Plate Tectonics

Internet Exercise  

 Dr. Anna Balog-Szabo

Use your favorite search engine to answer the following questions!

1. What is the highest and the lowest elevation on earth? Where are those points located? Put a small map right under your answer!





2. Print out a small map showing the tectonic plates on Earth!



3. The most well known person suggesting continental drift is Wegener. Who was he? When did he live? How did he come up with his theory?


4. What evidence supported Wegener's theory of continental drift?


5. What are magnetic strips?


6. What is divergent plate boundary? Make a sketch here! Location




6. Transform plate boundaries! Make a sketch! Location





7. Convergent plate boundaries! Make a sketch! Location





7. As one lithospheric plate is pushed or subducted under another plate, the solid rock again becomes molten and rises to the surface. What feature on the Earth's surface is formed by this magma as it rises?




Part Two: Volcanoes

Volcanoes pose a major hazard to life and property all over the world, and they generally occur along the margins of plates that are colliding. The science that studies volcanoes is called Volcanology - let's connect to the United States Geological Survey (USGS) Cascades Volcano Observatory (CVO) web site, which is truly spectacular, at:

Navigate through the many, many pictures you can find at this site and answer the following questions. We'll start by learning about volcanoes in the "Cascade Range" of the Pacific Northwest.

1. Give the names of five volcanoes found in the state of Washington:

a. _____________________________________________________________________________
b. _____________________________________________________________________________
c. _____________________________________________________________________________
d. _____________________________________________________________________________
e. _____________________________________________________________________________


2. From the Main Home Page again, let's "Visit a Volcano" in Washington State. Click on "Mount St. Helens National Volcanic Monument," then on "Description: Mount St. Helens Volcano." Scroll down to the very bottom of this page.

3. On what day about 26 years ago did Mt. St. Helens erupt in a massive explosion?

4. Click on this day where it also says "Eruption of Mount St. Helens." What was the precursor that happened at 8:32 a.m. Pacific Daylight Time on this day?


6. Go to "" And answer What are three main types of hazards associated with volcanic eruptions?
a. _________________________________________________________________________________
b. _________________________________________________________________________________
c. _________________________________________________________________________________

Part Three: Earthquakes

Earthquakes are another major natural hazard that we here in the U.S. are familiar with - earthquakes regularly rattle the west coast in places like California and Washington. You can find numerous sites on the web about earthquakes, but let's start at the National Earthquake Information Center (NEIC) of the USGS:

Notice that this center is part of the World Data Center for Seismology, itself part of the worldwide World Data Center system. At this site, we can learn of the major earthquakes that have occurred this year, and also map out where they've occurred.

1. Look at the graphic at " "  that shows the locations of recent earthquakes. What do you think the jagged, broken yellow lines indicate? ___________________________________________________________

2. Next  let's learn about the largest earthquakes ever to strike the United States. " " What was the highest magnitude earthquake ever to strike the United States, when did it occur, and what was its magnitude?


3. What was the greatest earthquake ever to strike the United States outside of Alaska, when did it occur, and what was its magnitude?



4. Return to the main home page of the NEIC, click on "Current Earthquake Information," followed by "Near Real-Time Earthquake Bulletin Finger List." This lists the most recent earthquakes worldwide in the last few days. What is the highest magnitude earthquake listed here, when did it occur, and what was its magnitude?