Digital World Tectonic Activity Map (DTAM) - visualization tool that presents an actual representational view of global tectonics; created using current global datasets of seismicity, volcanism, and plate motions.
Natural Hazards: Volcanoes - images and animations of volcanic activity from around the world, as observed by satellite. From the NASA Earth Observatory.
Earthquake Hazards and Preparedness - find out what earthquakes do, what hazards they pose, and how you can best prepare to protect yourself. From the U.S. Geological Survey.
IRIS Seismic Monitor - interactive map of global seismicity; updated every 30 minutes. Provided by the Incorporated Research Institutions for Seismology.