Sample records for endeavour hydrothermal system

  1. Imaging hydrothermal roots along the Endeavour segment of the Juan de Fuca ridge using elastic full waveform inversion.

    NASA Astrophysics Data System (ADS)

    Arnulf, A. F.; Harding, A. J.; Kent, G. M.

    2016-12-01

    The Endeavour segment is a 90 km-long, medium-spreading-rate, oceanic spreading center located on the northern Juan de Fuca ridge (JDFR). The central part of this segment forms a 25-km-long volcanic high that hosts five of the most hydrothermally active vent fields on the MOR system, namely (from north to south): Sasquatch, Salty Dawg, High Rise, Main Endeavour and Mothra. Mass, heat and chemical fluxes associated to vigorous hydrothermal venting are large, however the geometry of the fluid circulation system through the oceanic crust remains almost completely undefined. To produce high-resolution velocity/reflectivity structures along the axis of the Endeavour segment, here, we combined a synthetic ocean bottom experiment (SOBE), 2-D traveltime tomography, 2D elastic full waveform and reverse time migration (RTM). We present velocity and reflectivity sections along Endeavour segment at unprecedented spatial resolutions. We clearly image a set of independent, geometrically complex, elongated low-velocity regions linking the top of the magma chamber at depth to the hydrothermal vent fields on the seafloor. We interpret these narrow pipe-like units as focused regions of hydrothermal fluid up-flow, where acidic and corrosive fluids form pipe-like alteration zones as previously observed in Cyprus ophiolites. Furthermore, the amplitude of these low-velocity channels is shown to be highly variable, with the strongest velocity drops observed at Main Endeavour, Mothra and Salty Dawg hydrothermal vent fields, possibly suggesting more mature hydrothermal cells. Interestingly, the near-seafloor structure beneath those three sites is very similar and highlights a sharp lateral transition in velocity (north to south). On the other hand, the High-Rise hydrothermal vent field is characterized by several lower amplitudes up-flow zones and relatively slow near-surface velocities. Last, Sasquatch vent field is located in an area of high near-surface velocities and is not

  2. Evolution of the Mothra Hydrothermal Field, Endeavour Segment of the Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Glickson, D.; Kelley, D. S.; Delaney, J.

    2005-12-01

    The Mothra Hydrothermal Field (MHF) is a 600 m long, high-temperature hydrothermal field. It is located 2.7 km south of the Main Endeavour Field at the southern end of the central Endeavour Segment. Mothra is the most areally extensive field along the Endeavour Segment, composed of six active sulfide clusters that are 40-200 m apart. Each cluster contains rare black smokers (venting up to 319°C), numerous diffusely venting chimneys, and abundant extinct chimneys and sulfide talus. From north to south, these clusters include Cauldron, Twin Peaks, Faulty Towers, Crab Basin, Cuchalainn, and Stonehenge. As part of the Endeavour Integrated Study Site (ISS), the MHF is a site of intensive interdisciplinary studies focused on linkages among geology, geochemistry, fluid chemistry, seismology, and microbiology. Axial valley geology at MHF is structurally complex, consisting of lightly fissured flows that abut the walls and surround a core of extensively fissured, collapsed terrain. Fissure abundance and distribution indicates that tectonism has been the dominant process controlling growth of the axial graben. Past magmatic activity is shown by the 200 m long chain of collapse basins between Crab Basin and Stonehenge, which may have held at least ~7500 m3 of lava. Assuming a flow thickness of 0.5 m, this amount of lava could cover over half the valley floor during a single volcanic event. At a local scale, MHF clusters vary in size, activity, and underlying geology. They range in size from 400-1600 m2 and consist of isolated chimneys and/or coalesced cockscomb arrays atop ramps of sulfide talus. In the northern part of the field, Cauldron, Twin Peaks, Faulty Towers, and Crab Basin are located near the western valley wall, bounded by basalt talus and a combination of collapsed sheet flows, intermixed lobate and sulfide, disrupted terrain, and isolated pillow ridges. The southern clusters, Cuchalainn and Stonehenge, are associated with collapse basins in the central valley

  3. A Geographical Information System to Manage the Endeavour Hydrothermal Vents Marine Protected Area

    NASA Astrophysics Data System (ADS)

    Douglas, K. L.; Hillier, M. C. J.; Thornborough, K. J.; Jenkyns, R.; Juniper, K.

    2016-02-01

    The Endeavour Hydrothermal Vents Marine Protected Area (EHVMPA) is located approximately 250 km offshore of Vancouver Island, British Columbia. Since its discovery in 1982, there have been hundreds of dives, samples collected, measurements made, and debris left behind at the EHVMPA. In 2003, the Canadian government declared the region as a Marine Protected Area (MPA) under Canada's Oceans Act, to be managed by the Department of Fisheries and Oceans (DFO). Ocean Networks Canada (ONC) operates a cabled observatory in the EHVMPA, and streams data in near real-time via the Internet to science communities worldwide. ONC's observatory data, combined with observations made during maintenance expeditions provides insight assisting the management and preservation of the MPA. In 2014, DFO partnered with ONC to build a geodatabase to enhance and inform the knowledge base of the EHVMPA Management Plan. The geodatabase, built in ArcGIS, contains data integrated from ONC's Oceans 2.0 database, third parties, and relevant publications. Layers include annual observatory infrastructure deployments, remotely operated vehicle (ROV) dive tracks, sampling activity, anthropogenic debris, high-resolution bathymetry, observations of species of interest, and locations of hydrothermal vents. The combined data show both efforts to better understand the environment and the resulting stressors that impact the MPA. The tool also links observed features such as debris and biological observations to the time-correlated ROV dive video using ONC's SeaTube video viewing tool allowing for further analysis. Through 2017, the geodatabase will be maintained by ONC and enriched with expedition data from organizations such as Monterey Bay Aquarium Research Institute, Woods Hole Oceanographic Institute, and the University of Washington. The end result is a tool that can integrate many types of data obtained from the MPA, and encourages systematic management of a remote, dynamic and fragile environment.

  4. Linking Microearthquakes and Seismic Tomography on the Endeavour Segment of the Juan de Fuca Ridge: Implications for Hydrothermal Circulation

    NASA Astrophysics Data System (ADS)

    Wilcock, W. S.; Weekly, R. T.; Hooft, E. E.; Toomey, D. R.; Kim, E.

    2013-12-01

    We report on a remarkable correlation between the patterns of microearthquakes and three-dimensional upper crustal velocity anomalies on the Endeavour segment of the Juan de Fuca Ridge. Microearthquakes were monitored from 2003-2006 by a small seismic network deployed on the central part of the segment. The velocity model was obtained from a tomography experiment comprising over 5500 shots from a large airgun array that were recorded by ocean bottom seismometers deployed at 64 sites along the Endeavour segment and the adjacent overlapping spreading centers (OSCs). On the segment scale, upper crustal velocities are low in the OSCs indicating that the crust is highly fractured. These low velocities persist off-axis and record the history of ridge propagation. In 2005, two swarm sequences that were interpreted in terms of magmatic intrusions on the limbs of the Endeavour-West Valley OSC were accompanied by extensive seismicity within the overlap basin. Throughout the microearthquake experiment earthquakes were concentrated in a region surrounding the southern tip of the West Valley propagator that coincides closely with the southern limit of the low velocities imaged around the OSC. Beneath the hydrothermal vent fields in the center of the Endeavour segment, the earthquakes were mostly located in a 500-m-thick band immediately above the axial magma chamber. There was a close correlation between the rates of seismicity beneath each vent field and their thermal output. The highest rates of seismicity were observed beneath the High Rise and Main Endeavour fields that each have power outputs of several hundred megawatts. Seismic velocities are generally high beneath the vent fields relative to velocities along the ridge axis immediately to the north and south. However, the High Rise and Main Endeavour fields are underlain by a low velocity region at 2 km depth that coincides with the seismically active region. This is consistent with a region of increased fracturing and

  5. Precipitation and growth of barite within hydrothermal vent deposits from the Endeavour Segment, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Jamieson, John William; Hannington, Mark D.; Tivey, Margaret K.; Hansteen, Thor; Williamson, Nicole M.-B.; Stewart, Margaret; Fietzke, Jan; Butterfield, David; Frische, Matthias; Allen, Leigh; Cousens, Brian; Langer, Julia

    2016-01-01

    Hydrothermal vent deposits form on the seafloor as a result of cooling and mixing of hot hydrothermal fluids with cold seawater. Amongst the major sulfide and sulfate minerals that are preserved at vent sites, barite (BaSO4) is unique because it requires the direct mixing of Ba-rich hydrothermal fluid with sulfate-rich seawater in order for precipitation to occur. Because of its extremely low solubility, barite crystals preserve geochemical fingerprints associated with conditions of formation. Here, we present data from petrographic and geochemical analyses of hydrothermal barite from the Endeavour Segment of the Juan de Fuca Ridge, northeast Pacific Ocean, in order to determine the physical and chemical conditions under which barite precipitates within seafloor hydrothermal vent systems. Petrographic analyses of 22 barite-rich samples show a range of barite crystal morphologies: dendritic and acicular barite forms near the exterior vent walls, whereas larger bladed and tabular crystals occur within the interior of chimneys. A two component mixing model based on Sr concentrations and 87Sr/86Sr of both seawater and hydrothermal fluid, combined with 87Sr/86Sr data from whole rock and laser-ablation ICP-MS analyses of barite crystals indicate that barite precipitates from mixtures containing as low as 17% and as high as 88% hydrothermal fluid component, relative to seawater. Geochemical modelling of the relationship between aqueous species concentrations and degree of fluid mixing indicates that Ba2+ availability is the dominant control on mineral saturation. Observations combined with model results support that dendritic barite forms from fluids of less than 40% hydrothermal component and with a saturation index greater than ∼0.6, whereas more euhedral crystals form at lower levels of supersaturation associated with greater contributions of hydrothermal fluid. Fluid inclusions within barite indicate formation temperatures of between ∼120 °C and 240 °C during

  6. Impact-Facilitated Hydrothermal Alteration in the Rim of Endeavour Crater, Mars

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, D. W.; Schroeder, C.; Farrand, W. H.; Crumpler, L. S.; Yen, A. S.

    2017-01-01

    Endeavour crater, a Noachian-aged, 22 km diameter impact structure on Meridiani Planum, Mars, has been investigated by the Mars Exploration Rover Opportunuity for over 2000 sols (Mars days). The rocks of the western rim region (oldest to youngest) are: (i) the pre-impact Matijevic fm.; (ii) rim-forming Shoemaker fm. polymict impact breccias; (iii) Grasberg fm., fine-grained sediments draping the lower slopes; and (iv) Burns fm., sulfate-rich sandstones that onlap the Grasberg fm. The rim is segmented and transected by radial fracture zones. Evidence for fluid-mediated alteration includes m-scale detections of phyllosilicates from orbit, and cm-scale variations in rock/soil composition/mineralogy documented by the Opportunity instrument suite. The m-scale phyllosilicate detections include Fe(3+)-Mg and aluminous smectites that occur in patches in the Matijevic and Shoemaker fms. Rock compositions do not reveal substantial differences for smectite-bearing compared to smectite-free rocks. Interpretation: large-scale hydrothermal alteration powered by impact-deposited heat acting on limited water supplies engendered mineralogic transfomations under low water/rock, near-isochemical conditions. The cm-scale alterations, localized in fracture zones, occurred at higher water/rock as evidenced by enhanced Si and Al contents through leaching of more soluble elements, and deposition of Mg, Ni and Mn sulphates and halogen salts in soils. Visible/near infrared reflectance of narrow curvilinear red zones indicate higher nanophase ferric oxide contents and possibly hydration compared to surrounding outcrops. Broad fracture zones on the rim have reflectance features consistent with development of ferric oxide minerals. Interpretation: water fluxing through the fractures in a hydrothermal system resulting from the impact engendered alteration and leaching under high water/rock conditions. Late, localized alteration is documented by Ca-sulfate-rich veins that are not confined to

  7. Modeling mid-ocean ridge hydrothermal response to earthquakes, tides, and ocean currents: a case study at the Grotto mound, Endeavour Segment, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Xu, G.; Bemis, K. G.

    2014-12-01

    Seafloor hydrothermal systems feature intricate interconnections among oceanic, geological, hydrothermal, and biological processes. The advent of the NEPTUNE observatory operated by Ocean Networks Canada at the Endeavour Segment, Juan de Fuca Ridge enables scientists to study these interconnections through multidisciplinary, continuous, real-time observations. The multidisciplinary observatory instruments deployed at the Grotto Mound, a major study site of the NEPTUNE observatory, makes it a perfect place to study the response of a seafloor hydrothermal system to geological and oceanic processes. In this study, we use the multidisciplinary datasets recorded by the NEPTUNE Observatory instruments as observational tools to demonstrate two different aspects of the response of hydrothermal activity at the Grotto Mound to geological and oceanic processes. First, we investigate a recent increase in venting temperature and heat flux at Grotto observed by the Benthic and Resistivity Sensors (BARS) and the Cabled Observatory Vent Imaging Sonar (COVIS) respectively. This event started in Mar 2014 and is still evolving by the time of writing this abstract. An initial interpretation in light of the seismic data recorded by a neighboring ocean bottom seismometer on the NEPTUNE observatory suggests the temperature and heat flux increase is probably triggered by local seismic activities. Comparison of the observations with the results of a 1-D mathematical model simulation of hydrothermal sub-seafloor circulation elucidates the potential mechanisms underlying hydrothermal response to local earthquakes. Second, we observe significant tidal oscillations in the venting temperature time series recorded by BARS and the acoustic imaging of hydrothermal plumes by COVIS, which is evidence for hydrothermal response to ocean tides and currents. We interpret the tidal oscillations of venting temperature as a result of tidal loading on a poroelastic medium. We then invoke poroelastic

  8. Near-vent chemical processes in a hydrothermal plume: Insights from an integrated study of the Endeavour segment

    NASA Astrophysics Data System (ADS)

    Coogan, L. A.; Attar, A.; Mihaly, S. F.; Jeffries, M.; Pope, M.

    2017-04-01

    The Endeavour segment of the Juan de Fuca mid-ocean ridge is one of the best studied ridge segments and has recently been instrumented as part of Ocean Networks Canada's NEPTUNE cabled observatory. Here we investigate the interaction between high-temperature vent fluids and the overlying water column. A new tow-yo survey found that the average temperature anomaly in the neutrally buoyant plume was ˜0.043°C. The water column temperature and light attenuation anomalies correlate linearly in some areas of the plume but in other areas there is a low light attenuation anomaly relative to the temperature anomaly. This temperature excess is interpreted to reflect heat input through (particle-poor) diffuse flow. If this is correct, about half of the heat flux along the Endeavour segment comes from diffuse flow. Sediment trap and push core data show that the mass accumulation rate of the hydrothermal component of the sediments decreases rapidly with distance from the major vent fields. Large changes in the composition of the hydrothermal component of the sediments also occur with distance from the vent fields. The composition of the sediments indicates (i) sulfides precipitate early and accumulate most rapidly close to the vents with a preferential order of element removal from the plume of Cd > Ag > Cu > Co ˜ Fe; (ii) barite is deposited somewhat further from the vents. Strontium and Pb appear to be strongly incorporated in barite and/or other sulfate minerals; (iii) at most a few percent of the mass of these "insoluble" elements that is vented gets deposited within 1.5 km of the vents.

  9. Characterization of Magma-Driven Hydrothermal Systems at Oceanic Spreading Centers

    NASA Astrophysics Data System (ADS)

    Farough, A.; Lowell, R. P.; Corrigan, R.

    2012-12-01

    Fluid circulation in high-temperature hydrothermal systems involves complex water-rock chemical reactions and phase separation. Numerical modeling of reactive transport in multi-component, multiphase systems is required to obtain a full understanding of the characteristics and evolution of hydrothermal vent systems. We use a single-pass parameterized model of high-temperature hydrothermal circulation at oceanic spreading centers constrained by observational parameters such as vent temperature, heat output, and vent field area, together with surface area and depth of the sub-axial magma chamber, to deduce fundamental hydrothermal parameters such as mass flow rate, bulk permeability, conductive boundary layer thickness at the base of the system, magma replenishment rate, and residence time in the discharge zone. All of these key subsurface characteristics are known for fewer than 10 sites out of 300 known hydrothermal systems. The principal limitations of this approach stem from the uncertainty in heat output and vent field area. For systems where data are available on partitioning of heat and chemical output between focused and diffuse flow, we determined the fraction of high-temperature vent fluid incorporated into diffuse flow using a two-limb single pass model. For EPR 9°50` N and ASHES, the diffuse flow temperatures calculated assuming conservative mixing are nearly equal to the observed temperatures indicating that approximately 80%-90% of the hydrothermal heat output occurs as high-temperature flow derived from magmatic heat even though most of the heat output appears as low-temperature diffuse discharge. For the Main Endeavour Field and Lucky Strike, diffuse flow fluids show significant conductive cooling and heating respectively. Finally, we calculate the transport of various geochemical constituents in focused and diffuse flow at the vent field scale and compare the results with estimates of geochemical transports from the Rainbow hydrothermal field where

  10. Monitoring Endeavour vent field deep-sea ecosystem dynamics through NEPTUNE Canada seafloor observatory

    NASA Astrophysics Data System (ADS)

    Matabos, M.; NC Endeavour Science Team

    2010-12-01

    Mid-ocean ridges are dynamic systems where the complex linkages between geological, biological, chemical, and physical processes are not yet well understood. Indeed, the poor accessibility to the marine environment has greatly limited our understanding of deep-sea ecosystems. Undersea cabled observatories offer the power and bandwidth required to conduct long-term and high-resolution time-series observations of the seafloor. Investigations of mid-ocean ridge hydrothermal ecosystem require interdisciplinary studies to better understand the dynamics of vent communities and the physico-chemical forces that influence them. NEPTUNE Canada (NC) regional observatory is located in the Northeast Pacific, off Vancouver Island (BC, Canada), and spans ecological environments from the beach to the abyss. In September-October 2010, NC will be instrumenting its 5th node, including deployment of a multi-disciplinary suite of instruments in two vent fields on the Endeavour Segment of the Juan de Fuca Ridge. These include a digital camera, an imaging sonar for vent plumes and flow characteristics (i.e. COVIS), temperature resistivity probes, a water sampler and seismometers. In 2011, the TEMPO-mini, a new custom-designed camera and sensor package created by IFREMER for real-time monitoring of hydrothermal faunal assemblages and their ecosystems (Sarrazin et al. 2007), and a microbial incubator, will added to the network in the Main Endeavour and Mothra vent fields. This multidisciplinary approach will involve a scientific community from different institutions and countries. Significant experience aids in this installation. For example, video systems connected to VENUS and NC have led to the development of new experimental protocols for time-series observations using seafloor cameras, including sampling design, camera calibration and image analysis methodologies (see communication by Aron et al. and Robert et al.). Similarly, autonomous deployment of many of the planned instruments

  11. Constrained circulation at Endeavour ridge facilitates colonization by vent larvae.

    PubMed

    Thomson, Richard E; Mihály, Steven F; Rabinovich, Alexander B; McDuff, Russell E; Veirs, Scott R; Stahr, Frederick R

    2003-07-31

    Understanding how larvae from extant hydrothermal vent fields colonize neighbouring regions of the mid-ocean ridge system remains a major challenge in oceanic research. Among the factors considered important in the recruitment of deep-sea larvae are metabolic lifespan, the connectivity of the seafloor topography, and the characteristics of the currents. Here we use current velocity measurements from Endeavour ridge to examine the role of topographically constrained circulation on larval transport along-ridge. We show that the dominant tidal and wind-generated currents in the region are strongly attenuated within the rift valley that splits the ridge crest, and that hydrothermal plumes rising from vent fields in the valley drive a steady near-bottom inflow within the valley. Extrapolation of these findings suggests that the suppression of oscillatory currents within rift valleys of mid-ocean ridges shields larvae from cross-axis dispersal into the inhospitable deep ocean. This effect, augmented by plume-driven circulation within rift valleys having active hydrothermal venting, helps retain larvae near their source. Larvae are then exported preferentially down-ridge during regional flow events that intermittently over-ride the currents within the valley.

  12. Hydrothermal processes above the Yellowstone magma chamber: Large hydrothermal systems and large hydrothermal explosions

    USGS Publications Warehouse

    Morgan, L.A.; Shanks, W.C. Pat; Pierce, K.L.

    2009-01-01

    and vein-fi lling; and (5) areal dimensions of many large hydrothermal explosion craters in Yellowstone are similar to those of its active geyser basins and thermal areas. For Yellowstone, our knowledge of hydrothermal craters and ejecta is generally limited to after the Yellowstone Plateau emerged from beneath a late Pleistocene icecap that was roughly a kilometer thick. Large hydrothermal explosions may have occurred earlier as indicated by multiple episodes of cementation and brecciation commonly observed in hydrothermal ejecta clasts. Critical components for large, explosive hydrothermal systems include a watersaturated system at or near boiling temperatures and an interconnected system of well-developed joints and fractures along which hydrothermal fluids flow. Active deformation of the Yellowstone caldera, active faulting and moderate local seismicity, high heat flow, rapid changes in climate, and regional stresses are factors that have strong infl uences on the type of hydrothermal system developed. Ascending hydrothermal fluids flow along fractures that have developed in response to active caldera deformation and along edges of low-permeability rhyolitic lava flows. Alteration of the area affected, self-sealing leading to development of a caprock for the hydrothermal system, and dissolution of silica-rich rocks are additional factors that may constrain the distribution and development of hydrothermal fields. A partial lowpermeability layer that acts as a cap to the hydrothermal system may produce some over-pressurization, thought to be small in most systems. Any abrupt drop in pressure initiates steam fl ashing and is rapidly transmitted through interconnected fractures that result in a series of multiple large-scale explosions contributing to the excavation of a larger explosion crater. Similarities between the size and dimensions of large hydrothermal explosion craters and thermal fields in Yellowstone may indicate that catastrophic events which result in l

  13. Temporal and spatial variation in temperature experienced by macrofauna at Main Endeavour hydrothermal vent field

    NASA Astrophysics Data System (ADS)

    Lee, Raymond W.; Robert, Katleen; Matabos, Marjolaine; Bates, Amanda E.; Juniper, S. Kim

    2015-12-01

    A significant focus of hydrothermal vent ecological studies has been to understand how species cope with various stressors through physiological tolerance and biochemical resistance. Yet, the environmental conditions experienced by vent species have not been well characterized. This objective requires continuous observations over time intervals that can capture environmental variability at scales that are relevant to animals. We used autonomous temperature logger arrays (four roughly parallel linear arrays of 12 loggers spaced every 10-12 cm) to study spatial and temporal variations in the thermal regime experienced by hydrothermal vent macrofauna at a diffuse flow vent. Hourly temperatures were recorded over eight months from 2010 to 2011 at Grotto vent in the Main Endeavour vent field on the Juan de Fuca Ridge, a focus area of the Ocean Networks Canada cabled observatory. The conspicuous animal assemblages in video footage contained Ridgeia piscesae tubeworms, gastropods (primarily Lepetodrilus fucensis), and polychaetes (polynoid scaleworms and the palm worm Paralvinella palmiformis). Two dimensional spatial gradients in temperature were generally stable over the deployment period. The average temperature recorded by all arrays, and in some individual loggers, revealed distinctive fluctuations in temperature that often corresponded with the tidal cycle. We postulate that this may be related to changes in bottom currents or fluctuations in vent discharge. A marked transient temperature increase lasting over a period of days was observed in April 2011. While the distributions and behavior of Juan de Fuca Ridge vent invertebrates may be partially constrained by environmental temperature and temperature tolerance, except for the one transient high-temperature event, observed fluid temperatures were generally similar to the thermal preferences for some species, and typically well below lethal temperatures for all species. Average temperatures of the four arrays

  14. The Lassen hydrothermal system

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Bergfeld, Deborah; Clor, Laura; Evans, William C.

    2016-01-01

    The active Lassen hydrothermal system includes a central vapor-dominated zone or zones beneath the Lassen highlands underlain by ~240 °C high-chloride waters that discharge at lower elevations. It is the best-exposed and largest hydrothermal system in the Cascade Range, discharging 41 ± 10 kg/s of steam (~115 MW) and 23 ± 2 kg/s of high-chloride waters (~27 MW). The Lassen system accounts for a full 1/3 of the total high-temperature hydrothermal heat discharge in the U.S. Cascades (140/400 MW). Hydrothermal heat discharge of ~140 MW can be supported by crystallization and cooling of silicic magma at a rate of ~2400 km3/Ma, and the ongoing rates of heat and magmatic CO2 discharge are broadly consistent with a petrologic model for basalt-driven magmatic evolution. The clustering of observed seismicity at ~4–5 km depth may define zones of thermal cracking where the hydrothermal system mines heat from near-plastic rock. If so, the combined areal extent of the primary heat-transfer zones is ~5 km2, the average conductive heat flux over that area is >25 W/m2, and the conductive-boundary length <50 m. Observational records of hydrothermal discharge are likely too short to document long-term transients, whether they are intrinsic to the system or owe to various geologic events such as the eruption of Lassen Peak at 27 ka, deglaciation beginning ~18 ka, the eruptions of Chaos Crags at 1.1 ka, or the minor 1914–1917 eruption at the summit of Lassen Peak. However, there is a rich record of intermittent hydrothermal measurement over the past several decades and more-frequent measurement 2009–present. These data reveal sensitivity to climate and weather conditions, seasonal variability that owes to interaction with the shallow hydrologic system, and a transient 1.5- to twofold increase in high-chloride discharge in response to an earthquake swarm in mid-November 2014.

  15. Microbiology of ancient and modern hydrothermal systems.

    PubMed

    Reysenbach, A L; Cady, S L

    2001-02-01

    Hydrothermal systems have prevailed throughout geological history on earth, and ancient ARCHAEAN hydrothermal deposits could provide clues to understanding earth's earliest biosphere. Modern hydrothermal systems support a plethora of microorganisms and macroorganisms, and provide good comparisons for paleontological interpretation of ancient hydrothermal systems. However, all of the microfossils associated with ancient hydrothermal deposits reported to date are filamentous, and limited STABLE ISOTOPE analysis suggests that these microfossils were probably autotrophs. Therefore, the morphology and mode of carbon metabolism are attributes of microorganisms from modern hydrothermal systems that provide valuable information for interpreting the geological record using morphological and isotopic signatures.

  16. Cameras on the NEPTUNE Canada seafloor observatory: Towards monitoring hydrothermal vent ecosystem dynamics

    NASA Astrophysics Data System (ADS)

    Robert, K.; Matabos, M.; Sarrazin, J.; Sarradin, P.; Lee, R. W.; Juniper, K.

    2010-12-01

    Hydrothermal vent environments are among the most dynamic benthic habitats in the ocean. The relative roles of physical and biological factors in shaping vent community structure remain unclear. Undersea cabled observatories offer the power and bandwidth required for high-resolution, time-series study of the dynamics of vent communities and the physico-chemical forces that influence them. The NEPTUNE Canada cabled instrument array at the Endeavour hydrothermal vents provides a unique laboratory for researchers to conduct long-term, integrated studies of hydrothermal vent ecosystem dynamics in relation to environmental variability. Beginning in September-October 2010, NEPTUNE Canada (NC) will be deploying a multi-disciplinary suite of instruments on the Endeavour Segment of the Juan de Fuca Ridge. Two camera and sensor systems will be used to study ecosystem dynamics in relation to hydrothermal discharge. These studies will make use of new experimental protocols for time-series observations that we have been developing since 2008 at other observatory sites connected to the VENUS and NC networks. These protocols include sampling design, camera calibration (i.e. structure, position, light, settings) and image analysis methodologies (see communication by Aron et al.). The camera systems to be deployed in the Main Endeavour vent field include a Sidus high definition video camera (2010) and the TEMPO-mini system (2011), designed by IFREMER (France). Real-time data from three sensors (O2, dissolved Fe, temperature) integrated with the TEMPO-mini system will enhance interpretation of imagery. For the first year of observations, a suite of internally recording temperature probes will be strategically placed in the field of view of the Sidus camera. These installations aim at monitoring variations in vent community structure and dynamics (species composition and abundances, interactions within and among species) in response to changes in environmental conditions at different

  17. Aqueous Alteration of Endeavour Crater Rim Apron Rocks

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Ming, Douglas W.; Gellert, Ralf; Clark, Benton C.; Morris, Richard V.; Yen, Albert S.; Arvidson, Raymond E.; Crumpler, Larry S.; Farrand, William H.; Grant, John A.; hide

    2014-01-01

    Mars Exploration Rover Opportunity is exploring Noachian age rocks of the rim of 22 km diameter Endeavour crater. Overlying the pre-impact lithologies and rim breccias is a thin apron of fine-grained sediments, the Grasberg fm, forming annuli on the lower slopes of rim segments. Hesperian Burns fm sandstones overly the Grasberg fm. Grasberg rocks have major element compositions that are distinct from Burns fm sandstones, especially when comparing interior compositions exposed by the Rock Abrasion Tool. Grasberg rocks are also different from Endeavour rim breccias, but have general compositional similarities to them. Grasberg sediments are plausibly fine-grained materials derived from the impact breccias. Veins of CaSO4 transect Grasberg fm rocks demonstrating post-formation aqueous alteration. Minor/trace elements show variations consistent with mobilization by aqueous fluids. Grasberg fm rocks have low Mn and high Fe/Mn ratios compared to the other lithologies. Manganese likely was mobilized and removed from the Grasberg host rock by redox reactions. We posit that Fe2+ from acidic solutions associated with formation of the Burns sulfate-rich sandstones acted as an electron donor to reduce more oxidized Mn to Mn2+. The Fe contents of Grasberg rocks are slightly higher than in other rocks suggesting precipitation of Fe phases in Grasberg materials. Pancam spectra show that Grasberg rocks have a higher fraction of ferric oxide minerals than other Endeavour rim rocks. Solutions transported Mn2+ into the Endeavour rim materials and oxidized and/or precipitated it in them. Grasberg has higher contents of the mobile elements K, Zn, Cl, and Br compared to the rim materials. Similar enrichments of mobile elements were measured by the Spirit APXS on West Spur and around Home Plate in Gusev crater. Enhancements in these elements are attributed to interactions of hydrothermal acidic fluids with the host rocks. Interactions of fluids with the Grasberg fm postdate the genesis

  18. Aqueous Alteration of Endeavour Crater Rim Apron Rocks

    NASA Astrophysics Data System (ADS)

    Ming, D. W.; Mittlefehldt, D. W.; Gellert, R.; Clark, B. C.; Morris, R. V.; Yen, A. S.; Arvidson, R. E.; Crumpler, L. S.; Farrand, W. H.; Grant, J. A., III; Jolliff, B. L.; Parker, T. J.; Peretyazhko, T.

    2014-12-01

    Mars Exploration Rover Opportunity is exploring Noachian age rocks of the rim of 22 km diameter Endeavour crater. Overlying the pre-impact lithologies and rim breccias is a thin apron of fine-grained sediments, the Grasberg fm, forming annuli on the lower slopes of rim segments. Hesperian Burns fm sandstones overly the Grasberg fm. Grasberg rocks have major element compositions that are distinct from Burns fm sandstones, especially when comparing interior compositions exposed by the Rock Abrasion Tool. Grasberg rocks are also different from Endeavour rim breccias, but have general compositional similarities to them. Grasberg sediments are plausibly fine-grained materials derived from the impact breccias. Veins of CaSO4 transect Grasberg fm rocks demonstrating post-formation aqueous alteration. Minor/trace elements show variations consistent with mobilization by aqueous fluids. Grasberg fm rocks have low Mn and high Fe/Mn ratios compared to the other lithologies. Manganese likely was mobilized and removed from the Grasberg host rock by redox reactions. We posit that Fe2+ from acidic solutions associated with formation of the Burns sulfate-rich sandstones acted as an electron donor to reduce more oxidized Mn to Mn2+. The Fe contents of Grasberg rocks are slightly higher than in other rocks suggesting precipitation of Fe phases in Grasberg materials. Pancam spectra show that Grasberg rocks have a higher fraction of ferric oxide minerals than other Endeavour rim rocks. Solutions transported Mn2+ into the Endeavour rim materials and oxidized and/or precipitated it in them. Grasberg has higher contents of the mobile elements K, Zn, Cl, and Br compared to the rim materials. Similar enrichments of mobile elements were measured by the Spirit APXS on West Spur and around Home Plate in Gusev crater. Enhancements in these elements are attributed to interactions of hydrothermal acidic fluids with the host rocks. Interactions of fluids with the Grasberg fm postdate the genesis

  19. 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

  20. Dynamics of the Yellowstone hydrothermal system

    USGS Publications Warehouse

    Hurwitz, Shaul; Lowenstern, Jacob B.

    2014-01-01

    The Yellowstone Plateau Volcanic Field is characterized by extensive seismicity, episodes of uplift and subsidence, and a hydrothermal system that comprises more than 10,000 thermal features, including geysers, fumaroles, mud pots, thermal springs, and hydrothermal explosion craters. The diverse chemical and isotopic compositions of waters and gases derive from mantle, crustal, and meteoric sources and extensive water-gas-rock interaction at variable pressures and temperatures. The thermal features are host to all domains of life that utilize diverse inorganic sources of energy for metabolism. The unique and exceptional features of the hydrothermal system have attracted numerous researchers to Yellowstone beginning with the Washburn and Hayden expeditions in the 1870s. Since a seminal review published a quarter of a century ago, research in many fields has greatly advanced our understanding of the many coupled processes operating in and on the hydrothermal system. Specific advances include more refined geophysical images of the magmatic system, better constraints on the time scale of magmatic processes, characterization of fluid sources and water-rock interactions, quantitative estimates of heat and magmatic volatile fluxes, discovering and quantifying the role of thermophile microorganisms in the geochemical cycle, defining the chronology of hydrothermal explosions and their relation to glacial cycles, defining possible links between hydrothermal activity, deformation, and seismicity; quantifying geyser dynamics; and the discovery of extensive hydrothermal activity in Yellowstone Lake. Discussion of these many advances forms the basis of this review.

  1. Endeavour Payload Bay

    NASA Image and Video Library

    2010-02-20

    S130-E-012478 (20 Feb. 2010) --- Backdropped by Earth?s horizon and the blackness of space, a partial view of space shuttle Endeavour's payload bay, vertical stabilizer, orbital maneuvering system (OMS) pods, Remote Manipulator System/Orbiter Boom Sensor System (RMS/OBSS) and docking mechanism are featured in this image photographed by an STS-130 crew member from an aft flight deck window.

  2. Evolution of fine scale segmentation at intermediate ridges: example of Alarcon Rise and Endeavour Segment.

    NASA Astrophysics Data System (ADS)

    Le Saout, M.; Clague, D. A.; Paduan, J. B.; Caress, D. W.

    2016-12-01

    Mid-ocean ridges are marked by a segmentation of the axis and underlying magmatic system. Fine-scale segmentation is mainly studied along fast spreading ridges. Here we analyze the evolution of the 3rd and 4th order segmentation along two intermediate spreading centers, characterized by contrasting morphologies. Alarcon Rise, with a full spreading rate of 49 mm/yr, is characterized by an axial high and a relatively narrow axial summit trough. Endeavour segment has a spreading rate of 52.5 mm/yr and is represented by a wide axial valley affected by numerous faults. These two ridges are characterized by high and low volcanic periods, respectively. The segmentation is analyzed using high-resolution bathymetric cross-sections perpendicular to the axes. These profiles are 1200-m-long for Alarcon Rise and 2400-m-long at Endeavour Segment and are 100 m apart. The discontinuity order is based on variations, from either side of each offset, in: 1/the geometry and orientation of the axial summit trough or graben 2/ the lava morphology, and 3/ the distribution of hydrothermal vents. Alarcon Rise is marked by a recent southeast jump in volcanic activity. The comparison between actual and previous segmentation reveals a rapid evolution of the 3rd order segmentation in the most active part of the ridge, with a lengthening of the central 3rd segment of 8 km over 3-4 ky. However, no relation is observed in the 4th order segmentation before and after the axis jump. Along Endeavour, traces of the previous 3rd order discontinuities are still perceptible on the walls of the graben. This 3rd order segmentation has persisted at least during the last 4.5 ky. Indeed, it is visible in the distribution of the recent hydrothermal vents observed in the axial valley as well as in the segmentation of the axial magma lens. Analysis of the two ridges suggests that small-scale segmentation varies primarily during high magmatic phases.

  3. Ancient impact and aqueous processes at Endeavour Crater, Mars

    USGS Publications Warehouse

    Squyres, S. W.; Arvidson, R. E.; Bell, J.F.; Calef, F.J.; Clark, B. C.; Cohen, B. A.; Crumpler, L.A.; de Souza, P. A.; Farrand, W. H.; Gellert, Ralf; Grant, J.; Herkenhoff, K. E.; Hurowitz, J.A.; Johnson, J. R.; Jolliff, B.L.; Knoll, A.H.; Li, R.; McLennan, S.M.; Ming, D. W.; Mittlefehldt, D. W.; Parker, T.J.; Paulsen, G.; Rice, M.S.; Ruff, S.W.; Schröder, C.; Yen, A. S.; Zacny, K.

    2012-01-01

    The rover Opportunity has investigated the rim of Endeavour Crater, a large ancient impact crater on Mars. Basaltic breccias produced by the impact form the rim deposits, with stratigraphy similar to that observed at similar-sized craters on Earth. Highly localized zinc enrichments in some breccia materials suggest hydrothermal alteration of rim deposits. Gypsum-rich veins cut sedimentary rocks adjacent to the crater rim. The gypsum was precipitated from low-temperature aqueous fluids flowing upward from the ancient materials of the rim, leading temporarily to potentially habitable conditions and providing some of the waters involved in formation of the ubiquitous sulfate-rich sandstones of the Meridiani region.

  4. Cabled-observatory Regional Circulation Moorings on the Endeavour segment of the Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Mihaly, S. F.

    2011-12-01

    In September of 2010, one of four moorings was deployed on the Endeavour node of the NEPTUNE Canada cabled-observatory network. The installation included the laying of a 7km cable from the node to the mooring site in the axial valley about 3km north of the Main Endeavour Vent Field over extraordinary bathymetry. This September, three more cables and secondary junction boxes will be deployed to support the three additional moorings that complete the regional circulation array. The cable-laying is facilitated by the Canadian Scientific Submersible Facility's ROV ROPOS and a remotely operated cable-laying system, whereas the actual deployment of the moorings is a two ship operation. The CCGS John P. Tully lowers the mooring anchor first, while the RV Thomas G. Thompson supports the ROV operations which navigate the mooring to underwater mateable cable end. Precise navigation is needed because there are few areas suitable for placement of the junction boxes. Scientifically, the moorings are designed and located to best constrain the hydrothermally driven circulation within the rift valley, the regional circulation can then be used as a proxy measurement for hydrothermal fluxes. Each mooring carries a current meter/ ctd pair at 4, 50, 125, and 200m, with an upward looking ADCP at 250m. The northern moorings are located between the Hi-Rise and Salty Dawg fields about 700m apart in the ~1km wide rift valley and the southern moorings are located south of the Mothra vent field. Here we present initial results from the four mooring array.

  5. Fungal colonization of an Ordovician impact-induced hydrothermal system

    PubMed Central

    Ivarsson, Magnus; Broman, Curt; Sturkell, Erik; Ormö, Jens; Siljeström, Sandra; van Zuilen, Mark; Bengtson, Stefan

    2013-01-01

    Impacts are common geologic features on the terrestrial planets throughout the solar system, and on at least Earth and Mars impacts have induced hydrothermal convection. Impact-generated hydrothermal systems have been suggested to possess the same life supporting capability as hydrothermal systems associated with volcanic activity. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is scarce in the literature. Here we report of fossilized microorganisms in association with cavity-grown hydrothermal minerals from the 458 Ma Lockne impact structure, Sweden. Based on morphological characteristics the fossilized microorganisms are interpreted as fungi. We further infer the kerogenization of the microfossils, and thus the life span of the fungi, to be contemporaneous with the hydrothermal activity and migration of hydrocarbons in the system. Our results from the Lockne impact structure show that hydrothermal systems associated with impact structures can support colonization by microbial life. PMID:24336641

  6. Fungal colonization of an Ordovician impact-induced hydrothermal system

    NASA Astrophysics Data System (ADS)

    Ivarsson, Magnus; Broman, Curt; Sturkell, Erik; Ormö, Jens; Siljeström, Sandra; van Zuilen, Mark; Bengtson, Stefan

    2013-12-01

    Impacts are common geologic features on the terrestrial planets throughout the solar system, and on at least Earth and Mars impacts have induced hydrothermal convection. Impact-generated hydrothermal systems have been suggested to possess the same life supporting capability as hydrothermal systems associated with volcanic activity. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is scarce in the literature. Here we report of fossilized microorganisms in association with cavity-grown hydrothermal minerals from the 458 Ma Lockne impact structure, Sweden. Based on morphological characteristics the fossilized microorganisms are interpreted as fungi. We further infer the kerogenization of the microfossils, and thus the life span of the fungi, to be contemporaneous with the hydrothermal activity and migration of hydrocarbons in the system. Our results from the Lockne impact structure show that hydrothermal systems associated with impact structures can support colonization by microbial life.

  7. Fungal colonization of an Ordovician impact-induced hydrothermal system.

    PubMed

    Ivarsson, Magnus; Broman, Curt; Sturkell, Erik; Ormö, Jens; Siljeström, Sandra; van Zuilen, Mark; Bengtson, Stefan

    2013-12-16

    Impacts are common geologic features on the terrestrial planets throughout the solar system, and on at least Earth and Mars impacts have induced hydrothermal convection. Impact-generated hydrothermal systems have been suggested to possess the same life supporting capability as hydrothermal systems associated with volcanic activity. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is scarce in the literature. Here we report of fossilized microorganisms in association with cavity-grown hydrothermal minerals from the 458 Ma Lockne impact structure, Sweden. Based on morphological characteristics the fossilized microorganisms are interpreted as fungi. We further infer the kerogenization of the microfossils, and thus the life span of the fungi, to be contemporaneous with the hydrothermal activity and migration of hydrocarbons in the system. Our results from the Lockne impact structure show that hydrothermal systems associated with impact structures can support colonization by microbial life.

  8. Organic synthesis during fluid mixing in hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Shock, Everett L.; Schulte, Mitchell D.

