Speaker: Jessica Irving from Princeton Univerisy

Title:" Earth’s cores: variation across the length-scales"

Abstract: Earth’s core, the deepest region of our planet, stores heat used for plate tectonics and generates Earth’s magnetic field, yet details of its nature remain uncertain. The composition of the inner core, and the outer core from which it is slowly crystallizing, is not fully known, though it controls physical processes at work in the deep Earth. The outer core is thought to be well-mixed for the most part, but may contain stratified layers at its boundaries. The slowly growing inner core exhibits seismic heterogeneity at a variety of length-scales, ranging over more than two orders of magnitude. Both short period body-wave data, comprising seismic waves which travel through the inner and outer core, and long period normal mode frequencies, corresponding to vibrations of the whole Earth, can be used to enhance our understanding of both the inner core and the outer core.

This talk will address a variety of the seismological features which are present in the core, from the radially varying velocity and density of the outer core, through to the possibility of “hemispherical” differences in anisotropic texture and smaller scale variation in the inner core.[Background reading]