A P wave velocity model of Earth's core

Present Earth core models derived from the retrieval of global Earth structure are based on absolute travel times, and/or free-oscillation eigenfrequencies. Many core phase data are left out of these constructions. This study is an attempt to utilize the additional information to construct a model of core P wave velocity which is consistent with the different types of core phase data available. A one-dimensional P wave velocity model of the core, PREM2, is proposed. This model, modified from the Preliminary Reference Earth Model (Dziewonski and Anderson, 1981), shows a better fit to the combined data set than any of the existing core models. Major features of the model include a sharp velocity discontinuity at the inner core boundary, with a large jump (0.78 km/s), and a low velocity gradient at the base of the fluid core. -from Authors