Quakes & Plates

1. According to the Earth Science Reference Tables, which zone of the Earth has the greatest density?

Crust
Mantle
Outer core
Inner core

2. According to the Earth Science Reference Tables, for the last 200 million years, continents on opposite sides of the Atlantic Ocean have generally

Been drifting closer together.
Been drifting farther apart.
Remained the same distance apart.

3. A seismographic station records a travel time difference of 3 minutes between P-waves and S-waves of an earthquake. Approximately how far is the seismic station from the epicenter of the earth-quake?

1000 km
1500 km
3200 km
4800 km

4. The temperature of the rock located 1000 kilometers below the Earth's surface is about

1800 degrees C
2100 degrees C
3200 degrees C
4100 degrees C

5. The composition of some meteorites supports the inference that the Earth's core is composed of

Aluminum and calcium
Iron and nickel
Silicon and oxygen
Magnesium and potassium

6. Igneous rock along mid-ocean ridges is younger than the igneous rock farther from the ridges. This evidence supports the theory that

The ocean floor is stable.
The ocean floor is spreading.
Volcanoes once existed on both sides of ocean ridges.
Ocean ridges are areas of subsidence.

7. At which location would seismic measurements indicate that the Earth's crust is thickest?

The Gulf of Mexico
The Mississippi Valley
The Rocky Mountains
Lake Erie

8. The time that an earthquake occurred can be inferred by knowing the

Arrival time of the P-waves.
Arrival time of the S-waves.
Distance between seismic stations.
Epicenter distance and arrival time of the P-waves.

9. Why do geologists infer that the Earth's outer core is a liquid?

S-waves travel faster than P-waves in the outer core.
S-waves do not pass through the outer core of the Earth.
Instruments indicate that the Earth's temperature increases with depth.
P-waves can pass through the outer core of the earth

10. At what type of plate boundary would the fault shown in the diagram be found?



A convergent boundary
A divergent boundary
A transform boundary
A subduction boundary

11. Which statement best describes the continental and oceanic crusts?

Continental crust is thicker and less dense than oceanic crust.
Continental crust is thicker and more dense than oceanic crust.
Continental crust is thinner and less dense than oceanic crust.
Continental crust is thinner and more dense than oceanic crust.

12. Most of the world's volcanoes are located in

Chains throughout the world.
The central regions of the continents
The centers of oceanic areas
Regions in the late stages of erosion

13. What earth features are represented by the gray areas in the diagram?



Mid-ocean ridges
Subduction zones
Hot spots
Convergent plate boundaries

14. Our present understanding of the nature of the Earth's interior is based primarily upon information obtained from

Magnetic field values obtained at the Earth's surface.
Seismic wave evidence from earthquakes.
Gravity field values obtained from satellites.
Density distributions inferred from the Earth's rotational properties.

15. Useful information regarding the composition of the interior of the Earth can be derived from earthquakes because earthquake waves

Travel through the Earth at a constant velocity.
Travel at different rates through different materials.
Release materials from within the Earth.
Have a constant amplitude.

16. According to the plate tectonic theory

Mid-ocean ridges have lower than normal heat flows.
Plates are destroyed at mid-ocean ridges.
Continents drift because they rest on plates that are moving.
Plate thickness equals the thickness of the crust and mantle combined.

17. The actual point along a fault where slippage occurs and causes an earthquake is called a (an)

Orthocenter
Epicenter
Circumcenter
Focus

18. At equal depths in the Earth, S-waves travel

Always faster than P-waves.
Always slower than P-waves.
Always at the same rate as P-waves.
Sometimes slower and sometimes faster than P-waves.

19. What kind of boundary is shown in the diagram?



A convergent plate boundary
A divergent plate boundary
A transform plate boundary

20. At which location in the diagram would the age of the sea-floor be greatest?



A
B
C
D

21. The sea floor rock at location B is approximately 80 million years old. At which other location could rock of similar age be found?



A
C
D
E

22. According to the Earth Science Reference Tables, if a seismograph station records a difference in arrival times between P-waves and S-waves of 4 minutes, how far away is the epicenter of the Earthquake?

1000 Km.
1900 Km.
2600 Km.
5200 Km.

23. Using the Richter scale of earthquake magnitude, each higher number represents how many more times as much energy than the preceding number?

5
10
100
1000

24. Which evidence does NOT support the theory that Africa and South America were once part of the same large continent?

Correlation of rocks on opposite sides of the Altantic Ocean.
Correlation of fossils on opposite sides of the Atlantic Ocean.
Correlation of coastlines on opposite sides of the Atlantic Ocean.
Correlation of living animals on opposite sides of the Atlantic Ocean.

