top the pressure released very quickly shooting the gas and pop out.

 

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After a huge ejection of lava there may be no magma left in the chamber to fill the conduit and crater. When this happens there is a hollow space under the summit of the mountain where the magma used to be. The top of the mountain then collapses creating a caldera.

 

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The caldera may fill with water creating a lake. This is what happened at Crater Lake in Oregon. The ancient volcano Mount Mazama erupted violently about 6,000 years ago creating a caldera. The caldera slowly filled with snowmelt and rain forming beautiful Crater Lake.

Another caldera forms most of the first national park of the United States, Yellowtone. The geysers and hot springs that make the park famous the world over are all volcanic in origin. In other word the park sits on top of an active volcano!!!!

 

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This is a map of Yellowstone National Park. Yellowstone sits atop a continental hot spot. As the North American plate moves steadily westward the hot spot affects different areas of the continent. Volcanic activity can be traced across the United States as the plate has moved across this hot spot.

This caldera is one of the largest calderas in the world. It is over 65 miles across!!

 

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Millions of years ago the North American plate was hundreds of miles east of where it is today. As the plate moved west it slowly moved over the hot spot that is now under Yellowstone. The hot spot has created volcanic features through the western portion of the United States. Craters of the Moon National Monument in Idaho was created by the same hot spot.

 

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(Open image in another window to see animation)

 

This is exactly the same process that formed the Hawaiian Islands. The North American plate continues to move, which means that millions of years from now the hot spot will be under South Dakota or Iowa!!

Remember as you watch the animation, the hot spot is stationary and the North American plate is moving westward!!!

 

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Today Yellowstone National Park sits directly over the hot spot. The volcano is quiet today, only the geysers and hot springs remind us that there is a huge volcano under the beautiful scenery. Only 600,000 years ago a huge eruption filled the area with lava flows. After the huge eruption there was a void under the top of the volcano. The weight of the volcano caused the top to come crashing down forming the large caldera in the park.

 

Write the answers to the following questions in complete sentences on a piece of paper. Use the page titles located directly under the questions to navigate your way through the lesson to locate the answers. When you have finished the lesson click on the Earth icon so the next group can begin the lesson.

1. What is a Hot Spot?

2. How does and hot spot form?

3. How does a caldera form?

Chapter 3 Copymaster: Test, Reviews, Answer Keys, Chapter Schedule

Chapter #3 Copymaster includes tests and answers for students and teachers on material covered in Chapter 3.

Select options on the right hand side to proceed. 

Baseball Game

baseballgame

Materials:


  • One die
  • One baseball diamond transparency
  • Four markers for the runners


Instructions

Break your class into two teams.
Ask a student a question. If they answer correctly award them the base that they rolled with the die. (See rules below) If they answer incorrectly their team is out. One out per inning.

Rules for the game


  1. Shake the die 
    1. single
    2. double
    3. triple
    4. home run
    5. single
    6. single

  2. Ask the question-If they answer correctly award them the base that they rolled with the die. Place a marker on the base that they earned. If there is a runner on base ahead of them move the runner the same amount of bases as the batter. If they answer incorrectly their team is out. One out per inning.

  3. Keep rolling and asking questions until a player answers incorrectly. When they answer incorrectly switch batting teams.

Chapter 3 Review

Chapter 3 Review
Cones, Eruptions, and Pyroclasts

Name___________________

1. What is lava?



2. Name the two smallest particles of pyroclastic material.



3. Name the two largest particles of pyroclastic material.



4. What is a pyroclastic flow?



5. What is the difference between pahoehoe and aa lava flows?



6. What is the difference between high and low viscosity magma?



7. How does a lava tube form?



8. Name the two reasons that volcanic eruptions occur?




9-14. Draw the three volcanic cone shapes and label each.







15-16. What are the two most non-explosive eruption types?



17-18. What are the two most explosive eruption types?



19. What is a hot spot? Use the term mantle plume in your definition.



20. What is a caldera?



21. How does a caldera form?

Chapter 3 Review Answer Key

Chapter 3 Review
Cones, Eruptions, and Pyroclasts

Name Answer Key   

  1. What is lava?
    Lava is molten rock on the surface of the Earth. 

  2. Name the two smallest particles of pyroclastic material.
    Dust is the smallest of the pyroclasts and ash is the second smallest. 

