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Earth science is the study of | (A) solid Earth (B) Earths oceans (C) Earths atmosphere (D) all of the above | D | Geology is the study of the Earths solid material and structures and the processes that create them. Some ideas geologists might consider include how rocks and landforms are created or the composition of rocks, minerals, or various landforms. Geologists consider how natural processes create and destroy materials on Earth, and how humans can use Earth materials as resources, among other topics. Geologists study rocks in the field to learn what they can from them. |
A geologist would be most likely to investigate how | (A) mountains form (B) people cause pollution (C) tornadoes occur (D) two of the above | A | Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). |
Which type of Earth scientist might look for petroleum for an oil company? | (A) meteorologist (B) climatologist (C) geologist (D) ecologist | C | Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). |
Chemical oceanography is the study of the | (A) human pollution of ocean water (B) naturally occurring elements in ocean water (C) rising levels of ocean water (D) rocks on the ocean floor | B | Oceanography is the study of the oceans. The word oceanology might be more accurate, since ology is the study of. Graph is to write and refers to map making. But mapping the oceans is how oceanography started. More than 70% of Earths surface is covered with water. Almost all of that water is in the oceans. Scientists have visited the deepest parts of the ocean in submarines. Remote vehicles go where humans cant. Yet much of the ocean remains unexplored. Some people call the ocean the last frontier. Humans have had a big impact on the oceans. Populations of fish and other marine species have been overfished. Contaminants are polluting the waters. Global warming is melting the thick ice caps and warming the water. Warmer water expands and, along with water from the melting ice caps, causes sea levels to rise. There are many branches of oceanography. Physical oceanography is the study of water movement, like waves and ocean currents (Figure 1.13). Marine geology looks at rocks and structures in the ocean basins. Chemical oceanography studies the natural elements in ocean water. Marine biology looks at marine life. |
The problem of global warming is most likely to be the focus of a scientist known as a | (A) planetary geologist (B) seismologist (C) physical oceanographer (D) climatologist | D | With more greenhouse gases trapping heat, average annual global temperatures are rising. This is known as global warming. |
Which type of Earth scientist would you expect to give a weather report? | (A) volcanologist (B) meteorologist (C) climatologist (D) environmental scientist | B | Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Using modern technology such as radars and satellites, meteorologists are getting more accurate at forecasting the weather all the time. Climatology is the study of the whole atmosphere, taking a long-range view. Climatologists can help us better understand how and why climate changes (Figure 1.2). Carbon dioxide released into the atmo- sphere is causing the global climate to change. |
Tools typically used by meteorologists include | (A) satellites (B) radar (C) telescopes (D) two of the above | D | Predicting the weather requires a lot of weather data. Technology is used to gather the data and computers are used to analyze the data. Using this information gives meteorologists the best chance of predicting the weather. |
study of Earths weather | (A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology | G | Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Using modern technology such as radars and satellites, meteorologists are getting more accurate at forecasting the weather all the time. Climatology is the study of the whole atmosphere, taking a long-range view. Climatologists can help us better understand how and why climate changes (Figure 1.2). Carbon dioxide released into the atmo- sphere is causing the global climate to change. |
study of earthquakes | (A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology | F | Geologists study earthquake waves to see Earths interior. Waves of energy radiate out from an earthquakes focus. These are called seismic waves (Figure 6.1). Seismic waves change speed as they move through different materials. This causes them to bend. Some seismic waves do not travel through liquids or gases. Scientists use all of this information to understand what makes up the Earths interior. |
study of Earths oceans | (A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology | B | Oceanography is the study of everything in the ocean environment, which covers about 70% of the Earths surface. Recent technology has allowed people and probes to venture to the deepest parts of the ocean, but much of the ocean remains unexplored. Marine geologists learn about the rocks and geologic processes of the ocean basins. |
