Dynamic Earth!

Earth’s Structure: What are the levels of the Earth? CRUST: Outermost, thinnest layer. Only a few miles thick under the oceans but thicker under the continents- average 20 miles thick. Up to 1,000 degrees F

Earth’s Structure: What are the levels of the Earth? MANTLE: Hot, semisolid rock. About 1,800 miles thick. Between 1,000 – 7,000 degrees F.

Earth’s Structure: What are the levels of the Earth? OUTER CORE: Liquid layer of iron and nickel, about 1,400 miles thick. Between 7,000 – 11,000 degrees F.

Earth’s Structure: What are the levels of the Earth? INNER CORE: Extremely hot solid sphere of iron and nickel, 750 miles thick. Up to 13,000 degrees F.

No one believed me and I died alone in Greenland, but I was right! Ja! Plate Tectonics: Alfred Wegener Theory Introduced by: ___________________ No one believed me and I died alone in Greenland, but I was right! Ja!

Plate Tectonics- Definition: The outermost layer (the crust) of the Earth is broken into plates that slowly move.

Plate Tectonics- Evidence: Geological evidence (rock formations, and shapes) match

Plate Tectonics- Evidence: Fossils found on coasts of separate continents.

Map of the Tectonic Plates

Plates and Boundaries Continental Oceanic Boundary Two kinds of plates: ______________________: found under continents, thicker (20-40 miles), older, lighter. ______________________: found under oceans, thinner (4-6 miles), newer, denser. Border between plates is called: _____________ Continental Oceanic Boundary

Three Types of Movement: Convergent ___________________: Two plates moving towards each other. A collision!

Three Types of Movement: Divergent ___________________: Two plates moving away from each other. Breaking up is hard to do!

Three Types of Movement: Transform ___________________: Two plates sliding past each other. Slip Sliding away!

Convergent boundaries: Colliding plates If: Oceanic crust collides with continental crust Then: Ocean crust slides under continental crust. This is called: ______________________: the crust melts into _____________________ and forms in a chamber to create a____________________ Subduction Magma Volcano

Convergent boundaries: Colliding plates If: Oceanic crust collides with ocean crust Then: The older plate slides under the younger plate, making a chain of: ______________________ and can cause a_____________________. Islands (archipelago) tsunami

Convergent boundaries: Colliding plates If: Continental crust collides with continental crust Then: Both plates are so light, they do not slide under. Instead, they________________ and can form _____________________. crunch mountains

Divergent boundaries: Spreading plates If: Oceanic crust diverges from oceanic crust Then: Causes ____________________________: the plates spread apart, magma oozes up, making a mid-ocean ridge. Seafloor Spreading

Divergent boundaries: Spreading plates If: Continental crust diverges from continental crust Then: Causes a ___________________: the plates spread apart, forming a dropped zone which can become a valley with volcanoes, or water can come in forming a sea. Rift Valley

Transform boundaries: Sliding plates If: Two plates slide past each other Then: Movement results in a________________- a crack in the Earth’s crust. This sliding most often results in an __________________. fault earthquake

So what can plate tectonics cause? Earthquakes Volcanoes Mountains Valleys and trenches Tsunamis