  3. Name the two largest particles of pyroclastic material.
    Blocks are large, sharp edged pyroclasts. Bombs are large, smoothly shaped pyroclasts 

  4. What is a pyroclastic flow?  
    A twirling mixture of very hot ash, gases, and other pyroclastic materials that are heavier than air and flow down a volcano at high rates of speed. (700 degrees and 100 miles per hour) 

  5. What is the difference between pahoehoe and aa lava flows?
    Aa lava flows are very rough and fragmented. They are blocky in their appearance. Aa usually flows at a high rate of speed and cools slowly.  
    Pahoehoe usually flows at a very slow rate of speed. It is smooth and ropey in appearance. 

  6. What is the difference between high and low viscosity magma?
    High viscosity magma is very thick and pasty. It usually has a large amount of dissolved gas . It usually erupts violently.
    Low Viscosity magma is thin and runny with little dissolved gas. It usually erupts with thin flows of lava very quietly. 

  7. How does a lava tube form?
    A lava tube forms a tunnel when the surface of the lava flow cools and hardens, while the interior keeps flowing through, draining away , leaving the interior hollow. 

  8. Name the two reasons that volcanic eruptions occur?
    Magma will rise to the surface of the Earth when it is less dense than the surrounding rock in the mantle. When the magma reaches the surface of the Earth the pressure difference between the gases in the magma and the surface pressures allows the magma to boil out. 

9-14. Draw the three volcanic cone shapes and label each.

Shield Cone-


Cinder Cone-

Stratovolcano or composite cone-

15-16. What are the two most non-explosive eruption types?
Icelandic and Hawaiian eruptions are the least explosive and dangerous of the eruption types. 

17-18. What are the two most explosiveeruption types?
Plinian is the most explosive and Pelean is the deadliest. 
19. What is a hot spot? Use the term mantle plume in your definition.
A hot spot occurs near the crust where very hot solid rock rises through the mantle (a mantle plume) and forms magma near the surface of the Earth. Hot spots form volcanoes in both oceanic plates and continental plates. 

20. What is a caldera?
A caldera is a bowl-shaped depression caused by a volcanic eruption in which the top of the volcano collapses. 

21. How does a caldera form?
A caldera will form when a volcanic eruption depletes the magma chamber causing a void under the volcano's summit. The weight of the top of the volcano causes it to collapse. A bowl-like depression or hole forms there. 

Chapter 3 Student Vocabulary

Vocabulary
Chapter 3

Name____________________

  1. Lava-




  2. Pyroclasts (Pyroclastic Rock)-




  3. Pahoehoe-




  4. Aa-




  5. Viscosity-




  6. Tube-




  7. Dust-




  8. Ash-




  9. Blocks-




  10. Bombs-




  11. Pyroclastic Flows-




  12. Pumice-




  13. Obsidian-




Lesson #8 Volcanic Cones and Eruptions

  1. Three Volcanic Cone Shapes-
  2. Eruption Types-

Leson #9 Hot Spots-Hawaii and Yellowstone

  1. Hot Spot-





  2. Mantle Plume-




  3. Caldera-

Chapter 3 Teacher Vocabulary

Vocabulary
Chapter 3

Name____________________

  1. Lava
    Molten rock on the surface of the Earth.

  2. Pyroclasts (Pyroclastic Rock)-
    Pyro is Greek for fire and clastic means rock. Put them together and it translates into "Rock broken by fire". Pyroclasts are formed from the eruption of a volcano. Pyroclasts range in size from very small pieces of dust to ash to lapilli to bombs and block.  

  3. Pahoehoe-
    A Hawaiian term for lava that has a smooth and ropey surface. Pahoehoe forms when the flow is slow and cools slowly.

  4. Aa-
    A Hawaiian term for lava that is rough and fragmented.
    Aa lava forms when the lava flow is faster and the outside cools quickly causing the outside to become rough and fragmented.

  5. Viscosity-
    The resistance of flow in a liquid. Lava/Magma that is thick and pasty is said to have a high viscosity. High viscosity magma can hold a large amount of gas. This lava/magma usually will erupt violently when the gas that is dissolved in the magma escapes rapidly. Lava/magma that is thin and runny is said to have a low viscosity. These lava/magma will usually not erupt very violently. These eruptions will produce large amounts of lava and little pyroclastic material.

  6. Tube-
    A tunnel formed when the surface of a lava flow cools and hardens, while the still molten and flowing interior drains away.
  7. Dust-
    The smallest of the pyroclasts. Dust from volcanic eruptions have been known to stay floating in the atmosphere for years.

