20. Jules Brunhes

Jules Brunhes was a French geologist born in 1867, best known for his work in paleomagnetism, which studies Earth's magnetic field in rocks. He proposed that the Earth's magnetic poles could reverse over time, a concept now known as geomagnetic reversal. Brunhes' research laid the groundwork for understanding the Earth's magnetic history and its implications for geology and paleontology. His most significant contribution is the Brunhes-Matuyama boundary, marking the transition between two magnetic polarity epochs. This work helps scientists understand the planet's geological processes and has implications for dating geological formations. Brunhes passed away in 1910.