Jean-Louis Mugnier

• Doctor of Engineering
• CNRS

Glacial cirques are key indicators of interactions between glaciers, climate, and topography. Moraine formation in glacial cirques is mainly influenced by periglacial and subglacial erosion processes, glacier dynamics, and topography. The intensity and spatio-temporal variability of erosion processes are climate-driven, yet climate is rarely consid...

Since the end of the 20th century, each decade has been warmer than the previous one in the European Alps. As a consequence, Alpine rock walls are generally facing high rockfall activity, likely due to permafrost degradation. We use a unique terrestrial laser scanning derived rockfall catalog over 18 years (2005–2022) compared with photographs (185...

We studied a newly identified, multiple-kilometer-long rock slope failure in the Aiguilles Rouges massif (Chamonix valley, France). Owing to a high-resolution light detection and ranging (LiDAR) digital elevation model (DEM) and field work, we mapped morphostructures, including scarps, open fractures, and counterscarps. In some places, vertical off...

Present-day global warming raises important issues regarding sediment flux from glaciated catchments. The detrital export from such environments results from erosion processes operating in three geomorphic domains: the supraglacial rockwalls, the ice-covered substratum and the proglacial area, downstream from the glacier. The dominant process contr...

The pattern of active deformation of frontal structures in Darjeeling Himalaya is complex with out‐of‐sequence reactivations in the chain and development of scarps associated to earthquake ruptures reaching the surface in the piedmont. To clarify the distribution of active deformation in this area, we analyze passive seismic records by the Horizont...

The morphological boundary between the Himalayas and the foreland plain is well expressed and most often corresponds to the frontal emergence of the Main Himalayan Thrust (MHT). This boundary is affected by surface ruptures during very large Himalayan earthquakes (Mw > 8) that regularly induce (with a recurrence of the order of 500 to 1200 years) t...

See mai papers

Rockwall erosion due to rockfalls is one of the most efficient erosion processes in the highest parts of mountain ranges. It is therefore important to quantify this erosion to understand the long-term evolution of mountainous topography. In this study, we analyze how the 10 Be concentration of supraglacial debris can be used to quantify the rockwal...

In the days to weeks following an earthquake, landslides can display specific post-seismic motions, including delayed initiations and post-seismic relaxations. These motions have an uncertain origin, sometimes attributed to specificities of the landslide basal interface or to fluid transports in the landslide basal shear zone. Here we address this...

Mainland France is part of a plate interior with a strong structural heritage, undergoing a low rate of deformation, where destructive earthquakes can nevertheless occur. In this paper, we emphasize that the knowledge of active faults is still largely fragmentary, and that significant efforts are needed to generate robust data, in particular on the...

Mainland France is part of a plate interior with a strong structural heritage, undergoing a low rate of deformation, where destructive earthquakes can nevertheless occur. In this paper, we emphasize that the knowledge of active faults is still largely fragmentary, and that significant efforts are needed to generate robust data, in particular on the...

The reconstruction of mountain glacier response to rapid climate change in the past allows accessing the effects of current climate change. Yet, the spatial and temporal variability of past glacier fluctuations is not fully understood. In this study, we address the timing of glacier fluctuations in the European Alps during the Younger Dryas/Early H...

We used episodic GNSS measurements to quantify the present‐day velocity field in the northwestern Himalaya from the Himalayan foreland to the Karakoram Range. We report a progressive N‐S compressional velocity gradient with two noticeable exceptions: in the Salt Range, where important southward velocities are recorded, and in Nanga Parbat, where an...

In Kashmir Himalaya, the Medlicott-Wadia Thrust is a main active fault responsible for the crustal accretionary prism building during the Late Quaternary. Because of the long seismic silence during the last five centuries, it is a key structure to be studied in order to estimate the regional seismic hazard. In the Riasi area, the analysis of two pa...

The Mont-Blanc massif, being iconic with its large glaciers and peaks of over 4,000 m, will experience a sharp increase in summer temperatures during the twenty-frst century. By 2100, the impact of climate change on the cryosphere and hydrosphere in the Alps is expected to lead to a decrease in annual river discharge. In this work, we modelled the...

Cosmogenic nuclide dating of glacial landforms may lead to ambiguous results for ice retreat histories. The persistence of significant cosmogenic concentrations inherited from previous exposure may increase the apparent exposure ages for polished bedrocks affected by limited erosion under ice and for erratic boulders transported by glaciers and pre...

Fluviatile sediments comprising a 600‐m‐thick sequence of the Lower and Middle Siwaliks in the Karnali area in Nepal exhibit a distinct zonation revealed by magnetic and geochemical properties. Four magneto‐chemical zones (MCZ1–MCZ4), each about 150 m thick and 400 kyr in duration, provide new insights into Himalayan tectono‐climatic events during...

