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Your search keyword '"Ori, G."' showing total 6 results
Start Over Author "Ori, G." Topic [sdu.stu.gm]sciences of the universe [physics]/earth sciences/geomorphology
6 results on '"Ori, G."'

1. Morphological characterization of springtime seasonal activity on the Russell dune (Mars)

Author

Jouannic, G., Gargani, J., Costard, F., Chiara Marmo, Schmidt, F., Bourgeois, O., Massé, M., Ori, G. G., Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), International Research School of Planetary Sciences [Pescara] (IRSPS), and Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A)

Subjects
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology
Abstract

International audience; From a theoretical point of view, pure liquid water is not likely to be found at the present time on the Martian surface because atmospheric pressure/temperature conditions are below the water triple-point. However, gullies discovered by Malin and Edgett (2000) suggest that significant amounts of liquid water have flowed on Mars in a recent past. Recent works showed that Martian dunes have exhibited modifications over the past years, including topographic changes on aprons and new channel incisions into dune surfaces (Diniega et al., 2010; Dundas et al., 2010; Reiss et al., 2010; Hansen et al., 2011). These seasonal activities can be explained by CO 2 frost processes (Diniega et al., 2010; Dundas et al., 2010; Hansen et al., 2011) or melting of water frost and/or near surface ice triggering sand-water flows (Reiss et al., 2010). The new possibility given by HiRISE images to perform precise monitoring of present modifications of the surface of Mars allows to improve our understanding of the seasonal activity and of the topographic evolution of dunes. Numerous changes could be observed during the last three Martian years. Here, we show that there is a perennial activity on the Martian dune Russell: surface flows appear seasonally (Reiss et al., 2010), after the total disappearance of CO 2 at spring (Gardin et al., 2010; Reiss et al., 2010), and are able to erode their substrate. This perennial activity is constituted by a complex interconnected rill system that is recorded all year long and which grows from one year to the next at a rate of 10000 m2.yr-1. These flows are viscous and able to erode as well to transport a non negligible quantity of sand with a grain size of 500±100 [U+F06D]m at a minimum velocity of ∼1.4.10-4m.s-1. These flows could be composed in part of liquid water. The origin of the liquid water is probably from the melting of the water ice (accumulated on the dune surface by vapour condensation during winter) at spring or/and from the defrosting of a small active layer of permafrost. There are at least four processes that could explain the physical properties of this perennial activity: (1) brine flow (Chevrier et al., 2008), (2) liquid water flow mixed with sand (Reiss et al., 2010), (3) liquid water flow mixed with snow or ice, (4) a combination of the previous three processes.

Published
2012

2. Experimental Investigation of Gully Formation Under Low Pressure and Low Temperature Conditions

Author

Jouannic, G, Conway, S. J., Gargani, J, Costard, F, Patel, M. R., Ori, G. G., Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Planetary and Space Sciences Research Institute [Milton Keynes] (PSSRI), Centre for Earth, Planetary, Space and Astronomical Research [Milton Keynes] (CEPSAR), The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), International Research School of Planetary Sciences [Pescara] (IRSPS), and Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A)

Subjects
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology
Abstract

International audience; Introduction: A large morphological diversity of gullies is observed on Earth and on Mars. Debris flow – a non-newtonian flow comprising a sediment-water mix – is a common process attributed to gully formation on both planets [1, 2]. Many variables can influence the morphology of debris flows (grainsizes, discharge , slope, soil moisture, etc) and their respective influences are difficult to disentangle in the field. Furthermore effects specific to the martian environment have not yet been explored in detail. Some preliminary laboratory simulations have already been performed that isolate some of these variables. Cold room experiments [3] were already perfomed to test the effect of a melted surface layer on the formation of linear gullies over sand dunes. Low pressure experiments [4] were performed to test the effect of the atmospheric pressure on erosional capacity and runout distance of the flows. Our aim is to develop a new set of experiments both under Martian atmospheric pressure and terrestrial atmospheric pressure in order to reproduce the variability of the observed morphologies under well constrained experimental conditions.

