DOCSLIB.ORG

Pluto's Ocean Is Capped and Insulated by Gas Hydrates

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pluto's Ocean Is Capped and Insulated by Gas Hydrates ARTICLES https://doi.org/10.1038/s41561-019-0369-8 Pluto’s ocean is capped and insulated by gas hydrates Shunichi Kamata 1,8*, Francis Nimmo 2, Yasuhito Sekine 3, Kiyoshi Kuramoto 4, Naoki Noguchi 5, Jun Kimura 6 and Atsushi Tani 7 Many icy Solar System bodies possess subsurface oceans. On Pluto, Sputnik Planitia’s location near the equator suggests the presence of a subsurface ocean and a locally thinned ice shell. To maintain an ocean, Pluto needs to retain heat inside. On the other hand, to maintain large variations in its thickness, Pluto’s ice shell needs to be cold. Here we show, by thermal evolu- tion and viscous relaxation calculations, that the presence of a thin layer of clathrate hydrates (gas hydrates) at the base of the ice shell can explain both the long-term survival of the ocean and the maintenance of shell thickness contrasts. Clathrate hydrates act as a thermal insulator, preventing the ocean from completely freezing while keeping the ice shell cold and immo- bile. The most likely clathrate guest gas is methane, derived from precursor bodies and/or cracking of organic materials in the hot rocky core. Nitrogen molecules initially contained and/or produced later in the core would probably not be trapped as clath- rate hydrates, instead supplying the nitrogen-rich surface and atmosphere. The formation of a thin clathrate hydrate layer cap to a subsurface ocean may be an important generic mechanism to maintain long-lived subsurface oceans in relatively large but minimally heated icy satellites and Kuiper belt objects. iquid water oceans are thought to exist inside icy satellites of Another possibility is that the viscosity of the ice shell is high due gas giants such as Europa and Enceladus and the icy dwarf to the presence of high-strength material, such as salts12 or silicate planet Pluto1. Understanding the survival of subsurface oceans particles13. However, in a multiphase system, the weaker phase L 12,13 is of fundamental importance not only to planetary science but also (that is, water ice) dominates the flow . Consequently, inhibiting to astrobiology. One indication of a subsurface ocean on Pluto is substantial viscous relaxation requires the stronger phase (that is, Sputnik Planitia, a ~1,000-km-wide basin. It is a topographical low salts) to be the dominant component. Such an ice shell would have −3 and is located near the equator, indicating that it is a positive gravity a high density (for example, ~1.3 g cm for a mixture of 50% H2O anomaly. To make this basin a positive gravity anomaly, a subsurface ice and 50% epsomite). While the density of the ocean might also be ocean beneath a locally thinned ice shell (by ~90 km) is inferred2. high due to the presence of salts in the ocean11, their concentrations The presence of an ocean suggests a ‘warm’ (that is, not com- would be largely controlled by the formation of clay minerals and pletely frozen) Pluto. However, unlike icy satellites, tides do not play evaporates in the rocky core, keeping the ocean salinity <4–5 mol l−1 3 14 an important role in heating the dwarf planet , and radiogenic heat- or <10 mol% relative to H2O (ref. ) and, thus, the ocean density ing is insufficient to avoid complete freezing unless the ice shell is <1.3 g cm−3. For the ice shell to float on the ocean and for Sputnik highly viscous (greater than ~1016 Pa s (ref. 4)). Heat may be retained Planitia to be a positive gravity anomaly, the ice shell has a density inside Pluto owing to a thick surface thermal insulating layer much lower than the ocean (at least by ~0.2 g cm−3 (ref. 11)), and its resulting from high porosity and a high concentration of nitrogen major constituent needs to be water ice. ice5. However, if the ice shell is warm, its viscosity should be low6. Instead, we propose that the ice shell has a thin layer of clath- Substantial viscous flow of ice would then occur, eliminating any rate hydrates at its base (Fig. 1). Clathrate hydrates, or gas hydrates, local thickness contrasts7. Consequently, a locally thinned shell sug- are solids in which water molecules create cages trapping gas mol- gests a ‘cold’ Pluto (lower than ~200 K at the base of the ice shell2). ecules15. As the formation temperatures of clathrate hydrates are One way to reconcile these contradictory requirements is to depress higher than the melting point of pure water ice15 and the subsurface the freezing point of water by contaminating the ocean with anti- ocean is sufficiently pressurized by the overlying ice shell, a freezing freeze molecules, such as ammonia2. However, to avoid substantial ocean would form clathrate hydrates rather than water ice if dis- viscous relaxation of the ice shell, the ammonia concentration needs solved gas concentrations are sufficiently high16. The thermal con- to be ~30 