The Structure of the Earth and Plate Tectonics By: Ms. Nikki

Journey to the Center of the Earth What would I find if I journeyed to the center of the Earth?

How did the layers form?

The Earth’s layers were formed because of density.

How did the layers form? The Earth’s layers were formed because of density. –The heavier, more dense, materials were pulled in more by gravity. The Earth’s layers were formed because of density. –The heavier, more dense, materials were pulled in more by gravity.

How did the layers form? The Earth’s layers were formed because of density. –The heavier, more dense, materials were pulled in more by gravity. –Lighter, less dense, materials were not pulled in as much by gravity. The Earth’s layers were formed because of density. –The heavier, more dense, materials were pulled in more by gravity. –Lighter, less dense, materials were not pulled in as much by gravity.

What are the layers made of?

Inner Core: solid iron (Fe) and Nickel (Ni).

What are the layers made of? Inner Core: solid iron (Fe) and Nickel (Ni). –Pressure is 48 to 52 million psi. Inner Core: solid iron (Fe) and Nickel (Ni). –Pressure is 48 to 52 million psi.

What are the layers made of? Inner Core: solid iron (Fe) and Nickel (Ni). –Pressure is 48 to 52 million psi. –Temperatures range from about 9,000 to 12,000 degrees Fahrenheit. Inner Core: solid iron (Fe) and Nickel (Ni). –Pressure is 48 to 52 million psi. –Temperatures range from about 9,000 to 12,000 degrees Fahrenheit.

What are the layers made of? Outer core: liquid iron (Fe) and Nickel (Ni).

What are the layers made of? Outer core: liquid iron (Fe) and Nickel (Ni). –Temperatures range from about 4,400 to 6,100 degrees Fahrenheit. Outer core: liquid iron (Fe) and Nickel (Ni). –Temperatures range from about 4,400 to 6,100 degrees Fahrenheit.

What are the layers made of? Outer core: liquid iron (Fe) and Nickel (Ni). –Temperatures range from about 4,400 to 6,100 degrees Fahrenheit. –It is believed that the Earth’s magnetism is produced here. Outer core: liquid iron (Fe) and Nickel (Ni). –Temperatures range from about 4,400 to 6,100 degrees Fahrenheit. –It is believed that the Earth’s magnetism is produced here.

What are the layers made of? Mantle:

What are the layers made of? Mantle: –Made of various minerals (Iron (Fe), Magnesium (Mg), Aluminum (Al), Silicon (Si), and Oxygen silicates ) that are in constant motion. Mantle: –Made of various minerals (Iron (Fe), Magnesium (Mg), Aluminum (Al), Silicon (Si), and Oxygen silicates ) that are in constant motion.

What are the layers made of? Mantle: –Made of various minerals (Iron (Fe), Magnesium (Mg), Aluminum (Al), Silicon (Si), and Oxygen silicates ) that are in constant motion. –Temperatures of up to 6,700 degrees Fahrenheit. Mantle: –Made of various minerals (Iron (Fe), Magnesium (Mg), Aluminum (Al), Silicon (Si), and Oxygen silicates ) that are in constant motion. –Temperatures of up to 6,700 degrees Fahrenheit.

What are the layers made of? Crust:

What are the layers made of? Crust: The top layer of the Earth

What are the layers made of? Crust: The top layer of the Earth –The two types are continental and oceanic. Crust: The top layer of the Earth –The two types are continental and oceanic.

What are the layers made of? Crust: The top layer of the Earth –The two types are continental and oceanic. –Made of mostly Silicon (Si), Aluminum (Al), Calcium (Ca), Sodium (Na), and Potassium (K) Crust: The top layer of the Earth –The two types are continental and oceanic. –Made of mostly Silicon (Si), Aluminum (Al), Calcium (Ca), Sodium (Na), and Potassium (K)

What are the layers made of? Crust: The top layer of the Earth –The two types are continental and oceanic. –Made of mostly Silicon (Si), Aluminum (Al), Calcium (Ca), Sodium (Na), and Potassium (K) –Fractures during earthquakes. Crust: The top layer of the Earth –The two types are continental and oceanic. –Made of mostly Silicon (Si), Aluminum (Al), Calcium (Ca), Sodium (Na), and Potassium (K) –Fractures during earthquakes.

