Characteristic time of thermal and diffusional relaxation

Aryasova, Olga; Khazan, Ya. M.

doi:10.24028/gzh.0203-3100.v37i6.2015.111174

Cited by 4 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…lithospheric-drip, delamination, or slab break-off), bringing hotter asthenosphere to shallow depths, thereby weakening the overlying orogenic lithosphere [10][11][12] . Time scales to relax the heat anomaly from such upwelling vary in a range from 8 Myrs up to 22 Myrs 13 . This entails that their influence is likely to be diffused within only a few 10's Myrs.…”

Section: Mainmentioning

confidence: 99%

Stable equilibrium dynamics explains continental lithosphere deformation

Kumar

Cacace

Scheck‐Wenderoth

2023

Preprint

View full text Add to dashboard Cite

Plate tectonics theory postulates the existence of rigid mobile plates, however, what defines and controls their internal deformation, particularly within continents, is not well understood. Using data-driven thermomechanical modelling of the Alpine Himalayan Collision Zone, we hypothesize that deviations from an equilibrium state between mantle dynamics, plate-boundary forces, and the thermochemical configuration of the lithosphere controls continental deformation. The balance between the plate’s internal energy and tectonic forces is quantified by a critical crustal thickness that matches the global average of present-day continental crust. Thicker intraplate domains than the critical crust (orogens) undergo weakening due to their increased internal energy, and dissipate their acquired energy within diffused zone of deformation, unlike the localized deformation seen along plate boundaries. This dissipative evolution is controlled by the feedback between thermal and mechanical relaxation of the out of balance energy in the orogenic lithosphere. Potential runaway instabilities, exponentially growing oscillations, are efficiently dampened by enhanced dissipation from radioactive heat sources. This ultimately drives orogens with their thickened radiogenic crust towards a final equilibrium state. Our results suggest a genetic link between the thermochemical state of the crust and the tectonic evolution of silicate Earth-like planets.

show abstract

Section: Mainmentioning

confidence: 99%

Stable equilibrium dynamics explains continental lithosphere deformation

Kumar

Cacace

Scheck‐Wenderoth

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…As pointed out in [33], the initial state distribution affects the predictions only during a time of the same order as the characteristic diffusion time (depending on diffusivity and the thickness of the wall). For an expected thermal diffusivity k comprised in interval 10 −8 m 2 s −1 to 10 −7 m 2 s −1 , and for the wall thickness e = 22 cm, the characteristic diffusion time (including a factor corrector as suggested in [39]) is estimated following Equation ( 7):…”

Section: On the Choice Of Models And Approaches For Infield Thermal P...mentioning

confidence: 99%

Assessment of the Usability of Some Bio-Based Insulation Materials in Double-Skin Steel Envelopes

et al. 2022

View full text Add to dashboard Cite

In this paper, a double-skin steel building-demonstrator, set up using panels of five bio-based insulators and a classical mineral insulating material, is studied. The panels used in the demonstrator are made from industrially manufactured and commercialized bio-materials. To assess the suitability of these panels for use in cold formed steel envelope buildings, their advantages and/or the drawbacks (if any) of the synchronized records of temperatures, relative humidity and thermal flux of each panel are obtained using a system of continuous measurements. Data from 6 months of records in the roof of the demonstrator are used to assess the infield properties of the panels and the seasonal evolution of these properties in relation to the presence of the vapor barrier. The thermal resistance of each panel is determined from these data using two methods: the ISO 9869-1:2014 based on the Heat Flow Meter (HFM) method and an inverse problem identification method. All bio-sourced panels manifest higher thermal resistance than the classical insulation system, whatever conditions of use with or without barrier vapor. The seasonal variations of thermal properties are attenuated when a vapor barrier is used. No risk for water condensation inside the bio-insulations is revealed so far.

show abstract

“…lithospheric-drip, delamination, or slab break-off), bringing hotter asthenosphere to shallow depths, thereby weakening the overlying orogenic lithosphere (Bird 1979;Houseman and Molnar 1997; Huw Davies and von Blanckenburg 1995). Time scales to relax the heat anomaly from such upwelling vary in a range from 8 Myrs up to 22 Myrs (Aryasova and Khazan 2015). This entails that their in uence is likely to be diffused within only a few 10's Myrs.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics of continental deformation

Kumar,

Cacace,

Scheck-Wenderoth

2023

Preprint

View full text Add to dashboard Cite

Plate tectonics theory postulates the existence of rigid mobile plates. However, what defines and controls their internal deformation, particularly within continents, is not yet fully understood. Using data-driven thermomechanical modelling of the Alpine Himalayan Collision Zone, we hypothesize that deviations from an equilibrium between mantle dynamics, plate-boundary forces, and thermochemical configuration of the lithosphere controls continental deformation. We quantify such balance between the internal energy of the plate and tectonic forces in terms of a critical crustal thickness, that match the global average of present-day continental crust. It follows that thicker intraplate domains than the critical crust (orogens) must undergo weakening due to their increased internal energy, and, in doing so, they dissipate the acquired energy within a diffused zone of deformation, unlike the localized deformation seen along plate boundaries. This evolution is controlled by a dissipative thermodynamic feedback loop between thermal and mechanical relaxation of the driving energy in the orogenic lithosphere. Exponentially growing energy states, leading to runaway extension are efficiently dampened by enhanced dissipation from radioactive heat sources. This ultimately drives orogens with their thickened radiogenic crust towards a final equilibrium state. Our results suggest a genetic link between the thermochemical state of crust and the tectonic evolution of silicate Earth-like planets.

show abstract

Characteristic time of thermal and diffusional relaxation

Abstract: It is shown that frequently used dimensional estimate of a layer thermal relaxation time, t r , as L 2 based on the layer thickness, L, and thermal diffusivity, κ, strongly overestimates t r . The correct estimate t r =L 2 2 should contain a factor of 1/π 2 which is of the order of 0.1.

Cited by 4 publications

References 3 publications

Stable equilibrium dynamics explains continental lithosphere deformation

Stable equilibrium dynamics explains continental lithosphere deformation

Assessment of the Usability of Some Bio-Based Insulation Materials in Double-Skin Steel Envelopes

Thermodynamics of continental deformation

Contact Info

Product

Resources

About