Sektion 2.5: Geodynamische Modellierung
The ascent of Eifel plume and its interaction with European lithosphere and asthenosphere
The Eifel hotspot, situated in western Germany, has been volcanically active for several tens of millions of years. Previous studies have indicated that the source of these long-term volcanic activities is a plume visible in the upper mantle and in some models of the lower mantle. However, the deep origin of the plume is still under debate, since the tomography images do not consistently show a continuous plume conduit between the surface and the core-mantle boundary and the Eifel hotspot is not related to any flood basalt province or a clearly age-progressive hotspot track. It has also been proposed that there is a stagnant slab in the mantle transition zone created by the Alpine-Mediterranean subduction zone. This stagnant slab might be interacting with the Eifel plume, but so far this mechanism has not been studied in detail using a geodynamic approach. In addition, the ascent of the Eifel plume and the other sub-lithospheric drivers of vertical motion (such as edge-driven convection or cooling and accretion of sub-lithospheric mantle) as well as lithosphere deformation might cause dynamic topography at the earth surface in central Europe. However, so far the relative contributions of these processes during the Cenozoic are still controversial.
In this project, I intend to employ the geodynamic research software ASPECT to model the lithospheric-scale and surface response of Central Europe to plume impingement, small-scale convection and plate tectonic forcing, and try to decompose the present-day topography into individual components. Also, I will conduct 3D models with high resolution and complex rheologies to explain the possible origins of the Eifel hotspot and to address how the plume and the stagnant slab interact with each other
Project duration: 2022-2026
Funding agency:China Scholarship Council
PhD candidate:Yingying Li
Supervisors:Bernhard Steinberger, Sascha Brune, Eline Le Breton
Modelling mantle exhumation during rifting and basin inversion: Implications for natural hydrogen exploration
In the on-going push for developing new, eco-friendly resources and energy production, the potential of naturally occurring hydrogen, generated through the alteration (serpentinization) of tectonically exhumed mantle rocks, remains largely overlooked. The exhumation of mantle rocks can occur during rifting and continental break-up, but as well as during mountain building phases. In order to better assess the opportunities for natural hydrogen extraction from exhumed mantle material, we must improve our understanding of the tectonic processes leading to (and active during) their exhumation.
This project envisions the use of numerical tectonic modelling techniques to unravel these mantle exhumation proce cesses, with a special focus on the influence of structural inheritance, pressure and temperature evolution of exhumed mantle materials over time, and the importance of surface processes and the presence of reservoirs. The subsequent aim is to apply these modelling results to interpret the tectonic history of various natural cases (e.g. Pyrenees, offshore Iberia, European Alps), and to assess the feasibility of natural hydrogen extraction in these areas of interest.
Project duration: 2022 - 2025
Funding agency: GFZ Discovery Fund Fellowhsip
Primary Investigator: Frank Zwaan
Collaborators: Sascha Brune, Claudio Facenna, Ingo Sass, Cornelia Schmidt-Hattenberger, Peter Pilz
Rift propagation and linkage in the central Afar, East Africa
The East African Rift System (EARS) encompasses a wide variety of rifts including the immature Malawi rift in the south to the highly extended, seismically and volcanically active Afar rift to the north. The Afar rift offers an excellent opportunity to investigate continental break up and the formation of seafloor spreading centers on land. The opening of the Afar rift started at ∼30 million years ago (Myr), facilitated by the Afar plume and separation of Arabia from Africa and later by the rotation of the Danakil and Ali-Sabeh blocks at ∼7 Myr. Significant rift formation and propagation in central Afar occured at around 4 Myr.
The Quaternary to Recent opening of the Afar rift is mainly accommodated at the Dabbahu-Manda Harraro (DMH) and Asal-Ghobbet (ASAL) segments, at the tip of the Red Sea and Gulf of Aden rifts, respectively. However, how the two rift segments propagate towards each other is still enigmatic. Several contrasting models have been put forward to explain the rift propagation and linkage in the Afar rift. The discrepancy among these models could be due to the difference in timescale of observations. Here we aim to combine GPS and numerical geodynamic modeling observations coupled with paleomagnetic and earthquake data to fully understand rift propagation and linkage in the central Afar across the range of timescale.
