DOCSLIB.ORG

Ammonia Clathrate Hydrates As New Solid Phases for Titan, Enceladus, and Other Planetary Systems

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read 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. Here we show, through ble for diffraction were identified and mounted on a diffract- direct synthesis from solution and vapor deposition experiments ometer at low temperatures. The above experimental conditions under conditions consistent with extraterrestrial planetary atmo- can be compared with those in the study of Dong et al. (15, 16) spheres, that ammonia forms clathrate hydrates and participates who used THF:water ratios of about 1∶63 with up to 5% ammo- synergistically in clathrate hydrate formation in the presence of nia to study methane hydrate formation in the presence of methane gas at low temperatures. The binary structure II tetra- ammonia. In their experiments, Dong et al. (15, 16) did not use hydrofuran + ammonia, structure I ammonia, and binary structure sufficient THF to lead to the direct formation of the binary CHEMISTRY I ammonia + methane clathrate hydrate phases synthesized have THF þ NH3 clathrate hydrate and ammonia hydrate formation been characterized by X-ray diffraction, molecular dynamics simu- was not observed. lation, and Raman spectroscopy methods. Structural data were recorded at 100 K (see Materials and Methods). The structure was shown to be the usual cubic structure ice ∣ single crystal X-ray diffraction ∣ hydrogen bonding ∣ II (sII) clathrate hydrate (28), space group Fd-3m with a unit cell hydrate inhibitors ∣ ethane edge of 1.71413(6) nm. The THF molecules occupy the large cages, as expected, and 39% of the small cages are filled with am- mmonia has long been seen as a key species in extraterres- monia molecules (Fig. 1). This measured small cage occupancy is Atrial space, both interstellar and on outer planets, moons, likely to be a function of the starting composition. Whether small and comets and the interplay of ammonia, methane, and water cages could be completely filled with a more ammonia-rich liquid has been the subject of a considerable number of studies and is uncertain and should be studied separately. One of the water speculation (1–8). The main role assigned to ammonia has been molecules in the small cages which encapsulate the ammonia guests has moved out of its normal position, 0.118 nm inward into that of an antifreeze for ice and clathrate hydrate formation, ⋯ modifying the stability region of the solid ice and methane clath- the small cage thus forming H2O H-NH2 hydrogen bonds (0.267–0.272 nm) with NH3 (as suggested by hydrogen positions rate hydrate phases as a thermodynamic inhibitor (2, 5, 9). How- ⋯ ever, ammonia is a methane-sized molecule, thus based on size on the ammonia guest). The formation of HOH NH3 hydrogen alone it has the potential for being a suitable guest for clathrate bonding could also lead to this water displacement. This displace- ment breaks the hydrogen bond of this water molecule with hydrate cages. Issues that may have prevented ammonia from ⋯ being considered as a suitable clathrate guest molecule include another water from an adjacent large (or small) cage (O O dis- tance 0.393 nm), thus distorting both large and small cages. The the notion that guest species need to be hydrophobic in order to equivalent O⋯O distance in the undistorted edges of the water be incorporated into clathrates, and the observation of a number polyhedra is 0.279 nm. It should be noted that the minimum heavy of stoichiometric nonclathrate phases of ammonia and water atom N⋯O distance in the clathrate hydrate is smaller than in the obtained upon cooling aqueous ammonia solutions (2). Previous ammonia hydrates, where the more uniform local environment of experimental work on the water-ammonia and water-methane- the NH3 molecule results in N⋯O distances of 0.305 to 0.330 nm. ammonia systems had not shown evidence for the enclathration Because structural evidence for the mixed THF þ NH3 sII of ammonia (5, 10–19). Close inspection, however, shows that the hydrate showed that it is possible to incorporate ammonia into low pressure ammonia dihydrate (18) and the high pressure phase II of ammonia monohydrate (19) have structural features in com- mon with canonical clathrate and semiclathrate structures. Author Contributions: R.K., K.S., and J.A.R. performed the vapor deposition experiments; Recent structural analysis and molecular simulations have K.S., K.A.U., and J.A.R. did the powder and single-crystal XRD experiments; S.A., K.S., and shown that some guest molecules which form strong hydrogen J.A.R. performed the molecular dynamics simulations; and J.A.R., S.A., and K.S. wrote the manuscript. bonds with the water framework of the clathrate hydrate lattice The authors declare no conflict of interest. may nonetheless produce stable phases (20–23). It is therefore reasonable to consider that ammonia has potential as a clathrate This article is a PNAS Direct Submission. guest molecule. Furthermore, previous