Sample records for volcanoes fossils crystals

  1. Apatite crystal in hard tissue of conodont fossils

    Institute of Scientific and Technical Information of China (English)


    The present study was aimed at examining the nature of apatite crystal in the tooth apparatus of a conodont fossil using transmission electron microscopy (TEM),scanning electron microscopy (SEM),laser Raman microprobe spectrometry and electron-probe microanalysis (EPMA).The hard tissue of the condont consisted of 2 layers and the organization varied with the size of the crystal.Higher magnification showed that the crystals were observed in the lattice of (100) and the central dark lines were not present.Ca,P,and F were detected in the crystal using EPMA.Our results indicate that the apatite crystal in conodont fossils is not hydroxyapatite but fluorapatite.

  2. Viscosity measurements of crystallizing andesite from Tungurahua volcano (Ecuador) (United States)

    Cimarelli, Corrado; deBiasi, Lea; Hanson, Jonathan B.; Lavallée, Yan; Arzilli, Fabio; Dingwell, Donald B.


    Abstract Viscosity has been determined during isothermal crystallization of an andesite from Tungurahua volcano (Ecuador). Viscosity was continuously recorded using the concentric cylinder method and employing a Pt‐sheathed alumina spindle at 1 bar and from 1400°C to subliquidus temperatures to track rheological changes during crystallization. The disposable spindle was not extracted from the sample but rather left in the sample during quenching thus preserving an undisturbed textural configuration of the crystals. The inspection of products quenched during the crystallization process reveals evidence for heterogeneous crystal nucleation at the spindle and near the crucible wall, as well as crystal alignment in the flow field. At the end of the crystallization, defined when viscosity is constant, plagioclase is homogeneously distributed throughout the crucible (with the single exception of experiment performed at the lowest temperature). In this experiments, the crystallization kinetics appear to be strongly affected by the stirring conditions of the viscosity determinations. A TTT (Time‐Temperature‐Transformation) diagram illustrating the crystallization “nose” for this andesite under stirring conditions and at ambient pressure has been constructed. We further note that at a given crystal content and distribution, the high aspect ratio of the acicular plagioclase yields a shear‐thinning rheology at crystal contents as low as 13 vol %, and that the relative viscosity is higher than predicted from existing viscosity models. These viscosity experiments hold the potential for delivering insights into the relative influences of the cooling path, undercooling, and deformation on crystallization kinetics and resultant crystal morphologies, as well as their impact on magmatic viscosity. PMID:27656114

  3. Viscosity measurements of crystallizing andesite from Tungurahua volcano (Ecuador). (United States)

    Chevrel, Magdalena Oryaëlle; Cimarelli, Corrado; deBiasi, Lea; Hanson, Jonathan B; Lavallée, Yan; Arzilli, Fabio; Dingwell, Donald B


    Viscosity has been determined during isothermal crystallization of an andesite from Tungurahua volcano (Ecuador). Viscosity was continuously recorded using the concentric cylinder method and employing a Pt-sheathed alumina spindle at 1 bar and from 1400°C to subliquidus temperatures to track rheological changes during crystallization. The disposable spindle was not extracted from the sample but rather left in the sample during quenching thus preserving an undisturbed textural configuration of the crystals. The inspection of products quenched during the crystallization process reveals evidence for heterogeneous crystal nucleation at the spindle and near the crucible wall, as well as crystal alignment in the flow field. At the end of the crystallization, defined when viscosity is constant, plagioclase is homogeneously distributed throughout the crucible (with the single exception of experiment performed at the lowest temperature). In this experiments, the crystallization kinetics appear to be strongly affected by the stirring conditions of the viscosity determinations. A TTT (Time-Temperature-Transformation) diagram illustrating the crystallization "nose" for this andesite under stirring conditions and at ambient pressure has been constructed. We further note that at a given crystal content and distribution, the high aspect ratio of the acicular plagioclase yields a shear-thinning rheology at crystal contents as low as 13 vol %, and that the relative viscosity is higher than predicted from existing viscosity models. These viscosity experiments hold the potential for delivering insights into the relative influences of the cooling path, undercooling, and deformation on crystallization kinetics and resultant crystal morphologies, as well as their impact on magmatic viscosity.

  4. Magma heating by decompression-driven crystallization beneath andesite volcanoes. (United States)

    Blundy, Jon; Cashman, Kathy; Humphreys, Madeleine


    Explosive volcanic eruptions are driven by exsolution of H2O-rich vapour from silicic magma. Eruption dynamics involve a complex interplay between nucleation and growth of vapour bubbles and crystallization, generating highly nonlinear variation in the physical properties of magma as it ascends beneath a volcano. This makes explosive volcanism difficult to model and, ultimately, to predict. A key unknown is the temperature variation in magma rising through the sub-volcanic system, as it loses gas and crystallizes en route. Thermodynamic modelling of magma that degasses, but does not crystallize, indicates that both cooling and heating are possible. Hitherto it has not been possible to evaluate such alternatives because of the difficulty of tracking temperature variations in moving magma several kilometres below the surface. Here we extend recent work on glassy melt inclusions trapped in plagioclase crystals to develop a method for tracking pressure-temperature-crystallinity paths in magma beneath two active andesite volcanoes. We use dissolved H2O in melt inclusions to constrain the pressure of H2O at the time an inclusion became sealed, incompatible trace element concentrations to calculate the corresponding magma crystallinity and plagioclase-melt geothermometry to determine the temperature. These data are allied to ilmenite-magnetite geothermometry to show that the temperature of ascending magma increases by up to 100 degrees C, owing to the release of latent heat of crystallization. This heating can account for several common textural features of andesitic magmas, which might otherwise be erroneously attributed to pre-eruptive magma mixing.

  5. Investigation of a fossil geothermal system, Hamblin-Cleopatra Volcano, Clark County, Nevada. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Barker, D.S.


    The Hamblin-Cleopatra volcano, selected for study because erosion and fault displacement have exposed the entire volcanic succession, the intrusive core, a radial dike systems, and sedimentary and volcanic rocks that predate and postdate the volcano, was investigated to estimate the proportions of igneous materials forming lava flows, pyroclastic deposits, intrusive bodies, and reworked debris. Chemical changes in the magma throughout the active period of the volcano were documented. The geothermal system active within the pile after activity ceased was reconstructed. (ACR)

  6. Volcanoes (United States)

    ... or more from a volcano. Before a Volcanic Eruption The following are things you can do to ... in case of an emergency. During a Volcanic Eruption Follow the evacuation order issued by authorities and ...

  7. Volcanoes

    Institute of Scientific and Technical Information of China (English)


    In the past thousand years,volcanoes have claimed more than 300,000 lives. Volcanology is ayoung and dangerous science that helps us against the power of the Earth itself.We live on a fiery planet. Nearly 2000 miles beneath our feet, the Earth's inner core reachestemperatures of 12,000 degrees Fahrenheit. Molten rock or magma, rises to the earth's surface. Acold, rigid crust fractured into some twenty plates. When magma breaks through crust it becomes

  8. Crystal origins and magmatic system beneath Ngauruhoe volcano (New Zealand) revealed by plagioclase textures and compositions (United States)

    Coote, Alisha C.; Shane, Phil


    The textural variation and compositional zoning of plagioclase in pre-historic and historic basaltic andesite lava flows from Ngauruhoe volcano reveals extensive crystal recycling from a multi-level magma system. Most phenocrysts have a calcic (~ An80-90) resorbed core with diffuse or no zonation that is depleted in Fe and Mg. Some cores display patchy zonation from replacement by high An crystallization prior to resorption. The cores are mantled by oscillatory-zoned rims of lower An content (Mg. Rim zones vary in relative thickness and textural complexity, and include sieve-textured bands, and/or cyclic calcic growth following dissolution events. A subordinate crystal population display similar features, but lack a resorbed core. These latter crystals display overall rimward enrichment in An, Fe and Mg. The resorbed cores crystallized from magmas more mafic than those erupted at Ngauruhoe, and slow cooling and prolonged storage resulted in loss of An zoning patterns and depletion of Fe and Mg by diffusion. These crystals are likely to have originated from deep cumulates or intrusions, and were subsequently entrained in ascending magmas. Patchy-textured cores were produced during decompression in a water under-saturated magma and staged ascent. The diversity in crystal cores reflect different conduits and ascent histories. The crystal rims grew in a more differentiated magma reservoir, and are in equilibrium with the erupted melt. Most of the zoning patterns in the rim zone require water pressure and/or temperature changes. These changes could have been caused by convective self-mixing in a closed system and/or the intrusion of hydrous melts of similar bulk composition. Other crystals display rimward elemental enrichments consistent with mafic recharge. Previously reported rimward enrichment in 87Sr-86Sr compositions can be explained by the re-cycled origin of the crystal cores and progressive crustal assimilation at shallower depths in the magma system where

  9. Abrupt transition from fractional crystallization to magma mixing at Gorely volcano (Kamchatka) after caldera collapse (United States)

    Gavrilenko, Maxim; Ozerov, Alexey; Kyle, Philip R.; Carr, Michael J.; Nikulin, Alex; Vidito, Christopher; Danyushevsky, Leonid


    A series of large caldera-forming eruptions (361-38 ka) transformed Gorely volcano, southern Kamchatka Peninsula, from a shield-type system dominated by fractional crystallization processes to a composite volcanic center, exhibiting geochemical evidence of magma mixing. Old Gorely, an early shield volcano (700-361 ka), was followed by Young Gorely eruptions. Calc-alkaline high magnesium basalt to rhyolite lavas have been erupted from Gorely volcano since the Pleistocene. Fractional crystallization dominated evolution of the Old Gorely magmas, whereas magma mixing is more prominent in the Young Gorely eruptive products. The role of recharge-evacuation processes in Gorely magma evolution is negligible (a closed magmatic system); however, crustal rock assimilation plays a significant role for the evolved magmas. Most Gorely magmas differentiate in a shallow magmatic system at pressures up to 300 MPa, ˜3 wt% H2O, and oxygen fugacity of ˜QFM + 1.5 log units. Magma temperatures of 1123-1218 °C were measured using aluminum distribution between olivine and spinel in Old and Young Gorely basalts. The crystallization sequence of major minerals for Old Gorely was as follows: olivine and spinel (Ol + Sp) for mafic compositions (more than 5 wt% of MgO); clinopyroxene and plagioclase crystallized at ˜5 wt% of MgO (Ol + Cpx + Plag) and magnetite at ˜3.5 wt% of MgO (Ol + Cpx + Plag + Mt). We show that the shallow magma chamber evolution of Old Gorely occurs under conditions of decompression and degassing. We find that the caldera-forming eruption(s) modified the magma plumbing geometry. This led to a change in the dominant magma evolution process from fractional crystallization to magma mixing. We further suggest that disruption of the magma chamber and accompanying change in differentiation process have the potential to transform a shield volcanic system to that of composite cone on a global scale.

  10. Disequilibrium crystal-liquid processes at Hamblin-Cleopatra volcano, Lake Mead area, Nevada (United States)

    Barker, Daniel S.; Thompson, Keith G.; Smith, Eugene I.; McDowell, Fred W.


    The 60 km3 Hamblin-Cleopatra stratovolcano produced shoshonite, latite, and trachyte lavas throughout its Miocene eruptive history. Low-silica rhyolite and silica-undersaturated hawaiite erupted before and after lavas of the Hamblin-Cleopatra volcano. Shoshonite, latite, and trachyte resulted from contamination of felsic (trachyte to low-silica rhyolite) anatectic liquids with crystals from hawaiite. Most of the entrained crystals were not in equilibrium with liquid represented by groundmass, but were mingled with liquid shortly before eruption. Crystal aggregates are common inclusions in the lavas, and are sources of the contaminating minerals. The resulting bulk compositions of these porphyritic lavas form a continuum that resembles a liquid line of descent, as dictated by mass balance.

  11. Experimental study into the petrogenesis of crystal-rich basaltic to andesitic magmas at Arenal volcano (United States)

    Parat, F.; Streck, M. J.; Holtz, F.; Almeev, R.


    Arenal volcano is nearly unique among arc volcanoes with its 42 year long (1968-2010) continuous, small-scale activity erupting compositionally monotonous basaltic andesites that also dominate the entire, ~7000 year long, eruptive history. Only mineral zoning records reveal that basaltic andesites are the result of complex, open-system processes deriving minerals from a variety of crystallization environments and including the episodic injections of basalt. The condition of the mafic input as well as the generation of crystal-rich basaltic andesites of the recent, 1968-2010, and earlier eruptions were addressed by an experimental study at 200 MPa, 900-1,050 °C, oxidizing and fluid-saturated conditions with various fluid compositions [H2O/(H2O + CO2) = 0.3-1]. Phase equilibria were determined using a phenocryst-poor (~3 vol%) Arenal-like basalt (50.5-wt% SiO2) from a nearby scoria cone containing olivine (Fo92), plagioclase (An86), clinopyroxene (Mg# = 82) and magnetite (Xulvö = 0.13). Experimental melts generally reproduce observed compositional trends among Arenal samples. Small differences between experimental melts and natural rocks can be explained by open-system processes. At low pressure (200 MPa), the mineral assemblage as well as the mineral compositions of the natural basalt were reproduced at 1,000 °C and high water activity. The residual melt at these conditions is basaltic andesitic (55 wt% SiO2) with 5 wt% H2O. The evolution to more evolved magmas observed at Arenal occurred under fluid-saturated conditions but variable fluid compositions. At 1,000 °C and 200 MPa, a decrease of water content by approximately 1 wt% induces significant changes of the mineral assemblage from olivine + clinopyroxene + plagioclase (5 wt% H2O in the melt) to clinopyroxene + plagioclase + orthopyroxene (4 wt% H2O in the melt). Both assemblages are observed in crystal-rich basalt (15 vol%) and basaltic andesites. Experimental data indicate that the lack of orthopyroxene

  12. Constraints on the Rates of Replenishment, Magma Mixing, and Crystal Recycling at Santorini Volcano, Greece (United States)

    Martin, V. M.; Davidson, J. P.; Morgan, D. J.; Jerram, D. A.


    Santorini is a young, active volcano, which preserves abundant evidence for open-system processes such as magma replenishment and crystal recycling, and thus represents an ideal system in which to study magma chamber dynamics. Santorini is the largest volcanic centre in the Aegean arc, with an eruptive history spanning more than 250,000 years over two eruptive cycles. The cycles are dominated by extended periods of effusive shield-building activity with occasional large-magnitude explosive eruptions, the Minoan eruption of ~3600 years ago being the most recent. Current activity consists of a phase of post-caldera reconstruction, focused recently on the intra-caldera Kameni islands. Microsampling to measure 87Sr/86Sr ratios of plagioclase cores indicates the presence of a complex plumbing system beneath Santorini. Large rhyodacitic deposits typically contain a mafic component, interpreted as the eruption trigger. In some cases, the mafic magma groundmass and phenocrysts are isotopically similar to their rhyodacite host; other deposits show the opposite, implying the coexistence of isotopically distinct magma batches. To add further complexity, plagioclase phenocrysts are in some cases in equilibrium with their groundmass while others show the reverse, implying modification due to crystal recycling or shallow mixing processes prior to eruption. Mafic enclaves in the recent Kameni lavas, again interpreted as the probable eruption trigger, provide some constraints on the rates of these recycling, mixing, and triggering processes. Glomerocrysts and xenocrysts of recycled gabbroic cumulate material are present in a number of Kameni enclaves. Isotopic and chemical disequilibrium between the cumulate crystals and the host indicate that these fragments are derived from pre- existing crystal mush piles pervaded by the replenishing melts as they migrated to shallow levels, creating disequilibrium between the cumulate mineral cores and the replenishing melts. 87Sr/86Sr isotope

  13. Experimental Elucidation of the Oxygen Reduction Volcano in Base on a Pt Alloy Single Crystal

    DEFF Research Database (Denmark)

    Jensen, Kim Degn; Tymoczko, Jakub; Bandarenka, Aliaksandr S.;


    and base.[1,2] In our earlier studies, we mapped out the experimental Sabatier volcano for the oxygen reduction reaction in 0.1 M HClO4 using the Cu/Pt(111) near-surface alloy system, see Figure 1 for near-surface alloy schematic.[3,4] In this study, as those of [3,4], we found that by changing...... the subsurface coverage of Cu we could tune the surface binding of the key reaction intermediate, OH; we thus monitored the OH binding energy shift through the observable shifts in the base voltammograms in both acidic and alkaline media. Further, we elucidate the experimental oxygen reduction volcano in 0.1 M...... to Pt(111). However, all surfaces show a ~4 fold improvement in activity in 0.1 M KOH, relative to the same surface in 0.1 M HClO4. At the peak of the volcano the surface exhibits an exceptionally high specific activity of 90 mA/cm2 at 0.9 V with respect to the reversible hydrogen electrode. Thus, our...

  14. Timescales of storage and recycling of crystal mush at Krafla Volcano, Iceland (United States)

    Cooper, Kari M.; Sims, Kenneth W. W.; Eiler, John M.; Banerjee, Neil


    Processes in upper-crustal magma reservoirs such as recharge, magma mixing, recycling of previously crystallized material, and eruption affect both the physical state and the chemical composition of magmas. A growing body of evidence shows that crystals in intermediate or silicic volcanic rocks preserve records of these processes that may be obscured due to mixing in the liquid fraction of magmas. Fewer studies have focused on crystals in basaltic lavas, but these show evidence for a more subtle, but still rich record of magmatic processes. We present new 238U-230Th-226Ra data for plagioclase, combined with δ18O and trace-element measurements of the same crystal populations, from basalts erupted at Krafla Volcanic Center, Iceland. These data document the presence of multiple crystal populations within each sample, with chemical and oxygen isotope heterogeneity at a variety of scales: within individual crystals, between crystals in a given population, between crystal populations within the same sample, and between crystals in lavas erupted from different vents during the same eruption. Comparison to whole-rock or groundmass data shows that the majority of macroscopic crystals are not in trace-element or oxygen isotope equilibrium with their host liquids. The most likely explanation for these data is that the macroscopic crystals originated within a highly heterogeneous crystal mush in the shallow magma reservoir system. U-series and diffusion data indicate that the crystals (and therefore the mush) formed recently (likely within a few thousand years of eruption, and with a maximum age of 8-9 ka), and that the crystals resided in their host magma prior to eruption for decades to a few centuries at most. These data, in conjunction with other recent studies, suggest a model where erupted Icelandic magmas are the result of diverse magmas entering the crust, followed by complex interactions between melts and previously crystallized material at all crustal levels.

  15. Experimental Elucidation of the Oxygen Reduction Volcano in Base on a Pt Alloy Single Crystal

    DEFF Research Database (Denmark)

    Jensen, Kim Degn; Tymoczko, Jakub; Bandarenka, Aliaksandr S.


    to Pt(111). However, all surfaces show a ~4 fold improvement in activity in 0.1 M KOH, relative to the same surface in 0.1 M HClO4. At the peak of the volcano the surface exhibits an exceptionally high specific activity of 90 mA/cm2 at 0.9 V with respect to the reversible hydrogen electrode. Thus, our......It is of fundamental importance to understand the factors controlling trends in activity for electrocatalytic reactions as a function of pH. In the case of the oxygen reduction reaction, numerous reports suggest significant divergences between noble metals surface catalytic performances in acid...... and base.[1,2] In our earlier studies, we mapped out the experimental Sabatier volcano for the oxygen reduction reaction in 0.1 M HClO4 using the Cu/Pt(111) near-surface alloy system, see Figure 1 for near-surface alloy schematic.[3,4] In this study, as those of [3,4], we found that by changing...

  16. Crystal size and shape distribution systematics of plagioclase and the determination of crystal residence times in the micromonzogabbros of Qisir Dagh, SE of Sabalan volcano (NW Iran

    Directory of Open Access Journals (Sweden)

    Pourkhorsandi Hamed


    Full Text Available The Qisir Dagh igneous complex occurs as a combination of volcanic and intrusive rocks to the south-east of the Sabalan volcano, north-western Iran. Micromonzogabbroic rocks in the region consist of plagioclase, alkaline feldspar and clinopyroxene as the major mineral phases and orthopyroxene, olivine, apatite and opaque minerals as the accessory minerals. Microgranular and microporphyritic textures are well developed in these rocks. Considering the importance of plagioclase in reconstructing magma cooling processes, the size and shape distribution and chemical composition of this mineral were investigated. Based on microscopic studies, it is shown that the 2-dimensional size average of plagioclase in the micromonzogabbros is 538 micrometers and its 3-dimensional shape varies between tabular to prolate. Crystal size distribution diagrams point to the presence of at least two populations of plagioclase, indicating the occurrence of magma mixing and/or fractional crystallization during magma cooling. The chemical composition of plagioclase shows a wide variation in abundances of Anorthite-Albite-Orthoclase (An=0.31–64.58, Ab=29.26–72.13, Or=0.9–66.97, suggesting a complex process during the crystal growth. This is also supported by the formation of antiperthite lamellae, which formed as the result of alkali feldspar exsolution in plagioclase. The calculated residence time of magma in Qisir Dagh, based on 3D crystal size distribution data, and using growth rate G=10−10 mm/s, varies between 457 and 685 years, which indicates a shallow depth (near surface magma crystallization and subvolcanic nature of the studied samples.

  17. Asbestiform tremolite within the Holocene late pyroclastic deposits of Colli Albani volcano (Latium, Italy): Occurrence and crystal-chemistry

    CERN Document Server

    Della Ventura, Giancarlo; Bellatreccia, Fabio; De Benedetti, Arnaldo A; Mottana, Annibale


    This work relates the occurrence and the characterization of fibrous tremolite within the latest pyroclastic deposits of the Colli Albani (Alban Hills) volcano, to the south-east of Rome (Italy). These mineralizations were observed during a systematic rock-sampling undertaken to complete the geological survey for the new 1:50 000 map of this volcanic area. The examined specimens were collected inside distal deposits correlated to the last Albano Maar activity, which are geographically located within the boundaries of the Nemi community. Tremolite occurs within both carbonate ejecta and the host pyroclastic rocks. It shows up as whitish to light gray coloured aggregates of crystals with fibrous aspect and sericeous brightness. Due to the extremely small crystal dimensions, never exceeding 0.5 micron in diameter, the micro-chemical composition of the fibres could be obtained only by combining P-XRD, SEM-EDX and FTIR methods. Infrared spectroscopy, in particular, proved to be a valuable technique to characterize...

  18. Application of a new multiphase multicomponent volcanic conduit model with magma degassing and crystallization to Stromboli volcano. (United States)

    La Spina, Giuseppe; Burton, Mike; de'Michieli Vitturi, Mattia


    Volcanoes exhibit a wide range of eruption styles, from relatively slow effusive eruptions, generating lava flows and lava domes, to explosive eruptions, in which very large volumes of fragmented magma and volcanic gas are ejected high into the atmosphere. During an eruption, much information regarding the magma ascent dynamics can be gathered: melt and exsolved gas composition, crystal content, mass flow rate and ballistic velocities, to name just a few. Due to the lack of direct observations of the conduit itself, mathematical models for magma ascent provide invaluable tools for a better comprehension of the system. The complexity of the multiphase multicomponent gas-magma-solid system is reflected in the corresponding mathematical model; a set of non-linear hyperbolic partial differential and constitutive equations, which describe the physical system, has to be formulated and solved. The standard approach to derive governing equations for two-phase flow is based on averaging procedures, which leads to a system of governing equations in the form of mass, momentum and energy balance laws for each phase coupled with algebraic and differential source terms which represent phase interactions. For this work, we used the model presented by de' Michieli Vitturi et al. (EGU General Assembly Conference Abstracts, 2013), where a different approach based on the theory of thermodynamically compatible systems has been adopted to write the governing multiphase equations for two-phase compressible flow (with two velocities and two pressures) in the form of a conservative hyperbolic system of partial differential equations, coupled with non-differential source terms. Here, in order to better describe the multicomponent nature of the system, we extended the model adding several transport equations to the system for different crystal components and different gas species, and implementing appropriate equations of state. The constitutive equations of the model are chosen to

  19. Calc-alkali rocks derived from tholeiite magma in Hakone volcano; pyroxene crystallization trends and pyroxene geothermometry to estimate the magma temperature (United States)

    Ishii, T.


    Calc-alkali rocks are widely distributed in the island arcs. The several models of their magma-genesis were proposed by many geoscientists (e.g. Kuno 1950, Osborn 1959, Sakuyama 1981, Tatsumi 2011) on the bases of precise petrological investigations. Crystallization trends of rock forming minerals (pyroxene, feldspar etc.) in the individual lava flow of the hydrous tholeiitic magma are represented by chemical zoning from phenocryst through microphenocryst to the groundmass in each lava. Those trends indicate degassing (or dehydrating) trends of erupted lava (Ishii 1991). Crystallization trend of minerals of hydrous magma in the subvolcanic magma reservoir is represented by core of phenocrysts throughout lava-flow strata in each volcano. Those trends indicate water-enrichment (or hydrating) trend in the magma reservoir. On the bases of the detailed analyses of the pyroxene crystallization sequences as well as estimated magmatic temperatures using pyroxene geothermometer, for calc-alkali rocks from the Central Cone (CC) in the Hakone volcano, the following working hypothesis is suggested, i.e. those calc-alkali rocks are induced by magma mixing between high temperature (about 1120 Degree Centigrade) tholeiite magma and low temperature (about 970 Degree Centigrade) magma, the latter is originated from fractional crystallization of the primitive high temperature hydras island-arc tholeiite magma within magma reservoir under closed environment for water. Reference Ishii, T., 1991. Lava-flow and subvolcanic magma reservoir composition trends in the Ca-poor pyroxenes of Hakone Volcano, Japan. Jour. Petrol., 32, 429-450 Kuno, H., 1950. Petrology of Hakone volcano and the adjacent areas, Japan. Bull. Geol. Soc. Am., 61, 957-1019. Sakuyama, M., 1981. Petrological study of the Myoko and Kurohime volcanoes, Japan: crystallization sequence and evidence for magma mixing. Jour. Petrol., 22, 553-583. Osborn, E. F., 1959. Role of oxygen pressure in the crystallization and

  20. The release of trapped gases from amorphous solid water films. I. "Top-down" crystallization-induced crack propagation probed using the molecular volcano. (United States)

    May, R Alan; Smith, R Scott; Kay, Bruce D


    In this (Paper I) and the companion paper (Paper II; R. May, R. Smith, and B. Kay, J. Chem. Phys. 138, 104502 (2013)), we investigate the mechanisms for the release of trapped gases from underneath amorphous solid water (ASW) films. In prior work, we reported the episodic release of trapped gases in concert with the crystallization of ASW, a phenomenon that we termed the "molecular volcano." The observed abrupt desorption is due to the formation of cracks that span the film to form a connected pathway for release. In this paper, we utilize the "molecular volcano" desorption peak to characterize the formation of crystallization-induced cracks. We find that the crack length distribution is independent of the trapped gas (Ar, Kr, Xe, CH4, N2, O2, or CO). Selective placement of the inert gas layer is used to show that cracks form near the top of the film and propagate downward into the film. Isothermal experiments reveal that, after some induction time, cracks propagate linearly in time with an Arrhenius dependent velocity corresponding to an activation energy of 54 kJ∕mol. This value is consistent with the crystallization growth rates reported by others and establishes a direct connection between crystallization growth rate and the crack propagation rate. A two-step model in which nucleation and crystallization occurs in an induction zone near the top of the film followed by the propagation of a crystallization∕crack front into the film is in good agreement with the temperature programmed desorption results.

  1. Rapid crystal recycling at Krafla Volcano, Iceland, inferred from oxygen-isotope and trace- element compositions and U-Th-Ra disequilibria in plagioclase (United States)

    Cooper, K. M.; Sims, K. W.; Eiler, J. M.; Banerjee, N. R.


    The Icelandic central volcano of Krafla exhibits increasing assimilation of hydrothermally-altered crust with increasing differentiation of magmas, as evidenced by decreasing δ18O with decreasing MgO (Nicholson et al., 1991, J Pet 32, p.1005). The Krafla Fires eruption (1975-84) produced two different magma compositions simultaneously: quartz tholeiites near the center of the volcano, and olivine tholeiites north of the central volcano (Gronvold et al., 2008, Goldschmidt abstract). Examination of crystals in these magmas has the potential to provide information about the nature and timescales of mixing of distinct magmas and assimilation of crustal material at Krafla. We present oxygen-isotope compositions, trace-element compositions, and 238U-230Th-226Ra disequilibria measured in plagioclase crystals from samples of lavas erupted during two phases of the Krafla Fires eruption (ol tholeiite erupted Jan-Feb 1981, and qz tholeiite erupted Nov 1981). Oxygen-isotope data for multiple size fractions of plagioclase show a decrease in δ18O with increasing crystal size for the ol tholeiite (from ~4.1 permil to 3.5 permil), whereas there is no clear relationship between plagioclase size and oxygen-isotope composition in the qtz tholeiite (all size fractions average 4.1-4.3 permil). Furthermore, all measured plagioclase have δ18O lower than would be in equilibrium with the whole rock measurements (by up to 1.5 permil). These data imply that (1) few or none of the measured crystals precipitated from the host liquids, and (2) the crystals were entrained in the host magmas shortly prior to eruption, allowing them to maintain oxygen isotopic disequilibrium and heterogeneity within the crystal populations. These inferences are corroborated by trace element compositions measured in plagioclase by laser-ablation ICPMS, as the majority of analyzed points have Ba and Sr concentrations inconsistent with equilibrium partitioning between crystals and liquid. Furthermore, in the case

  2. Volcano Preparedness (United States)

    ... You might feel better to learn that an ‘active’ volcano is one that has erupted in the past ... miles away. If you live near a known volcano, active or dormant, following these tips will help you ...

  3. Fossil Explorers (United States)

    Moran, Sean; McLaughlin, Cheryl; MacFadden, Bruce; Jacobbe, Elizabeth; Poole, Michael


    Many young learners are fascinated with fossils, particularly charismatic forms such as dinosaurs and giant sharks. Fossils provide tangible, objective evidence of life that lived millions of years ago. They also provide a timescale of evolution not typically appreciated by young learners. Fossils and the science of paleontology can, therefore,…

  4. Marquee Fossils (United States)

    Clary, Renee; Wandersee, James


    Professors of an online graduate-level paleontology class developed the concept of marquee fossils--fossils that have one or more unique characteristics that capture the attention and direct observation of students. In the classroom, Marquee fossils integrate the geology, biology, and environmental science involved in the study of fossilized…

  5. Fossil Explorers (United States)

    Moran, Sean; McLaughlin, Cheryl; MacFadden, Bruce; Jacobbe, Elizabeth; Poole, Michael


    Many young learners are fascinated with fossils, particularly charismatic forms such as dinosaurs and giant sharks. Fossils provide tangible, objective evidence of life that lived millions of years ago. They also provide a timescale of evolution not typically appreciated by young learners. Fossils and the science of paleontology can, therefore,…

  6. Ediacara Fossils (United States)

    Science Teacher, 2005


    Now, a research team from Virginia Tech and Nanjing Institute of Geology and Paleontology has discovered uniquely well-preserved fossil forms from 550-million-year-old rocks of the Ediacaran Period. The research appears in the Proceedings of the National Academy of Sciences. The discovery of these unusually preserved fossils reveals unprecedented…

  7. Fossil Fuels. (United States)

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  8. Fossil Fuels. (United States)

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  9. Vanishing Volcano

    Institute of Scientific and Technical Information of China (English)



    Mauna Loa, the world’s largest active volcano,is sinking into the Pacific Ocean——and it’s taking the main island of Hawaii with it! The problem:The mighty volcano has gained too much weight, says Peter Lipman of the U. S. Geological Survey.

  10. Dante's volcano (United States)


    This video contains two segments: one a 0:01:50 spot and the other a 0:08:21 feature. Dante 2, an eight-legged walking machine, is shown during field trials as it explores the inner depths of an active volcano at Mount Spurr, Alaska. A NASA sponsored team at Carnegie Mellon University built Dante to withstand earth's harshest conditions, to deliver a science payload to the interior of a volcano, and to report on its journey to the floor of a volcano. Remotely controlled from 80-miles away, the robot explored the inner depths of the volcano and information from onboard video cameras and sensors was relayed via satellite to scientists in Anchorage. There, using a computer generated image, controllers tracked the robot's movement. Ultimately the robot team hopes to apply the technology to future planetary missions.

  11. What Are Volcano Hazards? (United States)

    ... Sheet 002-97 Revised March 2008 What Are Volcano Hazards? Volcanoes give rise to numerous geologic and ... as far as 15 miles from the volcano. Volcano Landslides A landslide or debris avalanche is a ...

  12. Crystallization conditions and petrogenesis of the lava dome from the ˜900 years BP eruption of Cerro Machín Volcano, Colombia (United States)

    Laeger, Kathrin; Halama, Ralf; Hansteen, Thor; Savov, Ivan P.; Murcia, Hugo F.; Cortés, Gloria P.; Garbe-Schönberg, Dieter


    The last known eruption at Cerro Machín Volcano (CMV) in the Central Cordillera of Colombia occurred ˜900 years BP and ended with the formation of a dacitic lava dome. The dome rocks contain both normally and reversely zoned plagioclase (An24-54), unzoned and reversely zoned amphiboles of dominantly tschermakite and pargasite/magnesio-hastingsite composition and olivine xenocrysts (Fo = 85-88) with amphibole/clinopyroxene overgrowth, all suggesting interaction with mafic magma at depth. Plagioclase additionally exhibits complex oscillatory zoning patterns reflecting repeated replenishment, fractionation and changes in intrinsic conditions in the magma reservoir. Unzoned amphiboles and cores of the reversely zoned amphiboles give identical crystallization conditions of 910 ± 30 °C and 360 ± 70 MPa, corresponding to a depth of about 13 ± 2 km, at moderately oxidized conditions (f = +0.5 ± 0.2 ΔNNO). The water content in the melt, calculated based on amphibole chemistry, is 7.1 ± 0.4 wt.%. Rims of the reversely zoned amphiboles are relatively enriched in MgO and yield higher crystallization temperatures (T = 970 ± 25 °C), slightly lower melt H2O contents (6.1 ± 0.7 wt.%) and overlapping pressures (410 ± 100 MPa). We suggest that these rims crystallized following an influx of mafic melt into a resident magma reservoir at mid-crustal depths, further supported by the occurrence of xenocrystic olivine. Crystallization of biotite, albite-rich plagioclase and quartz occurred at comparatively low temperatures (probably rock chemistry of the CMV lava dome dacites is homogenous. They have elevated (La/Nb)N ratios of 3.8-4.5, typical for convergent margin magmas, and display several geochemical characteristics of adakites. Both Sr and Nd isotope compositions (87Sr/86Sr ˜0.70497, 143Nd/144Nd ˜0.51267) are among the most radiogenic observed for the Northern Volcanic Zone of the Andes. They are distinct from oceanic crust that has been subducted in the region

  13. Santorini Volcano (United States)

    Druitt, T.H.; Edwards, L.; Mellors, R.M.; Pyle, D.M.; Sparks, R.S.J.; Lanphere, M.; Davies, M.; Barreirio, B.


    Santorini is one of the most spectacular caldera volcanoes in the world. It has been the focus of significant scientific and scholastic interest because of the great Bronze Age explosive eruption that buried the Minoan town of Akrotiri. Santorini is still active. It has been dormant since 1950, but there have been several substantial historic eruptions. Because of this potential risk to life, both for the indigenous population and for the large number of tourists who visit it, Santorini has been designated one of five European Laboratory Volcanoes by the European Commission. Santorini has long fascinated geologists, with some important early work on volcanoes being conducted there. Since 1980, research groups at Cambridge University, and later at the University of Bristol and Blaise Pascal University in Clermont-Ferrand, have collected a large amount of data on the stratigraphy, geochemistry, geochronology and petrology of the volcanics. The volcanic field has been remapped at a scale of 1:10 000. A remarkable picture of cyclic volcanic activity and magmatic evolution has emerged from this work. Much of this work has remained unpublished until now. This Memoir synthesizes for the first time all the data from the Cambridge/Bristol/Clermont groups, and integrates published data from other research groups. It provides the latest interpretation of the tectonic and magmatic evolution of Santorini. It is accompanied by the new 1:10 000 full-colour geological map of the island.

  14. Steklite, KAl(SO4)2: A finding at the Tolbachik Volcano, Kamchatka, Russia, validating its status as a mineral species and crystal structure (United States)

    Murashko, M. N.; Pekov, I. V.; Krivovichev, S. V.; Chernyatyeva, A. P.; Yapaskurt, V. O.; Zadov, A. E.; Zelensky, M. E.


    Steklite KAl(SO4)2 has been found in sublimates of the Yadovitaya (Poisonous) fumarole at the second cinder cone of the northern breach of the Great Fissure Tolbachik Eruption, Tolbachik volcano, Kamchatka Peninsula, Russia. Steklite was approved as a valid mineral species by the Commission on New Minerals, Nomenclature, and Mineral Classification of the International Mineralogical Association on June 2, 2011 (IMA no. 2011-041). The name steklite is left for this mineral, as it was named by Chesnokov et al. (1995) for its technogenic analog from a burnt dump of coal mine no. 47 at Kopeisk, the Southern Urals, Russia. It is named after the Russian word steklo, meaning glass, in allusion to the visual similarity of its lamellae to thin glass platelets. At Tolbachik, steklite is associated with alumoklyuchevskite, langbeinite, euchlorine, fedotovite, chalcocyanite, hematite, and lyonsite. It occurs as hexagonal or irregular-shaped lamellar crystals with the major form {001} reaching 30 μm in thickness and 0.2 mm (occasionally up to 1 mm) in width. The crystals are frequently split. They are combined into openwork aggregates or thin crusts up to 1.5 × 2.5 cm in area. Steklite is transparent and colorless, with vitreous luster. The cleavage is perfect, parallel to (001). The mineral is brittle. The Mohs' hardness is 2.5. D calc is 2.797 g/cm3. Steklite is optically uniaxial, (-), ω = 1.546(2), ɛ = 1.533(3). The chemical composition (wt %, electron-microprobe data) is as follows: 0.09 Na2O, 18.12 K2O, 0.08 CaO, 0.03 MnO, 2.02 Fe2O3, 18.18 Al2O3, 61.80 SO3. The total is 100.37. The empirical formula calculated on the basis of eight O atoms is: (K0.997Na0.008Ca0.004)Σ1.009(Al0.925Fe{0.066/3+}Mg0.003Mn0.001)Σ0.995S2.01O8. Steklite is trigonal, space group P321, a = 4.7281(3), c = 7.9936(5) Å, V = 154.76(17)Å3, Z =1. The strongest reflections in the X-ray powder diffraction pattern ( d, Å- I[ hkl]) are: 8.02-34[001], 4.085-11[100], 3.649-100[011, 101], 2

  15. Are the oldest 'fossils', fossils (United States)

    Schopf, J. W.


    A comparative statistical study has been carried out on populations of modern algae, Precambrian algal microfossils, the 'organized elements' of the Orgueil carbonaceous meteorite, and the oldest microfossil-like objects now known (spheroidal bodies from the Fig Tree and Onverwacht Groups of the Swaziland Supergroup, South Africa). The distribution patterns exhibited by the more than 3000 m.y.-old Swaziland microstructures bear considerable resemblance to those of the abiotic 'organized elements' but differ rather markedly from those exhibited by younger, assuredly biogenic, populations. Based on these comparisons, it is concluded that the Swaziland spheroids could be, at least in part, of nonbiologic origin; these oldest known fossil-like microstructures should not be regarded as constituting firm evidence of Archean life.

  16. Mount Rainier, a decade volcano

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.C.; Hooper, P.R. (Washington State Univ., Pullman, WA (United States). Dept. of Geology); Eggers, A.E. (Univ. of Puget Sound, Tacoma, WA (United States). Dept. of Geology)


    Mount Rainier, recently designated as a decade volcano, is a 14,410 foot landmark which towers over the heavily populated southern Puget Sound Lowland of Washington State. It last erupted in the mid-1800's and is an obvious threat to this area, yet Rainier has received little detailed study. Previous work has divided Rainier into two distinct pre-glacial eruptive episodes and one post-glacial eruptive episode. In a pilot project, the authors analyzed 253 well-located samples from the volcano for 27 major and trace elements. Their objective is to test the value of chemical compositions as a tool in mapping the stratigraphy and understanding the eruptive history of the volcano which they regard as prerequisite to determining the petrogenesis and potential hazard of the volcano. The preliminary data demonstrates that variation between flows is significantly greater than intra-flow variation -- a necessary condition for stratigraphic use. Numerous flows or groups of flows can be distinguished chemically. It is also apparent from the small variation in Zr abundances and considerable variation in such ratios as Ba/Nb that fractional crystallization plays a subordinate role to some form of mixing process in the origin of the Mount Rainier lavas.

  17. Global Volcano Locations Database (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a database of over 1,500 volcano locations obtained from the Smithsonian Institution Global Volcanism Program, Volcanoes of the World publication. The...

  18. A Scientific Excursion: Volcanoes. (United States)

    Olds, Henry, Jr.


    Reviews an educationally valuable and reasonably well-designed simulation of volcanic activity in an imaginary land. VOLCANOES creates an excellent context for learning information about volcanoes and for developing skills and practicing methods needed to study behavior of volcanoes. (Author/JN)

  19. Ediacaran Macro Body Fossils


    Huang, Timothy D.; Jei-Fu Shaw; Liang Zheng; Chun-Lan Huang; YiLung Chang; ChuanWei Yang


    This paper, Ediacaran Macro Body Fossils, reports a new discovery of well preserved three dimensional macro body fossils of the Ediacaran Period in central YunNan province in the People's Republic of China. These body fossils will enable more detailed and in-depth exploration of the evolution of multi-cellular macro organisms on this planet, whereas in the past, researches could only rely on cast or imprint fossils.

  20. The Fossile Episode


    Hassler, John; Sinn, Hans-Werner


    We build a two-sector dynamic general equilibrium model with one-sided substitutability between fossil carbon and biocarbon. One shock only, the discovery of the technology to use fossil fuels, leads to a transition from an inital pre-industrial phase to three following phases: a pure fossil carbon phase, a mixed fossil and biocarbon phase and an absorbing biocarbon phase. The increased competition for biocarbon during phase 3 and 4 leads to increasing food prices. We provide closed form expr...

  1. The Fossil Episode


    Hassler, John; Sinn, Hans-Werner


    We build a two-sector dynamic general equilibrium model with one-sided substitutability between fossil carbon and biocarbon. One shock only, the discovery of the technology to use fossil fuels, leads to a transition from an initial pre-industrial phase to three following phases: a pure fossil carbon phase, a mixed fossil and biocarbon phase and an absorbing biocarbon phase. The increased competition for biocarbon during phase 3 and 4 leads to increasing food prices. We provide closed form exp...

  2. Volcano seismology (United States)

    Chouet, B.


    A fundamental goal of volcano seismology is to understand active magmatic systems, to characterize the configuration of such systems, and to determine the extent and evolution of source regions of magmatic energy. Such understanding is critical to our assessment of eruptive behavior and its hazardous impacts. With the emergence of portable broadband seismic instrumentation, availability of digital networks with wide dynamic range, and development of new powerful analysis techniques, rapid progress is being made toward a synthesis of high-quality seismic data to develop a coherent model of eruption mechanics. Examples of recent advances are: (1) high-resolution tomography to image subsurface volcanic structures at scales of a few hundred meters; (2) use of small-aperture seismic antennas to map the spatio-temporal properties of long-period (LP) seismicity; (3) moment tensor inversions of very-long-period (VLP) data to derive the source geometry and mass-transport budget of magmatic fluids; (4) spectral analyses of LP events to determine the acoustic properties of magmatic and associated hydrothermal fluids; and (5) experimental modeling of the source dynamics of volcanic tremor. These promising advances provide new insights into the mechanical properties of volcanic fluids and subvolcanic mass-transport dynamics. As new seismic methods refine our understanding of seismic sources, and geochemical methods better constrain mass balance and magma behavior, we face new challenges in elucidating the physico-chemical processes that cause volcanic unrest and its seismic and gas-discharge manifestations. Much work remains to be done toward a synthesis of seismological, geochemical, and petrological observations into an integrated model of volcanic behavior. Future important goals must include: (1) interpreting the key types of magma movement, degassing and boiling events that produce characteristic seismic phenomena; (2) characterizing multiphase fluids in subvolcanic

  3. Carbonate assimilation at Merapi volcano, Java Indonesia

    DEFF Research Database (Denmark)

    Chadwick, J.P; Troll, V.R; Ginibre,, C.


    Recent basaltic andesite lavas from Merapi volcano contain abundant, complexly zoned, plagioclase phenocrysts, analysed here for their petrographic textures, major element composition and Sr isotope composition. Anorthite (An) content in individual crystals can vary by as much as 55 mol% (An40^95...

  4. Volcanoes: Nature's Caldrons Challenge Geochemists. (United States)

    Zurer, Pamela S.


    Reviews various topics and research studies on the geology of volcanoes. Areas examined include volcanoes and weather, plate margins, origins of magma, magma evolution, United States Geological Survey (USGS) volcano hazards program, USGS volcano observatories, volcanic gases, potassium-argon dating activities, and volcano monitoring strategies.…

  5. Selective Preservation of Fossil Ghost Fish (United States)

    Meacham, Amanda


    A unique type of fossil fish preservation has been discovered in the Angelo Member (Fossil Lake) of the Green River Formation. The Angelo Member is a predominately evaporative deposit dominated by dolomite, but contains facies of fossiliferous laminated calcimicrite. Fossil fish occurring in two beds conspicuously lack bones. Fish in the lower bed are only preserved as organic material, including skin, pigments, and eyes. Fish in the upper bed have three-dimensional etching where bones once existed but also contain skin, pigments, and eyes. The top third of the upper bed often contains calcite crystals that are pseudomorphs after trona and possibly halite. Preliminary mineralogical analysis and mapping of evaporate facies suggests that this unique preservation may be related to lake geochemical conditions, such as high pH and alkalinity. To our knowledge, this is the first time this type of preservation has been observed and studied. Fossils and sediments within these beds are being studied both vertically and laterally through the one-meter thick sequence containing the fossil fish using XRD, isotopic, SEM, thin section, and total organic carbon analysis. Nine quarries, 0.5-1 meter square, were excavated for both fossils and rock samples along with 17 additional rock sample locations across an approximately 25-kilometer square region. This investigation has the capability of reconstructing the paleoenvironment and lake chemistry of Fossil Lake during the deposition of the "ghost-fish" beds and solving the mystery of the "missing bones" and the unusual process of preservation.

  6. Degassing and differentiation in subglacial volcanoes, Iceland (United States)

    Moore, J.G.; Calk, L.C.


    Within the neovolcanic zones of Iceland many volcanoes grew upward through icecaps that have subsequently melted. These steep-walled and flat-topped basaltic subglacial volcanoes, called tuyas, are composed of a lower sequence of subaqueously erupted, pillowed lavas overlain by breccias and hyaloclastites produced by phreatomagmatic explosions in shallow water, capped by a subaerially erupted lava plateau. Glass and whole-rock analyses of samples collected from six tuyas indicate systematic variations in major elements showing that the individual volcanoes are monogenetic, and that commonly the tholeiitic magmas differentiated and became more evolved through the course of the eruption that built the tuya. At Herdubreid, the most extensively studies tuya, the upward change in composition indicates that more than 50 wt.% of the first erupted lavas need crystallize over a range of 60??C to produce the last erupted lavas. The S content of glass commonly decreases upward in the tuyas from an average of about 0.08 wt.% at the base to crystallization that generates the more evolved, lower-temperature melts during the growth of the tuyas, apparently results from cooling and degassing of magma contained in shallow magma chambers and feeders beneath the volcanoes. Cooling may result from percolation of meltwater down cracks, vaporization, and cycling in a hydrothermal circulation. Degassing occurs when progressively lower pressure eruption (as the volcanic vent grows above the ice/water surface) lowers the volatile vapour pressure of subsurface melt, thus elevating the temperature of the liquidus and hastening liquid-crystal differentiation. ?? 1991.

  7. Factors contributing to fossilization

    Institute of Scientific and Technical Information of China (English)



    As the most prominent feature of interlanguage, fossilization is a complex and essential topic in the field of SLA research. Various causes, in spite quantity of them are only theories, have been studied by different researchers from multiple points of view. Daiwei Dong(1990) has pointed out that virtually every inaccurate cause leads to language fossilization. This paper tries to conclude update causes of fossilization.

  8. Foci of Volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, I.


    One may assume a center of volcanic activities beneath the edifice of an active volcano, which is here called the focus of the volcano. Sometimes it may be a ''magma reservoir''. Its depth may differ with types of magma and change with time. In this paper, foci of volcanoes are discussed from the viewpoints of four items: (1) Geomagnetic changes related with volcanic activities; (2) Crustal deformations related with volcanic activities; (3) Magma transfer through volcanoes; and (4) Subsurface structure of calderas.

  9. Modes of fossil preservation (United States)

    Schopf, J.M.


    The processes of geologic preservation are important for understanding the organisms represented by fossils. Some fossil differences are due to basic differences in organization of animals and plants, but the interpretation of fossils has also tended to be influenced by modes of preservation. Four modes of preservation generally can be distinguished: (1) Cellular permineralization ("petrifaction") preserves anatomical detail, and, occasionally, even cytologic structures. (2) Coalified compression, best illustrated by structures from coal but characteristic of many plant fossils in shale, preserves anatomical details in distorted form and produces surface replicas (impressions) on enclosing matrix. (3) Authigenic preservation replicates surface form or outline (molds and casts) prior to distortion by compression and, depending on cementation and timing, may intergrade with fossils that have been subject to compression. (4) Duripartic (hard part) preservation is characteristic of fossil skeletal remains, predominantly animal. Molds, pseudomorphs, or casts may form as bulk replacements following dissolution of the original fossil material, usually by leaching. Classification of the kinds of preservation in fossils will aid in identifying the processes responsible for modifying the fossil remains of both animals and plants. ?? 1975.

  10. Zeolites replacing plant fossils in the Denver formation, Lakewood, Colorado. (United States)

    Modreski, P.J.; Verbeek, E.R.; Grout, M.A.


    Well-developed crystals of heulandite and stilbite, within fossil wood, occur in sedimentary rocks in Lakewood, Jefferson County. The rocks belong to the Denver formation, a locally fossiliferous deposit of fluvial claystone, siltstone, sandstone and conglomerate, containing some volcanic mudflows (andesitic) of late Cretaceous to Palaeocene age. Altered volcanic glass released Na and Ca into the ground-water and subsequently zeolites were crystallized in the open spaces between grains and within fossil plant structures. Minor pyrite, quartz (jasper), calcite and apatite also occur as replacements of fossil wood. Similar zeolite occurrences in other areas are reviewed.-R.S.M.

  11. Fossil turbulence revisited

    CERN Document Server

    Gibson, C H


    A theory of fossil turbulence presented in the 11th Liege Colloquium on Marine turbulence is "revisited" in the 29th Liege Colloquium "Marine Turbulence Revisited". The Gibson (1980) theory applied universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as it is constrained and fossilized by buoyancy forces. Towed oceanic microstructure measurements of Schedvin (1979) confirmed the predicted universal constants. Universal constants, spectra, hydrodynamic phase diagrams (HPDs) and other predictions of the theory have been reconfirmed by a wide variety of field and laboratory observations. Fossil turbulence theory has many applications; for example, in marine biology, laboratory and field measurements suggest phytoplankton species with different swimming abilities adjust their growth strategies differently by pattern recognition of several days of turbulence-fossil-turbulence dissipation and persistence times above thres...

  12. Volcanoes - Direct Download (United States)

    U.S. Geological Survey, Department of the Interior — This map layer includes Holocene volcanoes, which are those thought to be active in the last 10,000 years, that are within an extended area of the northern...

  13. Italian active volcanoes

    Institute of Scientific and Technical Information of China (English)

    RobertoSantacroce; RenawCristofolini; LuigiLaVolpe; GiovanniOrsi; MauroRosi


    The eruptive histories, styles of activity and general modes of operation of the main active Italian volcanoes,Etna, Vulcano, Stromboli, Vesuvio, Campi Flegrei and Ischia, are described in a short summary.

  14. First fossil chimpanzee. (United States)

    McBrearty, Sally; Jablonski, Nina G


    There are thousands of fossils of hominins, but no fossil chimpanzee has yet been reported. The chimpanzee (Pan) is the closest living relative to humans. Chimpanzee populations today are confined to wooded West and central Africa, whereas most hominin fossil sites occur in the semi-arid East African Rift Valley. This situation has fuelled speculation regarding causes for the divergence of the human and chimpanzee lineages five to eight million years ago. Some investigators have invoked a shift from wooded to savannah vegetation in East Africa, driven by climate change, to explain the apparent separation between chimpanzee and human ancestral populations and the origin of the unique hominin locomotor adaptation, bipedalism. The Rift Valley itself functions as an obstacle to chimpanzee occupation in some scenarios. Here we report the first fossil chimpanzee. These fossils, from the Kapthurin Formation, Kenya, show that representatives of Pan were present in the East African Rift Valley during the Middle Pleistocene, where they were contemporary with an extinct species of Homo. Habitats suitable for both hominins and chimpanzees were clearly present there during this period, and the Rift Valley did not present an impenetrable barrier to chimpanzee occupation.

  15. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  16. Fossilization of feathers (United States)

    Davis, Paul G.; Briggs, Derek E. G.


    Scanning electron microscopy of feathers has revealed evidence that a bacterial glycocalyx (a network of exocellular polysaccharide fibers) played a role in promoting their fossilization in some cases. This mode of preservation has not been reported in other soft tissues. The majority of fossil feathers are preserved as carbonized traces. More rarely, bacteria on the surface are replicated by authigenic minerals (bacterial autolithification). The feathers of Archaeopteryx are preserved mainly by imprintation following early lithification of the substrate and decay of the feather. Lacustrine settings provide the most important taphonomic window for feather preservation. Preservation in terrestrial and normal-marine settings involves very different processes (in amber and in authigenically mineralized coprolites, respectively). Therefore, there may be a significant bias in the avian fossil record in favor of inland water habitats.

  17. Volcanoes: Coming Up from Under. (United States)

    Science and Children, 1980


    Provides specific information about the eruption of Mt. St. Helens in March 1980. Also discusses how volcanoes are formed and how they are monitored. Words associated with volcanoes are listed and defined. (CS)

  18. Organizational changes at Earthquakes & Volcanoes (United States)

    Gordon, David W.


    Primary responsibility for the preparation of Earthquakes & Volcanoes within the Geological Survey has shifted from the Office of Scientific Publications to the Office of Earthquakes, Volcanoes, and Engineering (OEVE). As a consequence of this reorganization, Henry Spall has stepepd down as Science Editor for Earthquakes & Volcanoes(E&V).

  19. Mineralization of fossil wood

    NARCIS (Netherlands)

    Buurman, P.


    Several pieces of fossil wood have been analyzed with X-ray diffraction and were grouped on the basis of mineralogical composition. Various mineralizations were studied in thin sections and by means of the scanning electron microscope. Wood-opals appear to show a structure preservation that points t

  20. Fossils and decapod phylogeny

    NARCIS (Netherlands)

    Schram, Frederick R.; Dixon, Christopher


    An expanded series of morphological characters developed for a cladistic analysis of extant decapods has yielded a new hypothesis for the phylogeny of the group. Application of this database to selected fossil genera produces some interesting results and demonstrates the feasibility of treating foss

  1. Fossil Dot Com

    DEFF Research Database (Denmark)


    , and the transformation has moved 50% of us to live in cities, whereas a mere 3% dwelled in cities in 1800. However, this 200 year long fossil fuelled bubble is coming to an end, which affects societies around the world and the way we design products and services for these societies beyond imagination. With rich...

  2. Fossil energy research meeting

    Energy Technology Data Exchange (ETDEWEB)

    Kropschot, R. H.; Phillips, G. C.


    U.S. ERDA's research programs in fossil energy are reviewed with brief descriptions, budgets, etc. Of general interest are discussions related to the capabilities for such research of national laboratories, universities, energy centers, etc. Of necessity many items are treated briefly, but a general overview of the whole program is provided. (LTN)

  3. Hawaii's volcanoes revealed (United States)

    Eakins, Barry W.; Robinson, Joel E.; Kanamatsu, Toshiya; Naka, Jiro; Smith, John R.; Takahashi, Eiichi; Clague, David A.


    Hawaiian volcanoes typically evolve in four stages as volcanism waxes and wanes: (1) early alkalic, when volcanism originates on the deep sea floor; (2) shield, when roughly 95 percent of a volcano's volume is emplaced; (3) post-shield alkalic, when small-volume eruptions build scattered cones that thinly cap the shield-stage lavas; and (4) rejuvenated, when lavas of distinct chemistry erupt following a lengthy period of erosion and volcanic quiescence. During the early alkalic and shield stages, two or more elongate rift zones may develop as flanks of the volcano separate. Mantle-derived magma rises through a vertical conduit and is temporarily stored in a shallow summit reservoir from which magma may erupt within the summit region or be injected laterally into the rift zones. The ongoing activity at Kilauea's Pu?u ?O?o cone that began in January 1983 is one such rift-zone eruption. The rift zones commonly extend deep underwater, producing submarine eruptions of bulbous pillow lava. Once a volcano has grown above sea level, subaerial eruptions produce lava flows of jagged, clinkery ?a?a or smooth, ropy pahoehoe. If the flows reach the ocean they are rapidly quenched by seawater and shatter, producing a steep blanket of unstable volcanic sediment that mantles the upper submarine slopes. Above sea level then, the volcanoes develop the classic shield profile of gentle lava-flow slopes, whereas below sea level slopes are substantially steeper. While the volcanoes grow rapidly during the shield stage, they may also collapse catastrophically, generating giant landslides and tsunami, or fail more gradually, forming slumps. Deformation and seismicity along Kilauea's south flank indicate that slumping is occurring there today. Loading of the underlying Pacific Plate by the growing volcanic edifices causes subsidence, forming deep basins at the base of the volcanoes. Once volcanism wanes and lava flows no longer reach the ocean, the volcano continues to submerge, while

  4. Linking petrology and seismology at an active volcano. (United States)

    Saunders, Kate; Blundy, Jon; Dohmen, Ralf; Cashman, Kathy


    Many active volcanoes exhibit changes in seismicity, ground deformation, and gas emissions, which in some instances arise from magma movement in the crust before eruption. An enduring challenge in volcano monitoring is interpreting signs of unrest in terms of the causal subterranean magmatic processes. We examined over 300 zoned orthopyroxene crystals from the 1980-1986 eruption of Mount St. Helens that record pulsatory intrusions of new magma and volatiles into an existing larger reservoir before the eruption occurred. Diffusion chronometry applied to orthopyroxene crystal rims shows that episodes of magma intrusion correlate temporally with recorded seismicity, providing evidence that some seismic events are related to magma intrusion. These time scales are commensurate with monitoring signals at restless volcanoes, thus improving our ability to forecast volcanic eruptions by using petrology.

  5. Sustainability of Fossil Fuels (United States)

    Lackner, K. S.


    For a sustainable world economy, energy is a bottleneck. Energy is at the basis of a modern, technological society, but unlike materials it cannot be recycled. Energy or more precisely "negentropy" (the opposite of entropy) is always consumed. Thus, one either accepts the use of large but finite resources or must stay within the limits imposed by dilute but self-renewing resources like sunlight. The challenge of sustainable energy is exacerbated by likely growth in world energy demand due to increased population and increased wealth. Most of the world still has to undergo the transition to a wealthy, stable society with the near zero population growth that characterizes a modern industrial society. This represents a huge unmet demand. If ten billion people were to consume energy like North Americans do today, world energy demand would be ten times higher. In addition, technological advances while often improving energy efficiency tend to raise energy demand by offering more opportunity for consumption. Energy consumption still increases at close to the 2.3% per year that would lead to a tenfold increase over the course of the next century. Meeting future energy demands while phasing out fossil fuels appears extremely difficult. Instead, the world needs sustainable or nearly sustainable fossil fuels. I propose the following definition of sustainable under which fossil fuels would well qualify: The use of a technology or resource is sustainable if the intended and unintended consequences will not force its abandonment within a reasonable planning horizon. Of course sustainable technologies must not be limited by resource depletion but this is only one of many concerns. Environmental impacts, excessive land use, and other constraints can equally limit the use of a technology and thus render it unsustainable. In the foreseeable future, fossil fuels are not limited by resource depletion. However, environmental concerns based on climate change and other environmental

  6. Santa Maria Volcano, Guatemala (United States)


    The eruption of Santa Maria volcano in 1902 was one of the largest eruptions of the 20th century, forming a large crater on the mountain's southwest flank. Since 1922, a lava-dome complex, Santiaguito, has been forming in the 1902 crater. Growth of the dome has produced pyroclastic flows as recently as the 2001-they can be identified in this image. The city of Quezaltenango (approximately 90,000 people in 1989) sits below the 3772 m summit. The volcano is considered dangerous because of the possibility of a dome collapse such as one that occurred in 1929, which killed about 5000 people. A second hazard results from the flow of volcanic debris into rivers south of Santiaguito, which can lead to catastrophic flooding and mud flows. More information on this volcano can be found at web sites maintained by the Smithsonian Institution, Volcano World, and Michigan Tech University. ISS004-ESC-7999 was taken 17 February 2002 from the International Space Station using a digital camera. The image is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Searching and viewing of additional images taken by astronauts and cosmonauts is available at the NASA-JSC Gateway to

  7. Anatomy of a volcano

    NARCIS (Netherlands)

    Wassink, J.


    The Icelandic volcano Eyjafjallajökull caused major disruption in European airspace last year. According to his co-author, Freysteinn Sigmundsson, the reconstruction published in Nature six months later by aerospace engineering researcher, Dr Andy Hooper, opens up a new direction in volcanology. “W

  8. The Review of Interlanguage Fossilization

    Institute of Scientific and Technical Information of China (English)



    Interlanguage fossilization is a common phenomenon in second language acquisition. This paper reyiews the important achievements in the study of interlanguage fossilization, analyzing its definition, types and causes. And then find some ways to re- duce the interference of interlanguage fossilization in second language learning.

  9. Catalogue of Icelandic Volcanoes (United States)

    Ilyinskaya, Evgenia; Larsen, Gudrun; Gudmundsson, Magnus T.; Vogfjord, Kristin; Pagneux, Emmanuel; Oddsson, Bjorn; Barsotti, Sara; Karlsdottir, Sigrun


    The Catalogue of Icelandic Volcanoes is a newly developed open-access web resource in English intended to serve as an official source of information about active volcanoes in Iceland and their characteristics. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the effort of FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite. Volcanic activity in Iceland occurs on volcanic systems that usually comprise a central volcano and fissure swarm. Over 30 systems have been active during the Holocene (the time since the end of the last glaciation - approximately the last 11,500 years). In the last 50 years, over 20 eruptions have occurred in Iceland displaying very varied activity in terms of eruption styles, eruptive environments, eruptive products and the distribution lava and tephra. Although basaltic eruptions are most common, the majority of eruptions are explosive, not the least due to magma-water interaction in ice-covered volcanoes. Extensive research has taken place on Icelandic volcanism, and the results reported in numerous scientific papers and other publications. In 2010, the International Civil Aviation Organisation (ICAO) funded a 3 year project to collate the current state of knowledge and create a comprehensive catalogue readily available to decision makers, stakeholders and the general public. The work on the Catalogue began in 2011, and was then further supported by the Icelandic government and the EU through the FP7 project FUTUREVOLC. The Catalogue of Icelandic Volcanoes is a collaboration of the Icelandic Meteorological Office (the state volcano observatory), the Institute of Earth Sciences at the University of Iceland, and the Civil Protection Department of the National Commissioner of the Iceland Police, with contributions from a large number of specialists in Iceland and elsewhere. The Catalogue is built up of chapters with texts and various

  10. The largest fossil rodent (United States)

    Rinderknecht, Andrés; Blanco, R. Ernesto


    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000 kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2 Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. PMID:18198140

  11. Catalogue of Icelandic volcanoes (United States)

    Ilyinskaya, Evgenia; Larsen, Gudrun; Vogfjörd, Kristin; Tumi Gudmundsson, Magnus; Jonsson, Trausti; Oddsson, Björn; Reynisson, Vidir; Barsotti, Sara; Karlsdottir, Sigrun


    Volcanic activity in Iceland occurs on volcanic systems that usually comprise a central volcano and fissure swarm. Over 30 systems have been active during the Holocene. In the last 100 years, over 30 eruptions have occurred displaying very varied activity in terms of eruption styles, eruptive environments, eruptive products and their distribution. Although basaltic eruptions are most common, the majority of eruptions are explosive, not the least due to magma-water interaction in ice-covered volcanoes. Extensive research has taken place on Icelandic volcanism, and the results reported in scientific papers and other publications. In 2010, the International Civil Aviation Organisation funded a 3 year project to collate the current state of knowledge and create a comprehensive catalogue readily available to decision makers, stakeholders and the general public. The work on the Catalogue began in 2011, and was then further supported by the Icelandic government and the EU. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland (commenced in 2012), and the EU FP7 project FUTUREVOLC (2012-2016), establishing an Icelandic volcano Supersite. The Catalogue is a collaborative effort between the Icelandic Meteorological Office (the state volcano observatory), the Institute of Earth Sciences at the University of Iceland, and the Icelandic Civil Protection, with contributions from a large number of specialists in Iceland and elsewhere. The catalogue is scheduled for opening in the first half of 2015 and once completed, it will be an official publication intended to serve as an accurate and up to date source of information about active volcanoes in Iceland and their characteristics. The Catalogue is an open web resource in English and is composed of individual chapters on each of the volcanic systems. The chapters include information on the geology and structure of the volcano; the eruption history, pattern and products; the known precursory signals

  12. Volcano-hazard zonation for San Vicente volcano, El Salvador (United States)

    Major, J.J.; Schilling, S.P.; Pullinger, C.R.; Escobar, C.D.; Howell, M.M.


