Tectonophysics (or lithospheric geodynamics) concentrates on trying to understand mantle and lithospheric processes that shape our planet. Although formally part of geophysics, Tectonophysics is a field right at the interface between geophysics and geology, and geophysics and geodesy. Our approach commonly is to combine quantitative study (numerical model simulations) with geological, geodetic and geophysical observations.
Subduction zones dynamics
With 2002 Ph.D. student Roberta de Franco, we used finite element models to show that the physical state of the plate boundary is a controlling factor in developing or not of back-arc ex tension. We also examined the impact of collision of continental fragments on the overall subduction process. Based on this work, we were able to recognize the connection between shallow and deep parts of global subduction contacts.
With 2006 Ph.D. student Marzieh Baes, we are working on geodynamic models for initiation of subduction. We particularly wish to understand the Cenozoic evolution of the western Mediterranean. This is a collaborative research project with the Jaume Almeira team in Barcelona, headed by Manel Fernandez.
With Ph.D. student Gabriela Tanasescu, Liviu Matenco (Free University, Amsterdam), Boudewijn Ambrosius (Delft University), we have developed a three-dimensional mechanical model for the Vrancea region in Romania that explains surface GPS observations by slab detachment.
Celine Tirel is a post-doctoral researcher, who works with us on back-arc extension models that aim to reproduce HP-LT, HT-LP assemblages that are associated with Aegean core complexes. Through modeling (involving Jean-Pierre Brun of Rennes University, Eugeni Burov from Paris VI) she adopts a computational science approach to further her successful models of core complex formation.
Seismic cycle and fault zone rheology
A new Ph.D. project aims to integrate micro-rheological flow laws into a quantitative model that intends to predict the coalescence of small fissures into field scale faults into plate boundary faults. This is a collaborative project with Chris Spiers and Hans de Bresser from the Utrecht HPT group, and Reinoud Vissers from Structural Geology.
Together with Riccardo Riva (Milano, Italy) we developed a new method to infer complex media viscosities from GPS time series of post-seismic relaxation.
Together with M.Sc. student Mara van Eck van der Sluijs (2006), we investigated Coulomb stress buildup by earthquakes along the North Anatolian Fault system (Turkey). The 2000-year earthquake catalog is used to address seismic hazard predictions, and uncertainties therein.
With Ph.D. student Gina Schmalzle and Tim Dixon (both at University of Miami), we work on an inversion of GPS time series for slip on seismically active faults in complex media. The research focuses on the San Andreas Fault system, and on the Eastern California Shear Zone.
Subduction-Transform-Edge-Propagators are plate tectonic boundaries that are similar to tear faults in structural geology. We have shown by finite element modeling that the expected imprints of these margins can be significant. Together with Ph.D. student Karin Ruckstuhl (2004), we are predicting geodetic and geological surface expression of these deep seated features in and around Calabria (southern Italy).
With 2007 Ph.D. student Alí Özbakir we are investigating the evolution of the Anatolian stress field in response to plate boundary changes.
Lithospheric stress field
With 2007 Ph.D. student Steven van Benthem we are examining the forces that control the stress field of the Caribbean and Panama plates. High resolution seismic tomography helps us to decipher the post-Oligocene evolution of its plate boundaries.
With Pete Lafemina (Penn State University) and Tim Dixon (University of Miami), we use finite element models to examine whether collision of Cocos Ridge with the Middle America trench may explains newly acquired GPS observations in Costa Rica and Nicaragua.
With M.Sc. student Sterre Dortland, we developed a kinematic model for the Panama Basin and the Isthmus from focal mechanism and GPS data. M.Sc. student Alejandra Reynaldos tested the model predicted vertical motions against geological data.
Rob Govers and Paul Meijer computed the stress field in the Juan de Fuca plate, and verified the results against observations. An important outcome of this study is that observations do not require a "transform push" force, which is one of the plate tectonic forces that were thought to drive the plates.
Messinian Salinity Crisis
We determined the impact of evaporite deposition and evaporation of the Mediterranean basin during the Messinian Salinity Crisis. An important component of these flexure calculations was making a paleogeographic reconstruction of the basin shape and depth.
Flexural uplift was instrumental in the final closure of the Gibraltar Strait region. This lead to a substantial sea level lowering in the Mediterranean. We recently proposed that sinking of the Alboran slab caused subsidence that re-opened the seaway, and flooding.
With 2008 Ph.D. student Jeroen Bartol we are investigating the possibility of a salinity crisis in the Paratethys.
Temperature and rheology of the lithosphere
With Saskia Goes (Imperial College, London) and Piere Vacher (Université de Nantes), we developed a method to extract upper mantle temperatures from seismic tomography models. We hope to apply these techniques to high-resolution results by Maisha Amaru and Wim Spakman, to develop a new temperature model for western Europe and the Mediterranean.
Tectonic control on past ocean circulation
To explore a new type of link between insight into the tectonic evolution of the Mediterranean Sea and the sedimentary record of its basins we apply ocean circulation models of varying complexity. Our focus of attention is the effect of paleogeography, in particular the geometry of sea straits, on the circulation and water properties.
Postdoc Bahjat Alhammoud works on the development of an idealised model for land-locked basins in general. Ph.D. student Pasha Karami examines the Mediterranean/Paratethys system in the Miocene, starting at the time the basin was still connected to the Indian Ocean.