High Quality Content by WIKIPEDIA articles! Xavier Le Pichon (born June 18, 1937) is a French geophysicist. Among many other contributions, he is known for his comprehensive model of plate tectonics (1968). He is professor at the Collège de France. Geophysics, a major discipline of the Earth sciences and a subdiscipline of physics, is the study of the whole Earth by the quantitative observation of its physical properties. Geophysical data are used in academics to observe tectonic plate motions, study the internal structure of the Earth, supplement data provided by geologic maps, and to nondestructively observe shallow deposits.