6.
Earthquakes Beneath the Atlantic Ocean
Expedition Menu
1.
Introduction
2. Global Distribution
3. Earthquakes & Plate Boundaries
4. The Ring of Fire
5. Convergent Boundaries
6. Atlantic Ocean
7. Atlantic Ocean II
8. Alaska Earthquake
9. Vertical Slice
10. 3-D Look
11. California Plate Boundaries
Here we see the earthquake distribution in the Atlantic Ocean.
Notice how different it is from that which we observed in the Pacific.
Make sure that you ignore the earthquakes in the lower left part of the picture as these are along the edge of the Pacific Ocean and are not in the Atlantic.
Remember that the size of the dots is related to the magnitude of the earthquake and the color is the depth.
Do you remember the type of plate boundary that is found in the middle of the Atlantic ocean basin?
The boundary in the middle of the Atlantic Ocean separates the North American and Eurasian plates and lies along an underwater volcanic mountain range called the Mid-Atlantic Ridge. This boundary is composed of north-south oriented divergent boundary segments, which are sites where oceanic lithosphere is created by seafloor spreading, and east-west-trending transform segments marking regions where the plates slide by one another. Transform plate boundaries in ocean basins extend laterally into fracture zones, which are not fault zones, but instead mark the boundaries between oceanic crust and lithosphere of different ages within the same lithospheric plate.
Move on to answering the questions in your worksheet.
Contact Don Reed
Dept. of Geology
San José State University
©Copyright 1999
Last Updated on June 21, 1999
How is
the distribution of earthquakes in the Atlantic different from that which
you previously observed in the Pacific?
a)
the earthquakes are smaller along the divergent plate
boundary in the middle of the Atlantic
b) the depth of the earthquakes are shallower in the
middle of the Atlantic
c) the earthquakes are located in the middle of
the ocean basin
d) all of the above!