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Sample records for 2011-2012 submarine eruption

  1. Soil gas radon and volcanic activity at El Hierro (Canary Islands) before and after the 2011-2012 submarine eruption

    NASA Astrophysics Data System (ADS)

    Barrancos, J.; Padilla, G.; Hernandez Perez, P. A.; Padron, E.; Perez, N.; Melian Rodriguez, G.; Nolasco, D.; Dionis, S.; Rodriguez, F.; Calvo, D.; Hernandez, I.

    2012-12-01

    El Hierro is the youngest and southernmost island of the Canarian archipelago and represents the summit of a volcanic shield elevating from the surrounding seafloor at depth of 4000 m to up to 1501 m above sea level. The island is believed to be near the present hotspot location in the Canaries with the oldest subaerial rocks dated at 1.12 Ma. The subaerial parts of the El Hierro rift zones (NE, NW and S Ridges) are characterized by tightly aligned dyke complexes with clusters of cinder cones as their surface expressions. Since July 16, 2011, an anomalous seismicity at El Hierro Island was recorded by IGN seismic network. Volcanic tremor started at 05:15 hours on October 10, followed on the afternoon of October 12 by a green discolouration of seawater, strong bubbling and degassing indicating the initial stage of submarine volcanic eruption at approximately 2 km off the coast of La Restinga, El Hierro. Soil gas 222Rn and 220Rn activities were continuously measured during the period of the recent volcanic unrest occurred at El Hierro, at two different geochemical stations, HIE02 and HIE03. Significant increases in soil 222Rn activity and 222Rn/220Rn ratio from the soil were observed at both stations prior the submarine eruption off the coast of El Hierro, showing the highest increases before the eruption onset and the occurrence of the strongest seismic event (M=4.6). A statistical analysis showed that the long-term trend of the filtered data corresponded closely to the seismic energy released during the volcanic unrest. The observed increases of 222Rn are related to the rock fracturing processes (seismic activity) and the magmatic CO2 outflow increase, as observed in HIE03 station. Under these results, we find that continuous soil radon studies are important for evaluating the volcanic activity of El Hierro and they demonstrate the potential of applying continuous monitoring of soil radon to improve and optimize the detection of early warning signals of future

  2. Cristobalite in the 2011-2012 Cordón Caulle eruption (Chile)

    NASA Astrophysics Data System (ADS)

    Schipper, C. Ian; Castro, Jonathan M.; Tuffen, Hugh; Wadsworth, Fabian B.; Chappell, Debra; Pantoja, Andres E.; Simpson, Mark P.; Le Ru, Eric C.

    2015-05-01

    Cristobalite is a low-pressure high-temperature polymorph of SiO2 found in many volcanic rocks. Its volcanogenic formation has received attention because (1) pure particulate cristobalite can be toxic when inhaled, and its dispersal in volcanic ash is therefore a potential hazard; and (2) its nominal stability field is at temperatures higher than those of magmatic systems, making it an interesting example of metastable crystallization. We present analyses (by XRD, SEM, EPMA, Laser Raman, and synchrotron μ-cT) of representative rhyolitic pyroclasts and of samples from different facies of the compound lava flow from the 2011-2012 eruption of Cordón Caulle (Chile). Cristobalite was not detected in pyroclasts, negating any concern for respiratory hazards, but it makes up 0-23 wt% of lava samples, occurring as prismatic vapour-deposited crystals in vesicles and/or as a groundmass phase in microcrystalline samples. Textures of lava collected near the vent, which best represent those generated in the conduit, indicate that pore isolation promotes vapour deposition of cristobalite. Mass balance shows that the SiO2 deposited in isolated pore space can have originated from corrosion of the adjacent groundmass. Textures of lava collected down-flow were modified during transport in the insulated interior of the flow, where protracted cooling, additional vesiculation events, and shearing overprint original textures. In the most slowly cooled and intensely sheared samples from the core of the flow, nearly all original pore space is lost, and vapour-deposited cristobalite crystals are crushed and incorporated into the groundmass as the vesicles in which they formed collapse by strain and compaction of the surrounding matrix. Holocrystalline lava from the core of the flow achieves high mass concentrations of cristobalite as slow cooling allows extensive microlite crystallization and devitrification to form groundmass cristobalite. Vapour deposition and devitrification act

  3. InSAR and GPS measurements along the Kivu segment of the East African Rift System during the 2011-2012 Nyamulagira volcanic eruption.

    NASA Astrophysics Data System (ADS)

    Nobile, Adriano; Geirsson, Halldor; Smets, Benoît; d'Oreye, Nicolas; Kervyn, François

    2016-04-01

    Along the East African Rift System (EARS), magma intrusions represent a major component in continental rifting. When these intrusions reach the surface, they cause volcanic eruptions. This is the case of the last flank eruption of Nyamulagira, which occurred from November 6 2011 to April 2012. Nyamulagira is an active shield volcano with a central caldera, located in the eastern part of the Democratic Republic of Congo, along the Kivu segment of the East African Rift System. From 1948 to 2012, Nyamulagira mostly showed a particular eruptive cycle with 1) classical short-lived (i.e., 20-30 days) flank eruptions, sometimes accompanied with intracrateral activity, which occurred every 1-4 years on average, and 2) less frequent long-lived (i.e., several months) eruptions usually emitting larger volumes of lava that take place at larger distance (>8 km) from the central caldera. The 2011-2012 Nyamulagira eruption is of that second type. Here we used InSAR data from different satellite (Envisat, Cosmo SkyMed, TerraSAR-X and RADARSAT) to measure pre-, co and post-eruptive ground displacement associated with the Nyamulagira 2011-2012 eruption. Results suggest that a magma intrusion preceded by two days the eruption. This intrusion corresponded to the migration of magma from a shallow reservoir (~3km) below the caldera to the two eruptive fissures located ~11 km ENE of the central edifice. Available seismic data are in agreement with InSAR results showing increased seismic activity since November 4 2011, with long- and short-period earthquakes swarms. Using analytical models we invert the measured ground displacements during the first co-eruptive month to evaluate the deformation source parameters and the mechanism of magma emplacement for this eruption. GPS data from permanent stations in the KivuGNet network are used to constrain the temporal evolution of the eruption and evaluate far-field deformation, while the InSAR data is more sensitive to the near-field deformation

  4. High effusion rates of the Cordón Caulle 2011-2012 eruption (Southern Andes) and their relation with the quasi-harmonic tremor

    NASA Astrophysics Data System (ADS)

    Bertin, D.; Lara, L. E.; Basualto, D.; Amigo, Á.; Cardona, C.; Franco, L.; Gil, F.; Lazo, J.

    2015-09-01

    High effusion rates of intermediate-to-high-silica lavas seem to be less uncommon than previously thought, in particular during their initial eruptive stages. In this study, we report satellite-based time-averaged discharge rates for the 2011-2012 effusive phase at Cordón Caulle, which are well correlated with the evolution of the quasi-harmonic tremor, the most significant seismic signal after the initial explosive stage. Such a correspondence could become a key method for detection of the onset of effusive phases, especially in remote and/or very cloudy areas, supplying an additional tool for effective warnings and near-real-time hazard appraisal.

  5. The 2011-2012 eruption of Cordón Caulle volcano (Southern Andes): Evolution, crisis management and current hazards

    NASA Astrophysics Data System (ADS)

    Silva Parejas, C.; Lara, L. E.; Bertin, D.; Amigo, A.; Orozco, G.

    2012-04-01

    A new kind of integrated approach was for first time achieved during the eruptive crisis of Cordón Caulle volcano (Southern Andes, 40.59°S, 72.12°W) in Chile. The monitoring network of SERNAGEOMIN around the volcano detected the increasing precursory seismicity, alerting the imminence of an eruption about 5 hours before its onset, on June 4, 2011. In addition, SERNAGEOMIN generated daily forecasts of tephra dispersal and fall (ASHFALL advection-diffusion model), and prepared simulations of areas affected by the possible occurrence of lahars and pyroclastic flows. Models were improved with observed effects on the field and satellite imagery, resulting in a good correlation. The information was timely supplied to the authorities as well as recommendations in order to better precise the vulnerable areas. Eruption has initially occurred from a couple of overlapped cones located along the eastern fault scarp of the Pleistocene-Holocene extensional graben of Cordón Caulle. Eruptive products have virtually the same bulk composition as those of the historical 1921 and 1960 eruptions, corresponding to phenocryst-poor rhyodacites (67-70 % SiO2). During the first eruptive stage, a ca. 15-km strong Plinian column lasting 27 hours emitted 0.2-0.4 km3 of magma (DRE). Thick tephra deposits have been accumulated in Chile and Argentina, whereas fine particles and aerosols dispersion disrupted air navigation across the Southern Hemisphere. The second ongoing eruptive stage, which started in mid-June, has been characterized by lava emission already covering a total area comparable to the 1960 lava flows with a total estimated volume <0.25 km3 (at the end of December 2011). Weak but persistent plumes have caused preventive flight suspensions in Chile and Argentina until the end of the year. Main current hazards at Cordón Caulle volcano are fine tephra fallout, secondary lahars, minor explosions and lava flow front collapse. Even if this case can be considered successful from the

  6. Discovery of the Largest Historic Silicic Submarine Eruption

    NASA Astrophysics Data System (ADS)

    Carey, Rebecca J.; Wysoczanski, Richard; Wunderman, Richard; Jutzeler, Martin

    2014-05-01

    It was likely twice the size of the renowned Mount St. Helens eruption of 1980 and perhaps more than 10 times bigger than the more recent 2010 Eyjafjallajökull eruption in Iceland. However, unlike those two events, which dominated world news headlines, in 2012 the daylong submarine silicic eruption at Havre volcano in the Kermadec Arc, New Zealand (Figure 1a; ~800 kilometers north of Auckland, New Zealand), passed without fanfare. In fact, for a while no one even knew it had occurred.

  7. Long-term eruptive activity at a submarine arc volcano

    USGS Publications Warehouse

    Embley, R.W.; Chadwick, W.W., Jr.; Baker, E.T.; Butterfield, D.A.; Resing, J.A.; De Ronde, C. E. J.; Tunnicliffe, V.; Lupton, J.E.; Juniper, S.K.; Rubin, K.H.; Stern, R.J.; Lebon, G.T.; Nakamura, K.-I.; Merle, S.G.; Hein, J.R.; Wiens, D.A.; Tamura, Y.

    2006-01-01

    Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes. ?? 2006 Nature Publishing Group.

  8. What Pyroclasts Can Tell Us About Deep Submarine Pumice-Forming Silicic Eruptive Processes (Invited)

    NASA Astrophysics Data System (ADS)

    Rotella, M. D.; Wilson, C. J.; Barker, S. J.; Wright, I. C.

    2013-12-01

    Despite the increasing recognition of pumice-forming eruption deposits in deep water arc environments, the processes involved in explosive silicic submarine eruptions remain largely unexplored. Pyroclasts sampled from the Kermadec arc (SW Pacific) show that silicic pumices erupted in deep submarine environments are macroscopically very similar (colour, density, texture etc) to subaerial or shallow submarine erupted pumices, but show contrasting microscopic vesicle textures. Here we present data on pyroclast densities and associated vesicle sizes and number densities (number of bubbles per unit volume of glass matrix) for deep submarine erupted pumices (≥˜1000 m water depth) from three volcanoes (Healy, Raoul SW and Havre) along the Kermadec arc. We compare these textural data with those from chemically similar, subaerially erupted pyroclasts from Raoul volcano as well as newly described ';Tangaroan' fragments derived by non-explosive, buoyant detachment of submarine erupted pumice from Macauley volcano, also on the Kermadec arc. We use these data sets to evaluate processes in deep explosive submarine eruptions and to investigate the effects of a significant overlying water column and associated increased pressure on vesiculation and fragmentation processes. We find that despite having similar ranges in vesicularity, deep submarine erupted pyroclasts record a contrasting vesiculation history to subaerial erupted pyroclasts. The higher-pressure regime that deep submarine pyroclasts are erupted into (i.e. higher pressures, and the contrasting density and viscosity of water versus air) appears to play a major role in bubble nucleation and growth dynamics.

  9. New Insights into Basaltic Balloon Formation during Submarine Eruptions

    NASA Astrophysics Data System (ADS)

    Carey, S.; Kelly, J.; Rosi, M.; Pistolesi, M.; Marani, M.; Roman, C.; Croff Bell, K. L.

    2014-12-01

    Remotely operated vehicle (ROV) explorations in the area of the 1891 Foerstner submarine eruption (Pantelleria, Italy) during cruise NA-018 of the E/V Nautilus has provided the first examination of the vent site of a basaltic balloon-forming eruption. Ultra high-resolution bathymetric mapping defined a mound-like vent morphology in water depths of ~250 meter, constructed dominantly of highly vesicular scoriaceous fragments with minor pillow lava flows. The formation of floating basaltic balloons that reached the surface of the Strait of Sicily during the eruption is attributed to a hybrid Strombolian eruption mechanism that involved pre-concentration of volatiles into gas-rich portions of magma beneath the vent. An important difference of this Strombolian mechanism compared to its subaerial counterpart is the occurrence of buoyant magma discharge in the submarine environment caused by localized high gas contents. The added buoyancy flux modifies the fluid dynamic configuration of magma venting on the seafloor allowing for detachment of highly-inflated parcels of gas-rich magma. Some of these parcels contain large gas cavities that are enveloped in a partially quenched shell and maintain sufficient buoyancy to rise to the sea surface as a basaltic balloon. The majority of the vesicular magma maintains only partial positive buoyancy or negative buoyancy and is explosively fragmented to form large quantities of decimeter-scale fragments that accumulate close to the vent. Formation of the basaltic balloons is thus considered a somewhat accidental process that involves a subset of the total erupted volume of magma during the eruption. Suitable conditions for balloon formation include low magma viscosity, pre-concentration of gas, and moderate pressures (i.e.water depth). The dampening effect of seawater greatly reduces the dispersal of pyroclasts resulting in a mound-like vent morphology compared to subaerial scoria cones typically associated with Strombolian activity.

  10. Petrological and geochemical Highlights in the floating fragments of the October 2011 submarine eruption offshore El Hierro (Canary Islands): Relevance of submarine hydrothermal processes

    NASA Astrophysics Data System (ADS)

    Rodriguez-Losada, Jose A.; Eff-Darwich, Antonio; Hernandez, Luis E.; Viñas, Ronaldo; Pérez, Nemesio; Hernandez, Pedro; Melián, Gladys; Martinez-Frías, Jesús; Romero-Ruiz, M. Carmen; Coello-Bravo, Juan Jesús

    2015-02-01

    This paper describes the main physical, petrological and geochemical features of the floating fragments that were emitted in the initial stages of the 2011-2012 submarine eruption off the coast of the Canarian island of El Hierro, located 380 km from the Northwest African Coast. It attempts to assess the potential of radiometric analyses to discern the intriguing origin of the floating fragments and the differences between their constituent parts. In this regard, the material that conforms the core of the fragments contains the largest concentration of uranium (U) ever found in volcanic rocks of the Canary Islands. This enrichment in U is not found in the content of thorium (Th), hence the floating fragments have an unusual U/Th ratio, namely equal to or larger than 3. Although the origin of this material is under discussion, it is proposed that the enrichment in U is the result of hydrothermal processes.

  11. Submarine Explosive Eruptions: Physical Volcanology of NW Rota-1, Marianas

    NASA Astrophysics Data System (ADS)

    Deardorff, N. D.; Chadwick, W. W.; Embley, R. W.; Cashman, K. V.

    2006-12-01

    The discovery of an actively erupting submarine arc volcano is a scientific breakthrough that greatly extends our understanding of submarine volcanism. NW Rota-1, located at 14¢X40'N in the Mariana volcanic arc, is a conical basaltic andesite volcano with a summit at 517 m b.s.l, a base at 2700 m, and a diameter of 16- km. In April 2006, on the most recent cruise of the "Submarine Ring of Fire" (SROF) expeditions, violently explosive submarine eruptions were observed and sampled at the active vent, Brimstone Pit (550 m depth), through the use of JASON II remotely operated vehicle (ROV). During six dives repeated observations made at close range over a week documented a diverse and increasingly energetic range of activity that culminated in explosive bursts of glowing red lava propelled by violently expanding gases. Preliminary work shows erupted clasts to vary greatly in density (vesicularity) and crystallinity. Densities of representative larger clasts are moderately high (1700-1900 kg/m3, or ~ 30-40% vesicularity assuming a solid density of 2800 kg/m3; Fig 5b), although the more vigorous activity clearly produced some lower density (< 1000 kg/m3;> 66% vesicularity) material. Grain sizes were measured in 1.0 intervals from -5 to 3 using dry sieving techniques. The grain size distribution is approximately log normal with a mode at -1 (2 mm). Clast morphology consists of three components: (1) very glassy juveniles ranging from light to dark brown (sideromelane), often fluidal and irregularly shaped with obvious vesicle stretching, (2) phenocryst-rich blocky juveniles ranging from dark brown to black (tachylite), (3) non-juvenile lithics are equant, often rounded, ranging from light grey to dark grey and are often coated with altered material. Initial FTIR analyses show a lack of CO2 and a range of H20 from 0.3-1.15wt%, with the average approximately in equilibrium for 550 m water depth. The high vesicularity of the samples collected directly from Brimstone Pit and

  12. Submarine Volcanic Eruptions and Potential Analogs for Venus

    NASA Technical Reports Server (NTRS)

    Wilson, L.; Mouginismark, P. J.; Fryer, P.; Gaddis, L. R.

    1985-01-01

    As part of an analysis program to better understand the diversity of volcanic processes on the terrestrial planets, an investigation of the volcanic landforms which exist on the Earth's ocean floor was initiated. In part, this analysis is focused toward gaining a better understanding of submarine volcanic landforms in their own right, but also it is hoped that these features may show similarities to volcanic landforms on Venus, due to the high ambient water (Earth) and atmospheric (Venus) pressures. A series of numerical modelling experiments was performed to investigate the relative importance of such attributes as water pressure and temperature on the eruption process, and to determine the rate of cooling and emplacement of lava flows in the submarine environment. Investigations to date show that the confining water pressure and the buoyancy effects of the surrounding water significantly affect the styles of volcanism on the ocean floor. In the case of Venusian volcanism, confining pressures will not be as great as that found at the ocean's abyssal plains, but nevertheless the general trend toward reducing magma vesiculation will hold true for Venus as well as the ocean floor. Furthermore, other analogs may also be found between submarine volcanism and Venusian activity.

  13. Low sulfur content in submarine lavas: An unreliable indicator of subaerial eruption

    SciTech Connect

    Davis, A.S.; Clague, D.A.; Schulz, M.S.; Hein, J.R. )

    1991-07-01

    Low S content (< 250 ppm) has been used to identify subaerially erupted Hawaiian and Icelandic lavas. Large differences in S content of submarine-erupted lavas from different tectonic settings indicate that the behavior of S is complex. Variations is S abundance in undegassed, submarine-erupted lavas can result from different source compositions, different percentages of partial melting, and crystal fractionation. Low S concentrations in highly vesicular submarine lavas suggest that partial degassing can occur despite great hydrostatic pressure. These processes need to be evaluated before using S content as an indicator of eruption depth.

  14. The 2014 Submarine Eruption of Ahyi Volcano, Northern Mariana Islands

    NASA Astrophysics Data System (ADS)

    Haney, M. M.; Chadwick, W.; Merle, S. G.; Buck, N. J.; Butterfield, D. A.; Coombs, M. L.; Evers, L. G.; Heaney, K. D.; Lyons, J. J.; Searcy, C. K.; Walker, S. L.; Young, C.; Embley, R. W.

    2014-12-01

    On April 23, 2014, Ahyi Volcano, a submarine cone in the Northern Mariana Islands (NMI), ended a 13-year-long period of repose with an explosive eruption lasting over 2 weeks. The remoteness of the volcano and the presence of several seamounts in the immediate area posed a challenge for constraining the source location of the eruption. Critical to honing in on the Ahyi area quickly were quantitative error estimates provided by the CTBTO on the backazimuth of hydroacoustic arrivals observed at Wake Island (IMS station H11). T-phases registered across the NMI seismic network at the rate of approximately 10 per hour until May 8 and were observed in hindsight at seismic stations on Guam and Chichijima. After May 8, sporadic T-phases were observed until May 17. Within days of the eruption onset, reports were received from NOAA research divers of hearing explosions underwater and through the hull on the ship while working on the SE coastline of Farallon de Pajaros (Uracas), a distance of 20 km NW of Ahyi. In the same area, the NOAA crew reported sighting mats of orange-yellow bubbles on the water surface and extending up to 1 km from the shoreline. Despite these observations, satellite images showed nothing unusual throughout the eruption. During mid-May, a later cruise leg on the NOAA ship Hi'ialakai that was previously scheduled in the Ahyi area was able to collect some additional data in response to the eruption. Preliminary multibeam sonar bathymetry and water-column CTD casts were obtained at Ahyi. Comparison between 2003 and 2014 bathymetry revealed that the minimum depth had changed from 60 m in 2003 to 75 m in 2014, and a new crater ~95 m deep had formed at the summit. Extending SSE from the crater was a new scoured-out landslide chute extending downslope to a depth of at least 2300 m. Up to 125 m of material had been removed from the head of the landslide chute and downslope deposits were up to 40 m thick. Significant particle plumes were detected at all three

  15. Relative and probabilistic non linear relocation of the seismicity of El Hierro (Canary Islands, Spain): Implications for the 2011-2012 eruption.

    NASA Astrophysics Data System (ADS)

    Diaz-Moreno, Alejandro; Garcia-Yeguas, Araceli; De Angelis, Silvio; Prudencio, Janire; Ibañez, Jesus M.; Morales, José; Koulakov, Ivan

    2014-05-01

    El Hierro Island (Canary Islands, SPAIN) has recently attracted the interest of the international volcanological community. During a prolonged period of seismic and volcanic unrest, between July 2011 and April 2013, the local seismic network recorded more than 15,000 earthquakes accompanied by a submarine eruption. In this study we present an exhaustive relocation analysis of the original seismic catalog using two well established methods double-difference relative relocation (HypoDD), and probalistic non-linear location (NLLoc). Our relocations are based on 3D velocity models that were obtained from an active-source tomography experiment in the Canary Islands. The relocations constrain the spatial and temporal distribution of seismicity, and help to shed light on the patterns of stress propagation, and areas of crustal weakness under the island. The results show that the seismicity each of unrest recorded during this period is located within a small region close to the center of the island and located around 12 to 14 km depth. Then, the seismicity migrates away from the island. We confirm the presence of a high-velocity block centered underneath El Hierro (up to 15km depth) observed by other authors. This block may represent a barrier to magma propagation and it corresponds to the location of the bulk of seismicity at the beginning of each phase.

  16. Inside the Vent of the 2011-2012 Cordón Caulle Eruption, Chile: The Nature of a Rhyolitic Ash Plume Source

    NASA Astrophysics Data System (ADS)

    Tuffen, H.; Castro, J. M.; Schipper, C. I.; Wadsworth, F. B.

    2014-12-01

    The 2011-2012 activity at Cordon Caulle has provided an unprecedented opportunity to observe a sustained explosive rhyolitic eruption. An initial 27 hour Plinian phase commenced on 4 June 2011, followed by ten months of hybrid explosive-effusive activity, which generated disruptive ≤6 km ash plumes. In January 2012 our close observations of the active vent[1] revealed how episodic release of gas and ash from several sub-vents on an incipient lava dome (Fig. 1b) merged to form a sustained ash plume. Sub-vents ranged from metric point sources to arcuate fractures (>10 m) in the dome carapace. We visited the vent in January 2014, and found two ~50 m-wide, rubble-strewn vent areas adjacent to pancake-like obsidian domes, all within a breached, ~100 m-high tuff cone. Vent areas consist of fractured obsidian lava strewn by loose, rotated lava blocks ≤5 m across. Prominent red fracture surfaces (Fig. 1 d,e) occur in both the in-situ lava and the blocky veneer; these closely correspond to the type of sub-vents observed in 2012[1]. They range from smooth, curviplanar surfaces extending over several m to complex smaller-scale surfaces that follow pre-existing cooling joints in the lava carapace. In-situ fracture surfaces display prominent, predominantly vertical grooves and impact marks, but negligible displacement. Surfaces are coated by μm-mm thick veneers of fine-grained ash, to which larger ash-coated clasts have adhered. Veneer thickness and sintering degree strongly decrease towards the upper carapace of the lava. SEM analysis of ash veneers reveals 1) a high proportion of sub-micron clasts, 2) strong clast sintering, 3) abundant ash aggregation textures spanning submicron-mm scales, and 4) local surface scouring and corrosion of glass and phenocrysts. During ash venting the smallest particles are preferentially trapped on fracture surfaces and rapidly sintered, encouraging sub-vent blockage. Extensive ash aggregation may have been electrostatically aided, with

  17. Lava balloons—peculiar products of basaltic submarine eruptions

    NASA Astrophysics Data System (ADS)

    Kueppers, Ulrich; Nichols, Alexander R. L.; Zanon, Vittorio; Potuzak, Marcel; Pacheco, Jose M. R.

    2012-08-01

    Between December 1998 and April 2001, a submarine basaltic eruption occurred west of Terceira Island, Azores (Portugal) in water depths between 300 and 1,000 m. Physical evidence for the eruption was provided by the periodic occurrence of hot lava "balloons" floating on the sea surface. The balloons consisted of a large gas-filled cavity surrounded by a thin shell (a few centimetres thick). The shells of the collected balloons are composed of two layers, termed the outer layer and the inner layer, defined by different bubble number density, bubble sizes and crystal content. The inner layer is further divided into three sublayers defined by more subtle differences in vesicularity. The outer layer is glassy, golden-coloured and highly porous. It shows signs of fluidal deformation and late-stage extension cracks. Interstitial glass contains 0.29 wt% H2O and CO2 is below detection. Melt inclusions contain up to 1.18 wt% H2O and 1,500 ppm CO2 (from different inclusions). Cooling rates of the outermost glass of the outer layer are found to be as high as 1,259 K/s. During ascent of low viscosity magma to the ocean floor, volatiles, dominated by CO2, exsolved from the magma (melt + crystals). The buoyancy of the vapour phase that accumulated below a thin crust on lava ponded at the vent caused bulging and ultimately cracking of the crust. This allowed large bubbles (central cavity) surrounded by a film of vesicular magma (balloon shell) to leak into the water column. On contact with the seawater, the outermost part of the outer layer of the shell hyperquenched. If an entirely closed shell was produced during detachment, the trapped gas inside allowed buoyant rise. Only balloons with the right balance of physical properties (e.g. size and bulk density) rose all the way to the sea surface.

  18. Geological and petrological aspects of the ongoing submarine eruption at El Hierro Island (Canary Islands, Spain)

    NASA Astrophysics Data System (ADS)

    Meletlidis, S.; Di Roberto, A.; Iribarren, I.; Pompilio, M.; Bertagnini, A.; Torres, P. A.; Felpeto, A.; Lopez, C.; Blanco, M. J.

    2012-04-01

    The Canarian Archipelago comprises seven major and three minor islands, all of them of volcanic origin. The distribution of the islands forms an east-west volcanic chain, starting about 90 km west of the northwest African continental margin. The canary volcanism is unique among ocean islands (long lifetime, multiple periods of volcanic activity, extensive range of magma compositions) and various theories were developed in order to explain that specific volcanism, with such a variety of volcanic phases and chemical diversity. El Hierro, located at the SW end of this island group, is the youngest island with the oldest subaerial rocks dated at 1.12 Ma and is still in juvenile stage of shield growth. The island is the emergent summit of a 280 km2 volcanic shield which rises from a 3800-4000m depth and grows up to 1500 m above sea level. Although the whole island has been constructed by the volcanic material of two major volcanic edifices, Tiñor in the NE (0.8 -1.2 Ma) and El Golfo edifice in the NW (550 ka-130 ka), rift volcanism (134 ka - AD1793) has been very active after the second major tectonic event (gravitational collapse of El Golfo edifice), specially along the South ridge. Till July 2011 the most recent eruption was the Volcán de Lomo Negro (AD1793) located at the western part of the island. The products of the Tiñor and El Golfo edifice, massive lava flows, are typical mafic basalts with phenocrystals of olivine and only in El Golfo sequence evolved lava flows (trachytes with phenocrystals of plagioclase feldspars) could be observed. However, the recent rift lavas present varied compositional and textural features. During the eruption of 2011-2012 a variety of volcanic material has been observed and sampled. On 15 October, bicoloured lava fragments were observed floating on the sea with a bomb-like shape and sizes between 10 and 40 cm. The outer part, black, vesiculated and no more than 1 cm thick, had a basaltic composition, while the inner part was

  19. Insights into Explosive Eruption Processes: Density Studies of Subaerial and Submarine Pyroclastic Deposits, Kermadec Arc

    NASA Astrophysics Data System (ADS)

    Barker, S. J.; Rotella, M. D.; Wilson, C. J.; Wright, I. C.

    2008-12-01

    Explosive volcanism involving crystal-poor dacite to rhyolite magmas is common in the young records of many volcanoes along the intraoceanic Kermadec arc. Such volcanism occurs at both submarine and subaerial volcanoes, and is often of a size that caldera collapse occurs. Three volcanoes present unique circumstances that can provide insights into the processes involved in explosive volcanism. Healy, Macauley and Raoul volcanoes have erupted similar silicic magmas within the last 10 kyr in deep marine, shallow marine and subaerial settings, respectively. To investigate eruption processes from these three volcanoes we have characterized the density spectrum for juvenile pumice clasts in the 16-32 mm size fraction using water immersion techniques [Houghton & Wilson, Bull Volc. 51, 1989]. At Raoul, we have data from five eruption deposits of widely contrasting dispersal (strombolian to plinian). Four of these eruptions show no evidence for involvement of external water: all samples show narrowly-defined peaks of density despite wide differences in eruption size. Only one subaerial eruption shows evidence for interaction with external water, consistent with the large density range observed. Subaerial deposits from Macauley Island show a narrow peak in density, but display a slightly wider range caused by a subtle tail-off to denser clasts. Co-eruptive submarine deposits show large variations in density, with multiple peaks identified. Although from the same eruption (as shown by continuity on seismic profiles), these submarine deposits display a significant contrast in density spectra, which reflects the syn-eruptive redistribution of clasts with diverse densities. Material dredged from 1320 to 2110 m water depth at Healy also shows a large density range, but displays a unimodal low-density peak and lacks syn-eruptive selective redistribution of clast populations. Density spectra will be used to constrain the choice of clasts for imaging of vesicle textures and

  20. Diffuse degassing He/CO2 ratio before and during the 2011-12 El Hierro submarine eruption, Canary Islands

    NASA Astrophysics Data System (ADS)

    Padrón, Eleazar; Hernández, Pedro A.; Melián, Gladys V.; Barrancos, José; Padilla, Germán; Pérez, Nemesio M.; Dionis, Samara; Rodríguez, Fátima; Asensio-Ramos, María; Calvo, David

    2015-04-01

    the diffuse helium emissions measured after the eruption onset. Therefore, this study shows that higher diffuse He/CO2 emission ratios preceded the 2011-2012 El Hierro submarine eruption, clearly show the critical role that both gas species can play in the prediction of major volcanic events and demonstrates the importance of performing soil He and CO2 surveys as a useful geochemical monitoring tool in active volcanic regions. Padrón et al. (2013) Geology 41(5), 539-542; Melián et al. (2014) JGR, 119: 6976-6991, doi:10.1002/2014JB011013

  1. Direct video and hydrophone observations of submarine explosive eruptions at NW Rota-1 volcano, Mariana arc

    NASA Astrophysics Data System (ADS)

    Chadwick, W. W.; Cashman, K. V.; Embley, R. W.; Matsumoto, H.; Dziak, R. P.; de Ronde, C. E. J.; Lau, T. K.; Deardorff, N. D.; Merle, S. G.

    2008-08-01

    Extraordinary video and hydrophone observations of a submarine explosive eruption were made with a remotely operated vehicle in April 2006 at a depth of 550-560 m on NW Rota-1 volcano in the Mariana arc. The observed eruption evolved from effusive to explosive, while the eruption rate increased from near zero to 10-100 m3/h. During the peak in activity, cyclic explosive bursts 2-6 min long were separated by shorter non-eruptive pauses lasting 10-100 s. The size of the ejecta increased with the vigor of the explosions. A portable hydrophone deployed near the vent recorded sounds correlated with the explosive bursts; the highest amplitudes were ˜50 dB higher than ambient noise at frequencies between 10 and 50 Hz. The acoustic data allow us to quantify the durations, amplitudes, and evolution of the eruptive events over time. The low eruption rate, high gas/lava ratio, and rhythmic eruptive behavior at NW Rota-1 are most consistent with a Strombolian eruptive style. We interpret that the eruption was primarily driven by the venting of magmatic gases, which was also the primary source of the sound recorded during the explosive bursts. The rhythmic nature of the bursts can be explained by partial gas segregation in the conduit and upward migration in a transitional regime between bubbly flow and fully developed slug flow. The strongest explosive bursts were accompanied by flashes of red glow and oscillating eruption plumes in the vent, apparently caused by magma-seawater interaction and rapid steam formation and condensation. This is the first time submarine explosive eruptions have been witnessed with simultaneous near-field acoustic recordings.

  2. On the fate of pumice rafts formed during the 2012 Havre submarine eruption

    PubMed Central

    Jutzeler, Martin; Marsh, Robert; Carey, Rebecca J.; White, James D. L.; Talling, Peter J.; Karlstrom, Leif

    2014-01-01

    Pumice rafts are floating mobile accumulations of low-density pumice clasts generated by silicic volcanic eruptions. Pumice in rafts can drift for years, become waterlogged and sink, or become stranded on shorelines. Here we show that the pumice raft formed by the impressive, deep submarine eruption of the Havre caldera volcano (Southwest Pacific) in July 2012 can be mapped by satellite imagery augmented by sailing crew observations. Far from coastal interference, the eruption produced a single >400 km2 raft in 1 day, thus initiating a gigantic, high-precision, natural experiment relevant to both modern and prehistoric oceanic surface dispersal dynamics. Observed raft dispersal can be accurately reproduced by simulating drift and dispersal patterns using currents from an eddy-resolving ocean model hindcast. For future eruptions that produce potentially hazardous pumice rafts, our technique allows real-time forecasts of dispersal routes, in addition to inference of ash/pumice deposit distribution in the deep ocean. PMID:24755668

  3. On the fate of pumice rafts formed during the 2012 Havre submarine eruption

    NASA Astrophysics Data System (ADS)

    Jutzeler, Martin; Marsh, Robert; Carey, Rebecca J.; White, James D. L.; Talling, Peter J.; Karlstrom, Leif

    2014-04-01

    Pumice rafts are floating mobile accumulations of low-density pumice clasts generated by silicic volcanic eruptions. Pumice in rafts can drift for years, become waterlogged and sink, or become stranded on shorelines. Here we show that the pumice raft formed by the impressive, deep submarine eruption of the Havre caldera volcano (Southwest Pacific) in July 2012 can be mapped by satellite imagery augmented by sailing crew observations. Far from coastal interference, the eruption produced a single >400 km2 raft in 1 day, thus initiating a gigantic, high-precision, natural experiment relevant to both modern and prehistoric oceanic surface dispersal dynamics. Observed raft dispersal can be accurately reproduced by simulating drift and dispersal patterns using currents from an eddy-resolving ocean model hindcast. For future eruptions that produce potentially hazardous pumice rafts, our technique allows real-time forecasts of dispersal routes, in addition to inference of ash/pumice deposit distribution in the deep ocean.

  4. On the fate of pumice rafts formed during the 2012 Havre submarine eruption.

    PubMed

    Jutzeler, Martin; Marsh, Robert; Carey, Rebecca J; White, James D L; Talling, Peter J; Karlstrom, Leif

    2014-01-01

    Pumice rafts are floating mobile accumulations of low-density pumice clasts generated by silicic volcanic eruptions. Pumice in rafts can drift for years, become waterlogged and sink, or become stranded on shorelines. Here we show that the pumice raft formed by the impressive, deep submarine eruption of the Havre caldera volcano (Southwest Pacific) in July 2012 can be mapped by satellite imagery augmented by sailing crew observations. Far from coastal interference, the eruption produced a single >400 km(2) raft in 1 day, thus initiating a gigantic, high-precision, natural experiment relevant to both modern and prehistoric oceanic surface dispersal dynamics. Observed raft dispersal can be accurately reproduced by simulating drift and dispersal patterns using currents from an eddy-resolving ocean model hindcast. For future eruptions that produce potentially hazardous pumice rafts, our technique allows real-time forecasts of dispersal routes, in addition to inference of ash/pumice deposit distribution in the deep ocean. PMID:24755668

  5. Dynamics of deep submarine silicic explosive eruptions in the Kermadec arc, as reflected in pumice vesicularity textures

    NASA Astrophysics Data System (ADS)

    Rotella, Melissa D.; Wilson, Colin J. N.; Barker, Simon J.; Ian Schipper, C.; Wright, Ian C.; Wysoczanski, Richard J.

    2015-08-01

    Despite increasing recognition of silicic pumice-bearing deposits in the deep marine environment, the processes involved in explosive silicic submarine eruptions remain in question. Here we present data on bubble sizes and number densities (number of bubbles per unit of melt matrix) for deep submarine-erupted pumices from three volcanoes (Healy, Raoul SW and Havre) along the Kermadec arc (SW Pacific) to investigate the effects of a significant (>~1 km) overlying water column and the associated increased hydrostatic pressure on magma vesiculation and fragmentation. We compare these textural data with those from chemically similar, subaerially-erupted pyroclasts from nearby Raoul volcano as well as submarine-erupted 'Tangaroan' fragments derived by non-explosive, buoyant detachment of foaming magma from Macauley volcano, also along the Kermadec arc. Deep submarine-erupted pumices are macroscopically similar (colour, density, texture) to subaerial or shallow submarine-erupted pumices, but show contrasting microscopic bubble textures. Deep submarine-erupted pyroclasts have fewer small (< 10 μm diameter) bubbles and narrower bubble size distributions (BSDs) when compared to subaerially erupted pyroclasts from Raoul (35-55 μm vs. 20-70 μm range in volume based median bubble size, respectively). Bubble number density (BND) values are consistently lower than subaerial-erupted pyroclasts and do not display the same trends of decreasing BND with increasing vesicularity. We interpret these textural differences to result from deep submarine eruptions entering the water column at higher pressures than subaerial eruptions entering the atmosphere (~ 10 MPa vs. 0.1 MPa for a vent at 1000 mbsl). The presence of an overlying water column acts to suppress rapid acceleration of magma, as occurs in the upper conduit of subaerial eruptions, therefore suppressing coalescence, permeability development and gas loss, amounting to closed-system degassing conditions. The higher confining

  6. The 2011 submarine volcanic eruption of El Hierro Island (Canary Islands, Spain)

    NASA Astrophysics Data System (ADS)

    López, C.; Blanco, M. J.

    2012-04-01

    On 10 October 2011 a submarine volcanic eruption began 2 km SW of La Restinga village in the South coast of El Hierro Island (Spain). It became the first submarine eruption reported in 500 years of historical record in the Canary Islands. The eruption took place after three months of intensive seismic activity and ground deformation. The first signal evidencing the eruption was a harmonic tremor signal, located somewhere in the South sector of El Hierro Island and registered in every seismic station on the island. On the following day, the tremoŕs amplitude increased up enough to be felt by the residents of La Restinga. The first visual evidence of the eruption was observed during the afternoon of 12 October, a large light-green coloured area on the sea surface, 2 km to the SW of La Restinga. Three days later, steaming lava fragments were observed floating on the sea, in the area where the vent was supposed to be located. These fragments had a bomb-like shape and their sizes ranged between 10 and 40 cm long. They were bicoloured, a black outer part with a basaltic composition, and a white inner part, highly vesiculated and rich in silica content (>60%). This type of fragments was only observed during the first days of the eruption. Within the next two months further emission episodes have been observed with turbulent water, foam rings and large bubbles on the sea surface. On the 27th of November new lava fragments were observed while floating and degassing on the sea surface. Most of them were "lava balloons" or hollow fragments of lavas, with sizes between 30 and 200 cm, and highly vesiculated outer crust of basaltic-basanitic and sideromelane composition. The emission of these products continues intermitently up to date (January 2012) During the eruption, the GPS monitoring network detected episodes of inflation-deflation and a maximum vertical deformation of 4 cm. The horizontal deformation, which had reached up to 5 cm before the eruption, remains stable. The

  7. The 1891 submarine eruption offshore Pantelleria Island (Sicily Channel, Italy): Identification of the vent and characterization of products and eruptive style

    NASA Astrophysics Data System (ADS)

    Conte, A. M.; Martorelli, E.; Calarco, M.; Sposato, A.; Perinelli, C.; Coltelli, M.; Chiocci, F. L.

    2014-06-01

    bathymetry and seafloor sampling have been used to characterize the 1891 submarine eruption of the Pantelleria volcanic complex. This submarine eruption has been documented mainly by historical reports, describing basaltic scoria bombs floating on the sea surface (i.e., lava balloons). In this study, the 1891 eruptive vent has been identified as a small cone (volume of ˜700,000 m3) rising ˜90 m from 350 m w.d., and located within a newly discovered submarine volcanic field covering a wide area offshore from the NW coast of Pantelleria; recently, Kelly et al. (2012) confirmed this location by a multibeam and ROV survey. Pyroclasts from the 1891 eruption crop out directly on the seafloor and are fresh scoria clasts (i.e., small bombs, bomb fragments, and lapilli) and glass ash-sized grains; both have been characterized in their morphology, textures, and geochemistry. The distinctive vesicularity and crystallization characteristics displayed by the scoriaceous pyroclasts reflect modes of degassing in both syn and posteruptive regimes; these characteristics, along with the distribution of deposits suggest for the strongest eruptive phase of the 1891 eruption a style analogous to Hawaiian fountaining. Glass grains from a buoyant plume were dispersed northward from the vent, up to distances of 1.5 km, redirected by the Levantine Intermediate Water. The identification of the 1891 submarine eruptive vent offshore Pantelleria, as well as the features of erupted pyroclasts improve our knowledge of submarine explosive eruptions that occur at shallow-intermediate depths and, among these, of the rare eruptions producing lava balloons.

  8. Transient changes in bacterioplankton communities induced by the submarine volcanic eruption of El Hierro (Canary Islands).

    PubMed

    Ferrera, Isabel; Arístegui, Javier; González, José M; Montero, María F; Fraile-Nuez, Eugenio; Gasol, Josep M

    2015-01-01

    The submarine volcanic eruption occurring near El Hierro (Canary Islands) in October 2011 provided a unique opportunity to determine the effects of such events on the microbial populations of the surrounding waters. The birth of a new underwater volcano produced a large plume of vent material detectable from space that led to abrupt changes in the physical-chemical properties of the water column. We combined flow cytometry and 454-pyrosequencing of 16S rRNA gene amplicons (V1-V3 regions for Bacteria and V3-V5 for Archaea) to monitor the area around the volcano through the eruptive and post-eruptive phases (November 2011 to April 2012). Flow cytometric analyses revealed higher abundance and relative activity (expressed as a percentage of high-nucleic acid content cells) of heterotrophic prokaryotes during the eruptive process as compared to post-eruptive stages. Changes observed in populations detectable by flow cytometry were more evident at depths closer to the volcano (~70-200 m), coinciding also with oxygen depletion. Alpha-diversity analyses revealed that species richness (Chao1 index) decreased during the eruptive phase; however, no dramatic changes in community composition were observed. The most abundant taxa during the eruptive phase were similar to those in the post-eruptive stages and to those typically prevalent in oceanic bacterioplankton communities (i.e. the alphaproteobacterial SAR11 group, the Flavobacteriia class of the Bacteroidetes and certain groups of Gammaproteobacteria). Yet, although at low abundance, we also detected the presence of taxa not typically found in bacterioplankton communities such as the Epsilonproteobacteria and members of the candidate division ZB3, particularly during the eruptive stage. These groups are often associated with deep-sea hydrothermal vents or sulfur-rich springs. Both cytometric and sequence analyses showed that once the eruption ceased, evidences of the volcano-induced changes were no longer observed. PMID

  9. Transient Changes in Bacterioplankton Communities Induced by the Submarine Volcanic Eruption of El Hierro (Canary Islands)

    PubMed Central

    Ferrera, Isabel; Arístegui, Javier; González, José M.; Montero, María F.; Fraile-Nuez, Eugenio; Gasol, Josep M.

    2015-01-01

    The submarine volcanic eruption occurring near El Hierro (Canary Islands) in October 2011 provided a unique opportunity to determine the effects of such events on the microbial populations of the surrounding waters. The birth of a new underwater volcano produced a large plume of vent material detectable from space that led to abrupt changes in the physical-chemical properties of the water column. We combined flow cytometry and 454-pyrosequencing of 16S rRNA gene amplicons (V1–V3 regions for Bacteria and V3–V5 for Archaea) to monitor the area around the volcano through the eruptive and post-eruptive phases (November 2011 to April 2012). Flow cytometric analyses revealed higher abundance and relative activity (expressed as a percentage of high-nucleic acid content cells) of heterotrophic prokaryotes during the eruptive process as compared to post-eruptive stages. Changes observed in populations detectable by flow cytometry were more evident at depths closer to the volcano (~70–200 m), coinciding also with oxygen depletion. Alpha-diversity analyses revealed that species richness (Chao1 index) decreased during the eruptive phase; however, no dramatic changes in community composition were observed. The most abundant taxa during the eruptive phase were similar to those in the post-eruptive stages and to those typically prevalent in oceanic bacterioplankton communities (i.e. the alphaproteobacterial SAR11 group, the Flavobacteriia class of the Bacteroidetes and certain groups of Gammaproteobacteria). Yet, although at low abundance, we also detected the presence of taxa not typically found in bacterioplankton communities such as the Epsilonproteobacteria and members of the candidate division ZB3, particularly during the eruptive stage. These groups are often associated with deep-sea hydrothermal vents or sulfur-rich springs. Both cytometric and sequence analyses showed that once the eruption ceased, evidences of the volcano-induced changes were no longer observed

  10. The natural ocean acidification and fertilization event caused by the submarine eruption of El Hierro

    PubMed Central

    Santana-Casiano, J. M.; González-Dávila, M.; Fraile-Nuez, E.; de Armas, D.; González, A. G.; Domínguez-Yanes, J. F.; Escánez, J.

    2013-01-01

    The shallow submarine eruption which took place in October 10th 2011, 1.8 km south of the island of El Hierro (Canary Islands) allowed the study of the abrupt changes in the physical-chemical properties of seawater caused by volcanic discharges. In order to monitor the evolution of these changes, seven oceanographic surveys were carried out over six months (November 2011-April 2012) from the beginning of the eruptive stage to the post-eruptive phase. Here, we present dramatic changes in the water column chemistry including large decreases in pH, striking effects on the carbonate system, decreases in the oxygen concentrations and enrichment of Fe(II) and nutrients. Our findings highlight that the same volcano which was responsible for the creation of a highly corrosive environment, affecting marine biota, has also provided the nutrients required for the rapid recuperation of the marine ecosystem. PMID:23355953

  11. Transport and Deposition During The 2012 Submarine Explosive Eruption of Havre Volcano

    NASA Astrophysics Data System (ADS)

    Soule, S. A.; Carey, R.; Jones, M.; Ikegami, F.; Yoerger, D.; Fornari, D. J.

    2015-12-01

    Havre Volcano in the Kermadec Arc experienced a large eruption in 2012. The eruption was identified when ships in the area intersected a pumice raft, which was subsequently tracked by NASA MODIS satellite imagery. In 2015, an NSF-sponsored research cruise to the area conducted AUV and ROV dives to map and sample the deposits of this eruption. This presentation describes the high-resolution mapping data and seafloor observations that illustrate the processes of lava and pyroclast transport and deposition. The National Deep Submergence Facility (NDSF) AUV Sentry collected multibeam bathymetry data over the Havre caldera rim and floor - an area of 56 km2 - at a resolution of 1m. In addition, Sentry collected high-resolution sidescan sonar backscatter data over the same area. The NDSF ROV Jason collected HD video and down-looking still imagery along dive transects. These data allow us to document the depositional landforms in great detail. Notable features include effusive domes, lava flows, and a widespread blanket of giant pumice and ash. With constraints from seafloor imagery, we use the morphology of the imaged landforms to delineate deposit extents, identify intra-flow and intra-deposit features, pinpoint vent locations, and, in comparison with pre-eruption bathymetry, determine eruptive volumes. This information informs preliminary models of transport and deposition processes that are unique to submarine explosive eruptions.

  12. Can Detailed Mapping of Subglacial Pillow Lavas Inform our Understanding of Pillow-dominated Submarine Eruptions?

    NASA Astrophysics Data System (ADS)

    Pollock, M.; Edwards, B. R.; Bowman, L.; Was, E.; Alcorn, R.; Hauksdottir, S.

    2012-12-01

    Submarine pillows comprise a significant portion of the upper oceanic crust, yet the emplacement dynamics of pillow lavas are not well understood. For example, recent studies suggest that submarine pillow-dominated eruptions may be accompanied by explosive episodes, even at very deep (>3 km) depths (e.g., Sohn et al., 2008). Because these deep-water deposits are not easily examined in detail, we are studying the eruptive processes that control submarine pillow lavas by investigating their subglacial counterparts. Although the two environments have some physical differences, the main difficulty in comparing subglacial and submarine pillows primarily derives from the limited number of detailed studies on glaciovolcanic pillows. Here, we describe observations from Undirhlíthar, a quarry on the Reykjanes Peninsula in southwest Iceland that exposes an almost complete cross-section of a subglacial pillow ridge. Undirhlíthar's glaciovolcanic deposits reflect a complex sequence of multiple eruptive and intrusive events. The south and east walls are dominated by interbedded pillow and pillow-breccia units (Lp2 and Lp3) that consist of pillow basalts ranging in size from 0.5 m to 3 m in diameter. Lp3 is overlain by two pillow units (Lp4 and Lp5); Lp4 is clearly fed by a dike (D-3) and is separated from Lp3 by a lens of vitric tuff-breccia (LT3). The lowermost pillow unit (Lp1) occurs on the western end of the south wall, where it is separated from Lp2 by a layer of stratified vitric tuff-breccia. Two olivine phyric dikes (D-1 and D-2) cut units Lp1 and Lp2. The west wall is dominated by a distinct pillow unit (Lpw) that bears large (up to 1 cm) olivine phenocrysts. Compositionally, the Undirhlíthar units define two trace element populations: (1) incompatible element enriched (LaN/SmN ~1.6; Nb/Zr ~0.15) rocks comprising the lower (older) pillow units (Lp1-Lp3), and (2) less enriched (LaN/SmN ~1.3; Nb/Zr ~0.125) units including dikes (D-1 to D-3), west wall pillows (Lpw

  13. Contrasting pyroclast density spectra from subaerial and submarine silicic eruptions in the Kermadec arc: implications for eruption processes and dredge sampling

    NASA Astrophysics Data System (ADS)

    Barker, Simon J.; Rotella, Melissa D.; Wilson, Colin J. N.; Wright, Ian C.; Wysoczanski, Richard J.

    2012-08-01

    Pyroclastic deposits from four caldera volcanoes in the Kermadec arc have been sampled from subaerial sections (Raoul and Macauley) and by dredging from the submerged volcano flanks (Macauley, Healy, and the newly discovered Raoul SW). Suites of 16-32 mm sized clasts have been analyzed for density and shape, and larger clasts have been analyzed for major element compositions. Density spectra for subaerial dry-type eruptions on Raoul Island have narrow unimodal distributions peaking at vesicularities of 80-85%, whereas ingress of external water (wet-type eruption) or extended timescales for degassing generate broader distributions, including denser clasts. Submarine-erupted pyroclasts show two different patterns. Healy and Raoul SW dredge samples and Macauley Island subaerial-emplaced samples are dominated by modes at ~80-85%, implying that submarine explosive volcanism at high eruption rates can generate clasts with similar vesicularities to their subaerial counterparts. A minor proportion of Healy and Raoul SW clasts also show a pink oxidation color, suggesting that hot clasts met air despite 0.5 to >1 km of intervening water. In contrast, Macauley dredged samples have a bimodal density spectrum dominated by clasts formed in a submarine-eruptive style that is not highly explosive. Macauley dredged pyroclasts are also the mixed products of multiple eruptions, as shown by pumice major-element chemistry, and the sea-floor deposits reflect complex volcanic and sedimentation histories. The Kermadec calderas are composite features, and wide dispersal of pumice does not require large single eruptions. When coupled with chemical constraints and textural observations, density spectra are useful for interpreting both eruptive style and the diversity of samples collected from the submarine environment.

  14. 1891 Submarine eruption of Foerstner volcano (Pantelleria, Sicily) : insights into the vent structure of basaltic balloon eruptions

    NASA Astrophysics Data System (ADS)

    Kelly, J. T.; Carey, S.; Bell, K. L.; Rosi, M.; Marani, M.; Roman, C.; Pistolesi, M.; Baker, E. T.

    2012-12-01

    Numerous shallow water basaltic eruptions have produced abundant floating scoria up to several meters in diameter, yet little is known about the conditions that give rise to this unusual style of volcanism. On October 17, 1891, a submarine eruption began 4 kilometers northwest of the island of Pantelleria, Sicily. The eruptive vent was located at a depth of 250 meters along the NW-SE trending Sicily Channel Rift Zone. Evidence for the eruption was provided by the occurrence of hot, scoriaceous lava "balloons" floating on the sea surface along a narrow line about 850-1000 meters long trending along the rift. These extremely vesicular fragments were spherical to ellipsoidal in shape and ranged from <50 to 250 cm in diameter. Remotely Operated Vehicles (ROVs) and existing bathymetric maps have been used to conduct the first detailed investigation of a vent site associated with this unique style of volcanism. In 2011 the ROV Hercules, deployed from the E/V Nautilus, explored the 1891 Foerstner vent using high definition video cameras and produced a high resolution bathymetric map of the area using a BlueView multibeam imaging sonar. Light backscattering and oxidation-reduction potential sensors (MAPRs) were added to Hercules to detect discharge from active venting. ROV video footage has been used in conjunction with the high resolution bathymetric data to construct a geologic map of the vent area based on a variety of facies descriptors, such as abundance of scoria bombs, occurrence of pillow or scoria flow lobes, extent of sediment cover, and presence of spatter-like deposits. Initial results of the mapping have shown that there are two main vents that erupted within the observed area of floating scoria and most likely erupted at the same time as evidenced by similar bulk chemical compositions of recovered samples. Scoria bomb beds and some scoria flow lobes largely cover the suspected main vent, located at a depth of 250 meters. Distinct pillow flow lobes cover the

  15. Bubble Plumes above erupting NW Rota-1 submarine volcano, Mariana Arc

    NASA Astrophysics Data System (ADS)

    Chadwick, B.; Merle, S. G.; Embley, R. W.; Buck, N.; Resing, J. A.; Leifer, I.

    2013-12-01

    NW Rota-1 is a submarine volcano in the Mariana volcanic arc with a summit depth of 517 m, located ~100 km north of Guam. Underwater explosive eruptions driven by magmatic gases were first witnessed here in 2004 and the volcano has remained persistently active ever since. During a March 2010 expedition to NW Rota-1 with the remotely operated vehicle Jason, we observed intermittent explosive activity at five distinct eruptive vents along a line 100-m long near the summit of the volcano (550-590 m depth). The continuous but variable eruptive activity produced CO2 bubble plumes that rose in the water column over the volcano and could be readily imaged by sonar because they provide excellent acoustic reflectors. This study compares the manifestations of NW Rota's eruptive activity as measured by several independent methods, including: (1) an EM122 multibeam sonar system (12 kHz) on the R/V Kilo Moana that imaged bubble plumes in the water column over the volcano, (2) hydrophone data that recorded the sounds of the variable eruptive activity, and (3) visual observations of the activity at the eruptive vents on the seafloor from Jason. Throughout the 2010 expedition numerous passes were made over the volcano's summit to image the bubble plumes with the EM122 multibeam sonar, in order to capture the variability of the plumes over time and to relate them to the eruptive output of the volcano. The mid-water sonar dataset totals >95 hours of observations over a 12-day period. Analysis of the EM122 dataset shows: (1) bubble plumes were visible in the water column on every pass over the summit, (2) separate plumes were resolvable from up to 4 of the 5 eruptive vents at times, (3) plume heights and intensities were variable with time, (4) the highest observed bubble plume rise height was 415 meters above the seafloor to within 175 m of the ocean surface, while lower amplitude wisps rose to heights <100 m from the surface, (5) most of the bubble plumes were deflected to the WSW

  16. Self-made basins: how subglacial basaltic eruptions use the same eruptive styles, depositional processes and resulting lithofacies to build volcanoes different from submarine ones

    NASA Astrophysics Data System (ADS)

    White, J. D.

    2012-12-01

    Beneath oceans and glaciers eruptions begin under considerable confining pressure and with mostly unlimited access to water. Because of the shared pressure range, and the characteristic influence of water on particle formation and dispersal, there are few differences at scales from millimetres to tens of metres between subglacial basaltic eruptions and their deposits and submarine ones. In particular, both settings feature fragmentation with rapid chilling and edifice growth fed by by density currents formed during eruptions. Multiple venting is common, in part reflecting conduit instability in the weak particulate edifice, as are episodes of syn-eruptive slumping and sliding. Unidirectional fluid-gravity flow is more important in sedimentation and resedimentation from englacial eruptions, while wave-driven currents are more important in marine environments, but each current type exists in both environments. Despite these commonalities, volcanoes formed by subglacial eruptions have strong contrasts with those formed by submarine eruptions at large observation scales. Submarine volcanoes erupt to a single water level, and wave-driven redistribution and eruption-fed density currents disperse and deposit ash and lapilli in largely unconfined sheets. Wave erosion of emergent volcanoes that lack a lava cap quickly planes them off near wave-base in open-ocean settings. Subglacial volcanoes disperse tephra into ice-walled cavities or cauldrons in which water level can change abruptly, with more distal dispersal through subglacial or englacial tunnels or channels. Subsequent glacial activity typically truncates edifice edges. The overall effect of these differences is to produce broader edifices in marine settings, and narrower, steep-sided ones englacially, even though the dip angle of deposit strata is similar, and may be shallow, in both settings. These edifice geometry contrasts reflect the fact that water for subglacial eruptions is from melted ice, which is

  17. Effects of a submarine eruption on the performance of two brown seaweeds

    NASA Astrophysics Data System (ADS)

    Betancor, Séfora; Tuya, Fernando; Gil-Díaz, Teba; Figueroa, Félix L.; Haroun, Ricardo

    2014-03-01

    World oceans are becoming more acidic as a consequence of CO2 anthropogenic emissions, with multiple physiological and ecological implications. So far, our understanding is mainly limited to some species through in vitro experimentation. In this study, we took advantage of a recent submarine eruption (from October 2011 to March 2012) at ~ 1 nautical mile offshore El Hierro Island (Canary Islands, central east Atlantic) to determine whether altered physical-chemical conditions, mainly sudden natural ocean acidification, affected the morphology, photosynthesis (in situ Chl-a fluorescence) and physiological performance (photo-protective mechanisms and oxidative stress) of the conspicuous brown seaweeds Padina pavonica-a species with carbonate deposition - and Lobophora variegata-a species without carbonate on thallus surfaces - , both with similar morphology. Seaweeds were sampled twice: November 2011 (eruptive phase with a pH drop of ca. 1.22 units relative to standard conditions) and March 2012 (post-eruptive phase with a pH of ca. 8.23), on two intertidal locations adjacent to the eruption and at a control location. P. pavonica showed decalcification and loss of photo-protective compounds and antioxidant activity at locations affected by the eruption, behaving as a sun-adapted species during lowered pH conditions. At the same time, L. variegata suffered a decrease in photo-protective compounds and antioxidant activity during the volcanic event, but its photosynthetic performance remained unaltered. These results reinforce the idea that calcareous seaweeds, as a whole, are more sensitive than non-calcareous seaweeds to alter their performance under scenarios of reduced pH.

  18. Lava balloons - Proof of a submarine, non-emergent eruption (Serreta, 1998-2001)

    NASA Astrophysics Data System (ADS)

    Kueppers, U.; Potuzak, M.; Nichols, A.; Zanon, V.; Pacheco, J.

    2009-04-01

    Most volcanic eruptions on Earth take place in submarine settings, still, only a small fraction are emergent or possibly observed at the sea surface. Between December 1998 and April 2001, a submarine eruption occurred 10 km west of Terceira Island, Azores (Portugal) and was observable at the sea surface due to the periodic occurrence of "lava balloons". The witnessed lava balloons were up to 3 m long and remained floating for several minutes. In order to better constrain the genesis of these balloons and test models presented by Gaspar et al. (2003), we used a three-fold approach: 1) examination and understanding of the physical volcanology of the samples, 2) quantifying volatile contents of glassy matrix and melt inclusions hosted by olivine and pyroxene phenocrysts, and 3) measuring the cooling rate of glassy samples from the crust as a function of their distance from the exterior surface. The successfully collected balloons consist of a large cavity surrounded by a crust a few cm thick that shows signs of large-scale fluidal deformation and small-scale brittle cracking. The crust exhibits several different layers with varying bubble-number density, bubble size, and crystallinity. The outermost layer is glassy, golden-coloured, and highly porous. The concentration of volatiles in groundmass glass and melt inclusions was measured by micro-FTIR and indicate an efficient but incomplete degassing that started long before the magma reached the eruptive conditions. Cooling rates of glass from the different layers in the crust and the ash were determined using their cp-temperature paths, measured by differential scanning calorimetry. We discriminated values as high as 1259 K/s, the fourth fastest cooling rate known for volcanic glass. We believe that the balloons are gas-filled cavities that formed at and detached from ponded lava by gas accumulation. Balloon formation is possibly a more common feature than previously realised. Whether they are observed at the surface

  19. Serreta Submarine Eruption 1998-2001, Azores: a new compositional end-member?

    NASA Astrophysics Data System (ADS)

    Filipa Marques, Ana; Hamelin, Cédric; Madureira, Pedro; Rosa, Carlos; Silva, Pedro; Relvas, Jorge; Lourenço, Nuno; Conceição, Patrícia; Barriga, Fernando

    2014-05-01

    The Azores platform, where the Eurasian, Nubian and American plates meet, comprises nine volcanic islands extending to both sides of the Mid-Atlantic Ridge (MAR). East of the MAR, the plate boundary between Eurasian and Nubian plates is defined by the Terceira Rift, interpreted as an intra-oceanic spreading system where the Islands of S. Miguel, Terceira and Graciosa emerge as well and the submarine D.João de Castro Bank, separated by deep avolcanic zones [1, 2]. Submarine and subaerial lavas from the Terceira Rift are characterized by small-scale elemental and isotopic variations, and several distinct compositional end-members have been identified [2,3] supporting the concept of significant mantle source heterogeneity. A recent submarine eruption (1998-2001) occurred ~4-5 NM WNW of Terceira Island, at the Serreta Ridge where lava balloons were observed floating at the surface [4]. In 2008, an oceanographic cruise was conducted to the Serreta ridge to investigate the site of the 1998-2001 eruption, map the seafloor, identify vent location, and characterize possible products of eruption [5]. An ROV from the EMEPC (Task Group for the Extension of the Continental Shelf) was used in this survey providing high-definition video footage and fresh lava samples. Three survey ROV dives (D15, D16, D17) were made on the Serreta ridge. D15 and D17 dives were located on the southern wall of the crater, whereas D16 explored the central and northern areas of the crater floor. Sr-Nd-Pb isotope compositions of representative samples from the Serreta submarine ridge are presented for the first time. On the 208Pb/204Pb vs. 206Pb/204Pb diagram Serreta samples plot on a linear array with the remaining Terceira rift samples. However, these results show that Serreta submarine volcanics lay on the most depleted end of the Terceira Rift array. Radiogenic isotopes also show that samples from the central and northern wall of the crater are distinct from the younger southern wall sector

  20. The 2011 El Hierro submarine eruption: estimation of erupted lava flow volume on the basis of helicopter thermal surveys

    NASA Astrophysics Data System (ADS)

    Hernández, P. A.; Calvari, S.; Calvo, D.; Marquez, A.; Padron, E.; Pérez, N.; Melian, G.; Padilla, G.; Barrancos, J.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Hernández, I.

    2012-04-01

    been collected each time in order to compare the temperature distribution with the features observed on the sea surface. Calculation of lava flow volume and effusion rate from thermal images collected by helicopter surveys has been largely used during the last decade for monitoring effusive eruptions at Etna, Stromboli, Kilauea, and other volcanoes. In this study, lava flow volume is calculated on the basis of temperature difference between the seawater contained within the dark patch, and the temperature of the seawater surface away from the eruption. These values have to be considered as minimum values, because they do not take into account the volume of lava isolated from the seawater by a thick crust that did not contribute to seawater warming. To calculate the lava volume we have used the model proposed by Harris et al. (1998) for the portion of the lava flow field spreading below sea level. Preliminary results indicate that during the period of study, about 5Mm3 of magma have been needed to heat the observed surface heated sea water at the submarine eruption site.

  1. Experimental Insights on Natural Lava-Ice/Snow Interactions and Their Implications for Glaciovolcanic and Submarine Eruptions

    NASA Astrophysics Data System (ADS)

    Edwards, B. R.; Karson, J.; Wysocki, R.; Lev, E.; Bindeman, I. N.; Kueppers, U.

    2012-12-01

    Lava-ice-snow interactions have recently gained global attention through the eruptions of ice-covered volcanoes, particularly from Eyjafjallajokull in south-central Iceland, with dramatic effects on local communities and global air travel. However, as with most submarine eruptions, direct observations of lava-ice/snow interactions are rare. Only a few hundred potentially active volcanoes are presently ice-covered, these volcanoes are generally in remote places, and their associated hazards make close observation and measurements dangerous. Here we report the results of the first large-scale experiments designed to provide new constraints on natural interactions between lava and ice/snow. The experiments comprised controlled effusion of tens of kilograms of melted basalt on top of ice/snow, and provide insights about observations from natural lava-ice-snow interactions including new constraints for: 1) rapid lava advance along the ice-lava interface; 2) rapid downwards melting of lava flows through ice; 3) lava flow exploitation of pre-existing discontinuities to travel laterally beneath and within ice; and 4) formation of abundant limu o Pele and non-explosive vapor transport from the base to the top of the lava flow with minor O isotope exchange. The experiments are consistent with observations from eruptions showing that lava is more efficient at melting ice when emplaced on top of the ice as opposed to beneath the ice, as well as the efficacy of tephra cover for slowing melting. The experimental extrusion rates are as within the range of those for submarine eruptions as well, and reproduce some features seen in submarine eruptions including voluminous production of gas rich cavities within initially anhydrous lavas and limu on lava surfaces. Our initial results raise questions about the possibility of secondary ingestion of water by submarine and glaciovolcanic lava flows, and the origins of apparent primary gas cavities in those flows. Basaltic melt moving down

  2. The submarine volcano eruption at the island of El Hierro: physical-chemical perturbation and biological response

    PubMed Central

    Fraile-Nuez, E.; González-Dávila, M.; Santana-Casiano, J. M.; Arístegui, J.; Alonso-González, I. J.; Hernández-León, S.; Blanco, M. J.; Rodríguez-Santana, A.; Hernández-Guerra, A.; Gelado-Caballero, M. D.; Eugenio, F.; Marcello, J.; de Armas, D.; Domínguez-Yanes, J. F.; Montero, M. F.; Laetsch, D. R.; Vélez-Belchí, P.; Ramos, A.; Ariza, A. V.; Comas-Rodríguez, I.; Benítez-Barrios, V. M.

    2012-01-01

    On October 10 2011 an underwater eruption gave rise to a novel shallow submarine volcano south of the island of El Hierro, Canary Islands, Spain. During the eruption large quantities of mantle-derived gases, solutes and heat were released into the surrounding waters. In order to monitor the impact of the eruption on the marine ecosystem, periodic multidisciplinary cruises were carried out. Here, we present an initial report of the extreme physical-chemical perturbations caused by this event, comprising thermal changes, water acidification, deoxygenation and metal-enrichment, which resulted in significant alterations to the activity and composition of local plankton communities. Our findings highlight the potential role of this eruptive process as a natural ecosystem-scale experiment for the study of extreme effects of global change stressors on marine environments. PMID:22768379

  3. Looking for Larvae Above an Erupting Submarine Volcano, NW Rota-1, Mariana Arc

    NASA Astrophysics Data System (ADS)

    Hanson, M.; Beaulieu, S.; Tunnicliffe, V.; Chadwick, W.; Breuer, E. R.

    2015-12-01

    In 2009 the first marine protected areas for deep-sea hydrothermal vents in U.S. waters were established as part of the Volcanic Unit of the Marianas Trench Marine National Monument. In this region, hydrothermal vents are located along the Mariana Arc and back-arc spreading center. In particular hydrothermal vents are located near the summit of NW Rota-1, an active submarine volcano on the Mariana Arc which was erupting between 2003 through 2010 and ceased as of 2014. In late 2009, NW Rota-1 experienced a massive landslide decimating the habitat on the southern side of the volcano. This presented an enormous natural disturbance to the community. This project looked at zooplankton tow samples taken from the water column above NW Rota-1 in 2010, searching specifically for larvae which have the potential to recolonize the sea floor after such a major disturbance. We focused on samples for which profiles with a MAPR sensor indicated hydrothermal plumes in the water column. Samples were sorted in entirety into coarse taxa, and then larvae were removed for DNA barcoding. Overall zooplankton composition was dominated by copepods, ostracods, and chaetognaths, the majority of which are pelagic organisms. Comparatively few larvae of benthic invertebrates were found, but shrimp, gastropod, barnacle, and polychaete larvae did appear in low numbers in the samples. Species-level identification obtained via genetic barcoding will allow for these larvae to be matched to species known to inhabit the benthic communities at NW Rota-1. Identified larvae will give insight into the organisms which can re-colonize the seafloor vent communities after a disturbance such as the 2009 landslide. Communities at hydrothermal vents at other submarine volcanoes in the Monument also can act as sources for these planktonic, recolonizing larvae. As the microinvertebrate biodiversity in the Monument has yet to be fully characterized, our project also provides an opportunity to better describe both

  4. Stratigraphic relationships and timing of the 2012 Havre submarine silicic volcanic eruption revealed by high resolution bathymetric mapping and observations by underwater vehicles.

    NASA Astrophysics Data System (ADS)

    Carey, R.; Soule, S. A.; Houghton, B. F.; White, J. D. L.; Manga, M.; Wysoczanski, R. J.; Tani, K.; McPhie, J.; Fornari, D. J.; Jutzeler, M.; Caratori Tontini, F.; Ikegami, F.; Jones, M.; Murch, A.; Fauria, K.; Mitchell, S. J.; Cahalan, R. C.; Conway, C.; McKenzie, W.

    2015-12-01

    The 2012 deep rhyolitic caldera eruption of Havre volcano in the Kermadec arc is the first historic observed submarine eruption that produced a pumice raft observed at the ocean's surface. Ship-based bathymetric surveys before and after the eruption permit the intricacies of eruption styles, products and timescales to be quantified. In 2015 we mapped this submarine volcano in unprecedented detail with two submergence vehicles in tandem, facilitating a wide and comprehensive geological survey and sampling mission. These efforts and observations show highly complex and often simultaneous eruptive behavior from more than 14 vents along two 3 km-long fissures that represent massive ruptures of the caldera walls. This survey also revealed an important role for pre- and inter-eruptive periods of mass wasting processes derived from the intrusion of magma and destablisation of caldera walls. The detailed characterization of the eruption products, and quantification of timescales provides the scientific community with the first glimpse of the nature of submarine, intermediate magnitude, deep silicic caldera eruptions and permits unanswered yet first order fundamental questions of submarine eruption and transport processes to be addressed in the decades to come.

  5. Segmentation and Tracking of Anticyclonic Eddies during a Submarine Volcanic Eruption Using Ocean Colour Imagery

    PubMed Central

    Marcello, Javier; Eugenio, Francisco; Estrada-Allis, Sheila; Sangrà, Pablo

    2015-01-01

    The eruptive phase of a submarine volcano located 2 km away from the southern coast of El Hierro Island started on October 2011. This extraordinary event provoked a dramatic perturbation of the water column. In order to understand and quantify the environmental impacts caused, a regular multidisciplinary monitoring was carried out using remote sensing sensors. In this context, we performed the systematic processing of every MODIS and MERIS and selected high resolution Worldview-2 imagery to provide information on the concentration of a number of biological, physical and chemical parameters. On the other hand, the eruption provided an exceptional source of tracer that allowed the study a variety of oceanographic structures. Specifically, the Canary Islands belong to a very active zone of long-lived eddies. Such structures are usually monitored using sea level anomaly fields. However these products have coarse spatial resolution and they are not suitable to perform submesoscale studies. Thanks to the volcanic tracer, detailed studies were undertaken with ocean colour imagery allowing, using the diffuse attenuation coefficient, to monitor the process of filamentation and axisymmetrization predicted by theoretical studies and numerical modelling. In our work, a novel 2-step segmentation methodology has been developed. The approach incorporates different segmentation algorithms and region growing techniques. In particular, the first step obtains an initial eddy segmentation using thresholding or clustering methods and, next, the fine detail is achieved by the iterative identification of the points to grow and the subsequent application of watershed or thresholding strategies. The methodology has demonstrated an excellent performance and robustness and it has proven to properly capture the eddy and its filaments. PMID:25875193

  6. Segmentation and tracking of anticyclonic eddies during a submarine volcanic eruption using ocean colour imagery.

    PubMed

    Marcello, Javier; Eugenio, Francisco; Estrada-Allis, Sheila; Sangrà, Pablo

    2015-01-01

    The eruptive phase of a submarine volcano located 2 km away from the southern coast of El Hierro Island started on October 2011. This extraordinary event provoked a dramatic perturbation of the water column. In order to understand and quantify the environmental impacts caused, a regular multidisciplinary monitoring was carried out using remote sensing sensors. In this context, we performed the systematic processing of every MODIS and MERIS and selected high resolution Worldview-2 imagery to provide information on the concentration of a number of biological, physical and chemical parameters. On the other hand, the eruption provided an exceptional source of tracer that allowed the study a variety of oceanographic structures. Specifically, the Canary Islands belong to a very active zone of long-lived eddies. Such structures are usually monitored using sea level anomaly fields. However these products have coarse spatial resolution and they are not suitable to perform submesoscale studies. Thanks to the volcanic tracer, detailed studies were undertaken with ocean colour imagery allowing, using the diffuse attenuation coefficient, to monitor the process of filamentation and axisymmetrization predicted by theoretical studies and numerical modelling. In our work, a novel 2-step segmentation methodology has been developed. The approach incorporates different segmentation algorithms and region growing techniques. In particular, the first step obtains an initial eddy segmentation using thresholding or clustering methods and, next, the fine detail is achieved by the iterative identification of the points to grow and the subsequent application of watershed or thresholding strategies. The methodology has demonstrated an excellent performance and robustness and it has proven to properly capture the eddy and its filaments. PMID:25875193

  7. The May 2010 submarine eruption from South Sarigan seamount, Northern Mariana Islands

    NASA Astrophysics Data System (ADS)

    McGimsey, R. G.; Neal, C. A.; Searcy, C. K.; Camacho, J. T.; Aydlett, W. B.; Embley, R. W.; Trusdell, F.; Paskievitch, J. F.; Schneider, D. J.

    2010-12-01

    A sudden submarine explosive eruption occurred on May 29, 2010, from a seamount south of Sarigan Island in the Northern Mariana Islands, propelling a diffuse steam and ash cloud to high altitude. Pre-eruptive seismicity was recorded in early April by stations located on Sarigan and Anatahan Island, 42 km to the south, and indicated a source ~12-16 km south of Sarigan. On May 27-28, a change in seismicity—the appearance of tremor-like waveforms—may have marked the onset of volcanic activity. Also on May 27, an elongate patch of discolored ocean water and possible light-colored floating debris about 8-11 km south of Sarigan was observed from a helicopter. This material was likely produced during low-intensity eruptive activity, and an Information Statement from the Commonwealth of the Northern Mariana Islands (CNMI) Emergency Management Office (EMO) and USGS issued at 2353 UTC May 28 described the observation. The Guam Weather Forecast Office of the National Weather Service reported that the area of discoloration, visible on satellite images at 2313 and 2330 UTC on May 28, was about 10 km2, about twice the size of Sarigan Island. Pulses of tremor merged into a nearly continuous signal by 0305 UTC on May 29, lasting for ~4.5 hours followed by nearly 4.5 hours of quiescence. The EMO issued a declaration closing the region south of Sarigan to all local boating traffic and issued an advisory to aircraft. The explosive onset of the main plume-producing event occurred at ~1148 UTC as confirmed by seismic records on Anatahan Island, with the strongest phase ending ~1200 UTC. Soon after, the Washington Volcanic Ash Advisory Center reported an eruption cloud reaching an estimated 40,000 feet (12 km) ASL that diminished rapidly on satellite imagery suggesting it was water-vapor dominated. Winds carried the cloud southwest over Guam, and although no ash fall was reported, the cloud was visible and was detected in Aura/OMI aerosol index imagery. Biologists on Sarigan Island

  8. Precursory diffuse CO2 emission signature of the 2011 El Hierro submarine eruption, Canary Islands

    NASA Astrophysics Data System (ADS)

    Pérez, N. M.; Padilla, G. D.; Padrón, E.; Hernández, P. A.; Melián, G. V.; Barrancos, J.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Calvo, D.; Hernández, I.; Peraza, M. D.

