The best spots to find out what's happening beneath Earth's crust are the midocean ridges, where gooey molten rock spills from gashes in the sea floor, says geologist Charles Langmuir: "The series of ocean ridges are like a window into Earth's interior." One place to peer through that window is PetDB, a 3-year-old collection of rock chemistry measurements compiled by Langmuir and colleagues at Columbia's Lamont-Doherty Earth Observatory. Gleaned from the literature, the data record the geochemical composition of more than 30,000 samples taken from ocean-ridge locations around the world (above, the junction of the Pacific and Antarctic plates). You can search the database by expedition, location, ocean or sea, type of topography, or chemical characteristics such as isotope ratios. Along with the sample's chemical profile, the output provides the exact coordinates, sampling technique, and the original reference.
petdb.ldeo.columbia.edu/petdb
