Mini Project-Environmental Studies

· Connect earthquake activity to plate boundaries.

· Connect the type of volcano and its mechanism of magma generation to its plate boundary setting.

· Write clear, detailed, and grammatically correct paragraphs.

· Cite reliable sources using both in-text citations and more complete citations in a “Works Cited” section.

Part 1: Getting Started

1. Fire up Google Earth and load the Dynamic Earth layer and the USGS Plate Boundaries layer (from the “Dynamic_Earth.kmz” and “Earth’s Tectonic Plates.kmz” files available in the Course Documents on Blackboard).

2. In Google Earth, go to ‘View’ and de-select “Water Surface”. This will allow you to see the bathymetry better in the oceans.

3. Download the Microsoft Word document in this folder called MiniProject2Responses.docx.

4. Type your answers into that document and submit it on Blackboard using the SafeAssign module. Sketches can be completed on paper, digitally photographed or scanned, and inserted into the Word document.

Part 2: Writing and Citing Your Sources

Citing Your Sources

· In Part 4 of this assignment, there will be a few questions that require citations – indicated by the word CITE beside the question. You can cite sources for other questions if you wish, but if no citation is requested you should be able to figure the question out from things we’ve learned so far. Any idea or piece of information that you needed to look up should be cited, regardless of whether you are using a direct quote or not! We suggest you avoid direct quotes whenever possible—we will be looking for you to translate ideas into your own words as a demonstration that you really understand the information. Abundant or lengthy direct quotes will result in points being taken off your grade!

· For questions that require a citation, cite your source in your answer with an abbreviated form: for example (Marshak, 2001). In this example, the author is Marshak, and the publication date is 2001. At the end of Part 4, include a “Works Cited” section with the following information: Author, date, title, website URL or publisher info. Although some websites don’t contain author information, many reputable ones do, and most include a date when the page was last updated.

· Make sure you are citing reliable sources - Joe Schmoe’s blog is not acceptable! Google Earth links to Wikipedia for some information, but because of the way Wikipedia is created and managed, it doesn’t necessarily contain correct or accurate information! Unfortunately, many Wikipedia Geology articles are significantly less accurate than its average article quality (e.g. articles about Civil War battles). Find information to support your answers from more reputable sources - DO NOT CITE WIKIPEDIA.

· Appropriate citations include materials provided by the United States Geologic Survey (USGS), state (e.g. Washington) geologic surveys, the National Aeronautics and Space Administration (NASA), professional societies such as the Geological Society of America or American Geophysical Union, National Park Service websites, or your textbook. As a rule of thumb, websites ending in .edu and .gov are good sources, and websites ending in .com are not generally reliable. If you have concerns about whether your citations are appropriate and reliable, contact one of the TAs well in advance of the due date.

· Please visit the “Research/Writing Help” Tab on our Blackboard site if you need additional background on finding appropriate sources, reading them, and writing about them. As always, the instructors are happy to answer any questions that you have.

Plagiarism and Honor Policy

· You will upload your assignment using SafeAssign in Blackboard, which checks your text against materials on the Internet and against one another’s work. Don’t copy and paste text from websites. It is painfully obvious, and defeats the purpose of this exercise. If you are properly citing sources, SafeAssign will likely come back with a low percentage of duplication (~30% or less total, <70% on short passages), and this is acceptable. However, if you are caught plagiarizing existing work or the work of your classmates, you will receive a zero for the assignment, according to the University Senate Rules and Regulations, Section 2.6.

Part 3: Earthquakes

Under the “Dynamic_Earth” tab, in the “My Places” box (see figure at right) turn off all the layers EXCEPT “Seismicity”. Turn off all layers in the Gallery.

Now zoom in to an elevation where the earthquake markers are visible (an eye altitude of ~6000-7000 km—eye altitude information is located in the lower right hand corner, below the Google trademark). Explore the entire globe, including both ocean basins and continents, looking for patterns in earthquake occurrence.

