in recognition of his fundamental contributions to modelling of subduction zone dynamics

Wortel’s research interests are dynamics of the lithosphere, stress field in and deformation of the lithosphere, thermo-mechanical evolution of the lithosphere and upper mantle (in particular the subduction process), earthquake generation and seismic energy release, tectonic processes along convergent plate boundaries, relationship between processes in the lithosphere and upper mantle and geological processes at or near the surface, and the geodynamical evolution of the Mediterranean region. Professor Wortel opened new routes and perspectives in a field of plate tectonics that is attracting now considerable interest, related to the integration of numerical models for dynamic processes in the lithosphere and upper mantle with geological, geophysical (in particular seismological) and geodetic observations.

Recent and ongoing research in Wortel’s Tectonophysics research group at Utrecht University stems – to a significant extent – from the hypothesis which Wortel and his group developed in 1992 on “lateral migration of slab detachment”, involving the breaking-off and sinking of subducted lithosphere in convergence zones. This is a pioneering example of using modern seismological results in seismic tomography results to quantitatively study lithospheric and upper mantle processes. The hypothesis has been (and is) subjected to numerical modelling tests and analyses – concentrating on the thermo-mechanical aspects of the hypothesis – and, through its predictions on surface observables, to several tests against geological data from subduction zone regions. The latter type of data pertain to depocentre shifts, to uplift and subsidence patterns of continental margins, and to changes in lithospheric stress field. Professor Wortel’s recent work is also connected to the mineralization processes that accompany slab detachment along convergent plate boundaries, addressing the relation between “deep” processes and processes at or near the Earth’s surface. The hypothesis appears to contribute significantly to increase our understanding of this “depth-surface” relation, in general, and of the evolution of specific convergent plate boundary regions such as the Carpathians and the Apennines, in particular.

Another related line of research involves the testing of regional tectonic reconstructions by testing forward modelling results on lithosphere and upper mantle structure against completely independent 3D seismic tomography results. Again, this research directly connects information on seismic velocity structure of the deeper lithosphere and upper mantle with regional scale geology and a quantitative approach of lithospheric processes.

In recognition of the fundamental contributions to Geophysics and Geodynamics, the European Geophysical Society honours Professor Rinus Wortel with the Stefan Mueller medal.