ESSE1012_lab3_2024
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LE/ESSE 1012 3.0
The Earth Environment
Winter 2024
Lab. Section: M Name: Sadaf Bayat Student Number: 219267475
LAB 3: WEATHERING
Due February 16, 2024, 10:00 PM ET
IMPORTANT: This is a hands-on lab. You must attend the lab session in person in order
to receive credit for this lab.
Unless otherwise indicated, show your work for all problems. You can either enter your
answers into this document electronically using a computer or tablet, or you can print this
document, handwrite your answers in the spaces provided, and scan the pages. If you need
additional space, you can insert additional pages or you can add additional space within the
Word document. For all numerical answers, the units should be indicated. Students can
discuss this lab with each other, but copying from each other or copying from other sources
is cheating and is not permitted. You should not share your answer sheets with other
students or look at the answer sheets of other students. You should understand the
concepts well enough to explain your answers in your own words. Your answers for hands-
on portions of the lab should be based on work that you yourself performed in the lab
location. If the lab procedure indicates that you can form groups to complete particular
tasks, then you should still be physically present in the lab location contributing to the
completion of those tasks, you should write the names of other group members on your
answer sheets and show your work in your own words for all questions unless otherwise
indicated. If your work relies on information that is obtained from a legitimate source
other than ESSE 1012 course materials, please indicate the source of that information with
enough detail so that someone else can locate the source. Please see the course outline for
detailed policies.
This lab requires you to find three different examples of weathering outside near the lab location,
explain the physical processes responsible and the possible impact of climate change. You should review your notes, lecture slides and text chapter on weathering prior to the lab session. Dress warmly if the weather is cold. In addition to this procedure either in paper or electronic form, you will need the following materials: •
A phone, fully charged, with camera and location feature turned on. (Or you should have other devices with equivalent capabilities.)
•
Any helpful reference materials (e.g. lecture notes, lecture slides, text) LE/ESSE 1012 Lab 3 ©NTandon
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Procedure
Once your lab session starts, please do the following
1. Go to the lab location, sign in with the TA and leave any belongings there that you do not wish
or need to bring with you outside. The TA will remain in the lab to supervise.
2. Exit the lab and do the following:
a. Photograph an example of physical weathering on either a natural or man-made structure and take a screenshot of Google Maps indicating the location of the weathering. Zoom into the map enough so that your location relative to familiar York landmarks (e.g. the Petrie building) is clear. If your phone is not able to determine your location, explain why. You should be able to find such weathering easily around Petrie or the neighbouring
buildings. You should definitely not need to take risks, like stopping in the middle of a street or entering restricted areas. Do not go anywhere alone, especially after dark. The TAs will be available in the lab if you require assistance.
b. If the weathering you photographed in step 2a is located in a location with a slope, take
a picture of the slope to help assess possible slope instability.
c. Repeat steps 2a-b, but for an example of chemical weathering on either a natural or man-made structure. The location you choose should be different from the locations you chose in the previous steps. d. Repeat step 2a, but for an example of biological weathering on either a natural or man-
made structure. The location you choose should be different from the locations you chose
in the previous steps. 3. Return to the lab within 40 minutes of the start of the lab period and answer the questions below. 4. Since you are not allowed to copy from each other or from other sources, your pictures
should be distinct from those of other students. While you can photograph the same site as another student, no two students should have all three weathering examples in common.
Question 1: Physical Weathering
For your example of frost wedging, respond to the following:
a.
Insert a photo of the weathering in the space below. (2 points)
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b.
In the space below, insert a screenshot of the Google Maps location where you found the weathering. (2 points)
c.
What type of physical weathering is occurring in the location that you photographed? What evidence do you see for this type of weathering? (5 points)
Frost Wedging: Water permeates rock crevices, freezes, and expands, applying pressure that finally fractures the surrounding rock. as cracks and crevices
Thermal Expansion and Contraction: Rocks expand when heated and contract when chilled due to daily temperature variations. This constant expansion and contraction over time can lead to cracking and crumbling of rocks.
Evidence: Over time, cracks and fractures may appear because of materials repeatedly expanding and contracting because of temperature variations.
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d. Are there any additional types of weathering occurring at the photographed location? If so what are they? Do the different weathering processes interact with each other, and if so, how? If the weathering is in a sloped location and would potentially contribute to slope instability, please
insert a photo of the slope and comment on that as well. (9 points)
Chemical weathering could have occurred here as well.
The process of hydrolysis is the reaction of minerals with water that produces new minerals.
Dissolution: When water or acidic solutions dissolve minerals in rocks, dissolution takes place.