    2012-04-01

    El Hierro is the youngest and southernmost island of the Canarian archipelago and represents the summit of a volcanic shield elevating from the surrounding seafloor at depth of 4000 m to up to 1501 m above sea level. The island is believed to be near the present hotspot location in the Canaries with the oldest subaerial rocks dated at 1.12 Ma. The subaerial parts of the El Hierro rift zones (NE, NW and S Ridges) are characterized by tightly aligned dyke complexes with clusters of cinder cones as their surface expressions. Since 16 July, an anomalous seismicity at El Hierro Island was recorded by IGN seismic network. Volcanic tremor started at 05:15 on 10 October, followed on the afternoon of 12 October by a green discolouration of seawater, strong bubbling and degassing, and abundant bombs on a decimetre scale found floating on the ocean surface offshore, southwest of La Restinga village, indicating the occurrence of a submarine volcanic eruption at approximately 2 km far the coast line of La Restinga. Further episodes have occurred during November, December 2011 and January 2012, with turbulent water, foam rings, and volcanic material again reaching the sea surface. In order to improve the volcanic surveillance program of El Hierro Island and to provide a multidisciplinary approach, a continuous geochemical station to measure CO2 efflux was installed on September 2003 in Llanos de Guillen, the interception center of the three volcanic-rift zones of the island, with the aim of detecting changes in the diffuse emission of CO2 related to the seismic or volcanic activity. The station measures on an hourly basis the CO2 and H2S efflux, the CO2 and H2S air concentrations, the soil water content and temperature and the atmospheric parameters: wind speed and direction, air temperature and humidity and barometric pressure. The meteorological parameters together with the air CO2 concentration are measured 1 m above the ground and the soil water content and soil temperature

  9. Continuous, Long-term, Cyclic, Varied Eruptive Activity Observed at NW Rota-1 Submarine Volcano, Mariana Arc

    NASA Astrophysics Data System (ADS)

    Chadwick, B.; Dziak, R. P.; Baker, E. T.; Cashman, K. V.; Embley, R. W.; Ferrini, V.; de Ronde, C. E.; Butterfield, D. A.; Deardorff, N.; Haxel, J. H.; Matsumoto, H.; Fowler, M. J.; Walker, S. L.; Bobbitt, A. M.; Merle, S. G.

    2009-12-01

    NW Rota-1 is a conical, basaltic-andesite submarine volcano in the Mariana arc with a summit depth of 520 m. Eruptive activity was first witnessed here during remotely operated vehicle (ROV) dives in 2004, and was also observed during all four subsequent ROV expeditions in 2005, 2006, and 2009. Cyclic explosive bursts were documented by a portable hydrophone during the 2006 ROV dives. More recently, a year of instrumental monitoring data from a moored hydrophone and plume sensor show that the volcano was continuously active from February 2008 to February 2009, and that the cyclic character of the eruptions occurred with variable intensity and periodicity. The 2008-2009 hydrophone record includes explosive bursts every 1-2 minutes, with high acoustic amplitudes in the first half of the year and lower more variable amplitudes in the second half. In contrast, the moored turbidity sensor recorded major eruptive plumes on a time scale of every few days to weeks, and at approximately the same frequency throughout the year. This apparent disparity may be explained by the most recent ROV and portable hydrophone observations at NW Rota-1 in April 2009, which confirmed continuous and diverse eruptive activity with cyclicity over several time scales, from minutes to days. Visual observations at the eruptive vent provided new insight into the process of very slow lava extrusion on the seafloor. During slow extrusion (at rates of 1-2 m3/hr), lava spines rose in the eruptive vent, then gradually disintegrated into angular blocks as they cooled and were shoved aside by the next lava to emerge. Freshly erupted lava blocks periodically tumbled down the sides of a growing cone (40-m high and 300-m wide) that had been constructed by this process since the last visit in 2006. Thus auto-brecciation during slow lava extrusion underwater produces primary deposits that could easily be mistaken as secondary, and can construct substantial landforms on submarine arc volcanoes. Even during

  10. Source of the tsunami generated by the 1650 AD eruption of Kolumbo submarine volcano (Aegean Sea, Greece)

    NASA Astrophysics Data System (ADS)

    Ulvrova, Martina; Paris, R.; Nomikou, P.; Kelfoun, K.; Leibrandt, S.; Tappin, D. R.; McCoy, F. W.

    2016-07-01

    The 1650 AD explosive eruption of Kolumbo submarine volcano (Aegean Sea, Greece) generated a destructive tsunami. In this paper we propose a source mechanism of this poorly documented tsunami using both geological investigations and numerical simulations. Sedimentary evidence of the 1650 AD tsunami was found along the coast of Santorini Island at maximum altitudes ranging between 3.5 m a.s.l. (Perissa, southern coast) and 20 m a.s.l. (Monolithos, eastern coast), corresponding to a minimum inundation of 360 and 630 m respectively. Tsunami deposits consist of an irregular 5 to 30 cm thick layer of dark grey sand that overlies pumiceous deposits erupted during the Minoan eruption and are found at depths of 30-50 cm below the surface. Composition of the tsunami sand is similar to the composition of the present-day beach sand but differs from the pumiceous gravelly deposits on which it rests. The spatial distribution of the tsunami deposits was compared to available historical records and to the results of numerical simulations of tsunami inundation. Different source mechanisms were tested: earthquakes, underwater explosions, caldera collapse, and pyroclastic flows. The most probable source of the 1650 AD Kolumbo tsunami is a 250 m high water surface displacement generated by underwater explosion with an energy of ~ 2 × 1016 J at water depths between 20 and 150 m. The tsunamigenic explosion(s) occurred on September 29, 1650 during the transition between submarine and subaerial phases of the eruption. Caldera subsidence is not an efficient tsunami source mechanism as short (and probably unrealistic) collapse durations (< 5 min) are needed. Pyroclastic flows cannot be discarded, but the required flux (106 to 107 m3 · s- 1) is exceptionally high compared to the magnitude of the eruption.

  11. Geochemical monitoring network at El Hierro (Canary Islands) before and during 2011 submarine eruption

    NASA Astrophysics Data System (ADS)

    Torres, P. A.; Meletlidis, S.; Luengo-Oroz, N.; Moure, D.; Rodero, C.; Villasante-Marcos, V.; Abella, R.; López, C.; Blanco, M. J.

    2012-04-01

    . Temperature, pH, electric conductivity and total dissolved solids were periodically measured. Water samples were also collected in order to determine major and trace elements. In situ measurements did not show any significant changes that could be related directly to the volcanic-seismic activity. However, the highest water temperature and the lowest pH value were obtained in the well located closer to the zone where the maximum values of CO2 diffuse flux were detected. Water samples were also taken on the stain generated by the submarine eruption and the nearby area since the beginning of the eruptive process. Chemical analysis revealed that seawater directly affected by the volcanic emissions, experimented an important increase in the concentration of several heavy metals.

  12. Understanding a submarine eruption through time series hydrothermal plume sampling of dissolved and particulate constituents: West Mata, 2008-2012

    NASA Astrophysics Data System (ADS)

    Baumberger, Tamara; Lilley, Marvin D.; Resing, Joseph A.; Lupton, John E.; Baker, Edward T.; Butterfield, David A.; Olson, Eric J.; Früh-Green, Gretchen L.

    2014-12-01

    cruises between 2008 and 2012 monitored the continuing eruption of West Mata volcano in the NE Lau Basin as it produced plumes of chemically altered water above its summit. Although large enrichments in 3He, CO2, Fe, and Mn were observed in the plumes, the most notable enrichment was that of H2, which reached concentrations as high as 14,843 nM. Strongly enriched H2 concentrations in the water column result from reactions between seawater or magmatic water and extremely hot rocks. In 2008, the observation of elevated H2 concentrations in the water column above West Mata pointed to vigorous ongoing eruptions at the volcano's summit. The eruption was confirmed by visual observations made by the ROV Jason 2 in 2009 and demonstrated that H2 measurements are a vital instrument to detect ongoing volcanic eruptions at the seafloor. Elevated H2 in 2010 showed that the eruption was ongoing, although at a reduced level given a maximum H2 concentration of 4410 nM. In 2012, H2 levels in the water column declined significantly, to a maximum of only 7 nM, consistent with visual observations from the Quest-4000 ROV that found no evidence of an ongoing volcanic eruption. Methane behaved independently of other measured gases and its concentrations in the hydrothermal plume were very low. We attribute its minimal enrichments to a mixture of mantle carbon reduced to CH4 and biological CH4 from diffuse flow sites. This study demonstrates that ongoing submarine volcanic eruptions are characterized by high dissolved H2 concentrations present in the overlying water column.

  13. The submarine volcano eruption at the island of El Hierro: physical-chemical perturbation and biological response

    NASA Astrophysics Data System (ADS)

    Fraile-Nuez, E.; Santana-Casiano, J.; Gonzalez-Davila, M.

    2013-12-01

    On October 10 2011 an underwater eruption gave rise to a novel shallow submarine volcano south of the island of El Hierro, Canary Islands, Spain. During the eruption large quantities of mantle-derived gases, solutes and heat were released into the surrounding waters. In order to monitor the impact of the eruption on the marine ecosystem, periodic multidisciplinary cruises were carried out. Here, we present an initial report of the extreme physical-chemical perturbations caused by this event, comprising thermal changes, water acidification, deoxygenation and metal-enrichment, which resulted in significant alterations to the activity and composition of local plankton communities. Our findings highlight the potential role of this eruptive process as a natural ecosystem-scale experiment for the study of extreme effects of global change stressors on marine environments. (A) Natural color composite from the MEdium Resolution Imaging Spectrometer (MERIS) instrument aboard ENVISAT Satellite (European Space Agency), (November 9, 2011 at 14:45 UTC). Remote sensing data have been used to monitor the evolution of the volcanic emissions, playing a fundamental role during field cruises in guiding the Spanish government oceanographic vessel to the appropriate sampling areas. The inset map shows the position of Canary Islands west of Africa and the study area (solid white box). (B) Location of the stations carried out from November 2011 to February 2012 at El Hierro. Black lines denote transects A-B and C-D.

  14. Emplacement of submarine lava flow fields: A geomorphological model from the Niños eruption at the Galápagos Spreading Center

    NASA Astrophysics Data System (ADS)

    McClinton, J. Timothy; White, Scott M.

    2015-03-01

    In the absence of any direct observations of an active submarine eruption at a mid-ocean ridge (MOR), our understanding of volcanic processes there is based on the interpretation of eruptive products. Submarine lava flow morphology serves as a primary indicator of eruption and emplacement processes; however, there is typically a lack of visual observations and bathymetric data at a scale and extent relevant to submarine lava flows, which display meter to submeter-scale morphological variability. In this paper, we merge submersible-based visual observations with high-resolution multibeam bathymetry collected by an autonomous underwater vehicle (AUV) and examine the fine-scale geomorphology of Niños, a submarine lava flow field at the Galápagos Spreading Center (GSC).We identify separate morphological facies (i.e., morphofacies) within the lava flow field, each having distinct patterns of lava flow morphology and volcanic structures. The spatial and stratigraphic arrangement of morphofacies suggests that they were emplaced sequentially as the eruption progressed, implying that the Niños eruption consisted of at least three eruptive phases. We estimate eruption parameters and develop a chronological model that describes the construction of the Niños lava flow field. An initial phase with high effusion rates emplaced sheet flows, then an intermediate phase emplaced a platform of lobate lavas, and then an extended final phase with low effusion rates emplaced a discontinuous row of pillow lava domes. We then compare this model to mapped lava flow fields at other MORs. Despite disparities in scale, the morphological similarities of volcanic features at MORs with different spreading rates suggest common emplacement processes that are primarily controlled by local magma supply.

  15. Submarine, silicic, syn-eruptive pyroclastic units in the Mount Read Volcanics, western Tasmania: Influence of vent setting and proximity on lithofacies characteristics

    NASA Astrophysics Data System (ADS)

    McPhie, Jocelyn; Allen, Rodney L.

    Lithofacies characteristics of submarine, silicic, syn-eruptive pyroclastic units in the Cambrian Mount Read Volcanics, western Tasmania, have been used to infer the source vent setting and proximity. The submarine, syn-eruptive pyroclastic units typically consist of one or more, massive to graded, very thick (a few metres to >100 m) beds and are laterally extensive (>10 km along strike). They are composed of variable proportions of rhyolitic or dacitic pumice, crystals (mainly quartz and feldspar), shards, volcanic lithic clasts and non-volcanic sedimentary clasts. Although the dominant components are juvenile pyroclasts and the units are very thick, there is no textural evidence for hot emplacement. In some cases, pumice clasts define a bedding-parallel foliation formed during diagenetic compaction. Three types of units can be defined on the basis of lithofacies characteristics: (1) graded pumice-lithic breccia-shard-rich sandstone, probably generated by submarine explosive eruptions and deposited in relatively deep water at medial to distal sites; (2) very thick, graded to massive pumice brecciashard-rich sandstone, considered to be the proximal, mainly below-wave-base submarine record of a large-magnitude (>10 cubic km), explosive eruption from an intrabasinal submarine vent; (3) very thick, crystal-rich volcanic sandstone; the high crystal abundance in this facies is attributed to interaction between subaerial pyroclastic flows and seawater, and formation of crystal-enriched, submarine, water-supported, gravity currents; in this case, it is most likely that the source vent was subaerial, and that deposition took place at proximal to medial locations in relatively shallow water (probably <200 m).

  16. Vesiculation and fragmentation history in a submarine scoria cone-forming eruption, an example from Nishiizu (Izu Peninsula, Japan)

    NASA Astrophysics Data System (ADS)

    Jutzeler, Martin; White, James D. L.; Proussevitch, Alexander A.; Gordee, Sarah M.

    2016-02-01

    An uplifted, >50-m-thick, half-dissected, submarine-emplaced (below wave-base) scoria cone occurs as dipping beds in coastal outcrops at Nishiizu, on the Izu Peninsula in Japan. Concentrically outward-dipping, weakly stratified, ungraded, framework-supported thin-to-very thick beds consist of brown coarse tuff to scoria lapilli-tuff, with outsized fluidal bombs throughout; accessory lithic clasts chiefly occur in the lowermost visible beds. Scoria bombs have quenched margins, weak bread-crust textures and their vesicle number densities decrease inward, which is indicative of fast surface cooling. Composite textures in the scoria bombs indicate recycling and agglutination of quenched and semi-molten pyroclasts at the submarine vent. In contrast to weak concentric gradations in vesicle size distribution in the bombs, lapilli have asymmetrical gradients in vesicle size distribution, indicating that they are fragments of coarser, quenched lumps. Three grain-size modes characterise the Nishiizu brown scoria, with coarse magma lumps ejected during magmatic fragmentation and quench-jointed upon contact with seawater, to be subsequently fragmented into lapilli and coarse ash by various styles of fragmentation where seawater plays a critical role. The cone was constructed by slow-moving fallout-fed granular flow/creep, fed directly by suspension settling focused at the crater rim but extending onto the cone flanks, with only minor resedimentation by granular flows. Nishiizu deposits yield an exceptional record of eruption and sedimentation dynamics during submarine cone-building activity, and in this study we compare their vesiculation and fragmentation mechanisms with those of potential subaerial analogues.

  17. The Santorini Volcanic Complex: A detailed multi-parameter seismological approach with emphasis on the 2011-2012 unrest period

    NASA Astrophysics Data System (ADS)

    Papadimitriou, P.; Kapetanidis, V.; Karakonstantis, A.; Kaviris, G.; Voulgaris, N.; Makropoulos, K.

    2015-04-01

    The present study is focused on the examination of the state of the recently activated Santorini Volcanic Complex (SVC) area, located in the Southern Aegean Sea. The seismic activity was investigated in detail and different methodologies have been applied to examine whether the SVC area approached an eruptive phase during the 2011-2012 seismic crisis period. The detailed spatiotemporal analysis for the broader study area revealed two different seismic patterns: low seismic activity until 2010, mainly concentrated within the Anydros basin and close to the submarine volcano, Columbo, and activation during 2011 and 2012 of two previously quiescent regions. The first is the Santorini Caldera, which had been active for more than one year, and the second is the area south of Christiana Islands, which was activated in January 2012 with the occurrence of two major events of magnitude 5.1 and 5.2, respectively, followed by a large number of aftershocks. In this study, manual analysis and relocation of the 2011-2012 seismic crisis in the SVC was performed, in order to obtain a high-resolution image of the activated structures. The seismicity within the Santorini Caldera, which is oriented approximately NE-SW, was rapidly diminished after the activation of the Christiana area. A large number of focal mechanisms were determined which mainly indicated strike-slip faulting inside the Caldera. Furthermore, the fault plane solutions of the major events in the area south of Christiana, derived by waveform modeling, also suggested similar type of faulting. This type differs from the normal faults observed in the Anydros basin. However, the stress field in all cases is consistently oriented in a NW-SE direction. Since the Santorini Volcano was seismically activated for the first time after the 1950 eruption, changes of the physical properties of the medium were examined using different approaches to assess the state of the volcano. The shear-wave splitting analysis revealed the

  18. Source of the tsunami generated by the 1650 AD eruption of Kolumbo submarine volcano (Aegean Sea, Greece)

    NASA Astrophysics Data System (ADS)

    Ulvrova, Martina; Paris, Raphael; Nomikou, Paraskevi; Tappin, Dave

    2016-04-01

    The 1650 AD explosive eruption of Kolumbo submarine volcano (Aegean Sea, Greece) generated a destructive tsunami. In this paper we propose a source mechanism of this poorly documented tsunami using both geological investigations and numerical simulations. Sedimentary evidences of the 1650 AD tsunami were found along the coast of Santorini Island at maximum altitudes ranging between 3.5 m a.s.l. (Perissa, southern coast) and 20 m a.s.l. (Monolithos, eastern coast), corresponding to a minimum inundation of 360 and 630 m respectively. Tsunami deposits correspond to an irregular 5 to 30 cm thick layer of dark grey sand intercalated in soil at depths between 30 and 50 cm. Composition of the tsunami sand is similar to the composition of the present-day beach and clearly differs from the pumiceous gravelly soil. Spatial distribution of the tsunami deposits was confronted to available historical records and to the results of numerical simulations of tsunami inundation. Different scenarios of source mechanism were tested: earthquakes, underwater explosions, caldera collapse, and pyroclastic flows. The most probable source of the 1650 AD Kolumbo tsunami is a 250 m high water surface displacement generated by underwater explosion with an energy of ~2 E15 J at water depths between 20 and 150 m. The tsunamigenic explosion(s) occurred on September 29, 1650 during the transition between submarine and subaerial phases. Caldera subsidence is not an efficient source of tsunami, as short (and probably unrealistic) collapse durations (< 5 minutes) are needed. Pyroclastic flows cannot be discarded, but the required flux (E6 to E7 m³.s-1) is exceptionally high compared to the magnitude of the eruption.

  19. Two-dimensional simulations of explosive eruptions of Kick-em Jenny and other submarine volcanos

    SciTech Connect

    Gisler, Galen R.; Weaver, R. P.; Mader, Charles L.; Gittings, M. L.

    2004-01-01

    Kick-em Jenny, in the Eastern Caribbean, is a submerged volcanic cone that has erupted a dozen or more times since its discovery in 1939. The most likely hazard posed by this volcano is to shipping in the immediate vicinity (through volcanic missiles or loss-of-buoyancy), but it is of interest to estimate upper limits on tsunamis that might be produced by a catastrophic explosive eruption. To this end, we have performed two-dimensional simulations of such an event in a geometry resembling that of Kick-em Jenny with our SAGE adaptive mesh Eulerian multifluid compressible hydrocode. We use realistic equations of state for air, water, and basalt, and follow the event from the initial explosive eruption, through the generation of a transient water cavity and the propagation of waves away from the site. We find that even for extremely catastrophic explosive eruptions, tsunamis from Kick-em Jenny are unlikely to pose significant danger to nearby islands. For comparison, we have also performed simulations of explosive eruptions at the much larger shield volcano Vailuluu in the Samoan chain, where the greater energy available can produce a more impressive wave. In general, however, we conclude that explosive eruptions do not couple well to water waves. The waves that are produced from such events are turbulent and highly dissipative, and don't propagate well. This is consistent with what we have found previously in simulations of asteroid-impact generated tsunamis. Non-explosive events, however, such as landslides or gas hydrate releases, do couple well to waves, and our simulations of tsunamis generated by subaerial and sub-aqueous landslides demonstrate this.

  20. The Submarine Volcano Eruption off El Hierro Island: Effects on the Scattering Migrant Biota and the Evolution of the Pelagic Communities

    PubMed Central

    Ariza, Alejandro; Kaartvedt, Stein; Røstad, Anders; Garijo, Juan Carlos; Arístegui, Javier; Fraile-Nuez, Eugenio; Hernández-León, Santiago

    2014-01-01

    The submarine volcano eruption off El Hierro Island (Canary Islands) on 10 October 2011 promoted dramatic perturbation of the water column leading to changes in the distribution of pelagic fauna. To study the response of the scattering biota, we combined acoustic data with hydrographic profiles and concurrent sea surface turbidity indexes from satellite imagery. We also monitored changes in the plankton and nekton communities through the eruptive and post-eruptive phases. Decrease of oxygen, acidification, rising temperature and deposition of chemicals in shallow waters resulted in a reduction of epipelagic stocks and a disruption of diel vertical migration (nocturnal ascent) of mesopelagic organisms. Furthermore, decreased light levels at depth caused by extinction in the volcanic plume resulted in a significant shallowing of the deep acoustic scattering layer. Once the eruption ceased, the distribution and abundances of the pelagic biota returned to baseline levels. There was no evidence of a volcano-induced bloom in the plankton community. PMID:25047077

  1. Submarine eruption near Socorro Island, Mexico: Geochemistry and scanning electron microscopy studies of floating scoria and reticulite

    NASA Astrophysics Data System (ADS)

    Siebe, Claus; Komorowski, Jean-Christophe; Navarro, Carlos; McHone, John; Delgado, Hugo; Cortés, Abel

    1995-11-01

    Products of an underwater eruption near Socorro Island in the NE Pacific were observed directly on January 29, 1993, ten days after precursors were first recorded by SOFAR (Sound Fixing and Ranging) hydrophones located in Hawaii and Tahiti. Eruptive activity was noticed from boats and ships as small steam plumes rising from the sea at an area centered at 18 °48'N, 111 °05'W, 2.4 km NW of Punta Tosca and 4.6 km SSW of Cape Henslow on Socorro Island. The observed steam was produced by 1-3-m-large blocks of hot, dark-grey, highly vesiculated basalt rising buoyantly to the surface from two submarine shallow vents at 210 and 30 m depth. Tens of blocks accompanied by bubbles could be observed rising to the surface in irregular pulses. These scoriaceous blocks remained floating at the surface until they would crack into smaller pieces by thermal contraction, emitting hissing noises from vapourizing seawater in contact with the hot interior of the blocks. Steam jets several metres in height were produced and occasionally blocks were propelled laterally by the steam jet. Depending on vesicularity and permeability, blocks remained floating and drifting with the surface current for 1-15 minutes before sinking back. Floating rocks covered an area of about 6000 m 2. This intermittent activity has been observed ever since and has not stopped as of April 1994. Buoyant scoria and reticulite are indicative of volatile (mostly CO 2) supersaturation and exsolution in the magma prior to rapid quenching, which inhibits loss of volatiles by bubble escape. A high-velocity ascent of low-viscosity magma in a relatively narrow conduit is also required to prevent substantial gas escape and allow formation of reticulite. The buoyant scoria is most probably ejected by intermittent lava fountaining at fixed vents as a result of changes in eruption velocities due to changes in the exsolved gas content of the lava. Between January and July 1993 floating blocks of scoria and reticulite were

  2. Eruption style and flow emplacement in the Submarine North Arch Volcanic Field, Hawaii

    NASA Astrophysics Data System (ADS)

    Clague, David A.; Uto, Kozo; Satake, Kenji; Davis, Alicé S.

    The North Arch Volcanic Field covers about 24,000 km2 of seafloor north of Oahu and has an estimated volume between 1,000 and 1,250 km3. The field straddles the Hawaiian flexural arch about 250 km north of the axis of the island chain and surrounds numerous Cretaceous volcanic ridges, circular flat-topped volcanoes, and low-relief regions of sediment-covered seafloor. New SeaBeam bathymetric maps that cover about 1/3 of the flow field reveal nearly 100 volcanic structures ranging from low shields to steep cones. One shield is modified by a pit crater, approximately 1.1×1.25 km and 300 m deep. A lava flow in the SE part of the volcanic field covers about 3,600 km2, has an estimated volume of 36-72 km3, and apparently erupted from a 75-km-long NNW-trending fissure system. A 108-km-long flow advanced north in a graben parallel to the Cretaceous mid-ocean ridge that formed the crust; its surface gradient is 1.9 m/km (slope of 0.1°). Shinkai 6500 submersible dive 502 explored one of the composite volcanoes and observed and collected dense alkalic basalt sheet flows erupted after vesicular basanite pillow basalts and fragmental hyaloclastite that make up the steep-sided cone. Dive 503 collected alkalic basalt sheet flows and pillow basalt from the top 122 m of the southern wall of a pit crater that formed by collapse caused by a decrease in magma volume from a shallow storage chamber located 1-2 km below the surface. The volume change may have been caused by loss of gas bubbles from the stored magma when replenishment ceased at the end of the eruption. The surficial drapery-folded sheet flow is covered by only a few cm of sediment, indicating that it is younger than the 0.5-1.5 Ma ages previously estimated for North Arch flows and vents. The near-vent constructs and flow characteristics indicate that vigorous eruption of highly vesicular lava constructed steep-sided cones of pillow basalt and hyaloclastite whereas steady eruption of dense lava that had lost its bubbles

  3. Ice-Confined Basaltic Eruptive Fissure Complexes in Iceland: Accessible Analogs for Understanding Shallow Submarine Ridge Construction

    NASA Astrophysics Data System (ADS)

    Skilling, I. P.; Mercurio, E.; Cameron, B. I.

    2009-12-01

    In southwest Iceland, the onshore Mid-Atlantic Ridge (Reykjanes Ridge) forms a series of fissure and central vent (“shield”) volcanic complexes, known as the Western Volcanic Zone (WVZ). Sveifluháls is one of the longest fissure-fed complexes in the WVZ, and was erupted in an ice-confined environment during the Last Glacial Maximum. There are more than 1000 similar such glaciovolcanic ridges in Iceland, but there are few detailed studies of their construction. The complexes are both an important record of North Atlantic terrestrial ice presence and thicknesses in the Pleistocene, and are accessible analogs for submarine basaltic ridge volcanism in water less than a few hundred metres deep. This study focuses on the volcanic and sedimentary processes, products and depositional environments at Sveifluháls. Sveifluháls is a complex of closely spaced, sub-parallel, and multiple vent ridges. Ridges are constructed of numerous, regularly-spaced to overlapping and steep-sided topographic highs (point-source vents or tuff cones) and short, lower, intervening ridge segments (fissure vents or “tuff ridges”). Both tuff cones and tuff ridges consist dominantly of basal subaqueous lavas draped by phreatomagmatic tephra. Point-source vents have an average spacing of 0.7 km. Up to nine sub-parallel fissures/ridges occur, spaced 0.03-0.5 km apart. Ridges range from a few hundred metres to 21.5km in length. The majority of the phreatomagmatic has been rotated, slumped or slid. An upper sequence of inward and outward-dipping, over-steepened (rotated) “soft-margined” domains and angular blocks of bedded, subaqueously-deposited “Surtseyan” lapilli tuff, overlies more widespread aprons of very similar, but mostly slumped massive tephra. Important results to date include the observation that 1-2m wide dikes, emplaced into formerly wet unconsolidated tephra, form a volumetrically important part of the complex. The host tephra commonly shows evidence of deformation and

  4. Interaction of sea water and lava during submarine eruptions at mid-ocean ridges.

    PubMed

    Perfit, Michael R; Cann, Johnson R; Fornari, Daniel J; Engels, Jennifer; Smith, Deborah K; Ridley, W Ian; Edwards, Margo H

    2003-11-01

    Lava erupts into cold sea water on the ocean floor at mid-ocean ridges (at depths of 2,500 m and greater), and the resulting flows make up the upper part of the global oceanic crust. Interactions between heated sea water and molten basaltic lava could exert significant control on the dynamics of lava flows and on their chemistry. But it has been thought that heating sea water at pressures of several hundred bars cannot produce significant amounts of vapour and that a thick crust of chilled glass on the exterior of lava flows minimizes the interaction of lava with sea water. Here we present evidence to the contrary, and show that bubbles of vaporized sea water often rise through the base of lava flows and collect beneath the chilled upper crust. These bubbles of steam at magmatic temperatures may interact both chemically and physically with flowing lava, which could influence our understanding of deep-sea volcanic processes and oceanic crustal construction more generally. We infer that vapour formation plays an important role in creating the collapse features that characterize much of the upper oceanic crust and may accordingly contribute to the measured low seismic velocities in this layer. PMID:14603316

  5. Insights on volcanic behaviour from the 2015 July 23-24 T-phase signals generated by eruptions at Kick-'em-Jenny Submarine Volcano, Grenada, Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Dondin, F. J. Y.; Latchman, J. L.; Robertson, R. E. A.; Lynch, L.; Stewart, R.; Smith, P.; Ramsingh, C.; Nath, N.; Ramsingh, H.; Ash, C.

    2015-12-01

    Kick-'em-Jenny volcano (KeJ) is the only known active submarine volcano in the Lesser Antilles Arc. Since 1939, the year it revealed itself, and until the volcano-seismic unrest of 2015 July 11-25 , the volcano has erupted 12 times. Only two eruptions breached the surface: 1939, 1974. The volcano has an average eruption cycle of about 10-11 years. Excluding the Montserrat, Soufrière Hills, KeJ is the most active volcano in the Lesser Antilles arc. The University of the West Indies, Seismic Research Centre (SRC) has been monitoring KeJ since 1953. On July 23 and 24 at 1:42 am and 0:02 am local time, respectively, the SRC recorded T-phase signals , considered to have been generated by KeJ. Both signals were recorded at seismic stations in and north of Grenada: SRC seismic stations as well as the French volcano observatories in Guadeloupe and Martinique, Montserrat Volcano Observatory, and the Puerto Rico Seismic Network. These distant recordings, along with the experience of similar observations in previous eruptions, allowed the SRC to confirm that two explosive eruptions occurred in this episode at KeJ. Up to two days after the second eruption, when aerial surveillance was done, there was no evidence of activity at the surface. During the instrumental era, eruptions of the KeJ have been identified from T-phases recorded at seismic stations from Trinidad, in the south, to Puerto Rico, in the north. In the 2015 July eruption episode, the seismic station in Trinidad did not record T-phases associated with the KeJ eruptions. In this study we compare the T-phase signals of 2015 July with those recorded in KeJ eruptions up to 1974 to explore possible causative features for the T-phase recording pattern in KeJ eruptions. In particular, we investigate the potential role played by the Sound Fixing and Ranging (SOFAR) layer in influencing the absence of the T-phase on the Trinidad seismic station during this eruption.

  6. Submarine seismic monitoring of El Hierro volcanic eruption with a 3C-geophone string: applying new acquisition and data processing techniques to volcano monitoring

    NASA Astrophysics Data System (ADS)

    Jurado, Maria Jose; Ripepe, Maurizio; Lopez, Carmen; Blanco, Maria Jose; Crespo, Jose

    2015-04-01

    A submarine volcanic eruption took place near the southernmost emerged land of the El Hierro Island (Canary Islands, Spain), from October 2011 to February 2012. The Instituto Geografico Nacional (IGN) seismic stations network evidenced seismic unrest since July 2011 and was a reference also to follow the evolution of the seismic activity associated with the volcanic eruption. Right after the eruption onset, in October 2011 a geophone string was deployed by the CSIC-IGN to monitor seismic activity. Monitoring with the seismic array continued till May 2012. The array was installed less than 2 km away from the new vol¬cano, next to La Restinga village shore in the harbor from 6 to 12m deep into the water. Our purpose was to record seismic activity related to the volcanic activity, continuously and with special interest on high frequency events. The seismic array was endowed with 8, high frequency, 3 component, 250 Hz, geophone cable string with a separation of 6 m between them. Each geophone consists on a 3-component module based on 3 orthogonal independent sensors that measures ground velocity. Some of the geophones were placed directly on the seabed, some were buried. Due to different factors, as the irregular characteristics of the seafloor. The data was recorded on the surface with a seismometer and stored on a laptop computer. We show how acoustic data collected underwater show a great correlation with the seismic data recorded on land. Finally we compare our data analysis results with the observed sea surface activity (ash and lava emission and degassing). This evidence is disclosing new and innovative tecniques on monitoring submarine volcanic activity. Reference Instituto Geográfico Nacional (IGN), "Serie El Hierro." Internet: http://www.ign.es/ign/resources /volcanologia/HIERRO.html [May, 17. 2013

  7. Active Submarine Volcanoes and Electro-Optical Sensor Networks: The Potential of Capturing and Quantifying an Entire Eruptive Sequence at Axial Seamount, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Delaney, J. R.; Kelley, D. S.; Proskurowski, G.; Fundis, A. T.; Kawka, O.

    2011-12-01

    The NE Pacific Regional Scale Nodes (RSN) component of the NSF Ocean Observatories Initiative is designed to provide unprecedented electrical power and bandwidth to the base and summit of Axial Seamount. The scientific community is engaged in identifying a host of existing and innovative observation and measurement techniques that utilize the high-power and bandwidth infrastructure and its real-time transmission capabilities. The cable, mooring, and sensor arrays will enable the first quantitative documentation of myriad processes leading up to, during, and following a submarine volcanic event. Currently planned RSN instrument arrays will provide important and concurrent spatial and temporal constraints on earthquake activity, melt migration, hydrothermal venting behavior and chemistry, ambient currents, microbial community structure, high-definition (HD) still images and HD video streaming from the vents, and water-column chemistry in the overlying ocean. Anticipated, but not yet funded, additions will include AUVs and gliders that continually document the spatial-temporal variations in the water column above the volcano and the distal zones. When an eruption appears imminent the frequency of sampling will be increased remotely, and the potential of repurposing the tracking capabilities of the mobile sensing platforms will be adapted to the spatial indicators of likely eruption activity. As the eruption begins mobile platforms will fully define the geometry, temperature, and chemical-microbial character of the volcanic plume as it rises into the thoroughly documented control volume above the volcano. Via the Internet the scientific community will be able to witness and direct adaptive sampling in response to changing conditions of plume formation. A major goal will be to document the eruptive volume and link the eruption duration to the volume of erupted magma. For the first time, it will be possible to begin to quantify the time-integrated output of an underwater

  8. Long-distance magma transport from arc volcanoes inferred from the submarine eruptive fissures offshore Izu-Oshima volcano, Izu-Bonin arc

    NASA Astrophysics Data System (ADS)

    Ishizuka, Osamu; Geshi, Nobuo; Kawanabe, Yoshihisa; Ogitsu, Itaru; Taylor, Rex N.; Tuzino, Taqumi; Sakamoto, Izumi; Arai, Kohsaku; Nakano, Shun

    2014-09-01

    Long-distance lateral magma transport away from volcanic centers in island arcs is emerging as a common phenomenon where the regional stress regime is favorable. It should also be recognized as an important factor in the construction and growth of island arcs, and a potential trigger for devastating eruptions. In this contribution, we report on recent investigations into the magma dynamics of Izu-Oshima volcano, an active basaltic volcano with an extensive fissure system. Izu-Oshima is flanked by numerous, subparallel NW-SE trending submarine ridges extending up to 22 km to the NW and the SE from the central vent. During a recent submersible survey we have identified that these ridges are fissures which erupted basaltic spatter and lava flows. Furthermore, lavas are petrographically similar along each ridge, while there are noticeable differences between ridges. The subparallel ridges are observed to transect a series of seamounts - the Izu-Tobu monogenetic volcanoes - which are dispersed across this area of the rear-arc. However, there are consistent petrographic and chemical differences between these seamounts and the ridges, indicating that they have different magma sources, yet, they are essentially bounding each other in dive tracks. The most appropriate scenario for their development is one where the Izu-Tobu Volcanoes are fed by an "in-situ" underlying source, while the NW-SE ridges are fed by lateral magma transport from Izu-Oshima. Magma erupted from each ridge is of a consistent geochemistry along its length, but has experienced crystal fractionation and some plagioclase accumulation. Compositions of the ridges are also very similar to lavas from the subaerial cones that can be traced down the flanks of Izu-Oshima. This implies that pairs of subaerial cones and submarine ridges represent the locus of magma transport events away from the storage system beneath Izu-Oshima. Hence, magma from this crustal reservoir moved upward to feed the on-edifice cones

  9. Hydroacoustic, infrasonic and seismic monitoring of the submarine eruptive activity and sub-aerial plume generation at South Sarigan, May 2010

    NASA Astrophysics Data System (ADS)

    Green, David N.; Evers, Läslo G.; Fee, David; Matoza, Robin S.; Snellen, Mirjam; Smets, Pieter; Simons, Dick

    2013-05-01

    Explosive submarine volcanic processes are poorly understood, due to the difficulties associated with both direct observation and continuous monitoring. In this study hydroacoustic, infrasound, and seismic signals recorded during the May 2010 submarine eruption of South Sarigan seamount, Marianas Arc, are used to construct a detailed event chronology. The signals were recorded on stations of the International Monitoring System, which is a component of the verification measures for the Comprehensive Nuclear-Test-Ban Treaty. Numerical hydroacoustic and infrasound propagation modelling confirms that viable propagation paths from the source to receivers exist, and provide traveltimes allowing signals recorded on the different technologies to be associated. The eruption occurred in three stages, separated by three-hour periods of quiescence. 1) A 46 h period during which broadband impulsive hydroacoustic signals were generated in clusters lasting between 2 and 13 min. 95% of the 7602 identified events could be classified into 4 groups based on their waveform similarity. The time interval between clusters decreased steadily from 80 to 25 min during this period. 2) A five-hour period of 10 Hz hydroacoustic tremor, interspersed with large-amplitude, broadband signals. Associated infrasound signals were also recorded at this time. 3) An hour-long period of transient broadband events culminated in two large-amplitude hydroacoustic events and one broadband infrasound signal. A speculative interpretation, consistent with the data, suggests that during phase (1) transitions between endogenous dome growth and phreatomagmatic explosions occurred with the magma ascent rate accelerating throughout the period; during phase (2) continuous venting of fragmented magma occurred, and was powerful enough to breach the sea surface. During the climactic phase (3) discrete powerful explosions occurred, and sufficient seawater was vaporised to produce the contemporaneous 12 km altitude steam

  10. Houston Community College 2011-2012 Fact Book

    ERIC Educational Resources Information Center

    Houston Community College System, Office of Institutional Research, 2012

    2012-01-01

    The Houston Community College (HCC) 2011-2012 Fact Book provides statistical information about the college district. It is important for the reader to be aware that data presented in this publication may differ slightly from statistics found in other district reports. Such variances may result from differences methodology including the source of…

  11. What We Eat in America Food Categories, 2011-2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of the What We Eat in America (WWEIA) Food Categories is to provide an application for analyzing foods and beverages as consumed in the American diet. Each food and beverage code in the Food and Nutrient Database for Dietary Studies (FNDDS) 2011-2012 is sorted into one of the 150+ mutua...

  12. Volcanic deformation sources associated with Fogo 2011-2012 unrest, Azores - The first modelling result

    NASA Astrophysics Data System (ADS)

    Okada, Jun; Araújo, João; Bonforte, Alessandro; Guglielmino, Francesco; Lorenzo, Maria; Ferreira, Teresa

    2016-04-01

    Volcanic deformation is often observed at many active volcanoes in the world by using space geodesy techniques, namely GNSS and InSAR. More difficulties in judgement if eruptions are imminent or not arise when such phenomenon occurs at dormant volcanoes due to the lack of eruption experiences with monitoring data. The eruption triggering mechanism is still controversial at many cases, but many attempts to image deformation sources beneath volcanoes have been made using geophysical inversion techniques. In this study, we show the case study of Fogo (Água de Pau) volcano, S. Miguel Island, Azores which represents over 450 years of eruption dormancy since 1563-1564. In the recent decades Fogo has exhibited three prominent unrest episodes (1989, 2003-2006, and 2011-2012). The lack of geochemical and hydrothermal evidences for a magmatic intrusion during those episodes does not encourage discussions on resuming volcanic activity of Fogo. However, the inflation/uplift are evident on the edifices at least for the last two unrest episodes based on GPS data by Trota et al. (2009) and Okada et al. (2015), respectively. The preliminary deformation modelling based on repeated GPS campaign data suggested a shallow expanding spheroid (Trota et al. 2009) or a single Mogi sources beneath the summit caldera. We performed a more integrated inversion for the 2011-2012 episode using a genetic algorithm optimizing the source parameters. The best fit model agrees well with the regional/local tectonic lineament suggesting the close relation between the volcanic sources and the regional/local tectonics. The regional extensional stress (between Eurasia and Nubia plates) may play important roles for the ascent of volcanic fluids at Fogo volcano. We do not discard the possibility that Fogo may have been preparing for eruptions by intermittent ascents of magma at shallow crust (i.e. experiencing "failed eruptions") during the apparent dormant period. As a local monitoring agency, CIVISA

  13. Massive Pyroclastic Eruptions Accompanied the Sector Collapse of Oahu and the Nu`uanu Landslide: Petrological Evidence for a Submarine Directed Blast

    NASA Astrophysics Data System (ADS)

    Natland, J. H.; Atlas, Z.

    2003-12-01

    During ODP Leg 200 in December, 2002, a series of thinly bedded volcaniclastic turbidites and silty muds interbedded with two thicker and strongly indurated vitric tuffs was drilled at Site 1223 on the crest of the Hawaiian arch east of the island of Oahu. The massive Nu`uanu landslide debris field, derived from a massive collapse of the eastern half of Oahu at about 2 Ma, lies in the flexural moat between the site and the island. The shipboard interpretation (1) was that the muds and silts are typical turbidites derived by redeposition from beaches and nearshore benches, but that the tuffs represent the distal portions of large submarine pyroclastic eruptions that may have attended the landslide. We report electron probe microanalyses of basaltic glass, olivine, Cr-spinel, palagonite and secondary minerals in the tuffs supporting the shipboard interpretation. In particular, the glass compositions from individual thin sections match precisely the range of compositions obtained from numerous samples of coarse volcaniclastic breccia sampled from the steep flanks of landslide blocks in the moat (2). This includes somewhat higher SiO2 and lower total iron as FeO(T) at given MgO than similar basaltic glasses from other Hawaiian volcanoes, a distinctive attribute of tholeiitic basalt from Oahu's Ko`olau volcano. Key attributes of the glasses in the tuffs and the minerals in them are that they are poly-compositional and they are strongly differentiated, with a range of compositions typical of those erupted from modern Hawaiian volcanic rift systems supplied by lateral diking from central conduits. The finer-grained tuffs at Site 1223 thus are indeed a distal pyroclastic facies that seemingly tapped much of the suddenly exposed, magma-inflated, deep flanking rift system of Ko`olau volcano. Over-steepening of the NE flank of the volcano coupled with internal weakening provided by near saturation of its rift system with magma may have triggered the landslide. This was almost

  14. Pumice rafting and faunal dispersion during 2001 2002 in the Southwest Pacific: record of a dacitic submarine explosive eruption from Tonga

    NASA Astrophysics Data System (ADS)

    Bryan, S. E.; Cook, A.; Evans, J. P.; Colls, P. W.; Wells, M. G.; Lawrence, M. G.; Jell, J. S.; Greig, A.; Leslie, R.

    2004-10-01

    A new influx of sea-rafted pumice reached the eastern coast of Australia in October 2002, approximately 1 year after a felsic, shallow-marine explosive eruption at a previously unknown volcano (0403-091) along the Tofua volcanic arc (Tonga). The eruption produced floating pumice rafts that first became stranded in Fiji in November 2001, approximately 1 month after the eruption. Strandings of sea-rafted pumice along shorelines have been the only record of products from this submarine explosive eruption at the remote, submerged volcano. Computed drift trajectories of the sea-rafted pumice using numerical models of southwest Pacific surface wind fields and ocean currents indicate two cyclonic systems disturbed the drift of pumice to eastern Australia, as well as the importance of the combined wave and direct wind effect on pumice trajectory. Pumice became stranded along at least two-thirds (>2000 km) of the coastline of eastern Australia being deposited on beaches during a sustained period of fresh onshore winds. Typical amounts of pumice initially stranded on beaches were 500-4000 individual clasts per m 2, and a minimum volume estimate of pumice that arrived to eastern Australia is 1.25×10 5 m 3. Pumice was beached below maximum tidal/storm surge levels and was quickly reworked back into the ocean, such that the concentration of beached pumice rapidly dissipated within weeks of the initial stranding, and little record of this stranding event now exists. Most stranded pumice clasts ranged in size from 2 to 5 cm in diameter; the largest measured clasts were 10 cm in Australia and 20 cm in Fiji. The pumice has a low phenocryst content (<5% modal), containing the assemblage of calcic plagioclase (An 88-74), augite (En 35Fs 29Wo 36), pigeonite (En 45Fs 46Wo 9), and titanomagnetite. Examined pumice clasts are compositionally homogenous, although there is considerable variation in clast vesicularity, both within and between clasts. The pumice composition is low-K dacite

  15. The NeMO Explorer Web Site: Interactive Exploration of a Recent Submarine Eruption and Hydrothermal Vents, Axial Volcano, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Weiland, C.; Chadwick, W. W.; Embley, R. W.

    2001-12-01

    To help visualize the submarine volcanic landscape at NOAA's New Millennium Observatory (NeMO), we have created the NeMO Explorer web site: http://www.pmel.noaa.gov/vents/nemo/explorer.html. This web site takes visitors a mile down beneath the ocean surface to explore Axial Seamount, an active submarine volcano 300 miles off the Oregon coast. We use virtual reality to put visitors in a photorealistic 3-D model of the seafloor that lets them view hydrothermal vents and fresh lava flows as if they were really on the seafloor. At each of six virtual sites there is an animated tour and a 360o panorama in which users can view the volcanic landscape and see biological communities within a spatially accurate context. From the six sites there are hyperlinks to 50 video clips taken by a remotely operated vehicle. Each virtual site concentrates on a different topic, including the dynamics of the 1998 eruption at Axial volcano (Rumbleometer), high-temperature hydrothermal vents (CASM and ASHES), diffuse hydrothermal venting (Marker33), subsurface microbial blooms (The Pit), and the boundary between old and new lavas (Castle vent). In addition to exploring the region geographically, visitors can also explore the web site via geological concepts. The concepts gallery lets you quickly find information about mid-ocean ridges, hydrothermal vents, vent fauna, lava morphology, and more. Of particular interest is an animation of the January 1998 eruption, which shows the rapid inflation (by over 3 m) and draining of the sheet flow. For more info see Fox et al., Nature, v.412, p.727, 2001. This project was funded by NOAA's High Performance Computing and Communication (HPCC) and Vents Programs. Our goal is to present a representative portion of the vast collection of NOAA's multimedia imagery to the public in a way that is easy to use and understand. These data are particularly challenging to present because of their high data rates and low contextual information. The 3-D models create

  16. Reconstructing Final H2O Contents of Hydrated Rhyolitic Glasses: Insights into H2O Degassing and Eruptive Style of Silicic Submarine Volcanoes

    NASA Astrophysics Data System (ADS)

    McIntosh, I. M.; Nichols, A. R.; Tani, K.; Llewellin, E. W.

    2015-12-01

    H2O degassing influences the evolution of magma viscosity and vesicularity during ascent through the crust, and ultimately the eruptive style. Investigating H2O degassing requires data on both initial and final H2O contents. Initial H2O contents are revealed by melt inclusion data, while final H2O contents are found from dissolved H2O contents of volcanic glass. However volcanic glasses, particularly of silicic composition, are susceptible to secondary hydration i.e. the addition of H2O from the surrounding environment at ambient temperature during the time following pyroclast deposition. Obtaining meaningful final H2O data therefore requires distinguishing between the original final dissolved H2O content and the H2O added subsequently during hydration. Since H2O added during hydration is added as molecular H2O (H2Om), and the species interconversion between H2Om and hydroxyl (OH) species is negligible at ambient temperature, the final OH content of the glass remains unaltered during hydration. By using H2O speciation models to find the original H2Om content that would correspond to the measured OH content of the glass, the original total H2O (H2Ot) content of the glass prior to hydration can be reconstructed. These H2O speciation data are obtained using FTIR spectroscopy. In many cases, particularly where vesicular glasses necessitate thin wafers, OH cannot be measured directly and instead is calculated indirectly as OH = H2Ot - H2Om. Here we demonstrate the importance of using a speciation-dependent H2Ot molar absorptivity coefficient to obtain accurate H2Ot and H2O speciation data and outline a methodology for calculating such a coefficient for rhyolite glasses, with application to hydrated silicic pumice from submarine volcanoes in the Japanese Izu-Bonin Arc. Although hydrated pumice from Kurose Nishi and Oomurodashi now contain ~1.0 - 2.5 wt% H2Ot, their pre-hydration final H2O contents were typically ~0.3 - 0.4 wt% H2Ot. Furthermore, we show that pre

  17. Observations of CO2 Exsolution in Submarine Lava Flows: The 2005-6 Eruption on the East Pacific Rise, 9°50"N

    NASA Astrophysics Data System (ADS)

    Michael, P. J.; Perfit, M. R.; Palke, A.; Fornari, D. J.; Soule, S. A.

    2008-12-01

    The 2005-2006 eruption along a well-surveyed part of the East Pacific Rise (EPR) at 9°50"N, and the subsequent observations and collection of the flow (Soule et al., 2007) provide a rare opportunity to study how submarine basalts vesiculate as they ascend beneath the mid-ocean ridge (MOR) and are emplaced at the surface. We have measured dissolved CO2 and H2O contents and volume % vesicles in fresh natural glasses. Only the abundant tiny vesicles (5-140μm diameter) that define a good vesicle size distribution trend are considered in our study not the rare, large vesicles up to 1mm that probably existed in the magma chamber prior to eruption. There is a very good negative correlation between dissolved CO2 and the size and volume % vesicles. Glasses from the highest point of the flow, near the presumed eruptive vent, all contain 280-300 ppm dissolved CO2, and have roughly 0.2% vesicles, all <30μm diameter. Most of the glasses from deeper, distal locations (up to 12 km south or 7 km north) contain lower dissolved CO2 contents (as low as 140 ppm) and have up to 1% vesicles as large as 140μμm. The equilibrium CO2 content at the depth of eruption (2500 m) is 114 ppm. For all samples, the total CO2 content (dissolved + amount calculated in vesicles) is fairly constant at about 350 ppm, which would be in solution equilibrium at a depth of 1.6 km beneath the seafloor. This is very close to the seismically determined axial magma chamber (AMC) reflector at 1.43 km (Kent et al., 1993). The small size and volume of vesicles in the near- vent glasses suggests that the time spent by magmas ascending from the AMC in conduits was very short compared to the time spent flowing at or near the seafloor. For the distally emplaced lavas, most vesicle growth took place while the lava flowed down the axis at (or slightly below) the seafloor. The fairly constant total CO2 contents overall suggest that time was sufficient for vesicle formation but not loss. Modeling of vesicle growth

  18. Products of Submarine Fountains and Bubble-burst Eruptive Activity at 1200 m on West Mata Volcano, Lau Basin

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Rubin, K. H.; Keller, N. S.

    2009-12-01

    An eruption was observed and sampled at West Mata Volcano using ROV JASON II for 5 days in May 2009 during the NSF-NOAA eruption response cruise to this region of suspected volcanic activity. Activity was focused near the summit at the Prometheus and Hades vents. Prometheus erupted almost exclusively as low-level fountains. Activity at Hades cycled between vigorous degassing, low fountains, and bubble-bursts, building up and partially collapsing a small spatter/scoria cone and feeding short sheet-like and pillow flows. Fire fountains at Prometheus produced mostly small primary pyroclasts that include Pele's hair and fluidal fragments of highly vesicular volcanic glass. These fragments have mostly shattered and broken surfaces, although smooth spatter-like surfaces also occur. As activity wanes, glow in the vent fades, and denser, sometimes altered volcanic clasts are incorporated into the eruption. The latter are likely from the conduit walls and/or vent-rim ejecta, drawn back into the vent by inrushing seawater that replaces water entrained in the rising volcanic plume. Repeated recycling of previously erupted materials eventually produces rounded clasts resembling beach cobbles and pitted surfaces on broken phenocrysts of pyroxene and olivine. We estimate that roughly 33% of near vent ejecta are recycled. Our best sample of this ejecta type was deposited in the drawer of the JASON II ROV during a particularly large explosion that occurred during plume sampling immediately above the vent. Elemental sulfur spherules up to 5 mm in diameter are common in ejecta from both vents and occur inside some of the lava fragments Hades activity included dramatic bubble-bursts unlike anything previously observed under water. The lava bubbles, sometimes occurring in rapid-fire sequence, collapsed in the water-column, producing fragments that are quenched in less than a second to form Pele's hair, limu o Pele, spatter-like lava blobs, and scoria. All are highly vesicular

  19. Submarine fissure eruptions and hydrothermal vents on the southern Juan de Fuca Ridge: preliminary observations from the submersible Alvin.

    USGS Publications Warehouse

    Normark, W.R.

    1986-01-01

    The submersible Alvin was used to investigate 3 active hydrothermal discharge sites along the S Juan de Fuca Ridge in September 1984. The hydrothermal zones occur within a 10-30m-deep, 30-50m-wide cleft marking the center of the axial valley. This cleft is the eruptive locus for the axial valley. The hydrothermal vents coincide with the main eruptive vents along the cleft. Each hydrothermal zone has multiple discharge sites extending as much as 500m along the cleft. Sulfide deposits occur as clusters (15-100m2 area) of small chimneys (= or <2m high) and as individual and clustered fields of large, branched chimneys (= or <10m high). Recovered sulfide samples are predominantly the tops of chimneys and spires and typically contain more than 80% sphalerite and wurtzite with minor pyrrhotite, pyrite, marcasite, isocubanite, chalcopyrite, anhydrite, anhydrite, and amorphous silica. The associated hydrothermal fluids have the highest chlorinity of any reported to date.-Authors

  20. A model of tephra dispersal from an early Palaeogene shallow submarine Surtseyan-style eruption(s), the Red Bluff Tuff Formation, Chatham Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Sorrentino, Leonor; Stilwell, Jeffrey D.; Mays, Chris

    2014-03-01

    The Red Bluff Tuff Formation, an early Palaeogene volcano-sedimentary shallow marine succession from the Chatham Islands (New Zealand), provides a unique framework, in eastern 'Zealandia', to explore tephra dispersal processes associated with ancient small phreatomagmatic explosions (i.e. Surtseyan-style eruptions). Detailed sedimentological mapping, logging and sampling integrated with the results of extensive laboratory analyses (i.e. grain-size, componentry and applied palaeontological methods) elucidated the complex mechanisms of transport and deposition of nine identified resedimented fossiliferous volcaniclastic facies. These facies record the subaqueous reworking and deposition of tephra from the erosion and degradation of a proximal, entirely submerged ancient Surtseyan volcanic edifice (Cone II). South of this volcanic cone, the lowermost distal facies provides significant evidence of deposition as water-supported volcanic- or storm-driven mass flows (e.g. turbidity currents and mud/debris flows) of volcaniclastic and bioclastic debris, whereas the uppermost distal facies exhibit features of tractional sedimentary processes caused by shallow subaqueous currents. Further north, within the proximity of the volcanic edifice, the uppermost facies are represented by an abundant, diverse, large, and well preserved in situ fauna of shallow marine sessile invertebrates (e.g. corals and sponges) that reflect the protracted biotic stabiliszation and rebound following pulsed volcanic events. Over a period of time, these stable and wave-eroded volcanic platforms were inhabited by a flourishing and diversifying marine community of benthic and sessile pioneers (corals, bryozoans, molluscs, brachiopods, barnacles, sponges, foraminifera, etc.). This succession exhibits a vertical progression of sedimentary structures (i.e. density, cohesive and mass flows, and cross-bedding) and our interpretations indicate a shallowing upwards succession. This study reports for the first

  1. Progress toward measles preelimination--African Region, 2011-2012.

    PubMed

    Masresha, Balcha G; Kaiser, Reinhard; Eshetu, Messeret; Katsande, Reggis; Luce, Richard; Fall, Amadou; Dosseh, Annick R G A; Naouri, Boubker; Byabamazima, Charles R; Perry, Robert; Dabbagh, Alya J; Strebel, Peter; Kretsinger, Katrina; Goodson, James L; Nshimirimana, Deo

    2014-04-01

    In 2008, the 46 member states of the World Health Organization (WHO) African Region (AFR) adopted a measles preelimination goal to reach by the end of 2012 with the following targets: 1) >98% reduction in estimated regional measles mortality compared with 2000, 2) annual measles incidence of fewer than five reported cases per million population nationally, 3) >90% national first dose of measles-containing vaccine (MCV1) coverage and >80% MCV1 coverage in all districts, and 4) >95% MCV coverage in all districts by supplementary immunization activities (SIAs). Surveillance performance objectives were to report two or more cases of nonmeasles febrile rash illness per 100,000 population, one or more suspected measles cases investigated with blood specimens in ≥80% of districts, and 100% completeness of surveillance reporting from all districts. This report updates previous reports and describes progress toward the measles preelimination goal during 2011-2012. In 2012, 13 (28%) member states had >90% MCV1 coverage, and three (7%) reported >90% MCV1 coverage nationally and >80% coverage in all districts. During 2011-2012, four (15%) of 27 SIAs with available information met the target of >95% coverage in all districts. In 2012, 16 of 43 (37%) member states met the incidence target of fewer than five cases per million, and 19 of 43 (44%) met both surveillance performance targets. In 2011, the WHO Regional Committee for AFR established a goal to achieve measles elimination by 2020. To achieve this goal, intensified efforts to identify and close population immunity gaps and improve surveillance quality are needed, as well as committed leadership and ownership of the measles elimination activities and mobilization of adequate resources to complement funding from global partners. PMID:24699765

  2. Preliminary results from Submarine Ring of Fire 2012 - NE Lau: First explorations of hydrothermally active volcanoes across the supra-subduction zone and a return to the West Mata eruption site

    NASA Astrophysics Data System (ADS)

    Resing, J.; Embley, R. W.

    2012-12-01

    Several expeditions in the past few years have shown that the NE Lau basin has one of the densest concentrations of volcanically and hydrothermally active volcanoes on the planet. In 2008 two active submarine volcanic eruptions were discovered during a one week period and subsequent dives with the Jason remotely operated vehicle at one of the sites (West Mata) revealed an active boninite eruption taking place at 1200 m depth. Two dives at the other revealed evidence for recent eruption along the NE Lau Spreading Center. Several more expeditions in 2010-11 discovered additional evidence about the extent and types of hydrothermal activity in this area. Data from CTDO (conductivity, temperature, depth, optical) vertical casts, tow-yos, and towed camera deployments revealed more than 15 hydrothermal sites at water depths from ~800 to 2700 m that include sites from the magmatic arc, the "rear arc," and the back arc spreading centers. These sites range from high temperature black smoker sulfide-producing systems to those dominated by magmatic degassing. Dives by remotely operated vehicle (Quest 4000) in September 2012 will explore these sites and return samples for chemical, biological and geologic studies. One of the dives will be a return visit to West Mata volcano, the site of the deepest submarine eruption yet observed (in 2009). Recent multibeam data reveal large changes in West Mata's summit, suggesting that the nature of the eruption and the location of the erupting vents may have changed. In addition to the preliminary results from the science team, we will also discuss our use and experience with continuous live video transmission (through the High Definition video camera on the Quest 4000) back to shore via satellite and through the internet. Submarine Ring of Fire 2012 Science Team: Bradley Tebo, Bill Chadwick, Ed Baker, Ken Rubin, Susan Merle, Timothy Shank, Sharon Walker, Andra Bobbitt, Nathan Buck, David Butterfield, Eric Olson, John Lupton, Richard Arculus

  3. The intrusion of new magma triggered the 2011-2012 unrest at Santorini: evidence from noble-gas isotopes

    NASA Astrophysics Data System (ADS)

    Rizzo, A.; Barberi, F.; Carapezza, M.; Di Piazza, A.; Francalanci, L.; Sortino, F.; D'Alessandro, W.

    2013-12-01

    Santorini is one of the most famous active volcanoes of the world for its catastrophic explosive eruption that occurred during the Minoan civilization. Since then the Kameni eruptive centers that formed within the caldera erupted repeatedly until 1950. In 2011-2012 the volcano has been characterized by a seismic unrest, that was unprecedented at Santorini at least since the 1950 eruption, and that led to fear for an imminent eruption. Because more than 100,000 visitors are present on the island during the tourist season, and considering the eruptive potential of Santorini, it is crucial to evaluate the hazard of this volcano, which depends on the type of magma actually present in the volcanic system. With the aim to address this question, this research shows the first comparison between noble-gas isotope composition of the present fumarolic gases with that of fluid inclusions hosted in enclaves contained in the 1570 and 1925 AD dacitic magmas erupted at Nea Kameni. These enclaves are a portion of mafic magma batches that replenished the shallow chamber of the plumbing system hosting cooler and more silicic melts. Their Sr-Nd isotope ratios are quite similar to those measured in the host dacitic rocks, implying a common parental magma. Therefore, the analyzed enclaves may be considered representative of the historic magma erupted at Nea Kameni which could be still present in the volcano plumbing system feeding the crater fumaroles. The 3He/4He ratios of enclaves, once corrected for air contamination (3.1-3.6 Ra), partially overlap those of the gases (3.5-4.0 Ra) collected from Nea and Palea Kameni. The range of 3He/4He ratios (3.1-4.0 Ra) is appreciably lower than typical arc volcanoes (R/Ra ~7-8), implying that a contamination by 4He-rich fluids occurred either directly in the mantle and/or in the plumbing system. Comparison of 3He/4He and 4He/40Ar* ratios measured in enclaves with those of gases, as well as long-term monitoring of R/Ra in the latters, coherently

  4. Introduction to "Tsunamis in the Pacific Ocean: 2011-2012"

    NASA Astrophysics Data System (ADS)

    Rabinovich, Alexander B.; Borrero, Jose C.; Fritz, Hermann M.

    2014-12-01

    With this volume of the Pure and Applied Geophysics (PAGEOPH) topical issue "Tsunamis in the Pacific Ocean: 2011-2012", we are pleased to present 21 new papers discussing tsunami events occurring in this two-year span. Owing to the profound impact resulting from the unique crossover of a natural and nuclear disaster, research into the 11 March 2011 Tohoku, Japan earthquake and tsunami continues; here we present 12 papers related to this event. Three papers report on detailed field survey results and updated analyses of the wave dynamics based on these surveys. Two papers explore the effects of the Tohoku tsunami on the coast of Russia. Three papers discuss the tsunami source mechanism, and four papers deal with tsunami hydrodynamics in the far field or over the wider Pacific basin. In addition, a series of five papers presents studies of four new tsunami and earthquake events occurring over this time period. This includes tsunamis in El Salvador, the Philippines, Japan and the west coast of British Columbia, Canada. Finally, we present four new papers on tsunami science, including discussions on tsunami event duration, tsunami wave amplitude, tsunami energy and tsunami recurrence.

  5. Open-System Magma Reservoir Affects Gas Segregation, Vesiculation, Fragmentation and Lava/Pyroclast Dispersal During the 1.2 km-deep 2007-2010 Submarine Eruption at West Mata Volcano

    NASA Astrophysics Data System (ADS)

    Rubin, K. H.; Clague, D. A.; Embley, R. W.; Hellebrand, E.; Soule, S. A.; Resing, J.

    2014-12-01

    West Mata, a small, active rear-arc volcano in the NE Lau Basin, erupts crystal and gas rich boninite magma. Eruptions were observed at the summit (1.2 km water depth) during 5 ROV Jason dives in 2009 (the deepest erupting submarine volcano observed to date). Subsequent ROV and ship-based bathymetric mapping revealed that a pit crater formed and the summit eruption ceased in 2010, with roughly simultaneous eruptions along the SW rift zone. During the summit eruption, a combination of water depth, H2O-CO2-rich and high crystallinity magma, a split in the conduit to feed two vent sites, and waxing/waning magma supply led to a range of effusive/explosive eruption styles and volcanic deposit types. The 2-3 vent Hades cluster and the lone Prometheus vent had different eruption characteristics. Petrographic, petrologic and geochemical studies of erupted products indicate a change in magma composition in time and space over a period of 3.5 yrs, suggesting a small, open-system magma reservoir within the volcano. Prometheus (1174m depth) produced mostly pyroclastic material during our observations (e.g., highly vesicular glowing fluidal ejecta that cooled in the water column and rounded recycled dense clasts), but sampling and 210Po radiometric dating show that several months prior pillowed lava flows, subsequently covered with cm-sized pyroclasts, had flowed >50m from the vent. In contrast, vents at Hades (1200m depth) cycled between lava production and vigorous degassing, 10-20m high fire fountains and bursts of glowing lava-skinned bubbles, the products of which froze/broke in the water column, forming unstable cones of spatter and scoria near the vents. We hypothesize that bubbles collapse rather than form lava balloons because of skin brittleness (from high crystal content) and hydrostatic pressure. Clast settling times and patterns suggest >100m water column rise height for 10+ cm-sized fragments. Pillow flows were also observed to be issuing from the base of the

  6. Screening for colorectal cancer in Italy: 2011-2012 survey.

    PubMed

    Zorzi, Manuel; Da Re, Filippo; Mantellini, Paola; Naldoni, Carlo; Sassoli De'Bianchi, Priscilla; Senore, Carlo; Turrin, Anna; Visioli, Carmen Beatriz; Zappa, Marco

    2015-01-01

    We present the main results of the 2011-2012 survey of the Italian screening programmes for colorectal cancer carried out by the National centre for screening monitoring (Osservatorio nazionale screening, ONS) on behalf of the Ministry of Health. By the end of 2012, 112 programmes were active, of which 11 had been activated during 2012 and 4 during 2011. The national theoretical extension increased from 66% of Italians aged 50-69 years residing in areas covered by organized screening programmes in 2010 to 73.7% in 2012. The majority of programmes employ the fecal immunochemical test (FIT), while some have adopted flexible sigmoidoscopy (FS) once in a lifetime and FIT for non-responders to FS. Overall, about 7,744,000 subjects were invited to undergo FIT, 53.1% of those to be invited within the two years. The adjusted attendance rate was 47.1%and 3,531,937 subjects were screened. Large differences in the attendance rate were observed among regions. Positivity rate of FIT programmes was 5.2% at first screening (range: 1.0-12.4%) and 4.0% at repeat screening (range: 3.4-6.4%). The average attendance rate to total colonoscopy (TC) was 81.2% and in two regions (Molise and Campania) it was lower than 70%. Completion rate for total colonoscopy (TC) was 91%. Among the 1,316,327 subjects attending screening for the first time, the detection rate (DR) per 1,000 screened subjects was 2.0 for invasive cancer and 9.1 ‰ for advanced adenomas (AA, adenomas with a diameter ≥1 cm, with villous/tubulo-villous type or high-grade dysplasia). As expected, the corresponding figures in the 2,215,610 subjects at repeat screening were lower (1.0‰ and 6.8‰ for invasive cancer and AA, respectively). Many programmes reported some difficulties in guaranteeing TC in the appropriate time frame to FIT+ subjects: in 15% of cases the waiting time was longer than two months. Ten programmes in 2011 and eight in 2012 employed FS as the screening test: 24,549 subjects were screened in the two

  7. Active submarine volcano sampled

    USGS Publications Warehouse

    Taylor, B.

    1983-01-01

    On June 4, 1982, two full dredge hauls of fresh lava were recovered from the upper flanks of Kavachi submarine volcano, Solomon Islands, in the western Pacific Ocean, from the water depths of 1,200 and 2,700 feet. the shallower dredge site was within 0.5 mile of the active submarine vent shown at the surface by an area of slick water, probably caused by gas emissions. Kavachi is a composite stratovolcano that has been observed to erupt every year or two for at least the last 30 years (see photographs). An island formed in 1952, 1961, 1965, and 1978; but, in each case, it rapidly eroded below sea level. The latest eruption was observed by Solair pilots during the several weeks up to and including May 18, 1982. 

  8. Estimated CO2, SO2 and H2S emission to the atmosphere from the 2011 El Hierro submarine eruption (Canary Islands) on the basis of helicopter gas surveys

    NASA Astrophysics Data System (ADS)

    Barrancos, J.; Padilla, G.; Padrón, E.; Hernández, P. A.; Calvo, D.; Marquez, A.; Pérez, N. M.; Melian, G.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Hernández, I.

    2012-04-01

    An accurate estimation of SO2 emission rates is an important issue to elucidate the activity of volcanoes, moreover the monitoring of its temporal evolution might help to predict a possible eruption and thus, save the loss of human's lives in cities nearby volcanoes. In the lasts years new instruments have been developed and improved, in order to be more portable, cheaper and lighter. The miniDOAS consist of a small spectrometer with a lens for collecting scattered UV light, and are controlled/powered via USB with a laptop. Recently, new technical developments have allowed monitoring the emission of other gas species such as CO2, H2S, etc from volcanic plumes by means of portable multisensor system. With both devices we were able to evaluate the SO2 emission rates and the molar ratios of major volcanic gas components, respectively. Multiplying the observed SO2 emission rate times the observed (gas)i/SO2 mass ratios (CO2/SO2 and H2S/SO2) allowed us to estimate other volatiles emission rates. Between November 11, 2011, and January 16, 2012, and as a consequence of the submarine volcanic eruption started on October 10, 2011, south off shore El Hierro, Canary Islands, a regularly monitoring of the volcanic plume from the submarine volcano has been performed with remote sensors, always depending of helicopter availability. The instruments are mounted aboard on a helicopter belonged to the Helicopter Unit of Spanish Civil Guard. The SO2 flux measured during this period showed a maximum SO2 emission of 109 ± 19 t/d on November 6, just two days before the occurrence of a intense bubbling at the sea surface on November 8, producing a water, gas and ash column of about 15 meters over the sea surface. That day, CO2 and H2S emission also reached the maximum measured, with 5400 t/d and 3.6 t/d, respectively. Since then, SO2, CO2 and H2S emission rates have declined to values close to detection limit (~ 2 t/d for SO2). These results report the first SO2 emission rates measured

  9. The volcanic debris avalanche on the SE submarine slope of Nisyros volcano, Greece: geophysical exploration and implications for subaerial eruption history

    NASA Astrophysics Data System (ADS)

    Livanos, Isidoros; Nomikou, Paraskevi; Papanikolaou, Dimitris; Rousakis, Grigoris

    2013-12-01

    A spectacular hummocky topography was discovered offshore of the south-eastern slope of the Nisyros island volcano in the eastern sector of the Aegean volcanic arc in 2000-2001, using multibeam bathymetric mapping and seismic profiling, and interpreted as part of a volcanic debris avalanche originating onland. During E/V Nautilus cruise NA011 in 2010, a detailed side-scan sonar and ROV exploration aimed at evaluating the surface morphology of this avalanche field. Combining the new data with selected older datasets reveals that the debris avalanche is characterized by numerous (at least 78) variously sized and shaped hummocks. Some of these are distinctly round, either scattered or aligned in groups, whereas others are elongated in the form of ridges. This is consistent with existing models accounting for variations in the longitudinal and lateral velocity ratio of landslides. Maximum dimensions reach 60 m in height above the sea bottom, 220 m in length and 230 m in width. The structures outline a large tongue-shaped, submarine hummock field of about 22.2 km2, approx. 4.8 km wide and 4.6 km long and with an estimated volume of 0.277 km3. Due to its characteristic shape, the collapsed volcanic flank is interpreted to represent a singular failing event, involving a rapid and virtually instantaneous downslope movement of the slide mass into the sea. Indeed, the H/L (height of 280 m vs. run-out of 7 km) ratio for the Nisyros slide is 0.04; plotted against volume, this falls within the theoretical bounds as well as measured values typical of submarine landslides. The timing of the event is probably related to the extrusion of Nikia lavas and their subsequent failure and formation of a main scarp observed at about 120 m depth on an 8-km-long seismic profile and a map of slope angle distribution, at the depth where the palaeo-coastline was located 40 ka ago. An inferred age of ca. 40 ka for the avalanche awaits confirmation based on dating of core material.

  10. White submarine

    NASA Astrophysics Data System (ADS)

    While not everyone gets to live in a yellow submarine, the scientific community may get to have a decommissioned U.S. Navy nuclear submarine dedicated to it. The Sturgeon class of submarines, which scientists say are the ideal choice for the project, will be coming up for decommissioning in this next decade. So the time is ripe, scientists say. Two weeks ago, oceanographers, submarine specialists, marine biologists, and geophysicists, among others met at AGU headquarters in Washington to discuss how to get the project in the water. If all goes well, the project would be the "biggest thing that ever happened in ocean and Earth science," according to Lloyd Keigwin of the Woods Hole Oceanographic Institution, who convened the meeting. For example, the submarine could make many types of "compelling" research possible that can not be done now by other means, such as studies in the Arctic that may have significant bearing on global change research, Keigwin says. However, the imposing hurdles that the project must overcome are as big as the opportunities it offers. Foremost, there is a question as to who will pick up the tab for such an endeavor.

  11. The USDA Food and Nutrient Database for Dietary Studies, 2011-2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA Food and Nutrient Database for Dietary Studies (FNDDS) 2011-2012 is used to code foods/beverages and portion sizes and to calculate nutrients for national food surveys. This version of the FNDDS was used to process dietary intakes from What We Eat in America (WWIEA), the dietary intake com...

  12. What We Eat in America, NHANES 2011-2012: Documentation and Data Files

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New nationwide dietary intake data were collected in What We Eat in America (WWEIA), National Health and Nutrition Examination Survey (NHANES) for the years 2011-2012 and are now available for public use. Two days of dietary intake data are included for most participants. The dietary interview dat...

  13. 2011-2012 Federal Pell Grant Program End-of-Year Report

    ERIC Educational Resources Information Center

    Office of Postsecondary Education, US Department of Education, 2012

    2012-01-01

    The Federal Pell Grant End-of-Year Report presents primary aspects of Federal Pell Grant Program activity for the 2011-2012 award year. This presentation is a compilation of quantitative program data assembled to offer insights into the changes to the Title IV applicant universe and the Federal Pell Grant Program. The Federal Pell Grant…

  14. Alaska's Public Schools: 2011-2012 Report Card to the Public

    ERIC Educational Resources Information Center

    Alaska Department of Education & Early Development, 2012

    2012-01-01

    This "Report Card to the Public" is published in accordance with Alaska Statute 14.03.120 for the school year 2011-2012. Under state law, each school district is required to report information about its plans and performance to its community. This report includes a statewide summary of performance results. It reports the status of public…

  15. Outbreaks of Illness Associated with Recreational Water-United States, 2011-2012

    EPA Science Inventory

    Outbreaks of illness associated with recreational water use result from exposure to chemicals or infectious pathogens in recreational water venues that are treated (e.g., pools and hot tubs or spas) or untreated (e.g., lakes and oceans). For 2011-2012, the most recent years for w...

