Multiscale coupling and multiphysics approaches in earth sciences: Theory

Abstract

Measuring Earth material behaviour on time scales of millions of years transcends our current capability in the laboratory. We review an alternative path considering multiscale and multiphysics approaches with quantitative structure-property relationships. This approach allows a sound basis to incorporate physical principles such as chemistry, thermodynamics, diffusion and geometry-energy relations into simulations and data assimilation on the vast range of length and time scales encountered in the Earth. We identify key length scales for Earth systems processes and find a substantial scale separation between chemical, hydrous and thermal diffusion. We propose that this allows a simplified two-scale analysis where the outputs from the micro-scale model can be used as inputs for meso-scale simulations, which then in turn becomes the micro-model for the next scale up. We present two fundamental theoretical approaches to link the scales through asymptotic homogenisation from a macroscopic thermodynamic view and percolation renormalisation from a microscopic, statistical mechanics view.

Thermo‐poro‐mechanics of chemically active creeping faults: 3. The role of serpentinite in episodic tremor and slip sequences, and transition to chaos

“…Within the framework of the solid mechanical instabilities, this thickness emerges as a solution depending on the microstructure [ Muhlhaus and Vardoulakis , ; Papanicolopulos and Veveakis , ], as well as the hydraulic and thermal ambient conditions [ Sulem et al , ; Veveakis et al , , ]. In the field, these solid mechanical failure instabilities extend the laboratory‐scale derivations of centimeter‐thick shear bands, appearing as meter‐wide fault zones [ Regenauer‐Lieb et al , ].…”

Conditions for the localisation of plastic deformation in temperature sensitive viscoplastic materials

“…These concepts gave rise to the proposition of an energy based localisation theory in which instabilities emerge when the mechanical input rate rises significantly leading to a departure from the near isothermal limit towards the near adiabatic limit [Cherukuri and Shawki 1995b;1995a]. Since the energy equation can provide information about the time evolution of the system, this regime has been extensively studied in earth sciences [Regenauer-Lieb et al 2013a;Regenauer-Lieb et al 2013b] for one-dimensional failure patterns seen in landslides [Veveakis et al 2007] and fault mechanics [Veveakis et al 201 0].…”

Worldwide Status of CCUS Technologies and Their Development and Challenges in China

“…In addition, key to success in site selection for any such a project demands strict considerations of safety, economy, environment, and public acceptance at all levels of operation, that is, countrywide, basin-wide, regional, or subbasin levels [22][23][24][25][26], Figure 2. Although CCS and CCUS technologies share similarities in site selection, each will induce a series of different physical and chemical responses in the underground porous or fractured rock formations, in terms of the existing local hydrological (H), thermal (T), mechanical (M), and chemical (C) fields [27][28][29], Figure 2. Coupling of the THMC processes during and after CO 2 injection related to CCS and CCUS technologies has become a research hotspot in recent years [26,[30][31][32][33].…”