QUIZ 1.What are Earthquakes? 2._____ is the deformation of a material caused by stress. 3.Describe tension stress. 4.Faulting causes rock to _________.

Answers 1.Vibrations of the earth’s crust caused by a sudden release of energy 2. Strain 3. pulls apart 4. Break

Faulting When stress exceeds the strength of the rocks movement occurs along a weak region in the rock called a fault Movement along the fault results in EQ’s

Faults Fault Fault = any fracture or system of fractures along which the Earth moves Fault Plane Fault Plane = the surface along which the movement takes place

Example of Faulting Cracks in the concrete The crack represents strain resulting from stress use by cars & people The crack itself is a fault The concrete surface where the fault occurred is the fault plane The type and direction of stress on the concrete results in different types of faults

3 Types of Faults Normal Normal = rocks are pulled apart; Tension (stress) causing horizontal & vertical movement p. 531 Table 19.1

3 Types of Faults Reverse or Thrust Faults Reverse or Thrust Faults = rocks are forced together; Compression (stress) causing horizontal & vertical movement p. 531 Table 19.1

3 Types of Faults Strike Slip Strike Slip = rocks are shearing, twisting; Shear (stress) causing horizontal movement p. 531 Table 19.1

Animation of Faults ns/ ns/ Reference USGS

Comparison between types of fault & plate boundaries What type of fault is associated with converging plates? Reverse or Thrust Fault

What type of fault is associated with divergent plates? Normal Fault

What type of fault is associated with transforming plates? Strike – Slip Fault

Text read p. 530 – 532 Quiz ?????

ANY QUESTIONS?