    San Vicente volcano, also known as Chichontepec, is one of many volcanoes along the volcanic arc in El Salvador. This composite volcano, located about 50 kilometers east of the capital city San Salvador, has a volume of about 130 cubic kilometers, rises to an altitude of about 2180 meters, and towers above major communities such as San Vicente, Tepetitan, Guadalupe, Zacatecoluca, and Tecoluca. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and major transportation routes are located near the lowermost southern and eastern flanks of the volcano. The population density and proximity around San Vicente volcano, as well as the proximity of major transportation routes, increase the risk that even small landslides or eruptions, likely to occur again, can have serious societal consequences. The eruptive history of San Vicente volcano is not well known, and there is no definitive record of historical eruptive activity. The last significant eruption occurred more than 1700 years ago, and perhaps long before permanent human habitation of the area. Nevertheless, this volcano has a very long history of repeated, and sometimes violent, eruptions, and at least once a large section of the volcano collapsed in a massive landslide. The oldest rocks associated with a volcanic center at San Vicente are more than 2 million years old. The volcano is composed of remnants of multiple eruptive centers that have migrated roughly eastward with time. Future eruptions of this volcano will pose substantial risk to surrounding communities.

  13. Geology of Kilauea volcano

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.B. (Geological Survey, Denver, CO (United States). Federal Center); Trusdell, F.A. (Geological Survey, Hawaii National Park, HI (United States). Hawaiian Volcano Observatory)


    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower east rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. 71 refs., 2 figs.

  14. 4D volcano gravimetry (United States)

    Battaglia, Maurizio; Gottsmann, J.; Carbone, D.; Fernandez, J.


    Time-dependent gravimetric measurements can detect subsurface processes long before magma flow leads to earthquakes or other eruption precursors. The ability of gravity measurements to detect subsurface mass flow is greatly enhanced if gravity measurements are analyzed and modeled with ground-deformation data. Obtaining the maximum information from microgravity studies requires careful evaluation of the layout of network benchmarks, the gravity environmental signal, and the coupling between gravity changes and crustal deformation. When changes in the system under study are fast (hours to weeks), as in hydrothermal systems and restless volcanoes, continuous gravity observations at selected sites can help to capture many details of the dynamics of the intrusive sources. Despite the instrumental effects, mainly caused by atmospheric temperature, results from monitoring at Mt. Etna volcano show that continuous measurements are a powerful tool for monitoring and studying volcanoes.Several analytical and numerical mathematical models can beused to fit gravity and deformation data. Analytical models offer a closed-form description of the volcanic source. In principle, this allows one to readily infer the relative importance of the source parameters. In active volcanic sites such as Long Valley caldera (California, U.S.A.) and Campi Flegrei (Italy), careful use of analytical models and high-quality data sets has produced good results. However, the simplifications that make analytical models tractable might result in misleading volcanological inter-pretations, particularly when the real crust surrounding the source is far from the homogeneous/ isotropic assumption. Using numerical models allows consideration of more realistic descriptions of the sources and of the crust where they are located (e.g., vertical and lateral mechanical discontinuities, complex source geometries, and topography). Applications at Teide volcano (Tenerife) and Campi Flegrei demonstrate the

  15. Cycles in fossil diversity

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, Robert A.; Muller, Richard A.


    It is well-known that the diversity of life appears to fluctuate during the course the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 Ma). Using Sepkoski's compendium of the first and last stratigraphic appearances of 36380 marine genera, we report a strong 62 {+-} 3 Myr cycle, which is particularly strong in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance, we also consider contributing environmental factors and possible causes.

  16. Biodesulfurization of fossil fuels. (United States)

    Gray, Kevin A; Mrachko, Gregory T; Squires, Charles H


    Biotechnological techniques enabling the specific removal of sulfur from fossil fuels have been developed. In the past three years there have been important advances in the elucidation of the mechanisms of biodesulfurization; some of the most significant relate to the role of a flavin reductase, DszD, in the enzymology of desulfurization, and to the use of new tools that enable enzyme enhancement via DNA manipulation to influence both the rate and the substrate range of Dsz. Also, a clearer understanding of the unique desulfinase step in the pathway has begun to emerge.

  17. Pairing the Volcano

    CERN Document Server

    Ionica, Sorina


    Isogeny volcanoes are graphs whose vertices are elliptic curves and whose edges are $\\ell$-isogenies. Algorithms allowing to travel on these graphs were developed by Kohel in his thesis (1996) and later on, by Fouquet and Morain (2001). However, up to now, no method was known, to predict, before taking a step on the volcano, the direction of this step. Hence, in Kohel's and Fouquet-Morain algorithms, many steps are taken before choosing the right direction. In particular, ascending or horizontal isogenies are usually found using a trial-and-error approach. In this paper, we propose an alternative method that efficiently finds all points $P$ of order $\\ell$ such that the subgroup generated by $P$ is the kernel of an horizontal or an ascending isogeny. In many cases, our method is faster than previous methods. This is an extended version of a paper published in the proceedings of ANTS 2010. In addition, we treat the case of 2-isogeny volcanoes and we derive from the group structure of the curve and the pairing ...

  18. The petrological relationship between Kamen volcano and adjacent volcanoes of Klyuchevskaya group (United States)

    Churikova, Tatiana; Gordeychik, Boris; Wörner, Gerhard; Ivanov, Boris; Maximov, Alexander; Lebedev, Igor; Griban, Andrey


    rocks from monogenetic cones are systematically different from minerals of dikes and stratovolcano. Olivines in monogenetic cones varies from Fo70 to Fo92, Mg# of clinopyroxenes from 72 to 80 and plagioclases are represented by An60-80. All rocks of the volcano belong to medium-K calc-alkaline basalt-basaltic-andesitic series. The rocks of the stratovolcano are high-Al low-Mg (MgO≤7%, SiO2~50÷56%) and form the stable trends on all petrological diagrams with increasing K2О, decreasing Al2O3, TiO2, CaO, FeO and MgO from basalts to andesites. The melts of the dike complex are likely the least fractionated members of the same mantle source which is confirms by the same mineral composition. Lavas of the monogenetic cones are high-Mg basalts (MgO>6%, SiO2~50.5÷52.5%). They systematically differ from the stratovolcano samples by mineral composition and by higher MgO and CaO and low FeO, TiO2, Al2O3 and P2O5 at similar SiO2 content. The rocks of Ploskie Sopky volcano are systematically different from stratovolcano Kamen in major elements and mineral composition and thus can not originate from the same mantle source by fractional crystallization. In contrast Kamen and Bezymianny stratovolcanoes form the narrow single geochemical trends, where Bezymianny data points comprise a more silica-rich part of the overall trend. Klyuchevskoy high-Mg cinder cones are similar to cinder cones of Kamen. However, Klyuchevskoy stratovolcano rocks differ in major elements and mineral composition from dikes and stratovolcano of Kamen. Thus, using petrological and mineralogical data we conclude that (1) Kamen and Bezymianny volcanoes have a common source; (2) monogenetic cones, which were erupted at Kamen volcano, belong to the group of high-Mg cones of Klyuchevskoy.

  19. Radioactivity in fossils at the Hagerman Fossil Beds National Monument. (United States)

    Farmer, C Neal; Kathren, Ronald L; Christensen, Craig


    Since 1996, higher than background levels of naturally occurring radioactivity have been documented in both fossil and mineral deposits at Hagerman Fossil Beds National Monument in south-central Idaho. Radioactive fossil sites occur primarily within an elevation zone of 900-1000 m above sea level and are most commonly found associated with ancient river channels filled with sand. Fossils found in clay rich deposits do not exhibit discernable levels of radioactivity. Out of 300 randomly selected fossils, approximately three-fourths exhibit detectable levels of natural radioactivity ranging from 1 to 2 orders of magnitude above ambient background levels when surveyed with a portable hand held Geiger-Muller survey instrument. Mineral deposits in geologic strata also show above ambient background levels of radioactivity. Radiochemical lab analysis has documented the presence of numerous natural radioactive isotopes. It is postulated that ancient groundwater transported radioactive elements through sand bodies containing fossils which precipitated out of solution during the fossilization process. The elevated levels of natural radioactivity in fossils may require special precautions to ensure that exposures to personnel from stored or displayed items are kept as low as reasonably achievable (ALARA).

  20. Fossil turbulence and fossil turbulence waves can be dangerous

    CERN Document Server

    Gibson, Carl H


    Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any other forces that tend to damp the eddies out. By this definition, turbulence always cascades from small scales where vorticity is created to larger scales where turbulence fossilizes. Fossil turbulence is any perturbation in a hydrophysical field produced by turbulence that persists after the fluid is no longer turbulent at the scale of the perturbation. Fossil turbulence patterns and fossil turbulence waves preserve and propagate energy and information about previous turbulence. Ignorance of fossil turbulence properties can be dangerous. Examples include the Osama bin Laden helicopter crash and the Air France 447 Airbus crash, both unfairly blamed on the pilots. Observations support the proposed definitions, and suggest even direct numerical simulations of turbulence require caution.

  1. Italian Volcano Supersites (United States)

    Puglisi, G.


    Volcanic eruptions are among the geohazards that may have a substantial economic and social impact, even at worldwide scale. Large populated regions are prone to volcanic hazards worldwide. Even local phenomena may affect largely populated areas and in some cases even megacities, producing severe economic losses. On a regional or global perspective, large volcanic eruptions may affect the climate for years with potentially huge economic impacts, but even relatively small eruptions may inject large amounts of volcanic ash in the atmosphere and severely affect air traffic over entire continents. One of main challenges of the volcanological community is to continuously monitor and understand the internal processes leading to an eruption, in order to give substantial contributions to the risk reduction. Italian active volcanoes constitute natural laboratories and ideal sites where to apply the cutting-edge volcano observation systems, implement new monitoring systems and to test and improve the most advanced models and methods for investigate the volcanic processes. That's because of the long tradition of volcanological studies resulting into long-term data sets, both in-situ and from satellite systems, among the most complete and accurate worldwide, and the large spectrum of the threatening volcanic phenomena producing high local/regional/continental risks. This contribution aims at presenting the compound monitoring systems operating on the Italian active volcanoes, the main improvements achieved during the recent studies direct toward volcanic hazard forecast and risk reductions and the guidelines for a wide coordinated project aimed at applying the ideas of the GEO Supersites Initiative at Mt. Etna and Campi Flegrei / Vesuvius areas.

  2. Ruiz Volcano: Preliminary report (United States)

    Ruiz Volcano, Colombia (4.88°N, 75.32°W). All times are local (= GMT -5 hours).An explosive eruption on November 13, 1985, melted ice and snow in the summit area, generating lahars that flowed tens of kilometers down flank river valleys, killing more than 20,000 people. This is history's fourth largest single-eruption death toll, behind only Tambora in 1815 (92,000), Krakatau in 1883 (36,000), and Mount Pelée in May 1902 (28,000). The following briefly summarizes the very preliminary and inevitably conflicting information that had been received by press time.

  3. First fossil insectivores from Flores

    NARCIS (Netherlands)

    Hoek Ostende, van den L.W.; Berch, van der G.; Awe Due, R.


    The hominid bearing strata from the Liang Bua cave on Flores have yielded a large amount of microvertebrate remains. Among these are three mandibles of shrews, the first record of fossil insectivores from the island. The fossils, representing two different species, are not referable to any of the

  4. Preliminary volcano-hazard assessment for Iliamna Volcano, Alaska (United States)

    Waythomas, Christopher F.; Miller, Thomas P.


    Iliamna Volcano is a 3,053-meter-high, ice- and snow-covered stratovolcano in the southwestern Cook Inlet region about 225 kilometers southwest of Anchorage and about 100 kilometers northwest of Homer. Historical eruptions of Iliamna Volcano have not been positively documented; however, the volcano regularly emits steam and gas, and small, shallow earthquakes are often detected beneath the summit area. The most recent eruptions of the volcano occurred about 300 years ago, and possibly as recently as 90-140 years ago. Prehistoric eruptions have generated plumes of volcanic ash, pyroclastic flows, and lahars that extended to the volcano flanks and beyond. Rock avalanches from the summit area have occurred numerous times in the past. These avalanches flowed several kilometers down the flanks and at least two large avalanches transformed to cohesive lahars. The number and distribution of known volcanic ash deposits from Iliamna Volcano indicate that volcanic ash clouds from prehistoric eruptions were significantly less voluminous and probably less common relative to ash clouds generated by eruptions of other Cook Inlet volcanoes. Plumes of volcanic ash from Iliamna Volcano would be a major hazard to jet aircraft using Anchorage International Airport and other local airports, and depending on wind direction, could drift at least as far as the Kenai Peninsula and beyond. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Because Iliamna Volcano has not erupted for several hundred years, a future eruption could involve significant amounts of ice and snow that could lead to the formation of large lahars and downstream flooding. The greatest hazards in order of importance are described below and shown on plate 1.

  5. Elementary analysis of data from Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-ming; ZHANG Heng-rong; KONG Qing-jun; WU Cheng-zhi; GUO Feng; ZHANG Chao-fan


    Tianchi Volcano is the largest potential erupticve volcano in China. Analyzing these data on seismic monitoring, deformation observation and water chemistry investigation gained from the Tianchi Volcano Observatory (TVO), the authors consider that the Tianchi Volcano is in going into a new flourishing time.




    Unmineralized bacterial cells, mostly Micrococcus sp., but including also Streptococcus sp. and Actinomyces sp., were found in enormous numbers in lake beds of the Newark Canyon Formation of Early Cretaceous age, Eureka County, Nevada. The micrococci are black, and have an average diameter about 0.5 micro. Similar black micrococci (0.4 to 0.7 micro) were found in profusion in the bottom mud of Green Lake, New York. About 80 percent of this mud consists of minute idiomorphic calcite crystals and about 20 percent of these contain enormous numbers of the black micrococci. It is suggested that the Early Cretaceous bacterial cells owe their preservation to occlusion in calcite crystals that grew in a black, bacterial mud in a meromictic lake in which part of the Newark Canyon Formation accumulated.

  7. Mount Rainier active cascade volcano (United States)


    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  8. Mount Rainier active cascade volcano (United States)

    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  9. Fossilization of melanosomes via sulfurization. (United States)

    McNamara, Maria E; van Dongen, Bart E; Lockyer, Nick P; Bull, Ian D; Orr, Patrick J


    Fossil melanin granules (melanosomes) are an important resource for inferring the evolutionary history of colour and its functions in animals. The taphonomy of melanin and melanosomes, however, is incompletely understood. In particular, the chemical processes responsible for melanosome preservation have not been investigated. As a result, the origins of sulfur-bearing compounds in fossil melanosomes are difficult to resolve. This has implications for interpretations of original colour in fossils based on potential sulfur-rich phaeomelanosomes. Here we use pyrolysis gas chromatography mass spectrometry (Py-GCMS), fourier transform infrared spectroscopy (FTIR) and time of flight secondary ion mass spectrometry (ToF-SIMS) to assess the mode of preservation of fossil microstructures, confirmed as melanosomes based on the presence of melanin, preserved in frogs from the Late Miocene Libros biota (NE Spain). Our results reveal a high abundance of organosulfur compounds and non-sulfurized fatty acid methyl esters in both the fossil tissues and host sediment; chemical signatures in the fossil tissues are inconsistent with preservation of phaeomelanin. Our results reflect preservation via the diagenetic incorporation of sulfur, i.e. sulfurization (natural vulcanization), and other polymerization processes. Organosulfur compounds and/or elevated concentrations of sulfur have been reported from melanosomes preserved in various invertebrate and vertebrate fossils and depositional settings, suggesting that preservation through sulfurization is likely to be widespread. Future studies of sulfur-rich fossil melanosomes require that the geochemistry of the host sediment is tested for evidence of sulfurization in order to constrain interpretations of potential phaeomelanosomes and thus of original integumentary colour in fossils.

  10. Soufriere Hills Volcano (United States)


    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit.This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA

  11. FOSSIL2 energy policy model documentation: FOSSIL2 documentation

    Energy Technology Data Exchange (ETDEWEB)



    This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume III lists the model equations and a one line definition for equations, in a short, readable format.

  12. Characteristics of Hawaiian volcanoes (United States)

    Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.


    Founded in 1912 at the edge of the caldera of Kīlauea Volcano, HVO was the vision of Thomas A. Jaggar, Jr., a geologist from the Massachusetts Institute of Technology, whose studies of natural disasters around the world had convinced him that systematic, continuous observations of seismic and volcanic activity were needed to better understand—and potentially predict—earthquakes and volcanic eruptions. Jaggar summarized the aim of HVO by stating that “the work should be humanitarian” and have the goals of developing “prediction and methods of protecting life and property on the basis of sound scientific achievement.” These goals align well with those of the USGS, whose mission is to serve the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage natural resources; and enhance and protect our quality of life.

  13. Multibeam Bathymetry of Haleakala Volcano, Maui (United States)

    Eakins, B. W.; Robinson, J.


    The submarine northeast flank of Haleakala Volcano, Maui was mapped in detail during the summers of 2001 and 2002 by a joint team from the Japan Marine Science and Technology Center (JAMSTEC), Tokyo Institute of Technology, University of Hawaii, and the U.S. Geological Survey. JAMSTEC instruments used included SeaBeam 2112 hull-mounted multibeam sonar (bathymetry and sidescan imagery), manned submersible Shinkai 6500 and ROV Kaiko (bottom video, photographs and sampling of Hana Ridge), gravimeter, magnetometer, and single-channel seismic system. Hana Ridge, Haleakala's submarine east rift zone, is capped by coral-reef terraces for much of its length, which are flexurally tilted towards the axis of the Hawaiian Ridge and delineate former shorelines. Its deeper, more distal portion exhibits a pair of parallel, linear crests, studded with volcanic cones, that suggest lateral migration of the rift zone during its growth. The northern face of the arcuate ridge terminus is a landslide scar in one of these crests, while its southwestern prong is a small, constructional ridge. The Hana slump, a series of basins and ridges analogous to the Laupahoehoe slump off Kohala Volcano, Hawaii, lies north of Hana Ridge and extends down to the Hawaiian moat. Northwest of this slump region a small, dual-crested ridge strikes toward the Hawaiian moat and is inferred to represent a fossil rift zone, perhaps of East Molokai Volcano. A sediment chute along its southern flank has built a large submarine fan with a staircase of contour-parallel folds on its surface that are probably derived from slow creep of sediments down into the moat. Sediments infill the basins of the Hana slump [Moore et al., 1989], whose lowermost layers have been variously back-tilted by block rotation during slumping and flexural loading of the Hawaiian Ridge; the ridges define the outer edges of those down-dropped blocks, which may have subsided several kilometers. An apron of volcaniclastic debris shed from

  14. Volcanoes in Eruption - Set 1 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  15. Volcanoes in Eruption - Set 2 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  16. USGS Volcano Notification Service (VNS) (United States)

    U.S. Geological Survey, Department of the Interior — Website provides a subscription service to receive an email when changes occur in the activity levels for monitored U.S. volcanoes and/or when information releases...

  17. The legacy of fossil fuels. (United States)

    Armaroli, Nicola; Balzani, Vincenzo


    Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30 Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


    Directory of Open Access Journals (Sweden)

    T. M. Manevich


    Full Text Available The paper presents main glaciological characteristics of present-day glaciers located on the Koryaksky volcano. The results of fieldwork (2008–2009 and high-resolution satellite image analysis let us to specify and complete information on modern glacial complex of Koryaksky volcano. Now there are seven glaciers with total area 8.36 km2. Three of them advance, two are in stationary state and one degrades. Moreover, the paper describes the new crater glacier.

  19. Mahukona: The missing Hawaiian volcano

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.O.; Muenow, D.W. (Univ. of Hawaii, Honolulu (USA)); Kurz, M.D. (Woods Hole Oceanographic Institution, MA (USA))


    New bathymetric and geochemical data indicate that a seamount west of the island of Hawaii, Mahukona, is a Hawaiian shield volcano. Mahukona has weakly alkalic lavas that are geochemically distinct. They have high {sup 3}He/{sup 4}He ratios (12-21 times atmosphere), and high H{sub 2}O and Cl contents, which are indicative of the early state of development of Hawaiian volcanoes. The He and Sr isotopic values for Mahukona lavas are intermediate between those for lavas from Loihi and Manuna Loa volcanoes and may be indicative of a temporal evolution of Hawaiian magmas. Mahukona volcano became extinct at about 500 ka, perhaps before reaching sea level. It fills the previously assumed gap in the parallel chains of volcanoes forming the southern segment of the Hawaiian hotspot chain. The paired sequence of volcanoes was probably caused by the bifurcation of the Hawaiian mantle plume during its ascent, creating two primary areas of melting 30 to 40 km apart that have persisted for at least the past 4 m.y.

  20. Dating fossil opal phytoliths

    Energy Technology Data Exchange (ETDEWEB)

    Lentfer, C.; Boyd, B. [Southern Cross University, Lismore, NSW (Australia). School of Resource Science and Management; Torrence, R. [Australian Museum, Sydney, NSW (Australia). Division of Anthropology


    Full text: Opal phytoliths are microscopic silica bodies formed by the precipitation of hydrated silica dioxide (SiO{sub 2}nH{sub 2}0) in, around and between cell walls. They are relatively resistant to degradation in most environments and thus, can occur in large quantities in palaeosediments. Consequently, they are valuable tools for environmental reconstruction. Furthermore, phytoliths are often the only recoverable organic material in well oxidised sediments, the occluded carbon provides the opportunity for dating sediment whose ages have previously been difficult to determine, and thus, increase the potential for fine resolution determination of environmental change. This poster describes the results of an investigation assessing the viability of AMS radiocarbon dating of fossil phytolith inclusions using samples from Garua Island, West New Britain, PNG. Thirteen phytolith samples, isolated from sediments previously dated using tephrastratigraphy and C14 dating of macroremains of nutshells and wood charcoal, were used in the analysis. As a control measure, thirteen parallel samples of microscopic charcoal were also dated using AMS. The results show that the AMS dates for the microscopic charcoal samples are consistent with ages anticipated from the other dating methods, for all but one sample. However, the dates for eight of the thirteen phytolith samples are considerably younger than expected. This bias could be explained by several factors, including downwashing of phytolith through soils, bioturbation, carbon exchange through the siliceous matrix of the phytolith bodies, and contamination from extraneous sources of modern carbon retained in the samples. Research is currently focusing on the investigation of these issues and selected samples are in the process of being retreated with strong oxidising agents to clear contaminants prior to re-dating. Further to this, a full investigation of one profile with a long sequence is underway. High concentrations of

  1. "Mediterranean volcanoes vs. chain volcanoes in the Carpathians" (United States)

    Chivarean, Radu


    Volcanoes have always represent an attractive subject for students. Europe has a small number of volcanoes and Romania has none active ones. The curricula is poor in the study of volcanoes. We want to make a parallel between the Mediterranean active volcanoes and the old extinct ones in the Oriental Carpathians. We made an comparison of the two regions in what concerns their genesis, space and time distribution, the specific relief and the impact in the landscape, consequences of their activities, etc… The most of the Mediterranean volcanoes are in Italy, in the peninsula in Napoli's area - Vezuviu, Campi Flegrei, Puzzoli, volcanic islands in Tirenian Sea - Ischia, Aeolian Islands, Sicily - Etna and Pantelleria Island. Santorini is located in Aegean Sea - Greece. Between Sicily and Tunisia there are 13 underwater volcanoes. The island called Vulcano, it has an active volcano, and it is the origin of the word. Every volcano in the world is named after this island, just north of Sicily. Vulcano is the southernmost of the 7 main Aeolian Islands, all volcanic in origin, which together form a small island arc. The cause of the volcanoes appears to be a combination of an old subduction event and tectonic fault lines. They can be considered as the origin of the science of volcanology. The volcanism of the Carpathian region is part of the extensive volcanic activity in the Mediterranean and surrounding regions. The Carpathian Neogene/Quaternary volcanic arc is naturally subdivided into six geographically distinct segments: Oas, Gutai, Tibles, Calimani, Gurghiu and Harghita. It is located roughly between the Carpathian thrust-and-fold arc to the east and the Transylvanian Basin to the west. It formed as a result of the convergence between two plate fragments, the Transylvanian micro-plate and the Eurasian plate. Volcanic edifices are typical medium-sized andesitic composite volcanoes, some of them attaining the caldera stage, complicated by submittal or peripheral domes

  2. The Lusi eruption and implications for understanding fossil piercement structures in sedimentary basins (United States)

    Svensen, Henrik; Mazzini, Adriano; Planke, Sverre; Hadi, Soffian


    The Lusi eruption started in northeast Java, Indonesia, on May 29th 2006, and it has been erupting rocks, mud, water, and gas ever since. We have been doing field work and research on Lusi ever since the eruption commenced. This work was initially motivated from studying the initiation of a mud volcano. However, the longevity of the eruption has made it possible to describe and monitor the lifespan of this unique piercement structure. . One of the first-order questions regarding the eruption is how it should be classified and if there are any other modern or fossil analogues that can place Lusi in a relevant geological context. During the initial stages of eruption, Lusi was classified as a mud volcano, but following geochemical studies the eruption did not show the typical CH4-dominated gas composition of other mud volcanoes and the temperature was also too high. Moreover, mud volcano eruptions normally last a few days, but Lusi never stopped during the past decade. In particular, the crater fluid geochemistry suggests a connection to the neighboring volcanic complex. Lusi represent a sedimentary hosted hydrothermal system. This opens up new possibilities for understanding fossil hydrothermal systems in sedimentary basins, such as hydrothermal vent complexes and breccia-pipes found in sedimentary basins affected by the formation of Large igneous provinces. We will present examples from the Karoo Basin (South Africa) and the Vøring Basin (offshore Norway) and discuss how Lusi can be used to refine existing formation models. Finally, by comparing Lusi to fossil hydrothermal systems we may get insight into the processes operating at depth where the Lusi system interacts with the igneous rocks of the neighbouring volcanic arc.

  3. Travels with the Fossil Hunters (United States)

    Whybrow, Peter J.


    Whether dodging bullets in West Africa, or rabid dogs in Pakistan, surviving yak-butter tea in Tibet, or eating raw fish in China, the life of a globe-trotting fossil hunter is often hazardous and always filled with surprises. Travels with the Fossil Hunters lets readers share the wonder, joys of discovery, and excitement of these intrepid scientists. Packed with more than 100 beautiful, full-color photographs, the volume takes readers on twelve expeditions to remote parts of the world in search of diverse fossil remains, from those of dinosaurs to human ancestors. Each expedition by paleontologists from London's Natural History Museum reveals the problems and challenges of working in extreme conditions, from the deserts of the Sahara and Yemen to the frozen wastes of Antarctica, from the mountains of India to the forests of Latvia. Along the way they also describe the paleontology and geology of the countries they visit and the scientific reasons for their expeditions. With a foreword from Sir David Attenborough and an introduction from Richard Fortey, this fascinating book will appeal to amateur and professional fossil hunters alike and to readers interested in accounts of exotic locales. Peter Whybrow is a research scientist at the Natural History Museum, London. His research interests include Arabian Miocene vertebrates, paleoclimates, paleogeography, and biotic diversity. He is senior editor with A. Hill of Fossil Vertebrates of Arabia (Yale University Press, New Haven, 1999).

  4. Mud Volcanoes Formation And Occurrence (United States)

    Guliyev, I. S.


    Mud volcanoes are natural phenomena, which occur throughout the globe. They are found at a greater or lesser scale in Azerbaijan, Turkmenistan, Georgia, on the Kerch and Taman peninsulas, on Sakhalin Island, in West Kuban, Italy, Romania, Iran, Pakistan, India, Burma, China, Japan, Indonesia, Malaysia, New Zealand, Mexico, Colombia, Trinidad and Tobago, Venezuela and Ecuador. Mud volcanoes are most well-developed in Eastern Azerbaijan, where more than 30% of all the volcanoes in the world are concentrated. More than 300 mud volcanoes have already been recognized here onshore or offshore, 220 of which lie within an area of 16,000 km2. Many of these mud volcanoes are particularly large (up to 400 m high). The volcanoes of the South Caspian form permanent or temporary islands, and numerous submarine banks. Many hypotheses have been developed regarding the origin of mud volcanoes. Some of those hypotheses will be examined in the present paper. Model of spontaneous excitation-decompaction (proposed by Ivanov and Guliev, 1988, 2002). It is supposed that one of major factors of the movement of sedimentary masses and formation of hydrocarbon deposits are phase transitions in sedimentary basin. At phase transitions there are abnormal changes of physical and chemical parameters of rocks. Abnormal (high and negative) pressure takes place. This process is called as excitation of the underground environment with periodicity from several tens to several hundreds, or thousand years. The relationship between mud volcanism and the generation of hydrocarbons, particularly methane, is considered to be a critical factor in mud volcano formation. At high flow rates the gas and sediment develops into a pseudo-liquid state and as flow increases the mass reaches the "so-called hover velocity" where mass transport begins. The mass of fluid moves as a quasi-uniform viscous mass through the sediment pile in a piston like manner until expelled from the surface as a "catastrophic eruption

  5. Turbulence and diffusion fossil turbulence

    CERN Document Server

    Gibson, C H


    Fossil turbulence processes are central to turbulence, turbulent mixing, and turbulent diffusion in the ocean and atmosphere, in astrophysics and cosmology, and in most other natural flows. George Gamov suggested in 1954 that galaxies might be fossils of primordial turbulence produced by the Big Bang. John Woods showed that breaking internal waves on horizontal dye sheets in the interior of the stratified ocean form highly persistent remnants of these turbulent events, which he called fossil turbulence. The dark mixing paradox of the ocean refers to undetected mixing that must exist somewhere to explain why oceanic scalar fields like temperature and salinity are so well mixed, just as the dark matter paradox of galaxies refers to undetected matter that must exist to explain why rotating galaxies don't fly apart by centrifugal forces. Both paradoxes result from sampling techniques that fail to account for the extreme intermittency of random variables involved in self-similar, nonlinear, cascades over a wide ra...

  6. A Galactic Fossil (United States)


    How old are the oldest stars? Using ESO's VLT, astronomers recently measured the age of a star located in our Galaxy. The star, a real fossil, is found to be 13.2 billion years old, not very far from the 13.7 billion years age of the Universe. The star, HE 1523-0901, was clearly born at the dawn of time. "Surprisingly, it is very hard to pin down the age of a star", the lead author of the paper reporting the results, Anna Frebel, explains. "This requires measuring very precisely the abundance of the radioactive elements thorium or uranium, a feat only the largest telescopes such as ESO's VLT can achieve." ESO PR Photo 23a/07 ESO PR Photo 23a/07 The 'Cosmic Clock' This technique is analogous to the carbon-14 dating method that has been so successful in archaeology over time spans of up to a few tens of thousands of years. In astronomy, however, this technique must obviously be applied to vastly longer timescales. For the method to work well, the right choice of radioactive isotope is critical. Unlike other, stable elements that formed at the same time, the abundance of a radioactive (unstable) isotope decreases all the time. The faster the decay, the less there will be left of the radioactive isotope after a certain time, so the greater will be the abundance difference when compared to a stable isotope, and the more accurate is the resulting age. Yet, for the clock to remain useful, the radioactive element must not decay too fast - there must still be enough left of it to allow an accurate measurement, even after several billion years. "Actual age measurements are restricted to the very rare objects that display huge amounts of the radioactive elements thorium or uranium," says Norbert Christlieb, co-author of the report. ESO PR Photo 23b/07 ESO PR Photo 23b/07 Uranium Line in the Spectrum of an Old Star Large amounts of these elements have been found in the star HE 1523-0901, an old, relatively bright star that was discovered within the Hamburg/ESO survey [1]. The

  7. Fossil Group Origins VII. Galaxy substructures in fossil systems

    CERN Document Server

    Zarattini, S; Aguerri, J A L; Boschin, W; Barrena, R; del Burgo, C; Castro-Rodriguez, N; Corsini, E M; D'Onghia, E; Kundert, A; Méndez-Abreu, J; Sánchez-Janssen, R


    Fossil groups are expected to be the final product of galaxy merging within galaxy groups. In simulations, they are predicted to assemble their mass at high redshift. This early formation allows for the innermost $M^\\ast$ galaxies to merge into a massive central galaxy. Then, they are expected to maintain their fossil status because of the few interactions with the large-scale structure. In this context, the magnitude gap between the two brightest galaxies of the system is considered a good indicator of its dynamical status. As a consequence, the systems with the largest gaps should be dynamically relaxed. In order to examine the dynamical status of these systems, we systematically analyze, for the first time, the presence of galaxy substructures in a sample of 12 spectroscopically-confirmed fossil systems with redshift $z \\le 0.25$. We apply a number of tests in order to investigate the substructure in fossil systems in the two-dimensional space of projected positions out to $R_{200}$. Moreover, for a subsam...

  8. FOSSIL2 energy policy model documentation: FOSSIL2 documentation

    Energy Technology Data Exchange (ETDEWEB)



    This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume II provides the model equations with each of their variables defined, while Volume III lists the equations, and a one line definition for equations, in a shorter, more readable format.

  9. Global Volcano Model (United States)

    Sparks, R. S. J.; Loughlin, S. C.; Cottrell, E.; Valentine, G.; Newhall, C.; Jolly, G.; Papale, P.; Takarada, S.; Crosweller, S.; Nayembil, M.; Arora, B.; Lowndes, J.; Connor, C.; Eichelberger, J.; Nadim, F.; Smolka, A.; Michel, G.; Muir-Wood, R.; Horwell, C.


    Over 600 million people live close enough to active volcanoes to be affected when they erupt. Volcanic eruptions cause loss of life, significant economic losses and severe disruption to people's lives, as highlighted by the recent eruption of Mount Merapi in Indonesia. The eruption of Eyjafjallajökull, Iceland in 2010 illustrated the potential of even small eruptions to have major impact on the modern world through disruption of complex critical infrastructure and business. The effects in the developing world on economic growth and development can be severe. There is evidence that large eruptions can cause a change in the earth's climate for several years afterwards. Aside from meteor impact and possibly an extreme solar event, very large magnitude explosive volcanic eruptions may be the only natural hazard that could cause a global catastrophe. GVM is a growing international collaboration that aims to create a sustainable, accessible information platform on volcanic hazard and risk. We are designing and developing an integrated database system of volcanic hazards, vulnerability and exposure with internationally agreed metadata standards. GVM will establish methodologies for analysis of the data (eg vulnerability indices) to inform risk assessment, develop complementary hazards models and create relevant hazards and risk assessment tools. GVM will develop the capability to anticipate future volcanism and its consequences. NERC is funding the start-up of this initiative for three years from November 2011. GVM builds directly on the VOGRIPA project started as part of the GRIP (Global Risk Identification Programme) in 2004 under the auspices of the World Bank and UN. Major international initiatives and partners such as the Smithsonian Institution - Global Volcanism Program, State University of New York at Buffalo - VHub, Earth Observatory of Singapore - WOVOdat and many others underpin GVM.

  10. Geology and geochemical evaluation of Taftan Volcano, Sistan and Baluchestan Province, southeast of Iran

    Institute of Scientific and Technical Information of China (English)

    Biabangard H.; Moradian A.


    At a glance of its stratighraphy, the Taftan Volcano can be classified as three groups: pre-, syn- and post-volcanic deposits. The pre-volcanic deposits consist mostly of flysch facies and colored mélange complex. The syn-volcanic deposits are mainly the product of the Taftan Volcano which is mostly composed of pyroclastic and lava flows from the main body of this volcano. The post-volcanic deposits are mostly epiclastic and reworked materials from the Taftan Volcano due to its erosion and weathering. Major and trace elements, and Sr/Rb isotopic compositions determined on whole-rock samples from the Taftan Volcano showed that the volcano was formed at the continental margin. The whole-rock isotopic composition of the Taftan Volcano showed a feature of strong enrichment with 87Sr/86Sr=0.705326-0.705921. Geochronological samples of the Taftan Volcano determined by the 40K/40Ar method gave an age range of 6.95±0.72 to 0.71±0.03 Ma. The rare-earth element patterns are characterized by high LREE and nearly strongly linear patterns for MREE to HREE, suggesting that distinctive minerals such as olivine and pyroxene crystallized in the early magmatic stage and then were involved in reaction between the lower crust and residual magma. The integrated isotope and trace element systematics and tectonic structure beneath the Taftan Volcano suggested the lower-crust assimilation by the primary magma. The primary magma had generated from a heterogeneous mantle source and a secondary petrogenetical process. This magma could have been affected by the subduction of the Oman Sea underneath the continental Eurasia plate.

  11. Remote Sensing of Active Volcanoes (United States)

    Francis, Peter; Rothery, David

    The synoptic coverage offered by satellites provides unparalleled opportunities for monitoring active volcanoes, and opens new avenues of scientific inquiry. Thermal infrared radiation can be used to monitor levels of activity, which is useful for automated eruption detection and for studying the emplacement of lava flows. Satellite radars can observe volcanoes through clouds or at night, and provide high-resolution topographic data. In favorable conditions, radar inteferometery can be used to measure ground deformation associated with eruptive activity on a centimetric scale. Clouds from explosive eruptions present a pressing hazard to aviation; therefore, techniques are being developed to assess eruption cloud height and to discriminate between ash and meterological clouds. The multitude of sensors to be launched on future generations of space platforms promises to greatly enhance volcanological studies, but a satellite dedicated to volcanology is needed to meet requirements of aviation safety and volcano monitoring.

  12. Mount Rainier: A decade volcano (United States)

    Swanson, Donald A.; Malone, Stephen D.; Samora, Barbara A.

    Mount Rainier, the highest (4392 m) volcano in the Cascade Range, towers over a population of more than 2.5 million in the Seattle-Tacoma metropolitan area, and its drainage system via the Columbia River potentially affects another 500,000 residents of southwestern Washington and northwestern Oregon (Figure 1). Mount Rainier is the most hazardous volcano in the Cascades in terms of its potential for magma-water interaction and sector collapse. Major eruptions, or debris flows even without eruption, pose significant dangers and economic threats to the region. Despite such hazard and risk, Mount Rainier has received little study; such important topics as its petrologic and geochemical character, its proximal eruptive history, its susceptibility to major edifice failure, and its development over time have been barely investigated. This situation may soon change because of Mount Rainier's recent designation as a “Decade Volcano.”

  13. Systematic radon survey over active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M.; Garcia Vindas, J.R. [Centre National de la Recherche Cientifique, Montpellier (France). Lab. GBE; Ricard, L.P.; Staudacher, T. [Observatoire Volcanologique Du Pitou de la Fournaise, La Plaine des Cafres (France)


    Data obtained since 1993 on Costa Rica volcanos are presented and radon anomalies recorded before the eruption of the Irazu volcano (December 8, 1994) are discussed. The Piton de la Fournaise volcano is inactive since mid 1992. The influence of the external parameters on the radon behaviour is studied and the type of perturbations induced on short-term measurements are individuate.

  14. Basaltic cannibalism at Thrihnukagigur volcano, Iceland (United States)

    Hudak, M. R.; Feineman, M. D.; La Femina, P. C.; Geirsson, H.


    Magmatic assimilation of felsic continental crust is a well-documented, relatively common phenomenon. The extent to which basaltic crust is assimilated by magmas, on the other hand, is not well known. Basaltic cannibalism, or the wholesale incorporation of basaltic crustal material into a basaltic magma, is thought to be uncommon because basalt requires more energy than higher silica rocks to melt. Basaltic materials that are unconsolidated, poorly crystalline, or palagonitized may be more easily ingested than fully crystallized massive basalt, thus allowing basaltic cannibalism to occur. Thrihnukagigur volcano, SW Iceland, offers a unique exposure of a buried cinder cone within its evacuated conduit, 100 m below the main vent. The unconsolidated tephra is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to a vent that produced lava and tephra during the ~4 Ka fissure eruption. Preliminary petrographic and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) analyses indicate that there are two populations of plagioclase present in the system - Population One is stubby (aspect ratio 2.1), subhedral to euhedral, and has much higher Ba/Sr ratios. Population One crystals are observed in the cinder cone, dike, and surface lavas, whereas Population Two crystals are observed only in the dike and surface lavas. This suggests that a magma crystallizing a single elongate population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the stubbier population of phenocrysts. This conceptual model for basaltic cannibalism is supported by field observations of large-scale erosion upward into the tephra, which is coated by magma flow-back indicating that magma was involved in the thermal etching. While the unique exposure at Thrihnukagigur makes it an exceptional place to investigate basaltic cannibalism, we suggest that it is not limited to this volcanic system. Rather it is a process that likely

  15. Alaska volcanoes guidebook for teachers (United States)

    Adleman, Jennifer N.


    Alaska’s volcanoes, like its abundant glaciers, charismatic wildlife, and wild expanses inspire and ignite scientific curiosity and generate an ever-growing source of questions for students in Alaska and throughout the world. Alaska is home to more than 140 volcanoes, which have been active over the last 2 million years. About 90 of these volcanoes have been active within the last 10,000 years and more than 50 of these have been active since about 1700. The volcanoes in Alaska make up well over three-quarters of volcanoes in the United States that have erupted in the last 200 years. In fact, Alaska’s volcanoes erupt so frequently that it is almost guaranteed that an Alaskan will experience a volcanic eruption in his or her lifetime, and it is likely they will experience more than one. It is hard to imagine a better place for students to explore active volcanism and to understand volcanic hazards, phenomena, and global impacts. Previously developed teachers’ guidebooks with an emphasis on the volcanoes in Hawaii Volcanoes National Park (Mattox, 1994) and Mount Rainier National Park in the Cascade Range (Driedger and others, 2005) provide place-based resources and activities for use in other volcanic regions in the United States. Along the lines of this tradition, this guidebook serves to provide locally relevant and useful resources and activities for the exploration of numerous and truly unique volcanic landscapes in Alaska. This guidebook provides supplemental teaching materials to be used by Alaskan students who will be inspired to become educated and prepared for inevitable future volcanic activity in Alaska. The lessons and activities in this guidebook are meant to supplement and enhance existing science content already being taught in grade levels 6–12. Correlations with Alaska State Science Standards and Grade Level Expectations adopted by the Alaska State Department of Education and Early Development (2006) for grades six through eleven are listed at

  16. Inside the volcano: The how and why of Thrihnukagigur volcano, Iceland (United States)

    LaFemina, Peter; Hudak, Michael; Feineman, Maureen; Geirsson, Halldor; Normandeau, Jim; Furman, Tanya


    The Thrihnukagigur volcano, located in the Brennisteinsfjöll fissure swarm on the Reykjanes Peninsula, Iceland, offers a unique exposure of the upper magmatic plumbing system of a monogenetic volcano. The volcano formed during a dike-fed strombolian eruption ~3500 BP with flow-back leaving an evacuated conduit, elongated parallel to the regional maximum horizontal stress. At least two vents were formed above the dike, as well as several small hornitos south-southwest of the main vent. In addition to the evacuated conduit, a cave exists 120 m below the vent. The cave exposes stacked lava flows and a buried cinder cone. The unconsolidated tephra of the cone is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to the vent that produced lava and tephra during the ~3500 BP fissure eruption. We present geochemical, petrologic and geologic observations, including a high-resolution three-dimensional scan of the system that indicate the dike intersected, eroded and assimilated unconsolidated tephra from the buried cinder cone, thus excavating a region along the dike, allowing for future slumping and cave formation. Two petrographically distinct populations of plagioclase phenocrysts are present in the system: a population of smaller (maximum length 1 mm) acicular phenocrysts and a population of larger (maximum length 10 mm) tabular phenocrysts that is commonly broken and displays disequilibrium sieve textures. The acicular plagioclase crystals are present in the dike and lavas while the tabular crystals are in these units and the buried tephra. An intrusion that appears not to have interacted with the tephra has only acicular plagioclase. This suggests that a magma crystallizing a single acicular population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the tabular population of phenocrysts from the cone. Petrographic thin-sections of lavas sampled near the vent show undigested fragments of tephra from

  17. Preliminary volcano-hazard assessment for Augustine Volcano, Alaska (United States)

    Waythomas, Christopher F.; Waitt, Richard B.


    Augustine Volcano is a 1250-meter high stratovolcano in southwestern Cook Inlet about 280 kilometers southwest of Anchorage and within about 300 kilometers of more than half of the population of Alaska. Explosive eruptions have occurred six times since the early 1800s (1812, 1883, 1935, 1964-65, 1976, and 1986). The 1976 and 1986 eruptions began with an initial series of vent-clearing explosions and high vertical plumes of volcanic ash followed by pyroclastic flows, surges, and lahars on the volcano flanks. Unlike some prehistoric eruptions, a summit edifice collapse and debris avalanche did not occur in 1812, 1935, 1964-65, 1976, or 1986. However, early in the 1883 eruption, a portion of the volcano summit broke loose forming a debris avalanche that flowed to the sea. The avalanche initiated a small tsunami reported on the Kenai Peninsula at English Bay, 90 kilometers east of the volcano. Plumes of volcanic ash are a major hazard to jet aircraft using Anchorage International and other local airports. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Eruptions similar to the historical and prehistoric eruptions are likely in Augustine's future.

  18. Fossil Polypodiaceae and their spores

    NARCIS (Netherlands)

    Uffelen, van Gerda A.


    In this publication emphasis is laid on the modern definition of the family Polypodiaceae (Filicales), which is based on an extensive study of Recent material and which is much restricted with respect to older circumscriptions of the family as usually applied by palaeobotanists. Fossils of fems belo

  19. Equatorial spread F fossil plumes

    Directory of Open Access Journals (Sweden)

    S. L. Ossakow


    Full Text Available Behaviour of equatorial spread F (ESF fossil plumes, i.e., ESF plumes that have stopped rising, is examined using the NRL SAMI3/ESF three-dimensional simulation code. We find that fossil bubbles, plasma density depletions associated with fossil plumes, can persist as high-altitude equatorial depletions even while being "blown" by zonal winds. Corresponding airglow-proxy images of fossil plumes, plots of electron density versus longitude and latitude at a constant altitude of 288 km, are shown to partially "fill in" in most cases, beginning with the highest altitude field lines within the plume. Specifically, field lines upon which the E field has fallen entirely to zero are affected and only the low altitude (≤600 km portion if each field line fills in. This suggests that it should be possible to observe a bubble at high altitude on a field line for which the corresponding airglow image no longer shows a depletion. In all cases ESF plumes stop rising when the flux-tube-integrated ion mass density inside the upper edge of the bubble is equal to that of the nearby background, further supporting the result of Krall et al. (2010b.

  20. Fossil Polypodiaceae and their spores

    NARCIS (Netherlands)

    Uffelen, van Gerda A.


    In this publication emphasis is laid on the modern definition of the family Polypodiaceae (Filicales), which is based on an extensive study of Recent material and which is much restricted with respect to older circumscriptions of the family as usually applied by palaeobotanists. Fossils of fems

  1. Fossil Energy: Drivers and Challenges. (United States)

    Friedmann, Julio


    Concerns about rapid economic growth, energy security, and global climate change have created a new landscape for fossil energy exploration, production, and utilization. Since 85% of primary energy supply comes from fossil fuels, and 85% of greenhouse gas emissions come from fossil fuel consumption, new and difficult technical and political challenges confront commercial, governmental, and public stakeholders. As such, concerns over climate change are explicitly weighed against security of international and domestic energy supplies, with economic premiums paid for either or both. Efficiency improvements, fuel conservation, and deployment of nuclear and renewable supplies will help both concerns, but are unlikely to offset growth in the coming decades. As such, new technologies and undertakings must both provide high quality fossil energy with minimal environmental impacts. The largest and most difficult of these undertakings is carbon management, wherein CO2 emissions are sequestered indefinitely at substantial incremental cost. Geological formations provide both high confidence and high capacity for CO2 storage, but present scientific and technical challenges. Oil and gas supply can be partially sustained and replaced through exploitation of unconventional fossil fuels such as tar-sands, methane hydrates, coal-to-liquids, and oil shales. These fuels provide enormous reserves that can be exploited at current costs, but generally require substantial energy to process. In most cases, the energy return on investment (EROI) is dropping, and unconventional fuels are generally more carbon intensive than conventional, presenting additional carbon management challenges. Ultimately, a large and sustained science and technology program akin to the Apollo project will be needed to address these concerns. Unfortunately, real funding in energy research has dropped dramatically (75%) in the past three decades, and novel designs in fission and fusion are not likely to provide any

  2. Sanitary effects of fossil fuels; Effets sanitaires des combustibles fossiles

    Energy Technology Data Exchange (ETDEWEB)

    Nifenecker, H. [Centre National de la Recherche Scientifique (IN2P3/CNRS), 38 - Grenoble (France)


    In this compilation are studied the sanitary effects of fossil fuels, behavioral and environmental sanitary risks. The risks in connection with the production, the transport and the distribution(casting) are also approached for the oil(petroleum), the gas and the coal. Accidents in the home are evoked. The risks due to the atmospheric pollution are seen through the components of the atmospheric pollution as well as the sanitary effects of this pollution. (N.C.)

  3. Scanning electron microscope observations of sublimates from Merapi Volcano, Indonesia (United States)

    Symonds, R.


    Sublimates were sampled from high-temperature (up to 800??C) fumaroles at Merapi volcano in January 1984. Sampling is accomplished by inserting silica tubes into high-temperature vents. Volcanic glass flows through the tubes and sublimates precipitate on the inner walls in response to the temperature gradient. With decreasing temperature (800-500??C) in the tubes, there are five sublimate zones. Texturally, the sublimate phases grade from large, well-formed crystals at their highest-temperature occurrence to more numerous, smaller crystals that are less perfect at lower temperatures. These changes imply that the crystal nucleation and growth rates increase and decrease, respectively, as temperature decreases. Overall, the textural data suggest that the gas is saturated or slightly super-saturated with the phases at their hottest occurrence, but that the gas becomes increasingly super-saturated with the phases at lower temperatures. -from Author

  4. Looking at Fossils in New Ways (United States)

    Flannery, Maura C.


    Existing fossils could be studied from a different prospective with the use of new methods of analysis for gathering more information. The new techniques of studying fossils binds the new and the old techniques and information and provides another way to look at fossils.

  5. Cycads: Fossil evidence of late paleozoic origin (United States)

    Mamay, S.H.


    Plant fossils from Lower Permian strata of the southwestern United States have been interpreted as cycadalean megasporophylls. They are evidently descended from spermopterid elements of the Pennsylvanian Taeniopteris complex; thus the known fossil history of the cycads is extended from the Late Triassic into the late Paleozoic. Possible implications of the Permian fossils toward evolution of the angiosperm carpel are considered.

  6. Petrological model for the Minamigassan volcano, Nasu volcanoes, northeast Japan arc. Higashi Nippon ko, Nasu kazangun, Minamigassan kazan no gansekigakuteki model

    Energy Technology Data Exchange (ETDEWEB)

    Ban, M. (Yamagata University, Yamagata (Japan). Faculty of Science)


    Nasu volcanoes in Northeast Japan arc comprise ten small volcanoes, and Minamigassan is one of these volcanoes. A model of magmatic process of Minamigassan volcano is presented, based on the mineralogical and whole-rock chemical composition data. The eruption products of this volcano are divided into five units, E-1, E-2, L-1, L-2, and L-3 units from lower to upper. E-1, E-2, and L-2 units belong to tholeiite series and L-1 and L-3 units belong to calc-alkaline series. The caldera collapse occurred at the beginning stage of L-1 unit. The chemical variation within E-1 and E-2 units can be interpreted by fractional crystallization of phenocrystic minerals. On the other hand, calc-alkaline suites of L-1 and L-3 units suffered magma mixing, and were formed by mixing between basic magma which resembles E-1 unit magma and felsic magma which is derived from early stage magma through crustal contamination or crustal melt. 34 refs., 13 figs., 3 tabs.

  7. Aleutian Islands Coastal Resources Inventory and Environmental Sensitivity Maps: VOLCANOS (Volcano Points) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains point locations of active volcanoes as compiled by Motyka et al., 1993. Eighty-nine volcanoes with eruptive phases in the Quaternary are...

  8. Volcano Monitoring Using Google Earth (United States)

    Bailey, J. E.; Dehn, J.; Webley, P.; Skoog, R.


    At the Alaska Volcano Observatory (AVO), Google Earth is being used as a visualization tool for operational satellite monitoring of the region's volcanoes. Through the abilities of the Keyhole Markup Language (KML) utilized by Google Earth, different datasets have been integrated into this virtual globe browser. Examples include the ability to browse thermal satellite image overlays with dynamic control, to look for signs of volcanic activity. Webcams can also be viewed interactively through the Google Earth interface to confirm current activity. Other applications include monitoring the location and status of instrumentation; near real-time plotting of earthquake hypocenters; mapping of new volcanic deposits; and animated models of ash plumes within Google Earth, created by a combination of ash dispersion modeling and 3D visualization packages. The globe also provides an ideal interface for displaying near real-time information on detected thermal anomalies or "hotspot"; pixels in satellite images with elevated brightness temperatures relative to the background temperature. The Geophysical Institute at the University of Alaska collects AVHRR (Advanced Very High Resolution Radiometer) and MODIS (Moderate Resolution Imaging Spectroradiometer) through its own receiving station. The automated processing that follows includes application of algorithms that search for hotspots close to volcano location, flagging those that meet certain criteria. Further automated routines generate folders of KML placemarkers, which are linked to Google Earth through the network link function. Downloadable KML files have been created to provide links to various data products for different volcanoes and past eruptions, and to demonstrate examples of the monitoring tools developed. These KML files will be made accessible through a new website that will become publicly available in December 2006.

  9. Modeling eruptions of Karymsky volcano


    Ozerov, A.; Ispolatov, I.; Lees, J.


    A model is proposed to explain temporal patterns of activity in a class of periodically exploding Strombolian-type volcanos. These patterns include major events (explosions) which follow each other every 10-30 minutes and subsequent tremor with a typical period of 1 second. This two-periodic activity is thought to be caused by two distinct mechanisms of accumulation of the elastic energy in the moving magma column: compressibility of the magma in the lower conduit and viscoelastic response of...

  10. Earthquakes - Volcanoes (Causes and Forecast) (United States)

    Tsiapas, E.


    EARTHQUAKES - VOLCANOES (CAUSES AND FORECAST) ELIAS TSIAPAS RESEARCHER NEA STYRA, EVIA,GREECE TEL.0302224041057 The earthquakes are caused by large quantities of liquids (e.g. H2O, H2S, SO2, ect.) moving through lithosphere and pyrosphere (MOHO discontinuity) till they meet projections (mountains negative projections or projections coming from sinking lithosphere). The liquids are moved from West Eastward carried away by the pyrosphere because of differential speed of rotation of the pyrosphere by the lithosphere. With starting point an earthquake which was noticed at an area and from statistical studies, we know when, where and what rate an earthquake may be, which earthquake is caused by the same quantity of liquids, at the next east region. The forecast of an earthquake ceases to be valid if these components meet a crack in the lithosphere (e.g. limits of lithosphere plates) or a volcano crater. In this case the liquids come out into the atmosphere by the form of gasses carrying small quantities of lava with them (volcano explosion).

  11. Active Deformation of Etna Volcano Combing IFSAR and GPS data (United States)

    Lundgren, Paul


    The surface deformation of an active volcano is an important indicator of its eruptive state and its hazard potential. Mount Etna volcano in Sicily is a very active volcano with well documented eruption episodes.

  12. Campgrounds in Hawaii Volcanoes National Park (United States)

    National Park Service, Department of the Interior — This dataset provides campground locations in Hawaii Volcanoes National Park. Information about facilities, water availability, permit requirements and type of...

  13. Latent methane in fossil coals

    Energy Technology Data Exchange (ETDEWEB)

    A.D. Alexeev; E.V. Ulyanova; G.P. Starikov; N.N. Kovriga [Academy of Sciences of Ukraine, Donetsk (Ukraine). Institute for Physics of Mining Processes


    It is established experimentally using 1H NMR wide line spectroscopy that methane can exist in coals not only in open or closed porosity and fracture systems but also in solid solutions in coal substance, in particular, under methane pressure 2 MPa or higher. Methane dissolved in coal minerals reversibly modifies their lattice parameters as determined from X-ray diffraction analysis. Co-existence of these methane forms in fossil coals causes multi-step desorption kinetics. It is shown experimentally that the long-term latent methane desorption is effected mainly by closed porosity, which in turn is determined by coal rank. 21 refs., 3 figs., 2 tabs.

  14. Dinosaur fossils predict body temperatures.

    Directory of Open Access Journals (Sweden)

    James F Gillooly


    Full Text Available Perhaps the greatest mystery surrounding dinosaurs concerns whether they were endotherms, ectotherms, or some unique intermediate form. Here we present a model that yields estimates of dinosaur body temperature based on ontogenetic growth trajectories obtained from fossil bones. The model predicts that dinosaur body temperatures increased with body mass from approximately 25 degrees C at 12 kg to approximately 41 degrees C at 13,000 kg. The model also successfully predicts observed increases in body temperature with body mass for extant crocodiles. These results provide direct evidence that dinosaurs were reptiles that exhibited inertial homeothermy.

  15. Digging into Augustine Volcano's Silicic Past (United States)

    Nadeau, P. A.; Webster, J. D.; Goldoff, B. A.


    Activity at Augustine Volcano, Alaska, has been marked by intermediate composition domes, flows, and tephras during the Holocene. Erosive lahars associated with the 2006 eruption exposed voluminous rhyolite pumice fall beneath glacial tills. The rhyolite is both petrologically and mineralogically different from more recent eruptions, with abundant amphibole (both calcium-amphiboles and cummingtonite) and quartz, both rare in more recent products. Three distinct lithologies are present, with textural and chemical variations between the three. Fe-Ti oxide equilibria indicate temperatures of ~765°C and oxygen fugacities of NNO +1.5. Melt inclusions indicate that the stratigraphically lowest lithology began crystallizing isobarically at ~260 MPa with the contemporary mixed H2O-CO2 fluid phase becoming progressively H2O-rich. The other lithologies were likely crystallized under more H2O-dominated conditions, as indicated by the presence of cummingtonite. Apatites and melt inclusions have generally lower chlorine contents than more recently erupted material, which is typically high in chlorine. Xenocrysts of olivine and clinopyroxene in two of the three lithologies contain mafic (basalt to basaltic andesite) melt inclusions that indicate the likelihood of mixing and/or mingling of magmas as an eruption trigger. We interpret the three lithologies as representative of a smaller pumiceous rhyolite eruption, with subsequent extrusion of a rhyodacite banded lava dome or flow. This was followed by a large-scale rhyolitic pumice eruption that entrained portions of the banded flow as lithic inclusions. The unique qualities of this pre-glacial rhyolite and the potential hazards of a similarly large eruption in modern times indicate that further study is warranted.

  16. Alternative SEM techniques for observing pyritised fossil material. (United States)

    Poole; Lloyd


    Two scanning electron microscopy (SEM) electron-specimen interactions that provide images based on sample crystal structure, electron channelling and electron backscattered diffraction, are described. The SEM operating conditions and sample preparation are presented, followed by an example application of these techniques to the study of pyritised plant material. The two approaches provide an opportunity to examine simultaneously, at higher magnifications normally available optically, detailed specimen anatomy and preservation state. Our investigation suggests that whereas both techniques have their advantages, the electron channelling approach is generally more readily available to most SEM users. However, electron backscattered diffraction does afford the opportunity of automated examination and characterisation of pyritised fossil material.

  17. Research on Methods for Building Volcano Disaster Information System--taking Changbai Mountain as an example

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuexia; BO Liqun; LU Xingchang


    Volcano eruption is one of the most serious geological disasters in the world. There are volcanoes in every territory on the earth, about a thousand in China, among which Changbai Mountain Volcano, Wudalianchi Volcano and Tengchong Volcano are the most latent catastrophic eruptive active volcanoes. The paper, following an instance of Changbai Mountain Volcano, expounds that monitoring, forecasting and estimating volcano disaster by building Volcano Disaster Information System (VDIS) is feasible to alleviate volcano disaster.

  18. Fossil energy program. Summary document

    Energy Technology Data Exchange (ETDEWEB)



    This program summary document presents a comprehensive overview of the research, development, and demonstration (RD and D) activities that will be performed in FY 1981 by the Assistant Secretary for Fossil Energy (ASFE), US Department of Energy (DOE). The ASFE technology programs for the fossil resources of coal, petroleum (including oil shale) and gas have been established with the goal of making substantive contributions to the nation's future supply and efficienty use of energy. On April 29, 1977, the Administration submitted to Congress the National Energy Plan (NEP) and accompanying legislative proposals designed to establish a coherent energy policy structure for the United States. Congress passed the National Energy Act (NEA) on October 15, 1978, which allows implementation of the vital parts of the NEP. The NEP was supplemented by additional energy policy statements culminating in the President's address on July 15, 1979, presenting a program to further reduce dependence on imported petroleum. The passage of the NEA-related energy programs represent specific steps by the Administration and Congress to reorganize, redirect, and clarify the role of the Federal Government in the formulation and execution of national energy policy and programs. The energy technology RD and D prog4rams carried out by ASFE are an important part of the Federal Government's effort to provide the combination and amounts of energy resources needed to ensure national security and continued economic growth.

  19. Volcanic hazards at Atitlan volcano, Guatemala (United States)

    Haapala, J.M.; Escobar Wolf, R.; Vallance, James W.; Rose, William I.; Griswold, J.P.; Schilling, S.P.; Ewert, J.W.; Mota, M.


    Atitlan Volcano is in the Guatemalan Highlands, along a west-northwest trending chain of volcanoes parallel to the mid-American trench. The volcano perches on the southern rim of the Atitlan caldera, which contains Lake Atitlan. Since the major caldera-forming eruption 85 thousand years ago (ka), three stratovolcanoes--San Pedro, Toliman, and Atitlan--have formed in and around the caldera. Atitlan is the youngest and most active of the three volcanoes. Atitlan Volcano is a composite volcano, with a steep-sided, symmetrical cone comprising alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs. Eruptions of Atitlan began more than 10 ka [1] and, since the arrival of the Spanish in the mid-1400's, eruptions have occurred in six eruptive clusters (1469, 1505, 1579, 1663, 1717, 1826-1856). Owing to its distance from population centers and the limited written record from 200 to 500 years ago, only an incomplete sample of the volcano's behavior is documented prior to the 1800's. The geologic record provides a more complete sample of the volcano's behavior since the 19th century. Geologic and historical data suggest that the intensity and pattern of activity at Atitlan Volcano is similar to that of Fuego Volcano, 44 km to the east, where active eruptions have been observed throughout the historical period. Because of Atitlan's moderately explosive nature and frequency of eruptions, there is a need for local and regional hazard planning and mitigation efforts. Tourism has flourished in the area; economic pressure has pushed agricultural activity higher up the slopes of Atitlan and closer to the source of possible future volcanic activity. This report summarizes the hazards posed by Atitlan Volcano in the event of renewed activity but does not imply that an eruption is imminent. However, the recognition of potential activity will facilitate hazard and emergency preparedness.

  20. The beginning of explosive eruptions on a location lacking volcanoes: A case study on the Hijiori volcano, Northeastern Japan (United States)

    Miyagi, I.


    repeated input of crystal poor hot magma into a crystal rich cool magma chamber, and that the mass ratio of new magma input to the existing magma body may be small enough to retain the physical and chemical conditions of the crystal rich magma chamber almost the same. Due to rapid chemical diffusion Mt phenocrysts can easily be re-equilibrated with the new environments within a few months. The depth where the magma mixing happened is estimated to be about 10 km from the observed water concentration in melt inclusions. To summarize, repeated input of felsic magma prepared a crystal rich magma chamber beneath Hijiori volcano for the commencement of the first eruption.

