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Volcanoes VCE Geography. Mr OMeara 2007 RedSpaceRocket.com Aims Understand natural factors that create volcanic and other environments. Understand natural.

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Presentation on theme: "Volcanoes VCE Geography. Mr OMeara 2007 RedSpaceRocket.com Aims Understand natural factors that create volcanic and other environments. Understand natural."— Presentation transcript:

1 Volcanoes VCE Geography

2 Mr OMeara 2007 RedSpaceRocket.com Aims Understand natural factors that create volcanic and other environments. Understand natural factors that create volcanic and other environments. Understand how these natural factors interact. Understand how these natural factors interact. Understand the geographic features of volcanic environments. Understand the geographic features of volcanic environments. Demonstrate our spatial skills. Demonstrate our spatial skills.

3 Mr OMeara 2007 RedSpaceRocket.com What is a volcano? There is very hot (molten) rock under the earths surface. There is very hot (molten) rock under the earths surface. When the pressure builds up in the molten rock, lava and gas escapes through a fissure. When the pressure builds up in the molten rock, lava and gas escapes through a fissure. The word volcano applies to both the vent and the mountain left my the overflow. The word volcano applies to both the vent and the mountain left my the overflow.

4 Mr OMeara 2007 RedSpaceRocket.com Volcano fact #1 The study of volcanoes is called volcanology. The study of volcanoes is called volcanology.

5 Mr OMeara 2007 RedSpaceRocket.com Volcano fact #2 More than 80% of the earth's surface comes from volcanoes. More than 80% of the earth's surface comes from volcanoes.

6 Mr OMeara 2007 RedSpaceRocket.com Volcano fact #3 The name volcano is said to have come from Vulcano, a volcanic island in the Aeolian Islands of Italy. The name volcano is said to have come from Vulcano, a volcanic island in the Aeolian Islands of Italy. The name Vulcano originates from Vulcan, a god of fire in Roman mythology. The name Vulcano originates from Vulcan, a god of fire in Roman mythology.

7 Mr OMeara 2007 RedSpaceRocket.com Volcano fact #4 Seismographic monitoring, tiltmeters and surveillance by satellite all serve to predict activity in a volcano. Seismographic monitoring, tiltmeters and surveillance by satellite all serve to predict activity in a volcano. Gas and steam emissions can also indicate an impending volcanic eruption. Gas and steam emissions can also indicate an impending volcanic eruption.

8 Mr OMeara 2007 RedSpaceRocket.com Volcanic fact #5 There are three main types There are three main types Tephra volcanoes Tephra volcanoes Shield volcanoes Shield volcanoes Strato volcanoes Strato volcanoes

9 Mr OMeara 2007 RedSpaceRocket.com What factors create environments? We need to understand the structure of the earth. We need to understand the structure of the earth. The earth is made of many layers. The earth is made of many layers. Starting at the middle they are Starting at the middle they are Crust (where we live) 0-35km Crust (where we live) 0-35km Upper mantle 35-60km Upper mantle 35-60km Mantle 60 – 2890km Mantle 60 – 2890km A fluid outer core – 2890 – 5150km A fluid outer core – 2890 – 5150km A hard inner core – A hard inner core –

10 Mr OMeara 2007 RedSpaceRocket.com Activity Create a colour diagram of the layers of the earth. Create a colour diagram of the layers of the earth. This does not need to be to scale but does need to indicate distance with labels. This does not need to be to scale but does need to indicate distance with labels.

11 Mr OMeara 2007 RedSpaceRocket.com

12 Mr OMeara 2007 RedSpaceRocket.com Magma vs. Lava Magma is molten rock under the ground. Magma is molten rock under the ground. Once it is expelled it is called lava. Once it is expelled it is called lava.

13 Mr OMeara 2007 RedSpaceRocket.com Caution: Contents May Be Hot High temperatures and pressures are normal inside the earth. High temperatures and pressures are normal inside the earth. This happens because of the natural decay of radioactive elements. This happens because of the natural decay of radioactive elements. This makes the rock so hot it becomes fluid and gas. This is called magma. This makes the rock so hot it becomes fluid and gas. This is called magma.

14 Mr OMeara 2007 RedSpaceRocket.com What are the geographic features of a volcano? There are three main types of volcanoes. There are three main types of volcanoes.

