Helmholtz-Zentrum Deutsches Geoforschungszentrum

SUBITOP – Understanding Subduction Zone Topography through Modelling of Coupled Shallow and Deep Processes

SUBITOP is a Marie Skłodowska-Curie framework for training and career development of 15 Early Stage Researchers in Geodynamics, Geophysics, Geology and Geomorphology. It has a scientific focus on the dynamics of continental margins where tectonic plates are recycled through subduction. The Training Network provides a comprehensive range of modelling and observation techniques, exploiting the full diversity of active and ancient subduction systems within Europe. It fuses research and training at ten leading centres of the Earth Sciences in Europe and forges partnerships with 15 companies for its fellows, with participants in eight countries.

In our section we host the project ESR 11 “Topographic signals from the shallow megathrust seismic cycle”. In this project we focus on topographic effects of deformation processes related to megathrust earthquakes and their diagnostic continental uplift and subsidence patterns. The most spectacular of such processes are coseismic stress changes inducing almost instantaneous coastal uplift and subsidence, which are typically recovered slowly during the interseismic period. The spatial correlation of these transient topographic signals with bathymetric and topographic features (e.g. the outer arc high, coastal and main cordillera) suggests that part of the seismic cycle deformation is not recoverable, i.e. that seismic cycle deformation in the lithosphere is elastoplastic. Moreover, active deformation of the overriding plate might feed back into the seismogenic process by controlling the stress state along the megathrust. The project will consider topographic signals from the megathrust seismic cycle and seismotectonic feedback on relevant time scales (from seconds to Millions of years) experimentally by means or analogue modelling. We plan to develop current “seismotectonic” analogue models of elastoplastic seismic cycles (Rosenau et al. 2009) into those involving a coupling between a viscoelastic asthenosphere and an elastoplastic lithosphere. This coupling will induce a wider range of deformation patterns beyond elastic seismic cycles to occur (e.g. upper plate shortening, buckling, pressure waves, isotatic response, mantle relaxation). Experimental observations will be benchmarked by analytical and numerical models and validated against nature.

Read more on the SUBITOP Website: http://www.subitop.eu/home/

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