Plate Tectonics · 2019-12-10 · Plate Tectonics • lithosphere is broken up into tectonic plates...
Transcript of Plate Tectonics · 2019-12-10 · Plate Tectonics • lithosphere is broken up into tectonic plates...
Plate Tectonics
The Unifying Theory of Geology
Plate Tectonics
• lithosphere is broken up into tectonic plates
• seven major and many minor plates move on the asthenosphere’s convection currents
• These plates move in relation to one another
• Average Speed is __________ (we will fill in later)
Tectonic Plate Movements
• Divergence - away from each other
• Convergence - toward each other
• Transform motion - past each other
2-6,
Pangea
• The super continent that broke apart 190 million years ago to form the present continents.
http://www.wwnorton.com/college/geo/egeo/animations/ch2.htm#5
Wegner Continental Drift
Evidence of Plate Tectonics
http://wwnorton.com/college/geo/earth4/animations.aspx
• Fossils - same between continents formerly joined
• Ridges
• Volcanoes
• Earthquakes
• Trenches
• Sea Floor Spreading
• A ____________ of an organism that has been __________ in the earth's _________.
• Organism replaced by _________ to make a ________ _____
Fossil
part or track preservedcrust
minerals stone copy
• ________ and __________ at the surface of the earth resulting from underground __________ of _________ ______
Earthquake
shaking vibrationmovement tectonic plates
• A volcano is an _________ in the Earth's surface or crust, which allows ___, _______ _____, ____ and ______ to escape from deep below the surface.
• form ____________ over a period of time.
• Example:
Volcano
opening
hot molten rock ashgases
mountains
Challenge Deep , Mariana's Trench : Deepest point on the Earth Challenger Deep got its name from the British survey ship Challenger II, which pinpointed the deep water off the Marianas Islands in 1951. Then in 1960, the US Navy sent the Trieste (a submersible - a mini-submarine designed to go really deep) down into the depths of the Marianas trench to see just how far they would go. They touched bottom at 35,813 ft/10,915m. That means, while they were parked on the bottom in the bathyscaphe, there were almost seven miles/11km of water over their heads! If you cut Mount Everest off at sea level and put it on the ocean bottom in the Challenger Deep, there would still be over a mile of water over the top of it! The deepest measurement of the Challenger Deep currently available was taken by the Japanese and was found to be 35,838 feet.A plaque to commemorate the world record for the deepest dive to the bottom of the Mariana Trench in 1995
Trench•_________________- caused when an oceanic tectonic plate is pushed under another.
•Created by subduction
•Example:
Deepest Ocean
Mariana’s Trench
Ring of Fire
452 volcanoes, 81% of largest
Ridge
•_________________- caused by divergence
•As plate separates, the magma comes toward top of crust and cools as it mountains up
•Example:
Underwater Mts
Mid Atlantic Ridge
Sea Floor Spreading•New ________ _____ is created at mid ocean ridge from _________ ______
•Plate Movement - ____________
•Most important piece of _________ for _____ _______ theory
•Example:
http://www.wwnorton.com/college/geo/egeo/animations/ch2.htm#5
Sea Floor Spreading, Magnetic Reversal
Mid Atlantic Ridge
oceanic crustvolcanic activity
divergence
evidence plate tectonic
Subduction• Special type of convergence when one
tectonic plate moves _________ another
• Plate Movement - __________
• More _________ oceanic plates are pushed beneath the less dense ____________ plates
• Ex: ____________
The Process of Subduction
http://www.wwnorton.com/college/geo/egeo/animations/ch2.htm#5
beneath
dense
continental
Mariana Trench
convergence
• One tectonic plate moves ______ another
• Plate Movement - _____________
• creates lots of _____________
• Ex: ____________
Faults
past
transform motion
earthquakes
San Andreas Fault
India vs. Asia•Created by convergence - mountain building.
•Continental Plate vs. Continental plate
•Ex: Mount Everest (29,035 feet)
Mount Everest
Hot Spots
•pressure and heat builds up within a section of the asthenosphere
•Magma rises up through lithosphere to form a volcano and results in a new island.
•lithosphere moves over the hot spot to form a chain of islands
•40-50 around the globe
•Examples:
Hawaii, Galapagos
http://www.wwnorton.com/college/geo/egeo/animations/ch2.htm#5http://www.teachersdomain.org/resources/ess05/sci/ess/earthsys/hawaii/index.html
Plate movements
divergenceconvergence transform motion
RidgeEx: Mid Atlantic
FaultEx: San
Andreas
2 continental crust
continental & oceanic crust
mountainEx:
Mt. Everest
subduction
volcanoesEx: Mt. St Helens
trenchesEx: Mariana
Trench
RiftEx: AfricaRift Valley
oceanland