    1998-12-01

    Hydrothermal circulation can lead to fluid mixing on any planet with liquid water and a source of heat. Aqueous fluids with differing compositions, especially different oxidation states, are likely to be far from thermodynamic equilibrium when they mix, and provide a source of free energy that can drive organic synthesis from CO2 and H2, and/or supply a source of geochemical energy to chemolithoautotrophic organisms. Results are presented that quantify the potential for organic synthesis during unbuffered fluid mixing in present submarine hydrothermal systems, as well as hypothetical systems that may have existed on the early Earth and Mars. Dissolved hydrogen, present in submarine hydrothermal fluids owing to the high-temperature reduction of H2O as seawater reacts with oceanic crustal rocks, provides the reduction potential and the thermodynamic drive for organic synthesis from CO2 (or bicarbonate) as hydrothermal fluids mix with seawater. The potential for organic synthesis is a strong function of the H2 content of the hydrothermal fluid, which is, in turn, a function of the prevailing oxidation state controlled by the composition of the rock that hosts the hydrothermal system. Hydrothermal fluids with initial oxidation states at or below those set by the fayalite-magnetite-quartz mineral assemblage show the greatest potential for driving organic synthesis. These calculations show that it is thermodynamically possible for 100% of the carbon in the mixed fluid to be reduced to a mixture of carboxylic acids, alcohols, and ketones in the range 250-50°C as cold seawater mixes with the hydrothermal fluid. As the temperature drops, larger organic molecules are favored, which implies that fluid mixing could drive the geochemical equivalent of a metabolic system. This enormous reduction potential probably drives a large portion of the primary productivity around present seafloor hydrothermal vents and would have been present in hydrothermal systems on the early Earth

  9. Hydrothermal systems as environments for the emergence of life

    NASA Technical Reports Server (NTRS)

    Shock, E. L.

    1996-01-01

    Analysis of the chemical disequilibrium provided by the mixing of hydrothermal fluids and seawater in present-day systems indicates that organic synthesis from CO2 or carbonic acid is thermodynamically favoured in the conditions in which hyperthermophilic microorganisms are known to live. These organisms lower the Gibbs free energy of the chemical mixture by synthesizing many of the components of their cells. Primary productivity is enormous in hydrothermal systems because it depends only on catalysis of thermodynamically favourable, exergonic reactions. It follows that hydrothermal systems may be the most favourable environments for life on Earth. This fact makes hydrothermal systems logical candidates for the location of the emergence of life, a speculation that is supported by genetic evidence that modern hyperthermophilic organisms are closer to a common ancestor than any other forms of life. The presence of hydrothermal systems on the early Earth would correspond to the presence of liquid water. Evidence that hydrothermal systems existed early in the history of Mars raises the possibility that life may have emerged on Mars as well. Redox reactions between water and rock establish the potential for organic synthesis in and around hydrothermal systems. Therefore, the single most important parameter for modelling the geochemical emergence of life on the early Earth or Mars is the composition of the rock which hosts the hydrothermal system.

  10. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    A space shuttle main engine (SSME) is on display near the space shuttle Endeavour at the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  11. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    The space shuttle Endeavour is seen as workers prepare for the grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  12. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    California Governor Jerry Brown speaks from a podium underneath the space shuttle Endeavour during the grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  13. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    A police officer is seen underneath the wing of the space shuttle Endeavour during the grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  14. Endeavour Arival LAX

    NASA Image and Video Library

    2012-09-21

    Spectators look to the sky with cameras and other devices as the space shuttle Endeavour flies over prior to landing Friday, Sept. 21, 2012, at Los Angeles International Airport. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Paul E. Alers)

  15. Endeavour Arival LAX

    NASA Image and Video Library

    2012-09-21

    A U.S. Flag is flown out of the top of the Suttle Carrier Aircaft (SCA) as it taxis with space shuttle Endeavour atop Friday, Sept. 21, 2012, at Los Angeles International Airport. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Paul E. Alers)

  16. Endeavour Arival LAX

    NASA Image and Video Library

    2012-09-21

    NASA Deputy Administrator Lori Garver, right, holds her hand to her heart during the playing of the National Anthem at the welcoming ceremony for space shuttle Endeavour, Friday, Sept. 21, 2012, at Los Angeles International Airport. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Paul E. Alers)

  17. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    Vocalist James Ingram sings "I Believe I Can Fly" from underneath the space shuttle Endeavour during the grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  18. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    David D. McBride, director of NASA's Dryden Flight Research Center, speaks from a podium underneath the space shuttle Endeavour during the grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  19. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    President and CEO of the California Science Center Jeffrey N. Rudolph speaks from a podium underneath the space shuttle Endeavour during the grand opening ceremony for the center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  20. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    Chief Executive Officer of the Planetary Society, Bill Nye "The Science Guy", acts as emcee from a podium underneath the space shuttle Endeavour during the grand opening ceremony for the center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  1. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    Tires from space shuttle Endeavour's final flight are on display at the California Science Center's, California Experience gallery, Tuesday, Oct. 30, 2012, in Los Angeles. The grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion took place on Tuesday, Oct. 30, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  2. Peptide synthesis in early earth hydrothermal systems

    USGS Publications Warehouse

    Lemke, K.H.; Rosenbauer, R.J.; Bird, D.K.

    2009-01-01

    We report here results from experiments and thermodynamic calculations that demonstrate a rapid, temperature-enhanced synthesis of oligopeptides from the condensation of aqueous glycine. Experiments were conducted in custom-made hydrothermal reactors, and organic compounds were characterized with ultraviolet-visible procedures. A comparison of peptide yields at 260??C with those obtained at more moderate temperatures (160??C) gives evidence of a significant (13 kJ ?? mol-1) exergonic shift. In contrast to previous hydrothermal studies, we demonstrate that peptide synthesis is favored in hydrothermal fluids and that rates of peptide hydrolysis are controlled by the stability of the parent amino acid, with a critical dependence on reactor surface composition. From our study, we predict that rapid recycling of product peptides from cool into near-supercritical fluids in mid-ocean ridge hydrothermal systems will enhance peptide chain elongation. It is anticipated that the abundant hydrothermal systems on early Earth could have provided a substantial source of biomolecules required for the origin of life. Astrobiology 9, 141-146. ?? 2009 Mary Ann Liebert, Inc. 2009.

  3. Hydrothermal mineralising systems as critical systems

    NASA Astrophysics Data System (ADS)

    Hobbs, Bruce

    2015-04-01

    Hydrothermal mineralising systems as critical systems. Bruce E Hobbs1,2, Alison Ord1 and Mark A. Munro1. 1. Centre for Exploration Targeting, The University of Western Australia, M006, 35 Stirling Highway, Crawley, WA 6009, Australia. 2. CSIRO Earth and Resource Engineering, Bentley, WA, Australia Hydrothermal mineralising systems are presented as large, open chemical reactors held far from equilibrium during their life-time by the influx of heat, fluid and dissolved chemical species. As such they are nonlinear dynamical systems and need to be analysed using the tools that have been developed for such systems. Hydrothermal systems undergo a number of transitions during their evolution and this paper focuses on methods for characterising these transitions in a quantitative manner and establishing whether they resemble first or second (critical) phase transitions or whether they have some other kind of nature. Critical phase transitions are characterised by long range correlations for some parameter characteristic of the system, power-law probability distributions so that there is no characteristic length scale and a high sensitivity to perturbations; as one approaches criticality, characteristic parameters for the system scale in a power law manner with distance from the critical point. The transitions undergone in mineralised hydrothermal systems are: (i) widespread, non-localised mineral alteration involving exothermic mineral reactions that produce hydrous silicate phases, carbonates and iron-oxides, (ii) strongly localised veining, brecciation and/or stock-work formation, (iii) a series of endothermic mineral reactions involving the formation of non-hydrous silicates, sulphides and metals such as gold, (iv) multiple repetitions of transitions (ii) and (iii). We have quantified aspects of these transitions in gold deposits from the Yilgarn craton of Western Australia using wavelet transforms. This technique is convenient and fast. It enables one to establish if

  4. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    The space shuttle Endeavour is seen as it traverses through Inglewood, Calif. on Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  5. Endeavour lands atop 747 after downtime at Palmdale, CA

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Space Shuttle Orbiter Endeavour arrives at KSCs Shuttle Landing Facility atop NASAs Boeing 747 Shuttle Carrier Aircraft (SCA) as it returns March 27, 1997 from Palmdale, Calif., after an eight-month Orbiter Maintenance Down Period (OMDP). Nearly 100 modifications were made to Endeavour during that time period, including some that were directly associated with work required to support International Space Station Operations. The most extensive of those was the installation of an external airlock to allow the orbiter to dock with the Station. Other modifications included upgrades to Endeavours power supply system, general purpose computers and thermal protection system, along with the installation of new light-weight commander and pilot seats and other weight-saving modifications.

  6. Endeavour Lands at LAX

    NASA Image and Video Library

    2012-09-21

    Space shuttle Endeavour, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) performs a low flyby at Los Angeles International Airport, Friday, Sept. 21, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Bill Ingalls)

  7. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    Spectators watch space shuttle Endeavour as it passes by on its way to its new home at the California Science Center in Los Angeles, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  8. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    The space shuttle Endeavour is seen as it traverses through the streest of Los Angeles on its way to its new home at the California Science Center, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  9. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    A spectator photographs the space shuttle Endeavour as it passes by on its way to its new home at the California Science Center in Los Angeles, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  10. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    A spectator is seen photographing the space shuttle Endeavour as it is moved to its new home at the California Science Center in Los Angeles, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC’s Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

  11. Endeavour Lands at LAX

    NASA Image and Video Library

    2012-09-21

    Space shuttle Endeavour, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) performs a low flyby past the tower at Los Angeles International Airport, Friday, Sept. 21, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Bill Ingalls)

  12. Endeavour Lands at LAX

    NASA Image and Video Library

    2012-09-21

    Space shuttle Endeavour, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) lands at Los Angeles International Airport, Friday, Sept. 21, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Bill Ingalls)

  13. Endeavour Lands at LAX

    NASA Image and Video Library

    2012-09-21

    Space shuttle Endeavour, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) performs a flyby of the Theme Building at Los Angeles International Airport, Friday, Sept. 21, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Scott Andrews)

  14. Thermohydrodynamic model: Hydrothermal system, shallowly seated magma chamber

    NASA Astrophysics Data System (ADS)

    Kiryukhin, A. V.

    1985-02-01

    The results of numerical modeling of heat exchange in the Hawaiian geothermal reservoir demonstrate the possibility of appearance of a hydrothermal system over a magma chamber. This matter was investigated in hydrothermal system. The equations for the conservation of mass and energy are discussed. Two possible variants of interaction between the magma chamber and the hydrothermal system were computated stationary dry magma chamber and dry magma chamber changing volume in dependence on the discharge of magma and taking into account heat exchange with the surrounding rocks. It is shown that the thermal supplying of the hydrothermal system can be ensured by the extraction of heat from a magma chamber which lies at a depth of 3 km and is melted out due to receipt of 40 cubic km of basalt melt with a temperature of 1,300 C. The initial data correspond with computations made with the model to the temperature values in the geothermal reservoir and a natural heat transfer comparable with the actually observed values.

  15. The Biogeochemistry of Sulfur in Hydrothermal Systems

    NASA Technical Reports Server (NTRS)

    Schulte, Mitchell; Rogers, K. L.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. Understanding how sulfur became prevalent in biochemical processes and many biomolecules requires knowledge of the reaction properties of sulfur-bearing compounds. We have previously estimated thermodynamic data for thiols, the simplest organic sulfur compounds, at elevated temperatures and pressures. If life began in hydrothermal environments, it is especially important to understand reactions at elevated temperatures among sulfur-bearing compounds and other organic molecules essential for the origin and persistence of life. Here we examine reactions that may have formed amino acids with thiols as reaction intermediates in hypothetical early Earth hydrothermal environments. (There are two amino acids, cysteine and methionine, that contain sulfur.) Our calculations suggest that significant amounts of some amino acids were produced in early Earth hydrothermal fluids, given reasonable concentrations H2, NH3, H2S and CO. For example, preliminary results indicate that glycine activities as high as 1 mmol can be reached in these systems at 100 C. Alanine formation from propanethiol is also a favorable reaction. On the other hand, the calculated equilibrium log activities of cysteine and serine from propanethiol are -21 and -19, respectively, at 100 C. These results

  16. Hydrothermal systems in small ocean planets.

    PubMed

    Vance, Steve; Harnmeijer, Jelte; Kimura, Jun; Hussmann, Hauke; Demartin, Brian; Brown, J Michael

    2007-12-01

    We examine means for driving hydrothermal activity in extraterrestrial oceans on planets and satellites of less than one Earth mass, with implications for sustaining a low level of biological activity over geological timescales. Assuming ocean planets have olivine-dominated lithospheres, a model for cooling-induced thermal cracking shows how variation in planet size and internal thermal energy may drive variation in the dominant type of hydrothermal system-for example, high or low temperature system or chemically driven system. As radiogenic heating diminishes over time, progressive exposure of new rock continues to the current epoch. Where fluid-rock interactions propagate slowly into a deep brittle layer, thermal energy from serpentinization may be the primary cause of hydrothermal activity in small ocean planets. We show that the time-varying hydrostatic head of a tidally forced ice shell may drive hydrothermal fluid flow through the seafloor, which can generate moderate but potentially important heat through viscous interaction with the matrix of porous seafloor rock. Considering all presently known potential ocean planets-Mars, a number of icy satellites, Pluto, and other trans-neptunian objects-and applying Earth-like material properties and cooling rates, we find depths of circulation are more than an order of magnitude greater than in Earth. In Europa and Enceladus, tidal flexing may drive hydrothermal circulation and, in Europa, may generate heat on the same order as present-day radiogenic heat flux at Earth's surface. In all objects, progressive serpentinization generates heat on a globally averaged basis at a fraction of a percent of present-day radiogenic heating and hydrogen is produced at rates between 10(9) and 10(10) molecules cm(2) s(1).

  17. Endeavour backdropped against space with Sun displaying rayed effect

    NASA Image and Video Library

    1993-12-09

    STS061-105-024 (2-13 Dec. 1993) --- One of Endeavour's space walkers captured this view of Endeavour backdropped against the blackness of space, with the Sun displaying a rayed effect. The extended Remote Manipulator System (RMS) arm that the astronaut was standing on is seen on the left side of the view.

  18. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    The driver of the Over Land Transporter is seen as he maneuvers the space shuttle Endeavour on the streets of Los Angeles as it heads to its new home at the California Science Center, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC’s Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

  19. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    Spectators are seen as they watch space shuttle Endeavour as it passes by on its way to its new home at the California Science Center in Los Angeles, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  20. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    The driver of the Over Land Transporter (OLT) is seen as he maneuvers the space shuttle Endeavour on the streets of Los Angeles as it heads to its new home at the California Science Center, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  1. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    A spectator on the roof of a building photographs space shuttle Endeavour as it passes by on its way to its new home at the California Science Center in Los Angeles, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC’s Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  2. Endeavour Lands at LAX

    NASA Image and Video Library

    2012-09-21

    Space shuttle Endeavour, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) lands at Los Angeles International Airport, Friday, Sept. 21, 2012. The shadow of a NASA F-18 chase jet wing is shown in the foreground. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers.Photo Credit: (NASA/Bill Ingalls)

  3. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    The space shuttle Endeavour moves out of the Los Angeles International Airport and onto the streets of Los Angeles to make its way to its new home at the California Science Center, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  4. Hydrothermal systems and volcano geochemistry

    USGS Publications Warehouse

    Fournier, R.O.

    2007-01-01

    The upward intrusion of magma from deeper to shallower levels beneath volcanoes obviously plays an important role in their surface deformation. This chapter will examine less obvious roles that hydrothermal processes might play in volcanic deformation. Emphasis will be placed on the effect that the transition from brittle to plastic behavior of rocks is likely to have on magma degassing and hydrothermal processes, and on the likely chemical variations in brine and gas compositions that occur as a result of movement of aqueous-rich fluids from plastic into brittle rock at different depths. To a great extent, the model of hydrothermal processes in sub-volcanic systems that is presented here is inferential, based in part on information obtained from deep drilling for geothermal resources, and in part on the study of ore deposits that are thought to have formed in volcanic and shallow plutonic environments.

  5. Microbial processing of carbon in hydrothermal systems (Invited)

    NASA Astrophysics Data System (ADS)

    LaRowe, D.; Amend, J. P.

    2013-12-01

    Microorganisms are known to be active in hydrothermal systems. They catalyze reactions that consume and produce carbon compounds as a result of their efforts to gain energy, grow and replace biomass. However, the rates of these processes, as well as the size of the active component of microbial populations, are poorly constrained in hydrothermal environments. In order to better characterize biogeochemical processes in these settings, a quantitative relationship between rates of microbial catalysis, energy supply and demand and population size is presented. Within this formulation, rates of biomass change are determined as a function of the proportion of catabolic power that is converted into biomass - either new microorganisms or the replacement of existing cell components - and the amount of energy that is required to synthesize biomass. The constraints that hydrothermal conditions place on power supply and demand are explicitly taken into account. The chemical composition, including the concentrations of organic compounds, of diffuse and focused flow hydrothermal fluids, hydrothermally influenced sediment pore water and fluids from the oceanic lithosphere are used in conjunction with cell count data and the model described above to constrain the rates of microbial processes that influence the carbon cycle in the Juan de Fuca hydrothermal system.

  6. Thermodynamics of Strecker synthesis in hydrothermal systems

    NASA Technical Reports Server (NTRS)

    Schulte, Mitchell; Shock, Everett

    1995-01-01

    Submarine hydrothermal systems on the early Earth may have been the sites from which life emerged. The potential for Strecker synthesis to produce biomolecules (amino and hydroxy acids) from starting compounds (ketones, aldehydes, HCN and ammonia) in such environments is evaluated quantitatively using thermodynamic data and parameters for the revised Helgeson-Kirkham-Flowers (HKF) equation of state. Although there is an overwhelming thermodynamic drive to form biomolecules by the Strecker synthesis at hydrothermal conditions, the availability and concentration of starting compounds limit the efficiency and productivity of Strecker reactions. Mechanisms for concentrating reactant compounds could help overcome this problem, but other mechanisms for production of biomolecules may have been required to produce the required compounds on the early Earth. Geochemical constraints imposed by hydrothermal systems provide important clues for determining the potential of these and other systems as sites for the emergence of life.

  7. Electrochemistry of Prebiotic Early Earth Hydrothermal Chimney Systems

    NASA Astrophysics Data System (ADS)

    Hermis, N.; Barge, L. M.; Chin, K. B.; LeBlanc, G.; Cameron, R.

    2017-12-01

    Hydrothermal chimneys are self-organizing chemical garden precipitates generated from geochemical disequilibria within sea-vent environments, and have been proposed as a possible setting for the emergence of life because they contain mineral catalysts and transect ambient pH / Eh / chemical gradients [1]. We simulated the growth of hydrothermal chimneys in early Earth vent systems by using different hydrothermal simulants such as sodium sulfide (optionally doped with organic molecules) which were injected into an early Earth ocean simulant containing dissolved ferrous iron, nickel, and bicarbonate [2]. Chimneys on the early Earth would have constituted flow-through reactors, likely containing Fe/Ni-sulfide catalysts that could have driven proto-metabolic electrochemical reactions. The electrochemical activity of the chimney system was characterized non-invasively by placing electrodes at different locations across the chimney wall and in the ocean to analyze the bulk properties of surface charge potential in the chimney / ocean / hydrothermal fluid system. We performed in-situ characterization of the chimney using electrochemical impedance spectroscopy (EIS) which allowed us to observe the changes in physio-chemical behavior of the system through electrical spectra of capacitance and impedance over a wide range of frequencies during the metal sulfide chimney growth. The electrochemical properties of hydrothermal chimneys in natural systems persist due to the disequilibria maintained between the ocean and hydrothermal fluid. When the injection in our experiment (analogous to fluid flow in a vent) stopped, we observed a corresponding decline in open circuit voltage across the chimney wall, though the impedance of the precipitate remained lor. Further work is needed to characterize the electrochemistry of simulated chimney systems by controlling response factors such as electrode geometry and environmental conditions, in order to simulate electrochemical reactions

  8. Numerical simulation of magmatic hydrothermal systems

    USGS Publications Warehouse

    Ingebritsen, S.E.; Geiger, S.; Hurwitz, S.; Driesner, T.

    2010-01-01

    The dynamic behavior of magmatic hydrothermal systems entails coupled and nonlinear multiphase flow, heat and solute transport, and deformation in highly heterogeneous media. Thus, quantitative analysis of these systems depends mainly on numerical solution of coupled partial differential equations and complementary equations of state (EOS). The past 2 decades have seen steady growth of computational power and the development of numerical models that have eliminated or minimized the need for various simplifying assumptions. Considerable heuristic insight has been gained from process-oriented numerical modeling. Recent modeling efforts employing relatively complete EOS and accurate transport calculations have revealed dynamic behavior that was damped by linearized, less accurate models, including fluid property control of hydrothermal plume temperatures and three-dimensional geometries. Other recent modeling results have further elucidated the controlling role of permeability structure and revealed the potential for significant hydrothermally driven deformation. Key areas for future reSearch include incorporation of accurate EOS for the complete H2O-NaCl-CO2 system, more realistic treatment of material heterogeneity in space and time, realistic description of large-scale relative permeability behavior, and intercode benchmarking comparisons. Copyright 2010 by the American Geophysical Union.

  9. The hydrothermal evolution of the Kawerau geothermal system, New Zealand

    NASA Astrophysics Data System (ADS)

    Milicich, S. D.; Chambefort, I.; Wilson, C. J. N.; Charlier, B. L. A.; Tepley, F. J.

    2018-03-01

    Hydrothermal alteration zoning and processes provide insights into the evolution of heat source(s) and fluid compositions associated with geothermal systems. Traditional petrological techniques, combined with hydrothermal alteration studies, stable isotope analyses and geochronology can resolve the nature of the fluids involved in hydrothermal processes and their changes through time. We report here new findings along with previous unpublished works on alteration patterns, fluid inclusion measurements and stable isotope data to provide insights into the thermal and chemical evolution of the Kawerau geothermal system, New Zealand. These data indicate the presence of two hydrothermal events that can be coupled with chronological data. The earlier period of hydrothermal activity was initiated at 400 ka, with the heat driving the hydrothermal system inferred to be from the magmatic system that gave rise to rhyolite lavas and sills of the Caxton Formation. Isotopic data fingerprint fluids attributed to this event as meteoric, indicating that the magma primarily served as a heat source driving fluid circulation, and was not releasing magmatic fluids in sufficient quantity to affect the rock mineralogy and thus inferred fluid compositions. The modern Kawerau system was initiated at 16 ka with hydrothermal eruptions linked to shallow intrusion of magma at the onset of activity that gave rise to the Putauaki andesite cone. Likely associated with this later event was a pulse of magmatic CO2, resulting in large-scale deposition of hydrothermal calcite enriched in 18O. Meteoric water-dominated fluids subsequently overwhelmed the magmatic fluids associated with this 18O-rich signature, and both the fluid inclusion microthermometry and stable isotope data reflect a change to the present-day fluid chemistry of low salinity, meteoric-dominated waters.

  10. Geochemical constraints on chemolithoautotrophic reactions in hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Shock, Everett L.; McCollom, Thomas; Schulte, Mitchell D.

    1995-06-01

    Thermodynamic calculations provide the means to quantify the chemical disequilibrium inherent in the mixing of redeuced hydrothermal fluids with seawater. The chemical energy available for metabolic processes in these environments can be evaluated by taking into account the pressure and temperature dependence of the apparent standard Gibbs free energies of reactions in the S-H2-H2O system together with geochemical constraints on pH, activities of aqueous sulfur species and fugacities of H2 and/or O2. Using present-day mixing of hydrothermal fluids and seawater as a starting point, it is shown that each mole of H2S entering seawater from hydrothermal fluids represents about 200,000 calories of chemical energy for metabolic systems able to catalyze H2S oxidation. Extrapolating to the early Earth, which was likely to have had an atmosphere more reduced than at present, shows that this chemical energy may have been a factor of two or so less. Nevertheless, mixing of hydrothermal fluids with seawater would have been an abundant source of chemical energy, and an inevitable consequence of the presence of an ocean on an initially hot Earth. The amount of energy available was more than enough for organic synthesis from CO2 or CO, and/or polymer formation, indicating that the vicinity of hydrothermal systems at the sea floor was an ideal location for the emergence of the first chemolithoautotrophic metabolic systems.

  11. Geochemical constraints on chemolithoautotrophic reactions in hydrothermal systems

    NASA Technical Reports Server (NTRS)

    Shock, Everett L.; Mccollom, Thomas; Schulte, Mithell D.

    1995-01-01

    Thermodynamic calculations provide the means to quantify the chemical disequilibrium inherent in the mixing of reduced hydrothermal fluids with seawater. The chemical energy available for metabolic processes in these environments can be evaluated by taking into account the pressure and temperature dependence of the apparent standard Gibbs free energies of reactions in the S-H2-H2O system together with geochemical constraints on pH, activities of aqueous sulfur species and fugacities of H2 and/or O2. Using present-day mixing of hydrothermal fluids and seawater as a starting point, it is shown that each mole of H2S entering seawater from hydrothermal fluids represents about 200,000 calories of chemical energy for metabolic systems able to catalyze H2S oxidation. Extrapolating to the early Earth, which was likely to have had an atmosphere more reduced than at present, shows that this chemical energy may have been a factor of two or so less. Nevertheless, mixing of hydrothermal fluids with seawater would have been an abundant source of chemical energy, and an inevitable consequence of the presence of an ocean on an initially hot Earth. The amount of energy available was more than enough for organic synthesis from CO2 or CO, and/or polymer formation, indicating that the vicinity of hydrothermal systems at the sea floor was an ideal location for the emergence of the first chemolithoautotrophic metabolic systems.

  12. YELLOWSTONE MAGMATIC-HYDROTHERMAL SYSTEM, U. S. A.

    USGS Publications Warehouse

    Fournier, R.O.; Pitt, A.M.; ,

    1985-01-01

    At Yellowstone National Park, the deep permeability and fluid circulation are probably controlled and maintained by repeated brittle fracture of rocks in response to local and regional stress. Focal depths of earthquakes beneath the Yellowstone caldera suggest that the transition from brittle fracture to quasi-plastic flow takes place at about 3 to 4 km. The maximum temperature likely to be attained by the hydrothermal system is 350 to 450 degree C, the convective thermal output is about 5. 5 multiplied by 10**9 watts, and the minimum average thermal flux is about 1800 mW/m**2 throughout 2,500 km**2. The average thermal gradient between the heat source and the convecting hydrothermal system must be at least 700 to 1000 degree C/km. Crystallization and partial cooling of about 0. 082 km**3 of basalt or 0. 10 km**3 of rhyolite annually could furnish the heat discharged in the hot-spring system. The Yellowstone magmatic-hydrothermal system as a whole appears to be cooling down, in spite of a relatively large rate of inflation of the Yellowstone caldera.

  13. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    Mayor of Los Angeles Antonio Villaraigosa addresses a class of fourth graders during the grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  14. Current Research at the Endeavour Ridge 2000 Integrated Studies Site

    NASA Astrophysics Data System (ADS)

    Butterfield, D. A.; Kelley, D. S.; Ridge 2000 Community, R.

    2004-12-01

    investigations at MEF, Mothra, Sasquatch, and Middle Valley, collecting fluid, particle, and animal samples for culture and phylogenetic analysis. al Tiburon continued in late August/September with detailed petrological sampling. A Keck-sponsored al Thompson/ROPOS cruise in September continued work on chemical/physical sensor deployments and time-series chemical and microbial sampling. A graduate student workshop at Friday Harbor beginning October 2004 will analyze the first year of data from the seismic network and begin to correlate seismic activity with hydrothermal activity. The Endeavour ISS is still in a phase of data collection and sensor development, but moving toward data integration.

  15. STS-49 Endeavour/Intelsat Briefing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Lak Virdee of Intelsat, summarizes Intelsat's role in the STS-49 Endeavour mission. He discusses the reboost hardware, giving details on the capture arm and docker adapter assembly. He describes the rendezvous between Intelsat and the Endeavour Orbiter. Mr. Virdee then answers questions from the press.

  16. Space Shuttle Endeavour STS-134

    NASA Image and Video Library

    2011-04-29

    An faint profile outline of the space shuttle Endeavour is seen projected in the sky as powerful xenon lights illuminate launch pad 39a shortly after the rollback of the Rotating Service Structure (RSS) from Endeavour, Thursday, April 28, 2011, at Kennedy Space Center in Cape Canaveral, Fla. During the 14-day mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Launch is targeted for Friday, April 29 at 3:47 p.m. EDT. Photo credit: (NASA/Bill Ingalls)

  17. View of STS-100 orbiter Endeavour approaching for docking

    NASA Image and Video Library

    2001-04-21

    ISS002-E-5876 (21 April 2001) --- A distant view of the Space Shuttle Endeavour preparing to dock with the International Space Station (ISS) during the STS-100 mission. The STS-100 crewmembers are delivering the Canadarm2, Space Station Remote Manipulator System (SSRMS), and equipment stowed in the Multipurpose Logistics Module (MPLM) Raphaello to the ISS which are visible in Endeavour's payload bay. The image was taken with a digital still camera.

  18. View of STS-100 orbiter Endeavour approaching for docking

    NASA Image and Video Library

    2001-04-21

    ISS002-E-5887 (21 April 2001) --- A view of the Space Shuttle Endeavour preparing to dock with the International Space Station (ISS) during the STS-100 mission. The STS-100 crewmembers are delivering the Canadarm2, Space Station Remote Manipulator System (SSRMS), and equipment stowed in the Multipurpose Logistics Module (MPLM) Raphaello to the ISS which are visible in Endeavour's payload bay. The image was taken with a digital still camera.

  19. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    Members of the Debbie Allen Dance Academy perform “Men in Black” choreographed by the legendary Debbie Allen during the grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  20. Chemical environments of submarine hydrothermal systems. [supporting abiogenetic theory

    NASA Technical Reports Server (NTRS)

    Shock, Everett L.

    1992-01-01

    The paper synthesizes diverse information about the inorganic geochemistry of submarine hydrothermal systems, provides a description of the fundamental physical and chemical properties of these systems, and examines the implications of high-temperature, fluid-driven processes for organic synthesis. Emphasis is on a few general features, i.e., pressure, temperature, oxidation states, fluid composition, and mineral alteration, because these features will control whether organic synthesis can occur in hydrothermal systems.

  1. Heat and chemical flux variability within the Main Endeavour Field, Juan de Fuca Ridge, from 2000, 2004

    NASA Astrophysics Data System (ADS)

    Kellogg, J. P.; McDuff, R. E.; Hautala, S. L.; Stahr, F.

    2010-12-01

    The Main Endeavour Field (MEF) has had a split personality since it was discovered. The southern half of the field is regularly observed to be hotter and fresher than the northern half. Differences lessened after the 1999 earthquake event, but the thermal and chemical gradient remains. We examine CTD and MAVS current meter data collected during surveys, designed to intersect the rising hydrothermal plume, conducted with the Autonomous Benthic Explorer (ABE) in 2000 and 2004. By taking subsets of the data over known clusters of structures within the field, we attribute fractional contributions to the whole field heat and salt fluxes. Preliminary findings indicate that North MEF contributes ~90% and ~100% of the heat from MEF in 2000 and 2004 respectively. It is clear from this that the majority of the MEF buoyancy flux is from North MEF even though the source fluids from South MEF are estimated to be initially more buoyant than those from North MEF. Within North MEF, ~2/3 of the heat comes from the Grotto, Dante, Lobo sulfide cluster and ~1/4 from the Hulk and Crypto cluster. These data, for the intra-field spatial scales of heat and salt flux, may allow us to infer mechanisms capable of altering the porous network of the hydrothermal system.

  2. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    NASA Astronauts, from left, Danny Olivas, Garrett Reisman, Barbara Morgan, and, NASA Associate Administrator for Education and Astronaut, Leland Melvin give high fives to school children as they enter the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion, Tuesday, Oct. 30, 2012, in Los Angeles. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  3. Hydrogen-limited growth of hyperthermophilic methanogens at deep-sea hydrothermal vents.

    PubMed

    Ver Eecke, Helene C; Butterfield, David A; Huber, Julie A; Lilley, Marvin D; Olson, Eric J; Roe, Kevin K; Evans, Leigh J; Merkel, Alexandr Y; Cantin, Holly V; Holden, James F

    2012-08-21

    Microbial productivity at hydrothermal vents is among the highest found anywhere in the deep ocean, but constraints on microbial growth and metabolism at vents are lacking. We used a combination of cultivation, molecular, and geochemical tools to verify pure culture H(2) threshold measurements for hyperthermophilic methanogenesis in low-temperature hydrothermal fluids from Axial Volcano and Endeavour Segment in the northeastern Pacific Ocean. Two Methanocaldococcus strains from Axial and Methanocaldococcus jannaschii showed similar Monod growth kinetics when grown in a bioreactor at varying H(2) concentrations. Their H(2) half-saturation value was 66 μM, and growth ceased below 17-23 μM H(2), 10-fold lower than previously predicted. By comparison, measured H(2) and CH(4) concentrations in fluids suggest that there was generally sufficient H(2) for Methanocaldococcus growth at Axial but not at Endeavour. Fluids from one vent at Axial (Marker 113) had anomalously high CH(4) concentrations and contained various thermal classes of methanogens based on cultivation and mcrA/mrtA analyses. At Endeavour, methanogens were largely undetectable in fluid samples based on cultivation and molecular screens, although abundances of hyperthermophilic heterotrophs were relatively high. Where present, Methanocaldococcus genes were the predominant mcrA/mrtA sequences recovered and comprised ∼0.2-6% of the total archaeal community. Field and coculture data suggest that H(2) limitation may be partly ameliorated by H(2) syntrophy with hyperthermophilic heterotrophs. These data support our estimated H(2) threshold for hyperthermophilic methanogenesis at vents and highlight the need for coupled laboratory and field measurements to constrain microbial distribution and biogeochemical impacts in the deep sea.

  4. Vapor-Liquid Partitioning of Iron and Manganese in Hydrothermal Fluids: An Experimental Investigation with Application to the Integrated Study of Basalt-hosted Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Pester, N. J.; Seyfried, W. E.

    2010-12-01

    vent fluids (as modeled by the NaCl-H2O system) represents challenging experimental conditions due to the extreme sensitivity to pressure and temperature. Using a novel flow through system that allows pressure and temperature to be controlled within 0.5 bars and 1°C, respectively, we have derived vapor-liquid partition coefficients for several species, including Fe and Mn. Divalent cations partition more drastically into the liquid phase than monovalent species and the demonstrated temperature sensitivity of equilibrium Fe/Mn ratios in basalt alteration experiments make these two elements excellent candidates when attempting to interpret time series changes in the aftermath of eruptions. Our experiments demonstrate that with decreasing vapor salinity, the Fe/Mn ratio can effectively double, relative to the bulk fluid composition, as the vapors approach the extremely low dissolved Cl concentrations observed at both EPR, 9°N and Main Endeavour, JdFR. Our results suggest that phase separation can easily account for the observed deviation from apparent Fe-Mn equilibrium in these fluids and further suggests that it may take more than a year for these hydrothermal systems to return to steady state.

  5. Depth-Dependent Permeability and Heat Output at Basalt-Hosted Hydrothermal Systems Across Mid-Ocean Ridge Spreading Rates

    NASA Astrophysics Data System (ADS)

    Barreyre, Thibaut; Olive, Jean-Arthur; Crone, Timothy J.; Sohn, Robert A.

    2018-04-01

    The permeability of the oceanic crust exerts a primary influence on the vigor of hydrothermal circulation at mid-ocean ridges, but it is a difficult to measure parameter that varies with time, space, and geological setting. Here we develop an analytical model for the poroelastic response of hydrothermal exit-fluid velocities and temperatures to ocean tidal loading in a two-layered medium to constrain the discharge zone permeability of each layer. The top layer, corresponding to extrusive lithologies (e.g., seismic layer 2A) overlies a lower permeability layer, corresponding to intrusive lithologies (e.g., layer 2B). We apply the model to three basalt-hosted hydrothermal fields (i.e., Lucky Strike, Main Endeavour and 9°46'N L-vent) for which the seismic stratigraphy is well-established, and for which robust exit-fluid temperature data are available. We find that the poroelastic response to tidal loading is primarily controlled by layer 2A permeability, which is about 3 orders of magnitude higher for the Lucky Strike site (˜10-10 m2) than the 9°46'N L-vent site (˜10-13 m2). By contrast, layer 2B permeability does not exert a strong control on the poroelastic response to tidal loading, yet strongly modulates the heat output of hydrothermal discharge zones. Taking these constraints into account, we estimate a plausible range of layer 2B permeability between ˜10-15 m2 and an upper-bound value of ˜10-14 (9°46'N L-vent) to ˜10-12 m2 (Lucky Strike). These permeability structures reconcile the short-term response and long-term thermal output of hydrothermal sites, and provide new insights into the links between permeability and tectono-magmatic processes along the global mid-ocean ridge.

  6. Organic matter in hydrothermal metal ores and hydrothermal fluids

    USGS Publications Warehouse

    Orem, W.H.; Spiker, E. C.; Kotra, R.K.

    1990-01-01

    Massive polymetallic sulfides are currently being deposited around active submarine hydrothermal vents associated with spreading centers. Chemoautolithotrophic bacteria are responsible for the high production of organic matter also associated with modern submarine hydrothermal activity. Thus, there is a significant potential for organic matter/metal interactions in these systems. We have studied modern and ancient hydrothermal metal ores and modern hydrothermal fluids in order to establish the amounts and origin of the organic matter associated with the metal ores. Twenty-six samples from modern and ancient hydrothermal systems were surveyed for their total organic C contents. Organic C values ranged from 0.01% to nearly 4.0% in these samples. Metal ores from modern and ancient sediment-covered hydrothermal systems had higher organic C values than those from modern and ancient hydrothermal systems lacking appreciable sedimentary cover. One massive pyrite sample from the Galapagos spreading center (3% organic C) had stable isotope values of -27.4% (??13C) and 2.1% (??15N), similar to those in benthic siphonophors from active vents and distinct from seep sea sedimentary organic matter. This result coupled with other analyses (e.g. 13C NMR, pyrolysis/GC, SEM) of this and other samples suggests that much of the organic matter may originate from chemoautolithotrophic bacteria at the vents. However, the organic matter in hydrothermal metal ores from sediment covered vents probably arises from complex sedimentary organic matter by hydrothermal pyrolysis. The dissolved organic C concentrations of hydrothermal fluids from one site (Juan de Fuca Ridge) were found to be the same as that of background seawater. This result may indicate that dissolved organic C is effectively scavenged from hydrothermal fluids by biological activity or by co-precipitation with metal ores. ?? 1990.

  7. Endeavour Grand Opening Ceremony

    NASA Image and Video Library

    2012-10-30

    A government Transfer Order for Excess Personal Property is seen framed outside the office of President and CEO, California Science Center, Jeffrey N. Rudolph, on Tuesday, Oct. 30, 2012, in Los Angeles. The grand opening ceremony for the California Science center's Samuel Oschin Space Shuttle Endeavour Display Pavilion took place on Tuesday, Oct. 30, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Photo Credit: (NASA/Bill Ingalls)

  8. Heat flux from magmatic hydrothermal systems related to availability of fluid recharge

    USGS Publications Warehouse

    Harvey, M. C.; Rowland, J.V.; Chiodini, G.; Rissmann, C.F.; Bloomberg, S.; Hernandez, P.A.; Mazot, A.; Viveiros, F.; Werner, Cynthia A.

    2015-01-01

    Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface heat flux indicates system resource potential, and can be inferred from soil CO2 flux measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 flux surveys worldwide to compare heat flux from a variety of magma-hydrothermal areas. We infer that availability of water to recharge magmatic hydrothermal systems is correlated with heat flux. Recharge availability is in turn governed by permeability, structure, lithology, rainfall, topography, and perhaps unsurprisingly, proximity to a large supply of water such as the ocean. The relationship between recharge and heat flux interpreted by this study is consistent with recent numerical modeling that relates hydrothermal system heat output to rainfall catchment area. This result highlights the importance of recharge as a consideration when evaluating hydrothermal systems for electricity generation, and the utility of CO2 flux as a resource evaluation tool.

  9. Anhydrite precipitation in seafloor hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Theissen-Krah, Sonja; Rüpke, Lars H.

    2016-04-01

    The composition and metal concentration of hydrothermal fluids venting at the seafloor is strongly temperature-dependent and fluids above 300°C are required to transport metals to the seafloor (Hannington et al. 2010). Ore-forming hydrothermal systems and high temperature vents in general are often associated with faults and fracture zones, i.e. zones of enhanced permeabilities that act as channels for the uprising hydrothermal fluid (Heinrich & Candela, 2014). Previous numerical models (Jupp and Schultz, 2000; Andersen et al. 2015) however have shown that high permeabilities tend to decrease fluid flow temperatures due to mixing with cold seawater and the resulting high fluid fluxes that lead to short residence times of the fluid near the heat source. A possible mechanism to reduce the permeability and thereby to focus high temperature fluid flow are mineral precipitation reactions that clog the pore space. Anhydrite for example precipitates from seawater if it is heated to temperatures above ~150°C or due to mixing of seawater with hydrothermal fluids that usually have high Calcium concentrations. We have implemented anhydrite reactions (precipitation and dissolution) in our finite element numerical models of hydrothermal circulation. The initial results show that the precipitation of anhydrite efficiently alters the permeability field, which affects the hydrothermal flow field as well as the resulting vent temperatures. C. Andersen et al. (2015), Fault geometry and permeability contrast control vent temperatures at the Logatchev 1 hydrothermal field, Mid-Atlantic Ridge, Geology, 43(1), 51-54. M. D. Hannington et al. (2010), Modern Sea-Floor Massive Sulfides and Base Metal Resources: Toward an Estimate of Global Sea-Floor Massive Sulfide Potential, in The Challenge of Finding New Mineral Resources: Global Metallogeny, Innovative Exploration, and New Discoveries, edited by R. J. Goldfarb, E. E. Marsh and T. Monecke, pp. 317-338, Society of Economic Geologists

  10. Free-living bacterial communities associated with tubeworm (Ridgeia piscesae) aggregations in contrasting diffuse flow hydrothermal vent habitats at the Main Endeavour Field, Juan de Fuca Ridge

    PubMed Central

    Forget, Nathalie L; Kim Juniper, S

    2013-01-01

    We systematically studied free-living bacterial diversity within aggregations of the vestimentiferan tubeworm Ridgeia piscesae sampled from two contrasting flow regimes (High Flow and Low Flow) in the Endeavour Hydrothermal Vents Marine Protected Area (MPA) on the Juan de Fuca Ridge (Northeast Pacific). Eight samples of particulate detritus were recovered from paired tubeworm grabs from four vent sites. Most sequences (454 tag and Sanger methods) were affiliated to the Epsilonproteobacteria, and the sulfur-oxidizing genus Sulfurovum was dominant in all samples. Gammaproteobacteria were also detected, mainly in Low Flow sequence libraries, and were affiliated with known methanotrophs and decomposers. The cooccurrence of sulfur reducers from the Deltaproteobacteria and the Epsilonproteobacteria suggests internal sulfur cycling within these habitats. Other phyla detected included Bacteroidetes, Actinobacteria, Chloroflexi, Firmicutes, Planctomycetes, Verrucomicrobia, and Deinococcus–Thermus. Statistically significant relationships between sequence library composition and habitat type suggest a predictable pattern for High Flow and Low Flow environments. Most sequences significantly more represented in High Flow libraries were related to sulfur and hydrogen oxidizers, while mainly heterotrophic groups were more represented in Low Flow libraries. Differences in temperature, available energy for metabolism, and stability between High Flow and Low Flow habitats potentially explain their distinct bacterial communities. PMID:23401293

  11. Combined hydrothermal liquefaction and catalytic hydrothermal gasification system and process for conversion of biomass feedstocks

    DOEpatents

    Elliott, Douglas C.; Neuenschwander, Gary G.; Hart, Todd R.