  1. Social Perspective on Fossilization of Interlanguage


    Ren Hulin


    The paper is to investigate the role of social factors that influence the fossilization of learners’ interlanguage. In this context, "fossilization" refers to the stopping in the acquisition of a second language (L2) short of native-like proficiency(Towell and Hawkins, 1994). The paper begins with Wolfson’s (1989) overview of social settings that influence the fossilization of learners’ interlanguage and Ellis (2005) discussion of the impact of social factors on L2 proficiency evidenced with ...

  2. The crystallization of shoshonitic to peralkaline trachyphonolitic magmas in a H2O-Cl-F-rich environment at Ischia (Italy), with implications for the feeder system of the Campania Plain volcanoes (United States)

    Melluso, L.; Morra, V.; Guarino, V.; de'Gennaro, R.; Franciosi, L.; Grifa, C.


    Bulk-rock and mineralogical characterization of massive samples (lava flows, lava domes, scoria, spatter), chosen to be representative of different activity periods and of the whole known compositional range of Ischia island (Roman Magmatic Province, Campanian district) is reported in this paper. The rocks vary in composition from shoshonites to peralkaline trachyphonolites. Crystallization started with Al-rich chromite inclusions and their host magnesian olivine in shoshonites and latites, and ended with låvenite, rinkite, kochite, hiortdahlite, hainite, Mn-aenigmatite, britholite and Ti-Zr-rich aegirine in the groundmass of the peralkaline trachyphonolites. Removal of feldspar-bearing assemblages (with calcic-to-sodic plagioclase in shoshonites and latites, sodic sanidine and anorthoclase in trachytes and trachyphonolites) is established throughout the compositional range, and is accompanied by interaction between variably evolved magmas (with their differing phenocryst assemblage), mostly in mafic and intermediate compositions. This led to enrichment in Mn, alkalis, Zr, Nb, REE, Rb, Th, U, Cl and F, and depletion in Mg, Fe, V, Ca, Ba, Sr and Eu in the most evolved magmas. The Ischian rocks have a tendency to sodic affinity and by peculiar mineral compositions and compositional trends, which do not indicate extremely oxidizing conditions. The Ischian rocks thus differ from the Phlegrean Fields analogues and the ultrapotassic, more silica undersaturated rocks of Somma-Vesuvius. Overall, variations in the chemical compositions of the rocks and their trends imply unrelated feeding systems and thus are inconsistent with the hypothesis of a common magma reservoir beneath the main volcanic areas of the Campanian Plain.

  3. An AFM Observation on Fossil Cytoplasm

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; YU Junping; FANG Xiaohong


    Fossil cytoplasm is a new research topic of interest in paleobotany. Atomic force microscope (AFM) is a new technology applied widely in physics and biology; however, it is rarely used in paleontology. Here we applied AFM for the first time to study fossil cytoplasm. The results indicate that the fossil cytoplasm is heterogeneous and full of ultrastructures, just like extant cytoplasm, and that the application of AFM, especially in combination with other techniques, can reveal the subcellular details of fossil plants with more confidence.

  4. The potential of chemical fingerprinting of tephra for stratigraphic correlations in the fossil Lagerstätte of the Pisco Formation (Peru) (United States)

    Bosio, Giulia; Gioncada, Anna; Malinverno, Elisa; Villa, Igor Maria; Di Celma, Claudio; Gariboldi, Karen; Urbina, Mario; Bianucci, Giovanni


    The upper Miocene Pisco Formation (Peru) represents a world-known fossil Lagerstätte containing abundant and exceptionally well-preserved marine vertebrates. A detailed chronostratigraphic reconstruction is indispensable to study this fossil record and to understand the evolution of marine vertebrates. Recent work (Bianucci et al., 2016; Di Celma et al., 2016; Gariboldi et al., in press) in the area of the western Ica River Valley defined a detailed chronostratigraphic framework for the Pisco Formation, containing all the fossil vertebrates observed in the area. Such chronostratigraphic framework, based on new 40Ar/39Ar ages on biotite from tephra layers integrated with diatom biostratigraphy, implements previous scattered radiometric data (Brand et al., 2011; Esperante et al., 2015). Tephra layers representing primary air-fall deposition of volcanic ash from the Peruvian Andes volcanoes are very frequent in the Pisco Formation. Several of them do not show evidence of reworking or bioturbation. Due to their regional dispersal and to their geologically instantaneous deposition (Lowe, 2011), they provide the opportunity not only to date specific layers, when suitable for radiometric age determination, but also to correlate different localities, through the chemical fingerprinting of tephra. We collected more than 200 tephra layers from different localities in the Ica Desert along six measured stratigraphic sections. Based on the estimated stratigraphic position, we analyzed specific tephra layers through petrographic characterization, glass shard morphology, electron probe microanalyses of glass shards and, where present, biotite crystals. Despite some difficulties encountered, such as similar magma or mineral composition, local weathering, lack of record due to marine current transport and change in depositional environments among different localities, the correspondence of the obtained data allowed to verify correlations that were supposed during field work and to

  5. Fossilization Processes in Thermal Springs (United States)

    Farmer, Jack D.; Cady, Sherry; Desmarais, David J.; Chang, Sherwood (Technical Monitor)


    To create a comparative framework for the study of ancient examples, we have been carrying out parallel studies of the microbial biosedimentology, taphonomy and geochemistry of modem and sub-Recent thermal spring deposits. One goal of the research is the development of integrated litho- and taphofacies models for siliceous and travertline sinters. Thermal springs are regarded as important environments for the origin and early evolution of life on Earth, and we seek to utilize information from the fossil record to reconstruct the evolution of high temperature ecosystems. Microbial contributions to the fabric of thermal spring sinters occur when population growth rates keep pace with, or exceed rates of inorganic precipitation, allowing for the development of continuous biofilms or mats. In siliceous thermal springs, microorganisms are typically entombed while viable. Modes of preservation reflect the balance between rates of organic matter degradation, silica precipitation and secondary infilling. Subaerial sinters are initially quite porous and permeable and at temperatures higher than about 20 C, organic materials are usually degraded prior to secondary infilling of sinter frameworks. Thus, organically-preserved microfossils are rare and fossil information consists of characteristic biofabrics formed by the encrustation and underplating of microbial mat surfaces. This probably accounts for the typically low total organic carbon values observed in thermal spring deposits. In mid-temperature, (approx. 35 - 59 C) ponds and outflows, the surface morphology of tufted Phormidium mats is preserved through mat underplating by thin siliceous: crusts. Microbial taxes lead to clumping of ceils and/or preferred filament orientations that together define higher order composite fabrics in thermal spring stromatolites (e.g. network, coniform, and palisade). At lower temperatures (less than 35 C), Calothrix mats cover shallow terracette pools forming flat carpets or pustular

  6. Predictability of Volcano Eruption: lessons from a basaltic effusive volcano

    CERN Document Server

    Grasso, J R


    Volcano eruption forecast remains a challenging and controversial problem despite the fact that data from volcano monitoring significantly increased in quantity and quality during the last decades.This study uses pattern recognition techniques to quantify the predictability of the 15 Piton de la Fournaise (PdlF) eruptions in the 1988-2001 period using increase of the daily seismicity rate as a precursor. Lead time of this prediction is a few days to weeks. Using the daily seismicity rate, we formulate a simple prediction rule, use it for retrospective prediction of the 15 eruptions,and test the prediction quality with error diagrams. The best prediction performance corresponds to averaging the daily seismicity rate over 5 days and issuing a prediction alarm for 5 days. 65% of the eruptions are predicted for an alarm duration less than 20% of the time considered. Even though this result is concomitant of a large number of false alarms, it is obtained with a crude counting of daily events that are available fro...

  7. Newberry Volcano's youngest lava flows (United States)

    Robinson, Joel E.; Donnelly-Nolan, Julie M.; Jensen, Robert A.


    Most of Newberry Volcano's youngest lava flows are found within the Newberry National Volcanic Monument in central Oregon. Established November 5, 1990, the monument is managed by the U.S. Forest Service as part of the Deschutes National Forest. Since 2011, a series of aerial surveys over the monument collected elevation data using lidar (light detection and ranging) technology, which uses lasers to directly measure the ground surface. These data record previously unseen detail in the volcano’s numerous lava flows and vents. On average, a laser return was collected from the ground’s surface every 2.17 feet (ft) with ±1.3 inches vertical precision.

  8. Paleoradiology. Imaging mummies and fossils

    Energy Technology Data Exchange (ETDEWEB)

    Chhem, Rethy K. [Western Ontario Univ. London Health Sciences Centre, ON (Canada). Dept. of Diagnostic Radiology and Nuclear Medicine; Brothwell, Don R. [York Univ. (United Kingdom). Dept. of Archaeology


    This is an important work on a topic of huge interest to archaeologists and related scientists, since the use of imaging techniques in the field has been expanding rapidly in recent decades. Paleoradiology involves the use of X-rays and advanced medical imaging modalities to evaluate ancient human and animal skeletons as well as biological materials from archaeological sites. Paleoradiological studies have been performed on mummies, skeletal remains and fossils to determine their sex and age at death. Diagnostic paleoradiology is the use of X-ray studies to detect ancient diseases. The broad range of themes and imaging techniques in this volume reflects four decades of research undertaken by Don Brothwell in the fields of anthropology, human paleopathology, and zooarchaeology, combined with two decades of skeletal radiology experience during which Rethy Chhem read over 150,000 skeletal X-ray and CT studies. (orig.)

  9. Chemical and isotopic diversity in basalts dredged from the East Pacific Rise at 10°S, the fossil Galapagos Rise and the Nazca plate (United States)

    Batiza, Rodey; Oestrike, Richard; Futa, Kiyoto


    We present petrographic, chemical and isotopic data for fresh lava samples dredged from three regions: (1) the fossil Galapagos Rise; (2) an elongate volcano near this extinct spreading center; and (3) the East Pacific Rise at 10°S. The samples from the Galapagos Rise are among the first samples from any fossil spreading center to be analyzed. Alkalic picrites from the elongate seamount and transitional basalts from the East Pacific Rise are both somewhat unusual rock types considering their respective tectonic environments.

  10. Volcanic structure and composition of Old Shiveluch volcano, Kamchatka (United States)

    Gorbach, Natalia; Portnyagin, Maxim; Tembrel, Igor


    This paper reports results of a new comprehensive geological mapping of the Late Pleistocene Old Shiveluch volcano. The mapping results and geochemical data on major and trace element composition of the volcanic rocks are used to characterize spatial distribution, eruptive sequence and volumetric relationships between different rock types of the volcano. Old Shiveluch volcano had been constructed during two main stages: initial explosive and subsequent effusive ones. Pyroclastic deposits of the initial stage are represented by agglomerate and psephytic tuffs with very few lava flows and form at least 60% of volume of the Old Shiveluch edifice. The deposits of the second stage are dominantly lava flows erupted from four vents: Central, Western, Baidarny and Southern, reconstructed from the field relationships of their lava flows. About 75% of the Old Shiveluch edifice, both pyroclastic deposits and lava, are composed of magnesian andesites (SiO2 = 57.3-63.8 wt.%, Mg# = 0.53-0.57). The most abundant andesitic lavas were coevally erupted from the Central and Western vents in the central part of the edifice. Less voluminous high-Al basaltic andesites (SiO2 = 53.5-55.7 wt.%, Mg# = 0.52-0.56) were produced by the Western, Baidarny and Southern vents situated in the south-western sector. Small volume high-Mg basaltic andesites (SiO2 = 53.9-55.0 wt.%, Mg# = 0.59-0.64) occur in the upper part of the pyroclastic deposits. Andesites of Old and Young Shiveluch Volcanoes have similar compositions, whereas Old Shiveluch basaltic andesites are compositionally distinctive from those of the Young Shiveluch by having lower Mg#, SiO2, Cr and Ni, and higher Al2O3, FeOT, CaO, TiO2, and V contents at given MgO. Geochemical modeling suggests that the compositions of the intermediate Old Shiveluch magmas can be reasonably explained by simple fractional crystallization of olivine, clinopyroxene, plagioclase and magnetite (± hornblende) from water-bearing (~ 3 wt.% H2O) high-Mg# basaltic

  11. Magma dynamics at shield-volcanoes: New insights from Hualalai oceanites (United States)

    Welsch, B. T.; Hammer, J. E.; Hellebrand, E.


    Oceanites are olivine-rich basalts generally interpreted as resulting from the dismantling of a dunitic cumulate by percolating magmas. To constrain the possible origins of olivine forming during the shield stage of an ocean island volcano, we studied the texture and the composition of oceanite samples collected from the submarine extension of Hualalai volcano's NW rift zone (2002 JAMSTEC dive S690). These oceanites contain abundant magnesian olivine macrocrysts (Ø>0.5 mm, Fo90-86), mesocrysts (0.1Welsch et al., 2009; Welsch et al., submitted). Evidence of initial olivine crystallization at high undercooling (with dendrite formation) followed by low undercooling (and planar crystal faceting) in the shallow reservoirs of both ocean island volcanoes suggests this olivine growth history may be the rule rather than the exception. Welsch, B, F Faure, P Bachèlery, V Famin (2009). Microcrysts record convection at Piton de la Fournaise volcano (La Réunion hotspot). J Petrol. 50, 2287-2305.

  12. The non-uniformity of fossil preservation. (United States)

    Holland, Steven M


    The fossil record provides the primary source of data for calibrating the origin of clades. Although minimum ages of clades are given by the oldest preserved fossil, these underestimate the true age, which must be bracketed by probabilistic methods based on multiple fossil occurrences. Although most of these methods assume uniform preservation rates, this assumption is unsupported over geological timescales. On geologically long timescales (more than 10 Myr), the origin and cessation of sedimentary basins, and long-term variations in tectonic subsidence, eustatic sea level and sedimentation rate control the availability of depositional facies that preserve the environments in which species lived. The loss of doomed sediments, those with a low probability of preservation, imparts a secular trend to fossil preservation. As a result, the fossil record is spatially and temporally non-uniform. Models of fossil preservation should reflect this non-uniformity by using empirical estimates of fossil preservation that are spatially and temporally partitioned, or by using indirect proxies of fossil preservation. Geologically, realistic models of preservation will provide substantially more reliable estimates of the origination of clades.This article is part of the themed issue 'Dating species divergences using rocks and clocks'.

  13. Estimating body mass of fossil rodents

    NARCIS (Netherlands)

    Freudenthal, M.; Martín-Suárez, E.


    Reconstructing the body mass of a fossil animal is an essential step toward understanding its palaeoecological role. Length × width (L×W) of the first lower molar (m1) is frequently used as a proxy for body mass in fossil mammals. However, among rodents, Muroidea have no premolar and an elongated m1

  14. Fossil evidence of the zygomycetous fungi

    NARCIS (Netherlands)

    Krings, M.; Taylor, T.N.; Dotzler, N.


    Molecular clock data indicate that the first zygomycetous fungi occurred on Earth during the Precambrian, however, fossil evidence of these organisms has been slow to accumulate. In this paper, the fossil record of the zygomycetous fungi is compiled, with a focus on structurally preserved Carbonifer

  15. Radio properties of fossil galaxy groups (United States)

    Miraghaei, H.; Khosroshahi, H. G.


    We study 1.4 GHz radio properties of a sample of fossil galaxy groups using GMRT radio observations and the FIRST survey catalog. Fossil galaxy groups, having no recent major mergers in their dominant galaxies and also group scale mergers, give us the opportunity to investigate the effect of galaxy merger on AGN activity. In this work, we compare the radio properties of a rich sample of fossil groups with a sample of normal galaxy groups and clusters and show that the brightest group galaxies in fossil groups are under luminous at 1.4 GHz, relative to the general population of the brightest group galaxies, indicating that the dynamically relaxed nature of fossil groups has influenced the AGN activity in their dominant galaxy.

  16. Instrumentation Recommendations for Volcano Monitoring at U.S. Volcanoes Under the National Volcano Early Warning System (United States)

    Moran, Seth C.; Freymueller, Jeff T.; LaHusen, Richard G.; McGee, Kenneth A.; Poland, Michael P.; Power, John A.; Schmidt, David A.; Schneider, David J.; Stephens, George; Werner, Cynthia A.; White, Randall A.


    As magma moves toward the surface, it interacts with anything in its path: hydrothermal systems, cooling magma bodies from previous eruptions, and (or) the surrounding 'country rock'. Magma also undergoes significant changes in its physical properties as pressure and temperature conditions change along its path. These interactions and changes lead to a range of geophysical and geochemical phenomena. The goal of volcano monitoring is to detect and correctly interpret such phenomena in order to provide early and accurate warnings of impending eruptions. Given the well-documented hazards posed by volcanoes to both ground-based populations (for example, Blong, 1984; Scott, 1989) and aviation (for example, Neal and others, 1997; Miller and Casadevall, 2000), volcano monitoring is critical for public safety and hazard mitigation. Only with adequate monitoring systems in place can volcano observatories provide accurate and timely forecasts and alerts of possible eruptive activity. At most U.S. volcanoes, observatories traditionally have employed a two-component approach to volcano monitoring: (1) install instrumentation sufficient to detect unrest at volcanic systems likely to erupt in the not-too-distant future; and (2) once unrest is detected, install any instrumentation needed for eruption prediction and monitoring. This reactive approach is problematic, however, for two reasons. 1. At many volcanoes, rapid installation of new ground-1. based instruments is difficult or impossible. Factors that complicate rapid response include (a) eruptions that are preceded by short (hours to days) precursory sequences of geophysical and (or) geochemical activity, as occurred at Mount Redoubt (Alaska) in 1989 (24 hours), Anatahan (Mariana Islands) in 2003 (6 hours), and Mount St. Helens (Washington) in 1980 and 2004 (7 and 8 days, respectively); (b) inclement weather conditions, which may prohibit installation of new equipment for days, weeks, or even months, particularly at

  17. Shocked chromites in fossil L chondrites: A Raman spectroscopy and transmission electron microscopy study (United States)

    Rout, Surya S.; Heck, Philipp R.; Zaluzec, Nestor J.; Ishii, Takayuki; Wen, Jianguo; Miller, Dean J.; Schmitz, Birger


    Chromites from Middle Ordovician fossil L chondrites and from matrix and shock-melt veins in Catherwood, Tenham, and Coorara L chondrites were studied using Raman spectroscopy and TEM. Raman spectra of chromites from fossil L chondrites showed similarities with chromites from matrix and shock-melt veins in the studied L chondrite falls and finds. Chromites from shock-melt veins of L chondrites show polycrystallinity, while the chromite grains in fossil L chondrites are single crystals. In addition, chromites from shock-melt veins in the studied L chondrites have high densities of planar fractures within the subgrains and many subgrains show intergrowths of chromite and xieite. Matrix chromite of Tenham has similar dislocation densities and planar fractures as a chromite from the fossil meteorite Golvsten 001 and higher dislocation densities than in chromite from the fossil meteorite Sextummen 003. Using this observation and knowing that the matrix of Tenham experienced 20-22 GPa and shock stage S3-S6) and 20 GPa and 1000° C (S3-S5), respectively, and we conclude that the studied fossil meteorite chromites are from matrix.

  18. Volcanoes (United States)

    ... Part 3 of 3) Hot Weather Tips Heat Stress in Older Adults FAQs Extreme Heat PSAs Related Links MMWR Bibliography CDC's Program Floods Flood Readiness Personal Hygiene After a Disaster Cleanup of Flood Water After a Flood Worker Safety Educational Materials Floods ...

  19. Redoubt Volcano: 2009 Eruption Overview (United States)

    Bull, K. F.


    Redoubt Volcano is a 3110-m glaciated stratovolcano located 170 km SW of Anchorage, Alaska, on the W side of Cook Inlet. The edifice comprises a oil production in Cook Inlet was halted for nearly five months. Unrest began in August, 2008 with reports of H2S odor. In late September, the Alaska Volcano Observatory (AVO)’s seismic network recorded periods of volcanic tremor. Throughout the fall, AVO noted increased fumarolic emissions and accompanying ice- and snow-melt on and around the 1990 dome, and gas measurements showed elevated H2S and CO2 emissions. On January 23, seismometers recorded 48 hrs of intermittent tremor and discrete, low-frequency to hybrid events. Over the next 6 weeks, seismicity waxed and waned, an estimated 5-6 million m3 of ice were lost due to melting, volcanic gas emissions increased, and debris flows emerged repeatedly from recently formed ice holes near the 1990 dome, located on the crater’s N (“Drift”) side. On March 15, a phreatic explosion deposited non-juvenile ash from a new vent in the summit ice cap just S of the 1990 dome. Ash from the explosion rose to ~4500 m above sea level (asl). The plume was accompanied by weak seismicity. The first magmatic explosion occurred on March 22. Over the next two weeks, more than 19 explosions destroyed at least two lava domes and produced ash plumes that reached 6-18 km asl. Tephra was deposited along variable azimuths including trace to minor amounts on Anchorage and Kenai Peninsula communities, and reached Fairbanks, ~800 km to the N. Several lahars were produced by explosive disruption and melting of the “Drift” glacier. The largest lahars followed explosions on March 23 and April 4 and inundated the Drift River valley to the coast, causing temporary evacuation of the Drift River Oil Terminal, ~40 km from the vent. Time-lapse images captured pyroclastic flows and lahars in the “Drift” glacier valley during several of the explosions. Ballistics and pyroclastic flow deposits were

  20. Late Holocene volcanism at Medicine Lake Volcano, northern California Cascades (United States)

    Donnelly-Nolan, Julie M.; Champion, Duane E.; Grove, Timothy L.


    Late Holocene volcanism at Medicine Lake volcano in the southern Cascades arc exhibited widespread and compositionally diverse magmatism ranging from basalt to rhyolite. Nine well-characterized eruptions have taken place at this very large rear-arc volcano since 5,200 years ago, an eruptive frequency greater than nearly all other Cascade volcanoes. The lavas are widely distributed, scattered over an area of ~300 km2 across the >2,000-km2 volcano. The eruptions are radiocarbon dated and the ages are also constrained by paleomagnetic data that provide strong evidence that the volcanic activity occurred in three distinct episodes at ~1 ka, ~3 ka, and ~5 ka. The ~1-ka final episode produced a variety of compositions including west- and north-flank mafic flows interspersed in time with fissure rhyolites erupted tangential to the volcano’s central caldera, including the youngest and most spectacular lava flow at the volcano, the ~950-yr-old compositionally zoned Glass Mountain flow. At ~3 ka, a north-flank basalt eruption was followed by an andesite eruption 27 km farther south that contains quenched basalt inclusions. The ~5-ka episode produced two caldera-focused dacitic eruptions. Quenched magmatic inclusions record evidence of intrusions that did not independently reach the surface. The inclusions are present in five andesitic, dacitic, and rhyolitic host lavas, and were erupted in each of the three episodes. Compositional and mineralogic evidence from mafic lavas and inclusions indicate that both tholeiitic (dry) and calcalkaline (wet) parental magmas were present. Petrologic evidence records the operation of complex, multi-stage processes including fractional crystallization, crustal assimilation, and magma mixing. Experimental evidence suggests that magmas were stored at 3 to 6 km depth prior to eruption, and that both wet and dry parental magmas were involved in generating the more silicic magmas. The broad distribution of eruptive events and the relative

  1. Approaches to bioremediation of fossil fuel contaminated soil: An ...

    African Journals Online (AJOL)

    Biological methods for combating pollutants generated within the fossil fuels ... metabolism of fossil fuel contaminants in soil and water bodies is presented. ... Keywords: Fossil fuels, coal, petroleum hydrocarbons, biodegradation, pollutants

  2. Linking space observations to volcano observatories in Latin America: Results from the CEOS DRM Volcano Pilot (United States)

    Delgado, F.; Pritchard, M. E.; Biggs, J.; Arnold, D. W. D.; Poland, M. P.; Ebmeier, S. K.; Wauthier, C.; Wnuk, K.; Parker, A. L.; Amelug, F.; Sansosti, E.; Mothes, P. A.; Macedo, O.; Lara, L.; Zoffoli, S.; Aguilar, V.


    Within Latin American, about 315 volcanoes that have been active in the Holocene, but according to the United Nations Global Assessment of Risk 2015 report (GAR15) 202 of these volcanoes have no seismic, deformation or gas monitoring. Following the 2012 Santorini Report on satellite Earth Observation and Geohazards, the Committee on Earth Observation Satellites (CEOS) has developed a 3-year pilot project to demonstrate how satellite observations can be used to monitor large numbers of volcanoes cost-effectively, particularly in areas with scarce instrumentation and/or difficult access. The pilot aims to improve disaster risk management (DRM) by working directly with the volcano observatories that are governmentally responsible for volcano monitoring, and the project is possible thanks to data provided at no cost by international space agencies (ESA, CSA, ASI, DLR, JAXA, NASA, CNES). Here we highlight several examples of how satellite observations have been used by volcano observatories during the last 18 months to monitor volcanoes and respond to crises -- for example the 2013-2014 unrest episode at Cerro Negro/Chiles (Ecuador-Colombia border); the 2015 eruptions of Villarrica and Calbuco volcanoes, Chile; the 2013-present unrest and eruptions at Sabancaya and Ubinas volcanoes, Peru; the 2015 unrest at Guallatiri volcano, Chile; and the 2012-present rapid uplift at Cordon Caulle, Chile. Our primary tool is measurements of ground deformation made by Interferometric Synthetic Aperture Radar (InSAR) but thermal and outgassing data have been used in a few cases. InSAR data have helped to determine the alert level at these volcanoes, served as an independent check on ground sensors, guided the deployment of ground instruments, and aided situational awareness. We will describe several lessons learned about the type of data products and information that are most needed by the volcano observatories in different countries.

  3. Oskarssonite, AlF3, a new fumarolic mineral from Eldfell volcano, Heimaey, Iceland

    DEFF Research Database (Denmark)

    Jacobsen, Morten Jølnæs; Balic Zunic, Tonci; Mitolo, Donatella;


    The new mineral oskarssonite (IMA2012-088), with ideal formula AlF3, was found in August 2009 at the surface of fumaroles on the Eldfell volcano, Heimaey Island, Iceland (GPS coordinates 63º25’58.9’’N 20º14’50.3’’W). It occurs as sub-micron-sized crystals forming a white powder in association...

  4. Summary statistics for fossil spider species taxonomy

    Directory of Open Access Journals (Sweden)

    David Penney


    Full Text Available Spiders (Araneae are one of the most species-rich orders on Earth today, and also have one of the longest geological records of any terrestrial animal groups, as demonstrated by their extensive fossil record. There are currently around 1150 described fossil spider species, representing 2.6% of all described spiders (i.e. extinct and extant. Data for numbers of fossil and living spider taxa described annually (and various other metrics for the fossil taxa were compiled from current taxonomic catalogues. Data for extant taxa showed a steady linear increase of approximately 500 new species per year over the last decade, reflecting a rather constant research activity in this area by a large number of scientists, which can be expected to continue. The results for fossil species were very different, with peaks of new species descriptions followed by long troughs, indicating minimal new published research activity for most years. This pattern is indicative of short bursts of research by a limited number of authors. Given the frequent discovery of new fossil deposits containing spiders, a wealth of new material coming to light from previously worked deposits, and the application of new imaging techniques in palaeoarachnology that allow us to extract additional data from historical specimens, e.g. X-ray computed tomography, it is important not only to ensure a sustained research activity on fossil spiders (and other arachnids through training and enthusing the next generation of palaeoarachnologists, but preferably to promote increased research and expertise in this field.

  5. Bayesian phylogenetic estimation of fossil ages (United States)

    Drummond, Alexei J.; Stadler, Tanja


    Recent advances have allowed for both morphological fossil evidence and molecular sequences to be integrated into a single combined inference of divergence dates under the rule of Bayesian probability. In particular, the fossilized birth–death tree prior and the Lewis-Mk model of discrete morphological evolution allow for the estimation of both divergence times and phylogenetic relationships between fossil and extant taxa. We exploit this statistical framework to investigate the internal consistency of these models by producing phylogenetic estimates of the age of each fossil in turn, within two rich and well-characterized datasets of fossil and extant species (penguins and canids). We find that the estimation accuracy of fossil ages is generally high with credible intervals seldom excluding the true age and median relative error in the two datasets of 5.7% and 13.2%, respectively. The median relative standard error (RSD) was 9.2% and 7.2%, respectively, suggesting good precision, although with some outliers. In fact, in the two datasets we analyse, the phylogenetic estimate of fossil age is on average less than 2 Myr from the mid-point age of the geological strata from which it was excavated. The high level of internal consistency found in our analyses suggests that the Bayesian statistical model employed is an adequate fit for both the geological and morphological data, and provides evidence from real data that the framework used can accurately model the evolution of discrete morphological traits coded from fossil and extant taxa. We anticipate that this approach will have diverse applications beyond divergence time dating, including dating fossils that are temporally unconstrained, testing of the ‘morphological clock', and for uncovering potential model misspecification and/or data errors when controversial phylogenetic hypotheses are obtained based on combined divergence dating analyses. This article is part of the themed issue ‘Dating species divergences

  6. Volcano Monitoring Using Google Earth (United States)

    Cameron, W.; Dehn, J.; Bailey, J. E.; Webley, P.


    At the Alaska Volcano Observatory (AVO), remote sensing is an important component of its daily monitoring of volcanoes. AVO’s remote sensing group (AVORS) primarily utilizes three satellite datasets; Advanced Very High Resolution Radiometer (AVHRR) data, from the National Oceanic and Atmospheric Administration’s (NOAA) Polar Orbiting Satellites (POES), Moderate Resolution Imaging Spectroradiometer (MODIS) data from the National Aeronautics and Space Administration’s (NASA) Terra and Aqua satellites, and NOAA’s Geostationary Operational Environmental Satellites (GOES) data. AVHRR and MODIS data are collected by receiving stations operated by the Geographic Information Network of Alaska (GINA) at the University of Alaska’s Geophysical Institute. An additional AVHRR data feed is supplied by NOAA’s Gilmore Creek satellite tracking station. GOES data are provided by the Naval Research Laboratory (NRL), Monterey Bay. The ability to visualize these images and their derived products is critical for the timely analysis of the data. To this end, AVORS has developed javascript web interfaces that allow the user to view images and metadata. These work well for internal analysts to quickly access a given dataset, but they do not provide an integrated view of all the data. To do this AVORS has integrated its datasets with Keyhole Markup Language (KML) allowing them to be viewed by a number of virtual globes or other geobrowsers that support this code. Examples of AVORS’ use of KML include the ability to browse thermal satellite image overlays to look for signs of volcanic activity. Webcams can also be viewed interactively through KML to confirm current activity. Other applications include monitoring the location and status of instrumentation; near real-time plotting of earthquake hypocenters; mapping of new volcanic deposits using polygons; and animated models of ash plumes, created by a combination of ash dispersion modeling and 3D visualization packages.

  7. Fossil fuel support mechanisms in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Lampinen, Ari


    Fossil fuel subsidies and other state support for fossil fuels are forbidden by the Kyoto Protocol and other international treaties. However, they are still commonly used. This publication presents and analyses diverse state support mechanisms for fossil fuels in Finland in 2003-2010. Total of 38 support mechanisms are covered in quantitative analysis and some other mechanisms are mentioned qualitatively only. For some mechanisms the study includes a longer historical perspective. This is the case for tax subsidies for crude oil based traffic fuels that have been maintained in Finland since 1965.

  8. Investigating the long-term geodetic response to magmatic intrusions at volcanoes in northern California (United States)

    Parker, A. L.; Biggs, J.; Annen, C.; Houseman, G. A.; Yamasaki, T.; Wright, T. J.; Walters, R. J.; Lu, Z.


    Ratios of intrusive to extrusive activity at volcanic arcs are thought to be high, with estimates ranging between 5:1 and 30:1. Understanding the geodetic response to magmatic intrusion is therefore fundamental to large-scale studies of volcano deformation, providing insight into the dynamics of the inter-eruptive period of the volcano cycle and the building of continental crust. In northern California, we identify two volcanoes - Medicine Lake Volcano (MLV) and Lassen Volcanic Center (LaVC) - that exhibit long-term (multi-decadal) subsidence. We test the hypothesis that deformation at these volcanoes results from processes associated with magmatic intrusions. We first constrain the spatial and temporal characteristics of the deformation fields, establishing the first time-series of deformation at LaVC using InSAR data, multi-temporal analysis techniques and global weather models. Although the rates of deformation at the two volcanoes are similar (~1 cm/yr), our results show that the ratio of vertical to horizontal displacements is significantly different, suggesting contrasting source geometries. To test the origin of deformation, we develop modeling strategies to investigate thermal and viscoelastic processes associated with magmatic intrusions. The first model we develop couples analytical geodetic models to a numerical model of volume loss due to cooling and crystallization based upon temperature-melt fraction relationships from petrological experiments. This model provides evidence that magmatic intrusion at MLV has occurred more recently than the last eruption ~1 ka. The second model we test uses a finite element approach to simulate the time-dependent viscoelastic response of the crust to magmatic intrusion. We assess the magnitude and timescales of ground deformation that may result from these processes, exploring the model parameter space before applying the models to our InSAR observations of subsidence in northern California.

  9. Antisana volcano: A representative andesitic volcano of the eastern cordillera of Ecuador: Petrography, chemistry, tephra and glacial stratigraphy (United States)

    Hall, Minard L.; Mothes, Patricia A.; Samaniego, Pablo; Militzer, Annemarie; Beate, Bernardo; Ramón, Patricio; Robin, Claude


    Antisana volcano is representative of many active andesitic strato-volcanoes of Pleistocene age in Ecuador's Eastern Cordillera. This study represents the first modern geological and volcanological investigation of Antisana since the late 1890's; it also summarizes the present geochemical understanding of its genesis. The volcano's development includes the formation and destruction of two older edifices (Antisana I and II) during some 400 + ka. Antisana II suffered a sector collapse about 15,000 years ago which was followed by the birth and growth of Antisana III. During its short life Antisana III has generated ≥50 eruptions of small to medium intensity, often associated with andesitic to dacitic lava flows and tephra, as well as with late Pleistocene and Holocene glacial advances. Throughout its long history Antisana's lavas have been characterized by a persistent mineral assemblage, consisting of 30-40 vol% phenocrysts of plagioclase, both clino- and orthopyroxene, and Fe-Ti oxides, with rare occurrences of olivine or amphibole, frequently in a microcrystalline to glassy matrix. This uniformity occurs despite the magma's progressive chemical evolution over ≥400 ka from early basic andesites (53-58 wt% SiO2) to intermediate and Si-rich andesites (58-62% SiO2), and recently to dacites (63-67% SiO2). Chemical diagrams suggest that crystal fractionation was the most likely magmatic process of evolution. The exception to this slowly evolving history was the short-lived emission at ∼210 ka of the Cuyuja lavas from Antisana II that generated a 73 km long andesitic lava flow. Contrasting with Antisana's general magmatic trend, Cuyuja lava (∼11 km3) is a high-Mg andesite with unusually high concentrations of incompatible elements. Antisana developed within the Chacana caldera complex, a large active siliceous center that began ∼3 Ma ago, however its lavas are chemically distinct from coeval lavas of Chacana.

  10. Lahar hazards at Agua volcano, Guatemala (United States)

    Schilling, S.P.; Vallance, J.W.; Matías, O.; Howell, M.M.


    At 3760 m, Agua volcano towers more than 3500 m above the Pacific coastal plain to the south and 2000 m above the Guatemalan highlands to the north. The volcano is within 5 to 10 kilometers (km) of Antigua, Guatemala and several other large towns situated on its northern apron. These towns have a combined population of nearly 100,000. It is within about 20 km of Escuintla (population, ca. 100,000) to the south. Though the volcano has not been active in historical time, or about the last 500 years, it has the potential to produce debris flows (watery flows of mud, rock, and debris—also known as lahars when they occur on a volcano) that could inundate these nearby populated areas.

  11. Volcanoes muon imaging using Cherenkov telescopes

    CERN Document Server

    Catalano, Osvaldo; Mineo, Teresa; Cusumano, Giancarlo; Maccarone, Maria Concetta; Pareschi, Giovanni


    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energ...

  12. Radial anisotropy ambient noise tomography of volcanoes (United States)

    Mordret, Aurélien; Rivet, Diane; Shapiro, Nikolai; Jaxybulatov, Kairly; Landès, Matthieu; Koulakov, Ivan; Sens-Schönfelder, Christoph


    The use of ambient seismic noise allows us to perform surface-wave tomography of targets which could hardly be imaged by other means. The frequencies involved (~ 0.5 - 20 s), somewhere in between active seismic and regular teleseismic frequency band, make possible the high resolution imaging of intermediate-size targets like volcanic edifices. Moreover, the joint inversion of Rayleigh and Love waves dispersion curves extracted from noise correlations allows us to invert for crustal radial anisotropy. We present here the two first studies of radial anisotropy on volcanoes by showing results from Lake Toba Caldera, a super-volcano in Indonesia, and from Piton de la Fournaise volcano, a hot-spot effusive volcano on the Réunion Island (Indian Ocean). We will see how radial anisotropy can be used to infer the main fabric within a magmatic system and, consequently, its dominant type of intrusion.

  13. A field guide to Newberry Volcano, Oregon (United States)

    Jenson, Robert A.; Donnelly-Nolan, Julie M.; McKay, Daniele


    Newberry Volcano is located in central Oregon at the intersection of the Cascade Range and the High Lava Plains. Its lavas range in age from ca. 0.5 Ma to late Holocene. Erupted products range in composition from basalt through rhyolite and cover ~3000 km2. The most recent caldera-forming eruption occurred ~80,000 years ago. This trip will highlight a revised understanding of the volcano's history based on new detailed geologic work. Stops will also focus on evidence for ice and flooding on the volcano, as well as new studies of Holocene mafic eruptions. Newberry is one of the most accessible U.S. volcanoes, and this trip will visit a range of lava types and compositions including tholeiitic and calc-alkaline basalt flows, cinder cones, and rhyolitic domes and tuffs. Stops will include early distal basalts as well as the youngest intracaldera obsidian flow.

  14. Trace fossils in coal-bearing sequences

    Energy Technology Data Exchange (ETDEWEB)

    Pollard, J.E.


    In the past decade trace fossils have been recorded extensively from coal-bearing sediments, differing widely in facies, age and location. Westphalian or Stephanian 'coal-measures' in Britain, Europe and Eastern Canada contain an ichnofauna produced by invertebrates and/or vertebrates in upper delta plain sediments. This contrasts with the marine-related lower delta plain ichnofaunas known from Pennsylvanian rocks of the United States and Permian Gondwana 'coal-measures' of South Africa. Deltaic complexes of Middle Jurassic age in the North Sea basin and Upper Cretaceous age in North America contain marine trace fossils and dinosaur footprints in coastal coal- bearing facies. These case histories illustrate the importance of trace fossils both in facies analysis of coal-bearing sequences and in recording the presence of animals rarely known as body fossils in such clastic sediments. 80 refs., 5 figs.

  15. Evolution: Fossil Ears and Underwater Sonar. (United States)

    Lambert, Olivier


    A key innovation in the history of whales was the evolution of a sonar system together with high-frequency hearing. Fossils of an archaic toothed whale's inner ear bones provide clues for a stepwise emergence of underwater echolocation ability.

  16. Fossil energy program. Progress report, July 1980

    Energy Technology Data Exchange (ETDEWEB)

    McNeese, L. E.


    This report - the seventy-second of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component development and process evaluation, technical support to major liquefaction projects, process and program analysis, fossil energy environmental analysis, coal preparation and waste utilization, coal preparation plant automation, atmospheric fluidized bed coal combustor for cogeneration, technical support to the TVA fluidized bed combustion demonstration plant program, fossil energy applications assessments, performance assurance system support for fossil energy projects, international assessment of atmospheric fluidized bed combustion technology, and PFBC systems analysis.

  17. Biodiversity Risks from Fossil Fuel Extraction

    National Research Council Canada - National Science Library

    N. Butt; H. L. Beyer; J. R. Bennett; D. Biggs; R. Maggini; M. Mills; A. R. Renwick; L. M. Seabrook; H. P. Possingham


    .... Although fossil fuel (FF) extraction has traditionally been seen as a temporary and spatially limited perturbation to ecosystems , even local or limited biodiversity loss can have large cascade effects on ecosystem function and productivity...

  18. Lahar-hazard zonation for San Miguel volcano, El Salvador (United States)

    Major, J.J.; Schilling, S.P.; Pullinger, C.R.; Escobar, C.D.; Chesner, C.A.; Howell, M.M.


    San Miguel volcano, also known as Chaparrastique, is one of many volcanoes along the volcanic arc in El Salvador. The volcano, located in the eastern part of the country, rises to an altitude of about 2130 meters and towers above the communities of San Miguel, El Transito, San Rafael Oriente, and San Jorge. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and the PanAmerican and coastal highways cross the lowermost northern and southern flanks of the volcano. The population density around San Miguel volcano coupled with the proximity of major transportation routes increases the risk that even small volcano-related events, like landslides or eruptions, may have significant impact on people and infrastructure. San Miguel volcano is one of the most active volcanoes in El Salvador; it has erupted at least 29 times since 1699. Historical eruptions of the volcano consisted mainly of relatively quiescent emplacement of lava flows or minor explosions that generated modest tephra falls (erupted fragments of microscopic ash to meter sized blocks that are dispersed into the atmosphere and fall to the ground). Little is known, however, about prehistoric eruptions of the volcano. Chemical analyses of prehistoric lava flows and thin tephra falls from San Miguel volcano indicate that the volcano is composed dominantly of basalt (rock having silica content

  19. Fossil fuels in the 21st century. (United States)

    Lincoln, Stephen F


    An overview of the importance of fossil fuels in supplying the energy requirements of the 21st century, their future supply, and the impact of their use on global climate is presented. Current and potential alternative energy sources are considered. It is concluded that even with substantial increases in energy derived from other sources, fossil fuels will remain a major energy source for much of the 21st century and the sequestration of CO2 will be an increasingly important requirement.

  20. Primate diversification inferred from phylogenies and fossils. (United States)

    Herrera, James P


    Biodiversity arises from the balance between speciation and extinction. Fossils record the origins and disappearance of organisms, and the branching patterns of molecular phylogenies allow estimation of speciation and extinction rates, but the patterns of diversification are frequently incongruent between these two data sources. I tested two hypotheses about the diversification of primates based on ∼600 fossil species and 90% complete phylogenies of living species: 1) diversification rates increased through time; 2) a significant extinction event occurred in the Oligocene. Consistent with the first hypothesis, analyses of phylogenies consistently supported increasing speciation rates and negligible extinction rates. In contrast, fossils showed that while speciation rates increased, speciation and extinction rates tended to be nearly equal, resulting in zero net diversification. Partially supporting the second hypothesis, the fossil data recorded a clear pattern of diversity decline in the Oligocene, although diversification rates were near zero. The phylogeny supported increased extinction ∼34 Ma, but also elevated extinction ∼10 Ma, coinciding with diversity declines in some fossil clades. The results demonstrated that estimates of speciation and extinction ignoring fossils are insufficient to infer diversification and information on extinct lineages should be incorporated into phylogenetic analyses. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. The shadow price of fossil groundwater (United States)

    Bierkens, Marc F. P.; Reinhard, Stijn; de Bruijn, Jens A.; Wada, Yoshihide


    The expansion of irrigated agriculture into areas with limited precipitation and surface water during the growing season has greatly increased the use of fossil groundwater (Wada et al., 2012). As a result, the depletion rate of fossil groundwater resources has shown an increasing rate during the last decades (Wada et al, 2010; Konikow, 2011; Wada et al., 2012; De Graaf et al. 2015; Ritchy et al., 2015). Although water pricing has been used extensively to stimulate efficient application of water to create maximum value (e.g. Medellín-Azuara et al., 2012; Rinaudo et al., 2012; Dinar et al., 2015), it does not preclude the use of non-renewable water resources. Here, we use a global hydrological model and historical crop production and price data to assess the shadow price of non-renewable or fossil groundwater applied to major crops in countries that use large quantities of fossil groundwater. Our results show that shadow prices for many crops are very low, indicating economically inefficient or even wasteful use of fossil groundwater resources. Using India as an example, we show that small changes in the crop mix could lead to large reductions in fossil groundwater use or alternatively, create additional financial means to invest in water saving technologies. Our study thus provides a hydro-economic basis to further the sustainable use of finite groundwater resources.

  2. EARTHQUAKES - VOLCANOES (Causes - Forecast - Counteraction) (United States)

    Tsiapas, Elias


    Earthquakes and volcanoes are caused by: 1)Various liquid elements (e.g. H20, H2S, S02) which emerge from the pyrosphere and are trapped in the space between the solid crust and the pyrosphere (Moho discontinuity). 2)Protrusions of the solid crust at the Moho discontinuity (mountain range roots, sinking of the lithosphere's plates). 3)The differential movement of crust and pyrosphere. The crust misses one full rotation for approximately every 100 pyrosphere rotations, mostly because of the lunar pull. The above mentioned elements can be found in small quantities all over the Moho discontinuity, and they are constantly causing minor earthquakes and small volcanic eruptions. When large quantities of these elements (H20, H2S, SO2, etc) concentrate, they are carried away by the pyrosphere, moving from west to east under the crust. When this movement takes place under flat surfaces of the solid crust, it does not cause earthquakes. But when these elements come along a protrusion (a mountain root) they concentrate on its western side, displacing the pyrosphere until they fill the space created. Due to the differential movement of pyrosphere and solid crust, a vacuum is created on the eastern side of these protrusions and when the aforementioned liquids overfill this space, they explode, escaping to the east. At the point of their escape, these liquids are vaporized and compressed, their flow accelerates, their temperature rises due to fluid friction and they are ionized. On the Earth's surface, a powerful rumbling sound and electrical discharges in the atmosphere, caused by the movement of the gasses, are noticeable. When these elements escape, the space on the west side of the protrusion is violently taken up by the pyrosphere, which collides with the protrusion, causing a major earthquake, attenuation of the protrusions, cracks on the solid crust and damages to structures on the Earth's surface. It is easy to foresee when an earthquake will occur and how big it is

  3. Spreading and collapse of big basaltic volcanoes (United States)

    Puglisi, Giuseppe; Bonforte, Alessandro; Guglielmino, Francesco; Peltier, Aline; Poland, Michael


    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. In the frame of MED-SVU project, our work aims to investigate the relation between basement setting and volcanic activity and stability at three Supersite volcanoes: Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These

  4. The seismicity of Marapi volcano, West Sumatra. (United States)

    D'Auria, L.


    Marapi is one of the active volcanoes in West Sumatra. It is a stratovolcano with an edifice that is elongated in the ENE-WSW direction. Its elevation is about 2,900 m a.s.l. The summit area is characterized by a caldera that contains some active craters aligned along the ENE-WSW direction. The Marapi volcano is an attractive region for tourists and hosts many small communities its surrounding areas. The recent history of Mt. Marapi is characterized by explosive activity at the summit craters. No lava flows have passed the rim of the summit caldera in recent times. The last eruption occurred on August 5, 2004, and consisted of moderate explosive activity from the central crater. In 1975 an eruption with magmatic and phreatic explosive phases and mudflows and lahars occurred that caused fatalities in the surrounding areas. Since 1980 other eruptions have occurred at Marapi volcano. Even if the explosive intensities of those eruptions have been small to moderate, in some cases, there were fatalities. A cooperation project started between Italy and Indonesia (COVIN) for the monitoring of volcanoes in West Sumatra. In the context of this project a monitoring centre has been set up at the Bukittinggi Observatory and a seismological monitoring system for Marapi volcano has been realized. This system is based on a broadband seismic network including 4 three-component stations. The data acquired by the broadband network of Marapi volcano are continuous recordings of the seismic signals starting from 19/10/2006. Volcano-Tectonic and Long Period events of Marapi volcano together with regional and teleseismic earthquakes are recorded. Several events of high magnitude located at short distances from the network were also recorded such as on March 6, 2007, when two events of Magnitudes Mw 6.4 and 6.3 were recorded with the epicentres near the Marapi volcano. During the following days, there was a sequence of hundreds of aftershocks. The preliminary analysis of the seismicity of

  5. A Brief Analysis of Oral Fossilization of English Major Students

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-xia


    This paper on the basis of former studies and researches has analyzed fossilization particularly oral fossilization. Further more, this paper has analyzed the reasons of fossilization and at the same time put forward some tentative solutions to reduce or avoid fossilization. Hope that this paper can offer some help for both the second language learners and teachers.

  6. Petrological evidence for non-linear increase of magmatic intrusion rates before eruption at open vent mafic volcanoe (United States)

    Ruth, D. C. S.; Costa Rodriguez, F.


    The most active volcanoes on earth erupt in a yearly to decadal time scales, typically erupt mafic magmas and are open-vent systems with prominent degassing plumes (e.g. Mayon, Arenal, Llaima, Etna). Here we investigate the plumbing systems, dynamics, and processes that drive eruptions at these systems. These are key questions for improving hazard evaluation, and better understanding the unrest associated with these types of volcanoes. The petrology and geochemistry from six historical eruptions (1947-2006) of Mayon volcano (Philippines) shows that all lavas are basaltic andesite with phenocrysts of plagioclase + orthopyroxene (Opx) + clinopyroxene. Opx crystals show a variety of compositions and zoning patterns (reverse, normal or complex) with Mg# (= 100 *Mg/[Mg+Fe]) varying from 67 to 81. The simplest interpretation is that the low Mg# parts of the crystals resided on an upper crustal and crystal rich reservoir that was intruded by more primitive magmas from which the high Mg# parts of the crystals grew. Modelling Mg-Fe diffusion in Opx shows that times since magma injection and eruption range from a few days up to 3.5 years in all of the investigated eruptions. The longest diffusion times are shorter than the repose times between the eruptions, which implies that crystal recycling between eruptive events is negligible. This is a surprising result that shows that for each eruption a different part of the evolved crystal-rich plumbing system is activated. This can be due to random intrusion location or an irreversibility of the plumbing system that prevents multiple eruptions from the same crystal-rich part. Moreover, we find that the number of intrusions markedly increases before each eruption in a non-linear manner. Such an increased rate of intrusions with time might reflect non-linear rheological properties of the crystal-rich system, of the enclosing rocks, or the non-linear evolution of crystal-melt reaction-dissolution fronts during magma intrusions.

  7. Comparing primate crania: The importance of fossils. (United States)

    Fleagle, John G; Gilbert, Christopher C; Baden, Andrea L


    Extant primate crania represent a small subset of primate crania that have existed. The main objective here is to examine how the inclusion of fossil crania changes our understanding of primate cranial diversity relative to analyses of extant primates. We hypothesize that fossil taxa will change the major axes of cranial shape, occupy new areas of morphospace, change the relative diversity of major primate clades, and fill in notable gaps separating major primate taxa/clades. Eighteen 3D landmarks were collected on 157 extant and fossil crania representing 90 genera. Data were subjected to a Generalized Procrustes Analysis then principal components analysis. Relative diversity between clades was assessed using an F-statistic. Fossil taxa do not significantly alter major axes of cranial shape, but they do occupy unique areas of morphospace, change the relative diversity between clades, and fill in notable gaps in primate cranial evolution. Strepsirrhines remain significantly less diverse than anthropoids. Fossil hominins fill the gap in cranial morphospace between extant great apes and modern humans. The morphospace outlined by living primates largely includes that occupied by fossil taxa, suggesting that the cranial diversity of living primates generally encompasses the total diversity that has evolved in this Order. The evolution of the anthropoid cranium was a significant event allowing anthropoids to achieve significantly greater cranial diversity compared to strepsirrhines. Fossil taxa fill in notable gaps within and between clades, highlighting their transitional nature and eliminating the appearance of large morphological distances between extant taxa, particularly in the case of extant hominids. © 2016 Wiley Periodicals, Inc.

  8. Seismic unrest at Katla Volcano- southern Iceland (United States)

    jeddi, zeinab; Tryggvason, Ari; Gudmundsson, Olafur; Bödvarsson, Reynir; SIL Seismology Group


    Katla volcano is located on the propagating Eastern Volcanic Zone (EVZ) in South Iceland. It is located beneath Mýrdalsjökull ice-cap which covers an area of almost 600 km2, comprising the summit caldera and the eruption vents. 20 eruptions between 930 and 1918 with intervals of 13-95 years are documented at Katla which is one of the most active subglacial volcanoes in Iceland. Eruptions at Katla are mainly explosive due to the subglacial mode of extrusion and produce high eruption columns and catastrophic melt water floods (jökulhlaups). The present long Volcanic repose (almost 96 years) at Katla, the general unrest since 1955, and the 2010 eruption of the neighbouring Eyjafjallajökull volcano has prompted concerns among geoscientists about an imminent eruption. Thus, the volcano has been densely monitored by seismologists and volcanologists. The seismology group of Uppsala University as a partner in the Volcano Anatomy (VA) project in collaboration with the University of Iceland and the Icelandic Meteorological Office (IMO) installed 9 temporary seismic stations on and around the Mýrdalsjökull glacier in 2011. Another 10 permanent seismic stations are operated by IMO around Katla. The project's data collection is now finished and temporary stations were pulled down in August 2013. According to seismicity maps of the whole recording period, thousands of microearthquakes have occurred within the caldera region. At least three different source areas are active in Katla: the caldera region, the western Godaland region and a small cluster at the southern rim of Mýrdalsjökull near the glacial stream of Hafursarjökull. Seismicity in the southern flank has basically started after June 2011. The caldera events are mainly volcano-tectonic, while western and southern events are mostly long period (lp) and can be related to glacial or magmatic movement. One motivation of the VA Katla project is to better understand the physical mechanism of these lp events. Changes

  9. Volcanoes in the Classroom--an Explosive Learning Experience. (United States)

    Thompson, Susan A.; Thompson, Keith S.


    Presents a unit on volcanoes for third- and fourth-grade students. Includes demonstrations; video presentations; building a volcano model; and inviting a scientist, preferably a vulcanologist, to share his or her expertise with students. (JRH)

  10. Volcanostratigraphic Approach for Evaluation of Geothermal Potential in Galunggung Volcano (United States)

    Ramadhan, Q. S.; Sianipar, J. Y.; Pratopo, A. K.


    he geothermal systems in Indonesia are primarily associated with volcanoes. There are over 100 volcanoes located on Sumatra, Java, and in the eastern part of Indonesia. Volcanostratigraphy is one of the methods that is used in the early stage for the exploration of volcanic geothermal system to identify the characteristics of the volcano. The stratigraphy of Galunggung Volcano is identified based on 1:100.000 scale topographic map of Tasikmalaya sheet, 1:50.000 scale topographic map and also geological map. The schematic flowchart for evaluation of geothermal exploration is used to interpret and evaluate geothermal potential in volcanic regions. Volcanostratigraphy study has been done on Galunggung Volcano and Talaga Bodas Volcano, West Java, Indonesia. Based on the interpretation of topographic map and analysis of the dimension, rock composition, age and stress regime, we conclude that both Galunggung Volcano and Talaga Bodas Volcano have a geothermal resource potential that deserve further investigation.

  11. USGS U.S. Volcanoes with Elevated Status (United States)

    U.S. Geological Survey, Department of the Interior — Website provides list of elevated status volcanoes with access to activity updates and/or information releases for changes in activity at the volcanoes. activity at...

  12. Macroevolutionary developmental biology: Embryos, fossils, and phylogenies. (United States)

    Organ, Chris L; Cooper, Lisa Noelle; Hieronymus, Tobin L


    The field of evolutionary developmental biology is broadly focused on identifying the genetic and developmental mechanisms underlying morphological diversity. Connecting the genotype with the phenotype means that evo-devo research often considers a wide range of evidence, from genetics and morphology to fossils. In this commentary, we provide an overview and framework for integrating fossil ontogenetic data with developmental data using phylogenetic comparative methods to test macroevolutionary hypotheses. We survey the vertebrate fossil record of preserved embryos and discuss how phylogenetic comparative methods can integrate data from developmental genetics and paleontology. Fossil embryos provide limited, yet critical, developmental data from deep time. They help constrain when developmental innovations first appeared during the history of life and also reveal the order in which related morphologies evolved. Phylogenetic comparative methods provide a powerful statistical approach that allows evo-devo researchers to infer the presence of nonpreserved developmental traits in fossil species and to detect discordant evolutionary patterns and processes across levels of biological organization.

  13. Fossil fuels in a trillion tonne world (United States)

    Scott, Vivian; Haszeldine, R. Stuart; Tett, Simon F. B.; Oschlies, Andreas


    The useful energy services and energy density value of fossil carbon fuels could be retained for longer timescales into the future if their combustion is balanced by CO2 recapture and storage. We assess the global balance between fossil carbon supply and the sufficiency (size) and capability (technology, security) of candidate carbon stores. A hierarchy of value for extraction-to-storage pairings is proposed, which is augmented by classification of CO2 containment as temporary (100,000 yr). Using temporary stores is inefficient and defers an intergenerational problem. Permanent storage capacity is adequate to technically match current fossil fuel reserves. However, rates of storage creation cannot balance current and expected rates of fossil fuel extraction and CO2 consequences. Extraction of conventional natural gas is uniquely holistic because it creates the capacity to re-inject an equivalent tonnage of carbon for storage into the same reservoir and can re-use gas-extraction infrastructure for storage. By contrast, balancing the extraction of coal, oil, biomass and unconventional fossil fuels requires the engineering and validation of additional carbon storage. Such storage is, so far, unproven in sufficiency.

  14. On The Nature of Fossil Galaxy Groups

    CERN Document Server

    La Barbera, F; De la Rosa, I G; Sorrentino, G; Gal, R R; Kohl-Moreira, J L


    We present a new sample of 25 fossil groups (FGs) at z < 0.1, along with a control sample of seventeen bright ellipticals located in non-fossil systems. Both the global properties of FGs (e.g. X-ray luminosity) as well as the photometric properties (i.e. isophotal shape parameter, a4) and spectroscopic parameters (e.g. the alpha-enhancement) of their first-ranked ellipticals are consistent with those of the control sample. This result favors a scenario where FGs are not a distinct class of systems, but rather a common phase in the life of galaxy groups. We also find no evidence for an evolutionary sequence explaining the formation of galaxies in fossil systems through the merging of galaxies in compact groups.

  15. Recent synchronous radiation of a living fossil. (United States)

    Nagalingum, N S; Marshall, C R; Quental, T B; Rai, H S; Little, D P; Mathews, S


    Modern survivors of previously more diverse lineages are regarded as living fossils, particularly when characterized by morphological stasis. Cycads are often cited as a classic example, reaching their greatest diversity during the Jurassic-Cretaceous (199.6 to 65.5 million years ago) then dwindling to their present diversity of ~300 species as flowering plants rose to dominance. Using fossil-calibrated molecular phylogenies, we show that cycads underwent a near synchronous global rediversification beginning in the late Miocene, followed by a slowdown toward the Recent. Although the cycad lineage is ancient, our timetrees indicate that living cycad species are not much older than ~12 million years. These data reject the hypothesized role of dinosaurs in generating extant diversity and the designation of today's cycad species as living fossils.

  16. The Cenozoic Volcanoes in Northeast China

    Institute of Scientific and Technical Information of China (English)

    LIU Jiaqi; HAN Jingtai; GUO Zhengfu


    There are more than 600 Cenozoic volcanic cones and craters with abeut 50 000 km2of lava flows in northeast China, which formed many volcanic clusters and shown the features of the continental rift - type volcanoes. Most volcanic activities in this area, especially in the east part of Songliao graben, were usually controlled by rifts and faults with the main direction of NE / NNE in parallel and become younger from the central graben towards its both sides, especially to the east continental margin. It is revealed that the volcanism occurred in northeast China was as strong as that occurred in Japan during the Miocene and the Quaternary. The Quaternary basalt that is usually distributed along river valley is called "valley basalt"while Neogene basalt usually distributed in the top of mounts is called "high position basalt". These volcanoes and volcanic rocks are usually composed of alkaline basalts with ultramafic inclusions, except Changbaishan volcano that is built by trachyte and pantellerite.

  17. Renewed unrest at Mount Spurr Volcano, Alaska (United States)

    Power, John A.


    The Alaska Volcano Observatory (AVO),a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys, has detected unrest at Mount Spurr volcano, located about 125 km west of Anchorage, Alaska, at the northeast end of the Aleutian volcanic arc.This activity consists of increased seismicity melting of the summit ice cap, and substantial rates of C02 and H2S emission.The current unrest is centered beneath the volcano's 3374-m-high summit, whose last known eruption was 5000–6000 years ago. Since then, Crater Peak, 2309 m in elevation and 4 km to the south, has been the active vent. Recent eruptions occurred in 1953 and 1992.

  18. Living with Volcanoes: Year Eleven Teaching Resource Unit. (United States)

    Le Heron, Kiri; Andrews, Jill; Hooks, Stacey; Larnder, Michele; Le Heron, Richard


    Presents a unit on volcanoes and experiences with volcanoes that helps students develop geography skills. Focuses on four volcanoes: (1) Rangitoto Island; (2) Lake Pupuke; (3) Mount Smart; and (4) One Tree Hill. Includes an answer sheet and resources to use with the unit. (CMK)

  19. How Do Volcanoes Affect Human Life? Integrated Unit. (United States)

    Dayton, Rebecca; Edwards, Carrie; Sisler, Michelle

    This packet contains a unit on teaching about volcanoes. The following question is addressed: How do volcanoes affect human life? The unit covers approximately three weeks of instruction and strives to present volcanoes in an holistic form. The five subject areas of art, language arts, mathematics, science, and social studies are integrated into…

  20. Predicting the Timing and Location of the next Hawaiian Volcano (United States)

    Russo, Joseph; Mattox, Stephen; Kildau, Nicole


    The wealth of geologic data on Hawaiian volcanoes makes them ideal for study by middle school students. In this paper the authors use existing data on the age and location of Hawaiian volcanoes to predict the location of the next Hawaiian volcano and when it will begin to grow on the floor of the Pacific Ocean. An inquiry-based lesson is also…

  1. Cerium anomaly at microscale in fossils. (United States)

    Gueriau, Pierre; Mocuta, Cristian; Bertrand, Loïc


    Patterns in rare earth element (REE) concentrations are essential instruments to assess geochemical processes in Earth and environmental sciences. Excursions in the "cerium anomaly" are widely used to inform on past redox conditions in sediments. This proxy resources to the specificity of cerium to adopt both the +III and +IV oxidation states, while most rare earths are purely trivalent and share very similar reactivity and transport properties. In practical terms, the level of cerium anomaly is established through elemental point quantification and profiling. All these models rely on a supposed homogeneity of the cerium oxidation state within the samples. However, this has never been demonstrated, whereas the cerium concentration can significantly vary within a sample, as shown for fossils, which would vastly complicate interpretation of REE patterns. Here, we report direct micrometric mapping of Ce speciation through synchrotron X-ray absorption spectroscopy and production of local rare earth patterns in paleontological fossil tissues through X-ray fluorescence mapping. The sensitivity of the approach is demonstrated on well-preserved fishes and crustaceans from the Late Cretaceous (ca. 95 million years (Myr) old). The presence of Ce under the +IV form within the fossil tissues is attributed to slightly oxidative local conditions of burial and agrees well with the limited negative cerium anomaly observed in REE patterns. The [Ce(IV)]/[Ce(tot)] ratio appears remarkably stable at the microscale within each fossil and is similar between fossils from the locality. Speciation maps were obtained from an original combination of synchrotron microbeam X-ray fluorescence, absorption spectroscopy, and diffraction, together with light and electron microscopy. This work also highlights the need for more systematic studies of cerium geochemistry at the microscale in paleontological contexts, in particular across fossil histologies.

  2. Volcanoes muon imaging using Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Catalano, O. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Del Santo, M., E-mail: [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Mineo, T.; Cusumano, G.; Maccarone, M.C. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Pareschi, G. [INAF Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807, Merate (Italy)


    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  3. Applications of geophysical methods to volcano monitoring (United States)

    Wynn, Jeff; Dzurisin, Daniel; Finn, Carol A.; Kauahikaua, James P.; Lahusen, Richard G.


