UBEICH · Unravelling the first Babbles of the Earth Inner Core History

The existence of Earth's inner core was a major discovery almost a century ago, and since then the timing of its nucleation remains highly debated. This major event in the Earths history enhanced the energy necessary to maintain the magnetic field to the present-day, making our planet habitable. Earth has thus escaped the fate of planets like Mars that lost its protective shield. While the community agreed to place the inner core formation at ~600 million years ago in the Ediacaran Period, new evidence of a change in the Earths magnetic field regime during the Mid-Paleozoic (416332 Ma) challenge this hypothesis: Can we better constrain the Earth inner core history? UBEICH will tackle this issue with a new kind of experimental data describing the long-term evolution of the Earths dynamo strength. In paleomagnetism, the conventional approaches fail to retrieve ancient magnetic signal from old rocks due to their weathering along their complex geological history. To this end, I will develop a promising but challenging multispecimen-single crystal paleointensity. This pioneering approach can significantly increase the number of observations by extracting the magnetic signal from the protected nanometric magnetic inclusion in silicate crystals with the multispecimen technique developed for other purposes. By providing challenging-to-obtain but theoretically reliable data, UBEICH has the ambition to bring a new light on the deep Earth history between 1.1 and 0.3 billion years by unravelling the inner core nucleation. Far-reaching implications beyond the Earths evolution and the origin of the magnetic field are expected, with new clues about the planetary core evolution of all rocky planets to understand the relationships between thermal evolution, dynamo, and planet habitability. This is of paramount importance at a time where amateur astronomers and scientists are discovering many new exoplanets, and especially super-Earth located in the Habitable Zone of their star.