  16. Measuring School and Teacher Value Added in DC, 2011-2012 School Year: Final Report

    ERIC Educational Resources Information Center

    Isenberg, Eric; Hock, Heinrich

    2012-01-01

    This report describes the value-added models used as part of teacher evaluation systems in the District of Columbia Public Schools (DCPS) and in eligible DC charter schools participating in "Race to the Top." The authors estimated: (1) teacher effectiveness in DCPS and eligible DC charter schools during the 2011-2012 school year; and (2)…

  17. Measuring School and Teacher Value Added in DC, 2011-2012 School Year. Final Report

    ERIC Educational Resources Information Center

    Isenberg, Eric; Hock, Heinrich

    2012-01-01

    In this report, the authors describe the value-added models used as part of teacher evaluation systems in the District of Columbia Public Schools (DCPS) and in eligible DC charter schools participating in Race to the Top. They estimated (1) teacher effectiveness in DCPS and eligible DC charter schools during the 2011-2012 school year; and (2)…

  18. 2011-2012 Overview of M-DCPS' Academic Performance. Information Capsule. Volume 1203

    ERIC Educational Resources Information Center

    Blazer, Christie

    2012-01-01

    This Information Capsule answers the most frequently asked questions about M-DCPS' academic performance during the 2011-2012 school year. Over the past year, the Florida Department of Education made over 28 changes to the school grading formula, including the transition to new, more rigorous assessments, new accountability components, and…

  19. 76 FR 59304 - 2011-2012 Refuge-Specific Hunting and Sport Fishing Regulations; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... Register on September 9, 2011 (76 FR 56054), to finalize our yearly updates to the Code of Federal... paragraph should have been removed. PART 32-- Accordingly, in FR Doc. 2011-22752 appearing on page 56064 in... Fish and Wildlife Service 50 CFR Part 32 RIN 1018-AX54 2011-2012 Refuge-Specific Hunting and...

  20. 76 FR 39185 - 2011-2012 Refuge-Specific Hunting and Sport Fishing Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-05

    ... Refuge-Specific Hunting and Sport Fishing Regulations; Proposed Rule #0;#0;Federal Register / Vol. 76... Service 50 CFR Part 32 RIN 1018-AX54 2011-2012 Refuge-Specific Hunting and Sport Fishing Regulations... Service proposes to add one refuge to the list of areas open for hunting and/or sport fishing and...

  1. The submarine record of a large-scale explosive eruption in the Vanuatu Arc: ˜1 Ma Efaté Pumice Formation

    NASA Astrophysics Data System (ADS)

    Raos, Alison M.; McPhie, Jocelyn

    The Efaté Pumice Formation (EPF) is the record of a major explosive eruption that occurred in the Vanuatu arc, southwestern Pacific, at about 1 Ma. The EPF is the oldest stratigraphic unit of the Efaté Island Group and consists of a succession of non-welded, trachydacitic pumice breccia and shard-rich sand and silt beds with a minimum thickness of ˜500 m and a minimum bulk volume of approximately 85 km3. The lower part (Efaté Pumice Breccias) of the EPF comprises very thick beds composed almost exclusively of glassy, trachydacitic, pumice fragments with ragged terminations. In contrast, the upper part (Rentabau Tuffs) consists of up to 70 m of well-bedded and well-sorted shard-rich sand and silt. The clast population of this upper part comprises >95% glassy or formerly glassy shards, but fossil foraminifera are a ubiquitous and important non-volcanic component. Some glass shards have blocky, equant shapes and arcuate fracture surfaces, features typically associated with the influence of external water during fragmentation, but most are cuspate and platy bubble-wall shards. Pyroclast morphologies indicate that the Efaté Pumice Breccias were largely generated by magmatic-volatile-driven ("dry"), explosive fragmentation processes, and lithofacies characteristics indicate deposition in below-storm-wave-base environments, from eruption-sourced, water-supported density currents of waterlogged pumice. The Rentabau Tuffs are interpreted to represent a change to hydromagmatic activity in response to waning discharge that allowed ingress of water (presumably seawater) to the vent(s).

  2. Is Efate (Vanuatu, SW Pacific) a result of subaerial or submarine eruption? An alternative model for the 1 Ma Efate Pumice Formation

    NASA Astrophysics Data System (ADS)

    Stewart, Robert; Németh, Karoly; Cronin, Shane

    2010-09-01

    The Efate Pumice Formation (EPF) is a trachydacitic volcaniclastic succession widespread in the central part of Efate Island and also present on Hat and Lelepa islands to the north. The volcanic succession has been inferred to result from a major, entirely subaqueous explosive event north of Efate Island. The accumulated pumice-rich units were previously interpreted to be subaqueous pyroclastic density current deposits on the basis of their bedding, componentry and stratigraphic characteristics. Here we suggest an alternative eruptive scenario for this widespread succession. The major part of the EPF is distributed in central Efate, where pumiceous pyroclastic rock units several hundred meters thick are found within fault scarp cliffs elevated about 800 m above sea level. The basal 200 m of the pumiceous succession is composed of massive to weakly bedded pumiceous lapilli units, each 2-3 m thick. This succession is interbedded with wavy, undulatory and dune bedded pumiceous ash and fine lapilli units with characteristics of co-ignimbrite surges and ground surges. The presence of the surge beds implies that the intervening units comprise a subaerial ignimbrite-dominated succession. There are no sedimentary indicators in the basal units examined that are consistent with water-supported transportation and/or deposition. The subaerial ignimbrite sequence of the EPF is overlain by a shallow marine volcaniclastic Rentanbau Tuffs. The EPF is topped by reef limestone, which presumably preserved the underlying EPF from erosion. We here propose that the EPF was formed by a combination of initial subaerial ignimbrite-forming eruptions, followed by caldera subsidence. The upper volcaniclastic successions in our model represent intra-caldera pumiceous volcaniclastic deposits accumulated in a shallow marine environment in the resultant caldera. The present day elevated position of the succession is a result of a combination of possible caldera resurgence and ongoing arc

  3. Voluminous submarine lava flows from Hawaiian volcanoes

    SciTech Connect

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

    1988-05-01

    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.

  4. Deposition of the 2011-2012 Cordón Caulle tephra (Chile, 40°S) in lake sediments: Implications for tephrochronology and volcanology

    NASA Astrophysics Data System (ADS)

    Bertrand, Sébastien; Daga, Romina; Bedert, Robin; Fontijn, Karen

    2014-12-01

    Tephras preserved in lake sediments are commonly used to synchronize sedimentary archives of climate and environmental change and to correlate them with terrestrial environments. They also provide opportunities to reconstruct volcanic explosive activity, e.g., eruption frequency and tephra dispersal. Although sedimentary processes may affect the record of tephras in lakes, lake sediments are generally considered as one of the best archives of tephra stratigraphy. The 2011-2012 eruption of Cordón Caulle volcano (Chile, 40°S) offered an ideal opportunity to study the processes affecting tephra deposition in lakes. Although the prevailing westerlies transported the erupted pyroclastic material away from nearby Puyehue Lake, the tephra was identified within this relatively large lake with a thickness ranging from 1 to >10 cm. This is in contrast with smaller lakes, where tephra thickness was in agreement with ashfall distribution maps. Geomorphological observations and sedimentological analyses provide evidence that the tephra deposited in Puyehue Lake entirely consists of material reworked from the upper watershed, transported by rivers, and distributed by lake currents according to particle size and density. Our results have important implications for tephrochronology and volcanology. They suggest that (1) lakes do not act as passive tephra traps; (2) lakes with large watersheds record more eruptions than smaller lakes, which only register direct ashfalls, affecting conclusions regarding the recurrence of volcanic eruptions; and (3) using lakes with large watersheds for isopach mapping systematically leads to an overestimation of erupted tephra volumes. Smaller lakes with limited drainage basins are generally better suited for volcanological studies.

  5. 76 FR 63563 - Snapper-Grouper Fishery of the South Atlantic; Closure of the 2011-2012 Recreational Sector for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... FR 82280, December 30, 2010), set the recreational ACL for black sea bass in the South Atlantic EEZ... recreational ACL beginning October 4, 2011, for the 2011-2012 fishing year (76 FR 61285) due to an ACL overage... the South Atlantic; Closure of the 2011-2012 Recreational Sector for Black Sea Bass in the...

  6. Volcanic Unrest of Fogo Volcano in 2011-2012, S.Miguel Island, Azores, Observed by Continuous and Campaign GPS Analysis

    NASA Astrophysics Data System (ADS)

    Okada, Jun; Sigmundsson, Freysteinn; Ofeigsson, Benedikt; Ferreira, Teresa; Gaspar, Joao; Lorenzo, Maria; Araujo, Joao; Rodriques, Rita

    2014-05-01

    Volcanic eruptions can occur after long time of dormancy as has been seen from the recent examples: Mount St. Helens 1980, Pinatubo 1991, Unzen 1991, Soufrière Hills volcano 1995, Chaitén 2008, and Eyjafjallajökull 2010. By utilizing space geodesy techniques, namely GNSS and InSAR, it has been reported that the inflation-deflation processes exist at several dormant volcanoes in the world, but the mechanism responsible for this phenomena is still controversial. Fundamental questions such as magma vs. hydrothermal fluids and volcanic vs. tectonic process remain unanswered in many cases. In this study, we analyze both continuous and campaign GPS data from Fogo volcano, S. Miguel Island, Azores. Although no geochemical and hydrothermal evidences for a magmatic intrusion were reported during the past seismic swarm episodes (1989, 2003-2006, and 2011-2012), geophysical data, both seismic and ground deformation, indicate possible volcanic sources. GPS time series spanned 2008-2013 period characterize tectonic plate divergence between Eurasian and Nubian, and reveal two different types of ground deformation associated with the 2011-2012 volcanic unrest of Fogo. One is the permanent edifice-scale inflation centered at NE summit which corresponds to the increase of volcano-tectonic events. Another is the subsequent minor-scale inflation-deflation reversals between Congro, a trachyte maar, east of Fogo and Furnas volcano. Calculated strain rates and GPS campaign results indicate that the 2011-2012 deformation is one order smaller than the previous unrest episode. A strong similarity exists to Matsushiro earthquake swarm (1965-1966) and Campi Flegrei volcanic unrests (1969-1972 and 1982-1984), which is the coexistence of an edifice-scale main inflation associated with intense volcano-tectonic earthquakes with inflation to deflation reversal that coincided with a sharp drop of seismicity. High recovery rate of inflation-deflation may be an indicator for the existence of

  7. New mafic magma refilling a quiescent volcano: Evidence from He-Ne-Ar isotopes during the 2011-2012 unrest at Santorini, Greece

    NASA Astrophysics Data System (ADS)

    Rizzo, A. L.; Barberi, F.; Carapezza, M. L.; Di Piazza, A.; Francalanci, L.; Sortino, F.; D'Alessandro, W.

    2015-03-01

    In 2011-2012, Santorini was characterized by seismic-geodetic-geochemical unrest, which was unprecedented since the most-recent eruption occurred in 1950 and led to fear an eruption was imminent. This unrest offered a chance for investigating the processes leading to volcanic reactivation and the compositional characteristics of involved magma. We have thus analyzed the He-Ne-Ar-isotope composition of fluid inclusions in olivines and clinopyroxenes from cumulate mafic enclaves hosted in cogenetic dacitic lavas of the 1570-1573 and 1925-1928 eruptions of Nea Kameni. These unique data on Aegean volcanism were compared with those of gases collected in quiescent periods and during the unrest. The 3He/4He ratios (3.1-4.0 Ra) are significantly lower than the typical arc-volcano values (R/Ra ˜ 7-8), suggesting the occurrence of magma contamination in Santorini plumbing system, which would further modify the 3He/4He ratio of parental magmas generated in the local metasomatized mantle. The 3He/4He values of enclaves (3.1-3.6 Ra) are comparable to those measured in gases during quiescent periods, confirming that enclaves reflect the He-isotope signature of magma residing at shallow depths and feeding passive degassing. A significant increase in soil CO2 flux from Nea Kameni and anomalous compositional variations in the fumaroles were identified during the unrest, accordingly with previous studies. Simultaneously, 3He/4He ratios up to 4.0 Ra were also measured, demonstrating that the unrest was due to the intrusion into the shallow plumbing system of a more-primitive 3He-rich magma, which is even volatile richer and less contaminated than mafic magma erupted as enclaves. This new intrusion did not however trigger an eruption.

  8. [The ARI etiology among children in Belarus in 2011-2012].

    PubMed

    Gribkova, N V; Sivets, N V; Shmialiova, N P; Cheshenok, T V; Lapo, E P; Anoshka, O N

    2015-01-01

    The seasonal distribution of the respiratory viruses for the period of 2011-2012 is presented. The ARI etiological structure among children 0-17 years, who were admitted to the hospital for respiratory disease in Belarus, was defined by the PCR-method. It was found that the etiological agents of the infections were not only influenza viruses A and B, parainfluenza types 1-4, adeno- and respiratory syncytial viruses, but also described boca- and metapneumoviruses. The most complete spectrum of the respiratory viruses was detected among children aged 0-4 years. PMID:26281305

  9. National Bioenergy Center, Biochemical Platform Integration Project: Quarterly Update, Winter 2011-2012 (Newsletter)

    SciTech Connect

    Not Available

    2012-04-01

    Winter 2011-2012 issue of the National Bioenergy Center Biochemical Platform Integration Project quarterly update. Issue topics: 34th Symposium on Biotechnology for Fuels and Chemicals; feasibility of NIR spectroscopy-based rapid feedstock reactive screening; demonstrating integrated pilot-scale biomass conversion. The Biochemical Process Integration Task focuses on integrating the processing steps in enzyme-based lignocellulose conversion technology. This project supports the U.S. Department of Energy's efforts to foster development, demonstration, and deployment of 'biochemical platform' biorefineries that economically produce ethanol or other fuels, as well as commodity sugars and a variety of other chemical products, from renewable lignocellulosic biomass.

  10. Sun Corona Electron Densities Derived from VLBI Sessions in 2011/2012

    NASA Astrophysics Data System (ADS)

    Soja, B.; Sun, J.; Heinkelmann, R.; Schuh, H.; Böhm, J.

    2013-08-01

    Twelve IVS R&D sessions in 2011/2012 primarily aimed to increase the sensitivity of VLBI to relativistic phenomena by including observations closer than 15 degrees to the heliocenter. These observations are also affected by the plasma of the Sun corona, a dispersive medium which is the target of our research presented here. Starting with the ionospheric delay corrections derived from two-frequency VLBI measurements, Sun corona electron densities were estimated together with other dispersive effects like instrumental biases and the Earth ionosphere. The results for the R&D sessions were analysed and compared with external information like Sunspot numbers and solar flux indices. The estimated electron densities show good agreement with previous models of the Sun corona obtained by various spacecraft missions.

  11. Stress and mass changes during the 2011-2012 unrest at Kawah Ijen volcano, East Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Caudron, C.; Lecocq, T.; Syahbana, D.; Camelbeeck, T.; Bernard, A. M.; Surono, S.

    2013-12-01

    Kawah Ijen volcano (East Java, Indonesia) has been equipped since June 2010 with 3 broadband seismometers, temporary and permanent short-period seismometers. While the volcano did not experience any magmatic eruption for more than a century, several types of unrests occurred during the last years. Apart from the seismometers, temperature and leveling divers have been immerged in the extremely acidic volcanic lake (pH ~ 0). While finding instruments capable of resisting in such extreme conditions has been particularly challenging, the coupling of lake monitoring techniques with seismic data improves the understanding and monitoring of the volcanic-hydrothermal system. To detect small velocity changes, the approach developed by Brenguier et al. (2008) and Clarke et al. (2011) has been implemented to monitor Ijen volcano. First, the influence of several parameters detrimental to the recovering of the cross correlation function will be discussed (i.e.: different types of seismometers and their azimuthal distribution, presence of volcanic tremor in different frequency bands). At Kawah Ijen, the frequency band that is less affected by the volcanic tremor and the seasonal fluctuations at the source ranges between 0.5-1.0 Hz. Moreover, a stack of 5 days for the current CCF gives reliable results with low errors and allows to detect fluctuations which are missed using a 10-day stack. We will then present the results of this technique compared to other seismic parameters (e.g.: seismo volcanic events spectral analysis) and temporal changes in lake temperature, color or lake levels that occurred during 2011-2012 crises that were the strongest ever recorded by the seismic monitoring network. An unrest commenced in October 2011 with heightened VT (Volcano Tectonic) earthquakes and low frequency events activity, which culminated mid-December 2011. This unrest was correlated with an enhanced heat and hydrothermal fluids discharge to the crater and significant variations of the

  12. Submarine volcanic features west of Kealakekua Bay, Hawaii

    USGS Publications Warehouse

    Fornari, D.J.; Lockwood, J.P.; Lipman, P.W.; Rawson, M.; Malahoff, A.

    1980-01-01

    Visual observations of submarine volcanic vents were made from the submersible vehicle DSV "Sea Cliff" in water depths between 1310 and 690 m, west of Kealakekua Bay, Hawaii. Glass-rich, shelly submarine lavas surround circular 1- to 3-m-diameter volcanic vents between 1050 and 690 m depth in an area west-northwest of the southernpoint (Keei Pt.) of Kealakekua Bay. Eye-witness accounts indicate that this area was the site of a submarine eruption on February 24, 1877. Chemical analyses of lavas from these possible seafloor vent areas indicate that the eruptive products are very similar in composition to volcanic rocks produced by historic eruptions of Mauna Loa volcano. ?? 1980.

  13. Power Outages, Extreme Events and Health: a Systematic Review of the Literature from 2011-2012

    PubMed Central

    Klinger, Chaamala; Landeg, Owen; Murray, Virginia

    2014-01-01

    Background Extreme events (e.g. flooding) threaten critical infrastructure including power supplies. Many interlinked systems in the modern world depend on a reliable power supply to function effectively. The health sector is no exception, but the impact of power outages on health is poorly understood. Greater understanding is essential so that adverse health impacts can be prevented and/or mitigated. Methods We searched Medline, CINAHL and Scopus for papers about the health impacts of power outages during extreme events published in 2011-2012. A thematic analysis was undertaken on the extracted information. The Public Health England Extreme Events Bulletins between 01/01/2013 - 31/03/2013 were used to identify extreme events that led to power outages during this three-month period. Results We identified 20 relevant articles. Power outages were found to impact health at many levels within diverse settings. Recurrent themes included the difficulties of accessing healthcare, maintaining frontline services and the challenges of community healthcare. We identified 52 power outages in 19 countries that were the direct consequence of extreme events during the first three months of 2013. Conclusions To our knowledge, this is the first review of the health impacts of power outages. We found the current evidence and knowledge base to be poor. With scientific consensus predicting an increase in the frequency and magnitude of extreme events due to climate change, the gaps in knowledge need to be addressed in order to mitigate the impact of power outages on global health. PMID:24459613

  14. Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water - United States, 2011-2012.

    PubMed

    Beer, Karlyn D; Gargano, Julia W; Roberts, Virginia A; Hill, Vincent R; Garrison, Laurel E; Kutty, Preeta K; Hilborn, Elizabeth D; Wade, Timothy J; Fullerton, Kathleen E; Yoder, Jonathan S

    2015-08-14

    Advances in water management and sanitation have substantially reduced waterborne disease in the United States, although outbreaks continue to occur. Public health agencies in the U.S. states and territories* report information on waterborne disease outbreaks to the CDC Waterborne Disease and Outbreak Surveillance System (http://www.cdc.gov/healthywater/surveillance/index.html). For 2011-2012, 32 drinking water-associated outbreaks were reported, accounting for at least 431 cases of illness, 102 hospitalizations, and 14 deaths. Legionella was responsible for 66% of outbreaks and 26% of illnesses, and viruses and non-Legionella bacteria together accounted for 16% of outbreaks and 53% of illnesses. The two most commonly identified deficiencies† leading to drinking water-associated outbreaks were Legionella in building plumbing§ systems (66%) and untreated groundwater (13%). Continued vigilance by public health, regulatory, and industry professionals to identify and correct deficiencies associated with building plumbing systems and groundwater systems could prevent most reported outbreaks and illnesses associated with drinking water systems. PMID:26270059

  15. The diffusion of screening programmes in Italy, years 2011-2012.

    PubMed

    Zappa, Marco; Carozzi, Francesca Maria; Giordano, Livia; Sassatelli, Romano; Federici, Antonio; Zorzi, Manuel; Federici, Antonio

    2015-01-01

    In this report, we present the results of cancer screening programmes in Italy for the years 2011-2012. This report is produced by the National centre for screening monitoring (ONS), together with the Italian professional multidisciplinary screening groups: GISMa (Italian group for mammographic screening), GISCor (Italian group for colorectal screening), and GISCi (Italian group for cervical screening). Since 2004, ONS has been monitoring and supporting Italian screening programmes, in accordance with a decree issued by the Ministry of Health. Multidisciplinary groups work with ONS and provide the know-how required to promote the quality of public health programmes. The following is a brief outline of the Italian screening programme setting: screening programmes (cervical, mammographic, colorectal) have been a Basic Healthcare Parameter (livello essenziale di assistenza, LEA) since 2001; guidelines are provided by the Ministry of Health's Department of Prevention in agreement with regional governments; regional governments are responsible for the organization, management, and quality assurance of screening programmes; since 2004, ONS has been responsible for monitoring and promoting screening programmes nationwide; the results of the screening programmes of each region are evaluated annually by the Ministry of Health in terms of coverage and impact. PMID:26405771

  16. Physical and chemical properties of submarine basaltic rocks from the submarine flanks of the Hawaiian Islands

    USGS Publications Warehouse

    Yokose, H.; Lipman, P.W.; Kanamatsu, T.

    2005-01-01

    To evaluate physical and chemical diversity in submarine basaltic rocks, approximately 280 deep submarine samples recovered by submersibles from the underwater flanks of the Hawaiian Islands were analyzed and compared. Based on observations from the submersibles and hand specimens, these samples were classified into three main occurrence types (lavas, coarse-grained volcaniclastic rocks, and fine-grained sediments), each with several subtypes. The whole-rock sulfur content and porosity in submarine basaltic rocks, recovered from depths greater than 2000 m, range from < 10 ppm and 2 vol.% to 2200 ppm and 47 vol.%, respectively. These wide variations cannot be due just to different ambient pressures at the collection depths, as inferred previously for submarine erupted lavas. The physical and chemical properties of the recovered samples, especially a combination of three whole-rock parameters (Fe-oxidation state, Sulfur content, and Porosity), are closely related to the occurrence type. The FSP triangular diagram is a valuable indicator of the source location of basaltic fragments deposited in deep submarine areas. This diagram can be applied to basaltic rocks such as clasts in debris-flow deposits, submarine-emplaced lava flows that may have crossed the shoreline, and slightly altered geological samples. ?? 2005 Elsevier B.V. All rights reserved.

  17. Depth of origin of magma in eruptions.

    PubMed

    Becerril, Laura; Galindo, Ines; Gudmundsson, Agust; Morales, Jose Maria

    2013-01-01

    Many volcanic hazard factors--such as the likelihood and duration of an eruption, the eruption style, and the probability of its triggering large landslides or caldera collapses--relate to the depth of the magma source. Yet, the magma source depths are commonly poorly known, even in frequently erupting volcanoes such as Hekla in Iceland and Etna in Italy. Here we show how the length-thickness ratios of feeder dykes can be used to estimate the depth to the source magma chamber. Using this method, accurately measured volcanic fissures/feeder-dykes in El Hierro (Canary Islands) indicate a source depth of 11-15 km, which coincides with the main cloud of earthquake foci surrounding the magma chamber associated with the 2011-2012 eruption of El Hierro. The method can be used on widely available GPS and InSAR data to calculate the depths to the source magma chambers of active volcanoes worldwide. PMID:24067336

  18. Academic Majors and Subject-Area Certifications of Health Education Teachers in the United States, 2011-2012

    ERIC Educational Resources Information Center

    Cardina, Catherine

    2014-01-01

    Purpose: The purpose of this study was to identify academic preparation and subject-area certifications of K-12 public school staff teaching at least one health education class during 2011-2012 academic year. In general, teachers who are well qualified to teach a subject area are more likely to positively affect student achievement. Methods: Data…

  19. 77 FR 34973 - Announcement of Funding Awards for HUD's Fiscal Year 2011-2012 Technical Assistance and Capacity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ... 14, 2012 (FR-5600-N-32) and closed on March 15, 2012. The NOFA allowed up to $61 million for OneCPD... URBAN DEVELOPMENT Announcement of Funding Awards for HUD's Fiscal Year 2011-2012 Technical Assistance...: Office of the Assistant Secretary for Community Planning and Development, HUD. ACTION: Announcement...

  20. Implementation of the Master Plan for Statewide Professional Staff Development for 2011-2012: An Evaluation Study

    ERIC Educational Resources Information Center

    Hammer, Patricia Cahape

    2012-01-01

    This evaluation study examined the formation and implementation of the West Virginia Board of Education's Master Plan for Professional Staff Development for 2011-2012 (PD Master Plan). The performance of PD providers included in the PD Master Plan: Marshall University, all eight regional education service agencies (RESAs), the WV Center for…

  1. 78 FR 65758 - Receipt of Petition for Decision That Nonconforming 2011-2012 BMW S1000RR Motorcycles Are...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-28

    ... Order: Steel Wire Garment Hangers from the People's Republic of China, 73 FR 58111 (October 6, 2008). \\2... International Trade Administration Steel Wire Garment Hangers From the People's Republic of China: 2011-2012... antidumping duty order on steel wire garment hangers from the People's Republic of China (``PRC'') meets...

  3. Nutrient Intakes per 1000 Kilocalories: 2011-2012 What We Eat in America, NHANES Tables 41-44

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Food Surveys Research Group of the Beltsville Human Nutrition Research Center has analyzed dietary data from the What We Eat in America (WWEIA), National Health and Nutrition Examination Survey (NHANES) 2011-2012 and released 4 additional summary data tables for this latest 2-year survey release...

  4. Disparities in Adolescents' Residence in Neighborhoods Supportive of Physical Activity - United States, 2011-2012.

    PubMed

    Watson, Kathleen B; Harris, Carmen D; Carlson, Susan A; Dorn, Joan M; Fulton, Janet E

    2016-01-01

    In 2013, only 27% of adolescents in grades 9-12 met the current federal guideline for aerobic physical activity (at least 60 minutes of physical activity each day*), and sex and racial/ethnic disparities in meeting the guideline exist (1). The Community Preventive Services Task Force has recommended a range of community-level evidence-based approaches(†) to increase physical activity by improving neighborhood supports for physical activity.(§) To assess the characteristics of adolescents who live in neighborhoods that are supportive of physical activity, CDC analyzed data on U.S. children and adolescents aged 10-17 years (defined as adolescents for this report) from the 2011-2012 National Survey of Children's Health (NSCH). Overall, 65% of U.S. adolescents live in neighborhoods supportive of physical activity, defined as neighborhoods that are perceived as safe and have sidewalks or walking paths and parks, playgrounds, or recreation centers. Adolescents who were Hispanic and non-Hispanic black race/ethnicity; who lived in lower-income households, households with less educated parents, and rural areas; or who were overweight or obese were less likely to live in neighborhoods supportive of physical activity than were white adolescents and adolescents from higher income households, with a more highly educated parent, living in urban areas, and not overweight or obese. Within demographic groups, the largest disparity in the percentage of adolescents living in these neighborhoods was observed between adolescents living in households with a family income <100% of the Federal Poverty Level (FPL) (51%) and adolescents living in households with a family income ≥400% of the FPL (76%). Efforts to improve neighborhood supports, particularly in areas with a substantial percentage of low-income and minority residents, might increase physical activity among adolescents and reduce health disparities. PMID:27309671

  5. Drowsy driving and risk behaviors - 10 States and Puerto Rico, 2011-2012.

    PubMed

    Wheaton, Anne G; Shults, Ruth A; Chapman, Daniel P; Ford, Earl S; Croft, Janet B

    2014-07-01

    Findings in published reports have suggested that drowsy driving is a factor each year in as many as 7,500 fatal motor vehicle crashes (approximately 25%) in the United States. CDC previously reported that, in 2009-2010, 4.2% of adult respondents in 19 states and the District of Columbia reported having fallen asleep while driving at least once during the previous 30 days. Adults who reported usually sleeping ≤6 hours per day, snoring, or unintentionally falling asleep during the day were more likely to report falling asleep while driving compared with adults who did not report these sleep patterns. However, limited information has been published on the association between drowsy driving and other risk behaviors that might contribute to crash injuries or fatalities. Therefore, CDC analyzed responses to survey questions regarding drowsy driving among 92,102 respondents in 10 states and Puerto Rico to the 2011-2012 Behavioral Risk Factor Surveillance System (BRFSS) surveys. The results showed that 4.0% reported falling asleep while driving during the previous 30 days. In addition to known risk factors, drowsy driving was more prevalent among binge drinkers than non-binge drinkers or abstainers and also more prevalent among drivers who sometimes, seldom, or never wear seatbelts while driving or riding in a car, compared with those who always or almost always wear seatbelts. Drowsy driving did not vary significantly by self-reported smoking status. Interventions designed to reduce binge drinking and alcohol-impaired driving, to increase enforcement of seatbelt use, and to encourage adequate sleep and seeking treatment for sleep disorders might contribute to reductions in drowsy driving crashes and related injuries. PMID:24990488

  6. Impact of Schmallenberg virus on British sheep farms during the 2011/2012 lambing season.

    PubMed

    Harris, K A; Eglin, R D; Hayward, S; Milnes, A; Davies, I; Cook, A J C; Downs, S H

    2014-08-16

    British sheep farmers were invited to complete a questionnaire about the impact of Schmallenberg virus (SBV) on animal health, welfare and their own emotional wellbeing during the 2011-2012 lambing season, through Defra and Farming Industry websites, letters to farmers who had requested SBV laboratory tests and advertisement at Sheep 2012. The 494 responders included SBV confirmed (positive by RT-PCR) (n=76), SBV suspected by farmer (n=140) or SBV not suspected (n=278). Percentage of barren ewes was similar across SBV groups, however, lamb and ewe losses were higher on responder farms where SBV was confirmed or suspected. The median percentages of all lambs born (and lambs born deformed ) that died within one week of birth was 10.4 per cent (5.5 per cent), 7.0 per cent (2.9 per cent) and 5.3 per cent (0 per cent), respectively, on SBV confirmed, suspected and not suspected farms (P<0.001). Eight to 16 per cent of SBV confirmed or suspected farms reported lamb mortality of ≥40 per cent. Farmer perceived impact was greater where SBV was confirmed or suspected (P<0.001): 25 per cent reported a high impact on emotional wellbeing (4 per cent of SBV not suspected), 13 per cent reported a high impact on flock welfare and financial performance and 6 per cent were less likely to farm sheep next year because of SBV (<2 per cent in SBV not suspected). Overall, SBV impact has been large relative to reported sheep loss. PMID:24795165

  7. Population Health Considerations for Pediatric Asthma: Findings from the 2011-2012 California Health Interview Survey.

    PubMed

    Shaikh, Ulfat; Byrd, Robert S

    2016-04-01

    Childhood asthma is a prevalent and costly chronic condition. Optimal management enables secondary and tertiary prevention. The goal was to identify population health considerations for pediatric asthma in California to inform the development of quality improvement interventions. California Health Interview Survey 2011-2012 is a random-digit dial telephone survey conducted in 5 languages. It includes 44,000 households from all 58 counties in California. This study assessed factors related to symptom control and health care use in children ages 2-11 years with asthma. An estimated 492,385 (9.6%) of children in California currently have asthma. Urban and rural residents face comparable asthma disease burdens. School-age male children as well as Asian and African American children are disproportionately affected. Asthma causes significant morbidity, with poorer health status, high utilization of emergency care, and the need for daily medication use. Only 38% of children with asthma have a recent asthma management plan. Half of all children with asthma did not receive influenza immunization in the past year, although this reflects the overall low rate of influenza vaccination. Parents of children with asthma frequently utilize the Internet for health information and communication with their child's health care provider. Children with asthma in California face several population-level challenges, including poor health status, low influenza vaccination rates, high use of emergency care, and suboptimal use of health literacy tools. Focusing on improved care coordination and preventive care for high-risk groups is especially urgent given the expansion of public health insurance and impending shortages in the primary care workforce. (Population Health Management 2016;19:145-151). PMID:26103063

  8. Observations and Modeling of the North West Shelf of Australia during Austral Summer 2011/2012

    NASA Astrophysics Data System (ADS)

    Book, Jeffrey; Pequignet, A.-Christine; Macdonald, Helen; Jones, Nicole; Lowe, Ryan; Ivey, Gregory; Rice, Ana; Rowley, Clark; Brinkman, Richard; Steinberg, Craig; Strutton, Peter

    2015-04-01

    During the austral summer of 2011/2012, a series of collaborations between U.S. and Australian funded projects led to the collection of a large observational and modeling dataset for the North West Shelf of Australia. These partnerships resulted in the deployment of 30 moorings at 23 different sites and 5 AUV gliders for various intervals of measurement between November 2011 and August 2012. This region is best known for its strong tidal flows and highly energetic internal tides, but lower frequency flows are also significant with the postulated Holloway Current flowing towards the southwest along the coast and providing a possible limited connecting pathway between the Indonesian Throughflow and the Leeuwin Current. Observations from ADCP current meters over this austral summer showed a weak (3-12 cm/s) mean southwestward flow, but this mean masked generally stronger low-frequency, along-shore flows that reached 25 cm/s or more in either direction, reversing at weekly or longer periods. In general currents tended to be northeastward in Nov.-Dec. and southwestward in Jan.-Apr., but reversals from these trends occurred during both periods. Bottom pressure records from the moorings indicated highly coherent bottom pressure anomaly fluctuations at all sites but also showed a reversal of the onshore/offshore pressure gradient from Nov. to Apr. Two tropical cyclones (Iggy and Lua) passed close by the North West Shelf during the observational period, and in both cases the coastal circulation towards the southwest was strengthened during the storms and then reversed towards the northeast after the storms. Other reversals occurred that were not associated with tropical cyclone dynamics. Analyses of these data and associated modeling runs are ongoing and directed towards the goal of better understanding the low-frequency dynamics of this coastal current. Additionally, understanding the physical forcing of this connecting current will be helpful for future work on the

  9. Molecular Characterization of Enterotoxin-Producing Escherichia coli Collected in 2011-2012, Russia.

    PubMed

    Kartsev, Nikolay N; Fursova, Nadezhda K; Pachkunov, Dmitry M; Bannov, Vasiliy A; Eruslanov, Boris V; Svetoch, Edward A; Dyatlov, Ivan A

    2015-01-01

    Enterotoxin-producing Escherichia coli (ETEC) are one of the main causative agents of diarrhea in children especially in developing countries and travel diarrhoea in adults. Pathogenic properties of ETEC associated with their ability to produce a heat-stable (ST) and/or heat-labile (LT) enterotoxins, as well as adhesins providing bacterial adhesion to intestinal epithelial cells. This study presents the molecular characterization of the ETEC isolates collected from the Central and Far-Eastern regions of Russia in 2011-2012. It was shown that all ETEC under study (n=18) had the heat-labile enterotoxin-coding operon elt, and had no the genes of the heat-stable enterotoxin operon est. DNA sequencing revealed two types of nucleotide exchanges in the eltB gene coding subunit B of LT in isolates collected from Cherepovets city (Central region, Russia) and Vladivostok city (Far-East region, Russia). Only one ETEC strain carried genes cfaA, cfaB, cfaC and cfaD coding adhesion factor CFA/I. Expression of LT in four ETEC isolates in the agglutination reaction was detected using a latex test-system. The isolates were assigned to serogroups O142 (n = 6), О6 (n = 4), О25 (n = 5), О26 (n = 2), and O115 (n = 1). Genotyping showed that they belonged to an earlier described sequence-type ST4 (n = 3) as well as to 11 novel sequence-types ST1043, ST1312, ST3697, ST3707, ST3708, ST3709, ST3710, ST3755, ST3756, ST3757 and ST4509. The ETEC isolates displayed different levels of antimicrobial resistance. Eight isolates were resistant to only one drug, three isolates-to two drugs, one isolate-to three drugs, two isolates-to four antibacterials, and only one isolate to each of the five, six and ten antibacterials simultaneously. Genetic determinants of the resistance to beta-lactams and other classes of antibacterials on the ETEC genomes were identified. There are blaTEM (n = 10), blaCTX-M-15 (n = 1), class 1 integron (n = 3) carrying resistance cassettes to aminoglycosides and

  10. Children's Growth and Classroom Experiences in Georgia's Pre-K Program: Findings from the 2011-2012 Evaluation Study

    ERIC Educational Resources Information Center

    Peisner-Feinberg, Ellen; Schaaf, Jennifer; LaForett, Dore

    2013-01-01

    Georgia has one of the few state-funded universal pre-kindergarten programs in the United States, with the aim of providing pre-k services to all 4-year-olds whose families want their children to participate in the program, regardless of family income level. In the 2011-2012 school year, Georgia's Pre-K Program served a total of over 94,000…

  11. Near cessation of Eighteen Degree Water renewal in the western North Atlantic in the warm winter of 2011-2012

    NASA Astrophysics Data System (ADS)

    Billheimer, Sam; Talley, Lynne D.

    2013-12-01

    The winter of 2011-2012 was a particularly weak season for the renewal of "Eighteen Degree Water" (EDW), the Subtropical Mode Water of the western North Atlantic, as demonstrated by Argo and repeat hydrography. Weak, late winter buoyancy forcing produced shallower than usual winter mixed layers throughout the subtropical gyre, failing to thoroughly ventilate the underlying mode water, and can likely be attributed to the coinciding high, positive phase of the North Atlantic Oscillation (NAO). The only region where EDW was renewed was in the far northeastern Sargasso Sea where it is understood that the Gulf Stream plays a central role in formation; no EDW formed over the large regions of the gyre where deep winter mixed layers driven by surface buoyancy loss normally create EDW. The present investigation evaluates 2011-2012 winter buoyancy content anomalies, surface buoyancy fluxes, and advection of buoyancy via the Gulf Stream and compares them with the previous seven winters that exhibited more vigorous EDW formation. The weak 2011-2012 formation did not result from increased Gulf Stream heat advection, and was also not driven by preconditioning as the buoyancy content of the region prior to the onset of winter forcing was not unusually high. Rather, the weak formation resulted from climatologically weak surface cooling late in winter. The winter of 2007-2008 also experienced particularly weak EDW formation under similar conditions, including a high NAO and weak late winter surface cooling.

  12. Decommissioning of the remediation systems at Waverly, Nebraska, in 2011-2012.

    SciTech Connect

    LaFreniere, L. M.

    2012-06-29

    the CCC/USDA characterization and remediation efforts, including the quarterly monitoring reports, is on the compact disc inside the back cover of this report. The EPA reported on the progress of the remediation systems in a series of five-year reviews (EPA 1993, 1999, 2004, 2009). These reports and other EPA documentation are also on the compact disc inside the back cover of this report, along with the Woodward-Clyde (1986, 1988a,b) documentation cited. Starting in 2006, the analytical results for groundwater (the only medium still being monitored) showed no carbon tetrachloride concentrations above the maximum contaminant level (MCL) of 5.0 g/L. Because the cleanup goals specified in the ROD (EPA 1990) had been met, the EPA removed the site from the NPL in November 2006 (Appendix A). In 2008 the National Pollutant Discharge Elimination System (NPDES) permit for the remediation system was deactivated, and a year later the EPA released its fourth and final five-year report (EPA 2009), indicating that no further action was required for the site and that the site was ready for unlimited use. In 2011-2012, the CCC/USDA decommissioned the remediation systems at Waverly. This report documents the decommission process and closure of the site.

  13. Addressing submarine geohazards through scientific drilling

    NASA Astrophysics Data System (ADS)

    Camerlenghi, A.

    2009-04-01

    Natural submarine geohazards (earthquakes, volcanic eruptions, landslides, volcanic island flank collapses) are geological phenomena originating at or below the seafloor leading to a situation of risk for off-shore and on-shore structures and the coastal population. Addressing submarine geohazards means understanding their spatial and temporal variability, the pre-conditioning factors, their triggers, and the physical processes that control their evolution. Such scientific endeavour is nowadays considered by a large sector of the international scientific community as an obligation in order to contribute to the mitigation of the potentially destructive societal effects of submarine geohazards. The study of submarine geohazards requires a multi-disciplinary scientific approach: geohazards must be studied through their geological record; active processes must be monitored; geohazard evolution must be modelled. Ultimately, the information must be used for the assessment of vulnerability, risk analysis, and development of mitigation strategies. In contrast with the terrestrial environment, the oceanic environment is rather hostile to widespread and fast application of high-resolution remote sensing techniques, accessibility for visual inspection, sampling and installation of monitoring stations. Scientific Drilling through the IODP (including the related pre site-survey investigations, sampling, logging and in situ measurements capability, and as a platform for deployment of long term observatories at the surface and down-hole) can be viewed as the centre of gravity of an international, coordinated, multi-disciplinary scientific approach to address submarine geohazards. The IODP Initial Science Plan expiring in 2013 does not address openly geohazards among the program scientific objectives. Hazards are referred to mainly in relation to earthquakes and initiatives towards the understanding of seismogenesis. Notably, the only drilling initiative presently under way is the

  14. Paint-Stirrer Submarine

    ERIC Educational Resources Information Center

    Young, Jocelyn; Hardy, Kevin

    2007-01-01

    In this article, the authors discuss a unique and challenging laboratory exercise called, the paint-stir-stick submarine, that keeps the students enthralled. The paint-stir-stick submarine fits beautifully with the National Science Education Standards Physical Science Content Standard B, and with the California state science standards for physical…

  15. Submarine cable route survey

    SciTech Connect

    Herrouin, G.; Scuiller, T.

    1995-12-31

    The growth of telecommunication market is very significant. From the beginning of the nineties, more and more the use of optical fiber submarine cables is privileged to that of satellites. These submarine telecommunication highways require accurate surveys in order to select the optimum route and determine the cable characteristics. Advanced technology tools used for these surveys are presented along with their implementation.

  16. Neither Effusive nor Explosive: Origins of Pumice Fragments in Submarine Silicic Volcanism, Kermadec Arc, SW Pacific

    NASA Astrophysics Data System (ADS)

    Rotella, M. D.; Wilson, C. J.; Wysoczanski, R. J.; Barker, S. J.; Wright, I. C.

    2010-12-01

    Pumice textures from subaerial explosive eruptions have been relatively well documented yet little is known about their submarine equivalents. The Kermadec Arc presents a unique opportunity to investigate the processes of submarine explosive volcanism, as it contains silicic volcanoes of similar age that have erupted chemically similar magmas at differing water depths. Here we present textural analysis data for clasts collected from subaerial deposits on Raoul volcano, as well as clasts from Macauley volcano (a large submarine caldera with a 3 km{2} subaerial exposure) dredged from the seafloor and collected from the subaerial exposure. Variations in vesicle texture, size and abundance in pyroclasts from these eruptives have been quantified using stereological image analysis techniques. Initial results show that pyroclasts from five eruptions of contrasting size from the subaerial Raoul volcano show little variation in bubble number density, with similar values to other published subaerial silicic volcanoes. Submarine erupted pyroclasts from Macauley volcano, however, show vast variations in textural characteristics. These pyroclasts display a strong gradient in vesicularity not observed in the subaerial realm, with vesicularity in a single clast ranging from 50 - 80 vol. % over less than 3-4 cm. Vesicle shapes range from strongly elongate at the pyroclast margins to rounded large vesicles within the pyroclast interior suggesting that they have experienced rapid quenching with ongoing degassing at their cores. The differences in the vesicle textures of pyroclasts from Macauley volcano submarine eruptives are attributed to differences in eruptive style, and the interaction of degassing magma with a large amount of water. Although pyroclast chemistry indicates that many samples from Macauley volcano were erupted in separate events of unknown size or style, these new observations support a model of eruption that is not entirely effusive or explosive but a hybrid style

  17. Examining rhyolite lava flow dynamics through photo-based 3-D reconstructions of the 2011-2012 lava flow field at Cordón Caulle, Chile.

    NASA Astrophysics Data System (ADS)

    James, M. R.; Farquharson, J.; Tuffen, H.

    2014-12-01

    The 2011-2012 eruption at Cordón-Caulle, Chile, afforded the opportunity to observe and measure active rhyolitic lava for the first time. In 2012 and 2013, ~2500 photos were acquired on foot, parallel to flow fronts on the north and north-east of the flow field. Image suites were then processed into 3-D point clouds using Structure-from-Motion Multi-view Stereo (SfM-MVS) freeware. Interpolating these clouds into digital elevation models for dates in 2012-13 enabled analysis of the changing flow field dimensions [1], from which velocity, depth and rheological parameters, e.g.viscosity, could be estimated [see Fig. 1]. Viscosities ranged from 7.5 x109 to 1.1 x1011Pa s, allowing for uncertainties in slope, surface displacement and velocity. Temperatures were modeled using a 1D finite difference method; in concert with viscosities of flow units these values compared well with published non-Arrhenian viscosity models. Derived thermodynamic and force ratios confirmed flow characteristics inferred from the image analyses. SfM-MVS represents an effective method of quantifying and displaying variation in the flow field, indicating several parallels between rhyolite emplacement and that of low-silica lavas. Initially channelised lava spread laterally and stagnated due to topography and the influence of the surface crust. Continued effusion resulted in iterative emplacement of breakout lobes, promoting lateral extension of the flow field. Insulation of the flow core by the viscous crust allowed this process to continue after effusion had ceased, creating features comparable to low-silica lavas, despite high viscosity and low effusion rates. This suggests that compound flow emplacement may be described by universal, cross-compositional models encompassing rheological differences of many orders of magnitude. Tuffen et al. 2013, Nat. Comms., 4, 2709, doi:10.1038/ncomms3709

  18. Chemical environments of submarine hydrothermal systems

    NASA Technical Reports Server (NTRS)

    Shock, Everett L.

    1992-01-01

    Perhaps because black-smoker chimneys make tremendous subjects for magazine covers, the proposal that submarine hydrothermal systems were involved in the origin of life has caused many investigators to focus on the eye-catching hydrothermal vents. In much the same way that tourists rush to watch the spectacular eruptions of Old Faithful geyser with little regard for the hydrology of the Yellowstone basin, attention is focused on the spectacular, high-temperature hydrothermal vents to the near exclusion of the enormous underlying hydrothermal systems. Nevertheless, the magnitude and complexity of geologic structures, heat flow, and hydrologic parameters which characterize the geyser basins at Yellowstone also characterize submarine hydrothermal systems. However, in the submarine systems the scale can be considerably more vast. Like Old Faithful, submarine hydrothermal vents have a spectacular quality, but they are only one fascinating aspect of enormous geologic systems operating at seafloor spreading centers throughout all of the ocean basins. A critical study of the possible role of hydrothermal processes in the origin of life should include the full spectrum of probable environments. The goals of this chapter are to synthesize diverse information about the inorganic geochemistry of submarine hydrothermal systems, assemble a description of the fundamental physical and chemical attributes of these systems, and consider the implications of high-temperature, fluid-driven processes for organic synthesis. Information about submarine hydrothermal systems comes from many directions. Measurements made directly on venting fluids provide useful, but remarkably limited, clues about processes operating at depth. The oceanic crust has been drilled to approximately 2.0 km depth providing many other pieces of information, but drilling technology has not allowed the bore holes and core samples to reach the maximum depths to which aqueous fluids circulate in oceanic crust. Such

  19. Addressing submarine geohazards through scientific drilling

    NASA Astrophysics Data System (ADS)

    Camerlenghi, A.

    2009-04-01

    Natural submarine geohazards (earthquakes, volcanic eruptions, landslides, volcanic island flank collapses) are geological phenomena originating at or below the seafloor leading to a situation of risk for off-shore and on-shore structures and the coastal population. Addressing submarine geohazards means understanding their spatial and temporal variability, the pre-conditioning factors, their triggers, and the physical processes that control their evolution. Such scientific endeavour is nowadays considered by a large sector of the international scientific community as an obligation in order to contribute to the mitigation of the potentially destructive societal effects of submarine geohazards. The study of submarine geohazards requires a multi-disciplinary scientific approach: geohazards must be studied through their geological record; active processes must be monitored; geohazard evolution must be modelled. Ultimately, the information must be used for the assessment of vulnerability, risk analysis, and development of mitigation strategies. In contrast with the terrestrial environment, the oceanic environment is rather hostile to widespread and fast application of high-resolution remote sensing techniques, accessibility for visual inspection, sampling and installation of monitoring stations. Scientific Drilling through the IODP (including the related pre site-survey investigations, sampling, logging and in situ measurements capability, and as a platform for deployment of long term observatories at the surface and down-hole) can be viewed as the centre of gravity of an international, coordinated, multi-disciplinary scientific approach to address submarine geohazards. The IODP Initial Science Plan expiring in 2013 does not address openly geohazards among the program scientific objectives. Hazards are referred to mainly in relation to earthquakes and initiatives towards the understanding of seismogenesis. Notably, the only drilling initiative presently under way is the

  20. Ten-year trends in the health of young children in California: 2003 to 2011-2012.

    PubMed

    Holtby, Sue; Zahnd, Elaine; Grant, David

    2015-05-01

    This policy brief presents 10-year trends in several key health and wellness indicators for children ages 0-5 in California. These indicators are health insurance coverage; source of medical care; dental visits; overweight-for-age; parents singing and reading to their child and going out with the child; and preschool attendance. The data are from the California Health Interview Survey (CHIS), the largest state health survey in the U.S. The survey gathers information on a range of health behaviors and health conditions, as well as on access to health care among children, adolescents, and adults in California. A number of these key indicators are compared by income and by racial/ethnic group. This policy brief covers the years 2003 to 2011-2012, a period in which public health efforts for children focused on childhood obesity and improved nutrition, access to low-cost and free dental services, and the expansion of children's health insurance programs. CHIS data show improvement in health insurance coverage and access to dental services for low-income children over the 10-year period. However, the percentage of children who were overweight for their age remained unchanged among those in households with incomes below 200 percent of the federal poverty level (FPL). In terms of measures associated with school readiness, preschool attendance dropped overall between 2003 and 2011-2012, but the proportions of parents who sang, read, and went out with their children every day increased significantly during the 10-year period. PMID:26072529

  1. A case-control study to identify risk factors for acute salmonellosis in New Zealand dairy herds, 2011-2012.

    PubMed

    Stevenson, M A; Morgan, P L; Sanhueza, J; Oakley, G E; Bateman, R S; McFADDEN, A; MacPHERSON, N; Owen, K L; Burton, L; Walsh, S; Weston, J; Marchant, R

    2016-07-01

    In late 2011 the New Zealand Ministry for Primary Industries reported an increase in confirmed laboratory diagnoses of salmonellosis in dairy herds. To identify risk factors for herd-level outbreaks of salmonellosis we conducted a case-control study of New Zealand dairy herds in 2011-2012. In a multivariable analysis, use of continuous feed troughs [adjusted odds ratio (aOR) 6·2, 95% confidence interval (CI) 2·0-20], use of pelletized magnesium supplements (aOR 10, 95% CI 3·3-33) and use of palm kernel meal as a supplementary feed (aOR 8·7, 95% CI 2·5-30) were positively associated with a herd-level outbreak of salmonellosis between 1 July 2011 and 31 January 2012. We conclude that supplementary feeds used on dairy farms (regardless of type) need to be stored and handled appropriately to reduce the likelihood of bacterial contamination, particularly from birds and rodents. Magnesium supplementation in the pelletized form played a role in triggering outbreaks of acute salmonellosis in New Zealand dairy herds in 2011-2012. PMID:26956947

  2. Potential for SGD induced submarine geohazard off southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Su, C.; Lin, C.; Cheng, Y.; Chiu, H.

    2013-12-01

    The submarine groundwater discharge (SGD) is not only play important roles on material exchange between land and sea, it may also trigger liquefaction process and induce further submarine geohazards in coastal zone. Since 2006, Southern Taiwan was experienced a series of natural hazards including earthquakes and typhoon that induced severe landslides and flooding and caused huge human lives and economics losses. These natural hazards also touched off submarine cable-break incidents off southwestern Taiwan from Gaoping Slope to the northern terminus of the Manila Trench. After the 2006 Pingtung Earthquake, the local fishermen reported disturbed waters at the Fangliao submarine canyon head. Although many researches conjectured the disturbed waters may caused by the eruption of submarine volcanoes which has been widely discovered off the southwestern Taiwan. The subbottom profiles reveal a series of faults and liquefaction strata exist near the head of Fanliao submarine canyon and acoustically transparent sediments with doming structures also observed at the adjacent area. Moreover, we also found pockmarks with acoustic blanking under it on the Gaoping Shelf and a series of gaseous pluming gushed from the seafloor was also observed in the shallow waters. Integrate all these data, we may reasonably infer the disturbed waters which reported by the fishermen may caused by the liquefaction process on the seafloor. In addition to geophysical observations, natural geochemical tracers (radon and radium) in conjunction with side-scan sonar were used to evaluate the distribution of SGD system in the study area. All the evidences indicate that the large earthquake in conjunction with high pore fluid pressures in the surface sediment might have easily triggered liquefaction process and generated large debris flow and swept the submarine cables away from the Fangliao submarine canyon head to the abyss.

  3. A Miocene submarine volcano at Low Layton, Jamaica

    NASA Technical Reports Server (NTRS)

    Wadge, G.

    1982-01-01

    A submarine fissure eruption of Upper Miocene age produced a modest volume of alkaline basalt at Low Layton, on the north coast of Jamaica. The eruption occurred in no more than a few hundred meters of water and produced a series of hyaloclastites, pillow breccias and pillow lavas, massive lavas, and dikes with an ENE en echelon structure. The volcano lies on the trend of one of the island's major E-W strike-slip fault zones; the Dunavale Fault Zone. The K-Ar age of the eruption of 9.5 plus or minus 0.5 Ma. B.P. corresponds to an extension of the Mid-Cayman Rise spreading center inferred from magnetic anomalies and bathymetry of the Cayman Trough to the north and west of Jamaica. The Low Layton eruption was part of the response of the strike-slip fault systems adjacent to this spreading center during this brief episode of tectonic readjustment.

  4. Argo float observations of basin-scale deep convection in the Irminger sea during winter 2011-2012

    NASA Astrophysics Data System (ADS)

    Piron, Anne; Thierry, Virginie; Mercier, Herlé; Caniaux, Guy

    2016-03-01

    Analysis of Argo data obtained during winter 2011-2012 revealed the presence over the Irminger Basin of an exceptionally large number of profiles (41) with mixed layer depths (MLD) exceeding 700 m, which was deep enough to reach the pool of the intermediate Labrador Sea Water located in the Irminger Sea. Four of these profiles exhibited an MLD of 1000 m, which was the maximum value observed for the winter in question. The Argo sampling in the Irminger Sea during that winter, which was 3-4 times greater than for the preceding winters, enabled the different phases of the mixed layer deepening down to 1000 m, together with their spatial extents, to be observed for the first time. Two intense convective periods occurred: in late January south of Cape Farewell and in late February-early March east of Greenland. A final deepening period was observed in mid-March, during which the deepest mixed layers were observed. This long deepening period occurred in large regional areas and was followed by a rapid restratification phase. The temporal evolution of oxygen profiles from one Argo float testifies to the local and rapid ventilation of the mixed layer by the deep convection. A mixed layer heat budget along the trajectories of the 4 floats that sampled the deepest mixed layers showed that heat loss at the air-sea interface was mainly responsible for heat content variations in the mixed layer. Greenland Tip Jets were of primary importance for the development of deep convection in the Irminger Sea in the winter of 2011-2012. They enhanced the winter heat loss and two long (more than 24 h), intense late events close together in time pushed the mixed layer deepening down to 1000 m. Net air-sea fluxes, the number of Greenland Tip Jets, the stratification of the water column, the NAO index and the Ekman-induced heat flux are pertinent indicators to assess conditions that are favorable for the development of deep convection in the Irminger Sea. By considering each of those

  5. The First-ever Detection and Tracking of a Mid-Ocean Ridge Volcanic Eruption Using the Recently Completed, NSF-Funded, Submarine Fiber-Optic Network in the Juan de Fuca Region.

    NASA Astrophysics Data System (ADS)

    Delaney, J. R.

    2015-12-01

    The most scientifically diverse and technologically advanced component of the Ocean Observatories Initiative involves 900 km of electro-optical fiber, extending from Pacific City, OR, across active portions of the JDF tectonic plate, and upward into the overlying ocean. Completed in 2014, on time and under budget, this network enables real-time, high-bandwidth, 2-way communication with seafloor/water-column sensor arrays across: 1. the Cascadia accretionary prism, 2. the JdF spreading center, and, 3. portions of the overlying NE Pacific. Oceanographic processes in coastal environments, the California Current, and 400 km offshore, are captured by six remote-controlled, profiling moorings covering full-ocean depths. In August, 2015, all sections of cable, all six operational primary nodes, all 17 junction boxes, and 97% of all 146 instruments are transmitting data ashore to the Internet via the Pacific Northwest Gigapop (http://www.pnwgp.net/). All data are archived at the U of Washington, pending completion of the OOI CyberInfrastructure System in October 2015. In 2014, community requests to access seismic and seafloor deformational information for assessment of progressive inflation at Axial Seamount (Chadwick et al, 2012), resulted in NSF releasing, through IRIS (http://www.iris.edu/hq/), real-time data from 7 seismometers and 3 pressure sensors. At a community-initiated meeting on April 20-22, 90 participants covering the spectrum of Ocean Sciences, met in Seattle to explore scientific responses in the event Axial actually erupted (http://novae.ocean.washington.edu). On April 24, Axial did erupt; seismic event counts rose dramatically to many hundreds/hour (Wilcock, AGU-2015), the Axial caldera floor dropped 2.2 m in ~20 hours (Nooner et al, AGU-2015), and water temperatures in the caldera rose slowly by ~0.7°C, then declined in 3 weeks to normal values. Unusual water-bourn acoustic signals indicated ongoing seafloor activity along the rift zone extending north

  6. A submarine perspective of the Honolulu Volcanics, Oahu

    NASA Astrophysics Data System (ADS)

    Clague, David A.; Paduan, Jennifer B.; McIntosh, William C.; Cousens, Brian L.; Davis, Alicé S.; Reynolds, Jennifer R.

    2006-03-01

    Lavas and volcaniclastic deposits were observed and collected from 4 submarine cones that are part of the Honolulu Volcanics on Oahu, Hawaii. The locations of these and a few additional, but unsampled, vents demonstrate that nearly all the vents are located on or very close to the shoreline of Oahu, with the most distal vent just 12 km offshore. The clastic samples and outcrops range from coarse breccias to cross-bedded ash deposits and show that explosive volcanism at depths between about 350 and 590 m depth played a part in forming these volcanic cones. The eruptive styles appear to be dominantly effusive to strombolian at greater depths, but apparently include violent phreatomagmatic explosive activity at the shallower sites along the submarine southwest extension of the Koko Rift. The compositions of the recovered samples are broadly similar to the strongly alkalic subaerial Honolulu Volcanics lavas, but the submarine lavas, erupted further from the Koolau caldera, have slightly more radiogenic Sr isotopic ratios, and trace element patterns that are distinct from either the subaerial Honolulu Volcanics or the submarine North Arch lavas. These patterns are characterized by moderate to strong positive Sr and P anomalies, and moderate to strong negative Cs, Rb, U, Th, Zr, and Hf anomalies. Most samples have strong negative K and moderate negative Ti anomalies, as do all subaerial Honolulu Volcanics and North Arch samples, but one group of samples from the Koko Rift lack this chemical signature. The data are consistent with more garnet in the source region for the off-shore samples than for either the on-shore Honolulu Volcanics lavas. New Ar-Ar ages show that eruptions at the submarine vents and Diamond Head occurred between about 0.5 Ma and 0.1 Ma, with the youngest ages from the Koko Rift. These ages are in general agreement with most published ages for the formation and suggest that some much younger ages reported previously from the Koko Rift are probably

  7. Examining rhyolite lava flow dynamics through photo-based 3D reconstructions of the 2011-2012 lava flowfield at Cordón-Caulle, Chile

    NASA Astrophysics Data System (ADS)

    Farquharson, J. I.; James, M. R.; Tuffen, H.

    2015-10-01

    During the 2011-2012 eruption at Cordón-Caulle, Chile, an extensive rhyolitic flowfield was created (in excess of 0.5 km3 in volume), affording a unique opportunity to characterise rhyolitic lava advance. In 2012 and 2013, we acquired approximately 2500 digital photographs of active flowfronts on the north and east of the flowfield. These images were processed into three-dimensional point clouds using structure-from-motion and multi-view stereo (SfM-MVS) freeware, from which digital elevation models were derived. Sequential elevation models-separated by intervals of three hours, six days, and one year-were used to reconstruct spatial distributions of lava velocity and depth, and estimate rheological parameters. Three-dimensional reconstructions of flowfronts indicate that lateral extension of the rubbly, 'a'ā-like flowfield was accompanied by vertical inflation, which differed both spatially and temporally as a function of the underlying topography and localised supply of lava beneath the cooled upper carapace. Compressive processes also drove the formation of extensive surface ridges across the flowfield. Continued evolution of the flowfield resulted in the development of a compound flowfield morphology fed by iterative emplacement of breakout lobes. The thermal evolution of flow units was modelled using a one-dimensional finite difference method, which indicated prolonged residence of magma above its glass transition across the flowfield. We compare the estimated apparent viscosity (1.21-4.03 × 1010 Pa s) of a breakout lobe, based on its advance rate over a known slope, with plausible lava viscosities from published non-Arrhenian temperature-viscosity models and accounting for crystallinity (~ 50 vol.%). There is an excellent correspondence between viscosity estimates when the lava temperature is taken to be magmatic, despite the breakout being located > 3 km from the vent, and advancing approximately nine months after vent effusion ceased. This indicates the

  8. Making a Submarine.

    ERIC Educational Resources Information Center

    Cornacchia, Deborah J.

    2002-01-01

    Describes Archimedes principle and why a ship sinks when it gets a hole in it. Suggests an activity for teaching the concept of density and water displacement through the construction of a simple submarine. Includes materials and procedures for this activity. (KHR)

  9. Popocatepetl Erupts

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Popocatepetl Volcano, almost 30 miles south of Mexico City, erupted yesterday (December 18, 2000) in what authorities are calling its most spectacular eruption since 800 A.D. This morning, Popocatepetl (pronounced poh-poh-kah-TEH-peh-til) continued spewing red-hot rocks as well as a column of smoke and ash about 2.5 miles high into the atmosphere. This true-color image of the volcano was acquired today by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) flying aboard the OrbView-2 satellite. In this image, Popocatepetl's plume (greyish pixels) can be seen blowing southward, away from Mexico City. There is a large cloud bank (bright white pixels) just to the east of the volcanic plume. Although Popocatepetl has been active since 1994-when it awoke from a 70-year slumber-this most recent eruption is most concerning to the greater Mexico City region's 20 million residents. The volcano demonstrated what it can do in 800 A.D. when it belched forth enough lava to fill many of the valleys in the surrounding region. Earlier, scientists warned the citizens of Mexico that there is a dome of lava at the base of the volcano that is causing pressure to build inside. They are concerned that, if it continues to build unabated, this pressure could cause even larger eruptions in the future. Image provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  10. Comparative climatological study of large-scale traveling ionospheric disturbances over North America and China in 2011-2012

    NASA Astrophysics Data System (ADS)

    Ding, Feng; Wan, Weixing; Li, Qiang; Zhang, Rui; Song, Qian; Ning, Baiqi; Liu, Libo; Zhao, Biqiang; Xiong, Bo

    2014-01-01

    This paper describes a comparative study of the climatology of large-scale traveling ionospheric disturbances (LSTIDs) over North America and China based on observations obtained in 2011-2012 using two GPS networks characterized by dense regional coverage. We identified a total of 390 LSTIDs in China and 363 events in North America. These can be categorized into three types, namely south, north, and westward propagating LSTIDs. The southward LSTIDs over North America show similar diurnal and seasonal variations to those of geomagnetic disturbances, but the southward LSTIDs over China do not show such variations. The occurrence of southward LSTIDs over China increases at ~1-2 h after the time of geomagnetic activity maximum; this increase lasts several hours until the geomagnetic minimum, which happens during the local evening. The southward LSTIDs over North America show a semiannual variation with two peaks in March and October, while the southward LSTIDs over China show a major peak in January. Northward LSTIDs occur much less frequently than their southward counterparts, and they are mainly observed in China. They mostly occur during geomagnetic activity maximum, indicating a possible relation with the degree of geomagnetic activity. Westward LSTIDs are seen in both regions during local sunrise and may be excited by the moving solar terminator. No relationship was found between these latter LSTIDs and the geomagnetic disturbances. The propagation direction of westward events changed from northwestward during winter solstice to southwestward at summer solstice. This is consistent with the seasonal orientation of the solar terminator.

  11. Solidification and morphology of submarine lavas - A dependence on extrusion rate

    NASA Technical Reports Server (NTRS)

    Griffiths, Ross W.; Fink, Jonathan H.

    1992-01-01

    The results of recent laboratory experiments with wax extruded beneath relatively cold water may be extrapolated to predict the surface morphology of submarine lavas as a function of the extrusion rate and melt viscosity. The experiments with solidifying wax indicated that the surface morphology was controlled by a single parameter, the ratio of the time taken for the surface to solidify, and a time scale for lateral flow. For submarine basalts a solution of the cooling problem (which is dominated by conduction in the lava but convective heat transfer in the water) and estimates of lava viscosities place this parameter within the empirically determined 'pillowing' regime over a wide range of extrusion rates. This results is consistent with the observation that pillow basalts are the most common products of submarine eruptions. Smoother surfaces corresponding to the various types of submarine sheet flows are predicted for sufficiently rapid extrusion of basaltic magma. Still higher eruption rates in regions of low topographic relief may produce submarine lava lakes. Minimum emplacement times can be calculated for submarine volcanic constructs of a single lava flow type.

  12. H2O Contents of Submarine and Subaerial Silicic Pyroclasts from Oomurodashi Volcano, Northern Izu-Bonin Arc

    NASA Astrophysics Data System (ADS)

    McIntosh, I. M.; Tani, K.; Nichols, A. R.

    2014-12-01

    Oomurodashi volcano is an active shallow submarine silicic volcano in the northern Izu-Bonin Arc, located ~20 km south of the inhabited active volcanic island of Izu-Oshima. Oomurodashi has a large (~20km diameter) flat-topped summit located at 100 - 150 metres below sea level (mbsl), with a small central crater, Oomuro Hole, located at ~200 mbsl. Surveys conducted during cruise NT12-19 of R/V Natsushima in 2012 using the remotely-operated vehicle (ROV) Hyper-Dolphin revealed that Oomuro Hole contains numerous active hydrothermal vents and that the summit of Oomurodashi is covered by extensive fresh rhyolitic lava and pumice clasts with little biogenetic or manganese cover, suggesting recent eruption(s) from Oomuro Hole. Given the shallow depth of the volcano summit, such eruptions are likely to have generated subaerial eruption columns. A ~10ka pumiceous subaerial tephra layer on the neighbouring island of Izu-Oshima has a similar chemical composition to the submarine Oomurodashi rocks collected during the NT12-19 cruise and is thought to have originated from Oomurodashi. Here we present FTIR measurements of the H2O contents of rhyolitic pumice from both the submarine deposits sampled during ROV dives and the subaerial tephra deposit on Izu-Oshima, in order to assess magma degassing and eruption processes occurring during shallow submarine eruptions.

  13. Arctic Submarine Slope Stability

    NASA Astrophysics Data System (ADS)

    Winkelmann, D.; Geissler, W.

    2010-12-01

    Submarine landsliding represents aside submarine earthquakes major natural hazard to coastal and sea-floor infrastructure as well as to coastal communities due to their ability to generate large-scale tsunamis with their socio-economic consequences. The investigation of submarine landslides, their conditions and trigger mechanisms, recurrence rates and potential impact remains an important task for the evaluation of risks in coastal management and offshore industrial activities. In the light of a changing globe with warming oceans and rising sea-level accompanied by increasing human population along coasts and enhanced near- and offshore activities, slope stability issues gain more importance than ever before. The Arctic exhibits the most rapid and drastic changes and is predicted to change even faster. Aside rising air temperatures, enhanced inflow of less cooled Atlantic water into the Arctic Ocean reduces sea-ice cover and warms the surroundings. Slope stability is challenged considering large areas of permafrost and hydrates. The Hinlopen/Yermak Megaslide (HYM) north of Svalbard is the first and so far only reported large-scale submarine landslide in the Arctic Ocean. The HYM exhibits the highest headwalls that have been found on siliciclastic margins. With more than 10.000 square kilometer areal extent and app. 2.400 cubic kilometer of involved sedimentary material, it is one of the largest exposed submarine slides worldwide. Geometry and age put this slide in a special position in discussing submarine slope stability on glaciated continental margins. The HYM occurred 30 ka ago, when the global sea-level dropped by app. 50 m within less than one millennium due to rapid onset of global glaciation. It probably caused a tsunami with circum-Arctic impact and wave heights exceeding 130 meters. The HYM affected the slope stability field in its neighbourhood by removal of support. Post-megaslide slope instability as expressed in creeping and smaller-scaled slides are

  14. Annual Report: 2011-2012 Storm Season Sampling, Non-Dry Dock Stormwater Monitoring for Puget Sound Naval Shipyard, Bremerton, WA

    SciTech Connect

    Brandenberger, Jill M.; Metallo, David; Rupert, Brian; Johnston, Robert K.; Gebhart, Christine

    2013-07-03

    Annual PSNS non-dry dock storm water monitoring results for 2011-2012 storm season. Included are a brief description of the sampling procedures, storm event information, laboratory methods and data collection, a results and discussion section, and the conclusions and recommendations.

  15. Estimating vaccine effectiveness against severe influenza in England and Scotland 2011/2012: applying the screening method to data from intensive care surveillance systems.

    PubMed

    Thomas, H L; Andrews, N; Green, H K; Boddington, N L; Zhao, H; Reynolds, A; McMenamin, J; Pebody, R G

    2014-01-01

    Methods for estimating vaccine effectiveness (VE) against severe influenza are not well established. We used the screening method to estimate VE against influenza resulting in intensive care unit (ICU) admission in England and Scotland in 2011/2012. We extracted data on confirmed influenza ICU cases from severe influenza surveillance systems, and obtained their 2011/2012 trivalent influenza vaccine (TIV) status from primary care. We compared case vaccine uptake with population vaccine uptake obtained from routine monitoring systems, adjusting for age group, specific risk group, region and week. Of 60 influenza ICU cases reported, vaccination status was available for 56 (93%). Adjusted VE against ICU admission for those aged ≥ 65 years was -10% [95% confidence interval (CI) -207 to 60], consistent with evidence of poor protection from the 2011/2012 TIV in 2011/2012. Adjusted VE for those aged <65 years in risk groups was -296% (95% CI -930 to -52), suggesting significant residual confounding using the screening method in those subject to selective vaccination. PMID:23591102

  16. Argon geochronology of Kilauea's early submarine history

    USGS Publications Warehouse

    Calvert, A.T.; Lanphere, M.A.

    2006-01-01

    Submarine alkalic and transitional basalts collected by submersible along Kilauea volcano's south flank represent early eruptive products from Earth's most active volcano. Strongly alkalic basalt fragments sampled from volcaniclastic deposits below the mid-slope Hilina Bench yield 40Ar/39Ar ages from 212 ?? 38 to 280 ?? 20 ka. These ages are similar to high-precision 234 ?? 9 and 239 ?? 10 ka phlogopite ages from nephelinite clasts in the same deposits. Above the mid-slope bench, two intact alkalic to transitional pillow lava sequences protrude through the younger sediment apron. Samples collected from a weakly alkalic basalt section yield 138 ?? 30 to 166 ?? 26 ka ages and others from a transitional basalt section yield 138 ?? 115 and 228 ?? 114 ka ages. The ages are incompatible with previous unspiked K-Ar studies from samples in deep drill holes along the east rift of Kilauea. The submarine birth of Kilauea volcano is estimated at <300 ka. If the weakly alkalic sequence we dated is representative of the volcano as a whole, the transition from alkalic to tholeiitic basalt compositions is dated at ??? 150 ka. ?? 2005 Elsevier B.V. All rights reserved.

  17. Dietary glycaemic index and glycaemic load among Australian children and adolescents: results from the 2011-2012 Australian Health Survey.

    PubMed

    Jones, Molly; Barclay, Alan W; Brand-Miller, Jennie C; Louie, Jimmy Chun Yu

    2016-07-01

    This study aimed to examine the dietary glycaemic index (GI) and glycaemic load (GL) of Australian children and adolescents, as well as the major food groups contributing to GL, in the recent 2011-2012 Australian Health Survey. Plausible food intake data from 1876 children and adolescents (51 % boys), collected using a multiple-pass 24-h recall, were analysed. The GI of foods was assigned based on a step-wise published method using values from common GI databases. Descriptive statistics were calculated for dietary GI, GL and contribution to GL by food groups, stratified by age group and sex. Linear regression was used to test for trends across age groups for BMI, dietary GI and GL, and intakes of energy, nutrients and food groups. Pearson's χ 2 test was used to test for differences between age groups for categorical subject characteristic variables. Mean dietary GI and GL of participants were 55·5 (sd 5·3) and 137·4 (sd 50·8), respectively. The main contributors to dietary GL were starchy foods: breads, cereal-based dishes, breakfast cereals, flours, grains and potatoes accounted for 41 % of total GL. Sweetened beverages, fruit and vegetable juices/drinks, cake-type desserts and sweet biscuits contributed 15 %. No significant difference (at P<0·001) was observed between sexes. In conclusion, Australian children and adolescents appear to consume diets with a lower GI than European children. Exchanging high-GI foods for low-GI alternatives within core and non-core foods may improve diet quality of Australian children and adolescents. PMID:27171604

  18. Comparative climatological study of large-scale traveling ionospheric disturbances over North America and China in 2011-2012

    NASA Astrophysics Data System (ADS)

    Ding, Feng; Ning, Baiqi; Wan, Weixing; Zhao, Biqiang; Xiong, Bo

    This paper describes a comparative study of the climatology of large-scale traveling ionospheric disturbances (LSTIDs) over North America and China based on observations obtained in 2011-2012 using two GPS networks characterized by dense regional coverage. We identified a total of 390 LSTIDs in China and 363 events in North America. These can be categorized into three types, namely south-, north-, and westward-propagating LSTIDs. The southward-moving LSTIDs over North America show similar diurnal and seasonal variations to those of geomagnetic disturbances, but the southward LSTIDs over China do not show such variations. The occurrence of southward-propagating LSTIDs over China increases at ~1-2 hours after the time of geomagnetic activity maximum; this increase lasts several hours until the geomagnetic activity minimum, which happens during the local evening. The southward-moving LSTIDs over North America show a weak semiannual variation, with two major peaks in March and October, while the southward-propagating LSTIDs over China show a major peak in January. Northward-propagating LSTIDs occur much less frequently than their southward-moving counterparts, and they are mainly observed in China. They mostly occur during geomagnetic activity maximum, indicating a possible relation with the degree of geomagnetic activity. Westward-traveling LSTIDs are seen in both regions during local sunrise and may be excited by the moving solar terminator. No relationship was found between these latter LSTIDs and the geomagnetic disturbances. The propagation direction of westward-moving events changed from northwestward during winter solstice to southwestward at summer solstice. This is consistent with the seasonal orientation of the solar terminator.

  19. Minimal inhibitory concentration of microorganisms causing surgical site infection in referral hospitals in North of Iran, 2011-2012

    PubMed Central

    Alikhani, Ahmad; Babamahmoodi, Farhang; Foroutan Alizadegan, Laleh; Shojaeefar, Arman; Babamahmoodi, Abdolreza

    2015-01-01

    Background: A surgical site infection (SSI) is the most common nosocomial infection after surgery and is the third most common infection in hospitalized patients. The aim of this study was to asses minimum inhibitory concentration (MIC) of the causing agents of SSI and antimicrobial susceptibility patterns. Methods: This cross-sectional study was done in three referral hospitals in North of Iran during 2011-2012. The samples were taken one month after orthopedic, abdominal, cesarean section surgery and coronary artery bypass graft (CABG) in patients with scores compatible to SSIs criteria. The sample was sent for bacteriologic culture and MIC determination for positive cases by broth microdilution method. The data were collected and analyzed. Results: From 103 positive cases S. aureus, E.coli and coagulase negative staphylococci were the most common isolated agents as 29.12%, 23.3% and 21.3%, respectively. S. aureus was sensitive to vancomycin (70%), amikacin (70%) and teicoplanin (76.6%) and cogulase negative staphylococci was sensitive to vancomycin (68.1%) and teicoplanin (72.6%) and E.coli to amikacin (95.83%) and imipenem and meropenem (66.66%). P.aeroginosa showed no sensitivity to cefepime and was sensitive to imipenem (93.75%) and meropenem (81.25%). Conclusion: The most important point is worrisome problem of the increased MIC of S. aureus to vancomycin that causes difficult use in the treatment of staphylococcal SSIs. In spite of resistance of micro-organisms to cephalosporins, gram negative organisms had low MIC to carbapenemes especially P.aeroginosa although the rate of its MIC is increasing. PMID:26221495

  20. Adverse Childhood Experiences among American Indian/Alaska Native Children: The 2011-2012 National Survey of Children's Health.