Sidewall erosion because of rockfalls is one of the most efficient erosional processes in the highest parts of mountain ranges; it is therefore important to quantify sidewall erosion to understand the long‐term evolution of mountainous topography. In this study, we analyse how the ¹⁰Be concentration of supraglacial debris can be used to quantify si...

The postseismic deformation consecutive to the April 25, 2015 Gorkha earthquake (Mw 7.9) is estimated in this paper based on a cGNSS network installed prior to the earthquake and supplemented by 6 cGNSS stations installed after the main shock. Postseismic displacement are obtained from daily time series corrected for interseismic deformation and se...

The sediment yields of Alpine catchments are commonly determined from streamload measurements made some distance downstream from glaciers. However, this approach indiscriminately integrates erosion processes occurring in both the glacial and proglacial areas. A specific method is required to ascertain the respective inputs from (i) subglacial and s...

Cold climate carbonates can be used as paleoclimatic proxies. The mineralogy and isotopic composition of subglacially precipitated carbonate crusts (SPCCs) provide insights into the subglacial conditions and processes occurring at the meltwater-basement rock interface of glaciers. This study documents such crusts discovered on the lee side of a gne...

The recent activity of the Medlicott-Wadia Thrust (MWT) is investigated by geomorphic and tectonic studies in the Riasi zone, south of the Pir Panjal range (India, Jammu-Kasmir state of western Himalaya). In the Riasi area, the MWT forms a splay of five faults that dip northward. The recent activity of the splay is quantified using a set of deforme...

We present the results of a structural neotectonic survey undertaken on the Mahesian Anticline in the frontal Himalaya of Pakistan. This anticline resulted from the folding of Precambrian to Tertiary layers that was controlled by a thrust and a backthrust, interacting in a complex way. Four generations of fluvial terraces formed by the Jhelum River...

We put the 25 April 2015 earthquake of Nepal (Mw 7.9) into its structural geological context in order to specify the role of the segmentation of the Himalayan megathrust. The rupture is mainly located NW of Kathmandu, at a depth of 13–15 km on a flat portion of the Main Himalayan Thrust (MHT) that dips towards the N-NE by 7 to 10°. The northern bou...

L’érosion sous-glaciaire est estimée à partir du flux sédimentaire de torrents en provenance des glaciers. Pour ce faire, nous avons instrumenté les torrents des Bossons et de Crosette situés à l’aval du glacier des Bossons. Les solutions trouvées pour résoudre les problèmes liés à la complexité du terrain proglaciaire sont exposées. Elles reposent...

This dataset presents Differential Global Positioning System data (DGPS) acquired within the Bossons glacier proglacial area. Bossons glacier is a rapidly retreating glacier and its proglacial area is deglaciated for ~30 years. Bossons stream is one of the outlets of the subglacial drainage system. It starts as a 800 m steep cascade reach, then flo...

This dataset presents hydro-sedimentary data within the Bossons glacier proglacial area. Bossons glacier is rapidly retreating and its proglacial area is deglaciated for ~ 30 years. It is an intriguing location to study periglacial, proglacial and subglacial erosion processes which requires estimating Total Dissolved Solid (TDS) and Total Suspended...

Positive structural inversion involves the uplift of rocks on the hanging-walls of faults, by dip slip or oblique slip movements. Controlling factors include the strike and dip of the earlier normal faults, the type of normal faults — whether they were listric or rotated blocks, the time lapsed since extension and the amount of contraction relative...

Three main Cenozoic thrusts at the front of Northwestern Himalaya have accommodated most of the India–Eurasia convergence across the belt over the last million years and produced the present relief. Their recent tectonic activity is poorly known because of the long period of inaccessibility of the Jammu and Kashmir state, and because the latest and...

Deciphering the complex interplays between climate, uplift and erosion is not straightforward and estimating present-day erosion rates can provide useful insights. Glacier are thought to be powerful erosional agents, but most published “glacial” erosion rates combine periglacial, subglacial and proglacial erosion processes. Within a glaciated catch...

Sedimentary records in peripheral basins of mountain belts record changes in erosion dynamics and drainage-network reorganization, but it is often difficult to discriminate between these different controls. Geochemical provenance data on paleo-Indus deposits from the western Himalayan foreland provide constraints on the possible variation of the po...

Fast uplift and exhumation of the Himalaya and Tibet and fast subsidence in the foreland basin portray the primary Neogene evolution of the Indian-Eurasian collision zone. We relate these events to the relative northward drift of India over its own slab. Our mantle- flow model derived from seismic tomography shows that dynamic topography over the s...