It is not in slope instability e. Assume that, under climate change, Toronto will get warmer but continue to experience freeze-thaw cycles, and there will also be an increase in precipitation. How do you expect the physical weathering that you photographed to be affected? Specifically, compared to the present weathering rate, will the weathering become more rapid or less rapid and why? (8 points)
More rain and more freeze-thaw cycles are predicted for Toronto, which might lead to warmer temperatures and more violent physical weathering processes such frost wedging and thermal expansion and contraction. Even though the intensity of the freezing could be lessened by warmer weather, considerable rock fracturing could still result from more frequent freeze-thaw cycles and rain. Increased moisture penetration into rock cracks can intensify the temperature-
induced expansion and contraction, hastening the deterioration of rocks. In general, Toronto's physical weathering process is expected to accelerate as a result of these climatic changes.
f. Assume that under climate change, Toronto will warm so much that it no longer experiences freeze-thaw cycles, and there will also be an increase in precipitation. How do you expect the physical weathering that you photographed to be affected? Specifically, compared to the present weathering rate, will the weathering become more rapid or less rapid and why? (7 points)
The physical weathering processes that are currently observed, such as frost wedging and thermal expansion and contraction, would probably be significantly reduced in intensity or cease entirely if Toronto warmed to the point where freeze-thaw cycles are no longer occurring and precipitation increased as a result of climate change. Frost wedging would be less successful without freeze-thaw cycles since there wouldn't be any expansion of water in rock fissures to apply pressure and promote fracturing. Warmer temperatures would also cause thermal expansion and contraction to happen less frequently and with less force, which would slow down
weathering even further.
Even yet, chemical weathering processes like hydration and dissolution may still be somewhat aided by the increased precipitation, albeit they usually proceed more slowly than physical weathering. Because there would be no more freeze-thaw cycles, the physical weathering rate would probably be slower overall than it is now, which would slow down the rate at which rocks break down. Question 2: Chemical Weathering
For your example of chemical weathering respond to the following:
a.
Insert a photo of the weathering in the space below. (2 points)
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b.
In the space below, insert a screenshot of the Google Maps location where you found the weathering. (2 points)
c. What type of chemical weathering is occurring in this location? What evidence do you see of this type of weathering? (6 points)
Dissolution: When water or acidic solutions dissolve minerals in rocks, dissolution takes place.
The process of hydrolysis is the reaction of minerals with water that produces new minerals.
Dissolution is the process by which minerals in rocks dissolve and are washed out by water or acidic solutions. When minerals in rocks dissolve quickly in water, this process is particularly common. Chemical reactions cause certain minerals to disintegrate and dissolve into the water when they meet it. The dissolved ions are then carried by the water, which erodes and weakens the rock over time.
Evidence: LE/ESSE 1012 Lab 3 ©NTandon
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Rock Discoloration: The production of secondary minerals or the leaching of specific elements can result in chemical weathering that alters the color of rocks.
d. /what are they? Do the different weathering processes interact with each other, and if so, how?
If the weathering is in a sloped location and would potentially contribute to slope instability, please insert a photo of the slope and comment on that as well. (9 points)
Apart from the effects of frost wedging and thermal expansion and contraction, chemical weathering processes like dissolution and hydrolysis at the imaged area. Together, these processes erode the rock's integrity and open spaces for water to seep in, which accelerates chemical weathering. Over time, this may exacerbate slope instability. the photo is not in slope instability.
e. Assume that, under climate change, Toronto will get warmer but continue to experience freeze-thaw cycles, and there will also be an increase in precipitation and carbon dioxide concentration in the atmosphere. How do you expect the chemical weathering that you photographed to be affected? Specifically, compared to the present weathering rate, will the weathering become more rapid or less rapid and why? (8 points)
The observed chemical weathering processes, like dissolution and hydrolysis, are likely to be impacted by the projected climate change scenario for Toronto, which calls for warmer temperatures, ongoing freeze-thaw cycles, more precipitation, and higher concentrations of carbon dioxide. Higher temperatures have the ability to quicken chemical processes, which could
speed up the rate of hydrolysis and dissolution. Increased precipitation and more frequent freeze-
thaw cycles may lead to heightened physical weathering, which can expose new surfaces to chemical weathering. Higher atmospheric carbon dioxide concentrations can also result in more carbonic acid being formed when dissolved in water, which would further encourage chemical weathering through dissolving. All things considered, the convergence of these elements could result in a chemical weathering process that is faster than it is now, since the environment will be
more favorable for the chemical processes that dissolve minerals in rocks.
f. Assume that under climate change, Toronto will warm so much that it no longer experiences freeze-thaw cycles, and there will also be an increase in precipitation and atmospheric carbon dioxide concentration. How do you expect the chemical weathering that you photographed to be affected? Specifically, compared to the present weathering rate, will the weathering become more rapid or less rapid and why? (7 points)
The chemical weathering seen in the shot would probably be impacted if Toronto warmed to the point where freeze-thaw cycles stopped, along with an increase in precipitation and atmospheric carbon dioxide concentration because of climate change. The physical weathering processes that expose new surfaces to chemical weathering would decrease in the absence of freeze-thaw cycles, which could slow down the rate of chemical weathering. Through the processes of dissolution and hydrolysis, the increased precipitation and atmospheric carbon dioxide would nevertheless aid in chemical weathering. Elevated temperatures have the potential to hasten chemical reactions, resulting in a quicker breakdown of minerals within rocks. Furthermore, by generating carbonic acid when dissolved in water, a rise in carbon dioxide concentration can accelerate chemical weathering and facilitate the dissolving of minerals. As a result, even while the lack of freeze-thaw cycles may slow down chemical weathering relative to current circumstances, the combined impacts of rising precipitation and atmospheric carbon dioxide concentration might still cause chemical weathering to proceed very quickly overall.
