WOW! Volcano Webquest

__________________________________________________________________ Name: ________________________________ Date: ________________ Go to http://environment.nationalgeographic.com/environment/natural-disasters/forces-of-nature/ Choose a force: Volcanoes On the upper left menu, choose number 1. Read “What is a Volcano?”. How did the ancient Greeks and Romans explain volcanic activity? ____________________________________________________________________________________________________________________________________ What is a volcano? How can volcanoes be beneficial? On the upper left menu, choose number 2. Read “Where do Volcanoes Occur?”. How many active volcanoes are there today or historically? __________________________________________________________________ What is the Ring of Fire? Where do most volcanoes occur? __________________________________________________________________

On the upper left menu, choose number 3. Read “How do Volcanoes Form?”. How are volcanoes associated with plate tectonics? ____________________________________________________________________________________________________________________________________ Choose three of the five shown volcanoes. Explain each type of volcano and how it formed. 1. _________________________________________________________________ ___________________________________________________________________ 2. _________________________________________________________________ ___________________________________________________________________ 3. _________________________________________________________________ ___________________________________________________________________ On the upper left menu, choose number 4. Read “Types of Volcanoes”. List the four (6) types of volcanoes: 1. _______________________ 2. _______________________ 3. _______________________ 4. _______________________ 5. _______________________ 6. _______________________ Click on “Cinder Cone” Cinder cone volcanoes are mostly made up of what materials? Click on “Caldera” How are calderas formed?

Click on “Composite” How do composite volcanoes form? What is another name for this type of volcano? ______________________________________________________________________________________________________________________________________________________________________________________________________ Click on “Shield” How do shield volcanoes get their distinctive shape? What is one example of this type of volcano? ____________________________________________________________________________________________________________________________________ Click on “Submarine” What is unique about this type of volcano and how do scientists detect the explosions? Click on “Lava Dome” How high can a lava dome become? On the upper left menu, choose number 5. Click on “How do Volcanoes Erupt” What are the two traits that characterize volcanoes? 1. ________________________ 2. ________________________

Level of explosiveness Amt. of Dissolved Gases Explosive Higher or lower (circle one) Non-explosive Level of explosiveness Amt. of Dissolved Gases Explosive Higher or lower (circle one) Non-explosive On the upper left menu, choose number 6. Read “Make your own volcano”. Choose dissolved gases amount, silica content, and type of volcano and create several different explosions. On the top right side of your screen, click on “Map”. Roll the mouse over the U. S. and click on Mt. St. Helens in Washington State. What type of volcano is Mt. St. Helen’s? __________________________ What happened on May 18, 1980? ______________________________________________________________________________________________________________________ How old is Mt. St. Helen’s? _____________________________ What happened in the months preceding the May 18th eruption that alerted scientists to a possible eruption? ______________________________________________________________________________________________________________________________________________________________________________________________________ Roll the mouse over another volcano anywhere in the world and give three facts about it. In addition to these facts, give the location and type of volcano. Location: ______________________ Type of volcano: ___________________ Fact 1: _____________________________________________________ Fact 2: _____________________________________________________ Fact 3: _____________________________________________________

Name: ________________________________ Date: ________________ Go to http://environment.nationalgeographic.com/environment/natural-disasters/forces-of-nature/ Choose a force: Volcanoes On the upper left menu, choose number 1. Read “What is a Volcano?”. How did the ancient Greeks and Romans explain volcanic activity? They believed that volcanoes were under the control of gods. What is a volcano? Volcanoes are vents in the Earth’s surface from which molten rock, debris, and steam come. How can volcanoes be beneficial? Volcanoes can be beneficial by providing valuable mineral deposits, fertile soils, and geothermal energy. Lava flows can build new land. On the upper left menu, choose number 2. Read “Where do Volcanoes Occur?”. How many active volcanoes are there today or historically? There are about 1,900 active volcanoes today. What is the Ring of Fire? A band of volcanoes circling the edges of the Pacific Ocean Where do most volcanoes occur? Most volcanoes (about 90%) occur in the Ring of Fire.