    2017-09-12

    A combined hydrothermal liquefaction (HTL) and catalytic hydrothermal gasification (CHG) system and process are described that convert various biomass-containing sources into separable bio-oils and aqueous effluents that contain residual organics. Bio-oils may be converted to useful bio-based fuels and other chemical feedstocks. Residual organics in HTL aqueous effluents may be gasified and converted into medium-BTU product gases and directly used for process heating or to provide energy.

  12. Mathematical Models of Seafloor Hydrothermal Systems Driven by Serpentinization of Peridotite

    NASA Astrophysics Data System (ADS)

    Lowell, R. P.; Rona, P. A.; Germanovich, L. N.

    2001-12-01

    Most seafloor hydrothermal systems are driven by heat transfer from subsurface magma bodies. At slow spreading ridges of the Atlantic and Indian oceans, however, magma supply is low; and tectonic activity brings mantle rocks to shallow depths in the crust. Then, the heat of formation released upon serpentinization of peridotite provides the energy source for hydrothermal circulation. This latter class of system has been relatively unstudied, but recent discoveries of peridotite-hosted hydrothermal systems along the Mid-Atlantic Ridge suggest that such systems may play an important role in geochemical cycling and biogeochemical processes. The likelihood that peridotite-hosted hydrothermal systems was more prevalent during the Archean further suggests that such systems may have played a role in the origin of life. We present the first mathematical models of seafloor hydrothermal systems driven by heat released upon serpentinization of peridotite. We assume seawater circulates through a major crack network in the host-peridotite and that cooling of the host-rock leads to the formation of microcracks through which the fluid infiltrates. Reaction of the fluid in microcracks with the host rock results in serpentinization and the heat released upon serpentinization is transported to the seafloor by the fluid circulating in the main crack network. The temperature and heat output of the resulting hydrothermal system is a function of the main network permeability and the rate at which the serpentinization reaction proceeds via diffusion and propagation of the microcracks. Although the temperature of such a system can be quite variable, vent temperatures between 10° C and 100° C are likely for typical crustal parameters.

  13. Hydrothermal systems on Mars: an assessment of present evidence

    NASA Technical Reports Server (NTRS)

    Farmer, J. D.

    1996-01-01

    Hydrothermal processes have been suggested to explain a number of observations for Mars, including D/H ratios of water extracted from Martian meteorites, as a means for removing CO2 from the Martian atmosphere and sequestering it in the crust as carbonates, and as a possible origin for iron oxide-rich spectral units on the floors of some rifted basins (chasmata). There are numerous examples of Martian channels formed by discharges of subsurface water near potential magmatic heat sources, and hydrothermal processes have also been proposed as a mechanism for aquifer recharge needed to sustain long term erosion of sapping channels. The following geological settings have been identified as targets for ancient hydrothermal systems on Mars: channels located along the margins of impact crater melt sheets and on the slopes of ancient volcanoes; chaotic and fretted terranes where shallow subsurface heat sources are thought to have interacted with ground ice; and the floors of calderas and rifted basins (e.g. chasmata). On Earth, such geological environments are often a locus for hydrothermal mineralization. But we presently lack the mineralogical information needed for a definitive evaluation of hypotheses. A preferred tool for identifying minerals by remote sensing methods on Earth is high spatial resolution, hyperspectral, near-infrared spectroscopy, a technique that has been extensively developed by mineral explorationists. Future efforts to explore Mars for ancient hydrothermal systems would benefit from the application of methods developed by the mining industry to look for similar deposits on Earth. But Earth-based exploration models must be adapted to account for the large differences in the climatic and geological history of Mars. For example, it is likely that the early surface environment of Mars was cool, perhaps consistently below freezing, with the shallow portions of hydrothermal systems being dominated by magma-cryosphere interactions. Given the smaller

  14. Hydrothermal systems on Mars: an assessment of present evidence.

    PubMed

    Farmer, J D

    1996-01-01

    Hydrothermal processes have been suggested to explain a number of observations for Mars, including D/H ratios of water extracted from Martian meteorites, as a means for removing CO2 from the Martian atmosphere and sequestering it in the crust as carbonates, and as a possible origin for iron oxide-rich spectral units on the floors of some rifted basins (chasmata). There are numerous examples of Martian channels formed by discharges of subsurface water near potential magmatic heat sources, and hydrothermal processes have also been proposed as a mechanism for aquifer recharge needed to sustain long term erosion of sapping channels. The following geological settings have been identified as targets for ancient hydrothermal systems on Mars: channels located along the margins of impact crater melt sheets and on the slopes of ancient volcanoes; chaotic and fretted terranes where shallow subsurface heat sources are thought to have interacted with ground ice; and the floors of calderas and rifted basins (e.g. chasmata). On Earth, such geological environments are often a locus for hydrothermal mineralization. But we presently lack the mineralogical information needed for a definitive evaluation of hypotheses. A preferred tool for identifying minerals by remote sensing methods on Earth is high spatial resolution, hyperspectral, near-infrared spectroscopy, a technique that has been extensively developed by mineral explorationists. Future efforts to explore Mars for ancient hydrothermal systems would benefit from the application of methods developed by the mining industry to look for similar deposits on Earth. But Earth-based exploration models must be adapted to account for the large differences in the climatic and geological history of Mars. For example, it is likely that the early surface environment of Mars was cool, perhaps consistently below freezing, with the shallow portions of hydrothermal systems being dominated by magma-cryosphere interactions. Given the smaller

  15. Porosity evolution in Icelandic hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Thien, B.; Kosakowski, G.; Kulik, D. A.

    2014-12-01

    Mineralogical alteration of reservoir rocks, driven by fluid circulation in natural or enhanced hydrothermal systems, is likely to influence the long-term performance of geothermal power generation. A key factor is the change of porosity due to dissolution of primary minerals and precipitation of secondary phases. Porosity changes will affect fluid circulation and solute transport, which, in turn, influence mineralogical alteration. This study is part of the Sinergia COTHERM project (COmbined hydrological, geochemical and geophysical modeling of geotTHERMal systems, grant number CRSII2_141843/1) that is an integrative research project aimed at improving our understanding of the sub-surface processes in magmatically-driven natural geothermal systems. These are typically high enthalphy systems where a magmatic pluton is located at a few kilometers depth. These shallow plutons increase the geothermal gradient and trigger the circulation of hydrothermal waters with a steam cap forming at shallow depth. Field observations suggest that active and fossil Icelandic hydrothermal systems are built from a superposition of completely altered and completely unaltered layers. With help of 1D and 2D reactive transport models (OpenGeoSys-GEM code), we investigate the reasons for this finding, by studying the mineralogical evolution of protoliths with different initial porosities at different temperatures and pressures, different leaching water composition and gas content, and different porosity geometries (i.e. porous medium versus fractured medium). From this study, we believe that the initial porosity of protoliths and volume changes due to their transformation into secondary minerals are key factors to explain the different alteration extents observed in field studies. We also discuss how precipitation and dissolution kinetics can influence the alteration time scales.

  16. Basin scale permeability and thermal evolution of a magmatic hydrothermal system

    NASA Astrophysics Data System (ADS)

    Taron, J.; Hickman, S. H.; Ingebritsen, S.; Williams, C.

    2013-12-01

    Large-scale hydrothermal systems are potentially valuable energy resources and are of general scientific interest due to extreme conditions of stress, temperature, and reactive chemistry that can act to modify crustal rheology and composition. With many proposed sites for Enhanced Geothermal Systems (EGS) located on the margins of large-scale hydrothermal systems, understanding the temporal evolution of these systems contributes to site selection, characterization and design of EGS. This understanding is also needed to address the long-term sustainability of EGS once they are created. Many important insights into heat and mass transfer within natural hydrothermal systems can be obtained through hydrothermal modeling assuming that stress and permeability structure do not evolve over time. However, this is not fully representative of natural systems, where the effects of thermo-elastic stress changes, chemical fluid-rock interactions, and rock failure on fluid flow and thermal evolution can be significant. The quantitative importance of an evolving permeability field within the overall behavior of a large-scale hydrothermal system is somewhat untested, and providing such a parametric understanding is one of the goals of this study. We explore the thermal evolution of a sedimentary basin hydrothermal system following the emplacement of a magma body. The Salton Sea geothermal field and its associated magmatic system in southern California is utilized as a general backdrop to define the initial state. Working within the general framework of the open-source scientific computing initiative OpenGeoSys (www.opengeosys.org), we introduce full treatment of thermodynamic properties at the extreme conditions following magma emplacement. This treatment utilizes a combination of standard Galerkin and control-volume finite elements to balance fluid mass, mechanical deformation, and thermal energy with consideration of local thermal non-equilibrium (LTNE) between fluids and solids

  17. View of HST as it approaches Endeavour, taken from aft flight deck window

    NASA Image and Video Library

    1993-12-04

    STS061-53-026 (4 Dec 1993) --- One of the Space Shuttle Endeavour's aft flight deck windows frames this view of the Hubble Space Telescope (HST) as it approaches the Endeavour. Backdropped against western Australia, the Remote Manipulator System (RMS) arm awaits the arrival of the telescope. Once berthed in Endeavour's cargo bay, HST underwent five days of servicing provided by four space walking crew members. Shark Bay (upper left) and Perth (lower left) are visible in the frame.

  18. Hubble Space Telescope nears Shuttle Endeavour

    NASA Image and Video Library

    1993-12-04

    STS061-73-040 (4 Dec 1993) --- Backdropped against the blackness of space, the Hubble Space Telescope (HST) nears the Space Shuttle Endeavour. With the aid of the Remote Manipulator System (RMS), the STS-61 crew members later grappled the spacecraft and berthed it in the cargo bay for five-days of servicing chores by four space walkers.

  19. STS-88 Mission Specialist Currie prepares to enter Endeavour

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-88 Mission Specialist Nancy Jane Currie is assisted with her ascent and re-entry flight suit in the white room at Launch Pad 39A before entering Space Shuttle Endeavour for launch. During the nearly 12-day mission, the six-member crew will mate the first two elements of the International Space Station -- the already-orbiting Zarya control module with the Unity connecting module carried by Endeavour. She is making her third spaceflight as the crew's flight engineer and prime operator of the Remote Manipulator System, the robotic arm.

  20. Degradation of Endeavour Crater, Mars

    NASA Technical Reports Server (NTRS)

    Grant, J. A.; Crumpler, L. S.; Parker, T. J.; Golombek, M. P.; Wilson, S. A.; Mittlefehldt, D. W.

    2015-01-01

    The Opportunity rover has traversed portions of two western rim segments of Endeavour, a 22 km-diameter crater in Meridiani Planum, for the past three years. The resultant data enables the evaluation of the geologic expression and degradation state of the crater. Endeavour is Noa-chian-aged, complex in morphology, and originally may have appeared broadly similar to the more pristine 20.5 km-diameter Santa Fe complex crater in Lunae Palus (19.5degN, 312.0degE). By contrast, Endeavour is considerably subdued and largely buried by younger sulfate-rich plains. Exposed rim segments dubbed Cape York (CY) and Solander Point/Murray Ridge/Pillinger Point (MR) located approximately1500 m to the south reveal breccias interpreted as remnants of the ejecta deposit, dubbed the Shoemaker Formation. At CY, the Shoemaker Formation overlies the pre-impact rocks, dubbed the Matijevic Formation.

  1. STS-113 Space Shuttle Endeavour launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - Water near Launch Pad 39A provides a mirror image of Space Shuttle Endeavour blazing a path into the night sky after launch on mission STS-113. Liftoff occurred ontime at 7:49:47 p.m. EST. The launch is the 19th for Endeavour, and the 112th flight in the Shuttle program. Mission STS-113 is the 16th assembly flight to the International Space Station, carrying another structure for the Station, the P1 integrated truss. Also onboard are the Expedition 6 crew, who will replace Expedition 5. Endeavour is scheduled to land at KSC after an 11-day journey.

  2. Near-Seafloor Magnetic Exploration of Submarine Hydrothermal Systems in the Kermadec Arc

    NASA Astrophysics Data System (ADS)

    Caratori Tontini, F.; de Ronde, C. E. J.; Tivey, M.; Kinsey, J. C.

    2014-12-01

    Magnetic data can provide important information about hydrothermal systems because hydrothermal alteration can drastically reduce the magnetization of the host volcanic rocks. Near-seafloor data (≤70 m altitude) are required to map hydrothermal systems in detail; Autonomous Underwater Vehicles (AUVs) are the ideal platform to provide this level of resolution. Here, we show the results of high-resolution magnetic surveys by the ABE and Sentry AUVs for selected submarine volcanoes of the Kermadec arc. 3-D magnetization models derived from the inversion of magnetic data, when combined with high resolution seafloor bathymetry derived from multibeam surveys, provide important constraints on the subseafloor geometry of hydrothermal upflow zones and the structural control on the development of seafloor hydrothermal vent sites as well as being a tool for the discovery of previously unknown hydrothermal sites. Significant differences exist between the magnetic expressions of hydrothermal sites at caldera volcanoes ("donut" pattern) and cones ("Swiss cheese" pattern), respectively. Subseafloor 3-D magnetization models also highlight structural differences between focused and diffuse vent sites.

  3. Biological and environmental rhythms in (dark) deep-sea hydrothermal ecosystems

    NASA Astrophysics Data System (ADS)

    Cuvelier, Daphne; Legendre, Pierre; Laës-Huon, Agathe; Sarradin, Pierre-Marie; Sarrazin, Jozée

    2017-06-01

    During 2011, two deep-sea observatories focusing on hydrothermal vent ecology were up and running in the Atlantic (Eiffel Tower, Lucky Strike vent field) and the Northeast Pacific Ocean (NEP) (Grotto, Main Endeavour Field). Both ecological modules recorded imagery and environmental variables jointly for a time span of 23 days (7-30 October 2011) and environmental variables for up to 9 months (October 2011-June 2012). Community dynamics were assessed based on imagery analysis and rhythms in temporal variation for both fauna and environment were revealed. Tidal rhythms were found to be at play in the two settings and were most visible in temperature and tubeworm appearances (at NEP). A ˜ 6 h lag in tidal rhythm occurrence was observed between Pacific and Atlantic hydrothermal vents, which corresponds to the geographical distance and time delay between the two sites.

  4. The hydrothermal exploration system on the 'Qianlong2' AUV

    NASA Astrophysics Data System (ADS)

    Tao, W.; Tao, C.; Jinhui, Z.; Cai, L.; Guoyin, Z.

    2016-12-01

    ABSTRACT: Qianlong2, is a fully Autonomous Underwater Vehicle (AUV) designed for submarine resources research, especially for polymetallic sulphides, and the survey depths of is up to 4500 m. Qianlong2 had successfully explored hydrothermal vent field on the Southwest Indian Ridge (SWIR), and collected conductance, temperature and depth (CTD), turbidity, and Oxidation-Reduction Potential (ORP) data. It also had mapped precise topography by high resolution side scan sonar (HRBSSS) during every dive; and obtained photographs of sulfide deposits during some dives. Here, we detailedly described the implementation of investigation, data administration, and fast mapping of hydrothermal exploration system by Qianlong2. Giving a description of how to remove the platform magnetic interference by using magnetic data during Qianlong2 spin. Based on comprehensive hydrochemical anomalies, we get a rapid method for finding the localization of hydrothermal vents. Taking one dive as an example, we systemically showed the process about how to analyse hydrothermal survey data and acquire the location results of hydrothermal vents. Considering that this method is effective and can be used in other deep-submergence assets such as human occupied vehicles (HOVs) and remotely operated vehicles (ROVs) during further studies. Finally, we discussed how to promote and optimize the installation and application of those sensors and how to improve Qianlong2's autonomy of investigation.

  5. Payload Bay of Endeavour

    NASA Image and Video Library

    2008-11-26

    S126-E-11974 (26 Nov. 2008) --- Backdropped against white clouds, the aft section of Endeavour's cargo bay, now holding the multipurpose logistics module Leonardo, is featured in this digital still photo, framed through a window on the International Space Station. Endeavour and the orbital outpost have been docked for almost two weeks while their crews have joined efforts in home improvement on the station and other work. Astronauts Donald Pettit and Shane Kimbrough, operating the space station's robot arm from inside the Destiny laboratory module, detached the Leonardo cargo canister from its temporary parking place on the station a few hours earlier and re-berthed it in the cargo bay.

  6. Optimization of Large-Scale Daily Hydrothermal System Operations With Multiple Objectives

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Cheng, Chuntian; Shen, Jianjian; Cao, Rui; Yeh, William W.-G.

    2018-04-01

    This paper proposes a practical procedure for optimizing the daily operation of a large-scale hydrothermal system. The overall procedure optimizes a monthly model over a period of 1 year and a daily model over a period of up to 1 month. The outputs from the monthly model are used as inputs and boundary conditions for the daily model. The models iterate and update when new information becomes available. The monthly hydrothermal model uses nonlinear programing (NLP) to minimize fuel costs, while maximizing hydropower production. The daily model consists of a hydro model, a thermal model, and a combined hydrothermal model. The hydro model and thermal model generate the initial feasible solutions for the hydrothermal model. The two competing objectives considered in the daily hydrothermal model are minimizing fuel costs and minimizing thermal emissions. We use the constraint method to develop the trade-off curve (Pareto front) between these two objectives. We apply the proposed methodology on the Yunnan hydrothermal system in China. The system consists of 163 individual hydropower plants with an installed capacity of 48,477 MW and 11 individual thermal plants with an installed capacity of 12,400 MW. We use historical operational records to verify the correctness of the model and to test the robustness of the methodology. The results demonstrate the practicability and validity of the proposed procedure.

  7. Liftoff of STS-67 Space Shuttle Endeavour

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Carrying a crew of seven and a complement of astronomic experiments, the Space Shuttle Endeavour embarks on NASA's longest Shuttle flight to date. Endeavour's liftoff from Launch Pad 39A occurred at 1:38:13 a.m. (EST), March 2, 1995.

  8. Liftoff of STS-67 Space Shuttle Endeavour

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Carrying a crew of seven and a compliment of astronomic experiments, the Space Shuttle Endeavour embarks on NASA's longest Shuttle flight to date. Endeavour's liftoff from Launch Pad 39A occurred at 1:38:13 a.m. (EST), March 2, 1995.

  9. Asymmetrical hydrothermal system below Merapi volcano imaged by geophysical data.

    NASA Astrophysics Data System (ADS)

    Byrdina, Svetlana; Friedel, Sven; Budi-Santoso, Agus; Suryanto, Wiwit; Suhari, Aldjarishy; Vandemeulebrouck, Jean; Rizal, Mohhamed H.; Grandis, Hendra

    2017-04-01

    A high-resolution image of the hydrothermal system of Merapi volcano is obtained using electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT inversions identify two distinct low-resistivity bodies, at the base of the south flank and in the summit area, that represent likely two parts of an interconnected hydrothermal system. In the summit area, the extension of the hydrothermal system is clearly limited by the main geological structures which are actual and ancient craters. A sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20 - 50 Ωm) from the resistive andesite lava flows and pyroclastic deposits (2000 - 50 000 Ωm). High diffuse CO2 degassing (with a median value of 400g m -2 d -1) is observed in a narrow vicinity of the active crater rim and close to the Pasar-Bubar. The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The total CO2 degassing across the accessible summit area with a surface of 1.4 · 10 5 m 2 is around 20 td -1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200 - 230 td -1). This drop in the diffuse degassing can be related to the decrease in the magmatic activity, to the change of the summit morphology or to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100 000 Ωm, resistivity as low as 10 Ωm has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. We suggest that a sandwich-like structure of stratified pyroclastic deposits on the flanks of Merapi screen and separate the flow of hydrothermal fluids with the degassing occurring mostly through the fractured crater rims

  10. Aqueous geochemistry of the Thermopolis hydrothermal system, southern Bighorn Basin, Wyoming, U.S.A.

    DOE PAGES

    Kaszuba, John P.; Sims, Kenneth W.W.; Pluda, Allison R.

    2014-06-01

    The Thermopolis hydrothermal system is located in the southern portion of the Bighorn Basin, in and around the town of Thermopolis, Wyoming. It is the largest hydrothermal system in Wyoming outside of Yellowstone National Park. The system includes hot springs, travertine deposits, and thermal wells; published models for the hydrothermal system propose the Owl Creek Mountains as the recharge zone, simple conductive heating at depth, and resurfacing of thermal waters up the Thermopolis Anticline.

  11. New insights into the Kawah Ijen hydrothermal system from geophysical data

    USGS Publications Warehouse

    Caudron, Corentin; Mauri, G.; Williams-Jones, Glyn; Lecocq, Thomas; Syahbana, Devy Kamil; de Plaen, Raphael; Peiffer, Loic; Bernard, Alain; Saracco, Ginette

    2017-01-01

    Volcanoes with crater lakes and/or extensive hydrothermal systems pose significant challenges with respect to monitoring and forecasting eruptions, but they also provide new opportunities to enhance our understanding of magmatic–hydrothermal processes. Their lakes and hydrothermal systems serve as reservoirs for magmatic heat and fluid emissions, filtering and delaying the surface expressions of magmatic unrest and eruption, yet they also enable sampling and monitoring of geochemical tracers. Here, we describe the outcomes of a highly focused international experimental campaign and workshop carried out at Kawah Ijen volcano, Indonesia, in September 2014, designed to answer fundamental questions about how to improve monitoring and eruption forecasting at wet volcanoes.

  12. The potential hydrothermal systems unexplored in the Southwest Indian Ocean

    NASA Astrophysics Data System (ADS)

    Suo, Yanhui; Li, Sanzhong; Li, Xiyao; Zhang, Zhen; Ding, Dong

    2017-06-01

    Deep-sea hydrothermal vents possess complex ecosystems and abundant metallic mineral deposits valuable to human being. On-axial vents along tectonic plate boundaries have achieved prominent results and obtained huge resources, while nearly 90% of the global mid-ocean ridge and the majority of the off-axial vents buried by thick oceanic sediments within plates remain as relatively undiscovered domains. Based on previous detailed investigations, hydrothermal vents have been mapped along five sections along the Southwest Indian Ridge (SWIR) with different bathymetry, spreading rates, and gravity features, two at the western end (10°-16°E Section B and 16°-25°E Section C) and three at the eastern end (49°-52°E Section D, 52°-61°E Section E and 61°-70°E Section F). Hydrothermal vents along the Sections B, C, E and F with thin oceanic crust are hosted by ultramafic rocks under tectonic-controlled magmatic-starved settings, and hydrothermal vents along the Section D are associated with exceed magmatism. Limited coverage of investigations is provided along the 35°-47°E SWIR (between Marion and Indomed fracture zones) and a lot of research has been done around the Bouvet Island, while no hydrothermal vents has been reported. Analyzing bathymetry, gravity and geochemical data, magmatism settings are favourable for the occurrence of hydrothermal systems along these two sections. An off-axial hydrothermal system in the southern flank of the SWIR that exhibits ultra-thin oceanic crust associated with an oceanic continental transition is postulated to exist along the 100-Ma slow-spreading isochron in the Enderby Basin. A discrete, denser enriched or less depleted mantle beneath the Antarctic Plate is an alternative explanation for the large scale thin oceanic crust concentrated on the southern flank of the SWIR.

  13. Putative fossil life in a hydrothermal system of the Dellen impact structure, Sweden

    NASA Astrophysics Data System (ADS)

    Lindgren, Paula; Ivarsson, Magnus; Neubeck, Anna; Broman, Curt; Henkel, Herbert; Holm, Nils G.

    2010-07-01

    Impact-generated hydrothermal systems are commonly proposed as good candidates for hosting primitive life on early Earth and Mars. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is rarely reported in the literature. Here we present the occurrence of putative fossil microorganisms in a hydrothermal system of the 89 Ma Dellen impact structure, Sweden. We found the putative fossilized microorganisms hosted in a fine-grained matrix of hydrothermal alteration minerals set in interlinked fractures of an impact breccia. The putative fossils appear as semi-straight to twirled filaments, with a thickness of 1-2 μm, and a length between 10 and 100 μm. They have an internal structure with segmentation, and branching of filaments occurs frequently. Their composition varies between an outer and an inner layer of a filament, where the inner layer is more iron rich. Our results indicate that hydrothermal systems in impact craters could potentially be capable of supporting microbial life. This could have played an important role for the evolution of life on early Earth and Mars.

  14. Sulfur Metabolizing Microbes Dominate Microbial Communities in Andesite-Hosted Shallow-Sea Hydrothermal Systems

    PubMed Central

    Zhang, Yao; Zhao, Zihao; Chen, Chen-Tung Arthur; Tang, Kai; Su, Jianqiang; Jiao, Nianzhi

    2012-01-01

    To determine microbial community composition, community spatial structure and possible key microbial processes in the shallow-sea hydrothermal vent systems off NE Taiwan’s coast, we examined the bacterial and archaeal communities of four samples collected from the water column extending over a redoxocline gradient of a yellow and four from a white hydrothermal vent. Ribosomal tag pyrosequencing based on DNA and RNA showed statistically significant differences between the bacterial and archaeal communities of the different hydrothermal plumes. The bacterial and archaeal communities from the white hydrothermal plume were dominated by sulfur-reducing Nautilia and Thermococcus, whereas the yellow hydrothermal plume and the surface water were dominated by sulfide-oxidizing Thiomicrospira and Euryarchaeota Marine Group II, respectively. Canonical correspondence analyses indicate that methane (CH4) concentration was the only statistically significant variable that explains all community cluster patterns. However, the results of pyrosequencing showed an essential absence of methanogens and methanotrophs at the two vent fields, suggesting that CH4 was less tied to microbial processes in this shallow-sea hydrothermal system. We speculated that mixing between hydrothermal fluids and the sea or meteoric water leads to distinctly different CH4 concentrations and redox niches between the yellow and white vents, consequently influencing the distribution patterns of the free-living Bacteria and Archaea. We concluded that sulfur-reducing and sulfide-oxidizing chemolithoautotrophs accounted for most of the primary biomass synthesis and that microbial sulfur metabolism fueled microbial energy flow and element cycling in the shallow hydrothermal systems off the coast of NE Taiwan. PMID:22970260

  15. Sulfur metabolizing microbes dominate microbial communities in Andesite-hosted shallow-sea hydrothermal systems.

    PubMed

    Zhang, Yao; Zhao, Zihao; Chen, Chen-Tung Arthur; Tang, Kai; Su, Jianqiang; Jiao, Nianzhi

    2012-01-01

    To determine microbial community composition, community spatial structure and possible key microbial processes in the shallow-sea hydrothermal vent systems off NE Taiwan's coast, we examined the bacterial and archaeal communities of four samples collected from the water column extending over a redoxocline gradient of a yellow and four from a white hydrothermal vent. Ribosomal tag pyrosequencing based on DNA and RNA showed statistically significant differences between the bacterial and archaeal communities of the different hydrothermal plumes. The bacterial and archaeal communities from the white hydrothermal plume were dominated by sulfur-reducing Nautilia and Thermococcus, whereas the yellow hydrothermal plume and the surface water were dominated by sulfide-oxidizing Thiomicrospira and Euryarchaeota Marine Group II, respectively. Canonical correspondence analyses indicate that methane (CH(4)) concentration was the only statistically significant variable that explains all community cluster patterns. However, the results of pyrosequencing showed an essential absence of methanogens and methanotrophs at the two vent fields, suggesting that CH(4) was less tied to microbial processes in this shallow-sea hydrothermal system. We speculated that mixing between hydrothermal fluids and the sea or meteoric water leads to distinctly different CH(4) concentrations and redox niches between the yellow and white vents, consequently influencing the distribution patterns of the free-living Bacteria and Archaea. We concluded that sulfur-reducing and sulfide-oxidizing chemolithoautotrophs accounted for most of the primary biomass synthesis and that microbial sulfur metabolism fueled microbial energy flow and element cycling in the shallow hydrothermal systems off the coast of NE Taiwan.

  16. Launch of STS-67 Space Shuttle Endeavour

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Carrying a crew of seven and a complement of astronomic experiments, the Space Shuttle Endeavour embarks on NASA's longest shuttle flight to date. Endeavour's liftoff from Launch Pad 39A occurred at 1:38:13 a.m. (EST), March 2, 1995. In this view the fence line near the launch pad is evident in the foreground.

  17. Entropy production in a box: Analysis of instabilities in confined hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Börsing, N.; Wellmann, J. F.; Niederau, J.; Regenauer-Lieb, K.

    2017-09-01

    We evaluate if the concept of thermal entropy production can be used as a measure to characterize hydrothermal convection in a confined porous medium as a valuable, thermodynamically motivated addition to the standard Rayleigh number analysis. Entropy production has been used widely in the field of mechanical and chemical engineering as a way to characterize the thermodynamic state and irreversibility of an investigated system. Pioneering studies have since adapted these concepts to natural systems, and we apply this measure here to investigate the specific case of hydrothermal convection in a "box-shaped" confined porous medium, as a simplified analog for, e.g., hydrothermal convection in deep geothermal aquifers. We perform various detailed numerical experiments to assess the response of the convective system to changing boundary conditions or domain aspect ratios, and then determine the resulting entropy production for each experiment. In systems close to the critical Rayleigh number, we derive results that are in accordance to the analytically derived predictions. At higher Rayleigh numbers, however, we observe multiple possible convection modes, and the analysis of the integrated entropy production reveals distinct curves of entropy production that provide an insight into the hydrothermal behavior in the system, both for cases of homogeneous materials, as well as for heterogeneous spatial material distributions. We conclude that the average thermal entropy production characterizes the internal behavior of hydrothermal systems with a meaningful thermodynamic measure, and we expect that it can be useful for the investigation of convection systems in many similar hydrogeological and geophysical settings.

  18. Geophysical image of the hydrothermal system of Merapi volcano

    NASA Astrophysics Data System (ADS)

    Byrdina, S.; Friedel, S.; Vandemeulebrouck, J.; Budi-Santoso, A.; Suhari; Suryanto, W.; Rizal, M. H.; Winata, E.; Kusdaryanto

    2017-01-01

    We present an image of the hydrothermal system of Merapi volcano based on results from electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT models identify two distinct low-resistivity bodies interpreted as two parts of a probably interconnected hydrothermal system: at the base of the south flank and in the summit area. In the summit area, a sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20-50 Ω m) from the resistive andesite lava flows and pyroclastic deposits (2000-50,000 Ω m). The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The significative diffuse CO2 degassing (with a median value of 400 g m-2 d-1) is observed in a narrow vicinity of the active crater rim and close to the ancient rim of Pasar-Bubar. The total CO2 degassing across the accessible summital area with a surface of 1.4 ṡ 105 m2 is around 20 t d-1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200-230 t d-1). This drop in the diffuse degassing from the summit area can be related to the decrease in the magmatic activity, to the change of the summit morphology, to the approximations used by Toutain et al. (2009), or, more likely, to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100,000 Ω m, resistivity as low as 10 Ω m has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. No evidence of the hydrothermal system is found on the basis of the north flank at the same depth. This asymmetry might be caused by the asymmetry of the heat supply source of Merapi whose activity is moving south or/and to the asymmetry in

  19. Abiotic Organic Chemistry in Hydrothermal Systems.

    NASA Astrophysics Data System (ADS)

    Simoneit, B. R.; Rushdi, A. I.

    2004-12-01

    Abiotic organic chemistry in hydrothermal systems is of interest to biologists, geochemists and oceanographers. This chemistry consists of thermal alteration of organic matter and minor prebiotic synthesis of organic compounds. Thermal alteration has been extensively documented to yield petroleum and heavy bitumen products from contemporary organic detritus. Carbon dioxide, carbon monoxide, ammonia and sulfur species have been used as precursors in prebiotic synthesis experiments to organic compounds. These inorganic species are common components of hot spring gases and marine hydrothermal systems. It is of interest to further test their reactivities in reductive aqueous thermolysis. We have synthesized organic compounds (lipids) in aqueous solutions of oxalic acid, and with carbon disulfide or ammonium bicarbonate at temperatures from 175-400° C. The synthetic lipids from oxalic acid solutions consisted of n-alkanols, n-alkanoic acids, n-alkyl formates, n-alkanones, n-alkenes and n-alkanes, typically to C30 with no carbon number preferences. The products from CS2 in acidic aqueous solutions yielded cyclic thioalkanes, alkyl polysulfides, and thioesters with other numerous minor compounds. The synthesis products from oxalic acid and ammonium bicarbonate solutions were homologous series of n-alkyl amides, n-alkyl amines, n-alkanes and n-alkanoic acids, also to C30 with no carbon number predominance. Condensation (dehydration) reactions also occur under elevated temperatures in aqueous medium as tested by model reactions to form amide, ester and nitrile bonds. It is concluded that the abiotic formation of aliphatic lipids, condensation products (amides, esters, nitriles, and CS2 derivatives (alkyl polysulfides, cyclic polysulfides) is possible under hydrothermal conditions and warrants further studies.

  20. Endeavour on the Horizon

    NASA Image and Video Library

    2010-04-30

    NASA Mars Exploration Rover Opportunity used its panoramic camera Pancam to capture this view approximately true-color view of the rim of Endeavour crater, the rover destination in a multi-year traverse along the sandy Martian landscape.

  1. Context of ancient aqueous environments on Mars from in situ geologic mapping at Endeavour Crater

    USGS Publications Warehouse

    Crumpler, L.S.; Arvidson, R. E.; Bell, J.; Clark, B. C.; Cohen, B. A.; Farrand, W. H.; Gellert, Ralf; Golombek, M.; Grant, J. A.; Guinness, E.; Herkenhoff, Kenneth E.; Johnson, J. R.; Jolliff, B.; Ming, D. W.; Mittlefehldt, D. W.; Parker, T.; Rice, J. W.; Squyres, S. W.; Sullivan, R.; Yen, A. S.

    2015-01-01

    Using the Mars Exploration Rover Opportunity, we have compiled one of the first field geologic maps on Mars while traversing the Noachian terrain along the rim of the 22 km diameter Endeavour Crater (Latitude −2°16′33″, Longitude −5°10′51″). In situ mapping of the petrographic, elemental, structural, and stratigraphic characteristics of outcrops and rocks distinguishes four mappable bedrock lithologic units. Three of these rock units predate the surrounding Burns formation sulfate-rich sandstones and one, the Matijevic Formation, represents conditions on early Mars predating the formation of Endeavour Crater. The stratigraphy assembled from these observations includes several geologic unconformities. The differences in lithologic units across these unconformities record changes in the character and intensity of the Martian aqueous environment over geologic time. Water circulated through fractures in the oldest rocks over periods long enough that texturally and elementally significant alteration occurred in fracture walls. These oldest pre-Endeavour rocks and their network of mineralized and altered fractures were preserved by burial beneath impact ejecta and were subsequently exhumed and exposed. The alteration along joints in the oldest rocks and the mineralized veins and concentrations of trace metals in overlying lithologic units is direct evidence that copious volumes of mineralized and/or hydrothermal fluids circulated through the early Martian crust. The wide range in intensity of structural and chemical modification from outcrop to outcrop along the crater rim shows that the ejecta of large (>8 km in diameter) impact craters is complex. These results imply that geologic complexity is to be anticipated in other areas of Mars where cratering has been a fundamental process in the local and regional geology and mineralogy.

  2. Endeavour's crew is greeted by Dan Goldin

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Following a successful landing, the crew of Endeavour exit the Crew Transport Vehicle and are greeted by NASA Administrator Daniel Goldin. First down the stairs is Commander Brent Jett. Behind him are Pilot Michael Bloomfield and Mission Specialists Joseph Tanner, Marc Garneau and Carlos Noriega. Garneau is with the Canadian Space Agency. On the 4.4-million-mile mission, Endeavour carried the P6 Integrated Truss Structure with solar arrays to power the International Space Station. The arrays and other equipment were installed during three EVAs that totaled 19 hours, 20 minutes. Endeavour was docked with the Space Station for 6 days, 23 hours, 13 minutes. This is the 16th nighttime landing for a Space Shuttle and the 53rd at Kennedy Space Center.

  3. Starting Conditions for Hydrothermal Systems Underneath Martian Craters: Hydrocode Modeling

    NASA Technical Reports Server (NTRS)

    Pierazzo, E.; Artemieva, N. A.; Ivanov, B. A.

    2004-01-01

    Mars is the most Earth-like of the Solar System s planets, and the first place to look for any sign of present or past extraterrestrial life. Its surface shows many features indicative of the presence of surface and sub-surface water, while impact cratering and volcanism have provided temporary and local surface heat sources throughout Mars geologic history. Impact craters are widely used ubiquitous indicators for the presence of sub-surface water or ice on Mars. In particular, the presence of significant amounts of ground ice or water would cause impact-induced hydrothermal alteration at Martian impact sites. The realization that hydrothermal systems are possible sites for the origin and early evolution of life on Earth has given rise to the hypothesis that hydrothermal systems may have had the same role on Mars. Rough estimates of the heat generated in impact events have been based on scaling relations, or thermal data based on terrestrial impacts on crystalline basements. Preliminary studies also suggest that melt sheets and target uplift are equally important heat sources for the development of a hydrothermal system, while its lifetime depends on the volume and cooling rate of the heat source, as well as the permeability of the host rocks. We present initial results of two-dimensional (2D) and three-dimensional (3D) simulations of impacts on Mars aimed at constraining the initial conditions for modeling the onset and evolution of a hydrothermal system on the red planet. Simulations of the early stages of impact cratering provide an estimate of the amount of shock melting and the pressure-temperature distribution in the target caused by various impacts on the Martian surface. Modeling of the late stage of crater collapse is necessary to characterize the final thermal state of the target, including crater uplift, and distribution of the heated target material (including the melt pool) and hot ejecta around the crater.

  4. Chemistry of a serpentinization-controlled hydrothermal system at the Lost City hydrothermal vent field

    NASA Astrophysics Data System (ADS)

    Ludwig, K. A.; Kelley, D. S.; Butterfield, D. A.; Nelson, B. K.; Karson, J. A.

    2003-12-01

    The Lost City Hydrothermal Field (LCHF), at 30° N near the Mid-Atlantic Ridge, is an off-axis, low temperature, high-pH, ultramafic-hosted vent system. Within the field, carbonate chimneys tower up to 60 m above the seafloor, making them the tallest vent structures known. The chemistry of the vent structures and fluids at the LCHF is controlled by reactions between seawater and ultramafic rocks beneath the Atlantis massif. Mixing of warm alkaline vent fluids with seawater causes precipitation of calcium carbonate and growth of the edifaces, which range from tall, graceful pinnacles to fragile flanges and colloform deposits. Geochemical and petrological analyses of the carbonate rocks reveal distinct differences between the active and extinct structures. Actively venting chimneys and flanges are extremely porous, friable formations composed predominantly of aragonite and brucite. These structures provide important niches for well-developed microbial communities that thrive on and within the chimney walls. Some of the active chimneys may also contain the mineral ikaite, an unstable, hydrated form of calcium carbonate. TIMS and ICP-MS analyses of the carbonate chimneys show that the most active chimneys have low Sr isotope values and that they are low in trace metals (e.g., Mn, Ti, Pb). Active structures emit high-pH, low-Mg fluids at 40-90° C. The fluids also have low Sr values, indicating circulation of hydrothermal solutions through the serpentinite bedrock beneath the field. In contrast to the active structures, extinct chimneys are less porous, are well lithified, and they are composed predominantly of calcite that yields Sr isotopes near seawater values. Prolonged lower temperature seawater-hydrothermal fluid interaction within the chimneys results in the conversion of aragonite to calcite and in the enrichment of some trace metals (e.g., Mn, Ti, Co, Zn). It also promotes the incorporation of foraminifera within the outer, cemented walls of the carbonate

  5. Spatial distribution of marine crenarchaeota group I in the vicinity of deep-sea hydrothermal systems.

    PubMed

    Takai, Ken; Oida, Hanako; Suzuki, Yohey; Hirayama, Hisako; Nakagawa, Satoshi; Nunoura, Takuro; Inagaki, Fumio; Nealson, Kenneth H; Horikoshi, Koki

    2004-04-01

    Distribution profiles of marine crenarchaeota group I in the vicinity of deep-sea hydrothermal systems were mapped with culture-independent molecular techniques. Planktonic samples were obtained from the waters surrounding two geographically and geologically distinct hydrothermal systems, and the abundance of marine crenarchaeota group I was examined by 16S ribosomal DNA clone analysis, quantitative PCR, and whole-cell fluorescence in situ hybridization. A much higher proportion of marine crenarchaeota group I within the microbial community was detected in deep-sea hydrothermal environments than in normal deep and surface seawaters. The highest proportion was always obtained from the ambient seawater adjacent to hydrothermal emissions and chimneys but not from the hydrothermal plumes. These profiles were markedly different from the profiles of epsilon-Proteobacteria, which are abundant in the low temperatures of deep-sea hydrothermal environments.

