Earthquakes and Plate Boundaries (40 pts)
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Goals

Earthquakes were instrumental data used by geologists to unravelling the location and nature of plate boundaries. In this exercise you will evaluate the most recent earthquake data and determine if they support what you've learned about the distribution of earthquakes relative to plate boundaries.

Supporting skills: geography, calculation of percent, identification of range, data organization and critical thinking, report writing

Instructions

Be prepared to spend at least an hour at the computer getting your data. You will need to explore the links for each earthquake so you can determine their location and assign them to a plate boundary. Beware: This list changes daily so if you miss something important you might have to start over. You will not be able to access the same data list.

Completed work must be neatly typed, referenced,and proofread.

Procedure:

  1. Go to the sites listed below and print out the following:

    <http://wwwneic.cr.usgs.gov/neis/current/world.html> USGS Earthquake information: Map of current world seismicity (map of the last 21 earthquakes worldwide).  You can obtain a more detailed map showing the location of an earthquake relative to a plate boundary by double clicking the epicenter tag on the map.You may find the "historical seismicity" link informative

  2. Click on Near Real Time Earthquake List and print out the list of earthquakes
  3. You can also get a local map by double-clicking on an earthquake in the list.
  4. Both the world map and the list of earthquakes are to be included in your report.

Part I: Summarize your data by filling in the table below (10 pts)
Using the real-time earthquake map that you just printed, this Tectonic map compiled by researchers at NASA's Goddard Flight Center, and a map of plate boundaries fill out the table below. You should be able to interpret the tectonic setting of each earthquake from its location on the map.
Tectonic setting
Total number of earthquakes for each setting
% of all earthquakes
range of magnitudes

Plate boundaries

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  • subduction zone

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  • zone of continental convergence

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  • mid-oceanic ridge

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  • zone of continental rifting

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  • transform boundary

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Intraplate

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.

.

%=(number in each setting/Total number of earthquakes)*100

range = lowest-to-highest values. For example for a set of date obtained on 1/5/2001 the magnitudes of earthquakes along divergent boundaries ranged from 2-4.5. This Table must be completed and incorporated into your report. Click here to obtain a clean blank copy with caption.


Part II: Write a report (25).

Write a two- to four-page typed paper that covers the topics listed below. Use the topic headings as subheadings for your report. The text of your report should be in your own words and not copied from the textbook or from other sources. All books and sites used for reference must be listed and properly cited in a bibliography at the end of your report. Any figures used must have figure captions and must be reference if taken from a book or website.

shallow focus

<70 km

shallow-intermediate focus

70=150 km

deep-intermediate focus

150-350 km

deep focus

>350 km

Table 2. Terminology used when describing the depth of focus (hypocenter)

Topics:

Bibliography and Appendix

 
Lindley Hanson/Department of Geological Sciences/Salem State College