1.18: Lab 18 - Glacial Geomorphology

Learning Objectives

• Describe the processes that cause glaciers to advance or retreat.
• Analyze glacier mass balance data.
• Identify erosional and depositional glacial landscape features.
• Explain how glacial melting affects sea level rise.

Introduction

A glacier is a long-lasting body of ice (decades or more) that is large enough to move under its weight. About 10% of Earth’s land surface is currently covered with glacial ice, and although the vast majority of that is in Antarctica and Greenland, there are still a few glaciers in California, nestled within the Sierra Nevada. At various times during the past million years, glacial ice has been much more extensive, covering at least 30% of the land surface at times.^[322]

Glaciers represent the largest repository of freshwater on Earth, and they are highly sensitive to changes in climate. In the current warming climate, glaciers are melting rapidly worldwide, and although some of the larger glacial masses will last for centuries more, many smaller glaciers will be gone within decades, and in some cases, within years.¹

California has a very rich geologic history when it comes to glaciers, which for many may be a surprise. Glaciation and its effects are present in the Cascades region, in the Sierra Nevada, and in the San Gabriel and San Bernardino Mountains. Glaciers in California are not only a thing of the past; as of 2020, there are more than 1,700 ice/snow bodies found in California. Thirteen of them are within a few-hours drive of Los Angeles. Only 70 of these features are larger than 0.1 square kilometer. There are 20 named glaciers in California (7 on Mount Shasta and 13 within the Sierra Nevada).

In this lab, you will explore local regions that have been shaped through glacial processes as well as understand how glaciers are formed, retreat, and shape the landscape. You will also learn how to identify and understand the development of glacial features.

Part A. Glacial Processes

Snow and ice exist in a crystalline form. As snow falls, the flakes are light and fluffy in texture, often referred to as powder. After the flakes reach the ground, if conditions remain cold enough, they will continue to be layered and buried under additional fresh snow. The crystals gradually change to solid ice over a period of time; this depends on factors such as temperature and speed of burial. Ice is composed of water in the crystalline solid form and under short-term stress, ice behaves like a solid. An ice cube in an environment below freezing, such as your freezer at home, will have a fixed shape. If you smash it with a hammer, it will shatter into smaller pieces. Interestingly though, as a glacier flows, it is not shattering or breaking but instead bending. This is because solid ice responds to long-term stress by bending and deformation. It is important to point out that glaciers are not just frozen water. Glacial ice forms when compression causes buried snow to recrystallize and compact over time. The formation of glacial ice can take more than one hundred years.

There are two main types of glaciers. Continental glaciers, also known as ice sheets, cover vast areas of land in extreme polar regions, including Antarctica and Greenland. Alpine glaciers, also known as valley glaciers, originate in mountains, mostly in temperate and Polar regions. Figure 18.1 shows the present-day cryosphere, where water is found in solid form.

Figure 18.1 utilizes the Fuller map projection, sometimes called the dymaxion projection, created by Buckminster Fuller. The surface of the Earth is projected onto a polyhedron with twenty triangular sides. Writing in GIS Lounge, Maxwell (2013, n.p.) explains that:

➢ When flattened, the Dymaxion map shows the Earth’s continents as almost one contiguous land mass or island in the middle of one ocean.

➢ The Dymaxion map from Buckminster Fuller stands out because it is the only flat map of the Earth’s surface in its entirety that does not contain any obvious visual distortions of the shapes and sizes of land masses relative to their global scales. It also does this without splitting any of the continents.

➢ Fuller himself was critical of the way maps exhibited the northern hemisphere as superior and the southern hemisphere as inferior. He argued that his Dymaxion map had no right way up since there is no up or down in the universe.

