Our Dynamic Planet Map Activity: A study of Plate Margins

Refer to your National Geographic Map, The Earth's Fractured Surface, and your photocopy of the Physiographic Chart of the Seafloor.
Use "Area Maps" to get closer into the margin you are investigating.

A. Convergent Margins or Subduction Zones
Draw several profiles through the convergent margin you have chosen.
What do the profiles look like? Describe and sketch the general shape.




What is happening at this convergent margin?




Does it involve oceanic lithosphere or is it a continental collision?




Add Earthquake data. It will automatically give you an earthquake profile for the last profile you created. If you want to chose one of your other profile, choose it under the profile button and then click on "update."

What does the earthquake profile look like?

What is the depth of the deepest earthquake?

Why do you think the profile looks this way? (Remember what kind of margin this is.)


Add the volcano data
Are there volcanoes nearby?

Do they appear to be in a line or randomly placed? Why?




B. Divergent Margins or Spreading Centers
Depending on the rate of spreading, there is a lot of physical variation in divergent margins.

Draw several profiles across divergent margins.

What is the maximum elevation of your profile? Is this above or below sea level?



Sketch the general shape of your profile.




Add the earthquake data.
Where do the earthquakes appear to be concentrated?

What is the maximum depth of the earthquakes?

How does this compare to the maximum depth of the earthquakes at convergent margins? Is it shallower or deeper?

What is happening at your divergent margin? Is it a mid-ocean ridge or a land based rift?



Add the volcano database. Remember from the tutorial that the data along mid- ocean ridges is under represented. Do you remember why? Recall that mid-ocean ridges are underwater.


C. Transform Margins or Strike Slip Faults
Use your National Geographic map to identify transform faults-remember, you live by one.
Draw several profiles across transform margins.
Add the earthquake data.
What is the deepest earthquake?

How does this compare to the maximum depth of the earthquakes at convergent margins? Is it shallower or deeper?