study of solid Earth | (A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology | C | Geology is the study of the Earths solid material and structures and the processes that create them. Some ideas geologists might consider include how rocks and landforms are created or the composition of rocks, minerals, or various landforms. Geologists consider how natural processes create and destroy materials on Earth, and how humans can use Earth materials as resources, among other topics. Geologists study rocks in the field to learn what they can from them. |
study of human effects on Earth | (A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology | D | Environmental scientists study the effects people have on their environment, including the landscape, atmosphere, water, and living things. Climate change is part of climatology or environmental science. |
study of all aspects of planet Earth | (A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology | E | Oceanography is the study of everything in the ocean environment, which covers about 70% of the Earths surface. Recent technology has allowed people and probes to venture to the deepest parts of the ocean, but much of the ocean remains unexplored. Marine geologists learn about the rocks and geologic processes of the ocean basins. |
study of the universe | (A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology | A | The study of the universe is called cosmology. Cosmologists study the structure and changes in the present universe. The universe contains all of the star systems, galaxies, gas, and dust, plus all the matter and energy that exists now, that existed in the past, and that will exist in the future. The universe includes all of space and time. |
Earth science is a branch of geology. | (A) true (B) false | B | Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). |
Some geologists specialize in the study of soil. | (A) true (B) false | A | Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). |
Rock layers below Earths surface are a record of Earths history. | (A) true (B) false | A | To be able to discuss Earth history, scientists needed some way to refer to the time periods in which events happened and organisms lived. With the information they collected from fossil evidence and using Stenos principles, they created a listing of rock layers from oldest to youngest. Then they divided Earths history into blocks of time with each block separated by important events, such as the disappearance of a species of fossil from the rock record. Since many of the scientists who first assigned names to times in Earths history were from Europe, they named the blocks of time from towns or other local places where the rock layers that represented that time were found. From these blocks of time the scientists created the geologic time scale (Figure 1.1). In the geologic time scale the youngest ages are on the top and the oldest on the bottom. Why do you think that the more recent time periods are divided more finely? Do you think the divisions in the scale below are proportional to the amount of time each time period represented in Earth history? In what eon, era, period and epoch do we now live? We live in the Holocene (sometimes called Recent) epoch, Quaternary period, Cenozoic era, and Phanerozoic eon. |
The science of oceanography started with mapping the oceans. | (A) true (B) false | A | Oceanography is the study of the oceans. The word oceanology might be more accurate, since ology is the study of. Graph is to write and refers to map making. But mapping the oceans is how oceanography started. More than 70% of Earths surface is covered with water. Almost all of that water is in the oceans. Scientists have visited the deepest parts of the ocean in submarines. Remote vehicles go where humans cant. Yet much of the ocean remains unexplored. Some people call the ocean the last frontier. Humans have had a big impact on the oceans. Populations of fish and other marine species have been overfished. Contaminants are polluting the waters. Global warming is melting the thick ice caps and warming the water. Warmer water expands and, along with water from the melting ice caps, causes sea levels to rise. There are many branches of oceanography. Physical oceanography is the study of water movement, like waves and ocean currents (Figure 1.13). Marine geology looks at rocks and structures in the ocean basins. Chemical oceanography studies the natural elements in ocean water. Marine biology looks at marine life. |
Scientists have not yet visited the deepest parts of the ocean. | (A) true (B) false | B | Only a specially designed vehicle can venture beneath the sea surface. But only very special vehicles can reach the ocean floor. Three are described here and pictured in Figure 14.21: In 1960, scientists used the submersible Trieste to travel into the Mariana Trench. They succeeded, but the trip was very risky. Making humans safe at such depths costs a lot of money. People have not traveled to this depth again. In 2012, the film director, James Cameron, dove to the bottom of the Mariana Trench by himself in a submersible that he had built for the purpose. The vehicle named Alvin was developed soon after Trieste. The submersible has made over 4,000 dives deep into the ocean. People can stay underwater for up to 9 hours. Alvin has been essential for developing a scientific understanding the worlds oceans. Today, remote-control vehicles, called remotely operated vehicles (ROVs) go to the deepest ocean floor. They dont have any people on board. However, they carry devices that record many measurements. They also collect sediments and take photos. |