Figure 18.1: The Cryosphere. Figure is adapted from Hugo Ahlenius, UNEP/GRID-Arendal, is licensed under CC BY-SA 3.0

Exercise \(\PageIndex{1}\)

1. Refer to Figure 18.1. Where are alpine glaciers found?

Earth’s two great continental glaciers, on Antarctica and Greenland (shown in pink in Figure 18.1), comprise about 99% of all of the world’s glacial ice, and approximately 68% of all of Earth’s freshwater. The Antarctic Ice Sheet is vastly bigger than the Greenland Ice Sheet; it contains about 17 times as much ice. Speaking of large features, one of the fastest moving glaciers, the Jakobshavn Glacier in Greenland, moves at a rate of 12.5 to 16.4 kilometers (~7.8 to 10.2 miles) per year.

Exercise \(\PageIndex{2}\)

2. How fast is the Jakobshavn Glacier moving per day, assuming that on average it is moving 14 kilometers per year? Your final answer should be converted into meters per day. Show your work. Tip: there are 1,000 meters in one kilometer. Multiply 14 kilometers by 1,000 to find the number of meters the glacier moves per year. Then, divide this number by 365 to find meters per day.

The Jakobshavn glacier was also a point of interest in the 2012 documentary entitled Chasing Ice, by cinematographer Jeff Orlowski and environmental photographer James Balog. James and his team at the Extreme Ice Survey studied the visual change of ice through the use of time-lapse photography and were able to capture the largest calving event ever observed by humans. Calving is the sudden breaking of ice off of a glacier.

Exercise \(\PageIndex{3}\)

3. Watch the abbreviated Chasing Ice video (video length is 4:41).

1. James and his team stated that it took about 75 minutes from start to finish for this calving event. They also referred to the size of the calving event. What size comparison was provided in the video?

2. Now that you have been able to both observe and interpret the video, what aspect of the film did you most engage with? What will you remember and why? Was the film successful in providing visual evidence that supports the facts of climate change? Your response should be two to three sentences in length.

All glaciers have areas of accumulation and ablation (Figure 18.2). A zone of accumulation is an area in which snowfall accumulates and exceeds the amount of ice or snow that is lost. A zone of ablation refers to the low-altitude area of a glacier that experiences a net loss in ice mass due to melting, sublimation, evaporation, and calving. The area between the zone of ablation and accumulation is the equilibrium line, also known as the firn line. The greater the accumulation, the greater the glacial advancement. Glacier mass balance is the difference between the snow accumulated in the winter and the snow and ice melted over the summer. If the mass of snow accumulated on a glacier exceeds the mass of snow and ice lost during summer months, the mass balance is positive. Likewise, if summer melting exceeds what was gained in the previous winter, the mass balance of the glacier is negative.^[324]

Figure 18.2: Cross-Sectional View of the Zones of Ablation and Accumulation of a Glacier. Figure by Jeremy Patrich is licensed under CC BY-NC-SA 4.0

Figure 18.3 shows mass balance data from 1976 through 2018 for three alpine glaciers: the South Cascade glacier located in the Cascade Range in Washington, United States; the Sarennes glacier located in the French Alps; and the Echaurren Norte glacier located in the Andes Mountains in Chile. The y-axis represents the difference between accumulation and ablation in millimeters. Negative numbers represent a net loss. For reference:

➢ There are approximately 25 millimeters in one inch.

➢ There are 1,000 millimeters in one meter.

➢ There are approximately 3 feet in one meter.

Figure 18.3: Glacier Mass Balance Data. Figure by Waverly Ray is licensed under CC BY-NC-SA 4.0 with data from the World Glacier Monitoring Service, Zurich, Switzerland. DOI:10.5904/wgms-fog-2020-08. Online access: http://dx.doi.org/10.5904/wgms-fog-2020-08

Exercise \(\PageIndex{4}\)

4. Refer to Figure 18.3.

1. What is the overall trend in the mass balance data for the three glaciers?

2. Use Your Critical Thinking Skills: When looking at mass balance data, why would it be important to analyze data over a long time span?

