The Earth's magnetic field varies on many time scales, waxing and waning in strength, and periodically completely reversing direction. The geologic record of these variations provides important information on the history of our planet. Join Scripps Oceanography geoscientist Jeff Gee for a fascinating glimpse into his fieldwork in paleomagnetism -- from autonomous aircraft measurements over the open ocean to exploration of rock exposures in remote regions of Antarctica. Series: Perspectives on Ocean Science [8/2010] [Science] [Show ID: 19203]