Figure 9-21: Simulations of Earth’s Magnetic Dynamo Running for almost three months, a supercomputer was used to simulate the complex behavior of Earth’s liquid iron core and the magnetic field it produces. During the simulation, the computed magnetic field spontaneously flipped, consistent with reversals by Earth’s magnetic field. (a) Blue indicates magnetic field lines pointed toward Earth, as they do today at our north magnetic pole. (b) The field has reversed. (c) During field reversals, which can take a few thousand years to complete, the magnetic field structure can be very complicated.
(a, b, and c: The computer model was developed and run by Gary A. Glatzmaier [University of California, Santa Cruz] and Paul H. Roberts [University of California, Los Angeles])