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Unit: Volcanoes. Topic: Volcano Locations. Objectives: Day 1 of 3 I will understand what a volcano is and how it is formed I will understand the 3 locations where volcanoes form at. Quick Write:. Answer a question of your choice in 2-3 sentences:
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Unit: Volcanoes Topic: Volcano Locations • Objectives: Day 1 of 3 • I will understand what a volcano is and how it is formed • I will understand the 3 locations where volcanoes form at
Quick Write: Answer a question of your choice in 2-3 sentences: • Have you or your family ever visited a volcano? If so where at? Describe the experience: • How do volcanoes grow in size???? • What do you think volcanoes are made of????? • Where do you think volcanoes form at???
Volcanoes and You • A volcano is an opening in the earth’s surface that often forms a mountain when layers of lava and ash build up over time
What is a Volcano? • An opening in the earth’s surface that forms a mountain as ____of lava and ash build up over time Answer Bank apart constant rises collide layers
Magma Rising • How does magma make it to the surface? • Magma is hotter, lighter and less dense than the rock around it • This process is similar to a lava lamp • Therefore, it slowly makes its way upward toward the earth’s surface • Eventually it finally makes it’s way to the surface exiting a volcano
How does Magma make it to the Earth’s surface? • Because it is hotter and less dense, therefore it _____ up to the surface exiting a volcano Answer Bank apart constant rises collide layers
Volcano Locations • Volcanoes form at: - Divergent plate boundaries Here plates pull apart as new magma rises (Ex—Iceland) - Convergent plate boundaries Here plates collide and one plate subducts where it melts feeding volcanoes at the surface (Ex—Mt. St. Helens WA) -Hot spots Hereaconstantsteady flow of magma rises to the surface to form volcanoes (Ex—Hawaii)
Volcano Locations • Volcanoes form at: - Divergent plate boundaries Here plates pull apart as new magma rises (Ex—Iceland)
Volcano Locations • Volcanoes form at: - Convergent plate boundaries Here plates collide & one plate subducts where it melts feeding volcanoes at the surface (Ex—Mt. St. Helens)
Cascade Volcanoes • From Northern California up to Canada lies a series of volcanoes called the Cascade Mountain Range • Here the Juan de fuca plate subducts under the north American plate forming a series of volcanoes that stretch form Northern California Up to Canada • As the Juan de fuca plate subducts, it melts, feeding the volcanoes at the surface
Mount St. Helens • In 1980, Mt. Saint Helens erupted in the state of Washington • It was one of the largest recent volcanic eruptions in North America • Geologists warned people to leave, but despite this, 63 people lost their lives from this eruption • Heat from the eruption caused snow to melt, creating major floods
The Re-Birth of Mt. Saint Helens
Which way was the blast coming from?Trees behind the mountain were spared
Volcano Locations • Volcanoes form at: - Hot Spots Here a constantsteady flow of magma rises to the surface to form volcanoes (Ex—Hawaii)
Hot Spots • Hawaii formed as the Pacific plate slowly moved over a Hot Spot • Over Ten Million Years, A chain of Islands formed Ocean Lithospheric Plate Stationary Hot Spot
Where are the 3 locations volcanoes form? - Divergent plate boundaries Here plates pull _____ as new magma rises (Ex—Iceland) - Convergent plate boundaries Here plates _____ and one plate subducts where it melts feeding volcanoes at the surface (Ex—Mt. St. Helens WA) -Hot spots Herea ____steady flow of magma rises to the surface to form volcanoes (Ex—Hawaii) Answer Bank apart constant rises collide layers
Convergent plate boundaries are located all around the Pacific Rim Because of this, volcanoes are located all around the Pacific Ocean These volcanoes make up the Ring of Fire Ring of Fire = Volcanoes
What is the Ring of Fire? • A chain or ring of volcanoes ____ the pacific ocean created by convergent boundaries Answer Bank apart constant rises Collide around layers
Summarize: Answer Bank Convergent Spots constant mountains spread Volcanoes Form at: Divergent Plate Boundaries Hot ____ _______ Plate Boundaries Plates____ as magma rises ______ flow of magma to the surface Plates collide Feeding volcanic ______ above
Unit: Volcanoes Topic: Magma Composition • Objectives: Day 2 of 3 • I will know how magma composition effects whether a volcano will erupt violently or quietly • I will know how silica effects the viscosity or thickness of magma
Quick Write: Answer a question of your choice in 2-3 sentences: • What do you think makes a volcano erupt with deadly explosive force??? • Why do you think soda cans explode when you shake them up??? • What do you know about magma???
