Investigation 2: Sea Floor Spreading
Table of Contents
Folder 1: Sea Floor Features ....................................................................................................................... 12
Folder 2: Undersea Volcanoes .................................................................................................................... 13
Folder 3: The Hypothesis ............................................................................................................................ 14
Investigation Summary ............................................................................................................................... 16
CE3 Field Notebook - Module 3
Page 11
Folder 1: Sea Floor Features
Instructions
Step
1.
Click on the radio buttons next to “Inv 2: Sea Floor Spreading”. Open and read
the “Introduction” placemark balloon. Then close the balloon.
2.
Expand “Folder 1: Sea Floor Features”. Open and read the “Description”
placemark balloon. Then close the balloon and examine the Atlantic Ocean sea
floor to see the features described in the balloon.
3.
Open the “Transect” overlay to see a transect that has been drawn across the
South Atlantic Ocean. Right click on it in the Places panel and click on “Show
Elevation Profile”. Examine the elevation profile and record your observations.
4.
Open the “My Seafloor Features” folder. Use your path tool to trace the scarlike feature as far as you can across the globe. If it branches, add another path
to follow that branch. Look carefully for other similar features elsewhere on the
globe and add paths for each one. Hint: Some of these features are very faint!
Make all of your paths white with a width of 5.0. Save your paths in your “My
Sea Floor Features” folder.
5.
Refer to your “My Sea Floor Features” folder to make additional observations.
Complete
Observations
Is the scar-like feature in the middle of the sea
floor a ridge or a trench?
How deep is the highest point on the feature (m)?
Which oceans have a scar-like feature?
Where are the features located within the oceans
(edges or center)?
Are the features located between continents that
have moved apart?
Are any landmasses completely surrounded by
these features?
CE3 Field Notebook - Module 3
Page 12
Notes and Questions
Folder 2: Undersea Volcanoes
Instructions
Step
1.
Expand “Folder 2: Undersea Volcanoes” and open the “Description” placemark
balloon. Read the information and watch the video on undersea volcanoes.
Record any observations you can. Then close the balloon.
2.
Use your observations to answer the Interpretation question. Be sure to use
complete sentences.
Complete
Observations
Where does most volcanic activity on Earth occur?
What type of magma is present?
What are the important properties of this magma?
What is pillow lava?
What instrument is used to detect undersea
volcanic activity?
How are undersea volcanic eruptions located?
How are biological and geological samples
collected from undersea eruption sites?
CE3 Field Notebook - Module 3
Page 13
Notes and Questions
Interpretation
Could the mid-ocean ridge system be responsible for moving the continents apart?
Claim:
Evidence:
Reasoning:
Folder 3: The Hypothesis
Instructions
Step
1.
Expand “Folder 3: The Hypothesis” and click on the radio button. Open the
“Description” placemark balloon and read the information. Record any
information you can. Then close the balloon.
2.
Go back to Folder 1 (Sea Floor features). Click on your “My Sea Floor Features”
folder and drag and drop it into the “Evidence” folder. Turn this folder on.
3.
Examine the overlays to see how sea floor age relates to the mid-ocean ridges.
Use the legend to see what the colors mean. Record your observations.
4.
Use your observations to answer the Investigation question.
5.
Finally, use what you have learned to answer the Investigation Summary
questions. Be sure to use complete sentences.
CE3 Field Notebook - Module 3
Complete
Page 14
Observations
What is a magnetic field?
What is polarity?
What is a magnetic reversal?
What is a compass?
Where is the youngest sea floor found?
Where is the oldest sea floor found?
Notes and Questions
Interpretation
Does the map of sea floor age support the sea floor spreading hypothesis?
Claim:
Evidence:
Reasoning:
CE3 Field Notebook - Module 3
Page 15
Investigation Summary
How can Earth’s magnetic field help us determine how old a rock is?
How does the map of sea floor age support the sea floor spreading hypothesis?
What causes sea floor spreading?
CE3 Field Notebook - Module 3
Page 16