On the upper left menu, choose number 3. Read “How do Volcanoes Form?”. How are volcanoes associated with plate tectonics? As the Earth’s huge plates move and interact in the lithosphere, or the planet’s outer shell, they trigger a very gradual chain of events that can end with explosions. Choose three of the five shown volcanoes. Explain each type of volcano and how it formed. 1. Island arc volcanoes are subduction-zone volcanoes. They occur when one oceanic plate subducts, or descends, under another oceanic plate. This action can then create a chain of volcanic islands. 2. Hot Spots make up about 5% of volcanoes. They form in the middle of plates. These intraplate volcanoes are caused by hot spots, unusually hot areas deep within the Earth. Magma rises from the hot spots and erupts as lava through cracks in the Earth’s surface, forming volcanoes. 3. Volcanoes called rift volcanoes arise in areas called spreading centers. In these zones plates are moving away from each other, spreading or splitting the Earth’s crust. 4. When two plates come together, one of the plates may slide under another in a process called subduction. Heat from deep in the Earth melts rock in the descending plate.  5. Continental Rift Zones occur when spreading centers develop within continents. They form new plate boundaries and trigger volcanic activity.   On the upper left menu, choose number 4. Read “Types of Volcanoes”. List the four (6) types of volcanoes: Cinder Cone Caldera Shield Submarine Composite Lava dome Click on “Cinder Cone” Cinder cone volcanoes are mostly made up of what materials? They are mostly made up of ash and cinders. Click on “Caldera” How are calderas formed? Calderas are formed by the inward collapse of a volcano. They can also form on composite volcanoes and on the flat tops of shield volcanoes.

Click on “Composite” How do composite volcanoes form? What is another name for this type of volcano? Composite volcanoes form when pyroclastic eruptions (explosions of ash, cinders, and rock fragments) alternate with lava flows. Another name for composite volcanoes is stratovolcano. Click on “Shield” How do shield volcanoes get their distinctive shape? What is one example of this type of volcano? They get their unique shape from rapid streams of lava that spread easily and then cool, forming smooth, gentle slopes. Click on “Submarine” What is unique about this type of volcano and how do scientists detect the explosions? Submarine volcanoes can erupt under water! Scientific instruments called hydrophones can detect the explosions.   Click on “Lava Dome” How high can a lava dome become? A lava dome volcano can grow to become several hundred meters high and be more than 3, 280 feet in diameter! On the upper left menu, choose number 5. Click on “How do Volcanoes Erupt” What are the two traits that characterize volcanoes? 1. Explosiveness 2. Viscosity

Level of explosiveness Amt. of Dissolved Gases Explosive Higher or lower (circle one) Non-explosive Level of viscosity Amt. of Silica Less viscous Higher or low silica (circle one) More viscous On the upper left menu, choose number 6. Read “Make your own volcano”. Choose dissolved gases amount, silica content, and type of volcano and create several different explosions. On the top right side of your screen, click on “Map”. Roll the mouse over the U. S. and click on Mt. St. Helens in Washington State. What type of volcano is Mt. St. Helen’s? Composite What happened on May 18, 1980? Mt. St. Helen’s had a violent eruption. How old is Mt. St. Helen’s? Less than 27,000 years old. What happened in the months preceding the May 18th eruption that alerted scientists to a possible eruption? A few months before the May eruption, a series of earthquakes began to shake the volcano. Several small steam eruptions occurred, new fissures appeared, and a bulge developed on the north flank of the volcano. The bulge got larger and larger. A week before the big eruption, it was still expanding (at a rate of about seven feet per day!). Roll the mouse over another volcano anywhere in the world and give three facts about it. In addition to these facts, give the location and type of volcano. Location: Answers will vary Type of volcano: ___________________ Fact 1: _____________________________________________________ Fact 2: _____________________________________________________ Fact 3: _____________________________________________________