  8. Ash-
    Pyroclasts that are larger than dust. Very fine particles of exploded rock that can drift in the atmosphere for days.  

  9. Blocks-
    Angular pieces of pyroclastic rock that is exploded from a volcano during an eruption. 

  10. Bombs-
    Rounded pieces of pyroclastic material that are exploded during an eruption. These pyroclasts are in semi-plastic state and take their shape as they fly through the air.  

  11. Pyroclastic Flows-
    Very hot turbulent gases, ash, and pyroclasts that are heavier than air and will flow down the side of a mountain at high speeds. These flows have killed thousands of people in some famous eruptions such as Vesuvius in 79 A.D., and Pele on the island of Martinique in 1902.  

  12. Pumice-
    Pyroclastic rock that is in a semi-plastic state as it is shot through the air. The rock is full of gases that escape as the rock hardens. This rock is so full of holes that it floats on water.

  13. Obsidian-
    Lava rock that hardens very quickly. It can cool when it hits water or flowing down the side of a mountain. This rock is natures glass. It usually is dark green to black in color. Native peoples throughout the world have used it to make arrowheads, spears, and knives. It can be chipped to a very sharp edge.



Lesson #8 Volcanic Cones and Eruptions

  1. Three Volcanic Cone Shapes-
    • Cinder Cone-
      Formed from eruptions of pumice and cinders. These cones rarely become more than 1000 feet tall. They are formed from very violent eruptions and can produce large amounts of dangerous gases.

    • Shield Cone-
      The largest of the cone types. These cones are formed from many eruptions of runny lava through the main vent and also through fissures on the flanks of the mountain. The largest volcano in the world, Mauna Loa, is a shield cone along with the rest of the Hawaiian Islands.  

    • Stratovolcano-
      The most dangerous and beautiful of the volcanic cones. It is produced from the alternating eruptions of ash and lava. Some of the most famous volcanoes in the world are stratovolcanoes. Mt. Fujiama in Japan, Mt. Ranier and Mt. St. Helens in Washington, Mt. Etna in Sicily, and Mt. Vesuvius in Italy are all stratovolcanoes.

  2. Eruption Types-
    • Icelandic-
      These eruptions are produced from many long cracks in the Earth called fissures. They are sometimes called flood eruptions because of the amount of lava produced. The magma is thin and runny and pours out of these fissures in great quantities. The great Columbian Plateau of Washington and Idaho were produced from Icelandic Eruptions. The lava that cover the Columbia Plateau is over a mile thick in places. They usually form shield cones.

    • Hawaiian-
      Very similar to Icelandic eruptions, the difference lies in the fact that the majority of the lava flows from the main vent in Hawaiian eruptions instead of through fissures. The lava is thin and runny and the eruptions are usually not violent. They usually form shield cones.

    • Strombolian
      Strombolian eruptions are short lived explosive eruptions that shoot very thick and pasty lava into the air along with bursts of steam and gas. These eruptions usually produce cinder cones.  

    • Vulcanian-
      Vulcanian eruptions are more violent and explosive than strombolian eruptions. Vulcanian eruptions contain high dark clouds of steam, ash, and gas. The ash plume builds a cauliflower shaped head and a thinner more treetrunk-like base. When the volcano quits erupting ash and gases it then ejects thick pasty lava. Vulcanian eruptions usually build a steep sided cone that is more symmetrical than a cinder cone called stratovolcanoes (composite cones)

    • Pelean-
      Pelean eruptions are named for the catastrophic eruption on the island of Martinique in the Caribbean Sea in 1902. The eruption and the pyroclastic flow that followed killed 29,000 people almost instantly. "Glowing clouds" of gas and ash flew down the mountain at over 70 miles per hour. The cloud was so full of ash that it was heavier than air and hugged the ground as it approached the coast. The temperatures were probably around 700 degrees F. which would annihilate everything in its path. 

    • Plinian-
      A Plinian eruption is the most explosive of the eruption types. Mt. St. Helens eruption was a plinian eruption. Plinian eruptions are characterized by a very high ash cloud that rise upwards to 50,000 feet (almost 10 miles) high. Very deadly pyroclastic flows are also part of plinian eruptions.  
      Mt. Vesuvius, which erupted in 79 A.D. in Italy, was a classic Plinian eruption. Very hot ash falls killed thousands of people in the city of Pompeii. Ash falls as high as 17 feet buried the city. Plinian eruptions were named for Pliny the Elder of Rome who died in one of the many eruptions of Vesuvius.

