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Exit Menu RockOn #7
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Points Awarded 11
Points Missed 4
Percentage 73%
1.
A material is warmed to a temperature 1/3 of the way from absolute zero to the material’s melting temperature. You grab the ends of the material and pull. The likely behavior is:
A. The material will deform plastically (not snapping back when you let go).
B. The material will either deform elastically (snapping back when you let go) or break, depending on how hard you pull.
C. The material will either deform plastically (not snapping back when you let go) or break, depending on how hard you pull.
D. The material will not deform or break, no matter how hard you pull.
E. The material will either deform elastically (snapping back when you let go) or will deform plastically (not snapping back when you let go), depending on how hard you pull.
Above about half of the absolute melting temperature, plastic deformation becomes common; at lower temperatures, elastic deformation or breakage are the usual results, with elastic deformation for weaker pulls and breakage for stronger pulls.
Wrong Points Earned: 0/1
Correct Answer: B
Your Response: E
2.
A glacier almost always flows:
A. From south to north.
B. Up a mountain.
C. From where bedrock is high to where bedrock is low.
D. From where the glacier’s upper surface is high to where the glacier’s upper surface is low.
E. From north to south.
The great ice sheet of Greenland spreads from its central dome, so the ice on the south side is moving south, the ice on the north side is moving north, the east-side ice moves east and the west-side ice moves west. Ice flows down many mountains, such as Mount Rainier, but ice came across the Great Lakes and up into the US. Thus, ice flows from where its upper surface is high to where its upper surface is low.
Right Points Earned: 1/1
Correct Answer: D
Your Response: D
3.
Regions with mountain glaciers that experience much surface melting in the summer typically are eroded:
A. At a faster rate than regions with streams but no glaciers.
B. At the same rate that natural rainfall dissolves granite.
C. Not at all; no erosion occurs in typical regions with melting glaciers.
D. At a slower rate than regions with streams but no glaciers.
E. At the same rate as regions with streams but no glaciers.
Yosemite Valley, Glacier National Park and other glaciated regions still bear the unmistakable marks of glaciers despite more than 10,000 years of modification by streams. Glaciers experiencing melting change the landscape faster than streams do.
Wrong Points Earned: 0/1
Correct Answer: A
Your Response: E
4.
The things that glaciers deposit include:
A. Bedrock knobs that are rough on the upglacier side and rounded on the downglacier side.
B. Till (which is sorted) and outwash (which is unsorted).
C. Cirques and hanging valleys.
D. Till (which is unsorted) and outwash (which is sorted).
E. Striations and polish.
Striations, polish, cirques, hanging valleys, and rough-downglacier/rounded-upglacier (not vice versa) bedrock knobs are all features of glacier erosion, not deposition. Till, deposited directly from the ice, includes pieces of all different sizes because ice can carry all sizes without sorting by size; outwash is washed out of a glacier by meltwater and sorted by size.
Right Points Earned: 1/1
Correct Answer: D
Your Response: D
5.
Evidence that glaciers were much bigger about 20,000 years ago than they are now includes:
A. Land bearing the unique marks of glaciers is sinking today, while regions just around that land are rising as deep hot rock flows back after being displaced by the glaciers.
B. Sea level is lower now than it was then, as shown by there being no flooded river valleys anywhere today.
C. Global sea level today is falling as the water from the melted ice is returned to the oceans.
D. Shells of creatures that lived in the ocean about 20,000 years ago indicate that the ocean water was especially isotopically light then.
E. 20,000-year-old deceased shallow-water corals occur in growth position far below the surface on the sides of oceanic islands.
The land with the unique glacier marks was pushed down by the ice and now is bobbing back up, water returned to the oceans from the melting ice causes sea level to rise rather than to fall, and taking light water out of the oceans to grow ice sheets causes the remaining waters, and the shells, to be isotopically heavy. But, the dead corals in growth position down the sides of islands are evidence for the ice age.
Right Points Earned: 1/1
Correct Answer: E
Your Response: E
6.
The recent changes in the amount of ice on Earth over time occurred:
A. Because changes in the Earth’s orbit have caused changes in the amount of sunshine received during certain seasons at different places on Earth.
