LPKW+2.1

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=2.1 Earth's Crust in Motion=

Vocabulary

 * earthquake**- the shaking of plate tectonics
 * stress**- the force that changes rock and its shape and volume
 * shearing**- stress that pushes rock in opposite directions
 * tension**- stress that pulls on rock making it thinner in the middle
 * compression**- stress that squeezes rock until it breaks
 * deformation**- the change in the Earth's crust such as its shape
 * Strike-Slip Fault**- the rocks on both sides of the fault move past each other sideways
 * Normal Fault**- in a normal fault,the fault is at an angle where one block of rock hangs above the fault and the other block lies beneath the fault
 * Hanging Wall**- the block of rock that hangs above the fault is called the hanging wall
 * Footwall**- the block of rock that lies beneath the fault is called the footwall
 * Reverse Fault**- a reverse fault is the same as a normal fault, but instead of the block going underneath the other, in a reverse fault the blocks of rock move in opposite directions
 * Fault-block Mountain**- these mountains form when a normal fault lifts a block of rock
 * folds-** bends in rock that form when compression thickens part of the Earth's crust and shortens it
 * anticline-** forms when a fold in rock bends upward
 * syncline-** forms when a fold in rock bends downward forming a bowl
 * plateau-** a large area of flat land that is higher than sea level

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=Outline=

Introduction

 * Everything in your house starts to shake and fall
 * After the shaking ends, you hear that an earthquake happened
 * Earthquakes are very destructive and they can destroy homes and object

Stress in the Crust

 * For years people have been thinking what earthquakes are
 * An earthquake is the shaking and trembling of plate tectonics
 * There are three types of stresses:shearing, tension, and compression


 * Shearing**
 * stress that pushes rock in opposite directions
 * can cause rock to break or change its shape


 * Tension**
 * stress that pulls on rock making it thinner in the middle
 * is like pulling on a warm piece of gum


 * Compression**
 * stress that squeezes rock until it folds or breaks
 * compressing rock is like a giant compactor

Kinds of Faults

 * there are three different types of faults
 * they are strike-slip faults, normal faults, and reverse faults.


 * Strike-Slip Faults**
 * make rocks on both sides to move past each other sideways.
 * form boundaries between plates.


 * Normal Faults**
 * during a normal fault the fault is at an angle where one block of rock lies above the fault and the other block lies beneath the fault.
 * the stress force tension creates normal faults in the places where plates diverge creating a divergent boundary


 * Reverse Faults**
 * a reverse fault is the same design as a normal fault but instead of the block going underneath the other,in a reverse fault the blocks of rock move in opposite directions
 * The stress force compression creates a reverse fault


 * Friction Along Faults**
 * the movement of rocks along a fault depends on the amount of friction there is between the opposite sides of the fault
 * a place along the fault where the friction is low and both sides of the fault go by each other without much stickyness
 * place along the fault where the friction is normal, the sides of the fault collide together
 * a place along the fault where the friction is high, the rocks combine together and they stay
 * in some of these cases, the stress increases untill it's powerful enough to overcome the friction force


 * Mountain Building**
 * There are two ways by which mountains can form
 * They can by faulting and also by folding
 * Mountains formed by faulting
 * Mountains formed by faulting are called fault-block mountains
 * These mountains form when a normal fault uplifts a block of rock
 * a example of a fault-block mountain range is the Sierra Nevada


 * Mountains formed by folding**
 * Mountains formed by folding are mountains that have formed when compression thickens part of the Earth's crust and shortens it as well.
 * An example of mountains formed by folding are the Himalayas and the Alps


 * Anticlines and Synclines**
 * anticlines form when a fold in rock bends upward forming an arch
 * anticlines are found in many places on the Earth's surface where the stress force compression have folded the surface
 * One example of an anticline are the Black Hills
 * synclines form when a fold in rock bends downward forming a bowl.
 * synclines are also found in places on the Earth's surface where the stress force compression have folded the surface
 * One example of a syncline is the Illinois Basin


 * Plateaus**
 * a plateau is an area is a large area of flat land that is high above sea level
 * It has many flat layers and it is wider than tall
 * One example of a plateau is the " Four Corners " of Arizona, Utah, Colorado, and New Mexico.