Animations of Various Geomagnetic Field Components over 0-100 ka

Earth's magnetic field is generated in the fluid outer core by a self-sustaining dynamo process. Paleomagnetic records from a range of sediments and lava flows have been used to study the magnetic field changes from decadal to millennial timescales, and provide a solid foundation for the global, time-dependent (0-100 ka), spherical harmonic field models. Using the time-varying paleofield model, GGF100k, we predict rates of change in the geomagnetic field on a global grid for the past 100 kyr. Using Python, we created a snapshot every 10 years on several projections to produced animations of the time-varying model in order to visualize changes in the magnetic field for the past 100 ka. The rate of change in intensity of the magnetic field, direction, and the vertical component of the field provide differing perspectives of changes over time at Earths surface. The change in magnetic field intensities range from a maximum of 54.58 nT per year to a minimum of -54.58 nT per year with some areas that experienced no change. The median value of intensity change was 6.14 nT per year with a similar mean value of 7.88 nT per year. Directional changes in the magnetic field had a range of values from 0 to 1.42 degrees per year, with a median value of 0.009 degrees per year with a slightly larger mean value of 0.26 degrees per year. Analyzing the array of values of the directional change and change in magnetic field intensity we defined large values as greater than 0.1 degrees and 35 nT per year, respectively. Large changes in intensities were concentrated at mid to high latitudes. Positive changes in intensities favored the southern hemisphere while negative changes were dispersed more evenly. In contrast, larger directional changes in the magnetic field are located closer to the equator with a bias towards the southern hemisphere. The resulting animations provided a 100,000 year visualization from Earths surface to the core-mantle boundary including the global event known as the Laschamp excursion (~41 ka).