Quiz 2: Earthquakes

There are several ways to describe the "size" of an earthquake. The method that describes the amount of damage caused by an earthquake and what is felt at each location is called A.Intensity B.Acceleration Magnitude C.Richter Magnitude D.Moment Magnitude

A.Intensity

"There will be an earthquake of M7 or above sometime in the next month in the Parkfield region along the San Andreas Fault" according the the USGS spokesperson. A.This is best classified as an earthquake "prediction". B.This is best classified as "best guess". C.This is best classified as an earthquake "forecast".

A.This is best classified as an earthquake "prediction".

Which type of fault is most associated with convergent plate boundaries? (Involves compressional stress and seen at subduction zones and continental-continental collisions.) A.Thrust faults B.Gravitational faults C.Normal faults D.Strike-slip faults

A.Thrust faults

The factors that determine how much energy is released by an earthquake do NOT include: A.the depth of the focus B.the strength or stickiness of the fault zone (the friction across the fault that resists motion) C.the area (or length) of the fault that ruptures during the earthquake D.the offset or displacement of the fault during an earthquake (slip)

A.the depth of the focus

What is the correct relationship between faults and earthquakes? A.Earthquakes cause the ground to move along faults. B.Movement along faults causes earthquakes.

B.Movement along faults causes earthquakes.

Which of the following large historical earthquakes did not occur at an active plate boundary? A.Japan, 2011. B.New Madrid, 1811-1812 C.Chile, 1960. D.San Francisco, 1906.

B.New Madrid, 1811-1812

Buoyant materials, such as continents or hot rocks or hot water or hot air: A.Tend to sink into denser materials. B.Tend to float on denser material or to rise up through denser rock or water or air. C.Tend to resist any kind of motion.

B.Tend to float on denser material or to rise up through denser rock or water or air.

What causes the up-and-down wiggles on a seismogram (or "wiggle trace")? A.moment waves B.shaking of the ground C.tsunami D.variations in air pressure

B.shaking of the ground

The seismic wave that usually causes the most damage from an earthquake is A.the S-wave B.the surface wave C.the P-wave D.the gravitational shock wave

B.the surface wave

An earthquake of M8 causes the amplitude of ground motion to be _____ times larger than a M7 earthquake and ______ times larger than a M6 earthquake. A.10; 20 B.32; 64 C.10; 100 D.32; 1024

C.10; 100

Your book talks about a lot of earthquakes, including the Haiti earthquake of 2010 and the Chile earthquake of 2010. The main reason that so many more people died in Haiti (240,000) than in Chile (523) is: A.The Haiti earthquake had a higher magnitude than the Chile earthquake. B.There was a larger population in Haiti and therefore more people were exposed to the shaking from the earthquake. C.Buildings in Haiti were not built to withstand earthquakes and therefore collapsed whereas buildings in Chile are built to a strict earthquake resistance code. D.The Haiti earthquake generated a tsunami whereas the Chile earthquake did not.

C.Buildings in Haiti were not built to withstand earthquakes and therefore collapsed whereas buildings in Chile are built to a strict earthquake resistance code.

The San Andreas fault forms the transform plate boundary between the Pacific and North American plates. What type of fault is the San Andreas? A.Gravitational fault B.Reverse fault C.Strike-slip fault D.Normal fault E.Thrust fault

C.Strike-slip fault

Most people who die in an earthquake die because: A.they fall into a crack opening in the ground B.they get caught in a tsunami. C.a building falls or collapses on them D.the shaking makes their heart stop.

C.a building falls or collapses on them

The biggest earthquakes (M8.5 and above) are most likely to occur at A.mid-oceanic ridges B.transform plate boundaries C.subduction zones D.hot spots

C.subduction zones

Subduction zones are able to produce M9 earthquakes (unlike transform or divergent) plate boundaries because A.many people live along the coast of subduction zones, making a large segment of the population vulnerable. B.the volcanic activity at subduction zones makes the fault plane stickier and therefore they release more energy when they reach their elastic limit C.the length of the rupture can be so large - up to 1200 km along the megathrust - and the amount of slip is large. D.they usually go for hundreds of years between ruptures allowing a lot of stress to build up.

C.the length of the rupture can be so large - up to 1200 km along the megathrust - and the amount of slip is large.

The location at the surface of the Earth directly above the point of rupture of an earthquake is called the

Epicenter

Events or changes in the earth that have occasionally been observed to occur before a major hazard event such as an earthquake are called ______ (Foreshocks are an example of these)

Precursors

Delaware (and the rest of the US Atlantic margin) is currently located in the middle of a plate and is therefore not at an active plate boundary.

True

In any given year there are 10-20 earthquakes in the world of M7 or greater.

True

The Loma Prieta earthquake in California in 1989 is a good example of an earthquake that filled a "seismic gap".

True