    The array of geophysical technologies used in volcano hazards studies - some developed originally only for volcano monitoring - ranges from satellite remote sensing including InSAR to leveling and EDM surveys, campaign and telemetered GPS networks, electronic tiltmeters and strainmeters, airborne magnetic and electromagnetic surveys, short-period and broadband seismic monitoring, even microphones tuned for infrasound. They include virtually every method used in resource exploration except large-scale seismic reflection. By “geophysical ” we include both active and passive methods as well as geodetic technologies. Volcano monitoring incorporates telemetry to handle high-bandwith cameras and broadband seismometers. Critical geophysical targets include the flux of magma in shallow reservoir and lava-tube systems, changes in active hydrothermal systems, volcanic edifice stability, and lahars. Since the eruption of Mount St. Helens in Washington State in 1980, and the eruption at Pu’u O’o in Hawai’i beginning in 1983 and still continuing, dramatic advances have occurred in monitoring technology such as “crisis GIS” and lahar modeling, InSAR interferograms, as well as gas emission geochemistry sampling, and hazards mapping and eruption predictions. The on-going eruption of Mount St. Helens has led to new monitoring technologies, including advances in broadband Wi-Fi and satellite telemetry as well as new instrumentation. Assessment of the gap between adequate monitoring and threat at the 169 potentially dangerous Holocene volcanoes shows where populations are dangerously exposed to volcanic catastrophes in the United States and its territories . This paper focuses primarily on Hawai’ian volcanoes and the northern Pacific and Cascades volcanoes. The US Geological Survey, the US National Park System, and the University of Utah cooperate in a program to monitor the huge Yellowstone volcanic system, and a separate observatory monitors the restive Long Valley

  4. Volcanoes muon imaging using Cherenkov telescopes (United States)

    Catalano, O.; Del Santo, M.; Mineo, T.; Cusumano, G.; Maccarone, M. C.; Pareschi, G.


    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  5. Microbial Fossils Detected in Desert Varnish (United States)

    Flood, B. E.; Allen, C.; Longazo, T.


    Mars Global Surveyor Thermal Emission Spectrometer data indicate regions with significant levels of hematite (_Fe2O3). Fe-oxides, like hematite, can form as aqueous mineral precipitates and as such may preserve microscopic fossils or other biosignatures. Several potential terrestrial analogues to martian hematite like hydrothermal vents have preserved microfossils. Microbial fossilization in Fe-oxides is often a function of biomineralization. For example, goethite (FeO2H) encrustation of fungal mycelia from the mid-Tertiary preserved fungal morphologies such that their genera could be determined.

  6. Insect diversity in the fossil record (United States)

    Labandeira, C. C.; Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)


    Insects possess a surprisingly extensive fossil record. Compilation of the geochronologic ranges of insect families demonstrates that their diversity exceeds that of preserved vertebrate tetrapods through 91 percent of their evolutionary history. The great diversity of insects was achieved not by high origination rates but rather by low extinction rates comparable to the low rates of slowly evolving marine invertebrate groups. The great radiation of modern insects began 245 million years ago and was not accelerated by the expansion of angiosperms during the Cretaceous period. The basic trophic machinery of insects was in place nearly 100 million years before angiosperms appeared in the fossil record.

  7. Dinosaur Footprint Fossils Discovered in Xinjiang

    Institute of Scientific and Technical Information of China (English)


    @@ Recently,a Chinese-German science fieldwork investigation team,composed of staff from the SinoGerman Paleontology and Geography Joint Lab and the Xinjiang Geological Work Station,announced that they discovered a batch of dinosaur footprint fossils in the dessert 20 kilometers to the east of Shanshan County in the Turpan Basin,Xinjiang Uyghur Autonomous Region.These fossils spread around an area of 100 square meters and scientists believed that these footprints were left behind by carnivore dinosaurs.This major discovery has been published in Global Geology,an English journal published by the NorthEast Asia Geology Center.

  8. Fossils, Genes and The Origin of Organs

    Energy Technology Data Exchange (ETDEWEB)

    Shubin, Neil (University of Chicago)


    A toolkit of experimental and comparative biology can be applied to understand the great transformations in the history of life. Expeditionary paleontology can be used to target key nodes of the tree of life for which new fossils can provide insights into major morphological transformations. These fossils often have intermediate conditions that allow extant creatures to be compared in new ways. The tools of developmental genetics can then be used to explore these new comparisons to understand the genetic basis for macroevolutionary change. These different approaches can be used to predict new discoveries and this is only possible because of the empirical content of the tree of life.

  9. The origin of the Hawaiian Volcano Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Dvorak, John [University of Hawaii' s Institute for Astronomy (United States)


    I first stepped through the doorway of the Hawaiian Volcano Observatory in 1976, and I was impressed by what I saw: A dozen people working out of a stone-and-metal building perched at the edge of a high cliff with a spectacular view of a vast volcanic plain. Their primary purpose was to monitor the island's two active volcanoes, Kilauea and Mauna Loa. I joined them, working for six weeks as a volunteer and then, years later, as a staff scientist. That gave me several chances to ask how the observatory had started.

  10. Volcano geodesy in the Cascade arc, USA (United States)

    Poland, Michael P.; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Ben


    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  11. Volcano geodesy in the Cascade arc, USA (United States)

    Poland, Michael; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Benjamin


    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  12. Evolution and genesis of volcanic rocks from Mutnovsky Volcano, Kamchatka (United States)

    Simon, A.; Yogodzinski, G. M.; Robertson, K.; Smith, E.; Selyangin, O.; Kiryukhin, A.; Mulcahy, S. R.; Walker, J. D.


    This study presents new geochemical data for Mutnovsky Volcano, located on the volcanic front of the southern portion of the Kamchatka arc. Field relationships show that Mutnovsky Volcano is comprised of four distinct stratocones, which have grown over that past 80 ka. The youngest center, Mutnovsky IV, has produced basalts and basaltic andesites only. The three older centers (Mutnovsky I, II, III) are dominated by basalt and basaltic andesite (60-80% by volume), but each has also produced small volumes of andesite and dacite. Across centers of all ages, Mutnovsky lavas define a tholeiitic igneous series, from 48-70% SiO2. Basalts and basaltic andesites have relatively low K2O and Na2O, and high FeO* and Al2O3 compared to volcanic rocks throughout Kamchatka. The mafic lavas are also depleted in the light rare earth elements (REEs), with chondrite-normalized La/Sm arc volcanic rocks worldwide. Radiogenic isotope ratios (Sr, Nd, Pb, Hf) are similar for samples from all four eruptive centers, and indicate that all samples were produced by melting of a similar source mixture. No clear age-progressive changes are evident in the compositions of Mutnovsky lavas. Mass balance and assimilation-fractional crystallization (AFC) modeling of major and rare earth elements (REEs) indicate that basaltic andesites were produced by FC of plagioclase, clinopyroxene and olivine from a parental basalt, combined with assimilation of a melt composition similar to dacite lavas present at Mutnovsky. This modeling also indicates that andesites were produced by FC of plagioclase from basaltic andesite, combined with assimilation of dacite. Dacites erupted from Mutnovsky I and II have low abundances of REEs, and do not appear to be related to mafic magmas by FC or AFC processes. These dacites are modeled as the products of dehydration partial melting at mid-crustal levels of a garnet-free, amphibole-bearing basaltic rock, which itself formed in the mid-crust by emplacement of magma that

  13. Volcano shapes, entropies, and eruption probabilities (United States)

    Gudmundsson, Agust; Mohajeri, Nahid


    We propose that the shapes of polygenetic volcanic edifices reflect the shapes of the associated probability distributions of eruptions. In this view, the peak of a given volcanic edifice coincides roughly with the peak of the probability (or frequency) distribution of its eruptions. The broadness and slopes of the edifices vary widely, however. The shapes of volcanic edifices can be approximated by various distributions, either discrete (binning or histogram approximation) or continuous. For a volcano shape (profile) approximated by a normal curve, for example, the broadness would be reflected in its standard deviation (spread). Entropy (S) of a discrete probability distribution is a measure of the absolute uncertainty as to the next outcome/message: in this case, the uncertainty as to time and place of the next eruption. A uniform discrete distribution (all bins of equal height), representing a flat volcanic field or zone, has the largest entropy or uncertainty. For continuous distributions, we use differential entropy, which is a measure of relative uncertainty, or uncertainty change, rather than absolute uncertainty. Volcano shapes can be approximated by various distributions, from which the entropies and thus the uncertainties as regards future eruptions can be calculated. We use the Gibbs-Shannon formula for the discrete entropies and the analogues general formula for the differential entropies and compare their usefulness for assessing the probabilities of eruptions in volcanoes. We relate the entropies to the work done by the volcano during an eruption using the Helmholtz free energy. Many factors other than the frequency of eruptions determine the shape of a volcano. These include erosion, landslides, and the properties of the erupted materials (including their angle of repose). The exact functional relation between the volcano shape and the eruption probability distribution must be explored for individual volcanoes but, once established, can be used to

  14. Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake. (United States)

    Lepot, K; Compère, P; Gérard, E; Namsaraev, Z; Verleyen, E; Tavernier, I; Hodgson, D A; Vyverman, W; Gilbert, B; Wilmotte, A; Javaux, E J


    Lacustrine microbial mats in Antarctic ice-free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are geographically isolated. To better understand early fossilization and mineralization processes in this context, we studied the microstructure and chemistry of organo-mineral associations in a suite of sediments 50-4530 cal. years old from a lake in Skarvsnes, Lützow Holm Bay, East Antarctica. First, we report an exceptional preservation of fossil autotrophs and their biomolecules on millennial timescales. The pigment scytonemin is preserved inside cyanobacterial sheaths. As non-pigmented sheaths are also preserved, scytonemin likely played little role in the preservation of sheath polysaccharides, which have been cross-linked by ether bonds. Coccoids preserved thylakoids and autofluorescence of pigments such as carotenoids. This exceptional preservation of autotrophs in the fossil mats argues for limited biodegradation during and after deposition. Moreover, cell-shaped aggregates preserved sulfur-rich nanoglobules, supporting fossilization of instable intracellular byproducts of chemotrophic or phototrophic S-oxidizers. Second, we report a diversity of micro- to nanostructured CaCO3 precipitates intimately associated with extracellular polymeric substances, cyanobacteria, and/or other prokaryotes. Micro-peloids Type 1 display features that distinguish them from known carbonates crystallized in inorganic conditions: (i) Type 1A are often filled with globular nanocarbonates and/or surrounded by a fibrous fringe, (ii) Type 1B are empty and display ovoid to wrinkled fringes of nanocrystallites that can be radially oriented (fibrous or triangular) or multilayered, and (iii) all show small-size variations. Type 2 rounded carbonates 1-2 μm in diameter occurring inside autofluorescent

  15. Fossil fuels supplies modeling and research

    Energy Technology Data Exchange (ETDEWEB)

    Leiby, P.N.


    The fossil fuel supplies modeling and research effort focuses on models for US Strategic Petroleum Reserve (SPR) planning and management. Topics covered included new SPR oil valuation models, updating models for SPR risk analysis, and fill-draw planning. Another task in this program area is the development of advanced computational tools for three-dimensional seismic analysis.

  16. Fossil Energy Materials Program conference proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R. (comp.)


    The US Department of Energy Office of Fossil Energy has recognized the need for materials research and development to assure the adequacy of materials of construction for advanced fossil energy systems. The principal responsibility for identifying needed materials research and for establishing a program to address these needs resides within the Office of Technical Coordination. That office has established the Advanced Research and Technology Development (AR and TD) Fossil Energy Materials Program to fulfill that responsibility. In addition to the AR and TD Materials Program, which is designed to address in a generic way the materials needs of fossil energy systems, specific materials support activities are also sponsored by the various line organizations such as the Office of Coal Gasification. A conference was held at Oak Ridge, Tennessee on May 19-21, 1987, to present and discuss the results of program activities during the past year. The conference program was organized in accordance with the research thrust areas we have established. These research thrust areas include structural ceramics (particularly fiber-reinforced ceramic composites), corrosion and erosion, and alloy development and mechanical properties. Eighty-six people attended the conference. Papers have been entered individually into EDB and ERA. (LTN)

  17. On the fossil record of the Gekkota. (United States)

    Daza, Juan D; Bauer, Aaron M; Snively, Eric D


    Gekkota is often interpreted as sister to all remaining squamates, exclusive of dibamids, or as sister to Autarchoglossa. It is the only diverse lineage of primarily nocturnal lizards and includes some of the smallest amniotes. The skeleton of geckos has often been interpreted as paedomorphic and/or "primitive" but these lizards also display a wide range of structural specializations of the postcranium, including modifications associated with both scansorial locomotion and limb reduction. Although the concept of "Gekkota" has been variously applied by different authors, we here apply a rigorous apomorphy based definition, recent advances in gekkotan morphology and phylogenetics, and diverse comparative material to provide a comprehensive assessment of 28 known pre-Quaternary geckos, updating the last such review, published three decades ago. Fossils evaluated include both sedimentary fossils and amber-embedded specimens. Known Cretaceous geckos are exclusively Asian and exhibit character combinations not seen in any living forms. Cenozoic gekkotans derive from sites around the world, although Europe is especially well represented. Paleogene geckos are largely known from disarticulated remains and show similarities to Sphaerodactylidae and Diplodactylidae, although resemblances may be plesiomorphic in some cases. Many Neogene gekkotans are referable to living families or even genera, but their geographic occurrences are often extralimital to those of modern groups, as is consistent with paleoclimatic conditions. The phylogenetic placement of fossil gekkotans has important repercusions for timetree calibration, but at present only a small number of fossils can be confidently assigned to even family level groupings, limiting their utility in this regard.

  18. The Fascinating Story of Fossil Fuels (United States)

    Asimov, Isaac


    How this energy source was created, its meaning to mankind, our drastically reduced supply, and why we cannot wait for nature to make more are considered. Today fossil fuels supply 96 percent of the energy used but we must find alternate energy options if we are to combat the energy crisis. (BL)

  19. The Fascinating Story of Fossil Fuels (United States)

    Asimov, Isaac


    How this energy source was created, its meaning to mankind, our drastically reduced supply, and why we cannot wait for nature to make more are considered. Today fossil fuels supply 96 percent of the energy used but we must find alternate energy options if we are to combat the energy crisis. (BL)

  20. Fossil Hunting: Intracluster Stars in Virgo

    NARCIS (Netherlands)

    Murphy, Eric; Bridge, Carrie; Desai, Vandana; Kenney, Jeffrey; Krick, Jessica; Surace, Jason; van Gorkom, Jacqueline


    In dense clusters, galaxy interactions and mergers play a significant role in galaxy evolution. During these interactions, tidal forces can lead to the ejection of stars from their parent galaxies; these stars are a fossil record of environmentally-driven galaxy evolution. We propose to map the intr

  1. Growth and degradation of Hawaiian volcanoes: Chapter 3 in Characteristics of Hawaiian volcanoes (United States)

    Clague, David A.; Sherrod, David R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.


    The 19 known shield volcanoes of the main Hawaiian Islands—15 now emergent, 3 submerged, and 1 newly born and still submarine—lie at the southeast end of a long-lived hot spot chain. As the Pacific Plate of the Earth’s lithosphere moves slowly northwestward over the Hawaiian hot spot, volcanoes are successively born above it, evolve as they drift away from it, and eventually die and subside beneath the ocean surface.

  2. Toothpaste lava from the Barren Island volcano (Andaman Sea) (United States)

    Sheth, Hetu C.; Ray, Jyotiranjan S.; Kumar, Alok; Bhutani, Rajneesh; Awasthi, Neeraj


    Toothpaste lava is a basaltic lava flow type transitional between pahoehoe and aa and has been described from Paricutin, Kilauea and Etna volcanoes. Here we describe a spectacular example of toothpaste lava, forming part of a recent (possibly 1994-95) aa flow on the active volcano of Barren Island (Andaman Sea). This flow of subalkalic basalt shows abundant squeeze-ups of viscous toothpasate lava near its entry into the sea. The squeeze-ups are sheets and slabs, up to several meters across and tens of centimeters thick, extruded from boccas. They are often prominently curved, have striated upper surfaces with close-spaced, en echelon linear ridges and grooves, broad wave-like undulations perpendicular to the striations, and sometimes, clefts. Textural, geochemical, and Sr-Nd isotopic data on the squeeze-ups and the exposed aa flow core indicate very crystal-rich, viscous, and isotopically very homogeneous lava. We envisage that a greatly reduced speed of this viscous flow at the coastline, possibly aided by a shallowing of the basal slope, led to lateral spreading of the flow, which caused tension in its upper parts. This, with continued (albeit dwindling) lava supply at the back, led to widespread tearing of the flow surface and extrusion of the squeeze-ups. The larger slabs, while extruding in a plastic condition, curved under their own weight, whereas their surfaces experienced brittle deformation, forming the en echelon grooves. The extruded, detached, and rotated sheets and slabs were carried forward for some distance atop the very slowly advancing aa core, before the flow solidified.

  3. First recorded eruption of Nabro volcano, Eritrea, 2011. (United States)

    Goitom, Berhe; Oppenheimer, Clive; Hammond, James O S; Grandin, Raphaël; Barnie, Talfan; Donovan, Amy; Ogubazghi, Ghebrebrhan; Yohannes, Ermias; Kibrom, Goitom; Kendall, J-Michael; Carn, Simon A; Fee, David; Sealing, Christine; Keir, Derek; Ayele, Atalay; Blundy, Jon; Hamlyn, Joanna; Wright, Tim; Berhe, Seife

    We present a synthesis of diverse observations of the first recorded eruption of Nabro volcano, Eritrea, which began on 12 June 2011. While no monitoring of the volcano was in effect at the time, it has been possible to reconstruct the nature and evolution of the eruption through analysis of regional seismological and infrasound data and satellite remote sensing data, supplemented by petrological analysis of erupted products and brief field surveys. The event is notable for the comparative rarity of recorded historical eruptions in the region and of caldera systems in general, for the prodigious quantity of SO2 emitted into the atmosphere and the significant human impacts that ensued notwithstanding the low population density of the Afar region. It is also relevant in understanding the broader magmatic and tectonic significance of the volcanic massif of which Nabro forms a part and which strikes obliquely to the principal rifting directions in the Red Sea and northern Afar. The whole-rock compositions of the erupted lavas and tephra range from trachybasaltic to trachybasaltic andesite, and crystal-hosted melt inclusions contain up to 3,000 ppm of sulphur by weight. The eruption was preceded by significant seismicity, detected by regional networks of sensors and accompanied by sustained tremor. Substantial infrasound was recorded at distances of hundreds to thousands of kilometres from the vent, beginning at the onset of the eruption and continuing for weeks. Analysis of ground deformation suggests the eruption was fed by a shallow, NW-SE-trending dike, which is consistent with field and satellite observations of vent distributions. Despite lack of prior planning and preparedness for volcanic events in the country, rapid coordination of the emergency response mitigated the human costs of the eruption.

  4. Muons reveal the interior of volcanoes

    CERN Multimedia

    Francesco Poppi


    The MU-RAY project has the very challenging aim of providing a “muon X-ray” of the Vesuvius volcano (Italy) using a detector that records the muons hitting it after traversing the rock structures of the volcano. This technique was used for the first time in 1971 by the Nobel Prize-winner Louis Alvarez, who was searching for unknown burial chambers in the Chephren pyramid.   The location of the muon detector on the slopes of the Vesuvius volcano. Like X-ray scans of the human body, muon radiography allows researchers to obtain an image of the internal structures of the upper levels of volcanoes. Although such an image cannot help to predict ‘when’ an eruption might occur, it can, if combined with other observations, help to foresee ‘how’ it could develop and serves as a powerful tool for the study of geological structures. Muons come from the interaction of cosmic rays with the Earth's atmosphere. They are able to traverse layers of ro...

  5. The reawakening of Alaska's Augustine volcano (United States)

    Power, John A.; Nye, Christopher J.; Coombs, Michelle L.; Wessels, Rick L.; Cervelli, Peter F.; Dehn, Jon; Wallace, Kristi L.; Freymueller, Jeffrey T.; Doukas, Michael P.


    Augustine volcano, in south central Alaska, ended a 20-year period of repose on 11 January 2006 with 13 explosive eruptions in 20 days. Explosive activity shifted to a quieter effusion of lava in early February, forming a new summit lava dome and two short, blocky lava flows by late March (Figure 1).

  6. Volcano hazards at Fuego and Acatenango, Guatemala (United States)

    Vallance, J.W.; Schilling, S.P.; Matías, O.; Rose, William I.; Howell, M.M.


    The Fuego-Acatenango massif comprises a string of five or more volcanic vents along a north-south trend that is perpendicular to that of the Central American arc in Guatemala. From north to south known centers of volcanism are Ancient Acatenango, Yepocapa, Pico Mayor de Acatenango, Meseta, and Fuego. Volcanism along the trend stretches back more than 200,000 years. Although many of the centers have been active contemporaneously, there is a general sequence of younger volcanism, from north to south along the trend. This massive volcano complex towers more than 3500 meters (m) above the Pacific coastal plain to the south and 2000 m above the Guatemalan Highlands to the north. The volcano complex comprises remnants of multiple eruptive centers, which periodically have collapsed to form huge debris avalanches. The largest of these avalanches extended more than 50 kilometers (km) from its source and covered more than 300 square km. The volcano has potential to produce huge debris avalanches that could inundate large areas of the Pacific coastal plain. In areas around the volcanoes and downslope toward the coastal plain, more than 100,000 people are potentially at risk from these and other flowage phenomena.

  7. New volcanoes discovered in southeast Australia (United States)

    Wendel, JoAnna


    Scientists have discovered three new active volcanoes in the Newer Volcanics Province (NVP) in southeast Australia. Researchers from Monash University in Melbourne describe in the Australian Journal of Earth Sciences how they used a combination of satellite photographs, detailed topography models from NASA, the distribution of magnetic minerals in the rocks, and site visits to analyze the region.

  8. Exceptional fossil preservation and the cambrian explosion. (United States)

    Butterfield, Nicholas J


    Exceptionally preserved, non-biomineralizing fossils contribute importantly to resolving details of the Cambrian explosion, but little to its overall patterns. Six distinct "types" of exceptional preservation are identified for the terminal Proterozoic-Cambrian interval, each of which is dependent on particular taphonomic circumstances, typically restricted both in space and time. Taphonomic pathways yielding exceptional preservation were particularly variable through the Proterozoic-Cambrian transition, at least in part a consequence of contemporaneous evolutionary innovations. Combined with the reasonably continuous record of "Doushantuo-type preservation," and the fundamentally more robust records of shelly fossils, phytoplankton cysts and trace fossils, these taphonomic perturbations contribute to the documentation of major evolutionary and biogeochemical shifts through the terminal Proterozoic and early Cambrian.Appreciation of the relationship between taphonomic pathway and fossil expression serves as a useful tool for interpreting exceptionally preserved, often problematic, early Cambrian fossils. In shale facies, for example, flattened non-biomineralizing structures typically represent the remains of degradation-resistant acellular and extracellular "tissues" such as chaetae and cuticles, whereas three-dimensional preservation represents labile cellular tissues with a propensity for attracting and precipitating early diagenetic minerals. Such distinction helps to identify the acuticular integument of hyolithids, the chaetae-like nature of Wiwaxia sclerites, the chaetognath-like integument of Amiskwia, the midgut glands of various Burgess Shale arthropods, and the misidentification of deposit-feeding arthropods in the Chengjiang biota. By the same reasoning, putative lobopods in the Sirius Passet biota and putative deuterostomes in the Chengiang biota are better interpreted as arthropods.

  9. Hazard maps of Colima volcano, Mexico (United States)

    Suarez-Plascencia, C.; Nunez-Cornu, F. J.; Escudero Ayala, C. R.


    Colima volcano, also known as Volcan de Fuego (19° 30.696 N, 103° 37.026 W), is located on the border between the states of Jalisco and Colima and is the most active volcano in Mexico. Began its current eruptive process in February 1991, in February 10, 1999 the biggest explosion since 1913 occurred at the summit dome. The activity during the 2001-2005 period was the most intense, but did not exceed VEI 3. The activity resulted in the formation of domes and their destruction after explosive events. The explosions originated eruptive columns, reaching attitudes between 4,500 and 9,000 m.a.s.l., further pyroclastic flows reaching distances up to 3.5 km from the crater. During the explosive events ash emissions were generated in all directions reaching distances up to 100 km, slightly affected nearby villages as Tuxpan, Tonila, Zapotlán, Cuauhtemoc, Comala, Zapotitlan de Vadillo and Toliman. During the 2005 this volcano has had an intense effusive-explosive activity, similar to the one that took place during the period of 1890 through 1900. Intense pre-plinian eruption in January 20, 1913, generated little economic losses in the lower parts of the volcano due to low population density and low socio-economic activities at the time. Shows the updating of the volcanic hazard maps published in 2001, where we identify whit SPOT satellite imagery and Google Earth, change in the land use on the slope of volcano, the expansion of the agricultural frontier on the east and southeast sides of the Colima volcano, the population inhabiting the area is approximately 517,000 people, and growing at an annual rate of 4.77%, also the region that has shown an increased in the vulnerability for the development of economic activities, supported by the construction of highways, natural gas pipelines and electrical infrastructure that connect to the Port of Manzanillo to Guadalajara city. The update the hazard maps are: a) Exclusion areas and moderate hazard for explosive events

  10. Investigation of Fossil Insect Systematics of Specimens Collected at the Clare Quarry Site in the Florissant Fossil Beds, Florissant, Colorado from 1996 to Present (United States)

    Cancellare, J. A.; Villalobos, J. I.; Lemone, D.


    The Clare Quarry is located in the town of Florissant, Teller County, Colorado, approximately 30 miles west of Colorado Springs on State Highway 27. The elevation at the quarry face is 2500 meters ASL. Ar40/Ar39 dating of the upper beds of the Florissant Formation indicates an age of 34.07 +/- 0.10 Ma.An Oreodont fossil jaw and other mammalian fossils place the formation in the Chadronian Age.The basin in which the formation lies is undergirded by Wall Mountain Tuff dated at 37Ma, which sits on Pike's Peak Granite, which is dated at1080 Ma. In the Late Eocene the Florissant region was lacustrine in nature due to the damning of the river valley which runs north into Florissant. The ash and lahars from volcanic eruptions from the Thirty-nine Mile Volcano Field formed impoundments that produced shallow lakes for what is thought to been a period for 5000 years. Repeated ash falls placed plant matter and insect material in the lakes and streams that were formed intermittently during the period. The ash layers in the Florissant Formation are very fine grained, and contain diatomaceous mats that formed on the lake deposited ash layers aiding in the preservation of plant and insects material. Previous work on Florissant Fossils has been done by Lesquereaux (plants) 1878, Scudder (insects) 1890, and Mc Ginitie (plants) 1953. This project began 17 years ago and has consisted of collection trips ranging from one to eight days in the summers at a proprietary quarry owned land adjacent to The Florissant Fossil Beds National Monument. The collection consists of 2700 catalogued plants, insects, and fish fossils. Of this number, 513 are insect fossils (19% of the total collection). Quality of preservation ranges from very poor to very good with the average qualitative evaluation between poor to fair. The largest series identied to family are Tipulids (Craneflies) with 23 specimens in the series. In this series wing venation is often incomplete and smaller characters including

  11. An early Oligocene fossil demonstrates treeshrews are slowly evolving "living fossils". (United States)

    Li, Qiang; Ni, Xijun


    Treeshrews are widely considered a "living model" of an ancestral primate, and have long been called "living fossils". Actual fossils of treeshrews, however, are extremely rare. We report a new fossil species of Ptilocercus treeshrew recovered from the early Oligocene (~34 Ma) of China that represents the oldest definitive fossil record of the crown group of treeshrews and nearly doubles the temporal length of their fossil record. The fossil species is strikingly similar to the living Ptilocercus lowii, a species generally recognized as the most plesiomorphic extant treeshrew. It demonstrates that Ptilocercus treeshrews have undergone little evolutionary change in their morphology since the early Oligocene. Morphological comparisons and phylogenetic analysis support the long-standing idea that Ptilocercus treeshrews are morphologically conservative and have probably retained many characters present in the common stock that gave rise to archontans, which include primates, flying lemurs, plesiadapiforms and treeshrews. This discovery provides an exceptional example of slow morphological evolution in a mammalian group over a period of 34 million years. The persistent and stable tropical environment in Southeast Asia through the Cenozoic likely played a critical role in the survival of such a morphologically conservative lineage.

  12. The First Observation on Plant Cell Fossils in China

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; CUI Jinzhong


    For a long time, paleontologists have been focusing on hard parts of organisms during different geological periods while soft parts are rarely reported. Well-preserved plant cells, if found in fossils, are treated only as a rarity. Recent progress in research on fossil cytoplasm indicates that plant cytoplasm not only has excellent ultrastructures preserved but also may be a quite commonly seen fossil in strata. However, up to now there is no report of plant cell fossils in China yet. Here plant cell fossils are reported from Huolinhe Coal Mine (the early Cretaceous), Inner Mongolia, China. The presence of plant cytoplasm fossils in two cones on the same specimen not only provides further support for the recently proposed hypothesis on plant cytoplasm fossilization but also marks the first record of plant cytoplasm fossils in China, which suggests a great research potential in this new area.

  13. [Raman spectra of fossil dinosaurs from different regions]. (United States)

    Yang, Qun; Wang, Yi-lin


    Raman microscopic spectra in the higher wave number region were obtained from 7 fossil dinosaurs specimens from different regions. The specimens of fossil dinosaurs are different parts of bone. The Raman spectra of fossil dinosaurs indicate the high similarity among peak positions of different fossil dinosaurs; but important differences exist in the spectral peak figures. In the wave number region of 1000-1800 cm(-1) the Raman spectra of the same bone part fossils from different regions are very similar, example similarities between spectra of Lufeing backbone head and Yua nmou backbone head; Lufeng limb bone and Wuding limb bone. There are relations between the same bone part spectra of different fossil dinosaurs. The characteristic does not relate to regions. Raman spectra of fossil dinosaurs cannot be used to distinguish fossil source, although the part of bone can be used as an indicator to narrow the range of possible geographical origins.

  14. First known fossil bird tracks on San Salvador island, Bahamas

    National Research Council Canada - National Science Library

    Martin, A.J; Whitten, M.J


    ...) are the first known vertebrate trace fossils on this well-studied island. The trace fossils, preserved as bedding-plane impressions in an oolitic-bioclastic grainstone, match the size and form of tracks made by modern gulls...

  15. Fossils and palaeontological distributions of Macaranga and Mallotus (Euphorbiaceae)

    NARCIS (Netherlands)

    Nucete, M.; van Konijnenburg-van Cittert, J.H.A.; van Welzen, P.C.


    The correct identification of described plant fossils from the sister genera Macaranga and Mallotus (Euphorbiaceae) needs to be confirmed in order to correctly date their phylogeny and map their palaeontological distributions. Previous identifications of fossil specimens often appear to be

  16. New insights into the evolution of the magmatic system of a composite andesite volcano revealed by clasts from distal mass-flow deposits: Ruapehu volcano, New Zealand (United States)

    Tost, M.; Price, R. C.; Cronin, S. J.; Smith, I. E. M.


    Stratovolcanoes characteristically build large composite edifices over long periods with stacked lavas intercalated with pyroclastic deposits. In most cases, only the most recent volcanic products are exposed on the flanks of the volcano, and consequently the search for deposits recording an older eruptive and magmatic history is typically focussed far from the cone, within distal tephra deposits. Clasts within lahar and debris avalanche deposits may also provide unique insights into the earliest eruptive and magmatic history of long-lived volcanoes, especially when widespread fallout is absent. Careful sampling and subsequent petrological and geochemical analyses of lava and pumice clasts from six distal mass-flow deposit sequences (hyperconcentrated flow, debris flows and debris avalanche deposits) from Mt. Ruapehu (New Zealand), combined with detailed stratigraphic studies and radiometric age dating, give new perspectives on the pre-50 ka magmatic system of this complex volcano. A conglomerate emplaced between 340 and 310 ka contains evidence for the oldest episode of Mt. Ruapehu volcanism, and unusually for the composite cone, pumice clasts from this unit contain amphibole-bearing xenoliths. Chemical and petrological data for these oldest Ruapehu clasts indicate that a deep (˜40 km) crustal storage system had already developed under Mt. Ruapehu before ˜340 ka. From the very earliest stages, evolution was largely controlled by magma mixing, along with decoupled assimilation and fractional crystallization within numerous isolated small-scale magma batches stored throughout the crust. From around 340 to 160 ka, there was a progressive shift towards more primitive compositions, suggesting that during this period large-scale replenishment events involving mantle-derived basaltic magmas occurred within the mid- to upper crustal storage system. Subsequent magmas became progressively more evolved due to decoupled fractional crystallization and assimilation processes

  17. Quaternary fossil fauna from the Luangwa Valley, Zambia.


    Bishop, LC; Barham, LS; Ditchfield, P.; Elton, S; Harcourt-Smith, WH; Dawkins, P


    This paper describes a large collection of Quaternary fossil fauna from the Luangwa rift valley, Zambia. Stone Age artefacts have been recovered from stratified fluvial contexts, but no in situ fossil fauna have yet been recovered. We report on 500 fossil specimens collected from the surface of point bars exposed seasonally along the banks of the main Luangwa river channel. We used non-destructive x-ray fluorescence analysis of the fossils' chemical signatures to determine whether they derive...

  18. Pleistocene to recent alkalic volcanism in the region of Sanganguey volcano, Nayarit, Mexico (United States)

    Nelson, S. A.; Carmichael, I. S. E.


    Forty five cinder cones and associated lava flows have erupted within the last 300,000 years along five parallel lines through the calc-alkaline volcano, Sanganguey, in the northwestern segment of the Mexican Volcanic Belt. Lavas erupted from these cinder cones include ne- and hynormative alkali basalts, hawaiites, mugearites, and benmoreites. It is unusual that this suite has erupted in a calc-aikaline volcanic belt where volcanoes in the vicinity have been erupting calc-alkaline andesites, dacites and rhyodacites. Incompatible trace elements such Ba, Rb, Sr, and LREEs show little change with decreasing Mg, Ni, and Cr in the series alkali basalt to hawaiite, suggesting that simple crystal fractionation of observed phenocrysts has not been the dominant process in the derivation of the hawaiites from the alkali basalts. Petrographic evidence of magma mixing along with observed variation of trace element abundances suggests that the alkali basalts might represent mixtures of primitive magma with more evolved compositions. Crystal fractionation is capable of explaining major and most trace element trends in the series hawaiite — mugearite — benmoreite. However, such a process could only occur at pressure because of the requirement that clinopyroxene be a major crystallizing phase. The anomolous association of alkaline magmatism contemporaneously with calc-alkaline magmatism is probably related to the complex tectonic history associated with the rearrangement of plate boundaries in the vicinity of western Mexico.

  19. Space Radar Image of Colombian Volcano (United States)


    This is a radar image of a little known volcano in northern Colombia. The image was acquired on orbit 80 of space shuttle Endeavour on April 14, 1994, by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The volcano near the center of the image is located at 5.6 degrees north latitude, 75.0 degrees west longitude, about 100 kilometers (65 miles) southeast of Medellin, Colombia. The conspicuous dark spot is a lake at the bottom of an approximately 3-kilometer-wide (1.9-mile) volcanic collapse depression or caldera. A cone-shaped peak on the bottom left (northeast rim) of the caldera appears to have been the source for a flow of material into the caldera. This is the northern-most known volcano in South America and because of its youthful appearance, should be considered dormant rather than extinct. The volcano's existence confirms a fracture zone proposed in 1985 as the northern boundary of volcanism in the Andes. The SIR-C/X-SAR image reveals another, older caldera further south in Colombia, along another proposed fracture zone. Although relatively conspicuous, these volcanoes have escaped widespread recognition because of frequent cloud cover that hinders remote sensing imaging in visible wavelengths. Four separate volcanoes in the Northern Andes nations ofColombia and Ecuador have been active during the last 10 years, killing more than 25,000 people, including scientists who were monitoring the volcanic activity. Detection and monitoring of volcanoes from space provides a safe way to investigate volcanism. The recognition of previously unknown volcanoes is important for hazard evaluations because a number of major eruptions this century have occurred at mountains that were not previously recognized as volcanoes. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of

  20. The fossil trade: paying a price for human origins

    DEFF Research Database (Denmark)


    Fossils have been traded for centuries. Over the past two hundred years the market has developed into an organised enterprise with fossils serving multiple functions as scientific objects of study, collectors’ items and investments. Finding fossils, digging them up or purchasing them, transporting...

  1. Probe into the Internal Mechanism of Interlanguage Fossilization (United States)

    Huang, Qian


    Interlanguage fossilization is normal for second language acquisition. It is also a hotspot for studies on theory of foreign language acquisition. Many reasons cause the interlanguage fossilization. This paper probes into the internal mechanism of interlanguage fossilization from five aspects, namely the physiological aspect, the psychological…

  2. Early Archean serpentine mud volcanoes at Isua, Greenland, as a niche for early life. (United States)

    Pons, Marie-Laure; Quitté, Ghylaine; Fujii, Toshiyuki; Rosing, Minik T; Reynard, Bruno; Moynier, Frederic; Douchet, Chantal; Albarède, Francis


    The Isua Supracrustal Belt, Greenland, of Early Archean age (3.81-3.70 Ga) represents the oldest crustal segment on Earth. Its complex lithology comprises an ophiolite-like unit and volcanic rocks reminiscent of boninites, which tie Isua supracrustals to an island arc environment. We here present zinc (Zn) isotope compositions measured on serpentinites and other rocks from the Isua supracrustal sequence and on serpentinites from modern ophiolites, midocean ridges, and the Mariana forearc. In stark contrast to modern midocean ridge and ophiolite serpentinites, Zn in Isua and Mariana serpentinites is markedly depleted in heavy isotopes with respect to the igneous average. Based on recent results of Zn isotope fractionation between coexisting species in solution, the Isua serpentinites were permeated by carbonate-rich, high-pH hydrothermal solutions at medium temperature (100-300 °C). Zinc isotopes therefore stand out as a pH meter for fossil hydrothermal solutions. The geochemical features of the Isua fluids resemble the interstitial fluids sampled in the mud volcano serpentinites of the Mariana forearc. The reduced character and the high pH inferred for these fluids make Archean serpentine mud volcanoes a particularly favorable setting for the early stabilization of amino acids.

  3. Common processes at unique volcanoes – a volcanological conundrum

    Directory of Open Access Journals (Sweden)

    Katharine eCashman


    Full Text Available An emerging challenge in modern volcanology is the apparent contradiction between the perception that every volcano is unique, and classification systems based on commonalities among volcano morphology and eruptive style. On the one hand, detailed studies of individual volcanoes show that a single volcano often exhibits similar patterns of behaviour over multiple eruptive episodes; this observation has led to the idea that each volcano has its own distinctive pattern of behaviour (or personality. In contrast, volcano classification schemes define eruption styles referenced to type volcanoes (e.g. Plinian, Strombolian, Vulcanian; this approach implicitly assumes that common processes underpin volcanic activity and can be used to predict the nature, extent and ensuing hazards of individual volcanoes. Actual volcanic eruptions, however, often include multiple styles, and type volcanoes may experience atypical eruptions (e.g., violent explosive eruptions of Kilauea, Hawaii1. The volcanological community is thus left with a fundamental conundrum that pits the uniqueness of individual volcanic systems against generalization of common processes. Addressing this challenge represents a major challenge to volcano research.

  4. Crystals in crystals

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Schmidt, I.; Carlsson, A.;


    A major factor governing the performance of catalytically active particles supported on a zeolite carrier is the degree of dispersion. It is shown that the introduction of noncrystallographic mesopores into zeolite single crystals (silicalite-1, ZSM-5) may increase the degree of particle dispersion...... of the zeolite particles, particularly after thermal treatment. When using mesoporous zeolites, the particles were evenly distributed throughout the mesopore system of the zeolitic support, even after calcination, leading to nanocrystals within mesoporous zeolite single crystals....

  5. Stromboli volcano (Aeolian Archipelago, Italy): An open window on the deep-feeding system of a steady state basaltic volcano (United States)

    Bertagnini, A.; MéTrich, N.; Landi, P.; Rosi, M.


    Paroxysms at Stromboli are the most violent manifestations of the persistent activity and are related to the emission of small volumes (103-105 m3) of nearly aphyric HK-basaltic pumices. They offer the exceptional opportunity to detail the mixing-crystallization-degassing processes that occur in a steady state basaltic arc volcano. We present mineralogy, major, volatile, and trace element geochemistry of olivine-hosted melt inclusions of these pumices. In all the paroxysms, melt inclusions hosted in olivines Fo88-91 have recorded the parental melts rich in CaO (up to 14.5 wt %) but low in FeO (6-7 wt %). They demonstrate recurrent variations in the K2O content (1.6-1.3 wt %) and S/Cl ratios (1.2-0.8) of the melts that entered the deep system. Dynamic magma mixing between melts slightly distinct by their degree of evolution, rapid crystallization, and entrapment of gas-oversaturated melts during decompression are indicated by (1) the high density of irregular, clear melt inclusions, and embayments in homogeneous olivines (Fo87±0.5-Fo83±0.5), (2) the variable ratio between melt and gas bubble, and (3) the variability of melt inclusion compositions in both major (CaO/Al2O3 = 1-0.59) and volatile (3.4-1.8 wt % H2O, 1582-1017 ppm CO2) elements. FeO-rich melt inclusions in patchy, reversely zoned olivines also demonstrate interactions between ascending melt blobs and inherited olivine crystals. We propose a model involving a vertically extended dike-like system, where magmas progress and differentiate. On the basis of olivine growth rate calculations the volatile-rich magma blobs may ascend within few hours to few tenths of hours. Finally, we propose that sulfur degassing is possibly initiated during the early stage of magma differentiation.

  6. Danmarks Største Fossiler

    DEFF Research Database (Denmark)

    Lindow, Bent Erik Kramer; Cuny, Gilles Guy Roger


    For 8 millioner år siden myldrede Nordsøen af en mangfoldighed af hajer, hvaler, havskildpadder og sæler, mange flere end i dag. Blandt dem finder man Danmarks største fossiler som er udstillet på Museum Sønderjylland - Naturhistorie og Palæontologi i Gram.......For 8 millioner år siden myldrede Nordsøen af en mangfoldighed af hajer, hvaler, havskildpadder og sæler, mange flere end i dag. Blandt dem finder man Danmarks største fossiler som er udstillet på Museum Sønderjylland - Naturhistorie og Palæontologi i Gram....

  7. Cassini State Transitions with a Fossil Figure (United States)

    Matsuyama, Isamu; Tuttle Keane, James


    The Moon has experienced large obliquity variations during Cassini state transitions which greatly impact tidal heating, and the long-term stability of polar volatiles. It has been known for centuries that the lunar rotational and tidal bulges are much larger than expected. The South Pole-Aitken basin can explain a large fraction of the excess deformation. Accounting for the contribution of this basin (and other large basins), the remaining excess deformation arises due to a fossil figure established when the Moon orbited much closer to Earth than it does today. Previous studies assume that the present, excess deformation is entirely preserved throughout Cassini state transitions. This ignores basin contributions to the excess deformation, and requires an interior with infinite rigidity. We consider Cassini state transition models that take into account basin contributions to the excess deformation, and the effect of finite rigidity on the fossil figure.

  8. Fossil energy waste management. Technology status report

    Energy Technology Data Exchange (ETDEWEB)

    Bossart, S.J.; Newman, D.A.


    This report describes the current status and recent accomplishments of the Fossil Energy Waste Management (FE WM) projects sponsored by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The primary goal of the Waste Management Program is to identify and develop optimal strategies to manage solid by-products from advanced coal technologies for the purpose of ensuring the competitiveness of advanced coal technologies as a future energy source. The projects in the Fossil Energy Waste Management Program are divided into three types of activities: Waste Characterization, Disposal Technologies, and Utilization Technologies. This technology status report includes a discussion on barriers to increased use of coal by-products. Also, the major technical and nontechnical challenges currently being addressed by the FE WM program are discussed. A bibliography of 96 citations and a list of project contacts is included if the reader is interested in obtaining additional information about the FE WM program.

  9. Fossil Biodiversity: Red Noise Plus Signal

    CERN Document Server

    Melott, A L; Melott, Adrian L.; Lieberman, Bruce S.


    We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^5 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

  10. Diatoms: a fossil fuel of the future. (United States)

    Levitan, Orly; Dinamarca, Jorge; Hochman, Gal; Falkowski, Paul G


    Long-term global climate change, caused by burning petroleum and other fossil fuels, has motivated an urgent need to develop renewable, carbon-neutral, economically viable alternatives to displace petroleum using existing infrastructure. Algal feedstocks are promising candidate replacements as a 'drop-in' fuel. Here, we focus on a specific algal taxon, diatoms, to become the fossil fuel of the future. We summarize past attempts to obtain suitable diatom strains, propose future directions for their genetic manipulation, and offer biotechnological pathways to improve yield. We calculate that the yields obtained by using diatoms as a production platform are theoretically sufficient to satisfy the total oil consumption of the US, using between 3 and 5% of its land area. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Decarbonisation of fossil energy via methane pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kreysa, G.; Agar, D.W.; Schultz, I. [Technische Univ. Dortmund (Germany)


    Despite the rising consumption of energy over the last few decades, the proven reserves of fossil fuels have steadily increased. Additionally, there are potentially tremendous reserves of methane hydrates available, which remain to be exploited. The use of fossil energy sources is thus increasingly being dictated less by supply than by the environmental concerns raised by climate change. In the context of the decarbonisation of the global energy system that this has stimulated, new means must be explored for using methane as energy source. Noncatalytic thermal pyrolysis of methane is proposed here as a promising concept for utilising methane with low to zero carbon dioxide emissions. Following cracking, only the energy content of the hydrogen is used, while the carbon can be stored safely and retrievably in disused coal mines. The thermodynamics and different process engineering concepts for the technical realisation of such a carbon moratorium technology are discussed. The possible contribution of methane pyrolysis to carbon negative geoengineering is also addressed. (orig.)

  12. Future Fossil Fuel Alternative; DME (A review)


    Erdener, Hülya; Arinan, Ayca; Orman, Sultan


    The world energy consumption is steadily growing with the industrial improvements of the developing countries and the readily available fossil fuel reserves lack in fulfilling this energy requirement. The depletion of the easily achievable reserves; gives rise to the concept of oil production from oil shale and tar sands. However, the high cost and the operational difficulties stand as the major drawbacks in front of these technologies. Along with these circumstances, and the environmental co...

  13. Adaptation, plant evolution, and the fossil record (United States)

    Knoll, A. H.; Niklas, K. J.


    The importance of adaptation in determining patterns of evolution has become an important focus of debate in evolutionary biology. As it pertains to paleobotany, the issue is whether or not adaptive evolution mediated by natural selection is sufficient to explain the stratigraphic distributions of taxa and character states observed in the plant fossil record. One means of addressing this question is the functional evaluation of stratigraphic series of plant organs set in the context of paleoenvironmental change and temporal patterns of floral composition within environments. For certain organ systems, quantitative estimates of biophysical performance can be made on the basis of structures preserved in the fossil record. Performance estimates for plants separated in time or space can be compared directly. Implicit in different hypotheses of the forces that shape the evolutionary record (e.g. adaptation, mass extinction, rapid environmental change, chance) are predictions about stratigraphic and paleoenvironmental trends in the efficacy of functional performance. Existing data suggest that following the evolution of a significant structural innovation, adaptation for improved functional performance can be a major determinant of evolutionary changes in plants; however, there are structural and development limits to functional improvement, and once these are reached, the structure in question may no longer figure strongly in selection until and unless a new innovation evolves. The Silurian-Devonian paleobotanical record is consistent with the hypothesis that the succession of lowland floodplain dominants preserved in the fossil record of this interval was determined principally by the repeated evolution of new taxa that rose to ecological importance because of competitive advantages conferred by improved biophysical performance. This does not seem to be equally true for Carboniferous-Jurassic dominants of swamp and lowland floodplain environments. In these cases

  14. The phylogeny of fossil whip spiders. (United States)

    Garwood, Russell J; Dunlop, Jason A; Knecht, Brian J; Hegna, Thomas A


    Arachnids are a highly successful group of land-dwelling arthropods. They are major contributors to modern terrestrial ecosystems, and have a deep evolutionary history. Whip spiders (Arachnida, Amblypygi), are one of the smaller arachnid orders with ca. 190 living species. Here we restudy one of the oldest fossil representatives of the group, Graeophonus anglicus Pocock, 1911 from the Late Carboniferous (Duckmantian, ca. 315 Ma) British Middle Coal Measures of the West Midlands, UK. Using X-ray microtomography, our principal aim was to resolve details of the limbs and mouthparts which would allow us to test whether this fossil belongs in the extant, relict family Paracharontidae; represented today by a single, blind species Paracharon caecus Hansen, 1921. Tomography reveals several novel and significant character states for G. anglicus; most notably in the chelicerae, pedipalps and walking legs. These allowed it to be scored into a phylogenetic analysis together with the recently described Paracharonopsis cambayensis Engel & Grimaldi, 2014 from the Eocene (ca. 52 Ma) Cambay amber, and Kronocharon prendinii Engel & Grimaldi, 2014 from Cretaceous (ca. 99 Ma) Burmese amber. We recovered relationships of the form ((Graeophonus (Paracharonopsis + Paracharon)) + (Charinus (Stygophrynus (Kronocharon (Charon (Musicodamon + Paraphrynus)))))). This tree largely reflects Peter Weygoldt's 1996 classification with its basic split into Paleoamblypygi and Euamblypygi lineages; we were able to score several of his characters for the first time in fossils. Our analysis draws into question the monophyly of the family Charontidae. Our data suggest that Graeophonus is a crown group amblypygid, and falls within a monophyletic Paleoamblypgi clade, but outside the family Paracharontidae (= Paracharonopsis + Paracharon). Our results also suggest a new placement for the Burmese amber genus Kronocharon, a node further down from its original position. Overall, we offer a

  15. History of Red Crater volcano, Tongariro Volcanic Centre (New Zealand): Abrupt shift in magmatism following recharge and contrasting evolution between neighboring volcanoes (United States)

    Shane, Phil; Maas, Roland; Lindsay, Jan


    Red Crater volcano is one of several contemporaneously active vents on the Tongariro Volcanic Centre. Its history provides an opportunity to investigate the contrasting magmatic evolutionary paths of closely-spaced volcanoes. Rocks erupted at Red Crater over the last 3.4 ka display typical subduction-related trace element and isotopic signatures. Those erupted pre-1.8 ka are medium-K andesites (SiO2 59-62 wt%). They represent the most voluminous magmas and were emplaced in 5 lava flow events. An abrupt shift to the eruption of basaltic andesite (SiO2 53-54 wt%) with less radiogenic Sr-Nd-Pb isotope ratios, occurred post-1.8 ka. This period comprised 6 smaller volume, lava flow episodes and the contemporaneous development of a scoria cone. Plagioclase phenocrysts in post-1.8 ka lava flows have resorbed cores with diverse textural and compositional growth patterns, as would be expected from the disruption of a crystal mush. They are similar to phenocrysts of the pre-1.8 ka lava flows. The post-1.8 ka plagioclase is distinguished from those in the older lavas by overgrowths with elevated An ( 70-90), FeO and MgO contents, that mantle the resorbed cores ( An50-70). These rims are compositionally similar to groundmass plagioclase. This demonstrates that new mafic magma was intruded into the system, mixing with and entraining relic crystals from the older andesite system. Iron and Mg zoning patterns in the crystals are not consistent with significant re-equilibration via diffusion. Hence, the generation of eruptible magma during the last 1.8 ka required repeated mafic intrusion events. The emptying of the older andesitic magma reservoir early in the volcano's history removed buoyancy barriers to the direct eruption of more mafic magmas. This pattern of magmatism is not recorded at the contemporaneously active Ngauruhoe volcano, just 3 km to the SSW. Ngauruhoe rocks are compositionally distinct and are more heterogeneous in isotopic composition. Although mafic recharge is

  16. The Properties of Fossil Groups of Galaxies

    CERN Document Server

    Eigenthaler, Paul


    Numerical simulations as well as optical and X-ray observations over the last few years have shown that poor groups of galaxies can evolve to what is called a fossil group. Dynamical friction as the driving process leads to the coalescence of individual galaxies in ordinary poor groups leaving behind nothing more than a central, massive elliptical galaxy supposed to contain the merger history of the whole group. Due to merging timescales for less-massive galaxies and gas cooling timescales of the X-ray intragroup medium exceeding a Hubble time, a surrounding faint-galaxy population having survived this galactic cannibalism as well as an extended X-ray halo similar to that found in ordinary groups, is expected. Recent studies suggest that fossil groups are very abundant and could be the progenitors of brightest cluster galaxies (BCGs) in the centers of rich galaxy clusters. However, only a few objects are known to the literature. This article aims to summarize the results of observational fossil group research...

  17. Fossil harvestmen (Arachnida, Opiliones from Bitterfeld amber

    Directory of Open Access Journals (Sweden)

    Jason Dunlop


    Full Text Available Fossil harvestmen (Arachnida: Opiliones: Dyspnoi and Eupnoi are described from Bitterfeld amber, Sachsen-Anhalt, Germany deposited in the Museum für Naturkunde, Berlin. The exact age of this amber has been in dispute, but recent work suggests it is youngest Palaeogene (Oligocene: Chattian. Histricostoma tuberculatum (Koch & Berendt, 1854, Caddo dentipalpus (Koch & Berendt, 1854, Dicranopalpus ramiger (Koch & Berendt, 1854 and Leiobunum longipes Menge, 1854 – all of which are also known from Eocene Baltic amber – are reported from Bitterfeld amber for the first time. They support the idea that both ambers sampled a similar terrestrial arthropod fauna: irrespective of any difference in age. Mitostoma gruberi sp. n. and Amilenus deltshevi sp. n. are described as new. One fossil is, in our opinion, morphologically indistinguishable from the extant species Lacinius erinaceus Staręga, 1966 from the Caucuses, and is tentatively assigned to this taxon. The Bitterfeld material thus includes the first fossil record of the extant genera Amilenus Martens, 1969 and Lacinius Thorell, 1876 respectively.

  18. Darwin's triggering mechanism of volcano eruptions (United States)

    Galiev, Shamil


    Charles Darwin wrote that ‘… the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock;…' and ‘…a power, I may remark, which acts in paroxysmal upheavals like that of Concepcion, and in great volcanic eruptions,…'. Darwin reports that ‘…several of the great chimneys in the Cordillera of central Chile commenced a fresh period of activity ….' In particular, Darwin reported on four-simultaneous large eruptions from the following volcanoes: Robinson Crusoe, Minchinmavida, Cerro Yanteles and Peteroa (we cite the Darwin's sentences following his The Voyage of the Beagle and researchspace. auckland. ac. nz/handle/2292/4474). Let us consider these eruptions taking into account the volcano shape and the conduit. Three of the volcanoes (Minchinmavida (2404 m), Cerro Yanteles (2050 m), and Peteroa (3603 m)) are stratovolcanos and are formed of symmetrical cones with steep sides. Robinson Crusoe (922 m) is a shield volcano and is formed of a cone with gently sloping sides. They are not very active. We may surmise, that their vents had a sealing plug (vent fill) in 1835. All these volcanoes are conical. These common features are important for Darwin's triggering model, which is discussed below. The vent fill material, usually, has high level of porosity and a very low tensile strength and can easily be fragmented by tension waves. The action of a severe earthquake on the volcano base may be compared with a nuclear blast explosion of the base. It is known, that after a underground nuclear explosion the vertical motion and the surface fractures in a tope of mountains were observed. The same is related to the propagation of waves in conical elements. After the explosive load of the base. the tip may break and fly off at high velocity. Analogous phenomenon may be generated as a result of a

  19. A Benthic Invertebrate Survey of Jun Jaegyu Volcano: An active undersea volcano in Antarctic Sound, Antarctica (United States)

    Quinones, G.; Brachfeld, S.; Gorring, M.; Prezant, R. S.; Domack, E.


    Jun Jaegyu volcano, an Antarctic submarine volcano, was dredged in May 2004 during cruise 04-04 of the RV Laurence M. Gould to determine rock, sediment composition and marine macroinvertebrate diversity. The objectives of this study are to examine the benthic assemblages and biodiversity present on a young volcano. The volcano is located on the continental shelf of the northeastern Antarctic Peninsula, where recent changes in surface temperature and ice shelf stability have been observed. This volcano was originally swath-mapped during cruise 01-07 of the Research Vessel-Ice Breaker Nathaniel B. Palmer. During LMG04-04 we also studied the volcano using a SCUD video camera, and performed temperature surveys along the flanks and crest. Both the video and the dredge indicate a seafloor surface heavily colonized by benthic organisms. Indications of fairly recent lava flows are given by the absence of marine life on regions of the volcano. The recovered dredge material was sieved, and a total of thirty-three invertebrates were extracted. The compilation of invertebrate community data can subsequently be compared to other benthic invertebrate studies conducted along the peninsula, which can determine the regional similarity of communities over time, their relationship to environmental change and health, if any, and their relationship to geologic processes in Antarctic Sound. Twenty-two rock samples, all slightly weathered and half bearing encrusted organisms, were also analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES). Except for one conglomerate sample, all are alkali basalts and share similar elemental compositions with fresh, unweathered samples from the volcano. Two of the encrusted basalt samples have significantly different compositions than the rest. We speculate this difference could be due to water loss during sample preparation, loss of organic carbon trapped within the vesicles of the samples and/or elemental uptake by the

  20. Calcification and Silicification: Fossilization Potential of Cyanobacteria from Stromatolites of Niuafo‘ou's Caldera Lakes (Tonga) and Implications for the Early Fossil Record (United States)

    Kazmierczak, Józef; Łukomska-Kowalczyk, Maja; Kempe, Stephan


    Abstract Calcification and silicification processes of cyanobacterial mats that form stromatolites in two caldera lakes of Niuafo‘ou Island (Vai Lahi and Vai Si‘i) were evaluated, and their importance as analogues for interpreting the early fossil record are discussed. It has been shown that the potential for morphological preservation of Niuafo‘ou cyanobacteria is highly dependent on the timing and type of mineral phase involved in the fossilization process. Four main modes of mineralization of cyanobacteria organic parts have been recognized: (i) primary early postmortem calcification by aragonite nanograins that transform quickly into larger needle-like crystals and almost totally destroy the cellular structures, (ii) primary early postmortem silicification of almost intact cyanobacterial cells that leave a record of spectacularly well-preserved cellular structures, (iii) replacement by silica of primary aragonite that has already recrystallized and obliterated the cellular structures, (iv) occasional replacement of primary aragonite precipitated in the mucopolysaccharide sheaths and extracellular polymeric substances by Al-Mg-Fe silicates. These observations suggest that the extremely scarce earliest fossil record may, in part, be the result of (a) secondary replacement by silica of primary carbonate minerals (aragonite, calcite, siderite), which, due to recrystallization, had already annihilated the cellular morphology of the mineralized microbiota or (b) relatively late primary silicification of already highly degraded and no longer morphologically identifiable microbial remains. Key Words: Stromatolites—Cyanobacteria—Calcification—Silicification—Niuafo‘ou (Tonga)—Archean. Astrobiology 12, 535–548. PMID:22794297

  1. Calcification and silicification: fossilization potential of cyanobacteria from stromatolites of Niuafo'ou's Caldera Lakes (Tonga) and implications for the early fossil record. (United States)

    Kremer, Barbara; Kazmierczak, Józef; Lukomska-Kowalczyk, Maja; Kempe, Stephan


    Calcification and silicification processes of cyanobacterial mats that form stromatolites in two caldera lakes of Niuafo'ou Island (Vai Lahi and Vai Si'i) were evaluated, and their importance as analogues for interpreting the early fossil record are discussed. It has been shown that the potential for morphological preservation of Niuafo'ou cyanobacteria is highly dependent on the timing and type of mineral phase involved in the fossilization process. Four main modes of mineralization of cyanobacteria organic parts have been recognized: (i) primary early postmortem calcification by aragonite nanograins that transform quickly into larger needle-like crystals and almost totally destroy the cellular structures, (ii) primary early postmortem silicification of almost intact cyanobacterial cells that leave a record of spectacularly well-preserved cellular structures, (iii) replacement by silica of primary aragonite that has already recrystallized and obliterated the cellular structures, (iv) occasional replacement of primary aragonite precipitated in the mucopolysaccharide sheaths and extracellular polymeric substances by Al-Mg-Fe silicates. These observations suggest that the extremely scarce earliest fossil record may, in part, be the result of (a) secondary replacement by silica of primary carbonate minerals (aragonite, calcite, siderite), which, due to recrystallization, had already annihilated the cellular morphology of the mineralized microbiota or (b) relatively late primary silicification of already highly degraded and no longer morphologically identifiable microbial remains.

  2. Voluminous submarine lava flows from Hawaiian volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, R.T.; Moore, J.G.; Lipman, P.W.; Belderson, R.H.


    The GLORIA long-range sonar imaging system has revealed fields of large lava flows in the Hawaiian Trough east and south of Hawaii in water as deep as 5.5 km. Flows in the most extensive field (110 km long) have erupted from the deep submarine segment of Kilauea's east rift zone. Other flows have been erupted from Loihi and Mauna Loa. This discovery confirms a suspicion, long held from subaerial studies, that voluminous submarine flows are erupted from Hawaiian volcanoes, and it supports an inference that summit calderas repeatedly collapse and fill at intervals of centuries to millenia owing to voluminous eruptions. These extensive flows differ greatly in form from pillow lavas found previously along shallower segments of the rift zones; therefore, revision of concepts of volcano stratigraphy and structure may be required.

  3. Vulcan's fury: Man against the volcano (United States)

    Varekamp, Johan C.

    I read this book on an 11-hour flight back from a field trip in the Andes, where I got first-hand insight into how people live with a volcano that now and then explodes. Appropriate reading, I felt, especially as the fascination of the human world with volcanoes and eruptive disasters is indeed long standing. This book is a recent addition to a list of titles in this genre (e.g., the new book by Sigurdsson to be reviewed in Eos shortly). The scope of the book is summarized in the introductory sentence of the preface: “This book is about an unequal contest. It describes human reactions to volcanic eruptions.” This is the perspective of the book's descriptions of 16 large and not-so-large eruptions over the last two millennia.

  4. Geochemical features of the mantle source beneath Irazú and Turrialba volcanoes, Costa Rica (United States)

    Rizzo, A. L.; Di Piazza, A.; Alvarado-Induni, G.; Carapezza, M. L.; de Moor, M. J.; Martinez, M.


    Irazú and Turrialba are active arc volcanoes located at the southeastern terminus of the Central American Volcanic Arc (CAVA). These volcanoes have been considered in literature as "twin volcanoes" or as a linked volcanic system. Effectively their proximity may lead to the assumption that they share a common plumbing system, but geochemical data on rocks and fluids reveal a more complicated framework. In this study, we analyzed the rock chemistry of a selected suite of eruptive products emitted in the last 50ka from Irazú volcano, including products from the 1963-1965 eruption. We also analyzed He-Ne-Ar isotopes in fluid inclusions hosted in olivines and pyroxenes hand-picked from these products, and we compared our results with those available for Irazú and the neighboring Turrialba. Rock samples from Irazú are basalts to andesites with MgO content ranging between 3 and 8 wt%, with a variability that follows typical trends of fractional crystallization. The pattern of trace elements is subduction-related with an OIB-like component, testified by an unusual enrichment (e.g., K, REE; e.g., Benjamin et al., 2007 and references therein), associated with the subduction of the Galapagos seamounts. In addition, Turrialba volcano shows the presence of andesites with adakite-like affinity (Di Piazza et al., 2015) which is not observed in rocks from Irazú . The 3He/4He ratio measured in olivine crystals from Irazú varies from 7.1 to 7.5 Ra, overlapping the measurements performed in surface gases (7.2 Ra; Fischer et al., 2002). This range is also comprised in the measurements carried out in gases and rocks from Turrialba (7.0-8.1 Ra; Di Piazza et al., 2015), which showed the presence of a MORB- and OIB-like component at the mantle source. Based on these evidences, we propose that the mantle beneath Irazú reflects an intermediate composition respect to the extreme components recognized at Turrialba. Irazú shows more typical arc-like geochemical signatures, whereas

  5. Fossil Groups Origins III. Characterization of the sample and observational properties of fossil systems

    CERN Document Server

    Zarattini, S; Girardi, M; Castro-Rodriguez, N; Boschin, W; Aguerri, J A L; Méndez-Abreu, J; Sánchez-Janssen, R; Catalán-Torrecilla, C; Corsini, E M; del Burgo, C; D'Onghia, E; Herrera-Ruiz, N; Iglesias-Páramo, J; Bailon, E Jimenez; Muñoz, M Lozada; Napolitano, N; Vilchez, J M


    (Abridged) Fossil systems are group- or cluster-sized objects whose luminosity is dominated by a very massive central galaxy. In the current cold dark matter scenario, these objects formed hierarchically at an early epoch of the Universe and then slowly evolved until present day. That is the reason why they are called {\\it fossils}. We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical properties. Deep $r-$band images were taken for each candidate and optical spectroscopic observations were obtained for $\\sim$ 1200 galaxies. This new dataset was completed with SDSS DR7 archival data to obtain robust cluster membership and global properties of each fossil group candidate. For each system, we recomputed the magnitude gaps between the two brightest galaxies ($\\Delta m_{12}$) and the first and fourth ranked galaxies ($\\Delta m_{14}$) within 0.5 $R_{{\\rm 200}}$. We consider fossil systems those with $\\Delta m_{12} \\ge 2$ mag or $\\Del...

