Recognizing Seismic Patterns Objectives: Locate earthquake and volcanic activity information from Internet Web sites. Identify the location of current earthquakes and volcanic activity on a world map. Distinguish patterns in the data. Relate the occurrence of earthquakes and volcanic activity worldwide to the location of tectonic plate boundaries. Materials: Computer with Internet connection Colored pencils World map showing latitude and longitude Procedure: 1. Access the IRIS Web site. This Web site is managed by the Incorporated Research Institutions for Seismology (IRIS). The Seismic Monitor allows you to examine data about recent global earthquakes and visit seismic stations around the world. The Event Maps section allows access to information about earthquakes that have occurred within specific time periods. 2. Create a chart like the one shown below. Record data about 25-30 of the most recent earthquakes that have taken place. Try to find information about earthquakes of a variety of magnitudes. Make sure the data you collect reflects a variety of world locations. Date Latitude Longitude Location 3. Plot the data from your chart on your world map using a colored pencil. 4. Access the Global Volcanism Program Web site to gain information about recent volcanic activity. 5. Create another chart like the one above. Record data about 15 of the most recent locations of volcanic activity. (If you click on a location, you will be given latitude and longitude coordinates.) 6. Plot the data from your chart on your world map using a different colored pencil. (Be sure to create a key to show colors used for earthquakes and volcanoes.) 7. Use a highlighter to outline the location of plate boundaries on your map. Analysis: 1. Study the map you created. Where do most earthquakes occur? 2. Based on the data you have collected, what percentage of earthquakes occur along tectonic plate boundaries? 3. Where do most volcanoes occur? 4. What percentage of volcanoes occur along plate boundaries? Drawing Conclusions: 1. What do you think the relationship is between earthquakes and volcanic activity? 2. Based on your data, predict the likelihood that an earthquake of magnitude 5 or greater would occur in the general area where you live.