Figure 18.4 shows the cumulative mass balance loss for alpine glaciers worldwide. Lindsey (2020)⁵ explains that:

➢ Worldwide, most glaciers are shrinking or disappearing altogether.

➢ Between 1980 and 2018, glaciers tracked by the World Glacier Monitoring Service have lost ice equivalent to 21.7 meters of liquid water—the equivalent of cutting a 24-meter (79-foot) thick slice off the top of each glacier.

➢ Melting glaciers and ice sheets are the biggest cause of sea-level rise in recent decades.

➢ Glacier loss is a serious threat to ecological and human water supplies in many parts of the world.

➢ The pace of glacier loss has accelerated,

• From -228 millimeters (-9 inches) per year in the 1980s,
• to -443 millimeters (-17 inches) per year in the 1990s,
• to -676 millimeters (-2.2 feet) per year in the 2000s,
• to -921 millimeters (-3 feet) per year for 2010-2018.

Figure 18.4: Global Loss of Alpine Glaciers (1980-2016). Figure and text by NOAA are in the public domain

Exercise \(\PageIndex{5}\)

5. Use Your Critical Thinking Skills: When looking at mass balance data, why would it be important to analyze data from many different alpine glaciers in different parts of the world?

Part B. Glacial Erosional Landforms

Glaciers are a very effective agent of erosion, specifically when the ice is not frozen to the surface and can slide over the bedrock. What is interesting is that the ice itself is not very effective at erosion on its own, because it is relatively soft. But since ice can pluck and abrade, rock fragments are embedded in the ice and forced down onto the underlying surface. This action will often result in an observable feature known as glacial striations (refer to the definition below).

Check It Out! Devils Postpile

Devils Postpile National Monument near Mammoth in California is not just one of the few places to observe columnar basalt—extrusive igneous rock that crystallized in massive honeycomb columns—but it's also a place to observe the meeting of volcanics and glaciers. Scan the QR code or go to this Google Earth link to be transported atop the post pile, overlooking the valley. Observe the rocks you are standing on; do you see any distinct scratches or linear striations?

Exercise \(\PageIndex{6}\)

6. Review the definitions of erosional features found in regions that underwent alpine glaciation. In Figure 18.5 (below), label an example of each of these features by drawing a line from the feature to the margin of the diagram and then writing the name of the feature.
   1. Glacial Striations: As glacial ice moves under its weight, coarser material can become attached at the base of the glacier that will result in scratches or gouges being cut into the bedrock by a process known as abrasion. In some cases, finer sediment may also be found in the base of the glacier that will further polish or scour the bedrock into a polished surface. This finer grain material is referred to as glacial polish.
   2. U-Shaped Valleys or Troughs: In a fluvial (river) environment, as water flows through the channel, the energy generally focuses along the bottom; this ultimately carves a “V” shape. In a glacial environment, as water freezes, it expands. As glaciers flow through the main channel, they will carve a distinct “U” shape trough or valley. This shape is observed not just within the main trough but also in all the contributing channels.
   3. Cirques: Glacial cirques are found around the world, in regions that have experienced alpine glaciation. Cirque is Latin for “circus”, which relates to the shape observed: a large round amphitheater. Cirques are generally the first place to freeze and the last to melt. As the water freezes, it expands, carving a large bowl shape. If the accumulation exceeds ablation, the ice will continue downslope, resulting in additional glaciated topography.
   4. Hanging Valleys: Along the upper edge of the main glacial trough, tributary valleys can exist. These contributing channels have been eroded by a deep “U” shaped valley with nearly vertical sides, leaving behind an exposed shallow valley that appears to be hanging above the main valley. Often, waterfalls form at or near these hanging valleys.
   5. Arêtes: Narrow, bladelike ridges of rock which separate two valleys, often with cirques in between, are called arêtes. In addition to the development of a cirque and glacial erosion, freeze-thaw weathering further steepens the slopes along these sides, resulting in a sharp ridge. When three or more arêtes meet, a horn or pyramidal peak will be created.
   6. Cols: Along large ridges, such as arêtes, low points may be observed, and these saddle-notched shapes are called cols.
   7. Horns or Pyramidal Peaks: Due to the erosional development of cirques and arêtes, a sharply pointed mountain peak will result; these are known as a horn or pyramidal peak. These are best observed by identifying a collection of cirques that diverge (move away) from a central point. Tip: think of the Matterhorn in the Alps, which is copied in the Matterhorn bobsled ride at Disneyland.
   8. Truncated Spur: When a ridge or smaller valley that descends towards the main valley floor abruptly ends due to erosions, a truncated spur is often observed. These are observed along the edge of the hanging valley.