B. Because the Earth has swung through giant clouds of dust in space that blocked the sun and caused global cooling.
C. Because changes in the Earth’s orbit have caused large changes in the total amount of sunshine received by the Earth.
D. Because of the actions of a Serbian mathematician, Milutin Milankovitch.
E. Because flocks of giant ptarmigan and herds of giant marmots clustered on the edges of the ice sheets, which melted the ice.
Milankovitch studied the effect of orbital features on received sunshine, and hypothesized that this may have caused ice ages, but he surely didn’t cause the ice ages, which happened long before he was born. The orbital changes have little effect on the total sunshine, but do move that sunshine around, with important consequences. The giant-dust-cloud hypothesis was entertained seriously by scientists for a while but doesn’t work; however, like essentially all serious hypotheses that fail, this one is alive and well in the fringe-science web sites of the internet. I’d love to have seen flocks of ptarmigan and herds of marmots, but no one has found their bones, so it is highly likely that they did not exist.
Right Points Earned: 1/1
Correct Answer: A
Your Response: A
7.
During the most recent ice age:
A. Central Pennsylvania was overrun by ice from Canada.
B. Central Pennsylvania was just beyond the edge of the Canadian ice.
C. Central Pennsylvania was far from the nearest ice.
D. Central Pennsylvania was overrun by ice from the south.
E. We have no idea what central Pennsylvania was like.
This is just a fact of geography; we were near but beyond the edge of ice coming from the north. The last option, “no one knows”, is the last refuge of lazy minds, and not at all correct.
Right Points Earned: 1/1
Correct Answer: B
Your Response: B
8.
Glaciers form where:
A. The average temperature is well below freezing for a long enough time.
B. Snowfall exceeds melting for a long enough time.
C. Winters are really snowy for a long enough time.
D. Melting exceeds snowfall for a long enough time.
E. Rocks are being raised by tectonic motions.
Anyone from Erie can tell you that a snowy winter does not guarantee a glacier, and anyone from the permafrost of Siberia could add that cold does not guarantee a glacier. Many high mountains are free of ice, and some warm places are being raised tectonically. The way to make a glacier is to pile up more snow than melts.
Right Points Earned: 1/1
Correct Answer: B
Your Response: B
9.
In a glacier, the ice moves fastest:
A. At the bed, where ice meets rock.
B. When trying to escape from Pepsi commercials.
C. At the bed on some glaciers, halfway between the bed and the surface on other glaciers, and at the surface on still other glaciers.
D. Halfway between the bed and the surface.
E. At the upper surface, where ice meets air.
The ice at the surface rides along on that beneath but deforms a bit on its own, and so goes fastest. The fast-food ketchup-packet model in which the mid-depth ice goes fastest would require that the upper and lower pieces be especially strong and rigid (which they aren’t; and, it might require someone huge stomping on the glacier). The bed is held back by friction with the rock. And ice lacks the sentience needed to attempt to avoid commercials.
Right Points Earned: 1/1
Correct Answer: E
Your Response: E
Figure 1664688AD98555E2329D0AD864E504D6
10.
The top picture from the coast of Greenland, and the bottom picture from Bear Meadows Natural Area in central Pennsylvania, are geologically related. How?
A. The Greenland picture shows where a fast landslide went through, and Bear Meadows was formed when a fast landslide dammed a stream.
B. The Greenland picture shows a lava flow, and a lava flow dammed a creek to make Bear Meadows.
C. The Greenland picture shows rocks that have been creeping downhill on permafrost, and Bear Meadows probably was formed when such a creeping mass dammed a stream during the ice age.
D. The Greenland picture shows the tracks of glaciers, and a glacier hollowed out Bear Meadows.
E. The Greenland picture shows where a fast landslide went through, and Bear Meadows was formed when a fast landslide ran down a hill, leaving a hollow behind that filled with water to become Bear Meadows.
Indeed, the hillslope in Greenland bears the unmistakable signs of creep on permafrost, carrying streams of rocks and bits of tundra downhill. Geologists are fairly confident that the Appalachians looked like this just beyond the glaciers during the ice age, and that rocks carried downhill this way dammed a stream to form Bear Meadows in central Pennsylvania.
