See URL: http://www.ngdc.noaa.gov/mgg/image/
The National Geophysical Data Center at the National Oceanic and Atmospheric Administration (NOAA) has a wide range of educational materials designed for oceanographers, private industry partners, and a range of other users. This particular corner of the site brings together dozens of resources that deal with seafloor topography, sediment thickness, natural hazards, and unique animated dives to ocean floor features. This last collection is quite remarkable, as it allows visitors to dive into the Mariana and Puerto Rico Trenches in a way that would be impossible without some rather expensive equipment. Moving along, the Crustal Age of the Ocean Floor area is an absolute wonder, featuring high-quality images of the earth's tectonic plates. Additionally, the Globes and Global Relief Images area includes short videos of rotating relief globes, along with a very cool global relief origami piece that can be printed out as a type of decoration or class project. The site is rounded out by a link to the Natural Hazards Image Database, which contains thousands of photographs documenting the effects of earthquakes, tsunamis, and volcanoes.