Quartz Rheology and Short-time-scale Crustal Instabilities

Regenauer‐Lieb, Klaus; Yuen, David A.

doi:10.1007/978-3-7643-7992-6_12

Cited by 4 publications

(7 citation statements)

References 33 publications

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“…The depth extent of rupture in large continental earthquakes is found to be limited in the temperature regime approximately by the 570 K isotherm (STREHLAU, 1986). This is well within the estimated (REGENAUER-LIEB and YUEN, 2006; range of onset of creep between 450 and 500 degrees K for quartz. The far-reaching concept that the earthquake mechanism is possibly rooted in the ductile realm was first introduced in the classical work of HOBBS et al Natural expressions of these instabilities can be found in geological field evidence, which includes paleo-earthquakes, ice-quakes, landslides, pseudotachylytes found in fault zones and the phenomenon of grain-size reduction, and laboratory evidence for different types of faulting.…”

Section: Instabilities and Their Natural Expressionsupporting

confidence: 59%

Landslides, Ice Quakes, Earthquakes: A Thermodynamic Approach to Surface Instabilities

Regenauer-Lieb

Yuen

Fußeis

2009

Pure appl. geophys.

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The total rate of rock deformation results from competing deformation processes, including ductile and brittle mechanisms. Particular deformation styles arise from the dominance of certain mechanisms over others at different ambient conditions. Surprisingly, rates of deformation in naturally deformed rocks are found to cluster around two extremes, representing coseismic slip rates or viscous creep rates. Classical rock mechanics is traditionally used to interpret these instabilities. These approaches consider the principle of conservation of energy. We propose to go one step further and introduce a nonlinear far-from-equilibrium thermodynamic approach in which the central and explicit role of entropy controls instabilities. We also show how this quantity might be calculated for complex crustal systems. This approach provides strain-rate partitioning for natural deformation processes occurring at rates in the order of 10 -3 to 10 -9 s -1 . We discuss these processes using examples of landslides and ice quakes or glacial surges. We will then illustrate how the mechanical mechanisms derived from these near-surface processes can be applied to deformation near the base of the seismogenic crust, especially to the phenomenon of slow earthquakes.

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Section: Instabilities and Their Natural Expressionsupporting

confidence: 59%

Landslides, Ice Quakes, Earthquakes: A Thermodynamic Approach to Surface Instabilities

Regenauer-Lieb

Yuen

Fußeis

2009

Pure appl. geophys.

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“…Idealised Necking Lithosphere The purpose of this analysis is to illustrate the effects of creep damage and shear heating on localisation. Reference [151] proposed a simple numerical model of a notched lithospheric layer in extension (see Fig. 24).…”

Section: The Roles Of Shear Heating and Damage In Anmentioning

confidence: 99%

Multiscale coupling and multiphysics approaches in earth sciences: Applications

Regenauer‐Lieb¹,

Veveakis²,

Poulet³

et al. 2013

j coupled syst multiscale dyn

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Geoscientists are confronted with the challenge of assessing nonlinear phenomena that result from multiphysics coupling across multiple scales from the quantum level to the scale of the earth and from femtosecond to the 4.5 Ga of history of our planet. We neglect in this review electromagnetic modelling of the processes in the Earth's core, and focus on four types of couplings that underpin fundamental instabilities in the Earth. These are thermal (T), hydraulic (H), mechanical (M) and chemical (C) processes which are driven and controlled by the transfer of heat to the Earth's surface. Instabilities appear as faults, folds, compaction bands, shear/fault zones, plate boundaries and convective patterns. Convective patterns emerge from buoyancy overcoming viscous drag at a critical Rayleigh number. All other processes emerge from non-conservative thermodynamic forces with a critical critical dissipative source term, which can be characterised by the modified Gruntfest number Gr. These dissipative processes reach a quasi-steady state when, at maximum dissipation, THMC diffusion (Fourier, Darcy, Biot, Fick) balance the source term. The emerging steady state dissipative patterns are defined by the respective diffusion length scales. These length scales provide a fundamental thermodynamic yardstick for measuring instabilities in the Earth. The implementation of a fully coupled THMC multiscale theoretical framework into an applied workflow is still in its early stages. This is largely owing to the four fundamentally different lengths of the THMC diffusion yardsticks spanning micro-metre to tens of kilometres compounded by the additional necessity to consider microstructure information in the formulation of enriched continua for THMC feedback simulations (i.e., micro-structure enriched continuum formulation). Another challenge is to consider the important factor time which implies that the geomaterial often is very far away from initial yield and flowing on a time scale that cannot be accessed in the laboratory. This leads to the requirement of adopting a thermodynamic framework in conjunction with flow theories of plasticity. This framework allows, unlike consistency plasticity, the description of both solid mechanical and fluid dynamic instabilities. In the applications we show the similarity of THMC feedback patterns across scales such as brittle and ductile folds and faults.

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“…The rich spatial patterns developing out of an originally unpatterned state are typical for thermodynamic feedback. The 500K case, in particular, is accompanied by a dynamic pattern of creep/plastic slip events, which could throw a light on the dynamic events underlying the source region of major earthquakes such as the recent Sumatra event [15]. Only the final pattern after extension is shown.…”

Section: Resultsmentioning

confidence: 99%

Non-equilibrium Thermodynamics, Thermomechanics, Geodynamics

Regenauer‐Lieb

Hobbs

Ord

et al. 2007

Computational Science – ICCS 2007

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Abstract. The subject of non-equilibrium thermodynamics is now quite old, dating back to Prigogine, Biot and Truesdell in the 1950's and 1960's. It has had a resurgence in the physical sciences in the past five years largely due to a consolidation of ideas on thermodynamics as a whole and to advances in computer speeds. Non-equilibrium thermodynamics has now advanced to a stage where it forms an umbrella approach to understanding and modelling coupled phenomena in Earth Sciences. Currently, approaches are pioneered independently in geodynamics, seismology, material sciences (solid mechanics), atmospheric and marine sciences (fluid dynamics) and the chemical sciences. We present a first attempt at consolidating some ideas and show a simple example with potential significance for geodynamics, structural geology and seismology.

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Quartz Rheology and Short-time-scale Crustal Instabilities

Cited by 4 publications

References 33 publications

Landslides, Ice Quakes, Earthquakes: A Thermodynamic Approach to Surface Instabilities

Landslides, Ice Quakes, Earthquakes: A Thermodynamic Approach to Surface Instabilities

Multiscale coupling and multiphysics approaches in earth sciences: Applications

Non-equilibrium Thermodynamics, Thermomechanics, Geodynamics

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