Project duration: 2021 − 2023
Funding agency: Alexander von Humboldt Foundation
Primary Investigator: Ameha A. Muluneh
Collaborators: Sascha Brune, Derek Keir (University of Southampton, UK), Giacomo Corti (National Research Council of Italy, Italy), Carolina Pagli (University of Pisa, Italy), Tesfaye Kidane (University of Kwazulu Natal, South Africa)
Deep structure and geodynamic evolution of the South China Sea
Similar to many passive margins worldwide, the formation of the rifted continental margins of the South China Sea (SCS) features a complex tectonic history progressing from rift localization and lithospheric thinning to continental break-up and seafloor spreading. It is clear that the tectonic history of the SCS has been affected by several key regional factors, such as Mesozoic inherited structures and the initial thermal regime of a back-arc setting. In addition, a very recent IODP cruise provided compelling evidence that the common end-number scenarios of magma-rich or magma-poor rifted margins do not apply to the SCS. Based on the current research, this project will address the questions why and how the back-arc regime leads to the distinct tectonic history and final architecture of the SCS rifted margins. Using the state-of-the-art numerical modelling tools, the program will focus on the cross-scale geodynamic evolution of the SCS and its thermal evolution.
Project duration : 2021-2024
Funding agency : China Scholarship Council (CSC)
PhD candidate: Kai Li
Supervisors: Sascha Brune, Frederik Tilmann
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.
Project duration : 2021-2024
Funding agency :DAAD
PhD candidate: Poulami Roy
Supervisors: Bernhard Steinberger, Sascha Brune
Monitoring Earth Evolution through Time (MEET)
An ERC (European Research Council) Synergy grant of €12.8 million over six years (2020-2026) has been awarded to Alexander Sobolev (IsTerre, Grenoble), Stephan Sobolev (GFZ Potsdam, Germany) and John Valley (University of Wisconsin, Madison, USA) to study the evolution of Earth’s chemical composition and the underlying physical processes from 4.4 billion years ago to present in a project entitled “Monitoring Earth Evolution through Time” (MEET).
Project duration: 2020-2026
Funding agency:ERC Synergy Grant
Primary Investigator:Stephan Sobolev
Postdocs:Charitra Jain, Michael Pons
Cooperations:Alexander Sobolev (ISTerre, Grenoble), John Valley (University of Wisconsin, Madison,USA), Jean Braun (GFZ), Georg Feulner (PIK), Sascha Brune (GFZ)
EWRICA: Early-Warning and Rapid Impact Assessment with Real-time GNSS in the Mediterranean
EWRICA aims at calculation of robust local ground motion models shortly after an earthquake to assess secondary effects such as tsunamis and landslides as well as to identify areas of possible building damage and collapse. This should be achieved by, firstly, improving the accuracy of real-time GNSS processing to a cm-level with optionally collocated accelerometers (GFZ Section 1.1). Precise surface displacements will then be fed into the real-time source inversion (GFZ Section 2.1). The improved source assessment will allow more reliable prediction of ground motion (Dr. Matthias Ohrnberger, Uni Potsdam) which, in turn, will improve forecasting of secondary effects like landsliding and tsunami generation. At the end of the project, operational system prototype (GFZ Section 2.4) will be installed by our international partners: INGV (Italy) and NOA (Greece).
Project duration: 2020-2023
Funding agency:BMBF, Fachprogramm “Geoforschung für Nachhaltigkeit (GEO:N)“
Förderschwerpunkt: "Early detection of earthquakes and their consequences"
Project Coordinator:Andrey Babeyko
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
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
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
Fellow: Thilo Wrona
Supervisors: Sascha Brune (GFZ), Onno Oncken (GFZ) and Begüm Demir (TU Berlin)
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
Manfred Strecker, Henry Wichura, Simon Riedl (University of Potsdam)
Simon Williams, Dietmar Müller (EarthByte Group, University of Sydney, Australia)
Giacomo Corti (Florence University, Italy)
Project duration: 2017-2018
Funding Agency: DAAD
Primary Investigator: Sascha Brune
Cooperations: Simon Williams, Dietmar Müller , Andrew Merdith (EarthByte Group, University of Sydney)
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.