    PubMed

    Kenney, Mary Kay; Singh, Gopal K

    2016-01-01

    We examined parent-reported adverse childhood experiences (ACEs) and associated outcomes among American Indian and Alaska Native (AI/AN) children aged 0-17 years from the 2011-2012 National Survey of Children's Health. Bivariate and multivariable analyses of cross-sectional data on 1,453 AI/AN children and 61,381 non-Hispanic White (NHW) children assessed race-based differences in ACEs prevalence and differences in provider-diagnosed chronic emotional and developmental conditions, health characteristics, reported child behaviors, and health services received as a function of having multiple ACEs. AI/AN children were more likely to have experienced 2+ ACEs (40.3% versus 21%), 3+ ACEs (26.8% versus 11.5%), 4+ ACEs (16.8% versus 6.2%), and 5+ ACEs (9.9% versus 3.3%) compared to NHW children. Prevalence rates for depression, anxiety, and ADHD were higher among AI/AN children with 3+ ACEs (14.4%, 7.7%, and 12.5%) compared to AI/ANs with fewer than 2 ACEs (0.4%, 1.8%, and 5.5%). School problems, grade failures, and need for medication and counseling were 2-3 times higher among AI/ANs with 3+ ACEs versus the same comparison group. Adjusted odds ratio for emotional, developmental, and behavioral difficulties among AI/AN children with 2+ ACEs was 10.3 (95% CI = 3.6-29.3). Race-based differences were largely accounted for by social and economic-related factors. PMID:27529052

  1. Adverse Childhood Experiences among American Indian/Alaska Native Children: The 2011-2012 National Survey of Children's Health

    PubMed Central

    2016-01-01

    We examined parent-reported adverse childhood experiences (ACEs) and associated outcomes among American Indian and Alaska Native (AI/AN) children aged 0–17 years from the 2011-2012 National Survey of Children's Health. Bivariate and multivariable analyses of cross-sectional data on 1,453 AI/AN children and 61,381 non-Hispanic White (NHW) children assessed race-based differences in ACEs prevalence and differences in provider-diagnosed chronic emotional and developmental conditions, health characteristics, reported child behaviors, and health services received as a function of having multiple ACEs. AI/AN children were more likely to have experienced 2+ ACEs (40.3% versus 21%), 3+ ACEs (26.8% versus 11.5%), 4+ ACEs (16.8% versus 6.2%), and 5+ ACEs (9.9% versus 3.3%) compared to NHW children. Prevalence rates for depression, anxiety, and ADHD were higher among AI/AN children with 3+ ACEs (14.4%, 7.7%, and 12.5%) compared to AI/ANs with fewer than 2 ACEs (0.4%, 1.8%, and 5.5%). School problems, grade failures, and need for medication and counseling were 2-3 times higher among AI/ANs with 3+ ACEs versus the same comparison group. Adjusted odds ratio for emotional, developmental, and behavioral difficulties among AI/AN children with 2+ ACEs was 10.3 (95% CI = 3.6–29.3). Race-based differences were largely accounted for by social and economic-related factors. PMID:27529052

  2. Urinary polyaromatic hydrocarbons are associated with adult celiac disease and kidney stones: USA NHANES, 2011-2012.

    PubMed

    Shiue, Ivy

    2016-02-01

    Links between environmental chemicals and human health have emerged over the last few decades, but the effects from polyaromatic hydrocarbons (PAH) were less studied, compared to other commonly known environmental chemicals such as heavy metals, phthalates, arsenic, phenols, and pesticides. Therefore, it was aimed to study the relationships of urinary PAH and adult digestive conditions using a large human sample in a national and population-based study in recent years. Data was retrieved from the US National Health and Nutrition Examination Surveys, 2011-2012 including demographics, self-reported health conditions, and urinary PAH. Statistical analyses included chi-square test, t test, survey-weighted logistic regression modeling, and population attributable risk (PAR) estimation. Of 5560 American adults aged 20-80 and included in the statistical analysis, urinary 4-hydroxyphenanthrene was significantly associated with celiac disease (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.14-2.26, P = 0.009). In addition, urinary 2-hydroxyfluorene (OR 1.35, 95% CI 1.02-1.78, P = 0.038), 3-hydroxyfluorene (OR 1.35, 95% CI 1.07-1.70, P = 0.015), 1-hydroxyphenanthrene (OR 1.48, 95% CI 1.08-2.03, P = 0.017), 1-hydroxypyrene (OR 1.36, 95% CI 1.05-1.77, P = 0.023), and 2-hydroxynapthalene (OR 1.25, 95% CI 1.00-1.58, P = 0.054) were significantly associated with kidney stones, although not necessarily failing kidney. There were no statistically significant associations observed in the relationship of urinary PAH and liver problems, although higher levels of PAHs were observed. Urinary PAHs are associated with adult digestive conditions, although the causality cannot be established. From the research perspective, longitudinal monitoring from observational studies and experimental research understanding mechanism would be suggested. Regulation of minimizing PAHs exposure might need to be considered in future health and environmental policies. PMID:26728287

  3. A submarine welded ignimbrite-crystal-rich sandstone facies association in the Cambrian Tyndall Group, western Tasmania, Australia

    NASA Astrophysics Data System (ADS)

    White, Matthew J.; McPhie, Jocelyn

    1997-04-01

    Three occurrences of rhyolitic welded ignimbrite are intercalated within a submarine, below-storm-wave-base sedimentary succession in the Cambrian Tyndall Group, Mount Read Volcanics, western Tasmania. These occurrences are closely associated with very thick crystal-rich sandstone facies that is present at this stratigraphic level throughout the Tyndall Group. This facies is interpreted to comprise deposits from syn-eruptive, crystal-rich, submarine sediment gravity flows that were generated by interaction of subaerial pyroclastic flows with seawater. Removal of fine ash and pumice from the submarine flows by hydraulic sorting and flotation resulted in marked crystal enrichment in the deposits. Rapid, essentially syn-eruptive aggradation of crystal-rich sand led to temporary shoaling so that in some cases, subsequent pyroclastic flows deposited welded ignimbrite in shallow marine or possibly subaerial settings (e.g., Zig Zag Hill welded ignimbrite). Breccia units composed of welded ignimbrite clasts and crystal-rich matrix (e.g., Comstock and Anthony Road ignimbrite breccias) imply that some welded ignimbrite was submerged, providing clasts to syn-eruptive, submarine, crystal-rich sediment gravity flows. One example of welded ignimbrite (Cradle Mountain Link Road) may have been deposited in an entirely below-storm-wave-base environment. The distinctive facies association of welded ignimbrite, crystal-rich sandstone and ignimbrite-clast breccia in the Tyndall Group exemplifies the submarine record of a major rhyolitic explosive eruption in the source volcanic terrane.

  4. Flushing submarine canyons.

    PubMed

    Canals, Miquel; Puig, Pere; de Madron, Xavier Durrieu; Heussner, Serge; Palanques, Albert; Fabres, Joan

    2006-11-16

    The continental slope is a steep, narrow fringe separating the coastal zone from the deep ocean. During low sea-level stands, slides and dense, sediment-laden flows erode the outer continental shelf and the continental slope, leading to the formation of submarine canyons that funnel large volumes of sediment and organic matter from shallow regions to the deep ocean(1). During high sea-level stands, such as at present, these canyons still experience occasional sediment gravity flows(2-5), which are usually thought to be triggered by sediment failure or river flooding. Here we present observations from a submarine canyon on the Gulf of Lions margin, in the northwest Mediterranean Sea, that demonstrate that these flows can also be triggered by dense shelf water cascading (DSWC)-a type of current that is driven solely by seawater density contrast. Our results show that DSWC can transport large amounts of water and sediment, reshape submarine canyon floors and rapidly affect the deep-sea environment. This cascading is seasonal, resulting from the formation of dense water by cooling and/or evaporation, and occurs on both high- and low-latitude continental margins(6-8). DSWC may therefore transport large amounts of sediment and organic matter to the deep ocean. Furthermore, changes in the frequency and intensity of DSWC driven by future climate change may have a significant impact on the supply of organic matter to deep-sea ecosystems and on the amount of carbon stored on continental margins and in ocean basins. PMID:17108962

  5. Assessing exposure to tobacco-specific carcinogen NNK using its urinary metabolite NNAL measured in US population: 2011-2012.

    PubMed

    Wei, Binnian; Blount, Benjamin C; Xia, Baoyun; Wang, Lanqing

    2016-01-01

    Carcinogenic tobacco-specific nitrosamines (TSNAs) such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are found only in tobacco and derived products. Food and Drug Administration of the United States (US FDA) lists NNK as one of the 93 harmful and potentially harmful constituents (HPHCs) found in tobacco products and tobacco smoke. The aim of this study was to use the urinary concentration of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a major metabolite of NNK, to quantitatively estimate exposure to NNK in the US general population. In 2011-2012, the Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey (NHANES) collected urine and serum samples from a representative sample of US residents. We used a serum cotinine cutoff of 10 ng/ml with combination of questionnaire data to select non-users from cigarette users and used self-reported data to determine different tobacco product user groups. We estimated the absorbed total daily dose of NNK using a probabilistic method based on a two-compartment model. The geometric mean (GM) for the daily dose of NNK among smokers aged 12-16 years was significantly higher than that for non-users at the same age stage exposed to second-hand smoke (SHS) (P<0.001). Among those exposed to SHS, the GM for daily dose of NNK in young children (6-11 years) was nearly three times of those for adults in the age range 21-59 years. Among cigarette users, non-Hispanic Whites had the highest NNK daily dose and Mexican Americans had the lowest levels. Exclusive snuff or chewing product users had significantly higher daily dose of NNK than did cigarette smokers. Our study found that the maximum daily dose of NNK for children aged from 6 to 11 years and that for a significant percentage of cigarette users, chewing product and snuff users were higher than an estimated provisional "reference" risk level. PMID:25564369

  6. [Sensitivity surveillance of Streptococcus pneumoniae isolates for several antibacterial agents in Gifu and Aichi prefectures (2011-2012)].

    PubMed

    Funatsu, Tori; Mizunaga, Shingo; Fukuda, Yoshiko; Nomura, Nobuhiko; Hashido, Hikonori; Mitsuyama, Junichi; Hatano, Masakazu; Yamaoka, Kazukiyo; Watanabe, Kunitomo; Asano, Yuko; Suematsu, Hiroyuki; Sawamura, Haruki; Matsukawa, Yoko; Ohta, Hirotoshi; Yamagishi, Yuka; Mikamo, Hiroshige; Matsubara, Shigenori; Shibata, Naohiro

    2015-08-01

    We investigated the susceptibility to antibacterial agents, genotype of penicillin-binding protein (PBP) genes and macrolide resistant genes, and the serotypes against 270 strains of Streptococcus pneumoniae isolated from medical facilities in Gifu and Aichi prefectures between October 2011 and April 2012. These results were compared with those against S. pneumoniae isolated in 2008-2009 and 2010-2011. The number of gPSSP with 3 normal PBP genes, gPISP with 1 or 2 normal PBP genes and gPRSP with 3 abnormal genes isolated in 2011-2012 was 15 (5.6%), 162 (60.0%) and 93 (34.4%) strains, respectively. Compared with those isolated in 2008-2009 and 2010-2011, the numbers of gPRSP were decreasing. On the other hand, the isolates with no macrolide-resistant gene, only mefA, only ermB, and both mefA and ermB were 16 (5.9%), 75 (27.8%), 153 (56.7%) and 26 (9.6%). Compared with those isolated in 2008-2009 and 2010-2011, the numbers of isolates with ermB, which was usually associated with high-level resistance, were increasing. The prevalent pneumococcal serotypes in children were type 3 (14.4%), following by type 15 and 19F (9.3%). The coverages of 7-valent pneumococcal conjugate vaccine (PCV7) and 13-valent pneumococcal conjugate vaccine (PCV13) were calculated as 22.9% and 49.2%, respectively. The coverages of PCV7 and PCV13 in gPRSP isolated from children were 47.7% (21/44 strains) and 72.7% (32/44 strains). The MIC90 of each antibacterial agent was as follows; 0.125pg/mL for imipenem, panipenem and garenoxacin, 0.25 μg/mL for meropenem and doripenem, 0.5 μg/mL for cefditoren, moxifloxacin and tosufloxacin, 1 μg/mL for amoxicillin, clavulanic acid/amoxicillin, cefteram, cefcapene and ceftriaxone, 2 μg/mL for benzylpenicillin, ampicillin, sulbactam/ampicillin, piperacillin, tazobactam/piperacillin and levofloxacin, 4 μg/mL for cefdinir, flomoxef and pazufloxacin, 16 μg/mL for minocycline, > 64 μg/mL for clarithromycin and azithromycin, and these MIC90s were about the

  7. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV. The Fourth Year (2011-2012)

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Hambsch, Franz-Josef; Maehara, Hiroyuki; Masi, Gianluca; Miller, Ian; Noguchi, Ryo; Akasaka, Chihiro; Aoki, Tomoya; Kobayashi, Hiroshi; Matsumoto, Katsura; Nakagawa, Shinichi; Nakazato, Takuma; Nomoto, Takashi; Ogura, Kazuyuki; Ono, Rikako; Taniuchi, Keisuke; Stein, William; Henden, Arne; de Miguel, Enrique Kiyota, Seiichiro; Dubovsky, Pavol A.; Kudzej, Igor; Imamura, Kazuyoshi; Akazawa, Hidehiko; Takagi, Ryosuke; Wakabayashi, Yuya; Ogi, Minako; Tanabe, Kenji; Ulowetz, Joseph; Morelle, Etienne; Pickard, Roger D.; Ohshima, Tomohito; Kasai, Kiyoshi; Pavlenko, Elena P.; Antonyuk, Oksana I.; Baklanov, Aleksei V.; Antonyuk, Kirill; Samsonov, Denis; Pit, Nikolaj; Sosnovskij, Aleksei; Littlefield, Colin; Sabo, Richard; Ruiz, Javier; Krajci, Thomas; Dvorak, Shawn; Oksanen, Arto; Hirosawa, Kenji; Goff, William N.; Monard, Berto; Shears, Jeremy; Boyd, David; Voloshina, Irina B.; Shugarov, Sergey Yu.; Chochol, Drahomir; Miyashita, Atsushi; Pietz, Jochen; Katysheva, Natalia; Itoh, Hiroshi; Bolt, Greg; Andreev, Maksim V.; Parakhin, Nikolai; Malanushenko, Viktor; Martinelli, Fabio; Denisenko, Denis; Stockdale, Chris; Starr, Peter; Simonsen, Mike; Tristram, Paul J.; Fukui, Akihiko; Tordai, Tamas; Fidrich, Robert; Paxson, Kevin B.; Itagaki, Koh-ichi; Nakashima, Youichirou; Yoshida, Seiichi; Nishimura, Hideo; Kryachko, Timur V.; Samokhvalov, Andrey V.; Korotkiy, Stanislav A.; Satovski, Boris L.; Stubbings, Rod; Poyner, Gary; Muyllaert, Eddy; Gerke, Vladimir; MacDonald, Walter, II; Linnolt, Michael; Maeda, Yutaka; Hautecler, Hubert

    2013-02-01

    Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 86 SU UMa-type dwarf novae, mainly observed during the 2011-2012 season. We confirmed general trends recorded in our previous studies, such as the relation between period derivatives and orbital periods. There are some systems showing positive period derivatives despite the long orbital period. We observed the 2011 outburst of the WZ Sge-type dwarf nova BW Scl, and recorded an O - C diagram similar to those of previously known WZ Sge-type dwarf novae. The WZ Sge-type dwarf nova OT J184228.1+483742 showed an unusual pattern of double outbursts composed of an outburst with early superhumps and one with ordinary superhumps. We propose an interpretation that a very small growth rate of the 3:1 resonance due to an extremely low mass-ratio led to quenching the superoutburst before the ordinary superhump appeared. We systematically studied ER UMa-type dwarf novae, and found that V1159 Ori showed positive superhumps similar to ER UMa in the 1990s. The recently recognized ER UMa-type object BK Lyn dominantly showed negative superhumps, and its behavior was very similar to the present-day state of ER UMa. The pattern of period variations in AM CVn-type objects was very similar to that of short-period hydrogen-rich SU UMa-type dwarf novae, making them a helium analogue of hydrogen-rich SU UMa-type dwarf novae. SBS 1108+574, a peculiar hydrogen-rich dwarf nova below the period minimum, showed a very similar pattern of period variations to those of short-period SU UMa-type dwarf novae. The mass-ratio derived from the detected orbital period suggests that this secondary is a somewhat evolved star whose hydrogen envelope was mostly stripped during the mass-exchange. CC Scl, MASTER OT J072948.66+593824.4, and OT J173516.9+154708 showed only low-amplitude superhumps with complex profiles. These superhumps are likely to be a combination of two closely separated periods.

  8. Submarine laser communications

    NASA Astrophysics Data System (ADS)

    McConathy, D. R.

    The Department of the Navy and the Defense Advanced Research Projects Agency (DARPA) are sponsoring a joint study to investigate the use of blue-green laser technology to comunicate with submarines at operating depths. Two approaches are under investigation - one in which the laser itself is space-based, and the other in which the laser is ground-based with its beam redirected to the earth's surface by an orbiting mirror. This paper discusses these two approaches, and presents a brief history of activities which led to the current studies.

  9. Current submarine atmosphere control technology.

    PubMed

    Mazurek, W

    1998-01-01

    Air purification in submarines was introduced towards the end of World War II and was limited to the use of soda lime for the removal of carbon dioxide and oxygen candles for the regeneration of oxygen. The next major advances came with the advent of nuclear-powered submarines. These included the development of regenerative and, sometimes, energy-intensive processes for comprehensive atmosphere revitalization. With the present development of conventional submarines using air-independent propulsion there is a requirement for air purification similar to that of the nuclear-powered submarines but it is constrained by limited power and space. Some progress has been made in the development of new technology and the adoption of air purification equipment used in the nuclear-powered submarines for this application. PMID:11876194

  10. Long-term explosive degassing and debris flow activity at West Mata submarine volcano

    NASA Astrophysics Data System (ADS)

    Dziak, R. P.; Bohnenstiehl, D. R.; Baker, E. T.; Matsumoto, H.; Caplan-Auerbach, J.; Embley, R. W.; Merle, S. G.; Walker, S. L.; Lau, T.-K.; Chadwick, W. W.

    2015-03-01

    West Mata is a 1200 m deep submarine volcano where explosive boninite eruptions were observed in 2009. The acoustic signatures from the volcano's summit eruptive vents Hades and Prometheus were recorded with an in situ (~25 m range) hydrophone during ROV dives in May 2009 and with local (~5 km range) moored hydrophones between December 2009 and August 2011. The sensors recorded low frequency (1-40 Hz), short duration explosions consistent with magma bubble bursts from Hades, and broadband, 1-5 min duration signals associated with episodes of fragmentation degassing from Prometheus. Long-term eruptive degassing signals, recorded through May 2010, preceded a several month period of declining activity. Degassing episodes were not recorded acoustically after early 2011, although quieter effusive eruption activity may have continued. Synchronous optical measurements of turbidity made between December 2009 and April 2010 indicate that turbidity maxima resulted from occasional south flank slope failures triggered by the collapse of accumulated debris during eruption intervals.

  11. Submarine Volcanic Landforms and Endolithic Microorganisms

    NASA Astrophysics Data System (ADS)

    Fisk, M. R.

    2001-01-01

    Subaqueous volcanic eruptions produce characteristic landforms and lava flow morphologies that are distinct from subaerial eruptions. Eruptions from fissures on the sea floor produce hummocks rather than flat lava flows. Hummocky lava flows typically have dimensions of 500 meters wide, 5000 meters long, and 50 meters high. The hummocks are made of piles of bulbous pillows that are about 1 meter in diameter. Because of the high specific heat of water and the large temperature difference between magma and liquid water (about 1100 C) the exteriors of lava flows are quenched to glass. Cooling of lava flows in air does not have this effect, The quenched volcanic glass in aqueous environments contains microorganisms that dissolve the glass and leave secondary minerals such as clay, iron oxides, and sulfides in the voids. The microbial excavation of the glass produces a wide variety shapes and sizes. These microbially produced excavations may be 100 micrometers long by 3 micrometer diameter tubes, starbursts of radiating tubes, branching 1 micrometer diameter tubes, or other shapes. These tubes and excavations are distinctive, they are associated with bacteria, and they are preserved along with the glass. In surveys of volcanic glass from subaqueous lava flows we have found this evidence of microbial activity in rocks at ocean subbottom depths of a few meters to 1500 meters. These rocks range in age from about 1 million years to 170 millions years. Where submarine volcanic rocks have been uplifted to dry land, the glass may also preserve microbial patterns of glass alteration. Comparisons of terrestrial and Martian landforms could reveal the locations of subaqueous volcanic activity on Mars. Given the similarity of compositions of igneous rocks on the two planets, subaqueous eruptions on Mars will have quenched glass exteriors. Evidence of microbial colonization of the glass will be preserved as long as the glass is preserved. Also, the microbial activity that produces

  12. Children's Growth and Classroom Experiences in Georgia's Pre-K Program: Findings from the 2011-2012 Evaluation Study. Executive Summary

    ERIC Educational Resources Information Center

    Peisner-Feinberg, Ellen; Schaaf, Jennifer; LaForett, Dore

    2013-01-01

    Georgia has one of the few state-funded universal pre-kindergarten programs in the United States, with the aim of providing pre-k services to all 4-year-olds whose families want their children to participate in the program, regardless of family income level. In the 2011-2012 school year, Georgia's Pre-K Program served a total of over 94,000…

  13. Polymorphic light eruption

    MedlinePlus

    ... outdoors. Wear a sun hat. Wear sunglasses with UV protection. Use a lip balm with sunscreen. Alternative Names Polymorphic light eruption; Photodermatosis; PMLE Images Polymorphic light eruption on ...

  14. The Initiation of Submarine Debris Flow after 2006 Pingtung Earthquake Offshore Southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Su, C. C.; Liu, J. T.; Chiu, H. T.; Li, S. J.

    2014-12-01

    On 26-27 December 2006, a series of submarine cables were damaged offshore southwestern Taiwan from Gaoping Slope to the northern terminus of the Manila Trench. The cable breakages were caused by gravity flows which triggered by the Pingtung earthquake doublet occurred on 26 December 2006 at 20:26 (21.9°N, 120.6°E; ML 7.0) and 20:34 (21.97°N, 120.42°E; ML 7.0) offshore of Fangliao Twonship and meanwhile the local fishermen reported disturbed waters at the head of Fangliao submarine canyon. Although many researchers conjectured the disturbed waters may cause by the eruption of submarine volcanoes which has been widely discovered off the southwestern Taiwan, the actual mechanism is still unclear. In previous studies, a series of faults, liquefaction strata, pockmarks and acoustically transparent sediments with doming structures were observed at the head of Fanliao submarine canyon and may highly related to the submarine groundwater discharge off southwestern Taiwan. Recently, further multi-beam surveys were conducted at the east of Fangliao submarine canyon head and the result shows large area of seafloor subsidence after Pingtung Earthquake. The area of subsidence is over 60 km2 with maximum depth around 5 meters. The north end of the subsidence is connected to the Fangliao submarine canyon where the first cable was failed (CH-US CN-W2-1: 22°13.287'N, 120°33.722'E) after Pingtung Earthquake. All the evidences point out the large earthquake might triggered liquefaction process and generated large debris flow and swept the submarine cables away from the Fangliao submarine canyon head to the abyss.

  15. Subaqueous explosive eruption and welding of pyroclastic deposits.

    PubMed

    Kokelaar, P; Busby, C

    1992-07-10

    Silicic tuffs infilling an ancient submarine caldera, at Mineral King in California, show microscopic fabrics indicative of welding of glass shards and pumice at temperatures >500 degrees C. The occurrence indicates that subaqueous explosive eruption and emplacement of pyroclastic materials can occur without substantial admixture of the ambient water, which would cause chilling. Intracaldera progressive aggradation of pumice and ash from a thick, fast-moving pyroclastic flow occurred during a short-lived explosive eruption of approximately 26 cubic kilometers of magma in water >/=150 meters deep. The thickness, high velocity, and abundant fine material of the erupted gas-solids mixture prevented substantial incorporation of ambient water into the flow. Stripping of pyroclasts from upper surfaces of subaqueous pyroclastic flows in general, both above the vent and along any flow path, may be the main process giving rise to buoyant-convective subaqueous eruption columns and attendant fallout deposits. PMID:17794750

  16. Submarine lithification of carbonate sediments.

    PubMed

    Milliman, J D

    1966-08-26

    Recrystallized planktonic limestones from two guyots in the North Atlantic are in oxygen-isotopic equilibrium with their present ambient waters, suggesting submarine lithifica tion and recrystallization. The early stages of submarine lithification of carbonates may involve precipitation of, and replacement by, magnesium-rich calcite; with time this may invert to magnesium-poor calcite. This type of lithification probably requires very low rates of sediment accumulation. PMID:17837254

  17. Submarine landslides around the Canary Islands

    NASA Astrophysics Data System (ADS)

    Krastel, Sebastian; Schmincke, Hans-Ulrich; Jacobs, Colin L.; Rihm, Roland; Le Bas, Timothy P.; AlibéS, BáRbara

    2001-01-01

    The morphology and structure of the submarine flanks of the Canary Islands were mapped using the GLORIA long-range side-scan sonar system, bathymetric multibeam systems, and sediment echosounders. Twelve young (<2 Ma) giant landslides have been identified on the submarine flanks of the Canary Islands up to now. Older landslide events are long buried under a thick sediment cover due to high sedimentation rates around the Canary Islands. Most slides were found on the flanks of the youngest and most active islands of La Palma, El Hierro, and Tenerife, but young giant landslides were also identified on the flanks of the older (15-20 Ma) but still active eastern islands. Large-scale mass wasting is an important process during all periods of major magmatic activity. The long-lived volcanic constructive history of the islands of the Canary Archipelago is balanced by a correspondingly long history of destruction, resulting in a higher landslide frequency for the Canary Islands compared to the Hawaiian Islands, where giant landslides only occur late in the period of active shield growth. The lower stability of the flanks of the Canaries is probably due to the much steeper slopes of the islands, a result of the abundance of highly evolved intrusive and extrusive rocks. Another reason for the enhanced slope instability is the abundance of pyroclastic deposits on Canary Islands resulting from frequent explosive eruptions due to the elevated volatile contents in the highly alkalic magmas. Dike-induced rifting is most likely the main trigger mechanism for destabilization of the flanks. Flank collapses are a major geological hazard for the Canary Islands due to the sector collapses themselves as well as triggering of tsunamis. In at least one case, a giant lateral blast occurred when an active magmatic or hydrothermal system became unroofed during flank collapse.

  18. Jupiter Eruptions

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on the image for high resolution image of Nature Cover

    Detailed analysis of two continent-sized storms that erupted in Jupiter's atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding these outbreaks could be the key to unlock the mysteries buried in the deep Jovian atmosphere, say astronomers.

    This visible-light image is from NASA's Hubble Space Telescope taken on May 11, 2007. It shows the turbulent pattern generated by the two plumes on the upper left part of Jupiter.

    Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.

    According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vi gorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 kilometers) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's atmosphere at 375 miles per hour (600 kilometers per hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approximately100 kilometers) below the cloud tops where most sunlight is absorbed.

  19. Clouds and hazes vertical structure mapping of Saturn 2011 - 2012 giant vortex by means of Cassini VIMS data analysis.

    NASA Astrophysics Data System (ADS)

    Oliva, F.; Adriani, A.; Moriconi, M. L.; Liberti, G. L.; D'Aversa, E.

    On December 2010 a giant storm erupted in Saturn's North hemisphere. A giant vortex formed in the storm wake and persisted after the principal outburst exhausted on July 2011. The vortex had been imaged several times by the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini probe starting from May 2011 and it was still present in observations recorded on June 2013. In this work we have analyzed the vortex data recorded by the visual channel of the spectrometer (VIMS-V) in August 2011 and January 2012. An inverse model, based on the Bayesian approach and using the Gauss-Newton iterative method to minimize the cost function, has been developed to analyze those data. The model takes advantage of the results of a supporting forward radiative transfer model which relies on the assumptions of plane parallel atmosphere, multiple scattering, Mie theory to compute particles single scattering properties, and molecular scattering adapted to Saturn's atmosphere. Applying the inverse model we could retrieve the microphysical and geometrical properties of the clouds and hazes overlying the vortex and produce spatial maps for each retrieved parameter. Thanks to this study, the vertical structure of the hazes in this region has been quantitatively addressed for the first time. The comparative analysis of the results from the two observations seems to suggest that in 6 months the atmospheric dynamics, responsible for the formation and subsistence of the vortex, is weakening and the atmosphere is returning to a more stationary state. In addition, we suggest a correction for the imaginary part of the refractive index of the tropopause haze. This new value, that allows a better convergence between observed and simulated spectra, does not yet identify a composition of the haze and further investigation is needed to understand the real nature of the need for such a modification.

  20. Active Eruptions in the NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Resing, J. A.; Embley, R. W.

    2009-12-01

    submarine volcanoes including actively erupting NW Rota. Two dives were also conducted on the NELSC, which was no longer erupting and showed no signs of extensive eruption-related hydrothermal activity. A new lava flow was found beneath the Nov. 2008 zone of near-bottom water column temperature anomalies. Preliminary radiometric dating of lavas is consistent with a Nov. 2008 eruption. For >20 yrs the PMEL-Vents and NSF RIDGE programs have sought to observe active eruptions to understand their impacts and modes of occurrence, yet these dynamic events have been difficult to capture. This response cruise produced new insights on submarine volcanism, including the first documented back-arc spreading center eruption, the first boninitic eruption, and the first observation of pillow lava formation in the deep sea, arguably one of Earth’s most common surface rock forms. The “rapidity” with which we were able to return to these sites aided in this success. The cruise on the R/V TG Thompson was funded by NSF through the R2K, MARGINS, and MGG programs, and by NOAA Ocean Exploration and PMEL. Over 37 letters of interest were submitted from the scientific community to join the cruise and/or to receive samples, from which a multidisciplinary team of petrologists, fluid chemists, oceanographers, geophysicists, and macro- and micro- biologists was assembled.

  1. Time series analysis of discolored seawater reflectance observed by Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) at Fukutoku-Okonaba submarine volcano, Japan

    NASA Astrophysics Data System (ADS)

    Urai, Minoru

    2014-01-01

    Monitoring submarine volcanoes is not an easy task compared to land volcanoes because they are covered by seawater and located in remote areas. Satellite remote sensing is a powerful tool for monitoring underwater volcanic activities such as discolored seawater, floating material and volcanic plumes. Discolored seawater is a good indicator of submarine volcanic activities. Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) made extensive observations from 2006 to 2011 of the Fukutoku-Okanoba submarine volcano, which is located 1300 km south of Tokyo, and is one of the most active submarine volcanoes in Japan. The high discolored seawater brightness coincides with relatively high activity of Fukutoku-Okanoba. No discolored seawater was observed for 6 months before the 2010 Fukutoku-Okanoba submarine eruption, meaning that Fukutoku-Okanoba was quiescent before the eruption. Both high brightness and apparent color change of discolored seawater derived from AVNIR-2 mean emergence of large amount of hot spring water, implying that the submarine volcano is highly active. This study demonstrates that satellite remote sensing is an effective tool for monitoring activities of inaccessible submarine volcanoes.

  2. An erupted compound odontoma.

    PubMed

    Gupta, Anil; Vij, Hitesh; Vij, Ruchieka; Malhotra, Ritika

    2014-01-01

    Odontomas are familiar entities but their eruption into the oral cavity is an extraordinary occurrence, which may be associated with pain, infection, malocclusion, etc. Not many cases of erupted odontomas have been reported in the literature. This paper puts forth a case of erupting odontoma in an attempt to add to the list of reported cases of this unique pathology. PMID:24729109

  3. Growth history of Kilauea inferred from volatile concentrations in submarine-collected basalts

    USGS Publications Warehouse

    Coombs, M.L.; Sisson, T.W.; Lipman, P.W.

    2006-01-01

    Major-element and volatile (H2O, CO2, S) compositions of glasses from the submarine flanks of Kilauea Volcano record its growth from pre-shield into tholeiite shield-stage. Pillow lavas of mildly alkalic basalt at 2600-1900 mbsl on the upper slope of the south flank are an intermediate link between deeper alkalic volcaniclastics and the modern tholeiite shield. Lava clast glasses from the west flank of Papau Seamount are subaerial Mauna Loa-like tholeiite and mark the contact between the two volcanoes. H2O and CO2 in sandstone and breccia glasses from the Hilina bench, and in alkalic to tholeiitic pillow glasses above and to the east, were measured by FTIR. Volatile saturation pressures equal sampling depths (10 MPa = 1000 m water) for south flank and Puna Ridge pillow lavas, suggesting recovery near eruption depths and/or vapor re-equilibration during down-slope flow. South flank glasses are divisible into low-pressure (CO20.5 wt.%, S 1000-1700 ppm), and high-pressure groups (CO2 >40 ppm, S >???1000 ppm), corresponding to eruption ???sea level, at moderate water depths (300-1000 m) or shallower but in disequilibrium, and in deep water (> 1000 m). Saturation pressures range widely in early alkalic to strongly alkalic breccia clast and sandstone glasses, establishing that early Kilauea's vents spanned much of Mauna Loa's submarine flank, with some vents exceeding sea level. Later south flank alkalic pillow lavas expose a sizeable submarine edifice that grew concurrent with nearby subaerial alkalic eruptions. The onset of the tholeiitic shield stage is marked by extension of eruptions eastward and into deeper water (to 5500 m) during growth of the Puna Ridge. Subaerial and shallow water eruptions from earliest Kilauea show that it is underlain shallowly by Mauna Loa, implying that Mauna Loa is larger, and Kilauea smaller, than previously recognized.

  4. On sonobuoy placement for submarine tracking

    NASA Astrophysics Data System (ADS)

    Kouritzin, Michael A.; Ballantyne, David J.; Kim, Hyukjoon; Hu, Yaozhong

    2005-05-01

    This paper addresses the problem of detecting and tracking an unknown number of submarines in a body of water using a known number of moving sonobuoys. Indeed, we suppose there are N submarines collectively maneuvering as a weakly interacting stochastic dynamical system, where N is a random number, and we need to detect and track these submarines using M moving sonobuoys. These sonobuoys can only detect the superposition of all submarines through corrupted and delayed sonobuoy samples of the noise emitted from the collection of submarines. The signals from the sonobuoys are transmitted to a central base to analyze, where it is required to estimated how many submarines there are as well as their locations, headings, and velocities. The delays induced by the propagation of the submarine noise through the water mean that novel historical filtering methods need to be developed. We summarize these developments within and give initial results on a simplified example.

  5. Remote Analysis of Grain Size Characteristic in Submarine Pyroclastic Deposits from Kolumbo Volcano, Greece

    NASA Astrophysics Data System (ADS)

    Smart, C.; Whitesell, D. P.; Roman, C.; Carey, S.

    2011-12-01

    Grain size characteristics of pyroclastic deposits provide valuable information about source eruption energetics and depositional processes. Maximum size and sorting are often used to discriminate between fallout and sediment gravity flow processes during explosive eruptions. In the submarine environment the collection of such data in thick pyroclastic sequences is extremely challenging and potentially time consuming. A method has been developed to extract grain size information from stereo images collected by a remotely operated vehicle (ROV). In the summer of 2010 the ROV Hercules collected a suite of stereo images from a thick pumice sequence in the caldera walls of Kolumbo submarine volcano located about seven kilometers off the coast of Santorini, Greece. The highly stratified, pumice-rich deposit was likely created by the last explosive eruption of the volcano that took place in 1650 AD. Each image was taken from a distance of only a few meters from the outcrop in order to capture the outlines of individual clasts with relatively high resolution. Mosaics of individual images taken as the ROV transected approximately 150 meters of vertical outcrop were used to create large-scale vertical stratigraphic columns that proved useful for overall documentation of the eruption sequence and intracaldera correlations of distinct tephra units. Initial image processing techniques, including morphological operations, edge detection, shape and size estimation were implemented in MatLab and applied to a subset of individual images of the mosiacs. A large variety of algorithms were tested in order to best discriminate the outlines of individual pumices. This proved to be challenging owing to the close packing and overlapping of individual pumices. Preliminary success was achieved in discriminating the outlines of the large particles and measurements were carried out on the largest clasts present at different stratigraphic levels. In addition, semi-quantitative analysis of the

  6. Multifractal variability of Very Low Frequency (VLF) signal during Earthquakes (M greater than 5) occurred at Greece during the year 2011-2012

    NASA Astrophysics Data System (ADS)

    Sondhiya, Deepak Kumar; Gwal, Ashok Kumar; Verma, Shivali; Kasde, Satish Kumar; Sonakia, Anjana

    In this work Wavelet Transform Modulus Maxima (WTMM) based multifractal analysis method is used to extracts the earthquake precursory signatures from scaling characteristics of subionospheric Very Low Frequency (VLF) signals. We found specific dynamics of their fractal characteristics before the earthquake, appearance of the spike in the signal and increase of the fractal dimension. We analyze VLF signals of famous Turkey Bafa transmitter (N 370 24’, E 27019’) recorded by sudden Ionospheric Disturbance (SID) monitoring station located at South of France during the Earthquake occurred at Greece during the year 2011-2012. The analysis of VLF signal during some days before and after the occurrence of earthquake has been done. Keywords: Multifractal analysis, VLF signal, Sudden Ionospheric disturbances

  7. Vesiculation Characteristics in Pyroclasts of the 3.1 ka Oneraki Eruption, Raoul Island, Kermadec Arc

    NASA Astrophysics Data System (ADS)

    Rotella, M. D.; Barker, S. J.; Wilson, C. J.; Wright, I. C.; Houghton, B. F.

    2008-12-01

    Raoul Island is the emergent 30 square km portion of a > 200 cubic km volcanic edifice which rises 900 m from the sea floor along the Kermadec ridge. Although the island is composed mainly of basalt and basaltic andesite, the last 4000 years has seen several dacitic explosive eruptions associated with caldera formation [Lloyd & Nathan, N.Z. Geol. Surv. Bull., 1981; Smith et al., J.Volc. Geotherm. Res. v. 156, 2006]. Fall deposits of the 3.1 ka Oneraki eruption, of possible plinian dispersal, were sampled at five stratigraphic levels. The 16-32 mm size pumice clasts of the lower four levels display narrow, unimodal density ranges. The upper level fall deposit shows a bimodal density distribution, reflecting a change in eruption characteristics as dense, degassed fragments were also ejected, but without other signs of any interaction with external water. For this study, qualitative and quantitative vesicularity data have been collected from 16- 32 mm clasts from three of the stratigraphic levels to provide insights to the various processes involved in vesiculation and fragmentation of this magma. Future work will include comparisons of vesicle textures in this eruption to other dry and wet subaerially erupted Raoul deposits, and to submarine deposits of similar composition at Macauley and Healy volcanoes. By characterizing eruption products from these volcanoes and using constraints provided by the different degrees of interaction with water (and at different water depths in submarine examples) we hope to better understand the dynamics of the violent degassing processes driving these eruptions.

  8. Textural constraints on the dynamics of the 2000 Miyakejima eruption

    NASA Astrophysics Data System (ADS)

    Garozzo, Ileana; Romano, Claudia; Giordano, Guido; Geshi, Nobuo; Vona, Alessandro

    2016-04-01

    Miyakejima Volcano is a basaltic-andesite stratovolcano active from ~10.000 years, located on the north of the Izu-Bonin arc. During the last 600 years the volcano has been characterized mainly by flank fissure activity, with explosive phreatomagmatic eruptions on the coastal areas. In the last century, the activity became more frequent and regular with intervals of 20 to 70 years (1940, 1962, 1983 and 2000). The last activity started on 27 June 2000, with a minor submarine eruption on the west coast of the volcano, and proceeded with six major summit eruptions from July 8 to August 29. The eruptions led to the formation of a collapse caldera ~1.6 km across. The total erupted tephra represents only 1.7% in volume of the caldera, the high fragmentation of magma produced mainly fine-grained volcanic ash. In order to improve the understanding on the triggering and dynamics of this explosive eruption, we carried out a detailed investigation of the erupted materials with particular attention to the textural features of juvenile pyroclasts (Vesicle and Crystal Size Distributions). The stratigraphic record can be divided into six fall units, corresponding to the six summit eruptions, although juvenile materials were identified only in 4 units (unit 2, 4, 5, 6). We selected about 100 juvenile grains sampled from the bottom to the top of each level, to be analyzed by scanning electron microscopy. The study of juvenile morphological features allowed us to recognize the existence of three characteristic morphotypes, showing marked differences in their external morphologies and internal textures (from poorly to highly crystallized and vesiculated clasts). The distribution of these morphotypes is non-homogeneous along the eruptive sequence indicating changes of dynamics during magma ascent. Juveniles do not show features inherited from the interaction with external water. Vesicle Volume Distributions of the selected ash grains show that the three types of pyroclasts experienced

  9. 30. VIEW OF PHOTO CAPTIONED 'SUBMARINE BASE, NEW LONDON, CONNECTICUT. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. VIEW OF PHOTO CAPTIONED 'SUBMARINE BASE, NEW LONDON, CONNECTICUT. 2 JUNE 1930. SUBMARINE TRAINING TANK - STEELWORK 98% COMPLETE; BRICKWORK 95% COMPLETE, PIPING 10% IN PLACE. LOOKING NORTH. CONTRACT NO. Y-1539-ELEVATOR, SUBMARINE ESCAPE TANK.' - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  10. Scientific Ocean Drilling to Assess Submarine Geohazards along European Margins

    NASA Astrophysics Data System (ADS)

    Ask, M. V.; Camerlenghi, A.; Kopf, A.; Morgan, J. K.; Ocean DrillingSeismic Hazard, P. E.

    2008-12-01

    Submarine geohazards are some of the most devastating natural events in terms of lives lost and economic impact. Earthquakes pose a big threat to society and infrastructure, but the understanding of their episodic generation is incomplete. Tsunamis are known for their potential of striking coastlines world-wide. Other geohazards originating below the sea surface are equally dangerous for undersea structures and the coastal population: submarine landslides and volcanic islands collapse with little warning and devastating consequences. The European scientific community has a strong focus on geohazards along European and nearby continental margins, especially given their high population densities, and long historic and prehistoric record of hazardous events. For example, the Mediterranean is surrounded by very densely-populated coastline and is the World's leading holiday destination, receiving up 30% of global tourism. In addition, its seafloor is criss-crossed by hydrocarbon pipelines and telecommunication cables. However, the governing processes and recurrence intervals of geohazards are still poorly understood. Examples include, but are not limited to, earthquakes and volcanic eruptions along the active tectonic margins of the Mediterranean and Sea of Marmara, landslides on both active and passive margins, and tsunamites and seismites in the sedimentary record that suggest a long history of similar events. The development of geophysical networks, drilling, sampling and long-term monitoring are crucial to the understanding of earthquake, landslide, and tsunami processes, and to mitigate the associated risks in densely populated and industrialized regions such as Europe. Scientific drilling, particularly in the submarine setting, offers a unique tool to obtain drill core samples, borehole measurements and long-term observations. Hence, it is a critical technology to investigate past, present, and possible future influences of hazardous processes in this area. The

  11. 34. VIEW OF SUBMARINE ESCAPE TRAINING TANK PRIOR TO ADDITION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. VIEW OF SUBMARINE ESCAPE TRAINING TANK PRIOR TO ADDITION OF BLISTERS IN 1959, LOOKING SOUTHEAST - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  12. Russian nuclear-powered submarine decommissioning

    SciTech Connect

    Bukharin, O.; Handler, J.

    1995-11-01

    Russia is facing technical, economic and organizational difficulties in dismantling its oversized and unsafe fleet of nuclear powered submarines. The inability of Russia to deal effectively with the submarine decommissioning crisis increases the risk of environmental disaster and may hamper the implementation of the START I and START II treaties. This paper discusses the nuclear fleet support infrastructure, the problems of submarine decommissioning, and recommends international cooperation in addressing these problems.

  13. Saga is largest commercial submarine ever

    SciTech Connect

    Not Available

    1985-05-01

    The long-range autonomous submarine, Saga, went nuclear last year with an agreement between the French and two Canadian companies. The agreement to convert the prototype from Swedish Stirling closed-cycle combustion engines to a nuclear power supply will make Saga the first non-defense nuclear submarine. With an external hull displacement of 500 tons, Saga will be the largest commercial submarine ever built.

  14. Volcano-tectonic evolution of the polygenetic Kolumbo submarine volcano/Santorini (Aegean Sea)

    NASA Astrophysics Data System (ADS)

    Hübscher, Christian; Ruhnau, M.; Nomikou, P.

    2015-01-01

    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.

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

    SciTech Connect

    Dixon, J.E.; Stolper, E.M. ); Clague, D.A. )

    1991-05-01

    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).

  16. Earthquakes of Loihi submarine volcano and the Hawaiian hot spot.

    USGS Publications Warehouse

    Klein, F.W.

    1982-01-01

    Loihi is an active submarine volcano located 35km S of the island of Hawaii and may eventually grow to be the next and S most island in the Hawaiian chain. The Hawaiian Volcano Observatory recorded two major earthquake swarms located there in 1971-1972 and 1975 which were probably associated with submarine eruptions or intrusions. The swarms were located very close to Loihi's bathymetric summit, except for earthquakes during the second stage of the 1971-1972 swarm, which occurred well onto Loihi's SW flank. The flank earthquakes appear to have been triggered by the preceding activity and possible rifting along Loihi's long axis, similar to the rift-flank relationship at Kilauea volcano. Other changes accompanied the shift in locations from Loihi's summit to its flank, including a shift from burst to continuous seismicity, a rise in maximum magnitude, a change from small earthquake clusters to a larger elongated zone, a drop in b value, and a presumed shift from concentrated volcanic stresses to a more diffuse tectonic stress on Loihi's flank. - Author

  17. Active Submarine Hotspot Volcanism on the Kerguelen Plateau

    NASA Astrophysics Data System (ADS)

    Coffin, M. F.; Leser, T. E.

    2012-12-01

    Heard and McDonald Islands on the Kerguelen Plateau, southern Indian Ocean, are active intraplate hotspot volcanoes. Heard Island is approximately 43 km long, and encompasses an area of approximately 368 square km. It is dominated by Big Ben, a roughly circular volcano with a base diameter of 18-20 km, and a maximum elevation of 2745 m. The McDonald Islands have an area of approximately 2.5 square km. Due to a lack of human habitation and no geoscientific monitoring, and cloud cover precluding satellite remote sensing for geoscientific purposes, the level of volcanic activity of the islands is unknown, but observers on passing ships frequently report eruptions, including molten lava, volcanic plumes, and tephra, and active fumaroles. Bathymetric, seismic reflection, magnetic, and gravity data acquired around Heard and McDonald Islands suggest that submarine magmatism affects a broad region of surrounding Kerguelen Plateau seafloor. In this region, we have identified six distinct fields of sea knolls that we interpret to be volcanic in origin. Individual fields contain from approximately 14 to approximately 140 sea knolls, and are not uniformly distributed around Heard and McDonald Islands. Given that Heard and McDonald Islands are volcanically active, it is likely that at least some of the interpreted submarine volcanoes are active and drive hydrothermal circulation.

  18. Population susceptibility to a variant swine-origin influenza virus A(H3N2) in Vietnam, 2011-2012.

    PubMed

    Hoa, L N M; Bryant, J E; Choisy, M; Nguyet, L A; Bao, N T; Trang, N H; Chuc, N T K; Toan, T K; Saito, T; Takemae, N; Horby, P; Wertheim, H; Fox, A

    2015-10-01

    A reassortant swine-origin A(H3N2) virus (A/swine/BinhDuong/03-9/2010) was detected through swine surveillance programmes in southern Vietnam in 2010. This virus contains haemagglutinin and neuraminidase genes from a human A(H3N2) virus circulating around 2004-2006, and the internal genes from triple-reassortant swine influenza A viruses (IAVs). To assess population susceptibility to this virus we measured haemagglutination inhibiting (HI) titres to A/swine/BinhDuong/03-9/2010 and to seasonal A/Perth/16/2009 for 947 sera collected from urban and rural Vietnamese people during 2011-2012. Seroprevalence (HI ⩾ 40) was high and similar for both viruses, with 62·6% [95% confidence interval (CI) 59·4-65·7] against A/Perth/16/2009 and 54·6% (95% CI 51·4-57·8%) against A/swine/BinhDuong/03-9/2010, and no significant differences between urban and rural participants. Children aged <5 years lacked antibodies to the swine origin H3 virus despite high seroprevalence for A/Perth/16/2009. These results reveal vulnerability to infection to this contemporary swine IAV in children aged <5 years; however, cross-reactive immunity in adults would likely limit epidemic emergence potential. PMID:25761949

  19. Gravity wave characteristics in the middle atmosphere during the CESAR campaign at Palma de Mallorca in 2011/2012: Impact of extratropical cyclones and cold fronts

    NASA Astrophysics Data System (ADS)

    Kramer, R.; Wüst, S.; Schmidt, C.; Bittner, M.

    2015-06-01

    Based on a measuring campaign which was carried out at Mallorca (39.6°N, 2.7°E) as cooperation between Agència Estatal de Meteorologia (AEMET) and Deutsches Zentrum für Luft- und Raumfahrt, engl. 'German Aerospace Center' (DLR) in 2011/2012 (September-January), 143 radiosondes (day and night) providing vertical temperature and wind profiles were released. Additionally, nocturnal mesopause temperature measurements with a temporal resolution of about 1 min were conducted by the infrared (IR) - Ground-based Infrared P-branch Spectrometer (GRIPS) during the campaign period. Strongly enhanced gravity wave activity in the lower stratosphere is observed which can be attributed to a hurricane-like storm (so-called Medicane) and to passing by cold fronts. Statistical features of gravity wave parameters including energy densitiy and momentum fluxes are calculated. Gravity wave momentum fluxes turned out being up to five times larger during severe weather. Moreover, gravity wave horizontal propagation characteristics are derived applying hodograph and Stokes parameter analysis. Preferred directions are of southeast and northwest due to prevailing wind directions at Mallorca.

  20. Determination of serum lipid profile in patients with diabetic macular edema that referred to Shahid Beheshti and Ayatollah Rouhani Hospitals, Babol during 2011-2012

    PubMed Central

    Rasoulinejad, Seyed Ahmad; Iri, Habib-Ollah

    2015-01-01

    Background: Diabetes is a common metabolic disorder leading to the development of many complications, among which diabetic retinopathy and macular edema are the most significant. These complications can contribute to blindness if not diagnosed or treated properly, and several studies have been conducted to evaluate the methods for the prevention or slowing down their progression. Therefore, serum lipids, apparently play an effective role in the creation and acceleration of macular edema, we therefore determined the relationship of serum lipid level in patients with diabetic macular edema in the present study. Methods: 180 participants were selected from patients with the definite diagnosis of diabetes referred to the eye clinic of Shahid Beheshti and Ayatollah Rouhani Hospitals of Babol during 2011-2012, the patients with a history of taking lipid –lowering drugs and hypertension were excluded from the study. The study data were provided from the medical records of each patients. SPSS Version 18 was used for analyses. Results: In the present investigation, the mean age of participants was 53.22±with the age range of 18-77 years. Ninety patients with diabetic retinopathy and macular edema were compared with ninety patients with diabetic retinopathy without macular edema (control group) were compared. There was a significant difference in serum cholesterol and LDL-cholesterol between patients and groups (p<0.000). Conclusion: The results of this study indicate that high serum cholesterol and LDL-cholesterol is associated with severity of diabetic retinopathy particularly with macular edema PMID:26221504

  1. Isolation of Methicillin-Resistant Staphylococcus aureus (MRSA) from HIV Patients Referring to HIV Referral Center, Shiraz, Iran, 2011-2012.

    PubMed

    Hassanzadeh, Parvin; Hassanzadeh, Yashgin; Mardaneh, Jalal; Rezai, Esmaeel; Motamedifar, Mohammad

    2015-11-01

    Extension of drug resistant Staphylococcus aureus strains is one of the problems of modern society. Presence of methicillin-resistant Staphylococcus aureus (MRSA) in HIV-infected individuals is an important cause of severe infections. Therefore, the main goal of this study was to determine the prevalence rate of MRSA carriage rate among HIV patients referring to the Shiraz HIV referral center (Shiraz, Iran) during 2011-2012. Nasal swabs were obtained from HIV positive patients and were cultured on differential and selective media to isolate Staphylococcus aureus, which was confirmed by standard biochemical tests. For isolation of MRSA isolates, bacterial suspensions were cultured on Muller-Hinton Agar containing NaCl and Oxacillin. Finally, data were analyzed by the SPSS software. Of 180 HIV patients, MRSA was isolated from nasal cavity of 23 (12.8%) patients. Most of the isolates were recovered from male subjects who were under 40 years old. No variables such as skin disease, history of hospitalization or infectious disease had significant association with the MRSA colonization rate. The presence of MRSA isolates in the nasal cavity of HIV patients in such a rate warns us about the potential spreading of MRSA among HIV patients in our society and emphasizes on establishing better prevention strategies. PMID:26538782

  2. Evolution of H2O, CO, and CO2 production in Comet C/2009 P1 Garradd during the 2011-2012 apparition

    NASA Astrophysics Data System (ADS)

    McKay, Adam J.; Cochran, Anita L.; DiSanti, Michael A.; Villanueva, Geronimo; Russo, Neil Dello; Vervack, Ronald J.; Morgenthaler, Jeffrey P.; Harris, Walter M.; Chanover, Nancy J.

    2015-04-01

    We present analysis of high spectral resolution NIR spectra of CO and H2O in Comet C/2009 P1 (Garradd) taken during its 2011-2012 apparition with the CSHELL instrument on NASA's Infrared Telescope Facility (IRTF). We also present analysis of observations of atomic oxygen in Comet Garradd obtained with the ARCES echelle spectrometer mounted on the ARC 3.5-m telescope at Apache Point Observatory and the Tull Coude spectrograph on the Harlan J. Smith 2.7-m telescope at McDonald Observatory. The observations of atomic oxygen serve as a proxy for H2O and CO2. We confirm the high CO abundance in Comet Garradd and the asymmetry in the CO/H2O ratio with respect to perihelion reported by previous studies. From the oxygen observations, we infer that the CO2/H2O ratio decreased as the comet moved towards the Sun, which is expected based on current sublimation models. We also infer that the CO2/H2O ratio was higher pre-perihelion than post-perihelion. We observe evidence for the icy grain source of H2O reported by several studies pre-perihelion, and argue that this source is significantly less abundant post-perihelion. Since H2O, CO2, and CO are the primary ices in comets, they drive the activity. We use our measurements of these important volatiles in an attempt to explain the evolution of Garradd's activity over the apparition.

  3. Evaluation of Chronic Obstructive Pulmonary Disease (COPD) attributed to atmospheric O3, NO2, and SO2 using Air Q Model (2011-2012 year).

    PubMed

    Ghanbari Ghozikali, Mohammad; Heibati, Behzad; Naddafi, Kazem; Kloog, Itai; Oliveri Conti, Gea; Polosa, Riccardo; Ferrante, Margherita

    2016-01-01

    Chronic obstructive pulmonary disease (COPD) is an important disease worldwide characterized by chronically poor airflow. The economic burden of COPD on any society can be enormous if not managed. We applied the approach proposed by the World Health Organization (WHO) using the AirQ2.2.3 software developed by the WHO European Center for Environment and Health on air pollutants in Tabriz (Iran) (2011-2012 year). A 1h average of concentrations of ozone (O3), daily average concentrations of nitrogen dioxide (NO2) and sulfur dioxide (SO2) were used to assess human exposure and health effect in terms of attributable proportion of the health outcome and annual number of excess cases of Hospital Admissions for COPD (HA COPD). The results of this study showed that 2% (95% CI: 0.8-3.1%) of HA COPD were attributed to O3 concentrations over 10 μg/m(3). In addition, 0.7 % (95% CI: 0.1-1.8%) and 0.5% (95% CI: 0-1%) of HA COPD were attributed to NO2 and SO2 concentrations over 10 μg/m(3) respectively. In this study, we have shown that O3, NO2 and SO2 have a significant impact on COPD hospitalization. Given these results the policy decisions are needed in order to reduce the chronic pulmonary diseases caused by air pollution and furthermore better quantification studies are recommended. PMID:26599588

  4. Audit system on Quality of breast cancer diagnosis and Treatment (QT): results of quality indicators on screen-detected lesions in Italy, 2011-2012.

    PubMed

    Ponti, Antonio; Mano, Maria Piera; Tomatis, Mariano; Baiocchi, Diego; Barca, Alessandra; Berti, Rosa; Casella, Denise; D'Ambrosio, Enrico; Delos, Erika; Donati, Giovanni; Falcini, Fabio; Frammartino, Brunella; Frigerio, Alfonso; Giudici, Fabiola; Mantellini, Paola; Naldoni, Carlo; Olla Atzeni, Carlo; Orzalesi, Lorenzo; Pagano, Giovanni; Pietribiasi, Francesca; Pitarella, Sabina; Ravaioli, Alessandra; Silvestri, Anna; Taffurelli, Mario; Tidone, Enrica; Zanconati, Fabrizio; Segnan, Nereo

    2015-01-01

    This annual survey, conducted by the Italian group for mammography screening (GISMa), collects individual data on diagnosis and treatment of about 50% of screen-detected, operated lesions in Italy. The 2011-2012 results show good overall quality and an improving trend over time. A number of critical issues have been identified, including waiting times (which have had a worsening trend over the years) and compliance with the recommendation of not performing frozen section examination on small lesions. Pre-operative diagnosis improved constantly over time, but there is still a large variation between Regions and programmes. For almost 90% of screen-detected invasive cancers a sentinel lymph node (SLN) biopsy was performed on the axilla, avoiding a large number of potentially harmful dissections. On the other hand, potential overuse of SLN dissection for ductal carcinoma in situ, although apparently starting to decline, deserves further investigation. The detailed results have been distributed, among other ways by means of a web-based data-warehouse, to regional and local screening programmes, in order to allow multidisciplinary discussion and identification of the appropriate solutions to any issues documented by the data. The problem of waiting times should be assigned priority. Specialist Breast Units with adequate case volume and enough resources would provide the best setting for making monitoring effective in producing quality improvements with shorter waiting times. PMID:26405775

  5. The role of crystallinity and viscosity in the formation of submarine lava flow morphology

    NASA Astrophysics Data System (ADS)

    McClinton, J. Timothy; White, Scott M.; Colman, Alice; Rubin, Kenneth H.; Sinton, John M.

    2014-09-01

    Submarine lava flow morphology is commonly used to estimate relative flow velocity, but the effects of crystallinity and viscosity are rarely considered. We use digital petrography and quantitative textural analysis techniques to determine the crystallinity of submarine basaltic lava flows, using a set of samples from previously mapped lava flow fields at the hotspot-affected Galápagos Spreading Center. Crystallinity measurements were incorporated into predictive models of suspension rheology to characterize lava flow consistency and rheology. Petrologic data were integrated to estimate bulk lava viscosity. We compared the crystallinity and viscosity of each sample with its flow morphology to determine their respective roles in submarine lava emplacement dynamics. We find no correlation between crystallinity, bulk viscosity, and lava morphology, implying that flow advance rate is the primary control on submarine lava morphology. However, we show systematic variations in crystal size and shape distribution among pillows, lobates, and sheets, suggesting that these parameters are important indicators of eruption processes. Finally, we compared the characteristics of lavas from two different sampling sites with contrasting long-term magma supply rates. Differences between lavas from each study site illustrate the significant effect of magma supply on the physical properties of the oceanic upper crust.

  6. Volcanic Eruptions and Climate

    NASA Astrophysics Data System (ADS)

    Robock, A.

    2012-12-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of these aerosol clouds produce responses in the climate system. Observations and numerical models of the climate system show that volcanic eruptions produce global cooling and were the dominant natural cause of climate change for the past millennium, on timescales from annual to century. Major tropical eruptions produce winter warming of Northern Hemisphere continents for one or two years, while high latitude eruptions in the Northern Hemisphere weaken the Asian and African summer monsoon. The Toba supereruption 74,000 years ago caused very large climate changes, affecting human evolution. However, the effects did not last long enough to produce widespread glaciation. An episode of four large decadally-spaced eruptions at the end of the 13th century C.E. started the Little Ice Age. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade had a small effect on global temperature trends. The June 13, 2011 Nabro eruption in Eritrea produced the largest stratospheric aerosol cloud since Pinatubo, and the most of the sulfur entered the stratosphere not by direct injection, but by slow lofting in the Asian summer monsoon circulation. Volcanic eruptions warn us that while stratospheric geoengineering could cool the surface, reducing ice melt and sea level rise, producing pretty sunsets, and increasing the CO2 sink, it could also reduce summer monsoon precipitation, destroy ozone, allowing more harmful UV at the surface, produce rapid warming when stopped, make the sky white, reduce solar power, perturb the ecology with more diffuse radiation, damage airplanes flying in the stratosphere, degrade astronomical observations, affect remote sensing, and affect

  7. Submarines, spacecraft and exhaled breath.

    PubMed

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  8. Reference PMHS Sled Tests to Assess Submarining.

    PubMed

    Uriot, Jérôme; Potier, Pascal; Baudrit, Pascal; Trosseille, Xavier; Petit, Philippe; Richard, Olivier; Compigne, Sabine; Masuda, Mitsutoshi; Douard, Richard

    2015-11-01

    Sled tests focused on pelvis behavior and submarining can be found in the literature. However, they were performed either with rigid seats or with commercial seats. The objective of this study was to get reference tests to assess the submarining ability of dummies in more realistic conditions than on rigid seat, but still in a repeatable and reproducible setup. For this purpose, a semi-rigid seat was developed, which mimics the behavior of real seats, although it is made of rigid plates and springs that are easy to reproduce and simulate with an FE model. In total, eight PMHS sled tests were performed on this semirigid seat to get data in two different configurations: first in a front seat configuration that was designed to prevent submarining, then in a rear seat configuration with adjusted spring stiffness to generate submarining. All subjects sustained extensive rib fractures from the shoulder belt loading. No pelvis fractures and no submarining were observed in the front seat configuration, but two subjects sustained lumbar vertebrae fractures. In the rear seat configuration, all subjects sustained pelvic fractures and demonstrated submarining. Corridors were constructed for the external forces and the PMHS kinematics. They are provided in this paper as new reference tests to assess the biofidelity of human surrogates in different configurations that either result in submarining or do not. In future, it is intended to analyze further seat and restraint system configurations to be able to define a submarining predictor. PMID:26660745

  9. Sedimentary facies in submarine canyons

    NASA Astrophysics Data System (ADS)

    Sumner, E.; Paull, C. K.; Gwiazda, R.; Anderson, K.; Lundsten, E. M.; McGann, M.

    2013-12-01

    Submarine canyons are the major conduits by which sediment, pollutants and nutrients are transported from the continental shelf out into the deep sea. The sedimentary facies within these canyons are remarkably poorly understood because it has proven difficult to accurately sample these heterogeneous and bathymetrically complex environments using traditional ship-based coring techniques. This study exploits a suite of over 100 precisely located vibracores collected using remotely operated vehicles in ten canyons along the northern Californian margin, enabling better understanding of the facies that exist within submarine canyons, their distribution, and the processes responsible for their formation. The dataset reveals three major facies types within the submarine canyons: extremely poorly sorted, coarse-grained sands and gravels with complex and indistinct internal grading patterns and abundant floating clasts; classical normally graded thin bedded turbidites; and a variety of fine-grained muddy deposits. Not all facies are observed within individual canyons, in particular coarse-grained deposits occur exclusively in canyons where the canyon head cuts up to the modern day beach, whereas finer grained deposits have a more complex distribution that relates to processes of sediment redistribution on the shelf. Pairs of cores collected within 30 meters elevation of one another reveal that the coarse-grained chaotic deposits are restricted to the basal canyon floor, with finer-grained deposits at higher elevations on the canyon walls. The remarkable heterogeneity of the facies within these sediment cores illustrate that distinctive processes operate locally within the canyon. In the authors' experience the canyon floor facies represent an unusual facies rarely observed in ancient outcrops, which potentially results from the poor preservation of ancient coarse-grained canyon deposits in the geological record.

  10. Currents in monterey submarine canyon

    USGS Publications Warehouse

    Xu, J. P.; Noble, M.A.

    2009-01-01

    Flow fields of mean, subtidal, and tidal frequencies between 250 and 3300 m water depths in Monterey Submarine Canyon are examined using current measurements obtained in three yearlong field experiments. Spatial variations in flow fields are mainly controlled by the topography (shape and width) of the canyon. The mean currents flow upcanyon in the offshore reaches (>1000 m) and downcanyon in the shallow reaches (100-m amplitude isotherm oscillations and associated high-speed rectilinear currents. The 15-day spring-neap cycle and a ???3-day??? band are the two prominent frequencies in subtidal flow field. Neither of them seems directly correlated with the spring-neap cycle of the sea level.

  11. Solar Prominence Eruption

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.

    1998-01-01

    The prominence that erupts in a prominence eruption is a magnetic structure in the chromosphere and corona. It is visible in chromospheric images by virtue of chromospheric-temperature plasma suspended in the magnetic field, and belongs to that large class of magnetic structures appropriately called filaments because of their characteristic sinewy sigmoidal form. Hence, the term "filament eruption" is used interchangeably with the term "prominence eruption". The magnetic field holding a filament is prone to undergo explosive changes in configuration. In these upheavals, because the filament material is compelled by its high conductivity to ride with the magnetic field that threads it, this material is a visible tracer of the field motion. The part of the magnetic explosion displayed by the entrained filament material is the phenomenon known as a filament eruption, the topic of this article. This article begins with a description of basic observed characteristics of filament eruptions, with attention to the magnetic fields, flares, and coronal mass ejections in which erupting filaments are embedded. The present understanding of these characteristics in terms of the form and action of the magnetic field is then laid out by means of a rudimentary three-dimensional model of the field. The article ends with basic questions that this picture leaves unresolved and with remarks on the observations needed to probe these questions.

  12. Sympathetic Solar Filament Eruptions

    NASA Astrophysics Data System (ADS)

    Wang, Rui; Liu, Ying D.; Zimovets, Ivan; Hu, Huidong; Dai, Xinghua; Yang, Zhongwei

    2016-08-01

    The 2015 March 15 coronal mass ejection as one of the two that together drove the largest geomagnetic storm of solar cycle 24 so far was associated with sympathetic filament eruptions. We investigate the relations between the different filaments involved in the eruption. A surge-like small-scale filament motion is confirmed as the trigger that initiated the erupting filament with multi-wavelength observations and using a forced magnetic field extrapolation method. When the erupting filament moved to an open magnetic field region, it experienced an obvious acceleration process and was accompanied by a C-class flare and the rise of another larger filament that eventually failed to erupt. We measure the decay index of the background magnetic field, which presents a critical height of 118 Mm. Combining with a potential field source surface extrapolation method, we analyze the distributions of the large-scale magnetic field, which indicates that the open magnetic field region may provide a favorable condition for F2 rapid acceleration and have some relation with the largest solar storm. The comparison between the successful and failed filament eruptions suggests that the confining magnetic field plays an important role in the preconditions for an eruption.

  13. Base surge in recent volcanic eruptions

    USGS Publications Warehouse

    Moore, J.G.

    1967-01-01

    A base surge, first identified at the Bikini thermonuclear undersea explosion, is a ring-shaped basal cloud that sweeps outward as a density flow from the base of a vertical explosion column. Base surges are also common in shallow underground test explosions and are formed by expanding gases which first vent vertically and then with continued expansion rush over the crater lip (represented by a large solitary wave in an underwater explosion), tear ejecta from it, and feed a gas-charged density flow, which is the surge cloud. This horizontally moving cloud commonly has an initial velocity of more than 50 meters per second and can carry clastic material many kilometers. Base surges are a common feature of many recent shallow, submarine and phreatic volcanic eruptions. They transport ash, mud, lapilli, and blocks with great velocity and commonly sandblast and knock down trees and houses, coat the blast side with mud, and deposit ejecta at distances beyond the limits of throw-out trajectories. Close to the eruption center, the base surge can erode radial channels and deposit material with dune-type bedding. ?? 1967 Stabilimento Tipografico Francesco Giannini & Figli.

  14. An Erupted Silent Tumour.

    PubMed

    Kudva, Adarsh; Chithra, A; Rao, Nirmala N; Cariappa, K M

    2016-07-01

    Odontomas are the most common odontogenic tumors of the oral cavity which are nonaggressive, hamartomatous in nature consisting of enamel, dentin and cementum. They are called as composite because they contain more than one type of tissue. They are generally asymptomatic, hence recognised on routine radiologic examination. The compound odontoma is composed of multiple small tooth like structures, whereas the complex odontoma consists of a conglomerate mass of enamel and dentine, which bears no anatomical similarity to the tooth. The eruption and infection of odontoma are uncommon, only few cases of erupted complex odontoma are reported in the literature. We report a case of silent erupting complex odontoma. PMID:27408461

  15. Clinical Correlates of Surveillance Events Detected by National Healthcare Safety Network Pneumonia and Lower Respiratory Infection Definitions-Pennsylvania, 2011-2012.

    PubMed

    See, Isaac; Chang, Julia; Gualandi, Nicole; Buser, Genevieve L; Rohrbach, Pamela; Smeltz, Debra A; Bellush, Mary Jo; Coffin, Susan E; Gould, Jane M; Hess, Debra; Hennessey, Patricia; Hubbard, Sydney; Kiernan, Andrea; O'Donnell, Judith; Pegues, David A; Miller, Jeffrey R; Magill, Shelley S

    2016-07-01

    OBJECTIVE To determine the clinical diagnoses associated with the National Healthcare Safety Network (NHSN) pneumonia (PNEU) or lower respiratory infection (LRI) surveillance events DESIGN Retrospective chart review SETTING A convenience sample of 8 acute-care hospitals in Pennsylvania PATIENTS All patients hospitalized during 2011-2012 METHODS Medical records were reviewed from a random sample of patients reported to the NHSN to have PNEU or LRI, excluding adults with ventilator-associated PNEU. Documented clinical diagnoses corresponding temporally to the PNEU and LRI events were recorded. RESULTS We reviewed 250 (30%) of 838 eligible PNEU and LRI events reported to the NHSN; 29 reported events (12%) fulfilled neither PNEU nor LRI case criteria. Differences interpreting radiology reports accounted for most misclassifications. Of 81 PNEU events in adults not on mechanical ventilation, 84% had clinician-diagnosed pneumonia; of these, 25% were attributed to aspiration. Of 43 adult LRI, 88% were in mechanically ventilated patients and 35% had no corresponding clinical diagnosis (infectious or noninfectious) documented at the time of LRI. Of 36 pediatric PNEU events, 72% were ventilator associated, and 70% corresponded to a clinical pneumonia diagnosis. Of 61 pediatric LRI patients, 84% were mechanically ventilated and 21% had no corresponding clinical diagnosis documented. CONCLUSIONS In adults not on mechanical ventilation and in children, most NHSN-defined PNEU events corresponded with compatible clinical conditions documented in the medical record. In contrast, NHSN LRI events often did not. As a result, substantial modifications to the LRI definitions were implemented in 2015. Infect Control Hosp Epidemiol 2016;37:818-824. PMID:27072043

  16. Urinary heavy metals, phthalates and polyaromatic hydrocarbons independent of health events are associated with adult depression: USA NHANES, 2011-2012.

    PubMed

    Shiue, Ivy

    2015-11-01

    Links between environmental chemicals and human health have emerged, but the effects on mental health such as depression were less studied. Therefore, it was aimed to study the relationships between different sets of urinary environmental chemical concentrations and adult depression in a national and population-based setting in recent years. Data was retrieved from the US National Health and Nutrition Examination Survey in 2011-2012 including demographics, serum measurements, lifestyle factors, self-reported health conditions and urinary chemical concentrations. Depression was determined by using the Patient Health Questionnaire with a cutoff point at 9/10. Chi-square test, t test and survey-weighted logistic regression modeling were performed. Among 5560 American adults aged 20-80 years, 363 (7.8%) people were classified as having depression (Patient Health Questionnaire score ≥ 10). They tended to have history of health events. After full adjustment including urinary creatinine; demographic characteristics; lifestyle factors; health conditions (such as cardiovascular, neurological, respiratory, digestive and bone diseases, and injury); and subsample weighing; and higher levels of manganese, tin, and phthalates including mono-2-ethyl-5-carboxypentyl, mono-n-butyl, mono-isobutyl, and mono-benzyl were associated with adult depression. Similarly, urinary polyaromatic hydrocarbons including 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 1-hydroxypyrene, 1-hydroxynaphthalene (1-naphthol), 2-hydroxynaphthalene (2-naphthol) and 4-hydroxyphenanthrene were associated with depression. There were no associations observed in urinary arsenic, phenols, parabens, pesticides, perchlorate, nitrate, thiocyanate and polyfluorinated compounds. Urinary heavy metal, phthalates and polyaromatic hydrocarbons were associated with adult depression, being independent of health events. Further elimination

  17. Clinical Findings Leading to the Diagnosis of Sepsis in Neonates Hospitalized in Imam Khomeini and Bu Ali Hospitals, Sari, Iran: 2011-2012

    PubMed Central

    Farhadi, Roya; Yaghobian, Mahbobeh; Saravi, Benyamin Mohseni

    2014-01-01

    Background: One of the important diseases in neonatal period is sepsis. Clinical sign and symptoms in addition to lab tests are the most important way to accurate diagnosis and prevention of mortality. This study was conducted with the aim of determining the most clinical sign and symptoms which leading to diagnosis of sepsis. Materials and Methods: This is a descriptive cross-sectional study. The medical records of patients hospitalized in hospitals of Mazandaran University of Medical Sciences during 2011-2012 were reviewed. Variables were age, sex, birth and admission weight, clinical sign and symptoms, methods of delivery, admission and discharge condition, discharge status, the time elapsed between showing the symptom and admission to hospital, gestational age and the result of cultures. The data were recorded in a checklist and analyzed with SPSS and descriptive statistics. Results: finding showed that 120 patients discharged during period of study with diagnosis of sepsis. Discharged status of 27 (%22/5) were expired. Median age was 1 day with 8 hours SD, length of stay were 12±1 days, gestational age was 34±3 weeks and median birth weight was 2477±977 grams. The median time elapsed between showing the symptom and admission to hospital was 38±31 hours. Blood culture in 10 (%8/3) and urine culture in 8 (%7/6) patients were positive. None of patients have positive lumbar puncture culture. The frequent sign and symptpms in patients were respiratory distress, poor feeding and lethargy. Conclusion: Early diagnosis of neonatal sepsis is not possible only by specific laboratory exams. Clinical sign and symptoms can help us to prediction and diagnosis of neonatal sepsis. Results of this research revealed that it is not clear which one of manifestations was started first or the second because of medical history sheets don’t show this process. PMID:24999128

  18. Diabetes self-management education and training among privately insured persons with newly diagnosed diabetes--United States, 2011-2012.

    PubMed

    Li, Rui; Shrestha, Sundar S; Lipman, Ruth; Burrows, Nilka R; Kolb, Leslie E; Rutledge, Stephanie

    2014-11-21

    Diabetes is a complex chronic disease that requires active involvement of patients in its management. Diabetes self-management education and training (DSMT), "the ongoing process of facilitating the knowledge, skill, and ability necessary for prediabetes and diabetes self-care," is an important component of integrated diabetes care. It is an intervention in which patients learn about diabetes and how to implement the self-management that is imperative to control the disease. The curriculum of DSMT often includes the diabetes disease process and treatment options; healthy lifestyle; blood glucose monitoring; preventing, detecting and treating diabetes complications; and developing personalized strategies for decision making. The American Diabetes Association recommends providing DSMT to those with newly diagnosed diabetes, because data suggest that when diabetes is first diagnosed is the time when patients are most receptive to such engagement. However, little is known about the proportion of persons with newly diagnosed diabetes participating in DSMT. CDC analyzed data from the Marketscan Commercial Claims and Encounters database (Truven Health Analytics) for the period 2009-2012 to estimate the claim-based proportion of privately insured adults (aged 18-64 years) with newly diagnosed diabetes who participated in DSMT during the first year after diagnosis. During 2011-2012, an estimated 6.8% of privately insured, newly diagnosed adults participated in DSMT during the first year after diagnosis of diabetes. These data suggest that there is a large gap between the recommended guideline and current practice, and that there is both an opportunity and a need to enhance rates of DSMT participation among persons newly diagnosed with diabetes. PMID:25412060

  19. High-frequency monitoring of nitrogen and phosphorus response in three rural catchments to the end of the 2011-2012 drought in England

    NASA Astrophysics Data System (ADS)

    Outram, F. N.; Lloyd, C. E. M.; Jonczyk, J.; Benskin, C. McW. H.; Grant, F.; Perks, M. T.; Deasy, C.; Burke, S. P.; Collins, A. L.; Freer, J.; Haygarth, P. M.; Hiscock, K. M.; Johnes, P. J.; Lovett, A. L.