Lesson #9 Hot Spots-Hawaii and Yellowstone

  1. Hot Spot- 
    A hot spot occurs because of the intense heat of the outer core. This heat radiates through the mantle bringing hot solid rock upward to the hot spot. These areas of rising solid rock are called mantle plumes. Hot spots do not move, but the plates above the hot spot moves producing island chains and the spreading of the oceans at mid-ocean ridges.

  2. Mantle Plume-
    Mantle plumes are areas of hot solid rising rock. This rock moves from the lower reaches of the mantle to the surface of the Earth causing the formation of volcanoes.

  3. Caldera-
    A caldera is a large bowl-shaped crater that is formed by the collapse of a volcanic cone after an eruption.

Chapter 3 Test

Chapter 3 Test
Cones, Eruptions, and Pyroclasts

Name______________________

MATCHING


1. ___Lava  A. Rough and fragmented lava flows
2. ___Pahoehoe  B. The most explosive eruption type. Ash plumes may reach 50,000 feet.
3. ___Plinian  C. Molten rock on the surface of the Earth
4. ___Hawaiian  D. Large pyroclasts-over 2 inches long with a rounded shape
5. ___Aa  E. Smooth and ropey lava flows
6. ___Low Viscosity  F. Thin and runny magma that usually erupts quietly with large amounts of lava.
7. ___Bombs  G. Eruption type in which thin and runny magma reaches the surface of the Earth through the main vent and fissures.


8-9. Name two reasons that volcanic eruptions occur.




10-15. Name and draw the three kinds of volcanic cones.


16. What is a hot spot?



Fill in the blank with the correct answer. Use the following words to complete the blanks. Dust, Lava Tube, Mantle Plume, Ash, Caldera, Pyroclastic Flow, Blocks.

17. A large rough edged, angular pyroclast that is ejected during a volcanic eruption is called a _______________________.

18. A______________________ is a bowl-shaped depression caused by a volcanic eruption in which the top of the volcano collapses.

19. The smallest of the pyroclasts are called ___________________. They may stay in the atmosphere for years.

20. A ____________________ forms when the surface of the lava cools and hardens, while the molten interior flows through and drains away.

21. __________________ is the second smallest pyroclast. This material along with lava builds stratovolcanoes larger with repeated eruptions.

22. A ____________________ is very hot, solid rock that rises through the mantle and will become magma as it reaches the surface of the Earth. They form hot spots.

23. A_________________________ is a very hot, twirling mixture of ash, small pieces of pumice and other pyroclasts that are heavier than air and move down a volcano at high rates of speed.

Chapter 3 Test Answer Key

Chapter 3 Test
Cones, Eruptions, and Pyroclasts

Name Answer Key  

MATCHING


1.  ___C___Lava  A. Rough and fragmented lava flows 
2.  ___E___Pahoehoe  B. The most explosive eruption type. Ash plumes may reach 50,000 feet.
3.  ___B___Plinian  C. Molten rock on the surface of the Earth
4.  ___G___Hawaiian  D. Large pyroclasts-over 2 inches long with a rounded shape
5.  ___A___Aa  E. Smooth and ropey lava flows
6.  ___F___Low Viscosity  F. Thin and runny magma that usually erupts quietly with large amounts of lava.
7.  ___D___Bombs  G. Eruption type in which thin and runny magma reaches the surface of the Earth through the main vent and fissures.


8-9. Name two reasons that volcanic eruptions occur.
Magma will rise to the surface of the Earth when it is less dense than the surrounding rock in the mantle. When the magma reaches the surface of the Earth the pressure difference between the gases in the magma and the surface pressures allows the magma to boil out. 
This is like opening a can of pop when it has been shaken. 

10-15. Name and draw the three kinds of volcanic cones.

Shield cone- Low and broad shaped cone formed from many eruptions of thin and runny lava.

Cinder ConeSteep sided cone formed from the ejection of pyroclastic materials. 

Stratovolcano or composite cone- Formed from many alternating eruptions of ash and lava. Beautifully symmetrical cones. 


16. What is a hot spot?
A hot spot occurs near the crust where very hot solid rock rises through the mantle (a mantle plume) and forms magma near the surface of the Earth. Hot spots form volcanoes in both oceanic plates and continental plates. 

