Global Occurrence of Earthquakes:

• Aim: to explore the occurrence and characteristics of recent global earthquakes.
• Website:  http://gldss7.cr.usgs.gov/neis/bulletin/bulletin.html
• Alternate website: http://gldss7.cr.usgs.gov/neis/qed/qed.html  
• Contents: listings of the characteristics of recent earthquakes and links to further information.
• Relationship between earthquake location and plate boundaries.
• Maps of the region of the earthquake showing locations, depths and magnitude of seismic activity recorded since 1977.
• Relationships between depth and magnitude

• The site provides details of recent global earthquakes and links to maps that describe the tectonic framework of the locality.
• Select and click on a given earthquake from the list.
• The position of that earthquake will then be shown as a colored star on a local map (12°latitude by 12° longitude) and on a global view centered on the location. Yellow lines on the map represent plate boundaries.  These lines may be smooth curves (typical of convergent or transform plate boundaries), or appear as a series of zig-zags (typical of divergent boundaries offset by transform faults).  Details of the timing, depth and magnitude of the earthquake are given below the local map.
• The words "Historical Seismicity" below the Earthquake Bulletin provide a link to an image of the same map that depicts seismic activity in that area since 1977.  Individual earthquakes are shown as colored circles. The relationship between color codes and earthquake depths are shown on a vertical scale.  The size of the individual circles reflects the magnitude of the earthquake that they represent.
• The "Historical Seismicity" link also presents maps of the region that depict:
• earthquakes in 2002
  
• earthquakes of magnitude 7 or greater since 1900.

• The first website provides details of major earthquakes (typically about 20) that occurred within the past 7 days.
• The second website provides a longer listing (often >100) of earthquakes that occurred during the previous 30 days.  
• For geographic locations of individual plates see the global plate map at:    http://pubs.usgs.gov/publications/text/slabs.html
• A separate page describes background information on plate boundaries (plates ).
• The questions are outlined in two separate tables:
• a question set for individual activity ( next page )
• Reminder: you should submit your answers via oncourse.

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Department of Geological Sciences, 
1001 E. Tenth Street, Bloomington, IN 47405-1403
Phone: (812) 855-5582  Last updated: 15 September 2002
Comments: simon@indiana.edu
Copyright 2002, The Trustees of Indiana University