Figure 18.5: Diagram of Erosional Features from Alpine Glaciation for Labeling. Figure by Jeremy Patrich is licensed under CC BY-NC-SA 4.0

7. For each of the four photographs shown in Figure 18.6, identify the most prominent glacial erosional landform.

Figure 18.6: Photographs for Identification Exercise. Figure with public domain photographs by the National Park Service

Part C. Glacial Depositional Landforms

As a glacier retreats and exposes the landscape of crushed rocks and sands, sediments deposited can be observed as depositional landforms. Very large boulders can be observed that have massive linear striations atop. These rocks are called erratics, as they were dragged by glaciers for many, many miles and erratically placed atop the landscape. Big or small, glaciers move it all.

The sediments and material resulting from glaciation can be categorized into one of two families. The very fine material resulting from grinding and polishing is identified as glacial flour, while the materials larger than a grain of sand are called glacial till. Suspended glacial flour is what gives some alpine lakes, such as Lake Louise in Alberta, Canada, a turquoise blue color (Figure 18.7).

Figure 18.7: Lake Louise, Canada. Figure by Wenhao Ji is licensed under the Unsplash license

Check It Out! Olmsted Point

Olmsted Point in Yosemite National Park in California has some great views of the northern face of Half Dome, but it also has some unique glacial deposits. Scan the QR code or go to this Google Earth link to be transported atop the point, and in the foreground, you will observe massive round boulders that were erratically deposited on top of this rock feature by glaciers!

Exercise \(\PageIndex{7}\)

8. Review the following definitions of depositional features found in regions that underwent continental glaciation. In Figure 18.8 (below), label an example of each of these features by drawing a line from the feature to the margin of the diagram and then writing the name of the feature.
   1. Moraines: There are several variations or types of moraines, but the development and lithology are the same in both alpine and continental glaciated landscapes. A moraine is a glacially-formed accumulation of unconsolidated glacial till, or debris. As a glacier advances, it bulldozes material. The location of the moraine deposit is used to distinguish what type of moraine it is. The five main types of moraines are discussed next. A terminal moraine is found where the glacier terminated. There are also end moraines, just meaning that any time a glacier stops advancing, the material was deposited, or ended up in that spot (so a terminal moraine may also be an end moraine). Lateral moraines are parallel ridges of material along the sides of a glacier. Medial moraines are the result of two lateral moraines merging due to two glaciers converging. Recessional moraines are created during temporary halts in a glacier retreat. The glacier advances slightly before resuming its retreat; recession “speed bumps” will occur.
   2. Drumlins: These are asymmetrical hills made of drifted, glacial till.
   3. Eskers: When sediments are carried by glacial meltwaters in subglacial tunnels, the material is deposited in a sinuous (curving) ridge, called an esker. The result is often referred to as an inverted stream, meaning that the channel of the river is not being cut into the surface, but is stacked above the surface.
   4. Kames: These are irregularly-shaped mounds, or hills, of glacial till with sand and gravel. As the glacier melts, rivers of flowing water will bring additional material atop or through the glacier, making deposits similar to deltas. As the ice melts further, this material will be dropped on the surface of the Earth in a mound shape.

