About

Elvira Mulyukova is an Assistant Professor in the Department of Earth, Environmental, and Planetary Sciences at Northwestern University. She holds a Ph.D. in Geophysics and Geodynamic Modelling from the GFZ German Research Centre for Geosciences in Potsdam, Germany, and an M.S. in Physics of Geological Processes and a B.S. in Physics from the University of Oslo, Norway. Her research is aimed at understanding the physical processes that govern the evolution of terrestrial planets, ranging from the atomic scale physics of mineral grains to the planetary scale of mantle flow. She uses mathematical methods to develop physically consistent models of rock mechanics and incorporates them into larger-scale geodynamic models of mantle convection, plate tectonics, earthquake cycles, and other geological processes that shape rocky planets. Her work has primarily focused on Earth, utilizing observational data to study the microphysics of strain localization and weakening that lead to the formation and evolution of tectonic plate boundaries. She aims to develop models applicable not only to Earth but also to other terrestrial planets in our Solar System and beyond. Her research explores how plate tectonics influences Earth's surface dynamics, chemistry, climate stability, and biological evolution, emphasizing the importance of understanding these processes for comprehending the Earth system as a whole.

Research topics

• Computer Science
• Biology
• Political Science
• Geology
• Paleontology
• Physics

Selected publications

• Upscaling from mineral microstructures to tectonic macrostructures

  Geophysical Journal International · 2024-07-26 · 1 citations

  articleOpen accessSenior author

  SUMMARY Earth’s plate tectonic behaviour arises from lithospheric ductile weakening and shear-localization. The ubiquity of mylonites at lithospheric shear zones is evidence that localization is caused by mineral grain size reduction. Most lithospheric mylonites are polymineralic, suggesting that the interaction between mineral phases by Zener pinning promotes grain size reduction and weakening. Yet this interaction only occurs where mineral phases mix at the grain scale. Phase mixing and its effect on microstructure and strength have been shown in deformation experiments and natural field samples. Our theory for the interaction between phase mixing (treated as a stress driven diffusion) with two-phase grain damage has been compared to lab experiments. But using processes at the tiny grain-scale embedded within the small hand-sample and lab scales to model large-scale lithospheric processes, requires an upscaling scheme that captures the physics from micro- to macrostructures. For example, weakening from grain-damage in zones of mixing can lead to banded viscosity structure at the small scale that manifests as viscous anisotropy at the large scale. Here we provide a new framework for self-consistently upscaling from microscopic (grain) scales, to mesoscopic (petrological heterogeneity) scales to macroscopic (tectonic) scales. The first upscaling step models phase mixing and grain size evolution in a small ‘mesoscopic’ lab-scale volume or ‘patch’, which is equivalent to a point in the macroscopic space. Within this mesoscale patch, stress driven diffusive mixing is described by an analytical solution for mineral phase fraction, provided a minimalist Fourier representation of phase fraction, and a transformation to the patch frame of reference as well as to the principal stress directions at that point. The orientation and volume fraction of mixed-phase regions can then be extracted from the analytical solution for phase fraction. The grain size and viscosity in the mixed bands are determined by two-phase grain-damage theory; the unmixed zone properties follow from mono-phase grain damage theory. The mesoscale banded viscosity field leads to a macroscale anisotropic viscosity at that point in space. But, the evolution of properties at each macroscale point involves tracking only a few quantities (phase fraction, grain sizes) rather than modelling each patch of mesoscale space as its own 2-D or 3-D system. For the final upscaling, the anisotropic viscosity field is used in a macroscale lithosphere flow model. We show an example of this scheme for a lithospheric Rayleigh–Taylor drip driven by ridge-push compressive stress, which can cause anisotropic weakening via grain mixing and damage that may help initiate subduction and passive margin collapse.

  PublisherOA PDFDOI

• Contributors

  Elsevier eBooks · 2023-01-01

  book-chapter
  PublisherDOI

• NUMERICAL MODEL OF EARLY CONTINENT FORMATION

  Abstracts with programs - Geological Society of America · 2023-01-01

  articleSenior author
  PublisherDOI

• The Physics and Origin of Plate Tectonics From Grains to Global Scales

  Elsevier eBooks · 2023-01-01 · 3 citations

  book-chapter1st authorCorresponding
  PublisherDOI

• On the co-evolution of dislocations and grains in deforming rocks

  Physics of The Earth and Planetary Interiors · 2022-04-08 · 11 citations

  article1st authorCorresponding
  PublisherDOI

• A coupled model for phase mixing, grain damage and shear localization in the lithosphere: comparison to lab experiments

