Papers by Rodolphe Cattin
Geophysical Journal International, Aug 10, 2016
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Geophysical Journal International, Nov 1, 2009
Over the last decade, thermomechanical models have revealed the control of both tectonics and ero... more Over the last decade, thermomechanical models have revealed the control of both tectonics and erosion on the morphology of continental plateaus margins. However, unravelling the specific effects of these two coupled processes has been difficult in practice. Here, to assess the control of erosion, we investigate the dynamics of the eastern and the northern borders of the Tibetan Plateau, which are characterized by a low convergence rate and a steep topographic escarpment adjacent to the Sichuan and Tarim basins, respectively. Thermomechanical modelling of continental lithosphere coupled with fluvial denudation reveals that important crustal deformation with large-scale horizontal displacements can occur, without any convergence, as a response to mass transfer due to gravitational collapse and to erosional unloading. These processes are sensitive to crustal structure, geothermal gradient as well as surface erosion. At a timescale of several million years, our results suggest that this denudation-triggered deformation exerts a primary control on the evolution of those plateau margins by counterbalancing the mass removal due to erosion and stabilizing the topographic escarpment. This finding supports a possible explanation for the morphology of the Longmen Shan, eastern Tibet, in which the paradoxical combination of persistent high-topographic gradients close to the foreland and low convergence rates can be related to the influence of erosion on deformation patterns.
Geophysical Journal International, Nov 7, 2017
Vertical velocities obtained from uplifted river terrace dating near mountain fronts are commonly... more Vertical velocities obtained from uplifted river terrace dating near mountain fronts are commonly converted into overthrusting slip rates assuming simple geometry of the fault at depth. However, the lack of information on the dip angle of these shallow structures can lead to misinterpretation in the accommodation of convergence, and thus to erroneous conclusions on the transfer of shortening to the emergent thrust faults. Here, to assess the impact of fault geometry, we focus on the eastern Himalayan region in the south Central Bhutan, where the topographic frontal thrust (TFT) has been already documented by GPS, paleoseismic, geomorphic and geological studies. This study is based on high-resolution near-surface geophysical investigations, including electrical resistivity, seismic and gravity measurements. Using a similar stochastic inversion approach for all data sets, new quantitative constraints on both fault geometry and petrophysical parameters are obtained to image shallow depths, in the upper ca. 80 m. The combined results from both surface observations and geophysical measurement provide a TFT geometry that is dipping northwards with a shallow angle at the top (0-5 m), steeply dipping in the middle (5-40 m) and flattening at deeper depths (>40 m). Together, our new constraints on the fault geometry allow us to estimate a minimum overthrusting slip rate of 10 ± 2 mm yr −1 , which is only a part of the ca. 17 mm yr −1 GPS convergence. This suggests that, in the study area, significant deformation partitioning on several faults including TFT and the Main Boundary Thrust cannot be ruled out. More importantly, assuming constant slip rate, the obtained dip angle variations lead to uplift rate changes with distance to the TFT. This underlines that taking into account uplift rate from terrace dating only at the front location and assuming a constant dip angle fault geometry based on surface observations may significantly bias the slip rate estimates.