Right Points Earned: 1/1
Correct Answer: C
Your Response: C
Figure 1664688AD98555E2329D0AD864E51339
11.
What do the ptarmigan and the marmot below have in common?
A. They are both standing on glacially eroded surfaces.
B. They are both standing on glacially deposited surfaces.
C. They are both standing on periglacially cryoturbated surfaces.
D. They are both flatulent mammals.
E. They are both silicon-based life forms.
The carbon-based bird, top, would be unhappy if you accused him of being a silicon-based flatulent mammal. Periglacial cryoturbation produces sorted stone circles, and glacial deposition makes till or outwash. The striated, polished granites under these cold-climate critters were eroded by glaciers.
Wrong Points Earned: 0/1
Correct Answer: A
Your Response: B
Figure 1664688AD98555E2329D0AD864E51445
12.
The glacier shown above:
A. Has retreated, because a decrease in snowfall to the ablation zone (A) or an increase in melting of the accumulation zone (B) occurred.
B. Has advanced, because a decrease in snowfall to the ablation zone (A) or an increase in melting of the accumulation zone (B) occurred.
C. Has advanced, because a decrease in snowfall to the accumulation zone (A) or an increase in melting of the ablation zone (B) occurred.
D. Has not changed.
E. Has retreated, because a decrease in snowfall to the accumulation zone (A) or an increase in melting of the ablation zone (B) occurred.
Accumulation is a building up, ablation a wearing away or loss. The glacier builds at high elevation (A) and wears away at low elevation (B). And, the halo of moraine around this glacier at low elevation shows that the ice has retreated, so a decrease in snowfall to the accumulation zone or an increase in melting of the ablation zone is indicated.
Wrong Points Earned: 0/1
Correct Answer: E
Your Response: A
Figure 1664688AD98555E2329D0AD864E51711
13.
The bowl-shaped feature in the foreground of the above photo is:
A. A cirque, a bowl gnawed into a mountain at the head of a glacier.
B. A sinkhole, dissolved into the layered basalts, from the breakup that formed the Atlantic, by acidic groundwaters melted from the base of the ice by the Earth’s heat.
C. A blockfield, which moved downhill under gravity in the cold, permafrost conditions that are evident from the snow in the picture.
D. A moraine, bulldozed up around a glacier that flowed away from the camera.
E. A giant alien toilet, proof that we are visited by beings from another planet, but only evident from the air such as seen here.
This is indeed a cirque. The strong layering of the rock material is suggestive of bedrock, not loose pieces as seen in moraines and blockfields. This is basaltic bedrock from the breakup that formed the Atlantic, but basaltic bedrock does not dissolve easily in acidic groundwater. And whoooo, what would the alien use for TP???
Right Points Earned: 1/1
Correct Answer: A
Your Response: A
Figure 1664688AD98555E2329D0AD864E5048A
14.
In the picture above, the dark stripes on the surface of the glacier are:
A. Terminal moraines, deposited at the end of the glacier.
B. Sedimentary layering, formed by alternating dusty ice from late winter and clean ice from the rest of the year.
C. Schistosity, formed by metamorphic separation of minerals.
D. Medial moraines, rocks picked up from points where tributary glaciers flow together.
E. Basal moraines, deposited beneath the glacier.
The rocks are still in/on the ice, so they have not been deposited. Sedimentary layers would be spread over the surface like layers of paint, and mineral segregation would not act on such a huge scale.
Right Points Earned: 1/1
Correct Answer: D
Your Response: D
Figure 1664688AD98555E2329D0AD864E5025E
15.
In the picture above, the ice that modified the rock moved:
A. Directly from the rock toward the camera.
B. From left to right, striating the surfaces the ice reached first and plucking blocks loose from the far sides of bumps.
C. From top to bottom; ice flows downhill, and this is the downhill direction.
D. From bottom to top; ice often is forced uphill, as seen here.
E. From right to left, smashing the front of the rock and then sandpapering the back of the rock smooth.
Indeed, ice sandpapers and striates the rocks it hits first, and then plucks blocks loose from the other side. And the striae go in the direction that the ice moved.
Right Points Earned: 1/1
Correct Answer: B
Your Response: B
Your response has been submitted successfully.
