Ninth International Conference on Permafrost ... - IARC Research

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The Microtopography of Periglacial Landforms on MarsNicolas MangoldLaboratoire IDES, CNRS and Université Paris Sud, 91405 Orsay, FranceIntroductionThe planet Mars is covered by many landforms involvingwater ice, either at surface or at depth. These landforms areimportant in studying the geographic distribution of waterice, its temporal variation, and the possibility of freezethawcycles in past epochs. Geologically recent Martianhillside gullies, discovered in Mars Orbiter Camera (MOC)Narrow Angle (NA) images (Malin & Edgett 2000), exhibitcharacteristic morphologies similar to terrestrial debrisflows in mountain or arctic regions, formed by flowing wateror water-rich slurries, leading Malin and Edgett (2000) tosuggest that they, too, were formed by the action of water.Processes other than water erosion have been proposed toexplain the formation of gullies, including the action ofCO2-based debris flows (e.g., Musselwhite et al. 2001) andgranular avalanches or mass wasting of CO2 frost (e.g., Ishii& Sasaki 2004). The role of liquid water is still debated,especially given the subfreezing mean temperature (-60°C)that might only reach submelting temperatures during highobliquity periods of the past (Costard et al. 2002). The originof the fluid is also questioned. Various mechanisms for theformation of gullies by water have been proposed, althoughfundamentally they can be divided into either atmosphericor groundwater processes depending on the source of thewater.Until recently the only available images with sufficientresolution to detect gullies have been MOC NA data, andmost previous studies have used this dataset. However,the HiRISE camera of the Mars Reconnaissance Orbiterprovides high resolution (
Ni n t h In t e r n at i o n a l Co n f e r e n c e o n Pe r m a f r o s tand flow rates are typical of viscous debris flows formed by20 to 40% of liquid water mixed with rocks. This does notexclude other types of material to explain these properties,but excludes granular flows and pure liquid water as a goodexplanation for the channels observed. More data will beprocessed as soon as more images become available.Our study is only preliminary among the large amount ofdata that are acquired throughout years. We show that themethod used is powerful in extraction of material propertiesfrom remote sensing data. These results confirm materialproperties estimates of previous works using MOC images.Given the cold temperatures of Mars, liquid water mightform especially from melting of an active layer in summer.Debris flows activity would occur only on the steepest slopes(>20°).Figure 1. General view of HiRISE image 3464–1380 in NewtonBasin. The scarp is about 1 km high. Many gullies are visibleshowing alcoves in the upward section, channels which typicallyare found on 10–20° slopes, and large aprons on the downwardpart. The image is about 2 km large.ReferencesCostard, F., Forget, F., Mangold, N. & Peulvast, J.-P. 2002.Formation of recent Martian debris flows by meltingof near-surface ground ice at high obliquity. Science295: 110-113.Davis, P.A. & Soderblom, L.A. 1984. Modeling cratertopography and albedo from monoscopic orbiterimages 1. Methodology. J. Geophys. Res. 89 (B11):9449-9457.Ishii, T. & Sasaki, S. 2004. Formation of recent Martiangullies by avalanches of CO 2frost. 35th Lunar andPlanetary Science <strong>Conference</strong>, 2004, Abstract 1556.Johnson, A.M. & Rodine, J.R. 1984. Debris flow. In: D.Brundsen & D.B. Prior (eds.), Slope Instability. Wileyand Sons, 257-361.Malin, M.C. & Edgett, K.S. 2000. Evidence for recentgroundwater seepage and surface runoff on Mars,Science 288: 2330-2335.Mangold, N., Costard, F. & Forget, F. 2003. Debris flowsover sand dunes on Mars: Evidence for liquid water.J. Geophys. Res. 108(E4): 5027.Musselwhite, D.S., Swindle, T.D. & Lunine, J.I. 2001.Liquid CO2 breakout and the formation of recentsmall gullies on Mars. Geophys. Res. Let. 28(7):1283-1285.Figure 2. Close-up of Figure 1 on a sinuous channel. The profileshows the topography extracted from photoclinometry. Elevationsare exaggerated about 10 times.198
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NICOP 2008 Ninth <
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ContentsPreface ...................
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Mapping and Modeling the Distributi
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Satellite Observations of Frozen Gr
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xiiIce Wedge Thermal Regime in Nort
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xivPermafrost Response to Dynamics
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NICOP SponsorsUniversitiesUniversit
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Deep Permafrost Studies at the Lupi
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Effect of Fire on Pond Dynamics in
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Cryological Status of Russian Soils
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Acoustical Surveys of Methane Plume
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Permafrost Delineation Near Fairban
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Preparatory Work for a Permanent Ge
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A Provisional Soil Map of the Trans
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Martian Permafrost Depths from Orbi
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Time Series Analyses of Active Micr
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Impact of Permafrost Degradation on
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DC Resistivity Soundings Across a P
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Modeling Thermal and Moisture Regim
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A Provisional Permafrost Map of the
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Alpine Permafrost Distribution at M
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Cryogenic Formations of the Caucasu
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Modeling Potential Climatic Change
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A Hypothesis: A Condition of Growth
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Modeled Continual Surface Water Sto
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Freeze/Thaw Properties of Tundra So
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Discontinuous Permafrost Distributi
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Thermal Regime Within an Arctic Was
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Seasonal and Interannual Variabilit
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Twelve-Year Thaw Progression Data f
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Continued Permafrost Warming in Nor
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Landsliding Following Forest Fire o
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A Permafrost Model Incorporating Dy
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Seasonal Sources of Soil Respiratio
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Greenland Permafrost Temperature Si
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The Importance of Snow Cover Evolut
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The Account of Long-Term Air Temper
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The Combined Isotopic Analysis of L
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Adaptating and Managing Nunavik’s
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Human Experience of Cryospheric Cha
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HiRISE Observations of Fractured Mo
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A Soil Freeze-Thaw Model Through th
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Mapping and Modeling the Distributi
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First Results of Ground Surface Tem
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Historical Changes in the Seasonall
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Rock Glaciers in the Kåfjord Area,
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Snowpack Evolution on Permafrost, N
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Climate Change in Permafrost Region
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Maximizing Construction Season in a
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Pleistocene Sand-Wedge, Composite-W
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