  6. Entropy Production in Convective Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Boersing, Nele; Wellmann, Florian; Niederau, Jan

    2016-04-01

    Exploring hydrothermal reservoirs requires reliable estimates of subsurface temperatures to delineate favorable locations of boreholes. It is therefore of fundamental and practical importance to understand the thermodynamic behavior of the system in order to predict its performance with numerical studies. To this end, the thermodynamic measure of entropy production is considered as a useful abstraction tool to characterize the convective state of a system since it accounts for dissipative heat processes and gives insight into the system's average behavior in a statistical sense. Solving the underlying conservation principles of a convective hydrothermal system is sensitive to initial conditions and boundary conditions which in turn are prone to uncertain knowledge in subsurface parameters. There exist multiple numerical solutions to the mathematical description of a convective system and the prediction becomes even more challenging as the vigor of convection increases. Thus, the variety of possible modes contained in such highly non-linear problems needs to be quantified. A synthetic study is carried out to simulate fluid flow and heat transfer in a finite porous layer heated from below. Various two-dimensional models are created such that their corresponding Rayleigh numbers lie in a range from the sub-critical linear to the supercritical non-linear regime, that is purely conductive to convection-dominated systems. Entropy production is found to describe the transient evolution of convective processes fairly well and can be used to identify thermodynamic equilibrium. Additionally, varying the aspect ratio for each Rayleigh number shows that the variety of realized convection modes increases with both larger aspect ratio and higher Rayleigh number. This phenomenon is also reflected by an enlarged spread of entropy production for the realized modes. Consequently, the Rayleigh number can be correlated to the magnitude of entropy production. In cases of moderate

  7. Reconstruction of Ancestral Hydrothermal Systems on Mount Rainier Using Hydrothermally Altered Rocks in Holocene Debris Flows and Tephras

    NASA Astrophysics Data System (ADS)

    John, D. A.; Breit, G. N.; Sisson, T. W.; Vallance, J. W.; Rye, R. O.

    2005-12-01

    geophysical data, as well as analog fossil hydrothermal systems in volcanoes elsewhere, constrain hydrothermal alteration geometry on the pre-Osceola-collapse edifice of Mount Rainier. Relatively narrow zones of acid magmatic-hydrothermal alteration in the central core of the volcano grade to more widely distributed smectite-pyrite alteration farther out on the upper flanks, capped by steam-heated alteration with a large component of alteration resulting from condensation of fumarolic vapor above the water table. Alteration was polygenetic in zones formed episodically, and was strongly controlled by fluxes of heat and magmatic fluid and by local permeability.

  8. STS-108 Endeavour Launch from Pad 39-B

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-108 Endeavour Launch from Pad 39-B KSC-01PD-1785 KENNEDY SPACE CENTER, Fla. -- Space Shuttle Endeavour soars into a twilight sky on mission STS-108, the second attempt over two days. Liftoff occurred at 5:19:28 p.m. EST (10:19.28 GMT). Endeavour will dock with the International Space Station on Dec. 7. STS-108 is the final Shuttle mission of 2001and the 107th Shuttle flight overall. It is the 12th flight to the Space Station. Landing of the orbiter at KSC's Shuttle Landing Facility is targeted for 1:05 p.m. EST (6:05 p.m. GMT) Dec. 16.

  9. STS-108 Endeavour Launch from Pad 39-B

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-108 Endeavour Launch from Pad 39-B KSC-01PD-1786 KENNEDY SPACE CENTER, Fla. -- Like a lighted taper, Space Shuttle Endeavour shines atop its twisted contrail as it soars into space on mission STS-108. Liftoff occurred at 5:19:28 p.m. EST (10:19.28 GMT). Endeavour will dock with the International Space Station on Dec. 7. STS-108 is the final Shuttle mission of 2001and the 107th Shuttle flight overall. It is the 12th flight to the Space Station. Landing of the orbiter at KSC's Shuttle Landing Facility is targeted for 1:05 p.m. EST (6:05 p.m. GMT) Dec. 16.

  10. View of Endeavour's STBD longeron and MEPSI deploy during STS-113

    NASA Image and Video Library

    2002-12-02

    STS113-370-012 (2 December 2002) --- The horizon of a blue and white Earth and the blackness of space form the backdrop for this view, as two miniature satellites are released from the Space Shuttle Endeavour as part of an experiment referred to as MEPSI. Funded by the Defense Advance Research Projects Agency (DARPA), the two small satellites, which are tethered together, were released from Endeavour’s payload bay (visible in foreground) to fly free for three days as a technology demonstration of the launcher and use of micro- and nano-technologies in space systems.

  11. Catalytic Diversity in Alkaline Hydrothermal Vent Systems on Ocean Worlds

    NASA Astrophysics Data System (ADS)

    Cameron, Ryan D.; Barge, Laura; Chin, Keith B.; Doloboff, Ivria J.; Flores, Erika; Hammer, Arden C.; Sobron, Pablo; Russell, Michael J.; Kanik, Isik

    2016-10-01

    Hydrothermal systems formed by serpentinization can create moderate-temperature, alkaline systems and it is possible that this type of vent could exist on icy worlds such as Europa which have water-rock interfaces. It has been proposed that some prebiotic chemistry responsible for the emergence of life on Earth and possibly other wet and icy worlds could occur as a result ofredox potential and pH gradients in submarine alkaline hydrothermal vents (Russell et al., 2014). Hydrothermal chimneys formed in laboratory simulations of alkaline vents under early Earth conditions have precipitate membranes that contain minerals such as iron sulfides, which are hypothesized to catalyze reduction of CO2 (Yamaguchi et al. 2014, Roldan et al. 2014) leading to further organic synthesis. This CO2 reduction process may be affected by other trace components in the chimney, e.g. nickel or organic molecules. We have conducted experiments to investigate catalytic properties of iron and iron-nickel sulfides containing organic dopants in slightly acidic ocean simulants relevant to early Earth or possibly ocean worlds. We find that the electrochemical properties of the chimney as well as the morphology/chemistry of the precipitate are affected by the concentration and type of organics present. These results imply that synthesis of organics in water-rock systems on ocean worlds may lead to hydrothermal precipitates which can incorporate these organic into the mineral matrix and may affect the role of gradients in alkaline vent systems.Therefore, further understanding on the electroactive roles of various organic species within hydrothermal chimneys will have important implications for habitability as well as prebiotic chemistry. This work is funded by NASA Astrobiology Institute JPL Icy Worlds Team and a NAI Director's Discretionary Fund award.Yamaguchi A. et al. (2014) Electrochimica Acta, 141, 311-318.Russell, M. J. et al. (2014), Astrobiology, 14, 308-43.Roldan, A. (2014) Chem. Comm. 51

  12. Numerical Modeling of Multiphase Fluid Flow in Ore-Forming Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Weis, P.; Driesner, T.; Coumou, D.; Heinrich, C. A.

    2007-12-01

    Two coexisting fluid phases - a variably saline liquid and a vapor phase - are ubiquitous in ore-forming and other hydrothermal systems. Understanding the dynamics of phase separation and the distinct physical and chemical evolution of the two fluids probably plays a key role in generating different ore deposit types, e.g. porphyry type, high and low sulfidation Cu-Mo-Au deposits. To this end, processes within hydrothermal systems have been studied with a refined numerical model describing fluid flow in transient porous media (CSP~5.0). The model is formulated on a mass, energy and momentum conserving finite-element-finite-volume (FEFV) scheme and is capable of simulating multiphase flow of NaCl-H20 fluids. Fluid properties are computed from an improved equation of state (SOWAT~2.0). It covers conditions with temperatures of up to 1000 degrees~C, pressures of up to 500 MPa, and fluid salinities of 0~to 100%~NaCl. In particular, the new set-up allows for a more accurate description of fluid phase separation during boiling of hydrothermal fluids into a vapor and a brine phase. The geometric flexibility of the FEFV-meshes allows for investigations of a large variety of geological settings, ranging from ore-forming processes in magmatic hydrothermal system to the dynamics of black smokers at mid-ocean ridges. Simulations demonstrated that hydrothermal convection patterns above cooling plutons are primarily controlled by the system-scale permeability structure. In porphyry systems, high fluid pressures develop in a stock rising from the magma chamber which can lead to rock failure and, eventually, an increase in permeability due to hydrofracturing. Comparisons of the thermal evolution as inferred from modeling studies with data from fluid inclusion studies of the Pb-Zn deposits of Madan, Bulgaria are in a strikingly good agreement. This indicates that cross-comparisons of field observations, analytical data and numerical simulations will become a powerful tool towards a

  13. STS-111 Onboard Photo of Endeavour Docking With PMA-2

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The STS-111 mission, the 14th Shuttle mission to visit the International Space Station (ISS), was launched on June 5, 2002 aboard the Space Shuttle Orbiter Endeavour. On board were the STS-111 and Expedition Five crew members. Astronauts Kerneth D. Cockrell, commander; Paul S. Lockhart, pilot, and mission specialists Franklin R. Chang-Diaz and Philippe Perrin were the STS-111 crew members. Expedition Five crew members included Cosmonaut Valeri G. Korzun, commander, Astronaut Peggy A. Whitson and Cosmonaut Sergei Y. Treschev, flight engineers. Three space walks enabled the STS-111 crew to accomplish mission objectives: The delivery and installation of the Mobile Remote Servicer Base System (MBS), an important part of the Station's Mobile Servicing System that allows the robotic arm to travel the length of the Station, which is necessary for future construction tasks; the replacement of a wrist roll joint on the Station's robotic arm; and the task of unloading supplies and science experiments from the Leonardo multipurpose Logistics Module, which made its third trip to the orbital outpost. In this photograph, the Space Shuttle Endeavour, back dropped by the blackness of space, is docked to the pressurized Mating Adapter (PMA-2) at the forward end of the Destiny Laboratory on the ISS. Endeavour's robotic arm is in full view as it is stretched out with the S0 (S-zero) Truss at its end.

  14. STS-108 Endeavour Launch from Pad 39-B

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-108 Endeavour Launch from Pad 39-B KSC-01PD-1787 KENNEDY SPACE CENTER, Fla. -- Spewing flames and smoke, Space Shuttle Endeavour hurtles into the twilight sky on mission STS-108. The second attempt in two days, liftoff occurred at 5:19:28 p.m. EST (10:19.28 GMT). Endeavour will dock with the International Space Station on Dec. 7. STS-108 is the final Shuttle mission of 2001and the 107th Shuttle flight overall. It is the 12th flight to the Space Station. Landing of the orbiter at KSC's Shuttle Landing Facility is targeted for 1:05 p.m. EST (6:05 p.m. GMT) Dec. 16.

  15. Liftoff of STS-59 Shuttle Endeavour

    NASA Image and Video Library

    1994-04-09

    STS059-S-036 (9 April 1994) --- The liftoff of the Space Shuttle Endeavour is backdropped against a dawn sky at the Kennedy Space Center (KSC) as six NASA astronauts head for a week and a half in Earth orbit. The morning sky allows for a contrasting backdrop for the diamond shock effect of the thrust from Endeavour's main engines. Liftoff occurred at 7:05 a.m. (EDT), April 9, 1994. Onboard for the Space Radar Laboratory (SRL-1) mission were astronauts Sidney M. Gutierrez, Kevin P. Chilton, Jerome (Jay) Apt, Linda M. Godwin, Michael R. U. (Rich) Clifford and Thomas D. Jones.

  16. STS-69 crewmembers on Endeavour's flight deck

    NASA Image and Video Library

    1995-09-25

    STS069-363-010 (7-18 September 1995) --- Astronaut Kenneth D. Cockrell, pilot, looks over a logbook on Space Shuttle Endeavour’s flight deck during rendezvous operations involving one of two temporarily free-flying craft. Astronaut James H. Newman (background), mission specialist, eyeballs the target. Endeavour, with a five-member crew, launched on September 7, 1995, from the Kennedy Space Center (KSC). The multifaceted mission ended September 18, 1995, with a successful landing on Runway 33 at KSC.

  17. STS-99 Endeavour lifts off from Launch Pad 39A

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Through the shrubs surrounding the water near Launch Pad 39A can be seen Space Shuttle Endeavour roaring into the clear blue Florida sky on mission STS-99. aunch of Endeavour occurred at 12:43:40 p.m. EST. Known as the Shuttle Radar Topography Mission (SRTM), STS-99 will chart a new course to produce unrivaled 3-D images of the Earth's surface. The result of the SRTM could be close to 1 trillion measurements of the Earth's topography. The mission is expected to last 11days, with Endeavour landing at KSC Tuesday, Feb. 22, at 4:36 p.m. EST. This is the 97th Shuttle flight and 14th for Shuttle Endeavour.

  18. Fractures, Faults, and Hydrothermal Systems of Puna, Hawaii, and Montserrat, Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Kenedi, Catherine Lewis

    The focus of this work is to use geologic and geophysical methods to better understand the faults and fracture systems at Puna, in southeastern Hawaii, and southern Montserrat, in the Lesser Antilles. The particular interest is understanding and locating the deep fracture networks that are necessary for fluid circulation in hydrothermal systems. The dissertation first presents a study in which identification of large scale faulting places Montserrat into a tectonic context. Then follow studies of Puna and Montserrat that focus on faults and fractures of the deep hydrothermal systems. The first chapter consists of the results of the SEA-CALIPSO experiment seismic reflection data, recorded on a 48 channel streamer with the active source as a 2600 in3 airgun. This chapter discusses volcaniclastic debris fans off the east coast of Montserrat and faults off the west coast. The work places Montserrat in a transtensional environment (influenced by oblique subduction) as well as in a complex local stress regime. One conclusion is that the stress regime is inconsistent with the larger arc due to the influence of local magmatism and stress. The second chapter is a seismic study of the Puna hydrothermal system (PHS) along the Kilauea Lower East Rift Zone. The PHS occurs at a left step in the rift, where a fracture network has been formed between fault segments. It is a productive geothermal field, extracting steam and reinjecting cooled, condensed fluids. A network of eight borehole seismometers recorded >6000 earthquakes. Most of the earthquakes are very small (< M.2), and shallow (1-3 km depth), likely the result of hydrothermal fluid reinjection. Deeper earthquakes occur along the rift as well as along the south-dipping fault plane that originates from the rift zone. Seismic methods applied to the PHS data set, after the initial recording, picking, and locating earthquakes, include a tomographic inversion of the P-wave first arrival data. This model indicates a high

  19. Coupled cycling of Fe and organic carbon in submarine hydrothermal systems: Modelling approach

    NASA Astrophysics Data System (ADS)

    Legendre, Louis; German, Christopher R.; Sander, Sylvia G.; Niquil, Nathalie

    2014-05-01

    It has been recently proposed that hydrothermal plumes may be a significant source of dissolved Fe to the oceans. In order to assess this proposal, we investigated the fate of dissolved Fe released from hydrothermal systems to the overlying ocean using an approach that combined modelling and field values. We based our work on a consensus conceptual model developed by members of SCOR-InterRidge Working Group 135. The model was both complex enough to capture the main processes of dissolved Fe released from hydrothermal systems and chemical transformation in the hydrothermal plume, and simple enough to be parameterized with existing field data. It included the following flows: Fe, water and heat in the high temperature vent fluids, in the fluids diffusing around the vent, and in the entrained seawater in the buoyant plume; Fe precipitation in polymetallic sulphides near the vent; transport of Fe in the non-buoyant plume, and both its precipitation in particles onto the sea bottom away from the vent and dissolution into deep-sea waters. In other words, there were three Fe input flows into the buoyant hydrothermal plume (vent-fluids; entrained diffuse flow; entrained seawater) and three Fe output flows (sedimentation from the buoyant plume as polymetallic sulfides; sedimentation from the non-buoyant plume in particulate form; export to the deep ocean in dissolved or nanoparticulate form). The output flows balanced the input flows. We transformed the conceptual model into equations, and parameterized these with field data. To do so, we assumed that all hydrothermal systems, globally, can be represented by the circumstances that prevail at the EPR 9°50'N hydrothermal field, although we knew this assumption not to be accurate. We nevertheless achieved, by following this approach, two important goals, i.e. we could assemble into a coherent framework, for the first time, several discrete data sets acquired independently over decades of field work, and we could obtain model

  20. Cdr. Wilcutt shaves onboard Endeavour

    NASA Image and Video Library

    1998-03-02

    STS089-375-018 (22-31 Jan. 1998) --- Astronaut Terrence W. (Terry) Wilcutt, STS-89 mission commander, uses a battery-powered razor to shave aboard the Earth-orbiting space shuttle Endeavour. Photo credit: NASA

  1. Molybdenum isotope behaviour in groundwaters and terrestrial hydrothermal systems, Iceland

    NASA Astrophysics Data System (ADS)

    Neely, Rebecca A.; Gislason, Sigurdur R.; Ólafsson, Magnus; McCoy-West, Alex J.; Pearce, Christopher R.; Burton, Kevin W.

    2018-03-01

    Molybdenum (Mo) isotopes have proved useful in the reconstruction of paleoredox conditions. Their application generally relies upon a simplified model of ocean inputs in which rivers dominate Mo fluxes to the oceans and hydrothermal fluids are considered to be a minor contribution. To date, however, little attention has been paid to the extent of Mo isotope variation of hydrothermal waters, or to the potential effect of direct groundwater discharge to the oceans. Here we present Mo isotope data for two Icelandic groundwater systems (Mývatn and Þeistareykir) that are both influenced by hydrothermal processes. Relative to NIST 3134 = +0.25‰, the cold (<10 °C) groundwaters (δ98/95MoGROUNDWATER = -0.15‰ to +0.47‰; n = 13) show little, if any, fractionation from the host basalt (δ 98 / 95MoBASALT = +0.16‰ to -0.12‰) and are, on average, lighter than both global and Icelandic rivers. In contrast, waters that are hydrothermally influenced (>10 °C) possess isotopically heavy δ98/95MoHYDROTHERMAL values of +0.25‰ to +2.06‰ (n = 18) with the possibility that the high temperature endmembers are even heavier. Although the mechanisms driving this fractionation remain unresolved, the incongruent dissolution of the host basalt and both the dissolution and precipitation of sulfides are considered. Regardless of the processes driving these variations, the δ98Mo data presented in this study indicate that groundwater and hydrothermal waters have the potential to modify ocean budget calculations.

  2. STS-108 Endeavour Launch from Pad 39-B

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-108 Endeavour Launch from Pad 39-B KSC-01PD-1788 KENNEDY SPACE CENTER, Fla. -- A pool of water near Launch Pad 39B turns crimson from the reflection of flames at the launch of Space Shuttle Endeavour on mission STS-109. The second attempt in two days, liftoff occurred at 5:19:28 p.m. EST (10:19.28 GMT). Endeavour will dock with the International Space Station on Dec. 7. STS-108 is the final Shuttle mission of 2001and the 107th Shuttle flight overall. It is the 12th flight to the Space Station. Landing of the orbiter at KSC's Shuttle Landing Facility is targeted for 1:05 p.m. EST (6:05 p.m. GMT) Dec. 16.

  3. Endeavour on way to Pad 39B for STS-77

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A road sign points the way to Launch Pad 39B, the final earthly destination for the Space Shuttle Endeavour and its steppingstone into space. Endeavour began the slow journey from the Vehicle Assembly Building at about 10 a.m., April 16, perched atop the mobile launcher platform and carried by the crawler-transporter. Upcoming activities at the pad to prepare Endeavour for flight on Mission STS-77 include installation of the payloads in the orbiter's payload bay.

  4. Bacterial Diversity and Biogeochemistry of Two Marine Shallow-Water Hydrothermal Systems off Dominica (Lesser Antilles).

    PubMed

    Pop Ristova, Petra; Pichler, Thomas; Friedrich, Michael W; Bühring, Solveig I

    2017-01-01

    Shallow-water hydrothermal systems represent extreme environments with unique biogeochemistry and high biological productivity, at which autotrophic microorganisms use both light and chemical energy for the production of biomass. Microbial communities of these ecosystems are metabolically diverse and possess the capacity to transform a large range of chemical compounds. Yet, little is known about their diversity or factors shaping their structure or how they compare to coastal sediments not impacted by hydrothermalism. To this end, we have used automated ribosomal intergenic spacer analysis (ARISA) and high-throughput Illumina sequencing combined with porewater geochemical analysis to investigate microbial communities along geochemical gradients in two shallow-water hydrothermal systems off the island of Dominica (Lesser Antilles). At both sites, venting of hydrothermal fluids substantially altered the porewater geochemistry by enriching it with silica, iron and dissolved inorganic carbon, resulting in island-like habitats with distinct biogeochemistry. The magnitude of fluid flow and difference in sediment grain size, which impedes mixing of the fluids with seawater, were correlated with the observed differences in the porewater geochemistry between the two sites. Concomitantly, individual sites harbored microbial communities with a significantly different community structure. These differences could be statistically linked to variations in the porewater geochemistry and the hydrothermal fluids. The two shallow-water hydrothermal systems of Dominica harbored bacterial communities with high taxonomical and metabolic diversity, predominated by heterotrophic microorganisms associated with the Gammaproteobacterial genera Pseudomonas and Pseudoalteromonas , indicating the importance of heterotrophic processes. Overall, this study shows that shallow-water hydrothermal systems contribute substantially to the biogeochemical heterogeneity and bacterial diversity of coastal

  5. Bacterial Diversity and Biogeochemistry of Two Marine Shallow-Water Hydrothermal Systems off Dominica (Lesser Antilles)

    PubMed Central

    Pop Ristova, Petra; Pichler, Thomas; Friedrich, Michael W.; Bühring, Solveig I.

    2017-01-01

    Shallow-water hydrothermal systems represent extreme environments with unique biogeochemistry and high biological productivity, at which autotrophic microorganisms use both light and chemical energy for the production of biomass. Microbial communities of these ecosystems are metabolically diverse and possess the capacity to transform a large range of chemical compounds. Yet, little is known about their diversity or factors shaping their structure or how they compare to coastal sediments not impacted by hydrothermalism. To this end, we have used automated ribosomal intergenic spacer analysis (ARISA) and high-throughput Illumina sequencing combined with porewater geochemical analysis to investigate microbial communities along geochemical gradients in two shallow-water hydrothermal systems off the island of Dominica (Lesser Antilles). At both sites, venting of hydrothermal fluids substantially altered the porewater geochemistry by enriching it with silica, iron and dissolved inorganic carbon, resulting in island-like habitats with distinct biogeochemistry. The magnitude of fluid flow and difference in sediment grain size, which impedes mixing of the fluids with seawater, were correlated with the observed differences in the porewater geochemistry between the two sites. Concomitantly, individual sites harbored microbial communities with a significantly different community structure. These differences could be statistically linked to variations in the porewater geochemistry and the hydrothermal fluids. The two shallow-water hydrothermal systems of Dominica harbored bacterial communities with high taxonomical and metabolic diversity, predominated by heterotrophic microorganisms associated with the Gammaproteobacterial genera Pseudomonas and Pseudoalteromonas, indicating the importance of heterotrophic processes. Overall, this study shows that shallow-water hydrothermal systems contribute substantially to the biogeochemical heterogeneity and bacterial diversity of coastal

  6. STS-111 Onboard Photo of Endeavour Docking With PMA-2

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The STS-111 mission, the 14th Shuttle mission to visit the International Space Station (ISS), was launched on June 5, 2002 aboard the Space Shuttle Orbiter Endeavour. On board were the STS-111 and Expedition Five crew members. Astronauts Kerneth D. Cockrell, commander; Paul S. Lockhart, pilot, and mission specialists Franklin R. Chang-Diaz and Philippe Perrin were the STS-111 crew members. Expedition Five crew members included Cosmonaut Valeri G. Korzun, commander, Astronaut Peggy A. Whitson and Cosmonaut Sergei Y. Treschev, flight engineers. Three space walks enabled the STS-111 crew to accomplish the delivery and installation of the Mobile Remote Servicer Base System (MBS), an important part of the Station's Mobile Servicing System that allows the robotic arm to travel the length of the Station, which is necessary for future construction tasks; the replacement of a wrist roll joint on the Station's robotic arm; and the task of unloading supplies and science experiments from the Leonardo multipurpose Logistics Module, which made its third trip to the orbital outpost. In this photograph, the Space Shuttle Endeavour, back dropped by the blackness of space, is docked to the pressurized Mating Adapter (PMA-2) at the forward end of the Destiny Laboratory on the ISS. A portion of the Canadarm2 is visible on the right and Endeavour's robotic arm is in full view as it is stretched out with the S0 (S-zero) Truss at its end.

  7. Study of hydrothermal channels based on near-bottom magnetic prospecting: Application to Longqi hydrothermal area

    NASA Astrophysics Data System (ADS)

    Tao, W.; Tao, C.; Li, H.; Zhaocai, W.; Jinhui, Z.; Qinzhu, C.; Shili, L.

    2014-12-01

    Mid-ocean ridges, largely present far from the continental plates, are characterized by complex geological structures and numerous hydrothermal systems with complex controlling factors. Exploring seafloor sulfide resources for industrial and scientific applications is a challenge. With the advent of geophysical surveys for seabed investigation, near-bottom magnetic prospecting, which yields shallow geological structure, is an efficient method for investigating active and inactive hydrothermal fields and for researching the structure of hydrothermal systems (Tivey et al., 1993, 1996;German et al., 2008). We collected near-bottom magnetic data in the Longqi hydrothermal area, located in the southwest Indian ridge (49.6° E; Zhu et al., 2010; Tao et al., 2014), using the autonomous benthic explorer, an autonomous underwater vehicle, during the second leg of the Chinese cruise DY115-19 on board R/V DaYangYiHao. Based on the results of the intensity of the spatial differential vector method (Seaman et al., 1993), we outline the hydrothermal alternation zone. By building models, we subsequently infer a fault along the discovered hydrothermal vents; this fault line may be connected to a detachment fault (Zhao et al., 2013). In addition, we discuss the channels of the hydrothermal circulation system (Figure 1), and presume that heat was conducted to the sea subsurface by the detachment fault; the aqueous fluid that infiltrated the fault is heated and conveyed to the seafloor, promoting the circulation of the hydrothermal system.

  8. Stable isotopes in seafloor hydrothermal systems: Vent fluids, hydrothermal deposits, hydrothermal alteration, and microbial processes

    USGS Publications Warehouse

    Shanks, Wayne C.

    2001-01-01

    The recognition of abundant and widespread hydrothermal activity and associated unique life-forms on the ocean floor is one of the great scientific discoveries of the latter half of the twentieth century. Studies of seafloor hydrothermal processes have led to revolutions in understanding fluid convection and the cooling of the ocean crust, the chemical and isotopic mass balance of the oceans, the origin of stratiform and statabound massive-sulfide ore-deposits, the origin of greenstones and serpentinites, and the potential importance of the subseafloor biosphere. Stable isotope geochemistry has been a critical and definitive tool from the very beginning of the modern era of seafloor exploration.

  9. The Degradational History of Endeavour Crater, Mars

    NASA Technical Reports Server (NTRS)

    Grant, J. A.; Parker, T. J.; Crumpler, L. S.; Wilson, S. A.; Golombek, M. P.; Mittlefehldt, D. W.

    2015-01-01

    Endeavour crater (2.28 deg S, 354.77 deg E) is a Noachian-aged 22 km-diameter impact structure of complex morphology in Meridiani Planum. The degradation state of the crater has been studied using Mars Reconnaissance Orbiter and Opportunity rover data. Exposed rim segments rise approximately 10 m to approximately 100 m above the level of the embaying Burns Formation and the crater is 200-500 m deep with the southern interior wall exposing over approximately 300 m relief. Both pre-impact rocks (Matijevic Formation) and Endeavour impact ejecta (Shoemaker Formation) are present at Cape York, but only the Shoemaker crops out (up to approximately 140 m) along the rim segment from Murray Ridge to Cape Tribulation. Study of pristine complex craters Bopolu and Tooting, and morphometry of other martian complex craters, enables us to approximate Endeavour's pristine form. The original rim likely averaged 410 m (+/-)200 m in elevation and a 250-275 m section of ejecta ((+/-)50-60 m) would have composed a significant fraction of the rim height. The original crater depth was likely between 1.5 km and 2.2 km. Comparison between the predicted original and current form of Endeavour suggests approximately 100-200 m rim lowering that removed most ejecta in some locales (e.g., Cape York) while thick sections remain elsewhere (e.g., Cape Tribulation). Almost complete removal of ejecta at Cape York and minimal observable offset across fractures indicates current differences in rim relief are not solely due to original rim relief. Rim segments are embayed by approximately 100-200 m thickness of plains rocks outside the crater, but thicker deposits lie inside the crater. Ventifact textures confirm ongoing eolian erosion with the overall extent difficult to estimate. Analogy with degraded Noachian-aged craters south of Endeavour, however, suggests fluvial erosion dominated rim degradation in the Noachian and was likely followed by approximately 10s of meters modification by alternate

  10. Endeavour Lands at LAX

    NASA Image and Video Library

    2012-09-21

    The space shuttle Endeavour, atop the Shuttle Carrier Aircraft, or SCA, lands at Los Angeles International Airport on Tuesday, Sept. 21, 2012 in Los Angeles where it will be placed on public display at the California Science Center. Today's flight marks the final scheduled ferry flight of the Space Shuttle Program. Photo Credit: (NASA/Matt Hedges)

  11. Endeavour Lands at LAX

    NASA Image and Video Library

    2012-09-21

    The space shuttle Endeavour, atop the Shuttle Carrier Aircraft, or SCA, performs a fly-by of Los Angeles International Airport on Tuesday, Sept. 21, 2012 in Los Angeles where it will be placed on public display at the California Science Center. Today's flight marks the final scheduled ferry flight of the Space Shuttle Program. Photo Credit: (NASA/Joel Kowsky)

  12. Vein networks in hydrothermal systems provide constraints for the monitoring of active volcanoes.

    PubMed

    Cucci, Luigi; Di Luccio, Francesca; Esposito, Alessandra; Ventura, Guido

    2017-03-10

    Vein networks affect the hydrothermal systems of many volcanoes, and variations in their arrangement may precede hydrothermal and volcanic eruptions. However, the long-term evolution of vein networks is often unknown because data are lacking. We analyze two gypsum-filled vein networks affecting the hydrothermal field of the active Lipari volcanic Island (Italy) to reconstruct the dynamics of the hydrothermal processes. The older network (E1) consists of sub-vertical, N-S striking veins; the younger network (E2) consists of veins without a preferred strike and dip. E2 veins have larger aperture/length, fracture density, dilatancy, and finite extension than E1. The fluid overpressure of E2 is larger than that of E1 veins, whereas the hydraulic conductance is lower. The larger number of fracture intersections in E2 slows down the fluid movement, and favors fluid interference effects and pressurization. Depths of the E1 and E2 hydrothermal sources are 0.8 km and 4.6 km, respectively. The decrease in the fluid flux, depth of the hydrothermal source, and the pressurization increase in E2 are likely associated to a magma reservoir. The decrease of fluid discharge in hydrothermal fields may reflect pressurization at depth potentially preceding hydrothermal explosions. This has significant implications for the long-term monitoring strategy of volcanoes.

  13. Endeavour's crew poses for a photo

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The STS-97 crew pauses for a photograph before heading for crew quarters. They landed safely at the SLF at 6:04 p.m. EST after a successful mission. From the left are Mission Specialists Joseph Tanner and Carlos Noriega, Commander Brent Jett, Pilot Michael Bloomfield and Mission Specialist Marc Garneau of Canada. Endeavour carried the P6 Integrated Truss Structure with solar arrays to power the International Space Station. The arrays and other equipment were installed during three EVAs that totaled 19 hours, 20 minutes. Endeavour was docked with the Space Station for 6 days, 23 hours, 13 minutes. This was the 16th nighttime landing for a Space Shuttle and the 53rd at Kennedy Space Center.

  14. Resistivity structure and geochemistry of the Jigokudani Valley hydrothermal system, Mt. Tateyama, Japan

    NASA Astrophysics Data System (ADS)

    Seki, Kaori; Kanda, Wataru; Tanbo, Toshiya; Ohba, Takeshi; Ogawa, Yasuo; Takakura, Shinichi; Nogami, Kenji; Ushioda, Masashi; Suzuki, Atsushi; Saito, Zenshiro; Matsunaga, Yasuo

    2016-10-01

    This study clarifies the hydrothermal system of Jigokudani Valley near Mt. Tateyama volcano in Japan by using a combination of audio-frequency magnetotelluric (AMT) survey and hot-spring water analysis in order to assess the potential of future phreatic eruptions in the area. Repeated phreatic eruptions in the area about 40,000 years ago produced the current valley morphology, which is now an active solfatara field dotted with hot springs and fumaroles indicative of a well-developed hydrothermal system. The three-dimensional (3D) resistivity structure of the hydrothermal system was modeled by using the results of an AMT survey conducted at 25 locations across the valley in 2013-2014. The model suggests the presence of a near-surface highly conductive layer of < 50 m in thickness across the entire valley, which is interpreted as a cap rock layer. Immediately below the cap rock is a relatively resistive body interpreted as a gas reservoir. Field measurements of temperature, pH, and electrical conductivity (EC) were taken at various hot springs across the valley, and 12 samples of hot-spring waters were analyzed for major ion chemistry and H2O isotopic ratios. All hot-spring waters had low pH and could be categorized into three types on the basis of the Cl-/SO 42 - concentration ratio, with all falling largely on a mixing line between magmatic fluids and local meteoric water (LMW). The geochemical analysis suggests that the hydrothermal system includes a two-phase zone of vapor-liquid. A comparison of the resistivity structure and the geochemically inferred structure suggests that a hydrothermal reservoir is present at a depth of approximately 500 m, from which hot-spring water differentiates into the three observed types. The two-phase zone appears to be located immediately beneath the cap rock structure. These findings suggest that the hydrothermal system of Jigokudani Valley exhibits a number of factors that could trigger a future phreatic eruption.

  15. Bursch poses next to BPS installed in a slot on Endeavour's middeck for return on STS-111 UF-2

    NASA Image and Video Library

    2002-06-07

    STS111-E-5026 (7 June 2002) --- Astronaut Daniel W. Bursch, who has been aboard the International Space Station (ISS) for the past six months, wastes little time in going to work on board the Space Shuttle Endeavour following linkup of the shuttle and station on June 7, 2002. Bursch, who will return home aboard Endeavour in a few days, is pictured at the Biomass Production System (BPS) on Endeavour's mid deck.

  16. Tomographic imaging of the transition from asthenospheric to lithospheric melt migration processes: 3-D structure of the topmost mantle and crust at the Endeavour Segment, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Arnoux, G. M.; Toomey, D. R.; Hooft, E. E. E.; Wilcock, W. S. D.

    2017-12-01

    We present tomographic images of the intermediate-spreading Endeavour Segment that constrain the nature of an axial magmatic system as it transitions from asthenospheric- to lithospheric-dominated rheologies. We use seismic energy from 5500 air gun shots refracted through the crust (Pg), reflected off the Moho (PmP), and refracted below the Moho (Pn)—as recorded by 64 OBSs from the Endeavour tomography experiment—to image the isotropic and anisotropic P-wave velocity structure of the topmost mantle and crust, as well as crustal thickness. At crustal depths, results reveal a low-velocity zone (LVZ)—inferred to be the axial magmatic system—that: (i) is continuous along the entire Endeavour Segment at depths of 2-3 km below seafloor and closely follows the axis of spreading, (ii) broadens and becomes more discontinuous at lower crustal depths, and (iii) has its largest amplitude from the mid- to lower-crust at the segment center. The ridge-tracking trend of the mid-crustal LVZ is in contrast to the crustal thickness pattern; in particular, a swath of thin crust is skewed with respect to both the ridge axis and the mid-crustal magmatic system and connects two overlapping spreading centers bounding the segment. The trend of thinner crust, however, is aligned with the mantle LVZ, which constrains the thermal structure and distribution of melt within the topmost mantle. The systematic depth variation of the map-view orientation and structure of the magmatic system indicates a distinct transition from a broad, cross-axis regime in the topmost asthenosphere governed by a regional, north-south trending thermal structure, to a narrow, cross-axis regime in the mid- to upper-crust governed by lithospheric rifting, magma injection, and hydrothermal processes. The lower-crustal magmatic system connects these two regimes. We also postulate that accumulation and differentiation of magma immediately beneath the crust-mantle boundary increases temperatures and suppresses

  17. Geologic and hydrologic controls on the economic potential of hydrothermal systems associated with upper crustal plutons

    NASA Astrophysics Data System (ADS)

    Weis, Philipp; Driesner, Thomas; Scott, Samuel; Lecumberri-Sanchez, Pilar

    2016-04-01

    Heat and mass transport in hydrothermal systems associated with upper crustal magmatic intrusions can result in resources with large economic potential (Kesler, 1994). Active hydrothermal systems can form high-enthalpy geothermal reservoirs with the possibility for renewable energy production. Fossil continental or submarine hydrothermal systems may have formed ore deposits at variable crustal depths, which can be mined near today's surface with an economic profit. In both cases, only the right combination of first-order geologic and hydrologic controls may lead to the formation of a significant resource. To foster exploration for these hydrothermal georesources, we need to improve our understanding of subsurface fluxes of mass and energy by combining numerical process modelling, observations at both active and fossil systems, as well as knowledge of fluid and rock properties and their interactions in natural systems. The presentation will highlight the role of non-linear fluid properties, phase separation, salt precipitation, fluid mixing, permeability structure, hydraulic fracturing and the transition from brittle to ductile rock behavior as major geologic and hydrologic controls on the formation of high-enthalpy and supercritical geothermal resources (Scott et al., 2015), and magmatic-hydrothermal mineral resources, such as porphyry copper, massive sulfide and epithermal gold deposits (Lecumberri-Sanchez et al., 2015; Weis, 2015). References: Kesler, S. E., 1994: Mineral Resources, economics and the environment, New York, McMillan, 391. Lecumberri-Sanchez, P., Steele-MacInnis, M., Weis, P., Driesner, T., Bodnar, R.J. (2015): Salt precipitation in magmatic-hydrothermal systems associated with upper crustal plutons. Geology, v. 43, p. 1063-1066, doi:10.1130/G37163.1 Scott, S., Driesner, T., Weis, P. (2015): Geologic controls on supercritical geothermal resources above magmatic intrusions. Nature Communications, 6:7837 doi: 10.1038/ncomms8837 Weis, P. (2015): The

  18. Segments on Western Rim of Endeavour Crater, Mars

    NASA Image and Video Library

    2017-04-19

    This orbital image of the western rim of Mars' Endeavour Crater covers an area about 5 miles (8 kilometers) east-west by about 9 miles (14 kilometers) north-south and indicates the names of some of the raised segments of the rim. NASA's Mars Exploration Rover Opportunity arrived at Endeavour in 2011 after exploring smaller craters to the northwest during its first six years on Mars. It initially explored the "Cape York" segment, then headed south. It reached the northern end of "Cape Tribulation" in late 2014 and the southern tip of that segment in April 2017. A key destination in the "Cape Byron" segment is "Perseverance Valley," where the rover team plans to investigate whether the valley was carved by water, wind or a debris flow initiated by water. This image is from the Context Camera on NASA's Mars Reconnaissance Orbiter. Malin Space Science Systems, San Diego, California, built and operates that camera. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, built and operates Opportunity. https://photojournal.jpl.nasa.gov/catalog/PIA21490

  19. Payload Bay of Endeavour

    NASA Image and Video Library

    2008-11-26

    S126-E-012093 (27 Nov. 2008) --- Backdropped against a massive cloud cover, the aft portion of the Space Shuttle Endeavour, with the multi-purpose logistics module Leonardo in stow mode, was captured in a series of photographs by one of the STS-126 crewmembers on Nov. 27, Thanksgiving day, also the eve of departure from the International Space Station on Nov. 28.

  20. Payload Bay of Endeavour

    NASA Image and Video Library

    2008-11-26

    S126-E-012103 (27 Nov. 2008) --- --- Backdropped against the blackness of space, the aft portion of the Space Shuttle Endeavour, with the multi-purpose logistics module Leonardo in stow mode, was captured in a series of photographs by one of the STS-126 crewmembers on Nov. 27, Thanksgiving day, also the eve of departure from the International Space Station on Nov. 28.

  1. All above Average: Secondary School Improvement as an Impossible Endeavour

    ERIC Educational Resources Information Center

    Taylor, Phil

    2015-01-01

    This article argues that secondary school improvement in England, when viewed as a system, has become an impossible endeavour. This arises from the conflation of improvement with effectiveness, judged by a narrow range of outcome measures and driven by demands that all schools should somehow be above average. The expectation of comparable…

  2. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Robotic arm experts begin inspection of a scrape on the surface of the honeycomb shell on Endeavour's robotic arm. The scrape occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22..

  3. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Robotic arm experts get ready for ultrasound testing on Endeavour's robotic arm. A scrape of the honeycomb shell around the arm occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  4. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- A piece of the honeycomb shell around Endeavour's robotic arm has been cut to inspect the arm. A scrape of the shell occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  5. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Robotic arm experts begin inspection of a scrape on the surface of the honeycomb shell on Endeavour's robotic arm. The scrape occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  6. Caldera unrest driven by CO2-induced drying of the deep hydrothermal system.

    PubMed

    Moretti, R; Troise, C; Sarno, F; De Natale, G

    2018-05-29

    Interpreting volcanic unrest is a highly challenging and non-unique problem at calderas, since large hydrothermal systems may either hide or amplify the dynamics of buried magma(s). Here we use the exceptional ground displacement and geochemical datasets from the actively degassing Campi Flegrei caldera (Southern Italy) to show that ambiguities disappear when the thermal evolution of the deep hydrothermal system is accurately tracked. By using temperatures from the CO 2 -CH 4 exchange of 13 C and thermodynamic analysis of gas ascending in the crust, we demonstrate that after the last 1982-84 crisis the deep hydrothermal system evolved through supercritical conditions under the continuous isenthalpic inflow of hot CO 2 -rich gases released from the deep (~8 km) magma reservoir of regional size. This resulted in the drying of the base of the hot hydrothermal system, no more buffered along the liquid-vapour equilibrium, and excludes any shallow arrival of new magma, whose abundant steam degassing due to decompression would have restored liquid-vapour equilibrium. The consequent CO 2 -infiltration and progressive heating of the surrounding deforming rock volume cause the build-up of pore pressure in aquifers, and generate the striking temporal symmetry that characterizes the ongoing uplift and the post-1984 subsidence, both originated by the same but reversed deformation mechanism.