Points Awarded 11
Points Missed 4
Percentage 73%
1.
A material is warmed to a temperature 1/3 of the way from absolute zero to the material’s melting temperature. You grab the ends of the material and pull. The likely behavior is:
A. The material will deform plastically (not snapping back when you let go).
B. The material will either deform elastically (snapping back when you let go) or break, depending on how hard you pull.
C. The material will either deform plastically (not snapping back when you let go) or break, depending on how hard you pull.
D. The material will not deform or break, no matter how hard you pull.
E. The material will either deform elastically (snapping back when you let go) or will deform plastically (not snapping back when you let go), depending on how hard you pull.
Above about half of the absolute melting temperature, plastic deformation becomes common; at lower temperatures, elastic deformation or breakage are the usual results, with elastic deformation for weaker pulls and breakage for stronger pulls.
Wrong Points Earned: 0/1
Correct Answer: B
Your Response: E
2.
A glacier almost always flows:
A. From south to north.
B. Up a mountain.
C. From where bedrock is high to where bedrock is low.
D. From where the glacier’s upper surface is high to where the glacier’s upper surface is low.
E. From north to south.
The great ice sheet of Greenland spreads from its central dome, so the ice on the south side is moving south, the ice on the north side is moving north, the east-side ice moves east and the west-side ice moves west. Ice flows down many mountains, such as Mount Rainier, but ice came across the Great Lakes and up into the US. Thus, ice flows from where its upper surface is high to where its upper surface is low.
Right Points Earned: 1/1
Correct Answer: D
Your Response: D
3.
Regions with mountain glaciers that experience much surface melting in the summer typically are eroded:
A. At a faster rate than regions with streams but no glaciers.
B. At the same rate that natural rainfall dissolves granite.
C. Not at all; no erosion occurs in typical regions with melting glaciers.
D. At a slower rate than regions with streams but no glaciers.
E. At the same rate as regions with streams but no glaciers.
Yosemite Valley, Glacier National Park and other glaciated regions still bear the unmistakable marks of glaciers despite more than 10,000 years of modification by streams. Glaciers experiencing melting change the landscape faster than streams do.
Wrong Points Earned: 0/1
Correct Answer: A
Your Response: E
4.
The things that glaciers deposit include:
A. Bedrock knobs that are rough on the upglacier side and rounded on the downglacier side.
B. Till (which is sorted) and outwash (which is unsorted).
C. Cirques and hanging valleys.
D. Till (which is unsorted) and outwash (which is sorted).
E. Striations and polish.
Striations, polish, cirques, hanging valleys, and rough-downglacier/rounded-upglacier (not vice versa) bedrock knobs are all features of glacier erosion, not deposition. Till, deposited directly from the ice, includes pieces of all different sizes because ice can carry all sizes without sorting by size; outwash is washed out of a glacier by meltwater and sorted by size.
Right Points Earned: 1/1
Correct Answer: D
Your Response: D
5.
Evidence that glaciers were much bigger about 20,000 years ago than they are now includes:
A. Land bearing the unique marks of glaciers is sinking today, while regions just around that land are rising as deep hot rock flows back after being displaced by the glaciers.
B. Sea level is lower now than it was then, as shown by there being no flooded river valleys anywhere today.
C. Global sea level today is falling as the water from the melted ice is returned to the oceans.
D. Shells of creatures that lived in the ocean about 20,000 years ago indicate that the ocean water was especially isotopically light then.
E. 20,000-year-old deceased shallow-water corals occur in growth position far below the surface on the sides of oceanic islands.
The land with the unique glacier marks was pushed down by the ice and now is bobbing back up, water returned to the oceans from the melting ice causes sea level to rise rather than to fall, and taking light water out of the oceans to grow ice sheets causes the remaining waters, and the shells, to be isotopically heavy. But, the dead corals in growth position down the sides of islands are evidence for the ice age.
Right Points Earned: 1/1
Correct Answer: E
Your Response: E
6.
The recent changes in the amount of ice on Earth over time occurred:
A. Because changes in the Earth’s orbit have caused changes in the amount of sunshine received during certain seasons at different places on Earth.