Where is the lithosphere?

The lithosphere contains:

Where is the lithosphere? The lithosphere contains: –The crust. The lithosphere contains: –The crust.

Where is the lithosphere? The lithosphere contains: –The crust. –A small layer of the upper mantle. The lithosphere contains: –The crust. –A small layer of the upper mantle.

Where is the lithosphere? The lithosphere contains: –The crust. –A small layer of the upper mantle. Large chunks or plates that move gradually because they ride on hotter parts of the mantle. The lithosphere contains: –The crust. –A small layer of the upper mantle. Large chunks or plates that move gradually because they ride on hotter parts of the mantle.

Where is the lithosphere? The lithosphere contains: –The crust. –A small layer of the upper mantle. Large chunks or plates that move gradually because they ride on hotter parts of the mantle. –These “chunks” or plates make up the surface of the Earth. The lithosphere contains: –The crust. –A small layer of the upper mantle. Large chunks or plates that move gradually because they ride on hotter parts of the mantle. –These “chunks” or plates make up the surface of the Earth.

Structure of the Earth The Earth is made up of 3 main layers: –Core –Mantle –Crust The Earth is made up of 3 main layers: –Core –Mantle –Crust Inner core Outer core Mantle Crust

What IS the Lithosphere? The lithosphere is made up of the crust and small layer of the upper mantle that together form large chunks or plates that move gradually because they ride on hotter mantle. These plates make up the surface of the Earth.

Warm Up 1. Take out a piece of paper and put your name on it. 2. BE QUIET! 1. Take out a piece of paper and put your name on it. 2. BE QUIET!

The Crust This is where we live! The Earth’s crust is made of: This is where we live! The Earth’s crust is made of: Continental Crust - thick (10-70km) - buoyant (less dense than oceanic crust) - mostly old Oceanic Crust - thin (~7 km) - dense (sinks under continental crust) - young

How do we know what the Earth is made of? Geophysical surveys: seismic, gravity, magnetic, electrical, geodesy –Acquisition: land, air, sea and satellite –Geological surveys: fieldwork, boreholes, mines Geophysical surveys: seismic, gravity, magnetic, electrical, geodesy –Acquisition: land, air, sea and satellite –Geological surveys: fieldwork, boreholes, mines

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What are Plate Tectonics?

If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.

Plate Tectonics The Earth’s crust is divided into 12 major plates which are moved in various directions. This plate motion causes them to collide, pull apart, or scrape against each other. Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction. The Earth’s crust is divided into 12 major plates which are moved in various directions. This plate motion causes them to collide, pull apart, or scrape against each other. Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.

World Plates

What are tectonic plates made of? Plates are made of rigid lithosphere. The lithosphere is made up of the crust and the upper part of the mantle.

What lies beneath the tectonic plates? Below the lithosphere (which makes up the tectonic plates) is the asthenospher e.

Continents of the Past “Pangaea” : exists ~ 225 million years ago – Supercontinent: the only continent on Earth Division of Pangaea ~ 135 million years ago –Into “Laurasia” (N. Hem) Included modern North America & Eurasia –And “Gondwana” (S. Hem) Included modern South America, Africa, Antarctica, Australia, Madagascar, India and New Zealand “Pangaea” : exists ~ 225 million years ago – Supercontinent: the only continent on Earth Division of Pangaea ~ 135 million years ago –Into “Laurasia” (N. Hem) Included modern North America & Eurasia –And “Gondwana” (S. Hem) Included modern South America, Africa, Antarctica, Australia, Madagascar, India and New Zealand

250 Million Years Ago

200 Million Years Ago

135 Million Years Ago Jurassic Period

65 Million Years Ago

Present Day

In 50 Million Years

In 150 Million Years

In 250 Million Years

What is a convection current? A convection current is a circular flow due to molecules heating, moving faster, and becoming less dense-so they weigh less and rise. When they cool, they move slower and closer together-so they weigh more per space and sink. A convection current is a circular flow due to molecules heating, moving faster, and becoming less dense-so they weigh less and rise. When they cool, they move slower and closer together-so they weigh more per space and sink.

