Instructions:

You should have a paper copy of this web page in hand as you do your assignment. As you answer each question, please write the answer on the paper (or or any additional pages you are instructed to print out) to be turned in. If you do not have a paper copy of this assignment, please print this page out now. If you have any computer difficulties on this or any other assignment, please e-mail your instructor immediately so that he or she can get the problem resolved ASAP. You should use the web page version of this document as a "clickable page". Return to the Assignment 1 web page after answering each question (or set of related questions on a particular site). Then click on the next blue hyperlink to go on to the place where the next question can be answered.

First, I would like for you to learn something about the worldwide distribution of earthquakes, and how it is tied to the movement of the Earth's tectonic plates.

1. St. Louis University maintains a map of World Earthquakes of 1998. (Click on the blue words on the Assignment page or type this address: http://www.eas.slu.edu/Earthquake_Center/FQHTML/wrld98.html).
   1. What do the different sizes of the dots refer to?

   2. What do the different colors of the dots refer to?

   3. Print out the 1998 earthquake map.

   4. Using the map of the tectonic plates from the U.S. Geological Survey, or the map in Chapter 1 of your textbook, clearly and neatly label all of the tectonic plates on your earthquake map. Do not print it out. Use it online.
      (Click on the blue word on your Assignment page or type this address http://pubs.usgs.gov/publications/text/slabs.html).
      If you wish, you may color each plate using colored pencils and a color scheme like that on the USGS web page. If you color your map, please do not try to fax it to me as it will be black.

   5. How do the plate boundaries match up with the distribution of earthquakes?

   6. What does this tell you about one of the possible causes of earthquakes?

   7. Label the names of the oceans (Atlantic, Pacific, Indian, Arctic) around the edge of the map with an arrow pointing to their location. You may use the 1997 World Political Map to help you. Use it online. Do not try to print it out. Please be certain that you are also able to identify the names of the continents.

2. Now let's examine the largest earthquakes of the past week.
   Go to the U.S. Geological Survey (USGS) National Earthquake Information Center (http://wwwneic.cr.usgs.gov/neis/bulletin/bulletin.html) to see the near-real time earthquake bulletin and a map of the locations of the largest earthquakes during the past week. Scroll down to see the list of earthquakes (most recent at the bottom), and below that, the map.
   1. When was the map last updated? Give date and time. (MDT is Mountain Daylight Time; the NEIC is in Denver.)
      
      In Denver it is 2 hours earlier than in Atlanta.
      What time is it now in Atlanta?
      What time is it now in Denver?
      How long ago was the map updated?

   2. Where was the most recent earthquake? (See map AND comments in the data table above the map.) Give location description AND latitude and longitude.
      • Location description _________________________

      • Latitude _________________

      • Longitude _________________

   3. What was the magnitude (Mb) of the most recent earthquake? See the data table above the map.

   4. Click on the earthquake on the map for more detailed information. Scroll down the page.
      What is the approximate depth of the most recent earthquake?

   5. What is the plate tectonic setting of the most recent earthquake? See the arrows and legend on the plate tectonic map in Chapter 1 of your textbook. If it is near a plate boundary, is it a convergent, divergent, or transform boundary?

   6. See a seismogram of the most recent earthquakes (last 24 hours), as viewed from sites around the world. Pick any site, and click on SMALL VERSION. You may have to have a site nearest the most recent earthquake. You may need to try several sites before you can find an earthquake recorded on the seismograms. Print out a seismogram showing an earthquake.

   7. What is the largest magnitude listed in the data table for the past few days? Go back to the U.S. Geological Survey (USGS) National Earthquake Information Center page. (http://wwwneic.cr.usgs.gov/neis/bulletin/bulletin.html)

   8. Where did the largest earthquake occur?
      Give the location description, latitude and longitude of the epicenter of the largest earthquake.
      • Location description ____________________

      • Latitude _________________

      • Longitude _________________

   9. When did the largest earthquake occur? ____________________

      The time is given in UTC (Coordinated Universal Time). UTC is the time on the Greenwich Meridian or 0 degrees longitude line.

   10. How does UTC time differ from the time zone you are in? (scroll down the page to see).

   11. Convert UTC to the time in your time zone.

       When did the earthquake occur in Eastern Standard Time or Eastern Daylight Savings Time (whichever you are in now)? ____________________________.

   12. See the current seismicity for the United States. (http://www.geophys.washington.edu/us.epi.gif).
       Were there any earthquakes in the US last two weeks?

   13. If there were earthquakes in the continental US, list the states where the earthquakes occurred,and the approximate number of earthquakes in each state.

       To identify a state, you may use the online map of state outlines You should know the names of each of the 50 states and be able to identify them on a map.

   14. For more recent information on slightly larger earthquakes, see Current seismicity for the US (http://wwwneic.cr.usgs.gov/neis/current/usa.html).

       Where are the earthquakes on this map? (If any.) Click on the dots for more detailed information.

   15. Look at the map of World Seismicity, 1975-1995 (http://wwwneic.cr.usgs.gov/neis/general/seismicity/world.html). The colors indicate depth of the earthquake epicenters.
       Examining the Pacific Rim area (the edges of the Pacific Ocean and vicinity), what patterns of changes in earthquake depths do you observe? (In other words, do the earthquakes around the Pacific Ocean get deeper or shallower going toward the continent?)
       How might this pattern of depths be interpreted?
       What plate tectonic process is occurring around the edges of the Pacific?

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   This page created by Dr. Pamela J. W. Gore,
   Georgia Perimeter College, Clarkston, GA
   pgore@gpc.edu
   Revised September 1, 1998.
   Last revised August 30, 1999