Lesson 4 - What Are Volcanoes? PDF

Lesson 4 - What Are Volcanoes? Chapter: Our restless planet @ASCSduba i  5 TO START Date 1 Lesson 4 - What Are Volcanoes? 1. What do you already know a...

Lesson 4 - What Are Volcanoes? Chapter: Our restless planet @ASCSduba i  5 TO START Date 1 Lesson 4 - What Are Volcanoes? 1. What do you already know about volcanoes? 2 2. Write a list of things that you already know about volcanoes. This could include: 3 a. Examples of famous volcanoes b. How volcanoes are formed c. What volcanoes look like 4 d. Hazards that volcanoes cause e. Impacts of volcanic eruptions 5 This is just from prior knowledge, do not use research! Last Lesson: Assessment on Lessons 1, 2, 3 Next Lesson: What are earthquakes? Driving Question: What are volcanoes? Driving Question: What are volcanoes? @ASCSduba i Aspiration: Learning Objectives Set goals for this lesson based on your performance. One idea: Define a volcano and identify the key features of a volcano. Agency: Many ideas: Describe the 3 What aspect of this topic would you want to understand stages - active, dormant and better by the end of the lesson? extinct volcanoes; Describe the structure of volcanoes; Describe the types of volcanoes - composite, shield and cinder cone volcanoes. Skills: Labelling Diagrams Relate ideas: Describe and Careers: Volcanologist explain the distribution of volcanoes; Explain the formation of KEY VOCABULARY volcanoes at either constructive, destructive or hotspots. Constructive Destructive Hotspot Extend ideas: Draw the structure of a volcano and annotate; Suggest Lava Magma Vent Crater Magma why volcanoes are dangerous. Chamber  Differentiation Grid: @ASCSduba i One Idea (All): Define a volcano Identify the key features of a volcano. Driving Question: What are volcanoes?  Differentiation Grid: @ASCSduba i Many Ideas (Targets 5 - 6) : Describe the 3 stages - active, dormant and extinct volcanoes. Describe the structure of volcanoes. Describe the types of volcanoes - composite, shield and cinder cone volcanoes. Driving Question: What are volcanoes?  Differentiation Grid: @ASCSduba i Relate Ideas (Targets 7 - 9) : Describe and explain the distribution of volcanoes Explain the formation of volcanoes at either constructive, destructive or hotspots. Driving Question: What are volcanoes?  Differentiation Grid: @ASCSduba i Extend Ideas (Challenge) : Draw the structure of a volcano and annotate Suggest why volcanoes are dangerous. Driving Question: What are volcanoes?  Plenary @ASCSduba i Reflect: Learning Objectives 1. Can you define a volcano? One idea: Define a volcano and identify the key features of a volcano. Many ideas: Describe the 3 stages - active, dormant and extinct volcanoes; Describe the structure of volcanoes; Describe the types of volcanoes - composite, shield and cinder cone volcanoes. KEY VOCABULARY Relate ideas: Describe and explain the distribution of Constructive - volcanoes; Explain the formation of volcanoes at either constructive, Destructive - destructive or hotspots. Hotspot Extend ideas: Draw the structure of a volcano and annotate; Suggest Lava Magma Vent Crater Magma Chamber why volcanoes are dangerous. Driving Question: What are volcanoes?  What is a Volcano? @ASCSduba i A volcano is a surface geological landform resulting from the extrusion of magma from underground into the Earth’s crust and by the extrusive eruption of that magma onto the Earth’s surface through a vent. https://www.youtube.com/watch?v=yDy28QtdYJY  What Is a Volcano? A volcano is a hole or a crack in the earth’s crust through which magma erupts during an eruption. Magma builds up beneath the surface of the Earth inside the magma chamber. This increases the pressure inside the volcano. The pressure is released by shooting up material through the volcano in an eruption!  What Is Our Earth Made Of? + × + × × + × + The Outer Inner Crust MantleCore Core This is The the outer mantle layer of the Earth. It1,802 is approximately variesmiles in thickness thick andfrom 20-50 miles is made This Theisouter a solidcorelayer is aandliquid is made layer made of ironout and ofnickel. molten Itiron is the andhottest nickel.part Thisof thick. Itofisanot even solid, and substance rocky is made upcalled of pieces moltenwhich rockoverlap to cover the or magma. the Earth liquid entire and ismetal planet. This cancreates These what reach temperatures the pieces escapes Earth's are when calledmagnetic of uperupts. to field. “tectonic a volcano 10,800ºF! plates.”  How Are Volcanoes Formed? Deep in the Earth, it is extremely hot. It is so hot, in fact, that rocks actually melt and form magma, which makes up the mantle of the Earth. The upper mantle mixes and moves, which creates pressure underneath the crust. This pressure can sometimes cause the mantle to leak out onto the surface of the earth – this is a volcano! Over time, as this magma leaks out, the volcano will get bigger and bigger.  The Three Stages of Volcanoes Active Dormant Extinct An active volcano is A dormant volcano is An extinct volcano is one that has erupted one that has not one which has erupted recently, and there is erupted for a long time, thousands of years the possibility that it however, it may still ago, but it will probably may erupt again. erupt in the future. never erupt again. Scientists have placed volcanoes into three different categories.  