Papers by Francois Jouanne
Influence of Climate Changes and Catchment Altitudinal Distribution on Fluvial Terrace Formation in a Mountainous Area: The Example of Albanian Rivers
HAL (Le Centre pour la Communication Scientifique Directe), Jul 1, 2017
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary 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.
Active deformation at Gr�msv�tn subglacial volcano: a composite evolution to be deciphered
Tectonics, 1995
Two high‐precision leveling networks were successively surveyed in France, the NGF, measured duri... more Two high‐precision leveling networks were successively surveyed in France, the NGF, measured during the 1886–1907 period, and the IGN69, measured from 1965 to 1979. The accuracy of these levelings (standard deviation of 1.8mm/√km to 3.8mm/√km) allows us to compute the vertical displacements of the benchmarks between two different eras. The results indicate the occurrence of discrete zones of uplift and subsidence: (1) a regional uplift (up to 1.4 mm/yr) of the Subalpine Massifs; (2) an important uplift of the internal Jura (up to 2 mm/yr); (3) a relative subsidence of the southern part of the Jura (0.8 mm/yr); and (4) a relative subsidence of the Bresse Basin with respect to the external Jura. Comparing the spatial distribution of zones of uplift and their respective vertical displacement rates with a regional structural cross section leads to the conclusion that present‐day uplift of the Belledonne and Bornes Massifs and of the internal parts of the Jura Mountains, can be explained...
Bulletin de la Soci�t� G�ologique de France, 2006
The Boconó Fault system is a major active tectonic feature accommodating an important part of th... more The Boconó Fault system is a major active tectonic feature accommodating an important part of the dextral relative motion between the Caribbean Plate and northern South-America. The main trace follows an axial valley running SW-NE within the Mérida Andes (northwestern Venezuela), and crosscuts a series of moraines related to late Pleistocene glaciers developments and retreats, at an altitude between 2600 and 5000 m. Several lakes were generated after the last retreat (between the Late Glacial Maximum –LGM– and the Younger Dryas re-advance), dammed by lateral and frontal moraines. Among them, the Los Zerpa moraine system yielded rich outcrops ranging from an upstream very coarse torrential to deltaic fill, to a downstream clayey-silty horizontal laminated lacustrine accumulation; a fore-set-type heterogeneous “prograding” body links the two sets. The whole system, as well as the surrounding moraines, underwent successive major earthquakes during the Late Glacial/lower Holocene peri...
Comptes Rendus de l'Académie des Sciences - Series IIA - Earth and Planetary Science, 1998
Active deformation in the southern part of the Rhinegraben, studied by comparing leveling measure... more Active deformation in the southern part of the Rhinegraben, studied by comparing leveling measurements, is characterized by vertical movements. Upward movements greater than 1 mm.y-' have been measured near Mulhouse and Hestat. Smaller rates of uplift averaging 1 rnrn.y-' were also observed above some groups of salt plugs striking NW-SE. Both types of vertical uplift are compatible with the regional stress field. The movements may be associated with the reactivation of NE-striking Variscan thrusts and with continuing upward growth of those salt plugs that are perpendicular to the minimum horizontal stress. ( Academic des sciences / Elsevier, Paris.) leveling / present-day vertical movements / salt plugs / Alsace / Rhinegraben R&urn4 -Une ktude de la deformation de la partie sud du foss& rhbnan, en Alsace, par comparaison de nivellements, r&Ye un deplacement vertical actif & la surface de cet ancien rift. Les vitesses moyennes de mouvement vertical estimees font apparaitre une activite diffbrentielle : le Nord (region de Sblestat) et le Sud (region de Mulhouse) de la zone &udir?!e sont en soulkement relatif, h une vitesse supkrieure B 1 mm-an-' par rapport & un point de rkference situ& dans le fossk, au sud de Colmar. Une activite ascensionnelle des rides salif&es orientkes NW-SE a la vitesse de 1 mm.an-' est &alement mise en bvidence. Ces deux types de mouvement peuvent &tre expliquks par I'action du champ de contrainte actuel, qui rkactiverait en profondeur d'anciens chevauchements hercyniens et favoriserait I'ascension des rides saliferes perpendiculaires & la contrainte principale minimale connue dans la region. (0 Academic des sciences / Elsevier, Paris.
