Download The dynamic earth

Name ________________________________Date___________________Hr_____________
The Dynamic Earth Web Quest
Use the following website to complete: http://pubs.usgs.gov/gip/dynamic/dynamic.html
1) Preface

When did the theory of plate tectonics come about?

Why is it important?
2) Historical Perspective

What’s a plate?

Where does the word
tectonic come from?

What is plate tectonics?

What’s a
supercontinent?

Label the diagram of
supercontinents to the
right.

Summarize the
"Uniformitarian
Principle" and who is
responsible for it.
1
i) Tectonic plates
 Count and label the tectonic plates on the diagram page

Who is Abraham Ortelius?

Who is Alfred Lothar Wegener?

Explain how Wegener used fossils of animals, plants, and geologic structures to support his
theory.

What was the problem with his theory?
ii) Rejoined continents
 What observations can you make about this map?

Label the diagram of rejoined continents on the next page.
2

What happened to Wegener?

What still plagues the scientific community?
iii) SIDEBAR
(1) Inside the earth
 What did the Greeks know?

Describe each
layer and give
the approximate
thickness of the
earth.
3
(2) What is a tectonic plate
 What is a tectonic plate?

What are the two types of tectonic plates and how do they differ?

How do they compare to icebergs.
(a) Shrinking Farrallon Plate
 What happened to the Farallon Plate?
(3) Alfred Wegener
 Why was Wegener so important to science?

Why was the timing of his death so ironic?
(4) Polar dinosaurs in Australia
 Why do coal deposits, a relic of lush ancient forests, occur in the icy barrenness of
Antarctica? And why are glacial deposits found in now sweltering tropical Africa?

What are polar dinosaurs?

Where is dinosaur cove?

Why would Wegener like these dinos?
3) Developing a Theory

What were the four major scientific developments that spurred on plate tectonics?

What did Lieutenant Matthew Maury reveal?

How were echo sounding devices used?
i) The Mid-Oceanic Ridge
 Label the ridges on the next diagram.
4

What did Atlantis find?
ii) CGI mid oceanic ridge
 What do the colors indicate?

How does the Mid-Oceanic Ridge compare to other mountain systems?

What is magnetic striping?

What is normal polarity? Reversed polarity?
iii) Magnetic striping in the Pacific Northwest
 What does this graphic show?

What is sea floor spreading?

What is the evidence for this?

How was this discovered?
iv) Glomar and Joides
 What are these ships?

What’s the “expanding earth” idea?
5

Explain why the earth is not expanding.

Where are most earthquakes located?
v) Earthquake zone
 What do you notice about the dots and shaded areas?

How do trenches and ridges relate?
vi) SIDEBAR
(1) Magnetic stripes and isotopic clocks
 What does this graphic depict?

How did this help sea floor spreading?

How does an “isotopic clock work” work?
(2) Harry Hess
 What book did he write?

How did answer some of the most puzzling questions?
(3) Exploring deep ocean floor
 What is a geo-thermal vent and where are they located?

What was surprising about them?

Explore some of the ocean life in the links.

What is Alvin?
4) Understanding Plate Motions

List and describe the plate boundaries.
a) Illustration Main plate boundaries
 Sketch the three types of boundaries on
the right side of the page
DIVERGENT PLATE BOUNDARIES
 What is the best known divergent plate
boundary?

What is happening to Iceland?
6

Check out some of the links to pictures of Iceland.

What is happening to Africa?
b) Summit crater
 What is the Red in this photo?
CONVERGENT PLATE BOUNDARIES

What is a subduction zone?

What are the three types of convergent boundaries?
Sketch and label an oceanic-continental convergence.

Describe the Peru-Chile Trench.
c) Convergence of Nazca and south American
plates
 Can you see the uplift? Look at the
strata (lines).
d) Ring of fire
 What is the Ring of Fire?
Sketch and label a oceanic-oceanic convergence.

Describe the Marianas Trench.

How does an island arc form?

Sketch and label a continental-continental
convergence.

Where is this convergence represented in
the world?
TRANSFORM BOUNDARIES

What is a fracture zone and where are most found?

What is the San Andreas Fault?
e) San Andreas fault
 Check out this photo of the actual fault
PLATE BOUNDARY ZONES
7

What is a plate boundary zone?

Where can one be found?
RATES OF MOTION
 How can you measure the rate of motion of plates?
f) Easter Island
 What’s special about Easter Island?
g) GPS and Ground Receiver
 What are two ways that plate movement can be tracked using technology? Describe each.
5) Hotspots: Mantle Thermal Plumes

How has Hawaii formed?

How does an island become “extinct”?

How old is the “Big Island” compared to the others?

Label the hotspot diagram
on right
a) Prominent world hotspots
 Where are some other
hotspots located on
earth?

What is happening at Yellowstone?
b) Mauna loa volcano
 What kind of volcano is Mauna Loa?
c) SIDEBAR
i) J. Tuzo Wilson
 Who is J. Tuzo Wilson?

What important contributions did he make?
8
ii) Trail of Hawaiian hotspots
 What are the Hawaiian Ridge-Emperor Seamounts?
6) Some Unanswered Questions

What’s unanswered?

What is the generally accepted idea currently?

Label the plate movement on the right.

Where does heat within the earth come from?

What was the debate in the 1990’s?

Is there plate tectonics elsewhere in the
universe?
a) Before the break-up of Pangaea?
 Why is it hard to tell what happened?

What are the oldest rocks that we know of?

Identify where there are divergent, convergent, and transform boundaries in the graphic of
California.
7) Plate Tectonics and People

Will California fall into the ocean?

What’s a strike-slip fault?

What’s the earthquake-focus?

Describe some of the major earthquakes in California.

Are there earthquakes in other areas of the US? Is New York susceptible?

What tools do we use to measure and predict earthquakes?
VOLCANOES
 What are “subduction zone volcanoes”? Describe them.
9

What is a pyroclastic flow?
a) Mount Pinatubo plume – check out this photo.

What are the two layers of the atmosphere?

What’s a mudflow?
b) Armero, Columbia – check out this photo.

What is a composite cone? Describe.

Where can you find one?
c) Wahaula Visitor Center
 What’s happening in this photo?

What is a tsunami?

Are they tidal waves?

What are some of the natural resources of geologic activity?
d) Yosemite national park – check it out.
e) Geothermal power plant, the geysers
 What is geothermal energy?
8) Endnotes – SCROLL TO BOTTOM OF THE PAGE
 What is the Dept. of Interior?
10