This book introduces the new interdisciplinary fields of geochemical mechanics and applied geochemical mechanics, which form the foundation of data‑driven and neural‑network‑based approaches to earthquake prediction. Applied geochemical mechanics encompasses (1) micro‑petrography of silicate nanoparticles and kinetic models of their formation, which are related to short‑term void formation by slow to fast earthquake processes in the crust and mantle; (2) fracture cascades in rocks, governing various fragment‑size distributions, fragment geometry, and water–rock interactions; (3) rock fractography, based on experimental characterization of fracture‑surface geometries produced by shear crack and open crack formation; (4) fragment geometry analysis, a new method for classifying fragments produced by various fracturing and coagulation processes in rocks and minerals; and (5) extrusion processes of mantle‑derived fractured rocks, which contain diverse fragments and powdered matrices with aqueous fluids—phenomena analogous to debris flows and rockslides at Earth’s surface.

These topics are closely connected to data‑driven geoscience applications involving earthquakes, volcanic eruptions, active faults, and subduction processes, as well as engineering challenges related to rockslides, debris flows, rock basement stability, rockfill dams, tunnel engineering, and coastal foundation systems.

Furthermore, the book presents a comprehensive model of plate boundary metamorphism, spanning vast spacetime scales—from milliseconds to tens of millions of years, and from nanometer‑scale particles to hundred‑kilometer‑scale mantle and continental rocks.

These findings and newly developed models provide insight into global and regional correlated seismicity, governed strongly by Earth’s rotation rate and fluid–Earth zonal‑flow dynamics. They suggest that recent increases in correlated seismicity may be linked to global atmospheric and geomagnetic changes observed by geophysical monitoring networks. The book also considers the possibility that large‑scale volcanic eruptions, such as the Tonga–Hunga event, may be associated with variations in Earth’s rotation and correlated seismicity rates.

Overall, this book provides readers with up‑to‑date perspectives on the fundamentals of geochemistry‑related mechanics, especially, of small to large shear cracks related to the seismicity in the Earth’s crust and mantle, extrusion of deep‑seated rock masses, fracture mechanics combined with fragment geometry analysis, and nanoparticle mineral formation in various rocks.

Mitsuhiro Toriumi is a senior researcher at the Japan Agency for Marine‑Earth Science and Technology. He has served as Director of the Institute for Frontier Research on Earth Evolution and of the Division of Earth, Ocean, and Life at the Japan Agency for Marine‑Earth Science and Technology. He previously held academic positions as Professor at the Graduate School of Frontier Sciences, University of Tokyo (Kashiwa Campus, 1999–2010), Professor at the Faculty of Science, University of Tokyo (1985–1999), Associate Professor at the Faculty of Science, Ehime University (1977–1985), and Assistant Professor at the Faculty of Science, University of Tokyo (1973–1976). He has published extensively on metamorphic petrology and structural geology of plate‑boundary zones worldwide; data‑driven and deep neural‑network modeling; and experimental rheology of olivine and plagioclase in the mantle and crust conditions. His research interests include physical modeling of ductile and brittle deformation, mineral–water reactions, crystal growth, fragmentation processes, seismicity dynamics, and nonlinear dynamical systems within the Earth’s interior.He holds both a DSc and MSc from the University of Tokyo.