Fill in the blank with the correct answer. Use the following words to complete the blanks. Dust, Lava Tube, Mantle Plume, Ash, Caldera, Pyroclastic Flow, Blocks.

17. A large rough edged, angular pyroclast that is ejected during a volcanic eruption is called a block  .

18. A caldera  is a bowl-shaped depression caused by a volcanic eruption in which the top of the volcano collapses.

19. The smallest of the pyroclasts are called dust  . They may stay in the atmosphere for years.

20. A lava tube  forms when the surface of the lava cools and hardens, while the molten interior flows through and drains away.

21.  Ash  is the second smallest pyroclast. This material along with lava builds stratovolcanoes larger with repeated eruptions.

22. A mantle plume  is very hot, solid rock that rises through the mantle and will become magma as it reaches the surface of the Earth. They form hot spots.

23. A pyroclastic flow  is a very hot, twirling mixture of ash, gases, and small pieces of pumice and other pyroclasts that are heavier than air and move down a volcano at high rates of speed.

Discussion Questions

Discussion Questions 

Answer Key for Discussion and Hyperstudio Questions


 

Lesson 7 "Lava Flows and Pyroclasts 


 

Thought and Discussion Questions 

  1. What caused the death of so many people during the second eruption of Vesuvius?

  2. What is a pyroclastic flow?

  3. Describe pahoehoe and aa lava flows.

  4. What is a pyroclast and how do they form? 

  5. Write a definition for the following;
    1) High viscosity 2) Low viscosity


    Lesson 8 "Volcanic Cones and Eruptions" 

    No Content Center Today!!

  1. Name the six eruption types and the three cone shapes.


  2. Describe how a: 
    Shield cone forms
    Cinder cone forms
    Stratovolcano forms

  3. Draw diagrams to represent the six eruption types.


Lesson 9 "Hot Spots-Hawaii and Yellowstone" 

Discussion Questions 

  1. What is a Hot Spot? 

  2. How does and hot spot form?

  3. How does a caldera form?

Discussion Questions Answer Key

Discussion Questions 

Answer Key for Discussion and Hyperstudio Questions


 

Lesson 7 "Lava Flows and Pyroclasts 


 

Thought and Discussion Questions 

  1. What caused the death of so many people during the second eruption of Vesuvius?
    Pyroclastic flows of 700 degree ash, gas, and pyroclasts moving of around 70 miles per hour swept over the city killing over 20,000 people. 
  2. What is a pyroclastic flow?
    A turbulent mixture of very hot gas, ash, and pyroclasts flowing down the side of a mountain at from 70 -200 miles per hour. 
  3. Describe pahoehoe and aa lava flows.
    Pahoehoe lava has a smooth and ropey texture. Pahoehoe forms when the lava flows at a slower speed, cooling slowly. Aa lava has a rough and fragmented surface. The lava forms when the lava flows at a fast speed, cooling quickly. 
  4. What is a pyroclast and how do they form? 
    Pyroclasts are 
  5. Write a definition for the following;
    1) High viscosity 2) Low viscosity


    Lesson 8 "Volcanic Cones and Eruptions" 

    No Content Center Today!!

  1. Name the six eruption types and the three cone shapes.


  2. Describe how a: 
    Shield cone forms
    Cinder cone forms
    Stratovolcano forms

  3. Draw diagrams to represent the six eruption types.


Lesson 9 "Hot Spots-Hawaii and Yellowstone" 

Discussion Questions 

  1. What is a Hot Spot? 

  2. How does and hot spot form?

  3. How does a caldera form?

Lesson #7 Content Center

Content Center
Lesson #5 "Volcanoes"
Vesuvius "The Day it Rained Fire"

Pompeii and Herculaneum were bustling Roman cities in 79 A.D. Mt. Vesuvius hadn't erupted in over eight hundred years and the mountain was green with fig and olive trees. Farmers cultivated the sides of the cone. The people were used to earthquakes and didn't pay much attention to the numerous quakes that had been rattling their bowls and plates prior to the eruption. What they didn't know would kill thousands of people that beautiful August day in 79 A.D. Vesuvius was awakening from its long slumber.



Vesuvius awakened with a huge eruption of ash and pumice raining down on the city of Pompeii. Pompeii lay to the south of the volcano and that day the wind was from the north pushing the cloud toward the city. Pompeii was buried in up to 20 feet of pumice and ash. Many animals and people were suffocated and buried alive. Many people though, did survive the initial eruption. Some decided to flee but many stayed. 



