10.3 Types of Volcanoes
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10.3 TYPES OF VOLCANOES 1. Plate tectonics accounts for important features of Earth’s surface and major geologic events. As a basis for understanding this concept: d. Students know that earthquakes are sudden motions along breaks in the crust called faults and that volcanoes and fissures are locations where magma reaches the surface. e. Students know major geologic events, such as earthquakes, volcanic eruptions, and mountain building, result from plate motions.
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10.3 Types of Volcanoes. Plate tectonics accounts for important features of Earth’s surface and major geologic events. As a basis for understanding this concept: - PowerPoint PPT Presentation
Transcript of 10.3 Types of Volcanoes
10.3 TYPES OF VOLCANOES1. Plate tectonics accounts for
important features of Earth’s surface and major geologic events. As a basis for understanding this concept:
d. Students know that earthquakes are sudden motions along breaks in the crust called faults and that volcanoes and fissures are locations where magma reaches the surface.e. Students know major geologic events, such as earthquakes, volcanic eruptions, and mountain building, result from plate motions.
WHY ARE VOLCANOES DIFFERENT?
Different volcano shapes and volcano eruptions are caused by different magma.
HOW CAN WE COMPARE MAGMA? 1. The amount of SILICA
Silica is a material that makes things viscous (gooey)
Small amounts make lava runny
Large amounts make lava thick and sticky
2. The amount of DISSOLVED GAS Small amounts make magma
flat, quiet eruption Large amounts make lava
bubbly, explosive eruption (Just like soda!)
WHAT KIND OF VOLCANOES HAVE LOW LEVELS OF SILICA? Low levels of Silica and low levels of
dissolved gas produces SHIELD VOLCANOES. These are wider and flatter. There are no explosive eruptions.
Low levels of Silica and high levels of dissolved gas produces CINDERCONES. The gas in the magma creates FIRE FOUNTAINS!
WHAT KIND OF VOLCANOES HAVE HIGH LEVELS OF SILICA?
Composite volcanoes are tall and cone-shaped. Also known as a Stratovolcano Low gas = oozing out like toothpaste,
obsidian created High gas = pressure builds and builds and
then BOOM! , pumice and ash created
WHAT HAPPENS WITH EXPLOSIVE ERUPTIONS?
PYROCLASTIC FLOW – a cloud of volcanic material that races down the side of the volcano with high SPEED, FORCE and HEAT.
LAVA BOMBS – blobs of molten material that gets thrown in an eruption
LAHARS – Mudflows that occur if there is water present during an eruption.
HOW ARE VOLCANOES PART OF THE WATER CYCLE?
Water from the ocean gets pulled down during subduction
Water is evaporated during an eruption
Water condenses back into the ocean
EXIT TICKETCOPY THESE QUESTIONS AND ANSWER IN YOUR SCIENCE
NOTEBOOK.
1. What two ingredients in magma affect the type of explosion and shape of a volcano?
2. What type of volcano has no explosive eruptions?
3. What are the three types of volcanoes? Describe how they are different.
HOMEWORK
Bring your materials to work on your volcano tomorrow.