Most of Earths water is in rivers and lakes. | (A) true (B) false | B | One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). |
Humans have had relatively little impact on the oceans. | (A) true (B) false | B | The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. |
There are several branches of oceanography. | (A) true (B) false | A | Oceanography is the study of the oceans. The word oceanology might be more accurate, since ology is the study of. Graph is to write and refers to map making. But mapping the oceans is how oceanography started. More than 70% of Earths surface is covered with water. Almost all of that water is in the oceans. Scientists have visited the deepest parts of the ocean in submarines. Remote vehicles go where humans cant. Yet much of the ocean remains unexplored. Some people call the ocean the last frontier. Humans have had a big impact on the oceans. Populations of fish and other marine species have been overfished. Contaminants are polluting the waters. Global warming is melting the thick ice caps and warming the water. Warmer water expands and, along with water from the melting ice caps, causes sea levels to rise. There are many branches of oceanography. Physical oceanography is the study of water movement, like waves and ocean currents (Figure 1.13). Marine geology looks at rocks and structures in the ocean basins. Chemical oceanography studies the natural elements in ocean water. Marine biology looks at marine life. |
Meteorologists study meteors. | (A) true (B) false | B | Meteorologists dont study meteors they study the atmosphere! The word meteor refers to things in the air. Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Meteorology is very important. Using radars and satellites, meteorologists work to predict, or forecast, the weather (Figure 1.14). The atmosphere is a thin layer of gas that surrounds Earth. Climatologists study the atmosphere. These scientists work to understand the climate as it is now. They also study how climate will change in response to global warming. The atmosphere contains small amounts of carbon dioxide. Climatologists have found that humans are putting a lot of extra carbon dioxide into the atmosphere. This is mostly from burning fossil fuels. The extra carbon dioxide traps heat from the Sun. Trapped heat causes the atmosphere to heat up. We call this global warming (Figure 1.15). |
The burning of fossil fuels contributes to global warming. | (A) true (B) false | A | Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. |
Flowing water can cause erosion by dissolving minerals in rocks. | (A) true (B) false | A | Flowing water is a very important agent of erosion. Flowing water can erode rocks and soil. Water dissolves minerals from rocks and carries the ions. This process happens really slowly. But over millions of years, flowing water dissolves massive amounts of rock. Moving water also picks up and carries particles of soil and rock. The ability to erode is affected by the velocity, or speed, of the water. The size of the eroded particles depends on the velocity of the water. Eventually, the water deposits the materials. As water slows, larger particles are deposited. As the water slows even more, smaller particles are deposited. The graph in Figure 10.1 shows how water velocity and particle size influence erosion and deposition. |
More slowly flowing water can carry larger sediments. | (A) true (B) false | B | When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. |
The size of sediments determines how they are carried by flowing water. | (A) true (B) false | A | The size of particles determines how they are carried by flowing water. This is illustrated in Figure 10.2. Minerals that dissolve in water form salts. The salts are carried in solution. They are mixed thoroughly with the water. Small particles, such as clay and silt, are carried in suspension. They are mixed throughout the water. These particles are not dissolved in the water. Somewhat bigger particles, such as sand, are moved by saltation. The particles move in little jumps near the stream bottom. They are nudged along by water and other particles. The biggest particles, including gravel and pebbles, are moved by traction. In this process, the particles roll or drag along the bottom of the water. |
Clay and silt are carried in flowing water by suspension. | (A) true (B) false | A | The size of particles determines how they are carried by flowing water. This is illustrated in Figure 10.2. Minerals that dissolve in water form salts. The salts are carried in solution. They are mixed thoroughly with the water. Small particles, such as clay and silt, are carried in suspension. They are mixed throughout the water. These particles are not dissolved in the water. Somewhat bigger particles, such as sand, are moved by saltation. The particles move in little jumps near the stream bottom. They are nudged along by water and other particles. The biggest particles, including gravel and pebbles, are moved by traction. In this process, the particles roll or drag along the bottom of the water. |
