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77 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Consider the three types of rock mentioned in this section. Which one would be more likely to be found deep in the crust.
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Metamorphic rock is more likely to be found deep in the crust.
Remember, metamorphic rock forms because of great pressure. The deeper the rock is in the crust, the more weight presses down on it, so the more pressure it experiences. There are other ways to get a high pressure situation, however, so metamorphic rock does not have to be deep in the crust. |
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Suppose you had a long, steel rod, and you stood at one end of it while a friend stood at the other end. Consider the following experiment: Your friend hit his end of the rod with a hammer, and you listen for the sound. You then press an ear against the rod, and your friend hits it with the hammer again. In which case would the sound be louder?
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The sound would be louder when you put your ear to the rod.
Experiment 6.1 showed that sound travels better through a solid (the string) than through air. Since steel is solid, sound will travel better through it. |
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Suppose you were able to remove a sample of the plastic rock from the asthenosphere and take it into a laboratory. Would it behave differently than a rock sample you took from earth’s crust. Why or why not?
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It would not behave differently than any other rock.
Remember, the plastic nature of the rock in the mantle is due to the extreme heat and pressure found there. As soon as you remove the rock form the mantle and take it to the lab, that heat and pressure are gone. It will then behave just like any other rock. |
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Would water be subject to pressure freezing? Why or why not?
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No, it would not.
Water is one of the few substances in creation that has its molecules closer when it is a liquid compared to when it is a solid. Thus, if I press water molecules closer together they become more liquid. In fact, if you exert pressure on ice it will melt, because you are pushing the molecules closer together, like they are in liquid water. |
Please note that at extreme pressures, water can become a solid, but that solid is not what you and I would call “ice.”
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Regardless of whether the dynamo theory, the rapid-decay theory, or some as yet unknown theory is correct in explaining the earth’s magnetic field, we are reasonably certain that substances in the core of the earth are in motion. Why?
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The earth has a magnetic field that must be caused by the motion of electricity. Thus, something in the core must be moving, or there would be no electrical flow and thus no magnetic field.
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Would plate tectonics work if the mantle were made out of normal, solid rock?
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No, it will not work.
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If the mantle were normal, solid rock, the plates would not be able to move.
The plastic nature of the mantle's rock (a bit like the interior of the hard-boiled egg you used in the experiment) makes it possible for the plates to move |
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Look at figure 6.3. Assuming plate tectonics is true, where would you expect the majority of the earthquakes in the United States to occur?
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The majority of earthquakes should occur in California, Oregon, Washington, and Alaska.
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Those are the places in the U.S. that rest on a plate.
Since earthquakes can be caused by plates moving against each other, a lot of earthquakes should occur in these sates, which lie along a boundary between plates. Since most U.S. earthquakes do, indeed, occur in these states, this is another piece of evidence in favor of plate tectonics. |
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Suppose you could measure the energy of an earthquake at its focus. How would it compare to the energy of the earthquake at its epicenter?
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It would be larger.
Just like other vibrations, the farther the vibrations from an earthquake travel, the less energy they have. The focus is where the vibrations start, so they will have the most energy there. |
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A seismologist is studying a region near a fault. She measures two earthquakes. One measures 2 on the Richter scale and the next measures 5. How many times more energy does the second earthquake release as compared to the first?
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Since the Richter scale says that every unit corresponds to a 32-times increase in energy, an earthquake that measures 3 will release 32 times more energy than the one that measures 2.
An earthquake that measures 4 will release 32 x 32 = 1,024 times more energy than the one that measures 2. Finally, the one that measures 5 will release 32 x 32 x 32 = 32,768 times more energy than the one that measured 2. |
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Which kinds of mountains are formed as the result of rock masses moving against each other.
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Fault-block mountains and folded mountains are the result of the motion of rock masses against each other.
Domed mountains and volcanic mountains are formed as the result of magma pushing up from the mantle. |
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Define the following term:
Earth's crust |
Earth's outermost layer of rock
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Define the following term:
Sediment |
Small, solid fragments of rock and other materials that are carried and deposited by wind, water, or ice.
Examples would be sand, mud or gravel. |
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Define the following term:
Sedimentary rock |
Rock formed when chemical reactions cement sediments together, hardening them.