    2014-09-01

    This paper uses high-frequency bankside measurements from three catchments selected as part of the UK government-funded Demonstration Test Catchments (DTC) project. We compare the hydrological and hydrochemical patterns during the water year 2011-2012 from the Wylye tributary of the River Avon with mixed land use, the Blackwater tributary of the River Wensum with arable land use and the Newby Beck tributary of the River Eden with grassland land use. The beginning of the hydrological year was unusually dry and all three catchments were in states of drought. A sudden change to a wet summer occurred in April 2012 when a heavy rainfall event affected all three catchments. The year-long time series and the individual storm responses captured by in situ nutrient measurements of nitrate and phosphorus (total phosphorus and total reactive phosphorus) concentrations at each site reveal different pollutant sources and pathways operating in each catchment. Large storm-induced nutrient transfers of nitrogen and or phosphorus to each stream were recorded at all three sites during the late April rainfall event. Hysteresis loops suggested transport-limited delivery of nitrate in the Blackwater and of total phosphorus in the Wylye and Newby Beck, which was thought to be exacerbated by the dry antecedent conditions prior to the storm. The high rate of nutrient transport in each system highlights the scale of the challenges faced by environmental managers when designing mitigation measures to reduce the flux of nutrients to rivers from diffuse agricultural sources. It also highlights the scale of the challenge in adapting to future extreme weather events under a changing climate.

  20. Urinary arsenic, heavy metals, phthalates, pesticides, polyaromatic hydrocarbons but not parabens, polyfluorinated compounds are associated with self-rated health: USA NHANES, 2011-2012.

    PubMed

    Shiue, Ivy

    2015-06-01

    Links between environmental chemicals and human health have emerged, but the effects on self-rated health were less studied. Therefore, it was aimed to study the relationships of different sets of urinary environmental chemicals and the self-rated health in a national and population-based study in recent years. Data was retrieved from the US National Health and Nutrition Examination Surveys, 2011-2012, including demographics, serum measurements, lifestyle factors, self-rated health (with two grouping approaches) and urinary environmental chemical concentrations. T test and survey-weighted logistic regression modeling were performed. Among American adults aged 12-80 (n = 6833), 5892 people had reported their general health condition. Two thousand three hundred sixty-nine (40.2 %) people reported their general health condition as excellent or very good while 3523 (59.8 %) reported good, fair, or poor. People who reported their general health condition as good, fair, or poor had higher levels of urinary arsenic, heavy metals (including cadmium, cobalt, manganese, molybdenum, lead, antimony, strontium, tungsten and uranium), phthalates, pesticides and polyaromatic hydrocarbons but lower levels of benzophenone-3 and triclosan. There were no associations with urinary parabens, perchlorate, nitrate, thiocyanate or polyfluorinated compounds. However, only urinary cadmium, benzophenone-3, triclosan, and 2-hydroxynaphthalene remained significant when comparing between "good to excellent" and "poor to fair." This is the first time observing risk associations of urinary arsenic, heavy metal, phthalate, pesticide, and hydrocarbon concentrations and self-rated health in people aged 12-80, although the causality cannot be established. Further elimination of these environmental chemicals in humans might need to be considered in health and environmental policies. PMID:25943515

  1. Urinary heavy metals, phthalates, phenols, thiocyanate, parabens, pesticides, polyaromatic hydrocarbons but not arsenic or polyfluorinated compounds are associated with adult oral health: USA NHANES, 2011-2012.

    PubMed

    Shiue, Ivy

    2015-10-01

    Links between environmental chemicals and human health have emerged over the last few decades, but the effects on oral health have been less studied. Therefore, it was aimed to study the relationships of different sets of urinary chemical concentrations and adult oral health conditions in a national and population-based setting. Data was retrieved from the United States National Health and Nutrition Examination Surveys, 2011-2012 including demographics, self-reported oral health conditions and urinary environmental chemical concentrations (one third representative sample of the study population). Chi-square test, t test, and survey-weighted logistic and multi-nominal regression modeling were performed. Of 4566 American adults aged 30-80, 541 adults (11.9 %) reported poor teeth health while 1020 adults (22.4 %) reported fair teeth. Eight hundred fifty-five people (19.1 %) claimed to have gum disease, presented with higher levels of urinary cadmium, cobalt and polyaromatic hydrocarbons. Six hundred three adults (13.3 %) had bone loss around the mouth, presented with higher levels of cadmium, nitrate, thiocyanate, propyl paraben and polyaromatic hydrocarbons. Eight hundred forty-five adults (18.5 %) had tooth loose not due to injury, presented with higher level of cadmium, thiocyanate and polyaromatic hydrocarbons. Eight hundred forty-five adults (18.5 %) with higher levels of lead, uranium, polyaromatic hydrocarbons but lower level of triclosan noticed their teeth did not look right. Three hundred fifty-one adults (7.7 %) often had aching in the mouth and 650 (14.3 %) had it occasionally, presented with higher levels of phthalates, pesticides and polyaromatic hydrocarbons. Benzophenone-3 and triclosan elicited protective effects. Regulation of environmental chemicals in prevention of adult oral health might need to be considered in future health and environmental policies. PMID:26018285

  2. Dynamic interactions of snow and plants in the boreal forest, winter 2011-2012 revealed by time-lapse photography and LiDAR

    NASA Astrophysics Data System (ADS)

    Filhol, S. V.; Sturm, M.

    2012-12-01

    The winter blanket of snow in the boreal forest is anything but still. In winter 2011-2012 we followed the evolution of a snowpack on a boreal forest plot (0.5 ha) from first snowfall to the beginning of the melt in springtime. We used multiple methods such as time-lapse ground-based LiDAR (Light Detection and Ranging), time-lapse photography, imagery from a suspended cableway, snow-depth sensors, and frequent manual snow-pits. The experimental site is located near Fairbanks, Alaska, a typical boreal forest underlain by permafrost with sparse black spruce, larch, willow, and dwarf birch. We observed snowpack properties to be greatly affected by the vegetation substrate. Interactions between snow and plants are mainly dependent on falling snow properties (rate, wetness), plant heights and stiffness, plant canopy structure (leaves, number of branches, density), succession of weather events (wind before or after snow, thaw events) and pre-existing snow depth. Time-lapse imagery shows interception of snow by trees and shrubs controlled by air-temperature and wind events. LiDAR and snow pit measurements show one class of flexible shrubs (i.e. dwarf birch) bending under load, while a second class (willows) were far stiffer and resisted bending. Where dwarf birch branches were dense, it prevented snow from reaching the ground, leaving a significant air space under the snowpack. This vertical air gap can be as high as 10% of the total snow depth by the end of winter. Improving our understanding of the dynamic relationships between plants and snow is a fundamental key for studying boreal snow physics and snow ecology.

  3. Health Care, Family, and Community Factors Associated with Mental, Behavioral, and Developmental Disorders in Early Childhood - United States, 2011-2012.

    PubMed

    Bitsko, Rebecca H; Holbrook, Joseph R; Robinson, Lara R; Kaminski, Jennifer W; Ghandour, Reem; Smith, Camille; Peacock, Georgina

    2016-03-11

    Sociodemographic, health care, family, and community attributes have been associated with increased risk for mental, behavioral, and developmental disorders (MBDDs) in children (1,2). For example, poverty has been shown to have adverse effects on cognitive, socio-emotional, and physical development (1). A safe place to play is needed for gross motor development, and accessible health care is needed for preventive and illness health care (3). Positive parenting and quality preschool interventions have been shown to be associated with prosocial skills, better educational outcomes, and fewer health risk behaviors over time (2). Protective factors for MBDDs are often shared (4) and conditions often co-occur; therefore, CDC considered MBDDs together to facilitate the identification of factors that could inform collaborative, multidisciplinary prevention strategies. To identify specific factors associated with MBDDs among U.S. children aged 2-8 years, parent-reported data from the most recent (2011-2012) National Survey of Children's Health (NSCH) were analyzed. Factors associated with having any MBDD included inadequate insurance, lacking a medical home, fair or poor parental mental health, difficulties getting by on the family's income, employment difficulties because of child care issues, living in a neighborhood lacking support, living in a neighborhood lacking amenities (e.g., sidewalks, park, recreation center, and library), and living in a neighborhood in poor condition. In a multivariate analysis, fair or poor parental mental health and lacking a medical home were significantly associated with having an MBDD. There was significant variation in the prevalence of these and the other factors by state, suggesting that programs and policies might use collaborative efforts to focus on specific factors. Addressing identified factors might prevent the onset of MBDDs and improve outcomes among children who have one or more of these disorders. PMID:26963052

  4. 29. VIEW OF SUBMARINE ESCAPE TRAINING TANK DURING CONSTRUCTION AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. VIEW OF SUBMARINE ESCAPE TRAINING TANK DURING CONSTRUCTION AT POINT JUST ABOVE THE SUBMARINE SECTION AT THE 110-FOOT LEVEL 1929-1930 - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  5. 32 CFR 700.1058 - Command of a submarine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Command of a submarine. 700.1058 Section 700... Command Detail to Duty § 700.1058 Command of a submarine. The officer detailed to command a submarine... submarines....

  6. 32. VIEW OF PHOTO CAPTIONED 'SUBMARINE BASE, NEW LONDON, CONN. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. VIEW OF PHOTO CAPTIONED 'SUBMARINE BASE, NEW LONDON, CONN. OCTOBER 3, 1932. COMPLETION OF ERECTION OF STEELWORK FOR ELEVATOR. LOOKING NORTH. CONTRACT NO. Y-1539-ELEVATOR, SUBMARINE ESCAPE TANK.' - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  7. 32 CFR 700.1058 - Command of a submarine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Command of a submarine. 700.1058 Section 700... Command Detail to Duty § 700.1058 Command of a submarine. The officer detailed to command a submarine... submarines....

  8. 32 CFR 700.1058 - Command of a submarine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Command of a submarine. 700.1058 Section 700... Command Detail to Duty § 700.1058 Command of a submarine. The officer detailed to command a submarine... submarines....

  9. 32 CFR 700.1058 - Command of a submarine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Command of a submarine. 700.1058 Section 700... Command Detail to Duty § 700.1058 Command of a submarine. The officer detailed to command a submarine... submarines....

  10. 32 CFR 700.1058 - Command of a submarine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Command of a submarine. 700.1058 Section 700... Command Detail to Duty § 700.1058 Command of a submarine. The officer detailed to command a submarine... submarines....

  11. From pumice to obsidian: eruptive behaviors that produce tephra-flow dyads. I- The AD1100 Big Glass Mountain eruption at Medicine Lake Volcano (California).

    NASA Astrophysics Data System (ADS)

    Giachetti, T.; Shea, T.; Gonnermann, H. M.; Donnelly-Nolan, J. M.; Ramsey, D. W.

    2014-12-01

    Associations of tephra and lava flow/domes produced by eruptions involving evolved magmas are a common occurrence in various types of volcanic settings (e.g. Pu'u Wa'awa'a ~114ka, Hawaii; South Mono ~AD625, California; Newberry Big Obsidian flow ~AD700, Oregon; Big Glass Mountain ~AD1100, California; Inyo ~AD1350, California, Chaitén AD2008-2009, Chile; Cordón Caulle AD2011-2012, Chile), ejecting up to a few cubic km of material (tephra+flow/dome). Most, if not all, of these eruptions have in common the paradoxical coexistence of (1) eruptive styles which are inferred to be sustained in nature (subplinian and plinian), with (2) a pulsatory behavior displayed by the resulting fall deposits, and (3) the coeval ejection of vesicular tephra and pyroclastic obsidian. Through two case studies, we explore this apparent set of paradoxes, and their significance in understanding transitions from explosive to effusive behavior. In this first case study (also cf. Leonhardi et al., same session), we present a new detailed stratigraphy of the AD1100 Big Glass Mountain eruption (Medicine Lake Volcano), along with a series of density measurements of tephra collected from several key units identified in the proximal fall deposits. The geochemical character of pumice and obsidian clasts from both the tephra and the obsidian flow is used to trace the origins of the different lithologies involved. We find that tens of waxing and waning cycles occurred during this eruption with at least two protracted phases, and that perhaps the term (sub)plinian may not be completely adequate to describe this particular eruption style. We also review models for the formation of juvenile pyroclastic obsidian in the context of rhyolitic eruptions.

  12. Snake Filament Eruption

    NASA Video Gallery

    A very long solar filament that had been snaking around the Sun erupted on Dec. 6, 2010 with a flourish. NASA's Solar Dynamics Observatory (SDO) caught the action in dramatic detail in extreme ultr...

  13. Triple Solar Eruption

    NASA Video Gallery

    Solar activity surged on the morning of Dec 12, 2010 when the sun erupted three times in quick succession, hurling a trio of bright coronal mass ejections (CMEs) into space. Coronagraphs onboard th...

  14. Seasonality of volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Mason, B. G.; Pyle, D. M.; Dade, W. B.; Jupp, T.

    2004-04-01

    An analysis of volcanic activity during the last three hundred years reveals that volcanic eruptions exhibit seasonality to a statistically significant degree. This remarkable pattern is observed primarily along the Pacific "Ring of Fire" and locally at some individual volcanoes. Globally, seasonal fluctuations amount to 18% of the historical average monthly eruption rate. In some regions, seasonal fluctuations amount to as much as 50% of the average eruption rate. Seasonality principally reflects the temporal distribution of the smaller, dated eruptions (volcanic explosivity index of 0-2) that dominate the eruption catalog. We suggest that the pattern of seasonality correlates with the annual Earth surface deformation that accompanies the movement of surface water mass during the annual hydrological cycle and illustrate this with respect to global models of surface deformation and regional measurements of annual sea level change. For example, seasonal peaks in the eruption rate of volcanoes in Central America, the Alaskan Peninsula, and Kamchatka coincide with periods of falling regional sea level. In Melanesia, in contrast, peak numbers of volcanic eruptions occur during months of maximal regional sea level and falling regional atmospheric pressure. We suggest that the well-documented slow deformation of Earth's surface that accompanies the annual movements of water mass from oceans to continents acts to impose a fluctuating boundary condition on volcanoes, such that volcanic eruptions tend to be concentrated during periods of local or regional surface change rather than simply being distributed randomly throughout the year. Our findings have important ramifications for volcanic risk assessment and volcanoclimate feedback mechanisms.

  15. Generalized eruptive syringomas.

    PubMed

    Jamalipour, Mahnaz; Heidarpour, Mitra; Rajabi, Parvin

    2009-01-01

    Generalized eruptive syringoma is a rare clinical presentation of a benign adnexal tumor that derives from the intraepidermal portion of the eccrine sweat ducts. It presents as successive crops of small flesh-colored papules on the anterior body surfaces. It generally occurs in the peripubertal period. Treatment of this benign condition is cosmetic only. A case of a 28-year-old female with an eight-year history of eruptive syringoma is presented. PMID:20049275

  16. Global estimates of fresh submarine groundwater discharge

    NASA Astrophysics Data System (ADS)

    Luijendijk, Elco; Gleeson, Tom; Moosdorf, Nils

    2016-04-01

    Fresh submarine groundwater discharge, the flow of fresh groundwater to oceans, may be a significant contributor to the water and chemical budgets of the world's oceans. We present new estimates of the flux of fresh groundwater to the world's oceans. We couple density-dependent numerical simulations of generic models of coastal basins with geospatial databases of hydrogeological parameters and topography to resolve the rate of terrestrially-derived submarine groundwater discharge globally. We compare the model results to a new global compilation of submarine groundwater discharge observations. The results show that terrestrially-derived SGD is highly sensitive to permeability. In most watersheds only a small fraction of groundwater recharge contributes to submarine groundwater discharge, with most recharge instead contributing to terrestrial discharge in the form of baseflow or evapotranspiration. Fresh submarine groundwater discharge is only significant in watersheds that contain highly permeable sediments, such as coarse-grained siliciclastic sediments, karstic carbonates or volcanic deposits. Our estimates of global submarine groundwater discharge are much lower than most previous estimates. However, many tropical and volcanic islands are hotspots of submarine groundwater discharge and solute fluxes towards the oceans. The comparison of model results and data highlights the spatial variability of SGD and the difficulty of scaling up observations.

  17. CHALLENGES POSED BY RETIRED RUSSIAN NUCLEAR SUBMARINES

    SciTech Connect

    Rudolph, Dieter; Kroken, Ingjerd; Latyshev, Eduard; Griffith, Andrew

    2003-02-27

    The purpose of this paper is to provide an overview of the challenges posed by retired Russian nuclear submarines, review current U.S. and International efforts and provide an assessment of the success of these efforts.

  18. Eruption column physics

    SciTech Connect

    Valentine, G.A.

    1997-03-01

    In this paper the author focuses on the fluid dynamics of large-scale eruption columns. The dynamics of these columns are rooted in multiphase flow phenomena, so a major part of the paper sets up a foundation on that topic that allows one to quickly assess the inherent assumptions made in various theoretical and experimental approaches. The first part is centered on a set of complex differential equations that describe eruption columns, but the focus is on a general understanding of important physical processes rather than on the mathematics. The author discusses briefly the relative merits and weaknesses of different approaches, emphasizing that the largest advances in understanding are made by combining them. He then focuses on dynamics of steady eruption columns and then on transient phenomena. Finally he briefly reviews the effects of varying behavior of the ambient medium through which an eruption column moves. These final sections will emphasize concepts and a qualitative understanding of eruption dynamics. This paper relies on principles of continuum mechanics and transport processes but does not go into detail on the development of those principles. 36 refs., 36 figs., 3 tabs.

  19. North Kona slump: Submarine flank failure during the early(?) tholeiitic shield stage of Hualalai Volcano

    USGS Publications Warehouse

    Lipman, P.W.; Coombs, M.L.

    2006-01-01

    The North Kona slump is an elliptical region, about 20 by 60 km (1000-km2 area), of multiple, geometrically intricate benches and scarps, mostly at water depths of 2000-4500 m, on the west flank of Hualalai Volcano. Two dives up steep scarps in the slump area were made in September 2001, using the ROV Kaiko of the Japan Marine Science and Technology Center (JAMSTEC), as part of a collaborative Japan-USA project to improve understanding of the submarine flanks of Hawaiian volcanoes. Both dives, at water depths of 2700-4000 m, encountered pillow lavas draping the scarp-and-bench slopes. Intact to only slightly broken pillow lobes and cylinders that are downward elongate dominate on the steepest mid-sections of scarps, while more equant and spherical pillow shapes are common near the tops and bases of scarps and locally protrude through cover of muddy sediment on bench flats. Notably absent are subaerially erupted Hualalai lava flows, interbedded hyaloclastite pillow breccia, and/or coastal sandy sediment that might have accumulated downslope from an active coastline. The general structure of the North Kona flank is interpreted as an intricate assemblage of downdropped lenticular blocks, bounded by steeply dipping normal faults. The undisturbed pillow-lava drape indicates that slumping occurred during shield-stage tholeiitic volcanism. All analyzed samples of the pillow-lava drape are tholeiite, similar to published analyses from the submarine northwest rift zone of Hualalai. Relatively low sulfur (330-600 ppm) and water (0.18-0.47 wt.%) contents of glass rinds suggest that the eruptive sources were in shallow water, perhaps 500-1000-m depth. In contrast, saturation pressures calculated from carbon dioxide concentrations (100-190 ppm) indicate deeper equilibration, at or near sample sites at water depths of -3900 to -2800 m. Either vents close to the sample sites erupted mixtures of undegassed and degassed magmas, or volatiles were resorbed from vesicles during

  20. Personality characteristics of successful Navy submarine personnel.

    PubMed

    Moes, G S; Lall, R; Johnson, W B

    1996-04-01

    This study evaluated the personality characteristics of senior enlisted and occupationally successful Navy submarine personnel. One hundred subjects completed the Schedule for Nonadaptive and Adaptive Personality (SNAP). Results indicated that the traits of detachment, propriety, and workaholism were most descriptive of the sample. Thirty-seven percent met SNAP criteria for a personality disorder, typically antisocial, obsessive-compulsive, or avoidant. The results are discussed in terms of adaptation to environmental demands aboard submarines. Suggestions for further research are offered. PMID:8935516

  1. Submarine landslides: processes, triggers and hazard prediction.

    PubMed

    Masson, D G; Harbitz, C B; Wynn, R B; Pedersen, G; Løvholt, F

    2006-08-15

    Huge landslides, mobilizing hundreds to thousands of km(3) of sediment and rock are ubiquitous in submarine settings ranging from the steepest volcanic island slopes to the gentlest muddy slopes of submarine deltas. Here, we summarize current knowledge of such landslides and the problems of assessing their hazard potential. The major hazards related to submarine landslides include destruction of seabed infrastructure, collapse of coastal areas into the sea and landslide-generated tsunamis. Most submarine slopes are inherently stable. Elevated pore pressures (leading to decreased frictional resistance to sliding) and specific weak layers within stratified sequences appear to be the key factors influencing landslide occurrence. Elevated pore pressures can result from normal depositional processes or from transient processes such as earthquake shaking; historical evidence suggests that the majority of large submarine landslides are triggered by earthquakes. Because of their tsunamigenic potential, ocean-island flank collapses and rockslides in fjords have been identified as the most dangerous of all landslide related hazards. Published models of ocean-island landslides mainly examine 'worst-case scenarios' that have a low probability of occurrence. Areas prone to submarine landsliding are relatively easy to identify, but we are still some way from being able to forecast individual events with precision. Monitoring of critical areas where landslides might be imminent and modelling landslide consequences so that appropriate mitigation strategies can be developed would appear to be areas where advances on current practice are possible. PMID:16844646

  2. Recolonization of the intertidal and shallow subtidal community following the 2008 eruption of Alaska's Kasatochi Volcano

    NASA Astrophysics Data System (ADS)

    Jewett, S. C.; Drew, G. S.

    2014-03-01

    The intertidal and nearshore benthic communities of Kasatochi Island are described following a catastrophic volcanic eruption in 2008. Prior to the eruption, the island was surrounded by a dense bed of canopy-forming dragon kelp Eualaria fistulosa which supported a productive nearshore community. The eruption extended the coastline of the island approximately 400 m offshore to roughly the 20 m isobath. One year following the eruption a reconnaissance survey found the intertidal zone devoid of life. Subtidally, the canopy kelp, as well as limited understory algal species and associated benthic fauna on the hard substratum, were buried by debris from the eruption. The resulting substrate was comprised almost entirely of medium and coarse sands with a depauperate benthic community. Comparisons of habitat and biological communities with other nearby Aleutian Islands and the Icelandic submarine volcanic eruption of Surtsey confirm dramatic reductions in flora and fauna consistent with the initial stages of recovery from a large-scale disturbance event. Four and five years following the eruption brief visits revealed dramatic intertidal and subtidal recolonization of the flora and fauna in some areas. Signs of nesting and fledging of young pigeon guillemots Cepphus columba suggest that the recovery of the nearshore biota may have begun affecting higher trophic levels. Recolonization or lack thereof was tied to bathymetric changes from coastal and nearshore erosion over the study period.

  3. Acneiform facial eruptions

    PubMed Central

    Cheung, Melody J.; Taher, Muba; Lauzon, Gilles J.

    2005-01-01

    OBJECTIVE To summarize clinical recognition and current management strategies for four types of acneiform facial eruptions common in young women: acne vulgaris, rosacea, folliculitis, and perioral dermatitis. QUALITY OF EVIDENCE Many randomized controlled trials (level I evidence) have studied treatments for acne vulgaris over the years. Treatment recommendations for rosacea, folliculitis, and perioral dermatitis are based predominantly on comparison and open-label studies (level II evidence) as well as expert opinion and consensus statements (level III evidence). MAIN MESSAGE Young women with acneiform facial eruptions often present in primary care. Differentiating between morphologically similar conditions is often difficult. Accurate diagnosis is important because treatment approaches are different for each disease. CONCLUSION Careful visual assessment with an appreciation for subtle morphologic differences and associated clinical factors will help with diagnosis of these common acneiform facial eruptions and lead to appropriate management. PMID:15856972

  4. Erupting Volcano Mount Etna

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Expedition Five crew members aboard the International Space Station (ISS) captured this overhead look at the smoke and ash regurgitated from the erupting volcano Mt. Etna on the island of Sicily, Italy in October 2002. Triggered by a series of earthquakes on October 27, 2002, this eruption was one of Etna's most vigorous in years. This image shows the ash plume curving out toward the horizon. The lighter-colored plumes down slope and north of the summit seen in this frame are produced by forest fires set by flowing lava. At an elevation of 10,990 feet (3,350 m), the summit of the Mt. Etna volcano, one of the most active and most studied volcanoes in the world, has been active for a half-million years and has erupted hundreds of times in recorded history.

  5. Human-Powered Submarine Competition: World Submarine International 1996 [and] Design Technology Exhibit: A School Model.

    ERIC Educational Resources Information Center

    Hibberd, John C.; Edwards, Don

    1996-01-01

    Hibbard describes the process used by students at Millersville University to build a human-powered submarine for entry in an international submarine competition. Edwards discusses the Design Technology Exhibit held at Lu Sutton Elementary School, the purpose of which was to challenge students to design a useful structure and provide them with the…

  6. High-resolution monitoring of catchment nutrient response to the end of the 2011-2012 drought in England, captured by the demonstration test catchments

    NASA Astrophysics Data System (ADS)

    Outram, F. N.; Lloyd, C.; Jonczyk, J.; Benskin, C. McW. H.; Grant, F.; Dorling, S. R.; Steele, C. J.; Collins, A. L.; Freer, J.; Haygarth, P. M.; Hiscock, K. M.; Johnes, P. J.; Lovett, A. L.

    2013-12-01

    The Demonstration Test Catchments (DTC) project is a UK Government funded initiative to test the effectiveness of on-farm mitigation measures designed to reduce agricultural pollution without compromising farm productivity. Three distinct catchments in England have been chosen to test the efficacy of mitigation measures on working farms in small tributary sub-catchments equipped with continuous water quality monitoring stations. The Hampshire Avon in the south is a mixed livestock and arable farming catchment, the River Wensum in the east is a lowland catchment with predominantly arable farming and land use in the River Eden catchment in the north-west is predominantly livestock farming. One of the many strengths of the DTC as a national research platform is that it provides the ability to investigate catchment hydrology and biogeochemical response across different landscapes and geoclimatic characteristics, with a range of differing flow behaviours, geochemistries and nutrient chemistries. Although numerous authors present studies of individual catchment responses to storms, no studies exist of multiple catchment responses to the same rainfall event captured with in situ high-resolution nutrient monitoring at a national scale. This paper brings together findings from all three DTC research groups to compare the response of the catchments to a major storm event in April 2012. This was one of the first weather fronts to track across the country following a prolonged drought period affecting much of the UK through 2011-2012, marking an unusual meteorological transition when a rapid shift from drought to flood risk occurred. The effects of the weather front on discharge and water chemistry parameters, including nitrogen species (NO3-N and NH4-N) and phosphorus fractions (total P (TP) and total reactive P (TRP)), measured at a half-hourly time step are examined. When considered in the context of one hydrological year, flow and concentration duration curves reveal that

  7. Vapour dynamics during magma-water interaction experiments: hydromagmatic origins of submarine volcaniclastic particles (limu o Pele)

    NASA Astrophysics Data System (ADS)

    Schipper, C. Ian; Sonder, Ingo; Schmid, Andrea; White, James D. L.; Dürig, Tobias; Zimanowski, Bernd; Büttner, Ralf

    2013-03-01

    Recent observations have shattered the long-held theory that deep-sea (>500 m) explosive eruptions are impossible; however, determining the dynamics of unobserved eruptions requires interpretation of the deposits they produce. For accurate interpretation to be possible, the relative abilities of explosive magmatic degassing and non-explosive magma-water interaction to produce characteristic submarine volcaniclastic particles such as `limu o Pele' (bubble wall shards of glass) must be established. We experimentally address this problem by pouring remelted basalt (1300 °C, anhydrous) into a transparent, water-filled reservoir, recording the interaction with a high-speed video camera and applying existing heat transfer models. We performed the experiments under moderate to high degrees of water subcooling (˜8 l of water at 58 and 3 °C), with ˜0.1 to 0.15 kg of melt poured at ˜10-2 kg s-1. Videos show the non-explosive, hydromagmatic blowing and bursting of isolated melt bubbles to form limu o Pele particles that are indistinguishable from those found in submarine volcaniclastic deposits. Pool boiling around growing melt bubbles progresses from metastable vapour film insulation, through vapour film retraction/collapse, to direct melt-water contact. These stages are linked to the evolution of melt-water heat transfer to verify the inverse relationship between vapour film stability and the degree of water subcooling. The direct contact stage in particular explains the extremely rapid quench rates determined from glass relaxation speedometry for natural limu. Since our experimentally produced limu is made entirely by the entrapping of ambient water in degassed basaltic melt, we argue that the presence of fast-quenched limu o Pele in natural deposits is not diagnostic of volatile-driven explosive eruptions. This must be taken into account if submarine eruption dynamics are to be accurately inferred from the deposits and particles they produce.

  8. Ultra-long-range hydroacoustic observations of submarine volcanic activity at Monowai, Kermadec Arc

    NASA Astrophysics Data System (ADS)

    Metz, D.; Watts, A. B.; Grevemeyer, I.; Rodgers, M.; Paulatto, M.

    2016-02-01

    Monowai is an active submarine volcanic center in the Kermadec Arc, Southwest Pacific Ocean. During May 2011, it erupted over a period of 5 days, with explosive activity directly linked to the generation of seismoacoustic T phases. We show, using cross-correlation and time-difference-of-arrival techniques, that the eruption is detected as far as Ascension Island, equatorial South Atlantic Ocean, where a bottom moored hydrophone array is operated as part of the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organization. Hydroacoustic phases from the volcanic center must therefore have propagated through the Sound Fixing and Ranging channel in the South Pacific and South Atlantic Oceans, a source-receiver distance of ~15,800 km. We believe this to be the furthest documented range of a naturally occurring underwater signal above 1 Hz. Our findings, which are consistent with observations at regional broadband stations and long-range, acoustic parabolic equation modeling, have implications for submarine volcano monitoring.

  9. A large submarine sand-rubble flow on kilauea volcano, hawaii

    USGS Publications Warehouse

    Fornari, D.J.; Moore, J.G.; Calk, L.

    1979-01-01

    Papa'u seamount on the south submarine slope of Kilauea volcano is a large landslide about 19 km long, 6 km wide, and up to 1 km thick with a volume of about 39 km3. Dredge hauls, remote camera photographs, and submersible observations indicate that it is composed primarily of unconsolidated angular glassy basalt sand with scattered basalt blocks up to 1 m in size; no lava flows were seen. Sulfur contents of basalt glass from several places on the sand-rubble flow and nearby areas are low (< 240 ppm), indicating that the clastic basaltic material was all erupted on land. The Papa'u sandrubble flow was emplaced during a single flow event fed from a large near-shore bank of clastic basaltic material which in turn was formed as lava flows from the summit area of Kilauea volcano disintegrated when they entered the sea. The current eruptive output of the volcano suggests that the material in the submarine sand-rubble flow represents about 6000 years of accumulation, and that the flow event occurred several thousand years ago. ?? 1979.

  10. A multidisciplinary effort to assign realistic source parameters to models of volcanic ash-cloud transport and dispersion during eruptions

    USGS Publications Warehouse

    Mastin, L.G.; Guffanti, M.; Servranckx, R.; Webley, P.; Barsotti, S.; Dean, K.; Durant, A.; Ewert, J.W.; Neri, A.; Rose, William I., Jr.; Schneider, D.; Siebert, L.; Stunder, B.; Swanson, G.; Tupper, A.; Volentik, A.; Waythomas, C.F.

    2009-01-01

    During volcanic eruptions, volcanic ash transport and dispersion models (VATDs) are used to forecast the location and movement of ash clouds over hours to days in order to define hazards to aircraft and to communities downwind. Those models use input parameters, called "eruption source parameters", such as plume height H, mass eruption rate ???, duration D, and the mass fraction m63 of erupted debris finer than about 4??{symbol} or 63????m, which can remain in the cloud for many hours or days. Observational constraints on the value of such parameters are frequently unavailable in the first minutes or hours after an eruption is detected. Moreover, observed plume height may change during an eruption, requiring rapid assignment of new parameters. This paper reports on a group effort to improve the accuracy of source parameters used by VATDs in the early hours of an eruption. We do so by first compiling a list of eruptions for which these parameters are well constrained, and then using these data to review and update previously studied parameter relationships. We find that the existing scatter in plots of H versus ??? yields an uncertainty within the 50% confidence interval of plus or minus a factor of four in eruption rate for a given plume height. This scatter is not clearly attributable to biases in measurement techniques or to well-recognized processes such as elutriation from pyroclastic flows. Sparse data on total grain-size distribution suggest that the mass fraction of fine debris m63 could vary by nearly two orders of magnitude between small basaltic eruptions (??? 0.01) and large silicic ones (> 0.5). We classify eleven eruption types; four types each for different sizes of silicic and mafic eruptions; submarine eruptions; "brief" or Vulcanian eruptions; and eruptions that generate co-ignimbrite or co-pyroclastic flow plumes. For each eruption type we assign source parameters. We then assign a characteristic eruption type to each of the world's ??? 1500

  11. A multidisciplinary effort to assign realistic source parameters to models of volcanic ash-cloud transport and dispersion during eruptions

    NASA Astrophysics Data System (ADS)

    Mastin, L. G.; Guffanti, M.; Servranckx, R.; Webley, P.; Barsotti, S.; Dean, K.; Durant, A.; Ewert, J. W.; Neri, A.; Rose, W. I.; Schneider, D.; Siebert, L.; Stunder, B.; Swanson, G.; Tupper, A.; Volentik, A.; Waythomas, C. F.

    2009-09-01

    During volcanic eruptions, volcanic ash transport and dispersion models (VATDs) are used to forecast the location and movement of ash clouds over hours to days in order to define hazards to aircraft and to communities downwind. Those models use input parameters, called "eruption source parameters", such as plume height H, mass eruption rate Ṁ, duration D, and the mass fraction m63 of erupted debris finer than about 4ϕ or 63 μm, which can remain in the cloud for many hours or days. Observational constraints on the value of such parameters are frequently unavailable in the first minutes or hours after an eruption is detected. Moreover, observed plume height may change during an eruption, requiring rapid assignment of new parameters. This paper reports on a group effort to improve the accuracy of source parameters used by VATDs in the early hours of an eruption. We do so by first compiling a list of eruptions for which these parameters are well constrained, and then using these data to review and update previously studied parameter relationships. We find that the existing scatter in plots of H versus Ṁ yields an uncertainty within the 50% confidence interval of plus or minus a factor of four in eruption rate for a given plume height. This scatter is not clearly attributable to biases in measurement techniques or to well-recognized processes such as elutriation from pyroclastic flows. Sparse data on total grain-size distribution suggest that the mass fraction of fine debris m63 could vary by nearly two orders of magnitude between small basaltic eruptions (˜ 0.01) and large silicic ones (> 0.5). We classify eleven eruption types; four types each for different sizes of silicic and mafic eruptions; submarine eruptions; "brief" or Vulcanian eruptions; and eruptions that generate co-ignimbrite or co-pyroclastic flow plumes. For each eruption type we assign source parameters. We then assign a characteristic eruption type to each of the world's ˜ 1500 Holocene

  12. Kimberlite ascent and eruption.

    PubMed

    Sparks, R S J; Brown, R J; Field, M; Gilbertson, M

    2007-12-13

    Wilson and Head model kimberlite ascent and eruption by considering the propagation of a volatile-rich dyke. Wilson and Head's model has features in common with Sparks et al., but it is inconsistent with geological observations and constraints on volatile solubility. Here we show that this may be due to erroneous physical assumptions. PMID:18075522

  13. Volcanic Eruptions and Climate

    NASA Technical Reports Server (NTRS)

    LeGrande, Allegra N.; Anchukaitis, Kevin J.

    2015-01-01

    Volcanic eruptions represent some of the most climatically important and societally disruptive short-term events in human history. Large eruptions inject ash, dust, sulfurous gases (e.g. SO2, H2S), halogens (e.g. Hcl and Hbr), and water vapor into the Earth's atmosphere. Sulfurous emissions principally interact with the climate by converting into sulfate aerosols that reduce incoming solar radiation, warming the stratosphere and altering ozone creation, reducing global mean surface temperature, and suppressing the hydrological cycle. In this issue, we focus on the history, processes, and consequences of these large eruptions that inject enough material into the stratosphere to significantly affect the climate system. In terms of the changes wrought on the energy balance of the Earth System, these transient events can temporarily have a radiative forcing magnitude larger than the range of solar, greenhouse gas, and land use variability over the last millennium. In simulations as well as modern and paleoclimate observations, volcanic eruptions cause large inter-annual to decadal-scale changes in climate. Active debates persist concerning their role in longer-term (multi-decadal to centennial) modification of the Earth System, however.

  14. Eruption on Io

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This image, taken by NASA's Galileo spacecraft, shows a new blue-colored volcanic plume extending about 100 kilometers (about 60 miles) into space from Jupiter's moon Io (see inset at lower left). The blue color of the plume is consistent with the presence of sulfur dioxide gas and 'snow' condensing from the gas as the plume expands and cools. Galileo images have also shown that the Ra Patera plume glows in the dark, perhaps due to the fluorescence of sulfur and oxygen ions created by the breaking apart of sulfur dioxide molecules by energetic particles in the Jovian magnetosphere. The images at right show a comparison of changes seen near the volcano Ra Patera since the Voyager spacecraft flybys of 1979 (windows at right show Voyager image at top and Galileo image at bottom). This eruptive plume is an example of a new type of volcanic activity discovered during Voyager's flyby in 1979, believed to be geyser-like eruptions driven by sulfur dioxide or sulfur gas erupting and freezing in Io's extremely tenuous atmosphere. Volcanic eruptions on Earth cannot throw materials to such high altitudes. Ra Patera is the site of dramatic surface changes. An area around the volcano of about 40,000 square kilometers, area about the size of New Jersey, has been covered by new volcanic deposits. The image was taken in late June 28, 1996 from a distance of 972,000 kilometers (604,000 miles). The Galileo mission is managed by NASA's Jet Propulsion Laboratory.

  15. Reunion Island Volcano Erupts

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On January 16, 2002, lava that had begun flowing on January 5 from the Piton de la Fournaise volcano on the French island of Reunion abruptly decreased, marking the end of the volcano's most recent eruption. These false color MODIS images of Reunion, located off the southeastern coast of Madagascar in the Indian Ocean, were captured on the last day of the eruption (top) and two days later (bottom). The volcano itself is located on the southeast side of the island and is dark brown compared to the surrounding green vegetation. Beneath clouds (light blue) and smoke, MODIS detected the hot lava pouring down the volcano's flanks into the Indian Ocean. The heat, detected by MODIS at 2.1 um, has been colored red in the January 16 image, and is absent from the lower image, taken two days later on January 18, suggesting the lava had cooled considerably even in that short time. Earthquake activity on the northeast flank continued even after the eruption had stopped, but by January 21 had dropped to a sufficiently low enough level that the 24-hour surveillance by the local observatory was suspended. Reunion is essentially all volcano, with the northwest portion of the island built on the remains of an extinct volcano, and the southeast half built on the basaltic shield of 8,630-foot Piton de la Fournaise. A basaltic shield volcano is one with a broad, gentle slope built by the eruption of fluid basalt lava. Basalt lava flows easily across the ground remaining hot and fluid for long distances, and so they often result in enormous, low-angle cones. The Piton de la Fournaise is one of Earth's most active volcanoes, erupting over 150 times in the last few hundred years, and it has been the subject of NASA research because of its likeness to the volcanoes of Mars. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  16. Psychological aspects in a volcanic crisis: El Hierro Island eruption (October, 2011).

    NASA Astrophysics Data System (ADS)

    Lopez, P.; Llinares, A.; Garcia, A.; Marrero, J. M.; Ortiz, R.

    2012-04-01

    The recent eruption on the El Hierro Island (Canary Islands, Spain) has shown that Psychology plays an important role in the emergence management of a natural phenomenon. However, Psychology continues to have no social coverage it deserves in the mitigation of the effects before, during and after the occurrence of a natural phenomenon. Keep in mind that an unresolved psychological problem involves an individual and collective mismatch may become unrecoverable. The population of El Hierro has been under a state of alert since July 2011, when seismic activity begins, until the occurrence of submarine eruption in October 2011 that is held for more than three months. During this period the inhabitants of the small island have gone through different emotional states ranging from confusion to disappointment. A volcanic eruption occurs not unexpectedly, allowing to have a time of preparation / action before the disaster. From the psychological point of view people from El Hierro Island have responded to different stages of the same natural process. Although the island of El Hierro is of volcanic origin, the population has no historical memory since the last eruption occurred in 1793. Therefore, the educational system does not adequately address the formation in volcanic risk. As a result people feel embarrassment when the seismovolcanic crisis begins, although no earthquakes felt. As an intermediate stage, when the earthquakes are felt by the population, scientists and operational Emergency Plan care to inform and prepare actions in case of a possible eruption. The population feel safe despite the concerns expressed by not knowing where, how and when the eruption will occur. Once started the submarine eruption, taking into account that all the actions (evacuation, relocation, etc.) have worked well and that both their basic needs and security are covered there are new states of mind. These new emotional states ranging from disenchantment with the phenomenology of the

  17. Mathematical modelling of submarine landslide motion

    NASA Astrophysics Data System (ADS)

    Burminskij, A.

    2012-04-01

    Mathematical modelling of submarine landslide motion The paper presents a mathematical model to calculate dynamic parameters of a submarine landslide. The problem of estimation possible submarine landslides dynamic parameters and run-out distances as well as their effect on submarine structures becomes more and more actual because they can have significant impacts on infrastructure such as the rupture of submarine cables and pipelines, damage to offshore drilling platforms, cause a tsunami. In this paper a landslide is considered as a viscoplastic flow and is described by continuum mechanics equations, averaged over the flow depth. The model takes into account friction at the bottom and at the landslide-water boundary, as well as the involvement of bottom material in motion. A software was created and series of test calculations were performed. Calculations permitted to estimate the contribution of various model coefficients and initial conditions. Motion down inclined bottom was studied both for constant and variable slope angle. Examples of typical distributions of the flow velocity, thickness and density along the landslide body at different stages of motion are given.

  18. Quantitative constraints on the growth of submarine lava pillars from a monitoring instrument that was caught in a lava flow

    NASA Astrophysics Data System (ADS)

    Chadwick, William W.

    2003-11-01

    Lava pillars are hollow, vertical chimneys of solid basaltic lava that are common features within the collapsed interiors of submarine sheet flows on intermediate and fast spreading mid-ocean ridges. They are morphologically similar to lava trees that form on land when lava overruns forested areas, but the sides of lava pillars are covered with distinctive, evenly spaced, thin, horizontal lava crusts, referred to hereafter as "lava shelves." Lava stalactites up to 5 cm long on the undersides of these shelves are evidence that cavities filled with a hot vapor phase existed temporarily beneath each crust. During the submarine eruption of Axial Volcano in 1998 on the Juan de Fuca Ridge a monitoring instrument, called VSM2, became embedded in the upper crust of a lava flow that produced 3- to 5-m-high lava pillars. A pressure sensor in the instrument showed that the 1998 lobate sheet flow inflated 3.5 m and then drained out again in only 2.5 hours. These data provide the first quantitative constraints on the timescale of lava pillar formation and the rates of submarine lava flow inflation and drainback. They also allow comparisons to lava flow inflation rates observed on land, to theoretical models of crust formation on submarine lava, and to previous models of pillar formation. A new model is presented for the rhythmic formation of alternating lava crusts and vapor cavities to explain how stacks of lava shelves are formed on the sides of lava pillars during continuous lava drainback. Each vapor cavity is created between a stranded crust and the subsiding lava surface. A hot vapor phase forms within each cavity as seawater is syringed through tiny cracks in the stranded crust above. Eventually, the subsiding lava causes the crust above to fail, quenching the hot cavity and forming the next lava crust. During the 1998 eruption at Axial Volcano, this process repeated itself about every 2 min during the 81-min-long drainback phase of the eruption, based on the thickness

  19. Post-eruptive morphological evolution of island volcanoes: Surtsey as a modern case study

    NASA Astrophysics Data System (ADS)

    Romagnoli, C.; Jakobsson, S. P.

    2015-12-01

    Surtsey is a small volcanic island in the Vestmannaeyjar archipelago, off the south coast of Iceland. The eruption leading to the island's emersion lasted for 3.5 yr (1963-1967) while destructive forces have been active for over 50 yr (1963-present-day) during which Surtsey has suffered rapid subaerial and submarine erosion and undergone major morphological changes. Surtsey is a well-documented modern example of the post-eruptive degradational stage of island volcanoes, and has provided the unique opportunity to continuously observe and quantify the effects of intense geomorphic processes. In this paper we focus on coastal and marine processes re-shaping the shoreline and shallow-water portions of the Surtsey complex since its formation and on the related geomorphological record. Analogies with the post-eruptive morphological evolution of recently active island volcanoes at the emerging stage, encompassing different climatic conditions, wave regimes and geological contexts, are discussed.

  20. Submarine explosive volcanism in the southeastern Terceira Rift/São Miguel region (Azores)

    NASA Astrophysics Data System (ADS)

    Weiß, B. J.; Hübscher, C.; Wolf, D.; Lüdmann, T.

    2015-09-01

    Morphologic studies with sonar data and in situ observations of modern eruptions have revealed some information suggesting how submarine volcanic cones develop, but the information only addresses the modern surfaces of these features. Here, we describe a study combining morphological data with high-resolution seismic reflection data collected over cones within the southeastern Terceira Rift - a succession of deep basins, volcanic bathymetric highs and islands (e.g. São Miguel) representing the westernmost part of the Eurasian-Nubian plate boundary. The cones (252) are distributed in depths down to 3200 m and exhibit an average diameter of 743 m, an average slope of 20° and heights mainly between 50 and 200 m. The cones are here classified into three different categories by physiographic or tectonic setting (we find no particular morphometric differences in cone shapes between these areas). First, numerous cones located at the submarine flanks of São Miguel's Sete Cidades and Fogo Volcano are considered to be parasitic structures. Second, in the southeast of the island, they form a superstructure possibly reflecting an early submarine stadium of a posterior subaerial stratovolcano. Third, some cones are controlled by faults, mostly in a graben system southwest of the island. High-resolution multichannel seismic data indicates that the graben cones evolved synchronously with the graben formation. Bottom currents then probably removed the surficial fine grain-size fraction, leaving rough surface textures of the cones, which backscatter sonar signals strongly in the data recorded here. However, a young cone investigated in detail is characterized by a smooth surface, a marked increase of internal stratification with increasing distance from the summit and upwards concave flanks. Others exhibit central craters, suggesting an explosive than an effusive evolution of these structures. The morphological characteristics of these submarine cones show that they have similar

  1. 35. INTERIOR VIEW OF EQUIPMENT HOUSE, SUBMARINE ESCAPE TRAINING TANK, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. INTERIOR VIEW OF EQUIPMENT HOUSE, SUBMARINE ESCAPE TRAINING TANK, PRIOR TO ENLARGEMENT OF ROOM AND INSTALLATION OF TRIPLE-LOCK RECOMPRESSION CHAMBER IN 1957 - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  2. 36. VIEW OF CUPOLA, SUBMARINE ESCAPE TRAINING TANK, SHOWING ROVING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. VIEW OF CUPOLA, SUBMARINE ESCAPE TRAINING TANK, SHOWING ROVING RESCUE BELL SUSPENDED ABOVE TANK, WITH TWO-LOCK RECOMPRESSION CHAMBER AT REAR, LOOKING WEST. Photo taken after installation of recompression chamber in 1956. - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  3. Reducing Unsteady Loads on a Piggyback Miniature Submarine

    NASA Technical Reports Server (NTRS)

    Lin, John

    2009-01-01

    A small, simple fixture has been found to be highly effective in reducing destructive unsteady hydrodynamic loads on a miniature submarine that is attached in piggyback fashion to the top of a larger, nuclear-powered, host submarine. The fixture, denoted compact ramp, can be installed with minimal structural modification, and the use of it does not entail any change in submarine operations.

  4. 32 CFR 707.7 - Submarine identification light.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Submarine identification light. 707.7 Section... RULES WITH RESPECT TO ADDITIONAL STATION AND SIGNAL LIGHTS § 707.7 Submarine identification light. Submarines may display, as a distinctive means of identification, an intermittent flashing amber beacon...

  5. 31. VIEW OF SUBMARINE ESCAPE TRAINING TANK DURING CONSTRUCTION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. VIEW OF SUBMARINE ESCAPE TRAINING TANK DURING CONSTRUCTION OF THE ELEVATOR AND PASSAGEWAYS TO THE 18- AND 50-FOOT LOCKS AND CUPOLA 1932 - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  6. An experimental approach to submarine canyon evolution

    NASA Astrophysics Data System (ADS)

    Lai, Steven Y. J.; Gerber, Thomas P.; Amblas, David

    2016-03-01

    We present results from a sandbox experiment designed to investigate how sediment gravity flows form and shape submarine canyons. In the experiment, unconfined saline gravity flows were released onto an inclined sand bed bounded on the downstream end by a movable floor that was used to increase relief during the experiment. In areas unaffected by the flows, we observed featureless, angle-of-repose submarine slopes formed by retrogressive breaching processes. In contrast, areas influenced by gravity flows cascading across the shelf break were deeply incised by submarine canyons with well-developed channel networks. Normalized canyon long profiles extracted from successive high-resolution digital elevation models collapse to a single profile when referenced to the migrating shelf-slope break, indicating self-similar growth in the relief defined by the canyon and intercanyon profiles. Although our experimental approach is simple, the resulting canyon morphology and behavior appear similar in several important respects to that observed in the field.

  7. Geomorphic process fingerprints in submarine canyons

    USGS Publications Warehouse

    Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.; Twichell, David C.

    2013-01-01

    Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics.

  8. First Survey For Submarine Hydrothermal Vents In NE Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    McConachy, T.; Binns, R.; Permana, H.

    2001-12-01

    The IASSHA-2001 cruise (Indonesia-Australia Survey for Submarine Hydrothermal Activity) was successfully conducted from June 1 to June 29 on board Baruna Jaya VIII. Preliminary results are reported of the first expedition to locate and study submarine hydrothermal activity in north east Sulawesi. Leg A focussed on Tomini Bay, a virtually unexplored Neogene sedimentary basin. Its objective was to test whether modern sediment-hosted hydrothermal activity occurred on the sea floor. The results of new bathymetric mapping, sediment coring and CTD/transmissometer hydrocasts negate the likely presence in central Tomini Bay of large-scale modern analogues of hydrothermal massive sulfide environments involving hydrothermal venting of basinal or magma-derived fluids into reduced sediments. It is possible that the "heat engine" required to drive circulation of basinal and hydrothermal fluids is today too weak. Surveys around Colo volcano indicate that it may be in its final stage of evolution. Leg B studied the arc and behind-arc sectors of the Sangihe volcanic island chain extending northwards from Quaternary volcanoes on the northeastern tip of Sulawesi's North Arm, near Manado. West of the main active chain and extending northwards from Manado there is a subparallel ridge surmounted by a number of high (>2000 m) seamounts of uncertain age. Fifteen relatively high-standing submarine edifices were crossed during this leg, of which nine were tested for hydrothermal activity by hydrocast and dredging. Eight sites were known from previous bathymetric surveys, and seven are new discoveries made by narrow-beam or multibeam echo sounding. Two submarine edifices at least 1000 m high were discovered in the strait immediately north of Awu volcano on Sangihe Island. One, with crest at 206 m, is surrounded by a circular platform 300m deep which we infer to be a foundered fringing reef to a formerly emergent island. The other, lacking such a platform, appears relatively young and may be

  9. A model for the submarine depthkeeping team

    NASA Technical Reports Server (NTRS)

    Ware, J. R.; Best, J. F.; Bozzi, P. J.; Kleinman, D. W.

    1981-01-01

    The most difficult task the depthkeeping team must face occurs during periscope-depth operations during which they may be required to maintain a submarine several hundred feet long within a foot of ordered depth and within one-half degree of ordered pitch. The difficulty is compounded by the facts that wave generated forces are extremely high, depth and pitch signals are very noisy and submarine speed is such that overall dynamics are slow. A mathematical simulation of the depthkeeping team based on the optimal control models is described. A solution of the optimal team control problem with an output control restriction (limited display to each controller) is presented.

  10. Transporting submarine engines to power the PRT

    NASA Technical Reports Server (NTRS)

    1926-01-01

    The city of Hampton was unable to supply adequate electric power to operate the PRT. Navy Captain Walter S. Diehl, Bureau of Aeronautics, acquired two 1000 hp submarine engines which were to be disposed of. BuAer 'loaned' the engines to the NACA, one of which is shown here. Next to the engine is Donald H. Wood, a mechanical engineer from Rensselaer Polytechnic Institute and Fred Weick's assistant. Propeller Research Tunnel (PRT) engineer Donald H. Wood ponders the unlikely transfer of a submarine engine from rail car to NACA truck, May 1926. Two such diesel engines powered the PRT.

  11. Pattern classification of volcanic tremor data related to the 2007-2012 Mt. Etna (Italy) eruptive episodes

    NASA Astrophysics Data System (ADS)

    Spampinato, Salvatore; Falsaperla, Susanna; Langer, Horst; Messina, Alfio

    2013-04-01

    From March 2007 to April 2012 one of the main craters of Mt. Etna volcano, the South East Crater, was frequently active with spectacular, even though low dangerous, eruptions mainly in form of lava fountains. Thirty-three eruptive episodes occurred at that crater, encompassing thirty-two paroxysmal lava fountains (seven in 2007-2008 and twenty-five in 2011-2012), and a lava emission, started on 13 May 2008 and ended on 6 July 2009, along the upper eastern flank of the volcano. From the seismic point of view, the onset of all these eruptions was heralded by changes in the spectral characteristics of volcanic tremor recorded by digital broadband stations, which permanently monitor the volcanic region. On the basis of the tremor data collected between 2007 and 2009, some of us (Messina and Langer) developed a software which, combining unsupervised classification methods based on Kohonen Maps and the fuzzy cluster analysis, allows to identify transitions from pre-eruptive to eruptive activity through the classification of the tremor characteristics (i.e., amplitude and frequency content). Since 2010 an on-line version of this software is adopted at the Osservatorio Etneo as one of the automatic alerting tools to identify early stages of eruptive events. The software carries out the analysis of the continuous data stream of two key seismic stations, for which reference datasets were elaborated taking into account the tremor data recorded during the eruptive episodes from 2007 to 2009. The numerous paroxysmal eruptions occurred in 2011-2012 and the improved network density, in particular on the summit crater area, after 2009, lead us to extend the application of automatic volcanic tremor classification by using a larger number of stations at different elevation and distance from the summit craters. Datasets have been formed for the new stations, while for the previous key stations, the reference datasets were updated adding new patterns of the tremor signal. We discuss

  12. Nyamuragira Volcano Erupts

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Nyamuragira volcano erupted on July 26, 2002, spewing lava high into the air along with a large plume of steam, ash, and sulfur dioxide. The 3,053-meter (10,013-foot) volcano is located in eastern Congo, very near that country's border with Rwanda. Nyamuragira is the smaller, more violent sibling of Nyiragongo volcano, which devastated the town of Goma with its massive eruption in January 2002. Nyamuragira is situated just 40 km (24 miles) northeast of Goma. This true-color image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite, on July 28, 2002. Nyamuragira is situated roughly in the center of this scene, roughly 100 km south of Lake Edward and just north of Lake Kivu (which is mostly obscured by the haze from the erupting volcano and the numerous fires burning in the surrounding countryside). Due south of Lake Kivu is the long, narrow Lake Tanganyika running south and off the bottom center of this scene.

  13. Exploration of the 1891 Foerstner submarine vent site (Pantelleria, Italy): insights into the formation of basaltic balloons

    NASA Astrophysics Data System (ADS)

    Kelly, Joshua T.; Carey, Steven; Pistolesi, Marco; Rosi, Mauro; Croff-Bell, Katherine Lynn; Roman, Chris; Marani, Michael

    2014-07-01

    On October 17, 1891, a submarine eruption started at Foerstner volcano located within the Pantelleria Rift of the Strait of Sicily (Italy). Activity occurred for a period of 1 week from an eruptive vent located 4 km northwest of the island of Pantelleria at a water depth of 250 m. The eruption produced lava balloons that discharged gas at the surface and eventually sank to the seafloor. Remotely operated vehicle (ROV) video footage and high-resolution multi-beam mapping of the Foerstner vent site were used to create a geologic map of the AD 1891 deposits and conduct the first detailed study of the source area associated with this unusual type of submarine volcanism. The main Foerstner vent consists of two overlapping circular mounds with a total volume of 6.3 × 105 m3 and relief of 60 m. It is dominantly constructed of clastic scoriaceous deposits with some interbedded pillow lavas. Petrographic and geochemical analyses of Foerstner samples by X-ray fluorescence and inductively coupled plasma mass spectrometry reveal that the majority of the deposits are vesicular, hypocrystalline basanite scoria that display porphyritic, hyaloophitic, and vitrophyric textures. An intact lava balloon recovered from the seafloor consists of a large interior gas cavity surrounded by a thin lava shell comprising two distinct layers: a thin, oxidized, quenched crust surrounding the exterior of the balloon and a dark gray, tachylite layer lying beneath it. Ostwald ripening is proposed to be the dominant bubble growth mechanism of four representative Foerstner scoria samples as inferred by vesicle size distributions. Characterization of the diversity of deposit facies observed at Foerstner in conjunction with quantitative rock texture analysis indicates that submarine Strombolian-like activity is the most likely mechanism for the formation of lava balloons. The deposit facies observed at the main Foerstner vent are very similar to those produced by other known submarine Strombolian

  14. Using IMS hydrophone data for detecting submarine volcanic activity: Insights from Monowai, 26°S Kermadec Arc

    NASA Astrophysics Data System (ADS)

    Metz, Dirk; Watts, Anthony B.; Grevemeyer, Ingo; Rodgers, Mel; Paulatto, Michele

    2016-04-01

    Only little is known on active volcanism in the ocean. As eruptions are attenuated by seawater and fallout does not regularly reach the sea surface, eruption rates and mechanisms are poorly understood. Estimations on the number of active volcanoes across the modern seas range from hundreds to thousands, but only very few active sites are known. Monowai is a submarine volcanic centre in the northern Kermadec Arc, Southwest Pacific Ocean. During May 2011, it erupted over a period of five days, with explosive activity directly linked to the generation of seismoacoustic tertiary waves ('T-phases'), recorded at three broadband seismic stations in the region. We show, using windowed cross-correlation and time-difference-of-arrival techniques, that T-phases associated with this eruption are detected as far as Ascension Island, South Atlantic Ocean, where two bottom-moored hydrophone arrays are operated as part of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). We observe a high incidence of T-phase arrivals during the time of the eruption, with the angle of arrival stabilizing at the geodesic azimuth between the IMS arrays and Monowai. T-phases from the volcanic centre must therefore have propagated through the Sound Fixing And Ranging (SOFAR) channel in the South Pacific and South Atlantic Oceans and over a total geodesic range of approximately 15,800 km, one of the longest source-receiver distances of any naturally occurring underwater signal ever observed. Our findings, which are consistent with observations at regional broadband stations and two dimensional, long-range, parabolic equation modelling, highlight the exceptional capabilities of the hydroacoustic waveform component of the IMS for remotely detecting episodes of submarine volcanic activity. Using Monowai and the hydrophone arrays at Ascension Island as a natural laboratory, we investigate the long-term eruptive record of a submarine volcano from

  15. Broad-band spectroscopy of the ongoing large eruption of the luminous blue variable R71

    NASA Astrophysics Data System (ADS)

    Mehner, A.; Baade, D.; Rivinius, T.; Lennon, D. J.; Martayan, C.; Stahl, O.; Štefl, S.

    2013-07-01

    Aims: The luminous blue variable (LBV) R71 is currently undergoing an eruption, which differs photometrically and spectroscopically from its last outburst in the 1970s. Valuable information on the physics of LBV eruptions can be gained by analyzing the spectral evolution during this eruption and by comparing R71's present appearance to its previous outburst and its quiescent state. Methods: An ongoing monitoring program with VLT/X-shooter will secure key spectral data ranging from visual to near-infrared wavelengths. Here we present the first spectra obtained in 2012 and compare them to archival VLT/UVES and MPG/ESO-2.2 m/FEROS spectra from 2002 to 2011. The discussed data include pre-eruption spectra in 2002 and 2005, a spectrum of the transitionary phase between quiescent and eruptive state in 2007, and spectra of the eruption in 2011-2012. Information on R71's 1970s outburst is taken from the literature. Results: The 2011-2012 spectra are dominated by strong neutral and singly ionized metal absorption lines likely formed in a large "pseudo-photosphere". We find an unusually low apparent temperature of R71 of only Teff,2012 ~ 6 650 K; the star resembles a late F supergiant. R71's visual lightcurve had a maximum in 2012 with mV,2012 ~ 8.7 mag. Given the uncertainty in the extinction toward R71, this corresponds to a bolometric luminosity of Mbol,2012 ~ - 9.8 mag to - 10.3 mag. R71's 2011-2012 spectra do not show H i and Fe ii P Cyg profiles, which were present during its last outburst in the 1970s and which are normally observed during LBV outbursts. Low-excitation forbidden emission lines and Fe i P Cyg-like profiles from a slowly expanding nebula became apparent in late 2012. These lines originate likely in the rarefied region above the pseudo-photosphere up to 13 AU from the star. Conclusions: The rise in R71's visual magnitude and the low apparent temperature of its pseudo-photosphere during the current eruption are unprecedented for this star. R71 most likely

  16. Building the Volcanic Oceanic Crust One Eruption at a Time (Invited)

    NASA Astrophysics Data System (ADS)

    Sinton, J. M.; Rubin, K. H.; White, S. M.; Colman, A.; Bowles, J. A.; Gronvold, K.

    2010-12-01

    The physical and chemical characteristics of lava flow fields formed during individual volcanic eruptions provides critical information on the nature of underlying magma reservoirs and the diking events that feed magma to the surface. Chemical variability of individual flow fields can constrain important parameters, such as the depth, geometry, melt percentage, and cooling rate of magma reservoirs and, in some case, whether or not dikes traveled vertically from magma reservoirs to the surface, with examples from the East Pacific Rise, Juan de Fuca Ridge and Iceland. Lava flow morphology and the length of ridge activated during individual eruptions constrain eruption rates and, in some cases, how eruption rates and magma sources vary during the course of long-lived eruptions. Although the study of submarine volcanic eruptions has historically been dominated by study of very recent flow fields or remotely detected “events”, a recent cruise to the Galápagos Spreading Center demonstrated that volcanic geology can be deciphered for areas of seafloor using the same basic methods commonly employed on-land: near-bottom geological observations, remote images at the appropriate spatial resolution, and petrologic and geochronologic study of samples. For the Galápagos study we used the AUV Sentry to obtain very high resolution (~1-m spatial scale) bathymetry, 26 Alvin dives, 17 camera-tows, and on-shore chemical and magnetic paeleointensity sample analyses to identify the areal extents, chemical variability and age constraints of at least 14 previously unknown discrete eruptive units in two areas with highly contrasting average magma supply defined by variations in crustal thickness and spreading rate. Preliminary general results of this study indicate that, at high magma supply, relatively low-volume eruptions are fed from shallow, moderately to highly differentiated, melt-dominated magma chambers to elongate fissures at relatively high average eruption rates. At low

  17. Models of volcanic eruption hazards

    SciTech Connect

    Wohletz, K.H.

    1992-01-01

    Volcanic eruptions pose an ever present but poorly constrained hazard to life and property for geothermal installations in volcanic areas. Because eruptions occur sporadically and may limit field access, quantitative and systematic field studies of eruptions are difficult to complete. Circumventing this difficulty, laboratory models and numerical simulations are pivotal in building our understanding of eruptions. For example, the results of fuel-coolant interaction experiments show that magma-water interaction controls many eruption styles. Applying these results, increasing numbers of field studies now document and interpret the role of external water eruptions. Similarly, numerical simulations solve the fundamental physics of high-speed fluid flow and give quantitative predictions that elucidate the complexities of pyroclastic flows and surges. A primary goal of these models is to guide geologists in searching for critical field relationships and making their interpretations. Coupled with field work, modeling is beginning to allow more quantitative and predictive volcanic hazard assessments.

  18. Collapse and Re-growth of Monowai Submarine Volcano, Kermadec Arc, 1998-2004

    NASA Astrophysics Data System (ADS)

    Chadwick, W. W.; Wright, I. C.; de Ronde, C. E.; Reymond, D.; Hyvernaud, O.; Bannister, S.; Stoffers, P.

    2005-12-01

    Monowai submarine volcano is located at 25°53.5'S/177°11.1'W, about 1400 km NNE of New Zealand along the Kermadec arc, and consists of a shallow symmetrical cone with a summit depth of ~100 m. Monowai is one of the most active submarine volcanoes in the Kermadec arc, based on visual reports from overflights, oceanographic surveys of hydrothermal plumes, and seismoacoustic monitoring from French Polynesia and elsewhere. Since the late 1970's, Monowai has been the source of frequent swarms of acoustic T-wave events every few years. On 24 May 2002 there was a particularly large seismoacoustic event with a duration of 6-8 minutes and an exceptional amplitude that was 4-5 times larger than any other T-wave signal recorded from Monowai. Bathymetric surveys of Monowai that bracket this event were collected with multibeam sonars in 1998 and 2004 by R/V Sonne (Hydrosweep) and R/V Tangaroa (EM300), respectively. A new collapse feature is apparent on the SE side of the volcano in the 2004 bathymetry. The two surveys were compared using a quantitative technique that has been used for documenting depth changes due to volcanic eruptions on mid-ocean ridges. The results of this comparison show that the summit depth of Monowai changed from 69 m below sealevel in 1998 to 135 m in 2004, a difference of -66 m, and the location of the shallowest point moved ~200 m to the NNW. However, the maximum depth change between the surveys is -105 m and is located near the 1998-summit, which in 2004 is south of the new headwall scarp on the SE flank of the volcano. The total area of significant depth change is 1.26 x 106 m2, and the decrease in volume is 6.12 x 107 m3 (or 0.06 km3). From the distribution of the depth changes it is also clear that two things occurred between the surveys: removal of volume from slope failure and the subsequent addition of volume from an eruptive vent within the new slide scar. Therefore, the volume removed by slope failure was probably closer to 0.1 km3 whereas

  19. Seatbelt submarining injury and its prevention countermeasures: How a cantilever seat pan structure exacerbate submarining.

    PubMed

    Thorbole, Chandrashekhar K

    2015-01-01

    The purpose of this study and a case report was to demonstrate seat belt webbing induced injury due to seatbelt submarining during the frontal motor vehicle crash. Submarining is an undesired phenomenon during a frontal crash scenario and is dependent on design features of the seat pan and seatbelt system. The lack of adequate anti-submarining features at any seating position with three-point restraint can cause abdominal solid and hollow organ injuries. This paper reports a case of submarining and factors that exacerbated this phenomenon leading to critical occupant abdominal injury. This case report and the following injury causation analysis demonstrate the shortcomings of a cantilever seat pan design in context to the occupant safety. The inadequate seat pan anti-submarining feature in association with lack of seatbelt load-limiter and Pretensioner reduces the level of occupant protection offered by the seat belt system in the rear seat. This case report shows the dangers of cantilever seat pan design and its association with increased risk of submarining causing severe abdominal injuries. PMID:26985421

  20. Seatbelt submarining injury and its prevention countermeasures: How a cantilever seat pan structure exacerbate submarining

    PubMed Central

    Thorbole, Chandrashekhar K.

    2015-01-01

    The purpose of this study and a case report was to demonstrate seat belt webbing induced injury due to seatbelt submarining during the frontal motor vehicle crash. Submarining is an undesired phenomenon during a frontal crash scenario and is dependent on design features of the seat pan and seatbelt system. The lack of adequate anti-submarining features at any seating position with three-point restraint can cause abdominal solid and hollow organ injuries. This paper reports a case of submarining and factors that exacerbated this phenomenon leading to critical occupant abdominal injury. This case report and the following injury causation analysis demonstrate the shortcomings of a cantilever seat pan design in context to the occupant safety. The inadequate seat pan anti-submarining feature in association with lack of seatbelt load-limiter and Pretensioner reduces the level of occupant protection offered by the seat belt system in the rear seat. This case report shows the dangers of cantilever seat pan design and its association with increased risk of submarining causing severe abdominal injuries. PMID:26985421

  1. Phase 1 Final Report: Titan Submarine

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; Lorenz, Ralph D.; Paul, Michael V.

    2015-01-01

    The conceptual design of a submarine for Saturn's moon Titan was a funded NASA Innovative Advanced Concepts (NIAC) Phase 1 for 2014. The proposal stated the desire to investigate what science a submarine for Titan's liquid hydrocarbon seas might accomplish and what that submarine might look like. Focusing on a flagship class science system (100 kg), it was found that a submersible platform can accomplish extensive science both above and below the surface of the Kraken Mare. Submerged science includes mapping using side-looking sonar, imaging and spectroscopy of the lake, as well as sampling of the lake's bottom and shallow shoreline. While surfaced, the submarine will not only sense weather conditions (including the interaction between the liquid and atmosphere) but also image the shoreline, as much as 2 km inland. This imaging requirement pushed the landing date to Titan's next summer period (2047) to allow for lighted conditions, as well as direct-to-Earth communication, avoiding the need for a separate relay orbiter spacecraft. Submerged and surfaced investigation are key to understanding both the hydrological cycle of Titan as well as gather hints to how life may have begun on Earth using liquid, sediment, and chemical interactions. An estimated 25 Mb of data per day would be generated by the various science packages. Most of the science packages (electronics at least) can be safely kept inside the submarine pressure vessel and warmed by the isotope power system.The baseline 90-day mission would be to sail submerged and surfaced around and through Kraken Mare investigating the shoreline and inlets to evaluate the sedimentary interaction both on the surface and then below. Depths of Kraken have yet to be sensed (Ligeia to the north is thought to be 200 m (656 ft) deep), but a maximum depth of 1,000 m (3,281 ft) for Kraken Mare was assumed for the design). The sub would spend 20 d at the interface between Kraken Mare and Ligeia Mare for clues to the drainage of

  2. Erupted complex odontoma delayed eruption of permanent molar.

    PubMed

    Ohtawa, Yumi; Ichinohe, Saori; Kimura, Eri; Hashimoto, Sadamitsu

    2013-01-01

    Odontomas, benign tumors that develop in the jaw, rarely erupt into the oral cavity. We report an erupted odontoma which delayed eruption of the first molar. The patient was a 10-year-old Japanese girl who came to our hospital due to delayed eruption of the right maxillary first molar. All the deciduous teeth had been shed. The second premolar on the right side had erupted, but not the first molar. Slight inflammation of the alveolar mucosa around the first molar had exposed a tooth-like, hard tissue. Panoramic radiography revealed a radiopaque mass indicating a lesion approximately 1 cm in diameter. The border of the image was clear, and part of the mass was situated close to the occlusal surface of the first molar. The root of the maxillary right first molar was only half-developed. A clinical diagnosis of odontoma was made. The odontoma was subsequently extracted, allowing the crown of the first molar to erupt almost 5 months later. The dental germ of the permanent tooth had been displaced by the odontoma. However, after the odontoma had been extracted, the permanent tooth was still able to erupt spontaneously, as eruptive force still remained. When the eruption of a tooth is significantly delayed, we believe that it is necessary to examine the area radiographically. If there is any radiographic evidence of a physical obstruction that might delay eruption, that obstruction should be removed before any problems can arise. Regular dental checkups at schools might improve our ability to detect evidence of delayed eruption earlier. PMID:24521551

  3. Will Teide erupt again?

    NASA Astrophysics Data System (ADS)

    Marti, Joan; Geyer, Adelina

    2016-04-01

    The quantification of hazard in volcanic systems characterised by long repose period is difficult because the lack of knowledge of the past volcanic history and also because in many cases volcanism is not perceived as a potential problem, being only regarded as an attraction for tourism or a source of economic benefit, thus hiding the need to conduct hazard assessment. Teide, in the island of Tenerife (Canary Islands), is not an exception to this general rule and, despite being one of the largest composite volcanoes in the World, it is generally considered as a non-active volcano by population, visitors and even by some scientists. However, geological and geophysical evidence, including a large diversity of monitoring signals recorded during last decades, as well as a simple comparison with similar volcanoes that have erupted in recent times after hundreds or even thousands of years of quiescence, recommend to consider Teide as an active volcano and to take the necessary precaution in an island with nearly one million of permanent inhabitants and nearly 5 millions of visitors per year. What is the potential of Teide to erupt again? is the question that relies behind the fact of considering it as active, and that needs to be answered first. Based on the current volcanological, petrological and geophysical knowledge We propose a conceptual model on the magma recharge mechanisms, structure of the plumbing system, and eruption triggers and dynamics of Teide volcano that helps to understand its behaviour and to anticipate future activity. Ramón y Cajal contract (RYC-2012-11024)

  4. Granulomatous Drug Eruptions.

    PubMed

    Dodiuk-Gad, Roni P; Shear, Neil H

    2015-07-01

    Granuloma formation is usually regarded as a means of defending the host from persistent irritants of either exogenous or endogenous origin. Noninfectious granulomatous disorders of the skin encompass a challenging group of diseases owing to their clinical and histologic overlap. Drug reactions characterized by a granulomatous reaction pattern are rare, and defined by a predominance of histiocytes in the inflammatory infiltrate. This review summarizes current knowledge on the various types of granulomatous drug eruptions, focusing on the 4 major types: interstitial granulomatous drug reaction, drug-induced accelerated rheumatoid nodulosis, drug-induced granuloma annulare, and drug-induced sarcoidosis. PMID:26143430

  5. Constructional Talus: Formed during Eruption, Not By Later Tectonism

    NASA Astrophysics Data System (ADS)

    Paduan, J. B.; Clague, D. A.; Caress, D. W.

    2014-12-01

    Talus does not always indicate mass wasting due to destructive faulting, landslides, or caldera collapse. That talus slopes might be constructed during submarine volcanic eruptions was first recognized in 2005 from ROV observations and samples of lava that dripped over a cliff of a steep pillow mound of the 1996 eruption on the Gorda Ridge. Such talus was also found in 2013 along the steep pillow ridge that formed on the South Rift of Axial Volcano during the 2011 eruption. At each site, wedges and stubby cylinders of broken glass-rimmed pillow lava lie at the base of a vertical cliff of truncated pillows, as they do in other places where faults may have broken them. However, more telling evidence of this process is slender, elongate glassy rods of lava, which we call "lavacicles" from their resemblance to icicles, which were lying below the overhanging cliffs from which they had dripped and fallen. The drips can be phyric and aphyric lava, primitive to evolved in composition. Therefore they don't indicate a particular basaltic composition or viscosity; they probably result from very slow eruption rate that builds a steep stack of pillows. In 1 meter resolution AUV bathymetric maps, these talus slopes appear much like talus found at the base of fault-block slices at other parts of those ridges and at the highly faulted Endeavour Segment, however these pillow ridges are too young to have been tectonically faulted. Their orientations are not necessarily aligned with the dominant strike of faults in the area, but instead with the outline of the pillow mounds. We now have identified numerous other constructional talus slopes at Gorda and Juan de Fuca Ridges, Alarcon Rise, and Davidson Seamount off California that meet this criterion so are likely to be constructional also. At intermediate rate ridges constructional talus and cliffs contribute a small amount of the area, but perhaps significant permeability pathways for hydrothermal circulation.

  6. Recolonization of the intertidal and shallow subtidal community following the 2008 eruption of Alaska’s Kasatochi Volcano

    USGS Publications Warehouse

    Jewett, S.C.; Drew, Gary S.

