Please read about the different types of crust and answer the Questions 1- below
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1.
What are the differences between Oceanic and Continental Crust? Drag the Properties on the Left into Either Continental Crust or Ocean Crust boxe.
Thicker
Thinner
4-7 Miles Thick
Continually Recycled
Older
Less than 200 million years old
Over a billion years old in some places
Younger
Made of Basalt and Gabbro
Made of Granite
Forms 1/3 of Earth's Surface
Forms 2/3 of Earth's Surface
More Dense
Less Dense
6-23 Miles Thick
Continental Crust
Oceanic Crust
The Mantle
Please read about the mantle and answer the Questions 2-3 below
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2.
How are scientists able to study what is in the mantle?
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3.
Describe the conditions within the asthenosphere and the impact on on plate tectonics
Watch this video and answer the question below
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4.
How does rock in the mantle move? Click Show your Work below and describe movement in the mantle using a drawing and text.
Using the maps below to help answer the questions that follow. Map 1 shows earthquake and volcanic activity around the world. You can click on the fullscreen button on the bottom right to make it bigger and hover over the map for more information. Map 2 shows the tectonic plates that interlock below both the continental and oceanic crust. Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere (Basically just large pieces of rocks that the continents and ocean floors sit upon) .
Map 1
Map 2 Below
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5.
Look at the Earthquake and Volcano Data Map and Tectonic Plates Map to identify 5 observable trends in the data.
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6.
Where are most of the volcanoes and earthquakes on earth located?
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7.
Why do volcanoes and earthquakes occur close to each other?
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8.
What do you think is the driving force behind the formation of volcanoes and earthquakes? (Hint: think about the mantle)
How did the Andes Mountains form?
The Andes Mountains form the longest continental mountain range in the world.
We know from GPS data that a piece of Earth surface under the Pacific Ocean off the west coast of South America is moving towards the piece of Earth's surface where South America is found. This is also where the Andes Mountains have formed.
To understand what happens when two pieces of Earth's surface are moving towards each other and how that might form mountains, we are going to investigate this place in detail.
To begin our investigation, we will look at a geographic profile that gives us information about the elevation of the land along a profile line we chose in the area we are investigating (from point P1 to point P2 in the map).
The graph's y-axis shows the elevation above and below sea level (measured in meters) along that line. Sea level is at 0 meters, so negative numbers represent places underwater, or below sea level. Positive numbers represent places that are above water, or above sea level.
The graph’s x-axis shows distances in kilometers between points P1 and P2 on the map above.
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At what point on the geographic profile does the land elevation rise above sea level?
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10.
On the geographic profile, look at the 670 km mark on the x-axis. What feature might be represented by this elevation change?
To better understand the movement where these two pieces meet, we are going to look at data about earthquakes and volcanoes. You will use Seismic Explorer, which is zoomed in to the same area that you just investigated with the geographic profile data.
If you lose your place, you can click on the recentering icon to reset the view. (Recenter button is top left corner of map)
The map you see in Seismic Explorer is called a relief map. This type of map shows the elevations of land using different colors.
First, you will investigate earthquakes. Use the Data type menu to show earthquakes and volcanoes that have happened in the Andes. To show earthquakes, check the Earthquakes box, and press the Start button.
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11.
Use the information you collected from the geographic profile to examine the relief map in Seismic Explorer.
In the relief map in Seismic Explorer, what color represents the lowest point of the ocean?
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12.
Uncheck the Volcano and Earthquakes. Then take a snapshot (How to take a screenshot) of Seismic Explorer Map and click show your work below. Insert the image below and label the trench and the mountains.
Now, you will investigate volcanoes. In Seismic Explorer, click Data Type and select Volcanoes. This will add triangles that show the locations of volcanoes on the map.
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13.
Describe the pattern of volcanoes in the Andes.
Return to the Data Type button on Seismic Explorer. Uncheck Volcanoes and select Earthquakes. Click Play to make the earthquake data appear as colored circles on the map.
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14.
Based on Seismic Explorer, how deep are the earthquakes that have occurred in the Andes? (Select all correct answers.)
To understand what is happening, we need to look beneath the surface of the Earth. To do this, you can make a cross-section in Seismic Explorer to see the pattern of earthquakes underneath the Andes Mountains..Watch the video to learn how to make a cross-section in Seismic Explorer.
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15.
When you draw your cross-section, try to make it in the same place as the profile line so that you know you are looking at the same part of Earth's surface.