  7. Functional Metagenomic Investigations of Microbial Communities in a Shallow-Sea Hydrothermal System

    PubMed Central

    Tang, Kai; Liu, Keshao; Jiao, Nianzhi; Zhang, Yao; Chen, Chen-Tung Arthur

    2013-01-01

    Little is known about the functional capability of microbial communities in shallow-sea hydrothermal systems (water depth of <200 m). This study analyzed two high-throughput pyrosequencing metagenomic datasets from the vent and the surface water in the shallow-sea hydrothermal system offshore NE Taiwan. This system exhibited distinct geochemical parameters. Metagenomic data revealed that the vent and the surface water were predominated by Epsilonproteobacteria (Nautiliales-like organisms) and Gammaproteobacteria ( Thiomicrospira -like organisms), respectively. A significant difference in microbial carbon fixation and sulfur metabolism was found between the vent and the surface water. The chemoautotrophic microorganisms in the vent and in the surface water might possess the reverse tricarboxylic acid cycle and the Calvin−Bassham−Benson cycle for carbon fixation in response to carbon dioxide highly enriched in the environment, which is possibly fueled by geochemical energy with sulfur and hydrogen. Comparative analyses of metagenomes showed that the shallow-sea metagenomes contained some genes similar to those present in other extreme environments. This study may serve as a basis for deeply understanding the genetic network and functional capability of the microbial members of shallow-sea hydrothermal systems. PMID:23940820

  8. Hydrothermal Venting at Hinepuia Submarine Volcano, Kermadec Arc: Understanding Magmatic-Hydrothermal Fluid Chemistry

    NASA Astrophysics Data System (ADS)

    Stucker, Valerie K.; Walker, Sharon L.; de Ronde, Cornel E. J.; Caratori Tontini, Fabio; Tsuchida, Shinji

    2017-10-01

    The Hinepuia volcanic center is made up of two distinct edifices aligned northwest to southeast, with an active cone complex in the SE. Hinepuia is one of several active volcanoes in the northern segment of the Kermadec arc. Regional magnetic data show no evidence for large-scale hydrothermal alteration at Hinepuia, yet plume data confirm present-day hydrothermal discharge, suggesting that the hydrothermal system may be too young to have altered the host rocks with respect to measurable changes in magnetic signal. Gravity data are consistent with crustal thinning and shallow mantle under the volcanic center. Following the discovery of hydrothermal plumes over Hinepuia, the submersible Shinkai 6500 was used to explore the SE cone and sample hydrothermal fluids. The chemistry of hydrothermal fluids from submarine arc and backarc volcanoes is typically dominated by water-rock interactions and/or magmatic degassing. Chemical analyses of vent fluids show that Hinepuia does not quite fit either traditional model. Moreover, the Hinepuia samples fall between those typically ascribed to both end-member fluid types when plotted on a K-Mg-SO4 ternary diagram. Due to evidence of strong degassing, abundant native sulfur deposition, and H2S presence, the vent sampled at Hinepuia is ultimately classified as a magmatic-hydrothermal system with a water-rock influence. This vent is releasing water vapor and magmatic volatiles with a notable lack of salinity due to subcritical boiling and phase separation. Magmatic-hydrothermal fluid chemistry appears to be controlled by a combination of gas flux, phase separation processes, and volcano evolution and/or distance from the magma source.

  9. Post-impact hydrothermal system geochemistry and mineralogy: Rochechouart impact structure, France.

    NASA Astrophysics Data System (ADS)

    Simpson, Sarah

    2014-05-01

    Hypervelocity impacts generate extreme temperatures and pressures in target rocks and may permanently alter them. The process of cratering is at the forefront of research involving the study of the evolution and origin of life, both on Mars and Earth, as conditions may be favourable for hydrothermal systems to form. Of the 170 known impact structures on Earth, over one-third are known to contain fossil hydrothermal systems [1]. The introduction of water to a system, when coupled with even small amounts of heat, has the potential to completely alter the target or host rock geochemistry. Often, the mineral assemblages produced in these environments are unique, and are useful indicators of post-impact conditions. The Rochechouart impact structure in South-Central France is dated to 201 ± 2 Ma into a primarily granitic target [2]. Much of the original morphological features have been eroded and very little of the allochthonous impactites remain. This has, however, allowed researchers to study the shock effects on the lower and central areas of the structure, as well as any subsequent hydrothermal activity. Previous work has focused on detailed classification of the target and autochthonous and allochthonous impactites [3, 4], identification of the projectile [5], and dating the structure using Ar-isotope techniques [2]. Authors have also noted geochemical evidence of K-metasomatism, which is pronounced throughout all lithologies as enrichment in K2O and depletion in CaO and Na2O [3, 4, 5]. This indicates a pervasive hydrothermal system, whose effects throughout the structure have yet to be studied in detail, particularly in those parts at and below the transient floor. The purpose of this study is to classify the mineralogical and geochemical effects of the hydrothermal system. Samples were collected via permission from the Réserve Naturelle de l'Astroblème de Rochechouart-Chassenon [6]. Sample selection was based on the presence of secondary mineralization in hand

  10. NASCAR drivers pose in Endeavour

    NASA Image and Video Library

    2003-07-02

    NASCAR driver Dale Jarrett poses outside the hatch of orbiter Endeavour. Jarrett and other drivers Ryan Newman and Jimmie Johnson were on a tour of KSC. The men are scheduled to drive in the Pepsi 400 auto race being held July 5 at the Daytona International Speedway, Daytona Beach.

  11. NASCAR drivers pose in Endeavour

    NASA Image and Video Library

    2003-07-02

    NASCAR driver Jimmie Johnson poses outside the hatch of orbiter Endeavour. Johnson and other drivers Ryan Newman and Dale Jarrett were on a tour of KSC. The men are scheduled to drive in the Pepsi 400 auto race being held July 5 at the Daytona International Speedway, Daytona Beach.

  12. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The opening shown here is the site where the honeycomb shell around Endeavour's robotic arm has been cut to inspect the arm. A scrape of the shell occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  13. Volcano-hydrothermal system and activity of Sirung volcano (Pantar Island, Indonesia)

    NASA Astrophysics Data System (ADS)

    Caudron, Corentin; Bernard, Alain; Murphy, Sam; Inguaggiato, Salvatore; Gunawan, Hendra

    2018-05-01

    Sirung is a frequently active volcano located in the remote parts of Western Timor (Indonesia). Sirung has a crater with several hydrothermal features including a crater lake. We present a timeseries of satellite images of the lake and chemical and isotope data from the hyperacid hydrothermal system. The fluids sampled in the crater present the typical features of hyperacidic systems with high TDS, low pH and δ34SHSO4-δ34SS0 among the highest for such lakes. The cations concentrations are predominantly controlled by the precipitation of alunite, jarosite, silica phases, native sulfur and pyrite which dominate the shallow portions of the hydrothermal system. These minerals may control shallow sealing processes thought to trigger phreatic eruptions elsewhere. Sparse Mg/Cl and SO4/Cl ratios and lake parameters derived from satellite images suggest gradual increase in heat and gas flux, most likely SO2-rich, prior to the 2012 phreatic eruption. An acidic river was sampled 8 km far from the crater and is genetically linked with the fluids rising toward the active crater. This river would therefore be a relevant target for future remote monitoring purposes. Finally, several wells and springs largely exceeded the World Health Organization toxicity limits in total arsenic and fluoride.

  14. Endeavour Impulse Tests

    NASA Image and Video Library

    2003-10-27

    In the Orbiter Processing Facility, Eric Madaras, NASA-Langley Research Center, conducts impulse tests on the right wing leading edge (WLE) of Space Shuttle Endeavour. The tests monitor how sound impulses propagate through the WLE area. The data collected will be analyzed to explore the possibility of adding new instrumentation to the wing that could automatically detect debris or micrometeroid impacts on the Shuttle while in flight. The study is part of the initiative ongoing at KSC and around the agency to return the orbiter fleet to flight status.

  15. Endeavour on the Horizon False Color

    NASA Image and Video Library

    2010-04-30

    NASA Mars Exploration Rover Opportunity used its panoramic camera Pancam to capture this false-color view of the rim of Endeavour crater, the rover destination in a multi-year traverse along the sandy Martian landscape.

  16. NASCAR drivers pose in Endeavour

    NASA Image and Video Library

    2003-07-02

    NASCAR driver Jimmie Johnson gets a close look at the orbiter Endeavour. Johnson and other drivers Ryan Newman and Dale Jarrett were on a tour of KSC. The men are scheduled to drive in the Pepsi 400 auto race being held July 5 at the Daytona International Speedway, Daytona Beach.

  17. NASCAR drivers pose in Endeavour

    NASA Image and Video Library

    2003-07-02

    NASCAR driver Ryan Newman gets a close look at the orbiter Endeavour. Newman and other drivers Jimmie Johnson and Dale Jarrett were on a tour of KSC. The men are scheduled to drive in the Pepsi 400 auto race being held July 5 at the Daytona International Speedway, Daytona Beach.

  18. Acoustic measurement method of the volume flux of a seafloor hydrothermal plume

    NASA Astrophysics Data System (ADS)

    Xu, G.; Jackson, D. R.; Bemis, K. G.; Rona, P. A.

    2011-12-01

    Measuring fluxes (volume, chemical, heat, etc.) of the deep sea hydrothermal vents has been a crucial but challenging task faced by the scientific community since the discovery of the vent systems. However, the great depths and complexities of the hydrothermal vents make traditional sampling methods laborious and almost daunting missions. Furthermore, the samples, in most cases both sparse in space and sporadic in time, are hardly enough to provide a result with moderate uncertainty. In September 2010, our Cabled Observatory Vent Imaging Sonar System (COVIS, http://vizlab.rutgers.edu/AcoustImag/covis.html) was connected to the Neptune Canada underwater ocean observatory network (http://www.neptunecanada.ca) at the Main Endeavour vent field on the Endeavour segment of the Juan de Fuca Ridge. During the experiment, the COVIS system produced 3D images of the buoyant plume discharged from the vent complex Grotto by measuring the back-scattering intensity of the acoustic signal. Building on the methodology developed in our previous work, the vertical flow velocity of the plume is estimated from the Doppler shift of the acoustic signal using geometric correction to compensate for the ambient horizontal currents. A Gaussian distribution curve is fitted to the horizontal back-scattering intensity profile to determine the back-scattering intensity at the boundary of the plume. Such a boundary value is used as the threshold in a window function for separating the plume from background signal. Finally, the volume flux is obtained by integrating the resulting 2D vertical velocity profile over the horizontal cross-section of the plume. In this presentation, we discuss preliminary results from the COVIS experiment. In addition, several alternative approaches are applied to determination of the accuracy of the estimated plume vertical velocity in the absence of direct measurements. First, the results from our previous experiment (conducted in 2000 at the same vent complex using a

  19. View of the docking approach of Endeavour taken during Expedition Three

    NASA Image and Video Library

    2001-12-07

    ISS003-E-8326 (7 Dec 2001) --- The Space Shuttle Endeavour, controlled by the flight crew of STS-108, is backdropped over a large area of cloud cover on Earth as it nears its rendezvous with the International Space Station (ISS). The Raffaello logistics module that is being brought up to the orbiting outpost is clearly visible in Endeavour's cargo bay. Among other activities the Endeavour's mission will include the change out of the station crews. The image was recorded with a digital still camera.

  20. View of the docking approach of Endeavour taken during Expedition Three

    NASA Image and Video Library

    2001-12-07

    ISS003-E-8328 (7 December 2001) --- The Space Shuttle Endeavour, controlled by the flight crew of STS-108, is backdropped over a large area of cloud cover on Earth as it nears its rendezvous with the International Space Station (ISS). The Raffaello logistics module that is being brought up to the orbiting outpost is clearly visible in Endeavour's cargo bay. Among other activities the Endeavour's mission will include the change out of the station crews. The image was recorded with a digital still camera.

  1. The hydrothermal system of Long Valley Caldera, California

    USGS Publications Warehouse

    Sorey, M.L.; Lewis, Robert Edward; Olmsted, F.H.

    1978-01-01

    Long Valley caldera, an elliptical depression covering 450 km 2 on the eastern front of the Sierra Nevada in east-central California, contains a hot-water convection system with numerous hot springs and measured and estimated aquifer temperatures at depths of 180?C to 280?C. In this study we have synthesized the results of previous geologic, geophysical, geochemical, and hydrologic investigations of the Long Valley area to develop a generalized conceptual and mathematical model which describes the gross features of heat and fluid flow in the hydrothermal system. Cenozoic volcanism in the Long Valley region began about 3.2 m.y. (million years) ago and has continued intermittently until the present time. The major event that resulted in the formation of the Long Valley caldera took place about 0.7 m.y. ago with the eruption of 600 km 3 or more of Bishop Tuff of Pleistocene age, a rhyolitic ash flow, and subsequent collapse of the roof of the magma chamber along one or more steeply inclined ring fractures. Subsequent intracaldera volcanism and uplift of the west-central part of the caldera floor formed a subcircular resurgent dome about 10 km in diameter surrounded by a moat containing rhyolitic, rhyodacitic, and basaltic rocks ranging in age from 0.5 to 0.05 m.y. On the basis of gravity and seismic studies, we estimate an aver- age thickness of fill of 2.4 km above the precaldera granitic and metamorphic basement rocks. A continuous layer of densely welded Bishop Tuff overlies the basement rocks, with an average thickness of 1.4 km; the fill above the welded Bishop Tuff consists of intercalated volcanic flows and tuffs and fluvial and lacustrine deposits. Assuming the average grain density of the fill is between 2.45 and 2.65 g/cm 3 , we calculate the average bulk porosity of the total fill as from 0.11 to 0.21. Comparison of published values of porosity of the welded Bishop Tuff exposed southeast of the caldera with calculated values indicates average bulk porosity

  2. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- An ultrasound device is held at the site where the honeycomb shell around Endeavour's robotic arm has been cut to inspect the arm. A scrape of the shell occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  3. Endeavour update: a web resource for gene prioritization in multiple species

    PubMed Central

    Tranchevent, Léon-Charles; Barriot, Roland; Yu, Shi; Van Vooren, Steven; Van Loo, Peter; Coessens, Bert; De Moor, Bart; Aerts, Stein; Moreau, Yves

    2008-01-01

    Endeavour (http://www.esat.kuleuven.be/endeavourweb; this web site is free and open to all users and there is no login requirement) is a web resource for the prioritization of candidate genes. Using a training set of genes known to be involved in a biological process of interest, our approach consists of (i) inferring several models (based on various genomic data sources), (ii) applying each model to the candidate genes to rank those candidates against the profile of the known genes and (iii) merging the several rankings into a global ranking of the candidate genes. In the present article, we describe the latest developments of Endeavour. First, we provide a web-based user interface, besides our Java client, to make Endeavour more universally accessible. Second, we support multiple species: in addition to Homo sapiens, we now provide gene prioritization for three major model organisms: Mus musculus, Rattus norvegicus and Caenorhabditis elegans. Third, Endeavour makes use of additional data sources and is now including numerous databases: ontologies and annotations, protein–protein interactions, cis-regulatory information, gene expression data sets, sequence information and text-mining data. We tested the novel version of Endeavour on 32 recent disease gene associations from the literature. Additionally, we describe a number of recent independent studies that made use of Endeavour to prioritize candidate genes for obesity and Type II diabetes, cleft lip and cleft palate, and pulmonary fibrosis. PMID:18508807

  4. View of ASTRO-2 payload in cargo bay of STS-67 Endeavour

    NASA Image and Video Library

    1995-03-17

    STS067-713-072 (2-18 March 1995) --- This 70mm cargo bay scene, backdropped against a desert area of Namibia, typifies the view that daily greeted the Astro-2 crew members during their almost 17-days aboard the Space Shuttle Endeavour. Positioned on the Spacelab pallet amidst other hardware, the Astro-2 payload is in its operational mode. Visible here are the Instrument Pointing System (IPS), Hopkins Ultraviolet Telescope (HUT), Star Tracker (ST), Ultraviolet Imaging Telescope (UIT), Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE), and Integrated Radiator System (IRS). At this angle, the Optical Sensor Package (OPS) is not seen. The Igloo, which supports the package of experiments, is in center foreground. Two Get-Away Special (GAS) canisters are in lower left foreground. The Extended Duration Orbiter (EDO) pallet, located aft of the cargo bay, is obscured by the Astro-2 payload. The Endeavour was 190 nautical miles above Earth.

  5. MS Reilly at work on Endeavour

    NASA Image and Video Library

    1998-03-04

    S89-E-5536 (22-31 Jan 1998) --- This Electronic Still Camera (ESC) image taken on the Space Shuttle Endeavour's middeck, shows astronaut James F. Reilly, mission specialist, looks over a long roll of "mail" from ground controllers.

  6. Bursch and Chang-Diaz install the BPS in a slot on Endeavour's middeck for return on STS-111 UF-2

    NASA Image and Video Library

    2002-06-07

    STS111-E-5023 (7 June 2002) --- Astronaut Daniel W. Bursch (left), who has been aboard the International Space Station (ISS) for the past six months, wastes little time in going to work on board the Space Shuttle Endeavour following linkup of the shuttle and station on June 7, 2002. Bursch, who will return home aboard Endeavour in a few days, shares a task with astronaut Franklin R. Chang-Diaz at the Biomass Production System (BPS) on Endeavour's mid deck.

  7. Relative Importance of Chemoautotrophy for Primary Production in a Light Exposed Marine Shallow Hydrothermal System.

    PubMed

    Gomez-Saez, Gonzalo V; Pop Ristova, Petra; Sievert, Stefan M; Elvert, Marcus; Hinrichs, Kai-Uwe; Bühring, Solveig I

    2017-01-01

    The unique geochemistry of marine shallow-water hydrothermal systems promotes the establishment of diverse microbial communities with a range of metabolic pathways. In contrast to deep-sea vents, shallow-water vents not only support chemosynthesis, but also phototrophic primary production due to the availability of light. However, comprehensive studies targeting the predominant biogeochemical processes are rare, and consequently a holistic understanding of the functioning of these ecosystems is currently lacking. To this end, we combined stable isotope probing of lipid biomarkers with an analysis of the bacterial communities to investigate if chemoautotrophy, in parallel to photoautotrophy, plays an important role in autotrophic carbon fixation and to identify the key players. The study was carried out at a marine shallow-water hydrothermal system located at 5 m water depth off Dominica Island (Lesser Antilles), characterized by up to 55°C warm hydrothermal fluids that contain high amounts of dissolved Fe 2+ . Analysis of the bacterial diversity revealed Anaerolineae of the Chloroflexi as the most abundant bacterial class. Furthermore, the presence of key players involved in iron cycling generally known from deep-sea hydrothermal vents (e.g., Zetaproteobacteria and Geothermobacter ), supported the importance of iron-driven redox processes in this hydrothermal system. Uptake of 13 C-bicarbonate into bacterial fatty acids under light and dark conditions revealed active photo- and chemoautotrophic communities, with chemoautotrophy accounting for up to 65% of the observed autotrophic carbon fixation. Relatively increased 13 C-incorporation in the dark allowed the classification of ai C 15:0 , C 15:0 , and i C 16:0 as potential lipid biomarkers for bacterial chemoautotrophy in this ecosystem. Highest total 13 C-incorporation into fatty acids took place at the sediment surface, but chemosynthesis was found to be active down to 8 cm sediment depth. In conclusion, this

  8. Relative Importance of Chemoautotrophy for Primary Production in a Light Exposed Marine Shallow Hydrothermal System

    PubMed Central

    Gomez-Saez, Gonzalo V.; Pop Ristova, Petra; Sievert, Stefan M.; Elvert, Marcus; Hinrichs, Kai-Uwe; Bühring, Solveig I.

    2017-01-01

    The unique geochemistry of marine shallow-water hydrothermal systems promotes the establishment of diverse microbial communities with a range of metabolic pathways. In contrast to deep-sea vents, shallow-water vents not only support chemosynthesis, but also phototrophic primary production due to the availability of light. However, comprehensive studies targeting the predominant biogeochemical processes are rare, and consequently a holistic understanding of the functioning of these ecosystems is currently lacking. To this end, we combined stable isotope probing of lipid biomarkers with an analysis of the bacterial communities to investigate if chemoautotrophy, in parallel to photoautotrophy, plays an important role in autotrophic carbon fixation and to identify the key players. The study was carried out at a marine shallow-water hydrothermal system located at 5 m water depth off Dominica Island (Lesser Antilles), characterized by up to 55°C warm hydrothermal fluids that contain high amounts of dissolved Fe2+. Analysis of the bacterial diversity revealed Anaerolineae of the Chloroflexi as the most abundant bacterial class. Furthermore, the presence of key players involved in iron cycling generally known from deep-sea hydrothermal vents (e.g., Zetaproteobacteria and Geothermobacter), supported the importance of iron-driven redox processes in this hydrothermal system. Uptake of 13C-bicarbonate into bacterial fatty acids under light and dark conditions revealed active photo- and chemoautotrophic communities, with chemoautotrophy accounting for up to 65% of the observed autotrophic carbon fixation. Relatively increased 13C-incorporation in the dark allowed the classification of aiC15:0, C15:0, and iC16:0 as potential lipid biomarkers for bacterial chemoautotrophy in this ecosystem. Highest total 13C-incorporation into fatty acids took place at the sediment surface, but chemosynthesis was found to be active down to 8 cm sediment depth. In conclusion, this study

  9. The hydrothermal system associated with the Kilauea East Rift Zone, Hawaii

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thomas, D.M.; Conrad, M.E.

    1997-12-31

    During the last twenty years drilling and fluid production on the Kilauea East Rift Zone (KERZ) has shown that an active hydrothermal system is associated with much of the rift. Well logging and fluid geochemistry indicate that reservoir temperatures exceed 360 C but are highly variable. Although neither well testing nor pressure decline data have clearly demonstrated the lateral limits of the reservoir, divergent fluid compositions over short distances suggest that the larger hydrothermal system is strongly compartmentalized across the rift zone. The chemical compositions of production fluids indicate that recharge is derived from ocean water and meteoric recharge andmore » isotopic data suggest that the latter may be derived from subsurface inflow from the flanks of Mauna Loa.« less

  10. The hydrothermal-convection systems of Kilauea: An historical perspective

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moore, R.B.; Kauahikaua, J.P.

    1993-08-01

    Kilauea is one of only two basaltic volcanoes in the world where geothermal power has been produced commercially. Little is known about the origin, size and longevity of its hydrothermal-convection systems. The authors review the history of scientific studies aimed at understanding these systems and describe their commercial development. Geothermal energy is a controversial issue in Hawaii, partly because of hydrogen sulfide emissions and concerns about protection of rain forests.

  11. NASCAR drivers pose in Endeavour

    NASA Image and Video Library

    2003-07-02

    NASCAR driver Jimmie Johnson tries out a seat of another vehicle known for speed: the orbiter Endeavour. Johnson and other drivers Dale Jarrett and Ryan Newman were on a tour of KSC. The men are scheduled to drive in the Pepsi 400 auto race being held July 5 at the Daytona International Speedway, Daytona Beach.

  12. NASCAR drivers pose in Endeavour

    NASA Image and Video Library

    2003-07-02

    NASCAR driver Dale Jarrett tries out a seat of another vehicle known for speed: the orbiter Endeavour. Jarrett and other drivers Jimmie Johnson and Ryan Newman were on a tour of KSC. The men are scheduled to drive in the Pepsi 400 auto race being held July 5 at the Daytona International Speedway, Daytona Beach.

  13. NASCAR drivers pose in Endeavour

    NASA Image and Video Library

    2003-07-02

    NASCAR driver Ryan Newman tries out a seat of another vehicle known for speed: the orbiter Endeavour. Newman and other drivers Dale Jarrett and Jimmie Johnson were on a tour of KSC. The men are scheduled to drive in the Pepsi 400 auto race being held July 5 at the Daytona International Speedway, Daytona Beach.

  14. Recent Results From the Opportunity Rover's Exploration of Endeavour Crater, Mars

    NASA Technical Reports Server (NTRS)

    Arvidson, R. E.; Squyres, S. W.; Gellert, R.; Mittlefehldt, D. W.

    2014-01-01

    The Mars Exploration Rover Opportunity is beginning its 11th year of exploration and as of sol 3535 (1/3/14 UTC) has traversed 38,729 m (based on wheel turns) across the plains of Meridiani and the rim of the approx. 22 km wide Noachian Endeavour Crater. Opportunity has investigated ancient sulfate-rich sand-stones (Burns formation) that dominate the plains and formed in ancient playa and dune environments, characterized impact breccias (Shoemaker formation) and their aqueous alteration on Endeavour's Cape York rim segment, and investigated extensive aqueous alteration of rocks on Cape York's Matijevic Hill that stratigraphically underlie Shoemaker formation and predate the Endeavour-forming event. In this abstract results from Opportunity's recent exploration of Endeavour's rim are covered, focusing on comparing what was found on Matijevic Hill with observations acquired on Murray Ridge, where Opportunity will spend its sixth winter at Cook Haven.

  15. Endeavour, Orbiter Vehicle (OV) 105, roll out to KSC Launch Complex Pad 39B

    NASA Image and Video Library

    1992-03-13

    S92-34862 (13 March 1992) --- An otter, surprised by the unexpected presence of the photographer, seems unaware of the Space Shuttle Endeavour rolling behind it to Launch Pad 39B. Endeavour is the newest orbiter in the Shuttle fleet. Still ahead for Endeavour (OV-105) is a Flight Readiness Firing of its three main engines, and the Terminal Countdown Demonstration Test with the flight crew. Endeavour's maiden voyage on NASA's mission STS-49 will occur in late spring.

  16. The interplay of evolved seawater and magmatic-hydrothermal fluids in the 3.24 Ga panorama volcanic-hosted massive sulfide hydrothermal system, North Pilbara Craton, Western Australia

    USGS Publications Warehouse

    Drieberg, Susan L.; Hagemann, Steffen G.; Huston, David L.; Landis, Gary; Ryan, Chris G.; Van Achterbergh, Esmé; Vennemann, Torsten

    2013-01-01

    The ~3240 Ma Panorama volcanic-hosted massive sulfide (VHMS) district is unusual for its high degree of exposure and low degree of postdepositional modification. In addition to typical seafloor VHMS deposits, this district contains greisen- and vein-hosted Mo-Cu-Zn-Sn mineral occurrences that are contemporaneous with VHMS orebodies and are hosted by the Strelley granite complex, which also drove VHMS circulation. Hence the Panorama district is a natural laboratory to investigate the role of magmatic-hydrothermal fluids in VHMS hydrothermal systems. Regional and proximal high-temperature alteration zones in volcanic rocks underlying the VHMS deposits are dominated by chlorite-quartz ± albite assemblages, with lesser low-temperature sericite-quartz ± K-feldspar assemblages. These assemblages are typical of VHMS hydrothermal systems. In contrast, the alteration assemblages associated with granite-hosted greisens and veins include quartz-topaz-muscovite-fluorite and quartz-muscovite (sericite)-chlorite-ankerite. These vein systems generally do not extend into the overlying volcanic pile. Fluid inclusion and stable isotope studies suggest that the greisens were produced by high-temperature (~590°C), high-salinity (38–56 wt % NaCl equiv) fluids with high densities (>1.3 g/cm3) and high δ18O (9.3 ± 0.6‰). These fluids are compatible with the measured characteristics of magmatic fluids evolved from the Strelley granite complex. In contrast, fluids in the volcanic pile (including the VHMS ore-forming fluids) were of lower temperature (90°–270°C), lower salinity (5.0–11.2 wt % NaCl equiv), with lower densities (0.88–1.01 g/cm3) and lower δ18O (−0.8 ± 2.6‰). These fluids are compatible with evolved Paleoarchean seawater. Fluids that formed the quartz-chalcopyrite-sphalerite-cassiterite veins, which are present within the granite complex near the contact with the volcanic pile, were intermediate in temperature and isotopic composition between the greisen

  17. A loose bolt delays loading of Endeavour's external tank

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This view shows the pipe (center top) leading toward Endeavour from the side of the White Room at Launch Pad 39B. A loose bracket observed hanging down from the pipe delayed loading of Endeavour's external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.

  18. View of the Endeavour moving towards it launch pad

    NASA Image and Video Library

    1996-06-06

    STS077-S-044 (16 April 1996) --- The Space Shuttle Endeavour atop the Mobile Launcher Platform and Crawler-Transporter (MLP/CT) slowly lumbers past a tree alongside the crawlerway, at the Kennedy Space Center (KSC). The journey from the Vehicle Assembly Building (VAB) to Launch Pad 39B will take about five to six hours to complete. Once hard down at the pad, preparations will continue to ready Endeavour for its upcoming spaceflight on STS-77.

  19. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The site being identified in the photo is the scrape on the surface of the honeycomb shell on Endeavour's robotic arm. The scrape occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. The site will be cut out and ultrasound testing will be done on the structure underneath. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  20. Identifying bubble collapse in a hydrothermal system using hidden Markov models

    USGS Publications Warehouse

    Dawson, P.B.; Benitez, M.C.; Lowenstern, J. B.; Chouet, B.A.

    2012-01-01

    Beginning in July 2003 and lasting through September 2003, the Norris Geyser Basin in Yellowstone National Park exhibited an unusual increase in ground temperature and hydrothermal activity. Using hidden Markov model theory, we identify over five million high-frequency (>15Hz) seismic events observed at a temporary seismic station deployed in the basin in response to the increase in hydrothermal activity. The source of these seismic events is constrained to within ???100 m of the station, and produced ???3500-5500 events per hour with mean durations of ???0.35-0.45s. The seismic event rate, air temperature, hydrologic temperatures, and surficial water flow of the geyser basin exhibited a marked diurnal pattern that was closely associated with solar thermal radiance. We interpret the source of the seismicity to be due to the collapse of small steam bubbles in the hydrothermal system, with the rate of collapse being controlled by surficial temperatures and daytime evaporation rates. copyright 2012 by the American Geophysical Union.

  1. Identifying bubble collapse in a hydrothermal system using hiddden Markov models

    USGS Publications Warehouse

    Dawson, Phillip B.; Benitez, M.C.; Lowenstern, Jacob B.; Chouet, Bernard A.

    2012-01-01

    Beginning in July 2003 and lasting through September 2003, the Norris Geyser Basin in Yellowstone National Park exhibited an unusual increase in ground temperature and hydrothermal activity. Using hidden Markov model theory, we identify over five million high-frequency (>15 Hz) seismic events observed at a temporary seismic station deployed in the basin in response to the increase in hydrothermal activity. The source of these seismic events is constrained to within ~100 m of the station, and produced ~3500–5500 events per hour with mean durations of ~0.35–0.45 s. The seismic event rate, air temperature, hydrologic temperatures, and surficial water flow of the geyser basin exhibited a marked diurnal pattern that was closely associated with solar thermal radiance. We interpret the source of the seismicity to be due to the collapse of small steam bubbles in the hydrothermal system, with the rate of collapse being controlled by surficial temperatures and daytime evaporation rates.

  2. View of AMS-2 stowed in the Endeavour Payload Bay

    NASA Image and Video Library

    2011-05-19

    S134-E-007381 (19 May 2011) --- The Alpha Magnetic Spectrometer-2 (AMS) in the space shuttle Endeavour?s payload bay is featured in this image photographed by an STS-134 crew member while docked with the International Space Station. Shortly after this image was taken, the AMS was moved from the payload bay to the station?s starboard truss. Photo credit: NASA

  3. STS-108 Endeavour Launch from Pad 39-B

    NASA Technical Reports Server (NTRS)

    2001-01-01

    KENNEDY SPACE CENTER, Fla. -- Space Shuttle Endeavour soars into a twilight sky on mission STS-108, the second attempt over two days. Liftoff occurred at 5:19:28 p.m. EST (10:19.28 GMT). Endeavour will dock with the International Space Station on Dec. 7. STS-108 is the final Shuttle mission of 2001and the 107th Shuttle flight overall. It is the 12th flight to the Space Station. Landing of the orbiter at KSC's Shuttle Landing Facility is targeted for 1:05 p.m. EST (6:05 p.m. GMT) Dec. 16.

  4. Origin of magnetic highs at ultramafic hosted hydrothermal systems: Insights from the Yokoniwa site of Central Indian Ridge

    NASA Astrophysics Data System (ADS)

    Fujii, Masakazu; Okino, Kyoko; Sato, Taichi; Sato, Hiroshi; Nakamura, Kentaro

    2016-05-01

    High-resolution vector magnetic measurements were performed on an inactive ultramafic-hosted hydrothermal vent field, called Yokoniwa Hydrothermal Field (YHF), using a deep-sea manned submersible Shinkai6500 and an autonomous underwater vehicle r2D4. The YHF has developed at a non-transform offset massif of the Central Indian Ridge. Dead chimneys were widely observed around the YHF along with a very weak venting of low-temperature fluids so that hydrothermal activity of the YHF was almost finished. The distribution of crustal magnetization from the magnetic anomaly revealed that the YHF is associated with enhanced magnetization, as seen at the ultramafic-hosted Rainbow and Ashadze-1 hydrothermal sites of the Mid-Atlantic Ridge. The results of rock magnetic analysis on seafloor rock samples (including basalt, dolerite, gabbro, serpentinized peridotite, and hydrothermal sulfide) showed that only highly serpentinized peridotite carries high magnetic susceptibility and that the natural remanent magnetization intensity can explain the high magnetization of Yokoniwa. These observations reflect abundant and strongly magnetized magnetite grains within the highly serpentinized peridotite. Comparisons with the Rainbow and Ashadze-1 suggest that in ultramafic-hosted hydrothermal systems, strongly magnetized magnetite and pyrrhotite form during the progression of hydrothermal alteration of peridotite. After the completion of serpentinization and production of hydrogen, pyrrhotites convert into pyrite or nonmagnetic iron sulfides, which considerably reduces their levels of magnetization. Our results revealed origins of the magnetic high and the development of subsurface chemical processes in ultramafic-hosted hydrothermal systems. Furthermore, the results highlight the use of near-seafloor magnetic field measurements as a powerful tool for detecting and characterizing seafloor hydrothermal systems.

  5. The potential for prebiotic synthesis in hydrothermal systems. [Abstract only

    NASA Technical Reports Server (NTRS)

    Ferris, James P.

    1994-01-01

    Contemporary hydrothermal systems provide a reducing environment where organic compounds are formed and may react to generate the molecules used in the first living systems. The organic compounds percolate through mineral assemblages at a variety of temperatures so the proposed synthetic reactions are driven by heat and catalyzed by minerals (Ferris, 1992). Some examples of potential prebiotic reactions are discussed.

  6. Helium and carbon gas geochemistry of pore fluids from the sediment-rich hydrothermal system in Escanaba Trough

    USGS Publications Warehouse

    Ishibashi, J.-I.; Sato, M.; Sano, Y.; Wakita, H.; Gamo, T.; Shanks, Wayne C.

    2002-01-01

    Ocean Drilling Program (ODP) Leg 169, which was conducted in 1996 provided an opportunity to study the gas geochemistry in the deeper part of the sediment-rich hydrothermal system in Escanaba Trough. Gas void samples obtained from the core liner were analyzed and their results were compared with analytical data of vent fluid samples collected by a submersible dive program in 1988. The gas geochemistry of the pore fluids consisted mostly of a hydrothermal component and was basically the same as that of the vent fluids. The He isotope ratios (R/RA = 5.6-6.6) indicated a significant mantle He contribution and the C isotopic compositions of the hydrocarbons [??13C(CH4) = -43???, ??13C(C2H6) = -20???] were characterized as a thermogenic origin caused by hydrothermal activity. On the other hand, the pore fluids in sedimentary layers away from the hydrothermal fields showed profiles which reflected lateral migration of the hydrothermal hydrocarbons and abundant biogenic CH4. Helium and C isotope systematics were shown to represent a hydrothermal component and useful as indicators for their distribution beneath the seafloor. Similarities in He and hydrocarbon signatures to that of the Escanaba Trough hydrothermal system were found in some terrestrial natural gases, which suggested that seafloor hydrothermal activity in sediment-rich environments would be one of the possible petroleum hydrocarbon generation scenarios in unconventional geological settings. ?? 2002 Elsevier Science Ltd. All rights reserved.

  7. Fracture distribution and porosity in a fault-bound hydrothermal system (Grimsel Pass, Swiss Alps)

    NASA Astrophysics Data System (ADS)

    Egli, Daniel; Küng, Sulamith; Baumann, Rahel; Berger, Alfons; Baron, Ludovic; Herwegh, Marco

    2017-04-01

    The spatial distribution, orientation and continuity of brittle and ductile structures strongly control fluid pathways in a rock mass by joining existing pores and creating new pore space (fractures, joints) but can also act as seals to fluid flow (e.g. ductile shear zones, clay-rich fault gouges). In long-lived hydrothermal systems, permeability and the related fluid flow paths are therefore dynamic in space and time. Understanding the evolution and behaviour of naturally porous and permeable rock masses is critical for the successful exploration and sustainable exploitation of hydrothermal systems and can advance methods for planning and implementation of enhanced geothermal systems. This study focuses on an active fault-bound hydrothermal system in the crystalline basement of the Aar Massif (hydrothermal field Grimsel Pass, Swiss Alps) that has been exhumed from few kilometres depth and which documents at least 3 Ma of hydrothermal activity. The explored rock unit of the Aar massif is part of the External Crystalline Massifs that hosts a multitude of thermal springs on its southern border in the Swiss Rhône valley and furthermore represents the exhumed equivalent of potentially exploitable geothermal reservoirs in the deep crystalline subsurface of the northern Alpine foreland basin. This study combines structural data collected from a 125 m long drillhole across the hydrothermal zone, the corresponding drill core and surface mapping. Different methods are applied to estimate the porosity and the structural evolution with regard to porosity, permeability and fracture distribution. Analyses are carried out from the micrometre to decametre scale with main focus on the flow path evolution with time. This includes a large variety of porosity-types including fracture-porosity with up to cm-sized aperture down to grain-scale porosity. Main rock types are granitoid host rocks, mylonites, paleo-breccia and recent breccias. The porosity of the host rock as well as the

  8. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Workers in Endeavour's payload bay look at the site of the scrape on the surface of the honeycomb shell on the robotic arm that occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. The site will be cut out and ultrasound testing will be done on the structure underneath. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  9. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- One of a team of robotic experts looks at the site of the scrape on the surface of the the robotic arm's honeycomb shell. The scrape occurred while work platforms were being installed to gain access to repair the oxygen leak in Endeavour's mid-body. The site will be cut out and ultrasound testing will be done on the structure underneath. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  10. SRTM is removed from Endeavour's payload bay to ease wiring inspections

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Inside orbiter Endeavour's payload bay, a crane lifts the Shuttle Radar Topography Mission (SRTM) for its transfer out of the orbiter to a payload canister. The payload on mission STS-99, SRTM is being removed to allow technicians access to the orbiter's midbody for planned wiring inspections. Endeavour is in the Orbiter Processing Facility. The entire fleet of orbiters is being inspected for wiring abrasions after the problem was first discovered in Columbia. Shuttle managers are reviewing several manifest options and could establish new target launch dates for the balance of 1999 next week. Shuttle Endeavour currently remains slated for launch in early October.

  11. Eruptive and tectonic history of the Endeavour Segment, Juan de Fuca Ridge, based on AUV mapping data and lava flow ages

    USGS Publications Warehouse

    Clague, David A.; Dreyer, Brian M; Paduan, Jennifer B; Martin, Julie F; Caress, David W; Gillespie, James B.; Kelley, Deborah S; Thomas, Hans; Portner, Ryan A; Delaney, John R; Guilderson, Thomas P.; McGann, Mary L.

    2014-01-01

    High-resolution bathymetric surveys from autonomous underwater vehicles ABE and D. Allan B. were merged to create a coregistered map of 71.7 km2 of the Endeavour Segment of the Juan de Fuca Ridge. Radiocarbon dating of foraminifera in cores from three dives of remotely operated vehicle Doc Ricketts provide minimum eruption ages for 40 lava flows that are combined with the bathymetric data to outline the eruptive and tectonic history. The ages range from Modern to 10,700 marine-calibrated years before present (yr BP). During a robust magmatic phase from >10,700 yr BP to ~4300 yr BP, flows erupted from an axial high and many flowed >5 km down the flanks; some partly buried adjacent valleys. Axial magma chambers (AMCs) may have been wider than today to supply dike intrusions over a 2 km wide axial zone. Summit Seamount formed by ~4770 yr BP and was subsequently dismembered during a period of extension with little volcanism starting ~4300 yr BP. This tectonic phase with only rare volcanic eruptions lasted until ~2300 yr BP and may have resulted in near-solidification of the AMCs. The axial graben formed by crustal extension during this period of low magmatic activity. Infrequent eruptions occurred on the flanks between 2620–1760 yr BP and within the axial graben since ~1750 yr BP. This most recent phase of limited volcanic and intense hydrothermal activity that began ~2300 yr BP defines a hydrothermal phase of ridge development that coincides with the present-day 1 km wide AMCs and overlying hydrothermal vent fields.

  12. Approaching Endeavour Crater, Sol 2,680

    NASA Image and Video Library

    2011-10-10

    This image from the navigation camera on NASA Mars Exploration Rover Opportunity shows the view ahead on the day before the rover reached the rim of Endeavour crater. It was taken during the 2,680th Martian day, or sol, of the rover work on Mars.

  13. The Origin of Carbon-Bearing Volatiles in a Continental Hydrothermal System in the Great Basin: Water Chemistry and Isotope Characterizations

    NASA Technical Reports Server (NTRS)

    Fu, Qi; Socki, Richard A.; Niles, Paul B.; Romanek, Christopher; Datta, Saugata; Darnell, Mike

    2012-01-01

    Hydrothermal systems on Earth are active centers in the crust where organic molecules can be synthesized biotically or abiotically under a wide range of physical and chemical conditions [1-3]. Not only are volatile species (CO, CO2, H2, and hydrocarbons) a reflection of deep-seated hydrothermal alteration processes, but they also form an important component of biological systems. Studying carbon-bearing fluids from hydrothermal systems is of specific importance to understanding (bio-)geochemical processes within these systems. With recent detection of methane in the martian atmosphere [4-7] and the possibility of its hydrothermal origin [8, 9], understanding the formation mechanisms of methane may provide constraints on the history of the martian aqueous environments and climate.

