Earthquakes, Seismology, and Plate Tectonics

California Institute of Technology Seismological Laboratory   Includes a virtual earthquake and SSA resources for teachers.
Incorporated Research Institutions for Seismology (IRIS)  Consortium of U.S. universities seismology research programs.
Institute for Crustal Studies  Research on the formation of and processes within the crust and lithosphere using a multi-disciplinary approach and the expertise of scientists in academia, government, and industry.
Pacific Northwest Earthquake Information (PNEI)  Site uses information from the Pacific Northwest Seismograph Network (PNSN) which operates seismograph stations that locate earthquakes in Washington State.
St. Louis University Earthquake Center  Earthquake information for the central United States.
Seismicity Maps  A point-and-click global map access to the authorative earthquake maps available on the Web.
Seismosurfing the Internet for Earthquake Data  Links to original seismic data and seismic research information.
U.S. Geological Survey Earthquake Hazards Program  Site includes the latest earthquake information, information on hazards and preparedness, and other resources.
University of Helsinki, Institute of Seismology  Research institute with primary concentrations on lithospheric structure and detection seismology; additional research areas include seismic hazards and regional seismicity.
World-Wide Earthquake Locator  Developed at the University of Edinburgh, Department of Geography, the site uses data obtained dynamically over the Internet.