In this captivating episode, Dr. Tarduno delves into the mysteries of Earth's inner core, its structure, and how it began to crystallize. Through the lens of paleomagnetism, we explore the evolution of Earth's magnetic field, deciphering changes in its strength and understanding how these shifts provide clues about the core's history. Dr. Tarduno presents intriguing findings from single crystal paleointensity studies of early Cambrian anorthosites, which reveal a rapid resurgence of the magnetic field following a period of ultralow field strength in the Ediacaran Era. This dramatic shift pinpoints the inner core nucleation to around 550 million years ago. Further thermal modeling based on this age suggests the inner core had grown to half its present size by approximately 450 million years ago. Delving deeper, we discuss how seismic anisotropy within the inner core might reflect the development of global deep mantle structures, leaving an indelible imprint on our planet. Join us as we journey to the center of the Earth and back.

Key Words: Inner Core, Paleomagnetism, Earth's Magnetic Field, Core Crystallization, Anorthosites, Inner Core Nucleation, Thermal Modeling, Seismic Anisotropy, Deep Mantle Structure, Earth's Geodynamo, Ediacaran Period, Cambrian Period.

Zhou, T., Tarduno, J.A., Nimmo, F. et al. Early Cambrian renewal of the geodynamo and the origin of inner core structure. Nat Commun 13, 4161 (2022). https://doi.org/10.1038/s41467-022-31677-7