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Define the following term:
Igneous rock |
Rock that forms from molten rock
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Define the following term:
Metamorphic rock |
Rock that behaves like something between a liquid and a solid
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Define the following term:
Plastic rock |
Rock that behaves like something between a liquid and a solid
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Define the following term:
Earthquake |
Vibration of the earth that results either from volcanic activity or rock masses suddenly moving along a fault
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Define the following term:
Fault |
The boundary between two sections of rock that can move relative to one another
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Define the following term:
Focus |
The point where an earthquake begins
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Define the following term:
Epicenter |
The point on the surface of the earth directly above an earthquake's focus.
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Scientists often separate the earth into five distinct section. Name those sections.
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Atmosphere
Hydrosphere Crust Mantle Core |
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Of the 5 sections listed in problem 2, which can we observe directly?
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Atmosphere
Hydrosphere Crust |
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What two regions of the earth does the Moho discontinuity separate? What about the Gutenberg discontinuity?
What about the Lehmann discontinuity? |
The Moho separates the crust from the mantle, and the Gutenberg discontinuity separates the mantle from the core.
The Lehmann discontinuity separates the inner core from the outer core, |
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What is the difference between the ways that igneous rock and sedimentary rock form?
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Sedimentary rock is formed when sediments are solidified through chemical reactions.
Igneous rock forms when molten rock solidifies. |
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Of the 3 types of rock discussed in this module, which type starts out a different type of rock?
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Metamorphic rock starts out as either igneous or sedimentary rock and is then transformed by high temperature and pressure.
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What is unique about the rock in the asthenosphere?
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The extremes in temperature and pressure make the rock behave sometimes like a liquid and sometimes like a solid. That's why we call it plastic rock.
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What is the main thing scientists observe in order to learn about the makeup of the earth's interior?
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Scientists observe seismic waves, which are usually generated by earthquakes. The behavior of these waves tells us a lot about the makeup an properties of the mantle and core.
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Which is a solid: the inner core or the outer core? Why is it solid when the other is liquid?
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The inner core is solid because of pressure freezing.
Even though the inner core is hotter than the outer core, it remains solid because the pressure is so great that it forces iron atoms close enough together to be sold. |
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Where is the magnetic field of the earth generated?
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In the earth's core
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What causes the magnetic field of the earth?
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A large amount of electrical flow in the core.
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Give a brief description of the 2 main theories that attempt to explain the earth's magnetic field.
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The dynamo theory says that the motion of the core is due to temperature differences in the core and the rotation of the earth.
The motion causes the motion of electrical charges in the core, which creates electrical current. The rapid-decay theory states that the electrical current in the core started as a consequence of how the earth formed and is decreasing over time. |
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What makes the rapid-decay theory more scientifically valid than the dynamo theory?
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The rapid-decay theory has been used to accurately predict the magnetic fields of other planets. The dynamo theory fails miserably at this.
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Why is a catastrophe like the worldwide flood in Noah's time an essential part of earth's history if the rapid-decay theory is true?
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The rapid-decay theory requires a global catastrophe in order to be consistent with the data that indicate the magnetic field of the earth has reversed several times.
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What two reasons make otherwise good scientists ignore the more scientifically valid rapid-decay theory?
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The fact that the rapid-decay theory requires a catastrophe like the worldwide Flood and the fact that the rapid-decay theory indicates an earth 10,000 years old or younger tend to make many scientists shy away from it.
This is unfortunate, as there are good reasons to believe both of them. |
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Why would life cease to exist without the earth's magnetic field?
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Without the magnetic field, cosmic rays from the sun would hit the earth.
These rays would kill all life on the planet. |
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What are the 'plates' in the plate tectonics?
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The plates are large 'islands' of the earth's lithosphere. These plates float around on the plastic rock of the asthenosphere.
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What can happen when plates collide with one another?
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One plate can slide under another and form a trench; the plates can move away from each other, allowing magma to rise and create new crust; the plates can push against each other, causing the crust to fold; or the plates can slide along each other.
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What is Pangaea?
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Pangaea is a hypothetical super-continent that might have existed in earth's past. At one time, all the continents might have fit together to form this super-continent.
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Why do otherwise good scientists ignore the plate tectonics theory despite the evidence that exists for it?
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Some good scientists ignore plate tectonics because it is typically linked to the idea of an earth that is billions of years old.
