Plate Tectonics, volcanoes and earthquakes Write a lab report summarizing your work on the features of convergent plate boundaries. Review your work on subduction zone features from lab 3, volcanoes from lab 6 and earthquakes from lab 8. Your report should include: Title Introduction: Brief introduction to subduction zones and the work you did in these labs. Method: What techniques did you use to determine the type of volcano that was featured on the map? How did you determine the epicenter and magnitude of the earthquake? Results: What type of volcano is Crater Lake? Include your topographic profile to show your evidence for your conclusion. On which plate boundary is this volcano located? What type of magma would have been erupted? What was the magnitude of the earthquake you interpreted and where was the epicenter? On which plate boundary was this earthquake located? Discussion: Explain the relationship between the volcano, the earthquake and the processes that occur at subduction zones. WHY were this magma type and this type of volcano produced at this location? Why did the earthquake occur at this location. Include a subduction zone diagram to help explain these processes. Conclusion: Paragraph summarizing your findings from this lab. Remember: This report is a write up of what YOU did in the lab, NOT a general report about
Lab 6 Volcanoes
Tape or glue
Printout of Caldera-bw.pdf (from Blackboard)
Topographic map of Crater Lake National Park
1-inch graph paper (from Blackboard)
Computer with Google Earth software loaded
Pre-lab reading and quiz
Read Chapter 4 of Earth Science, and review your lecture notes on volcanoes.
What are the 3 types of magma that commonly form volcanoes?
How do these different magma types form?
Describe 3 different types of volcano, and explain what type of magma they each erupt.
In-class lab exercises
Part 1 Calderas
Cut out the model of a caldera that you printed out from Blackboard. Make all of the folds,
but dont glue it together yet.
On the land surface
Color the floor of the caldera in yellow.
Color the steep slopes inside the rim of the crater in orange.
Color the more gentle exterior slopes of the volcano in green.
Color the resurgent dome in black.
Highlight the rivers in blue.
In the cross-section, side view of the volcano
Color the stockwork of pipes feeding magma to the volcano in red.
Color the alternating layers of lava and pyroclastic material in purple.
Then finish constructing your 3-dimensional model using tape or glue.
This model is a very good representation of the structures you will be examining in the
map exercise in part 2 of the lab. Use it, along with the topographic map and Google Earth
to help you interpret the Crater Lake volcano.
Part 2 Interpretation of Crater Lake
The topographic map of Crater Lake National Park depicts a landscape shaped by volcanic
activity. Look at the map and read the information about Crater Lake on the reverse side.
What is the scale of the map expressed as a ratio?
How many inches represent 1 mile on the map?
What is the contour interval of the map?
Do the rivers on the map flow towards the lake or away from it?
Is this what you would expect, given the location of Crater Lake? Why?
What is the surface area of Crater Lake in square miles? Show your calculation. (It is
approximately a circle, and the area of a circle is r2)
Draw a topographic profile between BM 5920 (On the west side of the lake) and the
summit of Mount Scott (On the east side of the lake), using the graph paper provided. Show
both the bed of the lake and the surface of the water on your profile.
What is the vertical exaggeration of your profile?
How deep is the lake water at the deepest point on your profile?
Open Google Earth on your computer. Search for Crater Lake, Klamath County, OR in the
box at the top left of your screen. Scroll around using the tools at the top right of your
screen, until you see a good 3-dimensional view of the mountain and the lake.
Looking at the shape of your profile and the shape of the mountain on Google Earth,
describe the shape of the crater. Where are the steep and shallow slopes?
Describe the similarities and differences between your model from part 1 of the lab, and
the profile and Google Earth images from part 2.
What geologic feature is Crater Lake?
What geologic feature is Wizard Island?
What type of volcano is this?
What type of magma would you expect to be present here? Why?
At what type of plate boundary would this type of volcano form?
How does magma form at this type of plate boundary?
Scroll out on Google Earth to see the location of Crater Lake. Does this location correlate to
the type of plate boundary you predicted? Why?
Which two tectonic plates meet at this location? (go back to the textbook or your lecture
notes on plate tectonics)