Section 2.5: Geodynamic Modeling

Project opportunities

In case you are interested in joining our section for the duration of an internship, thesis, PhD or Postdoc project: click here for a list of representative project opportunities and funding options. Of course, we are also open for any great project idea that you may have. Our contact details can be found here.

Current projects

Insight into the dynamics of the large low shear velocity provinces from shear wave anisotropy of the lowermost mantle

This project aims at constraining the dynamics of LLSVPs, their deformation pattern and composition using the shear wave anisotropy of the lowermost mantle. The lowermost mantle, specifically the D” layer, is very difficult to explore due to the scarcity of seismic observations in that great depth. The two large low shear velocity provinces (LLSVPs) in the D” layer exhibit characteristic physico-chemical properties unlike the surrounding mantle. Although the plumes are being generated from these structures, the composition of plumes and LLSVPs are not the same. Using 3D numerical modelling of mantle convection, I will model the seismic anisotropy generated from different deformation mechanisms in the lower mantle and compare them with the observations. The deformation mechanisms and the flow pattern will tell us about the rheological property as well as the density structure of the LLSVPs. Adding to that, I will also try to address the geochemical composition of the D” layer with special focus on LLSVPs.


What can trigger destabilizing of Atlantic passive margins?

Understanding of how, when and where a subduction zone initiates is still one of the most enigmatic issues in geosciences. Various localities such as intra-oceanic transform faults/fracture zones, extinct mid-oceanic ridges and passive margins have been proposed as likely sites where new subduction zones are to begin. Geological observations confirm subduction initiation along some of these proposed locations. However, lack of Cenozoic examples makes subduction initiation along passive margins more controversial, even though the concept continues to be widely promulgated. The broad acceptance of passive margins as favourable site for trench formation comes from the key role that they play in Wilson cycle, which explains the repeated opening and closing of ocean basins in geological time. Most previous modelling studies have not succeeded in simulating conversion of an old passive margin into a subduction zone with realistic parameters. Here we aim to contribute to progress on this important geo-scientific problem by addressing the following questions: What are the conditions under which an old oceanic lithosphere adjacent to a passive continental margin can spontaneously collapse and begin to subduct? If spontaneous subduction initiation is impossible, can mantle flow associated with past and present subduction zones convert a passive continental margin into a subduction zone?

Project duration: 2020-2022

Funding agency:DFG

Primary Investigator: Marzieh Baes 

Cooperations: Andrea Hampel (Hannover University), Stephan Sobolev  (GFZ), Taras Gerya (ETH Zürich), Robert Stern (Universitiy of Texas at Dallas)

 

 


The seismic cycle of great earthquakes: Numerical multi-scale modelling of transients and tipping points

Great earthquakes are a catastrophic corollary of long-term plate tectonics that pose a major threat to societies worldwide. Understanding the underlying physical processes including their transient behaviour and tipping points is indispensable for identifying areas under high risk and to make a key step towards forecasting earthquakes. Numerical modelling can help to interpret observed events in the context of the seismic cycle since state-of-the-art models are able to capture the entire event chain from long-term buildup of tectonic stress and pre-seismic transients over the earthquake itself to post-seismic deformation. To overcome current limitations of seismic cycle models in terms of spatial and temporal resolution, I am implementing a rate and state friction law in the massively parallelised geodynamic research software ASPECT. By taking advantage of its pre-existing functionalities such as adaptive mesh refinement, adaptive time stepping, and elasto-visco-plastic rheology, I plan to conduct high resolution seismic cycle models in three dimensions. This is an interdisciplinary project that brings together expertise from numerical and analogue models, observational data, and the numerical analysis of partial differential equations.

Project type: Geo.X PhD project

Project duration: 2019-2022

Funding: Geo.X

PhD Candidate: Esther Heckenbach 

Supervisors: Sascha Brune, Stephan Sobolev , Matthias Rosenau , Anne Glerum , Ralf Kornhuber, Onno Oncken 

Cooperations:Joscha Podlesny, Alexander Mielke, Michael Rudolf  (FU Berlin, WIAS and GFZ) via SFB 1114 

Website: https://www.geo-x.net/en/young-academy/fellows-2019/esther-heckenbach/

Key publication: Sobolev, S. V., & Muldashev, I. A. (2017). Modeling Seismic Cycles of Great Megathrust Earthquakes Across the Scales With Focus at Postseismic Phase. Geochemistry, Geophysics, Geosystems, 18(12), 4387–4408. https://doi.org/10.1002/2017GC007230


Deciphering fault network evolution in continental rifts through deep learning analysis of geodynamic models and seismic data

Continental rifting is a fundamental process in plate tectonics, where continental crust is stretched, while faults and fractures initiate and grow. These tectonic faults are responsible for devastating earthquakes in places of active rifting such as Ethiopia and Tanzania. On longer timescales, these faults are critical to the formation of sedimentary basins hosting large quantities of the natural resources. Despite their importance, we still know relatively little about how normal fault networks grow in space and time (Gawthorpe and Leeder, 2000; Cowie et al., 2005; Bell et al., 2014; Ritter et al., 2018; Rotevatn et al., 2018). How do fault networks coalesce and which parameters control this process? Are normal faults growing simultaneously in length and displacement? How much of the total deformation do these faults accommodate?