Figure 18.8: Diagram of Depositional Features from Continental Glaciation for Labeling. Figure by Jeremy Patrich is adapted from Luis María Benítez is licensed under CC BY-NC-SA 4.0

9. Label an end moraine, a lateral moraine, and a recessional moraine from alpine glaciation on Figure 18.9.

Figure 18.9: Photograph for Identification Exercise. Figure by the National Park Service is in the public domain

Part D. Glacial Lakes

Lakes are common features in glacial environments. A lake that is confined to a glacial cirque is known as a tarn. Tarns are common in areas of alpine glaciation because the ice that forms a cirque typically carves out a depression in bedrock which then fills with water. In some cases, a series of such basins will form, and the resulting lakes are called rock basin lakes or paternoster lakes.^[333]

Check It Out! Lake Sabrina

Lake Sabrina is tarn nestled in the Sierra just west of Bishop, California. Scan the QR code or go to this Google Earth link to be transported to this beautifully carved cirque, and observe the tarn within it. Although the dam was built to generate hydroelectricity nearly a century ago, this still is an amazing example of glaciation in California.

Exercise \(\PageIndex{8}\)

10. Review the following definitions of the different types of glacial lakes. On Figures 18.6 and 18.8 (both shown earlier in the lab), label an example of each of these glacial lakes by drawing a line from the lake to the margin of the diagram and then writing the name of the type of glacial lake.
    1. Tarns: A proglacial lake, known as a tarn, develops in cirques. Cirques form in hollow mountainsides, providing a space for the ice to freeze that is the last to melt. As a result of the melt, a lake will form in the hollow. Tarns are found in alpine glaciated regions.
    2. Paternoster Lakes: A series of lakes connected by a single stream are called paternoster lakes. Paternoster is Latin for “Our Father”, as the lakes resemble rosary beads. Paternoster lakes are found in alpine glaciated regions.
    3. Kettles: These are depressions or potholes found in an outwash plain, beyond the terminal moraine. They are formed as a result of dead ice; as the glacier retreats, large pieces of ice break off creating a dimple or indentation. As the ice melts, a lake will develop. Kettles are found in continental glaciated regions, or in the flat-lying valley floors where an alpine glacier once extended.
    4. Moraine-dammed Lake: Often, end moraines will be large enough to prevent the meltwater from draining from the valley. When this occurs, the moraine acts as a dam and causes the meltwater to gather as a lake. Moraine-dammed lakes are found in both alpine and continental glaciated regions.

Part E. Case Study: Taku and Norris Glaciers

Taku Glacier is a tidewater glacier located in Taku Inlet in the U.S. state of Alaska, just southeast of the city of Juneau. A tidewater glacier is a valley glacier that extends to the ocean. Recognized as the deepest and thickest alpine temperate glacier in the world, the Taku Glacier was 1,477 meters (4,845 feet) thick and 58 kilometers (36 miles) long in 2020.

The map on the following page is of the Juneau Icefield in Alaska. An icefield is a large area that has many interconnected glaciers. You will observe both the Taku and Norris Glaciers, topographic contours, and the positions of the edge of each glacier at different times since 1750. Dates have been provided by using a few different methods, such as aerial photography, survey data, absolute dating of sediment-covered vegetation, and carbon dating of deposited material in moraines. Remember that glaciers naturally gain and lose ice and snow each year. If the amount of ice and snow accumulation exceeds the amount that is lost per year, the glacier will advance (and the glacial mass balance will be positive). If the amount of ice and snow gained is less than the amount that is lost that year, the glacier will retreat (and the glacial mass balance will be negative).

Check It Out! Taku and Norris Glaciers

The Taku Glacier is found in the Juneau Icefield of Alaska, and is a great example of active glaciation! Scan the QR code or go to this Google Earth link to be transported to Alaska. If you zoom in, you’re able to see the cracks, or crevices, in the glaciers, as well as the development of medial moraines!

