click below
click below
Normal Size Small Size show me how
Ch.16 (Exam 3)
Earthquakes
Question | Answer |
---|---|
Tsunami waves may move faster than ____. | 800 km/hr |
For most of the 20th century earthquake magnitude was reported on the _______ scale, a scale that has never exceeded a magnitude 8.6. | Richter |
____ focus earthquakes are the most common. | Shallow |
Perhaps 90 percent of the destruction in the 1906 San Francisco earthquake was caused by ____. | fires |
The time interval between the first arrival of P-waves and the first arrival of S-waves ____ with distance from the focus of an earthquake. | increases |
The paper record of an earthquake is a ____. | seismogram |
Although large earthquakes are rare in the central and eastern United States, when they do occur they tend to be very destructive because _______. | the crust there is cool and brittle |
Faulting and earthquakes are examples of ____________. | brittle behavior |
In the elastic rebound theory, earthquakes are caused by the sudden release of progressively stored _____ in rocks. | strain |
____ are seismic waves that travel through the Earth's interior, spreading out from the focus in all directions. | Body waves |
A _____ is the first wave to arrive at a recording station following an earthquake. | P-wave |
A(n) _______ is a seismic sea wave. | tsunami |
____ are the waves of energy produced by an earthquake | Seismic |
_____ is a measure of an earthquake's effect on people and buildings. | Intensity |
Rupture begins at the _____ and then spreads rapidly along the fault plane. | focus |
Deep focus earthquakes occur at a maximum depth of ______. | 670 km |
______ would be associated with Benioff zones. | All the answers are correct |
_____ earthquakes probably occur along older faults that are no longer at plate boundaries, for example the New Madrid Missouri earthquakes of 1811-1812. | Intraplate |
One suggested cause of deep focus earthquakes is ______. | collapse of minerals into denser forms |
The ______ is the most famous example of a right lateral transform fault. | San Andreas Fault in California |
A series of earthquakes that occurred near _____ in 1811-1812 were the most widely felt earthquakes to occur in recorded history. | New Madrid, Missouri |
Deep rocks behave as _____ material under stress rather than breaking. | ductile |
_____ can occur when water-saturated soil turns from a solid to a liquid as a result of an earthquake. | Liquefaction |
Both P-waves and S-waves can pass through ____. | solid rock |
____ -waves are the slowest body waves. | S |
The effects of ground motion caused by an earthquake do not include _____. | volcanism |
___ stations are the minimum needed to determine the location of an earthquake epicenter. | Three |
________ maps are useful for assessing how different areas respond to seismic waves and provide valuable information for earthquake planning. | Intensity |
Surface waves ____________. | produce most of the damage to buildings during earthquakes |
Richter scale values above 7 are not accurate. The ______ scale is a more objective method of measuring the energy of a large earthquake. | moment magnitude |
The point within the earth where seismic waves first originate is the _____. | focus |
Medium and deep focus earthquakes occur along _______________. | convergent plate boundaries only |
On the modified Mercalli intensity scale the maximum value is _______. | XII |
The most important concentration of earthquakes by far is ______. | the Circumpacific belt |
_____ waves tend to be incredibly destructive to buildings because they produce much ground movement and take a long time to pass. | Rayleigh |
Which of the following is not used to aid in earthquake prediction? | tsunamis |
The greatest loss of life in the 1964 southern Alaska earthquake was from _________. | tsunamis |
A ____ plots seismic-wave arrival time against distance. | travel-time curve |
Earthquake waves propagate most rapidly through ____________. | igneous rock |
____ are earthquake waves that cause the most property damage. | Surface waves |