2 Types of Eruptions Explosive! • Some volcanic eruptions are explosive, & violent and while others are non-explosive erupting quietly • For example, Mt. Saint Helens erupt violently (explosive) • Kilauea in Hawaii erupts quietly (non-explosive) Non-Explosive
What are the 2 types of Volcanic Eruptions? -Explosive, ____eruptions: (Ex: Mt. Saint Helens) -Non-Explosive, _____ eruptions (Ex: Kilauea) Answer Bank Traps silica Quiet Releases gases violent
Magma Composition Rhyolitic Magma = Explosive Eruptions • Why do some volcanoes erupt explosively and others non-explosively? • It has to do with 3 factors: -the amount of trapped gases in the magma -viscosity or thickness of the magma -silica content Basaltic Magma = Non-Explosive Eruptions
What factors make volcanoes explosive? • The amount of trapped ____in the magma • Viscosity or thickness of magma • _____ content Answer Bank Traps silica Quiet Releases gases violent
Magma Composition Rhyolitic Magma = Explosive Eruptions • Rhyolitic Felsic magma is high in silica, therefore it has a high viscosity (thick) and traps gases producing violent explosive eruptions • Basaltic Mafic (dark color) magma is low in silica, therefore it has a low viscosity and releases gases producing quiet non-explosive eruptions Basaltic Magma = Non-Explosive Eruptions
What is the difference between Rhyolitic and Basaltic magma? • Rhyolitic magma: • High in silica • High Viscosity (thick) • ____gases (increasing pressure) • creates violent, explosive eruptions • Basaltic magma: • Low in silica • Low Viscosity (Very fluid) • _____gas (reducing pressure) • creates quiet, non-Explosive eruptions Answer Bank Traps silica Quiet Releases gases violent
Who has been listening?Which one has the most silica?Which one has the least silica? Basaltic Rhyolitic Which magma traps gases? Which magma Releases gases? Which magma contains more silica? Silica Silica
Summarize! Answer Bank Thick High silica viscosity Yes(2) Fluid low No(2) • Magma high in _____ is _____ giving it a high viscosity therefore trapping gases • Magma low in silica is _____ giving it a ____viscosity therefore releasing gases
Unit: Volcanoes Topic: Volcano Types • Objectives: Day 3 of 3 • To understand the differences between the 3 major types of volcanoes • To understand how magma affects the shape and steepness of a volcano
Quick Write: Answer a question of your choice in 2-3 sentences: • Have you ever visited a volcano? Was it big or small? Steep or flat sloping? • What are some famous volcanoes you have heard of? Are they large or small in size?
Forms of Volcanoes • There are three basic types: • Cinder Cone Volcano • Composite Volcano • Shield Volcano
What are the 3 types of Volcanoes? • Cinder Cone Volcano • Composite Volcano • Shield Volcano
Cinder Cone Volcanoes Cinder Cone Volcanoes are made of cinder (hot rock) and ash The eruption of cinder produces very steep sided volcanoes Because of their size, cinder cone eruptions are not considered hazardous 0.5 miles wide
What is a Cinder Cone Volcano? Answer basaltic Steep Small Rhyolitic -____ in size -Made of layers Cinder (hot rock) and ash which produce _____slopes Ex. Paracutin Mexico (Draw picture below) 0.5 miles wide
Composite Volcanoes Composite Volcanoes are made of layers of ash and High viscosity lava Thick high viscosity Rhyolitic lava traps gases producing explosive, violent eruptions The thicker, high viscosity magma gives Composite volcanoes relatively steep slopes 20 miles wide
What is a Composite Volcano? Answer Bank small massive basaltic rhyolitic high -Volcano Made of layers Ash, and _____(thick) lava which produce moderately steep slopes -Thick, ____viscosity magma traps gases producing very explosive & violent eruptions Ex. Mt. St. Helens (Draw picture below) 20 miles wide
Shield Volcanoes Shield Volcanoes are large and flat in shape made only of layers of lava that travel long distances Magma from shield volcanoes is very fluid and runny (low viscosity), traveling large distances These layers of runny, low viscosity lava give shield Volcanoes their characteristic flat, gentle slopes Fluid, basaltic lava releases gases, producing Quiet, non-explosive eruptions 100 miles wide