15 Mr OMeara 2007 RedSpaceRocket.com Strato Volcanoes The most common type. The most common type. Composed of solid lava flows alternating with pyroclastic material. Composed of solid lava flows alternating with pyroclastic material. The lava flows act like a blanket for the rock layers. The lava flows act like a blanket for the rock layers. They are steeper than a shield but not as steep as Tephra volcanoes. They are steeper than a shield but not as steep as Tephra volcanoes.

16 Mr OMeara 2007 RedSpaceRocket.com Shield volcanoes Composed of solidified lava flows. Composed of solidified lava flows. The flattest type of volcano. The flattest type of volcano. Can spread out over a wide area. Can spread out over a wide area. Slope often less than 10 degrees Slope often less than 10 degrees For example Mauna Kea in Hawaii. For example Mauna Kea in Hawaii.

17 Mr OMeara 2007 RedSpaceRocket.com Shield Volcano

18 Mr OMeara 2007 RedSpaceRocket.com Tephra volcanoes Composed of magma and associated rocks. Composed of magma and associated rocks. Steep sided slopes (around 30) Steep sided slopes (around 30) Rarely more than 300 metres high. Rarely more than 300 metres high.

19 Mr OMeara 2007 RedSpaceRocket.com Ring of Fire Area of frequent eruptions and earthquakes around the Pacific Ocean. Area of frequent eruptions and earthquakes around the Pacific Ocean. Actually a horseshoe shape. Actually a horseshoe shape. 90% of the earthquakes. 90% of the earthquakes. Over 80% of the major volcanoes. Over 80% of the major volcanoes. Includes over 160 active volcanoes. Includes over 160 active volcanoes.

20 Mr OMeara 2007 RedSpaceRocket.com Ring of Fire

21 Mr OMeara 2007 RedSpaceRocket.com Famous volcanoes - Mt Vesuvius East of Naples, Italy East of Naples, Italy 40°49N, 14°26E 40°49N, 14°26E The only volcano in Europe to have erupted in the last 100 years. The only volcano in Europe to have erupted in the last 100 years. 79AD eruption destroyed the towns of Pompeii and Herculaneum. 79AD eruption destroyed the towns of Pompeii and Herculaneum. Between 15k and 30k people dead. Between 15k and 30k people dead. Today more than 3m people live close to Vesuvius making it a very dangerous volcano. Today more than 3m people live close to Vesuvius making it a very dangerous volcano.

22 Mr OMeara 2007 RedSpaceRocket.com Infrared Picture of Vesuvius This is a night-time infrared photo of Mount Vesuvius in

23 Mr OMeara 2007 RedSpaceRocket.com Famous volcanoes - Mt Vesuvius It is a stratovolcano. It is a stratovolcano. The last eruption was in The last eruption was in Destroyed several small villages and 88 US planes. Destroyed several small villages and 88 US planes. There is an emergency plan it place now which would involved moving 600,000 people to safety. There is an emergency plan it place now which would involved moving 600,000 people to safety.

24 Mr OMeara 2007 RedSpaceRocket.com Famous volcanoes - Mount St. Helens. In Washington State, Pacific Northwest of the USA. In Washington State, Pacific Northwest of the USA. 46°12N, 122°11W 46°12N, 122°11W Catastrophic eruption on May 18, Catastrophic eruption on May 18, dead 57 dead 250 homes lost 250 homes lost 47 bridges 47 bridges 300km of highways. 300km of highways.

25 Mr OMeara 2007 RedSpaceRocket.com Famous volcanoes - Mount St. Helens. It is a stratovolcano. It is a stratovolcano. Is still active and has has small volcanic activities in the years between 1980 and now. Is still active and has has small volcanic activities in the years between 1980 and now. Has been in continuous eruption since Has been in continuous eruption since 2004.

26 Mr OMeara 2007 RedSpaceRocket.com What spatial skills are useful here? Mapping skills, especially topography. Mapping skills, especially topography. Topography (heights) is expressed using contour lines or different heights for different colours. Topography (heights) is expressed using contour lines or different heights for different colours. Understanding of region. Understanding of region. Understanding of movement. Understanding of movement.

27 Mr OMeara 2007 RedSpaceRocket.com Useful links no no no no om/volcano-encyclopedia.htm om/volcano-encyclopedia.htm om/volcano-encyclopedia.htm om/volcano-encyclopedia.htm


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