  Geophysical Journal International · 2022-10-27 · 7 citations

  article

  SUMMARY The occurrence of plate tectonics on Earth is rooted in the physics of lithospheric ductile weakening and shear-localization. The pervasiveness of mylonites at lithospheric shear zones is a key piece of evidence that localization correlates with reduction in mineral grain size. Most lithospheric mylonites are polymineralic and the interaction between mineral phases, such as olivine and pyroxene, especially through Zener pinning, impedes normal grain growth while possibly enhancing grain damage, both of which facilitate grain size reduction and weakening, as evident in lab experiments and field observations. The efficacy of pinning, however, relies on the mineral phases being mixed and dispersed at the grain scale, where well-mixed states lead to greater mylonitization. To model grain mixing between different phases at the continuum scale, we previously developed a theory treating grain-scale processes as diffusion between phases, but driven by imposed compressive stresses acting on the boundary between phases. Here we present a new model for shearing rock that combines our theory for diffusive grain mixing, 2-D non-Newtonian flow and two-phase grain damage. The model geometry is designed specifically for comparison to torsional shear-deformation experiments. Deformation is either forced by constant velocity or constant stress boundary conditions. As the layer is deformed, mixing zones between different mineralogical units undergo enhanced grain size reduction and weakening, especially at high strains. For constant velocity boundary experiments, stress drops towards an initial piezometric plateau by a strain of around 4; this is also typical of monophase experiments for which this initial plateau is the final steady state stress. However, polyphase experiments can undergo a second large stress drop at strains of 10–20, and which is associated with enhanced phase mixing and resultant grain size reduction and weakening. Model calculations for polyphase media with grain mixing and damage capture the experimental behaviour when damage to the interface between phases is moderately slower or less efficient than damage to the grain boundaries. Other factors such as distribution and bulk fraction of the secondary phase, as well as grain-mixing diffusivity also influence the timing of the second stress drop. For constant stress boundary conditions, the strain rate increases during weakening and localization. For a monophase medium, there is theoretically one increase in strain rate to a piezometric steady state. But for the polyphase model, the strain rate undergoes a second abrupt increase, the timing for which is again controlled by interface damage and grain mixing. The evolution of heterogeneity through mixing and deformation, and that of grain size distributions also compare well to experimental observations. In total, the comparison of theory to deformation experiments provides a framework for guiding future experiments, scaling microstructural physics to geodynamic applications and demonstrates the importance of grain mixing and damage for the formation of plate tectonic boundaries.

  PublisherDOI

• Mantle Convection

  Encyclopedia of earth sciences series/Encyclopedia of earth sciences · 2021-01-01 · 12 citations

  book-chapterSenior author
  PublisherDOI

• Magnetization of sinking porous diapirs in planetesimal cores

  Physics of The Earth and Planetary Interiors · 2021-03-01 · 2 citations

  articleSenior author
  PublisherDOI

• Evolution and demise of passive margins through grain mixing and damage

  Proceedings of the National Academy of Sciences · 2021 · 30 citations

  Senior authorCorresponding
  • Political Science
  • Biology
  • Geology

  How subduction-the sinking of cold lithospheric plates into the mantle-is initiated is one of the key mysteries in understanding why Earth has plate tectonics. One of the favored locations for subduction triggering is at passive margins, where sea floor abuts continental margins. Such passive margin collapse is problematic because the strength of the old, cold ocean lithosphere should prohibit it from bending under its own weight and sinking into the mantle. Some means of mechanical weakening of the passive margin are therefore necessary. Spontaneous and accumulated grain damage can allow for considerable lithospheric weakening and facilitate passive margin collapse. Grain damage is enhanced where mixing between mineral phases in lithospheric rocks occurs. Such mixing is driven both by compositional gradients associated with petrological heterogeneity and by the state of stress in the lithosphere. With lateral compressive stress imposed by ridge push in an opening ocean basin, bands of mixing and weakening can develop, become vertically oriented, and occupy a large portion of lithosphere after about 100 million y. These bands lead to anisotropic viscosity in the lithosphere that is strong to lateral forcing but weak to bending and sinking, thereby greatly facilitating passive margin collapse.

  PublisherOA PDFDOI

• A transdisciplinary and community-driven database to unravel subduction zone initiation

  Nature Communications · 2020 · 146 citations

  • Computer Science
  • Computer Science
  • Biology

  Subduction zones are pivotal for the recycling of Earth's outer layer into its interior. However, the conditions under which new subduction zones initiate are enigmatic. Here, we constructed a transdisciplinary database featuring detailed analysis of more than a dozen documented subduction zone initiation events from the last hundred million years. Our initial findings reveal that horizontally forced subduction zone initiation is dominant over the last 100 Ma, and that most initiation events are proximal to pre-existing subduction zones. The SZI Database is expandable to facilitate access to the most current understanding of subduction zone initiation as research progresses, providing a community platform that establishes a common language to sharpen discussion across the Earth Science community.

  PublisherOA PDFDOI

Frequent coauthors

• David Bercovici

  Planetary Science Institute

  41 shared

• Bernhard Steinberger

  Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences

  10 shared

• Derya Gürer

  University of Tasmania

  8 shared

• Marcin Dąbrowski

  Polish Geological Institute

  7 shared

• George F. Cooper

  Cardiff University

  5 shared

• Mathew Domeier

  5 shared

• Fabio Crameri

  5 shared

• C. M. Eakin

  Australian National University

  5 shared

Labs

• Elvira Mulyukova's LabPI

  Not provided