    2014-01-01

    The intertidal and nearshore benthic communities of Kasatochi Island are described following a catastrophic volcanic eruption in 2008. Prior to the eruption, the island was surrounded by a dense bed of canopy-forming dragon kelp Eualaria fistulosa which supported a productive nearshore community. The eruption extended the coastline of the island approximately 400 m offshore to roughly the 20 m isobath. One year following the eruption a reconnaissance survey found the intertidal zone devoid of life. Subtidally, the canopy kelp, as well as limited understory algal species and associated benthic fauna on the hard substratum, were buried by debris from the eruption. The resulting substrate was comprised almost entirely of medium and coarse sands with a depauperate benthic community. Comparisons of habitat and biological communities with other nearby Aleutian Islands and the Icelandic submarine volcanic eruption of Surtsey confirm dramatic reductions in flora and fauna consistent with the initial stages of recovery from a large-scale disturbance event. Four and five years following the eruption brief visits revealed dramatic intertidal and subtidal recolonization of the flora and fauna in some areas. Signs of nesting and fledging of young pigeon guillemots Cepphus columba suggest that the recovery of the nearshore biota may have begun affecting higher trophic levels. Recolonization or lack thereof was tied to bathymetric changes from coastal and nearshore erosion over the study period.

  7. Drug Rash (Unclassified Drug Eruption) in Children

    MedlinePlus

    ... rash and rashes clinical tools newsletter | contact Share | Drug Eruption, Unclassified (Pediatric) A parent's guide to condition ... lesions coming together into larger lesions typical of drug rashes (eruptions). Overview A drug eruption, also known ...

  8. Nyamuragira Volcano Erupts

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Nyamuragira volcano erupted on July 26, 2002, spewing lava high into the air along with a large plume of steam, ash, and sulfur dioxide. The 3,053-meter (10,013-foot) volcano is located in eastern Congo, very near that country's border with Rwanda. Nyamuragira is the smaller, more violent sibling of Nyiragongo volcano, which devastated the town of Goma with its massive eruption in January 2002. Nyamuragira is situated just 40 km (24 miles) northeast of Goma. This pair of images was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite, on July 26. The image on the left shows the scene in true color. The small purple box in the upper righthand corner marks the location of Nyamuragira's hot summit. The false-color image on the right shows the plume from the volcano streaming southwestward. This image was made using MODIS' channels sensitive at wavelengths from 8.5 to 11 microns. Red pixels indicate high concentrations of sulphur dioxide. Image courtesy Liam Gumley, Space Science and Engineering Center, University of Wisconsin-Madison

  9. The physics of large eruptions

    NASA Astrophysics Data System (ADS)

    Gudmundsson, Agust

    2015-04-01

    Based on eruptive volumes, eruptions can be classified as follows: small if the volumes are from less than 0.001 km3 to 0.1 km3, moderate if the volumes are from 0.1 to 10 km3, and large if the volumes are from 10 km3 to 1000 km3 or larger. The largest known explosive and effusive eruptions have eruptive volumes of 4000-5000 km3. The physics of small to moderate eruptions is reasonably well understood. For a typical mafic magma chamber in a crust that behaves as elastic, about 0.1% of the magma leaves the chamber (erupted and injected as a dyke) during rupture and eruption. Similarly, for a typical felsic magma chamber, the eruptive/injected volume during rupture and eruption is about 4%. To provide small to moderate eruptions, chamber volumes of the order of several tens to several hundred cubic kilometres would be needed. Shallow crustal chambers of these sizes are common, and deep-crustal and upper-mantle reservoirs of thousands of cubic kilometres exist. Thus, elastic and poro-elastic chambers of typical volumes can account for small to moderate eruptive volumes. When the eruptions become large, with volumes of tens or hundreds of cubic kilometres or more, an ordinary poro-elastic mechanism can no longer explain the eruptive volumes. The required sizes of the magma chambers and reservoirs to explain such volumes are simply too large to be plausible. Here I propose that the mechanics of large eruptions is fundamentally different from that of small to moderate eruptions. More specifically, I suggest that all large eruptions derive their magmas from chambers and reservoirs whose total cavity-volumes are mechanically reduced very much during the eruption. There are two mechanisms by which chamber/reservoir cavity-volumes can be reduced rapidly so as to squeeze out much of, or all, their magmas. One is piston-like caldera collapse. The other is graben subsidence. During large slip on the ring-faults/graben-faults the associated chamber/reservoir shrinks in volume

  10. Numerical Modeling of Sound from the Eruption of Anatahan Volcano, Mariana Islands

    NASA Astrophysics Data System (ADS)

    Park, M.; Dziak, R. P.; Byun, S.; Fox, C. G.; Matsumoto, H.

    2003-12-01

    NOAA VENTS Program deployed an array of five autonomous underwater hydrophones within the SOFAR channel along the Mariana chain in February 2003 to monitor seafloor volcanic eruptions and submarine earthquakes (sponsored by NOAA's Ocean Exploration Program). These five hydrophones will be recovered in September 2003 using KORDI R/V Onnuri. The first historical eruption of Anatahan volcano in the Mariana Islands began on 10 May 2003. It is expected that the hydrophone data will include the hydroacoustic records of the eruption of Anatahan Volcano. The signals recorded from the eruption will be numerically modeled using a T-wave excitation mechanism developed from the mode scattering theory of Park et al. (2001). They found that scattering from the rough seabottom converts the acoustic energy of seafloor earthquakes from the directly excited ocean crustal/water column modes to the propagating acoustic modes of T-waves, and developed an algorithm to numerically model oceanic earthquake's T-waves. We modified this numerical model of Park et al. (2001) to predict the T-waves generated from volcanic sources by adopting a buried magmatic pipe model (Chouet, 1985). We derived a moment-tensor representation of a volcano-seismic source that is governed by the geometry of the source and the physical properties of magma. Numerical modeling of the sound from the eruption requires us to determine governing factors such as the pipe radius and magma viscosity that will enable us to grasp the inward nature of Anatahan volcano.

  11. Hydrothermal Helium Plumes over Submarine Volcanoes of the Marianas Arc

    NASA Astrophysics Data System (ADS)

    Lupton, J. E.; Baker, E. T.; Embley, R. W.; Resing, J. E.; Massoth, G. J.; Nakamura, K.; Greene, R.; Walker, S.; Lebon, G.

    2003-12-01

    During February-March, 2003, as part of the Submarine Ring of Fire project funded by NOAA's Ocean Exploration Program, the R/V T.G. Thompson conducted a comprehensive survey of hydrothermal activity along 1200 km of the Mariana Arc from 13.5° N to 22.5° N [see Embley et al., EOS Trans. AGU, 2003]. Plume surveys were conducted in the water-column above ~50 submarine volcanoes using a CTD/rosette system. A total of 70 CTD casts were completed, and discrete water samples were collected for analysis of a variety of hydrothermal tracers, including 3He, CH4, CO2, H2S, Fe, Mn, pH, and suspended particles. Although shorebased analysis of the samples is still underway, preliminary results indicate that about 11 of the 50 submarine volcanoes surveyed are hydrothermally active. Because many of the Marianas Arc volcanoes rise to within 500 m of the sea surface, hydrothermal plume signals such as light attenuation (suspended particles) and temperature anomaly have limited utility due to masking by near surface effects. For this reason 3He, an unambiguous hydrothermal tracer, has been particularly useful for identifying which of the shallow arc volcanoes are hydrothermally active. Our expectation was that the water-column helium signal might be reduced at shallow depths due to ventilation into the atmosphere. However, we observed very high 3He enrichments at shallow depths both at Maug Islands and at NW Rota #1 (14° 36'N; 144° 46.5'E). The 3He enrichments were strongly correlated with changes in pH, Mn, and other hydrothermal tracers. The three Maug Islands mark the perimeter of a caldera formed by an explosive eruption, and a single hydrocast in the center of the caldera detected a robust helium plume at 120-200 m depth with δ 3He reaching a maximum of 250% at 150m depth. Analysis of the co-variation of [3He] vs. [4He] at Maug gave R/Ra = 6.6 for an estimate of the end-member helium isotope ratio (R = 3He/4He and Ra = Rair). This value falls well within the range of R

  12. [Functional status of submariners after short-time submarine raid in the sea].

    PubMed

    Kalmanov, A S; Pisarev, A A; Khankevich, Yu R; Bloshchinskii, I A; Valskii, A V

    2015-10-01

    Short-time sea submarine raids (from a few days to a few weeks), performed during one working cycle, negatively influence on the functional state of the submariners organism. Upon returning to the point of basing the crew involved in the maintenance of the material and performs preparations for further access to the sea. Due to the high workload and lack of time personnel are not held in any correctional and rehabilitation activities, and therefore the time for the next release in the sea functional condition and functional reserves of the body does not have time to fully recover. The transfer of the submarine crew and referral to medical and psychological rehabilitation assumed only after the end of the operating cycle after the crew the task of further voyage. Based on the assessment of the functional systems of the submarine after a short voyage concluded on the need to develop a set of remedial measures for the recovery of submarine crews during inter-cruise period. PMID:26827506

  13. A new model for submarine volcanic collapse formation

    NASA Astrophysics Data System (ADS)

    Engels, Jennifer L.; Edwards, Margo H.; Fornari, Daniel J.; Perfit, Michael R.; Cann, Johnson R.

    2003-09-01

    Collapse pits and an associated suite of collapse-related features that form in submarine lava flows are ubiquitous on the global mid-ocean ridge crest. Collapse pits, the lava tube systems they expose, and lenses of talus created by the collapse process combine to produce a permeable region in the shallow ocean crust and are thought to contribute significantly to the 100-300 m thick low velocity zone observed at intermediate to fast-spreading mid-ocean ridges. This horizon of low-density, high-porosity material is likely to be an important aquifer for the transfer of hydrothermal fluids in the upper ocean crust. In a recent survey of the East Pacific Rise at 9°37'N, we used photographs, video and observations from the submersible Alvin, and DSL-120A side scan data to determine that 13% of the 720,000 m2 of seafloor imaged had foundered to form collapse pits. In 98% of the images collapse pits occurred in lobate flows, and the rest in sheet flows. On the basis of our observations and analyses of collapse features, and incorporating data from previous models for collapse formation plus laboratory and theoretical models of basalt lava behavior in the deep ocean, we develop a detailed multistage physical model for collapse formation in the deep ocean. In our model, lava extruded on the seafloor traps pockets of seawater beneath the flow that are instantly vaporized to a briny steam. The seawater is transformed to vapor at temperatures above 480°C with a 20 times expansion in volume. Bubbles of vapor rise through the lava and concentrate below the chilled upper crust of the lava flow, creating gas-filled cavities at magmatic temperatures. Fluid lava from the cavity roofs drips into the vapor pockets to create delicate drip and septa structures, a process that may be enhanced by water vapor diffusing into the magma and reducing its melting point. As the vapor pocket cools, the pressure within it drops, causing a pressure gradient to develop across the upper crust. The

  14. Submarine paleoseismology based on turbidite records.

    PubMed

    Goldfinger, Chris

    2011-01-01

    Many of the largest earthquakes are generated at subduction zones or other plate boundary fault systems near enough to the coast that marine environments may record evidence of them. During and shortly after large earthquakes in the coastal and marine environments, a spectrum of evidence may be left behind, mirroring onshore paleoseismic evidence. Shaking or displacement of the seafloor can trigger processes such as turbidity currents, submarine landslides, tsunami (which may be recorded both onshore and offshore), and soft-sediment deformation. Marine sites may also share evidence of fault scarps, colluvial wedges, offset features, and liquefaction or fluid expulsion with their onshore counterparts. This article reviews the use of submarine turbidite deposits for paleoseismology, focuses on the dating and correlation techniques used to establish stratigraphic continuity of marine deposits, and outlines criteria for distinguishing earthquake deposits and the strategies used to acquire suitable samples and data for marine paleoseismology. PMID:21329198

  15. Influence of Anchoring on Burial Depth of Submarine Pipelines

    PubMed Central

    Zhuang, Yuan; Li, Yang; Su, Wei

    2016-01-01

    Since the beginning of the twenty-first century, there has been widespread construction of submarine oil-gas transmission pipelines due to an increase in offshore oil exploration. Vessel anchoring operations are causing more damage to submarine pipelines due to shipping transportation also increasing. Therefore, it is essential that the influence of anchoring on the required burial depth of submarine pipelines is determined. In this paper, mathematical models for ordinary anchoring and emergency anchoring have been established to derive an anchor impact energy equation for each condition. The required effective burial depth for submarine pipelines has then been calculated via an energy absorption equation for the protection layer covering the submarine pipelines. Finally, the results of the model calculation have been verified by accident case analysis, and the impact of the anchoring height, anchoring water depth and the anchor weight on the required burial depth of submarine pipelines has been further analyzed. PMID:27166952

  16. Influence of Anchoring on Burial Depth of Submarine Pipelines.

    PubMed

    Zhuang, Yuan; Li, Yang; Su, Wei

    2016-01-01

    Since the beginning of the twenty-first century, there has been widespread construction of submarine oil-gas transmission pipelines due to an increase in offshore oil exploration. Vessel anchoring operations are causing more damage to submarine pipelines due to shipping transportation also increasing. Therefore, it is essential that the influence of anchoring on the required burial depth of submarine pipelines is determined. In this paper, mathematical models for ordinary anchoring and emergency anchoring have been established to derive an anchor impact energy equation for each condition. The required effective burial depth for submarine pipelines has then been calculated via an energy absorption equation for the protection layer covering the submarine pipelines. Finally, the results of the model calculation have been verified by accident case analysis, and the impact of the anchoring height, anchoring water depth and the anchor weight on the required burial depth of submarine pipelines has been further analyzed. PMID:27166952

  17. Solar Eruptive Events

    NASA Technical Reports Server (NTRS)

    Holman, Gordon D.

    2012-01-01

    It s long been known that the Sun plays host to the most energetic explosions in the solar system. But key insights into the forms that energy takes have only recently become available. Solar flares have been phenomena of both academic and practical interest since their discovery in 1859. From the academic point of view, they are the nearest events for studying the explosive release of energy in astrophysical magnetized plasmas. From the practical point of view, they disrupt communication channels on Earth, from telegraph communications in 1859 to radio and television signals today. Flares also wreak havoc on the electrical power grid, satellite operations, and GPS signals, and energetic charged particles and radiation are dangerous to passengers on high-altitude polar flights and to astronauts. Flares are not the only explosive phenomena on the Sun. More difficult to observe but equally energetic are the large coronal mass ejections (CMEs), the ejection of up to ten billion tons of magnetized plasma into the solar wind at speeds that can exceed 1000 km/s. CMEs are primarily observed from the side, with coronagraphs that block out the bright disk of the Sun and lower solar atmosphere so that light scattered from the ejected mass can be seen. Major geomagnetic storms are now known to arise from the interaction of CMEs with Earth's magnetosphere. Solar flares are observed without CMEs, and CMEs are observed without flares. The two phenomena often occur together, however, and almost always do in the case of large flares and fast CMEs. The term solar eruptive event refers to the combination of a flare and a CME. Solar eruptive events generate a lot of heat: They can heat plasma to temperatures as high at 50 million Kelvin, producing radiation across the electromagnetic spectrum. But that s not all. A fascinating aspect of solar eruptive events is the acceleration of electrons and ions to suprathermal often relativistic energies. The accelerated particles are primarily

  18. "Internal Waves" Advancing along Submarine Canyons.

    PubMed

    Shepard, F P; Marshall, N F; McLoughlin, P A

    1974-01-18

    Patterns of alternating up- and downcanyon currents have been traced along the axes of submarine canyons off California. The patterns arrive later at stations nearer the heads of coastal canyons. Where a canyon heads between two islands, the patterns advance down the axis. The propagation speeds of these patterns were estimated as 25 to 88 centimeters per second. Internal waves are the probable explanation. PMID:17777263

  19. An Eruption on Io

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The first images returned to Earth by New Horizons during its close encounter with Jupiter feature the Galilean moon Io, snapped with the Long Range Reconnaissance Imager (LORRI) at 0840 UTC on February 26, while the moon was 2.5 million miles (4 million kilometers) from the spacecraft.

    Io is intensely heated by its tidal interaction with Jupiter and is thus extremely volcanically active. That activity is evident in these images, which reveal an enormous dust plume, more than 150 miles high, erupting from the volcano Tvashtar. The plume appears as an umbrella-shaped feature of the edge of Io's disk in the 11 o'clock position in the right image, which is a long-exposure (20-millisecond) frame designed specifically to look for plumes like this. The bright spots at 2 o'clock are high mountains catching the setting sun; beyond them the night side of Io can be seen, faintly illuminated by light reflected from Jupiter itself.

    The left image is a shorter exposure -- 3 milliseconds -- designed to look at surface features. In this frame, the Tvashtar volcano shows as a dark spot, also at 11 o'clock, surrounded by a large dark ring, where an area larger than Texas has been covered by fallout from the giant eruption.

    This is the clearest view yet of a plume from Tvashtar, one of Io's most active volcanoes. Ground-based telescopes and the Galileo Jupiter orbiter first spotted volcanic heat radiation from Tvashtar in November 1999, and the Cassini spacecraft saw a large plume when it flew past Jupiter in December 2000. The Keck telescope in Hawaii picked up renewed heat radiation from Tvashtar in spring 2006, and just two weeks ago the Hubble Space Telescope saw the Tvashtar plume in ultraviolet images designed to support the New Horizons flyby.

    Most of those images will be stored onboard the spacecraft for downlink to Earth in March and April.

  20. Anomalous Chlorine Concentrations Indicate Recycling of Submarine Pyroclasts at NW Rota-1, Mariana Arc

    NASA Astrophysics Data System (ADS)

    Deardorff, N.; Cashman, K. V.; Chadwick, W. W.

    2009-12-01

    NW Rota-1 is a submarine volcano in the southern Mariana Arc. The active vent, Brimstone Pit, has shown activity that ranged from slow extrusion to explosive bursts that generate a sustained plume tens of meters above the vent. Eruptive activity was observed in April 2006 and 2009 using remotely operated vehicles (ROVs). In 2006, explosive bursts deposited coarse ash, lapilli and bombs within a few meters of the vent. Suppression of the eruptive plume by the overlying seawater caused many of the clasts to fall out of the plume directly over the vent, thus creating the opportunity for extensive recycling of erupted clasts. Recycled material can be identified in quenched pyroclasts as areas of high groundmass crystallinity. The transition from glassy groundmass to the crystalline groundmass of an inclusion is either sharp or gradual, often with a transitional area of apparent mixing. Elevated Cl and Na concentrations have been detected within these inclusions and mixing areas using both x-ray mapping and microprobe analysis. Cl concentrations reach 1.7 wt%, an enrichment of several times over magmatic Cl concentrations of < 3000 ppm. These recycled clasts are observed only in pyroclasts from the most energetic activity observed in 2006. Activity in April, 2009 was less energetic and characterized by slow lava extrusion. Lava extrusion was accompanied by vigorous degassing and the expulsion of tephra. Tephra morphologies are consistent with quench fragmentation driven by subsurface interaction with the surrounding seawater. Rapid changes in the surface color and texture of the extruded lava may provide further evidence of seawater interaction. Analyzing the composition and microcrystalline textures within the lava samples collected in 2009, and comparing them to the 2006 scoria, will allow us to constrain the timing and extent of chemical incorporation of seawater into juvenile material under different eruption conditions.

  1. 50. PIPING FOR SUBMARINE SECTION, Y&D No. 107728 Scale 3/8' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. PIPING FOR SUBMARINE SECTION, Y&D No. 107728 Scale 3/8' = 1'; August 26, 1929 - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  2. 16. INTERIOR VIEW OF SUBMARINE SECTION AT 110FOOT LEVEL, ESCAPE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. INTERIOR VIEW OF SUBMARINE SECTION AT 110-FOOT LEVEL, ESCAPE TRAINING TANK, SHOWING LADDER TO ESCAPE TANK, LOOKING SOUTH - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  3. Submarine Landslides: What we Know and Where we are Going!

    NASA Astrophysics Data System (ADS)

    Moscardelli, L. G.; Mountjoy, J. J.; Micallef, A.; Strasser, M.; Vanneste, M.; Chaytor, J. D.; Mosher, D.; Krastel, S.; Lo Iacono, C.; Yamada, Y.

    2015-12-01

    Submarine landslides and other gravity-induced movements can disrupt very large areas of continental margins resulting in long-term seafloor morphologic change and multi-scale mass transport deposits (MTDs). Potential consequences of submarine landslides include damage to seabed infrastructure, offshore facilities, as well as generation or enhancement of tsunamis. MTDs are common on the modern seafloor and within the stratigraphic record. Slides, slumps and debris flows can be constituents of MTDs and can co-occur in the same event or depositional unit. Recent research indicates that relationships exist between MTD geological setting, causal mechanisms, and geometries. Quantitative data analysis suggests that MTD morphometric parameters can be used to link these three parameters. Despite many advances in this field, it still remains unclear how to definitively identify pre-conditioning factors and triggers of submarine landslides in modern slopes, and how submarine landslides evolve after initiation. In addition, new questions regarding the interaction between submarine landslides and active marine processes, such as bottom currents and fluid flow, have emerged.One of the mandates of the S4SLIDE (IGCP-640) project, a joint endeavor of UNESCO and IGCP that represents the broad field of submarine landslide research, is to facilitate interactions at an international level among scientists, industry and government representatives to advance our knowledge on a number of outstanding science questions: (i) What is the nature of the interaction between current-controlled sedimentation and submarine landslides? (ii) What role do transient turbulent-laminar flows play in the formation of submarine landslides? (iii) Do climatic variations control the occurrence of submarine landslides? (iv) What is the economic significance of submarine landslides? (v) Do we understand the hazards that submarine landslides pose to the environment and to humans? This presentation will cover

  4. The submarine service of the future?

    PubMed

    Bland, S A

    2000-01-01

    Space missions, although now routine, are unique in terms of their environment and logistical requirements. The number of missions (man-hours) remains relatively small and planning still relies on comparisons with analogous missions, including submarine operations. Antarctic missions, which tend not to be classified, have provided more information about isolated communities because of the number of personnel per base. Space medicine has traditionally been an extension of aviation medicine with high g-forces involved in the transition from Earth to orbit and astronauts such as Neil Armstrong recruited from the test pilot fraternity. As the length of a mission increases and the space habitation relies more on regenerative systems, the environment becomes more analogous with today's nuclear submarines. As well as the air purification implications, radiation still is a significant hazard with even greater impact on future Mars missions requiring the provision of health physics monitoring, advice and countermeasures well established in the submarine flotilla. Nevertheless, the specialty space medicine will progress as a specialty in its own right, pooling expertise from other specialties such as aviation, radiation, emergency and occupational medicine taking human exploration beyond the confines of land and sea. PMID:11346925

  5. Submarine tower escape decompression sickness risk estimation.

    PubMed

    Loveman, G A M; Seddon, E M; Thacker, J C; Stansfield, M R; Jurd, K M

    2014-01-01

    Actions to enhance survival in a distressed submarine (DISSUB) scenario may be guided in part by knowledge of the likely risk of decompression sickness (DCS) should the crew attempt tower escape. A mathematical model for DCS risk estimation has been calibrated against DCS outcome data from 3,738 exposures of either men or goats to raised pressure. Body mass was used to scale DCS risk. The calibration data included more than 1,000 actual or simulated submarine escape exposures and no exposures with substantial staged decompression. Cases of pulmonary barotrauma were removed from the calibration data. The calibrated model was used to estimate the likelihood of DCS occurrence following submarine escape from the United Kingdom Royal Navy tower escape system. Where internal DISSUB pressure remains at - 0.1 MPa, escape from DISSUB depths < 200 meters is estimated to have DCS risk < 6%. Saturation at raised DISSUB pressure markedly increases risk, with > 60% DCS risk predicted for a 200-meter escape from saturation at 0.21 MPa. Using the calibrated model to predict DCS for direct ascent from saturation gives similar risk estimates to other published models. PMID:25109085

  6. Isotope Compositions of Submarine North Kona Tholeiitic Lavas, Hualalai Volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Yamasaki, S.; Tagami, T.; Kani, T.; Hanan, B. B.

    2006-12-01

    Four remote and manned submersible dives examined the deep submarine portion of the North Kona region, offshore Hualalai during 2001 and 2002 JAMSTEC cruises. The dives encountered compositionally homogeneous tholeiitic pillow lavas that are interpreted to have erupted from Hualalai during its shield stage. Hualalai volcano, the westernmost volcano on the Island of Hawaii is presently in the post-shield alkalic stage and most of its subaerial surface is covered by alkalic basalt. Difficulty accessing buried tholeiite is one reason that compositional data from the volumetrically dominant stage in the volcano's edifice are scarce. To identify source materials involved in shield stage of Hualalai can provide important information about the isotopic variation and evolution during Hawaiian volcano growth. We report the results of Hf, Pb, Sr, Nd isotopic compositions of 34 tholeiitic lava samples collected from submarine North Kona region. Hf, Nd, Sr isotopic compositions of the submarine North Kona lavas are similar to Mauna Loa tholeiites, and define a clear mixing line showing that the mantle source consists of at least two components. Some of new Pb isotopic data have higher 207Pb/204Pb and ^{208}Pb/204Pb, for a given 206Pb/204Pb, than published data from Mauna Loa and Hualalai. The trend emerges towards to 'Kea'-like component. Although in general Hawaiian basalts require more than two components to account for their geochemical variations, the isotopic variations in Hualalai shield lavas appear dominated by a mixture of two components: 'Koolau'-like enriched component and a 'Kea'-like depleted component, and contributed to relatively higher proportion of the 'Kea'-like component than the Mauna Loa.

  7. The proximal part of the giant submarine Wailau landslide, Molokai, Hawaii

    USGS Publications Warehouse

    Clague, D.A.; Moore, J.G.

    2002-01-01

    The main break-in-slope on the northern submarine flank of Molokai at -1500 to -1250 m is a shoreline feature that has been only modestly modified by the Wailau landslide. Submarine canyons above the break-in-slope, including one meandering stream, were subaerially carved. Where such canyons cross the break-in-slope, plunge pools may form by erosion from bedload sediment carried down the canyons. West Molokai Volcano continued infrequent volcanic activity that formed a series of small coastal sea cliffs, now submerged, as the island subsided. Lavas exposed at the break-in-slope are subaerially erupted and emplaced tholeiitic shield lavas. Submarine rejuvenated-stage volcanic cones formed after the landslide took place and following at least 400-500 m of subsidence after the main break-in-slope had formed. The sea cliff on east Molokai is not the headwall of the landslide, nor did it form entirely by erosion. It may mark the location of a listric fault similar to the Hilina faults on present-day Kilauea Volcano. The Wailau landslide occurred about 1.5 Ma and the Kalaupapa Peninsula most likely formed 330??5 ka. Molokai is presently stable relative to sea level and has subsided no more than 30 m in the last 330 ka. At their peak, West and East Molokai stood 1.6 and 3 km above sea level. High rainfall causes high surface runoff and formation of canyons, and increases groundwater pressure that during dike intrusions may lead to flank failure. Active shield or postshield volcanism (with dikes injected along rift zones) and high rainfall appear to be two components needed to trigger the deep-seated giant Hawaiian landslides. ?? 2002 Elsevier Science B.V. All rights reserved.

  8. Large and small volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Gudmundsson, Agust; Mohajeri, Nahid

    2013-04-01

    Despite great progress in volcanology in the past decades, we still cannot make reliable forecasts as to the likely size (volume, mass) of an eruption once it has started. Empirical data collected from volcanoes worldwide indicates that the volumes (or masses) of eruptive materials in volcanic eruptions are heavy-tailed. This means that most of the volumes erupted from a given magma chamber are comparatively small. Yet, the same magma chamber can, under certain conditions, squeeze out large volumes of magma. To know these conditions is of fundamental importance for forecasting the likely size of an eruption. Thermodynamics provides the basis for understanding the elastic energy available to (i) propagate an injected dyke from the chamber and to the surface to feed an eruption, and (ii) squeeze magma out of the chamber during the eruption. The elastic energy consists of two main parts: first, the strain energy stored in the volcano before magma-chamber rupture and dyke injection, and, second, the work done through displacement of the flanks of the volcano (or the margins of a rift zone) and the expansion and shrinkage of the magma chamber itself. Other forms of energy in volcanoes - thermal, seismic, kinetic - are generally important but less so for squeezing magma out of a chamber during an eruption. Here we suggest that for (basaltic) eruptions in rift zones the strain energy is partly related to minor doming above the reservoir, and partly to stretching of the rift zone before rupture. The larger the reservoir, the larger is the stored strain energy before eruption. However, for the eruption to be really large, the strain energy has to accumulate in the entire crustal segment above the reservoir and there will be additional energy input into the system during the eruption which relates to the displacements of the boundary of the rift-zone segment. This is presumably why feeder dykes commonly propagate laterally at the surface following the initial fissure

  9. Significant discharge of CO2 from hydrothermalism associated with the submarine volcano of El Hierro Island

    NASA Astrophysics Data System (ADS)

    Santana-Casiano, J. M.; Fraile-Nuez, E.; González-Dávila, M.; Baker, E. T.; Resing, J. A.; Walker, S. L.

    2016-05-01

    The residual hydrothermalism associated with submarine volcanoes, following an eruption event, plays an important role in the supply of CO2 to the ocean. The emitted CO2 increases the acidity of seawater. The submarine volcano of El Hierro, in its degasification stage, provided an excellent opportunity to study the effect of volcanic CO2 on the seawater carbonate system, the global carbon flux, and local ocean acidification. A detailed survey of the volcanic edifice was carried out using seven CTD-pH-ORP tow-yo studies, localizing the redox and acidic changes, which were used to obtain surface maps of anomalies. In order to investigate the temporal variability of the system, two CTD-pH-ORP yo-yo studies were conducted that included discrete sampling for carbonate system parameters. Meridional tow-yos were used to calculate the amount of volcanic CO2 added to the water column for each surveyed section. The inputs of CO2 along multiple sections combined with measurements of oceanic currents produced an estimated volcanic CO2 flux = 6.0 105 ± 1.1 105 kg d‑1 which is ~0.1% of global volcanic CO2 flux. Finally, the CO2 emitted by El Hierro increases the acidity above the volcano by ~20%.

  10. Significant discharge of CO2 from hydrothermalism associated with the submarine volcano of El Hierro Island

    PubMed Central

    Santana-Casiano, J. M.; Fraile-Nuez, E.; González-Dávila, M.; Baker, E. T.; Resing, J. A.; Walker, S. L.

    2016-01-01

    The residual hydrothermalism associated with submarine volcanoes, following an eruption event, plays an important role in the supply of CO2 to the ocean. The emitted CO2 increases the acidity of seawater. The submarine volcano of El Hierro, in its degasification stage, provided an excellent opportunity to study the effect of volcanic CO2 on the seawater carbonate system, the global carbon flux, and local ocean acidification. A detailed survey of the volcanic edifice was carried out using seven CTD-pH-ORP tow-yo studies, localizing the redox and acidic changes, which were used to obtain surface maps of anomalies. In order to investigate the temporal variability of the system, two CTD-pH-ORP yo-yo studies were conducted that included discrete sampling for carbonate system parameters. Meridional tow-yos were used to calculate the amount of volcanic CO2 added to the water column for each surveyed section. The inputs of CO2 along multiple sections combined with measurements of oceanic currents produced an estimated volcanic CO2 flux = 6.0 105 ± 1.1 105 kg d−1 which is ~0.1% of global volcanic CO2 flux. Finally, the CO2 emitted by El Hierro increases the acidity above the volcano by ~20%. PMID:27157062

  11. Significant discharge of CO2 from hydrothermalism associated with the submarine volcano of El Hierro Island.

    PubMed

    Santana-Casiano, J M; Fraile-Nuez, E; González-Dávila, M; Baker, E T; Resing, J A; Walker, S L

    2016-01-01

    The residual hydrothermalism associated with submarine volcanoes, following an eruption event, plays an important role in the supply of CO2 to the ocean. The emitted CO2 increases the acidity of seawater. The submarine volcano of El Hierro, in its degasification stage, provided an excellent opportunity to study the effect of volcanic CO2 on the seawater carbonate system, the global carbon flux, and local ocean acidification. A detailed survey of the volcanic edifice was carried out using seven CTD-pH-ORP tow-yo studies, localizing the redox and acidic changes, which were used to obtain surface maps of anomalies. In order to investigate the temporal variability of the system, two CTD-pH-ORP yo-yo studies were conducted that included discrete sampling for carbonate system parameters. Meridional tow-yos were used to calculate the amount of volcanic CO2 added to the water column for each surveyed section. The inputs of CO2 along multiple sections combined with measurements of oceanic currents produced an estimated volcanic CO2 flux = 6.0 10(5) ± 1.1 10(5 )kg d(-1) which is ~0.1% of global volcanic CO2 flux. Finally, the CO2 emitted by El Hierro increases the acidity above the volcano by ~20%. PMID:27157062

  12. Investigation of Solar Eruptive Prominences

    NASA Astrophysics Data System (ADS)

    Su, Yingna; McCauley, Patrick; van Ballegooijen, Adriaan; Ji, Haisheng; Reeves, Katharine; DeLuca, Edward

    2015-08-01

    At first, we will present an investigation of the polar crown prominence that erupted on 2012 March 12. This prominence is observed at the southeast limb by SDO/AIA (end-on view) and displays a quasi vertical-thread structure. Bright U-shape (horn-like) structure is observed surrounding the upper portion of the prominence (171 Angstrom) before the eruption and becomes more prominent during the eruption. When viewed on the disk, STEREO-B shows that this long prominence is composed of a series of vertical threads and displays a half loop-like structure during the eruption. We focus on the magnetic support of the prominence by studying the structure and dynamics of the prominence before and during the eruption using observations from SDO and STEREO. We construct a series of magnetic field models (including sheared arcade model, twisted flux rope model, and model with HFT), then compare with observations. Various observational characteristics appear to support the twisted flux rope model. Our study suggests that the flux rope supporting the prominence enters the regime of torus instability at the onset of the fast rise phase, and signature of reconnection appears about one hour later. In the second part, we will present a statistical study on the kinematics of limb eruptive prominences observed by SDO/AIA. A brief introduction on an online catalog of prominence eruptions observed by SDO/AIA will also be presented.

  13. Earthquake swarms reveal submarine magma unrest induced by distant mega-earthquakes: Andaman Sea region

    NASA Astrophysics Data System (ADS)

    Špičák, Aleš; Vaněk, Jiří

    2016-02-01

    Little is known about earthquake-triggered magma intrusions or eruptions of submarine volcanoes. The analysis of teleseismic earthquake occurrence performed in this study offers a tool to address such enigmatic and inaccessible processes. In the past ten years, the Andaman Sea region repeatedly became a site of shallow earthquake swarms that followed distant mega-earthquakes by days to weeks. The MW 9.1 December 26, 2004 Sumatra-Andaman earthquake was followed by two earthquake swarms about 600 km northward in the Andaman Sea region, delayed by 30 and 35 days, respectively. Earthquakes of one of these seismic episodes, the extensive January 2005 earthquake swarm, migrated laterally at a rate of about 0.25 km per hour during the swarm evolution. The strong Indian Ocean MW 8.6 and 8.2 April 11, 2012 earthquake doublet west of Northern Sumatra was followed by an earthquake swarm approximately 800 km northward in the Andaman Sea region, delayed by 13 days. All the three swarms that followed the 2004 and 2012 mega-earthquakes occurred beneath distinct seamounts and seafloor ridges. Based on the observations of migration of earthquakes during the swarm and swarm occurrence beneath distinct highs at the seafloor, we conclude that these earthquake swarms probably resulted as a consequence of magma unrest induced by static and/or dynamic stress changes following the distant mega-earthquakes. Repeated occurrence of such a phenomenon suggests that the arc magma reservoirs beneath the Andaman Sea have recently reached some form of criticality and are vulnerable to even small stress changes. The Andaman seafloor could thus become a site of submarine volcanic eruptions in near future and deserves close attention of Earth scientists.

  14. The Summer 1997 Eruption at Pillan Patera on Io: Implications for Ultrabasic Lava Flow Emplacement

    NASA Technical Reports Server (NTRS)

    Williams, David A.; Davies, Ashley G.; Keszthelyi, Laszlo P.; Greeley, Ronald

    2001-01-01

    than those for typical Mauna Loa/Kilaueaq flows but comparable to those for the (1783) Laki eruption and the inferred flow rates of the Roza flows in the Columbia River flood basalts. The differences in ultrabasic eruption styles on Earth and Io appear to be controlled by the different eruption environments; Plumes at sites of ultrabasic eruptions on Io suggest strong magma-volatile interactions on a low-gravity body lacking an atmosphere, whereas the geology at sites of komatiite eruptions on Earth suggest mostly submarine emplacement of thick flows with a pronounced lack of subaerial explosive activity.

  15. The Summer 1997 Eruption at Pillan Patera on Io: Implications for Ultrabasic Lava Flow Emplacement

    NASA Technical Reports Server (NTRS)

    Williams, David A.; Davies, Ashley G.; Keszthelyi, Laszlo; Greeley, Ronald

    2001-01-01

    greater than those for typical Mauna Loa/Kilauea flows but comparable to those for the (1783) Laki eruption and the inferred flow rates of the Roza flows in the Columbia River flood basalts. The differences in ultrabasic eruption styles on Earth and Io appear to be controlled by the different eruption environments: Plumes at sites of ultrabasic eruptions on Io suggest strong magma-volatile: interactions on a low-gravity body lacking an atmosphere, whereas the geology at sites of komatiite eruptions on Earth suggest mostly submarine emplacement of thick flows with a pronounced lack of subaerial explosive activity.

  16. An Analysis of Eruptions Detected by the LMSAL Eruption Patrol

    NASA Astrophysics Data System (ADS)

    Hurlburt, N. E.; Higgins, P. A.; Jaffey, S.

    2014-12-01

    Observations of the solar atmosphere reveals a wide range of real and apparent motions, from small scale jets and spicules to global-scale coronal mass ejections. Identifying and characterizing these motions are essential to advance our understanding the drivers of space weather. Automated and visual identifications are used in identifying CMEs. To date, the precursors to these — eruptions near the solar surface — have been identified primarily by visual inspection. Here we report on an analysis of the eruptions detected by the Eruption Patrol, a data mining module designed to automatically identify eruptions from data collected by Solar Dynamics Observatory's Atmospheric Imaging Assembly (SDO/AIA). We describe the module and use it both to explore relations with other solar events recorded in the Heliophysics Event Knowledgebase and to identify and access data collected by the Interface Region Imaging Spectrograph (IRIS) and Solar Optical Telescope (SOT) on Hinode for further analysis.

  17. Characterization of Solar Eruptions reported by EruptionPatrol

    NASA Astrophysics Data System (ADS)

    Hurlburt, Neal

    2015-04-01

    Observation of the solar atmosphere reveals a wide range of real and apparent motions, from small scale jets and spicules to global-scale coronal mass ejections. Identifying and characterizing these motions are essential to advance our understanding the drivers of space weather. A method for automatically identifying eruptions near the solar surface (either from filaments or otherwise) has recently been developed and integrated into the Heliophysics Events Knowledgebase. Here we report on the EruptionPatrol module for identifying eruptions in data collected by the SDO/AIA instrument and on the characterization and analysis of its output. A cluster analysis on the time periods reported by EruptionPatrol demarcates several large-scale events spanning significant portions of the solar disk with lifetimes of up to six hours.

  18. Comparing Dynamics in Eruptive and Non-Eruptive Flares

    NASA Astrophysics Data System (ADS)

    Nitta, Nariaki; Tarbell, Theodore D.; Slater, Gregory L.; Frank, Zoe Anne

    2016-05-01

    Close comparison of EUV and coronagraph data suggests that there may not be clear distinction between eruptive and non-eruptive flares as far as the coronal and chromospheric signatures are concerned. Here we define eruptive and non-eruptive flares in terms of the presence and absence of the associated coronal mass ejection (CME). We have studied several flares in both categories using Hinode/SOT and IRIS data. The pointing of the Hinode/SOT data has been updated by correlating them with AIA 1700 A images. We show our initial results about how the flare development compares in eruptive and non-eruptive flares, including the reconnection rate as derived from the magnetic field swept over by flare ribbons (in SOT Ca images), and the line-of-sight velocities at different locations and temperatures (in IRIS spectral data). We also discuss large-scale disturbances and related CMEs in SDO/AIA and SOHO/LASCO data as context information.

  19. Geochemistry of volcanic glasses from the Louisville Seamount Trail (IODP Expedition 330): Implications for eruption environments and mantle melting

    NASA Astrophysics Data System (ADS)

    Nichols, Alexander R. L.; Beier, Christoph; Brandl, Philipp A.; Buchs, David M.; Krumm, Stefan H.

    2014-05-01

    glasses recovered from four guyots during drilling along the Louisville Seamount Trail, southwest Pacific, have been analyzed for major, trace, and volatile elements (H2O, CO2, S, and Cl), and oxygen isotopes. Compared to other oceanic island settings, they are geochemically homogeneous, providing no evidence of the tholeiitic stage that characterizes Hawai'i. The degrees and depth of partial melting remained constant over 1-3 Ma represented by the drill holes, and along-chain over several million years. The only exception is Hadar Guyot with compositions that suggest small degree preferential melting of an enriched source, possibly because it erupted on the oldest and thickest lithosphere. Incompatible element enriched glass from late-stage volcaniclastics implies lower degrees of melting as the volcanoes moved off the melting anomaly. Volcaniclastic glasses from throughout the igneous basement are degassed suggesting generation during shallow submarine eruptions (<20 mbsl) or as subaerial flows entered the sea. Drill depths may no longer reflect relative age due to postquench downslope movement. Higher volatile contents in late-stage volcaniclastics indicate submarine eruptions at 118-258 mbsl and subsidence of the edifices below sea level by the time they erupted, or generation in flank eruptions. Glass from intrusion margins suggests emplacement ˜100 m below the surface. The required uplift to achieve these paleo-quench depths and the subsequent subsidence to reach their current depths exceeds that expected for normal oceanic lithosphere, consistent with the Louisville melting anomaly being <100°C hotter than normal asthenosphere at 50-70 Ma when the guyots were erupted.

  20. Volcanic Eruptions in Kamchatka

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Sheveluch Stratovolcano Click on the image for full resolution TIFF Klyuchevskoy Stratovolcano Click on the image for full resolution TIFF

    One of the most volcanically active regions of the world is the Kamchatka Peninsula in eastern Siberia, Russia. It is not uncommon for several volcanoes to be erupting at the same time. On April 26, 2007, the Advanced Spaceborne Thermal Emission and Reflection Radioneter (ASTER) on NASA's Terra spacecraft captured these images of the Klyuchevskoy and Sheveluch stratovolcanoes, erupting simultaneously, and 80 kilometers (50 miles) apart. Over Klyuchevskoy, the thermal infrared data (overlaid in red) indicates that two open-channel lava flows are descending the northwest flank of the volcano. Also visible is an ash-and-water plume extending to the east. Sheveluch volcano is partially cloud-covered. The hot flows highlighted in red come from a lava dome at the summit. They are avalanches of material from the dome, and pyroclastic flows.

    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 spacecraft. 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 provides 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

  1. Tenofovir induced lichenoid drug eruption

    PubMed Central

    Gupta, Mrinal; Gupta, Heena; Gupta, Anish

    2015-01-01

    Cutaneous adverse reactions are a common complication of anti-retroviral therapy. Tenofovir is a newer anti-retroviral drug belonging to the nucleotide reverse transcriptase inhibitor group. Systemic adverse effects like nausea, vomiting, diarrhea, hepatotoxicity and renal toxicity are common with tenofovir but cutaneous adverse effects are rare. Lichenoid drug eruptions are a common adverse effect seen with a large variety of drugs including antimalarials, antihypertensives, nonsteroidal anti-inflammatory drugs and diuretics. Lichenoid drug eruption is a rare cutaneous adverse effect of tenofovir with only a single case reported till date. Here, we report a case of tenofovir induced lichenoid drug eruption in a 54-year-old human immunodeficiency virus affected male who presented with generalized lichenoid eruption after 6 weeks of initiation of tenofovir and complete clearance on cessation of the drug. PMID:26229762

  2. Voyager 2 Jupiter Eruption Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie records an eruptive event in the southern hemisphere of Jupiter over a period of 8 Jupiter days. Prior to the event, an undistinguished oval cloud mass cruised through the turbulent atmosphere. The eruption occurs over avery short time at the very center of the cloud. The white eruptive material is swirled about by the internal wind patterns of the cloud. As a result of the eruption, the cloud then becomes a type of feature seen elsewhere on Jupiter known as 'spaghetti bowls'.

    As Voyager 2 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 8 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Violet filter around May 6, 1979. The spacecraft was about 50 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  3. No pre-eruptive uplift in the Emeishan large igneous province: New evidences from its 'inner zone', Dali area, Southwest China

    NASA Astrophysics Data System (ADS)

    Zhu, Bei; Guo, Zhaojie; Liu, Runchao; Liu, Dongdong; Du, Wei

    2014-01-01

    The Permian Emeishan large igneous province (ELIP) in Southwest China has been considered a typical example of crustal domal uplift caused by mantle plume upwelling prior to the onset of volcanism. However, this model has been questioned by the discovery of hydromagmatic volcaniclastic deposits formed in a marine environment, located near the central ELIP area (the 'inner zone') which is inferred to be the zone of maximum uplift. The volcanology of the inner zone has thus far been poorly documented, fueling the debate about whether or not pre-eruptive uplift occurred prior to plume upwelling. Understanding the volcanology of this inner zone is therefore critical in constraining the eruption environment of the central ELIP. Our work has revealed new volcanological observations in the inner zone (Dali area), which can systematically constrain volcanism and paleoenvironment. The Basal Succession of the sequence is a thick pillow lavas pile with hyaloclastites, implying an initial deeper submarine stage of eruptions. Limestones and submarine fallout tuffs are interbedded with these pillow lavas. Above that, abundant mafic volcaniclastic products developed, which contain palagonite-rimmed lapilli-tuffs, base surge deposits and peperites, suggesting hydroclastic volcanism in a shallower submarine environment. The Upper Succession of the sequence preserves columnar-jointed lava flows and subaerial fallout tuffs, reflecting subaerial volcanism after the volcanic center emerged above the sea level. These abundant and systematic natures of this evidence suggest that the initial volcanism of the central ELIP occurred in a deep submarine environment. The submarine-to-subaerial transition is caused by progressive emplacement of voluminous magmatic products infilling the inner zone during the continuous emplacement of ELIP, rather than by crustal doming prior to the onset of volcanisms.

  4. Volcanic inflation of Axial Seamount since the 1998 eruption

    NASA Astrophysics Data System (ADS)

    Nooner, S. L.; Chadwick, W.

    2010-12-01

    Since 2000, ambient seawater pressure has been precisely measured at five seafloor benchmarks inside the summit caldera at Axial Seamount in order to measure their relative depth and monitor volcanic inflation that has been occurring since an eruption in 1998. A remotely operated vehicle has been used to deploy a mobile pressure recorder (MPR) in campaign-style surveys, with additional seawater pressure data collected at the caldera center with multiyear deployments of continuously recording bottom pressure recorders (BPRs). Our previous measurements at Axial Seamount have shown steady inflation of the caldera center through 2007 and the spatial pattern of uplift has been consistent with magma storage in a shallow reservoir underlying the caldera at a depth of 3.5 km. This is the only location in the world where long-term monitoring of volcanic inflation has been accomplished at a submarine volcano. Here we present the results of new pressure data (both MPR and BPR) collected during a cruise on board the R/V Thomas Thompson in August-September 2010 and using the Jason ROV. Three years have passed since the previous survey, providing enough time to distinguish between two alternative models of inflation and magma recharge for the volcano. This allows us to refine our forecast for the next eruption at Axial and estimate total uplift that has occurred since the 1998 eruption. During the 2010 survey we also deployed new concrete benchmarks to replace our original galvanized steel benchmarks. The new benchmarks are larger and much heavier, and we expect them to be much more durable and stable over long time periods and help keep measurement errors as small as possible. We installed a sixth benchmark at a new site within the caldera, near the Ashes vent field, which will help constrain our modeling of the inflation signal in future years.

  5. Bubble Plumes at NW Rota-1 Submarine Volcano, Mariana Arc: Visualization and Analysis of Multibeam Water Column Data

    NASA Astrophysics Data System (ADS)

    Merle, S. G.; Chadwick, W. W.; Embley, R. W.; Doucet, M.

    2012-12-01

    During a March 2010 expedition to NW Rota-1 submarine volcano in the Mariana arc a new EM122 multibeam sonar system on the R/V Kilo Moana was used to repeatedly image bubble plumes in the water column over the volcano. The EM122 (12 kHz) system collects seafloor bathymetry and backscatter data, as well as acoustic return water column data. Previous expeditions to NW Rota-1 have included seafloor mapping / CTD tow-yo surveys and remotely operated vehicle (ROV) dives in 2004, 2005, 2006 and 2009. Much of the focus has been on the one main eruptive vent, Brimstone, located on the south side of the summit at a depth of ~440m, which has been persistently active during all ROV visits. Extensive degassing of CO2 bubbles have been observed by the ROV during frequent eruptive bursts from the vent. Between expeditions in April 2009 and March 2010 a major eruption and landslide occurred at NW Rota-1. ROV dives in 2010 revealed that after the landslide the eruptive vent had been reorganized from a single site to a line of vents. Brimstone vent was still active, but 4 other new eruptive vents had also emerged in a NW/SE line below the summit extending ~100 m from the westernmost to easternmost vents. During the ROV dives, the eruptive vents were observed to turn on and off from day to day and hour to hour. Throughout the 2010 expedition numerous passes were made over the volcano summit to image the bubble plumes above the eruptive vents in the water column, in order to capture the variability of the plumes over time and to relate them to the eruptive output of the volcano. The mid-water sonar data set totals >95 hours of observations over a 12-day period. Generally, the ship drove repeatedly over the eruptive vents at a range of ship speeds (0.5-4 knots) and headings. In addition, some mid-water data was collected during three ROV dives when the ship was stationary over the vents. We used the FMMidwater software program (part of QPS Fledermaus) to visualize and analyze the data

  6. Assessing Eruption Column Height in Ancient Flood Basalt Eruptions

    NASA Technical Reports Server (NTRS)

    Glaze, Lori S.; Self, Stephen; Schmidt, Anja; Hunter, Stephen J.

    2015-01-01

    A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12-16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13-17 km for source widths of between 4-16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at approximately 45 deg N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the approximately 180 km of known Roza fissure length could have supported approximately 36 explosive events/phases, each with a duration of 3-4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (approximately 66 Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained

  7. Solar Activity and Solar Eruptions

    NASA Technical Reports Server (NTRS)

    Sterling, Alphonse C.

    2006-01-01

    Our Sun is a dynamic, ever-changing star. In general, its atmosphere displays major variation on an 11-year cycle. Throughout the cycle, the atmosphere occasionally exhibits large, sudden outbursts of energy. These "solar eruptions" manifest themselves in the form of solar flares, filament eruptions, coronal mass ejections (CMEs), and energetic particle releases. They are of high interest to scientists both because they represent fundamental processes that occur in various astrophysical context, and because, if directed toward Earth, they can disrupt Earth-based systems and satellites. Research over the last few decades has shown that the source of the eruptions is localized regions of energy-storing magnetic field on the Sun that become destabilized, leading to a release of the stored energy. Solar scientists have (probably) unraveled the basic outline of what happens in these eruptions, but many details are still not understood. In recent years we have been studying what triggers these magnetic eruptions, using ground-based and satellite-based solar observations in combination with predictions from various theoretical models. We will present an overview of solar activity and solar eruptions, give results from some of our own research, and discuss questions that remain to be explored.

  8. Infrasound research of volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Marchetti, Emanuele; Ripepe, Maurizio

    2016-04-01

    Volcanic eruptions are efficient sources of infrasound produced by the rapid perturbation of the atmosphere by the explosive source. Being able to propagate up to large distances from the source, infrasonic waves from major (VEI 4 or larger) volcanic eruptions have been recorded for many decades with analogue micro-barometers at large regional distances. In late 1980s, near-field observations became progressively more common and started to have direct impact on the understanding and modeling of explosive source dynamics, to eventually play a primary role in volcano research. Nowadays, infrasound observation from a large variety of volcanic eruptions, spanning from VEI 0 to VEI 5 events, has shown a dramatic variability in terms of signature, excess pressure and frequency content of radiated infrasound and has been used to infer complex eruptive source mechanisms for the different kinds of events. Improved processing capability and sensors has allowed unprecedented precise locations of the explosive source and is progressively increasing the possibility to monitor volcanoes from distant records. Very broadband infrasound observations is also showing the relation between volcanic eruptions and the atmosphere, with the eruptive mass injection in the atmosphere triggering acoustic-gravity waves which eventually might control the ash dispersal and fallout.

  9. Formation of an `a'ā lava delta: insights from time-lapse multibeam bathymetry and direct observations during the Stromboli 2007 eruption

    NASA Astrophysics Data System (ADS)

    Bosman, Alessandro; Casalbore, Daniele; Romagnoli, Claudia; Chiocci, Francesco Latino

    2014-07-01

    Five consecutive multibeam bathymetries collected before, during, and after the 2007 Stromboli eruption, combined with visual inspections, allowed us to document the morphological evolution of an `a'ā lava-fed delta and to reconstruct the main processes acting during its submarine emplacement. The 2007 Stromboli delta extended down to 600-m water depth and covered an area of 420 × 103 m2, with a maximum thickness of 65 m and a total estimated volume of ≈7 × 106 m3, i.e., three times larger than its subaerial counterpart. The lava delta grew mainly through the emplacement of discrete lobes about 50-150 m in size. Lobes were fed from point sources along the paleoshoreline, and their subaqueous pathways seem to be mainly controlled by the submarine morphology, with flows mostly filling in depressions left by previous lobes. The main controlling factors on the lobe morphology and thickness are the effusion rates and the pre-eruption morphology, i.e., the geometry and gradients of the basal surface. Data also shows that sudden slope failure of portions of the submarine delta may occur simultaneously with accretion, implying that a significant part of the delta material can be transported to greater depths by submarine gravity flows. The present study is relevant for future monitoring and hazard assessment during the growth of active lava-fed deltas as well as for a better interpretation of ancient volcaniclastic successions inland.

  10. Sensitivity of Greenland outlet glacier dynamics to submarine melting

    NASA Astrophysics Data System (ADS)

    Beckmann, Johanna; Siegrfied, Merten; Perrette, Mahé; Carlov, Reinhard; Ganopolski, Andrey

    2015-04-01

    Over the last few decades Greenland ice mass loss has strongly increased due to surface melt and dynamic changes in marine-terminating outlet glaciers. A major reason for the retreat of these glaciers is believed to be related to increased submarine melting, which in turn is caused by surrounding ocean warming and the enhanced subglacial water discharge. These complex physical processes are not yet fully understood. Inspecting the sensitivities of submarine melting to model formulation and model parameters is crucial for investigations of outlet glacier response to future climate change. Different approaches have been used to compute submarine melt rates of outlet glaciers using experimental data, numerical modelling and simplified analytical solutions. To model the process of submarine melting for a selection of Greenland outlet glaciers, a simple submarine melt parameterization is incorporated into a one-dimensional dynamic ice-flow model. The behaviour of this submarine melt parameterization is demonstrated by running a suite of simulations to investigate the sensitivity of submarine melt to changes in ocean properties and the amount and distribution of subglacial water discharge. A comparison of the simple parameterization with three-dimensional models and experimental data is conducted to assess the quality of parameterization and improve the parameterization of submarine melting.

  11. 32 CFR 707.7 - Submarine identification light.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Submarine identification light. 707.7 Section... RULES WITH RESPECT TO ADDITIONAL STATION AND SIGNAL LIGHTS § 707.7 Submarine identification light... off-period. The light will be located where it can best be seen, as near as practicable, all...

  12. Identification of a ship or submarine from its magnetic signature

    NASA Technical Reports Server (NTRS)

    Ioannidis, G.

    1977-01-01

    The relationship between the measured time fluctuations of the ambient magnetic field due to the passage of a ship or submarine and the characteristic magnetization properties of this vessel are derived. This relationship would be useful in identifying or classifying ships and submarines according to their magnetization properties.

  13. Detail of conning tower atop the submarine. Note the wire ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of conning tower atop the submarine. Note the wire rope wrapped around the base of the tower, which may have been used in an attempt to pull the submarine offshore. - Sub Marine Explorer, Located along the beach of Isla San Telmo, Pearl Islands, Isla San Telmo, Former Panama Canal Zone, CZ

  14. 32 CFR 707.7 - Submarine identification light.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Submarine identification light. 707.7 Section... RULES WITH RESPECT TO ADDITIONAL STATION AND SIGNAL LIGHTS § 707.7 Submarine identification light... off-period. The light will be located where it can best be seen, as near as practicable, all...

  15. 32 CFR 707.7 - Submarine identification light.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Submarine identification light. 707.7 Section... RULES WITH RESPECT TO ADDITIONAL STATION AND SIGNAL LIGHTS § 707.7 Submarine identification light... off-period. The light will be located where it can best be seen, as near as practicable, all...

  16. 32 CFR 707.7 - Submarine identification light.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Submarine identification light. 707.7 Section... RULES WITH RESPECT TO ADDITIONAL STATION AND SIGNAL LIGHTS § 707.7 Submarine identification light... off-period. The light will be located where it can best be seen, as near as practicable, all...

  17. Submarine fans in a sequence stratigraphic framework

    SciTech Connect

    Posamentier, H.W.; Erskine, R.D.; Mitchum, R.M.; Vail, P.R.

    1987-05-01

    Submarine fans are fan- or cone-shaped turbiditic deposits formed in upper bathyal or deeper water depths. Within a sequence stratigraphic framework, these basin-floor turbidites can occur during lowstand-fan or lowstand-wedge systems tract time. During lowstand fan time, streams are rejuvenated and depocenters shift from the coastal plain to the upper slope, causing retrogradational slope failure and canyon formation. The sediment delivered here bypasses the canyon and continues down the slope as a succession of gravity flows and is deposited as fan-shaped turbiditic deposits at the base of the slope. Seismic and outcrop evidence suggest that these sand-prone deposits are abruptly introduced into the basin and are generally characterized by subtle external mounding and internal bidirectionally down lapping seismic reflections where seismically resolvable. Deep-water sediment deposited during this interval has no coeval shelf equivalent. During lowstand wedge time, streams cease down cutting and valleys which have been freshly incised begin to fill. Because coarse sediment will preferentially be deposited within these incised valleys, the sand-to-mud ratio delivered to the upper slope will be decreased and, consequently, there is an inherent difference between submarine fans deposited at this time and those deposited during lowstand fan time. Deposition during lowstand wedge time is characterized seismically by slope front fill or wedge-shaped geometries down lapping the earlier submarine fan (i.e., deposited during lowstand fan time). These shale-prone deposits are largely comprised of thinner-bedded turbidites as well as the occasional leveed channel.

  18. Miniature Robotic Submarine for Exploring Harsh Environments

    NASA Technical Reports Server (NTRS)

    Behar, Alberto; Bruhn, Fredrik; Carsey, Frank

    2004-01-01

    The miniature autonomous submersible explorer (MASE) has been proposed as a means of scientific exploration -- especially, looking for signs of life -- in harsh, relatively inaccessible underwater environments. Basically, the MASE would be a small instrumented robotic submarine (see figure) that could launch itself or could be launched from another vehicle. Examples of environments that might be explored by use of the MASE include subglacial lakes, deep-ocean hydrothermal vents, acidic or alkaline lakes, brine lenses in permafrost, and ocean regions under Antarctic ice shelves.

  19. Optical Guidance for a Robotic Submarine

    NASA Astrophysics Data System (ADS)

    Schulze, Karl R.; LaFlash, Chris

    2002-11-01

    There is a need for autonomous submarines that can quickly and safely complete jobs, such as the recovery of a downed aircraft's black box recorder. In order to complete this feat, it is necessary to use an optical processing algorithm that distinguishes a desired target and uses the feedback from the algorithm to retrieve the target. The algorithm itself uses many bit mask filters for particle information, and then uses a unique rectation method in order to resolve complete objects. The algorithm has been extensively tested on an AUV platform, and proven to succeed repeatedly in approximately five or more feet of water clarity.

  20. Submarine LNG tanker concept for the Arctic

    SciTech Connect

    Veliotis, P.T.; Reitz, S.

    1981-01-01

    If LNG tankers could travel underwater, they could transport natural gas from Arctic regions year-round. General Dynamics has designed just such a tanker - a 140,000-m/sup 3/ submarine with a methane-fired steam-propulsion system that uses recirculated exhaust gas injected with oxygen to sustain combustion. (Nuclear power would be cheaper but might not be practical if new regulations are imposed.) Developed from parametric variations in cargo capacity, hull material, and ballasting, the design identifies such ship characteristics as length, beam, depth, cargo-system arrangement, speed, and ship control. An economic analysis indicates the concept's competitiveness with both pipelines and icebreaking tankers.

  1. The key to Understand Submarine Canyon Evolution

    NASA Astrophysics Data System (ADS)

    Baztan, J.; Berne, S.; Olivet, J.; Rabineau, M.; Aslanian, D.

    2004-12-01

    Submarine canyons are the preferential path of sediment transfer from the shelf to the deep sea, they are the key to understand the source-to-sink sedimentation and, in consequence, the shelf, slope and rise evolution. Pioneer works on submarine canyons described and proposed hypothesis to explain the formation and evolution of them. However, submarine canyons remain a matter of speculation. Our work in the Gulf of Lions (Mediterranean Sea) is based on swath bathymetry data together with sub-bottom profiles, high resolution seismic reflection profiles and cores. These data allow a detailed morphologic and stratigraphic study from the shelf to the rise through time, from 2.600.000 yrs to present. We show that two main erosive features, of very different dimensions, constitute the canyons: the axial incision and the canyon's major valley. The axial incision is interpreted as an erosive path related to the passage of hyperpycnal turbidity currents, generated up-slope by river connection. In the Gulf of Lions such currents are most likely to have formed during each Glacial Maxima (with a cyclicity of 100.000 years for the last 900.000 years and 40.000 years between 900.000 and 2.600.000 years) as both proximity of the shoreline (due to the lowstand of sea level) and high detrital sediment supply (due to glacial abrasion upstream) increased the flow of sediments delivered to the canyon heads. The axial incisions observed at the sea floor and fossil incisions observed on seismic lines, are related to equivalent conditions. The axial incision activity has a key influence on canyon evolution, it triggers mass wasting that affect the canyon's major valley (head and flanks) allowing the progressive widening and deepening of the canyon. Consequently the canyon's major valley (typically bounded by flanks of more than 700 meters in height) is the result of the axial incision activity through successive lowering of sea level. In summary: our cross-disciplinary approach

  2. Hydrogen isotope systematics of submarine basalts

    USGS Publications Warehouse

    Kyser, T.K.; O'Neil, J.R.

    1984-01-01

    The D/H ratios and water contents in fresh submarine basalts from the Mid-Atlantic Ridge, the East Pacific Rise, and Hawaii indicate that the primary D/H ratios of many submarine lavas have been altered by processes including (1) outgassing, (2) addition of seawater at magmatic temperature, and (3) low-temperature hydration of glass. Decreases in ??D and H2O+ from exteriors to interiors of pillows are explained by outgassing of water whereas inverse relations between ??D and H2O+ in basalts from the Galapagos Rise and the FAMOUS Area are attributed to outgassing of CH4 and H2. A good correlation between ??D values and H2O is observed in a suite of submarine tholeiites dredged from the Kilauea East Rift Zone where seawater (added directly to the magma), affected only the isotopic compositions of hydrogen and argon. Analyses of some glassy rims indicate that the outer millimeter of the glass can undergo lowtemperature hydration by hydroxyl groups having ??D values as low as -100. ??D values vary with H2O contents of subaerial transitional basalts from Molokai, Hawaii, and subaerial alkali basalts from the Society Islands, indicating that the primary ??D values were similar to those of submarine lavas. Extrapolations to possible unaltered ??D values and H2O contents indicate that the primary ??D values of most thoteiite and alkali basalts are near -80 ?? 5: the weight percentages of water are variable, 0.15-0.35 for MOR tholeiites, about 0.25 for Hawaiian tholeiites, and up to 1.1 for alkali basalts. The primary ??D values of -80 for most basalts are comparable to those measured for deep-seated phlogopites. These results indicate that hydrogen, in marked contrast to other elements such as Sr, Nd, Pb, and O, has a uniform isotopic composition in the mantle. This uniformity is best explained by the presence of a homogeneous reservoir of hydrogen that has existed in the mantle since the very early history of the Earth. ?? 1984.

  3. Guide to Accreditation, 2011-2012

    ERIC Educational Resources Information Center

    Teacher Education Accreditation Council, 2011

    2011-01-01

    The Teacher Education Accreditation Council (TEAC) "Guide to Accreditation" includes a full description of TEAC's principles and standards, the accreditation process and audit, and detailed instruction on writing the "Brief." This revision includes expanded information on (1) preparing an "Inquiry Brief Proposal" and the audit of the "Inquiry…

  4. Arctic Sea Ice Changes 2011-2012

    NASA Video Gallery

    Animation showing changes in monthly Arctic sea ice volume using data from ESA's CryoSat-2 (red dots) and estimates from the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) (solid li...

  5. Distance Education Report, 2011-2012

    ERIC Educational Resources Information Center

    California Community Colleges, Chancellor's Office, 2013

    2013-01-01

    This is a report on distance education in the California Community College. This is the seventh report to the California Community Colleges Board of Governors (BOG) per BOG Standing Order 409 (b) "that evaluates the effectiveness of distance education and education technology system wide and provides analysis of data demographically (by age,…

  6. Eruptions from the Sun

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-11-01

    The Sun often exhibits outbursts, launching material from its surface in powerful releases of energy. Recent analysis of such an outburst captured on video by several Sun-monitoring spacecraft may help us understand the mechanisms that launch these eruptions.Many OutburstsSolar jets are elongated, transient structures that are thought to regularly release magnetic energy from the Sun, contributing to coronal heating and solar wind acceleration. Coronal mass ejections (CMEs), on the other hand, are enormous blob-like explosions, violently ejecting energy and mass from the Sun at incredible speeds.But could these two types of events actually be related? According to a team of scientists at the University of Science and Technology of China, they may well be. The team, led by Jiajia Liu, has analyzed observations of a coronal jet that they believe prompted the launch of a powerful CME.Observing an ExplosionGif of a movie of the CME, taken by the Solar Dynamics Observatorys Atmospheric Imaging Assembly at a wavelength of 304. The original movie can be found in the article. [Liu et al.]An army of spacecraft was on hand to witness the event on 15 Jan 2013 including the Solar Dynamics Observatory (SDO), the Solar and Heliospheric Observatory (SOHO), and the Solar Terrestrial Relations Observatory (STEREO). The instruments on board these observatories captured the drama on the northern limb of the Sun as, at 19:32 UT, a coronal jet formed. Just eight minutes later, a powerful CME was released from the same active region.The fact that the jet and CME occurred in the same place at roughly the same time suggests theyre related. But did the initial motions of the CME blob trigger the jet? Or did the jet trigger the CME?Tying It All TogetherIn a recently published study, Liu and collaborators analyzed the multi-wavelength observations of this event to find the heights and positions of the jet and CME. From this analysis, they determined that the coronal jet triggered the release

  7. Automated Detection of Eruptive Structures for Solar Eruption Prediction

    NASA Astrophysics Data System (ADS)

    Georgoulis, Manolis K.

    2012-07-01

    The problem of data processing and assimilation for solar eruption prediction is, for contemporary solar physics, more pressing than the problem of data acquisition. Although critical solar data, such as the coronal magnetic field, are still not routinely available, space-based observatories deliver diverse, high-quality information at such a high rate that a manual or semi-manual processing becomes meaningless. We discuss automated data analysis methods and explain, using basic physics, why some of them are unlikely to advance eruption prediction. From this finding we also understand why solar eruption prediction is likely to remain inherently probabilistic. We discuss some promising eruption prediction measures and report on efforts to adapt them for use with high-resolution, high-cadence photospheric and coronal data delivered by the Solar Dynamics Observatory. Concluding, we touch on the problem of physical understanding and synthesis of different results: combining different measures inferred by different data sets is a yet-to-be-done exercise that, however, presents our best opportunity of realizing benefits in solar eruption prediction via a meaningful, targeted assimilation of solar data.

  8. Dental eruption in afrotherian mammals

    PubMed Central

    Asher, Robert J; Lehmann, Thomas

    2008-01-01

    Background Afrotheria comprises a newly recognized clade of mammals with strong molecular evidence for its monophyly. In contrast, morphological data uniting its diverse constituents, including elephants, sea cows, hyraxes, aardvarks, sengis, tenrecs and golden moles, have been difficult to identify. Here, we suggest relatively late eruption of the permanent dentition as a shared characteristic of afrotherian mammals. This characteristic and other features (such as vertebral anomalies and testicondy) recall the phenotype of a human genetic pathology (cleidocranial dysplasia), correlations with which have not been explored previously in the context of character evolution within the recently established phylogeny of living mammalian clades. Results Although data on the absolute timing of eruption in sengis, golden moles and tenrecs are still unknown, craniometric comparisons for ontogenetic series of these taxa show that considerable skull growth takes place prior to the complete eruption of the permanent cheek teeth. Specimens showing less than half (sengis, golden moles) or two-thirds (tenrecs, hyraxes) of their permanent cheek teeth reach or exceed the median jaw length of conspecifics with a complete dentition. With few exceptions, afrotherians are closer to median adult jaw length with fewer erupted, permanent cheek teeth than comparable stages of non-afrotherians. Manatees (but not dugongs), elephants and hyraxes with known age data show eruption of permanent teeth late in ontogeny relative to other mammals. While the occurrence of delayed eruption, vertebral anomalies and other potential afrotherian synapomorphies resemble some symptoms of a human genetic pathology, these characteristics do not appear to covary significantly among mammalian clades. Conclusion Morphological characteristics shared by such physically disparate animals such as elephants and golden moles are not easy to recognize, but are now known to include late eruption of permanent teeth, in

  9. Deep-Sea Research Submarine 'Ben Franklin'

    NASA Technical Reports Server (NTRS)

    1969-01-01

    This is an aerial view of the deep-sea research submarine 'Ben Franklin' at dock. Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life, and also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effects of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  10. Deep-Sea Submarine 'Ben Franklin'

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The deep-sea submarine 'Ben Franklin' is being docked in the harbor. Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life. It also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effect of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  11. Mineralized microbes from Giggenbach submarine volcano

    NASA Astrophysics Data System (ADS)

    Jones, Brian; de Ronde, C. E. J.; Renaut, Robin W.

    2008-08-01

    The Giggenbach submarine volcano, which forms part of the Kermadec active arc front, is located ˜780 km NNE of the North Island of New Zealand. Samples collected from chimneys associated with seafloor hydrothermal vents on this volcano, at a depth of 160-180 m, contain silicified microbes and microbes entombed in reticular Fe-rich precipitates. The mineralized biota includes filamentous, rod-shaped, and rare coccoid microbes. In the absence of organic carbon for rDNA analysis or preserved cells, the taxonomic affinity of these microbes, in terms of extant taxa, remains questionable because of their architectural simplicity and the paucity of taxonomically significant features. The three-dimensional preservation of the microbes indicates rapid mineralization with a steady supply of supersaturated fluids to the nucleation sites present on the surfaces of the microbes. The mineralization styles evident in the microbes from the Giggenbach submarine volcano are similar to those associated with mineralized microbes found in terrestrial hot spring deposits in New Zealand, Iceland, Yellowstone, and Kenya. These similarities exist even though the microbes are probably different and the fluids become supersaturated with respect to opal-A by different mechanisms. For ancient rocks it means that interpretations of the depositional settings cannot be based solely on the silicified microbes or their style of silicification.

  12. Flow dynamics around downwelling submarine canyons

    NASA Astrophysics Data System (ADS)

    Spurgin, J. M.; Allen, S. E.

    2014-10-01

    Flow dynamics around a downwelling submarine canyon were analysed with the Massachusetts Institute of Technology general circulation model. Blanes Canyon (northwestern Mediterranean) was used for topographic and initial forcing conditions. Fourteen scenarios were modelled with varying forcing conditions. Rossby and Burger numbers were used to determine the significance of Coriolis acceleration and stratification (respectively) and their impacts on flow dynamics. A new non-dimensional parameter (χ) was introduced to determine the significance of vertical variations in stratification. Some simulations do see brief periods of upwards displacement of water during the 10-day model period; however, the presence of the submarine canyon is found to enhance downwards advection of density in all model scenarios. High Burger numbers lead to negative vorticity and a trapped anticyclonic eddy within the canyon, as well as an increased density anomaly. Low Burger numbers lead to positive vorticity, cyclonic circulation, and weaker density anomalies. Vertical variations in stratification affect zonal jet placement. Under the same forcing conditions, the zonal jet is pushed offshore in more uniformly stratified domains. The offshore jet location generates upwards density advection away from the canyon, while onshore jets generate downwards density advection everywhere within the model domain. Increasing Rossby values across the canyon axis, as well as decreasing Burger values, increase negative vertical flux at shelf break depth (150 m). Increasing Rossby numbers lead to stronger downwards advection of a passive tracer (nitrate), as well as stronger vorticity within the canyon. Results from previous studies are explained within this new dynamic framework.

  13. Flow dynamics around downwelling submarine canyons

    NASA Astrophysics Data System (ADS)

    Spurgin, J. M.; Allen, S. E.

    2014-05-01

    Flow dynamics around a downwelling submarine canyon were analysed with the Massachusetts Institute of Technology general circulation model. Blanes Canyon (Northwest Mediterranean) was used for topographic and initial forcing conditions. Fourteen scenarios were modelled with varying forcing conditions. Rossby number and Burger number were used to determine the significance of Coriolis acceleration and stratification (respectively) and their impacts on flow dynamics. A new non-dimensional parameter (χ) was introduced to determine the significance of vertical variations in stratification. Some simulations do see brief periods of upwards displacement of water during the 10 day model period, however, the presence of the submarine canyon is found to enhance downwards advection of density in all model scenarios. High Burger numbers lead to negative vorticity and a trapped anticyclonic eddy within the canyon, as well as an increased density anomaly. Low Burger numbers lead to positive vorticity, cyclonic circulation and weaker density anomalies. Vertical variations in stratification affect zonal jet placement. Under the same forcing conditions, the zonal jet is pushed offshore in more uniformly stratified domains. Offshore jet location generates upwards density advection away from the canyon, while onshore jets generate downwards density advection everywhere within the model domain. Increasing Rossby values across the canyon axis, as well as decreasing Burger values, increase negative vertical flux at shelf break depth (150 m). Increasing Rossby numbers lead to stronger downwards advection of a passive tracer (nitrate) as well as stronger vorticity within the canyon. Results from previous studies were explained within this new dynamic framework.

  14. Morphology of Submarine Landslides in Puget Sound

    NASA Astrophysics Data System (ADS)

    Smith, S. B.; Karlin, R.

    2003-12-01

    Submarine landslides, probably triggered by large earthquakes, disturb Holocene sediments in Puget Sound. High-resolution seismic reflection profiling and sidescan swath surveys were conducted over large submarine landslides and debris flows. These large slides are in close proximity to the South Whidbey Island fault zone at Possession Point, Mukilteo, and Edgewater; near the Seattle fault off Alki Point; and near the Tacoma fault at Maury Island. The boundaries of the slides were mapped using sidescan swath surveys. Preliminary slide morphologies were determined from the seismic cross-sections. Three large slide complexes with multiple block slides and debris flows are found off Possession Point; the largest of which is 1.5 km x 1.0 km with a maximum thickness of approximately 50 meters. Large sand flows with maximum thicknesses of 30 to 40 meters occur off Mukilteo and Edgewater. An approximately 3.3 km x 2.2 km, 30 meter thick flow off Alki Point was deposited on top of folded sediments within the deformation zone of the Seattle Fault zone. Three large block slides are present off Maury Island; the largest of which is 2.75 km x 1.0 km, with a maximum thickness of approximately 100 meters. The volumes of these landslides are more than an order of magnitude larger than subaerial landslides in the region. Tsunamis generated by landsliding potentially constitute a major seismic hazard in coastal areas of the Puget Lowland.

  15. Seismic response of buried submarine pipelines

    SciTech Connect

    Datta, T.K.; Mashaly, E.A.

    1988-12-01

    Submarine pipelines are many a time buried into a jet-blasted channel in the seabed. Seismic response of such buried pipelines are investigated in this paper. The earthquake is considered as a partially correlated stationary random proceeds characterized by a power spectral density function (PSDF). The cross-spectral density function between two random inputs along the length of the pipe is defined with the help of the local earthquake PSDF, which is the same for all points, and a frequency-dependent, exponentially decaying function (with distance). A lumped-mass model with 2-D beam elements is used to write the equation of motion. Soil resistance to dynamic excitation along the pipe length is obtained in an approximate manner with the help of frequency-independent impedance functions derived from half-space analysis and Mindlin's static stresses within the soil due to point loads. The responses are obtained by a spectral analysis for horizontal ground motions in two principal directions, which are assumed to coincide with pipe axis and the perpendicular to it. Using the proposed method of analysis, a parametric study is conducted. The results of the study help in understanding the behavior of buried submarine pipelines under seismic forces and its differences from that of the buried pipelines on land.