Exercise \(\PageIndex{9}\)

11. Refer to Figure 18.10 (below), which is a map of the Taku and Norris Glaciers.

1. Locate the blank legend on the map and distinguish among the features shown. Shade the glacial ice as light blue, represent land with a light brown color, and leave the Taku River as white.

2. Identify the contour lines on the map, these are numbers followed by the abbreviation for feet: ‘. What is the approximate total relief of the map? Hint: the total relief is the difference between the highest and the lowest elevation found within the map.

3. What is the width of the Taku Glacier between the 1,000’ contour lines? Tip: use the scale bar.

4. What is the width of the Norris Glacier between the 1,000’ contour lines? Tip: use the scale bar.

5. What is the width of the Hole-in-the-Wall Glacier between the 1,000’ contour lines? Tip: use the scale bar.

6. Observe the lines labeled with years on the map. Describe what happened to the Taku Glacier between 1890 and 1993.

7. Observe the lines labeled with years on the map. Describe what happened to the Norris Glacier between 1911 and 1988.

8. Observe the lines labeled with years on the map. Describe what happened to the Hole-in-the-Wall Glacier between 1948 and 1988.

9. The terminal mark from all three glaciers in 1750 is represented by the dashed line. What would have happened to the Taku River in 1750? How might that have changed the topography? Your response should be two to three sentences in length.

Figure 18.10: Topographic Map and Historical Glacial Extent of the Norris, Taku, and Hole-in-the-Wall Glaciers. Figure by Jeremy Patrich is licensed under CC BY-NC-SA 4.0

The Taku Glacier's advancement was the result of a positive mass balance, meaning that the glacier was accumulating more ice than it was losing each year. That was true until 2019. Dramatic climatic change between the 1990s and today has caused the Taku Glacier to deflate, or to become thinner. Deflation can be observed in ice cores or cross-sectional profiles.

Part F. Glaciers and Sea Level Rise

As you learned in this lab, glaciers are reservoirs of stored freshwater. We have observed changes in our climate or long-term weather, and in conjunction with these changes, we have documented a dramatic loss of ice around the world. Earth scientists estimate that if all the ice in the world were to melt, the global sea level would rise approximately 70 meters, which is nearly 230 feet! Below is a chart showing the sea height variance since 1993 with an average of 3.3 millimeters (~0.13 inches) of change per year (Figure 18.11).

Figure 18.11: Sea-Level Observations Between 1993 and 2018. Figure by NASA is in the public domain

Exercise \(\PageIndex{10}\)

12. Assuming that the average rate of sea-level increase is 3.3 millimeters per year, how many millimeters will the sea height increase in 30 years? Show your calculation.

1. How many inches will the sea height increase in 30 years? Hint: multiply your answer for the previous question by 0.393701. Show your calculation.

The National Oceanic and Atmospheric Administration (NOAA) is an American scientific agency within the United States Department of Commerce that focuses on the conditions of the oceans, major waterways, and the atmosphere. NOAA’s Sea Level Rise Viewer allows the public to view one of their many datasets. This online application allows us to observe and interpret the changes in our coastal cities and landscapes by increasing the global sea level. For this activity, you will use the provided website to observe and interpret sea-level change throughout the United States.

Step 1

Go to the Sea Level Rise Viewer and click on the Get Started button.

Step 2

In the search bar at the top, type in Huntington Beach.

Step 3

Move to the north and northwest on the map to view a blue water droplet pinpoint and click on it. This should be the Sunset Aquatic Park.

Step 4

On the left-hand side, you will see an adjustable bar labeled MHHW (Mean Higher High Water). Move the MHHW between the Current and 10ft water levels.

Exercise \(\PageIndex{11}\)

13. What do you observe? What happened to the park? (Leave the marker at the 10ft mark).

Step 5

Close the window for the park and observe the map.