wt% (Supplementary Fig. 1). Such a high concentration is ductivity of clathrate hydrates is about a factor of 5–10 smaller than hard to justify; the ammonia concentration in comets, whose chem- that of water ice17 and the viscosity of clathrate hydrates is about an ical composition should be representative of Kuiper belt objects order of magnitude higher than that of water ice18. As a result of including Pluto8, is mostly less than 1% with respect to water9. In these physical properties, a cap of clathrate hydrates would act as addition, an ammonia concentration >20 wt% leads to an ocean a highly viscous thermal insulator between a subsurface ocean and density <1,000 kg m−3 (Supplementary Fig. 2, ref. 10), which makes an ice shell. The temperature difference across this layer allows the it difficult for Sputnik Planitia to be a positive gravity anomaly11. presence of a subsurface ocean with a temperature near the melting 1Creative Research Institution, Hokkaido University, Sapporo, Japan. 2Department of Earth and Planetary Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA. 3Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan. 4Department of Cosmosciences, Hokkaido University, Sapporo, Japan. 5Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima, Japan. 6Department of Earth and Space Science, Osaka University, Toyonaka, Japan. 7Department of Human Environmental Science, Kobe University, Kobe, Japan. 8Present address: Department of Earth and Planetary Sciences, Hokkaido University, Sapporo, Japan. *e-mail: [email protected] NatURE GEOSCIENCE | www.nature.com/naturegeoscience ARTICLES NATURE GEOSCIENCE Nitrogen-rich ice Temperature of methane hydrates15,17,18 (Methods). The origin of the local inte- Without rior structure beneath Sputnik Planitia (a thin ice shell above a With Water-rich ice clathrate clathrate thick ocean) is considered to be associated with the large impact hydrates 2,11 hydrates that formed the Sputnik Planitia basin . Although the age of this Clathrate hydrate impact is unknown, the eroded rim of the basin suggests that it is 23 Subsurface ocean likely to be billions of years . Consequently, the timescale of viscous Depth relaxation should be at least one billion years. Rocky core If a clathrate hydrate layer does not exist, shell thickness contrasts can be maintained for only a few million years unless an extremely viscous ice shell and/or an extremely cold ocean is assumed (Fig. 3 and Supplementary Fig. 5). In contrast, if a clathrate hydrate layer of a few to 10 km in thickness exists at the base of the ice shell, the timescale of ice shell relaxation is increased even by 3 to 4 orders Fig. 1 | A schematic diagram of the interior structure of Pluto. The ice shell of magnitude and can exceed one billion years even if we assume has a thin clathrate hydrate layer at its base. The temperature changes typical pure-water properties both for the water ice layer and the substantially across this layer immediately above the subsurface ocean, ocean (Fig. 3). Such a large increase in the timescale results from the leading to a conductive shell rather than a convective shell. Nitrogen-rich combined effect of a low temperature in the water ice layer and the ice on the surface is the bright surface of Sputnik Planitia. high viscosity of clathrate hydrates (Supplementary Fig. 6). Thus, under the presence of a thin clathrate hydrate layer, an extremely ammonia- or salt-rich Pluto is no longer necessary to explain a long point of pure water ice while the overlying ice shell maintains a viscous relaxation timescale for the ice shell. much lower temperature at the same time. Its high viscosity would also maintain shell thickness contrasts for a long time. Implications for geochemical evolution Various gas species can form clathrate hydrates, although some Global thermal evolution of Pluto species (for example, CH4) occupy clathrate hydrates more read- 15,16 We first evaluate the effect of clathrate hydrates on the thermal evo- ily than others (for example, N2) (refs. ). This behaviour may lution of Pluto using the physical properties of methane hydrates explain the unique volatile composition observed on Pluto. Comets 15,17 9 (CH4 · nH2O, where n ≈ 6 (refs. )) (Methods). In the absence of contain ~1% of CH4 and a few percent of CO with respect to water , clathrate hydrates, a subsurface ocean is expected to freeze com- and even these low concentrations are sufficient to form a clath- pletely because thermal convection in the ice shell removes heat rate hydrate layer several tens of kilometres in thickness (Methods effectively from the deep interior4 (Fig. 2a,b). To maintain a thick and Supplementary Fig. 7). When Pluto formed, volatiles trapped in subsurface ocean, the ice shell needs to be conductive, requiring a precursor bodies would have been partitioned between the atmo- reference viscosity about one or two orders of magnitude higher sphere, the ice shell and the subsurface ocean.