The city of Herculaneum lays to the west of the volcano and much closer to Vesuvius than Pompeii. Herculaneum was a beautiful beachside resort city in 79 A.D. Herculaneum was barely touched by the first eruption. In fact, about only one inch of ash and pumice fell on the city during the first eruption. 
The next eruption was the deadly one. This eruption blanketed the whole surrounding area with very hot, turbulent, twirling gases and ash. This glowing cloud was very heavy and hugged the ground as it flowed down the side of Vesuvius. The temperatures of this pyroclastic flow were probably around 700 degrees F. and at a speed of over 70 miles per hour animals and people could not out run it. With temperatures this high everything in its path is killed instantly.  
Herculaneum didn't get lucky this time. It was buried in an extremely hot flood of volcanic mud. This steam filled volcanic mud buried the city with a layer over 50 feet high. Pompeii suffered through this eruption also. Over 20,000 citizens died in the pyroclastic flows only hours after the initial eruption.
A man by the name of Pliny the Younger wrote an account of this eruption as he viewed Vesuvius from Naples to the northwest of the volcanic mountain. His account was probably the first one ever written. His uncle, Pliny the Elder, died in the second eruption that day. Pliny the Elder was a commander of a fleet of Roman battleships. He was also a naturalist, a person who studies natures spectacles and writes about them. He was viewing the eruption when he was probably over come by hot gases.
Today Vesuvius is the most visited volcano in the world. The mountain that hadn't erupted in about eight hundred years has erupted many times since. In 1631, Vesuvius belched out another pyroclastic flow, which has been the worst eruption since 79 A.D. Many tourists pay to make the very difficult climb to the crater to view the steaming lava inside the volcano. They flock to the excavated ruins of Pompeii and Herculaneum to view the plaster casts of bodies as they lay when they died almost two thousand years ago during the day that rained fire. 
Discussion Questions

1. What caused the death of so many people during the second eruption of Vesuvius?

2. What is a pyroclastic flow?

Lesson #7 Goals, Objectives, and Materials

Goals, Objectives and Materials
For Lesson #7
"Lava Flows and Pyroclasts"

Goals:

To familiarize students with the vocabulary associated with volcanic processes and the structure of a volcano itself.

Objectives: 

The students will:

  1. Become familiar with the processes and concepts that create and build volcanoes;
  2. Become familiar with the terms associated with volcanic processes;
  3. Become familiar with the vocabulary associated with the structure of a volcano.

Materials: 

  1. Hands-On Lesson Plan Sheet

  2. Five colors of modeling clay or playdough-Red, Brown, Gray, Black, Blue

  3. 10 X 12 sheets of tag board

  4. Felt tip pen for labeling

  5. Thick Thread

Lesson #7 Hands-on Center

Hands-On Center
(Lava Flows and Pyroclasts)
Lesson #7
Modified and adapted from John Farndon's book 
"How the Earth Works"

Flowing Lava


Materials

  1. 4 plastic jars
  2. 4 spoons
  3. fine grained sand
  4. stop watch
  5. 4 plastic plates
  6. 1 tablespoon
  7. molasses
  8. liquid dish soap
  9. shampoo
  10. vinegar


Part 1

The students will need their science notebooks, pencils, and stop watches ready. One student will measure one tablespoon full of one of the liquids. They will slowly pour that liquid onto a plastic plate. Another student will time how long it takes for the liquid to stop spreading. Repeat this procedure with the other three liquids. 
The liquids that have the longest spreading times have the highest viscosities. Tell the students there are lavas with very low viscosities (very thin and runny) and lavas with very high viscosities (thick and pasty). There are also many different lavas in between.  
Low viscosity lavas are found in Hawaii and Iceland and are usually not violent. High viscosity lavas are very violent and erupt with little or no lava. High viscosity lavas shoot pyroclasts such as pumice, cinders and ash high into the air.