  16. Submarine 'safe to escape' studies in man.

    PubMed

    Jurd, K M; Seddon, F M; Thacker, J C; Blogg, S L; Stansfield, M R D; White, M G; Loveman, G A M

    2014-01-01

    The Royal Navy requires reliable advice on the safe limits of escape from a distressed submarine (DISSUB). Flooding in a DISSUB may cause a rise in ambient pressure, increasing the risk of decompression sickness (DCS) and decreasing the maximum depth from which it is safe to escape. The aim of this study was to investigate the pressure/depth limits to escape following saturation at raised ambient pressure. Exposure to saturation pressures up to 1.6 bar (a) (160 kPa) (n = 38); escapes from depths down to 120 meters of sea water (msw) (n = 254) and a combination of saturation followed by escape (n = 90) was carried out in the QinetiQ Submarine Escape Simulator, Alverstoke, United Kingdom. Doppler ultrasound monitoring was used to judge the severity of decompression stress. The trials confirmed the previously untested advice, in the Guardbook, that if a DISSUB was lying at a depth of 90 msw, then it was safe to escape when the pressure in the DISSUB was 1.5 bar (a), but also indicated that this advice may be overly conservative. This study demonstrated that the upper DISSUB saturation pressure limit to safe escape from 90 msw was 1.6 bar (a), resulting in two cases of DCS. PMID:25109084

  17. Eruption cysts in the neonate.

    PubMed

    Ricci, Hérica Adad; Parisotto, Thaís Manzano; Giro, Elisa Maria Aparecida; de Souza Costa, Carlos Alberto; Hebling, Josimeri

    2008-01-01

    Disturbances of the dental development may result in anomalies, which may be apparent as soon as the child is born. Eruption cysts are rarely observed in neonates considering that at this stage of the child's life teeth eruption is uncommon. Thus, the aim of this report is to describe a case of eruption cysts in a neonate. A male neonate was brought to the emergency service with the chief complaint of an elevated area on the anterior region of the inferior alveolar ridge. The lesion was clinically characterized as a compressive and floating swelling. Through a radiographic exam two mandibular primary incisors could be seen superficially located. Due to the patient's age and the initial diagnosis of eruption cysts the conduct adopted was clinical surveillance. Forty-five days after the first visit the lesions had significantly decreased in size, and completely disappeared after 4 months. At that age, both mandibular central incisors were already in the oral cavity exhibiting small hypoplastic areas in the incisal edges. The clinical and radiographic follow-up of eruption cysts in neonates appears to be an adequate conduct without differing from that recommended for older children. PMID:18524277

  18. Featured Image: Solar Prominence Eruptions

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-02-01

    In these images from the Solar Dynamics Observatorys AIA instrument (click for the full resolution!), two solar prominence eruptions (one from June 2011 and one from August 2012) are shown in pre- and post-eruption states. The images at the top are taken in the Fe XII 193 bandpass and the images at the bottom are taken in the He II 304 bandpass. When a team of scientists searched through seven years of solar images taken by the STEREO (Solar Terrestrial Relations Observatory) spacecraft, these two eruptions were found to extend all the way out to a distance of 1 AU. They were the only two examples of clear, bright, and compact prominence eruptions found to do so. The scientists, led by Brian Wood (Naval Research Laboratory), used these observations to reconstruct the motion of the eruption and model how prominences expand as they travel away from the Sun. Theimage to the rightshowsa STEREO observation compared to the teams 3D model of theprominences shape and expansion. To learn more about theresults from this study, check out the paper below.CitationBrian E. Wood et al 2016 ApJ 816 67. doi:10.3847/0004-637X/816/2/67

  19. Automated detection of solar eruptions

    NASA Astrophysics Data System (ADS)

    Hurlburt, N.

    2015-12-01

    Observation of the solar atmosphere reveals a wide range of motions, from small scale jets and spicules to global-scale coronal mass ejections (CMEs). Identifying and characterizing these motions are essential to advancing our understanding of the drivers of space weather. Both automated and visual identifications are currently used in identifying Coronal Mass Ejections. To date, eruptions near the solar surface, which may be precursors to CMEs, have been identified primarily by visual inspection. Here we report on Eruption Patrol (EP): a software module that is designed to automatically identify eruptions from data collected by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory (SDO/AIA). We describe the method underlying the module and compare its results to previous identifications found in the Heliophysics Event Knowledgebase. EP identifies eruptions events that are consistent with those found by human annotations, but in a significantly more consistent and quantitative manner. Eruptions are found to be distributed within 15 Mm of the solar surface. They possess peak speeds ranging from 4 to 100 km/s and display a power-law probability distribution over that range. These characteristics are consistent with previous observations of prominences.

  20. Bayesian analysis of volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Ho, Chih-Hsiang

    1990-10-01

    The simple Poisson model generally gives a good fit to many volcanoes for volcanic eruption forecasting. Nonetheless, empirical evidence suggests that volcanic activity in successive equal time-periods tends to be more variable than a simple Poisson with constant eruptive rate. An alternative model is therefore examined in which eruptive rate(λ) for a given volcano or cluster(s) of volcanoes is described by a gamma distribution (prior) rather than treated as a constant value as in the assumptions of a simple Poisson model. Bayesian analysis is performed to link two distributions together to give the aggregate behavior of the volcanic activity. When the Poisson process is expanded to accomodate a gamma mixing distribution on λ, a consequence of this mixed (or compound) Poisson model is that the frequency distribution of eruptions in any given time-period of equal length follows the negative binomial distribution (NBD). Applications of the proposed model and comparisons between the generalized model and simple Poisson model are discussed based on the historical eruptive count data of volcanoes Mauna Loa (Hawaii) and Etna (Italy). Several relevant facts lead to the conclusion that the generalized model is preferable for practical use both in space and time.

  1. What threat do turbidity currents and submarine landslides pose to submarine telecommunications cable infrastructure?

    NASA Astrophysics Data System (ADS)

    Clare, Michael; Pope, Edward; Talling, Peter; Hunt, James; Carter, Lionel

    2016-04-01

    The global economy relies on uninterrupted usage of a network of telecommunication cables on the seafloor. These submarine cables carry ~99% of all trans-oceanic digital data and voice communications traffic worldwide, as they have far greater bandwidth than satellites. Over 9 million SWIFT banks transfers alone were made using these cables in 2004, totalling 7.4 trillion of transactions per day between 208 countries, which grew to 15 million SWIFT bank transactions last year. We outline the challenge of why, how often, and where seafloor cables are broken by natural causes; primarily subsea landslides and sediment flows (turbidity currents and also debris flows and hyperpycnal flows). These slides and flows can be very destructive. As an example, a sediment flow in 1929 travelled up to 19 m/s and broke 11 cables in the NE Atlantic, running out for ~800 km to the abyssal ocean. The 2006 Pingtung earthquake triggered a sediment flow that broke 22 cables offshore Taiwan over a distance of 450 km. Here, we present initial results from the first statistical analysis of a global database of cable breaks and causes. We first investigate the controls on frequency of submarine cable breaks in different environmental and geological settings worldwide. We assess which types of earthquake pose a significant threat to submarine cable networks. Meteorological events, such as hurricanes and typhoons, pose a significant threat to submarine cable networks, so we also discuss the potential impacts of future climate change on the frequency of such hazards. We then go on to ask what are the physical impacts of submarine sediment flows on submerged cables? A striking observation from past cable breaks is sometimes cables remain unbroken, whilst adjacent cables are severed (and record powerful flows travelling at up to 6 m/s). Why are some cables broken, but neighbouring cables remain intact? We provide some explanations for this question, and outline the need for future in

  2. Comparison of the FilmArray RP, Verigene RV+, and Prodesse ProFLU+/FAST+ Multiplex Platforms for Detection of Influenza Viruses in Clinical Samples from the 2011-2012 Influenza Season in Belgium

    PubMed Central

    Meeuws, Hanne; Van Immerseel, Andrea; Ispas, Gabriela; Schmidt, Kristiane; Houspie, Lieselot; Van Ranst, Marc; Stuyver, Lieven

    2013-01-01

    Respiratory tract infections (RTIs) are caused by a plethora of viral and bacterial pathogens. In particular, lower RTIs are a leading cause of hospitalization and mortality. Timely detection of the infecting respiratory pathogens is crucial to optimize treatment and care. In this study, three U.S. Food and Drug Administration-approved molecular multiplex platforms (Prodesse ProFLU+/FAST+, FilmArray RP, and Verigene RV+) were evaluated for influenza virus detection in 171 clinical samples collected during the Belgian 2011-2012 influenza season. Sampling was done using mid-turbinate flocked swabs, and the collected samples were stored in universal transport medium. The amount of viral RNA present in the swab samples ranged between 3.07 and 8.82 log10 copies/ml. Sixty samples were concordant influenza A virus positive, and 8 samples were found to be concordant influenza B virus positive. Other respiratory viruses that were detected included human rhinovirus/enterovirus, respiratory syncytial virus, parainfluenza virus type 1, human metapneumovirus, and coronavirus NL63. Twenty-five samples yielded discordant results across the various assays which required further characterization by sequencing. The FilmArray RP and Prodesse ProFLU+/FAST+ assays were convenient to perform with regard to sensitivity, ease of use, and low percentages of invalid results. Although the limit of sensitivity is of utmost importance, many other factors should be taken into account in selecting the most convenient molecular diagnostic assay for the detection of respiratory pathogens in clinical samples. PMID:23824777

  3. Baseline Activity of Telavancin against Gram-Positive Clinical Isolates Responsible for Documented Infections in U.S. Hospitals (2011-2012) as Determined by the Revised Susceptibility Testing Method

    PubMed Central

    Farrell, David J.; Sader, Helio S.; Flamm, Robert K.; Jones, Ronald N.

    2014-01-01

    Telavancin had MIC50 and MIC90 values of 0.03 and 0.06 μg/ml (100.0% susceptible), respectively, against methicillin-resistant and -susceptible Staphylococcus aureus. Telavancin was active against vancomycin-susceptible Enterococcus faecalis (MIC50/90, 0.12/0.12 μg/ml; 100% susceptible) and Enterococcus faecium (MIC50/90, 0.03/0.06 μg/ml), while higher MIC values were obtained against vancomycin-resistant E. faecium (MIC50/90, 1/2 μg/ml) and E. faecalis (MIC50/90, >2/>2 μg/ml). Streptococci showed telavancin modal MIC results of ≤0.015 μg/ml, except against Streptococcus agalactiae (i.e., 0.03 μg/ml). This study reestablishes the telavancin spectrum of activity against isolates recovered from the United States (2011-2012) using the revised broth microdilution method. PMID:25348529

  4. Can rain cause volcanic eruptions?

    USGS Publications Warehouse

    Mastin, Larry G.

    1993-01-01

    Volcanic eruptions are renowned for their violence and destructive power. This power comes ultimately from the heat and pressure of molten rock and its contained gases. Therefore we rarely consider the possibility that meteoric phenomena, like rainfall, could promote or inhibit their occurrence. Yet from time to time observers have suggested that weather may affect volcanic activity. In the late 1800's, for example, one of the first geologists to visit the island of Hawaii, J.D. Dana, speculated that rainfall influenced the occurrence of eruptions there. In the early 1900's, volcanologists suggested that some eruptions from Mount Lassen, Calif., were caused by the infiltration of snowmelt into the volcano's hot summit. Most such associations have not been provable because of lack of information; others have been dismissed after careful evaluation of the evidence.

  5. A potential submarine landslide tsunami in South China Sea

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Zhang, Y.; Switzer, A. D.

    2010-12-01

    Submarine earthquakes and submarine landslides are two main sources of tsunamis. Tsunami hazard modeling in the South China Sea has been primarily concerned with the potential large submarine earthquakes in the Manila trench. In contrast, evaluating the regional risk posed by tsunamis generated from submarine landslide is a new endeavor. At offshore south central Vietnam, bathymetric and seismic surveys show evidence of potentially tsunamigenic submarine landslides although their ages remain uncertain. We model two hypothetical submarine landslide events at a potential site on the heavily sediment laden, seismically active, steep continental slope offshore southeast Vietnam. Water level rises along the coast of Vietnam are presented for the potential scenarios, which indicate that the southeast coastal areas of Vietnam are at considerable risk of tsunami generated offshore submarine landslides. Key references: Kusnowidjaja Megawati, Felicia Shaw, Kerry Sieh, Zhenhua Huang, Tso-Ren Wu, Y. Lin, Soon Keat Tan and Tso-Chien Pan.(2009). Tsunami hazard from the subduction megathrust of the South China Sea, Part I, Source characterization and the resulting tsunami, Journal of Asian Earth Sciences, Vol. 36(1), pp. 13-20. Enet, F., Grilli, S.T. and Watts, P. (2003). Laboratory experiments for tsunami generated by underwater landslides: comparison with numerical modeling, In: Proceedings of 13th International Conference on Offshore and Polar Engineering, Honolulu, Hawaii, USA, pp. 372-379.

  6. Olivine-rich submarine basalts from the southwest rift zone of Mauna Loa Volcano: Implications for magmatic processes and geochemical evolution

    NASA Astrophysics Data System (ADS)

    Garcia, Michael O.; Hulsebosch, Thomas P.; Rhodes, J. Michael

    The east Ka Lae landslide on the submarine south flank of Mauna Loa exposed a 1.3 km thick section into the interior of its southwest rift zone. We sampled this section in four dredge hauls and four submersible dives and made a multibeam survey of the rift zone. New magnetic data and our observations and bathymetric results indicate that the axis of the southwest rift is two to three kilometers west of the present topographic high. Our submersible observations of old beach deposits and the low sulfur content of pillow-rim glasses indicate that this portion of the southwest rift zone has subsided >400 m. Olivine-rich basalts are extremely abundant along the submarine portion of Mauna Loa's southwest rift zone but their abundance decreases significantly in the upper parts of the two sections examined. This change probably occurred, ˜60 ka when Mauna Loa's eruption rate slowed and was unable to keep up with its subsidence rate. The dense magmas for these olivine-rich basalts were probably intruded into the deeper portions of the rift zones and erupted from its distal regions during periods of high magma supply. The preferential eruption of olivine-rich lavas on the flanks of Mauna Loa and other Hawaiian volcanoes is a strong indication that a density filter operates within these volcanoes. These lavas contain abundant euhedral, undeforrned olivine with high forsterite contents (typically 90%). Some of these olivines grew in magmas with 17.5 wt% MgO at temperatures of 1415°C, indicating that Hawaiian tholeiitic magmas are some of the most mafic and hottest magmas erupted during the Cenozoic. All of the submarine lavas have major element contents typical of Mauna Loa, but unlike its subaerial lavas, some of the submarine lavas have trace element and isotope ratios that overlap with those of Kilauea lavas. Thus, the source for Mauna Loa contained a Kilauea-like component that has been consumed during the last hundred thousand years, but the melt extraction conditions

  7. Erupted odontoma: a case report.

    PubMed

    Raval, Nilesh; Mehta, Dhaval; Vachhrajani, Kanan; Nimavat, Abhishek

    2014-07-01

    Odontomas are nonaggressive, hamartomatous developmental malformations or lesions of odontogenic origin, which consist of enamel, dentin, cementum and pulpal tissue 'Erupted odontoma' is a term used to specifically denote odontomas, which are exposed into the oral cavity. These are rare entities with only 25-30 cases being reported so far in the dental literature. Here, we present a rare case of an erupted odontoma in an adolescent patient who came with a complaint of bad aesthetics due to the presence of multiple small teeth like structures in the upper front teeth region. PMID:25177649

  8. Sub-glacial volcanic eruptions

    USGS Publications Warehouse

    White, Donald Edward

    1956-01-01

    The literature on sub-glacial volcanic eruptions and the related flood phenomena has been reviewed as a minor part of the larger problem of convective and conductive heat transfer from intrusive magma. (See Lovering, 1955, for a review of the extensive literature on this subject.) This summary of data on sub-glacial eruptions is part of a program that the U.S. Geological Survey is conducting in connection with its Investigations of Geologic Processes project on behalf of the Division of Research, U.S. Atomic Energy Commission.

  9. Lava bubble-wall fragments formed by submarine hydrovolcanic explosions on Lo'ihi Seamount and Kilauea Volcano

    USGS Publications Warehouse

    Clague, D.A.; Davis, A.S.; Bischoff, J.L.; Dixon, J.E.; Geyer, R.

    2000-01-01

    Glassy bubble-wall fragments, morphologically similar to littoral limu o Pele, have been found in volcanic sands erupted on Lo'ihi Seamount and along the submarine east rift zone of Kilauea Volcano. The limu o Pele fragments are undegassed with respect to H2O and S and formed by mild steam explosions. Angular glass sand fragments apparently form at similar, and greater, depths by cooling-contraction granulation. The limu o Pele fragments from Lo'ihi Seamount are dominantly tholeiitic basalt containing 6.25-7.25% MgO. None of the limu o Pele samples from Lo'ihi Seamount contains less than 5.57% MgO, suggesting that higher viscosity magmas do not form lava bubbles. The dissolved CO2 and H2O contents of 7 of the limu o Pele fragments indicate eruption at 1200??300 m depth (120??30 bar). These pressures exceed that generally thought to limit steam explosions. We conclude that hydrovolcanic eruptions are possible, with appropriate pre-mixing conditions, at pressures as great as 120 bar.

  10. Submarine Volcano Collapses in the Tonga-Kermadec Arc

    NASA Astrophysics Data System (ADS)

    Arculus, R. J.; Wright, I. C.; de Ronde, C. E.

    2005-12-01

    In the last few years, discoveries by multibeam swath and hydrothermal plume mapping plus rock dredging during several research voyages (NZAPLUME I to III, Sonne 135 and 167, TELVE and NoToVE) include about 70 new major volcanic edifices, most with basal diameters >15 km, spaced approximately 30 km apart along the length (2,500 km) of the Tonga-Kermadec arc. About 40 percent of these are hydrothermally active. The edifices comprise stratovolcanoes of variable complexity, and steep-walled calderas with diameters <12 km. Large-scale sector collapses occur on many of these structures, and concentric ridges on the outer flanks of some calderas appear to be mega-bedforms associated with mass flows and edifice failures. Topographic rims of many calderas are capped by numerous conical vents; cones are also present within many calderas. Overall relationships exist along arc between depth of basement, nature of volcanic structures, and magma composition; more felsic (dacite to rhyolite) lavas are associated with higher basement elevation, multi-vent stratovolcanoes, and caldera complexes, but the exact relationship between formerly contiguous arc-remnant arc basement prior to formation of the Havre Trough-Lau Basin and establishment of the current arc edifices is complex. The predominant mode of formation of felsic magma-dominated calderas is interpreted to be mass pyroclastic discharge with syn-eruptive caldera collapse in water depths <1000 m. Other types of edifice failure are: sector collapses extending for full volcano flank heights that feed debris fields, and in some cases expose radial fissure dikes; mega-bedforms comprising a series of ridges striking parallel to adjacent projected caldera margins. Close to the caldera, these ridges have relative relief of about 150m decreasing to <10m at distances >20 km from the caldera. Terrain between many adjacent submarine volcanic edifices is blanketed by degraded and subdued equivalents of these mega-bedforms. Overall

  11. Mt. Etna Eruption

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1: Vis/NIR Image CloseupFigure 2: Difference Image

    October 2002 Mt. Etna, a volcano on the island of Sicily, erupted on October 26, 2002. Preliminary analysis of data taken by the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on October 28 shows the instrument can provide an excellent means to study the evolution and structure of the sulfur dioxide (SO2) plume emitted from volcanoes. These data also demonstrate that AIRS can be used to obtain the total mass of SO2 injected into the atmosphere during a volcanic event, information that may help us to better understand these dangerous natural occurrences in the future.

    This image was made from a sensor on the AIRS instrument that is sensitive to the visible and near-infrared portions of the spectrum. The visible/near infrared data show the smoke plume from Mt. Etna. The view is of Europe and the central Mediterranean with Italy in the center. Since the visible/near infrared sensor on AIRS is sensitive to wavelengths that are different than the human eye, vegetated regions appear red (compare the red color of Europe with the tan desert of North Africa in the lower left). Figure 1 is a closer view of Sicily and shows a long, brownish smoke plume extending across the Mediterranean to Africa. This is consistent with the enhanced feature in the difference image in Figure 2 and helps validate the information inferred from that image.

    Figure 2 clearly shows the SO2 plume. This image was created by comparing data taken at two different frequencies, or channels, and creating one image that highlights the differences between these two channels. Both channels are sensitive to water vapor, but one of the channels is also sensitive to SO2. By subtracting out the common water vapor signal in both channels, the SO2 feature remains and shows up as an enhancement in the difference image.

    The

  12. Predicting Major Solar Eruptions

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-05-01

    , whether an active region that produces a flare will also produce a CME. Bobra and Ilonidis then use a feature-selection algorithm to try to understand which features distinguish between flaring regions that dont produce a CME and those that do.Predictors of CMEsThe authors reach several interesting conclusions:Under the right conditions, their algorithm is able to predict whether an active region with a given set of features will produce a CME as well as a flare with a fairly high rate of success.None of the 18 features they tested are good predictors in isolation: its necessary to look at a combination of at least 6 features to have success predicting whether a flare will be accompanied by a CME.The features that are the best predictors are all intensive features ones that stay the same independent of the active regions size. Extensive features ones that change as the active region grows or shrinks are less successful predictors.Only the magnetic field properties of the photosphere were considered, so a logical next step is to extend this study to consider properties of the solar corona above active regions as well. In the meantime, these are interesting first results that may well help us better predict these major solar eruptions.BonusCheck out this video for a great description from NASA of the difference between solar flares and CMEs (as well as some awesome observations of both).CitationM. G. Bobra and S. Ilonidis 2016 ApJ 821 127. doi:10.3847/0004-637X/821/2/127

  13. Geologic mapping on the deep seafloor: Reconstructing lava flow emplacement and eruptive history at the Galápagos Spreading Center

    NASA Astrophysics Data System (ADS)

    McClinton, J. T.; White, S.; Colman, A.; Sinton, J. M.; Bowles, J. A.

    2012-12-01

    The deep seafloor imposes significant difficulties on data collection that require the integration of multiple data sets and the implementation of unconventional geologic mapping techniques. We combine visual mapping of geological contacts by submersible with lava flow morphology maps and relative and absolute age constraints to create a spatiotemporal framework for examining submarine lava flow emplacement at the intermediate-spreading, hotspot-affected Galápagos Spreading Center (GSC). We mapped 18 lava flow fields, interpreted to be separate eruptive episodes, within two study areas at the GSC using visual observations of superposition, surface preservation and sediment cover from submersible and towed camera surveys, augmented by high-resolution sonar surveys and sample petrology [Colman et al., Effects of variable magma supply on mid-ocean ridge eruptions: Constraints from mapped lava flow fields along the Galápagos Spreading Center; 2012 G3]. We also mapped the lava flow morphology within the majority of these eruptive units using an automated, machine-learning classification method [McClinton et al., Neuro-fuzzy classification of submarine lava flow morphology; 2012 PE&RS]. The method combines detailed geometric, acoustic, and textural attributes derived from high-resolution sonar data with visual observations and a machine-learning algorithm to classify submarine lava flow morphology as pillows, lobates, or sheets. The resulting lava morphology maps are a valuable tool for interpreting patterns in the emplacement of submarine lava flows at a mid-ocean ridge (MOR). Within our study area at 92°W, where the GSC has a relatively high magma supply, high effusion rate sheet and lobate lavas are more abundant in the oldest mapped eruptive units, while the most recent eruptions mostly consist of low effusion rate pillow lavas. The older eruptions (roughly 400yrs BP by paleomagnetic intensity) extend up to 1km off axis via prominent channels and tubes, while the

  14. Gas burst vs. gas-rich magma recharge: A multidisciplinary study to reveal factors controlling triggering of the recent paroxysmal eruptions at Mt. Etna

    NASA Astrophysics Data System (ADS)

    Viccaro, Marco; Garozzo, Ileana; Cannata, Andrea; Di Grazia, Giuseppe; Gresta, Stefano

    2014-05-01

    Since January 2011, Mt. Etna volcano has been affected by more than forty paroxysmal eruptions at the summit (New South East Crater; NSEC). On the basis of their very variable duration, seven eruptions have been selected among the twenty-five of 2011-2012 in order to decipher potential differences in their triggering mechanism. Paroxysms have been investigated through a multidisciplinary approach that integrates data from volcanic tremor and petrology (textures and micro-analysis on plagioclase crystals). Our results lead to the conclusion that close relationships exist between the duration of the eruptions and the temporal evolution of the volcanic tremor amplitude, especially during the Strombolian phase preceding the paroxysmal activity. In this regard, we distinguished: 1) paroxysms preceded by long-lasting initial Strombolian phases, characterized by low rate of volcanic tremor amplitude increase; and 2) eruptions preceded by short initial Strombolian phases, showing high rate of volcanic tremor amplitude increase. Based on the pattern of volcanic tremor amplitude increase, the former mainly showed a ramp-shaped morphology, while the latter a bell-shaped trend. Location of the volcanic tremor centroid during the quiescent intervals between the paroxysmal eruptions has highlighted the presence of a magmatic volume at 1-2 km a.s.l. beneath the North East Crater (NEC). During the syn-eruptive Strombolian and lava fountaining phases, the centroid of volcanic tremor migrates below the NSEC. This leads to the consideration that the magma batch residing beneath NEC played an important role in the volcanic activity at NSEC during the considered period. Also the textures and compositional zoning (anorthite and iron variations) in selected plagioclase crystals of the analyzed lavas suggest relations between duration of the paroxysms and dynamics of pre-eruptive magmatic processes at depth. Particularly, two mechanisms have been accounted for triggering of eruptions at

  15. Rootless eruption of a mandibular permanent canine.

    PubMed

    Shapira, Yehoshua; Kuftinec, Mladen M

    2011-04-01

    The purpose of this article was to describe the rootless eruption of a mandibular permanent canine in a 10-year-old boy; his mandible had been fractured in a car accident. The fracture was at the region of the developing canine, resulting in arrested root formation and causing abnormal, rootless eruption. Current theories on tooth eruption and the important role of the dental follicle in the process of eruption are discussed. PMID:21457868

  16. Transport of Fine Ash Through the Water Column at Erupting Volcanoes - Monowai Cone, Kermadec-Tonga Arc

    NASA Astrophysics Data System (ADS)

    Walker, S. L.; Baker, E. T.; Leybourne, M. I.; de Ronde, C. E.; Greene, R.; Faure, K.; Chadwick, W.; Dziak, R. P.; Lupton, J. E.; Lebon, G.

    2010-12-01

    Monowai cone is a large, active, basaltic stratovolcano, part of the submarine Monowai volcanic center (MVC) located at ~26°S on the Kermadec-Tonga arc. At other actively erupting submarine volcanoes, magma extrusions and hydrothermal vents have been located only near the summit of the edifice, generating plumes enriched with hydrothermal components and magmatic gasses that disperse into the ocean environment at, or shallower than, the summit depth. Plumes found deeper than summit depths are dominated by fresh volcaniclastic ash particles, devoid of hydrothermal tracers, emplaced episodically by down-slope gravity flows, and transport fine ash to 10’s of km from the active eruptions. A water column survey of the MVC in 2004 mapped intensely hydrothermal-magmatic plumes over the shallow (~130 m) summit of Monowai cone and widespread plumes around its flanks. Due to the more complex multiple parasitic cone and caldera structure of MVC, we analyzed the dissolved and particulate components of the flank plumes for evidence of additional sources. Although hydrothermal plumes exist within the adjacent caldera, none of the parasitic cones on Monowai cone or elsewhere within the MVC were hydrothermally or volcanically active. The combination of an intensely enriched summit plume, sulfur particles and bubbles at the sea surface, and ash-dominated flank plumes indicate Monowai cone was actively erupting at the time of the 2004 survey. Monowai cone is thus the fourth erupting submarine volcano we have encountered, and all have had deep ash plumes distributed around their flanks [the others are: Kavachi (Solomon Island arc), NW Rota-1 (Mariana arc) and W Mata (NE Lau basin)]. These deep ash plumes are a syneruptive phenomenon, but it is unknown how they are related to eruptive style and output, or to the cycles of construction and collapse that occur on the slopes of submarine volcanoes. Repeat multibeam bathymetric surveys have documented two large-scale sector collapse

  17. Underwater splice for submarine coaxial cable

    SciTech Connect

    Inouye, A.T.; Roe, T. Jr.; Tausing, W.R.; Wilson, J.V.

    1984-10-30

    The invention is a device for splicing submarine coaxial cable underwater on the seafloor with a simple push-on operation to restore and maintain electrical and mechanical strength integrity; the splice device is mateable directly with the severed ends of a coaxial cable to be repaired. Splicing assemblies comprise a dielectric pressure compensating fluid filled guide cavity, a gelled castor oil cap and wiping seals for exclusion of seawater, electrical contacts, a cable strength restoration mechanism, and a pressure compensation system for controlled extrusion of and depletion loss prevention of dielectric seal fluid during cable splicing. A splice is made underwater by directly inserting prepared ends of coaxial cable, having no connector attachments, into splicing assemblies.

  18. Submarine thermal springs on the Galapagos Rift

    USGS Publications Warehouse

    Corliss, J.B.; Dymond, J.; Gordon, L.I.; Edmond, J.M.; Von Herzen, R. P.; Ballard, Richard D.; Green, K.; Williams, D.; Bainbridge, A.; Crane, K.; Van Andel, T. H.

    1979-01-01

    The submarine hydrothermal activity on and near the Galápagos Rift has been explored with the aid of the deep submersible Alvin. Analyses of water samples from hydrothermal vents reveal that hydrothermal activity provides significant or dominant sources and sinks for several components of seawater; studies of conductive and convective heat transfer suggest that two-thirds of the heat lost from new oceanic lithosphere at the Galápagos Rift in the first million years may be vented from thermal springs, predominantly along the axial ridge within the rift valley. The vent areas are populated by animal communities. They appear to utilize chemosynthesis by sulfur-oxidizing bacteria to derive their entire energy supply from reactions between the seawater and the rocks at high temperatures, rather than photosynthesis

  19. Submarine thermal sprirngs on the galapagos rift.

    PubMed

    Corliss, J B; Dymond, J; Gordon, L I; Edmond, J M; von Herzen, R P; Ballard, R D; Green, K; Williams, D; Bainbridge, A; Crane, K; van Andel, T H

    1979-03-16

    The submarine hydrothermal activity on and near the Galápagos Rift has been explored with the aid of the deep submersible Alvin. Analyses of water samples from hydrothermal vents reveal that hydrothermal activity provides significant or dominant sources and sinks for several components of seawater; studies of conductive and convective heat transfer suggest that two-thirds of the heat lost from new oceanic lithosphere at the Galápagos Rift in the first million years may be vented from thermal springs, predominantly along the axial ridge within the rift valley. The vent areas are populated by animal communities. They appear to utilize chemosynthesis by sulfur-oxidizing bacteria to derive their entire energy supply from reactions between the seawater and the rocks at high temperatures, rather than photosynthesis. PMID:17776033

  20. A contaminant monitor for submarine atmospheres.

    NASA Technical Reports Server (NTRS)

    Ruecker, M. R.

    1973-01-01

    A requirement for monitoring selected atmospheric constituents on board nuclear powered submarines has been met by the development of the Central Atmosphere Monitoring System, Mark I. This system employs a mass spectrometer to monitor H2, H2O, N2, O2, CO2, Freon 11, Freon 12, and Freon 114, in addition to an infrared sensor for CO. The CAMS MKI development is discussed, including background, operating fundamentals, principal requirements, functional and physical descriptions, and summarized test results. Each of two prototype units has successfully completed over 9000 hr of operational sea trails, providing the necessary ground work for the manufacture of production units. At the same time, these units, which have benefited extensively from NASA hardware experience, may in turn provide useful data for the development of a new class of maintainable atmospheric monitoring instrumentation for manned spacecraft.

  1. EAARL submarine topography: Biscayne National Park

    USGS Publications Warehouse

    Brock, John C.; Wright, C. Wayne; Patterson, Matt; Nayegandhi, Amar; Patterson, Judd; Harris, Melanie S.; Mosher, Lance

    2006-01-01

    This lidar-derived submarine topography map was produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, National Park Service (NPS) South Florida/Caribbean Network Inventory and Monitoring Program, and the National Aeronautics and Space Administration (NASA) Wallops Flight Facility. One objective of this research is to create techniques to survey coral reefs for the purposes of habitat mapping, ecological monitoring, change detection, and event assessment (for example: bleaching, hurricanes, disease outbreaks). As part of this project, data from an innovative instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Airborne Advanced Research Lidar (EAARL) are being used. This sensor has the potential to make significant contributions in this realm for measuring water depth and conducting cross-environment surveys. High spectral resolution, water-column correction, and low costs were found to be key factors in providing accurate and affordable imagery to managers of coastal tropical habitats.

  2. Alternative OTEC Scheme for a Submarine Robot

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Chao, Yi

    2009-01-01

    A proposed system for exploiting the ocean thermal gradient to generate power would be based on the thawing-expansion/ freezing-contraction behavior of a wax or perhaps another suitable phase-change material. The power generated by this system would be used to recharge the batteries in a battery-powered unmanned underwater vehicle [UUV (essentially, a small exploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warming. A UUV of this type travels between the ocean surface and various depths, measuring temperature and salinity. This proposed system would be an alternative to another proposed ocean thermal energy conversion (OTEC) system that would serve the same purpose but would utilize a thermodynamic cycle in which CO2 would be the working fluid. That system is described in Utilizing Ocean Thermal Energy in a Submarine Robot (NPO-43304), immediately following this brief. The main advantage of this proposed system over the one using CO2 is that it could derive a useful amount of energy from a significantly smaller temperature difference. At one phase of its operational cycle, the system now proposed would utilize the surface ocean temperature (which lies between 15 and 20 C over most of the Earth) to melt a wax (e.g., pentadecane) that has a melting/freezing temperature of about 10 C. At the opposite phase of its operational cycle, the system would utilize the lower ocean temperature at depth (e.g., between 4 and 7 C at a depth of 300 m) to freeze the wax. The melting or freezing causes the wax to expand or contract, respectively, by about 8 volume percent.

  3. Nitrogen biogeochemistry of submarine groundwater discharge

    USGS Publications Warehouse

    Kroeger, K.D.; Charette, M.A.

    2008-01-01

    To investigate the role of the seepage zone in transport, chemical speciation, and attenuation of nitrogen loads carried by submarine groundwater discharge, we collected nearshore groundwater samples (n = 328) and examined the distribution and isotopic signature (??15N) of nitrate and ammonium. In addition, we estimated nutrient fluxes from terrestrial and marine groundwater sources. We discuss our results in the context of three aquifer zones: a fresh groundwater zone, a shallow salinity transition zone (STZ), and a deep STZ. Groundwater plumes containing nitrate and ammonium occurred in the freshwater zone, whereas the deep STZ carried almost exclusively ammonium. The distributions of redox-cycled elements were consistent with theoretical thermodynamic stability of chemical species, with sharp interfaces between water masses of distinct oxidation : reduction potential, suggesting that microbial transformations of nitrogen were rapid relative to dispersive mixing. In limited locations in which overlap occurs between distribution of nitrate with that of ammonium and dissolved Fe2+, changes in concentration and in ??15N suggest loss of all species. Concurrent removal of NO 3- and NH4+, both in freshwater and the deep STZ, might occur through a range of mechanisms, including heterotrophic or autotrophic denitrification, coupled nitrfication : denitrification, anammox, or Mn oxidation of NH4+. Loss of nitrogen was not apparent in the shallow STZ, perhaps because of short water residence time. Despite organic C-poor conditions, the nearshore aquifer and subterranean estuary are biogeochemically active zones, where attenuation of N loads can occur. Extent of attenuation is controlled by the degree of mixing of biogeochemically dissimilar water masses, highlighting the critical role of hydrogeology in N biogeochemistry. Mixing is related in part to thinning of the freshwater lens before discharge and to dispersion at the fresh : saline groundwater interface, features

  4. Improved OTEC System for a Submarine Robot

    NASA Technical Reports Server (NTRS)

    Chao, Yi; Jones, Jack; Valdez, Thomas

    2010-01-01

    An ocean thermal energy conversion (OTEC), now undergoing development, is a less-massive, more-efficient means of exploiting the same basic principle as that of the proposed system described in "Alternative OTEC Scheme for a Submarine Robot" (NPO-43500), NASA Tech Briefs, Vol. 33, No. 1 (January 2009), page 50. The proposed system as described previously would be based on the thawing-expansion/freezing-contraction behavior of a wax or perhaps another suitable phase-change material (PCM). The power generated by the system would be used to recharge the batteries in a battery- powered unmanned underwater vehicle [UUV (essentially, a small exploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warming. A UUV of this type travels between the ocean surface and depths, measuring temperature and salinity. At one phase of its operational cycle, the previously proposed system would utilize the surface ocean temperature (which lies between 15 and 30 C over most of the Earth) to melt a PCM that has a melting/freezing temperature of about 10 C. At the opposite phase of its operational cycle, the system would utilize the lower ocean temperature at depth (e.g., between 4 and 7 C at a depth of 300 m) to freeze the PCM. The melting or freezing would cause the PCM to expand or contract, respectively, by about 9 volume percent. The PCM would be contained in tubes that would be capable of expanding and contracting with the PCM. The PCM-containing tubes would be immersed in a hydraulic fluid. The expansion and contraction would drive a flow of the hydraulic fluid against a piston that, in turn, would push a rack-and-pinion gear system to spin a generator to charge a battery.

  5. Sorafenib induced eruptive melanocytic lesions.

    PubMed

    Uhlenhake, Elizabeth E; Watson, Alice C; Aronson, Peter

    2013-05-01

    Sorafenib is a multikinase inhibitor FDA-approved for the treatment of advanced renal cell and hepatocellular carcinoma. Dermatologic side effects include hand-foot skin reaction, facial and scalp erythema and desquamation, splinter subungual hemorrhages, alopecia, pruritus, xerosis, keratoacanthomas, and squamous cell carcinomas. We report sudden eruption of melanocytic nevi diffusely in a patient receiving sorafenib. PMID:24011281

  6. Eruptive viscosity and volcano morphology

    NASA Technical Reports Server (NTRS)

    Posin, Seth B.; Greeley, Ronald

    1988-01-01

    Terrestrial central volcanoes formed predominantly from lava flows were classified as shields, stratovolcanoes, and domes. Shield volcanoes tend to be large in areal extent, have convex slopes, and are characterized by their resemblance to inverted hellenic war shields. Stratovolcanoes have concave slopes, whereas domes are smaller and have gentle convex slopes near the vent that increase near the perimeter. In addition to these differences in morphology, several other variations were observed. The most important is composition: shield volcanoes tend to be basaltic, stratovolcanoes tend to be andesitic, and domes tend to be dacitic. However, important exceptions include Fuji, Pico, Mayon, Izalco, and Fuego which have stratovolcano morphologies but are composed of basaltic lavas. Similarly, Ribkwo is a Kenyan shield volcano composed of trachyte and Suswa and Kilombe are shields composed of phonolite. These exceptions indicate that eruptive conditions, rather than composition, may be the primary factors that determine volcano morphology. The objective of this study is to determine the relationships, if any, between eruptive conditions (viscosity, erupted volume, and effusion rate) and effusive volcano morphology. Moreover, it is the goal of this study to incorporate these relationships into a model to predict the eruptive conditions of extraterrestrial (Martian) volcanoes based on their morphology.

  7. Eruption conditions of spatter deposits

    NASA Astrophysics Data System (ADS)

    Rader, Erika; Geist, Dennis

    2015-10-01

    Spatter is an eruptive product that forms within a narrow range of thermal conditions: it must be hot enough to deform and agglutinate, but not so hot that clasts completely re-fuse and remobilize as clastogenic lava. This narrow thermal window of spatter-forming conditions allows for quantitative prediction of cooling rates and accumulation rates. Cooling and accumulation rates then provide information that enables estimates of eruption parameters for inaccessible and prehistoric deposits. High-temperature experiments conducted on basaltic scoria from Devil's Garden, Oregon have revealed the eruption temperature was ~ 1130 °C. The strength welds formed between experimental clasts is shown to depend on cooling rate. Natural samples are compared to the experimental samples by measuring tensile strength and welded area between clasts. The weld strength in natural deposits yields estimates of cooling rates that range between 2.5 °C and 48 °C/min, with the majority of the samples grouping between 7 °C and 14 °C/min. Thermal models based on these cooling rates yield spatter accumulation rates of 0.5-1.8 m/h in the Devil's Garden spatter deposits. We provide a general model for cooling and accumulation rates for spatter cones, ramparts, and hornitos, which allow estimation of the factors that control basaltic eruptive products.

  8. Effect of Submarine Groundwater Discharge on Relict Arctic Submarine Permafrost and Gas Hydrate

    NASA Astrophysics Data System (ADS)

    Frederick, J. M.; Buffett, B. A.

    2014-12-01

    Permafrost-associated gas hydrate deposits exist at shallow depths within the sediments of the circum-Arctic continental shelves. Degradation of this shallow water reservoir has the potential to release large quantities of methane gas directly to the atmosphere. Gas hydrate stability and the permeability of the shelf sediments to gas migration is closely linked with submarine permafrost. Submarine permafrost extent depends on several factors, such as the lithology, sea level variations, mean annual air temperature, ocean bottom water temperature, geothermal heat flux, and the salinity of the pore water. The salinity of the pore water is especially relevant because it partially controls the freezing point for both ice and gas hydrate. Measurements of deep pore water salinity are few and far between, but show that deep off-shore sediments are fresh. Deep freshening has been attributed to large-scale topographically-driven submarine groundwater discharge, which introduces fresh terrestrial groundwater into deep marine sediments. We investigate the role of submarine ground water discharge on the salinity field and its effects on the seaward extent of relict submarine permafrost and gas hydrate stability on the Arctic shelf with a 2D shelf-scale model based on the finite volume method. The model tracks the evolution of the temperature, salinity, and pressure fields given imposed boundary conditions, with latent heat of water ice and hydrate formation included. The permeability structure of the sediments is coupled to changes in permafrost. Results show that pore fluid is strongly influenced by the permeability variations imposed by the overlying permafrost layer. Groundwater discharge tends to travel horizontally off-shore beneath the permafrost layer and the freshwater-saltwater interface location displays long timescale transient behavior that is dependent on the groundwater discharge strength. The seaward permafrost extent is in turn strongly influenced by the

  9. Aurorae and Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    2001-06-01

    Thermal-IR Observations of Jupiter and Io with ISAAC at the VLT Summary Impressive thermal-infrared images have been obtained of the giant planet Jupiter during tests of a new detector in the ISAAC instrument on the ESO Very Large Telescope (VLT) at the Paranal Observatory (Chile). . They show in particular the full extent of the northern auroral ring and part of the southern aurora. A volcanic eruption was also imaged on Io , the very active inner Jovian moon. Although these observations are of an experimental nature, they demonstrate a great potential for regular monitoring of the Jovian magnetosphere by ground-based telescopes together with space-based facilities. They also provide the added benefit of direct comparison with the terrestrial magnetosphere. PR Photo 21a/01 : ISAAC image of Jupiter (L-band: 3.5-4.0 µm) . PR Photo 21b/01 : ISAAC image of Jupiter (Narrow-band 4.07 µm) . PR Photo 21c/01 : ISAAC image of Jupiter (Narrow-band 3.28 µm) . PR Photo 21d/01 : ISAAC image of Jupiter (Narrow-band 3.21 µm) . PR Photo 21e/01 : ISAAC image of the Jovian aurorae (false-colour). PR Photo 21f/01 : ISAAC image of volcanic activity on Io . Addendum : The Jovian aurorae and polar haze. Aladdin Meets Jupiter Thermal-infrared images of Jupiter and its volcanic moon Io have been obtained during a series of system tests with the new Aladdin detector in the Infrared Spectrometer And Array Camera (ISAAC) , in combination with an upgrade of the ESO-developed detector control electronics IRACE. This state-of-the-art instrument is attached to the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory. The observations were made on November 14, 2000, through various filters that isolate selected wavebands in the thermal-infrared spectral region [1]. They include a broad-band L-filter (wavelength interval 3.5 - 4.0 µm) as well as several narrow-band filters (3.21, 3.28 and 4.07 µm). The filters allow to record the light from different components of the Jovian atmosphere

  10. Aurorae and Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    2001-06-01

    Thermal-IR Observations of Jupiter and Io with ISAAC at the VLT Summary Impressive thermal-infrared images have been obtained of the giant planet Jupiter during tests of a new detector in the ISAAC instrument on the ESO Very Large Telescope (VLT) at the Paranal Observatory (Chile). . They show in particular the full extent of the northern auroral ring and part of the southern aurora. A volcanic eruption was also imaged on Io , the very active inner Jovian moon. Although these observations are of an experimental nature, they demonstrate a great potential for regular monitoring of the Jovian magnetosphere by ground-based telescopes together with space-based facilities. They also provide the added benefit of direct comparison with the terrestrial magnetosphere. PR Photo 21a/01 : ISAAC image of Jupiter (L-band: 3.5-4.0 µm) . PR Photo 21b/01 : ISAAC image of Jupiter (Narrow-band 4.07 µm) . PR Photo 21c/01 : ISAAC image of Jupiter (Narrow-band 3.28 µm) . PR Photo 21d/01 : ISAAC image of Jupiter (Narrow-band 3.21 µm) . PR Photo 21e/01 : ISAAC image of the Jovian aurorae (false-colour). PR Photo 21f/01 : ISAAC image of volcanic activity on Io . Addendum : The Jovian aurorae and polar haze. Aladdin Meets Jupiter Thermal-infrared images of Jupiter and its volcanic moon Io have been obtained during a series of system tests with the new Aladdin detector in the Infrared Spectrometer And Array Camera (ISAAC) , in combination with an upgrade of the ESO-developed detector control electronics IRACE. This state-of-the-art instrument is attached to the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory. The observations were made on November 14, 2000, through various filters that isolate selected wavebands in the thermal-infrared spectral region [1]. They include a broad-band L-filter (wavelength interval 3.5 - 4.0 µm) as well as several narrow-band filters (3.21, 3.28 and 4.07 µm). The filters allow to record the light from different components of the Jovian atmosphere

  11. View west of reserve basin of submarine trout and frigate ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View west of reserve basin of submarine trout and frigate Edward E. McDonnell - Naval Base Philadelphia-Philadelphia Naval Shipyard, Reserve Basin & Marine Railway, League Island, Philadelphia, Philadelphia County, PA

  12. Three-dimensional grid generation about a submarine

    NASA Technical Reports Server (NTRS)

    Abolhassani, Jamshid Samareh; Smith, Robert E.

    1988-01-01

    A systematic multiple-block grid method has been developed to compute grids about submarines. Several topologies are proposed, and an oscillatory transfinite interpolation is used in the grid construction.

  13. Duration of fever and other symptoms after the inhalation of laninamivir octanoate hydrate for influenza treatment; comparison among the four Japanese influenza seasons from 2011-2012 to 2014-2015.

    PubMed

    Ikematsu, Hideyuki; Kawai, Naoki; Iwaki, Norio; Kashiwagi, Seizaburo

    2016-09-01

    The duration of fever and other symptoms as markers of the clinical effectiveness of laninamivir octanoate hydrate (laninamivir) were investigated in the Japanese 2014-2015 influenza season and the results were compared with those of the previous three seasons, 2011-2012 to 2013-2014. From these four seasons, the data of 636 influenza A(H3N2) and 128 influenza B patients was available for analysis. No significant difference was found in their baseline characteristics. The median duration of fever for all A(H3N2) patients ranged from 32.0 to 41.0 h. The duration of fever in the 2014-2015 season was significantly shorter than that in the 2012-2013 and 2013-2014 seasons (p = 0.0204 and 0.0391, respectively), but the differences were within nine hours. The median duration of symptoms for A(H3N2) ranged from 80.0 to 89.0 h, with no significant difference among the four seasons (p = 0.2222). The median duration of fever for B patients ranged from 43.0 to 50.0 h, with no significant difference among the four seasons. The duration of the symptoms for B varied by season, but no significant difference was found among the four seasons. Over the four seasons, 44 adverse events were reported from among 921 patients, with all resolving without treatment. These results indicate the continuing effectiveness of laninamivir against influenza A(H3N2) and B, with no safety issues. It is unlikely that the clinical use of laninamivir has caused viral resistance in the currently epidemic viruses. PMID:27493024

  14. Online Health Information-Seeking Behavior and Confidence in Filling Out Online Forms Among Latinos: A Cross-Sectional Analysis of the California Health Interview Survey, 2011-2012

    PubMed Central

    Emory, Jason

    2016-01-01

    Background Health information is increasingly being disseminated online, but there is a knowledge gap between Latinos and non-Hispanic whites, particularly those whose English language proficiency is poor, in terms both of online health information-seeking behavior and computer literacy skills. This knowledge gap may also exist between US- and foreign-born Latinos. Objective The specific aim of this study was to examine Internet use, online health information-seeking behavior, and confidence in filling out online forms among Latinos, particularly as it relates to health-risk behaviors. We then stratified our sample by nativity. Methods We used the adult population file of the 2011-2012 California Health Interview Survey, analyzing Internet use, online health information-seeking behavior, and confidence in filling out online forms using binary logistic regression among Latinos and whites (N=27,289), Latinos (n=9506), and Latinos who use the Internet (n=6037). Results Foreign-born Latinos (OR 0.71, 95% CI 0.58-0.88, P=.002) have lower odds of engaging in online health information-seeking behavior, and higher odds (OR 2.90, 95% CI 2.07-4.06, P<.001) of reporting a lack of confidence in filling out online forms compared to US-born Latinos. Correlates of online health information-seeking behavior and form confidence varied by nativity. Conclusions Latinos, particularly foreign-born individuals, are at an increased risk of being left behind as the move to increase online content delivery and care expands. As online health information dissemination and online health portals become more popular, the impact of these sites on Latino gaps in coverage and care should be considered. PMID:27377466

  15. A record-breaking low ice cover over the Great Lakes during winter 2011/2012: combined effects of a strong positive NAO and La Niña

    NASA Astrophysics Data System (ADS)

    Bai, Xuezhi; Wang, Jia; Austin, Jay; Schwab, David J.; Assel, Raymond; Clites, Anne; Bratton, John F.; Colton, Marie; Lenters, John; Lofgren, Brent; Wohlleben, Trudy; Helfrich, Sean; Vanderploeg, Henry; Luo, Lin; Leshkevich, George

    2015-03-01

    A record-breaking low ice cover occurred in the North American Great Lakes during winter 2011/2012, in conjunction with a strong positive Arctic Oscillation/North Atlantic Oscillation (+AO/NAO) and a La Niña event. Large-scale atmosphere circulation in the Pacific/North America (PNA) region reflected a combined signal of La Niña and +NAO. Surface heat flux analysis shows that sensible heat flux contributed most to the net surface heat flux anomaly. Surface air temperature is the dominant factor governing the interannual variability of Great Lakes ice cover. Neither La Niña nor +NAO alone can be responsible for the extreme warmth; the typical mid-latitude response to La Niña events is a negative PNA pattern, which does not have a significant impact on Great Lakes winter climate; the positive phase of NAO is usually associated with moderate warming. When the two occurred simultaneously, the combined effects of La Niña and +NAO resulted in a negative East Pacific pattern with a negative center over Alaska/Western Canada, a positive center in the eastern North Pacific (north of Hawaii), and an enhanced positive center over the eastern and southern United States. The overall pattern prohibited the movement of the Arctic air mass into mid-latitudes and enhanced southerly flow and warm advection from the Gulf of Mexico over the eastern United States and Great Lakes region, leading to the record-breaking low ice cover. It is another climatic pattern that can induce extreme warming in the Great Lakes region in addition to strong El Niño events. A very similar event occurred in the winter of 1999/2000. This extreme warm winter and spring in 2012 had significant impacts on the physical environment, as well as counterintuitive effects on phytoplankton abundance.

  16. Hydrogen and Methane Dissolved in Plumes of the Northeast Lau Basin Eruption Sites

    NASA Astrophysics Data System (ADS)

    Baumberger, T.; Lilley, M. D.; Lupton, J. E.; Resing, J. A.; Baker, E. T.; Walker, S. L.; Rubin, K. H.; Frueh-Green, G. L.

    2009-12-01

    Exceptionally high hydrogen concentrations measured in the water column of the Northeast Lau Basin in the Southwest Pacific were instrumental in the discovery of two active eruption sites during a NOAA expedition in November 2008. High levels of hydrogen dissolved in the water column are indicative of seawater-hot rock interaction and provide strong evidence for ongoing or very recent volcanic eruptions on the seafloor. Methane concentrations are generally low in hot hydrothermal fluids from bare-rock systems and were low in the eruptive plumes at the two active sites. A rapid response cruise to the two eruption sites, West Mata Volcano and the back arc ridge Northeast Lau Spreading Center (NELSC), in May 2009 confirmed, by remotely operated vehicle operations, the predicted submarine volcanic eruption at West Mata. Water samples from the CTD-rosette package indicated that the dissolved hydrogen concentrations (up to 17 µM) in the plume of West Mata were in the same range as those measured in November 2008. However, at the NELSC, the measured dissolved hydrogen concentrations had returned to near-background values and no evidence for a continuing eruption was detected. These observations suggest ongoing volcanic activity at West Mata during both cruises, but only in November 2008 at the NELSC. Po/Pb dated lava samples at the NELSC from May 2009 suggest an eruption in November 2008 congruent with the high hydrogen values measured in the plume. Methane concentrations at West Mata were generally low during both cruises. Methane concentrations as high as 1 µM detected in bottom waters at the NELSC in November 2008 were not found again 6 months later. Elevated methane concentrations were also seen near bottom at another off-axis volcano (E. Mata) only a few kilometres east of West Mata in November 2008. These high methane concentrations are likely derived from near bottom diffuse venting where microbially produced methane is often seen. The shipboard dissolved

  17. Cardiometabolic Health in Submariners Returning from a 3-Month Patrol

    PubMed Central

    Gasier, Heath G.; Young, Colin R.; Gaffney-Stomberg, Erin; McAdams, Douglas C.; Lutz, Laura J.; McClung, James P.

    2016-01-01

    Confined space, limited exercise equipment, rotating shift work and reduced sleep may affect cardiometabolic health in submariners. To test this hypothesis, 53 male U.S. Submariners (20–39 years) were studied before and after a 3-month routine submarine patrol. Measures included anthropometrics, dietary and physical activity, biomarkers of cardiometabolic health, energy and appetite regulation, and inflammation. Before deployment, 62% of submariners had a body fat % (BF%) ≥ 25% (obesity), and of this group, 30% met the criteria for metabolic syndrome. In obese volunteers, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), leptin, the leptin/adiponectin ratio, and pro-inflammatory chemokines growth-related oncogene and macrophage-derived chemokine were significantly higher compared to non-obese submariners. Following the patrol, a significant mean reduction in body mass (5%) and fat-mass (11%) occurred in the obese group as a result of reduced energy intake (~2000 kJ) during the patrol; and, independent of group, modest improvements in serum lipids and a mean reduction in interferon γ-induced protein 10 and monocyte chemotactic protein 1 were observed. Since 43% of the submariners remained obese, and 18% continued to meet the criteria for metabolic syndrome following the patrol, the magnitude of weight loss was insufficient to completely abolish metabolic dysfunction. Submergence up to 3-months, however, does not appear to be the cause of obesity, which is similar to that of the general population. PMID:26867201

  18. Cardiometabolic Health in Submariners Returning from a 3-Month Patrol.

    PubMed

    Gasier, Heath G; Young, Colin R; Gaffney-Stomberg, Erin; McAdams, Douglas C; Lutz, Laura J; McClung, James P

    2016-02-01

    Confined space, limited exercise equipment, rotating shift work and reduced sleep may affect cardiometabolic health in submariners. To test this hypothesis, 53 male U.S. Submariners (20-39 years) were studied before and after a 3-month routine submarine patrol. Measures included anthropometrics, dietary and physical activity, biomarkers of cardiometabolic health, energy and appetite regulation, and inflammation. Before deployment, 62% of submariners had a body fat % (BF%) ≥ 25% (obesity), and of this group, 30% met the criteria for metabolic syndrome. In obese volunteers, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), leptin, the leptin/adiponectin ratio, and pro-inflammatory chemokines growth-related oncogene and macrophage-derived chemokine were significantly higher compared to non-obese submariners. Following the patrol, a significant mean reduction in body mass (5%) and fat-mass (11%) occurred in the obese group as a result of reduced energy intake (~2000 kJ) during the patrol; and, independent of group, modest improvements in serum lipids and a mean reduction in interferon γ-induced protein 10 and monocyte chemotactic protein 1 were observed. Since 43% of the submariners remained obese, and 18% continued to meet the criteria for metabolic syndrome following the patrol, the magnitude of weight loss was insufficient to completely abolish metabolic dysfunction. Submergence up to 3-months, however, does not appear to be the cause of obesity, which is similar to that of the general population. PMID:26867201

  19. Reconstruction of the paleo-coastline of Santorini island (Greece), after the 1613 BC volcanic eruption: A GIS-based quantitative methodology

    NASA Astrophysics Data System (ADS)

    Oikonomidis, Dimitrios; Albanakis, Konstantinos; Pavlides, Spyridon; Fytikas, Michael

    2016-02-01

    A catastrophic volcanic explosion took place in Thera/Santorini island around 1613 BC, known as the `Minoan' eruption. Many papers have dealt with the shape of the shoreline of the island before the eruption, but none with the shape of the shoreline exactly after it, assuming that it would be the same with the contemporary one. However, this is not correct due to the wave erosion. In this paper, a new DEM was constructed, covering both land and submarine morphology, then topographic sections were drawn around the island. Using these sections, the `missing parts' (sea-wave erosion) were calculated, the shoreline was reconstructed as it was one day after the eruption and finally the erosion rate was calculated.

  20. Submarine explosive activity and ocean noise generation at Monowai Volcano, Kermadec Arc: constraints from hydroacoustic T-waves

    NASA Astrophysics Data System (ADS)

    Grevemeyer, Ingo; Metz, Dirk; Watts, Anthony

    2016-04-01

    Submarine volcanic activity is difficult to detect, because eruptions at depth are strongly attenuated by seawater. With increasing depth the ambient water pressure increases and limits the expansion of gas and steam such that volcanic eruptions tend to be less violent and less explosive with depth. Furthermore, the thermal conductivity and heat capacity of water causes rapid cooling of ejected products and hence erupted magma cools much more quickly than during subaerial eruptions. Therefore, reports on submarine volcanism are restricted to those sites where erupted products - like the presence of pumice rafts, gas bubbling on the sea surface, and local seawater colour changes - reach the sea surface. However, eruptions cause sound waves that travel over far distances through the Sound-Fixing-And-Ranging (SOFAR) channel, so called T-waves. Seismic networks in French Polynesia recorded T-waves since the 1980's that originated at Monowai Volcano, Kermadec Arc, and were attributed to episodic growth and collapse events. Repeated swath-mapping campaigns conducted between 1998 and 2011 confirm that Monowai volcano is a highly dynamic volcano. In July of 2007 a network of ocean-bottom-seismometers (OBS) and hydrophones was deployed and recovered at the end of January 2008. The instruments were located just to the east of Monowai between latitude 25°45'S and 27°30'S. The 23 OBS were placed over the fore-arc and on the incoming subducting plate to obtain local seismicity associated with plate bending and coupling of the subduction megathrust. However, we recognized additional non-seismic sleuths in the recordings. Events were best seen in 1 Hz high-pass filtered hydrophone records and were identified as T-waves. The term T-wave is generally used for waves travelling through the SOFAR channel over large distances. In our case, however, they were also detected on station down to ~8000 m, suggesting that waves on the sea-bed station were direct waves caused by explosive

  1. Extensive and Diverse Submarine Volcanism and Hydrothermal Activity in the NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Embley, R. W.; Merle, S. G.; Lupton, J. E.; Resing, J.; Baker, E. T.; Lilley, M. D.; Arculus, R. J.; Crowhurst, P. V.

    2009-12-01

    The northeast Lau basin, the NE “corner” of the Tonga subduction zone, has an unusual concentration of young submarine volcanism and hydrothermal activity. The area is bounded on the west by overlapping spreading centers opening at rates up to 120 mm/yr, on the north by the E-W trending Tonga trench and on the east by the Tofua arc front. From the south, the Fonualei rift spreading center (FRSC) overlaps with the southern rift of The Mangatolo triple junction spreading center (MTJSC). The northern arm of the MTJSC overlaps with the northeast Lau spreading center (NELSC). Surveys of the area with an EM300 sonar system in November 2008 show high backscatter over the 10-20 km wide neovolcanic zones of the FRSC, MTJSC and NELSC. High backscatter is also associated with: (1) a 10-km diameter, hydrothermally active, volcanic caldera/cone (Volcano “O”) lying between the NELSC and the northern Tofua arc front; (2) a rift zone extending north from volcano “O” and intersecting the NELSC near the Tonga trench; and (3) a series of volcanoes constructed along SW-NE trending crustal tears in the northernmost backarc near the east-west portion of the Tonga Trench. Two eruptions were detected in November 2008 during hydrothermal plume surveys of the area. Subsequent dives with the remotely operated vehicle Jason 2 in May 2009 revealed that the southern NELSC eruption was a short-lived, primarily effusive eruption. The second eruption was detected on the summit of the largest SW-NE trending volcano (West Mata) and was ongoing when Jason 2 arrived on site more than 6 months later. It was producing both pillow lavas and abundant volcaniclastic debris streams that have a characteristic appearance on the sonar backscatter map. There is also an unusual series of lava flows emanating from ridges and scarps between Volcano “O” and West Mata. These flows contain drained-out lava ponds up to 2 km in diameter. The apparent high level of volcanic activity in the NE Lau basin

  2. Rapid quantitative assessment of land patterns change and erupted volumes by spaceborne SAR

    NASA Astrophysics Data System (ADS)

    Villeneuve, N.; Bianchi, M.; Cigna, F.; di Muro, A.; Fortunato, G.; Sedze, M.; Ferrucci, F.

    2013-12-01

    Synthetic Aperture Radar observations do not apply frequently to the quantitative mapping of lava flows and of eruptive patterns, as multispectral mid-to-high spatial/temporal resolution observations are naturally best suited for high-temperature contouring and eruptive rate assessment. However, in case of urgent need for quantitative geographical information, high-spatial and high-temporal resolution SAR data may become essential or unique in providing timely information support to officials in charge of volcano emergencies. This was the case of the early weeks of the 2011-2012 Nyiamulagira eruption (DR Congo), whose fast and large lava flow developed in an area off-limited by the ongoing military unrest, and persistent cloud cover spoiled the ground view to electro-optical high-resolution payloads. A combination of two automated techniques - one non-interferometric and one interferometric - on very-high resolution X-band images acquired during less-than-weekly revisits by the Cosmo SkyMED constellation, allowed locating the eruption site, highlighting the inherent landscape modifications, mapping the progression of the ~22 km lava flow, and carrying out volume estimates by precise DEM subtractions. The interferometric technique is based on the application of the PS-InSAR derived SqueeSAR procedure (Ferretti et al., IEEE Trans. Geosci. Rem. Sens.,49-9, 3460-3470; 2011) to series of Cosmo-SkyMED tandem pairs for obtaining high-precision/high-resolution DEMs anywhere-anytime within a limited time framework. Validation against a recent LiDAR DEM of the summit areas of Piton de la Fournaise (Reunion Island) returned a typical accuracy of 0.4m × 2.3m in one-orbit geometry. The non-interferometric technique exploits amplitude and coherence changes to single out, map and measure newly appeared volcanic features of significant dimensions. The overall observation-and-processing strategy was developed in the framework and under the specifications of project EVOSS (European

  3. Nyiragongo Volcano before the Eruption

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Nyiragongo is an active stratovolcano situated on the Eastern African Rift; it is part of Africa's Virunga Volcanic Chain. In a massive eruption that occurred on January 17, 2002, Nyiragongo sent a vast plume of smoke and ash skyward, and three swifly-moving rivers of lava streaming down its western and eastern flanks. Previous lava flows from Nyiragongo have been observed moving at speeds of up to 40 miles per hour (60 kph). The lava flows from the January 17 eruption destroyed more than 14 villages in the surrounding countryside, forcing tens of thousands to flee into the neighboring country of Rwanda. Within one day the lava ran to the city of Goma, situated on the northern shore of Lake Kivu about 12 miles (19 km) south of Nyiragongo. The lava cut a 200 foot (60 meter) wide swath right through Goma, setting off many fires, as it ran into Lake Kivu. Goma, the most heavily populated city in eastern Democratic Republic of Congo, is home to about 400,000 people. Most of these citizens were forced to flee, while many have begun to return to their homes only to find their homes destroyed. This true-color scene was captured by the Enhanced Thematic Mapper Plus (ETM+), flying aboard the Landsat 7 satellite, on December 11, 2001, just over a month before the most recent eruption. Nyiragongo's large crater is clearly visible in the image. As recently as June 1994, there was a large lava lake in the volcano's crater which had since solidified. The larger Nyamuragira Volcano is located roughly 13 miles (21 km) to the north of Nyiragongo. Nyamuragira last erupted in February and March 2001. That eruption was also marked by columns of erupted ash and long fluid lava flows, some of which are apparent in the image as dark greyish swaths radiating away from Nyamuragira. Both peaks are also notorious for releasing large amounts of sulfur dioxide, which presents another health hazard to people and animals living in close proximity. Image by Robert Simmon, based on data supplied

  4. Identification and Implications of a Submarine Monogenetic Field in the NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Rubin, K. H.; Embley, R. W.

    2012-12-01

    Short-lived, volcanism at discrete, closely spaced volcanic cones and low lying lava flows in the NE corner of the Lau backarc basin shares many characteristics with subaerial monogenetic fields. We use geological, morphological, petrological, and geochemical observations of this volcanic field made on five research expeditions since 2008, along with comparisons to well-known terrestrial monogenetic fields to assess whether the Mata volcanic group is best thought of as a submarine mongenetic volcanic field (a term rarely, if ever, applied to submarine settings). The volcanism has constructed a series of 9 small, very closely spaced, hydrothermally-active, elongate volcanic edifices near the east-west portion of the Tonga Trench, which are 1.5 to 7.5 km apart (summit to summit) and are 450 to 1400m tall. Only one of the volcanoes (West Mata) is currently active, erupting boninite pillow lavas along with explosively-generated volcaniclastic sediments. The ages of the youngest volcanics on the other Mata volcanoes are not yet determined but most are hydrothermally active and are surfaced with relatively young lava flows without significant sediment cover. The volcanoes are all formed predominantly of low effusion rate pillow lavas with variable amounts of pyroclastic deposits mantling the constructional topography, suggesting relatively long-lived volcanism (ca 100-200 yrs) at each center, similar to large lava shields in Iceland (e.g., skjaldbreidur). Detailed stratigraphic observations are as yet only available for one volcano (with more to come during an ROV field campaign in Sept. 2012). Bottom photographs provide no clear evidence for long-lived hiatuses at any of these cones and bathymetric data do not intricate overlapping constructional structures, resurgent construction, or large scale collapse or mass wasting structures, as might be expected for a protracted, many-eruption volcanic history at any single volcano. However, the oldest edifice does show evidence

  5. First Use of an Autonomous Glider for Exploring Submarine Volcanism in the SW Pacific

    NASA Astrophysics Data System (ADS)

    Matsumoto, H.; Embley, R. W.; Haxel, J. H.; Dziak, R. P.; Bohnenstiehl, D. R.; Stalin, S.; Meinig, C.

    2010-12-01

    A 1000-m Slocum glider® (Teledyne Webb Research Corporation) with CTD, turbidity, and hydrophone sensors was operated for two days in the Northeast Lau Basin. The survey was conducted near West Mata Volcano, where in November of 2008 the NOAA PMEL Vents program observed an active eruption at its 1207 m summit—the deepest submarine activity ever before witnessed. Our goal was to use the glider as a forensic tool to search for other nearby eruption sites with onboard sensors that detect the chemical and hydroacoustic signatures associated with the volcanic and hydrothermal plumes. The glider was launched approximately 40 km to the west of West Mata. It flew toward West Mata and was recovered near the summit of the volcano after repeating 13 yos during a 41-hour mission. Although the recordings were affected by mechanical noise from the glider’s rudder, the data demonstrate that the system can detect the wide-band noises (>1 kHz) associated with submarine volcanic and intense hydrothermal activity. The glider recorded complex acoustic amplitudes due to the multiple raypaths from West Mata as well as temporal variations in the volcano’s rate of activity, and demonstrated that these geologic processes contribute to the region’s high ambient noise levels. With the exception of the deployment and recovery, the mission was managed entirely by the shore teams in PMEL (Seattle, WA) and OSU labs (Newport, OR), ~5000 miles away without an engineer onboard. The dive cycle of the 950-m dives was ~3.5 hours and the average speed was ~0.27 cm/s. The CTD data were downloaded at every surface cycle and appeared to be of high quality. However we found that the sensitivity of the Wetlabs ECO flntu turbidity sensor was not adequate for the detection of volcanic plumes. The mission demonstrated PMEL’s ability to use autonomous gliders to monitor a variety of environmental parameters including ambient sound levels, temperature, salinity and turbidity for the purpose of finding

  6. From pumice to obsidian: eruptive behaviors that produce tephra-flow dyads. II- The 114ka trachyte eruption at Pu'u Wa'awa'a (Hawai'i).

    NASA Astrophysics Data System (ADS)

    Shea, T.; Leonhardi, T. C.; Giachetti, T.; Larsen, J. F.; Lindoo, A. N.

    2014-12-01

    Associations of tephra and lava flow/domes produced by eruptions involving evolved magmas are a common occurrence in various types of volcanic settings (e.g. Pu'u Wa'awa'a ~114ka, Hawaii; South Mono ~AD625, California; Newberry Big Obsidian flow ~AD700, Oregon; Big Glass Mountain ~AD1100, California; Inyo ~AD1350, California, Chaitén AD2008-2009, Chile; Cordón Caulle AD2011-2012, Chile), ejecting up to a few cubic km of material (tephra+flow/dome). Most, if not all, of these eruptions have in common the paradoxical coexistence of (1) eruptive styles which are inferred to be sustained in nature (subplinian and plinian), with (2) a pulsatory behavior displayed by the resulting fall deposits, and (3) the coeval ejection of vesicular tephra and pyroclastic obsidian. Through two case studies, we explore this apparent set of paradoxes, and their significance in understanding transitions from explosive to effusive behavior. In this second case study (also cf. Shea et al., same session), we present new field, textural and geochemical data pertaining to the 114ka Pu'u Wa'awa'a trachyte eruption in Hawai'i. This large volume (>5 km3) event produced both a tephra cone (~1.6 km in diameter) and a thick (>250 m) lava flow, which have been largely covered by the more recent basaltic Mauna Loa and Hualalai lava flows. The trachyte tephra contains juvenile material displaying a large textural variety (pumice, scoria, obsidian, microcrystalline trachyte and banded-clasts), which can be linked with the extent of degassing and the formation of feldspar microlites. Notably, the abundance of microlites can be used to reconstruct an ascent and devolatilization history that accounts for all the seemingly contradictory observations.

  7. Submarine Landslides at Santa Catalina Island, California

    NASA Astrophysics Data System (ADS)

    Legg, M. R.; Francis, R. D.

    2011-12-01

    Santa Catalina Island is an active tectonic block of volcanic and metamorphic rocks originally exposed during middle Miocene transtension along the evolving Pacific-North America transform plate boundary. Post-Miocene transpression created the existing large pop-up structure along the major strike-slip restraining bend of the Catalina fault that forms the southwest flank of the uplift. Prominent submerged marine terraces apparent in high-resolution bathymetric maps interrupt the steep submarine slopes in the upper ~400 meters subsea depths. Steep subaerial slopes of the island are covered by Quaternary landslides, especially at the sea cliffs and in the blueschist metamorphic rocks. The submarine slopes also show numerous landslides that range in area from a few hectares to more than three sq-km (300 hectares). Three or more landslides of recent origin exist between the nearshore and first submerged terrace along the north-facing shelf of the island's West End. One of these slides occurred during September 2005 when divers observed a remarkable change in the seafloor configuration after previous dives in the area. Near a sunken yacht at about 45-ft depth where the bottom had sloped gently into deeper water, a "sinkhole" had formed that dropped steeply to 100-ft or greater depths. Some bubbling sand was observed in the shallow water areas that may be related to the landslide process. High-resolution multibeam bathymetry acquired in 2008 by CSU Monterey Bay show this "fresh" slide and at least two other slides of varying age along the West End. The slides are each roughly 2 hectares in area and their debris aprons are spread across the first terrace at about 85-m water depth that is likely associated with the Last Glacial Maximum sealevel lowstand. Larger submarine slides exist along the steep Catalina and Catalina Ridge escarpments along the southwest flank of the island platform. A prominent slide block, exceeding 3 sq-km in area, appears to have slipped more than

  8. Pb, Hf, Nd, and Sr Isotopic Variations of Hualalai Shield Stage Tholeiites from the Submarine North Kona Region

    NASA Astrophysics Data System (ADS)

    Yamasaki, S.; Kani, T.; Hanan, B. B.; Tagami, T.

    2007-12-01

    We present the isotope and trace element compositions of tholeiitic lavas collected from deep submarine portions of North Kona region, the west flank of Hualalai volcano. The samples were collected from the lower section of the North Kona bench (dives K218 and K219), a submarine section at Hualalai volcano's northwest rift zone (dive S690), and an elongate ridge below the central section of the bench (dive S692) during 2001 and 2002 JAMSTEC Hawaii cruises. Hualalai volcano is presently in the post-shield alkalic stage and most of its subaerial surface is covered by alkalic basalt. All analyzed samples of the pillow lavas are tholeiites that erupted during Hualalai shield stage. It is important to identify source materials involved in the volumetrically dominant stage of Hualalai volcano in order to provide constraints for the size and distribution of compositional heterogeneities of Hawaiian plume. The isotopic compositions of the submarine North Kona tholeiites are similar to the data previously reported for Mauna Loa tholeiites. The data trends define clear mixing relationships that require at least three mantle source components. The mixing is dominated by a Koolau-like enriched component and a Kea-like depleted component. The K219 data trend toward higher epsilon Hf and 87Sr/86Sr relative to the K218, S690, and S692 arrays, requiring another component similar to that observed in post-shield lavas of Hualalai volcano. Pb isotopic compositions for samples from dive K218 and K219 form distinct non-overlapping Pb-Pb arrays suggesting further source heterogeneity. Samples from dive S690 and S692 plot on both of these trends. These findings suggest small-scale compositional heterogeneity in the source regions that can be attributed to anomalous irregular 'blobs' involved in late shield stage magmatism of Mauna Loa reported in previous works.

  9. The 3D visualization technology research of submarine pipeline based Horde3D GameEngine

    NASA Astrophysics Data System (ADS)

    Yao, Guanghui; Ma, Xiushui; Chen, Genlang; Ye, Lingjian

    2013-10-01

    With the development of 3D display and virtual reality technology, its application gets more and more widespread. This paper applies 3D display technology to the monitoring of submarine pipeline. We reconstruct the submarine pipeline and its surrounding submarine terrain in computer using Horde3D graphics rendering engine on the foundation database "submarine pipeline and relative landforms landscape synthesis database" so as to display the virtual scene of submarine pipeline based virtual reality and show the relevant data collected from the monitoring of submarine pipeline.

  10. Controls on plan-form evolution of submarine channels

    NASA Astrophysics Data System (ADS)

    Imran, J.; Mohrig, D. C.

    2014-12-01

    Vertically aggrading sinuous channels constitute a basic building block of modern submarine fans and the greater continental slope. Interpretation of seismically imaged channels reveals a significant diversity in internal architecture, as well as important similarities and differences in the evolution of submarine channels relative to better studied rivers. Many submarine channel cross sections possess a 'gull wing' shape. Successive stacking of such channels demonstrates that systematic bank erosion is not required in order for lateral migration to occur. The lateral shift of such aggrading channels, however, is expected to be much less dynamic than in the case of terrestrial rivers. Recent high-resolution 3D seismic data from offshore Angola and an upstream segment of the Bengal Submarine Fan show intensely meandering channels that experience considerable lateral shifting during periods of active migration within submarine valleys. The cross sections of the actively migrating channels are similar to meandering river channels characterized by an outer cut-bank and inner-bank accretion. In submarine channels, the orientation of the secondary flow can be river-like or river-reverse depending on the channel gradient, cross sectional shape, and the adaptation length of the channel bend. In river channels, a single circulation cell commonly occupies the entire channel relief, redistributing the bed-load sediment across the channel, and influencing the thread of high velocity and thus the plan-form evolution of the channel. In submarine environments, the height of the circulation cell will be significantly smaller than channel relief, thus leading to development of lower relief point bars from bed-load transport. Nevertheless these "underfit" bars may play an important role in plan-form evolution of submarine channels. In rivers and submarine channels, the inclined surface accretion can be constructed via pure bed-load, suspended-load, or a combination of both transport

  11. Two likely stratospheric volcanic eruptions in the 1450s C.E. found in a bipolar, subannually dated 800 year ice core record

    NASA Astrophysics Data System (ADS)

    Cole-Dai, Jihong; Ferris, David G.; Lanciki, Alyson L.; Savarino, Joël.; Thiemens, Mark H.; McConnell, Joseph R.

