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Vocabulary

 * Earthquake:** The shaking and trembling that happens to the movement of rock beneath Earth's surface.
 * Stress:** A force that can change the shape or volume of a rock.
 * Shearing:** Stress that pushes chunks of rock in two opposite directions.
 * Tension:** A stress force that pulls on the crust, stretching rock so that it becomes thinner in the middle, and then breaks.
 * Compression:** The stress force that squeezes rock until it breaks.
 * Deformation:** Any change in volume or shape of Earth's Crust.
 * Fault:** A crack in Earth's Crust where slabs of crust have slipped past each other.
 * Strike-Slip Fault:** Where rocks on either sides of the fault slip past each other, with a little up-or-down motion.
 * Normal Fault:** When the fault is at an angle, so one block of rock lies above the fault, while the other block lies below the fault.
 * Hanging Wall:** When half of the fault lies above the fault.
 * Footwall:** When half of the fault lies below.
 * Reverse Fault:** When blocks of rock move in opposite directions, like a divergent boundary.
 * Fault-block mountains:** When a normal fault uplifts a block of rock.
 * Folds:** Bends in rock that form when compression shortens and thickens part of Earth's crust.
 * Anticline:** A fold in rock that bends upward into an arch.
 * Syncline:** A fold in rock that bends downward in the middle, to form a bowl.
 * Plateau:** A large area of land that is above sea level.

**Stress in the Crust**

 * Movement of Earth's plates create powerful forces that squeeze/pull rock in the crust, stress
 * stress is a force, so it adds energy to the rock. Energy is stored until rock breaks/changes shape

Types of Stress

 * Three types of stress: shearing, tension, and compression, work over millions of years to change the shape and volume of rock
 * these forces cause some rock to become brittle and snap, some rocks bend like melted road tar
 * Tension stretches rock like stretching chewed bubble gum, occurs when two plates are moving apart
 * Compression squeezes rock together until it folds/breaks
 * Plates move very slowly, causes deformation

Kinds Of Faults

 * When enough stress builds up in rock, the rock breaks, making a fault
 * Faults usually occur along plate boundaries, where plate motion forces compress/pull/shear so much that crust breaks
 * Three faults: strike slip, normal, and reverse
 * Strike-Slip Faults**
 * Rocks on each side of fault slip past each other sideways, little up-or-down motion
 * A strike-slip fault is called a transform boundary where the plates meet
 * Normal Faults**
 * Caused by tension forces in crust
 * The fault is at an angle
 * on block above fault, one block below fault
 * Block above is the hanging wall
 * Block below is footwall
 * When movement occurs, hanging walls slips downward
 * Reverse Faults**
 * Hanging wall moves __over__ footwall
 * kind of like the opposite of a normal fault.

Friction Along Faults

 * Low friction, fault easily moves. High friction:Plates stick together, storing energy.
 * In earthquakes, stored energy from the plates with high friction finally release when plates eventually move.

Mountain Building

 * fault movement can change a flat surface into a tall mountain range. (over millions of years)
 * Mountains Formed by Faulting**
 * Formed when a normal fault uplifts a block of rock
 * when two normal faults are next to each other, the rock left behind forms a mountain.
 * mountains formed like this are in many places.
 * Mountains Formed By Folding**
 * Formed when rock wrinkles together, like skidding on a rug.
 * many big mountain ranges have been created by folding.
 * Anticlines And Synclines**
 * look like ocean waves, a bowl
 * formed by compression and folding of crust over millions of years.


 * Plateaus**
 * Same force that raises mountains can make plateaus
 * plateaus are like tables, wider than they are tall
 * many places have plateaus

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