  6. Decision Analysis Tools for Volcano Observatories (United States)

    Hincks, T. H.; Aspinall, W.; Woo, G.


    Staff at volcano observatories are predominantly engaged in scientific activities related to volcano monitoring and instrumentation, data acquisition and analysis. Accordingly, the academic education and professional training of observatory staff tend to focus on these scientific functions. From time to time, however, staff may be called upon to provide decision support to government officials responsible for civil protection. Recognizing that Earth scientists may have limited technical familiarity with formal decision analysis methods, specialist software tools that assist decision support in a crisis should be welcome. A review is given of two software tools that have been under development recently. The first is for probabilistic risk assessment of human and economic loss from volcanic eruptions, and is of practical use in short and medium-term risk-informed planning of exclusion zones, post-disaster response, etc. A multiple branch event-tree architecture for the software, together with a formalism for ascribing probabilities to branches, have been developed within the context of the European Community EXPLORIS project. The second software tool utilizes the principles of the Bayesian Belief Network (BBN) for evidence-based assessment of volcanic state and probabilistic threat evaluation. This is of practical application in short-term volcano hazard forecasting and real-time crisis management, including the difficult challenge of deciding when an eruption is over. An open-source BBN library is the software foundation for this tool, which is capable of combining synoptically different strands of observational data from diverse monitoring sources. A conceptual vision is presented of the practical deployment of these decision analysis tools in a future volcano observatory environment. Summary retrospective analyses are given of previous volcanic crises to illustrate the hazard and risk insights gained from use of these tools.

  7. On the morphometry of terrestrial shield volcanoes (United States)

    Grosse, Pablo; Kervyn, Matthieu


    Shield volcanoes are described as low angle edifices that have convex up topographic profiles and are built primarily by the accumulation of lava flows. This generic view of shields' morphology is based on a limited number of monogenetic shields from Iceland and Mexico, and a small set of large oceanic islands (Hawaii, Galapagos). Here, the morphometry of over 150 monogenetic and polygenetic shield volcanoes, identified inthe Global Volcanism Network database, are analysed quantitatively from 90-meter resolution DEMs using the MORVOLC algorithm. An additional set of 20 volcanoes identified as stratovolcanoes but having low slopes and being dominantly built up by accumulation of lava flows are documented for comparison. Results show that there is a large variation in shield size (volumes range from 0.1 to >1000 km3), profile shape (height/basal width ratios range from 0.01 to 0.1), flank slope gradients, elongation and summit truncation. Correlation and principal component analysis of the obtained quantitative database enables to identify 4 key morphometric descriptors: size, steepness, plan shape and truncation. Using these descriptors through clustering analysis, a new classification scheme is proposed. It highlights the control of the magma feeding system - either central, along a linear structure, or spatially diffuse - on the resulting shield volcano morphology. Genetic relationships and evolutionary trends between contrasted morphological end-members can be highlighted within this new scheme. Additional findings are that the Galapagos-type morphology with a central deep caldera and steep upper flanks are characteristic of other shields. A series of large oceanic shields have slopes systematically much steeper than the low gradients (<4-8°) generally attributed to large Hawaiian-type shields. Finally, the continuum of morphologies from flat shields to steeper complex volcanic constructs considered as stratovolcanoes calls for a revision of this oversimplified

  8. Buried caldera of mauna kea volcano, hawaii. (United States)

    Porter, S C


    An elliptical caldera (2.1 by 2.8 kilometers) at the summit of Mauna Kea volcano is inferred to lie buried beneath hawaiite lava flows and pyroclastic cones at an altitude of approximately 3850 meters. Stratigraphic relationships indicate that hawaiite eruptions began before a pre-Wisconsin period of ice-cap glaciation and that the crest of the mountain attained its present altitude and gross form during a glaciation of probable Early Wisconsin age.

  9. Publications of the Volcano Hazards Program 2014 (United States)

    Nathenson, Manuel


    The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Natural Hazards activity, as funded by Congressional appropriation. Investigations are carried out by the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaiʻi Mānoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all of these institutions.

  10. Traversing the mountaintop: world fossil fuel production to 2050. (United States)

    Nehring, Richard


    During the past century, fossil fuels--petroleum liquids, natural gas and coal--were the dominant source of world energy production. From 1950 to 2005, fossil fuels provided 85-93% of all energy production. All fossil fuels grew substantially during this period, their combined growth exceeding the increase in world population. This growth, however, was irregular, providing for rapidly growing per capita production from 1950 to 1980, stable per capita production from 1980 to 2000 and rising per capita production again after 2000. During the past half century, growth in fossil fuel production was essentially limited by energy demand. During the next half century, fossil fuel production will be limited primarily by the amount and characteristics of remaining fossil fuel resources. Three possible scenarios--low, medium and high--are developed for the production of each of the fossil fuels to 2050. These scenarios differ primarily by the amount of ultimate resources estimated for each fossil fuel. Total fossil fuel production will continue to grow, but only slowly for the next 15-30 years. The subsequent peak plateau will last for 10-15 years. These production peaks are robust; none of the fossil fuels, even with highly optimistic resource estimates, is projected to keep growing beyond 2050. World fossil fuel production per capita will thus begin an irreversible decline between 2020 and 2030.

  11. Fossil Energy Program semiannual progress report, October 1990--March 1991

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.


    This report covers progress made during the period October 1, 1990, through March 31, 1991, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Office of Basic Energy Sciences, the DOE Fossil Energy Office of Petroleum Reserves, the DOE Fossil Energy Naval Petroleum and Oil Shale Reserves, and the US Agency for International Development. The Fossil, Energy Program organization chart is shown in the appendix. Topics include: alloys, ceramics and composite research and development; corrosion and erosion research; environmental analysis and information systems; coal conversion development; mild gasification product characterization; coal combustion research; strategic petroleum reserve planning and modeling; and coal structure and chemistry.

  12. Distinguishing heat from light in debate over controversial fossils. (United States)

    Donoghue, Philip C J; Purnell, Mark A


    Fossil organisms offer our only direct insight into how the distinctive body plans of extant organisms were assembled. However, realizing the potential evolutionary significance of fossils can be hampered by controversy over their interpretation. Here, as a guide to evaluating palaeontological debates, we outline the process and pitfalls of fossil interpretation. The physical remains of controversial fossils should be reconstructed before interpreting homologies, and choice of interpretative model should be explicit and justified. Extinct taxa lack characters diagnostic of extant clades because the characters had not yet evolved, because of secondary loss, or because they have rotted away. The latter, if not taken into account, will lead to the spurious assignment of fossils to basally branching clades. Conflicting interpretations of fossils can often be resolved by considering all the steps in the process of anatomical analysis and phylogenetic placement, although we must accept that some fossil organisms are simply too incompletely preserved for their evolutionary significance to be realized.

  13. Monitoring active volcanoes: The geochemical approach

    Directory of Open Access Journals (Sweden)

    Takeshi Ohba


    Full Text Available

    The geochemical surveillance of an active volcano aims to recognize possible signals that are related to changes in volcanic activity. Indeed, as a consequence of the magma rising inside the volcanic "plumbing system" and/or the refilling with new batches of magma, the dissolved volatiles in the magma are progressively released as a function of their relative solubilities. When approaching the surface, these fluids that are discharged during magma degassing can interact with shallow aquifers and/or can be released along the main volcano-tectonic structures. Under these conditions, the following main degassing processes represent strategic sites to be monitored.

    The main purpose of this special volume is to collect papers that cover a wide range of topics in volcanic fluid geochemistry, which include geochemical characterization and geochemical monitoring of active volcanoes using different techniques and at different sites. Moreover, part of this volume has been dedicated to the new geochemistry tools.

  14. Geothermal Exploration of Newberry Volcano, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Waibel, Albert F. [Columbia Geoscience, Pasco, WA (United States); Frone, Zachary S. [Southern Methodist Univ., Dallas, TX (United States); Blackwell, David D. [Southern Methodist Univ., Dallas, TX (United States)


    Davenport Newberry (Davenport) has completed 8 years of exploration for geothermal energy on Newberry Volcano in central Oregon. Two deep exploration test wells were drilled by Davenport on the west flank of the volcano, one intersected a hydrothermal system; the other intersected isolated fractures with no hydrothermal interconnection. Both holes have bottom-hole temperatures near or above 315°C (600°F). Subsequent to deep test drilling an expanded exploration and evaluation program was initiated. These efforts have included reprocessing existing data, executing multiple geological, geophysical, geochemical programs, deep exploration test well drilling and shallow well drilling. The efforts over the last three years have been made possible through a DOE Innovative Exploration Technology (IET) Grant 109, designed to facilitate innovative geothermal exploration techniques. The combined results of the last 8 years have led to a better understanding of the history and complexity of Newberry Volcano and improved the design and interpretation of geophysical exploration techniques with regard to blind geothermal resources in volcanic terrain.

  15. Seismic and infrasound monitoring at Cotopaxi volcano (United States)

    Ruiz, M.; Yepes, H.; Palacios, P.; Troncoso, L.; Mothes, P.; Kumagai, H.


    Cotopaxi is an active ice-capped volcano (5967m) located 60 km SE from Quito and is one of the largest and more hazardous volcanoes in the Northern Andes. Monitoring of Cotopaxi, using seismic and infrasound techniques has improving significantly since 1976, when three short-period stations were deployed temporarily in response to an increase of fumarolic activity. Later in May 1977, a short-period vertical seismometer was installed on the NW flank at 7 km from the crater. Since 1986 a short-period seismic station is working at the northern flank of Cotopaxi and transmitting analog data to the Instituto Geofisico. In 1993 a network of 4 short-period seismic stations were installed on all flanks of the volcano. Between March 1996 and June 1997 a temporal network of 16 stations were deployed for several months in order to study local seismicity and internal structure (Metaxian et al., 1999). Since 2006, a network of five broad band stations (0.02-60 s) and low-frequency infrasound sensors (0.01-10 s) were installed through a JICA Cooperation Project (Kumagai et al., 2007). Data is transmitted to the Instituto Geofisico via a digital radio system. Through this network, LP and VLP events have been recorded and analyzed (Molina et al., 2008). VLP events were located beneath the north and north-eastern flank using waveform inversion and amplitude distribution methods (Kumagai et al., 2010).

  16. Detecting Blackholes and Volcanoes in Directed Networks

    CERN Document Server

    Li, Zhongmou; Liu, Yanchi


    In this paper, we formulate a novel problem for finding blackhole and volcano patterns in a large directed graph. Specifically, a blackhole pattern is a group which is made of a set of nodes in a way such that there are only inlinks to this group from the rest nodes in the graph. In contrast, a volcano pattern is a group which only has outlinks to the rest nodes in the graph. Both patterns can be observed in real world. For instance, in a trading network, a blackhole pattern may represent a group of traders who are manipulating the market. In the paper, we first prove that the blackhole mining problem is a dual problem of finding volcanoes. Therefore, we focus on finding the blackhole patterns. Along this line, we design two pruning schemes to guide the blackhole finding process. In the first pruning scheme, we strategically prune the search space based on a set of pattern-size-independent pruning rules and develop an iBlackhole algorithm. The second pruning scheme follows a divide-and-conquer strategy to fur...

  17. Nanoscale volcanoes: accretion of matter at ion-sculpted nanopores. (United States)

    Mitsui, Toshiyuki; Stein, Derek; Kim, Young-Rok; Hoogerheide, David; Golovchenko, J A


    We demonstrate the formation of nanoscale volcano-like structures induced by ion-beam irradiation of nanoscale pores in freestanding silicon nitride membranes. Accreted matter is delivered to the volcanoes from micrometer distances along the surface. Volcano formation accompanies nanopore shrinking and depends on geometrical factors and the presence of a conducting layer on the membrane's back surface. We argue that surface electric fields play an important role in accounting for the experimental observations.

  18. Citizen empowerment in volcano monitoring, communication and decision-making at Tungurahua volcano, Ecuador (United States)

    Bartel, B. A.; Mothes, P. A.


    Trained citizen volunteers called vigías have worked to help monitor and communicate warnings about Tungurahua volcano, in Ecuador, since the volcano reawoke in 1999. The network, organized by the scientists of Ecuador's Instituto Geofísico de la Escuela Politécnica Nacional (Geophysical Institute) and the personnel from the Secretaría Nacional de Gestión de Riesgos (Risk Management, initially the Civil Defense), has grown to more than 20 observers living around the volcano who communicate regularly via handheld two-way radios. Interviews with participants conducted in 2010 indicate that the network enables direct communication between communities and authorities; engenders trust in scientists and emergency response personnel; builds community; and empowers communities to make decisions in times of crisis.

  19. Crystal science fundamentals


    Ramachandran, V.; Halfpenny, PJ; Roberts, KJ


    The fundamentals of crystal science notably crystallography, crystal chemistry, crystal defects, crystal morphology and the surface chemistry of crystals are introduced with particular emphasis on organic crystals.

  20. Two differentiation trends in the Thingmuli volcano, Eastern Iceland (United States)

    Charreteur, G.; Tegner, C.; Haase, K. M.


    Since Carmichael’s study (1964), the Thingmúli central volcano (Tertiary Eastern Iceland) has been considered a complete and classic tholeiitic differentiation series from basalt to rhyolite. More recently the role of melting hydrated basaltic crust is often emphasized in the formation of rhyolite in Iceland. A new sample set collected on the Thingmúli central volcano demonstrates the existence of two distinct geochemical trends. For a MgO of 1.3%, a Fe-rich trend (HFe) contains about 13.4% FeO (total iron), while a Fe-poor trend (LFe) contains about 5.2% FeO. A few samples fall below the LFe trend, but they do not show a complete differentiation trend and are interpreted as an epiphenomenon of mixing between primitive basalt and rhyolite. The LFe trend displays a remarkably stable Mg# around 35 from the most evolved basalt (51 wt% SiO2) through to rhyolite with 72 wt% SiO2 before decreasing to almost zero through the rhyolitic field (up to 78 wt% SiO2). In contrast, Mg# of the HFe trend shows a progressive decrease from evolved basalt to rhyolite (52-77 wt% SiO2). Modeling using the MELTS algorithm indicates that the major element composition of the LFe trend can be explained by fractional crystallisation in system open to oxygen. The LFe trend, however, can also be explained by simple mixing between basaltic and rhyolitic magmas. The LFe-rhyolites show negative anomalies in Nb and Ta associated with positive anomalies in Pb. This favors mixing with melts originating by melting of hydrated crust as the dominant process resulting in the LFe trend. In contrast, the intermediate rocks of the HFe trend cannot be formed by any mixing process involving suitable basaltic and rhyolitic components. Instead, MELTS modeling assuming fractional crystallisation in a system closed to oxygen nicely reproduce the HFe trend. We therefore conclude that the Thingmúli volcano was fed by liquids originating from two magma chamber systems: one similar to Skaergaard producing Fe

  1. Pre-eruptive conditions of the ~31 ka rhyolitic magma of Tlaloc volcano, Sierra Nevada Volcanic Range, Central Mexico (United States)

    Macias, J.; Arce, J.; Rueda, H.; Gardner, J.


    Tlaloc volcano is located at the northern tip of the Sierra Nevada Volcanic Range in Central Mexico. This Pleistocene to Recent volcanic range consists from north to south of Tlaloc-Telapón-Teyotl-Iztaccíhuatl-and- Popocatépetl volcanoes. While andesitic to barely dacitic volcanism dominates the southern part of the range (i.e. Popocatépetl and Iztaccíhuatl); dacitic and rare rhyolithic volcanism (i.e. Telapón, Tlaloc) dominates the northern end. The known locus of rhyolitic magmatism took place at Tlaloc volcano with a Plinian-Subplinian eruption that occurred 31 ka ago. The eruption emplaced the so-called multilayered fallout and pumiceous pyroclastic flows (~2 km3 DRE). The deposit consists of 95% vol. of juvenile particles (pumice + crystals) and minor altered lithics 5% vol. The mineral association of the pumice fragments (74-76 % wt. SiO2) consists of quartz + plagioclase + sanidine + biotite and rare oxides set in a glassy groundmass with voids. Melt inclusions in quartz phenocrysts suggest that prior to the eruption the rhyolitic contain ~7% of H2O and Toluca volcano (~6 km) some 50 km to the southwest.

  2. Hawaii energy strategy project 2: Fossil energy review. Task 1: World and regional fossil energy dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Breazeale, K. [ed.; Isaak, D.T.; Yamaguchi, N.; Fridley, D.; Johnson, C.; Long, S.


    This report in the Hawaii Energy Strategy Project examines world and regional fossil energy dynamics. The topics of the report include fossil energy characteristics, the world oil industry including reserves, production, consumption, exporters, importers, refining, products and their uses, history and trends in the global oil market and the Asia-Pacific market; world gas industry including reserves, production, consumption, exporters, importers, processing, gas-based products, international gas market and the emerging Asia-Pacific gas market; the world coal industry including reserves, classification and quality, utilization, transportation, pricing, world coal market, Asia-Pacific coal outlook, trends in Europe and the Americas; and environmental trends affecting fossil fuels. 132 figs., 46 tabs.

  3. July 1973 ground survey of active Central American volcanoes (United States)

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.


    The author has identified the following significant results. Ground survey has shown that thermal anomalies of various sizes associated with volcanic activity at several Central American volcanoes should be detectable from Skylab. Anomalously hot areas of especially large size (greater than 500 m in diameter) are now found at Santiaguito and Pacaya volcanoes in Guatemala and San Cristobal in Nicaragua. Smaller anomalous areas are to be found at least seven other volcanoes. This report is completed after ground survey of eleven volcanoes and ground-based radiation thermometry mapping at these same points.

  4. The critical role of volcano monitoring in risk reduction

    Directory of Open Access Journals (Sweden)

    R. I. Tilling


    Full Text Available Data from volcano-monitoring studies constitute the only scientifically valid basis for short-term forecasts of a future eruption, or of possible changes during an ongoing eruption. Thus, in any effective hazards-mitigation program, a basic strategy in reducing volcano risk is the initiation or augmentation of volcano monitoring at historically active volcanoes and also at geologically young, but presently dormant, volcanoes with potential for reactivation. Beginning with the 1980s, substantial progress in volcano-monitoring techniques and networks – ground-based as well space-based – has been achieved. Although some geochemical monitoring techniques (e.g., remote measurement of volcanic gas emissions are being increasingly applied and show considerable promise, seismic and geodetic methods to date remain the techniques of choice and are the most widely used. Availability of comprehensive volcano-monitoring data was a decisive factor in the successful scientific and governmental responses to the reawakening of Mount St. elens (Washington, USA in 1980 and, more recently, to the powerful explosive eruptions at Mount Pinatubo (Luzon, Philippines in 1991. However, even with the ever-improving state-of-the-art in volcano monitoring and predictive capability, the Mount St. Helens and Pinatubo case histories unfortunately still represent the exceptions, rather than the rule, in successfully forecasting the most likely outcome of volcano unrest.

  5. Geologic map of Medicine Lake volcano, northern California (United States)

    Donnelly-Nolan, Julie M.


    Medicine Lake volcano forms a broad, seemingly nondescript highland, as viewed from any angle on the ground. Seen from an airplane, however, treeless lava flows are scattered across the surface of this potentially active volcanic edifice. Lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, cover more than 2,000 km2 east of the main axis of the Cascade Range in northern California. Across the Cascade Range axis to the west-southwest is Mount Shasta, its towering volcanic neighbor, whose stratocone shape contrasts with the broad shield shape of Medicine Lake volcano. Hidden in the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of Medicine Lake volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 8,000 ft (2,440 m). The maximum extent of lavas from this half-million-year-old volcano is about 80 km north-south by 45 km east-west. In postglacial time, 17 eruptions have added approximately 7.5 km3 to its total estimated volume of 600 km3, and it is considered to be the largest by volume among volcanoes of the Cascades arc. The volcano has erupted nine times in the past 5,200 years, a rate more frequent than has been documented at all other Cascades arc volcanoes except Mount St. Helens.

  6. Magma Supply System at Batur Volcano Inferred from Volcano-Tectonic Earthquakes and Their Focal Mechanism

    Directory of Open Access Journals (Sweden)

    Sri Hidayati


    Full Text Available DOI: 10.17014/ijog.v8i2.159The Volcano-Tectonic (VT earthquakes occurring during September - November 2009 were analyzed. The result shows that the epicentres aligning in NE- SW direction coincided with the weak zone of Batur Volcano Complex. The focal zone is located at the depth around 1.5 - 5.5 km beneath the summit. Migration of magma was detected by ground deformation measured by GPS and focal mechanism. Mechanism of VT earthquake shows mostly normal fault types during the swarm in November 2009.

  7. Abstracts: Eighth Annual Conference on Fossil Energy Materials. Fossil Energy Program

    Energy Technology Data Exchange (ETDEWEB)


    Abstracts are presented for about 40 papers. The Fossil Energy Advanced Research and Technology Development Materials program is an integrated materials research activity of the fossil energy coal program, whose objective is to conduct R and D for all advanced coal conversion and utilization technologies. The program is aimed at understanding materials behavior in coal system environments and the development of new materials for improving plant operations and reliability. A generic approach is used for addressing multiple coal technologies; for example, the hot-gas particulate filter development is applicable to pressurized fluidized bed combustion, integrated coal gasification combined-cycle, coal combustion, and indirectly fired combined-cycle systems.

  8. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 4: Energy from fossil fuels (United States)

    Williams, J. R.


    The conversion of fossil-fired power plants now burning oil or gas to burn coal is discussed along with the relaxation of air quality standards and the development of coal gasification processes to insure a continued supply of gas from coal. The location of oil fields, refining areas, natural gas fields, and pipelines in the U.S. is shown. The technologies of modern fossil-fired boilers and gas turbines are defined along with the new technologies of fluid-bed boilers and MHD generators.

  9. Energy Ontologies: Wind, Biomass, and Fossil Transportation

    Directory of Open Access Journals (Sweden)

    Heidi Scott


    Full Text Available This article uses literary sources to draw ontological distinctions among three distinct energy sources: wind power, biomass, and fossil fuels. The primary aim is to demonstrate how radically our fossil fuel regime has changed human ontology in the last two centuries during which we have entered the Anthropocene. Because this radical transformation contains myriad elements, this article will focus on transportation: the speed, quality, and quantity of travel permitted by successive energy sources. To consider the comparative literatures of energy as they relate to transportation, we will begin with wind, then consider muscle-driven biomass giving way to coal locomotion, and conclude with the highest octane fuel, petroleum. The central interest is in how the fuel depicted in literature illuminates historical moments in which the interfaces between self, society, and nature are configured by specific energy regimes. By using literature as a source text, we may arrive at an emotionally and philosophically more robust synthesis of energy history than the social and natural sciences, relying upon objective accounts and statistics, are able to provide. By re-reading literature through the lens of the Anthropocene, we gain perspective on how earlier insights into the relationship between energy and experience can inform our explorations of today’s ontological reality. Energy literature instructs us out of the fossil fuel mindset of world domination and back to a physical realm in which we are small actors in a world guided by capricious forces. Such a reality requires hard muscular work and emotional immersion to restore an ethic of care and sustainability.

  10. Initial H2O content and conditions of parent magma origin for Gorely volcano (Southern Kamchatka) estimated by trace element thermobarometry (United States)

    Nazarova, D. P.; Portnyagin, M. V.; Krasheninnikov, S. P.; Mironov, N. L.; Sobolev, A. V.


    The formation conditions of the parental magmas of Gorely volcano, which is located behind a volcanic front in Southern Kamchatka, have been evaluated using the modern methods of micro-element thermobarometry. These magmas contained 1.7 ± 0.8 (2σ) wt % of H2O, the majority (82%) of which has been lost from inclusions. They crystallized at 1121 ± 17°C and an oxygen fugacity of ΔQFM 1.2 ± 0.2, and could have been produced by about 11% melting of an enriched MORB source (E-DMM) at a temperature of about 1270°C, and a pressure of about 1.5 GPa. A distinctive feature of Gorely volcano, compared with frontal volcanoes of Kamchatka, is the unusually high temperature (925 ± 20°C) of formation of the subduction component corresponding to the region of existence of water-bearing melts.

  11. Comparing amber fossil assemblages across the Cenozoic. (United States)

    Penney, David; Langan, A Mark


    To justify faunistic comparisons of ambers that differ botanically, geographically and by age, we need to determine that resins sampled uniformly. Our pluralistic approach, analysing size distributions of 671 fossilized spider species from different behavioural guilds, demonstrates that ecological information about the communities of two well-studied ambers is retained. Several lines of evidence show that greater structural complexity of Baltic compared to Dominican amber trees explains the presence of larger web-spinners. No size differences occur in active hunters. Consequently, we demonstrate for the first time that resins were trapping organisms uniformly and that comparisons of amber palaeoecosystem structure across deep time are possible.

  12. Central heating: fossil-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Blazek, C.F.; Baker, N.R.; Tison, R.R.


    This evaluation provides performance and cost data for fossil-fuel-fired steam boilers, hot-water generators, and thermal fluid generators currently available from manufacturers. Advanced-technology fluidized-bed boilers also are covered. Performance characteristics investigated include unit efficiencies, turndown capacity, and pollution requirements. Costs are tabulated for equipment and installation of both field-erected and packaged units. The information compiled in this evaluation will assist in the process of selecting energy-conversion units required for industrial, commercial, and residential applications.

  13. Future requirements for fossil power plants

    Directory of Open Access Journals (Sweden)

    Spliethoff H.


    Full Text Available The fast increasing installation of technologies to convert renewable energy into power influences the operation of conventional power plants. New requirements on the technology, on the operation and on the economic have to be considered for already running and future power plants. Currently, first experiences with such a production and market situation are available. Technologies are discussed to store power and to reduce CO2 emissions. New compensation models are necessary to enable economic operation of fossil power plants in base load. This article gives a short review about available technologies and future challenges.

  14. Fossil Diatoms in a New Carbonaceous Meteorite (United States)

    Wickramasinghe, N. C.; Wallis, J.; Wallis, D. H.; Samaranayake, Anil


    We report the discovery for the first time of diatom frustules in a carbonaceous meteorite that fell in the North Central Province of Sri Lanka on 29 December 2012. Contamination is excluded by the circumstance that the elemental abundances within the structures match closely with those of the surrounding matrix. There is also evidence of structures morphologically similar to red rain cells that may have contributed to the episode of red rain that followed within days of the meteorite fall. The new data on "fossil" diatoms provide strong evidence to support the theory of cometary panspermia.

  15. Recent developments in biodesulfurization of fossil fuels. (United States)

    Xu, Ping; Feng, Jinhui; Yu, Bo; Li, Fuli; Ma, Cuiqing


    The emission of sulfur oxides can have adverse effects on the environment. Biodesulfurization of fossil fuels is attracting more and more attention because such a bioprocess is environmentally friendly. Some techniques of desulfurization have been used or studied to meet the stricter limitation on sulfur content in China. Recent advances have demonstrated the mechanism and developments for biodesulfurization of gasoline, diesel and crude oils by free cells or immobilized cells. Genetic technology was also used to improve sulfur removal efficiencies. In this review, we summarize recent progress mainly in China on petroleum biodesulfurization.

  16. H 2O in basalt and basaltic andesite glass inclusions from four subduction-related volcanoes (United States)

    Sisson, T. W.; Layne, G. D.


    Total dissolved H 2O and major element abundances were measured in basalt and basaltic andesite glass inclusions in olivine phenocrysts from Quaternary eruptions of four subduction-related volcanoes to test the hypothesis that low-MgO high-alumina basalts contain high H 2O at depth [1] and to reveal any petrogenetically significant correlations between arc basalt compositions and H 2O contents. Total dissolved H 2O (combined molecular H 2O and OH groups) measured by ion microprobe in mafic glass inclusions from the 1974 eruption of Fuego, Guatemala, reaches 6.2 wt.%. Dissolved H 2O contents decrease in more evolved Fuego glasses. Correlations of H 2O with MgO, Na 2O, K 2O, S and Cl indicate that aqueous fluid exsolution during magma ascent forced crystallization and differentiation of residual liquids. Low-K 2O magnesian high-alumina basalt glass inclusions from the 3 ka eruption of Black Crater (Medicine Lake volcano, California) have low H 2O contents, near 0.2 wt.%, which are consistent with the MORB-like character of these and other primitive lavas of the Medicine Lake region. Basalt and basaltic andesite glass inclusions from Copco Cone and Goosenest volcano on the Cascade volcanic front north of Mt. Shasta have H 2O contents of up to 3.3 wt.%. The range of H 2O contents in Cascade mafic magmas is too large to have resulted solely from enrichment by crystallization and indicates the participation of an H 2O-rich component in magma generation or crustal-level modification. Whereas fluid-absent melting of amphibole-bearing peridotite can account for the H 2O in most mafic arc liquids, the very high H 2O/alkali ratios of the 1974 Fuego eruptives suggest that an aqueous fluid was involved in the generation of Fuego basalts.

  17. Degassing history of water, sulfur, and carbon in submarine lavas from Kilauea Volcano, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, J.E.; Stolper, E.M. (California Institute of Technology, Pasadena (USA)); Clague, D.A. (Geological Survey, Menlo Park, CA (USA))


    Major, minor, and dissolved volatile element concentrations were measured in tholeiitic glasses from the submarine portion (Puna Ridge) of the east rift zone of Kilauea Volcano, Hawaii. Dissolved H{sub 2}O and S concentrations display a wide range relative to nonvolatile incompatible elements at all depths. This range cannot be readily explained by fractional crystallization, degassing of H{sub 2}O and S during eruption on the seafloor, or source region heterogeneities. Dissolved CO{sub 2} concentrations, in contrast, show a positive correlation with eruption depth and typically agree within error with the solubility at that depth. The authors propose that most magmas along the Puna Ridge result from (1) mixing of a relatively volatile-rich, undegassed component with magmas that experienced low pressure (perhaps subaerial) degassing during which substantial H{sub 2}O, S, and CO{sub 2} were lost, followed by (2) fractional crystallization of olivine, clinopyroxene, and plagioclase from this mixture to generate a residual liquid; and (3) further degassing, principally of CO{sub 2} for samples erupted deeper than 1,000 m, during eruption on the seafloor. They predict that average Kilauean primary magmas with 16% MgO contain {approximately}0.47 wt % H{sub 2}0, {approximately}900 ppm S, and have {delta}D values of {approximately}{minus}30 to {minus}40%. The model predicts that submarine lavas from wholly submarine volcanoes (i.e., Loihi), for which there is no opportunity to generate the degassed end member by low pressure degassing, will be enriched in volatiles relative to those from volcanoes whose summits have breached the sea surface (i.e., Kilauea and Mauna Loa).

  18. A dearth of intermediate melts at subduction zone volcanoes and the petrogenesis of arc andesites. (United States)

    Reubi, Olivier; Blundy, Jon


    Andesites represent a large proportion of the magmas erupted at continental arc volcanoes and are regarded as a major component in the formation of continental crust. Andesite petrogenesis is therefore fundamental in terms of both volcanic hazard and differentiation of the Earth. Andesites typically contain a significant proportion of crystals showing disequilibrium petrographic characteristics indicative of mixing or mingling between silicic and mafic magmas, which fuels a long-standing debate regarding the significance of these processes in andesite petrogenesis and ultimately questions the abundance of true liquids with andesitic composition. Central to this debate is the distinction between liquids (or melts) and magmas, mixtures of liquids with crystals, which may or may not be co-genetic. With this distinction comes the realization that bulk-rock chemical analyses of petrologically complex andesites can lead to a blurred picture of the fundamental processes behind arc magmatism. Here we present an alternative view of andesite petrogenesis, based on a review of quenched glassy melt inclusions trapped in phenocrysts, whole-rock chemistry, and high-pressure and high-temperature experiments. We argue that true liquids of intermediate composition (59 to 66 wt% SiO(2)) are far less common in the sub-volcanic reservoirs of arc volcanoes than is suggested by the abundance of erupted magma within this compositional range. Effective mingling within upper crustal magmatic reservoirs obscures a compositional bimodality of melts ascending from the lower crust, and masks the fundamental role of silicic melts (>/=66 wt% SiO(2)) beneath intermediate arc volcanoes. This alternative view resolves several puzzling aspects of arc volcanism and provides important clues to the integration of plutonic and volcanic records.

  19. Uzon-Geysernaya volcano-tectonic depression: geodynamics phenomena last years (United States)

    Kugaenko, Yulia


    greater than 4 km from beneath the eastern side of the caldera complex. Geological observations of extruded lavas and other deposits over the course of Uzon's history show that there have been episodic basalt intrusions into a granitic magma chamber, with the system becoming progressively more crystallized and lower in temperature with time [Belousov et al., 1984; Leonov et al., 1991]. By study of RADARSAT-1 synthetic aperture radar (SAR) data the interferometric SAR (InSAR) images of surface deformation at Uzon caldera was computed [Lundgren and Lu, 2006]. From 2000 to 2003 approximately 0.15 m of inflation occurred at Uzon caldera, extending beneath adjacent Kikhpinych volcano. This contrasts with InSAR data showing no significant deformation during either the 1999 to 2000, or 2003 to 2004, time periods. The preferred source model is an irregularly shaped, pressurized crack, dipping near 20° to the NW, 4 km below the surface. The geometry of this solution is similar to the upper boundary of the geologically inferred magma chamber. In the judgment of the authors, extension of the surface deformation and source to adjacent Kikhpinych volcano, without an eruption, suggests that the deformation is more likely of hydrothermal origin, possibly driven by recharge of the magma chamber. A natural disaster - big landslide with volume estimated 20x106 m3 - occurred on June 3, 2007 in the Valley of the Geysers (Leonov, 2007, Kugaenko, 2008). The results of landslide investigation show that heated rocks were involved in failure. One of the main reasons of landslide is weakening of semi-rock pumice soils due to their steaming during hidden unloading of hydrothermal system. Local field observations were organized in the eastern part of the Uzon-Geysernaya depression in 2008 and 2009. Main results of seismic investigation: - Shallow weak seismicity connected with Kikhpinych volcanic center and eastern part of the Uzon-Geysernaya depression was discovered; - Seismicity has spasmodic

  20. Thessaloniki Mud Volcano, the Shallowest Gas Hydrate-Bearing Mud Volcano in the Anaximander Mountains, Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    C. Perissoratis


    Full Text Available A detailed multibeam survey and the subsequent gravity coring carried out in the Anaximander Mountains, Eastern Mediterranean, detected a new active gas hydrate-bearing mud volcano (MV that was named Thessaloniki. It is outlined by the 1315 m bathymetric contour, is 1.67 km2 in area, and has a summit depth of 1260 m. The sea bottom water temperature is 13.7∘C. The gas hydrate crystals generally have the form of flakes or rice, some larger aggregates of them are up to 2 cm across. A pressure core taken at the site contained 3.1 lt. of hydrocarbon gases composed of methane, nearly devoid of propane and butane. The sediment had a gas hydrate occupancy of 0.7% of the core volume. These characteristics place the gas hydrate field at Thessaloniki MV at the upper boundary of the gas hydrate stability zone, prone to dissociation with the slightest increase in sea water temperature, decrease in hydrostatic pressure, or change in the temperature of the advecting fluids.

  1. Magma plumbing beneath Anak Krakatau volcano, Indonesia: evidence for multiple magma storage regions (United States)

    Dahren, Börje; Troll, Valentin R.; Andersson, Ulf B.; Chadwick, Jane P.; Gardner, Màiri F.; Jaxybulatov, Kairly; Koulakov, Ivan


    Understanding magma plumbing is essential for predicting the behaviour of explosive volcanoes. We investigate magma plumbing at the highly active Anak Krakatau volcano (Indonesia), situated on the rim of the 1883 Krakatau caldera by employing a suite of thermobarometric models. These include clinopyroxene-melt thermobarometry, plagioclase-melt thermobarometry, clinopyroxene composition barometry and olivine-melt thermometry. Petrological studies have previously identified shallow magma storage in the region of 2-8 km beneath Krakatau, while existing seismic evidence points towards mid- to deep-crustal storage zone(s), at 9 and 22 km, respectively. Our results show that clinopyroxene in Anak Krakatau lavas crystallized at a depth of 7-12 km, while plagioclase records both shallow crustal (3-7 km) and sub-Moho (23-28 km) levels of crystallization. These magma storage regions coincide with well-constrained major lithological boundaries in the crust, implying that magma ascent and storage at Anak Krakatau is strongly controlled by crustal properties. A tandem seismic tomography survey independently identified a separate upper crustal (7 km). Both petrological and seismic methods are sensitive in detecting magma bodies in the crust, but suffer from various limitations. Combined geophysical and petrological surveys, in turn, offer increased potential for a comprehensive characterization of magma plumbing at active volcanic complexes.

  2. Magmatic differentiation processes at Merapi Volcano: inclusion petrology and oxygen isotopes (United States)

    Troll, Valentin R.; Deegan, Frances M.; Jolis, Ester M.; Harris, Chris; Chadwick, Jane P.; Gertisser, Ralf; Schwarzkopf, Lothar M.; Borisova, Anastassia Y.; Bindeman, Ilya N.; Sumarti, Sri; Preece, Katie


    Indonesian volcano Merapi is one of the most hazardous volcanoes on the planet and is characterised by periods of active dome growth and intermittent explosive events. Merapi currently degasses continuously through high temperature fumaroles and erupts basaltic-andesite dome lavas and associated block-and-ash-flows that carry a large range of magmatic, coarsely crystalline plutonic, and meta-sedimentary inclusions. These inclusions are useful in order to evaluate magmatic processes that act within Merapi's plumbing system, and to help an assessment of which phenomena could trigger explosive eruptions. With the aid of petrological, textural, and oxygen isotope analysis we record a range of processes during crustal magma storage and transport, including mafic recharge, magma mixing, crystal fractionation, and country rock assimilation. Notably, abundant calc-silicate inclusions (true xenoliths) and elevated δ18O values in feldspar phenocrysts from 1994, 1998, 2006, and 2010 Merapi lavas suggest addition of limestone and calc-silicate materials to the Merapi magmas. Together with high δ13C values in fumarole gas, crustal additions to mantle and slab-derived magma and volatile sources are likely a steady state process at Merapi. This late crustal input could well represent an eruption trigger due to sudden over-pressurisation of the shallowest parts of the magma storage system independently of magmatic recharge and crystal fractionation. Limited seismic precursors may be associated with this type of eruption trigger, offering a potential explanation for the sometimes erratic behaviour of Merapi during volcanic crises.

  3. Earth's early fossil record: Why not look for similar fossils on Mars? (United States)

    Awramik, Stanley M.


    The oldest evidence of life on Earth is discussed with attention being given to the structure and formation of stromatolites and microfossils. Fossilization of microbes in calcium carbonate or chert media is discussed. In searching for fossil remains on Mars, some lessons learned from the study of Earth's earliest fossil record can be applied. Certain sedimentary rock types and sedimentary rock configurations should be targeted for investigation and returned by the Martian rover and ultimately by human explorers. Domical, columnar to wavy laminated stratiform sedimentary rocks that resemble stromatolites should be actively sought. Limestone, other carbonates, and chert are the favored lithology. Being macroscopic, stromatolites might be recognized by an intelligent unmanned rover. In addition, black, waxy chert with conchoidal fracture should be sought. Chert is by far the preferred lithology for the preservation of microbes and chemical fossils. Even under optimal geological conditions (little or no metamorphism or tectonic alteration, excellent outcrops, and good black chert) and using experienced field biogeologists, the chances of finding well preserved microbial remains in chert are very low.

  4. FOSSIL2 energy policy model documentation: generic structures of the FOSSIL2 model

    Energy Technology Data Exchange (ETDEWEB)



    This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. In Volume I, an overview of the basic structures, assumptions, and behavior of the FOSSIL2 model is presented so that the reader can understand the results of various policy tests. The discussion covers the three major building blocks, or generic structures, used to construct the model: supply/demand balance; finance and capital formation; and energy production. These structures reflect the components and interactions of the major processes within each energy industry that directly affect the dynamics of fuel supply, demand, and price within the energy system as a whole.

  5. Instability of Hawaiian volcanoes: Chapter 4 in Characteristics of Hawaiian volcanoes (United States)

    Denlinger, Roger P.; Morgan, Julia K.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.


    Hawaiian volcanoes build long rift zones and some of the largest volcanic edifices on Earth. For the active volcanoes on the Island of Hawai‘i, the growth of these rift zones is upward and seaward and occurs through a repetitive process of decades-long buildup of a magma-system head along the rift zones, followed by rapid large-scale displacement of the seaward flank in seconds to minutes. This large-scale flank movement, which may be rapid enough to generate a large earthquake and tsunami, always causes subsidence along the coast, opening of the rift zone, and collapse of the magma-system head. If magma continues to flow into the conduit and out into the rift system, then the cycle of growth and collapse begins again. This pattern characterizes currently active Kīlauea Volcano, where periods of upward and seaward growth along rift zones were punctuated by large (>10 m) and rapid flank displacements in 1823, 1868, 1924, and 1975. At the much larger Mauna Loa volcano, rapid flank movements have occurred only twice in the past 200 years, in 1868 and 1951.

  6. Atmospheric Lifetime of Fossil Fuel Carbon Dioxide (United States)

    Archer, David; Eby, Michael; Brovkin, Victor; Ridgwell, Andy; Cao, Long; Mikolajewicz, Uwe; Caldeira, Ken; Matsumoto, Katsumi; Munhoven, Guy; Montenegro, Alvaro; Tokos, Kathy


    CO2 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere, the ocean, and the terrestrial biosphere on timescales of a few centuries. However, a sizeable fraction of the CO2 remains in the atmosphere, awaiting a return to the solid earth by much slower weathering processes and deposition of CaCO3. Common measures of the atmospheric lifetime of CO2, including the e-folding time scale, disregard the long tail. Its neglect in the calculation of global warming potentials leads many to underestimate the longevity of anthropogenic global warming. Here, we review the past literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial results from a model intercomparison project on this topic. The models agree that 20-35% of the CO2 remains in the atmosphere after equilibration with the ocean (2-20 centuries). Neutralization by CaCO3 draws the airborne fraction down further on timescales of 3 to 7 kyr.

  7. Species longevity in North American fossil mammals. (United States)

    Prothero, Donald R


    Species longevity in the fossil record is related to many paleoecological variables and is important to macroevolutionary studies, yet there are very few reliable data on average species durations in Cenozoic fossil mammals. Many of the online databases (such as the Paleobiology Database) use only genera of North American Cenozoic mammals and there are severe problems because key groups (e.g. camels, oreodonts, pronghorns and proboscideans) have no reliable updated taxonomy, with many invalid genera and species and/or many undescribed genera and species. Most of the published datasets yield species duration estimates of approximately 2.3-4.3 Myr for larger mammals, with small mammals tending to have shorter species durations. My own compilation of all the valid species durations in families with updated taxonomy (39 families, containing 431 genera and 998 species, averaging 2.3 species per genus) yields a mean duration of 3.21 Myr for larger mammals. This breaks down to 4.10-4.39 Myr for artiodactyls, 3.14-3.31 Myr for perissodactyls and 2.63-2.95 Myr for carnivorous mammals (carnivorans plus creodonts). These averages are based on a much larger, more robust dataset than most previous estimates, so they should be more reliable for any studies that need species longevity to be accurately estimated. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  8. Cladistics and the hominid fossil record. (United States)

    Trinkaus, E


    Cladistic methodology has become common in phylogenetic analyses of the hominid fossil record. Even though it has correctly placed emphasis on morphology for the primary determination of affinities between groups and on explicit statements regarding traits and methods employed in making phylogenetic assessments, cladistics nonetheless has limitations when applied to the hominid fossil record. These include 1) the uncritical assumption of parsimony, 2) uncertainties in the identification of homoplasies, 3) difficulties in the appropriate delimitation of samples for analysis, 4) failure to account for normal patterns of variation, 5) methodological problems with the appropriate identification of morphological traits involving issues of biological relevance, intercorrelation, primary versus secondary characters, and the use of continuous variables, 6) issues of polarity identification, and 7) problems in hypothesis testing. While cladistics has focused attention on alternative phylogenetic reconstructions in hominid paleontology and on explicit statements regarding their morphological and methodological underpinnings, its biological limitations are too abundant for it to be more than a heuristic device for the preliminary ordering of complex human paleontological and neonatological data.

  9. A Study of Interlanguage Fossilization in College Students' English writing

    Institute of Scientific and Technical Information of China (English)



    English writing is the college students’synthetical application about the knowledge of English. English writing, how-ever, is the weak segment of the college students' English learning all the time. Based on the researches home and abroad, the pa-per makes an implicational study on interlanguage fossilization in English writing of Chinese college students. Though probing the causes of fossilization in English writing, the paper proposes some measures to reduce the fossilization. In the chapter one, the paper introduces simply the interlanguage fossilization. In the chapter two, the paper analyzes college students English writing and get the causal factors of fossilization:unfavorite learning motivation of students, ineffective feedback to errors, interference of the mother tongue. Then , at the last chapter, the paper put up some measures to overcome and avoid the fossilization in college stu-dents' English writing:promoting students' motivation, providing right feedback, avoiding mother tongue interference.

  10. Fossil energy biotechnology: A research needs assessment. Final report

    Energy Technology Data Exchange (ETDEWEB)


    The Office of Program Analysis of the US Department of Energy commissioned this study to evaluate and prioritize research needs in fossil energy biotechnology. The objectives were to identify research initiatives in biotechnology that offer timely and strategic options for the more efficient and effective uses of the Nation`s fossil resource base, particularly the early identification of new and novel applications of biotechnology for the use or conversion of domestic fossil fuels. Fossil energy biotechnology consists of a number of diverse and distinct technologies, all related by the common denominator -- biocatalysis. The expert panel organized 14 technical subjects into three interrelated biotechnology programs: (1) upgrading the fuel value of fossil fuels; (2) bioconversion of fossil feedstocks and refined products to added value chemicals; and, (3) the development of environmental management strategies to minimize and mitigate the release of toxic and hazardous petrochemical wastes.

  11. Volcano monitoring with an infrared camera: first insights from Villarrica Volcano (United States)

    Rosas Sotomayor, Florencia; Amigo Ramos, Alvaro; Velasquez Vargas, Gabriela; Medina, Roxana; Thomas, Helen; Prata, Fred; Geoffroy, Carolina


    This contribution focuses on the first trials of the, almost 24/7 monitoring of Villarrica volcano with an infrared camera. Results must be compared with other SO2 remote sensing instruments such as DOAS and UV-camera, for the ''day'' measurements. Infrared remote sensing of volcanic emissions is a fast and safe method to obtain gas abundances in volcanic plumes, in particular when the access to the vent is difficult, during volcanic crisis and at night time. In recent years, a ground-based infrared camera (Nicair) has been developed by Nicarnica Aviation, which quantifies SO2 and ash on volcanic plumes, based on the infrared radiance at specific wavelengths through the application of filters. Three Nicair1 (first model) have been acquired by the Geological Survey of Chile in order to study degassing of active volcanoes. Several trials with the instruments have been performed in northern Chilean volcanoes, and have proven that the intervals of retrieved SO2 concentration and fluxes are as expected. Measurements were also performed at Villarrica volcano, and a location to install a ''fixed'' camera, at 8km from the crater, was discovered here. It is a coffee house with electrical power, wifi network, polite and committed owners and a full view of the volcano summit. The first measurements are being made and processed in order to have full day and week of SO2 emissions, analyze data transfer and storage, improve the remote control of the instrument and notebook in case of breakdown, web-cam/GoPro support, and the goal of the project: which is to implement a fixed station to monitor and study the Villarrica volcano with a Nicair1 integrating and comparing these results with other remote sensing instruments. This works also looks upon the strengthen of bonds with the community by developing teaching material and giving talks to communicate volcanic hazards and other geoscience topics to the people who live "just around the corner" from one of the most active volcanoes

  12. SO2 camera measurements at Lastarria volcano and Lascar volcano in Chile (United States)

    Lübcke, Peter; Bobrowski, Nicole; Dinger, Florian; Klein, Angelika; Kuhn, Jonas; Platt, Ulrich


    The SO2 camera is a remote-sensing technique that measures volcanic SO2 emissions via the strong SO2 absorption structures in the UV using scattered solar radiation as a light source. The 2D-imagery (usually recorded with a frame rate of up to 1 Hz) allows new insights into degassing processes of volcanoes. Besides the large advantage of high frequency sampling the spatial resolution allows to investigate SO2 emissions from individual fumaroles and not only the total SO2 emission flux of a volcano, which is often dominated by the volcanic plume. Here we present SO2 camera measurements that were made during the CCVG workshop in Chile in November 2014. Measurements were performed at Lastarria volcano, a 5700 m high stratovolcano and Lascar volcano, a 5600 m high stratovolcano both in northern Chile on 21 - 22 November, 2014 and on 26 - 27 November, 2014, respectively. At both volcanoes measurements were conducted from a distance of roughly 6-7 km under close to ideal conditions (low solar zenith angle, a very dry and cloudless atmosphere and an only slightly condensed plume). However, determination of absolute SO2 emission rates proves challenging as part of the volcanic plume hovered close to the ground. The volcanic plume therefore is in front of the mountain in our camera images. An SO2 camera system consisting of a UV sensitive CCD and two UV band-pass filters (centered at 315 nm and 330 nm) was used. The two band-pass filters are installed in a rotating wheel and images are taken with both filter sequentially. The instrument used a CCD with 1024 x 1024 pixels and an imaging area of 13.3 mm x 13.3 mm. In combination with the focal length of 32 mm this results in a field-of-view of 25° x 25°. The calibration of the instrument was performed with help of a DOAS instrument that is co-aligned with the SO2 camera. We will present images and SO2 emission rates from both volcanoes. At Lastarria gases are emitted from three different fumarole fields and we will attempt

  13. Imaging magma plumbing beneath Askja volcano, Iceland (United States)

    Greenfield, Tim; White, Robert S.


    Volcanoes during repose periods are not commonly monitored by dense instrumentation networks and so activity during periods of unrest is difficult to put in context. We have operated a dense seismic network of 3-component, broadband instruments around Askja, a large central volcano in the Northern Volcanic Zone, Iceland, since 2006. Askja last erupted in 1961, with a relatively small basaltic lava flow. Since 1975 the central caldera has been subsiding and there has been no indication of volcanic activity. Despite this, Askja has been one of the more seismically active volcanoes in Iceland. The majority of these events are due to an extensive geothermal area within the caldera and tectonically induced earthquakes to the northeast which are not related to the magma plumbing system. More intriguing are the less numerous deeper earthquakes at 12-24km depth, situated in three distinct areas within the volcanic system. These earthquakes often show a frequency content which is lower than the shallower activity, but they still show strong P and S wave arrivals indicative of brittle failure, despite their location being well below the brittle-ductile boundary, which, in Askja is ~7km bsl. These earthquakes indicate the presence of melt moving or degassing at depth while the volcano is not inflating, as only high strain rates or increased pore fluid pressures would cause brittle fracture in what is normally an aseismic region in the ductile zone. The lower frequency content must be the result of a slower source time function as earthquakes which are both high frequency and low frequency come from the same cluster, thereby discounting a highly attenuating lower crust. To image the plumbing system beneath Askja, local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. Travel-time tables were created using a finite difference technique and the residuals were used to solve simultaneously for both the earthquake locations

  14. Lahar Hazard Modeling at Tungurahua Volcano, Ecuador (United States)

    Sorensen, O. E.; Rose, W. I.; Jaya, D.


    Tungurahua Volcano (Lat. 01^o28'S; Long. 78^o27'W), located in the central Ecuadorian Andes, is an active edifice that rises more than 3 km above surrounding topography. Since European settlement in 1532, Tungurahua has experienced four major eruptive episodes: 1641-1646, 1773-1781, 1886-1888 and 1916-1918 (Hall et al, JVGR V91; p1-21, 1999). In September 1999, Tungurahua began a new period of activity that continues to the present. During this time, the volcano has erupted daily, depositing ash and blocks on its steep flanks. A pattern of continuing eruptions, coupled with rainfall up to 28 mm in a 6 hour period (rain data collected in Baños at 6-hr intervals, 3000 meters below Tungurahua’s summit), has produced an environment conducive to lahar mobilization. Tungurahua volcano presents an immediate hazard to the town of Baños, an important tourist destination and cultural center with a population of about 25,000 residents located 8 km from the crater. During the current eruptive episode, lahars have occurred as often as 3 times per week on the northern and western slopes of the volcano. Consequently, the only north-south trending highway on the west side of Tungurahua has been completely severed at the intersection of at least ten drainages, where erosion has exceeded 10 m since 1999. The La Pampa quebrada, located 1 km west of Baños, is the most active of Tungurahua's drainages. At this location, where the slope is moderate, lahars continue to inundate the only highway linking Baños to the Pan American Highway. Because of steep topography, the conventional approach of measuring planimetric inundation areas to determine the scale of lahars could not be employed. Instead, cross sections were measured in the channels using volume/cross-sectional inundation relationships determined by (Iverson et al, GSABull V110; no. 8, p972-984, 1998). After field observations of the lahars, LAHARZ, a program used in a geographic information system (GIS) to objectively map

  15. Geochemical Similarities Between the Pre-Caldera and Modern Evolutionary Series of Eruptive Products from Gorely Volcano, Kamchatka (United States)

    Gavrilenko, M.; Ozerov, A.


    Gorely volcano, in southern Kamchatka, is a large, long-lived shield-type volcano that is currently in an eruptive phase. Prior eruptions occurred in 1980 and 1984. It is comprised of three structural units: Pra-Gorely volcano; thick ignimbrite complex, associated with a caldera forming eruption; modern edifice named ‘Young Gorely’. An integrated mineralogical-geochemical have been conducted on all structural units of the Gorely volcanic edifice to determine their genetic conditions. After geochemical analysis two evolution series were found. First, Pra-Gorely volcano is represented by a suite of compositions ranging from basalt to rhyolite, with in this series, high-Mg basalts were discovered. Second, Young Gorely edifice is composed of only basalt, andesite and dacite. The reconstruction of chemical evolution trends shows that both volcanic series of Gorely volcano share the same genetic history with similar evolutionary stages. We suggest fractionation of an upper mantle peridotite as a common means to produce both volcanic series as a result of which the evolution of all rocks was generated. The magmatic series of Pra-Gorely and Young Gorely volcanoes were formed under different geodynamic conditions. Between these two series was a powerful stage of caldera formation, during which 100 km3 of ignimbrites were emplaced. The 12-km diameter caldera collapse was the catalyst for large-scale reorganization of the volcanic feeding system. Nevertheless following caldera collapse, Young Gorely was formed by activity inside the caldera and shows very similar evolutionary trends to that of Pra-Gorely. It can be confidently stated that crustal components are practically absent in the evolution of the series, and the compositional range is attributed directly to the evolution of the magmatic melts of Gorely volcano. Microprobe analyses conducted on olivine and pyroxene phenocrysts of Gorely volcano lavas, show that there were at least two stages of crystallization

  16. 36 CFR 7.25 - Hawaii Volcanoes National Park. (United States)


    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Hawaii Volcanoes National Park. 7.25 Section 7.25 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.25 Hawaii Volcanoes National Park....

  17. A Probabilistic Approach for Real-Time Volcano Surveillance (United States)

    Cannavo, F.; Cannata, A.; Cassisi, C.; Di Grazia, G.; Maronno, P.; Montalto, P.; Prestifilippo, M.; Privitera, E.; Gambino, S.; Coltelli, M.


    Continuous evaluation of the state of potentially dangerous volcanos plays a key role for civil protection purposes. Presently, real-time surveillance of most volcanoes worldwide is essentially delegated to one or more human experts in volcanology, who interpret data coming from different kind of monitoring networks. Unfavorably, the coupling of highly non-linear and complex volcanic dynamic processes leads to measurable effects that can show a large variety of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded data, the volcano state needs to be expressed in probabilistic terms, thus making the fast volcano state assessment sometimes impracticable for the personnel on duty at the control rooms. With the aim of aiding the personnel on duty in volcano surveillance, we present a probabilistic graphical model to estimate automatically the ongoing volcano state from all the available different kind of measurements. The model consists of a Bayesian network able to represent a set of variables and their conditional dependencies via a directed acyclic graph. The model variables are both the measurements and the possible states of the volcano through the time. The model output is an estimation of the probability distribution of the feasible volcano states. We tested the model on the Mt. Etna (Italy) case study by considering a long record of multivariate data from 2011 to 2015 and cross-validated it. Results indicate that the proposed model is effective and of great power for decision making purposes.

  18. Using Google Earth to Study the Basic Characteristics of Volcanoes (United States)

    Schipper, Stacia; Mattox, Stephen


    Landforms, natural hazards, and the change in the Earth over time are common material in state and national standards. Volcanoes exemplify these standards and readily capture the interest and imagination of students. With a minimum of training, students can recognize erupted materials and types of volcanoes; in turn, students can relate these…

  19. Volcano ecology: Disturbance characteristics and assembly of biological communities (United States)

    Volcanic eruptions are powerful expressions of Earth’s geophysical forces which have shaped and influenced ecological systems since the earliest days of life. The study of the interactions of volcanoes and ecosystems, termed volcano ecology, focuses on the ecological responses of organisms and biolo...

  20. Monte Carlo Volcano Seismic Moment Tensors (United States)

    Waite, G. P.; Brill, K. A.; Lanza, F.


    Inverse modeling of volcano seismic sources can provide insight into the geometry and dynamics of volcanic conduits. But given the logistical challenges of working on an active volcano, seismic networks are typically deficient in spatial and temporal coverage; this potentially leads to large errors in source models. In addition, uncertainties in the centroid location and moment-tensor components, including volumetric components, are difficult to constrain from the linear inversion results, which leads to a poor understanding of the model space. In this study, we employ a nonlinear inversion using a Monte Carlo scheme with the objective of defining robustly resolved elements of model space. The model space is randomized by centroid location and moment tensor eigenvectors. Point sources densely sample the summit area and moment tensors are constrained to a randomly chosen geometry within the inversion; Green's functions for the random moment tensors are all calculated from modeled single forces, making the nonlinear inversion computationally reasonable. We apply this method to very-long-period (VLP) seismic events that accompany minor eruptions at Fuego volcano, Guatemala. The library of single force Green's functions is computed with a 3D finite-difference modeling algorithm through a homogeneous velocity-density model that includes topography, for a 3D grid of nodes, spaced 40 m apart, within the summit region. The homogenous velocity and density model is justified by long wavelength of VLP data. The nonlinear inversion reveals well resolved model features and informs the interpretation through a better understanding of the possible models. This approach can also be used to evaluate possible station geometries in order to optimize networks prior to deployment.

  1. VALVE: Volcano Analysis and Visualization Environment (United States)

    Cervelli, D. P.; Cervelli, P.; Miklius, A.; Krug, R.; Lisowski, M.


    Modern volcano observatories collect data using a wide variety of instruments. Visualizing these disparate data on a common time base is critical to interpreting and reacting to geophysical changes. With this in mind, the Hawaiian Volcano Observatory (HVO) created Valve, the Volcano Analysis and Visualization Environment. Valve integrates a wide range of both continuous and discontinuous data sources into a common, internet web-browser based interface that allows scientists to interactively select and visualize these data on a common time base and, if appropriate, in three dimensions. Advances in modern internet browser technology allow for a truly interactive user-interface experience that could previously only be found in stand-alone applications--all while maintaining client platform independence and network portability. This system aids more traditional in-depth analysis by providing a common front-end to retrieving raw data. In most cases, the raw data are being served from an SQL database, a system that lends itself to quickly retrieving, logically arranging, and safely storing data. Beyond Valve's visualization capabilities, the system also provides a variety of tools for time series analysis and source modeling. For example, a user could load several tilt and GPS time series, estimate co-seismic or co-intrusive deformation, and then model the event with an elastic point source or dislocation. From the source model, Coulomb stress changes could be calculated and compared to pre- and post-event hypocenter distribution. Employing a heavily object-oriented design, Valve is easily extensible, modular, portable, and remarkably cost efficient. Quickly visualizing arbitrary data is a trivial matter, while implementing methods for permanent, continuous data streams requires only minimal programming. Portability is ensured by using software that is readily available on a wide variety of operating systems; cost efficiency is achieved by using software that is open

  2. Copahue volcano and its regional magmatic setting (United States)

    Varekamp, J C; Zareski, J E; Camfield, L M; Todd, Erin


    Copahue volcano (Province of Neuquen, Argentina) has produced lavas and strombolian deposits over several 100,000s of years, building a rounded volcano with a 3 km elevation. The products are mainly basaltic andesites, with the 2000–2012 eruptive products the most mafic. The geochemistry of Copahue products is compared with those of the main Andes arc (Llaima, Callaqui, Tolhuaca), the older Caviahue volcano directly east of Copahue, and the back arc volcanics of the Loncopue graben. The Caviahue rocks resemble the main Andes arc suite, whereas the Copahue rocks are characterized by lower Fe and Ti contents and higher incompatible element concentrations. The rocks have negative Nb-Ta anomalies, modest enrichments in radiogenic Sr and Pb isotope ratios and slightly depleted Nd isotope ratios. The combined trace element and isotopic data indicate that Copahue magmas formed in a relatively dry mantle environment, with melting of a subducted sediment residue. The back arc basalts show a wide variation in isotopic composition, have similar water contents as the Copahue magmas and show evidence for a subducted sedimentary component in their source regions. The low 206Pb/204Pb of some backarc lava flows suggests the presence of a second endmember with an EM1 flavor in its source. The overall magma genesis is explained within the context of a subducted slab with sediment that gradually looses water, water-mobile elements, and then switches to sediment melt extracts deeper down in the subduction zone. With the change in element extraction mechanism with depth comes a depletion and fractionation of the subducted complex that is reflected in the isotope and trace element signatures of the products from the main arc to Copahue to the back arc basalts.

  3. Mechanical coupling between earthquakes, volcanos and landslides (United States)

    Feigl, K. L.; Retina Team


    "The eruption began as a large earthquake that triggered a massive landslide that culminated in a violent lateral explosion" [Malone et al., USGS 1981]. The 1980 eruption of Mount St. Helens taught a very powerful lesson -- that one natural hazard can trigger another. For example, earthquakes have triggered landslides in Papua New Guinea. Similarly, eruptions of Vesuvius are mechanically coupled to earthquakes in the Appenines, just as an inflating magma chamber can trigger earthquakes near Hengill volcano in SW Iceland and on the Izu Peninsula in Japan. The Luzon earthquake may have triggered the eruption of Mount Pinatubo. In many of these cases, the second triggered event caused more damage than the initial one. If we can better understand the mechanical coupling underlying the temporal and spatial correlation of such events, we will improve our assessments of the hazards they pose. The RETINA project has been funded by the European Commission's 5th Framework to study couplings between three classes of natural hazards: earthquakes, landslides, and volcanoes. These three phenomena are linked to and by the stress field in the crust. If the stress increases enough, the material will fail catastrophically. For example, magma injection beneath a volcano can trigger an earthquake by increasing stress on a fault. Increasing shear stress on unconsolidated materials on steep slopes can trigger landslides. Such stress change triggers may also be tectonic (from plate driving forces), hydrological (from heavy rain), or volcanic (magmatic injection). Any of these events can perturb the stress field enough to trigger another event. Indeed, stress changes as small as 0.1 bar (0.01 MPa) suffice to trigger an earthquake. If the medium is close to failure, this small change can increase the Coulomb stress beyond the yield threshold, breaking the material. This quantity is the primary means we will use for describing mechanical coupling. In this paper, we will review several case

  4. Sustainability of fossil fuels and alternative energies for Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Tasdemiroglu, E.


    Reserves and production of fossil fuels in Turkey are discussed, as well as projections of production rates to the year 2010. Sustainability of fossil-fuel production has been estimated on the basis of presently known data. Fossil fuels will have a very limited lifetime. Bitumens, hydropower, geothermal energy, solar energy, wind power, biomass, and nuclear energy are appropriate alternative technologies. The potentials of these alternatives are given and recommendations made to enhance their contributions. 19 refs., 1 fig., 2 tabs.

  5. Geology of El Chichon volcano, Chiapas, Mexico (United States)

    Duffield, W.A.; Tilling, R.I.; Canul, R.


