Section 2.5: Geodynamic Modeling

estimated tsunami wave hights
The images illustrate the plate speed-up of South America, Australia, and North America during the fragmentation of Pangea. The process is linked to the rift-induced damage of the breaking continent, as illustrated in the lower right image.


Our aim is to improve the understanding of geodynamic processes operating inside the solid Earth and their surface manifestation at a broad range of spatial and temporal scales through advanced numerical modeling. Our research focii are located at both plate boundaries and within the plate interiors, inside the deep mantle and at the surface. We constrain our models by multidisciplinary surface observations acquired by the GFZ and the international scientific community and look for practical applications of fundamental research, like tsunami early warning and hazard assessment. To approach our aims, we develop our own numerical methods and tools, but also extensively employ and co-develop numerical techniques provided by the international community.

Latest News

January 2021: Welcome to Poulami Roy

We are happy to welcome our new section member, Poulami Roy , to join us. Poulami obtained a M.Sc. from Presidency University, Kolkata and a M.Tech. from Indian Institute of Science, Bangalore. During her M.Tech project, Poulami worked on constraining mantle viscosity structure based on seismic anisotropy data. She computed deformations based on seismic tomography, and evaluated the sensitivity of seismic anisotropy to viscosity variations in the lithosphere and asthenosphere. Her result show that the lithosphere has a viscosity of 10 22 Pa-s and the viscosity of the asthenosphere ranges from 3 × 10 20 to 5 × 10 20 Pa-s. She wants to extrapolate this idea to the deep mantle which is far more challenging as seismic observations are far less in the lower mantle compared to upper mantle. Moreover, the lower mantle has different rheological as well as different chemical properties than the upper mantle. She will use the Aspect mantle convection code to track strain history and model seismic anisotropy by different deformation mechanisms.

November 2020: Welcome to Dr. Elodie Kendall

We are happy to welcome our new section member, Dr. Elodie Kendall , to join us. Elodie  completed her PhD at University College London, where her doctoral studies focused on combining mantle convection models with fabric calculations to better understand features in seismic tomography. Specifically, she used seismic forward and inverse modeling techniques to assess anisotropy in the Pacific upper mantle and ridge-flow models including plumes to identify the various mechanisms behind these features. In our section, Elodie will work on the hypothesis that surface processes (erosion/sedimentation, weathering, climate) largely controlled the emergence and evolution of plate tectonics (Sobolev and Brown, 2019) using modeling, existing and new geochemical data.

November 2020: Welcome to Dr. Charitra Jain

We are happy to welcome our new section member, Dr.Charitra Jain , to join us. His overarching research interests lie in advancing our understanding of planetary evolution using geodynamical modelling. In our section, he will be working within the framework of ERC project MEET to test models of early Earth evolution using new geochemical and geological data. Prior to joining GFZ Potsdam, he worked as a Post Doctoral Research Associate at Durham University to study the formation of cratonic lithosphere (old continental cores) in global mantle convection models. These models were constrained with petrological data such as the igneous protolith P-T conditions and the magnesium number of the Archean peridotites. During his PhD at ETH Zurich, he extended the melting parametrisation in the convection code StagYY to create Earth’s primordial continental crust (TTG rocks) self-consistently. A key finding of this research effort was a two-stage growth of TTG without the need for subduction-driven plate tectonics. Furthermore, he has quantified and elucidated the effect of core temperature, continental size, and radiogenic heating on subcontinental mantle warming.

Why does the Victoria-Microplate rotate?

June 2020 - The East African Rift System (EARS) is a newly forming plate tectonic boundary at which the African continent is being separated into several plates. This is not a clean break. The system includes several rift arms and one or more smaller so-called microplates. According to GPS data, the Victoria microplate is moving in a counterclockwise rotation relative to Africa in contrast to the other plates involved. Previous hypotheses suggested that this rotation is driven by the interaction of a mantle plume – an upward flow of hot rock within the Earth's mantle – with the microplate’s thick craton and the rift system. But now, researchers from the German Research Centre for Geosciences GFZ in Potsdam around Anne Glerum  have found evidence that suggests that the configuration of weaker and stronger lithospheric regions predominantly controls the rotation of continental microplates and Victoria in particular. Their findings were published in the journal Nature Communications.

https://www.nature.com/articles/s41467-020-16176-x

European Research Council Synergy Grant 2019 MEET Funded

May 2020 - 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).

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Working Groups

Subduction across the Scales

Subduction is a key process of Plate Tectonics. We develop thermomechanical models of subduction in a large range of temporal scales, from minutes (earthquake) to seismic cycle of great earthquake (centuries) and multiple seismic cycles (millennia), to long term evolution over the millions of years. We study initiation of subduction in early Earth and in present day settings including passive margins and oceanic basins. We also model effect of subduction on deformation of the overriding plate with a type example of South American Andes.

Webpage of working group Subduction across the Scales

Global Geodynamic Modeling

The Earth's mantle behaves like a very viscous liquid over extended geological periods. Cold earth plates sink from the surface to the core-mantle boundary, and hot material rises from there in the form of mantle plumes and as large-scale upwellings. By numerical modeling with different observation data, in particular from seismology, geodesy and mineral physics as boundary conditions, we try to better understand processes in the Earth's interior. In particular, we investigate the following topics:

Webpage of working group  Global Geodynamic Modeling

Continental Rifts and Rifted Margins

Continental rifting occurs where Earth’s plates are stretched like in the East African Rift System. During break-up two passive rifted margins are formed straddling a new ocean basin. We investigate the dynamics of continental rifts and passive margins by combining numerical simulations with geophysical and geological observations. To this aim we model processes that range from mantle convection and plumes over lithosphere deformation at plate boundaries to strain localization on the cm-scale.

Webpage of working group CRYSTALS

Tsunami Hazard Assessment and Early Warning

Since the Great Sumatra 2004 Boxing Day earthquake and tsunami GFZ provides research and methodologic development in the fields of tsunami hazard assessment and early warning. Section 2.5 Geodynamic Modeling supports these activities with numerical modeling of tsunami generation, propagation and coastal impact within both deterministic and probabilistic frameworks. Our Section also participates in the development of the innovative GNSS-based technology for tsunami early warning.

Webpage of Tsunami Hazard Assessment and Early Warning

Sascha Brune
Head
Priv. Doz. Dr. Sascha Brune
Geodynamic Modelling
Albert-Einstein-Straße 42-46
Building A 46, Room 202
14473 Potsdam
+49 331 288-1928
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