  14. Hydrothermal activity lowers trophic diversity in Antarctic hydrothermal sediments

    NASA Astrophysics Data System (ADS)

    Bell, James B.; Reid, William D. K.; Pearce, David A.; Glover, Adrian G.; Sweeting, Christopher J.; Newton, Jason; Woulds, Clare

    2017-12-01

    Hydrothermal sediments are those in which hydrothermal fluid is discharged through sediments and are one of the least studied deep-sea ecosystems. We present a combination of microbial and biochemical data to assess trophodynamics between and within hydrothermal and background areas of the Bransfield Strait (1050-1647 m of depth). Microbial composition, biomass, and fatty acid signatures varied widely between and within hydrothermally active and background sites, providing evidence of diverse metabolic activity. Several species had different feeding strategies and trophic positions between hydrothermally active and inactive areas, and the stable isotope values of consumers were not consistent with feeding morphology. Niche area and the diversity of microbial fatty acids was lowest at the most hydrothermally active site, reflecting trends in species diversity. Faunal uptake of chemosynthetically produced organics was relatively limited but was detected at both hydrothermal and non-hydrothermal sites, potentially suggesting that hydrothermal activity can affect trophodynamics over a much wider area than previously thought.

  15. Hydrogen, Oxygen and Silicon Isotope Systematics of Groundwater-Magma Interaction in Icelandic Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Kleine, B. I.; Stefansson, A.; Halldorsson, S. A.; Martin, W.; Barnes, J.; Jónasson, K.; Franzson, H.

    2016-12-01

    Magma often encounters groundwater (meteoric or seawater derived) when intruded into the crust. Magma-groundwater interactions result in the formation of hydrothermal fluids which can lead to contact metamorphism and elemental transport in the country rock. In fact, magma-hydrothermal fluid interaction (rather than magma-magmatic fluid interaction) may lead to classic contact metamorphic reactions. In order to explore the importance of hydrothermal fluid during contact metamorphism we use stable isotopes (δD, δ18O, δ30Si) from both active and extinct magma chambers and hydrothermal systems from across Iceland. Quartz grains from various hydrothermal systems, from crustal xenoliths from the Askja central volcano and from the Hafnarfjall pluton, as well as quartz grains associated with low-T zeolites were analysed for δ18O and δ30Si in-situ using SIMS. Whole rock material of these samples was analysed for δD values using a TCEA coupled to an IRMS. Our results indicate that low-T quartz (<150°C) are dominated by negative δ30Si values whereas positive δ30Si values prevail in quartz precipitated at higher T (>300°C). Combining the results from the analyses of δ18O and δD allows further division of samples into (i) seawater and/or rock dominated and (ii) meteoric water dominated hydrothermal systems. In order to isolate the effects of fluid-rock interaction, fluid source and formation temperature at the magma-groundwater contact, δD, δ18O and δ30Si values of rocks and fluids were modeled using the PHREEQC software. Comparison of analytical and model results shows that the isotopic compositions are influenced by multiple processes. In some cases, groundwater penetrates the contact zone and causes alteration at >400°C by groundwater-magma heat interaction. Other cases document "baked" contact zones without groundwater. Our analyses and modeling demonstrates that groundwater flow and permeability are crucial in setting the style of contact metamorphism

  16. Detection of Abiotic Methane in Terrestrial Continental Hydrothermal Systems: Implications for Methane on Mars

    NASA Technical Reports Server (NTRS)

    Socki, Richard A.; Niles, Paul B.; Gibson, Everett K., Jr.; Romanek, Christopher S.; Zhang, Chuanlun L.; Bissada, Kadry K.

    2008-01-01

    The recent detection of methane in the Martian atmosphere and the possibility that its origin could be attributed to biological activity, have highlighted the importance of understanding the mechanisms of methane formation and its usefulness as a biomarker. Much debate has centered on the source of the methane in hydrothermal fluids, whether it is formed biologically by microorganisms, diagenetically through the decomposition of sedimentary organic matter, or inorganically via reduction of CO2 at high temperatures. Ongoing research has now shown that much of the methane present in sea-floor hydrothermal systems is probably formed through inorganic CO2 reduction processes at very high temperatures (greater than 400 C). Experimental results have indicated that methane might form inorganically at temperatures lower still, however these results remain controversial. Currently, methane in continental hydrothermal systems is thought to be formed mainly through the breakdown of sedimentary organic matter and carbon isotope equilibrium between CO2 and CH4 is thought to be rarely present if at all. Based on isotopic measurements of CO2 and CH4 in two continental hydrothermal systems, we suggest that carbon isotope equilibration exists at temperatures as low as 155 C. This would indicate that methane is forming through abiotic CO2 reduction at lower temperatures than previously thought and could bolster arguments for an abiotic origin of the methane detected in the martian atmosphere.

  17. Rollout of Endeavour at Palmdale, California (Part 1 of 2)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Footage shows the rollout ceremonies for Endeavour, including the display of colors, invocation, and speeches by Sam Iacobellis, Executive Vice-President and CEO of Rockwell International, Richard H. Truly, Administrator for NASA, and Senator Jake Garn (Utah). The tape ends during the speech by Senator Garn and continues on part two (Input Processing ID 2000152220, Document ID 20010010951). Endeavour rolls out to music provided by the band on-site.

  18. Ancient Aqueous Environments at Endeavour Crater, Mars

    NASA Technical Reports Server (NTRS)

    Arvidson, R. E.; Squyres, S. W.; Bell, J. F.; Catalano, J. G.; Clark, B. C.; Crumpler, L. S.; de Souza, P. A.; Fairen, A. G.; Farrand, W. H.; Fox, V. K.; hide

    2014-01-01

    Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe(+3)-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins precipitated from fluids that circulated after the Endeavour impact. Compositional data for fractures in the layered rocks suggest formation of Al-rich smectites by aqueous leaching. Evidence is thus preserved for water-rock interactions before and after the impact, with aqueous environments of slightly acidic to circum-neutral pH that would have been more favorable for prebiotic chemistry and microorganisms than those recorded by younger sulfate-rich rocks at Meridiani Planum.

  19. Ancient aqueous environments at Endeavour crater, Mars

    USGS Publications Warehouse

    Arvidson, R. E.; Squyres, S. W.; Bell, J.F.; Catalano, J.G.; Clark, B. C.; Crumpler, L.S.; de Souza, P.A.; Fairén, A.G.; Farrand, W. H.; Fox, V.K.; Gellert, Ralf; Ghosh, A.; Golombeck, M.P.; Grotzinger, J.P.; Guinness, E.A.; Herkenhoff, Kenneth E.; Jolliff, B.L.; Knoll, A.H.; Li, R.; McLennan, S.M.; Ming, D. W.; Mittlefehldt, D. W.; Moore, Johnnie N.; Morris, R.V.; Murchie, S.L.; Parker, T.J.; Paulsen, G.; Rice, J.W.; Ruff, S.W.; Smith, M.D.; Wolff, M.J.

    2014-01-01

    Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe+3-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins precipitated from fluids that circulated after the Endeavour impact. Compositional data for fractures in the layered rocks suggest formation of Al-rich smectites by aqueous leaching. Evidence is thus preserved for water-rock interactions before and after the impact, with aqueous environments of slightly acidic to circum-neutral pH that would have been more favorable for prebiotic chemistry and microorganisms than those recorded by younger sulfate-rich rocks at Meridiani Planum.

  20. Identification and activity of acetate-assimilating bacteria in diffuse fluids venting from two deep-sea hydrothermal systems.

    PubMed

    Winkel, Matthias; Pjevac, Petra; Kleiner, Manuel; Littmann, Sten; Meyerdierks, Anke; Amann, Rudolf; Mußmann, Marc

    2014-12-01

    Diffuse hydrothermal fluids often contain organic compounds such as hydrocarbons, lipids, and organic acids. Microorganisms consuming these compounds at hydrothermal sites are so far only known from cultivation-dependent studies. To identify potential heterotrophs without prior cultivation, we combined microbial community analysis with short-term incubations using (13)C-labeled acetate at two distinct hydrothermal systems. We followed cell growth and assimilation of (13)C into single cells by nanoSIMS combined with fluorescence in situ hybridization (FISH). In 55 °C-fluids from the Menez Gwen hydrothermal system/Mid-Atlantic Ridge, a novel epsilonproteobacterial group accounted for nearly all assimilation of acetate, representing the first aerobic acetate-consuming member of the Nautiliales. In contrast, Gammaproteobacteria dominated the (13) C-acetate assimilation in incubations of 37 °C-fluids from the back-arc hydrothermal system in the Manus Basin/Papua New Guinea. Here, 16S rRNA gene sequences were mostly related to mesophilic Marinobacter, reflecting the high content of seawater in these fluids. The rapid growth of microorganisms upon acetate addition suggests that acetate consumers in diffuse fluids are copiotrophic opportunists, which quickly exploit their energy sources, whenever available under the spatially and temporally highly fluctuating conditions. Our data provide first insights into the heterotrophic microbial community, catalyzing an under-investigated part of microbial carbon cycling at hydrothermal vents. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  1. Microbial community structure across fluid gradients in the Juan de Fuca Ridge hydrothermal system.

    PubMed

    Anderson, Rika E; Beltrán, Mónica Torres; Hallam, Steven J; Baross, John A

    2013-02-01

    Physical and chemical gradients are dominant factors in shaping hydrothermal vent microbial ecology, where archaeal and bacterial habitats encompass a range between hot, reduced hydrothermal fluid and cold, oxidized seawater. To determine the impact of these fluid gradients on microbial communities inhabiting these systems, we surveyed bacterial and archaeal community structure among and between hydrothermal plumes, diffuse flow fluids, and background seawater in several hydrothermal vent sites on the Juan de Fuca Ridge using 16S rRNA gene diversity screening (clone libraries and terminal restriction length polymorphisms) and quantitative polymerase chain reaction methods. Community structure was similar between hydrothermal plumes and background seawater, where a number of taxa usually associated with low-oxygen zones were observed, whereas high-temperature diffuse fluids exhibited a distinct phylogenetic profile. SUP05 and Arctic96BD-19 sulfur-oxidizing bacteria were prevalent in all three mixing regimes where they exhibited overlapping but not identical abundance patterns. Taken together, these results indicate conserved patterns of redox-driven niche partitioning between hydrothermal mixing regimes and microbial communities associated with sinking particles and oxygen-deficient waters. Moreover, the prevalence of SUP05 and Arctic96BD-19 in plume and diffuse flow fluids indicates a more cosmopolitan role for these groups in the ecology and biogeochemistry of the dark ocean. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  2. Endeavour's payload bay with the Raphaello module and Canadarm 2

    NASA Image and Video Library

    2001-04-20

    S100-E-5015 (20 April 2001) --- One of the crew members of STS-100 aimed a digital still camera through Endeavour's aft flight deck windows to record this image of the cargo bay, backdropped against a scene of black space and Earth's horizon. Housed in the bay, beyond the docking mechanism in the foreground, is the Italian Space Agency-provided Raffaello cargo module, which is carrying several tons of equipment for the Expedition Two crew and racks of hardware for installation in Destiny which will be used for scientific research in the future. Raffaello, which is the second of three such logistics modules, will be berthed to the ISS on April 23 so its contents can be transferred to the station throughout the course of docked operations. Also in the bay is the 57-foot-long Canadarm2, which will be mounted on the Destiny Laboratory for future station assembly work. Endeavour's Canadian-built Remote Manipulator System (RMS) arm can be seen in its berthed position on the port side of the payload bay.

  3. Endeavour's payload bay with the Raphaello module and Canadarm 2

    NASA Image and Video Library

    2001-04-20

    S100-E-5018 (20 April 2001) --- One of the crew members of STS-100 aimed a digital still camera through Endeavour's aft flight deck windows to record this image of the cargo bay, backdropped against a scene of black space and Earth's horizon. Housed in the bay, beyond the docking mechanism in the foreground, is the Italian Space Agency-provided Raffaello cargo module, which is carrying several tons of equipment for the Expedition Two crew and racks of hardware for installation in Destiny which will be used for scientific research in the future. Raffaello, which is the second of three such logistics modules, will be berthed to the ISS on April 23 so its contents can be transferred to the station throughout the course of docked operations. Also in the bay is the 57-foot-long Canadarm2, which will be mounted on the Destiny Laboratory for future station assembly work. Endeavour's Canadian-built Remote Manipulator System (RMS) arm can be seen in its berthed position on the port side of the payload bay.

  4. Endeavour's payload bay with the Raphaello module and Canadarm 2

    NASA Image and Video Library

    2001-04-20

    S100-E-5002 (20 April 2001) --- One of the crew members of STS-100 aimed a digital still camera through Endeavour's aft flight deck windows to record this image of the cargo bay, backdropped against a scene of black space and Earth's horizon. Housed in the bay, beyond the docking mechanism in the foreground, is the Italian Space Agency-provided Raffaello cargo module, which is carrying several tons of equipment for the Expedition Two crew and racks of hardware for installation in Destiny which will be used for scientific research in the future. Raffaello, which is the second of three such logistics modules, will be berthed to the ISS on April 23 so its contents can be transferred to the station throughout the course of docked operations. Also in the bay is the 57-foot-long Canadarm2, which will be mounted on the Destiny Laboratory for future station assembly work. Endeavour's Canadian-built Remote Manipulator System (RMS) arm can be seen in its berthed position on the port side of the payload bay.

  5. Endeavour's payload bay with the Raphaello module and Canadarm 2

    NASA Image and Video Library

    2001-04-20

    S100-E-5017 (20 April 2001) --- One of the crew members of STS-100 aimed a digital still camera through Endeavour's aft flight deck windows to record this image of the cargo bay, backdropped against a scene of black space and Earth's horizon. Housed in the bay, beyond the docking mechanism in the foreground, is the Italian Space Agency-provided Raffaello cargo module, which is carrying several tons of equipment for the Expedition Two crew and racks of hardware for installation in Destiny which will be used for scientific research in the future. Raffaello, which is the second of three such logistics modules, will be berthed to the ISS on April 23 so its contents can be transferred to the station throughout the course of docked operations. Also in the bay is the 57-foot-long Canadarm2, which will be mounted on the Destiny Laboratory for future station assembly work. Endeavour's Canadian-built Remote Manipulator System (RMS) arm can be seen in its berthed position on the port side of the payload bay.

  6. Space Shuttle Endeavour flies by Johnson Space Center

    NASA Image and Video Library

    2008-12-11

    JSC2008-E-154359 (11 Dec. 2008) --- The Space Shuttle Endeavour flies over the Clear Lake area and the Johnson Space Center after having spent the night at a stopover in Tarrant County, while mounted on a modified Boeing 747 shuttle carrier aircraft. Endeavour landed in California on Nov. 30 and was en route back to Florida. This photo, taken from the rear station of a NASA T-38 aircraft, shows the main part of the 1625-acre JSC site. The extremely clear weather allows viewing all the way to Houston's central business district. Harris County Domed Stadium and the Houston NFL franchise's stadium are visible in the upper left quadrant of the photo.

  7. Hubble Space Telescope approaches Shuttle Endeavour

    NASA Image and Video Library

    1993-12-04

    STS061-93-031 (4 Dec 1993) --- Part of the vast Indian Ocean forms the backdrop for this scene of the Hubble Space Telescope (HST) as it approaches the Space Shuttle Endeavour. Denham Sound and Shark Bay, on Australia's west coast, are just below the waiting mechanical arm at lower right corner.

  8. [Chemical Potentials of Hydrothermal Systems and Formation of Coupled Modular Metabolic Pathways].

    PubMed

    Marakushev, S A; Belonogova, O V

    2015-01-01

    According to Gibbs J.W. the number of independent components is the least number of those chemical constituents, by combining which the compositions of all possible phases in the system can be obtained, and at the first stages of development of the primary metabolism of the three-component system C-H-O different hydrocarbons and molecular hydrogen were used as an energy source for, it. In the Archean hydrothermal conditions under the action of the phosphorus chemical potential the C-H-O system was transformed into a four-component system C-H-O-P setting up a gluconeogenic system, which became the basis of power supply for a protometabolism, and formation of a new cycle of CO2 fixation (reductive pentose phosphate pathway). It is shown that parageneses (association) of certain substances permitted the modular constructions of the central metabolism of the system C-H-O-P and the formed modules appear in association with each other in certain physicochemical hydrothermal conditions. Malate, oxaloacetate, pyruvate and phosphoenolpyruvate exhibit a turnstile-like mechanism of switching reaction directions.

  9. West Rim of Endeavour Crater on Mars

    NASA Image and Video Library

    2011-08-10

    A portion of the west rim of Endeavour crater sweeps southward in this color view from NASA Mars Exploration Rover Opportunity. The rover first destination on the rim, called Spirit Point in tribute to Opportunity now-inactive twin, Spirit.

  10. Microbial Community in the Hydrothermal System at Southern Mariana Trough

    NASA Astrophysics Data System (ADS)

    Kato, S.; Itahashi, S.; Kakegawa, T.; Utsumi, M.; Maruyama, A.; Ishibashi, J.; Marumo, K.; Urabe, T.; Yamagishi, A.

    2004-12-01

    There is unique ecosystem around deep-sea hydrothermal area. Living organisms are supported by chemical free energy provided by the hydrothermal water. The ecosystem is expected to be similar to those in early stage of life history on the earth, when photosynthetic organisms have not emerged. In this study, we have analyzed the microbial diversity in the hydrothermal area at southern Mariana trough. In the "Archaean Park Project" supported by special Coordination Fund, four holes were bored and cased by titanium pipes near hydrothermal vents in the southern Mariana trough in 2004. Hydrothermal fluids were collected from these cased holes and natural vents in this area. Microbial cells were collected by filtering the hydrothermal fluid in situ or in the mother sip. Filters were stored at -80C and used for DNA extraction. Chimneys at this area was also collected and stored at -80C. The filters and chimney samples were crushed and DNA was extracted. DNA samples were used for amplification of 16S rDNA fragments by PCR using archaea specific primers and universal primers. The PCR fragments were cloned and sequenced. These PCR clones of different samples will be compared. We will extend our knowledge about microbiological diversity at Southern Mariana trough to compare the results obtained at other area.

  11. Lithium isotopic systematics of submarine vent fluids from arc and back-arc hydrothermal systems in the western Pacific

    NASA Astrophysics Data System (ADS)

    Araoka, Daisuke; Nishio, Yoshiro; Gamo, Toshitaka; Yamaoka, Kyoko; Kawahata, Hodaka

    2016-10-01

    The Li concentration and isotopic composition (δ7Li) in submarine vent fluids are important for oceanic Li budget and potentially useful for investigating hydrothermal systems deep under the seafloor because hydrothermal vent fluids are highly enriched in Li relative to seawater. Although Li isotopic geochemistry has been studied at mid-ocean-ridge (MOR) hydrothermal sites, in arc and back-arc settings Li isotopic composition has not been systematically investigated. Here we determined the δ7Li and 87Sr/86Sr values of 11 end-member fluids from 5 arc and back-arc hydrothermal systems in the western Pacific and examined Li behavior during high-temperature water-rock interactions in different geological settings. In sediment-starved hydrothermal systems (Manus Basin, Izu-Bonin Arc, Mariana Trough, and North Fiji Basin), the Li concentrations (0.23-1.30 mmol/kg) and δ7Li values (+4.3‰ to +7.2‰) of the end-member fluids are explained mainly by dissolution-precipitation model during high-temperature seawater-rock interactions at steady state. Low Li concentrations are attributable to temperature-related apportioning of Li in rock into the fluid phase and phase separation process. Small variation in Li among MOR sites is probably caused by low-temperature alteration process by diffusive hydrothermal fluids under the seafloor. In contrast, the highest Li concentrations (3.40-5.98 mmol/kg) and lowest δ7Li values (+1.6‰ to +2.4‰) of end-member fluids from the Okinawa Trough demonstrate that the Li is predominantly derived from marine sediments. The variation of Li in sediment-hosted sites can be explained by the differences in degree of hydrothermal fluid-sediment interactions associated with the thickness of the marine sediment overlying these hydrothermal sites.

  12. Geochemical constraints on sources of metabolic energy for chemolithoautotrophy in ultramafic-hosted deep-sea hydrothermal systems.

    PubMed

    McCollom, Thomas M

    2007-12-01

    Numerical models are employed to investigate sources of chemical energy for autotrophic microbial metabolism that develop during mixing of oxidized seawater with strongly reduced fluids discharged from ultramafic-hosted hydrothermal systems on the seafloor. Hydrothermal fluids in these systems are highly enriched in H(2) and CH(4) as a result of alteration of ultramafic rocks (serpentinization) in the subsurface. Based on the availability of chemical energy sources, inferences are made about the likely metabolic diversity, relative abundance, and spatial distribution of microorganisms within ultramafic-hosted systems. Metabolic reactions involving H(2) and CH(4), particularly hydrogen oxidation, methanotrophy, sulfate reduction, and methanogenesis, represent the predominant sources of chemical energy during fluid mixing. Owing to chemical gradients that develop from fluid mixing, aerobic metabolisms are likely to predominate in low-temperature environments (<20-30 degrees C), while anaerobes will dominate higher-temperature environments. Overall, aerobic metabolic reactions can supply up to approximately 7 kJ of energy per kilogram of hydrothermal fluid, while anaerobic metabolic reactions can supply about 1 kJ, which is sufficient to support a maximum of approximately 120 mg (dry weight) of primary biomass production by aerobic organisms and approximately 20-30 mg biomass by anaerobes. The results indicate that ultramafic-hosted systems are capable of supplying about twice as much chemical energy as analogous deep-sea hydrothermal systems hosted in basaltic rocks.

  13. Hydrothermal Processes

    NASA Astrophysics Data System (ADS)

    German, C. R.; von Damm, K. L.

    2003-12-01

    What is Hydrothermal Circulation?Hydrothermal circulation occurs when seawater percolates downward through fractured ocean crust along the volcanic mid-ocean ridge (MOR) system. The seawater is first heated and then undergoes chemical modification through reaction with the host rock as it continues downward, reaching maximum temperatures that can exceed 400 °C. At these temperatures the fluids become extremely buoyant and rise rapidly back to the seafloor where they are expelled into the overlying water column. Seafloor hydrothermal circulation plays a significant role in the cycling of energy and mass between the solid earth and the oceans; the first identification of submarine hydrothermal venting and their accompanying chemosynthetically based communities in the late 1970s remains one of the most exciting discoveries in modern science. The existence of some form of hydrothermal circulation had been predicted almost as soon as the significance of ridges themselves was first recognized, with the emergence of plate tectonic theory. Magma wells up from the Earth's interior along "spreading centers" or "MORs" to produce fresh ocean crust at a rate of ˜20 km3 yr-1, forming new seafloor at a rate of ˜3.3 km2 yr-1 (Parsons, 1981; White et al., 1992). The young oceanic lithosphere formed in this way cools as it moves away from the ridge crest. Although much of this cooling occurs by upward conduction of heat through the lithosphere, early heat-flow studies quickly established that a significant proportion of the total heat flux must also occur via some additional convective process (Figure 1), i.e., through circulation of cold seawater within the upper ocean crust (Anderson and Silbeck, 1981). (2K)Figure 1. Oceanic heat flow versus age of ocean crust. Data from the Pacific, Atlantic, and Indian oceans, averaged over 2 Ma intervals (circles) depart from the theoretical cooling curve (solid line) indicating convective cooling of young ocean crust by circulating seawater

  14. Investigating Volcanic-Hydrothermal Systems in Dominica, Lesser Antilles: Temporal Changes in the Chemical Composition of Hydrothermal Fluids for Volcanic Monitoring Using Geothermometers

    NASA Astrophysics Data System (ADS)

    Onyeali, M. M. C.; Joseph, E. P.; Frey, H. M.

    2017-12-01

    Dominica has an abundance of volcanic activity, with nine potentially active volcanoes, many of which have highly active volcanic-hydrothermal systems. The waters are predominantly acid-sulphate in character (SO4=100-4200 mg/L, pH≤4), and likely formed because of dilution of acidic gases in near surface oxygenated groundwater. The waters are of primarily meteoric origin, but are likely affected by evaporation effects at/near the surface, with δ18O ranging from -1.75 to 10.67‰, and δD from -6.1 to 14.5‰. With updated water chemistry and isotopic data from five hydrothermal areas (Boiling Lake, Valley of Desolation, Sulphur Springs, Wotten Waven, Cold Soufriere) for the period 2014 to 2017, we will re-evaluate the characteristics of these systems, which were last reported in 2011. We will present updated reservoir temperatures using a variety of geothermometers and provide insight into water-rock interactions taking place in the reservoirs. Recent changes in chemistry of the waters have indicated that while the origin of the hydrothermal systems are still dominantly meteoric (δ18O = -3 to 8‰ and δD = -5 to 18‰), surface evaporation effects and variable amounts of mixing with shallow ground waters play an important role. Fumaroles appear to reflect a deeper source contribution as compared to thermal waters with differences in acidity, temperature, TDS, δ18O, and δD observed. The general composition of the waters for most of the hydrothermal systems studied indicate no significant changes, with the exception of the Boiling Lake, which experienced a draining event in November 2016 which lasted for 6 weeks. Decreases in temperature, pH, Na, K, and Cl were seen post draining, while SO4 remained relatively low (66 ppm), but showed a small increase. The chemistry of the Boiling Lake appears to show significant changes in response to changes in the groundwater system. Changes in the groundwater system at the lake observed during the 2004/2005 draining, which

  15. Ca isotope fractionation and Sr/Ca partitioning associated with anhydrite formation at mid-ocean ridge hydrothermal systems: An experimental approach

    NASA Astrophysics Data System (ADS)

    Syverson, D. D.; Scheuermann, P.; Pester, N. J.; Higgins, J. A.; Seyfried, W. E., Jr.

    2016-12-01

    The elemental and isotopic mass balance of Ca and Sr between seawater and basalt at mid-ocean ridge (MOR) hydrothermal systems is an integrated reflection of the various physiochemical processes, which induce chemical exchange, in the subseafloor. Specifically, the processes of anhydrite precipitation and recrystallization are recognized to be important controls on governing the Ca and Sr elemental and isotope compositions of high temperature vent fluids, however, few experimental data exist to constrain these geochemical effects. Thus, to better understand the associated Sr/Ca partitioning and Ca isotope fractionation and rate of exchange between anhydrite and dissolved constituents, anhydrite precipitation and recrystallization experiments were performed at 175, 250, and 350°C and 500 bar at chemical conditions indicative of active MOR hydrothermal systems. The experimental data suggest that upon entrainment of seawater into MOR hydrothermal systems, anhydrite will precipitate rapidly and discriminate against the heavy isotopes of Ca (Δ44/40Ca(Anh-Fluid) = -0.68 - -0.25 ‰), whereas Sr/Ca partitioning depends on the saturation state of the evolving hydrothermal fluid with respect to anhydrite at each PTX (KD(Anh-Fluid) = 1.24 - 0.55). Coupling experimental constraints with the temperature gradient inferred for high temperature MOR hydrothermal systems in the oceanic crust, data suggest that the Ca isotope and Sr elemental composition of anhydrite formed near the seafloor will be influenced by disequilibrium effects, while, at higher temperatures further into the oceanic crust, anhydrite will be representative of equilibrium Sr/Ca partitioning and Ca isotope fractionation conditions. These experimental observations are consistent with analyzed Sr/Ca and Ca isotope compositions of anhydrites and vent fluids sampled from modern MOR hydrothermal systems1,2 and can be used to further constrain the geochemical effects of hydrothermal circulation in the oceanic crust

  16. Back-Projection Imaging of extended, diffuse seismic sources in volcanic and hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Kelly, C. L.; Lawrence, J. F.; Beroza, G. C.

    2017-12-01

    Volcanic and hydrothermal systems exhibit a wide range of seismicity that is directly linked to fluid and volatile activity in the subsurface and that can be indicative of imminent hazardous activity. Seismograms recorded near volcanic and hydrothermal systems typically contain "noisy" records, but in fact, these complex signals are generated by many overlapping low-magnitude displacements and pressure changes at depth. Unfortunately, excluding times of high-magnitude eruptive activity that typically occur infrequently relative to the length of a system's entire eruption cycle, these signals often have very low signal-to-noise ratios and are difficult to identify and study using established seismic analysis techniques (i.e. phase-picking, template matching). Arrays of short-period and broadband seismic sensors are proven tools for monitoring short- and long-term changes in volcanic and hydrothermal systems. Time-reversal techniques (i.e. back-projection) that are improved by additional seismic observations have been successfully applied to locating volcano-seismic sources recorded by dense sensor arrays. We present results from a new computationally efficient back-projection method that allows us to image the evolution of extended, diffuse sources of volcanic and hydrothermal seismicity. We correlate short time-window seismograms from receiver-pairs to find coherent signals and propagate them back in time to potential source locations in a 3D subsurface model. The strength of coherent seismic signal associated with any potential source-receiver-receiver geometry is equal to the correlation of the short time-windows of seismic records at appropriate time lags as determined by the velocity structure and ray paths. We stack (sum) all short time-window correlations from all receiver-pairs to determine the cumulative coherence of signals at each potential source location. Through stacking, coherent signals from extended and/or repeating sources of short-period energy

  17. Evidence of a modern deep water magmatic hydrothermal system in the Canary Basin (eastern central Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Medialdea, T.; Somoza, L.; González, F. J.; Vázquez, J. T.; de Ignacio, C.; Sumino, H.; Sánchez-Guillamón, O.; Orihashi, Y.; León, R.; Palomino, D.