    The (pre-1982) 850-m-high andesitic stratovolcano El Chicho??n, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, Me??xico. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chicho??n is built on Tertiary siltstone and sandstone, underlain by Cretaceous dolomitic limestone; a 4-km-deep bore hole near the east base of the volcano penetrated this limestone and continued 770 m into a sequence of Jurassic or Cretaceous evaporitic anhydrite and halite. The basement rocks are folded into generally northwest-trending anticlines and synclines. El Chicho??n is built over a small dome-like structure superposed on a syncline, and this structure may reflect cumulative deformation related to growth of a crustal magma reservoir beneath the volcano. The cone of El Chicho??n consists almost entirely of pyroclastic rocks. The pre-1982 cone is marked by a 1200-m-diameter (explosion?) crater on the southwest flank and a 1600-m-diameter crater apparently of similar origin at the summit, a lava dome partly fills each crater. The timing of cone and dome growth is poorly known. Field evidence indicates that the flank dome is older than the summit dome, and K-Ar ages from samples high on the cone suggest that the flank dome is older than about 276,000 years. At least three pyroclastic eruptions have occurred during the past 1250 radiocarbon years. Nearly all of the pyroclastic and dome rocks are moderately to highly porphyritic andesite, with plagioclase, hornblende and clinopyroxene the most common phenocrysts. Geologists who mapped El Chicho??n in 1980 and 1981 warned that the volcano posed a substantial hazard to the surrounding region. This warning was proven to be prophetic by violent eruptions that occurred in March and April of 1982. These eruptions blasted away nearly all of the summit dome, blanketed the surrounding region with tephra, and sent

  6. Mud Volcanoes as Exploration Targets on Mars (United States)

    Allen, Carlton C.; Oehler, Dorothy Z.


    Tens of thousands of high-albedo mounds occur across the southern part of the Acidalia impact basin on Mars. These structures have geologic, physical, mineralogic, and morphologic characteristics consistent with an origin from a sedimentary process similar to terrestrial mud volcanism. The potential for mud volcanism in the Northern Plains of Mars has been recognized for some time, with candidate mud volcanoes reported from Utopia, Isidis, northern Borealis, Scandia, and the Chryse-Acidalia region. We have proposed that the profusion of mounds in Acidalia is a consequence of this basin's unique geologic setting as the depocenter for the tune fraction of sediments delivered by the outflow channels from the highlands.

  7. Galactic Super-volcano in Action (United States)


    A galactic "super-volcano" in the massive galaxy M87 is erupting and blasting gas outwards, as witnessed by NASA's Chandra X-ray Observatory and NSF's Very Large Array. The cosmic volcano is being driven by a giant black hole in the galaxy's center and preventing hundreds of millions of new stars from forming. Astronomers studying this black hole and its effects have been struck by the remarkable similarities between it and a volcano in Iceland that made headlines earlier this year. At a distance of about 50 million light years, M87 is relatively close to Earth and lies at the center of the Virgo cluster, which contains thousands of galaxies. M87's location, coupled with long observations over Chandra's lifetime, has made it an excellent subject for investigations of how a massive black hole impacts its environment. "Our results show in great detail that supermassive black holes have a surprisingly good control over the evolution of the galaxies in which they live," said Norbert Werner of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University and the SLAC National Accelerator Laboratory, who led one of two papers describing the study. "And it doesn't stop there. The black hole's reach extends ever farther into the entire cluster, similar to how one small volcano can affect practically an entire hemisphere on Earth." The cluster surrounding M87 is filled with hot gas glowing in X-ray light, which is detected by Chandra. As this gas cools, it can fall toward the galaxy's center where it should continue to cool even faster and form new stars. However, radio observations with the Very Large Array suggest that in M87 jets of very energetic particles produced by the black hole interrupt this process. These jets lift up the relatively cool gas near the center of the galaxy and produce shock waves in the galaxy's atmosphere because of their supersonic speed. The scientists involved in this research have found the interaction of this cosmic

  8. Volcano morphometry and volume scaling on Venus (United States)

    Garvin, J. B.; Williams, R. S., Jr.


    A broad variety of volcanic edifices have been observed on Venus. They ranged in size from the limits of resolution of the Magellan SAR (i.e., hundreds of meters) to landforms over 500 km in basal diameter. One of the key questions pertaining to volcanism on Venus concerns the volume eruption rate or VER, which is linked to crustal productivity over time. While less than 3 percent of the surface area of Venus is manifested as discrete edifices larger than 50 km in diameter, a substantial component of the total crustal volume of the planet over the past 0.5 Ga is related to isolated volcanoes, which are certainly more easily studied than the relatively diffusely defined plains volcanic flow units. Thus, we have focused our efforts on constraining the volume productivity of major volcanic edifices larger than 100 km in basal diameter. Our approach takes advantage of the topographic data returned by Magellan, as well as our database of morphometric statistics for the 20 best known lava shields of Iceland, plus Mauna Loa of Hawaii. As part of this investigation, we have quantified the detailed morphometry of nearly 50 intermediate to large scale edifices, with particular attention to their shape systematics. We found that a set of venusian edifices which include Maat, Sapas, Tepev, Sif, Gula, a feature at 46 deg S, 215 deg E, as well as the shield-like structure at 10 deg N, 275 deg E are broadly representative of the approx. 400 volcanic landforms larger than 50 km. The cross-sectional shapes of these 7 representative edifices range from flattened cones (i.e., Sif) similar to classic terrestrial lava shields such as Mauna Loa and Skjaldbreidur, to rather dome-like structures which include Maat and Sapas. The majority of these larger volcanoes surveyed as part of our study displayed cross-sectional topographies with paraboloidal shaped, in sharp contrast with the cone-like appearance of most simple terrestrial lava shields. In order to more fully explore the

  9. Volcano deformation and subdaily GPS products (United States)

    Grapenthin, Ronni

    Volcanic unrest is often accompanied by hours to months of deformation of the ground that is measurable with high-precision GPS. Although GPS receivers are capable of near continuous operation, positions are generally estimated for daily intervals, which I use to infer characteristics of a volcano’s plumbing system. However, GPS based volcano geodesy will not be useful in early warning scenarios unless positions are estimated at high rates and in real time. Visualization and analysis of dynamic and static deformation during the 2011 Tohokuoki earthquake in Japan motivates the application of high-rate GPS from a GPS seismology perspective. I give examples of dynamic seismic signals and their evolution to the final static offset in 30 s and 1 s intervals, which demonstrates the enhancement of subtle rupture dynamics through increased temporal resolution. This stresses the importance of processing data at recording intervals to minimize signal loss. Deformation during the 2009 eruption of Redoubt Volcano, Alaska, suggested net deflation by 0.05 km³ in three distinct phases. Mid-crustal aseismic precursory inflation began in May 2008 and was detected by a single continuous GPS station about 28 km NE of Redoubt. Deflation during the explosive and effusive phases was sourced from a vertical ellipsoidal reservoir at about 7-11.5 km. From this I infer a model for the temporal evolution of a complex plumbing system of at least 2 sources during the eruption. Using subdaily GPS positioning solutions I demonstrate that plumes can be detected and localized by utilizing information on phase residuals. The GPS network at Bezymianny Volcano, Kamchatka, records network wide subsidence at rapid rates between 8 and 12 mm/yr from 2005-2010. I hypothesize this to be caused by continuous deflation of a ˜30 km deep sill under Kluchevskoy Volcano. Interestingly, 1-2 explosive events per year cause little to no deformation at any site other than the summit site closest to the vent. I

  10. Magmatic gas scrubbing: Implications for volcano monitoring (United States)

    Symonds, R.B.; Gerlach, T.M.; Reed, M.H.


    Despite the abundance of SO2(g) in magmatic gases, precursory increases in magmatic SO2(g) are not always observed prior to volcanic eruption, probably because many terrestrial volcanoes contain abundant groundwater or surface water that scrubs magmatic gases until a dry pathway to the atmosphere is established. To better understand scrubbing and its implications for volcano monitoring, we model thermochemically the reaction of magmatic gases with water. First, we inject a 915??C magmatic gas from Merapi volcano into 25??C air-saturated water (ASW) over a wide range of gas/water mass ratios from 0.0002 to 100 and at a total pressure of 0.1 MPa. Then we model closed-system cooling of the magmatic gas, magmatic gas-ASW mixing at 5.0 MPa, runs with varied temperature and composition of the ASW, a case with a wide range of magmatic-gas compositions, and a reaction of a magmatic gas-ASW mixture with rock. The modeling predicts gas and water compositions, and, in one case, alteration assemblages for a wide range of scrubbing conditions; these results can be compared directly with samples from degassing volcanoes. The modeling suggests that CO2(g) is the main species to monitor when scrubbing exists; another candidate is H2S(g), but it can be affected by reactions with aqueous ferrous iron. In contrast, scrubbing by water will prevent significant SO2(g) and most HCl(g) emissions until dry pathways are established, except for moderate HCl(g) degassing from pH 100 t/d (tons per day) of SO2(g) in addition to CO2(g) and H2S(g) should be taken as a criterion of magma intrusion. Finally, the modeling suggests that the interpretation of gas-ratio data requires a case-by-case evaluation since ratio changes can often be produced by several mechanisms; nevertheless, several gas ratios may provide useful indices for monitoring the drying out of gas pathways. Published by Elsevier Science B.V.

  11. Slow slip event at Kilauea Volcano (United States)

    Poland, Michael P.; Miklius, Asta; Wilson, J. David; Okubo, Paul G.; Montgomery-Brown, Emily; Segall, Paul; Brooks, Benjamin; Foster, James; Wolfe, Cecily; Syracuse, Ellen; Thurbe, Clifford


    Early in the morning of 1 February 2010 (UTC; early afternoon 31 January 2010 local time), continuous Global Positioning System (GPS) and tilt instruments detected a slow slip event (SSE) on the south flank of Kilauea volcano, Hawaii. The SSE lasted at least 36 hours and resulted in a maximum of about 3 centimeters of seaward displacement. About 10 hours after the start of the slip, a flurry of small earthquakes began (Figure 1) in an area of the south flank recognized as having been seismically active during past SSEs [Wolfe et al., 2007], suggesting that the February earthquakes were triggered by stress associated with slip [Segall et al., 2006].

  12. Mud volcanoes of trinidad as astrobiological analogs for martian environments. (United States)

    Hosein, Riad; Haque, Shirin; Beckles, Denise M


    Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil's Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region.

  13. Mud Volcanoes of Trinidad as Astrobiological Analogs for Martian Environments

    Directory of Open Access Journals (Sweden)

    Riad Hosein


    Full Text Available Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i Digity; (ii Piparo and (iii Devil’s Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region.

  14. Water in volcanoes: evolution, storage and rapid release during landslides. (United States)

    Delcamp, Audray; Roberti, Gioachino; van Wyk de Vries, Benjamin


    Volcanoes can store and drain water that is used as a valuable resource by populations living on their slopes. The water drainage and storage pattern depend on the volcano lithologies and structure, as well as the geological and hydrometric settings. The drainage and storage pattern will change according to the hydrometric conditions, the vegetation cover, the eruptive activity and the long- and short-term volcano deformation. Inspired by our field observations and based on geology and structure of volcanic edifices, on hydrogeological studies, and modelling of water flow in opening fractures, we develop a model of water storage and drainage linked with volcano evolution. This paper offers a first-order general model of water evolution in volcanoes.

  15. Investigating the cores of fossil systems with Chandra

    CERN Document Server

    Bharadwaj, V; Sanders, J S; Schellenberger, G


    We investigate the cores of fossil galaxy groups and clusters (`fossil systems') using archival Chandra data for a sample of 17 fossil systems. We determined the cool-core fraction for fossils via three observable diagnostics, the central cooling time, cuspiness, and concentration parameter. We quantified the dynamical state of the fossils by the X-ray peak/brightest cluster galaxy (BCG), and the X-ray peak/emission weighted centre separations. We studied the X-ray emission coincident with the BCG to detect the presence of potential thermal coronae. A deprojection analysis was performed for z < 0.05 fossils to obtain cooling time and entropy profiles, and to resolve subtle temperature structures. We investigated the Lx-T relation for fossils from the 400d catalogue to see if the scaling relation deviates from that of other groups. Most fossils are identified as cool-core objects via at least two cool-core diagnostics. All fossils have their dominant elliptical galaxy within 50 kpc of the X-ray peak, and mo...

  16. Reconstructing Carotenoid-Based and Structural Coloration in Fossil Skin. (United States)

    McNamara, Maria E; Orr, Patrick J; Kearns, Stuart L; Alcalá, Luis; Anadón, Pere; Peñalver, Enrique


    Evidence of original coloration in fossils provides insights into the visual communication strategies used by ancient animals and the functional evolution of coloration over time [1-7]. Hitherto, all reconstructions of the colors of reptile integument and the plumage of fossil birds and feathered dinosaurs have been of melanin-based coloration [1-6]. Extant animals also use other mechanisms for producing color [8], but these have not been identified in fossils. Here we report the first examples of carotenoid-based coloration in the fossil record, and of structural coloration in fossil integument. The fossil skin, from a 10 million-year-old colubrid snake from the Late Miocene Libros Lagerstätte (Teruel, Spain) [9, 10], preserves dermal pigment cells (chromatophores)-xanthophores, iridophores, and melanophores-in calcium phosphate. Comparison with chromatophore abundance and position in extant reptiles [11-15] indicates that the fossil snake was pale-colored in ventral regions; dorsal and lateral regions were green with brown-black and yellow-green transverse blotches. Such coloration most likely functioned in substrate matching and intraspecific signaling. Skin replicated in authigenic minerals is not uncommon in exceptionally preserved fossils [16, 17], and dermal pigment cells generate coloration in numerous reptile, amphibian, and fish taxa today [18]. Our discovery thus represents a new means by which to reconstruct the original coloration of exceptionally preserved fossil vertebrates.

  17. Energy properties of solid fossil fuels and solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Holubcik, Michal, E-mail:; Jandacka, Jozef, E-mail: [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 8215/1, 010 26 Žilina (Slovakia); Kolkova, Zuzana, E-mail: [Research centre, University of Žilina, Univerzitna 8215/1, 010 26 Žilina (Slovakia)


    The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

  18. Energy properties of solid fossil fuels and solid biofuels (United States)

    Holubcik, Michal; Kolkova, Zuzana; Jandacka, Jozef


    The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

  19. Triassic leech cocoon from Antarctica contains fossil bell animal

    DEFF Research Database (Denmark)

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.


    Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however......, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica...

  20. Tilt prior to explosions and the effect of topography on ultra-long-period seismic records at Fuego volcano, Guatemala (United States)

    Lyons, John J.; Waite, Gregory P.; Ichihara, Mie; Lees, Jonathan M.


    Ground tilt is measured from broadband seismic records prior to frequent explosions at Fuego volcano, Guatemala. We are able to resolve tilt beginning 20-30 minutes prior to explosions, followed by a rapid reversal in deformation coincident with explosion onsets. The tilt amplitude and polarity recorded on the horizontal channels vary from station to station such that the steep and unusual topography of the upper cone of Fuego appears to affect the ultra-long-period signals. We account for the effect of topography and attempt to constrain the tilt source depth and geometry through finite-difference modeling. The results indicate a shallow spherical pressure source, and that topography must be considered when attempting to model tilt sources at volcanoes with steep topography. The tilt signals are interpreted as pressurization of the shallow conduit beneath a crystallized plug followed by elastic deflation concurrent with explosive pressure release.

  1. Geochemical investigation of Gabbroic Xenoliths from Hualalai Volcano: Implications for lower oceanic crust accretion and Hualalai Volcano magma storage system (United States)

    Gao, Ruohan; Lassiter, John C.; Barnes, Jaime D.; Clague, David A.; Bohrson, Wendy A.


    The patterns of axial hydrothermal circulation at mid-ocean ridges both affect and are influenced by the styles of magma plumbing. Therefore, the intensity and distribution of hydrothermal alteration in the lower oceanic crust (LOC) can provide constraints on LOC accretion models (e.g., "gabbro glacier" vs. "multiple sills"). Gabbroic xenoliths from Hualalai Volcano, Hawaii include rare fragments of in situ Pacific lower oceanic crust. Oxygen and strontium isotope compositions of 16 LOC-derived Hualalai gabbros are primarily within the range of fresh MORB, indicating minimal hydrothermal alteration of the in situ Pacific LOC, in contrast to pervasive alteration recorded in LOC xenoliths from the Canary Islands. This difference may reflect less hydrothermal alteration of LOC formed at fast ridges than at slow ridges. Mid-ocean ridge magmas from slow ridges also pond on average at greater and more variable depths and undergo less homogenization than those from fast ridges. These features are consistent with LOC accretion resembling the "multiple sills" model at slow ridges. In contrast, shallow magma ponding and limited hydrothermal alteration in LOC at fast ridges are consistent with the presence of a long-lived shallow magma lens, which limits the penetration of hydrothermal circulation into the LOC. Most Hualalai gabbros have geochemical and petrologic characteristics indicating derivation from Hualalai shield-stage and post-shield-stage cumulates. These xenoliths provide information on the evolution of Hawaiian magmas and magma storage systems. MELTS modeling and equilibration temperatures constrain the crystallization pressures of 7 Hualalai shield-stage-related gabbros to be ∼2.5-5 kbar, generally consistent with inferred local LOC depth. Therefore a deep magma reservoir existed within or at the base of the LOC during the shield stage of Hualalai Volcano. Melt-crust interaction between Hawaiian melts and in situ Pacific crust during magma storage partially

  2. A structural approach in the study of bones: fossil and burnt bones at nanosize scale (United States)

    Piga, Giampaolo; Baró, Maria Dolors; Escobal, Irati Golvano; Gonçalves, David; Makhoul, Calil; Amarante, Ana; Malgosa, Assumpció; Enzo, Stefano; Garroni, Sebastiano


    We review the different factors affecting significantly mineral structure and composition of bones. Particularly, it is assessed that micro-nanostructural and chemical properties of skeleton bones change drastically during burning; the micro- and nanostructural changes attending those phases manifest themselves, amongst others, in observable alterations to the bones colour, morphology, microstructure, mechanical strength and crystallinity. Intense changes involving the structure and chemical composition of bones also occur during the fossilization process. Bioapatite material is contaminated by an heavy fluorination process which, on a long-time scale reduces sensibly the volume of the original unit cell, mainly the a-axis of the hexagonal P63/m space group. Moreover, the bioapatite suffers to a varying degree of extent by phase contamination from the nearby environment, to the point that rarely a fluorapatite single phase may be found in fossil bones here examined. TEM images supply precise and localized information, on apatite crystal shape and dimension, and on different processes that occur during thermal processes or fossilization of ancient bone, complementary to that given by X-ray diffraction and Attenuated Total Reflection Infrared spectroscopy. We are presenting a synthesis of XRD, ATR-IR and TEM results on the nanostructure of various modern, burned and palaeontological bones.

  3. Eruptive History of the Rhyolitic Guangoche Volcano, Los Azufres Volcanic Field, Central Mexico (United States)

    Rangel Granados, E.; Arce, J. L.; Macias, J. L.; Layer, P. W.


    Guangoche is a rhyolitic and polygenetic volcano with a maximum elevation of 2,760 meters above sea level. It is situated to the southwest of the Los Azufres Volcanic Field (LAVF), in the central sector of the Trans-Mexican Volcanic Belt. Guangoche volcano is the youngest volcano described within the LAVF. It shows a horseshoe shaped crater open to the south, with a central lava dome. Its eruptive history during late Pleistocene has been intense with six explosive eruptions that consists of: 1) A southwards sector collapse of the volcano that generated a debris avalanche deposit with megablocks of heterogenous composition; 2) A plinian-type eruption that generated a pumice fall deposit and pyroclastic density currents by column collapse at 30.6 ka; 3) A plinian-type eruption "White Pumice Sequence" (29 ka) that developed a 22-km-high eruptive column, with a MDR of 7.0 x 107 kg/s (vol. = 0.53 km3); 4) A dome-destruction event, "Agua Blanca Pyroclastic Sequence" at 26.7 ka, that deposited a block-and-ash flow deposit; 5) A subplinian-plinian type eruption "Ochre Pyroclastic Sequence" (<26 ka) with an important initial phreatomagmatic phase, that generated pyroclastic density currents and pumice fallouts. The subplinian-plinian event generated a 16-km-high eruptive column, with a MDR of 1.9 x 107 kg/s, and magma volume of 0.38 km3; 6) The eruptive history ended with a subplinian eruption (<<26 ka), that generated a multilayered fall deposit, that developed a 11-km-high eruptive column, with a MDR of 2.9 x 106 kg/s and a magma volume of 0.26 km3. Volcanic activity at Guangoche volcano has been intense and future activity should not be discarded. Unfortunately, the last two events have not been dated yet. Guangoche rhyolitic magma is characterized by low-Ba contents suggesting crystal mush extraction for their genesis.

  4. Translating Volcano Hazards Research in the Cascades Into Community Preparedness (United States)

    Ewert, J. W.; Driedger, C. L.


    Research by the science community into volcanic histories and physical processes at Cascade volcanoes in the states of Washington, Oregon, and California has been ongoing for over a century. Eruptions in the 20th century at Lassen Peak and Mount St. Helen demonstrated the active nature of Cascade volcanoes; the 1980 eruption of Mount St. Helens was a defining moment in modern volcanology. The first modern volcano hazards assessments were produced by the USGS for some Cascade volcanoes in the 1960s. A rich scientific literature exists, much of which addresses hazards at these active volcanoes. That said community awareness, planning, and preparation for eruptions generally do not occur as a result of a hazard analyses published in scientific papers, but by direct communication with scientists. Relative to other natural hazards, volcanic eruptions (or large earthquakes, or tsunami) are outside common experience, and the public and many public officials are often surprised to learn of the impacts volcanic eruptions could have on their communities. In the 1980s, the USGS recognized that effective hazard communication and preparedness is a multi-faceted, long-term undertaking and began working with federal, state, and local stakeholders to build awareness and foster community action about volcano hazards. Activities included forming volcano-specific workgroups to develop coordination plans for volcano emergencies; a concerted public outreach campaign; curriculum development and teacher training; technical training for emergency managers and first responders; and development of hazard information that is accessible to non-specialists. Outcomes include broader ownership of volcano hazards as evidenced by bi-national exchanges of emergency managers, community planners, and first responders; development by stakeholders of websites focused on volcano hazards mitigation; and execution of table-top and functional exercises, including evacuation drills by local communities.

  5. Changing depths of magma fractionation and stagnation during the evolution of an oceanic island volcano: La Palma (Canary Islands) (United States)

    Galipp, Karsten; Klügel, Andreas; Hansteen, Thor H.


    La Palma (Canary Islands) represents an oceanic island volcano with an active rift zone, inferred to have formed during the last 800 ka following southward growth of the former radial-symmetrical stratovolcano Taburiente. We carried out clinopyroxene-melt thermobarometry and microthermometry of fluid inclusions to reconstruct the evolution of the magma plumbing systems over time and to understand the genetic relationship between Taburiente and the presently active Cumbre Vieja rift zone. Clinopyroxene-melt equilibria of phenocryst rims and glassy groundmass indicate pressures of 0.60-1.04 GPa (˜19-34 km depth) for Taburiente, 0.47-1.17 GPa (16-40 km) for the former Cumbre Nueva rift arm of Taburiente, and 0.50-0.78 GPa (16-26 km) for Bejenado volcano that formed after collapse of the Cumbre Nueva rift. These pressures are interpreted to reflect depths of magma storage and major crystal fractionation. CO 2-dominated fluid inclusions hosted by clinopyroxenes and olivines indicate pressures of formation or re-equilibration within an overall range of 0.25-0.61 GPa (˜8-19 km depth). Respective frequency maxima are at 0.41-0.50 GPa for Taburiente dunite xenoliths, 0.26-0.43 GPa for Cumbre Nueva ankaramites, and 0.26-0.32 GPa for Bejenado cumulate xenoliths. These pressures are interpreted to reflect levels of temporary magma stagnation during ascent. Our data show that the magma pathways during all volcanic phases including the presently active Cumbre Vieja rift [Klügel, A., Hansteen, T.H., Galipp, K., 2005. Magma storage and underplating beneath Cumbre Vieja volcano, La Palma (Canary Islands). Earth and Planetary Science Letters 236, 211-226] are characterized by two distinct storage levels: a system of prolonged storage within the upper mantle, and a system of short-term stagnation within the lower crust or near to the Moho. Both the mantle and crustal storage systems show a migration to shallower levels from 1.0 Ma to present, probably as a result of changing

  6. The volcanoes and clouds of Venus (United States)

    Prinn, R. G.


    One of the earth's most intriguing features is its geologic activity. However, volcanic eruptions have not been observed on any other body in the solar system, except for a detection of such eruptions on Jupiter's moon Io. As in a number of respects Venus is similar to earth, questions arise regarding the presence of active volcanoes on Venus. In the past, the study of such questions was made difficult or impossible by the layer of clouds surrounding the Venusian surface. In the past half decade the situation has changed. These changes are mainly related to studies based on a utilization of radio waves and microwaves which can pass through the cloud layer. Such studies have been conducted with the aid of terrestrial radio telescopes, the Pioneer Venus satellite orbiting Venus, and two Russian spacecraft. The results of these studies are discussed in detail. It appears that there are active volcanoes on Venus. This volcanism is a key link in the chemical cycle which produces the clouds. The levels of volcanic activity on Venus and earth seem to be roughly comparable.

  7. Volcano-ice interactions on Mars (United States)

    Allen, C. C.


    Central volcanic eruptions beneath terrestrial glaciers have built steep-sided, flat-topped mountains composed of pillow lava, glassy tuff, capping flows, and cones of basalt. Subglacial fissure eruptions produced ridges of similar composition. In some places the products from a number of subglacial vents have combined to form widespread deposits. The morphologies of these subglacial volcanoes are distinctive enough to allow their recognition at the resolutions characteristic of Viking orbiter imagery. Analogs to terrestrial subglacial volcanoes have been identified on the northern plains and near the south polar cap of Mars. The polar feature provides probable evidence of volcanic eruptions beneath polar ice. A mixed unit of rock and ice is postulated to have overlain portions of the northern plains, with eruptions into this ground ice having produced mountains and ridges analogous to those in Iceland. Subsequent breakdown of this unit due to ice melting revealed the volcanic features. Estimated heights of these landforms indicate that the ice-rich unit once ranged from approximately 100 to 1200 m thick.

  8. Monitoring Santorini volcano (Greece) breathing from space (United States)

    Foumelis, Michael; Trasatti, Elisa; Papageorgiou, Elena; Stramondo, Salvatore; Parcharidis, Issaak


    Since its last eruption in 1950, Santorini volcano (Greece) remained in a dormant state. This is also evidenced for the period 1992-2010 by the gradual deflation signal over Nea Kameni as measured by satellite Synthetic Aperture Radar Interferometry (InSAR) with low rates of about 5-6 mm yr-1 as well as by the absence of seismic activity within the caldera. However, at the beginning of 2011 the volcano showed signs of unrest with increased microseismic activity and significant ground uplift, reaching 14 cm within a year (2011 March-2012 March), according to InSAR time-series. ALOS PALSAR data indicate the onset of the phenomenon in early 2010 where an aseismic pre-unrest phase of increased subsidence (1-3 cm) preceded the uplift. Joint inversions of SAR and GPS velocities using spherical and spheroidal magmatic source types indicate their location offshore at about 1 km north of Nea Kameni and between 3.5 and 3.8 km depth. The estimated volume variation rate is 6 × 106 m3 yr-1 to 9 × 106 m3 yr-1. A gradual slowing in the rate of inflation within the first quarter of 2012 is apparent by ENVISAT data, while subsequent observations from RADARSAT-2 confirm the observed trend.

  9. Paleoarchean trace fossils in altered volcanic glass (United States)

    Staudigel, Hubert; Furnes, Harald; DeWit, Maarten


    Microbial corrosion textures in volcanic glass from Cenozoic seafloor basalts and the corresponding titanite replacement microtextures in metamorphosed Paleoarchean pillow lavas have been interpreted as evidence for a deep biosphere dating back in time through the earliest periods of preserved life on earth. This interpretation has been recently challenged for Paleoarchean titanite replacement textures based on textural and geochronological data from pillow lavas in the Hooggenoeg Complex of the Barberton Greenstone Belt in South Africa. We use this controversy to explore the strengths and weaknesses of arguments made in support or rejection of the biogenicity interpretation of bioalteration trace fossils in Cenozoic basalt glasses and their putative equivalents in Paleoarchean greenstones. Our analysis suggests that biogenicity cannot be taken for granted for all titanite-based textures in metamorphosed basalt glass, but a cautious and critical evaluation of evidence suggests that biogenicity remains the most likely interpretation for previously described titanite microtextures in Paleoarchean pillow lavas. PMID:26038543

  10. Paleoarchean trace fossils in altered volcanic glass. (United States)

    Staudigel, Hubert; Furnes, Harald; DeWit, Maarten


    Microbial corrosion textures in volcanic glass from Cenozoic seafloor basalts and the corresponding titanite replacement microtextures in metamorphosed Paleoarchean pillow lavas have been interpreted as evidence for a deep biosphere dating back in time through the earliest periods of preserved life on earth. This interpretation has been recently challenged for Paleoarchean titanite replacement textures based on textural and geochronological data from pillow lavas in the Hooggenoeg Complex of the Barberton Greenstone Belt in South Africa. We use this controversy to explore the strengths and weaknesses of arguments made in support or rejection of the biogenicity interpretation of bioalteration trace fossils in Cenozoic basalt glasses and their putative equivalents in Paleoarchean greenstones. Our analysis suggests that biogenicity cannot be taken for granted for all titanite-based textures in metamorphosed basalt glass, but a cautious and critical evaluation of evidence suggests that biogenicity remains the most likely interpretation for previously described titanite microtextures in Paleoarchean pillow lavas.

  11. Paleophysiology: From Fossils to the Future. (United States)

    Vermeij, Geerat J


    Future environments may resemble conditions that have not existed for millions of years. To assess the adaptive options available to organisms evolving under such circumstances, it is instructive to probe paleophysiology, the ways in which ancient life coped with its physical and chemical surroundings. To do this, we need reliable proxies that are based on fundamental principles, quantitatively verified in living species, and observable in fossil remains. Insights have already come from vertebrates and plants, and others will likely emerge for marine animals if promising proxies are validated. Many questions remain about the circumstances for the evolution of environmental tolerances, metabolic rates, biomineralization, and physiological responses to interacting species, and about how living organisms will perform under exceptional conditions.

  12. Hygroscopic motions of fossil conifer cones (United States)

    Poppinga, Simon; Nestle, Nikolaus; Šandor, Andrea; Reible, Bruno; Masselter, Tom; Bruchmann, Bernd; Speck, Thomas


    Conifer cones represent natural, woody compliant structures which move their scales as passive responses to changes in environmental humidity. Here we report on water-driven opening and closing motions in coalified conifer cones from the Eemian Interglacial (approx. 126,000–113,000 years BP) and from the Middle Miocene (approx. 16.5 to 11.5 million years BP). These cones represent by far the oldest documented evidence of plant parts showing full functionality of such passive hydraulically actuated motion. The functional resilience of these structures is far beyond the biological purpose of seed dispersal and protection and is because of a low level of mineralization of the fossils. Our analysis emphasizes the functional-morphological integrity of these biological compliant mechanisms which, in addition to their biological fascination, are potentially also role models for resilient and maintenance-free biomimetic applications (e.g., adaptive and autonomously moving structures including passive hydraulic actuators).

  13. Fossil birds of the Kibish Formation. (United States)

    Louchart, Antoine; Haile-Selassie, Y; Vignaud, P; Likius, A; Brunet, M


    The Kibish Formation has yielded a small collection of bird fossils, which are identified here as belonging to five species in four different families: Pelecanidae (pelicans), Anhingidae (darters), Ardeidae (herons) and Phasianidae (gamefowl). Two species of pelicans are identified: Pelecanus cf. P. onocrotalus, and P. aff. P. rufescens. The darter is referrable to Anhinga melanogaster. The heron is identifiable as Ardea sp., and the gamefowl as Numidinae indet. (guineafowl). Pelecanus cf. P. onocrotalus is represented by, among other remains, a well-preserved partial skull. Four of the birds are thus referrable to extant taxa that provide some paleoenvironmental clues for Member I of the Kibish Formation. The two species of pelican, the darter, and the heron indicate the presence of local freshwater bodies, a lake or a slow river, supporting resources of fish. The guineafowl is poorly informative ecologically, but probably excludes the notion that the local terrestrial landscape was treeless.

  14. Hygroscopic motions of fossil conifer cones (United States)

    Poppinga, Simon; Nestle, Nikolaus; Šandor, Andrea; Reible, Bruno; Masselter, Tom; Bruchmann, Bernd; Speck, Thomas


    Conifer cones represent natural, woody compliant structures which move their scales as passive responses to changes in environmental humidity. Here we report on water-driven opening and closing motions in coalified conifer cones from the Eemian Interglacial (approx. 126,000–113,000 years BP) and from the Middle Miocene (approx. 16.5 to 11.5 million years BP). These cones represent by far the oldest documented evidence of plant parts showing full functionality of such passive hydraulically actuated motion. The functional resilience of these structures is far beyond the biological purpose of seed dispersal and protection and is because of a low level of mineralization of the fossils. Our analysis emphasizes the functional-morphological integrity of these biological compliant mechanisms which, in addition to their biological fascination, are potentially also role models for resilient and maintenance-free biomimetic applications (e.g., adaptive and autonomously moving structures including passive hydraulic actuators). PMID:28074936

  15. The future of oil: unconventional fossil fuels. (United States)

    Chew, Kenneth J


    Unconventional fossil hydrocarbons fall into two categories: resource plays and conversion-sourced hydrocarbons. Resource plays involve the production of accumulations of solid, liquid or gaseous hydro-carbons that have been generated over geological time from organic matter in source rocks. The character of these hydrocarbons may have been modified subsequently, especially in the case of solids and extra-heavy liquids. These unconventional hydrocarbons therefore comprise accumulations of hydrocarbons that are trapped in an unconventional manner and/or whose economic exploitation requires complex and technically advanced production methods. This review focuses primarily on unconventional liquid hydro-carbons. The future potential of unconventional gas, especially shale gas, is also discussed, as it is revolutionizing the energy outlook in North America and elsewhere.

  16. Microbial biocatalyst developments to upgrade fossil fuels. (United States)

    Kilbane, John J


    Steady increases in the average sulfur content of petroleum and stricter environmental regulations concerning the sulfur content have promoted studies of bioprocessing to upgrade fossil fuels. Bioprocesses can potentially provide a solution to the need for improved and expanded fuel upgrading worldwide, because bioprocesses for fuel upgrading do not require hydrogen and produce far less carbon dioxide than thermochemical processes. Recent advances have demonstrated that biodesulfurization is capable of removing sulfur from hydrotreated diesel to yield a product with an ultra-low sulfur concentration that meets current environmental regulations. However, the technology has not yet progressed beyond laboratory-scale testing, as more efficient biocatalysts are needed. Genetic studies to obtain improved biocatalysts for the selective removal of sulfur and nitrogen from petroleum provide the focus of current research efforts.


    Energy Technology Data Exchange (ETDEWEB)

    Melatos, A., E-mail: [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)


    It is argued that the superfluid core of a neutron star super-rotates relative to the crust, because stratification prevents the core from responding to the electromagnetic braking torque, until the relevant dissipative (viscous or Eddington-Sweet) timescale, which can exceed {approx}10{sup 3} yr and is much longer than the Ekman timescale, has elapsed. Hence, in some young pulsars, the rotation of the core today is a fossil record of its rotation at birth, provided that magnetic crust-core coupling is inhibited, e.g., by buoyancy, field-line topology, or the presence of uncondensed neutral components in the superfluid. Persistent core super-rotation alters our picture of neutron stars in several ways, allowing for magnetic field generation by ongoing dynamo action and enhanced gravitational wave emission from hydrodynamic instabilities.

  18. The eukaryotic fossil record in deep time (United States)

    Butterfield, N.


    Eukaryotic organisms are defining constituents of the Phanerozoic biosphere, but they also extend well back into the Proterozoic record, primarily in the form of microscopic body fossils. Criteria for identifying pre-Ediacaran eukaryotes include large cell size, morphologically complex cell walls and/or the recognition of diagnostically eukaryotic cell division patterns. The oldest unambiguous eukaryote currently on record is an acanthomorphic acritarch (Tappania) from the Palaeoproterozoic Semri Group of central India. Older candidate eukaryotes are difficult to distinguish from giant bacteria, prokaryotic colonies or diagenetic artefacts. In younger Meso- and Neoproterozoic strata, the challenge is to recognize particular grades and clades of eukaryotes, and to document their macro-evolutionary expression. Distinctive unicellular forms include mid-Neoproterozoic testate amoebae and phosphate biomineralizing 'scale-microfossils' comparable to an extant green alga. There is also a significant record of seaweeds, possible fungi and problematica from this interval, documenting multiple independent experiments in eukaryotic multicellularity. Taxonomically resolved forms include a bangiacean red alga and probable vaucheriacean chromalveolate algae from the late Mesoproterozoic, and populations of hydrodictyacean and siphonocladalean green algae of mid Neoproterozoic age. Despite this phylogenetic breadth, however, or arguments from molecular clocks, there is no convincing evidence for pre-Ediacaran metazoans or metaphytes. The conspicuously incomplete nature of the Proterozoic record makes it difficult to resolve larger-scale ecological and evolutionary patterns. Even so, both body fossils and biomarker data point to a pre-Ediacaran biosphere dominated overwhelming by prokaryotes. Contemporaneous eukaryotes appear to be limited to conspicuously shallow water environments, and exhibit fundamentally lower levels of morphological diversity and evolutionary turnover than

  19. Space Radar Image of Karisoke & Virunga Volcanoes (United States)


    This is a false-color composite of Central Africa, showing the Virunga volcano chain along the borders of Rwanda, Zaire and Uganda. This area is home to the endangered mountain gorillas. The image was acquired on October 3, 1994, on orbit 58 of the space shuttle Endeavour by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). In this image red is the L-band (horizontally transmitted, vertically received) polarization; green is the C-band (horizontally transmitted and received) polarization; and blue is the C-band (horizontally transmitted and received) polarization. The area is centered at about 2.4 degrees south latitude and 30.8 degrees east longitude. The image covers an area 56 kilometers by 70 kilometers (35 miles by 43 miles). The dark area at the top of the image is Lake Kivu, which forms the border between Zaire (to the right) and Rwanda (to the left). In the center of the image is the steep cone of Nyiragongo volcano, rising 3,465 meters (11,369 feet) high, with its central crater now occupied by a lava lake. To the left are three volcanoes, Mount Karisimbi, rising 4,500 meters (14,800 feet) high; Mount Sabinyo, rising 3,600 meters (12,000 feet) high; and Mount Muhavura, rising 4,100 meters (13,500 feet) high. To their right is Nyamuragira volcano, which is 3,053 meters (10,017 feet) tall, with radiating lava flows dating from the 1950s to the late 1980s. These active volcanoes constitute a hazard to the towns of Goma, Zaire and the nearby Rwandan refugee camps, located on the shore of Lake Kivu at the top left. This radar image highlights subtle differences in the vegetation of the region. The green patch to the center left of the image in the foothills of Karisimbi is a bamboo forest where the mountain gorillas live. The vegetation types in this area are an important factor in the habitat of mountain gorillas. Researchers at Rutgers University in New Jersey and the Dian Fossey Gorilla Fund in London will use this data to produce

  20. Terrestrial Real-Time Volcano Monitoring (United States)

    Franke, M.


    As volcano monitoring involves more and different sensors from seismic to GPS receivers, from video and thermal cameras to multi-parameter probes measuring temperature, ph values and humidity in the ground and the air, it becomes important to design real-time networks that integrate and leverage the multitude of available parameters. In order to do so some simple principles need to be observed: a) a common time base for all measurements, b) a packetized general data communication protocol for acquisition and distribution, c) an open and well documented interface to the data permitting standard and emerging innovative processing, and d) an intuitive visualization platform for scientists and civil defense personnel. Although mentioned as simple principles, the list above does not necessarily lead to obvious solutions or integrated systems, which is, however, required to take advantage of the available data. Only once the different data streams are put into context to each other in terms of time and location can a broader view be obtained and additional information extracted. The presentation is a summary of currently available technologies and how they can achieve the goal of an integrated real-time volcano monitoring system. A common time base are standard for seismic and GPS networks. In different projects we extended this to video feeds and time-lapse photography. Other probes have been integrated with vault interface enclosures (VIE) as used in the Transportable Array (TA) of the USArray. The VIE can accommodate the sensors employed in volcano monitoring. The TA has shown that Antelope is a versatile and robust middleware. It provides the required packetized general communication protocol that is independent from the actual physical communication link leaving the network design to adopt appropriate and possible hybrid solutions. This applies for the data acquisition and the data/information dissemination providing both a much needed collaboration platform, as

  1. Igneous Petrogenesis of Tequila Volcano, Western Mexico (United States)

    Vázquez-Duarte, A.; Gómez-Tuena, A.; Díaz-Bravo, B.


    Tequila volcano belongs to a Quaternary volcanic chain that runs in parallel to the Middle American Trench, but that have been constructed within the so-called Tepic-Zacoalco rift: an extensional tectonic structure that has been active for the past 3.5 Ma. This unusual tectonic setting, and the existence of a high-resolution stratigraphy for the Tequila Volcanic Field (Lewis-Kenedi, 2005, Bull Volcanol), provide an excellent opportunity to study andesite petrogenesis. New comprehensive geochemical data allow the recognition of at least four different magmatic series around Tequila: 1) The Santa Rosa intraplate basalts (1.0 - 0.2 Ma), a volcanic plateau constructed along the Santiago River Fault north of Tequila volcano. These Na-alkaline basalts are olivine-phyric, have negligible subduction signatures (Ba/Nb= 11.75 - 49.36), and display Sr-Nd-Pb isotopic compositions that correlate with fractionation indexes, probably indicating melt-crust interactions. 2) A group of vitreous domes and flows of dacitic to rhyolitic compositions, mostly contemporaneous to the Santa Rosa basalts, that were emplaced on the periphery of Tequila volcano. These rocks can have very low Sr and Eu contents but their isotopic compositions are remarkably constant and similar to the Santa Rosa basalts, probably indicating a genetic link through low pressure fractionation in the stability field of plagioclase. 3) The main edifice of Tequila volcano (~0.2 Ma) is made of two pyroxene andesites and dacites with strong subduction signatures (Ba/Nb= 53-112), that inversely correlate with MgO contents, but that follow a diverging evolutionary trend as the rest of the sequences. The isotopic compositions of Tequila main edifice can extend to slightly more enriched values, but do not correlate with fractionation indexes, thus indicating provenance from a different source. 4) The youngest activity on Tequila volcano (~0.09 Ma) is represented by amphibole bearing andesites that erupted through the

  2. Ground survey of active Central American volcanoes in November - December 1973 (United States)

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.


    The author has identified the following significant results. Thermal anomalies at two volcanoes, Santiaguito and Izalco, have grown in size in the past six months, based on repeated ground survey. Thermal anomalies at Pacaya volcano have became less intense in the same period. Large (500 m diameter) thermal anomalies exist at 3 volcanoes presently, and smaller scale anomalies are found at nine other volcanoes.

  3. Carbonate organo-mineral micro- and ultrastructures in sub-fossil stromatolites: Marion lake, South Australia. (United States)

    Perri, E; Tucker, M E; Spadafora, A


    Sub-fossil stromatolites (5000-3000 years old) occur on the marginal flat surrounding Marion Lake (South Australia). A micrite/microsparite crystal fabric characterises these fine-grained, well-laminated stromatolites, which lack trapped grains. The internal lamination is characterised by a sub-millimetric alternation of porous and dense laminae. The microfabric of the laminae is ubiquitously composed of a fine (10-20 μm) peloidal texture, with many thinner aphanitic layers. Aggregates of very fine, low-Mg calcite and aragonite constitute both peloidal and aphanitic micrite, which is coated, respectively, by spherulitic and fringing acicular microspar. Micrite, with a high organic matter content, is formed of coalescing nanospheres grading into small polyhedrons, probably composed mainly of aragonite, with less calcite enriched in Mg, Sr, Na and S. Bacteria-like microfossils and relics of extracellular polymeric substance (EPS) occur abundantly within this micritic framework. The former consist of empty moulds and mineralised bodies of coccoid forms, whereas EPS relics consist of sheet-like or filamentous structures that appear both mineralised and more often still preserved as a C-enriched dehydrated substance that represents the main organic matter component of the deposit. Acicular crystals, which show a prismatic elongate shape, are composed of Mg-depleted aragonite that lacks fossils or organic relicts. Degrading EPS and micro-organisms appear gradually to be replaced and entombed by the nanospherical precipitates, implying the existence of processes of organo-mineralisation within an original syn-sedimentary microbial community. Succeeding micron-scale crystals merge to form isolated or connected micritic aggregates (the peloids), followed by the gradual formation of the acicular crystals as purely inorganic precipitates.

  4. Fossil Leaves and Fossil Leaf n-Alkanes: Reconstructing the First Closed Canopied Rainforests (United States)

    Graham, H. V.; Freeman, K. H.


    Although the age and location is disputed, the rise of the first closed-canopy forest is likely linked with the expansion of angiosperms in the late Cretacous or early Cenozoic. The carbon isotope 'canopy effect' reflects the extent of canopy closure, and is well documented in δ13C values of the leaves and leaf lipids in modern forests. To test the extent of canopy closure among the oldest documented angiosperm tropical forests, we analyzed isotopic characteristics of leaf fossils and leaf waxes from the Guaduas and Cerrejón Formations. The Guaduas Fm. (Maastrichtian) contains some of the earliest angiosperm fossils in the Neotropics, and both leaf morphology and pollen records at this site suggest an open-canopy structure. The Cerrejón Fm. (Paleocene) contains what are believed to be the first recorded fossil leaves from a closed-canopy forest. We analyzed the bulk carbon isotope content (δ13Cleaf) of 199 fossil leaves, as well as the n-alkane concentration and chain-length distribution, and δ13C of alkanes (δ13Clipid) of 73 fossil leaves and adjacent sediment samples. Fossil leaves are dominated by eudicots and include ten modern plant families (Apocynaceae, Bombaceae, Euphorbaceae, Fabaceae, Lauraceae, Malvaceae, Meliaceae, Menispermaceae, Moraceae, Sapotaceae). We interpreted extent of canopy coverage based on the range of δ13Cleaf values. The narrow range of δ13C values in leaves from the Guaduas Fm (2.7‰) is consistent with an open canopy. A significantly wider range in values (6.3‰) suggests a closed-canopy signature for site 0315 of the Cerrejón Fm,. In contrast, at Site 0318, a lacustrine deposit, leaves had a narrow range (3.3‰) in δ13C values, and this is not consistent with a closed-canopy, but is consistent with leaf assemblages from a forest edge. Leaves that accumulate in lake sediments tend to be biased toward plants living at the lake edge, which do not experience closed-canopy conditions, and do not express the isotopic

  5. Dataset for analysing the relationships among economic growth, fossil fuel and non-fossil fuel consumption. (United States)

    Asafu-Adjaye, John; Byrne, Dominic; Alvarez, Maximiliano


    The data presented in this article are related to the research article entitled 'Economic Growth, Fossil Fuel and Non-Fossil Consumption: A Pooled Mean Group Analysis using Proxies for Capital' (J. Asafu-Adjaye, D. Byrne, M. Alvarez, 2016) [1]. This article describes data modified from three publicly available data sources: the World Bank׳s World Development Indicators (, the U.S. Energy Information Administration׳s International Energy Statistics ( and the Barro-Lee Educational Attainment Dataset ( These data can be used to examine the relationships between economic growth and different forms of energy consumption. The dataset is made publicly available to promote further analyses.

  6. Literature Review of Fossilization Research in Interlanguage Development

    Institute of Scientific and Technical Information of China (English)



    Fossilization has always been a hot area of research for many years, the overcoming of which has been many scholars' top concerns. This thesis reviews the definition, classification, causes and characteristics of fossilization. Also, the research limitations are presented with suggestions for more empirical future study provided.

  7. Microalgal and terrestrial transport biofuels to displace fossil fuels

    NARCIS (Netherlands)

    Reijnders, L.


    Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn, s

  8. Microalgal and terrestrial transport biofuels to displace fossil fuels

    NARCIS (Netherlands)

    Reijnders, L.


    Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn,

  9. Size variation in samples of fossil and recent murid teeth

    NARCIS (Netherlands)

    Freudenthal, M.; Martín Suárez, E.


    The variability coefficient proposed by Freudenthal & Cuenca Bescós (1984) for samples of fossil cricetid teeth, is calculated for about 200 samples of fossil and recent murid teeth. The results are discussed, and compared with those obtained for the Cricetidae.

  10. Fossils and palaeontological distributions of Macaranga and Mallotus (Euphorbiaceae)

    NARCIS (Netherlands)

    Nucete, M.; van Konijnenburg-van Cittert, J.H.A.; van Welzen, P.C.


    The correct identification of described plant fossils from the sister genera Macaranga and Mallotus (Euphorbiaceae) needs to be confirmed in order to correctly date their phylogeny and map their palaeontological distributions. Previous identifications of fossil specimens often appear to be unreliabl

  11. Divesting from Fossil Fuels Makes Sense Morally… and Financially (United States)

    Cleveland, Cutler J.; Reibstein, Richard


    Should university endowments divest from fossil fuels? A public discussion of this question has seen some university presidents issuing statements that they would not divest--that investments should not be used for "political action." Many universities hold large endowments that have significant positions in fossil fuel companies or…

  12. Fossil remains of fungi, algae and other organisms from Jamaica

    NARCIS (Netherlands)

    Germeraad, J.H.


    Fungal remains and other fossils from Cainophytic strata of Jamaica have been compared with species described in mycological and algological publications. Only in a few cases morphologically related taxons have been encountered. The stratigraphie significance of these Jamaican fossils is unknown as

  13. Development of concepts for a zero-fossil-energy greenhouse

    NARCIS (Netherlands)

    Ooster, A. van 't; Henten, E.J. van; Janssen, E.G.O.N.; Bot, G.P.A.; Dekker, E.


    Dutch government and greenhouse horticultural practice aim for strongly reduced fossil energy use and of environmental loads in 2010 and energy neutral greenhouses in 2020. This research aims to design a greenhouse concept with minimal use of fossil energy and independent of nearby greenhouses. The

  14. Maximum fossil fuel feedstock replacement potential of petrochemicals via biorefineries

    NARCIS (Netherlands)

    Brehmer, B.; Boom, R.M.; Sanders, J.P.M.


    The search for feedstock replacement options within the petrochemical industry should logically be based upon non-fossil resources. Retaining the functionality of the biochemicals in biomass for use as chemical products and precursors can lead to a sizeable reduction of fossil fuel consumption. This

  15. Size variation in samples of fossil and recent murid teeth

    NARCIS (Netherlands)

    Freudenthal, M.; Martín Suárez, E.


    The variability coefficient proposed by Freudenthal & Cuenca Bescós (1984) for samples of fossil cricetid teeth, is calculated for about 200 samples of fossil and recent murid teeth. The results are discussed, and compared with those obtained for the Cricetidae.

  16. The financial impact of divestment from fossil fuels

    NARCIS (Netherlands)

    Plantinga, Auke; Scholtens, Bert


    Divesting from fossil companies has been put forward as a means to address climate change. We study the impact of such divesting on investment portfolio performance. To this extent, we systematically investigate the investment performance of portfolios with and without fossil fuel company stocks. We

  17. Fossil Odobenidae in some Dutch collections (Mammalia, Carnivora)

    NARCIS (Netherlands)

    Bosscha Erdbrink, D.P.; Bree, van P.J.H.


    Eight cranial and five postcranial fossil specimens are described and identified as remains of Odobenidae. Two of these (one, from Rhenen, certainly, and the other tentatively) are ascribed to the fossil, Early Pleistocene Odobenus huxleyi (Lankester, 1865), the others to the recent form, O.

  18. Fossilization of Oral Comoetence and Enlightenments on Oral English Teaching

    Institute of Scientific and Technical Information of China (English)



    This thesis is going m demonstrate the fossilized or fossilizing tendency in oral productions, to explore its underlying causes and to probe possible approaches to postpone or defossilize these phenomena in oral language training and teaching so that the overall level of oral competence for English learners can be further promoted.

  19. Maximum fossil fuel feedstock replacement potential of petrochemicals via biorefineries

    NARCIS (Netherlands)

    Brehmer, B.; Boom, R.M.; Sanders, J.P.M.


    The search for feedstock replacement options within the petrochemical industry should logically be based upon non-fossil resources. Retaining the functionality of the biochemicals in biomass for use as chemical products and precursors can lead to a sizeable reduction of fossil fuel consumption. This

  20. The preliminary study of urbanization, fossil fuels consumptions and ...

    African Journals Online (AJOL)



    Mar 29, 2010 ... As a result the demand of more energy in form of fossil fuels increased for domestic ... Key words: Urbanization, fossil fuels, CO2 emission, energy consumption, population growth. ..... energy and biofuels. It will help to reduce ...

  1. Divesting from Fossil Fuels Makes Sense Morally… and Financially (United States)

    Cleveland, Cutler J.; Reibstein, Richard


    Should university endowments divest from fossil fuels? A public discussion of this question has seen some university presidents issuing statements that they would not divest--that investments should not be used for "political action." Many universities hold large endowments that have significant positions in fossil fuel companies or…

  2. Carbon monoxide : A quantitative tracer for fossil fuel CO2?

    NARCIS (Netherlands)

    Gamnitzer, Ulrike; Karstens, Ute; Kromer, Bernd; Neubert, Rolf E. M.; Meijer, Harro A. J.; Schroeder, Hartwig; Levin, Ingeborg


    Carbon monoxide (CO), carbon dioxide (CO2), and radiocarbon ((CO2)-C-14) measurements have been made in Heidelberg from 2001 to 2004 in order to determine the regional fossil fuel CO2 component and to investigate the application of CO as a quantitative tracer for fossil fuel CO2 (CO2(foss)). The obs

  3. The financial impact of divestment from fossil fuels

    NARCIS (Netherlands)

    Plantinga, Auke; Scholtens, Bert


    Divesting from fossil companies has been put forward as a means to address climate change. We study the impact of such divesting on investment portfolio performance. To this extent, we systematically investigate the investment performance of portfolios with and without fossil fuel company stocks. We

  4. Implication of IL Fossilization in Second Language Acquisition (United States)

    Wei, Xueping


    Since the phenomenon of fossilization in interlanguage is proposed by Selinker in 1972, it has drawn much attention and commonly acknowledged at home and abroad. This paper introduces the definition, classification, presentation, and causal factors of fossilization in an attempt to help Chinese students better understand the phenomenon and avoid…

  5. Development of concepts for a zero-fossil-energy greenhouse

    NARCIS (Netherlands)

    Ooster, A. van 't; Henten, E.J. van; Janssen, E.G.O.N.; Bot, G.P.A.; Dekker, E.


    Dutch government and greenhouse horticultural practice aim for strongly reduced fossil energy use and of environmental loads in 2010 and energy neutral greenhouses in 2020. This research aims to design a greenhouse concept with minimal use of fossil energy and independent of nearby greenhouses. The

  6. Triassic leech cocoon from Antarctica contains fossil bell animal

    DEFF Research Database (Denmark)

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.


    , exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica...

  7. World catalog of extant and fossil Corethrellidae (Diptera). (United States)

    Borkent, Art


    A world catalog of extant and fossil frog-biting midges (Diptera: Corethrellidae) provides full type information, known life stages, and distribution of each species. There are 105 extant and seven fossil species of Corethrellidae but unnamed species are known from Costa Rica, Colombia and Madagascar. New information on types and other important specimens are provided.

  8. Microtremor study of Gunung Anyar mud volcano, Surabaya, East Java (United States)

    Syaifuddin, Firman; Bahri, Ayi Syaeful; Lestari, Wien; Pandu, Juan


    The existence of mud volcano system in East Java is known from the ancient period, especially in Surabaya. Gunung Anyar mud volcano is one of the mud volcano system manifestation was appeared close to the residence. Because of this phenomenon we have to learn about the impact of this mud volcano manifestation to the neighbourhood. The microtremor study was conducted to evaluate the possible influence effect of the mud volcano to the environment and get more information about the subsurface condition in this area. Microtremor is one of the geophysical methods which measure the natural tremor or vibration of the earth, the dominant frequency of the tremor represent thickness of the soft sediment layer overlay above the bed rock or harder rock layer beneath our feet. In this study 90 stations was measured to record the natural tremor. The result from this study shows the direct influenced area of this small mud volcano system is close to 50m from the centre of the mud volcano and bed rock of this area is range between 66 to 140 meter.

  9. Acoustic scattering from mud volcanoes and carbonate mounds. (United States)

    Holland, Charles W; Weber, Thomas C; Etiope, Giuseppe


    Submarine mud volcanoes occur in many parts of the world's oceans and form an aperture for gas and fluidized mud emission from within the earth's crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering 10-15 dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or particulates (emitted) in the water column, (3) the carbonate bio-construction covering the mud volcano edifice. The experimental evidence, including visual, acoustic, and nonacoustic sensors, rules out the second hypothesis (at least during the observation time) and suggests that, for this particular mud volcano the dominant mechanism is associated with carbonate chimneys on the mud volcano. In terms of scattering levels, target strengths of 4-14 dB were observed from 800 to 3600 Hz for a monostatic geometry with grazing angles of 3-5 degrees. Similar target strengths were measured for vertically bistatic paths with incident and scattered grazing angles of 3-5 degrees and 33-50 degrees, respectively.

  10. Sustainable Development and the Relative Prices of Fossil and Non-fossil Energy

    DEFF Research Database (Denmark)

    Larsen, Torben


    direction of the market forces relevant to a sustainable supply of physical energy for a globalized HiTec-culture taking into account the redoubling of the price of crude oil during the last years.      Changes in the supply pattern of physical energy is supposed to be ruled by the relative unit costs...... of production in new (marginal) plants for substituting sources of energy, primarily.      A review of the production price per kWh of electricity according to statistics from OECD/IEA where substitution relationships between fossil and non-fossil energy are multiple gives the following results: (1) Sun...... are expected to rise while the price of wind energy is expected to continue a trend of moderate decline due to economies of scale. In all, renewables as wind energy are becoming more and more competitive relative to fossil energy in the production of electricity and may approach a level of 50%. However...

  11. Fossil Group Origins. VI. Global X-ray scaling relations of fossil galaxy clusters

    CERN Document Server

    Kundert, A; D'Onghia, E; Girardi, M; Aguerri, J A L; Barrena, R; Corsini, E M; De Grandi, S; Jiménez-Bailón, E; Lozada-Muñoz, M; Méndez-Abreu, J; Sánchez-Janssen, R; Wilcots, E; Zarattini, S


    We present the first pointed X-ray observations of ten candidate fossil galaxy groups and clusters. With these Suzaku observations, we determine global temperatures and bolometric X-ray luminosities of the intracluster medium (ICM) out to $r_{500}$ for six systems in our sample. The remaining four systems show signs of significant contamination from non-ICM sources. For the six objects with successfully determined $r_{500}$ properties, we measure global temperatures between $2.8 \\ \\mathrm{keV} \\leq T_{\\mathrm{X}} \\leq 5.3 \\ \\mathrm{keV}$, bolometric X-ray luminosities of $0.6 \\times 10^{44} \\ \\mathrm{ergs} \\ \\mathrm{s}^{-1} \\leq L_{\\mathrm{X,bol}} \\leq 7.2\\times 10^{44} \\ \\mathrm{ergs} \\ \\mathrm{s}^{-1}$, and estimate masses, as derived from $T_{\\mathrm{X}}$, of $M_{500} \\gtrsim 10^{14} \\ \\mathrm{M}_{\\odot}$. Scaling relations are constructed for an assembled sample of fossil and non-fossil systems using global X-ray luminosities, temperatures, optical luminosities, and velocity dispersions. The fit of the sc...

  12. Rejuvenation of shallow-crustal silicic magma bodies at Augustine and Hayes volcanoes, Alaska (United States)

    Coombs, M. L.; Vazquez, J. A.; Hayden, L. A.; Calvert, A. T.; Lidzbarski, M. I.; Andersen, N. L.; Till, C. B.


    Rejuvenation of crystal-rich magma bodies leading to eruption can occur on a variety of scales and in varied tectonic settings. Two examples from the Aleutian arc highlight 1) segregation of silicic melt from an intermediate mush, and 2) "defrosting" of a shallowly emplaced intrusion. Augustine Volcano erupted a late Pleistocene rhyolite pumice fall that we link through zircon geochronology to cumulate dioritic blocks, ripped from Augustine's shallow magmatic plumbing system and ejected during the 2006 eruption. Unpolished zircon rims from the rhyolite yield a U-Th age of ~25 ka, and interiors yield a dominant age population of ~26 ka. Zircons from diorites have interior ages and compositions indistinguishable from those of the rhyolite. The diorites, rhyolite, and early Holocene dacites define whole-rock linear unmixing trends consistent with melt (rhyolite) extraction from a mush (dacites), leaving behind a cumulate residue (diorites). A volatile-rich basalt erupted just prior to the rhyolite likely facilitated melt extraction from the mush. The rhyolitic Hayes River ignimbrite, erupted from Hayes volcano, contains dense porphyry blocks that match pumices in composition and phenocryst content and are samples of a shallow intrusion. Autocrystic monazite accommodated up to several weight % Th and significantly affected the U-Th ratio of the magma during differentiation. An isochron for early melt and low-U monazites yields an age of ~67 ka, whereas one for late melt and high-U monazites yields ~42 ka. This younger age is indistinguishable from the laser single crystal Ar-Ar age for sanidine of 41±2 ka (1 sigma). We interpret the apparent ~25 k.y. crystallization interval to represent the assembly and differentiation timescale associated with the Hayes magma body. Sharp reverse zoning in sanidine from pumice (but not porphyry) records a thermal pulse not seen in the more slowly reacting phases, suggesting that a rejuvenation event occurred just prior to eruption.

  13. Contrasting compositional trends of rocks and olivine-hosted melt inclusions from Cerro Negro volcano (Central America): implications for decompression-driven fractionation of hydrous magmas (United States)

    Portnyagin, Maxim V.; Hoernle, Kaj; Mironov, Nikita L.


    Melt inclusions in olivine Fo83-72 from tephras of 1867, 1971 and 1992 eruptions of Cerro Negro volcano represent a series of basaltic to andesitic melts of narrow range of MgO (5.6-8 wt %) formed by ~46 wt % fractional crystallization of olivine (~6 wt %), plagioclase (~27 wt %), pyroxene (~13 wt %) and magnetite (high-Mg basalts reflects the process of phenocryst re-distribution in progressively evolving melt. The crystallization scenario is anticipated to operate everywhere in dykes feeding basaltic volcanoes and can explain the predominance of plagioclase-rich high-Al basalts in island arc as well as typical compositional variations of magmas during single eruptions.

  14. Development of volcano monitoring technique using repeating earthquakes observed by the Volcano Observation Network of NIED (United States)

    Kohno, Y.; Ueda, H.; Kimura, H.; Nagai, M.; Miyagi, Y.; Fujita, E.; Kozono, T.; Tanada, T.


    After the Grate East Japan Earthquake (M9.0) on March 11, 2011, the M6.4 earthquake occurred beneath Mt. Fuji on March 15, 2011. Although the hypocenter seemed to be very close to an assumed magma chamber of Fuji volcano, no anomalies in volcanic activity have been observed until August 2012. As an example, after the M6.1 earthquake occurred in 1998 at southwest of Iwate volcano, a change of seismic velocity structure (e.g. Nishimura et al., 2000) was observed as well as active seismicity and crustal deformation. It had affected waveforms of repeating earthquakes occurring at a plate subduction zone, that is, the waveform similarities were reduced just after the earthquake due to upwelling of magma. In this study, first we analyzed for Mt. Fuji where such changes are expected by the occurrence of the earthquake to try to develop a tool for monitoring active volcanoes using the Volcano Observation network (V-net) data. We used seismic waveform data of repeating earthquakes observed by short period seismometers of V-net and the High Sensitivity Seismograph Network Japan (Hi-net) stations near Fuji volcano after 2007. The seismic data were recorded with a sampling rate of 100 Hz, and we applied 4-8 Hz band pass filter to reduce noise. The repeating earthquakes occurred at the plate subduction zone and their catalog is compiled by Hi-net data (Kimura et al., 2006). We extracted repeating earthquake groups that include earthquakes before and after the M6.4 earthquake on March 15, 2011. A waveform of the first event of the group and waveforms of the other events are compared and calculated cross-correlation coefficients. We adjusted P wave arrivals of each event and calculate the coefficients and lag times of the latter part of the seismic waves with the time window of 1.25 s. We searched the best fit maximizing the cross-correlation coefficients with 0.1 s shift time at each time window. As a result we found three remarkable points at this time. [1] Comparing lag times

  15. Volcano instability induced by strike-slip faulting (United States)

    Lagmay, A. M. F.; van Wyk de Vries, B.; Kerle, N.; Pyle, D. M.