Exercise \(\PageIndex{12}\)

14. What happened to Seal Beach and the surrounding areas? (Be sure to move the MHHW values between the 10ft level and the Current level).

Step 6

Let’s move to a different place. Type Corpus Christi into the search bar at the top, scroll north, and click on the water droplet pushpin. This will open up Driscoll Rooke Covenant Park.

Step 7

Move the MHHW between the Current and 10ft water levels.

Exercise \(\PageIndex{13}\)

15. What do you observe? What happens to the park? (Leave the marker at the 10ft mark).

Step 8

Close the window for the park and observe the map.

Exercise \(\PageIndex{14}\)

16. What happens to Corpus Christi and the surrounding areas? (Be sure to move the MHHW values between the 10ft level and the Current level).

Step 9

Search for a new area of your choice or click and drag your way along the coastline of the United States, and look for one of the water droplet pushpins.

Exercise \(\PageIndex{15}\)

17. What location did you choose?

18. Move the MHHW between the Current and 10ft water levels. What do you observe? What happens to the area? (Leave the marker at the 10ft level).

Step 10

Close the window for the area and observe the map.

Exercise \(\PageIndex{16}\)

19. What happens to the location you selected and the surrounding areas? (Be sure to move the MHHW values between the 10ft level and the Current level).

20. Are there noticeable changes in sea level for the 30-year sea level increase that you found in question 12a?

Step 11

Now that you have spent some time looking at NOAA’s Sea Level Rise Viewer, answer the following summary questions.

Exercise \(\PageIndex{17}\)

21. Based on your observations, what regions of the U.S. are most affected by changes in sea-level? Tip: zoom out to see the entire United States and adjust the water level bar.

21. If you could ask the NOAA scientists that put this data together a question, what would it be?

Part G. Wrap-Up

Consult with your geography lab instructor to find out which of the following wrap-up questions you should complete. Attach additional pages to answer the questions as needed.

Exercise \(\PageIndex{18}\)

23. What is the most important idea that you learned in this lab? In two to three sentences, explain the concept and why it is important to know.

24. What was the most challenging part of this lab? In two to three sentences, explain why it was challenging. If nothing challenged you in the lab, write about what you think challenged your classmates.

25. What is one question that you have about what you learned in this lab? Write your question along with one to two sentences explaining why you think your question is important to ask.

26. Review the learning objectives on page 1 of this lab. How would you rate your understanding or ability for each learning objective? Write one sentence that addresses each learning objective.

27. Sketch a concept map that includes the key ideas from this lab. Include at least five of the terms shown in bold-faced type.

28. Create an advertisement to educate your peers on the important information that you learned in this lab. Include at least three key terms in your advertisement. The advertisement should be about half a page in size (about 4 inches by 6 inches).

29. One way to think of physical geography is that it is the study of the relationships among variables that impact the Earth's surface. Select two variables discussed in this lab and describe how they are related.

30. How does what you learned in this lab relate to your everyday life? In two to three sentences, explain a concept that you learned in this lab and how it relates to your day-to-day actions.

31. How does what you learned in this lab relate to current events?
    1. Write the title, source, and date of a news item that relates to this lab.
    2. In two to three sentences, discuss how the news item relates to what you have learned in this lab.
    3. In one to two sentences, discuss whether or not the news item accurately represents the science that you learned. Tip: consider whether or not the news item includes the complexity of the topic.

32. Search O*NET OnLine to find an occupation that is relevant to the topics presented in today's lab. Your lab instructor may provide you with possible keywords to type in the Occupation Quick Search field on the O*NET website.
    1. What is the name of the occupation that you found?
    2. Write two to three sentences that summarize the most important information that you learned about this occupation.
    3. What is one question that you would want to ask a person with this occupation?

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^[322] Text by Steven Earle is licensed by CC BY 4.0

^[324] Text by USGS is in the public domain

^[333] Text by Steven Earle is licensed under CC BY 4.0