We will explore these questions by linking geodynamic simulations of continental rifting with seismic observations of rifted continental crust. Recent advances in geodynamic modelling allow us to the run large-scale geodynamic models of continental rifting (Brune et al., 2017)⁠ resolving for the first time the 3-D evolution of fault networks. At the same time, new 3-D seismic surveys reveal entire faults systems in rifted continental crust at unprecedented detail (Wrona et al., 2017)⁠. Comparing simulations and observations has however been difficult so far, as it involves the interpretation of large volumes of data (GBs to TBs) in complex 3-D fault configurations. This project will employ artificial intelligence in order to overcome this difficulty by extracting key fault properties (e.g. geometry, strain) from both types of data. This is a unique opportunity to isolate the processes governing normal fault network evolution by bridging geodynamic models and seismic observations using cutting edge deep learning techniques.

Project type: Geo.X fellowship

Project duration: 2019-2022

Funding: Geo.X

Fellow: Thilo Wrona 

Supervisors: Sascha Brune  (GFZ), Onno Oncken  (GFZ) and Begüm Demir (TU Berlin)

Website: https://www.thilowrona.com/

Key Publications: 

Wrona T., Pan I., Bell R.E., Gawthorpe R.L., Fossen H., Brune S. (2020) Deep learning of geological structures in seismic reflecion data. EarthArXiv.  https://doi.org/10.31223/X5S88B

Naliboff J.B., Glerum A., Brune S., Peron-Pinvidic G. & Wrona T. (2020) Development of 3‐D Rift Heterogeneity Through Fault Network Evolution. Geophysical Research Letters. https://doi.org/10.1029/2019GL086611


How the complexity of continental breakup controls ocean circulation

Global and regional climate are profoundly influenced by patterns of ocean circulation, which in turn is modulated by the distribution of continents and seafloor topography. Motions of the continents over millions of years shift and reshape the ocean basins, causing ocean currents to change. Dramatic changes can occur when continents break apart opening ‘seaways’ that control seawater flow between major ocean basins. This project combines plate tectonic reconstructions with 3D lithospheric extension simulations to create high-resolution boundary conditions for paleo-oceanographic circulation models of the Tasman and North Atlantic seaways. We investigate how quickly, and by how much, tectonic processes change the width, depth and latitude of a seaway. The geodynamic evolution may be influenced by long transform boundaries, continental fragments or vertical motions due to mantle plume activity. Subsequently we will provide calculations how the seaway evolution affects oceanographic flow and long-term temperature trends in the oceans.

Project duration:  2018-2021

Funding agency:  Australian Research Council

Primary Investigator: Joanne Whittaker (University of Tasmania, Hobart, Australia)

Cooperations: Sascha Brune Simon Williams(EarthByte Group, University of Sydney), Andreas Klocker (University of Tasmania, Hobart, Australia), Carmen Gaina (University of Oslo, Norway) and David Munday (British Antarctic Survey, UK)


CRYSTALS (Continental Rift Dynamics across the Scales)

Rifts provide a unique window into the geodynamic system of our planet and the processes that shape the surface of the Earth. The CRYSTALS project aims at a thorough understanding of continental rift dynamics and rifted margin formation by means of a comprehensive multi-scale numerical modelling design. Find out more.

Project type: Helmholtz Young Investigators Group

Time frame:  2016 - 2021

Funding agency:  Helmholtz Association

Principal investigator:  Sascha Brune 

Cooperations: 

Manfred Strecker, Henry Wichura, Simon Riedl (University of Potsdam)

Simon Williams, Dietmar Müller (EarthByte Group, University of Sydney, Australia)

Giacomo Corti (Florence University, Italy)

Website:  Link


StRATEGy (Surface processes, Tectonics and Georesources: The Andean foreland basin of Argentina)

The Andean foreland basin of Argentina is an ideal area to study the interaction between deep and surface processes, including volcanism and tectonics, climate and erosion/sedimentation, as well as their impact on metallogenesis, hydrocarbon resource generation and fluid migration. Our project aims to model these multi-spatial and multi-temporal processes using geodynamics numerical modelling tools to give a relevant picture for the society. More details: Website

The image illustrates the different tectonic styles of deformation associate to the foreland basins in Central Andes. Red area shows where the deformation localizes in the lithosphere. (Sibiao 2020, Thesis)

Project type: International Research Training Group IGK2018

Time frame: 2015 - 2021

Funding agency: DFG, German Research Foundation and The federal state of Brandenburg

Principal investigator:Stephan Sobolev 

Cooperations:Andrey Babeyko  (GFZ, Potsdam), Manfred Strecker, (University of Potsdam)

