I recommend this site for people ages 12 and up. This is a very detailed and thorough site. This is a good site for people who want to learn about volcanoes. In this WebQuest, student teams research and debate whether they would rather live near an earthquake fault or a volcano. Web links help students learn earth science principles as they consider their task.
Students finish the quest by writing e-mail to a geologist.
This page is a good example of how teachers can use Filamentality to create a web-infused learning activity. Users interpret simulated seismograms from three seismic recording stations in an effort to triangulate the location of an earthquake's epicenter. The user's results are plotted on a map and compared to the actual results. In this activity, students print and color-code a map based on seismic activity.