Natural Hazards Databases at the National Geophysical Data Center (NGDC)
http://www.ngdc.noaa.gov/seg/hazard/hazards.shtml

The highlight of this government-maintained site is the amazing photo gallery of earthquakes, tsunamis, volcanoes, and other natural hazards (and the debris they leave behind). Also check out the databases that can be searched online: there's a Significant Earthquake Database, U.S. Earthquake Intensity Database, Strong Motion Data Catalog Inventory, Tsunami Event Database, Tsunami Runup Database, and Volcano Database. The Natural Hazards Data Resources Directory includes information on other data resources and lists of related organizations.

U.S. Geological Survey Hazards Pages
http://www.usgs.gov/themes/hazard.html

Gateway to reams of great information on earthquakes, volcanoes, and tsunamis, all courtesy of the U.S. Geological Survey. Visit the Alaska, Cascades, and Hawaiian Volcano Observatories, or check out the "Listen to Quakes for Fun" page, featuring sound files that represent in sound form what some real earthquakes felt like.

Alan L. Jones
http://www.geol.binghamton.edu/faculty/jones/jones.html

Download two snazzy programs for visualizing earthquakes and volcanoes (they run on Windows only), written by a geologist at Binghamton University. With the Seismic/Eruption program, the user sees lights that represent historical earthquakes and volcanic eruptions flash on a world map in speeded-up chronological time. Seismic Waves shows how the waves propagate from an earthquake hypocenter and arrive at seismic data stations throughout the world.