1) Click on a few of the earthquake markers: What does the size of the red circle marker in Google Earth correspond to? When you click on the circle, what does M stand for? In your own words, what does M mean? Generally describe what conditions must be present at any of these locations to create earthquakes. (2-3 sentences)

2) In the ocean, describe three geographic/geologic features you commonly see in association with earthquakes. Write a hypothesis about why and how these features and earthquakes are related (1 paragraph, plausibility)

3) On the continents describe three geographic/geologic features you commonly see in association with earthquakes and explain the relationship. (2-3 sentences)

4) Check out the plate boundaries in the “Earth’s Tectonic Plates” layer you loaded in with the Earth’s Tectonic Plates.kmz file (see Part 1). Compare earthquakes that occur on plate boundaries to those that do not: which are larger, on average? Write and explain a hypothesis about why you think this might be. (2-3 sentences, plausibility)

5) Choose a specific location around a deep ocean trench where earthquakes are common- some suggestions: Japan, the Aleutian islands off Alaska, or the West coast of South America.

a. First, figure out (and explain) how to distinguish which plate is down-going and which is overriding. In map-view, are earthquakes in the vicinity of the trench more often marked on the down-going plate or on the overriding plate? In terms of depth within Earth, how are earthquakes on the down-going plate different in magnitude from those on the overriding plate? (2-3 sentences)

b. Using the measuring tool (little blue ruler in the top toolbar) in Google Earth, measure out ~800-km length of trench, and take a screenshot of your location to embed within your Word document. You must have at least 10 earthquakes in your selected area, but more will make it easier to identify the pattern! Then, for each earthquake in the area, note its distance from the trench (on a perpendicular line) and its depth (make sure you record both in units of kilometers). Finally, use Excel or another graphing program to create a graph of distance from the trench on the x-axis vs. earthquake depth on the y-axis. Be sure to label your axes, your units, and your entire graph—you will get something that looks like the figure at right. If you need help, ask a TA or go to SI sessions ahead of time! (graph!)

Part 4: Volcanoes

1) Cascades, USA: In the Search box, type “Mount St. Helens” (located in the state of Washington on the U.S. west coast). Turn off layers in the Gallery, but turn on the “Volcanoes of the World” layer in the Dynamic_Earth.kmz.

a) Zoom out to an eye altitude of about 500 km. Is Mount St. Helens the only volcano near the west coast of the U.S.? If there are others, what pattern do they produce? (1-2 full sentences)

b) Check out the plate boundaries in the “Earth’s Tectonic Plates” layer you loaded in with the Earth’s Tectonic Plates.kmz file (see Part 1). What is the tectonic setting of the northwest coast of the U.S. (Oregon and Washington) - convergent boundary, divergent boundary, or transform boundary? In your own words, describe what is occurring at this boundary and identify the plate(s) involved. (1-2 full sentences)

c) Based on your knowledge of the tectonic setting you identified in the previous question, what process is generating the magma at this boundary (decompression melting, hydrous melting, a rise in temperature)? Explain. (1-2 sentences)

d) Based on the distribution of volcanoes you noted in question (a) and the process causing melting you noted in question (c), how widespread do you think is the area of origin for this magma? For example, is it more likely that there is a vast magma reservoir all throughout the Earth’s core and mantle, or a localized body of partially molten rock in the crust just under the line of volcanoes? Explain your reasoning. (1 paragraph, 3-4 sentences)

e) Turn off the Volcanoes Layer and zoom in to an eye elevation between 5-15 km above Mount St. Helens. Name at least two specific volcanic features you observe, and explain how each type of volcanic feature would form. (1-2 sentences each)

f) Create an elevation profile across Mount St. Helens in Google Earth, then take a screenshot or photo of it to paste into your answers. Based on the geomorphology of the volcano, would you classify Mount St. Helens as a shield volcano, stratovolcano, cinder cone, lava dome, or a fissure?