North-western Himalayan active front: what paleoseismology tells us about very large thrusts
Along the North-western Himalayan front, in the Riasi town area (India), the Medlikot-Wadia thrus... more Along the North-western Himalayan front, in the Riasi town area (India), the Medlikot-Wadia thrust (MWT) splays into 3 segments that put in contact Precambrian limestones with Quaternary fluvial deposits of the Chenab river and its tributaries. While the internal-most segments are sealed by late quaternary deposits of the Nodda river, the two external-most segments affect these deposits, dated at 14 +/-2 ka. These two segments forms two sub-parallel scarps of 20 2 m and 23 2 m at a distance of a few hundred meters. Two trenches were excavated on these segments, showing each the occurrence of at least 2-3 main events with co-seismic displacements of several meters. First radiocarbon ages obtained on these trenches tend to show an in-sequence rupture behavior at the local scale, with the last event that would correspond to the major 1555 Kashmir historical earthquake.
Journal of Geophysical Research: Solid Earth, 2014
Episodic GPS measurements are used to quantify the present-day velocity field in the northwestern... more Episodic GPS measurements are used to quantify the present-day velocity field in the northwestern Himalaya from the southern Pamir to the Himalayan foreland. We report large postseismic displacements following the 2005 Kashmir earthquake and several mm/yr thrusting of the central segment of the Salt Ranges and Potwar Plateau over the foreland, westward thrusting of Nanga Parbat above the Kohistan Plateau, and ~12 mm/yr SSE velocities of the Karakorum Ranges and of the Deosai and Kohistan Plateaus relative to the Indian Plate. Numerical simulations allow to determine a first approximation of slip along active faults: (1) substantial creep of ~87 mm/yr between 2006 and 2012 along the flat northeast of the Balakot-Bagh Thrust affected by the 2005 earthquake; (2) ~5 mm/yr slip of the central segment of the Salt Ranges and Potwar Plateau, whereas their western boundaries are clearly inactive over the time span covered by our measurements; (3) 13 mm/yr ductile slip along the Main Himalayan Thrust modeled by a dislocation dipping 7°northward, locked at a depth of 15 km; and (4) ~20 mm/yr slip along the shear zone forming the western boundary of Nanga Parbat, between depths of 1.6 and 6.5 km. Residuals velocities suggest the existence of left-lateral strike slip along the Jhelum Fault.
Estimation of active faulting in a slow deformation area: Culoz fault as a case study (Jura-Western Alps junction)
The north-western Alps foreland is considered as still experiencing distal effects of Alpine coll... more The north-western Alps foreland is considered as still experiencing distal effects of Alpine collision, resulting in both horizontal and vertical relative displacements. Based on seismological and geodetic surveys, detailed patterns of active faulting (including subsurface décollements, blind ramps and deeper crustal thrusts have been proposed (Thouvenot et al., 1998), underlining the importance of NW–SE left-lateral strike-slip offsets as along the Vuache and Culoz faults (cf. the 1996 Epagny event: M=5.4; Thouvenot et al., 1998 and the 1822 Culoz event I=VII-VIII; Vogt, 1979). In parallel to this tectonic evolution, the last glaciation-deglaciation cycles contributed to develop large and over-deepened lacustrine basins, such as Lake Le Bourget (Perrier, 1980). The fine grain, post LGM (ie post 18 ky), sedimentary infill gives a good opportunity to evidence late quaternary tectonic deformations. This study focuses on the Culoz fault, extending from the Jura to the West, to the Chau...
Eos, Transactions American Geophysical Union, 1995
High resolution geodetic surveys of the present day deformation along the South-Caribbean margin
In early 2003, a joint effort by FUNVISIS and University of Savoie installed 36 new brass benchma... more In early 2003, a joint effort by FUNVISIS and University of Savoie installed 36 new brass benchmarks covering eastern Venezuela in order to estimate the slip along the El Pilar Fault (EPF) system and of other minor active faults, as well as the eventual rotation of tectonic blocks. Most of these benchmarks were planted into stable natural rock outcrops, when possible. Sites were occupied in 2003, 2005 and 2013. More recently, we have targeted western Venezuela, where 19 new brass benchmarks were installed into rock outcrops in late 2011. Late in the same year and in early 2013, 30 sites (including new sites and already existing benchmarks) were measured in the western network. The sites have been measured with dual-frequency GPS and geodetic antennas for at least two 24h sessions with 30s sampling intervals. Data have been analyzed with Bernese 5.2 software using absolute antenna phase center offsets models, as well as IGS -final precise orbits and Earth rotation parameters- and dat...