Why Do Volcanoes Erupt? We know that the Earth's crust is made up of huge slabs called tectonic plates. These fit together like a jigsaw puzzle and they sometimes move. The movement causes friction which causes earthquakes and volcanic eruptions near the edges of the plates. The theory that explains this process is called “plate tectonics” – this means the plates are moving in different directions and at different speeds. Sometimes they collide or brush past each Friction: the the Click on resistance word increated bold when to other and cause these earthquakes one find surface out rubs whatagainst another. it means! and volcanic eruptions. Where Are Most Volcanoes Located? The “Ring of Fire” is an area of the Pacific Ocean that is shaped like a horseshoe. It is home to 90% of the It contains a string of world's earthquakes 452 volcanoes, which and 75% of the stretches from the world's volcanoes. southern tip of South America, up along the coast of North America, down through Japan, and into New Zealand. Where Are Volcanoes Located? @ASCSduba i Task: Describe the distribution of volcanoes. TEA Method: T - Trend: What is the overall pattern? Where are the majority of volcanoes located? E - Evidence: Use specific evidence from the map e.g. the name of a plate boundary. A country or continent. A - Anomaly: Are there any examples that do not fit your overall trend? Where Are Volcanoes Located? @ASCSduba i Example Answer: T: The majority of volcanoes are located on or close to tectonic plate boundaries. E: For example, there are lots of volcanoes around the edge of the Pacific Plate. A: Some volcanoes also occur away from plate boundaries or in the middle of a plate such as those in Africa. Key Question: What are Volcanoes?  What Types of Volcanoes Exist? Composite Volcanoes These types of volcanoes have steep slopes and thick, sticky lava. They look like regular mountains. Because their lava is so sticky, the lava will clog the passageways out of the volcano. Pressure builds up and eventually the volcano will explode violently. However, because their lava is so sticky, it does not flow very quickly or very far. They erupt far less frequently than other types of volcanoes.  What Types of Volcanoes Exist? Shield Volcanoes These types of volcanoes have very fluid lava that easily run down the hill of the volcano and travel long distances before cooling. They do not have very steep sides because the lava that erupts cannot pile up along the sides of the volcano. This lava forms long, gentle slopes that look like a warrior's shield, which is how they got their name. These volcanoes do not often explode. What Types of Volcanoes Exist? Cinder Cone volcanoes These types of volcanoes are made up of a bunch of cinders called scoria. These volcanoes differ from composite volcanoes in that they have a bowl-shape hole, or crater, at the top. The magma underneath the volcano contains gas bubbles, which causes pressure to build up within the volcano. Eventually, the volcano erupts and lava will fly into the air. The lava that is ejected from the volcano accumulates around the volcano and eventually contributes to the body of it. They are the most common type of volcano.  Famous Volcanic Eruptions Volcanoes can cause huge The site was not discovered amounts of damage to until the mid 1800’s when communities living near the archaeologists excavated, or volcano. cleared the site of debris. Scientists and historians have studied Pompeii and its On a summer morning in 79 demise for hundreds of years B.C.E Mount Vesuvius now. Mount Vesuvius is erupted near the Roman city considered a dormant of Pompeii. Many of the volcano today. citizens living in Pompeii were buried beneath tons of the volcanic ash and debris that fell from the sky from the volcanic eruption. Why are each of these volcanoes famous? FamousMount Volcanic Eruptions St. Helens is located in the Cascade Range in western Washington state. In 1980, it erupted. It was the largest volcanic eruption in the continental U.S. since 1915. The blast from the volcano blew everything away in its path, with winds over 300 miles per hour. Over 200 It is still miles square an active volcano of forest nearand theisvolcano expected to destroyed! were erupt again in the future. Where Are Volcanoes Formed? @ASCSduba i Key Question: What are Volcanoes? What Happens At A Constructive Boundary? Plates are moving away from each other. Magma rises up and fills in the gap. New crust is formed on the sea bed. Creates underwater volcanoes. Key Question: What are Volcanoes? What Happens At A Destructive Boundary? Plates are moving towards each other. Denser oceanic crust is subducted beneath less dense continental crust. As the plate sinks it melts creating magma which then rises. Explosive volcanoes are formed. Key Question: What are Volcanoes? What Happens At Hotspots? @ASCSduba i Key Question: What are Volcanoes? What Happens At Hotspots? @ASCSduba i At hotspots magma, rises through cracks in the Earth’s crust and erupts to form volcanoes. Hot spots create a chain of volcanic islands as plates move e.g. Pacific Plate moving over the Hawaiian hotspot to create the Hawaiian islands. Key Question: What are Volcanoes? What Are The Features of a Volcano? @ASCSduba i Task: Label the features of the volcano using the words from the list below. Ash, steam, gas Magma chamber Volcanic bombs Main vent Crater Secondary cone Lava flow Secondary vent Layers of lava and ash Extension: Compare and contrast pictures of different volcanoes. Do all volcanoes look the same? What features are similar or different? Challenge: Key Explain Question: What the formation are Volcanoes? of volcanoes at either constructive, destructive or hotspots. What Are The Features of a Volcano? @ASCSduba i Key Question: What are Volcanoes? What Are The Features of a Volcano? @ASCSduba i Key Question: What are Volcanoes?  @ASCSduba i What Hazards Do Volcanoes Cause? What Hazards Do Volcanoes @ASCSduba i Cause? Key Question: What are Volcanoes? Plenary: @ASCSduba i Keywords: Which of the volcanic hazards do you think is the most deadly? Justify Constructive your opinion. Destructive Hotspot Lava Magma Vent Chamber Key Question: What are Volcanoes?