Load more

Recommended publications
  • Bioinspired Intrinsic Control of Freeze Cast Composites: Harnessing Hydrophobic Hydration and Clathrate Hydrates
    Acta Materialia 114 (2016) 67e79 Contents lists available at ScienceDirect Acta Materialia journal homepage: www.elsevier.com/locate/actamat Full length article Bioinspired intrinsic control of freeze cast composites: Harnessing hydrophobic hydration and clathrate hydrates * Steven E. Naleway a, , Christopher F. Yu b, Rachel L. Hsiong b, Arijit Sengupta e, Peter M. Iovine e, John A. Hildebrand c, Marc A. Meyers a, b, d, Joanna McKittrick a, b a Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA b Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA c Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA d Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA e Department of Chemistry and Biochemistry, University of San Diego, San Diego, CA 92110, USA article info abstract Article history: Bioinspired ZrO2-epoxy, two-phase composite materials were fabricated by the freeze casting fabrication Received 7 January 2016 technique followed by polymer infiltration. These materials were intrinsically controlled by adding Received in revised form varying concentrations of the monofunctional alcohols ethanol (EtOH), n-propanol (n-PrOH) and n- 9 May 2016 butanol (n-BuOH). The microstructures of freeze cast scaffolds created with these alcohol additives Accepted 10 May 2016 demonstrated maximum pore areas (peak Ap) at concentrations of 10, 5e7 and 3 vol% for EtOH, n-PrOH and n-BuOH respectively. Differential scanning calorimetry analyses of binary mixtures of these additives and water suggested only n-PrOH was capable of developing clathrate hydrates.
    [Show full text]
  • Journées “Hydrates”
    Journées Hydrates, Brest, 09‐13 septembre 2019 Journées “Hydrates” 09‐13 septembre 2019 IFREMER Pôle Numérique 305 Avenue Alexis de Rochon 29280 PLOUZANE 1 Journées Hydrates, Brest, 09‐13 septembre 2019 2 Journées Hydrates, Brest, 09‐13 septembre 2019 WELCOME We are pleased to welcome you for the 2nd meeting of the French research consortium GdR2026 Hydrates at the University of Bordeaux. This event brings together leading experimental, theoretical, and computational scientists from among the unusually broad community of researchers interested in the various research areas of gas hydrates going from chemical and energy engineering to geosciences and astrophysics through physical‐ chemistry and thermodynamics. The issues addressed during this meeting concern major aspects of “hydrate sciences” such as hydrate/substrates interactions, thermodynamics, formation kinetics, cage occupancy and as well as formation at extreme conditions. The workshop is divided into two parts. The first part is dedicated to meetings of french research consortiums working on a common project (ANR, EU, etc.) in closed session. The second part is the general meeting, gathering about 60 participants. Its scientific program contains about 31 presentations, including invited talks, oral contributions and poster presentations. Organizing committee Livio Ruffine ‐ IFREMER, Brest Hélène Ondréas ‐ IFREMER, Brest Marie‐Odile Lamirault‐Gall ‐ IFREMER, Brest Alison Chalm‐ IFREMER, Brest Elisabeth Savoye ‐ IFREMER, Brest Olivia Fandino‐Torres – IFREMER, Brest Arnaud Desmedt, ISM CNRS ‐ Univ. Bordeaux Karine Ndiaye, ISM CNRS ‐ Univ. Bordeaux Audrey Bourgeois, ISM CNRS ‐ Univ. Bordeaux Daniel Broseta – LFC‐R UMR 5150 CNRS, Total, Univ. Pau Scientific Committee Baptiste Bouillot ‐ LGF, UMR 5703 CNRS, Mines Saint‐Etienne Daniel Broseta – LFC‐R UMR 5150 CNRS, Total, Univ.
