Earthquakes Ch. 5 Review for Exam

Earthquakes Three different kinds of stress can occur in the crust. What are they? How does tension affect the crust? How does compression affect the crust? How does shearing affect the crust? Tension, compression, and shearing Tension pulls on the crust, stretching it and making it thinner Compression squeezes the crust until it breaks Shearing pushes rock in two opposite directions.

Earthquakes There are three main kinds of faults that occur at plate boundaries. What are they? What direction do normal faults move? What direction do reverse faults move? What direction do strike- slip faults move? Normal faults, reverse faults, and strike-slip faults Normal faults pull apart Reverse faults push together Strike-slip faults move past each other in opposite directions

Earthquakes What landforms can be produced by folding of Earth’s crust? What landforms can be produced by stretching of Earth’s crust? What landforms can be produced by uplifting of Earth’s crust? Anticlines, synclines, and mountain ranges such as the Himalayas and the Alps Fault-block mountains such as the Panamint Range Plateaus

Earthquakes A downward fold in rock is called a __________. An upward fold in rock is therefore called an ________. A large area of flat land elevated high above sea level is a ___________. Syncline Anticline Plateau

Earthquakes A force that acts on rock to change its shape or volume is called _______ A break in the rock of the crust where rock surfaces slip past each other is called a _______. Stress Fault

Earthquakes What is the shaking that results from the sudden movement of rock along a fault? What is the area beneath Earth’s surface where rock that is under stress breaks, triggering an earthquake. An earthquake The focus

Earthquakes What is the point on the surface directly above the focus called? What are the three types of seismic waves? What order do they arrive? How are they different from each other? The epicenter P waves, S waves, and surface waves As listed above P waves compress and expand the ground, S waves vibrate from side to side and cannot go through liquids, surface waves produce severe ground movements and roll like ocean waves.

Earthquakes What are the three scales used to measure earthquakes? Describe each - Mercalli, Richter, and moment magnitude. Mercalli – rates strength at a given location Richter – assigns a magnitude number to an earthquake based on the size of seismic waves Moment magnitude – estimates the total energy released by an earthquake

Earthquakes What is the minimum number of recording stations needed to locate the epicenter of an earthquake? How is the distance from the epicenter measured using seismic waves? Three The difference in arrival time between the P and S waves tells geologists how far away the epicenter is from a particular location

Earthquakes What are the four instruments used to monitor faults? The force that opposes the motion of one surface as it moves across another surface is called___________. Tiltmeters, creep meters, laser-ranging devices, and GPS satellites Friction

Earthquakes Why can’t geologists accurately predict earthquakes? A) They are dumb B) sometimes energy builds up along a fault but an earthquake doesn’t occur C) One or more small quakes relieve the pressure D) Both B and C

Earthquakes What is an earthquake that occurs after a large earthquake in the same area called? What can happen to soft, loose soil that is full of moisture during an earthquake? An aftershock Liquefaction

Earthquakes Water displaced by an earthquake may form a huge wave called a ________________. What causes most earthquake related injuries and deaths? What is the best way to protect yourself during an earthquake? Tsunami Falling debris from damaged buildings Drop, cover, and hold.

Earthquakes What conditions tell a geologist that an earthquake is likely? What direction do seismic waves travel from the focus? Whenever plate movement stores energy along faults, an earthquake is likely. All directions like the ripple of a pebble thrown in a pond.