Scholastic
Scholastic: Disaster in the Pacific
Articles on the devastation in Japan due to the earthquake in March, 2011. Also find resources on tsunamis, tectonic plates, and earthquakes.
Other
Federal Emergency Management Agency: Tremor Troop: Earthquakes [Pdf]
A 260-page unit of activities on earthquakes. Covers what they are, their cause, why and where they occur, their impact on the Earth, how they are measured, and safety and survival. Includes worksheets and has a glossary at the end.
Other
Ceri: Earthquake Facts and Follies
A list of frequently asked questions about earthquakes. This is a good source for earthquake trivia and separating fact from fiction.