25. A state of balance may exist between continents and ocean basins. Any upset of this balance may cause the crust to move and readjust. The term most closely associated with this statement is

Continental drift
Convection cells or currents
Isostacy
Orogeny

26. Where do most earthquakes occur?

In the continental interiors
At the mantle-core boundary
Randomly over the Earth's surface
In specific earthquake belts within the crust

27. The time lapse between the arrival of P-waves and S-waves at one seismograph recording station can be used to determine the

Magnitude of the earthquake
Exact location of the epicenter
Exact depth of the earthquake
Distance to the epicenter

28. The term isostasy refers to a

Line of equal air pressure
A zone of earthquake activity
Deflection of winds on the Earth's surface caused by rotation
Condition of balance between segments of the Earth's crust

29. As the distance between an observer and an earthquake decreases, the difference in arrival times of P and S waves

Decreases
Increases
Remains the same

30. Igneous materials found along ocean ridges contain magnetic iron particles that show reversal of magnetic orientation. This is evidence that

Volcanic activity has occurred constantly throughout history
The Earth's magnetic poles have reversed positions in the past
The Earth's crust does not move
Igneous materials are always formed beneath oceans

31. The density of the Earth's core would be most nearly the same as the density of

Ocean water (1.02 g/cm3)
A meteorite (11.20 g/cm3)
The Moon (3.36 g/cm3)
A granite rock (2.72 g/cm3)

32. Based on the Reference Tables, about how far away from the receiving station is the epicenter of an earthquake if the difference in arrival times of P-waves and S-waves is six minutes and thirty seconds?

3000 Km.
5000 Km.
6300 Km.
8000 Km.

33. An earthquake occurred at 5:00:00 A.M. At what time would the P-wave reach a seismic station 3000 kilometers from the epicenter?

5:04:30 A.M.
5:05:40 A.M.
5:10:12 A.M.
6:15:00 A.M.

34. The oceanic crust is thought to be composed mainly of

Granite
Sandstone
Basalt
Rhyolite

35. At what depth below the surface of the Earth is the temperature higher than the melting point of the rocks found at that depth?

1200 Km.
2000 Km
3500 Km.
6000 Km.

36. What is the pressure at the boundary between the mantle and the outer core?

500,000 atmospheres
1,000,000 atmospheres
1,500,000 atmospheres
3,200,000 atmospheres

37. According to the Earth Science Reference Tables, the temperature of the rock at a depth of 6000 Km. in the Earth is lower than the melting point of those rocks. This would indicate that

The Earth gets cooler at great depths
The pressure at this depth is less than the pressure at 5000 Km.
The rocks at this depth are liquid
The rocks at this depth are solid

38. The epicenter of an earthquake is located near Massena, New York. According to the Earth Science Reference Tables, the greatest difference in arrival times of P-waves and S-waves for this earthquake would be recorded in

Albany, N.Y.
Utica, N.Y.
Plattsburgh, N.Y.
Binghamton, N.Y.

39. According to the Earth Science Reference Tables, what is the relationship between density, temperature, and pressure inside the Earth as depth increases?

Density, temperature and pressure all decrease.
Density and temperature increase but pressure decreases.
Density increases but temperature and pressure increase.
Density, temperature and pressure all increase.

40. Compared to the continental crust of North America, the oceanic crust in the area of the Hawaiian Islands is probably

Thinner and similar in composition.
Thinner and different in composition.
Thicker and similar in composition.
Thicker and different in composition.

41. Which event provides direct evidence of crustal movement?

The erosion of the outside of a river curve.
The deposition of sediment in the ocean.
The displacement of rock strata during an earthquake.
The weathering of rock to form a residual soil.

42. Which statement about the Earth's mantle is best supported by data given in the Earth Science Reference Tables?

The density of the mantle is greatest 300 km below the surface.
The highest temperatures within the Earth occur in the mantle.
The greatest pressures within the Earth exist in the mantle.
At 300 km below the surface, the mantle is very near its melting point.

43. An abrupt change in the speed of seismic waves is an indication that the

Seismic waves are colliding
Shear wave has overtaken the compressional wave
Waves are going into a material with different properties
Waves are passing through material of the same destiny

44. It takes P waves 4 minutes to travel from the epicenter of an earthquake to a seismic station. How long will it take S waves from the same earthquake to reach that seismic station?

2 minutes
4 minutes
7 minutes and 20 seconds
12 minutes and 30 seconds

45. At which location in the diagram is new sea floor probably being created?



A
B
C
D

46. Which location in the diagram represents a region where sea floor is being subducted?



A
B
C
D

47. According to the Earth Science Reference Tables, approximately how far will a P-wave travel in eight minutes?

2,200 Km
4,800 Km
6,500 Km
11,200 Km

48. Following an earthquake, a seismograph station recorded the arrival of a P-waveat 3:09:30 a.m. and an S-wave at 3:14:00a.m. According to the Earth Science Reference tables, what is the distance from the seismic station to the epicenter of the earthquake

1,200 km
3,000 km
6,100 km
7,500 km

49. A seismograph station determines that its distance from the epicenter of an earthquake is 4000 kilometers. According to the Reference Tables, if the P-wave arrived at the station at 10:15 a.m., the time of the earthquakes's origin was

10:02 a.m.
10:08 a.m.
10:10 a.m.
10:22 a.m.

50. Two samples of ocean floor basaltic bedrock are found at equal distances from, and on opposite sides of, a mid-ocean ridge. The best evidence that both samples were formed at the ridge at the same time is that both samples also

Have the same density
Contain different crystal sizes
Are located at different depths below sea level
Have the same magnetic field orientation

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