Enregistrement d'une activité sismo-tectonique récente dans les sédiments du Lac du Bourget. Abstracts of the'14ième Réunion des Sciences de la Terre', April 1992, Toulouse. Edit. Soc. Géol. Fr., 1992, p. 49
Seismic and Volcanic Hazard In Iceland: Contribution of Continuous GPS Measurements
To better assess seismic hazard in Iceland, 14 continuous GPS (CGPS) stations have been installed... more To better assess seismic hazard in Iceland, 14 continuous GPS (CGPS) stations have been installed since the beginning of 1999. These stations are located mostly in the southern and northern seismic zones where transform motions occur. These transform faults zones are affected by the largest seismic events in Iceland. Indeed, numerous M>6 earthquakes occurred during the last century in the
Ongoing inflation and magma accumulation of Grimsvotn subglacial volcano, Iceland
The sub-glacial Grimsvotn volcano, one of Iceland&#39... more The sub-glacial Grimsvotn volcano, one of Iceland's most active volcanoes, erupted in 1983, 1998 and 2004. Since 1998, annual GPS measurements have been conducted at the only available nunatak at the volcano, located on the rim of its caldera. A clear pattern of deformation is observed that can be attributed to magma inflow and outflow, uplift due to glacial thinning,
Active deformation at Grímsvötn subglacial volcano: a composite evolution to be deciphered
The sub-glacial Grímsvötn volcano, Iceland's currently most frequently erupting v... more The sub-glacial Grímsvötn volcano, Iceland's currently most frequently erupting volcano, is located under Vatnajökull, the largest ice cap in Europe. This volcano has experienced 20 eruptions the last 200 years, with the most recent in 1998 and 2004. Since the 1998 eruption, annual campaign GPS measurements have been conducted at the only available nunatak, located on the south caldera rim.
Asymmetrical and heterogeneous elasto-static deformation along the El Pilar Fault in Northeastern Venezuela
ABSTRACT Velocities field in both sides of the El Pilar fault, the most important right-lateral s... more ABSTRACT Velocities field in both sides of the El Pilar fault, the most important right-lateral strike-slip fault of the Caribbean–South America plate boundary, present an important asymmetry. This pattern suggests a change in elastic properties when crossing the fault. We have applied an asymmetric model to simulate observed velocities with 20 mm/yr creep at depth, corresponding at the relative velocity of Caribbean plate versus South America plate. The preferred model indicated a shallow locking depth at 4.5 km. In a second part, a near-fault low-rigidity compliant zone from 3 km of depth with a 30 per cent of rigidity reduction respect to the environment is proposed using a 3D elasto-static model. We use GPS data from 23 stations collected in 2002 and 2005 like input parameters as well as geometry parameters based in previous work. The shallow locking depth and the interseismic velocities used in the asymmetry and compliant zone models respectively support: i) the hypothesis of a partially locked seismogenic upper part, ii) the concentration of the Caribbean- South America relative displacement entirely along the El Pilar Fault. Reinoza Carlos PhD thesis and stay in ISTerre Laboratory is funded through Venezuela’s FUNDAYACUCHO Grant N° 756514C. This research is a contribution to FONACIT-ECOS Nord grant V10U01.
Ground surface deformation induced by salt diapirism in oil field zones: Some examples in SE Zagros (Iran)
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary 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.
