Geophysics is the application of physics, chemistry, and mathematics to the problems and processes of the earth, from its innermost core to its outermost environs in space. Fields within geophysics include the atmospheric sciences; geodesy; geomagnetism and paleomagnetism; hydrology; oceanography; planetology; seismology; solar-planetary relationships; tectonophysics; and volcanology, geochemistry, and petrology. This booklet, designed to serve as an introduction to geophysics for high school students, provides descriptions of each of the fields as well as brief comments on careers in geophysics. (JN)