Plate Movement “Plates” of lithosphere are moved around by the underlying hot mantle convection cells

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Warm Up 1. What is the lithosphere? 2. List the EM spectrum in order from lowest frequency to highest. 3. How do we hear? 4. What is refraction? 5. How do plates move? 1. What is the lithosphere? 2. List the EM spectrum in order from lowest frequency to highest. 3. How do we hear? 4. What is refraction? 5. How do plates move?

What happens at tectonic plate boundaries?

Divergent Convergent Transform Divergent Convergent Transform Three types of plate boundary

Spreading ridges –As plates move apart new material is erupted to fill the gap Spreading ridges –As plates move apart new material is erupted to fill the gap Divergent Boundaries

What happens when plates move toward each other? This is called a Convergent boundary –The continental plates push up and make mountains OR…. This is called a Convergent boundary –The continental plates push up and make mountains OR…. DRAW

Plate Boundaries It’s called Subduction –When one plate dives under the other. It’s called Subduction –When one plate dives under the other.

Subduction

Plate Boundaries Transform boundary –Happens when 2 plates beside each other move in opposite directions Transform boundary –Happens when 2 plates beside each other move in opposite directions

shows/greatest- discoveries/videos/100-greatest- discoveries-plate-tectonics.htmhttp://science.discovery.com/tv- shows/greatest- discoveries/videos/100-greatest- discoveries-plate-tectonics.htm =KCSJNBMOjJs&safe=active (15 mins) =KCSJNBMOjJs&safe=active shows/greatest- discoveries/videos/100-greatest- discoveries-plate-tectonics.htmhttp://science.discovery.com/tv- shows/greatest- discoveries/videos/100-greatest- discoveries-plate-tectonics.htm =KCSJNBMOjJs&safe=active (15 mins) =KCSJNBMOjJs&safe=active

Age of Oceanic Crust Courtesy of

Iceland has a divergent plate boundary running through its middle Iceland: An example of continental rifting

There are three styles of convergent plate boundaries –Continent-continent collision –Continent-oceanic crust collision –Ocean-ocean collision There are three styles of convergent plate boundaries –Continent-continent collision –Continent-oceanic crust collision –Ocean-ocean collision Convergent Boundaries

Forms mountains, e.g. European Alps, Himalayas Continent-Continent Collision

Himalayas

Called SUBDUCTION Continent-Oceanic Crust Collision

Oceanic lithosphere subducts underneath the continental lithosphere Oceanic lithosphere heats and dehydrates as it subsides The melt rises forming volcanism E.g. The Andes Oceanic lithosphere subducts underneath the continental lithosphere Oceanic lithosphere heats and dehydrates as it subsides The melt rises forming volcanism E.g. The Andes Subduction

When two oceanic plates collide, one runs over the other which causes it to sink into the mantle forming a subduction zone. The subducting plate is bent downward to form a very deep depression in the ocean floor called a trench. The worlds deepest parts of the ocean are found along trenches. –E.g. The Mariana Trench is 11 km(6.8 miles) deep! When two oceanic plates collide, one runs over the other which causes it to sink into the mantle forming a subduction zone. The subducting plate is bent downward to form a very deep depression in the ocean floor called a trench. The worlds deepest parts of the ocean are found along trenches. –E.g. The Mariana Trench is 11 km(6.8 miles) deep! Ocean-Ocean Plate Collision

Where plates slide past each other Transform Boundaries Above: View of the San Andreas transform fault

Plate Tectonics Summary The Earth is made up of 3 main layers (core, mantle, crust) On the surface of the Earth are tectonic plates that slowly move around the globe Plates are made of crust and upper mantle (lithosphere) There are 2 types of plate There are 3 types of plate boundaries Volcanoes and Earthquakes are closely linked to the margins of the tectonic plates The Earth is made up of 3 main layers (core, mantle, crust) On the surface of the Earth are tectonic plates that slowly move around the globe Plates are made of crust and upper mantle (lithosphere) There are 2 types of plate There are 3 types of plate boundaries Volcanoes and Earthquakes are closely linked to the margins of the tectonic plates