Question 3: Biological Weathering
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For your example of biological weathering respond to the following:
a. Insert a photo of the weathering in the space below. (2 points)
b. In the space below, insert a screenshot of the Google Maps location where you found the weathering. (2 points)
c. Explain the biological weathering process occurring in the location that you photographed. Specifically, what is the life form that is causing the weathering, and how is it causing the weathering? (5 points.)
Plant Growth Patterns: The amount and intensity of biological weathering processes can be inferred from observations of plant growth patterns on the wall surface, including the distribution
of vegetation and the direction of root growth.
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The growth of these plants, especially their root systems, is what mostly drives the biological weathering process in the imaged site where plants are shown growing on a wall surface. The roots of the plants sift through the substrate or rock's fissures as they take root on the wall. As the
roots enlarge and grow over time, they put pressure on the surrounding material, weakening it and possibly causing it to fracture or break apart. Root wedging is a process that physically erodes the substrate or rock, causing weathering and ultimately disintegration. Furthermore, the existence of organic materials and plant matter might encourage chemical weathering processes, hastening the degradation of the wall surface. Thus, in this case, the plants themselves—more especially, their roots, which apply mechanical pressure and aid in the gradual disintegration of the wall surface—are the life form responsible for weathering.
d. Are there any additional types of weathering occurring at the photographed location? If so what are they? Do the different weathering processes interact with each other, and if so, how? If the weathering is in a sloped location and would potentially contribute to slope instability, please
insert a photo of the slope and comment on that as well. (9 points)
At the site of the shot, chemical weathering processes like rock discoloration might be happening
in addition to biological weathering brought on by plant growth. When minerals start to create secondary minerals or certain elements start to leak out of the rock, it is a symptom of chemical weathering. Synergistic interactions between these processes can occur: biological weathering facilitates chemical weathering by allowing water and organic acids to enter through plant root penetration. Furthermore, physical weathering processes like root wedging can expose recently exposed surfaces to chemicals, hastening chemical reactions and causing discoloration of the rock. As a result of the interactions between the physical, chemical, and biological weathering processes, the rock or substrate at the imaged location gradually deteriorates and changes. Each weathering process acts to strengthen and magnify the impacts of the others.
e. Assume that, under climate change, Toronto will get warmer but continue to experience freeze-thaw cycles, and there will also be an increase in precipitation. How do you expect the biological weathering that you photographed to be affected? Specifically, compared to the present weathering rate, will the weathering become more rapid or less rapid and why? (8 points)
The biological weathering seen in the shot is probably going to be impacted by Toronto's forecasted climate change scenario, which calls for warmer temperatures, more frequent freeze-
thaw cycles, and more precipitation. Warmer weather coupled with higher precipitation can encourage the growth of vegetation and result in a greater colonization of plants on the surface of
walls. Because more plant roots can pierce through substrate or rock fissures, there may be a rise in the intensity of biological weathering as a result. Furthermore, by causing cracks and holes in the wall surface, the ongoing freeze-thaw cycles may aid in root penetration. As a result, biological weathering is anticipated to occur more quickly in Toronto under predicted climate change conditions than it does now, as the favorable conditions for plant development and root penetration facilitate biological weathering. f. Assume that under climate change, Toronto will warm so much that it no longer experiences freeze-thaw cycles, and there will also be an increase in precipitation. How do you expect the biological weathering that you photographed to be affected? Specifically, compared to the present weathering rate, will the weathering become more rapid or less rapid and why? (7 points)
The biological weathering seen in the shot would probably be impacted if Toronto warmed to the
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point where freeze-thaw cycles eliminated, and precipitation increased as a result of climate change. The physical weathering processes, including crack formation, that provide openings for plant root penetration would decrease in the absence of freeze-thaw cycles. As a result, relative to the current weathering rate, the rate of biological weathering—which is mostly driven by plant
root growth and expansion—may drop. The increased precipitation may still, however, encourage the growth of vegetation and aid in biological weathering by supplying the nutrients and moisture needed to keep plants alive.
Consequently, the influence of increased precipitation may somewhat offset the potential reduction in the rate of biological weathering caused by the lack of freeze-thaw cycles, leaving the rate of biological weathering largely unchanged or slightly reduced.
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