    Analogue sand cone experiments were conducted to study instability generated on volcanic cones by basal strike-slip movement. The results of the analogue models demonstrate that edifice instability may be generated when strike-slip faults underlying a volcano move as a result of tectonic adjustment. This instability occurs on flanks of the volcano above the strike-slip shear. On the surface of the volcano this appears as a pair of sigmoids composed of one reverse and one normal fault. In the interior of the cone the faults form a flower structure. Two destabilised regions are created on the cone flanks between the traces of the sigmoidal faults. Bulging, intense fracturing and landsliding characterise these unstable flanks. Additional analogue experiments conducted to model magmatic intrusion show that fractures and faults developed within the volcanic cone due to basal strike-slip motions strongly control the path of the intruding magma. Intrusion is diverted towards the areas where previous development of reverse and normal faults have occurred, thus causing further instability. We compare our model results to two examples of volcanoes on strike-slip faults: Iriga volcano (Philippines), which underwent non-magmatic collapse, and Mount St. Helens (USA), where a cryptodome was emplaced prior to failure. In the analogue and natural examples, the direction of collapse takes place roughly parallel to the orientation of the underlying shear. The model presented proposes one mechanism for strike-parallel breaching of volcanoes, recently recognised as a common failure direction of volcanoes found in regions with transcurrent and transtensional deformation. The recognition of the effect of basal shearing on volcano stability enables prediction of the likely direction of eventual flank failure in volcanoes overlying strike-slip faults.

  16. Turtles to Terabytes: The Ongoing Revolution in Volcano Geodesy (United States)

    Dzurisin, D.


    Volcano geodesy is in the midst of a revolution. GPS and InSAR, together with extensive ground-based sensor networks, have enabled major advances in understanding how and why volcanoes deform. Surveying techniques that produced a few bytes of information per benchmark per year have been replaced by continuously operating deformation networks and imaging radar satellites that generate terabytes of data at resolutions unattainable only a few decades ago. These developments have enabled more detailed assessments of volcano hazards, more accurate forecasts of volcanic activity, and better insights into how volcanoes behave over a variety of spatial and temporal scales. Forty years ago, repeated leveling surveys showed that the floor of the Yellowstone caldera had risen more than 70 cm in the past 5 decades. Today a network of GPS stations tracks surface movements continuously with millimeter-scale accuracy and the entire deformation field is imaged frequently by a growing number of SAR satellites, revealing a far more complex style of deformation than was recognized previously. At Mount St. Helens, the 1980-1986 eruption taught us that a seemingly quiescent volcano can suddenly become overtly restless, and that accurate eruption predictions are possible at least in some limited circumstances given sufficient observations. The lessons were revisited during the volcano's 2004-2008 eruption, during which a new generation of geodetic sensors and methods detected a range of co-eruptive changes that enabled new insights into the volcano's magma storage and transport system. These examples highlight volcano deformation styles and scales that were unknown just a few decades ago but now have been revealed by a growing number of data types and modeling methods. The rapid evolution that volcano geodesy is currently experiencing provides an ongoing challenge for geodesists, while also demonstrating that geodetic unrest is common, widespread, and illuminating. Vive la révolution!

  17. Fossil-energy program. Progress report for June 1981

    Energy Technology Data Exchange (ETDEWEB)


    This report - the eighty-third of series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component development and process evaluation, technical support to major liquefaction projects, process analysis and engineering evaluations, fossil energy environmental analysis, flue gas desulfurization, coal preparation waste utilization, atmospheric fluidized bed coal combustor for cogeneration, TVA FBC demonstration plant program technical support, PFBC systems analysis, fossil fuel applications assessments, performance assurance system support for fossil energy projects, international energy technology assessment, generalized equilibrium models for liquid and gaseous fuel supplies, analyses of coal production goals, and fossil energy information center.

  18. [Infrared spectroscopy and XRD studies of coral fossils]. (United States)

    Chen, Quan-li; Zhou, Guan-min; Yin, Zuo-wei


    Coral fossil is an old remain of multicellular animal on the earth, and formed by various geological processes. The structural characteristics and compositions of the coral fossils with different color and radial texture on the surface were studied by infrared absorption spectroscopy and X-ray powder diffraction analyses. The results show that the studied coral fossils mainly are composed of SiO2, and the radial microstructure characterized by the calcareous coral cross-section is preserved. It is formed by metasomatism by SiO2. The infrared absorption spectra of the coral fossil with different color and texture are essentially the same, showing typical infrared absorption spectra of the quartz jade. XRD analysis shows that the main components of the coral fossils with different color and texture are consistent and mainly composed of SiO2 with a trace amount of other minerals and without CaCO3.

  19. Fossil plants from Romanian deposits of Bacles, Dolj District, Romania

    Directory of Open Access Journals (Sweden)

    Nicolae T̡icleanu


    Full Text Available From the Middle Romanian lacustrine deposits of the Oltenia province, the authors describe the youngest fossil flora known until now in Oltenia. The inventory of the fossil flora includes the following taxa: Taxodium dubium, ?Platanus platanifolia, Ulmus laevis, Quercus roburoides, Q. cf. muehlenbergii, Carya serraefolia, Acer cf. tricuspidatum and Salix sp. In the Bâcleş fossil flora, Glyptostrobus europaeus, which is a thermophilous and shows a high frequency in all Oltenia area till the XV-th coal seam, is absent. Consequently, having in view the high frequency of Taxodium dubium, which indicate temperate climate conditions, the other consider that the fossil flora from Bâcleş is much more younger and marks an important cooling. From palaeofloristic point of view, the study of Bâcleş fossil flora is indicative for river meadow forest and, probably, flat plain forest environments.

  20. Gabbroic xenoliths in alkaline lavas in the region of Sanganguey Volcano, Nayarit, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Giosa, T.A.; Nelson, S.A.


    Gabbroic xenoliths occur in alkaline cinder cones and lava flows erupted from vents along five parallel lines trending through the calc-alkaline volcano, Sanganguey in the northwestern portion of the Mexican Volcanic Belt. The xenoliths consist of varying proportions of olivine, clinopyroxene, orthopyroxene, and plagioclase. The complete lack of hydrous phases indicates that the gabbros crystallized under conditions of low PH/sub 2/O. Many xenoliths show textures indicative of a cumulate origin and others exhibit recrystallization indicative of subsolidus reactions prior to incorporation in the host liquids. Reaction between xenolithic minerals and host liquids are also observed. The range of Mg numbers calculated for liquids that would have been in equilibrium with olivines in the xenoliths suggests that these olivines crystallized from magmas such as those represented by either calc-alkaline basaltic andesites and andesites or the more evolved alkalic rocks which occur throughout the area. Crystal fractionation models show that the xenoliths may be related to such magmas. The fact that xenoliths occur most commonly in the alkaline rocks suggests that alkaline magmas rise to the surface more rapidly than the more chemically evolved calc-alkaline and alkaline magmas. Alternatively the lack of xenoliths in the more evolved magmas produced by high level crystal fractionation may indicate that the xenoliths are derived from zones below that from which the differentiated magmas begin their final ascent to the surface.

  1. The Magma feeding system of Somma-Vesuvius (Italy)strato-volcano:new inferences from a review of geochemical and Sr,Nd,Pb and O isotope data. Volcanism in the Campania Plain: Vesuvius, Campi Flegrei and Ignimbrites


    Piochi, M.; De Vivo, B.; Ayuso, R. A.


    A large database of major, trace and isotope (Sr, Nd, Pb, O) data exists for rocks produced by the volcanic activity of Somma-Vesuvius volcano. Variation diagrams strongly suggest a major role for evolutionary processes such as fractional crystallization, contamination, crystal trapping and magma mixing, occurring after magma genesis in the mantle. Most mafic magmas are enriched in LILE (K, Rb, Ba), REE (Ce, Sm) and Y, show small Nb–Ta negative anomalies, and have values of Nb/Zr ...

  2. Mount Meager Volcano, Canada: a Case Study for Landslides on Glaciated Volcanoes (United States)

    Roberti, G. L.; Ward, B. C.; van Wyk de Vries, B.; Falorni, G.; Perotti, L.; Clague, J. J.


    Mount Meager is a strato-volcano massif in the Northern Cascade Volcanic Arc (Canada) that erupted in 2350 BP, the most recent in Canada. To study the stability of the Massif an international research project between France ( Blaise Pascal University), Italy (University of Turin) and Canada (Simon Fraser University) and private companies (TRE - sensing the planet) has been created. A complex history of glacial loading and unloading, combined with weak, hydrothermally altered rocks has resulted in a long record of catastrophic landslides. The most recent, in 2010 is the third largest (50 x 106 m3) historical landslide in Canada. Mount Meager is a perfect natural laboratory for gravity and topographic processes such as landslide activity, permafrost and glacial dynamics, erosion, alteration and uplift on volcanoes. Research is aided by a rich archive of aerial photos of the Massif (1940s up to 2006): complete coverage approximately every 10 years. This data set has been processed and multi-temporal, high resolution Orthophoto and DSMs (Digital Surface Models) have been produced. On these digital products, with the support on field work, glacial retreat and landslide activity have been tracked and mapped. This has allowed for the inventory of unstable areas, the identification of lava flows and domes, and the general improvement on the geologic knowledge of the massif. InSAR data have been used to monitor the deformation of the pre-2010 failure slope. It will also be used to monitor other unstable slopes that potentially can evolve to catastrophic collapses of up to 1 km3 in volume, endangering local communities downstream the volcano. Mount Meager is definitively an exceptional site for studying the dynamics of a glaciated, uplifted volcano. The methodologies proposed can be applied to other volcanic areas with high erosion rates such as Alaska, Cascades, and the Andes.

  3. New Hypocenter Relocation Results From Volcano-Tectonic Events (1995-2006) at Popocatepetl Volcano, Mexico (United States)

    Berger, P.; Nava, F. A.; Valdes-Gonzalez, C.


    Popocatepetl, one of the most active strato-volcanoes in Mexico, started a fumarolic and seismic reactivation in December 1994. New hypocenter relocation results have been calculated for some 1,800 volcano-tectonic (VT) events recorded by the seismic network operating at Popocatepetl during 1995-2006, and previously located by the National Center for Disasters Prevention (CENAPRED). We used two location programs to determine hypocenter relocation. One is a recently developed genetic algorithm program, Disloca, which adjusts the differences in arrival times between the recording seismic stations. The second is HypoDD, which uses the double difference earthquake location algorithm. Disloca allowed evaluation of station corrections, plus location of non-clustered hypocenters, while HypoDD refined the locations of clustered ones. Thus, for a given velocity model, hypocenters of clustered events varied slightly depending on the location program. For both programs, four different crustal velocity models were used, two of which include a low velocity zone (LVZ) below 6 km depth. This LVZ represents the presence of magma, which has been suggested to exist at this depth. The spatial distribution of the relocated hypocenters varies from one model to another, but a carefully considered combination of features common to the four distributions, allows a new characterization of the VT activity at Popocatepetl. The distribution of the relocated hypocenters found in this study differs from that of former investigations at Popocatépetl, and gives new insights into the volcano's structures. Hypocenters occur mainly above 10 km depth, with a horizontal range of about 5 km. Features of the spatial distribution allow a tentative interpretation of several internal volcanic structures. Chief among these are branched dike complexes and different sized zones free of volcano-tectonic events, which are in turn surrounded by zones of magma-rock interaction, as indicated by the presence of

  4. The volcano in a gravel pit: Volcano monitoring meets experimental volcanology (United States)

    Kueppers, U.; Alatorre-Ibargüengoitia, M. A.; Hort, M.; Kremers, S.; Meier, K.; Scarlato, P. G.; Scheu, B.; Taddeucci, J.; Wagner, R.; Walk, F.; Dingwell, D. B.


    Volcanic eruptions are an inevitable natural threat. During explosive eruptions, gas and pyroclasts are ejected at high speed over variable time spans and at variable intensity. As magma fragmentation inside a volcanic edifice defies direct observation, our mechanistic and quantitative understanding of the syn-eruptive processes is still incomplete. In an attempt to bridge this gap, we used a supra-disciplinary approach and combined experimental volcanology and volcano monitoring devices. We performed 34 field-based fragmentation experiments using cylindrical samples, drilled from natural volcanic rock samples. Decompression and particle ejection were monitored with (1) Doppler Radar (DR), (2) high-speed and high-definition cameras, (3) high-speed thermal camera, (4) acoustic and infrasound sensors and (5) pressure transducers. The experiments were performed at controlled sample porosity (25 to 75 vol.%) and size (60 mm height and 25 mm and 60 mm diameter, respectively), confinement geometry, applied pressure (4 to 18 MPa) and temperature (25 and 850 °C). We present how the velocity of the ejected pyroclasts was measured by and evaluated for the different approaches and how it was affected by the experimental conditions and sample characteristics. We show that all deployed instruments successfully measured the pyroclast ejection, giving coherent results of up to 130 m/s. Close and high-resolution volcano monitoring, spiced with results from our experiments, will allow for "calibrating volcanoes". An enhanced understanding of the pressurisation state of a volcano is an essential factor in ballistic hazard evaluation and eruption energy estimation and will contribute to adequate risk mitigation.

  5. Muon imaging of volcanoes with Cherenkov telescopes (United States)

    Carbone, Daniele; Catalano, Osvaldo; Cusumano, Giancarlo; Del Santo, Melania; La Parola, Valentina; La Rosa, Giovanni; Maccarone, Maria Concetta; Mineo, Teresa; Pareschi, Giovanni; Sottile, Giuseppe; Zuccarello, Luciano


    The quantitative understanding of the inner structure of a volcano is a key feature to model the processes leading to paroxysmal activity and, hence, to mitigate volcanic hazards. To pursue this aim, different geophysical techniques are utilized, that are sensitive to different properties of the rocks (elastic, electrical, density). In most cases, these techniques do not allow to achieve the spatial resolution needed to characterize the shallowest part of the plumbing system and may require dense measurements in active zones, implying a high level of risk. Volcano imaging through cosmic-ray muons is a promising technique that allows to overcome the above shortcomings. Muons constantly bombard the Earth's surface and can travel through large thicknesses of rock, with an energy loss depending on the amount of crossed matter. By measuring the absorption of muons through a solid body, one can deduce the density distribution inside the target. To date, muon imaging of volcanic structures has been mainly achieved with scintillation detectors. They are sensitive to noise sourced from (i) the accidental coincidence of vertical EM shower particles, (ii) the fake tracks initiated from horizontal high-energy electrons and low-energy muons (not crossing the target) and (iii) the flux of upward going muons. A possible alternative to scintillation detectors is given by Cherenkov telescopes. They exploit the Cherenkov light emitted when charged particles (like muons) travel through a dielectric medium, with velocity higher than the speed of light. Cherenkov detectors are not significantly affected by the above noise sources. Furthermore, contrarily to scintillator-based detectors, Cherenkov telescopes permit a measurement of the energy spectrum of the incident muon flux at the installation site, an issue that is indeed relevant for deducing the density distribution inside the target. In 2014, a prototype Cherenkov telescope was installed at the Astrophysical Observatory of Serra

  6. Large-N in Volcano Settings: Volcanosri (United States)

    Lees, J. M.; Song, W.; Xing, G.; Vick, S.; Phillips, D.


    We seek a paradigm shift in the approach we take on volcano monitoring where the compromise from high fidelity to large numbers of sensors is used to increase coverage and resolution. Accessibility, danger and the risk of equipment loss requires that we develop systems that are independent and inexpensive. Furthermore, rather than simply record data on hard disk for later analysis we desire a system that will work autonomously, capitalizing on wireless technology and in field network analysis. To this end we are currently producing a low cost seismic array which will incorporate, at the very basic level, seismological tools for first cut analysis of a volcano in crises mode. At the advanced end we expect to perform tomographic inversions in the network in near real time. Geophone (4 Hz) sensors connected to a low cost recording system will be installed on an active volcano where triggering earthquake location and velocity analysis will take place independent of human interaction. Stations are designed to be inexpensive and possibly disposable. In one of the first implementations the seismic nodes consist of an Arduino Due processor board with an attached Seismic Shield. The Arduino Due processor board contains an Atmel SAM3X8E ARM Cortex-M3 CPU. This 32 bit 84 MHz processor can filter and perform coarse seismic event detection on a 1600 sample signal in fewer than 200 milliseconds. The Seismic Shield contains a GPS module, 900 MHz high power mesh network radio, SD card, seismic amplifier, and 24 bit ADC. External sensors can be attached to either this 24-bit ADC or to the internal multichannel 12 bit ADC contained on the Arduino Due processor board. This allows the node to support attachment of multiple sensors. By utilizing a high-speed 32 bit processor complex signal processing tasks can be performed simultaneously on multiple sensors. Using a 10 W solar panel, second system being developed can run autonomously and collect data on 3 channels at 100Hz for 6 months

  7. Degassing Processes at Persistently Active Explosive Volcanoes (United States)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with explosions with periods of minutes to hours for the past several decades. Semeru produces an average of 21-71 tons of SO2 per day, amounting to a yearly output of 8-26 Mt. Using the Semeru data, along with a 1-D transient numerical model of magma ascent, I test the validity of a model in which a viscous plug at the top of the conduit produces cycles of eruption and gas release. I find that it can be a valid hypothesis to explain the observed patterns of degassing at Semeru. Periodic behavior in such a system occurs for a very narrow range of conditions, for which the mass balance between magma flux and open-system gas escape repeatedly generates a viscous plug, pressurizes the magma beneath the plug, and

  8. Isotopic evolution of Mauna Loa volcano

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, M.D.; Kammer, D.P. (Chemistry Dept., Woods Hole Oceanographic Institution, MA (USA))


    In an effort to understand the temporal helium isotopic variations in Mauna Loa volcano, we have measured helium, strontium and lead isotopes in a suite of Mauna Loa lavas that span most of the subaerial eruptive history of the volcano. The lavas range in age from historical flows to Ninole basalt which are thought to be several hundred thousand years old. Most of the samples younger than 30 ka in age (Kau Basalt) are radiocarbon-dated flows, while the samples older than 30 ka are stratigraphically controlled (Kahuku and Ninole Basalt). The data reveal a striking change in the geochemistry of the lavas approximately 10 ka before present. The lavas older than 10 ka are characterized by high {sup 3}He/{sup 4}He ({approx equal} 16-20 times atmospheric), higher {sup 206}Pb/{sup 204}Pb ({approx equal} 18.2), and lower {sup 87}Sr/{sup 86}Sr({approx equal} 0.70365) ratios than the younger Kau samples (having He, Pb and Sr ratios of approximately 8.5 x atmospheric, 18.1 and 0.70390, respectively). The historical lavas are distinct in having intermediate Sr and Pb isotopic compositions with {sup 3}He/{sup 4}He ratios similar to the other young Kau basalt ({approx equal} 8.5 x atmospheric). The isotopic variations are on a shorter time scale (100 to 10,000 years) than has previously been observed for Hawaiian volcanoes, and demonstrate the importance of geochronology and stratigraphy to geochemical studies. The data show consistency between all three isotope systems, which suggests that the variations are not related to magma chamber degassing processes, and that helium is not decoupled from the other isotopes. However, the complex temporal evolution suggests that three distinct mantle sources are required to explain the isotopic data. Most of the Mauna Loa isotopic variations could be explained by mixing between a plume type source, similar to Loihi, and an asthenospheric source with helium isotopic composition close to MORB and elevated Sr isotopic values. (orig./WL).


    Directory of Open Access Journals (Sweden)

    S. G. Pugacheva


    Full Text Available In article the basic geological and morphological features of a volcanic relief of a surface of a planet Mars are considered. The volcanic relief of a planet represents relic ancient shield volcanoes, linear forms of volcanic mountains, areal and central lava flooding, radial and concentric breaks. Results of researches of morphology of volcanic and tectonic formations of a relief of Mars are given in article. On materials of shooting of a surface of Mars spacecrafts constructed hypsometric high-rise profiles of volcanoes and average steepness of slopes are defined. The relative age of volcanoes and volcanic plains is estimated on density of shock craters.

  10. Monitoring Thermal Activity of Eastern Anatolian Volcanoes Using MODIS Images (United States)

    Diker, Caner; Ulusoy, Inan


    MODIS (Moderate Resolution Imaging Spectroradiometer) instrument is used for imaging atmosphere, land and ocean with 36 bands. Both AQUA and TERRA platforms acquire 2 images daily (daytime and nighttime). Low temperature anomalies on volcanoes comprise important clues. Low temperature anomalies on Holocene volcanoes of Eastern Anatolia were investigated for these clues using MODIS Land Surface Temperature (LST) images. A total of 16800 daily LST images dated between 2001 and 2012 have been processed using a code written in IDL (Interactive Data Language). Factors like shadow, ice/snow and clouds that are affecting the reflectance data are masked. The mask is derived from MODIS reflectance data state image. Various LST images are calculated: Two nested region of interest (ROI) windows (square/rectangular) have been selected on the images. First is the bigger window, which covers the whole area of the volcano (Total volcano area). Second one is a smaller window which circumference the summit (crater and/or caldera) of the volcano (Summit cone) where thermal output is generally higher when compared to the flanks. Two data sets have been calculated using the ROI's for each volcano. The first set contains daytime and nighttime raw data without any correction. The second set contains topographically corrected images; daytime images are corrected using Cosine and Minnaert methods and nighttime images are corrected using three step normalization method. Calculated surface temperatures (Tmax, Tmin, Tmean) are plotted annually. On Nemrut Volcano as an example, maximum and minimum temperatures are between 26.31oC and -44.87oC on nighttime data for twelve years period. Temperature difference between total volcano area ROI and summit cone ROI are calculated (ΔT). High ΔT indicates that there is an increase of temperature at the summit cone when compared to the total volcano area. STA/LTA (Short Term Average/Long Term Average) filter was applied to maximum temperature and

  11. Progresses in geology and hazards analysis of Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

    WEI Hai-quan; JIN Bo-lu; LIU Yong-shun


    A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temperature feature of the deposits indicates a relationship between the lahar and the Millennium eruption event of Tianchi Volcano. The lahars caused a dramatic disaster. Recognize of the huge avalanche scars and deposits around Tianchi Volcano imply another highly destructive hazard. Three types of different texture of the avalanche deposits have been recognized. There was often magma mixing processes during the Millennium eruption of Tianchi Volcano, indicating a mixing and co-eruption regime of the eruption.

  12. Volcano-tectonic evolution of the polygenetic Kolumbo submarine volcano/Santorini (Aegean Sea) (United States)

    Hübscher, Christian; Ruhnau, M.; Nomikou, P.


    Here we show for the first time the 3D-structural evolution of an explosive submarine volcano by means of reflection seismic interpretation. Four to five vertically stacked circular and cone-shaped units consisting mainly of volcaniclastics build the Kolumbo underwater volcano which experienced its first eruption > 70 ka ago and its last explosive eruption 1650 AD, 7 km NE of Santorini volcano (southern Aegean Sea). The summed volume of volcaniclastics is estimated to range between 13-22 km3. The entire Kolumbo volcanic complex has a height of ≥ 1 km and a diameter of ≥ 11 km. All volcaniclastic units reveal the same transparent reflection pattern strongly suggesting that explosive underwater volcanism was the prevalent process. Growth faults terminate upwards at the base of volcaniclastic units, thus representing a predictor to an eruption phase. Similarities in seismic reflection pattern between Kolumbo and near-by volcanic cones imply that the smaller cones evolved through explosive eruptions as well. Hence, the central Aegean Sea experienced several more explosive eruptions (≥ 23) than previously assumed, thus justifying further risk assessment. However, the eruption columns from the smaller volcanic cones did not reach the air and- consequently - no sub-aerial pyroclastic surge was created. The Anydros basin that hosts Kolumbo volcanic field opened incrementally NW to SE and parallel to the Pliny and Strabo trends during four major tectonic pulses prior to the onset of underwater volcanism.

  13. Zircon xenocryst resorption and magmatic regrowth at El Chichón Volcano, Chiapas, Mexico (United States)

    Pack, Brenda; Schmitt, Axel K.; Roberge, Julie; Tenorio, Felipe Garcia; Damiata, Brian N.


    El Chichón volcano is the only active volcano located within the Chiapanecan Volcanic Arc in southern Mexico, which lies between the Trans-Mexican Volcanic Belt and the Central American Volcanic Arc. Previous studies have shown that ~ 12 eruptions have occurred at El Chichón within the last 8000 years, forming a complex of lava domes with a central crater and surrounding pyroclastic deposits. Here, we report the discovery of zircon in Holocene El Chichón rocks, which were analyzed by high spatial resolution imaging (color cathodoluminescence CCL) and isotopic (secondary ionization mass spectrometry SIMS) methods to resolve core and rim crystallization ages. Pumice samples from five proximal pyroclastic flow and fall-out deposits were collected based on published stratigraphy. Two of the samples were further (re-)classified by new 14C dates. In addition, we sampled two lavas from the 1982 eruption and from remnants of the older Somma lava complex. Zircon crystals were dated using 230Th/238U disequilibrium (U-Th) and U-Pb geochronology. U-Th zircon ages fall between near eruption ages and ca. 84 ka, with overlapping ages in all samples. By contrast, zircon core U-Pb ages range between ca. 290 Ma and 1.9 Ga. These ages are consistent with xenocrystic origins and their heterogeneity indicates derivation from clastic country rocks. Strong age contrasts between inherited xenocrystic and young magmatic domains in individual zircon crystals are evidence for arrested assimilation of crustal rocks where initially zircon-undersaturated magmas cooled rapidly to form a crystal mush or subsolidus amalgamate as a crustally contaminated boundary layer. This layer contributed zircon crystals to eruptible magma during episodic recharge events followed by partial melt extraction, mixing and homogenization. Zircon overgrowths are significantly older than major minerals whose U-series ages and sharp zonation boundaries suggest crystallization only within a few ka before eruption

  14. Divergence time estimates of mammals from molecular clocks and fossils: Relevance of new fossil finds from India

    Indian Academy of Sciences (India)

    G V R Prasad


    This paper presents a brief review of recent advances in the classification of mammals at higher levels using fossils and molecular clocks. It also discusses latest fossil discoveries from the Cretaceous – Eocene (66–55 m.y.) rocks of India and their relevance to our current understanding of placental mammal origins and diversifications.

  15. Axion Crystals

    CERN Document Server

    Ozaki, Sho


    The low-energy effective theories for gapped insulators are classified by three parameters: permittivity $\\epsilon$, permeability $\\mu$, and theta angle $\\theta$. Crystals with periodic $\\epsilon$ are known as photonic crystals. We here study the band structure of photons in a new type of crystals with periodic $\\theta$ (modulo $2\\pi$) in space, which we call the axion crystals. We find that the axion crystals have a number of new properties that the usual photonic crystals do not possess, such as the helicity-dependent photonic band gaps and the nonrelativistic gapless dispersion relation at small momentum. We briefly discuss possible realizations of axion crystals in condensed matter systems as well as high-energy physics.

  16. Eruptive Dynamics Inferred from Textural Analysis of Ash Time Series: The 2015 Reawakening of Cotopaxi Volcano (United States)

    Gaunt, H. E.; Bernard, B.; Hidalgo, S.; Proaño, A.; Wright, H. M. N.; Mothes, P. A.; Criollo, E.


    Analysis of the composition and texture of ash ejected during eruptive episodes can provide valuable information about magma storage and ascent conditions. After 73 years of repose, Cotopaxi volcano erupted after approximately four months of precursory activity that included an increase in seismicity, gas emissions, and minor ground deformation. High frequency ash sampling was realized throughout the new eruptive period and near real-time petrological monitoring of ash samples was used to infer eruption dynamics at Cotopaxi volcano. We collected twenty ash samples between August 14 and November 23, 2015 from a seismic monitoring site on the west flank of the volcano. We classified the different components of the ash into four groups: hydrothermal/altered grains, lithic fragments, potentially juvenile material, and free crystals. The relative proportions of theses grains evolved as the eruption progressed, with increasing amounts of potentially juvenile material and a decrease in hydrothermally altered material through time. Potentially juvenile grains from the initial explosion are microlite-poor and contain hydrothermal minerals (opal and alunite) in contact with fresh glass. The interaction of juvenile magma with the hydrothermal system may have provided the energy to trigger phreatomagmatic explosions at Cotopaxi. However, only the initial explosions preserve textural evidence for this process. Completely aphyric, glassy fragments are absent; likewise, the absence of highly vesiculated pumice or scoria indicates that fragmentation was not the result of bubble wall breakage due to rapid exsolution and expansion of gas in the melt. Furthermore, the crystallinity of juvenile particles increased through time, indicating slowing integrated ascent rates. Nevertheless, continued high SO2 emission rates indicate that the system was open to gas loss, which inhibited the pressurization of the conduit through gas accumulation, reducing the short term possibility of a large

  17. Geochronology of Zircon from Modern Plutons Beneath Two Contrasting Arc Volcanoes (United States)

    Bacon, C. R.


    Ion microprobe (SHRIMP RG) 238U-230Th zircon dating documents recent crystallization of shallow plutons beneath two caldera volcanoes where magmas evolved mainly by crystallization differentiation. Mount Mazama, Oregon, is a medium-K calc-alkaline Cascade arc volcano whose 7.7-ka climactic eruption ejected granodiorite and related plutonic blocks during formation of Crater Lake caldera. Mount Veniaminof, Alaska, is a medium-K tholeiitic Aleutian arc volcano that ejected granodiorite, diorite, and gabbro blocks in its 3.7-ka caldera-enlarging eruption. Zircons in four granodiorite blocks from Mazama crystallized at various times between 20 ka and greater than 300 ka, with concentrations of model ages near 50-70, 110, and 200 ka that correspond to periods of dacitic volcanism dated by K-Ar (Bacon and Lowenstern, 2005, EPSL 233:277-293). Multiple-age zircon populations are common. The youngest zircon model ages in blocks from different locations around the caldera are similar to ages of nearby volcanic vents and may help map the distribution of intrusions within a composite pluton. Mazama zircons typically have many 10's to 100's of ppm U and Th, and grew relatively late in high- crystallinity magmas. U-Th model ages of zircon from a 27-ka rhyodacite, the only eruptive unit known with common zircon, are similar to those from granodiorite. Survival of these recycled crystals in zircon- undersaturated hydrous rhyodacitic magma suggests little time from entrainment to the 27-ka eruption. In contrast, the voluminous 7.7-ka climactic rhyodacite is virtually lacking in zircon, indicating dissolution of any granodioritic debris in the hot, vigorously growing silicic magma body during the intervening period. Veniaminof erupted basaltic through rhyodacitic magmas over the past 250 kyr. Gabbro, diorite, and miarolitic granodiorite blocks from Veniaminof represent cumulate mush and vapor-saturated residual melt segregations (Bacon, Sisson, and Mazdab, 2006, EOS 87:36:U41B-05

  18. The assessment of size in fossil felidae

    Directory of Open Access Journals (Sweden)

    O' Regan, H.


    Full Text Available Estimations of body size in fossil vertebrates depend on establishing the relationships between body mass, overall length or some measure of stature and measurements taken on skeletal elements in living relatives or close proxies. However, most osteological collections lack information on body size for individual specimens, and published investigations usually fa11 back on summary data derived from the literature to plot against measurements taken directly on the skeletal material. The utility of such approaches beyond very general indications of size is open to question. In an effort to reduce these problems we attempt to establish some objective basis for using skeletal elements for the purpose of size estimation in the larger Felidae of the genus Panthera, using data for the jaguar, Panthera onca. We show that cranial length offers a good indication of overall size in the living animal, and that various other cranial dimensions correlate closely with that measurement, while individual teeth, despite their frequent occurrence in assemblages, show a looser relationship and therefore appear less useful for size estimations of fossil material than has been thought.Las estimaciones de la talla corporal en vertebrados fósiles depende de las relaciones establecidas entre el peso corporal, la longitud total o alguna medida de estatura tomada de los elementos esqueléticos de animales actuales emparentados o muy afines. Sin embargo, en muchas colecciones osteológicas falta información sobre la talla corporal de los ejemplares, de forma que las investigaciones publicadas usualmente recurren a datos sintetizados de la literatura que se relacionan con medidas tomadas directamente del material esquelético. La utilidad de estas aproximaciones más allá de indicaciones generales sobre la talla es discutible. En un esfuerzo de minimizar estos problemas intentamos establecer bases objetivas para el uso de los elementos esqueléticos con el propósito de

  19. Space Radar Image of Kilauea Volcano, Hawaii (United States)


    This is a deformation map of the south flank of Kilauea volcano on the big island of Hawaii, centered at 19.5 degrees north latitude and 155.25 degrees west longitude. The map was created by combining interferometric radar data -- that is data acquired on different passes of the space shuttle which are then overlayed to obtain elevation information -- acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar during its first flight in April 1994 and its second flight in October 1994. The area shown is approximately 40 kilometers by 80 kilometers (25 miles by 50 miles). North is toward the upper left of the image. The colors indicate the displacement of the surface in the direction that the radar instrument was pointed (toward the right of the image) in the six months between images. The analysis of ground movement is preliminary, but appears consistent with the motions detected by the Global Positioning System ground receivers that have been used over the past five years. The south flank of the Kilauea volcano is among the most rapidly deforming terrains on Earth. Several regions show motions over the six-month time period. Most obvious is at the base of Hilina Pali, where 10 centimeters (4 inches) or more of crustal deformation can be seen in a concentrated area near the coastline. On a more localized scale, the currently active Pu'u O'o summit also shows about 10 centimeters (4 inches) of change near the vent area. Finally, there are indications of additional movement along the upper southwest rift zone, just below the Kilauea caldera in the image. Deformation of the south flank is believed to be the result of movements along faults deep beneath the surface of the volcano, as well as injections of magma, or molten rock, into the volcano's 'plumbing' system. Detection of ground motions from space has proven to be a unique capability of imaging radar technology. Scientists hope to use deformation data acquired by SIR-C/X-SAR and future imaging

  20. On Prediction of Depreciation Time of Fossil Fuel in Malaysia

    Directory of Open Access Journals (Sweden)

    Tey Jin Pin


    Full Text Available Problem statement: The fossil fuels play a crucial role in the world energy markets. Demand for fossil fuels become increasingly high and worrisome, because of fossil fuels will be significantly reduced and ultimately exhausted. This study was conducted to predict the depreciation time of fossil fuels in Malaysia and estimate the time remaining before the fossil fuels will finish. Approach: To predict the depreciation time of fossil fuels, the reserves, consumption and prices of fossil fuel will be used. The prediction of fossil fuel reserves were estimated using ratio of fossil fuel reserve versus consumption, Klass Model and Modified Klass Model. The prediction time will give us the opportunity to prepare for the coming energy crisis and discover new energy sources. The results from the analysis will be concluded alongside with the Olduvai Theory and Hubbert Peak Theory. Both of the theories are highly related to the energy crisis. The Olduvai Theory states that the industrial civilization will last for approximately 100 year: circa 1930-2030. As for Hubbert Peak Theory, it can estimate the total amount of fossil fuels available based on the production rate from time to time. Results: Due to the vast usage of petroleum, it will be depleted faster than natural gas and coal. After 14 years, natural gas and coal will replace petroleum as a fossil fuel and coal would then be the major fossil fuels. Based on the results from Hubbert Peak Theory, the rate of production of petroleum has reached the maximum level in 2004 and started to decline since that time; while in the Olduvai theory, it has explained that the life expectancy of the industrial civilization was found to be ended in 2030. Petroleum will be spent over in 2020, followed by natural gas in 2058 and coal around the year 2066. Conclusion: So far, Malaysia has not facing disconnection of electricity as other developed countries. When this happens, it gives the meaning of the end of the

  1. Open System evolution of peralkaline trachyte and phonolite from the Suswa volcano, Kenya rift (United States)

    White, John Charles; Espejel-García, Vanessa V.; Anthony, Elizabeth Y.; Omenda, Peter


    Suswa is the southernmost volcanic center in the Central Kenya Peralkaline Province (CKPP) and represents the only salic center to have erupted significant volumes of peralkaline silica-undersaturated lavas and tuffs (trachyte, nepheline trachyte and phonolite). The eruptive products of Suswa can be clearly divided into two series, which correspond closely to the volcano's eruptive history. The earlier series (C1) includes lavas and tuffs that built the initial shield volcano (pre-caldera, unit S1) and erupted during the first caldera collapse (syn-caldera, units S2-S5); these rocks are dominated by peralkaline, silica-saturated to mildly under-saturated trachyte. The later series (C2) includes lavas and tuffs that erupted within the caldera structure following the initial collapse (post-caldera, units S6-S7) and during the creation of a second smaller, nested caldera and central "island block" (ring trench group, RTG, unit S8); these rocks are dominated by peralkaline phonolite. In this study, we combine mineralogical evidence with the results of major-element, trace-element, and thermodynamic modelling to propose a complex model for the origin of the Suswa volcano. From these results we conclude that C1 is the result of protracted fractional crystallization of a fairly "dry" alkali basalt (< 1 wt.% H2O) under relatively high pressure (400 MPa) and low oxygen fugacity (FMQ to FMQ-1). Although C1 appears to be primarily the result of closed system processes, a variety of open system processes are responsible for C2. We propose that crystallization of C1 trachyte resulted in the formation of a syenitic residue, which was assimilated (Ma/Mc = 0.1) during a later stage of recharge and differentiation of alkali basalt to produce post-caldera ne-trachyte. Post-caldera (S6-7) phonolites were in turn the result of fractional crystallization of this ne-trachyte. RTG phonolites, however, are the result of feldspar resorption prompted perhaps by magma recharge as evidenced

  2. Antarctic volcanoes: A remote but significant hazard (United States)

    Geyer, Adelina; Martí, Alex; Folch, Arnau; Giralt, Santiago


    Ash emitted during explosive volcanic eruptions can be dispersed over massive areas of the globe, posing a threat to both human health and infrastructures, such as the air traffic. Some of the last eruptions occurred during this decade (e.g. 14/04/2010 - Eyjafjallajökull, Iceland; 24/05/2011-Grímsvötn, Iceland; 05/06/2011-Puyehue-Cordón Caulle, Chile) have strongly affected the air traffic in different areas of the world, leading to economic losses of billions of euros. From the tens of volcanoes located in Antarctica, at least nine are known to be active and five of them have reported volcanic activity in historical times. However, until now, no attention has been paid to the possible social, economical and environmental consequences of an eruption that would occur on high southern latitudes, perhaps because it is considered that its impacts would be minor or local, and mainly restricted to the practically inhabited Antarctic continent. We show here, as a case study and using climate models, how volcanic ash emitted during a regular eruption of one of the most active volcanoes in Antarctica, Deception Island (South Shetland Islands), could reach the African continent as well as Australia and South America. The volcanic cloud could strongly affect the air traffic not only in the region and at high southern latitudes, but also the flights connecting Africa, South America and Oceania. Results obtained are crucial to understand the patterns of volcanic ash distribution at high southern latitudes with obvious implications for tephrostratigraphical and chronological studies that provide valuable isochrones with which to synchronize palaeoclimate records. This research was partially funded by the MINECO grants VOLCLIMA (CGL2015-72629-EXP)and POSVOLDEC(CTM2016-79617-P)(AEI/FEDER, UE), the Ramón y Cajal research program (RYC-2012-11024) and the NEMOH European project (REA grant 34 agreement n° 289976).

  3. Shallow velocity imaging of an active volcano (United States)

    Fry, B.; Chardot, L.; Jolly, A. D.


    We use a linear array of temporary seismometers to derive a shear-wave velocity model of the upper ~1000m of the crater area of White Island, an active volcano in New Zealand. We use noise interferometry to generate dispersion curves and invert these dispersion curves to obtain a layered 1D model. By exploiting the varying interstation distances along the array, we are able to define a strong shallow impedance contrast in the upper 10 meters as well as a depth to 'effective' bedrock at about 100m. We limit the bandwidth of the measured dispersion using a 2-wave cycle approximation and construct a composite dispersion curve. We then invert the dispersion curves with two separate inversion algorithms in an effort to test the validity of using this broadband approach for monitoring active volcanoes. The first method is a non-linear approach and is useful when an a-priori starting model is poorly known or if a velocity inversion is likely. Unfortunately, this type of non-linear inversion is more sensitive to small perturbations in the recovered Green's Functions, which may be due to non-equipartitioning of the wavefield as well as to velocity changes. The second is a linearized and damped LSQR approach which we envision will be more useful for routine monitoring in situations in which the starting model is well defined. In this case, selective regularization can be used to stablize moving time-window inversion. Lastly, our results will be used as input for hydrothermal fluid flow modelling conducted in a concurrent study.

  4. Geomechanical rock properties of a basaltic volcano

    Directory of Open Access Journals (Sweden)

    Lauren N Schaefer


    Full Text Available In volcanic regions, reliable estimates of mechanical properties for specific volcanic events such as cyclic inflation-deflation cycles by magmatic intrusions, thermal stressing, and high temperatures are crucial for building accurate models of volcanic phenomena. This study focuses on the challenge of characterizing volcanic materials for the numerical analyses of such events. To do this, we evaluated the physical (porosity, permeability and mechanical (strength properties of basaltic rocks at Pacaya Volcano (Guatemala through a variety of laboratory experiments, including: room temperature, high temperature (935 °C, and cyclically-loaded uniaxial compressive strength tests on as-collected and thermally-treated rock samples. Knowledge of the material response to such varied stressing conditions is necessary to analyze potential hazards at Pacaya, whose persistent activity has led to 13 evacuations of towns near the volcano since 1987. The rocks show a non-linear relationship between permeability and porosity, which relates to the importance of the crack network connecting the vesicles in these rocks. Here we show that strength not only decreases with porosity and permeability, but also with prolonged stressing (i.e., at lower strain rates and upon cooling. Complimentary tests in which cyclic episodes of thermal or load stressing showed no systematic weakening of the material on the scale of our experiments. Most importantly, we show the extremely heterogeneous nature of volcanic edifices that arise from differences in porosity and permeability of the local lithologies, the limited lateral extent of lava flows, and the scars of previous collapse events. Input of these process-specific rock behaviors into slope stability and deformation models can change the resultant hazard analysis. We anticipate that an increased parameterization of rock properties will improve mitigation power.

  5. Submarine volcanoes along the Aegean volcanic arc (United States)

    Nomikou, Paraskevi; Papanikolaou, Dimitrios; Alexandri, Matina; Sakellariou, Dimitris; Rousakis, Grigoris


    The Aegean volcanic arc has been investigated along its offshore areas and several submarine volcanic outcrops have been discovered in the last 25 years of research. The basic data including swath bathymetric maps, air-gun profiles, underwater photos and samples analysis have been presented along the four main volcanic groups of the arc. The description concerns: (i) Paphsanias submarine volcano in the Methana group, (ii) three volcanic domes to the east of Antimilos Volcano and hydrothermal activity in southeast Milos in the Milos group, (iii) three volcanic domes east of Christiana and a chain of about twenty volcanic domes and craters in the Kolumbo zone northeast of Santorini in the Santorini group and (iv) several volcanic domes and a volcanic caldera together with very deep slopes of several volcanic islands in the Nisyros group. The tectonic structure of the volcanic centers is described and related to the geometry of the arc and the neotectonic graben structures that usually host them. The NE-SW direction is dominant in the Santorini and Nisyros volcanic groups, located at the eastern part of the arc, where strike-slip is also present, whereas NW-SE direction dominates in Milos and Methana at the western part, where co-existence of E-W disrupting normal faults is observed. The volcanic relief reaches 1100-1200 m in most cases. This is produced from the outcrops of the volcanic centers emerging usually at 400-600 m depth and ending either below sea level or at high altitudes of 600-700 m on the islands. Hydrothermal activity at relatively high temperatures observed in Kolumbo is remarkable whereas low temperature phenomena have been detected in the Santorini caldera around Kameni islands and in the area southeast of Milos. In Methana and Nisyros, hydrothermal activity seems to be limited in the coastal areas without other offshore manifestations.

  6. Embedded multiparametric system for volcano monitoring (United States)

    Moure, David; Torres, Pedro A.; Meletlidis, Stavros; Lopez, Carmen; José Blanco, María


    A low cost and low power consumption multiparametric system designed for volcano monitoring is presented. Once tested with various sensors, at present it is installed in two locations in Tenerife, Canary Islands, acquiring and transmitting data in real time. The system is based on a commercial board (Raspberry Pi®, RPi®) that uses an embedded ARMTM processor with a Debian (Wheezy-Raspbian) Linux Operating System. This configuration permits different standard communication systems between devices as USB and ETHERNET, and also communication with integrated circuits is possible. The whole system includes this platform and self-developed hardware and software. Analog signals are acquired at an expansion board with an ADC converter with three 16 bits channels. This board, which is powered directly from the RPi®, provides timing to the sampling data using a Real Time Clock (RTC). Two serial protocols (I2C and SPI) are responsible for communications. Due to the influence of atmospheric phenomena on the volcano monitoring data, the system is complemented by a self-developed meteorological station based on ArduinoCC and low cost commercial sensors (atmospheric pressure, humidity and rainfall). It is powered with the RPi® and it uses a serial protocol for communications. Self-developed software run under Linux OS and handles configuration, signal acquisition, data storage (USB storage or SD card) and data transmission (FTP, web server). Remote configuration, data plotting and downloading is available through a web interface tool. Nowadays, the system is used for gravimetric and oceanic tides data acquisition in Tenerife and soon it will be applied for clinometric data.

  7. Newberry Volcano EGS Demonstration - Phase I Results

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, William L. [AltaRock Energy, Inc., Seattle, WA (United States); Petty, Susan [AltaRock Energy, Inc., Seattle, WA (United States); Cladouhos, Trenton T. [AltaRock Energy, Inc., Seattle, WA (United States); Iovenitti, Joe [AltaRock Energy, Inc., Seattle, WA (United States); Nofziger, Laura [AltaRock Energy, Inc., Seattle, WA (United States); Callahan, Owen [AltaRock Energy, Inc., Seattle, WA (United States); Perry, Douglas S. [Davenport Newberry Holdings LLC, Stamford, CT (United States); Stern, Paul L. [PLS Environmental, LLC, Boulder, CO (United States)


    Phase I of the Newberry Volcano Enhanced Geothermal System (EGS) Demonstration included permitting, community outreach, seismic hazards analysis, initial microseismic array deployment and calibration, final MSA design, site characterization, and stimulation planning. The multi-disciplinary Phase I site characterization supports stimulation planning and regulatory permitting, as well as addressing public concerns including water usage and induced seismicity. A review of the project's water usage plan by an independent hydrology consultant found no expected impacts to local stakeholders, and recommended additional monitoring procedures. The IEA Protocol for Induced Seismicity Associated with Enhanced Geothermal Systems was applied to assess site conditions, properly inform stakeholders, and develop a comprehensive mitigation plan. Analysis of precision LiDAR elevation maps has concluded that there is no evidence of recent faulting near the target well. A borehole televiewer image log of the well bore revealed over three hundred fractures and predicted stress orientations. No natural, background seismicity has been identified in a review of historic data, or in more than seven months of seismic data recorded on an array of seven seismometers operating around the target well. A seismic hazards and induced seismicity risk assessment by an independent consultant concluded that the Demonstration would contribute no additional risk to residents of the nearest town of La Pine, Oregon. In Phase II of the demonstration, an existing deep hot well, NWG 55-29, will be stimulated using hydroshearing techniques to create an EGS reservoir. The Newberry Volcano EGS Demonstration is allowing geothermal industry and academic experts to develop, validate and enhance geoscience and engineering techniques, and other procedures essential to the expansion of EGS throughout the country. Successful development will demonstrate to the American public that EGS can play a significant role

  8. Augustine Volcano's late Pleistocene rhyolite eruption and its modern-day residuum (United States)

    Coombs, M. L.; Vazquez, J. A.


    The pre-Holocene eruptive history of Augustine Volcano, the most active volcano in the populated Cook Inlet region of Alaska, is poorly known due to the effects of glaciation and voluminous products of Holocene eruptions that cover the majority of this island volcano. Among its oldest known deposits, thought to be latest Pleistocene in age, are a basalt-rhyolite hyaloclastite, which is interbedded with an overlying pumiceous rhyolite tephra fall, that crop out on the south side of the island (Waitt and Beget, 2009). Dense and pumiceous rhyolite clasts from the deposits are compositionally similar (71-74 wt. % SiO2; Larsen et al., 2010) and contain phenocrysts of plagioclase, quartz, amphibole, and Fe-Ti oxides. These basalt-rhyolite deposits are the most compositionally extreme products of the volcano; Holocene eruptions, including historical eruptions in 1976, 1986, and 2006, produced andesites and dacites. In 2006, one such eruption produced gabbro inclusions (54.4-60.2 wt% SiO2) that consist of plagioclase, amphibole, pyroxenes, Fe-Ti oxides, and small amounts of interstitial glass, suggesting a cumulate origin. Both the Pleistocene-age rhyolite and the 2006 gabbro inclusions fall along a whole-rock compositional trend depleted in incompatible elements relative to mid-Holocene-present andesites and dacites. To investigate differentiation and the timing of rhyolite magma generation at Augustine, we have determined high-spatial resolution 238U-230Th ages of zircon crystallization for the rhyolite as well as for the gabbros and high-silica andesites erupted in 2006. Sensitive high-resolution ion microprobe (SHRIMP-RG) analyses of indium-mounted, unpolished zircon rims from the rhyolite yield a single 238U-230Th isochron age of ca. 27 ka, which we interpret to reflect the final interval of crystallization immediately prior to eruption. Sectioned core ages for rhyolite zircon, however, fall into two populations: one at ca. 27 ka, and a second, smaller population that

  9. Anhydrite in the 1989 1990 lavas and xenoliths from Redoubt Volcano, Alaska (United States)

    Swanson, S. E.; Kearney, C. S.


    The eruption of Redoubt Volcano in Alaska produced a moderate sulfur emission (estimated at 1 × 10 tons SO 2), but relatively small volume of lava (0.11 km ) with pre-eruption estimates of 840-950 °C and fO 21.5 to 2.0 log units above NNO (Swanson, S.E., Nye, C.J., Miller, T.P., Avery, V.F., 1994. Magma mixing in the 1989-1990 eruption of Redoubt Volcano: Part II. Evidence from mineral and glass chemistry. Journal of Volcanology and Geothermal Research 62, 453-468). Petrologic estimates of sulfur production (Sigurdsson, H., Devine, J.D.,Davis, A.N., 1985. The petrologic estimation of volcanic degassing. Jokull 35, 1-8) from this eruption (Gerlach, T., Westrich, H.R., Casadevall, T.J., Finnegan, D.L., 1994. Vapor Saturation and accumulation in magmas of the 1989-1990 eruption of Redoubt Volcano, Alaska. Journal of Volcanology and Geothermal Research 62, 317-337) are considerably less than the measured sulfur emission, leading workers to propose the existence of a pre-eruption vapor phase to explain the "excess" sulfur. Initial examination of the 1989-1990 Redoubt eruptive products reported anhydrite (Nye, C.J., Swanson, S.E., Avery, V.F., Miller, T.P., 1994. Geochemistry of the 1989-1990 eruption of Redoubt Volcano: Part I, whole-rock, major- and trace-element chemistry. Journal of Volcanology and Geothermal Research 62, 429-452.) in interstitial glass from some cognate gabbroic xenoliths, but anhydrite was not noted in any of the andesites. A Boeing 747 encountered the ash plume from the initial eruptive phase on December 15, 1989 and provided ash samples that reportedly contained gypsum (Bayhurst, G.K., Wohletz, K.H., Mason, A.S., 1994. A method for characterizing volcanic ash from the December 15, 1989, eruption of Redoubt Volcano, Alaska. U.S. Geological Survey Bulletin 2047, 13-17). However, the identification was based on EDS analyses on a SEM and the mineral could have been anhydrite. Reexamination of the 1989-1990 Redoubt lavas and xenoliths revealed the

  10. Fluctuation analysis of the hourly time variability of volcano-magnetic signals recorded at Mt. Etna Volcano, Sicily (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Currenti, Gilda [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma 2, 95123 Catania (Italy); Del Negro, Ciro [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma 2, 95123 Catania (Italy); Lapenna, Vincenzo [Istituto di Metodologie per l' Analisi Ambientale, Consiglio Nazionale delle Ricerche, IMAA-CNR, C.da S.Loja 5, 85050 Tito, PZ (Italy); Telesca, Luciano [Istituto di Metodologie per l' Analisi Ambientale, Consiglio Nazionale delle Ricerche, IMAA-CNR, C.da S.Loja 5, 85050 Tito, PZ (Italy)]. E-mail:


    The time-correlation properties in the hourly time variability of volcano-magnetic data measured at the active volcano Mt. Etna, Sicily (southern Italy), are investigated by using the detrended fluctuation analysis (DFA). DFA is a data processing method that allows for the detection of scaling behaviors in observational time series even in the presence of nonstationarities. The procedure adopted has revealed unambiguous link between the dynamics of the measured data and the recent eruptive episode of the volcano occurred on October 27, 2002.

  11. Magma supply, storage, and transport at shield-stage Hawaiian volcanoes: Chapter 5 in Characteristics of Hawaiian volcanoes (United States)

    Poland, Michael P.; Miklius, Asta; Montgomery-Brown, Emily K.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.


    The characteristics of magma supply, storage, and transport are among the most critical parameters governing volcanic activity, yet they remain largely unconstrained because all three processes are hidden beneath the surface. Hawaiian volcanoes, particularly Kīlauea and Mauna Loa, offer excellent prospects for studying subsurface magmatic processes, owing to their accessibility and frequent eruptive and intrusive activity. In addition, the Hawaiian Volcano Observatory, founded in 1912, maintains long records of geological, geophysical, and geochemical data. As a result, Hawaiian volcanoes have served as both a model for basaltic volcanism in general and a starting point for many studies of volcanic processes.

  12. Investigation of Chemical and Physical Changes to Bioapatite During Fossilization Using Trace Element Geochemistry, Infrared Spectroscopy and Stable Isotopes (United States)

    Suarez, C. A.; Kohn, M. J.


    Bioapatite in the form of vertebrate bone can be used for a wide variety of paleo-proxies, from determination of ancient diet to the isotopic composition of meteoric water. Bioapatite alteration during diagenesis is a constant barrier to the use of fossil bone as a paleo-proxy. To elucidate the physical and chemical alteration of bone apatite during fossilization, we analyzed an assortment of fossil bones of different ages for trace elements, using LA-ICP-MS, stable isotopes, and reflected IR spectroscopy. One set of fossil bones from the Pleistocene of Idaho show a diffusion recrystallization profile, however, rare earth element (REE) profiles indicate diffusion adsorption. This suggests that REE diffusion is controlled by changing (namely decreasing) boundary conditions (i.e. decreasing concentration of REE in surrounding pore fluids). Reflected IR analysis along this concentration profile reveal that areas high in U have lost type A carbonate from the crystal structure in addition to water and organics. Stable isotopic analysis of carbon and oxygen will determine what, if any, change in the isotopic composition of the carbonate component of apatite has occurred do to the diffusion and recrystallization process. Analysis of much older bone from the Cretaceous of China reveal shallow REE and U concentration profiles and very uniform reflected IR spectra with a significant loss of type A carbonate throughout the entire bone cortex. Analysis of stable isotopes through the bone cortex will be compared to the stable isotopes collected from the Pleistocene of Idaho.

  13. 78 FR 9016 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Revisions to Fossil... (United States)


    ...; Revisions to Fossil Fuel Utilization and Source Registration Regulations and Boiler Industrial Standards... revisions add new monitoring, inspection, maintenance and testing requirements for certain fossil fuel... approval of the state's revised fossil fuel utilization facility regulation, source registration...

  14. Fossil evidence for the early ant evolution (United States)

    Perrichot, Vincent; Lacau, Sébastien; Néraudeau, Didier; Nel, André


    Ants are one of the most studied insects in the world; and the literature devoted to their origin and evolution, systematics, ecology, or interactions with plants, fungi and other organisms is prolific. However, no consensus yet exists on the age estimate of the first Formicidae or on the origin of their eusociality. We review the fossil and biogeographical record of all known Cretaceous ants. We discuss the possible origin of the Formicidae with emphasis on the most primitive subfamily Sphecomyrminae according to its distribution and the Early Cretaceous palaeogeography. And we review the evidence of true castes and eusociality of the early ants regarding their morphological features and their manner of preservation in amber. The mid-Cretaceous amber forest from south-western France where some of the oldest known ants lived, corresponded to a moist tropical forest close to the shore with a dominance of gymnosperm trees but where angiosperms (flowering plants) were already diversified. This palaeoenvironmental reconstruction supports an initial radiation of ants in forest ground litter coincident with the rise of angiosperms, as recently proposed as an ecological explanation for their origin and successful evolution.

  15. Biochar, a substitute for fossil fuels (United States)

    Supriya, Akankshya; Samantray, R.; Mishra, S. C.


    The present piece of research is envisaged for the possibilities and usefulness of coco peat (coir dust) which is generally not considered for usefulness. Pyrolysis of coco peat was done at two different temperatures to obtain biochars and their properties were investigated. Proximate analysis gave the fixed carbon content which gave a good value for the required purpose. Characterization techniques like Scanning Electron Microscopy, X-Ray Diffraction and Fourier Transform Infra-Red Spectroscopy were employed. It was observed that depending on the pyrolysis temperature and conditions, new substances formed, the diffraction peaks changed and also there were major changes in functional groups. The cross-links were found to disintegrate with increasing temperature. The peaks unveiled the presence of silicon carbide in the biochar pyrolysed at 1000ºC. The change in the functional groups with increase in temperature manifested higher aromaticity which is an important attribute of fuels viz. petroleum, etc. Thus the present investigation can open up a new era for processing biochar from unutilized biowaste for its use as an alternative to fossil fuels.

  16. Modeling neck mobility in fossil turtles. (United States)

    Werneburg, Ingmar; Hinz, Juliane K; Gumpenberger, Michaela; Volpato, Virginie; Natchev, Nikolay; Joyce, Walter G


    Turtles have the unparalleled ability to retract their heads and necks within their shell but little is known about the evolution of this trait. Extensive analysis of neck mobility in turtles using radiographs, CT scans, and morphometry reveals that basal turtles possessed less mobility in the neck relative to their extant relatives, although the anatomical prerequisites for modern mobility were already established. Many extant turtles are able to achieve hypermobility by dislocating the central articulations, which raises cautions about reconstructing the mobility of fossil vertebrates. A 3D-model of the Late Triassic turtle Proganochelys quenstedti reveals that this early stem turtle was able to retract its head by tucking it sideways below the shell. The simple ventrolateral bend seen in this stem turtle, however, contrasts with the complex double-bend of extant turtles. The initial evolution of neck retraction therefore occurred in a near-synchrony with the origin of the turtle shell as a place to hide the unprotected neck. In this early, simplified retraction mode, the conical osteoderms on the neck provided further protection. © 2014 Wiley Periodicals, Inc.

  17. Fossilized excreta associated to dinosaurs in Brazil (United States)

    Souto, P. R. F.; Fernandes, M. A.


    This work provides an updated register of the main occurrences of fossilized excreta (coprolites and urolites) associated with dinosaurs found in the Brazil. The goal is to provide a relevant guide to the interpretation of the environment in the context of Gondwana. In four geographic areas, the excreta are recovered from Cretaceous sedimentary deposits in outcrops of the Bauru and São Luis basins and the Upper Jurassic aeolian deposits of the Parana Basin in the state of São Paulo. The coprolites were analyzed by X-ray diffraction and X-ray fluorescence methods. The results of these analyses reveal compositions that differ from the surrounding matrix, indicating a partial substitution of the organic material due to the feeding habits of the producers. Additionally, we describe the urolite excavations in epirelief and hyporelief, the result of gravitational flow the impact from urine jets on sand. These are associated with ornithopod and theropod dinosaur footprints preserved in the aeolian flagstones of the Botucatu Formation, Parana Basin.

  18. Origin of Metazoa: Sponges as Living Fossils (United States)

    Müller, Werner E. G.


    , which code for proteins. The analyses of their deduced amino acid sequences allowed a molecular biological approach to solve the problem of monophyly of Metazoa. Molecules of the extracellular matrix/basal lamina, with the integrin receptor, fibronectin, and galectin as prominent examples, cell-surface receptors (tyrosine kinase receptor), elements of sensory systems (crystallin, metabotropic glutamate receptor), and homologs/modules of an immune system (immunoglobulin like molecules, scavenger receptor cysteine-rich, and short consensus repeats, rhesus system) classify the Porifera as true Metazoa. As living fossils, provided with simple, primordial molecules allowing cell-cell and cell-matrix adhesion as well as processes of signal transduction as known in a more complex manner from higher Metazoa, they also show peculiarities not known in other metazoan phyla. Tissues of sponges are rich in telomerase activity, suggesting a high plasticity in the determination of cell lineages. It is concluded that molecular biological studies with sponges as model will not only help to understand the evolution of Protoctista to Metazoa but also the complex, hierarchial regulatory network of cells in higher Metazoa.

  19. The first darter (Aves: Anhingidae) fossils from India (late Pliocene). (United States)

    Stidham, Thomas; Patnaik, Rajeev; Krishan, Kewal; Singh, Bahadur; Ghosh, Abhik; Singla, Ankita; Kotla, Simran S


    New fossils from the latest Pliocene portion of the Tatrot Formation exposed in the Siwalik Hills of northern India represent the first fossil record of a darter (Anhingidae) from India. The darter fossils possibly represent a new species, but the limited information on the fossil record of this group restricts their taxonomic allocation. The Pliocene darter has a deep pit on the distal face of metatarsal trochlea IV not reported in other anhingids, it has an open groove for the m. flexor perforatus et perforans digiti II tendon on the hypotarsus unlike New World anhingid taxa, and these darter specimens are the youngest of the handful of Neogene records of the group from Asia. These fossil specimens begin to fill in a significant geographic and temporal gap in the fossil record of this group that is largely known from other continents and other time periods. The presence of a darter and pelican (along with crabs, fish, turtles, and crocodilians) in the same fossil-bearing horizon strongly indicates the past presence of a substantial water body (large pond, lake, or river) in the interior of northern India in the foothills of the Himalayan Mountains.

  20. Single-station monitoring of volcanoes using seismic ambient noise (United States)

    De Plaen, Raphael S. M.; Lecocq, Thomas; Caudron, Corentin; Ferrazzini, Valérie; Francis, Olivier


    Seismic ambient noise cross correlation is increasingly used to monitor volcanic activity. However, this method is usually limited to volcanoes equipped with large and dense networks of broadband stations. The single-station approach may provide a powerful and reliable alternative to the classical "cross-station" approach when measuring variation of seismic velocities. We implemented it on the Piton de la Fournaise in Reunion Island, a very active volcano with a remarkable multidisciplinary continuous monitoring. Over the past decade, this volcano has been increasingly studied using the traditional cross-correlation technique and therefore represents a unique laboratory to validate our approach. Our results, tested on stations located up to 3.5 km from the eruptive site, performed as well as the classical approach to detect the volcanic eruption in the 1-2 Hz frequency band. This opens new perspectives to successfully forecast volcanic activity at volcanoes equipped with a single three-component seismometer.

  1. Distribution of acidic groundwater around quaternary volcanoes in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Asamori, Koichi; Ishimaru, Tsuneari; Iwatsuki, Teruki [Japan Nuclear Cycle Development Inst., Toki, Gifu (Japan). Tono Geoscience Center


    One important key issue in the understanding of the long-term stability of the geological environment is the influence of magmatism. In this study, we examined the general spatial distribution of acidic groundwater around Quaternary volcanoes in Japan using a database of groundwater geochemistry. The results may be summarized as follows: Acidic groundwater with pH < 4.8 mainly occur in present volcanic regions and are distributed from several kilometers to about 20 km from Quaternary volcanoes. The pH value of groundwater tends to decrease with increasing distance from a volcano. However, these results may be affected by inhomogeneity of groundwater data distribution and the characteristic activity of each volcano. In order to assess a specific volcanic region, a detailed analysis that considers volcanic activity, using a data set with high spatial density is necessary. (author)

  2. Vegetation damage and recovery after Chiginagak Volcano Crater drainage event (United States)

    US Fish and Wildlife Service, Department of the Interior — From August 20 — 23, 2006, I revisited Chiginigak volcano to document vegetation recovery after the crater drainage event that severely damaged vegetation in May of...

  3. Chasing lava: a geologist's adventures at the Hawaiian Volcano Observatory (United States)

    Duffield, Wendell A.