B. Because the Earth has swung through giant clouds of dust in space that blocked the sun and caused global cooling.
C. Because changes in the Earth’s orbit have caused large changes in the total amount of sunshine received by the Earth.
D. Because of the actions of a Serbian mathematician, Milutin Milankovitch.
E. Because flocks of giant ptarmigan and herds of giant marmots clustered on the edges of the ice sheets, which melted the ice.
Milankovitch studied the effect of orbital features on received sunshine, and hypothesized that this may have caused ice ages, but he surely didn’t cause the ice ages, which happened long before he was born. The orbital changes have little effect on the total sunshine, but do move that sunshine around, with important consequences. The giant-dust-cloud hypothesis was entertained seriously by scientists for a while but doesn’t work; however, like essentially all serious hypotheses that fail, this one is alive and well in the fringe-science web sites of the internet. I’d love to have seen flocks of ptarmigan and herds of marmots, but no one has found their bones, so it is highly likely that they did not exist.
Right Points Earned: 1/1
Correct Answer: A
Your Response: A
7.
During the most recent ice age:
A. Central Pennsylvania was overrun by ice from Canada.
B. Central Pennsylvania was just beyond the edge of the Canadian ice.
C. Central Pennsylvania was far from the nearest ice.
D. Central Pennsylvania was overrun by ice from the south.
E. We have no idea what central Pennsylvania was like.
This is just a fact of geography; we were near but beyond the edge of ice coming from the north. The last option, “no one knows”, is the last refuge of lazy minds, and not at all correct.
Right Points Earned: 1/1
Correct Answer: B
Your Response: B
8.
Glaciers form where:
A. The average temperature is well below freezing for a long enough time.
B. Snowfall exceeds melting for a long enough time.
C. Winters are really snowy for a long enough time.
D. Melting exceeds snowfall for a long enough time.
E. Rocks are being raised by tectonic motions.
Anyone from Erie can tell you that a snowy winter does not guarantee a glacier, and anyone from the permafrost of Siberia could add that cold does not guarantee a glacier. Many high mountains are free of ice, and some warm places are being raised tectonically. The way to make a glacier is to pile up more snow than melts.
Right Points Earned: 1/1
Correct Answer: B
Your Response: B
9.
In a glacier, the ice moves fastest:
A. At the bed, where ice meets rock.
B. When trying to escape from Pepsi commercials.
C. At the bed on some glaciers, halfway between the bed and the surface on other glaciers, and at the surface on still other glaciers.
D. Halfway between the bed and the surface.
E. At the upper surface, where ice meets air.
The ice at the surface rides along on that beneath but deforms a bit on its own, and so goes fastest. The fast-food ketchup-packet model in which the mid-depth ice goes fastest would require that the upper and lower pieces be especially strong and rigid (which they aren’t; and, it might require someone huge stomping on the glacier). The bed is held back by friction with the rock. And ice lacks the sentience needed to attempt to avoid commercials.
Right Points Earned: 1/1
Correct Answer: E
Your Response: E
Figure 1664688AD98555E2329D0AD864E504D6
10.
The top picture from the coast of Greenland, and the bottom picture from Bear Meadows Natural Area in central Pennsylvania, are geologically related. How?
A. The Greenland picture shows where a fast landslide went through, and Bear Meadows was formed when a fast landslide dammed a stream.
B. The Greenland picture shows a lava flow, and a lava flow dammed a creek to make Bear Meadows.
C. The Greenland picture shows rocks that have been creeping downhill on permafrost, and Bear Meadows probably was formed when such a creeping mass dammed a stream during the ice age.
D. The Greenland picture shows the tracks of glaciers, and a glacier hollowed out Bear Meadows.
E. The Greenland picture shows where a fast landslide went through, and Bear Meadows was formed when a fast landslide ran down a hill, leaving a hollow behind that filled with water to become Bear Meadows.
Indeed, the hillslope in Greenland bears the unmistakable signs of creep on permafrost, carrying streams of rocks and bits of tundra downhill. Geologists are fairly confident that the Appalachians looked like this just beyond the glaciers during the ice age, and that rocks carried downhill this way dammed a stream to form Bear Meadows in central Pennsylvania.
