Focuses on the social and policies implications of natural hazards but has a good list of resources, including web resources broken down by disaster type.
IRIS is a consortium of over 100 US universities dedicated to the operation of science facilities for the acquisition, management, and distribution of seismological data. Includes the Seismic Monitor which allows you to monitor earthquakes in near real-time.
Includes features allowing you to search for volcanoes by region, name or eruption data. Also has a wonderful image gallery and provides access to volcanic activity reports that provide recent and historic information on volcanic activity.
Provided by the Department of Geosciences at Oregon State University this site includes information on national parks with volcanoes, current volcanic activity and interviews with people in the field.
The Flood Observatory facilitates use of space-based information for international flood detection, flood response, future risk assessment, and hydrological research.