Transcript Plate Tectonics Vocabulary Terms

Plate Tectonics
Vocabulary Terms
Emily Leonard
2/2/12
Core1
Inner Core
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A ball of hot, solid metals
It is solid.
It is about 2400 km in diameter.
Intense pressure makes it solid.
Outer Core
 A layer of liquid metals that surround the
inner core.
 The pressure is lower than the inner
core.
 The metal is liquid.
 It is about 2300 km thick.
Mantle
 Hot rock that is less dense than the
metallic core.
 It is Earth’s thickest layer.
 It measures nearly 2900 kilometers.
 It is not solid.
Crust
 The thin layer of rock above Earth’s
mantle
 It is the layer we walk on
 It is the thinnest layer
 It is solid
Lithosphere
 The layer in Earth made up of the crust
and the rigid rock of the upper mantle
 It is the crust
 The very upper part of the mantle is solid
rock
 It does not include the sky
Asthenosphere
 The layer in Earth’s upper mantle directly
under the lithosphere
 It lies below the lithosphere
 It has a relatively low density
 Seismic waves pass slowly through this
layer
Tectonic Plate
 One of the large, moving pieces into
which Earth’s lithosphere is broken and
which commonly carry both oceanic and
continental crust
 There are 10 different plates
 They are part of the lithosphere
 They are on top of the athenosphere
Continental Drift
 The hypothesis that Earth’s continents
move on Earths’ surface
 It was first put out by Abraham Ortelius
 It was first introduced in 1596
 Plate tectonics helped the theory of the
continental drift.
Pangaea
 A hypothetical supercontinent that once
included all of the landmasses on Earth
 The name comes from Ancient Greek
 They say it formed 300 million years ago
 They say it began to break up about 200
million years ago
Convection Current
 A circulation pattern in which material is
heated and rises in one area, then cools
and sinks in another area
 Convection is caused by them.
 They circle throughout Earth’s layers
 They are very important
Divergent Boundary
 A boundary along which two tectonic
plates move apart
 It is related to plate tectonics
 It is part of the process of two plates
moving apart
 It occurs in the lithosphere
Convergent Boundary
 A boundary along which two tectonic
plates push together
In plate tectonics, a convergent boundary, also known as a
destructive plate boundary (because of subduction), is an
actively deforming region where two (or more) tectonic plates or
fragments of lithosphere move toward one another and collide. As
a result of pressure, friction, and plate material melting in the
mantle, earthquakes and volcanoes are common near convergent
boundaries
Transform Boundary
 A boundary along which two tectonic
plates scrape past each other
A transform fault or transform boundary, also known as
conservative plate boundary since these faults neither create nor
destroy lithosphere, is a type of fault whose relative motion is
predominantly horizontal in either sinistral or dextral direction
Magnetic Reversal
 A switch in the direction of Earth’s
magnetic field so that the magnetic north
pole becomes the magnetic south pole
A geomagnetic reversal is a change in the Earth's magnetic field such
that the positions of magnetic north and magnetic south are
interchanged.
Hot Spot
 An area where a column of hot material
rises from deep within a planet’s mantle
Subduction
 The process by which an oceanic
tectonic plate sinks under another plate
In geology, subduction is the process that takes place at convergent boundaries by
which one tectonic plate moves under another tectonic plate, sinking into the Earth's
mantle, as the plates converge. These 3D regions of mantle downwellings are
known as "Subduction Zones