This is unfortunate because there is no reason to believe that the continents always moved slowly. Indeed, in a catastrophe like a worldwide Flood, they could have moved very quickly. |
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What causes earthquakes?
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Earthquakes are caused by the motion of rock masses along a fault or by volcanic activity.
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Briefly describe the elastic rebound theory of earthquakes
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In the elastic rebound theory, rock masses moving relative to one another get caught on the rough, jagged edges of the fault that lies between them.
The rock masses start to bend as they keep trying to move. At some point, the stress becomes too great, and the moving rock breaks free, causing the rock masses on both sides of the fault to snap back into their original shapes. The resulting vibrations are what we feel as an earthquake. |
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A seismologist detects an earthquake that measures 4 on the Richterscale.
Later, he detects one that measures 8. How many times more energy does the second earthquake release as compared to the first? |
Fore every one step up in the Richter scale, the energy of the earthquake multiplies by 32. The first earthquake measured 4, and the second measured 8.
The second earthquake was 4 units higher, which means it released 32 x 32 x 32 x 32= 1,048,576 times more energy than the first! |
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Name the 4 kinds of mountains. What is required for the formation of each?
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Volcanic mountains
Domed mountains Fault-block mountains Folded mountains Volcanic and domed mountains need magma from the earth's mantle, fault-block mountains need vertical motion along a fault, and folded mountains need rock masses pushing against each other. |
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What have scientists observed in order to learn about earth's interior?
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Seismic waves.
The behavior of these waves tells us a lot about the makeup and properties of the mantle and core. |
You can also say 'sound waves' or just 'waves' instead of seismic waves.
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Between what two regions of the earth can you find the Moho?
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The Moho separates the crust form the mantle
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What causes the earth's magnetic field?
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Electrical flow in the core causes the earth's magnetic field
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What two theories attempt to explain the earth's magnetic field? Which theory is the most scientifically valid?
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Electrical flow in the core causes the earth's magnetic field
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What two theories attempt to explain the earth's magnetic field?
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The dynamo theory and the rapid-decay theory both attempt to explain the earth's magnetic field.
The rapid-decay theory is more scientifically valid. |
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What major benefit do we derive from the earth's magnetic field?
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The earth's magnetic field blocks cosmic rays from the sun
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In a survey of the deep ocean, sonar measurements detect a deep trench on the bottom that runs as far as the instruments detect. What is the most likely cause of the trench?
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The trench is probably the site where one plate interacts with another.
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The earthquake activity of two regions on earth is measured. The first region sits near the middle of one of the plates in the earth's crust, while the other is very near a boundary between two plates. Which will (most likely) have the greatest earthquake activity?
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The region nearest the plate boundary should have more earthquakes.
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Many powerful earthquakes are followed later by less-powerful earthquakes called "aftershocks." If an earthquake measures 6 on the Richter scale and is followed by an aftershock that measures 4, how many times more energy was released in the original earthquake as compared to the aftershock?
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Each step on the Richter scale means a factor of 32 in energy.
Since the quake and aftershock are off by 2 units, the quake was 32 x 32 = 1,024 times more energetic than the aftershock. |
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If a region of the earth has a lot of volcanic activity, what kinds of mountains do you expect to find there?
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Volcanic mountains
Domed mountains |
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Many scientists think that at one time, all the continents might have fit together to form a super-continent. What is the name of this super-continent?
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Pangaea
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The earth is typically divided into 5 regions: the atmosphere, the hydrosphere, the_________, the________, and the______. The deepest region is further subdivided into the _________and__________. We have learned about the lowest regions with__________, such as observing how sound waves pass through the earth.
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Crust
Mantle Core outer core inner core indirect observation |
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The earth’s crust is its ________layer of_____. It is separated from the mantle by the________________, which is typically called the ______for short. We have never been able to drill _______the crust. The crust also contains _______and small, solid fragments of rock and other materials called________. Many of the rocks of the earth’s crust are______________, which are formed when chemical reactions cement sediments together. Other rock types found in the crust are _______(rock that forms from molten rock) and ________(rock that has been changed as a result of great pressure and temperature).
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Outermost
Rocks Mohorovicic discontinuity Moho Below soil sediment sedimentary rocks igneous metamorphic |
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The mantle is _______the crust, and it is separated from the outer core by the_______________. Its principal ingredient is______. Deeper portions of the mantle have a ________temperature than shallower portions of the mantle. The crust and the upper layers of the mantle form the_________, and directly below that is the__________, where the rock is called _________because it behaves like something between a liquid and a solid.
