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Visualizing Strain Anisotropy in Mantle Flow Fields

H. Obermaier, M. I. Billen, H. Hagen, M. Hering-Bertram, B. Hamann
2011 Computer graphics forum (Print)  
anisotropy and the actual mantle flow field.  ...  The evolution of strain and development of material anisotropy in models of Earth's mantle flow convey important information about how to interpret the geometric relationship between observation of seismic  ...  A visualization technique for strain analysis in mantle flow fields should be able to convey the following key properties: • Display boundary and shape of strain volumes • Illustrate strain orientation  ... 
doi:10.1111/j.1467-8659.2011.02036.x fatcat:3bophuu67jg25n2gq2lliax5la

Mantle-flow diversion beneath the Iranian plateau induced by Zagros' lithospheric keel

Ayoub Kaviani, Meysam Mahmoodabadi, Georg Rümpker, Simone Pilia, Mohammad Tatar, Faramarz Nilfouroushan, Farzam Yamini-Fard, Ali Moradi, Mohammed Y. Ali
2021 Scientific Reports  
Our study reveals a complex pattern of seismic anisotropy that implies a similarly complex mantle flow field.  ...  We also examine the correlation between the pattern of seismic anisotropy, plate motion using GPS velocities and surface strain fields.  ...  keels results in a deflection of the mantle flow field 43 .  ... 
doi:10.1038/s41598-021-81541-9 pmid:33531534 fatcat:p2bpbz4f6za23iqrnr3exyslc4

Two-dimensional modelling of subduction zone anisotropy with application to southwestern Japan

Maureen D. Long, Bradford H. Hager, Maarten V. de Hoop, Rob D. van der Hilst
2007 Geophysical Journal International  
of thermal buoyancy forces and a temperature-dependent viscosity law) on the velocity and finite strain field in the mantle wedge.  ...  From the numerical flow models we construct models of anisotropy in the wedge by calculating the evolution of the finite strain ellipse and combining its geometry with appropriate elastic constants for  ...  Our approach takes the strain field and geometry of anisotropy obtained from purely 2-D flow models.  ... 
doi:10.1111/j.1365-246x.2007.03464.x fatcat:vzyfft5idjdlbfmb2jtjqnjzlq

Development of finite strain in the convecting lower mantle and its implications for seismic anisotropy

Allen K. McNamara, Peter E. van Keken, Shun-Ichiro Karato
2003 Journal of Geophysical Research  
Development of finite strain in the convecting lower mantle and its implications for seismic anisotropy,  ...  1] Seismological observations have revealed patches of seismic anisotropy in regions related to mantle upwelling and paleosubduction within an otherwise isotropic lower mantle.  ...  mantle by volume, we predict (Mg, Fe)O to play a larger role in anisotropy of the lowermost mantle.  ... 
doi:10.1029/2002jb001970 fatcat:jqhotgscyne25cw6h4gbtxgmmy

Mantle deformation during slow seafloor spreading constrained by observations of seismic anisotropy in the western Atlantic

James B. Gaherty, Daniel Lizarralde, John A. Collins, Greg Hirth, Sangmyung Kim
2004 Earth and Planetary Science Letters  
This fabric can be detected by seismic imaging, as it produces an azimuthal anisotropy in the velocity of seismic waves that propagate in the shallow mantle.  ...  By scaling our field observations to laboratory experiments, we estimate that total viscous strain during slow seafloor spreading is of order 0.5, as opposed to~1-2 for the fast-spreading case.  ...  In contrast, the 2h model implies that the upper-mantle fabric is rotated 16F48 relative to fossil spreading, which suggests a three-dimensional subaxial flow field with a component in the ridge-parallel  ... 
doi:10.1016/j.epsl.2004.10.026 fatcat:5eh6m5mwrfgqbozh6t6bjpusoq

Mantle flow under the western United States from shear wave splitting

2006 Earth and Planetary Science Letters  
Linked models of geodynamic flow and mineral alignment in the mantle provide a means to test the relationship between strain and the saturation of texturing.  ...  In general, our results show that seismic anisotropy, when interpreted jointly with mineral physics theories, may be used to quantitatively constrain the spatial character of flow, and the degree of force  ...  Gurnis and others involved in for sharing this code, W. Menke for providing his splitting routines, S. Chevrot for the help with kernel splitting intensity computations, B.  ... 
doi:10.1016/j.epsl.2006.05.010 fatcat:bdtldrezjzabfojdxomftuzlam

Dynamic models for mantle flow and seismic anisotropy in the North Atlantic region and comparison with observations

Gabriele Marquart, Harro Schmeling, Ondřej Čadek
2007 Geochemistry Geophysics Geosystems  
gravity field.  ...  From the modeled flow fields, lattice preferred orientations (LPO) of olivine are calculated.  ...  Our colleagues in the ''Frankfurt-Mainz Iceland Plume Working Group,''especially Wolfgang Jacoby and Peter Mihalffy, made essential contributions to this work through their interest and discussions.  ... 
doi:10.1029/2006gc001359 fatcat:sf5w6ovshbd2xlep4b3s5e7hva

Shear wave splitting along a nascent plate boundary: the North Anatolian Fault Zone

C. Berk Biryol, George Zandt, Susan L. Beck, A. Arda Ozacar, Hande E. Adiyaman, Christine R. Gans
2010 Geophysical Journal International  
We analysed the properties of the upper-mantle strain field and mantle anisotropy in the vicinity of NAFZ via splitting of SKS and SKKS phases.  ...  This is the first study that analyses the upper-mantle anisotropy in this region and our results indicate that the observed upper-mantle strain field is uniform underneath the array with consistent NE-SW  ...  In our study we attempt to constrain the direction of flow by linking the upper-mantle strain field to dynamics of the major tectonic elements of the region.  ... 
doi:10.1111/j.1365-246x.2010.04576.x fatcat:7e3pdfaiwzdl3ily7bs5bwhvmy