    2017-08-01

    New seismic profiles, bathymetric data, and sediment-rock sampling document for the first time the discovery of hydrothermal vent complexes and volcanic cones at 4800-5200 m depth related to recent volcanic and intrusive activity in an unexplored area of the Canary Basin (Eastern Atlantic Ocean, 500 km west of the Canary Islands). A complex of sill intrusions is imaged on seismic profiles showing saucer-shaped, parallel, or inclined geometries. Three main types of structures are related to these intrusions. Type I consists of cone-shaped depressions developed above inclined sills interpreted as hydrothermal vents. Type II is the most abundant and is represented by isolated or clustered hydrothermal domes bounded by faults rooted at the tips of saucer-shaped sills. Domes are interpreted as seabed expressions of reservoirs of CH4 and CO2-rich fluids formed by degassing and contact metamorphism of organic-rich sediments around sill intrusions. Type III are hydrothermal-volcanic complexes originated above stratified or branched inclined sills connected by a chimney to the seabed volcanic edifice. Parallel sills sourced from the magmatic chimney formed also domes surrounding the volcanic cones. Core and dredges revealed that these volcanoes, which must be among the deepest in the world, are constituted by OIB-type, basanites with an outer ring of blue-green hydrothermal Al-rich smectite muds. Magmatic activity is dated, based on lava samples, at 0.78 ± 0.05 and 1.61 ± 0.09 Ma (K/Ar methods) and on tephra layers within cores at 25-237 ky. The Subvent hydrothermal-volcanic complex constitutes the first modern system reported in deep water oceanic basins related to intraplate hotspot activity.Plain Language SummarySubmarine volcanism and associated <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are relevant processes for the evolution of the ocean basins, due their impact on the geochemistry of the oceans, their potential to form significant ore</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts099-703-082.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts099-703-082.html"><span>Views of <span class="hlt">Endeavour</span>'s payload bay and an Earth limb taken during STS-99</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2000-02-12</p> <p>STS099-703-082 (11-22 February 2000) --- Part of the Space Shuttle <span class="hlt">Endeavour</span>'s aft cargo bay, its vertical stabilizer and orbital maneuvering <span class="hlt">system</span> (OMS) pods are seen in this 70mm frame. Part of Earth's horizon, with an expanse of heavy cloud cover over land and water, is at bottom of frame.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B13B0473R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B13B0473R"><span><span class="hlt">Hydrothermal</span> Reactivity of Amines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robinson, K.; Shock, E.; Hartnett, H. E.; Williams, L. B.; Gould, I.</p> <p>2013-12-01</p> <p>The reactivity of aqueous amines depends on temperature, pH, and redox state [1], all of which are highly variable in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Temperature and pH affect the ratio of protonated to unprotonated amines (R-NH2 + H+ = R-NH3+), which act as nucleophiles and electrophiles, respectively. We hypothesize that this dual nature can explain the pH dependence of reaction rates, and predict that rates will approach a maximum at pH = pKa where the ratio of protonated and unprotonated amines approaches one and the two compounds are poised to react with one another. Higher temperatures in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> allow for more rapid reaction rates, readily reversible reactions, and unique carbon-nitrogen chemistry in which water acts as a reagent in addition to being the solvent. In this study, aqueous benzylamine was used as a model compound to explore the reaction mechanisms, kinetics, and equilibria of amines under <span class="hlt">hydrothermal</span> conditions. Experiments were carried out in anoxic silica glass tubes at 250°C (Psat) using phosphate-buffered solutions to observe changes in reaction rates and product distributions as a function of pH. The rate of decomposition of benzylamine was much faster at pH 4 than at pH 9, consistent with the prediction that benzylamine acts as both nucleophile and an electrophile, and our estimate that the pKa of benzylamine is ~5 at 250°C and Psat. Accordingly, dibenzylamine is the primary product of the reaction of two benzylamine molecules, and this reaction is readily reversible under <span class="hlt">hydrothermal</span> conditions. Extremely acidic or basic pH can be used to suppress dibenzylamine production, which also suppresses the formation of all other major products, including toluene, benzyl alcohol, dibenzylimine, and tribenzylamine. This suggests that dibenzylamine is the lone primary product that then itself reacts as a precursor to produce the above compounds. Analog experiments performed with ring-substituted benzylamine derivatives and chiral</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997E%26PSL.153..239F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997E%26PSL.153..239F"><span>Tide-related variability of TAG <span class="hlt">hydrothermal</span> activity observed by deep-sea monitoring <span class="hlt">system</span> and OBSH</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fujioka, Kantaro; Kobayashi, Kazuo; Kato, Kazuhiro; Aoki, Misumi; Mitsuzawa, Kyohiko; Kinoshita, Masataka; Nishizawa, Azusa</p> <p>1997-12-01</p> <p><span class="hlt">Hydrothermal</span> activities were monitored by an ocean bottom seismometer with hydrophone (OBSH) and a composite measuring <span class="hlt">system</span> (Manatee) including CTD, current meter, transmission meter and cameras at a small depression on the TAG <span class="hlt">hydrothermal</span> mound in the Mid-Atlantic Ridge. Low-frequency pressure pulses detected by the hydrophone with semi-diurnal periodicity seem to correspond to cycles of <span class="hlt">hydrothermal</span> upflow from a small and short-lived smoker vent close to the observing site. The peaks of pressure pulses are synchronous with the maximum gradient of areal strain decrease due to tidal load release. Microearthquakes with very near epicenters occur sporadically and do not appear to be directly correlatable to <span class="hlt">hydrothermal</span> venting. Temporal variations in bottom water temperature also have semi-diurnal periodicity but are more complicated than the pressure events. Temperatures may be affected both by upwelling of hot water and by lateral flow of the bottom current changing its directions with ocean tide.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V51C0373S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V51C0373S"><span>Fluid geochemistry of Fault zone <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in the Yidun-Litang area, eastern Tibetan Plateau geothermal belt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Z.; Wang, G.</p> <p>2017-12-01</p> <p>Understanding the geochemical and geothermal characteristic of the <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> provide useful information in appropriate evaluating the geothermal potential in this area. In this paper, we investigate the chemical and isotopic composition of thermal water in an underexploited geothermal belt, Yidun-Litang area, in eastern Tibetan Plateau geothermal belt. 24 hot springs from the Yidun and Litang area were collected and analyzed. The chemical facies of the hot springs are mainly Na-HCO3 type water. Water-rock interaction, cation exchange are the dominant hydrogeochemical processes in the <span class="hlt">hydrothermal</span> evolution. All the hot springs show long-time water-rock interaction and significant 18O shift occurred in the Yindun area. Tritium data indicate the long-time water-rock interaction time in the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. According to the isotope and geochemical data, the <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in Yidun and Litang area may share a common deep parent geothermal liquid but receive different sources of meteoric precipitation and undergone different geochemical processes. The Yidun area have relative high reservoir equilibrium temperature (up to 230 °C) while the reservoir temperature at Litang area is relative low (up to 128 °C).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920019807&hterms=modeling+reactions+chemical&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmodeling%2Breactions%2Bchemical','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920019807&hterms=modeling+reactions+chemical&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmodeling%2Breactions%2Bchemical"><span>Chemical reaction path modeling of <span class="hlt">hydrothermal</span> processes on Mars: Preliminary results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Plumlee, Geoffrey S.; Ridley, W. Ian</p> <p>1992-01-01</p> <p><span class="hlt">Hydrothermal</span> processes are thought to have had significant roles in the development of surficial mineralogies and morphological features on Mars. For example, a significant proportion of the Martian soil could consist of the erosional products of <span class="hlt">hydrothermally</span> altered impact melt sheets. In this model, impact-driven, vapor-dominated <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> <span class="hlt">hydrothermally</span> altered the surrounding rocks and transported volatiles such as S and Cl to the surface. Further support for impact-driven <span class="hlt">hydrothermal</span> alteration on Mars was provided by studies of the Ries crater, Germany, where suevite deposits were extensively altered to montmorillonite clays by inferred low-temperature (100-130 C) <span class="hlt">hydrothermal</span> fluids. It was also suggested that surface outflow from both impact-driven and volcano-driven <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> could generate the valley networks, thereby eliminating the need for an early warm wet climate. We use computer-driven chemical reaction path calculation to model chemical processes which were likely associated with postulated Martian <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010020499&hterms=anticipation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Danticipation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010020499&hterms=anticipation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Danticipation"><span>Impact Crater <span class="hlt">Hydrothermal</span> Niches for Life on Mars: Question of Scale</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pope, K. O.; Ames, D. E.; Kieffer, S. W.; Ocampo, A. C.</p> <p>2000-01-01</p> <p>A major focus in the search for fossil life on Mars is on ancient <span class="hlt">hydrothermal</span> deposits. Nevertheless, remote sensing efforts have not found mineral assemblages characteristic of <span class="hlt">hydrothermal</span> activity. Future remote sensing work, including missions with higher spatial resolution, may detect localized <span class="hlt">hydrothermal</span> deposits, but it is possible that dust mantles will prohibit detection from orbit and lander missions will be required. In anticipation of such missions, it is critical to develop a strategy for selecting potential <span class="hlt">hydrothermal</span> sites on Mars. Such a strategy is being developed for volcanogenic <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, and a similar strategy is needed for impact <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984ESRv...20....1R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984ESRv...20....1R"><span><span class="hlt">Hydrothermal</span> mineralization at seafloor spreading centers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rona, Peter A.</p> <p>1984-01-01</p> <p>The recent recognition that metallic mineral deposits are concentrated by <span class="hlt">hydrothermal</span> processes at seafloor spreading centers constitutes a scientific breakthrough that opens active sites at seafloor spreading centers as natural laboratories to investigate ore-forming processes of such economically useful deposits as massive sulfides in volcanogenic rocks on land, and that enhances the metallic mineral potential of oceanic crust covering two-thirds of the Earth both beneath ocean basins and exposed on land in ophiolite belts. This paper reviews our knowledge of processes of <span class="hlt">hydrothermal</span> mineralization and the occurrence and distribution of <span class="hlt">hydrothermal</span> mineral deposits at the global oceanic ridge-rift <span class="hlt">system</span>. Sub-seafloor <span class="hlt">hydrothermal</span> convection involving circulation of seawater through fractured rocks of oceanic crust driven by heat supplied by generation of new lithosphere is nearly ubiquitous at seafloor spreading centers. However, ore-forming <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are extremely localized where conditions of anomalously high thermal gradients and permeability increase <span class="hlt">hydrothermal</span> activity from the ubiquitous low-intensity background level (⩽ 200°C) to high-intensity characterized by high temperatures ( > 200-c.400°C), and a rate and volume of flow sufficient to sustain chemical reactions that produce acid, reducing, metal-rich primary <span class="hlt">hydrothermal</span> solutions. A series of mineral phases with sulfides and oxides as high- and low-temperature end members, respectively, are precipitated along the upwelling limb and in the discharge zone of single-phase <span class="hlt">systems</span> as a function of increasing admixture of normal seawater. The occurrence of <span class="hlt">hydrothermal</span> mineral deposits is considered in terms of spatial and temporal frames of reference. Spatial frames of reference comprise structural features along-axis (linear sections that are the loci of seafloor spreading alternating with transform faults) and perpendicular to axis (axial zone of volcanic extrusion and marginal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFMOS11A0338B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFMOS11A0338B"><span>The Third Dimension of an Active Back-arc <span class="hlt">Hydrothermal</span> <span class="hlt">System</span>: ODP Leg 193 at PACMANUS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Binns, R.; Barriga, F.; Miller, D.</p> <p>2001-12-01</p> <p>This first sub-seafloor examination of an active <span class="hlt">hydrothermal</span> <span class="hlt">system</span> hosted by felsic volcanics, at a convergent margin, obtained drill core from a high-T "smoker" site (penetrated to sim200 mbsf) and a low-T site of diffuse venting (~400mbsf). We aimed to delineate the lateral and vertical variability in mineralisation and alteration patterns, so as to understand links between volcanological, structural and <span class="hlt">hydrothermal</span> phenomena and the sources of fluids, and to establish the nature and extent of microbial activity within the <span class="hlt">system</span>. Technological breakthroughs included deployment of a new hard-rock re-entry <span class="hlt">system</span>, and direct comparison in a hardrock environment of structural images obtained by wireline methods and logging-while-drilling. The PACMANUS <span class="hlt">hydrothermal</span> site, at the 1700m-deep crest of a 500m-high layered sequence of dacitic lavas, is notable for baritic massive sulfide chimneys rich in Cu, Zn, Au and Ag. Below an extensive cap 5-40m thick of fresh dacite-rhyodacite, we found unexpectedly pervasive <span class="hlt">hydrothermal</span> alteration of vesicular and flow-banded precursors, accompanied by variably intense fracturing and anhydrite-pyrite veining. Within what appears one major <span class="hlt">hydrothermal</span> event affecting the entire drilled sequence, there is much overprinting and repetition of distinctly allochemical argillaceous (illite-chlorite), acid-sulfate (pyrophyllite-anhydrite) and siliceous assemblages. The alteration profiles include a transition from metastable cristobalite to quartz at depth, and are similar under low-T and high-T vent sites but are vertically condensed in a manner suggesting higher thermal gradients beneath the latter. The altered rocks are surprisingly porous (average 25%). Retention of intergranular pore spaces and open vesicles at depth implies elevated <span class="hlt">hydrothermal</span> pressures, whereas evidence from fluid inclusions and <span class="hlt">hydrothermal</span> brecciation denotes local or sporadic phase separation. A maximum measured temperature of 313 degC measured 8 days</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s96-07957.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s96-07957.html"><span>Pre-flight views of orbiter <span class="hlt">Endeavour</span> on way to launch pad for STS-77</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1996-05-01</p> <p>S96-07957 (16 April 1996) --- A road sign points to Launch Pad 39B, the final earthly destination for the Space Shuttle <span class="hlt">Endeavour</span> and its final stepping stone into space. <span class="hlt">Endeavour</span> began the slow journey from the Vehicle Assembly Building (VAB) at about 10:00a.m., April 16, 1996, perched atop the Mobile Launcher Platform and carried by the Crawler-Transporter. Upcoming activities at the pad to prepare <span class="hlt">Endeavour</span> for flight on STS-77 include installation of the payloads in the Orbiter?s payload bay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H32F..01W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H32F..01W"><span>The Interplay Between Saline Fluid Flow and Dynamic Permeability in Magmatic-<span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weis, P.</p> <p>2014-12-01</p> <p>Magmatic-<span class="hlt">hydrothermal</span> ore deposits document the interplay between saline fluid flow and rock permeability. Numerical simulations of multi-phase flow of variably miscible, compressible H20-NaCl fluids in concert with a dynamic permeability model can reproduce characteristics of porphyry copper and epithermal gold <span class="hlt">systems</span>. This dynamic permeability model incorporates depth-dependent permeability profiles characteristic for tectonically active crust as well as pressure- and temperature-dependent relationships describing hydraulic fracturing and the transition from brittle to ductile rock behavior. In response to focused expulsion of magmatic fluids from a crystallizing upper crustal magma chamber, the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> self-organizes into a hydrological divide, separating an inner part dominated by ascending magmatic fluids under near-lithostatic pressures from a surrounding outer part dominated by convection of colder meteoric fluids under near-hydrostatic pressures. This hydrological divide also provides a mechanism to transport magmatic salt through the crust, and prevents the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> to become "clogged" by precipitation of solid halite due to depressurization of saline, high-temperature magmatic fluids. The same physical processes at similar permeability ranges, crustal depths and flow rates are relevant for a number of active <span class="hlt">systems</span>, including geothermal resources and excess degassing at volcanos. The simulations further suggest that the described mechanism can separate the base of free convection in high-enthalpy geothermal <span class="hlt">systems</span> from the magma chamber as a driving heat source by several kilometers in the vertical direction in tectonic settings with hydrous magmatism. This hydrology would be in contrast to settings with anhydrous magmatism, where the base of the geothermal <span class="hlt">systems</span> may be closer to the magma chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994Tectp.237..155C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994Tectp.237..155C"><span>The North Tanganyika <span class="hlt">hydrothermal</span> fields, East African Rift <span class="hlt">system</span>: Their tectonic control and relationship to volcanism and rift segmentation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coussement, C.; Gente, P.; Rolet, J.; Tiercelin, J.-J.; Wafula, M.; Buku, S.</p> <p>1994-10-01</p> <p>The two branches of the East African Rift <span class="hlt">system</span> include numerous <span class="hlt">hydrothermal</span> fields, which are closely related to the present fault motion and to volcanic and seismic activity. In this study structural data from Pemba and Cape Banza <span class="hlt">hydrothermal</span> fields (western branch, North Tanganyika, Zaire) are discussed in terms of neotectonic phenomena. Different types of records, such as fieldwork (onshore and underwater) and LANDSAT and SPOT imagery, are used to explain structural controls on active and fossil <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> and their significance. The Pemba site is located at the intersection of 000-020°-trending normal faults belonging to the Uvira Border Fault <span class="hlt">System</span> and a 120-130°-trending transtensional fault zone and is an area of high seismicity, with events of relatively large magnitude ( Ms < 6.5). The Cape Banza site occurs at the northern end of the Ubawari Peninsula horst. It is bounded by two fault <span class="hlt">systems</span> trending 015° and is characterized seismically by events of small magnitude ( Ms < 4). The <span class="hlt">hydrothermal</span> area itself is tectonically controlled by structures striking 170-180° and 080°. The analysis of both <span class="hlt">hydrothermal</span> areas demonstrates the rejuvenation of older Proterozoic structures during Recent rift faulting and the location of the <span class="hlt">hydrothermal</span> activity at the junctions of submeridian and transverse faults. The fault motion is compatible with a regional direction of extension of 090-110°. The Cape Banza and Pemba <span class="hlt">hydrothermal</span> fields may testify to magma chambers existing below the junctions of the faults. They appear to form at structural nodes and may represent a future volcanic province. Together with the four surface volcanic provinces existing along the western branch, they possibly indicate an incipient rift segmentation related to 'valley-valley' or 'transverse fault-valley' junctions, contrasting with the spacing of the volcanoes measured in the eastern branch. These spacings appear to express the different elastic thicknesses between</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040034738&hterms=narrator&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnarrator','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040034738&hterms=narrator&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnarrator"><span>STS-111/<span class="hlt">Endeavour</span>/ISS UF2 Pre-Launch Activities: Launch with Playbacks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p>This video of the preflight preparations for and launch of Space Shuttle <span class="hlt">Endeavour</span> on STS-111 begins with a view of <span class="hlt">Endeavour</span> on the launch pad. Additional launch pad views leading up to liftoff are interspersed with footage from the Firing Room at Kennedy Space Center, the crew's prelaunch activities, and inspection of the crew members in the White Room before boarding <span class="hlt">Endeavour</span>. The crew is introduced by a narrator during the preflight banquet and suiting up, and a later clip shows them departing to the launch site. The crew consists of Commander Kenneth Cockrell, Pilot Paul Lockhart, Mission Specialists Philippe Perrin and Franklin Chang-Diaz, and the Expedition 5 crew of the International Space Station (ISS) (Commander Valery Korzun and Flight Engineers Peggy Whitsun and Sergei Treschev). The nozzles on <span class="hlt">Endeavour</span>'s Space Shuttle Main Engine (SSME) are swiveled before liftoff, and the launch is shown past the separation of the solid rocket boosters. After a brief clip from the Mission Control Center at Johnson Space Center, the following launch replays are shown: Beach Tracker, VAB, Pad A, Tower 1, UCS-15, Grandstand, Cocoa Beach DOAMS, Playalinda DOAMS, UCS-23, and OTV-070.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.H21B0809G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.H21B0809G"><span>High-resolution simulations of multi-phase flow in magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">systems</span> with realistic fluid properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geiger, S.; Driesner, T.; Matthai, S.; Heinrich, C.</p> <p>2002-12-01</p> <p>Realistic modelling of multi-phase fluid flow, energy and component transport in magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">systems</span> is very challenging because hydrological properties of fluids and rocks vary over many orders of magnitude and the geometric complexities of such <span class="hlt">systems</span>. Furthermore, density dependent component transport and transient permeability variations due to P-T changes and fluid-rock interactions introduce additional difficulties. As a result, the governing equations for the hydrodynamics, energy and component transport, and thermodynamics in magmatic <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are highly non-linear and strongly coupled. Essential requirements of a numerical formulation for such a <span class="hlt">system</span> are: (1) a treatment of the hydrodynamics that can accurately resolve complex geological structures and represent the highly variable fluid velocities herein, (2) a realistic thermodynamic representation of the fluid properties including the wide P-T-X range of liquid+vapour coexistence for the highly saline fluids, and (3) an accurate handling of the highly contrasting transport properties of the two fluids. We are combining higher order finite-element (FE) methods with total variation diminishing finite volume (TVDFV) methods to model the hydrodynamics and energy and component transport of magmatic <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Combined FE and TVDFV methods are mass and shock preserving, yield great geometric flexibility in 2D and 3D [2]. Furthermore, efficient matrix solvers can be employed to model fluid flow in geologically realistic structures [5]. The governing equations are linearized by operator-splitting and solved sequentially using a Picard iteration scheme. We chose the <span class="hlt">system</span> water-NaCl as a realistic proxy for natural fluids occurring in magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. An in-depth evaluation of the available experimental and theoretical data led to a consistent and accurate set of formulations for the PVTXH relations that are valid from 0 to 800 C, 0 to 500 MPa, and 0 to 1 XNa</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s89e5534.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s89e5534.html"><span>MS Reilly at work on <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1998-03-04</p> <p>S89-E-5534 (22-31 Jan 1998) --- This Electronic Still Camera (ESC) image shows astronaut James F. Reilly, mission specialist, floating in the tunnel connecting the Spacehab module to the mid-deck of the Earth-orbiting Space Shuttle <span class="hlt">Endeavour</span>. Having disconnected from the Russian Mir Space Station a day earlier, the STS-89 crew was in a mode of wrapping up final chores before a scheduled January 31st landing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GGG....18..531L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GGG....18..531L"><span>Rapid variations in fluid chemistry constrain <span class="hlt">hydrothermal</span> phase separation at the Main <span class="hlt">Endeavour</span> Field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Love, Brooke; Lilley, Marvin; Butterfield, David; Olson, Eric; Larson, Benjamin</p> <p>2017-02-01</p> <p>Previous work at the Main <span class="hlt">Endeavour</span> Field (MEF) has shown that chloride concentration in high-temperature vent fluids has not exceeded 510 mmol/kg (94% of seawater), which is consistent with brine condensation and loss at depth, followed by upward flow of a vapor phase toward the seafloor. Magmatic and seismic events have been shown to affect fluid temperature and composition and these effects help narrow the possibilities for sub-surface processes. However, chloride-temperature data alone are insufficient to determine details of phase separation in the upflow zone. Here we use variation in chloride and gas content in a set of fluid samples collected over several days from one sulfide chimney structure in the MEF to constrain processes of mixing and phase separation. The combination of gas (primarily magmatic CO2 and seawater-derived Ar) and chloride data, indicate that neither variation in the amount of brine lost, nor mixing of the vapor phase produced at depth with variable quantities of (i) brine or (ii) altered gas rich seawater that has not undergone phase separation, can explain the co-variation of gas and chloride content. The gas-chloride data require additional phase separation of the ascending vapor-like fluid. Mixing and gas partitioning calculations show that near-critical temperature and pressure conditions can produce the fluid compositions observed at Sully vent as a vapor-liquid conjugate pair or as vapor-liquid pair with some remixing, and that the gas partition coefficients implied agree with theoretically predicted values.<abstract type="synopsis"><title type="main">Plain Language SummaryWhen the chemistry of fluids from deep sea hot springs changes over a short time span, it allows us to narrow down the conditions and processes that created those fluids. This gives us a better idea what is happening under the seafloor where the water is interacting with hot rocks and minerals, boiling, and taking on the character it will have when it emerges at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRE..123..690F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRE..123..690F"><span>Unraveling the History of Meridiani Planum, Mars: New Chemical Clues From the Rim of <span class="hlt">Endeavour</span> Crater</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fraeman, Abigail A.</p> <p>2018-03-01</p> <p>Mittlefehldt et al. (2018, https://doi.org/10.1002/2017JE005474) synthesize Alpha Particle X-Ray Spectrometer chemical measurements along more than 4.5 km of <span class="hlt">Endeavour</span> crater's rim. Their analyses clarify details of <span class="hlt">Endeavour</span>'s geologic history, including evidence for three to four distinct episodes of aqueous alteration. Fracture-driven aqueous <span class="hlt">systems</span> and Mn mobility are particularly important both here and at Curiosity's landing site on the opposite side of the planet. The detailed documentation of Alpha Particle X-Ray Spectrometer data products within this paper will be a key reference for researchers who want to perform future work on questions related to Mars aqueous geochemistry, impact processes, and Martian crustal and atmospheric evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts059-s-107.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts059-s-107.html"><span>Landing of STS-59 Shuttle <span class="hlt">Endeavour</span> at Edwards Air Force Base</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1994-04-20</p> <p>STS059-S-107 (20 April 1994) --- The main landing gear of the Space Shuttle <span class="hlt">Endeavour</span> touches down at Edwards Air Force Base to complete the 11-day STS-59/SRL-1 mission. Landing occurred at 9:54 a.m. (PDT), April 20, 1994. Mission duration was 11 days, 5 hours, 49 minutes. Guiding <span class="hlt">Endeavour</span> to a landing was astronaut Sidney M. Gutierrez, STS-59 commander. His crew was Kevin P. Chilton, Linda M. Godwin, Jerome (Jay) Apt, Michael R. (Rich) Clifford and Thomas D. Jones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010044700&hterms=Xxxii&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DXxxii','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010044700&hterms=Xxxii&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DXxxii"><span>Availability of Heat to Drive <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span> in Large Martian Impact Craters</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thorsos, I. E.; Newsom, H. E.; Davies, A. G.</p> <p>2001-01-01</p> <p>The central uplift in large craters on Mars can provide a substantial source of heat, equivalent to heat produced by the impact melt sheet. The heat generated in large impacts could play a significant role in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> on Mars. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CoMP..173...40K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CoMP..173...40K"><span>Constraints on the source of Cu in a submarine magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">system</span>, Brothers volcano, Kermadec island arc</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keith, Manuel; Haase, Karsten M.; Klemd, Reiner; Smith, Daniel J.; Schwarz-Schampera, Ulrich; Bach, Wolfgang</p> <p>2018-05-01</p> <p>Most magmatic-<span class="hlt">hydrothermal</span> Cu deposits are genetically linked to arc magmas. However, most continental or oceanic arc magmas are barren, and hence new methods have to be developed to distinguish between barren and mineralised arc <span class="hlt">systems</span>. Source composition, melting conditions, the timing of S saturation and an initial chalcophile element-enrichment represent important parameters that control the potential of a subduction setting to host an economically valuable deposit. Brothers volcano in the Kermadec island arc is one of the best-studied examples of arc-related submarine magmatic-<span class="hlt">hydrothermal</span> activity. This study, for the first time, compares the chemical and mineralogical composition of the Brothers seafloor massive sulphides and the associated dacitic to rhyolitic lavas that host the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Incompatible trace element ratios, such as La/Sm and Ce/Pb, indicate that the basaltic melts from L'Esperance volcano may represent a parental analogue to the more evolved Brothers lavas. Copper-rich magmatic sulphides (Cu > 2 wt%) identified in fresh volcanic glass and phenocryst phases, such as clinopyroxene, plagioclase and Fe-Ti oxide suggest that the surrounding lavas that host the Brothers <span class="hlt">hydrothermal</span> <span class="hlt">system</span> represent a potential Cu source for the sulphide ores at the seafloor. Thermodynamic calculations reveal that the Brothers melts reached volatile saturation during their evolution. Melt inclusion data and the occurrence of sulphides along vesicle margins indicate that an exsolving volatile phase extracted Cu from the silicate melt and probably contributed it to the overlying <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Hence, the formation of the Cu-rich seafloor massive sulphides (up to 35.6 wt%) is probably due to the contribution of Cu from a bimodal source including wall rock leaching and magmatic degassing, in a mineralisation style that is hybrid between Cyprus-type volcanic-hosted massive sulphide and subaerial epithermal-porphyry deposits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JVGR..192...57A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JVGR..192...57A"><span>Water-rock interaction in the magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">system</span> of Nisyros Island (Greece)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ambrosio, Michele; Doveri, Marco; Fagioli, Maria Teresa; Marini, Luigi; Principe, Claudia; Raco, Brunella</p> <p>2010-04-01</p> <p>In this work, we investigated the water-rock interaction processes taking place in the <span class="hlt">hydrothermal</span> reservoir of Nisyros through both: (1) a review of the <span class="hlt">hydrothermal</span> mineralogy encountered in the deep geothermal borehole Nisyros-2; and (2) a comparison of the analytically-derived redox potentials and acidities of fumarolic-related liquids, with those controlled by redox buffers and pH buffers, involving <span class="hlt">hydrothermal</span> mineral phases. The propylitic zone met in the deep geothermal borehole Nisyros-2, from 950 to 1547 m (total depth), is characterised by abundant, well crystallised epidote, adularia, albite, quartz, pyrite, chlorite, and sericite-muscovite, accompanied by less abundant anhydrite, stilpnomelane, wairakite, garnet, tremolite and pyroxene. These <span class="hlt">hydrothermal</span> minerals were produced in a comparatively wide temperature range, from 230 to 300 °C, approximately. <span class="hlt">Hydrothermal</span> assemblages are well developed from 950 to 1360 m, whereas they are less developed below this depth, probably due to low permeability. Based on the RH values calculated for fumarolic gases and for the deep geothermal fluids of Nisyros-1 and Nisyros-2 wells, redox equilibrium with the (FeO)/(FeO 1.5) rock buffer appears to be closely attained throughout the <span class="hlt">hydrothermal</span> reservoir of Nisyros. This conclusion may be easily reconciled with the nearly ubiquitous occurrence of anhydrite and pyrite, since RH values controlled by coexistence of anhydrite and pyrite can be achieved by gas separation. The pH of the liquids feeding the fumarolic vents of Stephanos and Polybote Micros craters was computed, by means of the EQ3 code, based on the Cl- δD relationship which is constrained by the seawater-magmatic water mixing occurring at depth in the <span class="hlt">hydrothermal</span>-magmatic <span class="hlt">system</span> of Nisyros. The temperature dependence of analytically-derived pH values for the reservoir liquids feeding the fumarolic vents of Stephanos and Polybote Micros craters suggests that some unspecified pH buffer fixes the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70175410','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70175410"><span>Three-dimensional electrical resistivity model of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in Long Valley Caldera, California, from magnetotellurics</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Peacock, Jared R.; Mangan, Margaret T.; McPhee, Darcy K.; Wannamaker, Phil E.</p> <p>2016-01-01</p> <p>Though shallow flow of <span class="hlt">hydrothermal</span> fluids in Long Valley Caldera, California, has been well studied, neither the <span class="hlt">hydrothermal</span> source reservoir nor heat source has been well characterized. Here a grid of magnetotelluric data were collected around the Long Valley volcanic <span class="hlt">system</span> and modeled in 3-D. The preferred electrical resistivity model suggests that the source reservoir is a narrow east-west elongated body 4 km below the west moat. The heat source could be a zone of 2–5% partial melt 8 km below Deer Mountain. Additionally, a collection of hypersaline fluids, not connected to the shallow <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, is found 3 km below the medial graben, which could originate from a zone of 5–10% partial melt 8 km below the south moat. Below Mammoth Mountain is a 3 km thick isolated body containing fluids and gases originating from an 8 km deep zone of 5–10% basaltic partial melt.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSM.U33A..08K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSM.U33A..08K"><span>Impact-generated <span class="hlt">Hydrothermal</span> Activity at the Chicxulub Crater</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kring, D. A.; Zurcher, L.; Abramov, O.</p> <p>2007-05-01</p> <p>Borehole samples recovered from PEMEX exploration boreholes and an ICDP scientific borehole indicate the Chicxulub impact event generated <span class="hlt">hydrothermal</span> alteration throughout a large volume of the Maya Block beneath the crater floor and extending across the bulk of the ~180 km diameter crater. The first indications of <span class="hlt">hydrothermal</span> alteration were observed in the crater discovery samples from the Yucatan-6 borehole and manifest itself in the form of anhydrite and quartz veins. Continuous core from the Yaxcopoil-1 borehole reveal a more complex and temporally extensive alteration sequence: following a brief period at high temperatures, impact- melt-bearing polymict breccias and a thin, underlying unit of impact melt were subjected to metasomatism, producing alkali feldspar, sphene, apatite, and magnetite. As the <span class="hlt">system</span> continued to cool, smectite-series phyllosilicates appeared. A saline solution was involved. Stable isotopes suggest the fluid was dominated by a basinal brine created mostly from existing groundwater of the Yucatan Peninsula, although contributions from down-welling water also occurred in some parts of the <span class="hlt">system</span>. Numerical modeling of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> suggests circulation occurred for 1.5 to 2.3 Myr, depending on the permeability of the <span class="hlt">system</span>. Our understanding of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, however, is still crude. Additional core recovery projects, particularly into the central melt sheet, are needed to better evaluate the extent and duration of <span class="hlt">hydrothermal</span> alteration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V21A4731T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V21A4731T"><span>A Blind <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> in an Ocean Island Environment: Humu'ula Saddle, Hawaii Island</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, D. M.; Wallin, E.; Lautze, N. C.; Lienert, B. R.; Pierce, H. A.</p> <p>2014-12-01</p> <p>A recently drilled groundwater investigation borehole, drilled to a depth of 1760 m in the Humu'ula Saddle of Hawaii Island, encountered an unexpectedly high temperature gradient of more than 160 ̊C/km. Although prior MT surveys across the region identified conductive formations of modest extent in the region, there were few surface manifestations of geologic structures likely to host a geothermal <span class="hlt">system</span> and no evidence of an active, extensive <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Cores recovered from the borehole showed the presence of intrusive formations and moderate <span class="hlt">hydrothermal</span> alteration at depth with progressive infilling of fractures and vesicles with depth and temperature. Independent modeling of gravity data (Flinders et al., 2013) suggests the presence of a broad intrusive complex within the region that is consistent with the borehole's confirmation of a high-elevation (~1400 m amsl) regional water table. A subsequent MT survey covering much of the western Saddle region has confirmed the presence of highly conductive conditions, consistent with thermal activity, to depths of 4 km and greater. Light stable isotope data for the borehole fluids indicate that the regional water table is derived from recharge from the upper elevations of Mauna Kea; major element chemistry indicates that formation temperatures exceed 200 ̊C. A conceptual model of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, along with isotopic and fluid chemistry of the thermal fluids will be presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018464','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018464"><span>Hydrogen isotope systematics of phase separation in submarine <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>: Experimental calibration and theoretical models</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Berndt, M.E.; Seal, R.R.; Shanks, Wayne C.; Seyfried, W.E.</p> <p>1996-01-01</p> <p>Hydrogen isotope fractionation factors were measured for coexisting brines and vapors formed by phase separation of NaCl/H2O fluids at temperatures ranging from 399-450??C and pressures from 277-397 bars. It was found that brines are depleted in D compared to coexisting vapors at all conditions studied. The magnitude of hydrogen isotope fractionation is dependent on the relative amounts of Cl in the two phases and can be empirically correlated to pressure using the following relationship: 1000 ln ??(vap-brine) = 2.54(??0.83) + 2.87(??0.69) x log (??P), where ??(vap-brine) is the fractionation factor and ??P is a pressure term representing distance from the critical curve in the NaCl/H2O <span class="hlt">system</span>. The effect of phase separation on hydrogen isotope distribution in subseafloor <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> depends on a number of factors, including whether phase separation is induced by heating at depth or by decompression of <span class="hlt">hydrothermal</span> fluids ascending to the seafloor. Phase separation in most subseafloor <span class="hlt">systems</span> appears to be a simple process driven by heating of seawater to conditions within the two-phase region, followed by segregation and entrainment of brine or vapor into a seawater dominated <span class="hlt">system</span>. Resulting vent fluids exhibit large ranges in Cl concentration with no measurable effect on ??D. Possible exceptions to this include <span class="hlt">hydrothermal</span> fluids venting at Axial and 9??N on the East Pacific Rise. High ??D values of low Cl fluids venting at Axial are consistent with phase separation taking place at relatively shallow levels in the oceanic crust while negative ??D values in some low Cl fluids venting at 9??N suggest involvement of a magmatic fluid component or phase separation of D-depleted brines derived during previous <span class="hlt">hydrothermal</span> activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B11J0571L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B11J0571L"><span>Insight from Genomics on Biogeochemical Cycles in a Shallow-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, G. S.; Amend, J.</p> <p>2015-12-01</p> <p>Shallow-sea <span class="hlt">hydrothermal</span> ecosystems are dynamic, high-energy <span class="hlt">systems</span> influenced by sunlight and geothermal activity. They provide accessible opportunities for investigating thermophilic microbial biogeochemical cycles. In this study, we report biogeochemical data from a shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span> offshore Paleochori Bay, Milos, Greece, which is characterized by a central vent covered by white microbial mats with <span class="hlt">hydrothermally</span> influenced sediments extending into nearby sea grass area. Geochemical analysis and deep sequencing provide high-resolution information on the geochemical patterns, microbial diversity and metabolic potential in a two-meter transect. The venting fluid is elevated in temperature (~70oC), low in pH (~4), and enriched in reduced species. The geochemical pattern shows that the profile is affected by not only seawater dilution but also microbial regulation. The microbial community in the deepest section of vent core (10-12 cm) is largely dominated by thermophilic archaea, including a methanogen and a recently described Crenarcheon. Mid-core (6-8 cm), the microbial community in the venting area switches to the hydrogen utilizer Aquificae. Near the sediment-water interface, anaerobic Firmicutes and Actinobacteria dominate, both of which are commonly associated with subsurface and <span class="hlt">hydrothermal</span> sites. All other samples are dominated by diverse Proteobacteria. The sulfate profile is strongly correlated with the population size of delta- and episilon-proteobactia. The dramatic decrease in concentrations of As and Mn in pore fluids as a function of distance from the vent suggests that in addition to seawater dilution, microorganisms are likely transforming these and other ions through a combination of detoxification and catabolism. In addition, high concentrations of dissolved Fe are only measurable in the shallow sea grass area, suggesting that iron-transforming microorganisms are controlling Fe mobility, and promoting biomineralization. Taken</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSCT44A0211N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSCT44A0211N"><span><span class="hlt">Hydrothermal</span> <span class="hlt">systems</span> are a sink for dissolved black carbon in the deep ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niggemann, J.; Hawkes, J. A.; Rossel, P. E.; Stubbins, A.; Dittmar, T.</p> <p>2016-02-01</p> <p>Exposure to heat during fires on land or geothermal processes in Earth's crust induces modifications in the molecular structure of organic matter. The products of this thermogenesis are collectively termed black carbon. Dissolved black carbon (DBC) is a significant component of the oceanic dissolved organic carbon (DOC) pool. In the deep ocean, DBC accounts for 2% of DOC and has an apparent radiocarbon age of 18,000 years. Thus, DBC is much older than the bulk DOC pool, suggesting that DBC is highly refractory. Recently, it has been shown that recalcitrant deep-ocean DOC is efficiently removed during <span class="hlt">hydrothermal</span> circulation. Here, we hypothesize that <span class="hlt">hydrothermal</span> circulation is also a net sink for deep ocean DBC. We analyzed DBC in samples collected at different vent sites in the Atlantic, Pacific and Southern oceans. DBC was quantified in solid-phase extracts as benzenepolycarboxylic acids (BPCAs) following nitric acid digestion. Concentrations of DBC were much lower in <span class="hlt">hydrothermal</span> fluids than in surrounding deep ocean seawater, confirming that <span class="hlt">hydrothermal</span> circulation acts as a net sink for oceanic DBC. The relative contribution of DBC to bulk DOC did not change during <span class="hlt">hydrothermal</span> circulation, indicating that DBC is removed at similar rates as bulk DOC. The ratio of the oxidation products benzenehexacarboxylic acid (B6CA) to benzenepentacarboxylic acid (B5CA) was significantly higher in <span class="hlt">hydrothermally</span> altered samples compared to ratios typically found in the deep ocean, reflecting a higher degree of condensation of DBC molecules after <span class="hlt">hydrothermal</span> circulation. Our study identified <span class="hlt">hydrothermal</span> circulation as a quantitatively important sink for refractory DBC in the deep ocean. In contrast to photodegradation of DBC at the sea surface, which is more efficient for more condensed DBC, i.e. decreasing the B6CA/B5CA ratio, <span class="hlt">hydrothermal</span> processing increases the B6CA/B5CA ratio, introducing a characteristic <span class="hlt">hydrothermal</span> DBC signature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017098','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017098"><span><span class="hlt">Hydrothermal</span> alteration in oceanic ridge volcanics: A detailed study at the Galapagos Fossil <span class="hlt">Hydrothermal</span> Field</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ridley, W.I.; Perfit, M.R.; Josnasson, I.R.; Smith, M.F.</p> <p>1994-01-01</p> <p>The Galapagos Fossil <span class="hlt">Hydrothermal</span> Field is composed of altered oceanic crust and extinct <span class="hlt">hydrothermal</span> vents within the eastern Galapagos Rift between 85??49???W and 85??55???W. The discharge zone of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> is revealed along scarps, thus providing an opportunity to examine the uppermost mineralized, and highly altered interior parts of the crust. Altered rocks collected in situ by the submersible ALVIN show complex concentric alteration zones. Microsamples of individual zones have been analysed for major/minor, trace elements, and strontium isotopes in order to describe the complex compositional details of the <span class="hlt">hydrothermal</span> alteration. Interlayered chlorite-smectite and chlorite with disequilibrium compositions dominate the secondary mineralogy as replacement phases of primary glass and acicular pyroxene. Phenocrysts and matrix grains of plagioclase are unaffected during alteration. Using a modification of the Gresens' equation we demonstrate that the trivalent rare earth elements (REEs) are relatively immobile, and calculate degrees of enrichment and depletion in other elements. Strontium isotopic ratios increase as Sr concentrations decrease from least-altered cores to most-altered rims and cross-cutting veins in individual samples, and can be modeled by open <span class="hlt">system</span> behaviour under low fluid-rock ratio (< 10) conditions following a period of lower-temperature weathering of volcanics within the rift zone. The complex patterns of element enrichment and depletion and strontium isotope variations indicate mixing between pristine seawater and ascending hot fluids to produce a compositional spectrum of fluids. The precipitation of base-metal sulfides beneath the seafloor is probably a result of fluid mixing and cooling. If, as suggested here, the discharge zone alteration occurred under relatively low fluid-rock ratios, then this shallow region must play an important role in determining the exit composition of vent fluids in marine <span class="hlt">hydrothermal</span> <span class="hlt">systems</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-96PC-0703&hterms=left&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dleft','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-96PC-0703&hterms=left&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dleft"><span>STS-77 Shuttle <span class="hlt">Endeavour</span> clears tower (front left)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1996-01-01</p> <p>A flawless countdown culminates with an on-time liftoff as the Space Shuttle <span class="hlt">Endeavour</span> lights up the morning sky. <span class="hlt">Endeavour</span> was launched on Mission STS-77 from Pad 39B at 6:30:00 a.m. EDT, May 19. The fourth Shuttle mission of 1996 is devoted to the continuing effort to help open the commercial space frontier. Heading up the six-member crew is Commander John H. Casper. Curtis L. Brown Jr. is the pilot and there are four mission specialists on board: Daniel W. Bursch, Mario Runco Jr., Andrew S. W. Thomas and Marc Garneau, who represents the Canadian Space Agency. During the approximately 10-day mission, the astronauts will perform a variety of payload activities, including microgravity research aboard the SPACEHAB-4 module, deployment and retrieval of the Spartan 207 carrying the Inflatable Antenna Experiment (IAE) and deployment and rendezvous with the Passive Aerodynamically-Stabilized Magnetically-Damped Satellite (PAMS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9825E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9825E"><span><span class="hlt">Hydrothermal</span> activity at slow-spreading ridges: variability and importance of magmatic controls</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Escartin, Javier</p> <p>2016-04-01</p> <p><span class="hlt">Hydrothermal</span> activity along mid-ocean ridge axes is ubiquitous, associated with mass, chemical, and heat exchanges between the deep lithosphere and the overlying envelopes, and sustaining chemiosynthetic ecosystems at the seafloor. Compared with <span class="hlt">hydrothermal</span> fields at fast-spreading ridges, those at slow spreading ones show a large variability as their location and nature is controlled or influenced by several parameters that are inter-related: a) tectonic setting, ranging from 'volcanic <span class="hlt">systems</span>' (along the rift valley floor, volcanic ridges, seamounts), to 'tectonic' ones (rift-bounding faults, oceanic detachment faults); b) the nature of the host rock, owing to compositional heterogeneity of slow-spreading lithosphere (basalt, gabbro, peridotite); c) the type of heat source (magmatic bodies at depth, hot lithosphere, serpentinization reactions); d) and the associated temperature of outflow fluids (high- vs.- low temperature venting and their relative proportion). A systematic review of the distribution and characteristics of <span class="hlt">hydrothermal</span> fields along the slow-spreading Mid-Atlantic Ridge suggests that long-lived <span class="hlt">hydrothermal</span> activity is concentrated either at oceanic detachment faults, or along volcanic segments with evidence of robust magma supply to the axis. A detailed study of the magmatically robust Lucky Strike segment suggests that all present and past <span class="hlt">hydrothermal</span> activity is found at the center of the segment. The association of these fields to central volcanos, and the absence of indicators of <span class="hlt">hydrothermal</span> activity along the remaining of the ridge segment, suggests that long-lived <span class="hlt">hydrothermal</span> activity in these volcanic <span class="hlt">systems</span> is maintained by the enhanced melt supply and the associated magma chamber(s) required to build these volcanic edifices. In this setting, <span class="hlt">hydrothermal</span> outflow zones at the seafloor are systematically controlled by faults, indicating that <span class="hlt">hydrothermal</span> fluids in the shallow crust exploit permeable fault zones to circulate. While</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-STS072-S-001.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-STS072-S-001.html"><span>STS-72 <span class="hlt">Endeavour</span>, Orbiter Vehicle (OV-105), crew insignia</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1995-05-01</p> <p>STS072-S-001 (May 1995) --- The crew patch of STS-72 depicts the space shuttle <span class="hlt">Endeavour</span> and some of the payloads on the flight. The Japanese satellite, Space Flyer Unit (SFU) is shown in a free-flying configuration with the solar array panels deployed. The inner gold border of the patch represents the SFU's distinct octagonal shape. <span class="hlt">Endeavour</span> will rendezvous with and retrieve SFU at an altitude of approximately 250 nautical miles. The Office of Aeronautics and Space Technology's (OAST) flyer satellite is shown just after release from the Remote Manipulator <span class="hlt">System</span> (RMS). The OAST satellite will be deployed at an altitude of 165 nautical miles to fly free for two days gathering scientific data. The payload bay contains equipment for the secondary payloads - the Shuttle Laser Altimeter (SLA) and the Shuttle Solar Backscatter Ultraviolet Instrument (SSBUI). There are two spacewalks planned to test hardware for assembly of the International Space Station. The stars represent the hometowns of the crew members in the United States and Japan. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1110353F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1110353F"><span>The main factors controlling petrophysical alteration in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> of the Kuril-Kamchatka island arch</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frolova, J.; Ladygin, V.; Rychagov, S.; Shanina, V.; Blyumkina, M.