Runoff is only a minor cause of soil erosion. | (A) true (B) false | B | Runoff carved channels in the soil in Figure 19.1. Running water causes most soil erosion, but wind can carry soil away too. What humans do to soil makes it more or less likely to be eroded by wind or water. Human actions that can increase soil erosion are described below. |
Rapidly flowing mountain streams cause little deposition. | (A) true (B) false | A | Streams often start in mountains, where the land is very steep. You can see an example in Figure 10.4. A mountain stream flows very quickly because of the steep slope. This causes a lot of erosion and very little deposition. The rapidly falling water digs down into the stream bed and makes it deeper. It carves a narrow, V-shaped channel. |
Slowly flowing rivers erode their channels more at the bottom than at the sides. | (A) true (B) false | B | Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. |
Floodplains are poor places for growing crops. | (A) true (B) false | B | Within the floodplain of the Nile, soils are fertile enough for productive agriculture. Beyond this, infertile desert soils prevent viable farming. Not all the consequences of flooding are negative. Rivers deposit new nutrient-rich sediments when they flood, so floodplains have traditionally been good for farming. Flooding as a source of nutrients was important to Egyptians along the Nile River until the Aswan Dam was built in the 1960s. Although the dam protects crops and settlements from the annual floods, farmers must now use fertilizers to feed their cops. Floods are also responsible for moving large amounts of sediments about within streams. These sediments provide habitats for animals, and the periodic movement of sediment is crucial to the lives of several types of organisms. Plants and fish along the Colorado River, for example, depend on seasonal flooding to rearrange sand bars. |
A levee forms from the largest sediments a river carries. | (A) true (B) false | A | A flood occurs when a river overflows it banks. This might happen because of heavy rains. Floodplains As the water spreads out over the land, it slows down and drops its sediment. If a river floods often, the floodplain develops a thick layer of rich soil because of all the deposits. Thats why floodplains are usually good places for growing plants. For example, the Nile River in Egypt provides both water and thick sediments for raising crops in the middle of a sandy desert. Natural Levees A flooding river often forms natural levees along its banks. A levee is a raised strip of sediments deposited close to the waters edge. You can see how levees form in Figure 10.8. Levees occur because floodwaters deposit their biggest sediments first when they overflow the rivers banks. |
Sinkholes are caused by groundwater erosion. | (A) true (B) false | A | As erosion by groundwater continues, the ceiling of a cave may collapse. The rock and soil above it sink into the ground. This forms a sinkhole on the surface. You can see an example of a sinkhole in Figure 10.10. Some sinkholes are big enough to swallow vehicles and buildings. |
broad flat area on both sides of a river where it floods its banks | (A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake | D | Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. |
underground hole or cavern eroded by groundwater | (A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake | E | Working slowly over many years, groundwater travels along small cracks. The water dissolves and carries away the solid rock, gradually enlarging the cracks. Eventually, a cave may form (Figure 1.2). |
deposit that forms when a mountain stream flows suddenly onto flatter land | (A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake | A | When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. |
raised strip of sediments deposited along the bank of a river | (A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake | C | Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. |
hole on the surface of the ground that forms when a cave collapses | (A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake | F | If the roof of a cave collapses, a sinkhole could form. Some sinkholes are large enough to swallow up a home or several homes in a neighborhood (Figure 1.3). Water flows through Russell Cave Na- tional Monument in Alabama. |
triangular deposit that forms when a river empties into a body of still water | (A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake | B | When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. |
body of water that forms when a meander is cut off from the rest of the river | (A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake | G | Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. |