    [Show full text]
  • Final Investigation Report: E.I
    Toxic Chemical Release at the U.S. Chemical Safety and DuPont La Porte Chemical Facility Hazard Investigation Board La Porte, Texas | Incident Date: November 15, 2014 | No. 2015-01-I-TX Investigation Report Published: June 2019 Investigation Report EY SSUES K I : • Emergency Planning and Response (Preparedness) • Implementation of Process Safety Management Systems • Assessment of Process Safety Culture FINAL COPY Toxic Chemical Release at the DuPont La Porte Chemical Facility U.S. Chemical Safety and Hazard Investigation Board La Porte, Texas | Incident Date: November 15, 2014 | No. 2015-01-I-TX The U.S. Chemical Safety and Hazard Investigation Board (CSB) is an independent federal agency whose mission is to drive chemical safety change through independent investigations to protect people and the environment. The CSB is a scientific investigative organization, not an enforcement or regulatory body. Established by the Clean Air Act Amendments of 1990, the CSB is responsible for determining accident causes, issuing safety recommendations, studying chemical safety issues, and evaluating the effectiveness of other government agencies involved in chemical safety. More information about the CSB is available at www.csb.gov. The CSB makes public its actions and decisions through investigative publications, all of which may include safety recommendations when appropriate. Types of publications include: Investigation Reports: Formal, detailed reports on significant chemical incidents that include key findings, root causes, and safety recommendations Investigation Digests: Plain-language summaries of Investigation Reports Case Studies: Reports that examine fewer issues than Investigation Reports Safety Bulletins: Short publications typically focused on a single safety topic Hazard Investigations: Broader studies of significant chemical hazards Safety Videos: Videos that animate aspects of an incident or amplify CSB safety messages CSB products can be freely accessed at www.csb.gov or obtained by contacting: U.S.
    [Show full text]
  • Mechanical Characterization Via Full Atomistic Simulation: Applications to Nanocrystallized Ice
    Mechanical Characterization via Full Atomistic Simulation: Applications to Nanocrystallized Ice A thesis presented By Arvand M.H. Navabi to The Department of Civil and Environmental Engineering in partial fulfillment of the requirements for the degree of Master of Science in the field of Civil Engineering Northeastern University Boston, Massachusetts August, 2016 Submitted to Prof. Steven W. Cranford Acknowledgements I acknowledge generous support from my thesis advisor Dr. Steven W. Cranford whose encouragement and availability was crucial to this thesis and also my parents for allowing me to realize my own potential. The simulations were made possible by LAMMPS open source program. Visualization has been carried out using the VMD visualization package. 3 Abstract This work employs molecular dynamic (MD) approaches to characterize the mechanical properties of nanocrystalline materials via a full atomistic simulation using the ab initio derived ReaxFF potential. Herein, we demonstrate methods to efficiently simulate key mechanical properties (ultimate strength, stiffness, etc.) in a timely and computationally inexpensive manner. As an illustrative example, the work implements the described methodology to perform full atomistic simulation on ice as a material platform, which — due to its complex behavior and phase transitions upon pressure, heat exchange, energy transfer etc. — has long been avoided or it has been unsuccessful to ascertain its mechanical properties from a molecular perspective. This study will in detail explain full atomistic MD methods and the particulars required to correctly simulate crystalline material systems. Tools such as the ReaxFF potential and open-source software package LAMMPS will be described alongside their fundamental theories and suggested input methods to simulate further materials, encompassing both periodic and finite crystalline models.
