earthquakes

Question 1

fracture, fault and joint

Answer 1

fractured - break in the earths crust
fault - fracture in crustal rock that involved the displacement of rock on one side of the fracture
joint - fracture without displacement of rock

Question 2

faults

Answer 2

occur when rocks rupture strength is exceeds dby imposed stress , rocks break and return t o their original shape on either side of the fault
slippage along a fault produced an earthquake

Question 3

types of stress that cause faults - compressional stress

Answer 3

converging or collide rocks are crushed tightly together

Question 4

tensional stress

Answer 4

spreading or diverging rocks are being pulled apart

Question 5

transverse stress

Answer 5

sliding more likely at margins , scarp - exposed cliff like face of a fault place caused by one side moving down slope

Question 6

fold structures

Answer 6

when rocks are compressed they respond to the stress by folding as well as faulting , most chataristic of sedimentary rock

uphold - anticlines
downfold - synclines

Question 7

earthquake

Answer 7

release of energy that has built up during the stress of increasing deformation of rocks energy release come sas seismic waves that radiate in all directions form place of movement
focus - origin of earthquake
epicenter - location on earths surface directly above focus

Question 8

caused of earthquakes

Answer 8

90% are intraplate earthquakes due to the movement at plate margins
intraplate 10% due to fault movements, land movement under ice and volcanic activity
human activity induced earthquakes form dams, injection of wastewater and extracting resources

Question 9

measuring earthquakes

Answer 9

seismograph - measures the amount of shaking of the ground as a quake passes
Richter scale 0 measurement of physical force of ground motion
intensity - reflects impact of earthquake on cultural landscape
soft soils amplify the spread of shaking