Agents of erosion include | (A) gravity (B) waves (C) ice (D) all of the above | D | The agents of soil erosion are the same as the agents of all types of erosion: water, wind, ice, or gravity. Running water is the leading cause of soil erosion, because water is abundant and has a lot of power. Wind is also a leading cause of soil erosion because wind can pick up soil and blow it far away. Activities that remove vegetation, disturb the ground, or allow the ground to dry are activities that increase erosion. What are some human activities that increase the likelihood that soil will be eroded? |
Erosion is always followed by | (A) deposition (B) weathering (C) suspension (D) saltation | A | Erosion by gravity is called mass wasting. Mass wasting can be slow and virtually imperceptible, or rapid, massive, and deadly. Weathered material may fall away from a cliff because there is nothing to keep it in place. Rocks that fall to the base of a cliff make a talus slope. Sometimes as one rock falls, it hits another rock, which hits another rock, and begins a landslide. |
Factors that determine how much erosion runoff can cause include | (A) how fast the water is moving (B) how much water is flowing (C) whether the land is bare or covered with plants (D) all of the above | D | When a lot of rain falls in a short period of time, much of the water is unable to soak into the ground. Instead, it runs over the land. Gravity causes the water to flow from higher to lower ground. As the runoff flows, it may pick up loose material on the surface, such as bits of soil and sand. Runoff is likely to cause more erosion if the land is bare. Plants help hold the soil in place. The runoff water in Figure 10.3 is brown because it eroded soil from a bare, sloping field. Can you find evidence of erosion by runoff where you live? What should you look for? Much of the material eroded by runoff is carried into bodies of water, such as streams, rivers, ponds, lakes, or oceans. Runoff is an important cause of erosion. Thats because it occurs over so much of Earths surface. |
A waterfall forms when a stream flows | (A) from lower to higher elevations (B) from harder to softer rocks (C) from one meander to another (D) from side to side in its floodplain | B | Mountain streams may erode waterfalls. As shown in Figure 10.5, a waterfall forms where a stream flows from an area of harder to softer rock. The water erodes the softer rock faster than the harder rock. This causes the stream bed to drop down, like a step, creating a waterfall. As erosion continues, the waterfall gradually moves upstream. |
When flowing water slows down, which of the following sediments does it drop first? | (A) gravel (B) sand (C) silt (D) clay | A | Flowing water slows down when it reaches flatter land or flows into a body of still water. What do you think happens then? The water starts dropping the particles it was carrying. As the water slows, it drops the largest particles first. The smallest particles settle out last. |
Which statement about stalactites is false? | (A) They form on the floors of caves (B) They consist of mineral deposits (C) They look like icicles (D) They grow slowly | A | Groundwater carries dissolved minerals in solution. The minerals may then be deposited, for example, as stalag- mites or stalactites (Figure 1.4). Stalactites form as calcium carbonate drips from the ceiling of a cave, forming beautiful icicle-like formations. The word stalactite has a c, and it forms from the ceiling. Stalagmites form as calcium carbonate drips from the ceiling to the floor of a cave and then grow upwards. The g in stalagmite means it forms on the ground. If a stalactite and stalagmite join together, they form a column. One of the wonders of visiting a cave is to witness the beauty of these amazing and strangely captivating structures. Some of the largest, and most beautiful, natural crystals can be found in the Naica mine, in Mexico. These gypsum crystals were formed over thousands of years as groundwater, rich in calcium and sulfur flowed through an underground cave. Check it out: A relatively small sinkhole in a Georgia parking lot. Stalactites hang from the ceiling and stalagmites rise from the floor of Carlsbad Caverns in New Mexico. The large stalagmite on the right is almost tall enough to reach the ceiling (or a stalactite) and form a column. Click image to the left or use the URL below. URL: |
What forms when a river erodes the outside of a curve and deposits sediments on the inside of the curve? | (A) delta (B) floodplain (C) meander (D) sinkhole | C | Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. |
landform that results when a sandbar builds up enough to rise above the waters surface | (A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater | B | Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. |
artificial barrier parallel to a shore that reduces beach erosion | (A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater | G | Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters. Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure 10.18. It runs parallel to the coast like a barrier island. |
