Crustal fault reactivation facilitating lithospheric folding/buckling in the central Indian Ocean

High-quality, normal-incidence seismic reflection data confirm that tectonic deformation in the central Indian Ocean occurs at two spatial scales: whole lithosphere folding with wavelengths varying between 100 and 300 km, and compressional reactivation of crustal faults with a characteristic spacing of c. 5 km. Faults penetrate through the crust and probably into the upper mantle. Both types of deformation are driven by regional large intraplate stresses originating from the Indo-Eurasian collision. Numerical modelling of the spatial and temporal relationships between these two modes of deformations shows that, in agreement with geophysical observations, crustal faults are reactivated first with stick-slip behaviour. Subsequent lithospheric folding does not start until horizontal loading has significantly reduced the mechanical strength of the lithosphere, as predicted by elasto-plastic buckling theory. Modelling suggests that lithospheric folding does not develop in the absence of fault reactivation. Crustal fault reactivation, therefore, appears to be a key facilitating mechanism for oceanic lithospheric buckling in the central Indian Ocean

GOLD MEDAL LECTURE GIVEN at the ACADEMIA EUROPAEA BUILDING BRIDGES CONFERENCE 2022 : Bottom-up Probing Earth System: A Journey in Deep Time and Space

The quantitative understanding of processes operating in the earth system has advanced significantly over the last few decades. This has led to the realization that a close interaction between deep earth and surface processes is a key element in earth dynamics and its impact on geo-environment, geo-energy, geo-resources and geo-hazards in general. The European continent and its ocean-continent margins provide an excellent natural laboratory to examine the impact of geodynamics and climate on topography at the earth’s surface. The overview presented here demonstrates the need for a further understanding of the earth system across space and timescales. Cross-border scientific cooperation on a full pan-European scale, benefiting from funding opportunities offered by the European Commission and a pro-active role in bottom-up self-organization involving members of the Earth and Cosmic Sciences section of Academia Europaea, is needed more than ever

Plume-like upper mantle instabilities drive subduction initiation

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