experimental and com- Data deposition: The single-crystal XRD structure of the binary tetrahydrofuran and ammonia structure II clathrate hydrate has been deposited in the Cambridge Structural putational studies have shown that in the gas phase, water forms Database, Cambridge Crystallographic Data Centre, Cambridge CB2 1EZ, United Kingdom dodecahedral cages around ammonia and ammonium ions. (CSD reference no. 864781). These structures may be indicative of a geometric tendency to- 1To whom correspondence should be addressed. E-mail: [email protected]. wards clathrate hydrate structures for the ammonia and ammo- This article contains supporting information online at www.pnas.org/lookup/suppl/ nium molecules (24–27). doi:10.1073/pnas.1205820109/-/DCSupplemental. www.pnas.org/cgi/doi/10.1073/pnas.1205820109 PNAS Early Edition ∣ 1of6 Downloaded by guest on September 29, 2021 Fig. 1. The large and small cages of the cubic structure II THF-ammonia binary clathrate hydrate from single crystal X-ray diffraction. The ammonia guest has moved a water molecule out of its normal position by pulling it into the small cavity by forming a H2N-H⋯OH2 or H3N⋯HOH hydrogen bond. clathrate cages, attempts were made to form clathrate hydrates with only ammonia as guest. Pure ammonia clathrate hydrate synthesis cannot be done by simply cooling aqueous ammonia solutions, as a variety of stoichiometric hydrates of ammonia are known to form preferentially (2, 11, 18, 19). Other ways of form- ing clathrate hydrates include vapor deposition of water at low temperatures to yield amorphous ice, followed by exposure of the ice to a pressure of guest gas and annealing (29), or vapor code- position of water and the potential guest material at low tempera- tures, again, followed by annealing (23, 30, 31). It has been shown that below approximately 140 K ice surfaces are relatively inert unless strong hydrogen-bond donors or acceptors are present. For example, molecules normally hydrolyzed by water such as formal- dehyde will not do so when in contact with ices at low tempera- ture and will template clathrate hydrate lattices when amorphous ice is annealed (30). Following the latter procedure, described in detail in Materials and Methods, vapor codeposits of ammonia and water were pre- pared at T < 20 K. The codeposited crystals were harvested at 77 K and kept in liquid nitrogen until appropriate measurements Fig. 2. PXRD patterns of NH3 and H2O co-deposition sample (A) recorded at could be made. A portion of each amorphous product was 100, 140, and 150 K; (B) expansion of the pattern at 150 K. Lattice parameters mounted in a low temperature cell on a powder X-ray diffract- (150 K) are: a ¼ 0.4527ð1Þ nm, b ¼ 0.5586ð1Þ nm, c ¼ 0.9767ð3Þ nm for am- 2 2 2 ¼ 0 4496ð1Þ ¼ ometer and the samples annealed stepwise, increasing tempera- monia monohydrate (space group: P 1 1 1); a . nm and c 0.7339ð1Þ nm for ice Ih (space group P63∕mmc); a ¼ 1.1818ð2Þ nm for sI ture from approximately 100 K. Fig. 2 shows the transformation ¼ 0 8404ð2Þ ¼ A ammonia clathrate hydrate (space group Pm-3n); a . nm, b of the amorphous deposit upon annealing. Fig. 2 shows the pow- 0.8441ð3Þ nm, and c ¼ 5.345ð1Þ nm for ammonia hemihydrate (space group der X-ray diffraction (PXRD) pattern for amorphous ice with Pbnm); and a ¼ 0.7125ð1Þ nm for ammonia dihydrate (space group P213).
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]
  • Understanding the Clathrate Hydrate
    Janda Lab Understanding the By Kathy Marvin K – 12 Teacher Outreach Clathrate 2010 Hydrate Some Facts ABout Water (H2O) • Ice floats in water • Water molecules share electrons and are “polar”, with a posi8ve and a negave side • All 3 phases of water are present in great abundance • 70% of the earth’s surface is solid or liquid water • Over ½ our body mass is water • Lightning is due to collisions between ice par8cles • There are 13 known phases of ice • It is one of the most difficult substances for theory to simulate or model Molecular Structure oF H2O • Basic components • Single bonded of water contain 1 molecule of water oxygen (O) atom containing 1 oxygen and 2 hydrogen (H) (O) and 2 hydrogen atoms (H) atoms Structure of H2O as a Gas • Molecules are randomly arranged both close together and far apart • Molecules spread out as far as they can • No definite shape or volume Structure of H2O as a Liquid • Water molecules touch but are able to move around easily and slip and slide past other molecules • Liquid H2O is able to take on shape of its container Structure of H2O as a Solid (Ice) • This is the structure of ice from your freezer • Repeang paern of uniform crystals • No8ce the empty space in the center of the crystal Structure of Solid H2O Frozen water creates a lace work of repeang crystalline structures that trap air as they freeze. Ice From Your Freezer • Ice from your refrigerator is made of icosohedrons and forms hexagonal structures • No8ce the long repeang tubes of crystal lace work • Any other type of molecule trapped in these
    [Show full text]