landform that results when waves create a hole in a wave-cut cliff | (A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater | F | Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. |
artificial barrier perpendicular to the shore that reduces erosion by longshore drift | (A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater | C | Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. |
landform that results when waves erode the top of a sea arch | (A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater | D | Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. |
underwater ridge of sand running parallel to shore that is deposited by waves | (A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater | E | Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. |
ridge of sand extending out from shore that is caused by longshore drift | (A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater | A | Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. |
Factors that determine the size of ocean waves include | (A) speed of the wind (B) length of time the wind blows (C) distance the wind blows (D) all of the above | D | Figure 14.9 also shows how the size of waves is measured. The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days. |
Sediments you are most likely to find on a beach include | (A) clay (B) silt (C) pieces of shell (D) all of the above | C | In relatively quiet areas along a shore, waves may deposit sand. Sand forms a beach, like the one in Figure 10.13. Many beaches include bits of rock and shell. You can see a close-up photo of beach deposits in Figure 10.14. |
Erosion by ocean waves can cause | (A) sandbars (B) spits (C) cliffs (D) beaches | C | Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. |
Landforms created by longshore drift include | (A) spits (B) sea arches (C) sea stacks (D) two of the above | A | Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. |
A breakwater is most similar to a | (A) spit (B) barrier island (C) wave-cut cliff (D) pillar of rock | B | Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters. Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure 10.18. It runs parallel to the coast like a barrier island. |
Landforms caused by ocean wave deposition include | (A) groins (B) sea stacks (C) sea caves (D) sandbars | D | Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. |
Which series of landforms shows the correct order in which a stretch of rocky shoreline may be eroded? | (A) sea arch (B) cliff (C) sea stack (D) b cliff (E) sea arch (F) sea stack (G) c sea stack (H) cliff (I) sea arch (J) d cliff (K) sea stack (L) sea arch | B | Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. |
Bigger waves can carry more sediment. | (A) true (B) false | A | Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. |
The smallest sediments in ocean water are deposited on the shore. | (A) true (B) false | B | Eventually, the sediment in ocean water is deposited. Deposition occurs where waves and other ocean motions slow. The smallest particles, such as silt and clay, are deposited away from shore. This is where water is calmer. Larger particles are deposited on the beach. This is where waves and other motions are strongest. |
Most waves strike the shore at an angle rather than straight on. | (A) true (B) false | A | Most waves strike the shore at an angle. This causes longshore drift. Longshore drift moves sediment along the shore. Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. This motion is show in Figure 10.15 and at the link below. |
Longshore drift carries sediments far inland. | (A) true (B) false | B | Most waves strike the shore at an angle. This causes longshore drift. Longshore drift moves sediment along the shore. Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. This motion is show in Figure 10.15 and at the link below. |
Groins are built to prevent the formation of sandbars. | (A) true (B) false | B | Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. |
Sediment in ocean water scrapes rocks like sandpaper. | (A) true (B) false | A | Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. |
Longshore drift moves sand opposite to the direction of prevailing winds. | (A) true (B) false | B | Most waves strike the shore at an angle. This causes longshore drift. Longshore drift moves sediment along the shore. Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. This motion is show in Figure 10.15 and at the link below. |
The end of a spit may hook around toward the open ocean. | (A) true (B) false | B | Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. |
A barrier island is generally small and round in shape. | (A) true (B) false | B | Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters. Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure 10.18. It runs parallel to the coast like a barrier island. |
Sand collects on both sides of a groin. | (A) true (B) false | B | Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. |
Glaciers presently cover about 40 percent of Earths surface. | (A) true (B) false | B | Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. |