PhD students: (2015-2018) Sibiao Liu , (2018-2021) Michaël Pons 

Publications: Ibarra, F., S. Liu, C. Meeßen, C. B. Prezzi, J. Bott, M. Scheck-Wenderoth, S. Sobolev, and M. R. Strecker. ‘3D Data-Derived Lithospheric Structure of the Central Andes and Its Implications for Deformation: Insights from Gravity and Geodynamic Modelling’. Tectonophysics 766 (5 September 2019): 453–68. https://doi.org/10.1016/j.tecto.2019.06.025

 

Liu, Sibiao. (2020). Controls of foreland-deformation patterns in the orogen-foreland shortening system. Thesis  https://doi.org/10.25932/publishup-44573


Past projects

Plume-induced subduction initiation: Insights from the south-western margin of the Caribbean

Subductions zones are main components of plate tectonics and around 90% of the plate driving forces derive from the negative buoyancy of sinking lithosphere in subduction zones. However, despite their vital role, it is still enigmatic how and where subduction zones form. A recently proposed scenario that is independent of any pre-existing weakness zone, is plume-induced subduction initiation, which can explain the beginning of the first sucbduction zone without the help of plate tectonics. However, many key aspects of this new scenario have not been investigated yet. In this project, we answer the following questions by using cutting-edge 3-d numerical models: What is the lithosphere's response to plateau-plume interaction and which processes control lithospheric deformation? What is the impact of regional extension on plume-plateau interaction? Which parameters play key roles for the formation of a single one-sided plume-induced subduction zone (instead of formation of several slabs around the plateau)? We apply our models to the geologically most recent example of plume-induced subduction at the south-western margin of the Caribbean plate, which occurred around 100 million years ago.

                                                                                                                                                                                                                                                                                                             

Project duration: 2018-2020

Funding agency:DFG

Primary Investigator: Sascha Brune 

Personnel: Marzieh Baes 

Cooperations: Taras Gerya (ETH Zürich), Stephan Sobolev  (GFZ), Robert Stern (University of Texas at Dallas), Scott Whattam (Indian Institute of Technology)

Publication:

Baes, M., Sobolev, S. V., Gerya, T., &  Brune, S.(2020). Plume-Induced Subduction Initiation: Single-Slab or Multi-Slab Subduction? Geochemistry Geophysics Geosystems (G3), 21 (2):  e2019GC008663.  https://doi.org/10.1029/2019GC008663


RiftCO2 (Linking continental breakup dynamics to climate changes)

Many fundamental evolutionary cycles on Earth - including the dispersal of supercontinents and the global carbon cycle - are driven by our planet's dynamic engine, plate tectonics. Geodynamic processes hold important implications for climate science since CO2 is released from Earth’s interior into the atmosphere. In order to link plate tectonics and complex lithospheric deformation to the global carbon cycle we combine plate tectonic reconstruction with numerical carbon cycle simulation. This allows quantifying the tectonic evolution of plate boundaries as well as tectonic CO2 release rates through deep time with profound implications for long-term climate simulations.

Project duration:  2017-2018

Funding Agency:  DAAD

Primary Investigator: Sascha Brune 

Cooperations: Simon Williams, Dietmar Müller , Andrew Merdith (EarthByte Group, University of Sydney)

Publications:

Brune, S., Williams, S.E., and Müller, R.D., 2017, Potential links between continental rifting, CO2 degassing and climate change through time: Nature Geoscience, v. 10, p. 941, doi: 10.1038/s41561-017-0003-6.


RHUM-RUM (Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel)

RHUM-RUM (Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel) is a French-German passive seismic experiment designed to image a classical oceanic mantle plume – or lack of plume – from crust to core beneath Réunion Island. The results enable insights into the material and heat flow in the Earth's deep interior and provide a geodynamic context for the still controversially debated deep mantle plumes.

Modelling the mantle plume underneath Réunion Island in the Indian Ocean is a valuable contribution to the RHUM-RUM project, because the plume in a geodynamic model can be studied in a dynamic context - in contrast to seismic tomography. The present-day model state can be regarded as a "true" prediction for the dynamics in the Earth's interior und can therefore be compared to the seismic results.

Time frame: 2014 - 2017

Funding: DFG - Deutsche Forschungsgemeinschaft (STE 907/11-1)

Principal Investigators:  Dr. Bernhard Steinberger 

Personnel:  Eva Bredow

Project website:www.rhum-rum.net/en/

Cooperations:  Guilhem Barruol (IPG Paris & Géosciences Réunion, France), Karin Sigloch, University of Oxford, UK

Publication:

Bredow, E., B. Steinberger, R. Gassmöller, and J. Dannberg (2017), How plume-ridge interaction shapes the crustal thickness pattern of the Réunion hotspot track, Geochem. Geophys. Geosyst., 18, 2930–2948, doi:10.1002/2017GC006875.