Part 2
Have the students add one teaspoon of sand to one cup of the four liquids used in part 1.  
Stir the mixture thoroughly.  
Have the students repeat the pouring and timing portion as in part 1. Have all students record the times and compare Part 1 to Part 2 times.
Explain to the students that lavas with a high silica content(sand and quartz) have high viscosities(aa) and lavas with low silica contents have low viscosities (pahohoe)
Add sand to a cup of molasses until its viscosity is so high that will not flow. Spoon the mixture onto a dish and explain that they have just created a lava dome.
High or Low Viscosity

Materials: 
  1. 2 plastics jars
  2. molasses
  3. water
  4. 2 straws


Fill a small plastic jar to within one inch of the rim with water and the other jar with molasses. Put one straw into each jar. Have one student blow bubbles with the same pressure. Record what happens. The students will see rapid bubbling in the water because the water has a low viscosity. This is what pahoehoe lava is like. The gases escape quickly from the low viscosity lava and usually are not very violent. 
The students will see a slow bubbling from the molasses because of its high viscosity. Lava with a high viscosity will hold a lot of gas and will loose the gas as it nears the surface of the Earth and the pressures become lower (like opening a bottle of pop and releasing the pressure). These magmas erupt violently frequently.

Floating Rocks????
Materials: 
Pumice
Clear plastic container
Water
Float pumice in a container full of water. Have the students draw what they see. Show the students the holes in the pumice explaining they were formed as the rock hurtles through the air.  

Lesson #8 Goals, Objectives, and Materials

Goals, Objectives and Materials
For Lesson #8
"Volcanic Cones and Eruptions"

Goals:

To familiarize students with the processes involved in volcanic eruptions and how these eruptions form volcanic cones.

Objectives: 

The students will:

  1. become familiar with the processes involved in volcanic eruptions;
  2. become familiar with the way eruption types form volcanic cones;
  3. become familiar with the differences in magma viscosity and how it relates to eruption explosiveness.

Materials: 

  • Hands-On Lesson Plan Sheet

  • Glass jar 9/10 filled with honey
  • small cork
  • Small steel ball (steel marble)
  • modeling clay, playdough, or art clay
  • popsicle sticks for shaping cones
  • wax paper
  • tag board
  • colored markers



  • Lesson #8 Hands-on Center

    Hands-On Lesson #8
    (Volcanic Cones and Eruptions)
    Why Does Magma Rise??
    Materials: Glass jar 9/10 filled with honey
    small cork
    Small steel ball (steel marble)

    The students will place a small cork and a small steel ball into an empty glass jar. The students will then fill the jar with honey and watch what happens. They should write down their predictions as to what will happen after the honey is placed in the jar. The students should write down what they see occurring and why they believe it happened..  
    The students will observe that materials made of less dense material (cork) will rise in a much denser medium (honey). The steel ball will remain on the bottom of the jar because it is denser than the medium that it is in (honey). Magma will rise in the Earth for the same reason, the magma is produced by the melting of the oceanic crust and the top layer of the mantle. The melting material is less dense than the surrounding mantle and that causes it to rise.




    Cone Shapes
    Materials: 
    1. modeling clay or playdough
    2. popsicle sticks for shaping cones
    3. wax paper


    The students will construct a 3-d model of the three basic  
    volcano cone shapes using modeling clay or playdough.

    1. shield cone

    2. cinder cone

    3. composite cone or stratovolcano

    Lesson #9 Content Center

    Content Center 
    (Lesson #9)
    Hot Spots-Hawaii and Yellowstone

    Geysers and Hot Springs

    Old Faithful geyser in Yellowstone Nation Park is a famous tourist attraction. Every hour or so it sends a stream of scalding hot water from 135-200 feet in the air. Why does this occur? The same scientific principle that makes a volcano erupt turns a hole in the ground into a spectacular fountain.
    Hot springs and geysers form over magma chambers in very similar ways. Geysers though, are more complex in how they form and much more spectacular in the display that they put on. Here is how the Earth works like a giant hot water heater and boiler.  
    Rain water seeps into the ground and slowly percolates down through cracks in the layers of the upper crust. Here it collects in porous rock that holds the water like a sponge.  
    The huge magma chamber that sits under the park is the heating source. This magma chamber is located over two miles below the porous rock layer that holds the water. The rock below radiates the heat up to the water by a method called conduction. You have felt conduction when you have picked up a glass handled dish of hot water from the microwave oven. The glass handle is hot because the heat from the water radiates through the bowl to the handle.  
    The water in the layer of porous rock is heated but will not boil because it is under extreme pressure from the overlying rock. The water is superheated like in a steam boiler. The temperatures may reach over 500 degrees Fahrenheit! At the same time that the water is heating, more water from the surface keeps coming into the rock layer. This cooler water sinks to the bottom causing the hot water to rise. When the water rises the pressure from the surrounding rock layers drops. The result is the hot water will continue to rise untill it reaches the surface of the Earth. Some of these hot springs become filled with mud and form hot mud pots. People throughout the world come to hot springs and mud pots for enjoyment and some even believe they have medicinal or magical healing powers.
    Geysers, the giant boilers of the Earth, are produced in a slightly more complex way. As the heated groundwater rises it collects in rock pockets that are under extreme pressure. Because of the high pressure the water is not able to boil. The temperature continues to rise until some of the water boils. The steam then rises very fast and takes some of the non-boiling water with it. This reduces the pressure in the rock pocket. Thr superheated groundwater then heats to steam quickly because of the drop in pressure around it. When this happens the rest of the water in the rock pocket explodes out through the fissure and will continue to erupt until the steamy groundwater is gone.  
    Sometimes these eruptions will last for over an hour. When the eruption is over the rock pocket will fill with groundwater and start the cycle again.  
    Old faithful in Yelowstone Nation Park goes through this cycle every 65 minutes or so.  