Continental glaciers are long and narrow. | (A) true (B) false | B | Glaciers form when more snow falls than melts each year. Over many years, layer upon layer of snow compacts and turns to ice. There are two different types of glaciers: continental glaciers and valley glaciers. Each type forms some unique features through erosion and deposition. An example of each type is pictured in Figure 10.27. A continental glacier is spread out over a huge area. It may cover most of a continent. Today, continental glaciers cover most of Greenland and Antarctica. In the past, they were much more extensive. A valley glacier is long and narrow. Valley glaciers form in mountains and flow downhill through mountain river valleys. |
Valley glaciers flow downhill through river valleys. | (A) true (B) false | A | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
Continental glaciers form cirques and horns. | (A) true (B) false | B | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
A glacier picks up sediments when they freeze to ice at the bottom of the glacier. | (A) true (B) false | A | Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. |
The narrow end of a drumlin points in the direction that the glacier moved. | (A) true (B) false | A | Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. |
All glaciers move because of gravity. | (A) true (B) false | A | Whether an ice field moves or not depends on the amount of ice in the field, the steepness of the slope and the roughness of the ground surface. Ice moves where the pressure is so great that it undergoes plastic flow. Ice also slides at the bottom, often lubricated by water that has melted and travels between the ground and the ice. The speed of a glacier ranges from extremely fast, where conditions are favorable, to nearly zero. Because the ice is moving, glaciers have crevasses, where cracks form in the ice as a result of movement. The large crevasse at the top of an alpine glacier where ice that is moving is separated from ice that is stuck to the mountain above is called a bergshrund. Crevasses in a glacier are the result of movement. |
The main way glaciers cause erosion is by ice wedging. | (A) true (B) false | B | Like flowing water, flowing ice erodes the land and deposits the material elsewhere. Glaciers cause erosion in two main ways: plucking and abrasion. Plucking is the process by which rocks and other sediments are picked up by a glacier. They freeze to the bottom of the glacier and are carried away by the flowing ice. Abrasion is the process in which a glacier scrapes underlying rock. The sediments and rocks frozen in the ice at the bottom and sides of a glacier act like sandpaper. They wear away rock. They may also leave scratches and grooves that show the direction the glacier moved. |
Glaciers are getting smaller because of global warming. | (A) true (B) false | A | Glaciers are melting back in many locations around the world. When a glacier no longer moves, it is called an ice sheet. This usually happens when it is less than 0.1 km2 in area and 50 m thick. |
The valley carved by a mountain glacier has gently sloping walls. | (A) true (B) false | B | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
rounded hollow carved in the side of a mountain by a glacier | (A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin | D | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
type of glacier that is spread out over a large area | (A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin | A | The types of glaciers are: Continental glaciers are large ice sheets that cover relatively flat ground. These glaciers flow outward from where the greatest amounts of snow and ice accumulate. Alpine (valley) glaciers flow downhill from where the snow and ice accumulates through mountains along existing valleys. Ice caps are large glaciers that cover a larger area than just a valley, possibly an entire mountain range or region. Glaciers come off of ice caps into valleys. The Greenland ice cap covers the entire landmass. |
long low hill of sediments deposited by a glacier | (A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin | G | Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. |
type of glacier that forms in mountains | (A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin | E | Glaciers form when more snow falls than melts each year. Over many years, layer upon layer of snow compacts and turns to ice. There are two different types of glaciers: continental glaciers and valley glaciers. Each type forms some unique features through erosion and deposition. An example of each type is pictured in Figure 10.27. A continental glacier is spread out over a huge area. It may cover most of a continent. Today, continental glaciers cover most of Greenland and Antarctica. In the past, they were much more extensive. A valley glacier is long and narrow. Valley glaciers form in mountains and flow downhill through mountain river valleys. |
winding ridge of sand deposited by a stream of meltwater | (A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin | C | Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. |
jagged ridge that remains when two cirques form on opposite sides of a mountain | (A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin | B | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