HAL (Le Centre pour la Communication Scientifique Directe), Mar 7, 2012
Comptes rendus de l'Académie des sciences. Série 2. Sciences de la terre et des planètes, Jul 1, 2001
The present-day displacement field in Taiwan based on geodetic measurements is interpreted in ter... more The present-day displacement field in Taiwan based on geodetic measurements is interpreted in terms of seismic cycle strain fields due to the subduction of the China margin. We model the surface displacements, using dislocation theory, as due to variable slip on buried faults in an elastic half-space. The interseismic velocities are interpreted as a seismic slip on a 10 km deep 'décollement' leading to strain accumulation on the locked Chelungpu thrust fault (CTF), and on the partly locked Longitudinal Valley fault. The slip model on the CTF that we obtain for the Chichi earthquake, is consistent with some of the main features of the slip distribution seen in seismological and geological results. The slip increases both toward the surface and northward. The inferred WNW-ESE northern end of the rupture surface coincides with the Sanyi transfer fault zone. We conclude that the results obtained are compatible with a simple model of subduction of the Chinese margin. 2001 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS elastic modelling / dislocation / seismic cycle / Chichi earthquake / GPS / Taiwan Résumé-Cycle sismique à Taiwan d'après les données GPS. Le champ de déplacement mesuré à Taiwan par GPS est interprété en termes de cycle sismique associé à la subduction de la marge chinoise dans cette région. À partir de la théorie des dislocations, nous modélisons les déplacements en surface par des distributions de glissement sur des failles dans un demi-espace élastique. Les vitesses intersismiques sont interprétées comme résultant du glissement asismique sur un décollement transférant les contraintes sur la faille bloquée de Chelungpu (CTF) et sur la faille partiellement bloquée de la Vallée longitudinale. Pour le séisme de Chichi, les glissements obtenus sur la faille de Chelungpu sont compatibles avec les distributions de glissement déterminées à partir des observations sismologiques et géologiques, le glissement augmentant à la fois vers la surface et vers le nord. Au nord, la terminaison WNW-ESE de la rupture déduite de la modélisation coïncide avec la zone de failles de transfert de Sanyi. En conclusion, nous interprétons les résultats à l'aide d'un modèle simple de subduction de la marge chinoise. 2001 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS modèle élastique / dislocation / cycle sismique / séisme de Chichi / GPS / Taiwan Version abrégée
Geophysical Research Letters, Feb 1, 2010
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Nature Communications, Nov 21, 2014
Assessing seismic hazards remains one of the most challenging scientific issues in Earth sciences... more Assessing seismic hazards remains one of the most challenging scientific issues in Earth sciences. Deep tectonic processes are classically considered as the only persistent mechanism driving the stress loading of active faults over a seismic cycle. Here we show via a mechanical model that erosion also significantly influences the stress loading of thrust faults at the timescale of a seismic cycle. Indeed, erosion rates of about B0.1-20 mm yr À 1 , as documented in Taiwan and in other active compressional orogens, can raise the Coulomb stress by B0.1-10 bar on the nearby thrust faults over the inter-seismic phase. Mass transfers induced by surface processes in general, during continuous or short-lived and intense events, represent a prominent mechanism for inter-seismic stress loading of faults near the surface. Such stresses are probably sufficient to trigger shallow seismicity or promote the rupture of deep continental earthquakes up to the surface.
HAL (Le Centre pour la Communication Scientifique Directe), May 10, 2022
EGU General Assembly Conference Abstracts, Apr 1, 2009
AGUFM, Dec 1, 2008
Vigorous processes of collision and mountain building take place in Taiwan, where the 90 mm/yr of... more Vigorous processes of collision and mountain building take place in Taiwan, where the 90 mm/yr of convergence between the Eurasian and the Philippine Sea plates is distributed on a wide deep detachment and active faults. Consequently, Taiwan shows a very high seismic activity, including the well documented 1999 Chi-Chi earthquake on the Chelungpu fault. Here to improve seismic hazard assessment
Eos, Transactions American Geophysical Union, Aug 13, 2018
A multinational research team discovered an underestimated earthquake hazard during their 7-year ... more A multinational research team discovered an underestimated earthquake hazard during their 7-year exploration of the unique geodynamics of the eastern Himalayas in Bhutan.
AGU Fall Meeting Abstracts, Dec 1, 2019
Abstract: The interplay between t ctonics and erosion has a predominant control on the evolution ... more Abstract: The interplay between t ctonics and erosion has a predominant control on the evolution of the morphology of mountain belts. Here we investigate he modalities of defor-mation in Central Nepal on a c. 100 ka time scale in response to tectonic and external for-cings, through the use of a finite-element thermomechanical model coupled with an integrative denudation formulation that accounts for fluvial incision and hillslope land-sliding. We study the complex coupling existing between tectonics and erosion, with special emphasis on the influences of rock strength and rainfall distributions. Our results underline the key role played by lithologic variations in the elevation of both rivers and mean topogra-phy. We show that the location of the Main Frontal Thrust is mainly controlled by the low erodability of the unconsolidated sandstone in the Siwaliks Hills. As previously suspected (Burbank et al. 2003), our simulations demonstrate that the pattern of uplift in Nepal is mainly ...
La chaine himalayenne, situee sur la bordure sud du plateau tibetain, est sans doute la manifesta... more La chaine himalayenne, situee sur la bordure sud du plateau tibetain, est sans doute la manifestation la plus spectaculaire de la collision entre l’Inde et l’Eurasie. La vitesse de convergence actuelle, d’environ 40 mm/an entre ces deux plaques, est accommodee pour moitie au travers de l’Himalaya, le long d’une grande faille chevauchante communement appelee le MHT (pour Main Himalayan Thrust).
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Papers by Rodolphe Cattin