Topics: Earth, Plate tectonics, Atlantic Ocean Pages: 5 (763 words) Published: April 4, 2015
Laurel Goodell
February 2013

Introduction to Plate Tectonics via Google Earth (24 pts)
B. Topographic Patterns

Uncheck all of the layers and focus on topographic features of the earth.

Topography of the earth ABOVE sea level
Questions

1. Are mountains randomly distributed on
the continents, or do they tend to occur in
particular patterns (clusters, linear chains,
arcs, etc.)?

Some appear in lines and others in arcs

1pt
2. Find Mt. Everest, the highest point on
earth. Zoom in enough to see the summit,
then pan your cursor around to locate the 8840_______ meters highest point (elevations shows up in the
status bar at the bottom, as long as
View/Status Bar is selected):
1pt

Laurel Goodell
February 2013

Topography of the earth BELOW sea level
3. If the earth’s lowest spots aren’t in the
 Some are along the coastlines of continents
middle of the ocean, where are they? Focus
 From South America westward, the depth of
on the west coast of South America, and in
the ocean increases rapidly until you reach the
describe the change in bathymetry off the
bottom of the trench; then the depth decreases
coast. What is the deepest spot, and how far
as you leave the trench. See the image below.
is it found off the coast?
 6,000m deep, 110 km from the coast
The deep linear features, the lowest points
on Earth, are called ocean trenches.
3pts
4. Using Google Earth, search for Challenger
In the Pacific near Guam
Deep, the deepest place on Earth (once
Google Earth gets you there, you may have
to zoom out to see where you are). Where is
it?
1pt
5. Challenger Deep reaches 11 km (36,000 ft)
Depth of Challenger Deep by over 3 km
below sea level. Which is greater, the
elevation of Mt Everest (see question 2)
above sea level, or the depth of Challenger
Deep below sea level, and by how much?
2pts
6. Give the locations of three other ocean
Puerto Rico Trench, Aleutian Trench, Tonga Trench
trenches on earth (Challenger Deep is in the
Marianas Trench so find three more!).
3pts
Question 3 image

Laurel Goodell
February 2013

Challenger Deep

E. Plate Boundaries
Find the boundary between the African and South American plates 7. Where is this plate boundary, relative to the
coastlines of Africa and South America?
1pt
8. Now click the other layers on and off so that
you can see relationships between plate
boundaries and these features. If you did not
have the “plate boundary layer” available to
you, how could you determine where this
plate boundary was? Be sure to consider
topography/bathymetry as well as the
earthquake and volcano layers. List several
ways and be specific.
3pts

In the middle between the two

Without the plate boundary feature, you would still
see the change in depth where the mountains are,
still feel earthquakes, and see volcanic eruptions.

Laurel Goodell
February 2013

Mid-Atlantic Ridge

F. Plate motion
Motion across the mid-Atlantic ridge: the South American plate vs. the African plate 9. How many years does each colored band
represent?
1pt
10. On average, continental crust is 2 billion years
old; the oldest rocks are 3.8 billion years old,
and some of the grains in those rocks are even
older.
a. What is the age of the oldest seafloor?

10 million years

b. On average, which is oldest – the continents
b. continents
or the ocean basins?
1pt each
11. Find the South American plate, the African
The crust gets older as you move away from the
plate, and the Mid-Atlantic Ridge that marks
ridge towards the continents
the boundary between them. What happens to
the age of the seafloor as distance increases
away from the Mid-Atlantic Ridge?
1pt