2What are some things that can cause them? EarthquakesSo….What is an Earthquake?And…What are some things that can cause them?
3Stress in the CrustAn earthquake is the shaking that results from the movement of rock beneath Earth's surface.This is a super powerful force!!!These forces are examples of stress.Stress is a force that acts on rock to change its shape or volume.
4Types of StressThere are three different kinds of stress that occur in the Earth’s crust…ShearingTensionCompressionAll of this stress works over millions of years to change the shape of rock.So…Any change in the shape of Earth's crust is called deformation.
5ShearingStress that pushes a mass of rock in two opposite directions is called shearing.Shearing can cause two slabs of rock to slip past each other like the picture below.What feature in California is an example of this?
6Tension Think of pulling a Milky Way candy bar apart. Tension is a stress that pulls on the crust, stretching rock so that it becomes thinner in the middle.Tension occurs where two plates are moving apart.Think of pulling a Milky Way candy bar apart.What ocean feature is this an example of?
7CompressionCompression is a stress force that squeezes rock until it folds or breaks.One plate pushing against another plate can compress rock easily….Almost like Mr. Wise’s strength!!!
8Kinds of FaultsWhen enough stress builds up in rock, the rock can break, creating a fault.A fault is a break in the crust where two slabs of crust slip past each other.The rocks on both sides of a fault can either move up or down or sideways.Faults usually occur along plate boundariesThere are three main types of faults:Strike-slip faultsNormal faultsReverse faults
9Strike-Slip Faults What fault in California is an example of this? Shearing creates strike-slip faults.In a strike-slip fault, the rocks on either side of the fault slip past each other sidewaysA strike-slip fault that forms the boundary between two plates is called a transform boundary.What fault in California is an example of this?
10Normal Faults Tension forces in Earth's crust cause normal faults. In a normal fault, the fault is at an angle, so one block of rock lies above the fault while the other block lies below the fault.Tension forces create normal faults where plates diverge, or pull apart.What ocean feature is an example of this?
12Compression forces produce reverse faults. A reverse fault has the same structure as a normal fault, but the blocks move in the opposite direction.What geologic feature is an example created by compression?
14Mountain BuildingThe forces of plate movement can build up Earth's surface.Over millions of years, fault movement can change a flat plain into a towering mountain range
15Mountains Formed by Faulting When normal faults uplift a block of rock, a fault-block mountain forms.
16Mountains Formed by Folding Under certain conditions, plate movement can cause crust to fold.Folds are bends in rock that form when compression shortens and thickens part of Earth's crust.The collisions of two plates can cause compression and folding of the crust.Some of the world's largest mountain ranges, such as the Himalayas and the Alps, formed when pieces of the crust folded during the collision of two plates.Such plate collisions also lead to earthquakes!
18Anticlines and Synclines A fold in rock that bends upward into an arch is an anticline.A fold in rock that bends downward in the middle to form a bowl is a syncline.Anticlines and synclines are found on many parts of Earth's surface where compression forces have folded the crust.