This dataset presents sediment load grain size distributions of Bossons stream, one of the subglacial streams draining Bossons glacier meltwater. Bossons glacier is rapidly retreating and its proglacial area is deglaciated for ~ 30 years. Within this area, Bossons stream flows through an alluvial plain with day-to-day morphological evolution. It i...

In this paper, 3 years of surface displacement measurements obtained by space-borne synthetic aperture radar (SAR) observations are presented over the Argentière glacier in the Mont-Blanc massif, France. This temperate glacier is instrumented by a network of four Global Positioning System (GPS) stations used as ground truth. Thirty-eight pairs of d...

We provide empirical evidence for the impact of surface processes on the structure of the present-day foreland fold-and-thrust belt of the Himalaya. We have reconstructed and analyzed ten balanced cross sections distributed along the entire length of the Himalayan arc. Here, we focus on the Siwalik Group, which represents the deformed part of the f...

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 thru...

Notre étude est basée sur la datation des morphologies glaciaires par la méthode des nucléides cosmogéniques in situ sur quatre sites dans la vallée de la Maurienne et la vallée du Mont Blanc. En utilisant une nouvelle stratégie d’échantillonnage, nous avons cherché à mieux contraindre les processus qui influencent les âges d’expositions (facteurs...

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 exter...

Geometric and kinematic analyses of minor thrusts and folds, which record earthquakes between 1200 AD and 1700 AD, were performed for two trench sites (Rampur Ghanda and Ramnagar) located across the Himalayan Frontal Thrust (HFT) in the western Indian Himalaya. The present study aims to re-evaluate the slip estimate of these two trench sites by est...

Fluvial terraces of Shkumbin, Devoll, Osum and Vjosa rivers (southern Albania and northwestern Greece) are studied in order to quantify the vertical slip rates of the large active faults of the Dinaric-Albanic-Hellenic Alpine fold belt. The spatial and temporal variations of the incision rates along these rivers were estimated from the geomorpholog...

Current tectonics of Albania is documented by neotectonics evidences and by a large number of medium size earthquakes. Focal mechanisms suggest a current shortening across the external Albanides whereas internal Albanides are affected by extension with direction varying from E–W to N–S extension. To investigate the kinematics of Albanides, we integ...

The efficiency of erosional processes is classically considered from detrital composition at the outlet of a shed that reflects the rocks eroded within the shed. We adapt fluvial detrital thermochronology (DeCelles et al., 2004) and lithology (Attal and Lavé, 2006) methods to the subglacial streams of the north face of the Mont Blanc. The lithology...

We present measurements of the surface velocity of the Argentière glacier in the Mont Blanc massif, France, obtained by SAR and GPS observations. We produce surface velocity fields from several couples of descending and ascending TerraSAR-X acquisitions repeated at 11 days intervals in spring 2009, using the offset power tracking technique. Moreove...

Over the last millions years, the crustal shortening across the Himalaya of the Indian Kashmir have been accommodated by three sub-parallel emerging thrusts: the Main Boundary Thrust (MBT), the Medlicott-Wadia Thrust (MWT) and the Main Frontal Thrust (MFT). The alternate occurrence of in sequence and out of sequence deformational patterns at the hi...

A better knowledge about erosion is needed to understand the relief evolution in glacial and peri-glacial context. In the Mont-Blanc area, Bossons Alpine glacier was choosen: to estimate 1) the part of glacial erosion versus peri-glacial denudation and 2) the total detrital sediment fluxes in this partially glaciated watershed in a context of glaci...

The Ganga River is one of the main conveyors of sediments produced by Himalayan erosion. Determining the flux of elements transported through the system is essential to understand the dynamics of the basin. This is hampered by the chemical heterogeneity of sediments observed both in the water column and under variable hydrodynamic conditions. Using...

3) LISTIC, Polytech Annecy-Chambéry, BP 80439, 74944 Annecy-le-Vieux cedex, France (emmanuel.trouve@univ-savoie.fr), (4) now at GePaSud, Université de Polynésie française, B.P. ABSTRACT We present four years of GPS data acquired continuously on the Argentière glacier in the Mont Blanc massif, France. Our local permanent GPS network is composed of t...

Soft-sediment deformation structures have been analyzed at six sites of the Kathmandu valley. Microgranulometric study reveals that silty levels (60 to 80% silt) favor the development of soft-sediment deformation structures, while sandy levels (60 to 80% sand) are passively deformed. Nonetheless well sorted sand levels (more than 80% sand) generate...

The 8 October 2005 Kashmir earthquake ruptured an out-of-sequence Himalayan thrust known as the Balakot-Bagh thrust. The earthquake's hypocenter was located at a depth of 15 km on the ramp close to a possible ramp/flat transition. In the weeks following the earthquake a GPS network was installed to measure postseismic displacement. The initial meas...