Published
2012

3. GEOMORPHIC STUDY OF DEBRIS FLOWS ON THE RUSSELL DUNE (MARS) : COMPARISON OF DEBRIS FLOWS AND PRESENT FLOWS ACTIVITY

Author

Gwenaël Jouannic, Gargani, J., Costard, F., Ori, G., Marmo, C., Frédéric Schmidt, Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), International Research School of Planetary Sciences [Pescara] (IRSPS), Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), Géosciences Paris Sud (GEOPS), and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology
Abstract

International audience; Introduction : Liquid water is not likely to be found on the surface of Mars because of atmospheric pres-sure/temperature conditions below water's triple-point. However, the discovery of gullies suggests that significant amounts of liquid water has flowed on Mars in a recent past [1]. This study focus on morphology of gullies over dunes on the Russell crater (54.5°S ; 12.7°E). Recent numerical simulations have shown that sinuous shapes of these Martian gullies over dunes can be better reproduced with liquid-water-bearing flows [2]. The discovery of debris flows on sand dunes is unexpexted and the origin of the fluid necessary for the formation of debris flows remains currently a mystery. Recent work shows that the gullies located on the Russell dune are not only extremely youthfull but seem also to be still active [3]. This study aims to : 1/ realize a morphological description of the debris flows of the Russell dune and the Present flow activity using the HiRISE images ; 2/ estimates the physical properties of the flows (velocities, flow rates) and the maximum grain size of the dune surface material ; 3/ use the different flow morphologies and the calculated parameters to compare the debris flows and the Present flow activity.

Published
2011

4. Evolution of polygenic debris flows on a sand dune (Russell crater, Mars)

Author

Jouannic, G., Gargani, J., Costard, F., Chiara Marmo, Mangold, N., Schmidt, F., Ori, G. G., Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), International Research School of Planetary Sciences [Pescara] (IRSPS), and Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A)

Subjects
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology
Abstract

International audience; Recent work has shown that gullies are among the most youthful features on Mars [1] and have been taken as evidence for significant amounts of liquid water in the recent past. Recent studies show that the gullies located on the Russell Crater dune are not only extremely youthful but also appear to be still active [2]. Here we report of a polygenic evolution of debris flow dunes with two phases: 1/ debris flows on hill slopes in recent Martian times (less than 10 My) could be formed by (i) runoff and debris flows with liquid water from groundwater aquifers [1]; [3], (ii) snow-melt ([4]; [5], (iii) various CO 2-driven mechanisms ([6]; [7]; [8]) or (iv) melting of near-surface ground ice (< 1m meter) at high obliquity [9]; 2/ defrosting activity at present time with formation of relatively small sinuous hand branching channels.

Published
2010

5. Processes of formation of debris flows on the Russell dune under a periglacial environment (Mars)

Author

Gwenaël Jouannic, Gargani, J., Costard, F., Marmo, C., Frédéric Schmidt, Ori, G., Lucas, A., Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), International Research School of Planetary Sciences [Pescara] (IRSPS), Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology
Abstract

International audience; The presence of gullies on sand dunes is rare on Earth, and their discoveries on Mars and the origin as well as mechanical properties of fluid necessary to the formation of gullies remains currently misunderstood. This study focuses on morphology of gullies over the Russell megadune (54.5°S; 12.7°E). The aim of this study is to better constrain the origin as well as the mechanical properties of the fluid involved into the debris flows. A new HiRISE DTM allowed to better characterize 3D geometry of these morphologies. It makes it possible to measure mass balance for one gully and estimate the eroded and deposited volume. It allows us also to estimate erosion and sedimentation rates along the channel. A series of cross-sections on a gully allowed us to estimate flow velocities, flow discharge and physical parameters such as viscosity, Reynolds number and yield strength (Fig. 1). Based on terrestrial methods ([1], [2], [3], [4]), this approach aims to understand the flow dynamic necessary for the formation of gullies on Martian dunes. Finally, we discuss a model of formation for the Russell's gullies under a periglacial environment.

