报告题目：What is powering the Earth's Engine?

报 告 人：Bill McDonough (Earth Sciences & Res Center Neutrino Sci, Tohoku University, Geology, University of Maryland)

报告时间：2024-03-28 14:30

报告地点：理科楼C302

报告摘要：The fuel driving plate tectonics, volcanoes, mantle convection, and the Earth’s magnetic field comes from two sources: primordial energy from assembling the planet and nuclear energy from the heat produced during natural radioactive decay. Various models with widely varying estimates have been proposed as to how much primordial and nuclear fuel remains inside Earth. However, teams of geologists and neutrino physicists are boldly claiming that the new field of Neutrino Geophysics can determine how much nuclear fuel (i.e., radioactive power) remains in the Earth’s tank. For the last two decades neutrino physicists have been detecting low energy (MeV) electron anti-neutrino being emitted from the Earth (geoneutrinos), produced via beta minus radioactive decay of U and Th. Collectively, the flux of geoneutrinos measured at detectors in Japan and Italy, soon a report from Canada, and in 2026 data from China reveal the radiogenic power driving the Earth’s engine. These data will define the compositional model of the Earth, place tight constraints on its thermal evolution, and independently confirm the planets chondritic ratio of refractory elements.

报告人简介：William F. McDonough is a Professor at University of Maryland. He obtained his PhD degree in 1988 from Australian National University. From 1987-1989, his was an Alexander Von Humboldt Fellow at Max-Planck-Institute. After that, he was a Research Fellow at the Australian National University Research School of Earth Science from 1989 to 1994. He then became a lecturer at Boston University at 1995. From 1994 to 2000, he was a Research Associate at Harvard University. From 2000 to 2005, he was an Associate Professor at Department of Geology of University of Maryland, and has been a Professor there since 2005. During 2010-2018, he was also an Affiliate Professor at Department of Chemistry and Biochemistry of University of Maryland. From 2017 to present, he has been a Professor in International Joint Graduate Programs in Earth and Environmental Sciences and Physics of the Origin and Formation of the Universe, at Tohoku University. He became a Guest Professor at China University of Geosciences (Wuhan) at 2011.

Professor McDonough was the President of the Volcanology Geochemistry Petrology Section, American Geophysical Union. His dominant research theme is to understand the composition, structure and evolution of the Earth and the other terrestrial planets. Chemical and isotopic studies of terrestrial and meteoritic samples provide insights into the timing and details of the various differentiation processes occurring in planetary domains including radioactively produced energy differentiating and powering 3 reservoirs of the Earth (i.e., the core, the mantle-crust system, and the atmosphere-hydrosphere system).

Professor McDonough expertises in analytical instrumentation and neutrino geoscience. Working with geologists, biologist, chemists, physicists and members of the US intelligence community, he uses laser ablation systems and plasma mass spectrometers for the chemical and isotopic analyses of samples. He is developing and improving upon methods of modeling and detecting the Earth’s geoneutrino (electron antineutrino) flux and anti-neutrino detection for nuclear monitoring. He provides chemical and isotopic data that constrain geological processes and data for forensics, nuclear chemistry and archaeology with his students.