    A lively account of the three years (1969-1972) spent by geologist Wendell Duffield working at the Hawaiian Volcano Observatory at Kilauea, one of the world's more active volcanoes. Abundantly illustrated in b&w and color, with line drawings and maps, as well. Volcanologists and general readers alike will enjoy author Wendell Duffield's report from Kilauea--home of Pele, the goddess of fire and volcanoes. Duffield's narrative encompasses everything from the scientific (his discovery that the movements of cooled lava on a lava lake mimic the movements of the earth's crust, providing an accessible model for understanding plate tectonics) to the humorous (his dog's discovery of a snake on the supposedly snake-free island) to the life-threatening (a colleague's plunge into molten lava). This charming account of living and working at Kilauea, one of the world's most active volcanoes, is sure to be a delight.

  4. Mount Rainier: living safely with a volcano in your backyard (United States)

    Driedger, Carolyn L.; Scott, William E.


    Majestic Mount Rainier soars almost 3 miles (14,410 feet) above sea level and looms over the expanding suburbs of Seattle and Tacoma, Washington. Each year almost two million visitors come to Mount Rainier National Park to admire the volcano and its glaciers, alpine meadows, and forested ridges. However, the volcano's beauty is deceptive - U.S. Geological Survey (USGS) research shows that Mount Rainier is one of our Nation's most dangerous volcanoes. It has been the source of countless eruptions and volcanic mudflows (lahars) that have surged down valleys on its flanks and buried broad areas now densely populated. To help people live more safely with the volcano, USGS scientists are working closely with local communities, emergency managers, and the National Park Service.

  5. Notes on fish, reptilian, and several fragmentary mammalian dental fossils from the Pondaung Formation


    Tsubamoto, Takehisa; Egi, Naoko; Takai, Masanaru


    We provide photos of fish and reptile fossils and several fragmentary mammalian dento-gnathic fossils from the Eocene Pondaung Formation of Myanmar with description of primate-like dento-gnathic fossils. The figured fossils consist of four specimens of fishes, 11 specimens of reptiles (two vertebral specimens of snake-like reptile, six lower jaws of agamid lizard, three jaws of indeterminate lizard, and two teeth of crocodile), and 42 specimens of mammals (24 fragmentary fossils, 12 fossils o...

  6. New record of a fossil haplotilapiine cichlid from Central Kenya

    Directory of Open Access Journals (Sweden)

    Stefanie B. R. Penk


    Full Text Available African freshwater cichlids (Cichlidae: Pseudocrenilabrinae are well known for their exceptionally great diversity and their capability of rapid speciation as well as diverse adaptations. The extant Pseudocrenilabrinae can be grouped into 27 tribes, with more than 2000 species harbored in the Great Lakes and surrounding water bodies of the East African Rift System. However, this unique diversity is not reflected in the fossil record because fossil cichlids were predominantly reported based on isolated teeth and bones. Moreover, the few articulated specimens that are known have not been analyzed sufficiently with regard to their systematic position due to lack of comparative material. Here we present a new extraordinarily well-preserved cichlid fish fossil from the Middle Miocene (c. 12.5 Ma Lagerstaette Kabchore, which was recovered during recent fieldwork in the Tugen Hills (Baringo County, Central Kenya Rift. Based on the evidence of tricuspid teeth, the Kabchore fossil can be assigned to the subclade of the Haplotilapiines within the Pseudocrenilabrinae. The multivariate analysis of a large meristic data set, derived from 1014 extant specimens (encompassing all main lineages of Haplotilapiines and usage of available osteological data suggest that this fossil is most likely related to one of the three haplotilapiine tribes Tilapiini, Haplochromini or Oreochromini. Moreover, the fossil specimen closely resembles the extinct cichlid Oreochromis martyni (Van Couvering, 1982, previously described as species of Sarotherodon from the Middle Miocene alkaline Kapkiamu Lake in the Tugen Hills. The analysis of the greatly preserved fossil fish specimen from Kabchore definitely supplements the fragmentary fossil record of Africa’s Cichlidae and will afford new insights into its evolutionary history. We also expect that this fossil will be useful as calibration point for new divergence-time estimates.

  7. Sulfur dioxide contributions to the atmosphere by volcanoes. (United States)

    Stoiber, R E; Jepsen, A


    The first extensive measurements by remote-sensing correlation spectrometry of the sulfur dioxide emitted by volcanic plumes indicate that on the order of 10(3) metric tons of sulfur dioxide gas enter the atmosphere daily from Central American volcanoes. Extrapolation gives a minimum estimate of the annual amount of sulfur dioxide emitted from the world's volcanoes of about 10(7) metric tons.

  8. Three-dimensional shallow velocity structure beneath Taal Volcano, Philippines (United States)

    You, Shuei-Huei; Konstantinou, Konstantinos I.; Gung, Yuancheng; Lin, Cheng-Horng


    Based on its numerous historical explosive eruptions and high potential hazards to nearby population of millions, Taal Volcano is one of the most dangerous "Decade Volcanoes" in the world. To provide better investigation on local seismicity and seismic structure beneath Taal Volcano, we deployed a temporary seismic network consisting of eight stations from March 2008 to March 2010. In the preliminary data processing stage, three periods showing linear time-drifting of internal clock were clearly identified from noise-derived empirical Green's functions. The time-drifting errors were corrected prior to further data analyses. By using VELEST, 2274 local earthquakes were manually picked and located. Two major earthquake groups are noticed, with one lying beneath the western shore of Taal Lake showing a linear feature, and the other spreading around the eastern flank of Taal Volcano Island at shallower depths. We performed seismic tomography to image the 3D structure beneath Taal Volcano using the LOTOS algorithm. Some interesting features are revealed from the tomographic results, including a solidified magma conduit below the northwestern corner of Taal Volcano Island, indicated by high Vp, Vs, and low Vp/Vs ratio, and a large potential hydrothermal reservoir beneath the center of Taal Volcano Island, suggested by low Vs and high Vp/Vs ratio. Furthermore, combining earthquake distributions and tomographic images, we suggest potential existence of a hydrothermal reservoir beneath the southwestern corner of Taal Lake, and a fluid conduit extending to the northwest. These seismic features have never been proposed in previous studies, implying that new hydrothermal activity might be formed in places away from the historical craters on Taal Volcano Island.

  9. Fossiler i Grønland. 2. del

    DEFF Research Database (Denmark)

    Harper, David Alexander Taylor; Lindow, Bent Erik Kramer


    Dette er anden og sidste del af POST Greenlands serie om fossiler i Grønland med tre frimærker, der beretter om de mange og spændende fossilfund fra Grønland. Mærkerne fortsætter vores rejse gennem nogle af nøglebegivenhederne i livets historie, smukt illustreret af endnu flere unikke fossiler....... Disse tre fossiler, en plante, et bløddyr og et hvirveldyr, er fra de yngre aflejringer i Grønland med aldre spændende fra for 200 millioner og indtil kun 8.000 år siden....

  10. Structure and evolution of fossil H II regions (United States)

    Mccray, R.; Schwarz, J.


    The structure and evolution of a fossil H II region created by a burst of ionizing radiation from a supernova is considered. The cooling time scale for the shell is about 10 to the 6th power years. Superposition of million-year-old fossil H II regions may account for the temperature and ionization of the interstellar medium. Fossil H II regions are unstable to growth of thermal condensations. Highly ionized filamentary structures form and dissipate in about 10,000 years. Partially ionized clouds form and dissipate in about 10 to the 6th power years.

  11. Fossil fuel prospects for the twenty-first century

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, R.C. [Institute on Energy and Man, Seattle, WA (United States)


    The consumption of fossil fuels for power generation to sustain global economic development is bound to fail, it is argued. By examining data on global natural gas, coal and petroleum reserves, in relation to historic data and various forecasts for economic and industrial growth measures (as fossil fuel consumption total use and per capita use) the author points out two inevitable consequences of fossil fuel consumption, subsoil depletion and environmental damage, and reveals the urgent necessity to find a new primary energy source. (UK)

  12. A Study of Dispelling Lexical Fossilization for English Learners

    Institute of Scientific and Technical Information of China (English)

    QI Ai-ling


    Fossilization was first proposed by the famous British linguist Larry Selinker in his article Interlanguage in 1972. Non-English majors make many lexical errors in the process of English writings in universities. Therefore, their writing levels may reach a plateau and fail to make progress. Once English vocabulary is fossilized, it will prevent the development of students’ writing competence. Inspired and stimulated by the observation of lexical errors in the university, the author intends to explore effective and feasible methods of dispelling lexical fossilization from the perspective of the theories of prototype and basic-level category and tries to provide a useful supplement in this area.

  13. Fossil proboscidea and edentata of the San Pedro Valley, Arizona (United States)

    Gidley, James Williams


    A preliminary report on the fossil vertebrates of the San Pedro Valley, Ariz., collected by Kirk Bryan and me in the winter of 1920 and 1921 was published in 1922. This report includes a brief statement regarding the geology of the locality and a preliminary list of fossil vertebrates obtained by the expedition of 1921, with descriptions of the rodents and rabbits. Two additional papers on this interesting fauna have also appeared, one on the turtles by C.W. Gilmore and one on the birds by Alexander Wetmore. The present contribution deals with the proboscideans and edentates and gives a somewhat fuller discussion of the geology of the fossil-bearing beds.

  14. Distinguishing between biologically induced and biologically controlled mineralization in fossil organisms using electron backscatter diffraction (EBSD) (United States)

    Päßler, Jan-Filip; Jarochowska, Emilia; Bestmann, Michel; Munnecke, Axel


    Although carbonate-precipitating cyanobacteria are ubiquitous in aquatic ecosystems today, the criteria used to identify them in the geological record are subjective and rarely testable. Differences in the mode of biomineralization between cyanobacteria and metazoans, i.e. biologically induced calcification (BIM) vs. biologically controlled calcification (BCM) might be possible to discern through different crystallographic structures in which they result. We employed electron backscatter diffraction (EBSD) to investigate the structure of calcareous skeletons in two microproblematica widespread in Paleozoic marine ecosystems: Rothpletzella Wood 1945, considered to be a cyanobacterium, and Allonema Ulrich & Bassler 1904. We used a calcareous trilobite shell as a reference. The shell of Allonema has a simple single-layered structure of acicular crystals perpendicular to the surface of the organism. The c-axes of these crystals are parallel to the elongation and thereby normal to the surface of the organism. The pole figures and misorientation axis distribution reveal a fiber texture around the c-axis with a small degree of variation (up to 30°), indicating a well-organized structure. A comparable pattern was found in the trilobite shell. This structure allows excluding biologically induced mineralization as the mechanism of shell formation in Allonema. In Rothpletzella the c-axes of the microcrystalline sheath show a broader clustering compared to Allonema, but still reveal crystals tending to be perpendicular to the surface of the organism. The misorientation axes of adjacent crystals show a random distribution. However, Rothpletzella also shares other morphological similarities with fossil and extant cyanobacteria. We propose that the strict limitation of rotations (misorientations) between adjacent crystals around a specific axis of the crystal system can be used as a criterion to distinguish shells formed through biologically controlled biomineralization.

  15. Fossil energy will take the most lives; The catastrophe in Japan; Fossil energi tar flest liv

    Energy Technology Data Exchange (ETDEWEB)

    Hovland, Kjetil Malkenes; Nilsen, Jannicke; Seehusen, Joachim; Valmot, Odd Richard


    Nuclear accident in Japan has blown life into the debate about nuclear power's future. But to replace nuclear power with fossil fuels will likely lead to more death. Examples of energy-related deaths: Hydropower - nearly 30 000 people dead and millions of buildings disappeared when Banqio Dam in China collapsed in 1975. Coal Production - 2433 died in Chinese coal mines in 2010; nuclear power - there have been 20 nuclear accidents with fatalities. Oil - in the period 1969 - 2000 3700 people died in connection with oil production in OECD countries. (AG)

  16. Before the turning point. Pt. 1. Fossil energy economy; Vor dem Scheitelpunkt. T. 1. Fossile Energiewirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Seltmann, Thomas [' Energy Watch Group' (Germany)


    Energy policy has so far neglected the real availability of energy resources. From the global point of view a dramatic shortage of fossil fuels must be expected; uranium is even now in short supply. At the same time, the availability of renewable energy sources has increased faster than even optimists would have expected. To develop realistic strategies, energy policy, energy economy and also the general public need more objective information and greater transparency. Because of this, the Energy Watch Group meticulousnessly gathered, analysed and combined data to make them available. (orig./GL)

  17. RNA Crystallization (United States)

    Golden, Barbara L.; Kundrot, Craig E.


    RNA molecules may be crystallized using variations of the methods developed for protein crystallography. As the technology has become available to syntheisize and purify RNA molecules in the quantities and with the quality that is required for crystallography, the field of RNA structure has exploded. The first consideration when crystallizing an RNA is the sequence, which may be varied in a rational way to enhance crystallizability or prevent formation of alternate structures. Once a sequence has been designed, the RNA may be synthesized chemically by solid-state synthesis, or it may be produced enzymatically using RNA polymerase and an appropriate DNA template. Purification of milligram quantities of RNA can be accomplished by HPLC or gel electrophoresis. As with proteins, crystallization of RNA is usually accomplished by vapor diffusion techniques. There are several considerations that are either unique to RNA crystallization or more important for RNA crystallization. Techniques for design, synthesis, purification, and crystallization of RNAs will be reviewed here.

  18. Geomorphometric comparative analysis of Latin-American volcanoes (United States)

    Camiz, Sergio; Poscolieri, Maurizio; Roverato, Matteo


    The geomorphometric classifications of three groups of volcanoes situated in the Andes Cordillera, Central America, and Mexico are performed and compared. Input data are eight local topographic gradients (i.e. elevation differences) obtained by processing each volcano raster ASTER-GDEM data. The pixels of each volcano DEM have been classified into 17 classes through a K-means clustering procedure following principal component analysis of the gradients. The spatial distribution of the classes, representing homogeneous terrain units, is shown on thematic colour maps, where colours are assigned according to mean slope and aspect class values. The interpretation of the geomorphometric classification of the volcanoes is based on the statistics of both gradients and morphometric parameters (slope, aspect and elevation). The latter were used for a comparison of the volcanoes, performed through classes' slope/aspect scatterplots and multidimensional methods. In this paper, we apply the mentioned methodology on 21 volcanoes, randomly chosen from Mexico to Patagonia, to show how it may contribute to detect geomorphological similarities and differences among them. As such, both its descriptive and graphical abilities may be a useful complement to future volcanological studies.

  19. Effects of Basement, Structure, and Stratigraphic Heritages on Volcano Behavior (United States)

    Lagmay, Alfredo Mahar Francisco A.


    Effective natural hazard mitigation requires that the science surrounding geophysical events be thoroughly explored. With millions of people living on the flanks of volcanoes, understanding the parameters that effect volcanic behavior is critically important. In particular, basements can influence the occurrence of volcanic eruptions and landslides. This control by the substrate on volcano behavior usually has been considered questionable or less important than the conditions of the deep magma source. However, due to recent findings, this view is changing, specifically with regard to approaches in assessing volcanic hazards. The November 2005 AGU Chapman Conference ``Effects of Basement, Structure, and Stratigraphic Heritages on Volcano Behavior'' brought together geologists and geophysicists from North and South America, Europe, and Asia to discuss the results of their research on the reciprocal effects of the interaction between volcanos and their basements. The conference also highlighted the importance of holding Chapman conferences in developing countries such as the Philippines because many hazardous volcanos are situated in these countries. Apart from having natural field laboratories, these are the very same places that need to promote scientific discourse on volcano research, which can lead to more effective hazard mitigation programs.

  20. GlobVolcano pre-operational services for global monitoring active volcanoes (United States)

    Tampellini, Lucia; Ratti, Raffaella; Borgström, Sven; Seifert, Frank Martin; Peltier, Aline; Kaminski, Edouard; Bianchi, Marco; Branson, Wendy; Ferrucci, Fabrizio; Hirn, Barbara; van der Voet, Paul; van Geffen, J.


    The GlobVolcano project (2007-2010) is part of the Data User Element programme of the European Space Agency (ESA). The project aims at demonstrating Earth Observation (EO) based integrated services to support the Volcano Observatories and other mandate users (e.g. Civil Protection) in their monitoring activities. The information services are assessed in close cooperation with the user organizations for different types of volcano, from various geographical areas in various climatic zones. In a first phase, a complete information system has been designed, implemented and validated, involving a limited number of test areas and respective user organizations. In the currently on-going second phase, GlobVolcano is delivering pre-operational services over 15 volcanic sites located in three continents and as many user organizations are involved and cooperating with the project team. The set of GlobVolcano offered EO based information products is composed as follows: Deformation Mapping DInSAR (Differential Synthetic Aperture Radar Interferometry) has been used to study a wide range of surface displacements related to different phenomena (e.g. seismic faults, volcanoes, landslides) at a spatial resolution of less than 100 m and cm-level precision. Permanent Scatterers SAR Interferometry method (PSInSARTM) has been introduced by Politecnico of Milano as an advanced InSAR technique capable of measuring millimetre scale displacements of individual radar targets on the ground by using multi-temporal data-sets, estimating and removing the atmospheric components. Other techniques (e.g. CTM) have followed similar strategies and have shown promising results in different scenarios. Different processing approaches have been adopted, according to data availability, characteristic of the area and dynamic characteristics of the volcano. Conventional DInSAR: Colima (Mexico), Nyiragongo (Congo), Pico (Azores), Areanal (Costa Rica) PSInSARTM: Piton de la Fournaise (La Reunion Island

  1. Protein Crystallization (United States)

    Chernov, Alexander A.


    Nucleation, growth and perfection of protein crystals will be overviewed along with crystal mechanical properties. The knowledge is based on experiments using optical and force crystals behave similar to inorganic crystals, though with a difference in orders of magnitude in growing parameters. For example, the low incorporation rate of large biomolecules requires up to 100 times larger supersaturation to grow protein, rather than inorganic crystals. Nucleation is often poorly reproducible, partly because of turbulence accompanying the mixing of precipitant with protein solution. Light scattering reveals fluctuations of molecular cluster size, its growth, surface energies and increased clustering as protein ages. Growth most often occurs layer-by-layer resulting in faceted crystals. New molecular layer on crystal face is terminated by a step where molecular incorporation occurs. Quantitative data on the incorporation rate will be discussed. Rounded crystals with molecularly disordered interfaces will be explained. Defects in crystals compromise the x-ray diffraction resolution crucially needed to find the 3D atomic structure of biomolecules. The defects are immobile so that birth defects stay forever. All lattice defects known for inorganics are revealed in protein crystals. Contribution of molecular conformations to lattice disorder is important, but not studied. This contribution may be enhanced by stress field from other defects. Homologous impurities (e.g., dimers, acetylated molecules) are trapped more willingly by a growing crystal than foreign protein impurities. The trapped impurities induce internal stress eliminated in crystals exceeding a critical size (part of mni for ferritin, lysozyme). Lesser impurities are trapped from stagnant, as compared to the flowing, solution. Freezing may induce much more defects unless quickly amorphysizing intracrystalline water.

  2. Petrologic insights into basaltic volcanism at historically active Hawaiian volcanoes: Chapter 6 in Characteristics of Hawaiian volcanoes (United States)

    Helz, Rosalind L.; Clague, David A.; Sisson, Thomas W.; Thornber, Carl R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.


    Study of the petrology of Hawaiian volcanoes, in particular the historically active volcanoes on the Island of Hawai‘i, has long been of worldwide scientific interest. When Dr. Thomas A. Jaggar, Jr., established the Hawaiian Volcano Observatory (HVO) in 1912, detailed observations on basaltic activity at Kīlauea and Mauna Loa volcanoes increased dramatically. The period from 1912 to 1958 saw a gradual increase in the collection and analysis of samples from the historical eruptions of Kīlauea and Mauna Loa and development of the concepts needed to evaluate them. In a classic 1955 paper, Howard Powers introduced the concepts of magnesia variation diagrams, to display basaltic compositions, and olivine-control lines, to distinguish between possibly comagmatic and clearly distinct basaltic lineages. In particular, he and others recognized that Kīlauea and Mauna Loa basalts must have different sources.

  3. Computational crystallization. (United States)

    Altan, Irem; Charbonneau, Patrick; Snell, Edward H


    Crystallization is a key step in macromolecular structure determination by crystallography. While a robust theoretical treatment of the process is available, due to the complexity of the system, the experimental process is still largely one of trial and error. In this article, efforts in the field are discussed together with a theoretical underpinning using a solubility phase diagram. Prior knowledge has been used to develop tools that computationally predict the crystallization outcome and define mutational approaches that enhance the likelihood of crystallization. For the most part these tools are based on binary outcomes (crystal or no crystal), and the full information contained in an assembly of crystallization screening experiments is lost. The potential of this additional information is illustrated by examples where new biological knowledge can be obtained and where a target can be sub-categorized to predict which class of reagents provides the crystallization driving force. Computational analysis of crystallization requires complete and correctly formatted data. While massive crystallization screening efforts are under way, the data available from many of these studies are sparse. The potential for this data and the steps needed to realize this potential are discussed.

  4. The diversity of mud volcanoes in the landscape of Azerbaijan (United States)

    Rashidov, Tofig


    As the natural phenomenon the mud volcanism (mud volcanoes) of Azerbaijan are known from the ancient times. The historical records describing them are since V century. More detail study of this natural phenomenon had started in the second half of XIX century. The term "mud volcano" (or "mud hill") had been given by academician H.W. Abich (1863), more exactly defining this natural phenomenon. All the previous definitions did not give such clear and capacious explanation of it. In comparison with magmatic volcanoes, globally the mud ones are restricted in distribution; they mainly locate within the Alpine-Himalayan, Pacific and Central Asian mobile belts, in more than 30 countries (Columbia, Trinidad Island, Italy, Romania, Ukraine, Georgia, Azerbaijan, Turkmenistan, Iran, Pakistan, Indonesia, Burma, Malaysia, etc.). Besides it, the zones of mud volcanoes development are corresponded to zones of marine accretionary prisms' development. For example, the South-Caspian depression, Barbados Island, Cascadia (N.America), Costa-Rica, Panama, Japan trench. Onshore it is Indonesia, Japan, and Trinidad, Taiwan. The mud volcanism with non-accretionary conditions includes the areas of Black Sea, Alboran Sea, the Gulf of Mexico (Louisiana coast), Salton Sea. But new investigations reveal more new mud volcanoes and in places which were not considered earlier as the traditional places of mud volcanoes development (e.g. West Nile Rive delta). Azerbaijan is the classic region of mud volcanoes development. From over 800 world mud volcanoes there are about 400 onshore and within the South-Caspian basin, which includes the territory of East Azerbaijan (the regions of Shemakha-Gobustan and Low-Kura River, Absheron peninsula), adjacent water area of South Caspian (Baku and Absheron archipelagoes) and SW Turkmenistan and represents an area of great downwarping with thick (over 25 km) sedimentary series. Generally, in the modern relief the mud volcanoes represent more or less large uplifts

  5. The enormous Chillos Valley Lahar: An ash-flow-generated debris flow from Cotopaxi Volcano, Ecuador (United States)

    Mothes, P.A.; Hall, M.L.; Janda, R.J.


    The Chillos Valley Lahar (CVL), the largest Holocene debris flow in area and volume as yet recognized in the northern Andes, formed on Cotopaxi volcano's north and northeast slopes and descended river systems that took it 326 km north-northwest to the Pacific Ocean and 130+ km east into the Amazon basin. In the Chillos Valley, 40 km downstream from the volcano, depths of 80-160 m and valley cross sections up to 337000m2 are observed, implying peak flow discharges of 2.6-6.0 million m3/s. The overall volume of the CVL is estimated to be ???3.8 km3. The CVL was generated approximately 4500 years BP by a rhyolitic ash flow that followed a small sector collapse on the north and northeast sides of Cotopaxi, which melted part of the volcano's icecap and transformed rapidly into the debris flow. The ash flow and resulting CVL have identical components, except for foreign fragments picked up along the flow path. Juvenile materials, including vitric ash, crystals, and pumice, comprise 80-90% of the lahar's deposit, whereas rhyolitic, dacitic, and andesitic lithics make up the remainder. The sand-size fraction and the 2- to 10-mm fraction together dominate the deposit, constituting ???63 and ???15 wt.% of the matrix, respectively, whereas the silt-size fraction averages less than ???10 wt.% and the clay-size fraction less than 0.5 wt.%. Along the 326-km runout, these particle-size fractions vary little, as does the sorting coefficient (average = 2.6). There is no tendency toward grading or improved sorting. Limited bulking is recognized. The CVL was an enormous non-cohesive debris flow, notable for its ash-flow origin and immense volume and peak discharge which gave it characteristics and a behavior akin to large cohesive mudflows. Significantly, then, ash-flow-generated debris flows can also achieve large volumes and cover great areas; thus, they can conceivably affect large populated regions far from their source. Especially dangerous, therefore, are snowclad volcanoes

  6. Environmental audit: Fossil energy sites in Wyoming

    Energy Technology Data Exchange (ETDEWEB)


    This report documents the results of the Comprehensive Baseline Environmental Audit completed for Selected Fossil Energy Sites in Wyoming. During this Audit, facilities, field sites, and activities were investigated and inspected in several areas of Wyoming that are considered to be representative of offsite work falling under the purview of the Morgantown Energy Technology Center (METC) in Morgantown, West Virginia. Department of Energy (DOE) personnel at METC and at the Liquid Fuels Technology Branch (LFTB) in Laramie, Wyoming were interviewed as were DOE contractors and Federal and state regulators. Extensive document review was also a key part of this Audit. The on-site portion of the Audit occurred in Morgantown from May 18 to 22, 1992, and throughout Wyoming from May 26 through June 10, 1992. EH-24 carries out independent assessments of DOE facilities and DOE-funded off-site activities as part of the Assistant Secretary's Environmental Audit Program. That program is designed to evaluate the status of facilities and activities regarding compliance with environmental laws, regulations, DOE Directives, formal written procedures, compliance agreements, and Best Management Practices (BMPs). This internal oversight function plays an important role in improving the compliance status of DOE operations. The Audit stresses the fact that it is the responsibility of line management to conduct operations in an environmentally sound and safe manner. The scope of this Environmental Audit was comprehensive, covering all areas of environmental activities and waste management operations with the exception of the National Environmental Policy Act (NEPA), which is beyond the purview of EH-24. Specifically included within this Audit were Air, Soils/Sediment/Biota, Surface Water/Drinking Water, Groundwater, Waste Management, Toxic and Chemical Materials, Quality Assurance, Radiation, Inactive Waste Sites, and Environmental Management.

  7. Environmental audit: Fossil energy sites in Wyoming

    Energy Technology Data Exchange (ETDEWEB)


    This report documents the results of the Comprehensive Baseline Environmental Audit completed for Selected Fossil Energy Sites in Wyoming. During this Audit, facilities, field sites, and activities were investigated and inspected in several areas of Wyoming that are considered to be representative of offsite work falling under the purview of the Morgantown Energy Technology Center (METC) in Morgantown, West Virginia. Department of Energy (DOE) personnel at METC and at the Liquid Fuels Technology Branch (LFTB) in Laramie, Wyoming were interviewed as were DOE contractors and Federal and state regulators. Extensive document review was also a key part of this Audit. The on-site portion of the Audit occurred in Morgantown from May 18 to 22, 1992, and throughout Wyoming from May 26 through June 10, 1992. EH-24 carries out independent assessments of DOE facilities and DOE-funded off-site activities as part of the Assistant Secretary`s Environmental Audit Program. That program is designed to evaluate the status of facilities and activities regarding compliance with environmental laws, regulations, DOE Directives, formal written procedures, compliance agreements, and Best Management Practices (BMPs). This internal oversight function plays an important role in improving the compliance status of DOE operations. The Audit stresses the fact that it is the responsibility of line management to conduct operations in an environmentally sound and safe manner. The scope of this Environmental Audit was comprehensive, covering all areas of environmental activities and waste management operations with the exception of the National Environmental Policy Act (NEPA), which is beyond the purview of EH-24. Specifically included within this Audit were Air, Soils/Sediment/Biota, Surface Water/Drinking Water, Groundwater, Waste Management, Toxic and Chemical Materials, Quality Assurance, Radiation, Inactive Waste Sites, and Environmental Management.

  8. Elucidating the activity of stepped Pt single crystals for oxygen reduction

    DEFF Research Database (Denmark)

    Bandarenka, Aliaksandr S.; Hansen, Heine Anton; Rossmeisl, Jan;


    obtained by different groups), a well-defined Sabatier-type volcano is observed for the activities measured for the Pt[n(111) × (111)] and Pt[n(111) × (100)] stepped single crystals, in remarkable agreement with earlier theoretical studies. We propose that the observed destabilisation of *OH species...

  9. Origin of a rhyolite that intruded a geothermal well while drilling at the Krafla volcano, Iceland (United States)

    Elders, W.A.; Fridleifsson, G.O.; Zierenberg, R.A.; Pope, E.C.; Mortensen, A.K.; Gudmundsson, A.; Lowenstern, J. B.; Marks, N.E.; Owens, L.; Bird, D.K.; Reed, M.; Olsen, N.J.; Schiffman, P.


    Magma flowed into an exploratory geothermal well at 2.1 km depth being drilled in the Krafla central volcano in Iceland, creating a unique opportunity to study rhyolite magma in situ in a basaltic environment. The quenched magma is a partly vesicular, sparsely phyric, glass containing ~1.8% of dissolved volatiles. Based on calculated H2O-CO2 saturation pressures, it degassed at a pressure intermediate between hydrostatic and lithostatic, and geothermometry indicates that the crystals in the melt formed at ~900 ??C. The glass shows no signs of hydrothermal alteration, but its hydrogen and oxygen isotopic ratios are much lower than those of typical mantle-derived magmas, indicating that this rhyolite originated by anhydrous mantle-derived magma assimilating partially melted hydrothermally altered basalts. ?? 2011 Geological Society of America.

  10. 2006-2008 Eruptions and Volcano Hazards Of Soputan Volcano, North Sulawesi, Indonesia (United States)

    Hendratno, K.; Pallister, J. S.; McCausland, W. A.; Kristianto, M.; Bina, F. R.; Carn, S. A.; Haerani, N.; Griswold, J.; Keeler, R.


    Soputan is a basalt volcano located in North Sulawesi near the southern margin of the Quaternary Tondano Caldera. Unusual for a basalt volcano, Soputan produces summit lava domes and explosive eruptions, as well as voluminous basaltic tephra deposits and lava flows. Soputan erupted five times during 2006-2008: on 14 December, 2006, 12-15 August, 2007, 25-26 October, 2007, 5-6 June, 2008, and 5-6 October, 2008. The 2006-2007 eruptions destroyed a lava dome at the volcano’s summit and exposed the conduit, resulting in Vulcanian eruptions and St. Vincent type pyroclastic flows from an open vent structure. We used high-resolution satellite images and digital elevation models to make photo-geologic maps of the deposits from the 2006, 2007 and 2008 eruptions, to estimate volumes of deposits using GIS and to model potential flow hazards. In March, 2008 and in March 2009 we conducted reconnaissance geologic field investigations at Soputan. This work was done to field-check our photo-geologic mapping, to reconstruct the sequence of eruptive events in 2006-2008 and to collect samples for geochemical and petrographic analysis. We also analyzed seismic records and SO2 emission data from the eruptions and we interpreted these data in the context of our geologic and geochemical data to provide insights into the ascent and degassing of magmas. On the basis of the eruptive history and modeling of potential lahar inundation areas we present an updated assessment of volcano hazards and a forecast for future eruptions at Soputan. Our analysis of field and petrologic data indicates that Soputan is an open-system volcano, which taps basalt magma from great depth, apparently with little shallow storage of this magma. Degassing of the magma as it rises within the conduit results in growth of micro-phenocrysts, evolution of the matrix melt and a commensurate increase in the viscosity of the magma. This, in turn, results in growth of lava domes and more explosive eruptions than are

  11. Felsic maar-diatreme volcanoes: a review (United States)

    Ross, Pierre-Simon; Carrasco Núñez, Gerardo; Hayman, Patrick


    Felsic maar-diatreme volcanoes host major ore deposits but have been largely ignored in the volcanology literature, especially for the diatreme portion of the system. Here, we use two Mexican tuff rings as analogs for the maar ejecta ring, new observations from one diatreme, and the economic geology literature on four other mineralized felsic maar-diatremes to produce an integrated picture of this type of volcano. The ejecta rings are up to 50 m+ thick and extend laterally up to ˜1.5 km from the crater edge. In two Mexican examples, the lower part of the ejecta ring is dominated by pyroclastic surge deposits with abundant lithic clasts (up to 80% at Hoya de Estrada). These deposits display low-angle cross-bedding, dune bedforms, undulating beds, channels, bomb sags, and accretionary lapilli and are interpreted as phreatomagmatic. Rhyolitic juvenile clasts at Tepexitl have only 0-25% vesicles in this portion of the ring. The upper parts of the ejecta ring sequences in the Mexican examples have a different character: lithic clasts can be less abundant, the grain size is typically coarser, and the juvenile clasts can be different in character (with some more vesicular fragments). Fragmentation was probably shallower at this stage. The post-eruptive maar crater infill is known at Wau and consists of reworked pyroclastic deposits as well as lacustrine and other sediments. Underneath are bedded upper diatreme deposits, interpreted as pyroclastic surge and fall deposits. The upper diatreme and post-eruptive crater deposits have dips larger than 30° at Wau, with approximately centroclinal attitudes. At still lower structural levels, the diatreme pyroclastic infill is largely unbedded; Montana Tunnels and Kelian are good examples of this. At Cerro de Pasco, the pyroclastic infill seems bedded despite about 500 m of post-eruptive erosion relative to the pre-eruptive surface. The contact between the country rocks and the diatreme is sometimes characterized by country rock

  12. Geochemical and isotopic profile of Pico de Orizaba (Citlaltépetl) volcano, Mexico: Insights for magma generation processes (United States)

    Schaaf, Peter; Carrasco-Núñez, Gerardo


    Pico de Orizaba or Citlaltépetl volcano is the easternmost and highest stratovolcano of the subduction-related Mexican Volcanic Belt (MVB) located > 400 km NNE of the Middle America Trench. This active volcano comprises four evolutionary stages, ranging in age from 0.65 Ma to the Holocene, and is surrounded by Quaternary monogenetic scoria cones and maar volcanoes. Magmatic products of the stratocone range from basaltic andesites to rhyolites and the cinder cones erupted basalts and basaltic andesites. All rock compositions form a continuous calc-alkaline suite. Petrogenetic processes involved in magma generation and evolution include fractional crystallization and mid-crustal assimilation. Trace element patterns with elevated Ba/Nb, positive Pb spikes, and Th enrichments indicate contributions from subducted sediment. Low Ba/Th ratios suggest melting of hydrous sediment without significant loss of fluid-mobile elements prior to melting. Sr-Nd isotopic ratios of Pico de Orizaba and cinder cones are nearly chondritic and are located on a mixing curve between Pacific MORB and Paleozoic crust of SE Mexico. However, vertical Nd distributions in an 87Sr/ 86Sr vs. ɛNd diagram cannot be explained by crustal assimilation and indicate contributions of a sedimentary component with unradiogenic Nd. In contrast to other eastern MVB volcanic centres, Pico de Orizaba magmas are derived almost exclusively from a depleted mantle source. Compared to other MVB stratocones, Pico de Orizaba shows the least radiogenic Nd isotope ratios at nearly identical 87Sr/ 86Sr. Steep trends in a 206Pb/ 204Pb vs. 207Pb/ 204Pb diagram favour the involvement of young, 207Pb-enriched oceanic sediments in magma generation processes of Pico de Orizaba volcano. The Pb isotope data do not support any assimilation of lower crustal Grenvillian basement.

  13. The 13 ka Pelée-Type Dome Collapse at Nevado de Toluca Volcano, México. (United States)

    D'Antonio, M.; Capra, L.; Sarocchi, D.; Bellotti, F.


    The Nevado de Toluca is an active volcano located in the central sector of the Trans-Mexican Volcanic Belt, 80 km southwest of Mexico City. Activity at this andesitic to dacitic stratovolcano began ca. 2.6 Ma ago. During the last 42 ka, the volcano has been characterized by different eruptive styles, including five dome collapses dated at 37, 32, 28, 26, and 13 ka and five Plinian eruptions at 42 ka, 36 ka, 21.7 ka, 12.1 ka and 10.5 ka. The 13 ka dome collapse is the youngest event of this type, and originated a 0.11 km3 block-and-ash flow deposit on the north-eastern sector of the volcano. The deposit consists of two facies: channel-like, 10 m thick, monolitologic, that is composed of up to five units, with decimetric dacitic clasts set in a sandy matrix; and a lateral facies that consists of a gray, sandy horizon, up to 4 m thick, with a 30 cm-thick surge layer at the base. The main component is a dacitic lava, with different degree of vesciculation, with mineral association of Pl-Hbl-Opx. Plagioclases show two different textures: in equilibrium, with normal zoning (core = An37-64.3, rim = An30.7-45.8) or with spongy cellular texture with inverse zoning (core = An38-43.5, rim = An45-51.2). Hornblende is normally light green, barren of oxidation. The rock matrix contains up to 53 perc. of glass with abundant microlites, indicating over-pressure on the crystallizing magma and a rapid expulsion. All these stratigraphic and petrographic features indicate that the dome was quickly extruded on the summit of the volcano, probably triggered by a magma mixing process, and its collapse was accompanied by an explosive component, being classified as a Pelée-type event.

  14. Instrumentation and Control for Fossil-Energy Processes (United States)

    Mark, A., Jr.


    Instrumentation and control requirements for fossil-energy processes discussed in working document. Published to foster advancement of instrumentation and control technology by making equipment suppliers and others aware of specifications, needs, and potential markets.

  15. Formative Assessment Probes: Mountaintop Fossil: A Puzzling Phenomenon (United States)

    Keeley, Page


    This column focuses on promoting learning through assessment. This month's issue describes using formative assessment probes to uncover several ways of thinking about the puzzling discovery of a marine fossil on top of a mountain.

  16. Legislative and Regulatory Timeline for Fossil Fuel Combustion Wastes (United States)

    This timeline walks through the history of fossil fuel combustion waste regulation since 1976 and includes information such as regulations, proposals, notices, amendments, reports and meetings and site visits conducted.

  17. First Record of Fossil Mesocupes from China (Coleoptera: Archostemata: Cupedidae)

    Institute of Scientific and Technical Information of China (English)


    Three new fossil species of the genus Mesocupes of fossil cupedids, M. angustilabialis sp.nov., M. latilabialis sp. nov. and M. collaris sp. nov., are described from the Jiulongshan Formation of Inner Mongolia, China. These new species are the first three records of fossil Mesocupes in China as well as the oldest ones in the world now. This finding also extends the geographical distribution of this genus from Central to East Asia. In addition, based on the ratio of the length of the last to the penultimate abdominal ventrites of new beetles distinctly lower than that of the species from the Karabastau Formation, the age of Daohugou fossil-bearing beds might be older than that of Karatau assemblage and consequently of Middle Jurassic.

  18. The first fossil cyphophthalmid harvestman from Baltic amber

    Directory of Open Access Journals (Sweden)

    Dunlop, Jason A.


    Full Text Available The first fossil cyphophthalmid harvestman (Opiliones: Cyphophthalmi from Palaeogene (Eocene Baltic amber is described. This is only the third fossil example of this basal harvestman lineage; the others being from the probably slightly younger Bitterfeld amber and the much older, early Cretaceous, Myanmar (Burmese amber. Although incomplete and lacking most of the appendages, the new Baltic amber fossil can be identified as a female. The somatic characters preserved, especially spiracle morphology and the coxo-genital region, allow it to be assigned with some confidence to the extant genus Siro Latreille, 1796 (Sironidae. This fossil is formally described here as Siro balticus sp. nov. It resembles modern North American Siro species more than modern European ones, and can be distinguished principally on its relatively large size and the outline form of the body.

  19. Proceedings of the fourth annual conference on fossil energy materials

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.; Braski, D.N. (comps.)


    The Fourth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on may 15--17, 1990. The meeting was sponsored by the US Department of Energy's Office of Fossil Energy through the Advanced Research and Technology Development (AR TD) Materials Program, and ASM International. The objective of the AR TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The work is divided into the following categories: (1) Ceramics, (2) New Alloys, (3) Corrosion and Erosion, and (4) Technology Assessment and Technology Transfer. Individual projects are processed separately for the data bases.

  20. Fossil Proboscidea from the Malay Archipelago and the Punjab

    NARCIS (Netherlands)

    Hooijer, D.A.


    CONTENTS Introduction............... 1 Fossil Proboscidea and the stratigraphy of the Pleistocene in Southeastern Asia. 3 Order Proboscidea............. 9 Suborder Elephantoidea.......................... 9 Family Elephantidae............ 9 Subfamily Stegodontinae........... 9 Stegolophodon stegodont

  1. Spatial Analysis of Volcanoes at Convergent Margins on Earth (United States)

    Roberts, R. V.; de Silva, S. L.; Meyers, M.


    One of the most obvious patterns seen on the surface of the terrestrial planets is the distribution of volcanoes. On Earth, most volcanoes are distributed in volcanic “arcs” that signal the primary relationship between subduction and volcanism. The distributions of major composite volcanoes in volcanic arcs are thought to reflect the primary magmatic pathways from source to surface. Understanding these patterns therefore may allow fundamental controls on the organization of magmatic plumbing in arcs to be identified. Using a control dataset from the Central Volcanic Zone of the Andes (de Silva and Francis, 1991; Springer-Verlag) we have examined several popular approaches to spatial analysis of volcano distribution in several volcanic arcs (Aleutian, Alaskan, Central American, Northern and Southern volcanic zones of the Andes). Restricting our analysis to major volcanoes of similar age, we find that while clustering is visually obvious in many volcanic arcs it has been rejected as a primary signal by previous analytical efforts (e.g. Bremont d'Ars et al (1995)). We show that the fractal box or grid counting method used previously does not detect clusters and statistical methods such as the Kernel Density Analysis or Single-link Cluster Analysis are better suited for cluster detection. Utilizing both ARC GIS and Matlab to conduct density analyses in combination with statistical software SPlus for the appropriate hypothesis testing methods such as the pooled variance t-test, the Welch Modified two sample t-test, and the f-test we find evidence of clustering in four volcanic arcs whose crustal thickness is greater than or equal to 40 kilometres (Central America, CVZ, NVZ, SVZ). We suggest that clustering is the surface manifestation of upper crustal diffusion of primary magmatic pathways, which in other places manifests as a single volcano. The inter-cluster distance is a thus reflection of primary magmatic pathways and thus equivalent to inter-volcano distance

  2. Geology, zircon geochronology, and petrogenesis of Sabalan volcano (northwestern Iran) (United States)

    Ghalamghash, J.; Mousavi, S. Z.; Hassanzadeh, J.; Schmitt, A. K.


    Sabalan Volcano (NW Iran) is an isolated voluminous (4821 m elevation; > 800 km2) composite volcano that is located within the Arabia-Eurasia collision zone. Its edifice was assembled by recurrent eruptions of trachyandesite and dacite magma falling into a relatively restricted compositional range (56-67% SiO2) with high-K calc-alkaline and adakitic trace element (Sr/Y) signatures. Previous K-Ar dating suggested protracted eruptive activity between 5.6 and 1.4 Ma, and a two stage evolution which resulted in the construction of the Paleo- and Neo-Sabalan edifices, respectively. The presence of a topographic moat surrounding Neo-Sabalan and volcanic breccias with locally intense hydrothermal alteration are indicative of intermittent caldera collapse of the central part of Paleo-Sabalan. Volcanic debris-flow and debris-avalanche deposits indicate earlier episodes of volcanic edifice collapse during the Paleo-Sabalan stage. In the Neo-Sabalan stage, three dacitic domes extruded to form the summits of Sabalan (Soltan, Heram, and Kasra). Ignimbrites and minor pumice fall-out deposits are exposed in strongly dissected drainages that in part have breached the caldera depression. Lavas and pyroclastic rocks are varyingly porphyritic with Paleo-Sabalan rocks being trachyandesites carrying abundant phenocrysts (plagioclase + amphibole + pyroxene + biotite). The Neo-Sabalan rocks are slightly more evolved and include dacitic compositions with phenocrysts of plagioclase + amphibole ± alkali-feldspar ± quartz. All Sabalan rock types share a common accessory assemblage (oxides + apatite + zircon). High spatial resolution and sensitivity U-Pb geochronology using Secondary Ionization Mass Spectrometry yielded two clusters of zircon ages which range from 4.5 to 1.3 Ma and 545 to 149 ka, respectively (all ages are averages of multiple determinations per sample). U-Th zircon geochronology for selected Neo-Sabalan rocks agrees with the U-Pb ages, with the youngest zircon rims dating

  3. The 2009 eruption of Redoubt Volcano, Alaska (United States)

    Bull, Katharine F.; Cameron, Cheryl; Coombs, Michelle L.; Diefenbach, Angie; Lopez, Taryn; McNutt, Steve; Neal, Christina; Payne, Allison; Power, John A.; Schneider, David J.; Scott, William E.; Snedigar, Seth; Thompson, Glenn; Wallace, Kristi; Waythomas, Christopher F.; Webley, Peter; Werner, Cynthia A.; Schaefer, Janet R.


    Redoubt Volcano, an ice-covered stratovolcano on the west side of Cook Inlet, erupted in March 2009 after several months of escalating unrest. The 2009 eruption of Redoubt Volcano shares many similarities with eruptions documented most recently at Redoubt in 1966–68 and 1989–90. In each case, the eruptive phase lasted several months, consisted of multiple ashproducing explosions, produced andesitic lava and tephra, removed significant amounts of ice from the summit crater and Drift glacier, generated lahars that inundated the Drift River valley, and culminated with the extrusion of a lava dome in the summit crater. Prior to the 2009 explosive phase of the eruption, precursory seismicity lasted approximately six months with the fi rst weak tremor recorded on September 23, 2008. The first phreatic explosion was recorded on March 15, and the first magmatic explosion occurred seven days later, at 22:34 on March 22. The onset of magmatic explosions was preceded by a strong, shallow swarm of repetitive earthquakes that began about 04:00 on March 20, 2009, less than three days before an explosion. Nineteen major ash-producing explosions generated ash clouds that reached heights between 17,000 ft and 62,000 ft (5.2 and 18.9 km) ASL. During ash fall in Anchorage, the Ted Stevens International Airport was shut down for 20 hours, from ~17:00 on March 28 until 13:00 on March 29. On March 23 and April 4, lahars with fl ow depths to 10 m in the upper Drift River valley inundated parts of the Drift River Terminal (DRT). The explosive phase ended on April 4 with a dome collapse at 05:58. The April 4 ash cloud reached 50,000 ft (15.2 km) and moved swiftly to the southeast, depositing up to 2 mm of ash fall in Homer, Anchor Point, and Seldovia. At least two and possibly three lava domes grew and were destroyed by explosions prior to the final lava dome extrusion that began after the April 4 event. The fi nal lava dome ceased growth by July 1, 2009, with an estimated volume of 72

  4. Volcano surveillance by ACR silver fox (United States)

    Patterson, M.C.L.; Mulligair, A.; Douglas, J.; Robinson, J.; Pallister, J.S.


    Recent growth in the business of unmanned air vehicles (UAVs) both in the US and abroad has improved their overall capability, resulting in a reduction in cost, greater reliability and adoption into areas where they had previously not been considered. Uses in coastal and border patrol, forestry and agriculture have recently been evaluated in an effort to expand the observed area and reduce surveillance and reconnaissance costs for information gathering. The scientific community has both contributed and benefited greatly in this development. A larger suite of light-weight miniaturized sensors now exists for a range of applications which in turn has led to an increase in the gathering of information from these autonomous vehicles. In October 2004 the first eruption of Mount St Helens since 1986 caused tremendous interest amoUg people worldwide. Volcanologists at the U.S. Geological Survey rapidly ramped up the level of monitoring using a variety of ground-based sensors deployed in the crater and on the flanks of the volcano using manned helicopters. In order to develop additional unmanned sensing methods that can be used in potentially hazardous and low visibility conditions, a UAV experiment was conducted during the ongoing eruption early in November. The Silver Fox UAV was flown over and inside the crater to perform routine observation and data gathering, thereby demonstrating a technology that could reduce physical risk to scientists and other field operatives. It was demonstrated that UAVs can be flown autonomously at an active volcano and can deliver real time data to a remote location. Although still relatively limited in extent, these initial flights provided information on volcanic activity and thermal conditions within the crater and at the new (2004) lava dome. The flights demonstrated that readily available visual and infrared video sensors mounted in a small and relatively low-cost aerial platform can provide useful data on volcanic phenomena. This was

  5. Gold recycling and enrichment beneath volcanoes: A case study of Tolbachik, Kamchatka (United States)

    Zelenski, Michael; Kamenetsky, Vadim S.; Hedenquist, Jeffrey


    Magmas supply metals to hydrothermal ore deposits, although typical arc basalts may be unable to produce a gold-rich ore-forming fluid, as such basalts rarely exceed 5 ppb Au. Consistent with this, the occurrence of native gold of magmatic origin is extremely rare, and only a few finds of micron-sized gold particles in unaltered basalts have been documented. Surprisingly, some lava flows and scoria cones of the historic basaltic eruptions of Tolbachik volcano (Kamchatka) are unusually gold-rich. Tolbachik basalts contain up to 11.6 ppb Au based on whole rock analyses, nuggets of gold (electrum) up to 900 μm in size and native gold droplets up to 200 μm, plus numerous vapor-deposited gold crystals within fumarolic incrustations and directly on surfaces of basaltic lapilli. Our results demonstrate that the gold nuggets in Tolbachik basalt are of hydrothermal origin and were physically scavenged from epithermal veins hosted by country rocks during intrusion of mafic magmas. Depending on the melt temperature and/or time span of the melt-rock interaction, gold was ejected by the erupting volcano either in the form of abraded nuggets or liquid droplets, or was fully assimilated (dissolved) into the shallow long-lived magma chamber to provide a 4-fold increase in gold content over background concentration of 2.7 ppb Au, characteristic of mafic volcanic rocks in Kamchatka. Upon the end of the eruption, the continued discharge of volcanic vapors enriched in gold deposited abundant crystals of gold on cooling lava and scoria. Similar to Tolbachik, recycling of metals from prior accumulations (ore deposits) in the shallow crust may take place in other long-lived magma reservoirs, thus upgrading the gold and other metal contents and contributing to the ore-forming potential of a magma.

  6. Fossil AGN jets as ultra high energy particle accelerators



    Remnants of AGN jets and their surrounding cocoons leave colossal magnetohydrodynamic (MHD) fossil structures storing total energies ~10^{60} erg. The original active galacic nucleus (AGN) may be dead but the fossil will retain its stable configuration resembling the reversed-field pinch (RFP) encountered in laboratory MHD experiments. In an RFP the longitudinal magnetic field changes direction at a critical distance from the axis, leading to magnetic re-connection there, and to slow decay of...

  7. Proceedings of the Eight Annual Conference on Fossil Energy Materials

    Energy Technology Data Exchange (ETDEWEB)

    Cole, N.C.; Judkins, R.R. [comps.


    Objective of the meeting was to conduct R and D on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The work is divided into ceramics, new alloys, corrosion, and technology assessment/transfer. The 39 papers are arranged under the session headings: ceramics, ceramics and new alloys, and intermetallics and advanced austenitics; a workshop on new materials development and applications is summarized briefly. The papers are processed separately for the data base.

  8. Instrumentation and control for fossil-energy processes

    Energy Technology Data Exchange (ETDEWEB)


    The 1982 symposium on instrumentation and control for fossil energy processes was held June 7 through 9, 1982, at Adam's Mark Hotel, Houston, Texas. It was sponsored by the US Department of Energy, Office of Fossil Energy; Argonne National Laboratory; and the Society for Control and Instrumentation of Energy Processes. Fifty-two papers have been entered individually into EDB and ERA; eleven papers had been entered previously from other sources. (LTN)

  9. Future fossil fuel electricity generation in Europe: options and consequences

    Energy Technology Data Exchange (ETDEWEB)

    Tzimas, E.; Georgakaki, A.; Peteves, S.D.


    The study investigates the development of the fossil fuel fired power generation in Europe up to 2030 and identifies the critical factors that influence its evolution. Through the application of the least-cost expansion planning methods, the technology and fuel mix of fossil fuel power plant portfolios emerging from the twenty-four techno-economic scenarios are described. The different scenarios present alternative views for the role of non-fossil fuel power generation, the development of the world fuel and carbon markets and the carbon capture power generating technologies. The study estimates the needs for new fossil fuel capacity and identifies the optimal power plant mix for all possible combinations of the cases mentioned above. The impacts of the resulting portfolios on the objectives of the European energy policy are assessed using as indicators the capital investment fo the construction of the required capacity, the fuel consumption, the composition of the fuel mix, the CO{sub 2} emission levels, and the average production cost of electricity from the fossil fuelled fleet. The report finds that high CO{sub 2} prices need to be maintained and carbon capture technology must be developed and become commercialised. If these conditions re met and medium or high fossil fuel prices prevail, the portfolio of fossil fuel power plants that will be deployed will be compatible wit the European goal for the development of a more sustainable and secure energy system. The key conclusion is that for a sustainable and secure energy system we need to invest, both in the increase of non-fossil fuel power generation and to ensure that carob n capture and storage technologies are ready to be deployed when needed. 46 refs.,

  10. Water Use of Fossil Energy Production and Supply in China

    Directory of Open Access Journals (Sweden)

    Gang Lin


    Full Text Available Fossil energy and water resources are both important for economic and social development in China, and they are tightly interlinked. Fossil energy production consumes large amounts of water, and it is essential to investigate the water footprint of fossil energy production (WFEP in China. In addition, fossil energy is supplied to consumers in China by both domestic and foreign producers, and understanding the water footprint of fossil energy supply (WFES is also highly significant for water and energy development programs in the long-term. The objectives of this paper were to provide an estimation of the blue component of WFEP and WFES in China for the period from 2001 to 2014, and to evaluate the impact on water resources from energy production, the contribution of internal and external WFES, and water-energy related issues of the international energy trade by applying water footprint analysis based on the bottom-up approach. The results indicate that generally, the WFEP and WFES in China both maintained steady growth before 2013, with the WFEP increasing from approximately 3900 million m3/year to 10,400 million m3/year, while the WFES grew from 3900 million m3/year to 11,600 million m3/year. The fossil energy production caps of the 13th Five Year Plan can bring the water consumed for fossil energy production back to a sustainable level. Over the long-term, China’s energy trade plan should also consider the water and energy resources of the countries from which fossil energy is imported.

  11. Hydrogen production econometric studies. [hydrogen and fossil fuels (United States)

    Howell, J. R.; Bannerot, R. B.


    The current assessments of fossil fuel resources in the United States were examined, and predictions of the maximum and minimum lifetimes of recoverable resources according to these assessments are presented. In addition, current rates of production in quads/year for the fossil fuels were determined from the literature. Where possible, costs of energy, location of reserves, and remaining time before these reserves are exhausted are given. Limitations that appear to hinder complete development of each energy source are outlined.

  12. New burgess shale fossil sites reveal middle cambrian faunal complex. (United States)

    Collins, D; Briggs, D; Morris, S C


    Soft-bodied and lightly sclerotized Burgess shale fossils have been found at more than a dozen new localities in an area extending for 20 kilometers along the front of the Cathedral Escarpment in the Middle Cambrian Stephen Formation of the Canadian Rockies. Five different fossil assemblages from four stratigraphic levels have been recognized. These assemblages represent distinct penecontemporaneous marine communities that together make up a normal fore-reef faunal complex.

  13. Fossil Energy Advanced Research and Technology Development Materials Program

    Energy Technology Data Exchange (ETDEWEB)

    Cole, N.C.; Judkins, R.R. (comps.)


    Objective of this materials program is to conduct R and D on materials for fossil energy applications with focus on longer-term and generic needs of the various fossil fuel technologies. The projects are organized according to materials research areas: (1) ceramics, (2) new alloys: iron aluminides, advanced austenitics and chromium niobium alloys, and (3) technology development and transfer. Separate abstracts have been prepared.

  14. Likelihood of tree topologies with fossils and diversification rate estimation. (United States)

    Didier, Gilles; Fau, Marine; Laurin, Michel


    Since the diversification process cannot be directly observed at the human scale, it has to be studied from the information available, namely the extant taxa and the fossil record. In this sense, phylogenetic trees including both extant taxa and fossils are the most complete representations of the diversification process that one can get. Such phylogenetic trees can be reconstructed from molecular and morphological data, to some extent. Among the temporal information of such phylogenetic trees, fossil ages are by far the most precisely known (divergence times are inferences calibrated mostly with fossils). We propose here a method to compute the likelihood of a phylogenetic tree with fossils in which the only considered time information is the fossil ages, and apply it to the estimation of the diversification rates from such data. Since it is required in our computation, we provide a method for determining the probability of a tree topology under the standard diversification model.Testing 21 our approach on simulated data shows that the maximum likelihood rate estimates from the phylogenetic tree topology and the fossil dates are almost as accurate as those obtained by taking into account all the data, including the divergence times. Moreover, they are substantially more accurate than the estimates obtained only from the exact divergence times (without taking into account the fossil record).We also provide an empirical example composed of 50 Permo-carboniferous eupelycosaur (early synapsid) taxa ranging in age from about 315 Ma (Late Carboniferous) to 270 Ma (shortly after the end of the Early Permian). Our analyses suggest a speciation (cladogenesis, or birth) rate of about 0.1 per lineage and per My, a marginally lower extinction rate, and a considerable hidden paleobiodiversity of early synapsids. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email

  15. World catalog of extant and fossil Chaoboridae (Diptera). (United States)

    Borkent, Art


    A world catalog of extant and fossil Chaoboridae provides full type information, distribution of each species, references to keys, references to latest descriptions of each species, and summaries of bionomic information.  There are 51 extant species in six genera and 41 fossil species (2 unplaced) in 19 genera, two of which are extant. Chaoborus lanei (Belkin, Heinemann & Page) is a new synonym of C. braziliensis (Theobald) and C. annulatus Cook is a new synonym of C. festivus Dyar & Shannon.

  16. Constraints of fossil fuels depletion on global warming projections

    Energy Technology Data Exchange (ETDEWEB)

    Chiari, Luca, E-mail: [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy); Zecca, Antonio, E-mail: [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy)


    A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO{sub 2} concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO{sub 2} emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO{sub 2} concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: > CO{sub 2} and global temperature are projected under fossil fuels exhaustion scenarios. > Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. > Temperature projections are possibly lower than the IPCC ones. > Fossil fuels exhaustion will not avoid dangerous global warming.

  17. Geochemistry of the volcano-hydrothermal system of El Chichón Volcano, Chiapas, Mexico (United States)

    Taran, Yuri; Fischer, Tobias P.; Pokrovsky, Boris; Sano, Yuji; Armienta, Maria Aurora; Macias, Jose Luis

    The 1982 eruption of El Chichón volcano ejected more than 1km3 of anhydrite-bearing trachyandesite pyroclastic material to form a new 1-km-wide and 300-m-deep crater and uncovered the upper 500m of an active volcano-hydrothermal system. Instead of the weak boiling-point temperature fumaroles of the former lava dome, a vigorously boiling crater spring now discharges / 20kg/s of Cl-rich ( 15 000mg/kg) and sulphur-poor ( / 200mg/kg of SO4), almost neutral (pHup to 6.7) water with an isotopic composition close to that of subduction-type magmatic water (δD=-15‰, δ18O=+6.5‰). This spring, as well as numerous Cl-free boiling springs discharging a mixture of meteoric water with fumarolic condensates, feed the crater lake, which, compared with values in 1983, is now much more diluted ( 3000mg/kg of Cl vs 24 030mg/kg), less acidic (pH=2.6 vs 0.56) and contains much lower amounts of S ( / 200mg/kg of SO4, vs 3550mg/kg) with δ34S=0.5-4.2‰ (+17‰ in 1983). Agua Caliente thermal waters, on the southeast slope of the volcano, have an outflow rate of approximately 100kg/s of 71 °C Na-Ca-Cl water and are five times more concentrated than before the eruption (B. R. Molina, unpublished data). Relative N2, Ar and He gas concentrations suggest extensional tectonics for the El Chichón volcanic centre. The 3He/4He and 4He/20Ne ratios in gases from the crater fumaroles (7.3Ra, 2560) and Agua Caliente hot springs (5.3Ra, 44) indicate a strong magmatic contribution. However, relative concentrations of reactive species are typical of equilibrium in a two-phase boiling aquifer. Sulphur and C isotopic data indicate highly reducing conditions within the system, probably associated with the presence of buried vegetation resulting from the 1982 eruption. All Cl-rich waters at El Chichón have a common source. This water has the appearence of a "partially matured" magmatic fluid: condensed magmatic vapour neutralized by interaction with fresh volcaniclastic deposits and depleted in S

  18. Geochemical models of melting and magma storage conditions for basalt lava from Santorini Volcano, Greece (United States)

    Baziotis, Ioannis; Kimura, Jun-Ichi; Pantazidis, Avgoustinos; Klemme, Stephan; Berndt, Jasper; Asimow, Paul


    Santorini volcano sits ˜150 km above the Wadati-Benioff zone of the Aegean arc, where the African plate subducts northward beneath the Eurasian continent (Papazachos et al. 2000). Santorini volcano has a long history: activity started ca. 650 ka (mainly rhyolites and rhyodacites), with active pulses following ca. 550 ka (basalt to rhyodacite) and ca. 360 ka (large explosive eruptions of andesite to rhyodacite and minor basalt), culminating in the caldera-forming Bronze-age Minoan event (Druitt et al. 1999). As in many arc volcanoes, scenarios of fractional crystallization with or without mixing between felsic and mafic magmas have been proposed to explain the compositions, textures, and eruptive styles of Santorini products (e.g., Huijsmans & Barton 1989; Montazavi & Sparks 2004; Andújar et al. 2015). Here we focus on a basalt lava from the southern part of Santorini volcano (Balos cove, 36˚ 21.7'N, 25˚ 23.8'E), one of the few basaltic localities in the Aegean arc. The goals are to infer constraints on the magma chamber conditions which lead to mafic eruption at Santorini Volcano and to evaluate the slab and mantle wedge conditions via geochemical and petrological mass balance modelling. We collected and characterised 20 samples for texture (SEM), mineral chemistry (FE-EPMA) and whole-rock chemistry (XRF). The basalts contain phenocrystic olivine (Ol) and clinopyroxene (Cpx) (Santorini basalts exhibit a pilotaxitic to trachytic texture defined by randomly to flow-oriented tabular Pl, respectively. The predominant minerals are calcic Pl (core An78-85 and rim An60-76; 45-50 vol.%), Cpx (En36-48Wo41-44Fs11-21; 10-15 vol.%) and Ol (Fo74-88; 10-12 vol.%). Idiomorphic to subidiomorphic Mt (<10μm diameter) with variable TiO2 contents (1.9-16.5 wt%) is a minor constituent (˜1-2 vol.%) in the less mafic samples. Observed mineralogy and major element chemistry suggest fractionation in a shallow magma chamber. Using the major element chemistry and PRIMACALC2 (Kimura

  19. Crystal Data (United States)

    SRD 3 NIST Crystal Data (PC database for purchase)   NIST Crystal Data contains chemical, physical, and crystallographic information useful to characterize more than 237,671 inorganic and organic crystalline materials. The data include the standard cell parameters, cell volume, space group number and symbol, calculated density, chemical formula, chemical name, and classification by chemical type.

  20. Survival of fossils under extreme shocks induced by hypervelocity impacts. (United States)

    Burchell, M J; McDermott, K H; Price, M C; Yolland, L J


    Experimental data are shown for survival of fossilized diatoms undergoing shocks in the GPa range. The results were obtained from hypervelocity impact experiments which fired fossilized diatoms frozen in ice into water targets. After the shots, the material recovered from the target water was inspected for diatom fossils. Nine shots were carried out, at speeds from 0.388 to 5.34 km s(-1), corresponding to mean peak pressures of 0.2-19 GPa. In all cases, fragmented fossilized diatoms were recovered, but both the mean and the maximum fragment size decreased with increasing impact speed and hence peak pressure. Examples of intact diatoms were found after the impacts, even in some of the higher speed shots, but their frequency and size decreased significantly at the higher speeds. This is the first demonstration that fossils can survive and be transferred from projectile to target in hypervelocity impacts, implying that it is possible that, as suggested by other authors, terrestrial rocks ejected from the Earth by giant impacts from space, and which then strike the Moon, may successfully transfer terrestrial fossils to the Moon.