    [Show full text]
  • Methane Clathrate Behavior in Martian Surface Ice, and Supporting Morphological Observations
    Lunar and Planetary Science XXXIX (2008) 1163.pdf Methane Clathrate Behavior in Martian Surface Ice, and Supporting Morphological Observations. D.S. McMenamin and George E. McGill, Department of Geosciences, University of Massachusetts, Amherst, MA. Email: [email protected]. Introduction: Earlier, we reported on the likeli- If clathrate dissociates due to deformation in the hood that methane clathrate hydrate in martian glaciers HSZ, some methane may escape to the atmosphere. and other surface ice is the source of ancient glacial Trapped methane can re-combine with water to make meltwater features and modern atmospheric methane clathrate again, but if methane does escape and the [1, 2, 3]. In the current work, we consider the behavior temperature is high enough, films and small pockets of of methane clathrate in surface ice, and describe geo- water or brine can form [6]. In a glacier or debris flow morphic features that we interpret as being related to with an ice matrix, this increases pore pressure and clathrate dissociation. Methane clathrate may also be allows slippage of the surrounding layers of ice. When present in permafrost ice [4 5], but because sublima- the ice regelates or the clathrate re-associates, slippage tion of ice at the surface is inevitable, downward mi- stops. If ruptures are on a large enough scale, the ice gration of the HSZ (Hydrate Stability Zone) must re- will move episodically, with most of the movement sult in the gradual destabilization of any clathrate pre- probably near the toe of the glacier or debris flow, sent in surface ice, without the need to hypothesize any where strain rates are highest.
    [Show full text]
  • The Origin of Titan's Atmosphere: Some Recent Advances
    The origin of Titan’s atmosphere: some recent advances By Tobias Owen1 & H. B. Niemann2 1University of Hawaii, Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822, USA 2Laboratory for Atmospheres, Goddard Space Fight Center, Greenbelt, MD 20771, USA It is possible to make a consistent story for the origin of Titan’s atmosphere starting with the birth of Titan in the Saturn subnebula. If we use comet nuclei as a model, Titan’s nitrogen and methane could easily have been delivered by the ice that makes up ∼50% of its mass. If Titan’s atmospheric hydrogen is derived from that ice, it is possible that Titan and comet nuclei are in fact made of the same protosolar ice. The noble gas abundances are consistent with relative abundances found in the atmospheres of Mars and Earth, the sun, and the meteorites. Keywords: Origin, atmosphere, composition, noble gases, deuterium 1. Introduction In this note, we will assume that Titan originated in Saturn’s subnebula as a result of the accretion of icy planetesimals: particles and larger lumps made of ice and rock. Alibert & Mousis (2007) reached this same point of view using an evolutionary, turbulent model of Saturn’s subnebula. They found that planetesimals made in the solar nebula according to their model led to a huge overabundance of CO on Titan. We obviously have no direct measurements of the composition of these planetes- imals. We can use comets as a guide, always remembering that comets formed in the solar nebula where conditions must have been different from those in Saturn’s subnebula, e.g., much colder.
    [Show full text]
  • Methane Clathrate: General Idea and Overview
    International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 09 | Sep 2020 www.irjet.net p-ISSN: 2395-0072 Methane Clathrate: General Idea and Overview Tanmay Tatu1, Ajinkya Mandlik2, Aniruddha Kambekar3, Prof.Rupali Karande4 1,2,3BE, Department of Chemical Engineering, Dwarkadas J Sanghvi College of Engineering, Mumbai, India 4Assistant Professor, Department of Chemical Engineering, Dwarkadas J Sanghvi College of Engineering, Mumbai, India ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract -The demand for energy has grown significantly releases the innate water or ice(if the temperature is over the past few years and to meet the ever increasing below the freezing point) and the guest gas. demand, we have increased the rate of power consumption by amping up the extraction of energy from their respective Methane Clathrate (4CH4.23H2O) is a compound formed sources. This has caused the drying up of the current major when a large number of methane molecules coalesce sources of energy to the heavy industries or powerplants, together and get trapped inside a water molecule under thus requiring an alternate source of energy which can be low temperature and high pressure to form an ice-like utilized once the major sources such as Oil, Natural Gas, substance. Such conditions are commonly found at a few Coal, etc. get diminished. Renewable sources of energy such metres of depth below the waterbodies or beneath the as solar energy, wind energy, tidal energy, geothermal permafrost or in deep ocean sediments where methane energy etc. are being researched upon for maximum clathrates exist naturally and is called as gas hydrate exploitation but the main problem of these sources is that stability zone(GHSZ).