Right Points Earned: 1/1
Correct Answer: C
Your Response: C
Figure 1664688AD98555E2329D0AD864E51339
11.
What do the ptarmigan and the marmot below have in common?
A. They are both standing on glacially eroded surfaces.
B. They are both standing on glacially deposited surfaces.
C. They are both standing on periglacially cryoturbated surfaces.
D. They are both flatulent mammals.
E. They are both silicon-based life forms.
The carbon-based bird, top, would be unhappy if you accused him of being a silicon-based flatulent mammal. Periglacial cryoturbation produces sorted stone circles, and glacial deposition makes till or outwash. The striated, polished granites under these cold-climate critters were eroded by glaciers.
Wrong Points Earned: 0/1
Correct Answer: A
Your Response: B
Figure 1664688AD98555E2329D0AD864E51445
12.
The glacier shown above:
A. Has retreated, because a decrease in snowfall to the ablation zone (A) or an increase in melting of the accumulation zone (B) occurred.
B. Has advanced, because a decrease in snowfall to the ablation zone (A) or an increase in melting of the accumulation zone (B) occurred.
C. Has advanced, because a decrease in snowfall to the accumulation zone (A) or an increase in melting of the ablation zone (B) occurred.
D. Has not changed.
E. Has retreated, because a decrease in snowfall to the accumulation zone (A) or an increase in melting of the ablation zone (B) occurred.
Accumulation is a building up, ablation a wearing away or loss. The glacier builds at high elevation (A) and wears away at low elevation (B). And, the halo of moraine around this glacier at low elevation shows that the ice has retreated, so a decrease in snowfall to the accumulation zone or an increase in melting of the ablation zone is indicated.
Wrong Points Earned: 0/1
Correct Answer: E
Your Response: A
Figure 1664688AD98555E2329D0AD864E51711
13.
The bowl-shaped feature in the foreground of the above photo is:
A. A cirque, a bowl gnawed into a mountain at the head of a glacier.
B. A sinkhole, dissolved into the layered basalts, from the breakup that formed the Atlantic, by acidic groundwaters melted from the base of the ice by the Earth’s heat.
C. A blockfield, which moved downhill under gravity in the cold, permafrost conditions that are evident from the snow in the picture.
D. A moraine, bulldozed up around a glacier that flowed away from the camera.
E. A giant alien toilet, proof that we are visited by beings from another planet, but only evident from the air such as seen here.
This is indeed a cirque. The strong layering of the rock material is suggestive of bedrock, not loose pieces as seen in moraines and blockfields. This is basaltic bedrock from the breakup that formed the Atlantic, but basaltic bedrock does not dissolve easily in acidic groundwater. And whoooo, what would the alien use for TP???
Right Points Earned: 1/1
Correct Answer: A
Your Response: A
Figure 1664688AD98555E2329D0AD864E5048A
14.
In the picture above, the dark stripes on the surface of the glacier are:
A. Terminal moraines, deposited at the end of the glacier.
B. Sedimentary layering, formed by alternating dusty ice from late winter and clean ice from the rest of the year.
C. Schistosity, formed by metamorphic separation of minerals.
D. Medial moraines, rocks picked up from points where tributary glaciers flow together.
E. Basal moraines, deposited beneath the glacier.
The rocks are still in/on the ice, so they have not been deposited. Sedimentary layers would be spread over the surface like layers of paint, and mineral segregation would not act on such a huge scale.
Right Points Earned: 1/1
Correct Answer: D
Your Response: D
Figure 1664688AD98555E2329D0AD864E5025E
15.
In the picture above, the ice that modified the rock moved:
A. Directly from the rock toward the camera.
B. From left to right, striating the surfaces the ice reached first and plucking blocks loose from the far sides of bumps.
C. From top to bottom; ice flows downhill, and this is the downhill direction.
D. From bottom to top; ice often is forced uphill, as seen here.
E. From right to left, smashing the front of the rock and then sandpapering the back of the rock smooth.
Indeed, ice sandpapers and striates the rocks it hits first, and then plucks blocks loose from the other side. And the striae go in the direction that the ice moved.
Right Points Earned: 1/1
Correct Answer: B
Your Response: B