Take a screenshot of your cross-section.
On the screenshot, draw a picture of what you think the pieces of Earth are doing as they come together beneath the surface. Use arrows to show movement.
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16.
Explain what you think is happening with these two pieces of Earth's surface to create that pattern of earthquakes.
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17.
What might you look for in another place on Earth to know if its surface pieces are moving towards each other?
Deep ocean trenches
Trenches are an important piece of evidence to help us explore where pieces of Earth are moving towards each other.
In the picture of the Andes mountains, the trench is shown as the darkest blue on the map. You can see the trench along the entire coast of the South American continent.
Ocean trenches are long narrow depressions in the seafloor. These oceanic features are the deepest parts of the ocean floor. In the profile, you can see the trench as very deep and pointed.
As you explore different parts of the world, look for this landform as a place where pieces of Earth's surface are moving towards each other.
How did the Aleutian Islands form?
Another place where the GPS data indicate two pieces of Earth's surface are moving towards each other is part of the state of Alaska. Just like in South America, there are mountains forming, but in this place, the mountains are mostly underwater and have created a chain of small islands that separate the Bering Sea, to the north, from the Pacific Ocean, to the south.
Let's investigate how this chain of islands formed and see what is the same and what is different from the Andes.
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18.
What evidence would tell you if two pieces of Earth’s surface are moving towards each other?
Just like with our investigation of the Andes, we will start by looking at the geographic profile of the area, which provides clues about important land features along the chain of islands.
The graph's y-axis shows the elevation above and below sea level (measured in meters) along that line. Sea level is at 0 meters, so negative numbers represent places that are underwater, or below sea level. Positive numbers represent places that are above water, or above sea level.
The graph’s x-axis shows distances in kilometers between points P1 and P2 on the map above.
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19.
At 530 km from P1, the geographic profile shows an island above the water.
Based on the geographic profile, how tall is the island from the seafloor on the right side (P2 side) to its peak?
Now that we know what the profile looks like, we can use Seismic Explorer to investigate what earthquakes and volcanoes have happened there. Seismic Explorer is zoomed into a relief map of the Aleutian Islands.
If you lose your place, you can click on the recentering icon to reset the view.
Set the Data type menu to show earthquakes and volcanoes. To show earthquakes, check the Earthquakes box, and press the Start button.
Use the relief map and the earthquake and volcano data to answer the questions below.
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20.
Based on Seismic Explorer, are there volcanoes in the Aleutians?
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21.
Based on Seismic Explorer, how deep are the earthquakes that have occurred in the Aleutians? (Select all correct answers.)
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22.
Create a cross-section of the earthquakes that is in same region as the geographic profile line (shown below). Take a screenshot and Click Show your York and Insert it there.
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23.
Describe the earthquakes you see in the 3D cross-section of the Aleutians.
Based on where the earthquakes are, what do you think is happening with the two pieces of Earth's surface? Be specific.
Hint: Think about what the pattern of earthquakes might mean in terms of how the pieces of Earth's surface interact below the surface.
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What would you look for in the geographic profile and in the earthquake and volcano data to know if two pieces of Earth's surface are moving toward each other? You can use information about the Andes Mountains and Aleutians.
How did the Himalayan Mountains form?
We have investigated what happens when plates with oceanic crust move towards plates with continental crust and what happens when two plates with oceanic crust move towards each other. What happens when two plates with continental crust are moving toward each other?
The Himalayan mountain range, home of Mount Everest (the highest mountain on Earth), is located between India and Asia, in the middle of a continent.
How did these large mountains form?
Scientists can create paleomaps based on the historic movement of plates that give us an idea of what Earth looked like in the past. The paleomaps below show how the two continents – India and Asia – came together to form the Himalayan mountains and Tibetan plateau, as an ocean closed up between them. Three timepoints are shown: 60 million years ago (60 Ma), 40 million years ago (40 Ma), and 20 million years ago (20 Ma).
We will use the Tectonic Explorer model to see if we can better understand what happens when two continentnal plates with continents on them move toward each other.
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25.
Based on what you know about converging plates, what types of landforms would be created by two continental plates moving toward each other?
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26.
Describe the depth of continental-continental convergent earthquakes.
Use the Earth Science Reference Table pg 5 below to answer the next few questions
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27.
What landforms exist where the Juan de Fuca plate and the Pacific Plate meet? Check all that apply.
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28.
Why do you think so many volcanoes are found around the outside of the Pacific Plate?
