Earth's magnetic field is generated by convective motion in the liquid iron outer core, commonly referred to as the geodynamo.  The magnetic field has been protecting Earth from harmful charged particles for at least the last 2.5 billion years, and possibly longer.  In this talk Dr. Driscoll will discuss the physical mechanisms that produce the geomagnetic field, conduct a brief survey of planetary magnetism, and explore Earth’s rich paleomagnetic history preserved in ancient rocks, including polarity reversals, superchrons, paleointensity, and the impact of the solidification of the inner core.  He will highlight the pioneering contributions from the Department of Terrestrial Magnetism on early studies of geomagnetism.

Dr. Peter Driscoll: Staff Scientist, Department of Terrestrial Magnetism, Carnegie Institution for Science