    [Show full text]
  • Formation of Clathrate Hydrate from Amorphous Ice During Warming R
    Formation of clathrate hydrate from amorphous ice during warming R. Netsu, T. Ikeda-Fukazawa Department of Applied Chemistry, Meiji University, Japan Water molecules are condensed on dust grains in interstellar molecular clouds and protester nebulae. The water exists as amorphous ice in the cold clouds and is transformed into various structures depending on thermal conditions and compositions with various deposited molecules. Blake et al. [1] proposed the presence of CO2 clathrate hydrate in cometary ice. From the results using the transmission electron microscopy (TEM) and fourier transformed infrared spectroscopy (FT-IR), they showed the phase transition of vapor deposited amorphous ice including CO2 and CH3OH into type-II clathrate hydrate at around 120 K. Clathrate hydrates are inclusion compounds consisting of water molecules and a variety of guests molecules. Most clathrate hydrates form one of two distinct crystallographic structures, type-I and –II, depending on the sizes and shapes of the guest molecules. The cubic unit cell of type-I clathrate hydrate contains 46 water molecules in a framework of two dodecahedral and six tetrakaidecahedral cages, and that of type-II clathrate hydrate contains 136 water molecules in a framework of 16 dodecahedral and eight hexakaidecahedral cages. The structure of CO2 clathrate hydrate formed under a high pressure condition is type-I [2]. For the hydrate from the vapor deposited amorphous ice [1], the structure is type-II due to the help-gasses effect of CH3OH. For the CO2 clathrate hydrate grown epitaxially on a hydrate in low pressure conditions, the structure depends on the structure of the hydrate as the substrate [3].
    [Show full text]
  • Effects of Additives on the Formation of Methane and Carbon Dioxide Gas Hydrates
    Effects of Additives on the Formation of Methane and Carbon Dioxide Gas Hydrates Nguyen Ngoc Nguyen B.E. & M.Sc. of Chemical Engineering A thesis submitted for the degree of Doctor of Philosophy at The University of Queensland in 2017 School of Chemical Engineering Abstract Gas hydrates (GHs) are ice-like crystalline solids comprising water and suitable gases in which gas molecules are physically encaged in a cage-like hydrogen-bonded structure formed by water molecules. Under the presence of appropriate additives, the formation of GHs can be controlled in a desired manner thereby opening novel ways of using GHs for gas storage and transportation, carbon dioxide sequestration, gas separation, desalination, etc. Although significant works have been undertaken to investigate the effects of additives on gas hydrate formation, there still remains a substantial gap in the understanding of the fundamentals behind the experimental observations. This thesis aims to provide new molecular insights into the effects of surfactants, hydrophobic solid surfaces and sodium halides on the formation of GHs. These effects are studied at the molecular level using synergic combinations of experimental and computational techniques. Kinetics experiments using a high-pressure reactor are carried out to quantify the effect of additives on the kinetics of gas enclathration. A see-through reactor is used for in situ visual observations of the effects of the hydrophobicity of solid surfaces on the formability of GHs. Interface-susceptible sum frequency generation (SFG) vibrational spectroscopy is employed to analyse water structure at gas- solution interfaces. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) is employed to analyse water structure in the bulk solution.
    [Show full text]
  • Chemical Properties of Glacial and Ground Ice – Yu
    TYPES AND PROPERTIES OF WATER – Vol. II– Chemical Properties of Glacial and Ground Ice – Yu. K. Vasil’chuk CHEMICAL PROPERTIES OF GLACIAL AND GROUND ICE Yu. K. Vasil'chuk Departments of Geography and Geology, Lomonosov's Moscow State University, Moscow, Russia Keywords: Ions, methane hydrate, air clathrate, heavy metals, stable oxygen and hydrogen isotopes Contents 1. Ionic composition in glaciers 2. Ice and snow chemistry 3. Ion migration in ice and frozen soils 4. Methane hydrate 5. Chemical physics of air clathrate hydrates in ice core 6. Chemistry of ice in dependence of electrical conductivity 7. Ionic composition in ground ice 8. Subpermafrost water geochemistry 9. Heavy metals in glaciers 10. Heavy metals in ground ice 11. Stable oxygen and hydrogen isotope of the ice 12. Temporal variations of isotopic composition of glacial-river water during summer; oxygen isotope composition of water sources 13. Stable isotope composition in glaciers 14. Stable isotopes in ground ice 15. Isotope composition of ice-wedge ice Acknowledgements Glossary Bibliography Biographical Sketch Summary Marine aerosols are the main source of Cl, Mg, Na, K, Mg, SO4, in ice sheets of Greenland and Antarctic. Marine salts accumulate along the coastline, their concentration decreasesUNESCO sharply away from the coastline. – ConcentrationEOLSS of elements of continental origin is independent on the distance from coastline. In Greenland dust concentrations in ice–age ice are SAMPLE3 to 70 times those in Holocene CHAPTERS ice. The ice–age dust contains a strong component of calcium carbonate. This neutralized acid aerosols in atmosphere so that in contrast to Holocene ice, nearly all ice–age ice is alkaline.
