Joint modeling of lithosphere and mantle dynamics elucidating lithosphere‐mantle coupling

Ghosh, A.; Holt, W. E.; Wen, Lianxing; Haines, A. J.; Flesch, L. M.

doi:10.1029/2008gl034365

Cited by 52 publications

(125 citation statements)

References 16 publications

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“…Deriving all force contributions from a single calculation resolves any inconsistency that might arise from treating individual force contributions to the stress field separately, as has been done in earlier studies (Bird et al, 2008;Steinberger et al, 2001;Lithgow-Bertelloni and Guynn, 2004;Ghosh et al, 2008;Naliboff et al, 2012;Ghosh et al, 2013;Wang et al, 2015).…”

Section: Introductionmentioning

confidence: 92%

Effects of upper mantle heterogeneities on lithospheric stress field and dynamic topography

Tutu¹,

Steinberger²,

Sobolev³

et al. 2017

Preprint

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Abstract. The orientation and tectonic regime of the observed crustal/lithospheric stress field contribute to our knowledge of different deformation processes occurring within the Earth's crust and lithosphere. In this study, we analyze the influence of the thermal and density structure of the upper mantle on the lithospheric stress field and topography. We use a 3D lithosphereasthenosphere numerical model with power-law rheology, coupled to a spectral mantle flow code at 300 km depth. Our results are validated against the World Stress Map 2016 and the observation-based residual topography. We derive the upper mantle 5 thermal structure from either a heat flow model combined with a sea floor age model (TM1) or a global S-wave velocity model (TM2). We show that lateral density heterogeneities in the upper 300 km have a limited influence on the modeled horizontal stress field as opposed to the resulting dynamic topography that appears more sensitive to such heterogeneities. There is hardly any difference between the stress orientation patterns predicted with and without consideration of the heterogeneities in the upper mantle density structure across North America, Australia, and North Africa. In contrast, we find that the dynamic 10 topography is to a greater extent controlled by the upper mantle density structure. After correction for the chemical depletion of continents, the TM2 model leads to a much better fit with the observed residual topography giving a correlation of 0.51 in continents, but this correction leads to no significant improvement in the resulting lithosphere stresses. In continental regions with abundant heat flow data such as, for instant, Western Europe, TM1 results in relatively a small angular misfits of 18.30

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Section: Introductionmentioning

confidence: 92%

Effects of upper mantle heterogeneities on lithospheric stress field and dynamic topography

Tutu¹,

Steinberger²,

Sobolev³

et al. 2017

Preprint

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show abstract

“…An alternative method documented in the literature is to compare the strain rate estimated from the modeled deviatoric stresses (Ghosh et al, 2008) with the Global Strain Rate Map (Kreemer et al, 2003). However, the lithospheric stress in plate interiors (i.e., far from the plate boundaries) is not well constrained with the Global Strain Rate Map.…”

mentioning

confidence: 99%

“…On the one hand, Bird et al (2008) have estimated the lithospheric stress from a model that disregards the mantle flow contribution and used the fit between modeled and observed plate velocities as a sole criterion. On the other hand, Ghosh et al (2013), Ghosh and Holt (2012), Lithgow-Bertelloni and Guynn (2004), Steinberger et al (2001) and Wang et al (2015) have aimed at assessing the influence of mantle flow on the lithospheric stress field and have shown that the bulk mantle flow explains a large part (about 80-90 %) of the stress field accumulated in the lithosphere (Steinberger et al, 2001), in both magnitude and the most compressive horizontal direction. The aim of the present study is to evaluate the contribution of the upper mantle density and viscosity heterogeneities above the transition zone to the observed spatial stress regimes of the lithosphere (Heidbach et al, 2016), while testing different approaches and data sets used to describe the thermal and rheological structure of the upper mantle and the crust.…”