    Questions


    1. What is the difference between a hot spring and a geyser?







    2. Why does the release of pressure cause the geyser to erupt so explosively?

    Lesson #9 Goals, Objectives, and Materials

    Goals, Objectives and Materials
    For Lesson #9
    "Hot Spot Volcanoes-Hawaii and Yellowstone"

     

    Goals:

    To familiarize students with the vocabulary and  
    processes involved in understanding hot spot 
    volcanism.

    Objectives: 

    The students will:

    1. become familiar with the processes of plate  
      movement that causes hot spot volcanoes to 
      form;
    2. become familiar with the processes that 
      cause mantle plumes to form and rise.


    Materials: 

    1. One "Content Center Lesson" for each student

    2. Hands-On Lesson Plan Sheet

    3. Cooking Oil
    4. Squeeze Bottle (Example: dish soap bottle)
    5. Large Clear Plastic Container
    6. Water
    7. Red Food Coloring

    Lesson #9 Hands-on Center

    Hands-on Center 

    (Hot Spots: Hawaii and Yellowstone) 
    Lesson #9

    The mantle's convection experiment
    Modified and adapted from John Farndon's book 
    "How the Earth Works"

    The teacher must set up and run this experiment! The oil and dish will get hot!!!!!


    Materials: 

    1. 1 heat proof glass dish
    2. 1 tea candle
    3. 3 cups of cooking oil
    4. 1 book of matches
    5. 1 bottle of dark colored food coloring 
    6. 1 eye dropper
    7. 2 clay bricks
    8. 4 small pieces of packing foam 



    1. Pour the 4 cups of cooking oil into the glass dish.
    2. Place the glass dish onto the 2 clay bricks.
    3. Light the tea candle and place it under the glass dish.
    4. Put dark colored food coloring into the eyedropper.
    5. Squeeze some of the food coloring into the cooking oil near the bottom of the glass dish.  
    6. When the food coloring begins to move lay some pieces of Styrofoam on top of the cooking oil and observe the movement. (The flowing of the Styrofoam will represent the movement of the Earth's plates) The cooking oil will heat up and convection currents will be generated. The food coloring will enable the students to see the movement of the convection currents. The oil and food coloring will rise as they heat up. The rising material will cool as it nears the surface of the liquid. The farther the material gets from the heat source the cooler it will become. As the material cools it will slowly desend.  
      This process of gaining energy (heat) and rising and then losing energy (cooling) will go on and on. These are convection currents. This rising and cooling sets up a current in the cooking oil. The teacher should explain that this is a theory of how the mantle "flows" and the plates (Styrofoam pieces) of the Earth are carried with these movements.
      The students should draw and label a diagram of the experiment.  

      Magma Rising
      Materials: 
      1. Cooking Oil
      2. Squeeze Bottle (Example: dish soap bottle)
      3. Large Clear Plastic Container
      4. Water
      5. Red Food Coloring
      1. Have the students fill a plastic squeeze bottle full of cooking oil with red food coloring in it.  
      2. Place the squeeze bottle into a large clear plastic container full of water.  
      3. Tell the students to squeeze slowly the bottle full of cooking  oil.  
      1. Have the students record what they observe.  
        The students will observe the cooking oil rise through the water because the oil is less dense than the water. The same process causes magma in the Earth to rise from the bottom of the Mantle to the Earth's crust causing volcanism.