    [Show full text]
  • Genesis and Geometry of the Meiklejohn Peak Lime Mud-Mound
    University of Calgary PRISM: University of Calgary's Digital Repository Science Science Research & Publications 2001-12 Genesis and geometry of the Meiklejohn Peak lime mud-mound, Bare Mountain Quadrangle, Nevada, USA: Ordovician limestone with submarine frost heave structures- a possible response to gas clathrate hydrate evolution Krause, Federico F. Elsevier Krause, Frederico F.. (2001). "Genesis and geometry of the Meiklejohn Peak lime mud-mound, Bare Mountain Quadrangle, Nevada, USA: Ordovician limestone with submarine frost heave structures- a possible response to gas clathrate hydrate evolution". In: Carbonate mounds: Sedimentation, organismal response and diagenesis, D. W. Kopaska-Merkel and D. C. Haywick (editors). Sedimentary Geology, 145: 189-213. http://hdl.handle.net/1880/44457 journal article Downloaded from PRISM: https://prism.ucalgary.ca Sedimentary Geology Sedimentary Geology 145 (2001) 189-213 Genesis and geometry of the Meiklejohn Peak lime mud-mound, Bare Mountain Quadrangle, Nevada, USA: Ordovician limestone with submarine frost heave structures-a possible response to gas clathrate hydrate evolution Federico F. Krause* University qfcalgarv. Department of Geology and Geophysics, 2500 Universiiy Drive N. K, Calgaly, Alberta, Canada T2N IN4 Received 3 August 2000; accepted 15 May 2001 Abstract During the Early Middle Ordovician (Early Whiterockian) the Meiklejohn Peak lime mud-mound, a large whaleback or dolphin back dome, grew on a carbonate ramp tens to hundreds of kilometres offshore. This ramp extended from the northwest margin of Laurentia into the open waters of the ancestral Pacific Ocean to the north. The mound developed in an outer ramp environment, in relatively deep and cold water. A steep northern margin with a slope that exceeds 55' characterizes the mound.
    [Show full text]
  • Ammonia Clathrate Hydrates As New Solid Phases for Titan, Enceladus, and Other Planetary Systems
    Ammonia clathrate hydrates as new solid phases for Titan, Enceladus, and other planetary systems Kyuchul Shina, Rajnish Kumarb, Konstantin A. Udachina, Saman Alavia, and John A. Ripmeestera,1 aSteacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, ON, Canada K1A 0R6; and bNational Chemical Laboratory, Council of Scientific and Industrial Research, Pune 411008, India Edited by Mark H. Thiemens, University of California San Diego, La Jolla, CA, and approved July 26, 2012 (received for review April 12, 2012) There is interest in the role of ammonia on Saturn’s moons Titan Results and Enceladus as the presence of water, methane, and ammonia As a first step in this study we show that in the presence of other under temperature and pressure conditions of the surface and in- clathrate hydrate forming substances, ammonia indeed can be terior make these moons rich environments for the study of phases incorporated in cages within the clathrate lattice. Incorporation formed by these materials. Ammonia is known to form solid hemi-, of ammonia in a clathrate hydrate phase was accomplished by mono-, and dihydrate crystal phases under conditions consistent freezing a solution of the well known clathrate hydrate former with the surface of Titan and Enceladus, but has also been assigned tetrahydrofuran (THF) and approximately 5% aqueous ammonia a role as water-ice antifreeze and methane hydrate inhibitor which with an approximate THF:water mole ratio of 1∶17 at −10 °C. is thought to contribute to the outgassing of methane clathrate Crystals formed were harvested after a few days and those suita- hydrates into these moons’ atmospheres.
    [Show full text]