A new generation of space-borne SAR sensors were launched in 2006-2007 with ALOS, TerraSAR-X, COSMO-Sky-Med and RadarSat-2 satellites. The data available in different bands (L, C and X bands), with High Resolution (HR) or multi-polarization modes offer new possibilities to monitor glacier displacement and surface evolution by SAR remote sensing. In...

The Himalayan range is commonly presented as largely laterally uniform from west to east. However, geological structures, topography, precipitation rate, convergence rates, and low-temperature thermochronological ages all vary significantly along strike. Here, we focus on the interpretation of thermochronological data sets in terms of along-strike...

1] The Ganga River is one of the main conveyors of sediments produced by Himalayan erosion. Determining the flux of elements transported through the system is essential to understand the dynamics of the basin. This is hampered by the chemical heterogeneity of sediments observed both in the water column and under variable hydrodynamic conditions. Us...

Four structural cross-sections through the central segment of the Upper Rhine Graben (URG) were balanced by means of Thermo-Tectono-Stratigraphic Forward Modelling (TTSF-Modelling). Results were compared to geometric retro-deformation of pre-rift reference horizons applying line length and area balancing methods. TTSF-Modelling with a deep necking...

Soft-sediment deformation structures have been analyzed at six sites of the Kathmandu valley. Microgranulometric study (this Supplement and Fig. 3B of Mugnier et al., Tectonophysics, 2011) reveals that silty levels (60 to 80% silt) favor the development of soft-sediment deformation structures, while sandy levels (60 to 80% sand) are passively defor...

We study the main emergence of the Main Himalayan Thrust (MHT), in the western Himalaya. The MHT is the active Indian/Asian plate boundary and is responsible for M > 8 shallow earthquakes. Its main emergence in west Himalaya occurred along the Medlicott Wadia Thrust (MWT) responsible for the 2005 M 7.6 Balakot earthquake in Pakistan. In the Riasi a...

This paper explores the possibilities to estimate the 3D displacement field of Alpine glaciers by using high resolution TerraSAR-X images. The amplitude correlation technique applied on 11-day repeat pass data provides two projections of the surface displacement. The combined use of ascending and descending data acquired over almost the same period...

The Siwaliks are the currently active foothills of the Himalayas, in which erosion, sedimentation, and faulting are proceeding simultaneously. Cross-sections in western Nepal show at least three major north-dipping thrust zones. Displacement is transferred laterally from one thrust to another, and anticlines form at the tips of the propagating faul...

A geomorphological map was constructed, based on satellite imagery of the recent geomorphological evolution of the delta of the Seman and the Vjosa rivers, Albania. Results of the analysis of data collected from unpublished geological profiles carried out by Russian and Albanian geologists indicate that concentrations of heavy minerals are clearly...

Although the Himalayan range is commonly presented as cylindrical along-strike, geological structures, topography, precipitation rate, convergence rates and low - temperature thermochronological ages all vary significantly from west to east. Here, we focus on the interpretation of thermochronological datasets in term of cylindricity in geometry and...

We study the recent dynamics of the central Nepal Himalaya, focusing on possible reactivation of the footwall of the Main Central thrust, which is marked by an abrupt topographic transition. Different tectonic mechanisms, such as overthrusting of a major crustal ramp, underplating, or out-of-sequence thrusting, have been suggested to explain the mo...

In Albania, the Osum and Vjoje rivers cross the active graben system and the active frontal thrust system of the Albanides. The effects of climatic and geodynamic forcing on the development of these two rivers were investigated by the means of field mapping, topographic surveying and absolute exposure-age dating. We established the chronology of te...

We study the recent dynamics of the Himalayan orogen in central Nepal with the specific goal of quantifying the onset of activity and the deformation history recorded by the different major thrusts along the Himalayan range, and propose a structural and kinematic model of the major crustal Himalayan thrust, the MHT. We report 27 new apatite fission...

We have conducted a systematic inversion of striated fault planes throughout northern Pakistan in order to better depict the temporal and spatial variations in stress patterns. Two domains are evidenced at a regional scale, separated by the active Raikhot fault, the western boundary of the Nanga Parbat spur. West of this fault, a wrench-type stress...

DOI = 10.3126/hjs.v5i7.1296 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.106

Lake Shkodra (northern Albania, southern Montenegro) is a large (45km length, 15km width) and shallow (5m mean depth) lake, developed on a mainly karstic carbonate substratum. Its recent sedimentary fill (mixed calcareous/siliciclastic clayey silts) was analysed through short gravity cores representing five centuries of environmental archive. A com...