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Why is the movement of lithospheric plates significant?

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myleatha | Student, Undergraduate | eNotes Newbie

Posted November 4, 2009 at 10:59 AM via web

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Why is the movement of lithospheric plates significant?

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pohnpei397 | College Teacher | (Level 3) Distinguished Educator

Posted November 4, 2009 at 11:08 AM (Answer #1)

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The movement of these plates (there are about 20 of them) is significant to us today mostly because it is their movements that cause earthquakes.

The lithospheric plates are the plates that are involved in plate tectonics.  As they move past one another (or push into one another) they can cause earthquakes.

Speaking more in the long term, it is the movement of these plates that have shaped the landforms we now have.  For example, the Himalayas were pushed up as the Indian subcontinent (and the plate it's on) pushed up against the rest of Asia.

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krishna-agrawala | College Teacher | Valedictorian

Posted November 4, 2009 at 12:19 PM (Answer #2)

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Lithosphere refers to the outermost shell of earth consisting of its solid crust and uppermost part of mantle. This is made up of about 10 large and 20 smaller plates, called tectonic plates. Each plate consists of a section of earth's crust and a portion of mantle. These plates move continuously and slowly over asthenosphere.

This movement has been responsible in the past for changing the geography of the earth including size, shape, and position of the continents and oceans. The continents are embedded on these plates and move with them.

The movement of these plates also causes earthquakes. Earthquakes occur due to disturbances caused when two tectonic plates slide past each other.

Strictly speaking, the the tectonic plates are not called lithospheric plates. The tectonic plates are about 100 kilometers thickness. However at some places their thickness can be as low as 8 kilometers. They move at an average speed of about 10 centimeter a year.

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giorgiana1976 | College Teacher | Valedictorian

Posted November 4, 2009 at 4:34 PM (Answer #3)

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Most earthquakes can be explained coherent by the theory of tectonics plate . According to this theory, the outer shell of the Earth (the lithosphere) consists of some relatively stable massive huge rock, called tectonic plates. The main tectonic plates have an average thickness of about 80 km and are moved by the movement of convection in the mantle, which in turn is created by heat generated in the nucleus.

Relative movement of tectonics plate  is responsible for a part of significant seismic activity worldwide. Collision between lithosphere plates, edges destruction of tectonic plates in subduction zones (convergent area) at a slip of a plate
under another plate,or expansion in the ocean divergent areas, are all mechanisms that produce significant tensions and fractures in the earth's crust. Many major earthquakes 
is due to sliding along transcurrents faults .

Earthquakes generated from the active edges of tectonic plates is called earthquakes inter-plate. Strongest surface earthquakes in Chile, Peru, Eastern Caribbean, Central America, southern Mexico, California, Alaska South and Aleut Kuril Islands, Japan, Taiwan, Philippines, Indonesia, New Zealand, belt Alps - the Caucasus - the Himalayas are the type of Intra-plate earthquake. Average speed of movement of tectonic plates is 2-5 cm / year.

 

In addition to earthquakes generated in the active edges of tectonic plates, sometimes occur devastating earthquakes within the plate tectonics. The latter is called intra-plate earthquakes. Such earthquakes indicate that the lithosphere plates are indeformabile and inside them that can cause fractures. Examples of such earthquakes are north-east Iran, New Madrid (Missouri), Charleston (South Carolina, USA), northern China.

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