mentioning

confidence: 99%

“…Ghosh and Holt (2012) and Steinberger et al (2001) used different approaches to show that the contribution of the crust (shallow density structures) to the overall lithospheric stress pattern is rather small compared to that of the mantle buoyancy forces, amounting to ∼ 10 %, except for regions characterized by high altitudes, especially the Tibetan Plateau, where the contribution is larger. In these previous modeling studies, the effect of the crust was determined separately by computing the gravitational potential energy from a crust model, which was subsequently applied as a correction (Steinberger et al, 2001;Ghosh et al, 2013;Ghosh and Holt, 2012). The contribution of the crust with a shallow lithospheric density contrast generates the second-order pattern (mid-to-short wavelength) in the stress field, mostly coming from topography and crustal isostasy (Zoback, 1992;Zoback and Mooney, 2003;Bird et al, 2006).…”

mentioning

confidence: 99%

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Effects of upper mantle heterogeneities on the lithospheric stress field and dynamic topography

et al. 2018

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Abstract. The orientation and tectonic regime of the observed crustal/lithospheric stress field contribute to our knowledge of different deformation processes occurring within the Earth's crust and lithosphere. In this study, we analyze the influence of the thermal and density structure of the upper mantle on the lithospheric stress field and topography. We use a 3-D lithosphere-asthenosphere numerical model with power-law rheology, coupled to a spectral mantle flow code at 300 km depth. Our results are validated against the World Stress Map 2016 (WSM2016) and the observationbased residual topography. We derive the upper mantle thermal structure from either a heat flow model combined with a seafloor age model (TM1) or a global S-wave velocity model (TM2). We show that lateral density heterogeneities in the upper 300 km have a limited influence on the modeled horizontal stress field as opposed to the resulting dynamic topography that appears more sensitive to such heterogeneities. The modeled stress field directions, using only the mantle heterogeneities below 300 km, are not perturbed much when the effects of lithosphere and crust above 300 km are added. In contrast, modeled stress magnitudes and dynamic topography are to a greater extent controlled by the upper mantle density structure. After correction for the chemical depletion of continents, the TM2 model leads to a much better fit with the observed residual topography giving a good correlation of 0.51 in continents, but this correction leads to no significant improvement of the fit between the WSM2016 and the resulting lithosphere stresses. In continental regions with abundant heat flow data, TM1 results in relatively small angular misfits. For example, in western Europe the misfit between the modeled and observation-based stress is 18.3 • . Our findings emphasize that the relative contributions coming from shallow and deep mantle dynamic forces are quite different for the lithospheric stress field and dynamic topography.

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“…Few studies have tried to address this question by modelling both sources [69][70][71][72][73][74] . These studies showed that coupling depends on the viscosity variations.…”

Section: Forces Driving Plate Tectonicsmentioning

confidence: 99%

Understanding Deep Earth Dynamics:A Numerical Modelling Approach

Singh¹,

Agrawal²,

Ghosh³

2017

Current Science

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Enhancement in computing power and better data availability have paved the way for deciphering the earth's deeper dynamics and have provided viable explanations for various surface phenomena. Tools such as seismic tomography, numerical modelling and geophysical observations such as stresses, gravity anomalies, heat flow, etc. have helped us in addressing the mechanisms of plate driving forces, anomalous geoid variations, cratonic stability, topographic support, intraplate earthquakes and similar outstanding issues in geodynamics. Due to lack of direct observations from deep earth, numerical modelling has aided considerably in learning about subsurface processes. With better algorithms being developed everyday, it is the right time to tap their potential to push the frontiers of human knowledge.

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Joint modeling of lithosphere and mantle dynamics elucidating lithosphere‐mantle coupling

Cited by 52 publications

References 16 publications

Effects of upper mantle heterogeneities on lithospheric stress field and dynamic topography

Effects of upper mantle heterogeneities on lithospheric stress field and dynamic topography

Effects of upper mantle heterogeneities on the lithospheric stress field and dynamic topography

Understanding Deep Earth Dynamics:A Numerical Modelling Approach

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