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Under
Gutenberg discontinuity Silica Higher Lithosphere Asthenosphere plastic rock |
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When earthquakes occur, they emit vibrations called_______, which travel through the earth, eventually reaching the surface. They can be detected with________, which can be used to tell how the waves travelled through the inner parts of the earth. This allows scientists to develop ______of the earth’s mantle and core, which allow us to understand their makeup.
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seismic waves
seismographs models |
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The core’s principal ingredient is_____. In the outer core, the iron is______, but in the inner core, it is______. Nevertheless, the inner core has a ______temperature that the outer core. The reason the inner core is solid is because of___________. The boundary between the inner and outer cores is the____________.
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Iron
Liquid Solid Higher pressure freezing Lehmann discontinuity |
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Electrical currents in earth’s core are responsible for earth’s_______, the strength of which has been __________for the past 170 years. In addition, its direction has ________a few times in the past. The data indicate that at least some of these reversals have happened over a ______time period.
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magnetic field
decreasing reversed short |
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The earth’s magnetic field deflects the vast majority of ________that come from the sun. Without such protection, _______would cease to exist as a result of the ______of these particles. If the earth’s magnetic field were too small, ________of them would be deflected. If it were too strong, it would cause deadly ___________that would make life impossible. Thus, the earth has a magnetic field that is____________________.
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cosmic rays
life energy too few magnetic storms life just the right strength to support |
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There are basically two views of how the electrical currents in the core originated, and they are called the __________and the_________. The ________assumes that the earth is billions of years old and is ________when compared to the data. The ________assumes that the earth is only thousands of years old and is ______ when compared to the data. The fact that most scientists believe in the ___________in spite of the data indicates that there is no such thing as an _______scientist. The __________says that all planets initially had a magnetic field, but some planet’s fields have decayed away to nothing by now. The ______________says that once a planet has a magnetic field, its strength might change, but it will never be completely gone.
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dynamo theory
rapid-decay theory dynamo theory not very successful rapid-decay theory very successful dynamo theory unbiased rapid-decay theory dynamo theory |
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The theory of views the earth’s lithosphere as composed of several _______that all move about on the plastic rock of the________. When they move away from each other, _________leaks up from the mantle, creating new________. When they collide, one can slide under the other, generally forming a ________with mountains on one side. When this happens, ______is destroyed as it melts into the mantle. When they collide and neither slides under the other, they buckle, forming mountains. When they _______(or shear) against each other, their edges scrape against each other. This motion can result in severe_________.
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plate tectonics
‘plates’ asthenosphere magma crust trench crust slide earthquakes |
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Many of our observations of_______, _______, and volcanoes seem to support the theory of plate tectonics. There are deep trenches at the bottom of the oceans, the characteristics of which are well described by the theory that the plates in that region of the earth are moving______________. In the end, them, most geologists believe that the plate tectonics theory is_______.
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Earthquakes
Mountains away from each other correct |
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The fact that the continents appear as if they fit together like a jigsaw puzzle has led some scientists to speculate that years ago, all the continents were connected in a giant supercontinent, which has been called_______. Evidence to support this idea includes the fact that sections of rock from different continents are___________, and they _________when you put the continents together the way they are assumed to have existed in_________. Although most scientists believe that the plates have always moved________, a theory called ‘catastrophic plate tectonics’ uses rapid ______movements as a result of a global catastrophe to explain how the supercontinent split in a short amount of time.
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Pangaea
very similar ‘match up’ Pangaea Slowly plate |
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Vibration of the earth that results either from volcanic activity or rock masses suddenly moving along a fault is called an______. A fault is the _________between two sections of rock that can ________relative to one another. Wherever a fault exists, there is the possibility of an________.
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Earthquake
Boundary Move earthquake |
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The most successful theory regarding fault-relate earthquakes is the___________. In this theory, as rock masses on a fault try to move relative to each other, they get _________on one another. As a result, they______. Eventually, the rock masses ______________of each other, and they ‘rebound’ to their normal shape.