The role of rheology and slab shape on rapid mantle flow: Three-dimensional numerical models of the Alaska slab edge

M. A. Jadamec, M. I. Billen
2012 Journal of Geophysical Research  
In models using the composite viscosity, a laterally variable mantle viscosity emerges as a consequence of the lateral variations in the mantle flow and strain rate.  ...  1] Away from subduction zones, the surface motion of oceanic plates is well correlated with mantle flow direction, as inferred from seismic anisotropy.  ...  We thank Oliver Kreylos and the UC Davis Keck Center for Active Visualization in the Earth Sciences (Keck-CAVES) for enabling the incorporation 3D immersive data visualization into this research.  ... 
doi:10.1029/2011jb008563 fatcat:5ezkdtgqqne4fkqisaitvw6rky

Seismic anisotropy in eastern Africa, mantle flow, and the African superplume

Brian Bagley, Andrew A. Nyblade
2013 Geophysical Research Letters  
We thank Samantha Hansen for providing the tomographic image shown in Figure 3 and Jim Gaherty and two anonymous reviewers for their constructive reviews.  ...  Field support is gratefully acknowledged from IRIS-PASSCAL, the Ugandan, Tanzanian, and Zambian Geological Surveys, the University of Dar es Salaam and from many individuals at those institutions and at  ...  (i.e., multilayer) arising from fossil anisotropy in a heterogeneous lithosphere above the superplume-driven flow field in the sublithospheric mantle or, alternatively, in the case of stations within  ... 
doi:10.1002/grl.50315 fatcat:eis3faldfnf5hc6vnki6uwhtpy

Shear wave anisotropy beneath the Aegean inferred from SKS splitting observations

C. P. Evangelidis, W.-T. Liang, N. S. Melis, K. I. Konstantinou
2011 Journal of Geophysical Research  
Our preferred source of anisotropy in the back-arc region is the mantle wedge flow, induced by the retreating descending slab.  ...  This reflects a similar subslab flow that may become toroidal around the slab edge beneath western Turkey. This may also produce a trench-parallel flow within the mantle wedge.  ...  There is not a uniform relationship between the observed anisotropy and the crustal velocity or strain field. [27] The observed anisotropy in the back-arc area shows a gradual increase in delay times from  ... 
doi:10.1029/2010jb007884 fatcat:gwtsfvo4mfdcfn5unghd4haeym

Shallow Mantle Anisotropy Beneath the Juan de Fuca Plate

Brandon P. VanderBeek, Douglas R. Toomey
2017 Geophysical Research Letters  
The mean mantle velocity is 7.85 ± 0.02 km/s with 4.6% ± 0.4% anisotropy.  ...  Synthesis of the plate-averaged Pn anisotropy signal with measurements of Pn anisotropy beneath the JdF Ridge and SKS splits across the JdF plate suggests that the anisotropic structure of the topmost  ...  Acknowledgments We thank the members of the Cascadia Initiative Expedition Team for their efforts in planning and executing the experiment that yielded the data for our analysis.  ... 
doi:10.1002/2017gl074769 fatcat:5avavjzrjvbupcpcayd7ntwt7q

Geodynamic Tomography: Constraining Upper Mantle Deformation Patterns from Bayesian Inversion of Surface Waves

J K Magali, T Bodin, N Hedjazian, H Samuel, S Atkins
2020 Geophysical Journal International  
Large-scale observation of anisotropy in surface wave tomography models provides unique constraints on present-day mantle flow.  ...  In the Earth's upper mantle, seismic anisotropy mainly originates from the crystallographic preferred orientation (CPO) of olivine due to mantle deformation.  ...  Finite-strain models derived from the flow are subsequently compared with azimuthal anisotropy in surface waves.  ... 
doi:10.1093/gji/ggaa577 fatcat:7zg6xlphhjgojo2gs2w25mufxu

Mantle Deformation in the Eastern Himalaya, Burmese Arc and Adjoining Regions

Dipankar Saikia, M. Ravi Kumar, Arun Singh, Sunil K. Roy, P. Solomon Raju, A.C Lyngdoh
2018 Geochemistry Geophysics Geosystems  
In the Bengal Basin, the Nulls could be due to annihilation of frozen anisotropy in the downwelling Indian lithosphere and the APM-related strain, or a highly heterogeneous mantle affected by the Kereguelen  ...  plate motion related strain are playing a role.  ...  Venkatesh and Yugun Kumar for field support and D. Srinagesh and N. Purnachandra Rao for help in planning and execution of the project.  ... 
doi:10.1029/2018gc007691 fatcat:cg3iljkrcrezvex5pozetgxpsi

The Role of Pre-existing Mechanical Anisotropy on Shear Zone Development within Oceanic Mantle Lithosphere: an Example from the Oman Ophiolite

2004 Journal of Petrology  
Detailed structural mapping in the mantle section revealed a gently undulating structure with an eastEEEwest flow direction. A NWEEESE strike-slip shear zone cuts across this horizontal structure.  ...  We propose that primary olivine CPO fabrics may play a significant role in the subsequent structural development of the mantle.  ...  Tommasi, and other colleagues in Laboratoire de Tectonophysique for their hospitality in Montpellier, and A.  ... 
doi:10.1093/petrology/egg099 fatcat:kguei747lvcwlghrmurlty4tdy
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