Ms.KennE's 6th period
fcat standard 12
SC.7.E.6.5
Explore the scientific theory of plate tectonics by describing how the movement of Earth's crustal plates causes both slow and rapid changes in Earth's surface, including volcanic eruptions, earthquakes, and mountain building.
Explore the scientific theory of plate tectonics by describing how the movement of Earth's crustal plates causes both slow and rapid changes in Earth's surface, including volcanic eruptions, earthquakes, and mountain building.
Plate tectonics
Plate tectonics is the theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The plates act like a hard and rigid shell compared to Earth's mantle. This strong outer layer is called the lithosphere.
Divergent boundaries
Divergent boundaries occur where plates are moving apart. Hot mantle rock rises and partial melting occurs. New crust is created by the magma pushing up from the mantle.
Fast spreading ridges- Mountain chain forms along the crest of the ridge. High heat and magma form new crust is added as both dikes and erupted lava.
Slow spreading ridges- Form valleys on the ridge crests. Lower heat input (Ex. Mid-Atlantic Ridge). Also forms a basin-and-range providence of parallel mountains and valleys.
Fast spreading ridges- Mountain chain forms along the crest of the ridge. High heat and magma form new crust is added as both dikes and erupted lava.
Slow spreading ridges- Form valleys on the ridge crests. Lower heat input (Ex. Mid-Atlantic Ridge). Also forms a basin-and-range providence of parallel mountains and valleys.
transform boundaries
Two plates slide against each other. An offset is seen like on the picture to the left of a road
Ex. San Andreas Fault, California). Transform faults also form the margin between offset spreading ridges as seen on the picture to the right.
Ex. San Andreas Fault, California). Transform faults also form the margin between offset spreading ridges as seen on the picture to the right.
Convergent boundaries
Crust is destroyed as two plates move towards each other. The heavier plate dives (subducts) beneath the more-bouyant plate.
Oceanic-oceanic convergenceWhen two oceans plates converge. One sub ducts (goes under) beneath the other, and in the process a trench is formed.
Oceanic-continental convergenceAn oceanic plate meets a continental plate and the denser crust sinks beneath the less dense continental plate. In this type of convergence, trenches, strong destructive earthquakes, and mountain ranges are common. Rising melt builds volcanic arcs.
continental-continental convergenceTwo plates meet, neither sub ducts (sinks) because continental rocks are relatively light and, resist downward motion. Instead, the crust tends to buckle (lock) and is pushed upward or sideways, becoming mountains.
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(3 pictures above) http://www.harding.edu/lmurray/113_files/html/d2_earth%20revised/sld122.htm
Extra vocabulary
~Crust—the outermost major layer of the earth.
~Lithosphere—the outer solid part of the earth.
~Locked fault- a fault that is not slipping because frictional resistance on the fault is greater that the shear stress across the fault.
~Mantle—the part of the earth’s interior between the metallic outer core and the crust.
~Subduction— the process of the oceanic lithosphere colliding with and descending beneath the continental lithosphere.
~Tectonic plates— the large, thin, relatively rigid plates that move relative to one another on the outer surface of the Earth.
~Lithosphere—the outer solid part of the earth.
~Locked fault- a fault that is not slipping because frictional resistance on the fault is greater that the shear stress across the fault.
~Mantle—the part of the earth’s interior between the metallic outer core and the crust.
~Subduction— the process of the oceanic lithosphere colliding with and descending beneath the continental lithosphere.
~Tectonic plates— the large, thin, relatively rigid plates that move relative to one another on the outer surface of the Earth.
http://www.msnucleus.org/membership/html/jh/earth/platetectonics/lesson1/platetec1a.html
Divergent Boundary Videohttps://www.youtube.com/watch?v=uSKzdbEVsI8
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Convergent boundary videohttps://www.youtube.com/watch?v=Wt_jJUnTFhg
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Transform boundary videohttps://www.youtube.com/watch?x-yt-cl=85114404&x-yt-ts=1422579428&v=6wWcjNM_kRM
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