g) Is Mt. St. Helens formed on a continental or an oceanic plate? How might the thickness of plate influence the range of compositions of lavas erupted there? Give the range of magma/lava types that erupt/solidify at these locations and explain how magma composition is differentiated from where it forms to where it erupts or crystallizes in the crust. (1 paragraph)

h) How might this range of compositions influence the explosive vs. effusive nature of the eruptions? (1 paragraph)

i) When was the most recent major eruption of Mount Saint Helens? Was this an explosive or effusive eruption? Which direction (N-S-E-W) was the eruption directed? (CITE). What evidence do you see of this direction on the satellite image in Google Earth? (3-4 sentences)

j) Based on your knowledge of how and where different types of igneous rocks are created, what type(s) of rock would you expect this eruption to generate, and why? What minerals would likely be present in each of these types of rock? (1 paragraph)

k) What was the impact of the eruption on the surrounding ecosystem, landscape, and population? How far away from the volcano were the impacts of the eruption felt? (CITE; 1 paragraph)

2) Hawaiian Islands, USA: In the Search box, type “Mauna Loa” (located in the state of Hawaii on the “Big Island”). Turn off layers in the Gallery, but turn on the “Volcanoes of the World” layer in the Dynamic_Earth.kmz.

a) Zoom out to an eye altitude of about 3,000 km (eye altitude information is located in the lower right hand corner, below the Google trademark). Is Mauna Loa the only volcano in the Hawaiian Island chain? If there are others, what pattern do they produce? 1-2 full sentences

b) Check out the plate boundaries in the “Earth’s Tectonic Plates” layer you loaded in with the Earth’s Tectonic Plates.kmz file (see Part 1). What is the tectonic setting of Hawaii (convergent boundary, divergent boundary, transform boundary, intraplate ocean or continent)? In your own words, what is occurring at this location (please identify the plate(s) involved)? 1-2 full sentences

c) Based on your answers in a) and b), explain how the Hawaiian Island chain was formed (CITE; 1 paragraph)

d) Based on the tectonic setting you identified in the previous question, what process is generating the magma at this boundary (decompression melting, water addition, a rise in temperature; CITE)? Explain. (1-2 sentences)

e) Turn off the Volcanoes Layer and zoom in to an eye elevation between 7-30 km above Mauna Loa. You can use the tilt and turn functions (upper right corner, with the N) to move around and explore the area around Mauno Loa. Name at least two specific volcanic features you observe, and explain how each type of volcanic feature would form. CITATION not required, but if you use anything other than the Google Earth basic display, be sure to cite (additional photographs or other satellite images embedded within Google Earth must be cited). (1 paragraph)

f) Using the path tool, draw a line across the volcano. Use the elevation profile of this line to create a cross-sectional sketch (take a photo of your sketch and embed it in your document). Based on the geomorphology of the volcano, how would you classify Mount St. Helens (shield, stratovolcano, cinder cone, lava dome, or fissure eruption)?

g) What is the composition(s) of magma/lava that erupts here? Explain whether the composition of magma does/does not change from formation to its eruption or solidification near the surface. How might this range of compositions influence the explosive vs. effusive nature of the eruptions? (1 paragraph)

h) When was the most recent major eruption of Mauna Loa (CITE)? Was this an explosive or effusive eruption (CITE)? Which direction (N-S-E-W) was the eruption directed? Based on the satellite image in Google Earth, how can you tell? (1 paragraph)

i) Based on your knowledge of how and where different types of igneous rocks are created, what type(s) of rock would you expect this eruption to generate, and why? What minerals would likely be present in each of these types of rock? (1 paragraph)

3) Include a Works Cited section at the end of this section (for both the Cascades and Hawaiian Island work). Include complete bibliographic information for all of the citations. Within the text include in-text citations.

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Content by McLean, N., Roberts, J.A., and Bitting, K. (2015)