sharp peak that is left behind when glaciers erode all sides of a mountain | (A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin | F | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
Today, continental glaciers cover most of | (A) Alaska (B) Canada (C) Greenland (D) all of the above | C | Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. |
Features caused by valley glacier erosion include | (A) eskers (B) cirques (C) drumlins (D) end moraines | B | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
A trimline shows the | (A) highest level a valley glacier reached (B) direction in which a glacier traveled (C) greatest distance a glacier advanced (D) ending edge of a continental glacier | A | Transmission lines on big towerslike those in the opening photo abovecarry high-voltage electric current from power plants to electric substations. Smaller towers and individual power poles carry lower-voltage current from electric substations to homes and businesses. |
A headwall is the | (A) starting point of a continental glacier (B) highest ridge of an esker (C) highest cliff of a cirque (D) low spot in an arte | C | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
A valley glacier changes a V-shaped river valley to a | (A) kettle lake (B) drumlin field (C) U-shaped valley (D) meltwater stream | C | Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. |
A thick layer of sediments left behind by a retreating continental glacier is called | (A) ground moraine (B) end moraine (C) glacial till (D) none of the above | A | Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. |
The last time glaciers dipped as far south as Chicago and New York City was | (A) 10 million years ago (B) 1 million years ago (C) 120 (D) 000 years ago (E) d 12 (F) 000 years ago | D | During the Quaternary Period, the climate cooled. This caused a series of ice ages. Glaciers advanced southward from the North Pole. They reached as far south as Chicago and New York City. Sea levels fell because so much water was frozen in glaciers. This exposed land bridges between continents. The land bridges allowed land animals to move to new areas. Some mammals adapted to the cold by evolving very large size and thick fur. An example is the woolly mammoth, shown in Figure 7.25. Other mammals moved closer to the equator. Those that couldnt adapt or move went extinct, along with many plants. The last ice age ended about 12,000 years ago. By then, our own species, Homo sapiens, had evolved. After that, we were eyewitnesses to the story of life. As a result, the recent past is less of a mystery than the billions of years before it. |
Examples of imprint fossils made by compression are | (A) drawings on rock made by prehistoric humans (B) frozen remains of elephant-like mammoths (C) footprints and animal tracks (D) fossil leaves | D | Some fossils form when their remains are compressed by high pressure, leaving behind a dark imprint. Compression is most common for fossils of leaves and ferns, but can occur with other organisms. Click image to the left or use the URL below. URL: Click image to the left or use the URL below. URL: |
Fossilized insects have been found preserved in amber which is hardened | (A) flower nectar (B) tree sap (C) wood (D) None of the above | B | The soft parts of organisms almost always decompose quickly after death. Thats why most fossils consist of hard parts such as bones. Its rare even for hard parts to remain intact long enough to become fossils. Fossils form when water seeps through the remains and deposits minerals in them. The remains literally turn to stone. Remains are more likely to form fossils if they are covered quickly by sediments. Once in a while, remains are preserved almost unchanged. For example, they may be frozen in glaciers. Or they may be trapped in tree resin that hardens to form amber. Thats what happened to the wasp in Figure 7.8. The wasp lived about 20 million years ago, but even its fragile wings have been preserved by the amber. |
Fossilized stomach contents may indicate | (A) the diet of the animal (B) the vegetation type in its habitat (C) whether an animal walked (D) swam or flew (E) d a b | D | By knowing something about the type of organism the fossil was, geologists can determine whether the region was terrestrial (on land) or marine (underwater) or even if the water was shallow or deep. The rock may give clues to whether the rate of sedimentation was slow or rapid. The amount of wear and fragmentation of a fossil allows scientists to learn about what happened to the region after the organism died; for example, whether it was exposed to wave action. |
An animal is more likely to a fossil if it: | (A) is buried deeply in the ground (B) is left on the surface of the ground (C) does not contain bones or other hard body parts (D) all of the above are about equally likely to result in fossilization | A | Despite these problems, there is a rich fossil record. How does an organism become fossilized? A rare insect fossil. |
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