Slow deformation in the Western Alps from a decade of continuous GPS measurements
REGAL: a permanent GPS network in the western Alps. Configuration and first results
Bulletin De La Societe Geologique De France, 2001
The kinematics of the present-day deformation in the western Alps is still poorly known, mostly b... more The kinematics of the present-day deformation in the western Alps is still poorly known, mostly because of a lack of direct measurements of block motion and internal deformation. Geodetic measurements have the potential to provide quantitative estimates of crustal strain and block motion in the Alps, but the low expected rates, close to the accuracy of the geodetic techniques, make such measurements challenging. Indeed, an analysis of 2.5 years of continuous GPS data at Torino (Italy), Grasse (France), and Zimmerwald (Switzerland), showed that the present-day differential motion across the western Alps does not exceed 3 mm/yr [Calais, 1999]. Continuous measurements performed at permanent GPS stations provide unique data sets for rigorously assessing crustal deformation in regions of low strain rates by reducing the amount of time necessary to detect a significant strain signal, minimizing systematic errors, providing continuous position time series, and possibly capturing co- and post-seismic motion. In 1997, we started the implementation of a network of permanent GPS stations in the western Alps and their surroundings (REGAL network). The REGAL network mostly operates dual frequency Ashtech Z12 CGRS GPS stations with choke-ring antennae. In most cases, the GPS antenna is installed on top of a 1.5 to 2.5 m high concrete pilar directly anchored into the bedrock. The data are currently downloaded once daily and sent to a data center located at Geosciences Azur, Sophia Antipolis where they are converted into RINEX format, quality checked, archived, and made available to users. Data are freely available in raw and RINEX format at http://kreiz.unice.fr/regal/. The GPS data from the REGAL network are routinely processed with the GAMIT software, together with 10 global IGS stations (KOSG, WZTR, NOTO, MATE, GRAZ, EBRE, VILL, CAGL, MEDI, UPAD) that serve as ties with the ITRF97. We also include the stations ZIMM, TORI, GRAS, TOUL, GENO, HFLK, OBER because of their tectonic interest. We obtain long term repeatabilities on the order of 2-3 mm for the horizontal components, 8-10 mm for the vertical component. Using a noise model that combines white and coloured noise (flicker noise, spectral index 1), we find uncertainties on the velocities ranging from 1 mm/yr for the oldest stations (ZIMM, GRAS, TOUL, TORI, SJDV) to 4-5 mm/yr for the most recently installed (CHAT, MTPL). Station velocities obtained in ITRF97 are rotated into a Eurasian reference by substracting the rigid rotation computed from ITRF97 velocities at 11 central European sites located away from major active tectonic structures (GOPE, JOZE, BOR1, LAMA, ZWEN, POTS, WETT, GRAZ, PENC, Effelsberg, ONSA). The resulting velocity field shows residual motions with respect to Eurasia lower than 3 mm/yr. We obtain at TORI, in the Po plain, a residual velocity of 2.3+ or -0.8 mm/yr to the SSW and a velocity of 1.9+ or -1.1 mm/yr at SJDV, on the Alpine foreland. These results indicate that the current kinematic boundary conditions across the western Alps are extensional, as also shown by the SJDV-TORI baseline time series. We obtain at MODA (internal zones) a residual velocity of 1.2+ or -1.2 mm/yr to the SSE. The MODA-FCLZ baseline show lengthening at a rate of 1.6+ or -0.8 mm/yr. These results are still marginally significant but suggest that the current deformation regime along the Lyon-Torino transect is extension, as also indicated by from recent seismotectonic data. It is in qualitative agreement with local geodetic measurements in the internal zones (Briancon area) but excludes more than 2.4 mm/yr of extension (FCLZ-MODA baseline, upper uncertainty limit at 95% confidence). Our results indicate a different tectonic regime in the southern part of the western Alps and Provence, with NW-SE to N-S compression. The GRAS-TORI baseline, for instance, shows shortening at a rate of 1.4+ or -1.0 mm/an. This result is consistent with seismotectonic data and local geodetic measurements in these areas. The Middle Durance fault zone, one of the main active faults in this area, is crossed by the GINA-MICH baseline, which shows shortening at a rate of 1.0+ or -0.8 mm/an. This result is only marginally significant, but confirms the upper bound of 2 mm/yr obtained from triangulation-GPS comparisons. The REGAL permanent GPS network has been operating since the end of 1997 for the oldest stations and will continue to be densified. Although they are still close to or within their associated uncertainties, preliminary results provide, for the first time, a direct estimate of crustal deformation across and within the western Alps.
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Papers by Francois Jouanne