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elastic rebound theory
caught up bend break free |
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The point where an earthquake begins is called the earthquake’s______. The _________is the point on the surface of the earth directly above an earthquake’s focus. The study of earthquakes is called_______, and it uses delicate instruments called ________that can measure vibrations that are too small for us to notice. This has led to a scale that classifies earthquakes based on their strength, called the______________. This scale runs from 0 to 10, and each step along this scale is an increase of approximately 32 in the energy of an earthquake. An earthquake that measures 5 on the Ricther scale is 32 times more energetic than one that measures 4 and _____________less energetic than one that measures 8.
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Focus
Epicentre Seismology Seismographs Richter scale 32,768 (32 x 32 x 32) |
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If a fault exists in which one rock mass is moving up and the other is stationary or moving down, the upward-moving mass of rock will form a_____________. When two moving rock masses push against each other with extreme force, the crust can bend in an up-and-down, rolling pattern forming_______________. A mountain formed by lava leaking up through the crust from the mantle is a_____________, while one formed by magma that does not leave the mantle is called a__________________.
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fault-block mountain
folded mountains volcanic mountain domed mountain |
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The core’s principal ingredient is_____. In the outer core, the iron is______, but in the inner core, it is______. Nevertheless, the inner core has a ______temperature that the outer core. The reason the inner core is solid is because of___________. The boundary between the inner and outer cores is the____________.
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Iron
Liquid Solid Higher pressure freezing Lehmann discontinuity |
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Electrical currents in earth’s core are responsible for earth’s_______, the strength of which has been __________for the past 170 years. In addition, its direction has ________a few times in the past. The data indicate that at least some of these reversals have happened over a ______time period.
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magnetic field
decreasing reversed short |
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The earth’s magnetic field deflects the vast majority of ________that come from the sun. Without such protection, _______would cease to exist as a result of the ______of these particles. If the earth’s magnetic field were too small, ________of them would be deflected. If it were too strong, it would cause deadly ___________that would make life impossible. Thus, the earth has a magnetic field that is____________________.
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cosmic rays
life energy too few magnetic storms life just the right strength to support |
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There are basically two views of how the electrical currents in the core originated, and they are called the __________and the_________. The ________assumes that the earth is billions of years old and is ________when compared to the data. The ________assumes that the earth is only thousands of years old and is ______ when compared to the data. The fact that most scientists believe in the ___________in spite of the data indicates that there is no such thing as an _______scientist. The __________says that all planets initially had a magnetic field, but some planet’s fields have decayed away to nothing by now. The ______________says that once a planet has a magnetic field, its strength might change, but it will never be completely gone.
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dynamo theory
rapid-decay theory dynamo theory not very successful rapid-decay theory very successful dynamo theory unbiased rapid-decay theory dynamo theory |
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The theory of views the earth’s lithosphere as composed of several _______that all move about on the plastic rock of the________. When they move away from each other, _________leaks up from the mantle, creating new________. When they collide, one can slide under the other, generally forming a ________with mountains on one side. When this happens, ______is destroyed as it melts into the mantle. When they collide and neither slides under the other, they buckle, forming mountains. When they _______(or shear) against each other, their edges scrape against each other. This motion can result in severe_________.
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plate tectonics
‘plates’ asthenosphere magma crust trench crust slide earthquakes |
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Many of our observations of_______, _______, and volcanoes seem to support the theory of plate tectonics. There are deep trenches at the bottom of the oceans, the characteristics of which are well described by the theory that the plates in that region of the earth are moving______________. In the end, them, most geologists believe that the plate tectonics theory is_______.
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Earthquakes
Mountains away from each other correct |
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The fact that the continents appear as if they fit together like a jigsaw puzzle has led some scientists to speculate that years ago, all the continents were connected in a giant supercontinent, which has been called_______. Evidence to support this idea includes the fact that sections of rock from different continents are___________, and they _________when you put the continents together the way they are assumed to have existed in_________. Although most scientists believe that the plates have always moved________, a theory called ‘catastrophic plate tectonics’ uses rapid ______movements as a result of a global catastrophe to explain how the supercontinent split in a short amount of time.
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Pangaea
very similar ‘match up’ Pangaea Slowly plate |
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Vibration of the earth that results either from volcanic activity or rock masses suddenly moving along a fault is called an______. A fault is the _________between two sections of rock that can ________relative to one another. Wherever a fault exists, there is the possibility of an________.
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Earthquake
Boundary Move earthquake |
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