6. Titan as Revealed by the Cassini Radar

Author

Federico Tosi, L. A. Soderblom, Charles Elachi, G. Mitri, Zhimeng Zhang, Alexander G. Hayes, S. D. Wall, Jason M. Soderblom, P. Paillou, Elizabeth P. Turtle, Richard West, R. L. Kirk, Gian Gabriele Ori, Tom G. Farr, Howard A. Zebker, Claudia Notarnicola, Paul Corlies, M. Mastroguiseppe, Jason W. Barnes, Antoine Lucas, K. L. Mitchell, Jason D. Hofgartner, Bryan Stiles, Athena Coustenis, Valerio Poggiali, A. Solomonidou, Cyril Grima, Roberto Orosei, O. Karatekin, E. R. Stofan, Jani Radebaugh, Spd Birch, Rmc Lopes, Domenico Casarano, A. LeGall, P Encrenaz, Michael Malaska, Charles A. Wood, Flora Paganelli, Douglas J. Hemingway, Daniele Riccio, Sebastien Rodriguez, Catherine D. Neish, M. A. Janssen, R. D. Lorenz, Paul Ries, Jonathan I. Lunine, Ashley Schoenfeld, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Astronomy [Ithaca], Cornell University, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Astrogeology Science Center [Flagstaff], United States Geological Survey [Reston] (USGS), University of Arizona, Lunar and Planetary Laboratory [Tucson] (LPL), Università degli Studi di Roma 'La Sapienza' [Rome], Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Florida Institute of Technology [Melbourne], Institut de génétique humaine (IGH), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Service de cardiologie [Hôpital Nord - APHM], Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)- Hôpital Nord [CHU - APHM], Observatoire Bordeaux, Université Sciences et Technologies - Bordeaux 1, Department of Geological Sciences [BYU], Brigham Young University (BYU), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Proxemy Research Inc, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Wheeling Jesuit University, Department of Electrical Engineering [Stanford], Stanford University [Stanford], Istituto di Ricerca per la Protezione Idrogeologica [Bari] (IRPI), Consiglio Nazionale delle Ricerche [Roma] (CNR), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Miller Institute for Basic Research in Science, University of California [Berkeley], Royal Observatory of Belgium [Brussels], Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), International Research School of Planetary Sciences [Pescara] (IRSPS), Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Sciences [London, ON], University of Western Ontario (UWO), Institute for Earth Observation [Bolzano], EURAC Research, Search for Extraterrestrial Intelligence Institute (SETI), ASP 2019, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Smithsonian National Air and Space Museum, Smithsonian Institution, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Planetary Science Institute [Tucson] (PSI), Department of Physics [Moscow,USA], University of Idaho [Moscow, USA], Istituto di Ricerca per la Protezione Idrogeologica [Padova] (IRPI), Institute of Geophysics [Austin] (IG), University of Texas at Austin [Austin], Istituto di Radioastronomia (IRA), Dipartimento di Ingegneria Elettrica e delle Tecnologie dell'Informazione [Napoli] (DIETI), Università degli studi di Napoli Federico II, Cornell University [New York], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], European Academy Bozen/Bolzano (EURAC), Stanford University, Royal Observatory of Belgium [Brussels] (ROB), Istituto di Radioastronomia [Bologna] (IRA), Lopes, R. M. C., Wall, S. D., Elachi, C., Birch, S. P. D., Corlies, P., Coustenis, A., Hayes, A. G., Hofgartner, J. D., Janssen, M. A., Kirk, R. L., Legall, A., Lorenz, R. D., Lunine, J. I., Malaska, M. J., Mastroguiseppe, M., Mitri, G., Neish, C. D., Notarnicola, C., Paganelli, F., Paillou, P., Poggiali, V., Radebaugh, J., Rodriguez, S., Schoenfeld, A., Soderblom, J. M., Solomonidou, A., Stofan, E. R., Stiles, B. W., Tosi, F., Turtle, E. P., West, R. D., Wood, C. A., Zebker, H. A., Barnes, J. W., Casarano, D., Encrenaz, P., Farr, T., Grima, C., Hemingway, D., Karatekin, O., Lucas, A., Mitchell, K. L., Ori, G., Orosei, R., Ries, P., Riccio, D., Soderblom, L. A., Zhang, Z., ITA, USA, FRA, and Hôpital Nord [CHU - APHM]-Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)

Subjects
Exploration of Saturn, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, Liquid methane, law.invention, Astrobiology, symbols.namesake, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, law, 0103 physical sciences, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Radar, Enceladus, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Cassini, radar, Titan, Planetary science, 13. Climate action, Space and Planetary Science, symbols, Titan (rocket family), Geology
Abstract

International audience; Titan was a mostly unknown world prior to the Cassini spacecraft’s arrival in July 2004. We review the major scientific advances made by Cassini’s Titan Radar Mapper (RADAR) during 13 years of Cassini’s exploration of Saturn and its moons. RADAR measurements revealed Titan’s surface geology, observed lakes and seas of mostly liquid methane in the polar regions, measured the depth of several lakes and seas, detected temporal changes on its surface, and provided key evidence that Titan contains an interior ocean. As a result of the Cassini mission, Titan has gone from an uncharted world to one that exhibits a variety of Earth-like geologic processes and surface-atmosphere interactions. Titan has also joined the ranks of “ocean worlds” along with Enceladus and Europa, which are prime targets for astrobiological research.

Published
2019
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