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...

The NASA Astrophysics Data System (ADS) Web site, which is hosted by the Harvard-Smithsonian Center for Astrophysics, is described as a Digital Library for Physics, Astrophysics, and Instrumentation. ADS maintains four bibliographic databases containing more than 3.2 million records that can be searched or browsed by various interfaces including a Journal/ Volume/ Page Service, Table of Contents...