    2013-07-01

    An 800 year volcanic record is constructed from high-resolution chemical analysis of recently obtained West Antarctica and central Greenland ice cores. The high accuracy and precision of the ice core chronologies are a result of dating by annual ice layer counting. Nineteen bipolar volcanic signals in this record represent large, explosive eruptions in the tropics with probable climatic impact. One of the two bipolar volcanic signals dated at 1453 and 1459 is probably left by the eruption of the submarine volcano Kuwae in the tropical Pacific, one of the largest volcanic eruptions in the last millennium. The discovery of the two signals in the 1450s casts doubt on the eruption year of 1452 or 1453 for Kuwae based on previous ice core records. The volcanic sulfate deposition patterns in this bipolar record suggest that the later signal is likely from the Kuwae eruption in 1458, although a firm attribution is not possible. Sulfur isotope composition in the volcanic sulfate in the central Greenland cores indicates that both eruptions in the 1450s injected sulfur gases into the stratosphere with probable impact on the global climate. These results are in agreement with tree ring records showing two short cold episodes during that decade. The bipolar volcanic record supports the hypothesis that unusually active volcanism in the thirteenth century contributed to the onset of the Little Ice Age and another active period in the mid fifteenth century may have helped to sustain the Little Ice Age.

  12. Volcanic eruption detection with TOMS

    NASA Technical Reports Server (NTRS)

    Krueger, Arlin J.

    1987-01-01

    The Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) is designed for mapping of the atmospheric ozone distribution. Absorption by sulfur dioxide at the same ultraviolet spectral wavelengths makes it possible to observe and resolve the size of volcanic clouds. The sulfur dioxide absorption is discriminated from ozone and water clouds in the data processing by their spectral signatures. Thus, the sulfur dioxide can serve as a tracer which appears in volcanic eruption clouds because it is not present in other clouds. The detection limit with TOMS is close to the theoretical limit due to telemetry signal quantization of 1000 metric tons (5-sigma threshold) within the instrument field of view (50 by 50 km near the nadir). Requirements concerning the use of TOMS in detection of eruptions, geochemical cycles, and volcanic climatic effects are discussed.

  13. Volcanic eruptions and solar activity

    NASA Technical Reports Server (NTRS)

    Stothers, Richard B.

    1989-01-01

    The historical record of large volcanic eruptions from 1500 to 1980 is subjected to detailed time series analysis. In two weak but probably statistically significant periodicities of about 11 and 80 yr, the frequency of volcanic eruptions increases (decreases) slightly around the times of solar minimum (maximum). Time series analysis of the volcanogenic acidities in a deep ice core from Greenland reveals several very long periods ranging from about 80 to about 350 yr which are similar to the very slow solar cycles previously detected in auroral and C-14 records. Solar flares may cause changes in atmospheric circulation patterns that abruptly alter the earth's spin. The resulting jolt probably triggers small earthquakes which affect volcanism.

  14. Eruption column modeling of supervolcanoes

    NASA Astrophysics Data System (ADS)

    Dobran, F.

    2010-12-01

    Eruption columns consists of multiphase mixtures of gases and particulate matter in thermodynamic non-equilibrium, and tracking the multitude of interfaces associated with the liquid, solid, and plastic bodies of a wide spectrum of sizes is not practical. The current modeling practice is to use different averaging procedures by employing single-phase continuum models or those from the kinetic theory, together with various conditions that specify the microphysical processes of mixtures. But these models are inadequate to model the eruption columns of supervolcanoes, where the plumes reach the stratosphere and phase change processes contribute to the columns’ dispersion properties on the regional and global scales. A more effective multiphase flow modeling procedure is presented and its computer implementation is discussed.

  15. Solar Eruptions and Energetic Particles

    NASA Astrophysics Data System (ADS)

    Gopalswamy, Natchimuthukonar; Mewaldt, Richard; Torsti, Jarmo

    Coronal mass ejections (CMEs) are the most energetic events in the heliosphere. During solar cycle 23, the close connection between CMEs and solar energetic particles (SEPs) was studied in much greater detail than was previously possible, including effects on space weather. This book reviews extensive observations of solar eruptions and SEPs from orbiting and ground-based systems. From SOHO and ACE to RHESSI and TRACE, we now have measurements of unprecedented sensitivity by which to test assumptions and refine models. Discussion and analysis of: • Coronal mass ejections and energetic particles over one solar cycle • Implications of solar eruptions for space weather and human space exploration • The elemental, isotopic, and ionic charge state composition of accelerated particles • Complex interconnections among CMEs, flares, shocks, and energetic particles will make this book an indispensable resource for scientists working on the Sun-Earth connection, including space physicists, magnetospheric physicists, atmospheric physicists, astrophysicists, and aeronomists.

  16. The 1883 eruption of Krakatau

    NASA Technical Reports Server (NTRS)

    Self, S.; Rampino, M. R.

    1981-01-01

    The 1883 eruption of Krakatau was a modest ignimbrite-forming event. The deposits are primarily coarse-grained dacitic, non-welded ignimbrite. Large explosions produced pyroclastic flows that entered the sea, generating destructive tsunami. Grain-size studies of the ignimbrite suggest that these explosions were not driven by magma-seawater interaction. The total bulk volume of pyroclastic deposits, including co-ignimbrite ash, is estimated to be 18-21 cu km.

  17. Mass eruptions from the Sun

    NASA Astrophysics Data System (ADS)

    Green, Lucie

    2015-08-01

    This review talk will address the recent developments and current understanding of the physical mechanisms that underlie the ejection of matter and magnetic field from the atmosphere of the Sun, known as coronal mass ejections. These eruptions are intitiated within and between active regions throughout an active region's entire lifetime; from the emergence phase, when strong and concentrated magnetic fields are present, through the long decay phase during which time the active region magnetic field fragments and disperses over a larger and larger area, eventually fading into the background quiet sun magnetic field. All coronal mass ejection models invoke the presence of a twisted magnetic field configuration known as a magnetic flux rope either before or after eruption. The observational identification of these structures using remote sensing data of the lower solar atmosphere will be discussed. Do such magnetic field configurations exist in the solar atmosphere prior to the eruption? And if so what can they tell us about the physical mechanisms that trigger and drive coronal mass ejections and the timescales over which an eruptive magnetic field configuration forms? However, not all coronal mass ejections are easily identifiable at the Sun. For example, in situ observations of coronal mass ejections in interplanetary space reveal small magnetic flux rope coronal mass ejections which are not detected leaving the Sun using the remote sensing data. And so-called stealth coronal mass ejections which also have no lower atmosphere signatures. Are there different populations of flux ropes that have different origins? And what might this say about the physical mechanisms behind coronal mass ejections and the consequences for the Sun's evolving global magnetic field?

  18. Medical effects of volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Baxter, Peter J.

    1990-09-01

    Excluding famine and tsunamis, most deaths in volcanic eruptions have been from pyroclastic flows and surges (nuées ardentes) and wet debris flows (lahars). Information on the causes of death and injury in eruptions is sparse but the available literature is summarised for the benefit of volcanologists and emergency planners. In nuées, thermal injury may be at least as important as asphyxia in causing immediate deaths. The high temperature of the gases and entrained particles readily causes severe burns to the skin and the air passages and the presence of both types of injury in an individual may combine to increase the delayed mortality risk from respiratory complications or from infection of burns. Trauma from missiles or body displacement is also common, but the role of asphyxiant or irritant gases, and steam, remains unclear. The ratio of dead: injured is much higher than in other natural disasters. At the periphery of a nuée being protected inside buildings which remain intact appears to greatly increase the chances of survival. In lahars, infected wounds and crush injury are the main delayed causes of death, and the scope for preventive measures, other than evacuation, is small. The evidence from Mount St. Helens, 1980, and other major eruptions indicates that, although mortality is high within the main zone of devastation and in the open, emergency planning should concentrate on the periphery of a nuée where preventive measures are feasible and could save many lives in densely populated areas.

  19. Continuous overnight observation of human premolar eruption.

    PubMed

    Risinger, R K; Proffit, W R

    1996-01-01

    Such observation was made possible by transmitting the image of a mobile ceramic ruling on the erupting maxillary second premolar to a video-microscope via a coaxial fibreoptic cable. The cable was inserted into a reference bar secured to the adjacent first molar and first premolar. The image of the ruling was superimposed with the image from a surveillance camera focused on the patient and continuously recorded on video-tape along with the participant's blood pressure, pulse rate, electromyographic activity and occlusal contact sounds. Overnight data from 12 individuals clearly revealed a circadian rhythm in eruption during the prefunctional spurt. On average, the maxillary second premolar erupted 41 microns during an 11-h overnight observation, with almost all the eruption occurring in the late evening from 8 p.m. to 1 a.m. After 1 a.m., eruption typically ceased, with a tendency for intrusion to occur until 7 a.m. Sleep increased the rate of eruption during the late evening, but did not influence the eruption rate during the early morning. Haemodynamic changes, including blood pressure and pulse rate, did not have a significant impact on the rhythm of eruption. The observed eruption rhythm is most probably caused by changing hormone levels and their effect on the periodontal ligament. The late-evening eruption of human premolars coincides with the late-evening secretion of growth hormone and thyroid hormone typically found in humans. PMID:9022915

  20. Historical bathymetric charts and the evolution of Santorini submarine volcano, Greece

    NASA Astrophysics Data System (ADS)

    Watts, A. B.; Nomikou, P.; Moore, J. D. P.; Parks, M. M.; Alexandri, M.

    2015-03-01

    Historical bathymetric charts are a potential resource for better understanding the dynamics of the seafloor and the role of active processes, such as submarine volcanism. The British Admiralty, for example, have been involved in lead line measurements of seafloor depth since the early 1790s. Here, we report on an analysis of historical charts in the region of Santorini volcano, Greece. Repeat lead line surveys in 1848, late 1866, and 1925-1928 as well as multibeam swath bathymetry surveys in 2001 and 2006 have been used to document changes in seafloor depth. These data reveal that the flanks of the Kameni Islands, a dacitic dome complex in the caldera center, have shallowed by up to ˜175 m and deepened by up to ˜80 m since 1848. The largest shallowing occurred between the late 1866 and 1925-1928 surveys and the largest deepening occurred during the 1925-1928 and 2001 and 2006 surveys. The shallowing is attributed to the emplacement of lavas during effusive eruptions in both 1866-1870 and 1925-1928 at rates of up to 0.18 and 0.05 km3 a-1, respectively. The deepening is attributed to a load-induced viscoelastic stress relaxation following the 1866-1870 and 1925-1928 lava eruptions. The elastic thickness and viscosity that best fits the observed deepening are 1.0 km and ˜1016 Pa s, respectively. This parameter pair, which is consistent with the predictions of a shallow magma chamber thermal model, explains both the amplitude and wavelength of the historical bathymetric data and the present day rate of subsidence inferred from InSAR analysis.

  1. Identification of topographic fingerprints of eruption environments: Geomorphometric evidence from volcanoes of the Reykjanes Peninsula, Iceland

    NASA Astrophysics Data System (ADS)

    Pedersen, G. B.; Grosse, P.

    2012-12-01

    in slope, such as lava cap, hyaloclastite apron, hyaloclastite slope and hyaloclastite summit. The boundary between hyaloclastite breccia and lava cap represents a passage zone that marks late-stage subaerial lava-fed deltas and is clearly defined by convex breaks in slope. Large elevation changes in the passage zone is diagnostic of lava deltas emplaced in a glacial environment, and thus mapping of elevation changes of convex breaks in slope is a potential tool for distinguishing big table-shaped volcanic edifices emplaced in a submarine or subglacial environment. This study shows that volcano morphometry can be used to obtain information on processes operating during volcano construction, its eruption environment and the resulting evolutionary growth trends. A significant advantage of this method is its application for remote and inaccessible areas such as submarine or subglacial environments as well as extraterrestrial planets. Moreover, the break in slope delimitation of edifice bases and the possibility of resolving individual landform elements makes this geomorphometric analysis directly applicable for advanced mapping techniques such as object-based image analysis.

  2. An ergodic approach to eruption hazard scaling

    NASA Astrophysics Data System (ADS)

    De la Cruz-Reyna, Servando; Mendoza-Rosas, Ana Teresa

    2014-05-01

    The complexity and indeterminacy of volcanic processes demand the use of statistical methods to analyze the expectations of the occurrence and size of future eruptions. The probability of a volcano producing potentially destructive eruptions in a given time interval may be estimated analyzing the sequence of past eruptions assuming a physically plausible process. Since the threat posed by eruptions depends on their mass or energy release (magnitude) and on their emission rate (intensity), the Volcanic Explosivity Index is a suitable measure to quantify the eruptive events, particularly considering that the largest available global catalogues use that measure. The definition of volcanic hazard is thus posed here in terms of the expected annual release of energy by eruptions in each VEI category. This concept is based on the ergodic property of a large set of volcanoes to release about the same amount of energy in each VEI category over a sufficiently large time interval. This property is however constrained to the VEI range of eruptions that constitute complete catalogues (VEI >2) in the lower end, and to the extreme eruptions that may destroy or significantly alter a volcanic system, such as the large caldera-forming eruptions (VEI < 7). In such conditions, a simple power law for eruptions at the global level relating the global rate of energy release to the eruption magnitude has been proposed as a statistical basis for eruptive event model development. Following the above mentioned arguments, we assume that a similar scaling law rules the annual rate at which energy is released by eruptions at individual volcanoes as log(EmRm)=bM+a, where Em is the energy released by eruptions in the VEI magnitude class M, and Rm is the occurrence rate of such eruptions over times ranges in which catalogues may be considered complete. The parameters b and a depend on the eruptive history of individual volcanoes, the former determining the preferred mode of the volcano to release

  3. Volcanic Eruptions and Climate: Outstanding Research Issues

    NASA Astrophysics Data System (ADS)

    Robock, Alan

    2016-04-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Based on observations after major eruptions of the past and experiments with numerical models of the climate system, we understand much about their climatic impact, but there are also a number of unanswered questions. Volcanic eruptions produce global cooling, and are an important natural cause of interannual, interdecadal, and even centennial-scale climate change. One of the most interesting volcanic effects is the "winter warming" of Northern Hemisphere continents following major tropical eruptions. During the winter in the Northern Hemisphere following every large tropical eruption of the past century, surface air temperatures over North America, Europe, and East Asia were warmer than normal, while they were colder over Greenland and the Middle East. This pattern and the coincident atmospheric circulation correspond to the positive phase of the Arctic Oscillation. While this response is observed after recent major eruptions, most state-of-the-art climate models have trouble simulating winter warming. Why? High latitude eruptions in the Northern Hemisphere, while also producing global cooling, do not have the same impact on atmospheric dynamics. Both tropical and high latitude eruptions can weaken the Indian and African summer monsoon, and the effects can be seen in past records of flow in the Nile and Niger Rivers. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade have had a small effect on global temperature trends. Some important outstanding research questions include: How much seasonal, annual, and decadal predictability is possible following a large volcanic eruption? Do

  4. Chronology and products of the 2000 eruption of Miyakejima Volcano, Japan

    NASA Astrophysics Data System (ADS)

    Nakada, S.; Nagai, M.; Kaneko, T.; Nozawa, A.; Suzuki-Kamata, K.

    2005-03-01

    Lateral migration of magma away from Miyakejima volcanic island, Japan, generated summit subsidence, associated with summit explosions in the summer of 2000. An earthquake swarm beneath Miyakejima began on the evening of 26 June 2000, followed by a submarine eruption the next morning. Strong seismic activity continued under the sea from beneath the coast of Miyakejima to a few tens of kilometers northwest of the island. Summit eruptive event began with subsidence of the summit on 8 July and both explosions and subsidence continued intermittently through July and August. The most intense eruptive event occurred on 18 August and was vulcanian to subplinian in type. Ash lofted into the stratosphere fell over the entire island, and abundant volcanic bombs were erupted at this time. Another large explosion took place on 29 August. This generated a low-temperature pyroclastic surge, which covered a residential area on the northern coast of the island. The total volume of tephra erupted was 9.3×106 m3 (DRE), much smaller than the volume of the resulting caldera (6×108 m3). Migration of magma away from Miyakejima was associated with crustal extension northwest of Miyakejima and coincident shrinkage of Miyakejima Island itself during July August 2000. This magma migration probably caused stoping of roof rock into the magma reservoir, generating subsurface cavities filled with hydrothermal fluid and/or magmatic foam and formation of a caldera (Oyama Caldera) at the summit. Interaction of hydrothermal fluid with ascending magma drove a series of phreatic to phreatomagmatic eruptions. It is likely that new magma was supplied to the reservoir from the bottom during waning stage of magma’s migration, resulting in explosive discharge on 18 August. The 18 August event and phreatic explosions on 29 August produced a conduit system that allowed abundant SO2 emission (as high as 460 kg s-1) after the major eruptive events were over. At the time of writing, inhabitants of the

  5. Forces in Erupting Flux Ropes: CMEs and Failed Eruptions

    NASA Astrophysics Data System (ADS)

    Chen, James

    2016-05-01

    A range of dynamical behaviors that can be exhibited by a quasi-statically evolving flux rope is studied. Starting with a CME-like flux rope in equilibrium balanced by the ambient coronal pressure (non-force-free) and an overlying coronal magnetic field (Bc), the poloidal flux is slowly increased, on a timescale much longer than the eruptive timescale of several to tens of minutes. In this configuration, the overlying field Bc provides an external downward restraining force, constituting an effective potential barrier. Slowly increasing poloidal flux causes the flux rope to gradually rise, following a sequence of quasi-static equilibria. As the apex of the flux rope rises past a critical height Z*, slightly higher than the peak of the potential barrier Bc(Z), it expands on a faster, dynamical (Alfvenic) timescale determined by the magnetic field and geometry of the flux rope. The expanding flux rope may reach a new equilibrium at height Z1. Observationally, this behavior would be recognized as a ``failed eruption.'' The new equilibrium flux rope is established if the magnetic tension force due to the toroidal magnetic field component Bt can balance the outward hoop force due to the poloidal component Bp. The flux rope may also expand without reaching a new equilibrium, provided a sufficiennt amount of poloidal flux is injected on a dynamical timescale so that the tension force cannot balance the hoop force. This scenario would result in a CME eruption. The influence of the poloidal flux injection, the Bc(Z) profile, and boundary conditions on the quantitative balance of the forces in an expanding flux rope is elucidated. Potentially observable consequences of the difference scenarios/models are discussed.Work supported by the Naval Research Laboratory Base Research Program

  6. Erosion of the submarine flanks of the Canary Islands

    NASA Astrophysics Data System (ADS)

    Mitchell, Neil C.; Dade, W. Brian; Masson, Douglas G.

    2003-12-01

    Surveying with multibeam echo sounders around old (≫1 Ma) volcanic ocean islands reveals that their submarine flanks contain a strong downslope-oriented ridge-and-valley corrugation, which modifies the original volcanic morphology of lava terraces and cones. By analogy with canyons in other settings, this corrugation was probably caused by channel incision by erosive sedimentary mass flows such as turbidity currents and debris flows. We adapt a method first used in subaerial geomorphology to isolate the erosion depth (exhumation) and apply it to the eroded flanks of the 6-8 Ma Anaga massif of Tenerife. The channels formed around this massif divert around local topographic highs. These highs, which are probably original volcanic cones, are therefore preferentially preserved during erosion, so that their elevations can be used to construct an artificial reference surface. Terrain depth was calculated by subtracting this reference surface from measured bathymetry. Comparison of the terrain depth of the old, eroded submarine flank of Anaga with that of the young, mostly unaltered submarine flank of El Hierro allows us to infer the mean depth of Anaga's submarine erosion, which is ˜100 m. Volcanic terrains can be dated by radiometric methods, so they also provide a way of quantifying long-term denudation rates. We infer that submarine denudation of Anaga has occurred at comparable rates to that of subaerial lowlands and much slower than denudation of highlands, illustrated locally by the more extensive erosion of the subaerial Anaga edifice.

  7. High-resolution Geophysical Mapping of Submarine Glacial Landforms

    NASA Astrophysics Data System (ADS)

    Jakobsson, M.; Dowdeswell, J. A.; Canals, M.; Todd, B. J.; Dowdeswell, E. K.; Hogan, K. A.; Mayer, L. A.

    2014-12-01

    Glacial landforms are generated from the activity of glaciers and display spatial dimensions ranging from below one meter up to tens of kilometers. Glacial landforms are used as diagnostic features of past activity of ice sheets and glaciers; they are specifically important in the field of palaeoglaciology. Mapping of submarine glacial landforms is largely dependent on geophysical survey methods capable of imaging the seafloor and sub-bottom through the water column. Full "global" seafloor mapping coverage, equivalent to what exists for land elevation, is to-date only achieved by the powerful method of deriving bathymetry from altimeters on satellites like GEOSAT and ERS-1. The lateral resolution of satellite derived bathymetry is, however, limited by the footprint of the satellite and the need to average out local wave and wind effects resulting in values of around 15 km. Consequently, mapping submarine glacial landforms requires for the most part higher resolution than is achievable by satellite derived bathymetry. The most widely-used methods for mapping submarine glacial landforms are based on echo-sounding principles. This presentation shows how the evolution of marine geophysical mapping techniques, in particular the advent of side-scan and multibeam bathymetric sonars, has made it possible to study submarine glacial landforms in unprecedented detail. Examples are shown from the Atlas of Submarine Glacial Landforms: Modern, Quaternary and Ancient, which will be published in late 2015 in the Memoir Series of the Geological Society of London.

  8. Nuclear-electric magnetohydrodynamic propulsion for submarine. Master's thesis

    SciTech Connect

    Bednarczyk, A.A.

    1989-05-01

    The thesis analyzes the superconducting technology for a shipboard magnetohydrodynamic propulsion system. Based on the the principles of magnetohydrodynamics (MHD), the concept of open-water efficiency was used to optimize the preliminary design of the MHD thruster. After the baseline submarine hull modeled after the Los Angeles class submarine was selected, propulsive efficiency and the top speed for four variant MHD submarines were evaluated. The design criteria were set at a 100-MWt nuclear reactor power upper limit and a requirement of 30 knots for the top speed. This required advanced reactor plants and advanced energy conversion systems. The selection of High Temperature Gas Reactor (HTGR) and Liquid-Metal Fast Breeder Reactor (LMFBR) was based on the combined merits of safety, environmental impact, high source temperature and maximum-volume power density (KW/L). With the reactor outlet temperatures of 2000 K, direct-cycle energy conversion-systems gave the best results in terms of thermal efficiency and propulsion plant power density. Two energy conversion systems selected were closed-cycle gas turbine geared to a superconducting generator, and closed-cycle liquid-metal MHD generator. Based on submarine reliability and safety, the option of using an intermediate heat exchanger was also considered. Finally, non-nuclear support systems affected by the advanced power plant and MHD propulsion, stressing submarine safety, are proposed.

  9. Adverse reaction of topical etofenamate: petechial eruption.

    PubMed

    Orbak, Z; Yildirim, Z K; Sepetci, O; Karakelleoglu, C; Alp, H

    2012-10-01

    Etofenamate is a non-steroidal anti-inflammatory drug (NSAID). Clinical findings caused by etofenamate are uncommon. Allergic contact dermatitis is the most common cutaneous reaction reported. But petechial eruption due to etofenamate had not been reported yet. This report concerns an 11-year old male with petechial eruption after application of topical etofenamate. Physicians need to be aware that patients can develop an asymptomatic purpuric eruption when etofenamate is ordered. PMID:23620980

  10. How and Why Do Geysers Erupt?

    NASA Astrophysics Data System (ADS)

    Manga, M.

    2014-12-01

    Geysers are features that produce episodic eruptions of water, steam and sometimes non-condensable gases. Natural geysers are rare, with fewer than 1,000 worldwide. They are more than curiosities and popular tourist attractions: they offer a direct window into geothermal processes, and may serve as a natural small-scale laboratory to study larger-scale eruptive process such as those at volcanoes, and other self-organized, intermittent processes that result from phase separation and localized input of energy and mass. Despite > 200 years of scientific study, basic questions remain: Do eruptions begin from the bottom or top of the geyser? What controls eruption duration? Why do eruptions end? What are the required special subsurface geometries? Why are some geysers periodic, and others irregular? How and why do they respond to external influences such as weather, tides, and earthquakes? This presentation will review new insights from field studies at Lone Star geyser, Yellowstone National Park, geysers in the El Tatio geyser field, Chile, and laboratory models. At Lone Star we infer that dynamics are controlled by thermal and mechanical coupling between the conduit and a deeper, laterally-offset reservoir (called a "bubble trap" in previous studies). At El Tatio, we measured pressure and temperature within geysers over multiple eruption cycles: this data document the heating of liquid water by steam delivered from below. The laboratory experiments reveal how episodic release of steam from a bubble trap prepares a conduit for eruption and can generate a range of eruption intensities. In all cases, the eruption initiation, duration and termination are controlled by the interaction between the accumulation and transport of steam and liquid, and modulated by the geometry of the geyser's plumbing. Time series of thousands of eruptions confirm that internal processes control eruptions, with only pool geysers showing a sensitivity to air temperature; only very large stress

  11. Winter warming from large volcanic eruptions

    NASA Technical Reports Server (NTRS)

    Robock, Alan; Mao, Jianping

    1992-01-01

    An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95-percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.

  12. Tornados and Transverse Oscillations during Prominence Eruption

    NASA Astrophysics Data System (ADS)

    Banerjee, Dipankar; Chandrashekhar, K.; Morton, Richard; Pant, Vaibhav; Datta, Ajanta

    2016-07-01

    We report and analyse different phases of a prominence eruption. The winding-unwinding of two footpoints and a tornado like swirling motion is studied. The prominence eruption is observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). This prominence eruption is associated with a CME at a central principal angle of 340 degree, according to the SOHO/LASCO CME catalogue. We can observe the prominence threads and the time distance maps reveal that the loop threads are entangled. We also study the transverse oscillations in the threads. Swirling motions after the eruptions are also quantified and its possible link with the CME kinematics is also studied

  13. Winter warming from large volcanic eruptions

    SciTech Connect

    Robock, A.; Mao, J.

    1992-01-01

    An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95 percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.

  14. Why do Martian Magmas erupt?

    NASA Astrophysics Data System (ADS)

    Balta, J. B.; McSween, H. Y.

    2011-12-01

    Eruption of silicate lava, whether on Earth or another planet, requires that at some depth the melt has lower density than the surrounding rocks. As the densities of silicate liquids change during crystallization, whether a particular silicate liquid will erupt or be trapped at a level of neutral buoyancy is a complex yet fundamental issue for planetary dynamics. In general, 3 factors drive surface eruptions: inherent buoyancy relative to mantle phases, compositional evolution, and volatile contents. These factors manifest on Earth as terrestrial basalts commonly have compositions close to a density minimum [1]. Recent work has produced estimates of Martian parental magma compositions [2-5] based on shergottite meteorites and from Gusev crater. Using the MELTS algorithm [6] and other density calibrations, we simulated evolution of these liquids, focusing on density changes. For much of the crystallization path, density is controlled by FeO. All of the liquids begin with ρ ~ 2.8 g/cc at 1 bar, and the evolution of liquid density is controlled by the liquidus phases. At low pressures, olivine is the liquidus phase for each melt, and as FeO is not incompatible in olivine, olivine crystallization decreases liquid density, increasing buoyancy with crystallization. However, FeO is incompatible in pyroxene, and thus liquids crystallizing pyroxene become denser and less buoyant with crystallization, producing liquids with densities up to and above 3.0 g/cc. As the olivine-pyroxene saturation relationship is affected by pressure and chemistry, the identity of the liquidus phase and density evolution will vary between magmas. Without spreading centers, Mars has no location where the mantle approaches the surface, and it is likely that any magma which is denser than the crust will stall below or within that crust. The crystallization path of a liquid is a function of pressure, with pyroxene crystallizing first at P > 10 kbar (~80 km depth), close to the base of the Martian

  15. A simple and efficient GIS tool for volume calculations of submarine landslides

    NASA Astrophysics Data System (ADS)

    Völker, David Julius

    2010-10-01

    A numeric tool is presented for calculating volumes of topographic voids such as slump scars of landslides, canyons or craters (negative/concave morphology), or alternatively, bumps and hills (positive/convex morphology) by means of digital elevation models embedded within a geographical information system (GIS). In this study, it has been used to calculate landslide volumes. The basic idea is that a (singular) event (landslide, meteorite impact, volcanic eruption) has disturbed an intact surface such that it is still possible to distinguish between the former (undisturbed) landscape and the disturbance (crater, slide scar, debris avalanche). In such cases, it is possible to reconstruct the paleo-surface and to calculate the volume difference between both surfaces, thereby approximating the volume gain or loss caused by the event. I tested the approach using synthetically generated land surfaces that were created on the basis of Shuttle Radar Topography Mission data. Also, I show the application to two real cases, (1) the calculation of the volume of the Masaya Slide, a submarine landslide on the Pacific continental slope of Nicaragua, and (2) the calculation of the void of a segment of the Fish River Canyon, Namibia. The tool is provided as a script file for the free GIS GRASS. It performs with little effort, and offers a range of interpolation parameters. Testing with different sets of interpolation parameters results in a small range of uncertainty. This tool should prove useful in surface studies not exclusively on earth.

  16. What Generated the Eruptive Tremor During the Bardarbunga Eruption, Iceland?

    NASA Astrophysics Data System (ADS)

    Eibl, Eva P. S.; Bean, Christopher J.; Vogfjörd, Kristin S.; Jónsdóttir, Ingibjörg; Höskuldsson, Armann; Þórðarson, Þorvaldur

    2016-04-01

    The Bárðarbunga eruption in Iceland 2014/15 led to the formation of a 85 km2 big lavafield and the extrusion of ~1.5 km3 of magma. The eruption initially started for 4 hours on August 29th. It stopped but restarted on the same fissure on August 31st. We installed a seismic array on August 30th. Harmonic tremor was seen on August 31st consistent with the visual opening of the fissure and continued through February 2015. The harmonic tremor with most energy from 0.8-1.5 Hz is remarkably stable over 6 months but 3 characteristic features occur from time to time: (i) Stronger harmonic tremor bursts in the same frequency range, (ii) Stronger non-harmonic bursts with energy up to 5 Hz and (iii) Step like increases or decreases in the tremor amplitude. Seemingly uncorrelated the array results show (iv) three very stable tremor directions until mid October and (v) tremor sources moving by up to 9 km in 4 days. We compare these five seismic observations with the features of the growing lavafield and discuss the relative importance of possible tremor sources such as: a resonating conduit, boiling magma in the vent, a resonating lavafield, interactions at the edges of the lavafield and inflation of the lavafield.

  17. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  18. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  19. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  20. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  1. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  2. 33 CFR 165.1302 - Bangor Naval Submarine Base, Bangor, WA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Bangor Naval Submarine Base... Bangor Naval Submarine Base, Bangor, WA. (a) Location. The following is a security zone: The waters of... States Naval vessels. (ii) Vessels that are performing work at Naval Submarine Base Bangor pursuant to...

  3. 33 CFR 165.1302 - Bangor Naval Submarine Base, Bangor, WA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Bangor Naval Submarine Base... Bangor Naval Submarine Base, Bangor, WA. (a) Location. The following is a security zone: The waters of... States Naval vessels. (ii) Vessels that are performing work at Naval Submarine Base Bangor pursuant to...

  4. 33 CFR 334.75 - Thames River, Naval Submarine Base New London, restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Thames River, Naval Submarine....75 Thames River, Naval Submarine Base New London, restricted area. (a) The area: The open waters of... restricted area provided their vessels display registration numbers issued by the Naval Submarine Base,...

  5. 33 CFR 334.75 - Thames River, Naval Submarine Base New London, restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Thames River, Naval Submarine....75 Thames River, Naval Submarine Base New London, restricted area. (a) The area: The open waters of... restricted area provided their vessels display registration numbers issued by the Naval Submarine Base,...

  6. 33 CFR 165.1302 - Bangor Naval Submarine Base, Bangor, WA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Bangor Naval Submarine Base... Bangor Naval Submarine Base, Bangor, WA. (a) Location. The following is a security zone: The waters of... States Naval vessels. (ii) Vessels that are performing work at Naval Submarine Base Bangor pursuant to...

  7. 33 CFR 165.1302 - Bangor Naval Submarine Base, Bangor, WA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Bangor Naval Submarine Base... Bangor Naval Submarine Base, Bangor, WA. (a) Location. The following is a security zone: The waters of... States Naval vessels. (ii) Vessels that are performing work at Naval Submarine Base Bangor pursuant to...

  8. 33 CFR 334.75 - Thames River, Naval Submarine Base New London, restricted area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Thames River, Naval Submarine....75 Thames River, Naval Submarine Base New London, restricted area. (a) The area: The open waters of... notified by personnel of the New London Submarine Base that such use will interfere with...

  9. 33 CFR 334.75 - Thames River, Naval Submarine Base New London, restricted area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Thames River, Naval Submarine....75 Thames River, Naval Submarine Base New London, restricted area. (a) The area: The open waters of... notified by personnel of the New London Submarine Base that such use will interfere with...

  10. 33 CFR 165.1302 - Bangor Naval Submarine Base, Bangor, WA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Bangor Naval Submarine Base... Bangor Naval Submarine Base, Bangor, WA. (a) Location. The following is a security zone: The waters of... States Naval vessels. (ii) Vessels that are performing work at Naval Submarine Base Bangor pursuant to...

  11. 33 CFR 334.75 - Thames River, Naval Submarine Base New London, restricted area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Thames River, Naval Submarine....75 Thames River, Naval Submarine Base New London, restricted area. (a) The area: The open waters of... notified by personnel of the New London Submarine Base that such use will interfere with...

  12. 49. DETAILS OF SUBMARINE SECTION, Y&D No. 107727 Scale 3/8' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. DETAILS OF SUBMARINE SECTION, Y&D No. 107727 Scale 3/8' and 1-1/2' = 1'; July 2, 1929 - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  13. [MORBIDITY OF SUBMARINE CREW SAILORS IN LONG-DISTANCE CRUISES].

    PubMed

    Myznikov, I L; Burtsev, N N; Bondarenko N V; Khamidullina, A Ya

    2015-01-01

    Morbidity among the personnel of a Kola-based (beyond the Arctic circle) atomic (ASM) and diesel-powered (DSM) submarines in the course of long-distance cruises in different waters of the world ocean was studied. Statistics was collected from the reports of submarine medical officers since 1969. Levels and causes of morbidity were analyzed. According to the data of many years' observations, within the structure of primary diseases of military contractors on cruises the leading place has been occupied by respiratory disorders followed by skin and subcutaneous fat problems, and digestive diseases. Incidence of chronic diseases among ASM and DSM personnel was evaluated. The authors raise the issue of dental care quality provided to submariners. PMID:26554134

  14. Contemporary sediment-transport processes in submarine canyons.

    PubMed

    Puig, Pere; Palanques, Albert; Martín, Jacobo

    2014-01-01

    Submarine canyons are morphological incisions into continental margins that act as major conduits of sediment from shallow- to deep-sea regions. However, the exact mechanisms involved in sediment transfer within submarine canyons are still a subject of investigation. Several studies have provided direct information about contemporary sedimentary processes in submarine canyons that suggests different modes of transport and various triggering mechanisms. Storm-induced turbidity currents and enhanced off-shelf advection, hyperpycnal flows and failures of recently deposited fluvial sediments, dense shelf-water cascading, canyon-flank failures, and trawling-induced resuspension largely dominate present-day sediment transfer through canyons. Additionally, internal waves periodically resuspend ephemeral deposits within canyons and contribute to dispersing particles or retaining and accumulating them in specific regions. These transport processes commonly deposit sediments in the upper- and middle-canyon reaches for decades or centuries before being completely or partially flushed farther down-canyon by large sediment failures. PMID:23937169

  15. Origin of Izu-Bonin forearc submarine canyons

    SciTech Connect

    Fujioka, Kantaro ); Yoshida, Haruko )

    1990-06-01

    Submarine canyons on the Izu-Bonin forearc are morphologically divided from north to south into four types based on their morphology, long profiles, and seismic profiles: Mikura, Aogashima, Sofu, and Chichijima types, respectively. These types of canyons are genetically different from each other. Mikura group is formed by the faults related to bending of the subducting Philippine Sea Plate. Aogashima type genetically relates to the activity of large submarine calderas that supply large amounts of volcaniclastic material to the consequent forearc slope. The third, Sofu group, is thought to be formed by the large-scale mega mass wasting in relation to the recent movement of the Sofugan tectonic line. The last, Chichijima group, is formed by collision of the Uyeda Ridge and the Ogasawara Plateau on the subducting Pacific Plate with Bonin Arc. Long profiles of four types of submarine canyons also support this.

  16. A havelock source panel method for near-surface submarines

    NASA Astrophysics Data System (ADS)

    Gourlay, Tim; Dawson, Edward

    2015-07-01

    A panel method is described for calculating potential flow around near-surface submarines. The method uses Havelock sources which automatically satisfy the linearized free-surface boundary condition. Outputs from the method include pressure field, pressure drag, wave resistance, vertical force, trim moment and wave pattern. Comparisons are made with model tests for wave resistance of Series 58 and DARPA SUBOFF hulls, as well as with wave resistance, lift force and trim moment of three length-to-diameter variants of the DSTO Joubert submarine hull. It is found that the Havelock source panel method is capable of determining with reasonable accuracy wave resistance, vertical force and trim moment for submarine hulls. Further experimental data are required in order to assess the accuracy of the method for pressure field and wave pattern prediction. The method is implemented in the computer code "HullWave" and offers potential advantages over RANS-CFD codes in terms of speed, simplicity and robustness.

  17. Titan Submarine: Exploring the Depths of Kraken Mare

    NASA Technical Reports Server (NTRS)

    Hartwig, Jason; Colozza, Anthony; Oleson, Steven; Landis, Geoff; Schmitz, Paul; Lorenz, Ralph; Paul, Michael; Walsh, Justin

    2015-01-01

    To explore the depths of the hydrocarbon rich seas on the Saturn moon Titan, a conceptual design of an unmanned submarine concept was recently developed for a Phase I NASA Innovative Advanced Concept (NIAC) study. Data from Cassini Huygens indicates that the Titan polar environment sustains stable seas of variable concentrations of ethane, methane, and nitrogen, with a surface temperature around 93K. To meet science exploration objectives, the submarine must operate autonomously, study atmosphere sea exchange, interact with the seabed at pressures up to 10 atm, traverse large distances with limited energy, hover at the surface and at any depth within the lake, and be capable of tolerating multiple different concentration levels of hydrocarbons. Therefore Titan presents many cryogenic design challenges. This paper presents the trade studies and preliminary design of the power, thermal, and ballast control subsystems for the Saturn Titan submarine.

  18. Floating sandstones off El Hierro (Canary Islands, Spain): the peculiar case of the October 2011 eruption

    NASA Astrophysics Data System (ADS)

    Troll, V. R.; Klügel, A.; Longpré, M.-A.; Burchardt, S.; Deegan, F. M.; Carracedo, J. C.; Wiesmaier, S.; Kueppers, U.; Dahren, B.; Blythe, L. S.; Hansteen, T.; Freda, C.; Budd, D. A.; Jolis, E. M.; Jonsson, E.; Meade, F.; Berg, S.; Mancini, L.; Polacci, M.

    2011-12-01

    The eruption that started off the south coast of El Hierro, Canary Islands, in October 2011 has emitted intriguing eruption products found floating in the sea. These specimens appeared as floating volcanic "bombs" that have in the meantime been termed "restingolites" (after the close-by village of La Restinga) and exhibit cores of white and porous pumice-like material. Currently the nature and origin of these "floating stones" is vigorously debated among researchers, with important implications for the interpretation of the hazard potential of the ongoing eruption. The "restingolites" have been proposed to be either (i) juvenile high-silica magma (e.g. rhyolite), (ii) remelted magmatic material (trachyte), (iii) altered volcanic rock, or (iv) reheated hyaloclastites or zeolite from the submarine slopes of El Hierro. Here, we provide evidence that supports yet a different conclusion. We have collected and analysed the structure and composition of samples and compared the results to previous work on similar rocks found in the archipelago. Based on their high silica content, the lack of igneous trace element signatures, and the presence of remnant quartz crystals, jasper fragments and carbonate relicts, we conclude that "restingolites" are in fact xenoliths from pre-island sedimentary rocks that were picked up and heated by the ascending magma causing them to partially melt and vesiculate. They hence represent messengers from depth that help us to understand the interaction between ascending magma and crustal lithologies in the Canary Islands as well as in similar Atlantic islands that rest on sediment/covered ocean crust (e.g. Cape Verdes, Azores). The occurrence of these "restingolites" does therefore not indicate the presence of an explosive high-silica magma that is involved in the ongoing eruption.

  19. Is the Iceland hot spot also wet? Evidence from the water contents of undegassed submarine and subglacial pillow basalts

    NASA Astrophysics Data System (ADS)

    Nichols, A. R. L.; Carroll, M. R.; Höskuldsson, Á.

    2002-08-01

    Water contents have been measured in basaltic glasses from submarine and subglacial eruption sites along the Reykjanes Ridge and Iceland, respectively, in order to evaluate the hypothesis of Schilling et al. [Phil. Trans. R. Soc. London A 56 (1980) 147-178] that hot spots are also wet spots. Having erupted under pressure the water contents measured in these samples are potentially unaffected by degassing. After correcting these water contents for the effects of crystallisation (to give H 2O(8) values) they indicate that the concentration of water in the source regions increases from 165 ppm at the southern end of the Reykjanes Ridge to between 620 and 920 ppm beneath Iceland. This suggests that Iceland is a wet spot and the H 2O(8) values indicate that its influence on basalt compositions increases northwards along the Reykjanes Ridge from ˜61°N (650 km from the plume centre) towards Iceland. The existence of wetter Icelandic source regions have important implications for mantle melting, as enrichments of this magnitude depress the mantle solidus, increasing the degree of melting at a given temperature. Therefore the enhanced rates of volcanism on Iceland may be a result of wetter sources in addition to a thermal anomaly beneath Iceland.

  20. An Experimental Study of Submarine Canyon Evolution on Continental Slopes

    NASA Astrophysics Data System (ADS)

    Lai, S. Y.; Gerber, T. P.; Amblas, D.

    2013-12-01

    Submarine canyons define the morphology of many continental slopes and are conduits for the transport of sediment from shallow to deep water. Though the origin and evolution of submarine canyons is still debated, there is general agreement that sediment gravity flows play an important role. Here we present results from a simple, reduced-scale sandbox experiment designed to investigate how sediment gravity flows generate submarine canyons. In the experiments, gravity flows were modeled using either sediment-free or turbid saline currents. Unconfined flows were released onto an inclined bed of sand bounded on the downstream end by a movable floor that was incrementally lowered during the course of an experiment to produce an escarpment. This design was developed to represent the growth of relief across the continental slope. To monitor canyon evolution on the slope, we placed an overhead DSLR camera to record vivid time-lapse videos. At the end of each experimental stage we scanned the topography by imaging a series of submerged laser stripes, each projected from a motor-driven transverse laser sheet, onto a calibrated Cartesian coordinate system to produce high resolution bathymetry without draining the ambient water. In areas unaffected by the flows, we observe featureless, angle-of-repose submarine slopes formed by retrogressive breaching processes. In contrast, areas influenced by gravity flows cascading across the shelf break are deeply incised by submarine canyons with well-developed channel networks. Our results show that downslope gravity flows and submarine falling base level are both required to produce realistic canyon morphologies at laboratory scale. Though our mechanism for generating relief may be a rather crude analogue for the processes driving slope evolution, we hope our novel approach can stimulate new questions about the coevolution of canyons and slopes and motivate further experimental work to address them.

  1. Nannofossils in 2011 El Hierro eruptive products reinstate plume model for Canary Islands.

    PubMed

    Zaczek, Kirsten; Troll, Valentin R; Cachao, Mario; Ferreira, Jorge; Deegan, Frances M; Carracedo, Juan Carlos; Soler, Vicente; Meade, Fiona C; Burchardt, Steffi

    2015-01-01

    The origin and life cycle of ocean islands have been debated since the early days of Geology. In the case of the Canary archipelago, its proximity to the Atlas orogen led to initial fracture-controlled models for island genesis, while later workers cited a Miocene-Quaternary east-west age-progression to support an underlying mantle-plume. The recent discovery of submarine Cretaceous volcanic rocks near the westernmost island of El Hierro now questions this systematic age-progression within the archipelago. If a mantle-plume is indeed responsible for the Canaries, the onshore volcanic age-progression should be complemented by progressively younger pre-island sedimentary strata towards the west, however, direct age constraints for the westernmost pre-island sediments are lacking. Here we report on new age data obtained from calcareous nannofossils in sedimentary xenoliths erupted during the 2011 El Hierro events, which date the sub-island sedimentary rocks to between late Cretaceous and Pliocene in age. This age-range includes substantially younger pre-volcanic sedimentary rocks than the Jurassic to Miocene strata known from the older eastern islands and now reinstate the mantle-plume hypothesis as the most plausible explanation for Canary volcanism. The recently discovered Cretaceous submarine volcanic rocks in the region are, in turn, part of an older, fracture-related tectonic episode. PMID:25609055

  2. Nannofossils in 2011 El Hierro eruptive products reinstate plume model for Canary Islands

    PubMed Central

    Zaczek, Kirsten; Troll, Valentin R.; Cachao, Mario; Ferreira, Jorge; Deegan, Frances M.; Carracedo, Juan Carlos; Soler, Vicente; Meade, Fiona C.; Burchardt, Steffi

    2015-01-01

    The origin and life cycle of ocean islands have been debated since the early days of Geology. In the case of the Canary archipelago, its proximity to the Atlas orogen led to initial fracture-controlled models for island genesis, while later workers cited a Miocene-Quaternary east-west age-progression to support an underlying mantle-plume. The recent discovery of submarine Cretaceous volcanic rocks near the westernmost island of El Hierro now questions this systematic age-progression within the archipelago. If a mantle-plume is indeed responsible for the Canaries, the onshore volcanic age-progression should be complemented by progressively younger pre-island sedimentary strata towards the west, however, direct age constraints for the westernmost pre-island sediments are lacking. Here we report on new age data obtained from calcareous nannofossils in sedimentary xenoliths erupted during the 2011 El Hierro events, which date the sub-island sedimentary rocks to between late Cretaceous and Pliocene in age. This age-range includes substantially younger pre-volcanic sedimentary rocks than the Jurassic to Miocene strata known from the older eastern islands and now reinstate the mantle-plume hypothesis as the most plausible explanation for Canary volcanism. The recently discovered Cretaceous submarine volcanic rocks in the region are, in turn, part of an older, fracture-related tectonic episode. PMID:25609055

  3. Nannofossils in 2011 El Hierro eruptive products reinstate plume model for Canary Islands

    NASA Astrophysics Data System (ADS)

    Zaczek, Kirsten; Troll, Valentin R.; Cachao, Mario; Ferreira, Jorge; Deegan, Frances M.; Carracedo, Juan Carlos; Soler, Vicente; Meade, Fiona C.; Burchardt, Steffi

    2015-01-01

    The origin and life cycle of ocean islands have been debated since the early days of Geology. In the case of the Canary archipelago, its proximity to the Atlas orogen led to initial fracture-controlled models for island genesis, while later workers cited a Miocene-Quaternary east-west age-progression to support an underlying mantle-plume. The recent discovery of submarine Cretaceous volcanic rocks near the westernmost island of El Hierro now questions this systematic age-progression within the archipelago. If a mantle-plume is indeed responsible for the Canaries, the onshore volcanic age-progression should be complemented by progressively younger pre-island sedimentary strata towards the west, however, direct age constraints for the westernmost pre-island sediments are lacking. Here we report on new age data obtained from calcareous nannofossils in sedimentary xenoliths erupted during the 2011 El Hierro events, which date the sub-island sedimentary rocks to between late Cretaceous and Pliocene in age. This age-range includes substantially younger pre-volcanic sedimentary rocks than the Jurassic to Miocene strata known from the older eastern islands and now reinstate the mantle-plume hypothesis as the most plausible explanation for Canary volcanism. The recently discovered Cretaceous submarine volcanic rocks in the region are, in turn, part of an older, fracture-related tectonic episode.

  4. Shallow water submarine hydrothermal activity - A case study in the assessment of ocean acidification and fertilization

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Yoshida, K.; Hagiwara, T.; Nagao, K.; Kusakabe, M.; Wang, B.; Chen, C. A.

    2012-12-01

    Most natural Shallow Water submarine Hydrothermal activates (SWH) along coastlines are related to hydrothermal eruptions involving heating of groundwater with the volcanic gas. These SWHs supply nutrients such as phosphorus and micro nutrients like iron to the euphotic zone, contributing to the overall natural fertility and primary productivity of coastal waters. However, SWHs also have a negative effect, dispersing toxic materials such as mercury and arsenic, and affecting the acidification of the surrounding waters. In this study, we evaluate the impact of "iron supply" and "ocean acidification" on the primary production in a coastal marine environment, at a SWH area discovered off Gueshandao Island, northeast Taiwan. In the past three years, expeditions were conducted and observations made around this SWH site. Divers, small boats and a research vessel (R/V OR1, Ocean University National Taiwan) were used to survey successively larger areas around the site. Some of the results obtained are as follows. Hydrothermal vents are located in a hilly terrain rich with hot spring water with gas erupting intermittently. There are two types of vents, roughly divided by color, yellow hot spring water with higher temperature >110 degC ejected from sulfur chimneys of various sizes, and colorless water with lower temperature ~80 degC ejected directly from the crevices of the andesitic bedrock. Natural sulfur solidifying in the mouth of a small chimney was captured by a video camera, and explosions were also observed at intervals of a few minutes. Sediment, sand and particles of sulfur were deposited on the sides to a radius of about 50 m condensing around the chimney. The bottom type changes from sand/particles to outcrop/rock away from the vents. Moreover, gas samples were collected from the vents; the ratios of gas concentrations (N2/Ar) and isotopic composition of noble gas (3He/4He) suggest that these volcanic gases are mantle-derived. Hydrothermal fluid with high p

  5. El Cobreloa: A geyser with two distinct eruption styles

    NASA Astrophysics Data System (ADS)

    Namiki, Atsuko; Muñoz-Saez, Carolina; Manga, Michael

    2014-08-01

    We performed field measurements at a geyser nicknamed "El Cobreloa," located in the El Tatio Geyser Field, Northern Andes, Chile. The El Cobreloa geyser has two distinct eruption styles: minor eruptions and more energetic and long-lived major eruptions. Minor eruptions splash hot water intermittently over an approximately 4 min time period. Major eruptions begin with an eruption style similar to minor eruptions, but then transition to a voluminous liquid water-dominated eruption, and finally end with energetic steam discharge that continues for approximately 1 h. We calculated eruption intervals by visual observations, acoustic measurements, and ground temperature measurements and found that each eruption style has a regular interval: 4 h and 40 min for major eruptions and ˜14 min for minor eruptions. Eruptions of El Cobreloa and geochemical measurements suggest interaction of three water sources. The geyser reservoir, connected to the surface by a conduit, is recharged by a deep, hot aquifer. More deeply derived magmatic fluids heat the reservoir. Boiling in the reservoir releases steam and hot liquid water to the overlying conduit, causing minor eruptions, and heating the water in the conduit. Eventually the water in the conduit becomes warm enough to boil, leading to a steam-dominated eruption that empties the conduit. The conduit is then recharged by a shallow, colder aquifer, and the eruption cycle begins anew. We develop a model for minor eruptions which heat the water in the conduit. El Cobreloa provides insight into how small eruptions prepare the geyser system for large eruptions.

  6. Wilmington Submarine Canyon: a marine fluvial-like system.

    USGS Publications Warehouse

    McGregor, B.; Stubblefield, W.L.; Ryan, William B. F.; Twichell, D.C.

    1982-01-01

    Midrange sidescan sonar data show that a system of gullies and small channels feeds into large submarine canyons on the Middle Atlantic Continental Slope of the US. The surveyed canyons all have relatively flat floors, but they have different channel morphologies. Wilmington Canyon has a meandering channel that extends down the Continental Slope and across the Continental Rise, whereas two canyons south of Wilmington Canyon have straight channels that trend directly downslope onto the rise. The morphology of these submarine canyon systems is remarkably similar to that of terrestrial fluvial systems.-Authors

  7. Eruption Depths, Magma Storage and Magma Degassing at Sumisu Caldera, Izu-Bonin Arc: Evidence from Glasses and Melt Inclusions

    NASA Astrophysics Data System (ADS)

    Johnson, E. R.

    2015-12-01

    Island arc volcanoes can become submarine during cataclysmal caldera collapse. The passage of a volcanic vent from atmospheric to under water environment involves complex modifications of the eruption style and subsequent transport of the pyroclasts. Here, we use FTIR measurements of the volatile contents of glass and melt inclusions in the juvenile pumice clasts in the Sumisu basin and its surroundings (Izu-Bonin arc) to investigate changes in eruption depths, magma storage and degassing over time. This study is based on legacy cores from ODP 126, where numerous unconsolidated (<65 ka), extremely thick (few m to >250 m), massive to normally graded pumice lapilli-tuffs were recovered over four cores (788C, 790A, 790B and 791A). Glass and clast geochemistry indicate the submarine Sumisu caldera as the source of several of these pumice lapilli-tuffs. Glass chips and melt inclusions from these samples were analyzed using FTIR for H2O and CO2 contents. Glass chips record variable H2O contents; most chips contain 0.6-1.6 wt% H2O, corresponding to eruption depths of 320-2100 mbsl. Variations in glass H2O and pressure estimates suggest that edifice collapse occurred prior-to or during eruption of the oldest of these samples, and that the edifice may have subsequently grown over time. Sanidine-hosted melt inclusions from two units record variably degassed but H2O-rich melts (1.1-5.6 wt% H2O). The lowest H2O contents overlap with glass chips, consistent with degassing and crystallization of melts until eruption, and the highest H2O contents suggest that large amounts of degassing accompanied likely explosive eruptions. Most inclusions, from both units, contain 2-4 wt% H2O, which further indicates that the magmas crystallized at pressures of ~50-100 MPa, or depths ~400-2800 m below the seafloor. Further glass and melt inclusion analyses, including major element compositions, will elucidate changes in magma storage, degassing and evolution over time.

  8. The Effects of Preeruptive Magma Viscosity on Eruption Styles and Magma Eruption Rates

    NASA Astrophysics Data System (ADS)

    Tomiya, A.; Koyaguchi, T.; Kozono, T.; Takeuchi, S.

    2014-12-01

    We have collected data on magma eruption rate, which is one of the most fundamental parameters for a volcanic eruption. There are several compilations on eruption rates, for example, for Plinian eruptions (Carey and Sigurdsson, 1989), basaltic eruptions (Wadge, 1981), lava dome eruptions (Newhall and Melson, 1983), and all combined (Tomiya and Koyaguchi, 1998; Pyle, 2000). However, they did not quantitatively discuss the effects of magma viscosity, which must control eruption rates. Here, we discuss the effects of magma viscosity on eruption rates, by using 'preeruptive magma viscosities', which are important measures of magma eruptibility (Takeuchi, 2011). Preeruptive magma viscosity is the viscosity of magma (melt, dissolved water, and crystals) in the magma chamber at the preeruptive conditions, and can be approximately obtained only by the bulk rock SiO2 and phenocryst content, using an empirical formula (Takeuchi, 2010). We have found some interesting relationships, such as (1) eruption styles and rates are correlated to preeruptive magma viscosity but not correlated to bulk rock composition, and (2) the gap (ratio) in eruption rates between explosive and effusive phases in a series of eruptions is proportional to preeruptive magma viscosity. We also propose, by combining (1) and (2), that (3) the radius (or width) of volcanic conduit is positively correlated with preeruptive magma viscosity. Our data also show that the eruptive magmas are divided into two types. One is the low-viscosity type (basalt ~ phenocryst-poor andesite), characterized by lava flow and sub-Plinian eruptions. The other is the high-viscosity type (phenocryst-rich andesite ~ rhyolite), characterized by lava dome and Plinian eruptions. The boundary is at about 104 Pa s. These two types may be closely linked to the magma generation processes (fractional/batch crystallization vs. extraction from a mushy magma chamber).

  9. Fixed drug eruptions with modafinil

    PubMed Central

    Ghoshal, Loknath; Sinha, Mausumi

    2015-01-01

    Modafinil is a psychostimulant drug, which has been approved by the US Food and Drug Administration for the treatment of narcolepsy associated excessive daytime sleepiness, sleep disorder related to shift work, and obstructive sleep apnea syndrome. However, presently it is being used as a lifestyle medicine; in India, it has been misused as an “over the counter” drug. Modafinil is known to have several cutaneous side effects. Fixed drug eruption (FDE) is a distinctive drug induced reaction pattern characterized by recurrence of eruption at the same site of the skin or mucous membrane with repeated systemic administration. Only two case reports exist in the literature describing modafinil induced FDE until date. Here, we report two similar cases. The increasing use of this class of drug amongst the medical personnel might be posing a threat to the proper use and encouraging subsequent abuse. There might be a considerable population using these drugs unaware of the possible adverse effects. Authorities should be more alert regarding the sale and distribution of such medicines. PMID:25878389

  10. Jupiter Eruptions Captured in Infrared

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on the image for high resolution image of Nature Cover

    Detailed analysis of two continent-sized storms that erupted in Jupiter's atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding these outbreaks could be the key to unlock the mysteries buried in the deep Jovian atmosphere, say astronomers.

    This infrared image shows two bright plume eruptions obtained by the NASA Infrared Telescope Facility on April 5, 2007.

    Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.

    According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vigorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 kilometers) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's atmosphere at 375 miles per hour (600 kilometers per hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approximately100 kilometers) below the cloud tops where most sunlight is absorbed.

  11. Herculaneum: Clues to Vesuvius eruption

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    More than 80 skeletons have been unearthed in the ancient Mediterranean town of Herculaneum, west of Italy's Mount Vesuvius. This anthropological find corroborates a reinterpretation by three University of Rhode Island scientists of the sequence of the August A.D. 79 eruption of Vesuvius. In addition, the discovery is the first proof that large numbers of people perished as they tried to flee from the eruption, estimated to have been about 10 times more powerful than the May 1980 Mount St. Helens blast.‘Who says dead men don't talk? Their bones have something to say about them and their everyday lives,’ says Sara C. Bisel, a physical anthropologist who analyzed the skeletons. Among the remains are a cluster of skeletons from six adults, four children, and two infants trying to shield themselves from the volcanic onslaught; the skeleton of a sailor, still clutching an oar, lying on his back beside an 8-m-long capsized boat; a woman whose now bony hand was still graced with gem-encrusted gold rings; and a soldier (see Figure 1). From these and other finds the anthropological team was able to discern that the ancient Romans, on average, were shorter than modern citizens and, judging from the condition of some of the teeth, probably had a low-sugar diet.

  12. Mechanism of Human Tooth Eruption: Review Article Including a New Theory for Future Studies on the Eruption Process

    PubMed Central

    Kjær, Inger

    2014-01-01

    Human eruption is a unique developmental process in the organism. The aetiology or the mechanism behind eruption has never been fully understood and the scientific literature in the field is extremely sparse. Human and animal tissues provide different possibilities for eruption analyses, briefly discussed in the introduction. Human studies, mainly clinical and radiological, have focused on normal eruption and gender differences. Why a tooth begins eruption and what enables it to move eruptively and later to end these eruptive movements is not known. Pathological eruption courses contribute to insight into the aetiology behind eruption. A new theory on the eruption mechanism is presented. Accordingly, the mechanism of eruption depends on the correlation between space in the eruption course, created by the crown follicle, eruption pressure triggered by innervation in the apical root membrane, and the ability of the periodontal ligament to adapt to eruptive movements. Animal studies and studies on normal and pathological eruption in humans can support and explain different aspects in the new theory. The eruption mechanism still needs elucidation and the paper recommends that future research on eruption keeps this new theory in mind. Understanding the aetiology of the eruption process is necessary for treating deviant eruption courses. PMID:24688798

  13. Modeling eruptive coronal magnetohydrodynamic systems with FLUX

    NASA Astrophysics Data System (ADS)

    Rachmeler, L. A.

    In this dissertation I explore solar coronal energetic eruptions in the context of magnetic reconnection, which is commonly thought to be a required trigger mechanism for solar eruptions. Reconnection is difficult to directly observe in the corona, and current numerical methods cannot model reconnectionless control cases. Thus, it is not possible to determine if reconnection is a necessary component of these eruptions. I have executed multiple controlled simulations to determine the importance of reconnection for initiation and evolution of several eruptive systems using FLUX, a numerical model that uses the comparatively new fluxon technique. I describe two types of eruptions modeled with FLUX: a metastable confined flux rope theory for coronal mass ejection (CME) initiation, and symmetrically twisted coronal jets in a uniform vertical background field. In the former, I identified an ideal magnetohydrodynamic (MHD) instability that allows metastable twisted flux rope systems to suddenly lose stability and erupt even in the absence of reconnection, contradicting previous conjecture. The CME result is in contrast to the azimuthally symmetric coronal jet initiation model, where jet-like behavior does not manifest without reconnection. My work has demonstrated that some of the observed eruptive phenomena may be triggered by non-reconnective means such as ideal MHD instabilities, and that magnetic reconnection is not a required element in all coronal eruptions.

  14. Recovery From Giant Eruptions in Massive Stars

    NASA Astrophysics Data System (ADS)

    Kashi, A.; Davidson, K.; Humphreys, R. M.

    2015-12-01

    We perform radiation hydrodynamic simulations to study how very massive stars recover from giant eruptions. The post eruption star experience strong mass loss due to strong winds, driven by radial pulsations in the star*s interior, that operate by the κ-mechanism. The mass loss history obtained in our simulations resembles η Car*s history.

  15. Numerical model of crater lake eruptions

    NASA Astrophysics Data System (ADS)

    Morrissey, M.; Gisler, G.; Weaver, R.; Gittings, M.

    2010-12-01

    We present results from a numerical investigation of subaqueous eruptions involving superheated steam released through a lake mimicking the volcanic setting at Mt. Ruapehu. The simulations were conducted using an adaptive mesh, multi-material, hydrodynamics code with thermal conduction SAGE, (Simple Adaptive Grid Eulerian). Parameters investigated include eruption pressure, lake level and mass of superheated vapor. The simulations produced a spectrum of eruption styles from vapor cavities to radial jets that resulted in hazards that ranged from small-scale waves to high amplitude surges that reached and cascaded over the edge of the crater rim. There was an overall tendency for lake surface activity to increase (including wave amplitude) with increasing mass of superheated vapor and eruption pressure. Surface waves were induced by the formation and collapse of a gas cavity. The collapse of the cavity is considered to play a major role in the characteristic features observed during a subaqueous eruption. The additional mass of superheated vapor produced a larger cavity that displaced a larger area of the lake surface resulting in fast moving surges upon the collapse of the cavity. High lake levels (>90 m) appear to suppress the development of explosive jetting activity when eruption pressures are <10 MPa. At very large eruption pressures (>10 MPa), vertical jets and radial ejections of steam and water can occur in water depths >90 m. Less explosive eruption styles can produce hazardous events such as lahars by the outward movement of surface waves over the crater rim.

  16. Relationships between pre-eruptive conditions and eruptive styles of phonolite-trachyte magmas

    NASA Astrophysics Data System (ADS)

    Andújar, Joan; Scaillet, Bruno

    2012-11-01

    Phonolitic eruptions can erupt either effusively or explosively, and in some cases develop highly energetic events such as caldera-forming eruptions. However, the mechanisms that control the eruptive behaviour of such compositions are not well understood. By combining pre-eruptive data of well studied phonolitic eruptions we show that the explosive-effusive style of the phonolitic magma is controlled by the amount of volatiles, the degree of water-undersaturation and the depth of magma storage, the explosive character generally increasing with pressure depth and water contents. However, external factors, such as ingestion of external water, or latter processes occurring in the conduit, can modify the starting eruptive dynamic acquired at the levels of magma ponding.

  17. Chronology of Postglacial Eruptive Activity and Calculation of Eruption Probabilities for Medicine Lake Volcano, Northern California

    USGS Publications Warehouse

    Nathenson, Manuel; Donnelly-Nolan, Julie M.; Champion, Duane E.; Lowenstern, Jacob B.

    2007-01-01

    Medicine Lake volcano has had 4 eruptive episodes in its postglacial history (since 13,000 years ago) comprising 16 eruptions. Time intervals between events within the episodes are relatively short, whereas time intervals between the episodes are much longer. An updated radiocarbon chronology for these eruptions is presented that uses paleomagnetic data to constrain the choice of calibrated ages. This chronology is used with exponential, Weibull, and mixed-exponential probability distributions to model the data for time intervals between eruptions. The mixed exponential distribution is the best match to the data and provides estimates for the conditional probability of a future eruption given the time since the last eruption. The probability of an eruption at Medicine Lake volcano in the next year from today is 0.00028.

  18. Paving the seafloor: Volcanic emplacement processes during the 2005-2006 eruptions at the fast spreading East Pacific Rise, 9°50‧N

    NASA Astrophysics Data System (ADS)

    Fundis, A. T.; Soule, S. A.; Fornari, D. J.; Perfit, M. R.

    2010-08-01

    The 2005-2006 eruptions near 9°50'N at the East Pacific Rise (EPR) marked the first observed repeat eruption at a mid-ocean ridge and provided a unique opportunity to deduce the emplacement dynamics of submarine lava flows. Since these new flows were documented in April 2006, a total of 40 deep-towed imaging surveys have been conducted with the Woods Hole Oceanographic Institution's (WHOI) TowCam system. More than 60,000 digital color images and high-resolution bathymetric profiles of the 2005-2006 flows from the TowCam surveys were analyzed for lava flow morphology and for the presence of kipukas, collapse features, faults and fissures. We use these data to quantify the spatial distributions of lava flow surface morphologies and to investigate how they relate to the physical characteristics of the ridge crest, such as seafloor slope, and inferred dynamics of flow emplacement. We conclude that lava effusion rate was the dominant factor controlling the observed morphological variations in the 2005-2006 flows. We also show that effusion rates were higher than in previously studied eruptions at this site and varied systematically along the length of the eruptive fissure. This is the first well-documented study in which variations in seafloor lava morphology can be directly related to a well documented ridge-crest eruption where effusion rate varied significantly.

  19. The largest volcanic eruptions on Earth

    NASA Astrophysics Data System (ADS)

    Bryan, Scott E.; Peate, Ingrid Ukstins; Peate, David W.; Self, Stephen; Jerram, Dougal A.; Mawby, Michael R.; Marsh, J. S. (Goonie); Miller, Jodie A.

    2010-10-01

    Large igneous provinces (LIPs) are sites of the most frequently recurring, largest volume basaltic and silicic eruptions in Earth history. These large-volume (> 1000 km 3 dense rock equivalent) and large-magnitude (> M8) eruptions produce areally extensive (10 4-10 5 km 2) basaltic lava flow fields and silicic ignimbrites that are the main building blocks of LIPs. Available information on the largest eruptive units are primarily from the Columbia River and Deccan provinces for the dimensions of flood basalt eruptions, and the Paraná-Etendeka and Afro-Arabian provinces for the silicic ignimbrite eruptions. In addition, three large-volume (675-2000 km 3) silicic lava flows have also been mapped out in the Proterozoic Gawler Range province (Australia), an interpreted LIP remnant. Magma volumes of > 1000 km 3 have also been emplaced as high-level basaltic and rhyolitic sills in LIPs. The data sets indicate comparable eruption magnitudes between the basaltic and silicic eruptions, but due to considerable volumes residing as co-ignimbrite ash deposits, the current volume constraints for the silicic ignimbrite eruptions may be considerably underestimated. Magma composition thus appears to be no barrier to the volume of magma emitted during an individual eruption. Despite this general similarity in magnitude, flood basaltic and silicic eruptions are very different in terms of eruption style, duration, intensity, vent configuration, and emplacement style. Flood basaltic eruptions are dominantly effusive and Hawaiian-Strombolian in style, with magma discharge rates of ~ 10 6-10 8 kg s -1 and eruption durations estimated at years to tens of years that emplace dominantly compound pahoehoe lava flow fields. Effusive and fissural eruptions have also emplaced some large-volume silicic lavas, but discharge rates are unknown, and may be up to an order of magnitude greater than those of flood basalt lava eruptions for emplacement to be on realistic time scales (< 10 years). Most

  20. The magmatic plumbing of the submarine Hachijo NW volcanic chain, Hachijojima, Japan: long distance lateral magma transport?

    NASA Astrophysics Data System (ADS)

    Ishizuka, O.; Geshi, N.; Itoh, J.; Kawanabe, Y.; Tsujino, T.

    2005-12-01

    Recent geophysical observations on basaltic composite volcanoes in Izu-Bonin arc reveal the process of long distance lateral magma transport within the shallow middle crust. Such intrusion events sometimes caused flank fissure eruption and also triggered a formation of collapsed caldera (Miyakejima 2000). To clarify a long-distance magma transport system of the basaltic composite volcano in volcanic arc from geological and petrological aspects, we investigated a submarine volcanic chain (Hachijo NW chain) nested Hachijo Nishiyama volcano, a frontal composite volcano in the northern Izu arc. The volcanic chain extends 15 km from Hachijo-Nishiyama volcano and is composed of ridges and many small cones with basal diameters generally less than 2km. Dredge sampling recovered basaltic lavas and spatters. A diving survey using a ROV (Hyper Dolphin) revealed pillow lava flows on steep slopes and accumulation of spatters and agglutinates near the eruption center. Basalts from the Hachijo NW chain generally have more primitive composition (up to nearly 7% of MgO) compared to the basaltic rocks from the Nishiyama. The bulk magma composition of Hachijo NW chain is controlled by fractionation of clinopyroxene, olivine and plagioclase while plagioclase accumulation was indicated by aluminum-rich character of the Nishiyama volcano and its subaerial satellite cones. Trace element ratios unaffected by melting or crystal fractionation (e.g., Nb/Zr) are not significantly different between the Nishiyama and the Hachijo NW chain. This implies that the sources of magma for these volcanic systems are basically identical. However, ratios affected by melting process are significantly different between the two. Hachijo NW chain shows lower LREE/HREE and Zr/Y, implying difference in degree of partial melting of the source. Other possible processes for producing these differences in trace element characteristics include crustal assimilation. These results obtained so far appear to

  1. Forecasting eruptions using pre-eruptive seismic patterns at Sinabung Volcano, Indonesia

    NASA Astrophysics Data System (ADS)

    McCausland, W. A.; White, R. A.; Hendrasto, M.; Gunawan, H.; Indrastuti, N.; Triastuti, H.; Suparman, Y.; Putra, A.

    2015-12-01

    Forecasting the size, timing and style of volcanic eruptions is of primary interest to observatories and civil authorities world-wide, yet most observatories only have access to long-term data at a very limited number of volcanoes under their jurisdiction. When extensive long-term data sets are available to responsible agencies, volcanic eruptive size, timing and style can usually be successfully forecast using current monitoring data and knowledge of precursory eruptive patterns, enabling the communication of timely forecasts to civil authorities. Experienced agencies, such as Indonesia's Center for Volcanology and Geologic Hazards Mitigation and the USAID-USGS Volcano Disaster Assistance Program, utilize extensive collective experiences with multiple monitoring streams over multiple eruption cycles and across volcano types to successfully forecast eruption size, style and onset, as well as changes in eruptive style and size within ongoing eruptions. The longest-term real-time monitoring parameter commonly available at volcanoes worldwide is seismic data. Seismic data is a direct measure of rate-dependent strain changes in the magmatic system from the deep magmatic input to shallow eruptive processes. Patterns of pre-eruptive earthquakes coupled with other available monitoring data and conceptual models of magma ascent enable short-term forecasting of eruption size, style, and onset. First order event locations, characterization of background seismicity, and changes in earthquake types and energy release are most important to successful eruption forecasting. This study demonstrates how this approach has been used to successfully forecast eruption onsets, changes in eruptive style, and to change alert levels and extend or contract evacuation zones during the ongoing eruption of Sinabung Volcano, Indonesia.

  2. Estimates of mass eruption rates in Icelandic eruptions 1913-2015

    NASA Astrophysics Data System (ADS)

    Tumi Gudmundsson, Magnus; Dürig, Tobias; Larsen, Gudrún

    2016-04-01

    In the period from 1913 to 2015 about 35 eruptions occurred in Iceland, although some uncertainty exists about the number of the smallest events, particularly within the ice covered regions. For the smaller events in the earlier part of the period, only order of magnitude estimates of mass eruption rates (MER) are possible, based on the approximate amount of erupted products, duration of eruption, and information on eruption plume height in some cases. After 1947 estimates are more reliable. This is not least due to the detailed observations and interpretations of Sigurdur Thorarinsson and co-workers until the early 1980s. After 1980, various observations and instrumental data, e.g. on plume height, coupled with detailed mapping by several workers of tephra fallout and lava flow extent provide a good basis for MER estimates. The most frequent events are explosive eruptions producing tephra, often basaltic phreatomagmatic eruptions. A contributing factor to the large number of explosive eruptions is unusually frequent eruptions in Hekla since 1947. Eruptions under glaciers are also common, while a majority of these become explosive as they break through the ice. For the initially subglacial eruptions ice melting rates provide the best estimate of the MER in the first and usually most powerful phase. If the whole data set is considered, the magma volumes erupted in a single eruption span three orders of magnitude, ˜0.001 km3 to 1 km3. The range of intensity is similar, with the smallest Krafla or Askja events having maximum mass eruption rates (MER) of order 10-100 tonnes/second while the most powerful ones (Hekla 1947 and Katla 1918) had MER ˜50,000 tonnes/second (˜5 x 107 kg/s). All the events with the highest MER were explosive, including Katla 1918 where initial subglacial melting caused the largest volcanogenic flood observed since the 18th century. The period 1913-2015 had no events that belong to the class of the largest observed eruptions in Iceland. In

  3. Large, Moderate or Small? The Challenge of Measuring Mass Eruption Rates in Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Gudmundsson, M. T.; Dürig, T.; Hognadottir, T.; Hoskuldsson, A.; Bjornsson, H.; Barsotti, S.; Petersen, G. N.; Thordarson, T.; Pedersen, G. B.; Riishuus, M. S.

    2015-12-01

    The potential impact of a volcanic eruption is highly dependent on its eruption rate. In explosive eruptions ash may pose an aviation hazard that can extend several thousand kilometers away from the volcano. Models of ash dispersion depend on estimates of the volcanic source, but such estimates are prone to high error margins. Recent explosive eruptions, including the 2010 eruption of Eyjafjallajökull in Iceland, have provided a wealth of data that can help in narrowing these error margins. Within the EU-funded FUTUREVOLC project, a multi-parameter system is currently under development, based on an array of ground and satellite-based sensors and models to estimate mass eruption rates in explosive eruptions in near-real time. Effusive eruptions are usually considered less of a hazard as lava flows travel slower than eruption clouds and affect smaller areas. However, major effusive eruptions can release large amounts of SO2 into the atmosphere, causing regional pollution. In very large effusive eruptions, hemispheric cooling and continent-scale pollution can occur, as happened in the Laki eruption in 1783 AD. The Bárdarbunga-Holuhraun eruption in 2014-15 was the largest effusive event in Iceland since Laki and at times caused high concentrations of SO2. As a result civil protection authorities had to issue warnings to the public. Harmful gas concentrations repeatedly persisted for many hours at a time in towns and villages at distances out to 100-150 km from the vents. As gas fluxes scale with lava fluxes, monitoring of eruption rates is therefore of major importance to constrain not only lava but also volcanic gas emissions. This requires repeated measurements of lava area and thickness. However, most mapping methods are problematic once lava flows become very large. Satellite data on thermal emissions from eruptions have been used with success to estimate eruption rate. SAR satellite data holds potential in delivering lava volume and eruption rate estimates

  4. The longevity of lava dome eruptions

    NASA Astrophysics Data System (ADS)

    Wolpert, Robert L.; Ogburn, Sarah E.; Calder, Eliza S.