Geology.com is devoted to Earth science articles, geologic news, and geographic information. The site has articles about rocks, minerals, gems, oil and gas, geologic hazards, and many other topics. There is also an Earth Science News page that is updated daily.
By NOAA. A database of destructive earthquakes around the world. Sort by date, location, quake magnitude, number of deaths, dollar amount of damage done, etc. (Explore the links, this site has a lot of information in it.)
National Atlas of the US (with printable maps), WaterWatch (stream levels throughout the US), earthquake information, databases of geological information, and more. (Scroll down and click links, there is a lot here.)
There are 161 potentially active volcanoes in the U.S. The mission of the USGS Volcano Hazards Program is to enhance public safety and minimize social and economic disruption from volcanic unrest and eruption. They deliver effective forecasts, warnings, and information about volcano hazards based on scientific understanding of volcanic processes. (Lots of information on volcanoes.)