</p> <p>2009-04-01</p> <p>This report is based on the results of petrophysical studies obtained on a number of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the Kuril-Kamchatka island arc (Pauzhetsky, Mutnovsky, Koshelevsky, Essovsky, a volcano of Ebeko, Oceansky). Mineral composition and pore-space structure of primary rocks change intensively during <span class="hlt">hydrothermal</span> process, results in alteration of petrophysical properties - porosity, density, permeability, hygroscopy, sonic velocity, elastic modulus, mechanical properties, thermal and magnetic characteristics. Petrophysical alterations gradually lead to the change of the structure of <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, and its hydrodynamic and temperature regime. The tendency of petrophysical alteration can be different. In some cases rocks "improvement" is observed i.e. consolidation, hardening, decrease of porosity and permeability, removal of hygroscopy. In other cases rocks "deterioration" occurs, i.e. formation of secondary porosity and permeability, a decrease of density, strength, and elastic modulus, and occurrence of hygroscopic moisture. The classical example of cardinal petrophysical alteration is the transformation of hard basalts to plastic clays. The opposite example is the transformation of only slightly consolidates porous tuffs to hard and dense secondary quartzite. The character of petrophysical alteration depends on a number of factors including peculiarities of primary rocks, temperature, pressure and composition of thermal fluids, duration of fluid-rock interaction, and condition of fluid (steam, water, boiling water). The contribution of each factor to change of volcanic rocks properties is considered and analyzed in details. In particular, primary rocks controls speed, intensity and character of petrophysical alterations. Factors favorable for alteration are high porosity and permeability, micro crakes, weak cementation, glassy structure, basaltic composition. Kuril-Kamchatka region represents the volcanic island arch so host rocks in <span class="hlt">hydrothermal</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MinDe..50..281S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MinDe..50..281S"><span>Mo isotope fractionation during <span class="hlt">hydrothermal</span> evolution of porphyry Cu <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shafiei, Behnam; Shamanian, GholamHossein; Mathur, Ryan; Mirnejad, Hassan</p> <p>2015-03-01</p> <p>We present Mo isotope compositions of molybdenite types from three successive stages of ore deposition in several porphyry copper deposits of the Kerman region, Iran. The data provide new insights into controlling processes on Mo isotope fractionation during the <span class="hlt">hydrothermal</span> evolution of porphyry <span class="hlt">systems</span>. The Mo isotope compositions of 27 molybdenite samples show wide variations in δ97Mo ranging from -0.37 to +0.92 ‰. The data reveal that molybdenites in the early and transitional stages of mineralization (preferentially 2H polytypes; δ97Mo mean = 0.35 ‰) have higher δ97Mo values than late stage (mainly 3R polytypes; δ97Mo mean = 0.02 ‰) molybdenites. This trend suggests that fractionation of Mo isotopes occurred in high-temperature stages of mineralization and that <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> generally evolve towards precipitation of molybdenite with lower δ97Mo values. Taking into account the genetic models proposed for porphyry Cu deposits along with the temperature-dependent fractionation of Mo isotope ratios, it is proposed that large variations of Mo isotopes in the early and the transitional stages of ore deposition could be controlled by the separation of the immiscible ore-forming fluid phases with different density, pH, and ƒO2 properties (i.e., brine and vapor). The fractionation of Mo isotopes during fluid boiling and Rayleigh distillation processes likely dominates the Mo isotope budget of the remaining ore-forming fluids for the late stage of mineralization. The lower δ97Mo values in the late stage of mineralization can be explained by depletion of the late ore-forming <span class="hlt">hydrothermal</span> solutions in 97Mo, as these fluids have moved to considerable distance from the source. Finally, the relationship observed between MoS2 polytypes (2H and 3R) and their Mo isotopic compositions can be explained by the molecular vibration theory, in which heavier isotopes are preferentially partitioned into denser primary 2H MoS2 crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016607','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016607"><span><span class="hlt">Hydrothermal</span> ore-forming processes in the light of studies in rock- buffered <span class="hlt">systems</span>: II. Some general geologic applications</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hemley, J.J.; Hunt, J.P.</p> <p>1992-01-01</p> <p>The experimental metal solubilities for rock-buffered <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> provide important insights into the acquisition, transport, and deposition of metals in real <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> that produced base metal ore deposits. Water-rock reactions that determine pH, together with total chloride and changes in temperature and fluid pressure, play significant roles in controlling the solubility of metals and determining where metals are fixed to form ore deposits. Deposition of metals in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> occurs where changes such as cooling, pH increase due to rock alteration, boiling, or fluid mixing cause the aqueous metal concentration to exceed saturation. Metal zoning results from deposition occurring at successive saturation surfaces. Zoning is not a reflection simply of relative solubility but of the manner of intersection of transport concentration paths with those surfaces. Saturation surfaces will tend to migrate outward and inward in prograde and retrograde time, respectively, controlled by either temperature or chemical variables. -from Authors</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70013982','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70013982"><span>Castro ring zone: a 4,500-km2 fossil <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in the Challis volcanic field, central Idaho.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Criss, R.E.; Ekren, E.B.; Hardyman, R.F.</p> <p>1984-01-01</p> <p>The largest fossil <span class="hlt">hydrothermal</span> <span class="hlt">system</span> occupying a 4500 km2 area in central Idaho is revealed by delta 18O studies. The remains of this meteoric-<span class="hlt">hydrothermal</span> <span class="hlt">system</span> are preserved within a sharply bounded, 15 km wide, 70-km-diameter annulus of low delta 18O rock (+2.0 to -8.8per mille) termed the Castro ring zone. The zone is centred on a less depleted (+4.5) core zone consisting of granitic rocks of the Castro pluton. This 700-km2 Eocene subvolcanic batholith has intruded, domed, and <span class="hlt">hydrothermally</span> metamorphosed a thick sequence of Challis Volcanics, the stratigraphically low rocks in the 2000-km2 Van Horn Peak and the 1000-km2 Thunder Mountain cauldron complexes being most strongly altered. Less extreme 18O depletions occur in the youngest major ash-flow sheets of these complexes, indicating a vertical 18O gradient. Water/rock ratios of geothermal <span class="hlt">systems</span> are surprisingly insensitive to the circulation scale.-L.-di H.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-077.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-077.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-077 (1 June 2011) --- Xenon lights help lead space shuttle <span class="hlt">Endeavour</span> home to NASA's Kennedy Space Center in Florida. <span class="hlt">Endeavour</span> landed for the final time on the Shuttle Landing Facility's Runway 15, marking the 24th night landing of NASA's Space Shuttle Program. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-074.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-074.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-074 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Heat from the shuttle's auxiliary power units, which provide hydraulic control, can be seen at the back of <span class="hlt">Endeavour</span>, near the vertical tail. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-113.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-113.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-03</p> <p>STS134-S-113 (1 June 2011) --- Xenon lights help lead space shuttle <span class="hlt">Endeavour</span> home to NASA's Kennedy Space Center in Florida. <span class="hlt">Endeavour</span> landed for the final time on the Shuttle Landing Facility's Runway 15, marking the 24th night landing of NASA's Space Shuttle Program. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-089.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-089.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-089 (1 June 2011) --- Xenon lights help lead space shuttle <span class="hlt">Endeavour</span> home to NASA's Kennedy Space Center in Florida. <span class="hlt">Endeavour</span> landed for the final time on the Shuttle Landing Facility's Runway 15, marking the 24th night landing of NASA's Space Shuttle Program. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-088.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-088.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-088 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Heat from the shuttle's auxiliary power units, which provide hydraulic control, can be seen at the back of <span class="hlt">Endeavour</span>, near the vertical tail. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-087.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-087.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-087 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Heat from the shuttle's auxiliary power units, which provide hydraulic control, can be seen at the back of <span class="hlt">Endeavour</span>, near the vertical tail. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-115.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-115.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-03</p> <p>STS134-S-115 (1 June 2011) --- Xenon lights help lead space shuttle <span class="hlt">Endeavour</span> home to NASA's Kennedy Space Center in Florida. <span class="hlt">Endeavour</span> landed for the final time on the Shuttle Landing Facility's Runway 15, marking the 24th night landing of NASA's Space Shuttle Program. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-085.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-085.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-085 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Heat from the shuttle's auxiliary power units, which provide hydraulic control, can be seen at the back of <span class="hlt">Endeavour</span>, near the vertical tail. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-079.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-079.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-079 (1 June 2011) --- Xenon lights help lead space shuttle <span class="hlt">Endeavour</span> home to NASA's Kennedy Space Center in Florida. <span class="hlt">Endeavour</span> landed for the final time on the Shuttle Landing Facility's Runway 15, marking the 24th night landing of NASA's Space Shuttle Program. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-086.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-086.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-086 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Heat from the shuttle's auxiliary power units, which provide hydraulic control, can be seen at the back of <span class="hlt">Endeavour</span>, near the vertical tail. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-99PP-1057&hterms=1057&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2526%25231057','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-99PP-1057&hterms=1057&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2526%25231057"><span>SRTM is removed from <span class="hlt">Endeavour</span>'s payload bay to ease wiring inspections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1999-01-01</p> <p>In the Orbiter Processing Facility, workers observe as an overhead crane lowers the Shuttle Radar Topography Mission (SRTM) into a payload canister. The payload on mission STS-99, SRTM was removed from orbiter <span class="hlt">Endeavour</span>'s payload bay to allow technicians access to the orbiter's midbody for planned wiring inspections. The entire fleet of orbiters is being inspected for wiring abrasions after the problem was first discovered in Columbia. Shuttle managers are reviewing several manifest options and could establish new target launch dates for the balance of 1999 next week. Shuttle <span class="hlt">Endeavour</span> currently remains slated for launch in early October.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=EC01-0129-3&hterms=space+force&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dspace%2Bforce','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=EC01-0129-3&hterms=space+force&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dspace%2Bforce"><span>A lone desert Joshua tree greeted the arrival of Space Shuttle <span class="hlt">Endeavour</span> at Edwards Air Force Base,</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2001-01-01</p> <p>A lone desert Joshua tree greeted the arrival of Space Shuttle <span class="hlt">Endeavour</span> at Edwards Air Force Base, California, May 1, 2001. A large drag chute helped slow <span class="hlt">Endeavour</span> on the runway. After mounting the shuttle on a converted 747 airliner at NASA's Dryden Flight Research Center, <span class="hlt">Endeavour</span> will be carried back to the Kennedy Space Center for its next mission. Weather in Florida necessitated landing in California.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.8487B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.8487B"><span>Distribution, structure and temporal variability of <span class="hlt">hydrothermal</span> outflow at a slow-spreading <span class="hlt">hydrothermal</span> field from seafloor image mosaics.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barreyre, Thibaut; Escartin, Javier; Cannat, Mathilde; Garcia, Rafael; Science Party, Momar'08; Science Party, Bathyluck'09</p> <p>2010-05-01</p> <p>The Lucky Strike <span class="hlt">hydrothermal</span> site, located South of the Azores along the Mid-Atlantic Ridge, is one of the largest and best-known active <span class="hlt">hydrothermal</span> fields along the ridge <span class="hlt">system</span>. This site within the MoMAR area is also the target for the installation in 2010 of a pilot deep-sea observatory with direct telemetry to land, to be part of the European Seafloor Observatory Network (ESONET). The Lucky Strike <span class="hlt">hydrothermal</span> site has seen extensive high-resolution, near-bottom geophysical surveys in 1996 (Lustre'96), 2006 (Momareto06), 2008 (MOMAR08) and 2009 (Bathyluck09). Vertically acquired black-and-white electronic still camera images have been projected and georeferenced to obtain 3 image mosaics covering the zone of active venting, extending ~ 700x800 m2, and with full image resolution (~10 mm pixels). These data allow us to study how <span class="hlt">hydrothermal</span> outflow is structured, including the relationships between the zones of active high-temperature venting, areas of diffuse outflow, and the geological structure (nature of the substrate, faults and fissures, sediments, etc.). <span class="hlt">Hydrothermal</span> outflow is systematically associated with bacterial mats that are easily identified in the imagery, allowing us to study temporal variability at two different scales. Over the 13-year period we can potentially track changes in both the geometry and intensity of <span class="hlt">hydrothermal</span> activity throughout the <span class="hlt">system</span>; our preliminary study of the Eiffel Tower, White Castle and Mt Segur indicate that activity has been sustained in recent times, with small changes in the detailed geometry of the diffuse outflow and its intensity. At longer times scales (hundreds to 1000 years?) imagery also shows evidence of areas of venting that are no longer active, often associated with the active structures. In combination with the high-resolution bathymetry, the imagery data thus allow us to characterize the shallow structure of <span class="hlt">hydrothermal</span> outflow at depth, the structural and volcanic control, and ultimately</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1803b0011S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1803b0011S"><span><span class="hlt">Hydrothermal</span> pretreatment of palm oil empty fruit bunch</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simanungkalit, Sabar Pangihutan; Mansur, Dieni; Nurhakim, Boby; Agustin, Astrid; Rinaldi, Nino; Muryanto, Fitriady, Muhammad Ariffudin</p> <p>2017-01-01</p> <p><span class="hlt">Hydrothermal</span> pretreatment methods in 2nd generation bioethanol production more profitable to be developed, since the conventional pretreatment, by using acids or alkalis, is associated with the serious economic and environmental constraints. The current studies investigate <span class="hlt">hydrothermal</span> pretreatment of palm oil empty fruit bunch (EFB) in a batch tube reactor <span class="hlt">system</span> with temperature and time range from 160 to 240 C and 15 to 30 min, respectively. The EFB were grinded and separated into 3 different particles sizes i.e. 10 mesh, 18 mesh and 40 mesh, prior to <span class="hlt">hydrothermal</span> pretreatment. Solid yield and pH of the treated EFB slurries changed over treatment severities. The chemical composition of EFB was greatly affected by the <span class="hlt">hydrothermal</span> pretreatment especially hemicellulose which decreased at higher severity factor as determined by HPLC. Both partial removal of hemicellulose and migration of lignin during <span class="hlt">hydrothermal</span> pretreatment caused negatively affect for enzymatic hydrolysis. This studies provided important factors for maximizing <span class="hlt">hydrothermal</span> pretreatment of EFB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033475','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033475"><span>Diffuse flow <span class="hlt">hydrothermal</span> manganese mineralization along the active Mariana and southern Izu-Bonin arc <span class="hlt">system</span>, western Pacific</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hein, J.R.; Schulz, M.S.; Dunham, R.E.; Stern, R.J.; Bloomer, S.H.</p> <p>2008-01-01</p> <p>Abundant ferromanganese oxides were collected along 1200 km of the active Izu-Bonin-Mariana arc <span class="hlt">system</span>. Chemical compositions and mineralogy show that samples were collected from two deposit types: Fe-Mn crusts of mixed hydrogenetic/<span class="hlt">hydrothermal</span> origin and <span class="hlt">hydrothermal</span> Mn oxide deposits; this paper addresses only the second type. Mn oxides cement volcaniclastic and biogenic sandstone and breccia layers (Mn sandstone) and form discrete dense stratabound layers along bedding planes and within beds (stratabound Mn). The Mn oxide was deposited within coarse-grained sediments from diffuse flow <span class="hlt">systems</span> where precipitation occurred below the seafloor. Deposits were exposed at the seabed by faulting, mass wasting, and erosion. Scanning electron microscopy and microprobe analyses indicate the presence of both amorphous and crystalline 10 ?? and 7 ?? manganate minerals, the fundamental chemical difference being high water contents in the amorphous Mn oxides. Alternation of amorphous and crystalline laminae occurs in many samples, which likely resulted from initial rapid precipitation of amorphous Mn oxides from waxing pulses of <span class="hlt">hydrothermal</span> fluids followed by precipitation of slow forming crystallites during waning stages. The chemical composition is characteristic of a <span class="hlt">hydrothermal</span> origin including strong fractionation between Fe (mean 0.9 wt %) and Mn (mean 48 wt %) for the stratabound Mn, generally low trace metal contents, and very low rare earth element and platinum group element contents. However, Mo, Cd, Zn, Cu, Ni, and Co occur in high concentrations in some samples and may be good indicator elements for proximity to the heat source or to massive sulfide deposits. For the Mn sandstones, Fe (mean-8.4%) and Mn (12.4%) are not significantly fractionated because of high Fe contents in the volcaniclastic material. However, the proportion of <span class="hlt">hydrothermal</span> Fe (nondetrital Fe) to total Fe is remarkably constant (49-58%) for all the sample groups, regardless of the degree of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRB..113.8S14H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRB..113.8S14H"><span>Diffuse flow <span class="hlt">hydrothermal</span> manganese mineralization along the active Mariana and southern Izu-Bonin arc <span class="hlt">system</span>, western Pacific</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hein, James R.; Schulz, Marjorie S.; Dunham, Rachel E.; Stern, Robert J.; Bloomer, Sherman H.</p> <p>2008-08-01</p> <p>Abundant ferromanganese oxides were collected along 1200 km of the active Izu-Bonin-Mariana arc <span class="hlt">system</span>. Chemical compositions and mineralogy show that samples were collected from two deposit types: Fe-Mn crusts of mixed hydrogenetic/<span class="hlt">hydrothermal</span> origin and <span class="hlt">hydrothermal</span> Mn oxide deposits; this paper addresses only the second type. Mn oxides cement volcaniclastic and biogenic sandstone and breccia layers (Mn sandstone) and form discrete dense stratabound layers along bedding planes and within beds (stratabound Mn). The Mn oxide was deposited within coarse-grained sediments from diffuse flow <span class="hlt">systems</span> where precipitation occurred below the seafloor. Deposits were exposed at the seabed by faulting, mass wasting, and erosion. Scanning electron microscopy and microprobe analyses indicate the presence of both amorphous and crystalline 10 Å and 7 Å manganate minerals, the fundamental chemical difference being high water contents in the amorphous Mn oxides. Alternation of amorphous and crystalline laminae occurs in many samples, which likely resulted from initial rapid precipitation of amorphous Mn oxides from waxing pulses of <span class="hlt">hydrothermal</span> fluids followed by precipitation of slow forming crystallites during waning stages. The chemical composition is characteristic of a <span class="hlt">hydrothermal</span> origin including strong fractionation between Fe (mean 0.9 wt %) and Mn (mean 48 wt %) for the stratabound Mn, generally low trace metal contents, and very low rare earth element and platinum group element contents. However, Mo, Cd, Zn, Cu, Ni, and Co occur in high concentrations in some samples and may be good indicator elements for proximity to the heat source or to massive sulfide deposits. For the Mn sandstones, Fe (mean 8.4%) and Mn (12.4%) are not significantly fractionated because of high Fe contents in the volcaniclastic material. However, the proportion of <span class="hlt">hydrothermal</span> Fe (nondetrital Fe) to total Fe is remarkably constant (49-58%) for all the sample groups, regardless of the degree of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeCoA.202..101J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeCoA.202..101J"><span>Environmental controls on biomineralization and Fe-mound formation in a low-temperature <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the Jan Mayen Vent Fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johannessen, Karen C.; Vander Roost, Jan; Dahle, Håkon; Dundas, Siv H.; Pedersen, Rolf B.; Thorseth, Ingunn H.</p> <p>2017-04-01</p> <p>Diffuse low-temperature <span class="hlt">hydrothermal</span> vents on the seafloor host neutrophilic microaerophilic Fe-oxidizing bacteria that utilize the Fe(II) supplied by <span class="hlt">hydrothermal</span> fluids and produce intricate twisted and branching extracellular stalks. The growth behavior of Fe-oxidizing bacteria in strongly opposing gradients of Fe(II) and O2 have been thoroughly investigated in laboratory settings to assess whether extracellular stalks and aligned biomineralized fabrics may serve as biosignatures of Fe-oxidizing bacteria and indications of palaeo-redox conditions in the rock record. However, the processes controlling the growth of biogenic Fe-oxyhydroxide deposits in natural, modern <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are still not well constrained. In this study, we aimed to establish how variations in the texture of stratified <span class="hlt">hydrothermal</span> Fe-oxyhydroxide deposits are linked to the physicochemical conditions of the <span class="hlt">hydrothermal</span> environment. We conducted 16S rRNA gene analyses, microscopy and geochemical analyses of laminated siliceous Fe-mounds from the Jan Mayen Vent Fields at the Arctic Mid-Ocean Ridge. Chemical analyses of low- and high-temperature <span class="hlt">hydrothermal</span> fluids were performed to characterize the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in which the Fe-deposits form. Our results reveal synchronous inter-laminar variations in texture and major and trace element geochemistry. The Fe-deposits are composed of alternating porous laminae of mineralized twisted stalks and branching tubes, Mn-rich horizons with abundant detrital sediment, domal internal cavities and thin P- and REE-enriched lamina characterized by networks of ≪1 μm wide fibers. Zetaproteobacteria constitute one third of the microbial community in the surface layer of actively forming mounds, indicating that microbial Fe-oxidation is contributing to mound accretion. We suggest that Mn-oxide precipitation and detrital sediment accumulation take place during periodically low <span class="hlt">hydrothermal</span> fluid discharge conditions. The elevated concentrations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P23H..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P23H..04K"><span>Exploring the <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> in the Chicxulub Crater and Implications for the Early Evolution of Life on Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kring, D. A.; Schmieder, M.; Tikoo, S.; Riller, U. P.; Simpson, S. L.; Osinski, G.; Cockell, C. S.; Coolen, M.; Gulick, S. P. S.; Morgan, J. V.</p> <p>2017-12-01</p> <p>Impact cratering, particularly large basin-size craters with diameters >100 km, have the potential to generate vast subsurface <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. There were dozens of such impacts during the Hadean and early Archean, some of which vaporized seas for brief periods of time, during which the safest niches for early life may have been in those subsurface <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. The Chicxulub crater can serve as a proxy for those events. New IODP-ICDP core recovered by Expedition 364 reveals a high-temperature (>300 degree C) <span class="hlt">system</span> that may have persisted for more than 100,000 years. Of order 105 to 106 km3 of crust was structurally deformed, melted, and vaporized within about 10 minutes of the impact. The crust had to endure immense strain rates of 104/s to 106/s, up to 12 orders of magnitude greater than those associated with igneous and metamorphic processes. The outcome is a porous, permeable region that is a perfect host for <span class="hlt">hydrothermal</span> circulation across the entire diameter of the crater to depths up to 5 or 6 km. The target rocks at Chicxulub are composed of an 3 km-thick carbonate platform sequence over a crystalline basement composed of igneous granite, granodiorite, and a few other intrusive components, such as dolerite, and metamorphic assemblages composed, in part, of gneiss and mica schist. Post-impact <span class="hlt">hydrothermal</span> alteration includes Ca-Na- and K-metasomatism, pervasive hydration to produce layered silicates, and lower-temperature vug-filling zeolites as the <span class="hlt">system</span> cycled from high temperatures to low temperatures. While the extent of granitic crust on early Earth is still debated and, thus, the direct application of those mineral reactions to the Hadean and early Archean can be debated, the thermal evolution of the <span class="hlt">system</span> should be applicable to diverse crustal compositions. It is important to point out that pre-impact thermal conditions of Hadean and early Archean crust can affect the size of an impact basin and, in turn, the proportion of that basin</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.V34B..01P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.V34B..01P"><span>Drilling of Submarine Shallow-water <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span> in Volcanic Arcs of the Tyrrhenian Sea, Italy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petersen, S.; Augustin, N.; de Benedetti, A.; Esposito, A.; Gaertner, A.; Gemmell, B.; Gibson, H.; He, G.; Huegler, M.; Kleeberg, R.; Kuever, J.; Kummer, N. A.; Lackschewitz, K.; Lappe, F.; Monecke, T.; Perrin, K.; Peters, M.; Sharpe, R.; Simpson, K.; Smith, D.; Wan, B.</p> <p>2007-12-01</p> <p>Seafloor <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> related to volcanic arcs are known from several localities in the Tyrrhenian Sea in water depths ranging from 650 m (Palinuro Seamount) to less than 50 m (Panarea). At Palinuro Seamount 13 holes (<5m) were drilled using Rockdrill 1 of the British Geological Survey 1 into the heavily sediment-covered deposit recovering 11 m of semi-massive to massive sulfides. Maximum recovery within a single core was 4.8 m of massive sulfides/sulfates with abundant late native sulfur overprint. The deposit is open to all sides and to depth since all drill holes ended in mineralization. Metal enrichment at the top of the deposit is evident in some cores with polymetallic (Zn, Pb, Ag) sulfides overlying more massive and dense pyritic ore. The massive sulfide mineralization at Palinuro Seamount contains a number of unusual minerals, including enargite, tennantite, luzonite, and Ag-sulfosalts, that are not commonly encountered in mid-ocean ridge massive sulfides. In analogy to epithermal deposits forming on land, the occurrence of these minerals suggests a high sulfidation state of the <span class="hlt">hydrothermal</span> fluids during deposition implying that the mineralizing fluids were acidic and oxidizing rather than near-neutral and reducing as those forming typical base metal rich massive sulfides along mid-ocean ridges. Oxidizing conditions during sulfide deposition can probably be related to the presence of magmatic volatiles in the mineralizing fluids that may be derived from a degassing magma chamber. Elevated temperatures within sediment cores and TV-grab stations (up to 60°C) indicate present day <span class="hlt">hydrothermal</span> fluid flow. This is also indicated by the presence of small tube-worm bushes present on top the sediment. A number of drill holes were placed around the known phreatic gas-rich vents of Panarea and recovered intense clay-alteration in some holes as well as abundant massive anhydrite/gypsum with only trace sulfides along a structural depression suggesting the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts059-s-108.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts059-s-108.html"><span>Landing of STS-59 <span class="hlt">Endeavour</span>, OV-105, at Edwards Air Force Base</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1999-04-20</p> <p>STS059-S-108 (20 April 1994) --- The main landing gear of the Space Shuttle <span class="hlt">Endeavour</span> touches down at Edwards Air Force Base to complete the 11-day STS-59/SRL-1 mission. Landing occurred at 9:54 a.m. (PDT), April 20, 1994. Mission duration was 11 days, 5 hours, 49 minutes. Guiding <span class="hlt">Endeavour</span> to a landing was astronaut Sidney M. Gutierrez, STS-59 commander. His crew was Kevin P. Chilton, Linda M. Godwin, Jerome (Jay) Apt, Michael R. (Rich) Clifford and Thomas D. Jones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS41C1992H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS41C1992H"><span>Seismic and Tectonic Monitoring of the <span class="hlt">Endeavour</span> Ridge Segment—Recent and Future Expansion of Ocean Networks Canada's NEPTUNE Observatory on the Juan de Fuca Ridge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heesemann, M.; Davis, E. E.; Scherwath, M.; Kao, H.; Coogan, L. A.; Rogers, G. C.; Wilcock, W. S. D.</p> <p>2016-12-01</p> <p>Ocean Networks Canada's (ONC) NEPTUNE observatory provides real-time access to sensors on the <span class="hlt">Endeavour</span> Ridge Segment (<span class="hlt">Endeavour</span>)—a focus site on the Juan de Fuca Ridge <span class="hlt">System</span> that is complementary to one on Axial Volcano that is connected through the Ocean Observatories Initiative's (OOI) Cabled Array. While first instruments (including cameras, a short-period seismometer, and vent monitoring instruments) installed at the Main <span class="hlt">Endeavour</span> vent field have been sending data since summer 2010, unreliable extension cables precluded continuous time-series from other nearby locations. With the successful installation of four extension cables, the summer of 2016 represents an important milestone in the instrumentation of the <span class="hlt">Endeavour</span> Ridge Segment. We will present an overview of the data that are available in near real-time from <span class="hlt">Endeavour</span> and new instrumentation that is scheduled for installation in 2017, and highlight first results derived from the new seismo-tectonic network now in operation. This network consists of three short-period seismometers (Mothra Field, Main <span class="hlt">Endeavour</span> Field, Regional Circulation North), one broadband seismometer (western Ridge Flank), and four bottom pressure recorders (Mothra Field, Regional Circulation South, Main <span class="hlt">Endeavour</span> Field, western Ridge Flank). The pressure recorders will provide both seismic and oceanographic data, and allow to measure differential vertical motion among the sites. We will also highlight a new technique to determine long period seafloor deformation from broadband seismometer mass-position measurements, using data from the Ridge Flank instrument as an example.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DokES.477.1301R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DokES.477.1301R"><span>Specific mineral associations of <span class="hlt">hydrothermal</span> shale (South Kamchatka)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rychagov, S. N.; Sergeeva, A. V.; Chernov, M. S.</p> <p>2017-11-01</p> <p>The sequence of <span class="hlt">hydrothermal</span> shale from the East Pauzhet thermal field within the Pauzhet <span class="hlt">hydrothermal</span> <span class="hlt">system</span> (South Kamchatka) was studied in detail. It was established that the formation of shale resulted from argillization of an andesitic lava flow under the influence of an acidic sulfate vapor condensate. The horizons with radically different compositions and physical properties compared to those of the overlying homogeneous plastic shale were distinguished at the base of the sequence. These horizons are characterized by high (up to two orders of magnitude in comparison with average values in <span class="hlt">hydrothermal</span> shale) concentrations of F, P, Na, Mg, K, Ca, Sc, Ti, V, Cr, Cu, and Zn. We suggested a geological-geochemical model, according to which a deep metal-bearing chloride-hydrocarbonate solution infiltrated into the permeable zone formed at the root of the andesitic lava flow beneath plastic shale at a certain stage of evolution of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28372053','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28372053"><span>The relative effect of particles and turbulence on acoustic scattering from deep sea <span class="hlt">hydrothermal</span> vent plumes revisited.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Guangyu; Jackson, Darrell R; Bemis, Karen G</p> <p>2017-03-01</p> <p>The relative importance of suspended particles and turbulence as backscattering mechanisms within a <span class="hlt">hydrothermal</span> plume located on the <span class="hlt">Endeavour</span> Segment of the Juan de Fuca Ridge is determined by comparing acoustic backscatter measured by the Cabled Observatory Vent Imaging Sonar (COVIS) with model calculations based on in situ samples of particles suspended within the plume. Analysis of plume samples yields estimates of the mass concentration and size distribution of particles, which are used to quantify their contribution to acoustic backscatter. The result shows negligible effects of plume particles on acoustic backscatter within the initial 10-m rise of the plume. This suggests turbulence-induced temperature fluctuations are the dominant backscattering mechanism within lower levels of the plume. Furthermore, inversion of the observed acoustic backscatter for the standard deviation of temperature within the plume yields a reasonable match with the in situ temperature measurements made by a conductivity-temperature-depth instrument. This finding shows that turbulence-induced temperature fluctuations are the dominant backscattering mechanism and demonstrates the potential of using acoustic backscatter as a remote-sensing tool to measure the temperature variability within a <span class="hlt">hydrothermal</span> plume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016LPICo1912.2083J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016LPICo1912.2083J"><span>Organic Biomarker Preservation in Silica-Rich <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span> with Implications to Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jahnke, L. L.; Parenteau, M. N.; Farmer, J. D.</p> <p>2016-05-01</p> <p>Microbial community structure and preservation of organic matter in siliceous <span class="hlt">hydrothermal</span> environments is a critical issue given the discovery of <span class="hlt">hydrothermal</span> vents and silica on Mars. Here we discuss preservation of cyanobacterial biomarker lipid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........87N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........87N"><span><span class="hlt">Hydrothermal</span> Habitats: Measurements of Bulk Microbial Elemental Composition, and Models of <span class="hlt">Hydrothermal</span> Influences on the Evolution of Dwarf Planets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neveu, Marc Francois Laurent</p> <p></p> <p>Finding habitable worlds is a key driver of solar <span class="hlt">system</span> exploration. Many solar <span class="hlt">system</span> missions seek environments providing liquid water, energy, and nutrients, the three ingredients necessary to sustain life. Such environments include <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, spatially-confined <span class="hlt">systems</span> where hot aqueous fluid circulates through rock by convection. I sought to characterize <span class="hlt">hydrothermal</span> microbial communities, collected in hot spring sediments and mats at Yellowstone National Park, USA, by measuring their bulk elemental composition. To do so, one must minimize the contribution of non-biological material to the samples analyzed. I demonstrate that this can be achieved using a separation method that takes advantage of the density contrast between cells and sediment and preserves cellular elemental contents. Using this method, I show that in spite of the tremendous physical, chemical, and taxonomic diversity of Yellowstone hot springs, the composition of microorganisms there is surprisingly ordinary. This suggests the existence of a stoichiometric envelope common to all life as we know it. Thus, future planetary investigations could use elemental fingerprints to assess the astrobiological potential of <span class="hlt">hydrothermal</span> settings beyond Earth. Indeed, <span class="hlt">hydrothermal</span> activity may be widespread in the solar <span class="hlt">system</span>. Most solar <span class="hlt">system</span> worlds larger than 200 km in radius are dwarf planets, likely composed of an icy, cometary mantle surrounding a rocky, chondritic core. I enhance a dwarf planet evolution code, including the effects of core fracturing and <span class="hlt">hydrothermal</span> circulation, to demonstrate that dwarf planets likely have undergone extensive water-rock interaction. This supports observations of aqueous products on their surfaces. I simulate the alteration of chondritic rock by pure water or cometary fluid to show that aqueous alteration feeds back on geophysical evolution: it modifies the fluid antifreeze content, affecting its persistence over geological timescales; and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=dependency&pg=6&id=EJ1113099','ERIC'); return false;" href="https://eric.ed.gov/?q=dependency&pg=6&id=EJ1113099"><span>Exploring Talenting: Talent Management as a Collective <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gold, Jeff; Oldroyd, Tony; Chesters, Ed; Booth, Amanda; Waugh, Adrian</p> <p>2016-01-01</p> <p>Purpose: This paper seeks to show appreciation for the collective <span class="hlt">endeavour</span> of work practices based on varying degrees of dependence, interdependence and mutuality between at least two people. Such dependencies have to be concerned with how talent is used and how this use is an interaction between people, a process called talenting. The aim of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5069527','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5069527"><span>Impact of <span class="hlt">hydrothermalism</span> on the ocean iron cycle</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Resing, Joseph</p> <p>2016-01-01</p> <p>As the iron supplied from <span class="hlt">hydrothermalism</span> is ultimately ventilated in the iron-limited Southern Ocean, it plays an important role in the ocean biological carbon pump. We deploy a set of focused sensitivity experiments with a state of the art global model of the ocean to examine the processes that regulate the lifetime of <span class="hlt">hydrothermal</span> iron and the role of different ridge <span class="hlt">systems</span> in governing the <span class="hlt">hydrothermal</span> impact on the Southern Ocean biological carbon pump. Using GEOTRACES section data, we find that stabilization of <span class="hlt">hydrothermal</span> iron is important in some, but not all regions. The impact on the Southern Ocean biological carbon pump is dominated by poorly explored southern ridge <span class="hlt">systems</span>, highlighting the need for future exploration in this region. We find inter-basin differences in the isopycnal layer onto which <span class="hlt">hydrothermal</span> Fe is supplied between the Atlantic and Pacific basins, which when combined with the inter-basin contrasts in oxidation kinetics suggests a muted influence of Atlantic ridges on the Southern Ocean biological carbon pump. Ultimately, we present a range of processes, operating at distinct scales, that must be better constrained to improve our understanding of how <span class="hlt">hydrothermalism</span> affects the ocean cycling of iron and carbon. This article is part of the themed issue ‘Biological and climatic impacts of ocean trace element chemistry’. PMID:29035256</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29035256','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29035256"><span>Impact of <span class="hlt">hydrothermalism</span> on the ocean iron cycle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tagliabue, Alessandro; Resing, Joseph</p> <p>2016-11-28</p> <p>As the iron supplied from <span class="hlt">hydrothermalism</span> is ultimately ventilated in the iron-limited Southern Ocean, it plays an important role in the ocean biological carbon pump. We deploy a set of focused sensitivity experiments with a state of the art global model of the ocean to examine the processes that regulate the lifetime of <span class="hlt">hydrothermal</span> iron and the role of different ridge <span class="hlt">systems</span> in governing the <span class="hlt">hydrothermal</span> impact on the Southern Ocean biological carbon pump. Using GEOTRACES section data, we find that stabilization of <span class="hlt">hydrothermal</span> iron is important in some, but not all regions. The impact on the Southern Ocean biological carbon pump is dominated by poorly explored southern ridge <span class="hlt">systems</span>, highlighting the need for future exploration in this region. We find inter-basin differences in the isopycnal layer onto which <span class="hlt">hydrothermal</span> Fe is supplied between the Atlantic and Pacific basins, which when combined with the inter-basin contrasts in oxidation kinetics suggests a muted influence of Atlantic ridges on the Southern Ocean biological carbon pump. Ultimately, we present a range of processes, operating at distinct scales, that must be better constrained to improve our understanding of how <span class="hlt">hydrothermalism</span> affects the ocean cycling of iron and carbon.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'. © 2016 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-01PP-1675&hterms=hatch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dhatch','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-01PP-1675&hterms=hatch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dhatch"><span>STS-108 and Expedition 4 pose outside <span class="hlt">Endeavour</span>'s hatch</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2001-01-01</p> <p>KENNEDY SPACE CENTER, Fla. -- The STS-108 and Expedition 4 crews pose outside the hatch to <span class="hlt">Endeavour</span>. Standing left to right are Daniel W. Bursch, Mission Commander Dominic L. Gorie, Pilot Mark E. Kelly and Expedition 4 Commander Yuri Onufrienko. Gorie and Onufrienko hold the patch for the mission. Kneeling in front are Expedition 4 member Carl E. Walz and Mission Specialists Daniel M. Tani and Linda A. Godwin. Crew members are at KSC for Terminal Countdown Demonstration Test activities that include a simulated launch countdown, plus the emergency exit training from the orbiter and launch pad. STS-108 is a Utilization Flight that will carry the replacement Expedition 4 crew to the International Space Station, as well as the Multi-Purpose Logistics Module Raffaello, filled with supplies and equipment. The l1-day mission is scheduled for launch Nov. 29 on Space Shuttle <span class="hlt">Endeavour</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V24A..04F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V24A..04F"><span>Plumbing the depths of Yellowstone's <span class="hlt">hydrothermal</span> <span class="hlt">system</span> from helicopter magnetic and electromagnetic data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Finn, C.; Bedrosian, P.; Holbrook, W. S.; Auken, E.; Lowenstern, J. B.; Hurwitz, S.; Sims, K. W. W.; Carr, B.; Dickey, K.</p> <p>2017-12-01</p> <p>Although Yellowstone's iconic <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> and lava flows are well mapped at the surface, their groundwater flow <span class="hlt">systems</span> and thickness are almost completely unknown. In order to track the geophysical signatures of geysers, hot springs, mud pots, steam vents, <span class="hlt">hydrothermal</span> explosion craters and lava flows at depths to hundreds of meters, we collected helicopter electromagnetic and magnetic (HEM) data. The data cover significant portions of the caldera including a majority of the known thermal areas. HEM data constrain electrical resistivity which is sensitive to groundwater salinity and temperature, phase distribution (liquid-vapor), and clay formed during chemical alteration of rocks. The magnetic data are sensitive to variations in the magnetization of lava flows, faults and <span class="hlt">hydrothermal</span> alteration. The combination of electromagnetic and magnetic data is ideal for mapping zones of cold fresh water, hot saline water, steam, clay, and altered and unaltered rock. Preliminary inversion of the HEM data indicates very low resistivity directly beneath the northern part of Yellowstone Lake, intersecting with the lake bottom in close correspondence with mapped vents, fractures and <span class="hlt">hydrothermal</span> explosion craters and are also associated with magnetic lows. Coincident resistivity and magnetic lows unassociated with mapped alteration occur, for example, along the southeast edge of the Mallard Lake dome and along the northeastern edge of Sour Creek Dome, suggesting the presence of buried alteration. Low resistivities unassociated with magnetic lows may relate to hot and/or saline groundwater or thin (<50 m) layers of early lake sediments to which the magnetic data are insensitive. Resistivity and magnetic lows follow interpreted caldera boundaries in places, yet deviate in others. In the Norris-Mammoth Corridor, NNE-SSW trending linear resistivity and magnetic lows align with mapped faults. This pattern of coincident resistivity and magnetic lows may reflect fractures</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993CoMP..113..502G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993CoMP..113..502G"><span>Metabasalts from the Mid-Atlantic Ridge: new insights into <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in slow-spreading crust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gillis, Kathryn M.; Thompson, Geoffrey</p> <p>1993-12-01</p> <p>An extensive suite of <span class="hlt">hydrothermally</span> altered rocks were recovered by Alvin and dredging along the MARK [Mid-Atlantic Ridge, south of the Kane Fracture Zone (23 24°N)] where detachment faulting has provided a window into the crustal component of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Rocks of basaltic composition are altered to two assemblages with these characteristics: (i) type I: albitic plagioclase (An02 10)+mixed-layer smectite/chlorite or chlorite±actinolite±quartz±sphene, <10% of the clinopyroxene is altered, and there is no trace metal mobility; (ii) type II: plagioclase (An10 30)+amphibole (actinolite-magnesio-hornblende) +chlorite+sphene, >20% of the clinopyroxene is altered, and Cu and Zn are leached. The geochemical signature of these alteration types reflects the relative proportion and composition of secondary minerals, and the degree of alteration of primary phases, and does not show simple predictive relationships. Element mobilities indicate that both alteration types formed at low water/rock ratios. The MARK assemblages are typical of the greenschist and transition to the amphibolite facies, and represent two distinct, albeit overlapping, temperature regimes: type I-180 to 300°C and type II-250 to 450°C. By analogy with DSDP/ODP Hole 504B and many ophiolites, the MARK metabasalts were altered within the downwelling limb of a <span class="hlt">hydrothermal</span> cell and type I and II samples formed in the upper and lower portions of the sheeted like complex, respectively. Episodic magmatic and <span class="hlt">hydrothermal</span> events at slow-spreading ridges suggest that these observed mineral assemblages represent the cumulative effects of more than one <span class="hlt">hydrothermal</span> event. Groundmass and vein assemblages in the MARK metabasalts indicate either that alteration conditions did not change during successive <span class="hlt">hydrothermal</span> events or that these assemblages record only the highest temperature event. Lack of retrograde reactions or overprinting of lower temperature assemblages (e.g., zeolites) suggests that there</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMOS12A..08H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMOS12A..08H"><span>Molecular Diversity and Activity of Methanogens in the Subseafloor at Deep-Sea <span class="hlt">Hydrothermal</span> Vents of the Pacific Ocean (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huber, J. A.; Merkel, A.; Holden, J. F.; Lilley, M. D.; Butterfield, D. A.</p> <p>2009-12-01</p> <p>Methanogenesis is thought to represent one of the most ancient metabolic pathways on Earth, and methanogens may serve as important primary producers in warm crustal habitats at deep-sea <span class="hlt">hydrothermal</span> vents. Many of these obligate chemolithoautotrophs depend solely on geochemically-derived energy and carbon sources and grow at high temperatures under strictly anaerobic conditions. A combined geochemical and microbiological approach was used to determine the distribution and molecular diversity of methanogens in low temperature diffuse vent fluids from the <span class="hlt">Endeavour</span> Segment R2K ISS site, as well as Axial Seamount and volcanoes of the Mariana Arc. Geochemical data from hot and adjacent warm diffuse vent fluids provided chemical indicators to guide sample selection for detailed polymerase chain reaction (PCR)-based analysis of the key enzyme for methane formation, methyl-coenzyme M reductase (mcrA), as well as archaeal 16S rRNA genes. At most <span class="hlt">Endeavour</span> vent sites, hydrogen concentrations were too low to support hydrogenotrophic methanogensis directly and only one diffuse site, Easter Island, had a positive signal for the mcrA gene. These sequences were most closely related to members of the order Methanococcales, as well as anaerobic methane oxidizers (ANME-1). The presence of ANME, which are rarely found in non-sedimented marine environments, is another line of evidence supporting the occurrence of buried sediments at <span class="hlt">Endeavour</span>. At Axial, a number of diffuse vents have strong chemical indicators of methanogenesis. Methanogenic communities were detected at 3 sites on the southeast side of the caldera: the northern end of the 1998 lava flow, the International District, and on the pre-1987 lava flow. Time series work at Marker 113 showed that in 4 different years over the last 6 years methanogenic communities are active and abundant, suggesting a stable anaerobic, warm subseafloor habitat. Results show that members of the order Methanococcales dominate at this site</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70014455','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70014455"><span>Vapor-dominated zones within <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>: evolution and natural state</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ingebritsen, S.E.; Sorey, M.L.</p> <p>1988-01-01</p> <p>Three conceptual models illustrate the range of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in which vapor-dominated conditions are found. The first model (model I) represents a <span class="hlt">system</span> with an extensive near-vaporstatic vapor-dominated zone and limited liquid throughflow and is analogous to <span class="hlt">systems</span> such as The Geysers, California. Models II and III represent <span class="hlt">systems</span> with significant liquid throughflow and include steam-heated discharge features at higher elevations and high-chloride springs at lower elevations connected to and fed by a single circulation <span class="hlt">system</span> at depth. In model II, as in model I, the vapor-dominated zone has a near-vaporstatic vertical pressure gradient and is generally underpressured with respect to local hydrostatic pressure. The vapor-dominated zone in model III is quite different, in that phase separation takes place at pressures close to local hydrostatic and the overall pressure gradient is near hydrostatic. -from Authors</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P43B2882B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P43B2882B"><span>Simulating Electrochemistry of <span class="hlt">Hydrothermal</span> Vents on Enceladus and Other Ocean Worlds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barge, L. M.; Krause, F. C.; Jones, J. P.; Billings, K.; Sobron, P.</p> <p>2017-12-01</p> <p>Gradients generated in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> provide a significant source of free energy for chemosynthetic life, and may play a role in present-day habitability on ocean worlds such as Enceladus that are thought to host <span class="hlt">hydrothermal</span> activity. <span class="hlt">Hydrothermal</span> vents are similar in some ways to typical fuel cell devices: redox/pH gradients between seawater and <span class="hlt">hydrothermal</span> fluid are analogous to the oxidant and fuel reservoirs; conductive natural mineral deposits are analogous to electrodes; and, in <span class="hlt">hydrothermal</span> chimneys, the porous chimney wall can function as a separator or ion-exchange membrane. Electrochemistry, founded on quantitative study of redox and other chemical disequilibria as well as the chemistry of interfaces, is uniquely suited to studying these <span class="hlt">systems</span>. We have performed electrochemical studies to better understand the catalytic potential of seafloor minerals and vent chimneys, using samples from a black smoker vent chimney as an initial demonstration. Fuel cell experiments with electrodes made from black smoker chimney material accurately simulated the redox reactions that occur in a geological setting with this particular catalyst. Similar methods with other geo-catalysts (natural or synthetic) could be utilized to test which redox reactions or metabolisms could be driven in other <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, including putative vent <span class="hlt">systems</span> on other worlds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29527196','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29527196"><span>Cultivation-Independent and Cultivation-Dependent Analysis of Microbes in the Shallow-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> Off Kueishantao Island, Taiwan: Unmasking Heterotrophic Bacterial Diversity and Functional Capacity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tang, Kai; Zhang, Yao; Lin, Dan; Han, Yu; Chen, Chen-Tung A; Wang, Deli; Lin, Yu-Shih; Sun, Jia; Zheng, Qiang; Jiao, Nianzhi</p> <p>2018-01-01</p> <p>Shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> experience continuous fluctuations of physicochemical conditions due to seawater influx which generates variable habitats, affecting the phylogenetic composition and metabolic potential of microbial communities. Until recently, studies of submarine <span class="hlt">hydrothermal</span> communities have focused primarily on chemolithoautotrophic organisms, however, there have been limited studies on heterotrophic bacteria. Here, fluorescence in situ hybridization, high throughput 16S rRNA gene amplicon sequencing, and functional metagenomes were used to assess microbial communities from the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span> off Kueishantao Island, Taiwan. The results showed that the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span> harbored not only autotrophic bacteria but abundant heterotrophic bacteria. The potential for marker genes sulfur oxidation and carbon fixation were detected in the metagenome datasets, suggesting a role for sulfur and carbon cycling in the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Furthermore, the presence of diverse genes that encode transporters, glycoside hydrolases, and peptidase indicates the genetic potential for heterotrophic utilization of organic substrates. A total of 408 cultivable heterotrophic bacteria were isolated, in which the taxonomic families typically associated with oligotrophy, copiotrophy, and phototrophy were frequently found. The cultivation-independent and -dependent analyses performed herein show that Alphaproteobacteria and Gammaproteobacteria represent the dominant heterotrophs in the investigated shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Genomic and physiological characterization of a novel strain P5 obtained in this study, belonging to the genus Rhodovulum within Alphaproteobacteria, provides an example of heterotrophic bacteria with major functional capacity presented in the metagenome datasets. Collectively, in addition to autotrophic bacteria, the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span> also harbors many heterotrophic bacteria with versatile</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5829616','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5829616"><span>Cultivation-Independent and Cultivation-Dependent Analysis of Microbes in the Shallow-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> Off Kueishantao Island, Taiwan: Unmasking Heterotrophic Bacterial Diversity and Functional Capacity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tang, Kai; Zhang, Yao; Lin, Dan; Han, Yu; Chen, Chen-Tung A.; Wang, Deli; Lin, Yu-Shih; Sun, Jia; Zheng, Qiang; Jiao, Nianzhi</p> <p>2018-01-01</p> <p>Shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> experience continuous fluctuations of physicochemical conditions due to seawater influx which generates variable habitats, affecting the phylogenetic composition and metabolic potential of microbial communities. Until recently, studies of submarine <span class="hlt">hydrothermal</span> communities have focused primarily on chemolithoautotrophic organisms, however, there have been limited studies on heterotrophic bacteria. Here, fluorescence in situ hybridization, high throughput 16S rRNA gene amplicon sequencing, and functional metagenomes were used to assess microbial communities from the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span> off Kueishantao Island, Taiwan. The results showed that the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span> harbored not only autotrophic bacteria but abundant heterotrophic bacteria. The potential for marker genes sulfur oxidation and carbon fixation were detected in the metagenome datasets, suggesting a role for sulfur and carbon cycling in the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Furthermore, the presence of diverse genes that encode transporters, glycoside hydrolases, and peptidase indicates the genetic potential for heterotrophic utilization of organic substrates. A total of 408 cultivable heterotrophic bacteria were isolated, in which the taxonomic families typically associated with oligotrophy, copiotrophy, and phototrophy were frequently found. The cultivation-independent and -dependent analyses performed herein show that Alphaproteobacteria and Gammaproteobacteria represent the dominant heterotrophs in the investigated shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Genomic and physiological characterization of a novel strain P5 obtained in this study, belonging to the genus Rhodovulum within Alphaproteobacteria, provides an example of heterotrophic bacteria with major functional capacity presented in the metagenome datasets. Collectively, in addition to autotrophic bacteria, the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span> also harbors many heterotrophic bacteria with versatile</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMMR33B0475R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMMR33B0475R"><span>Fault-controlled development of shallow <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>: Structural and mineralogical insights from the Southern Andes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roquer, T.; Arancibia, G.; Rowland, J. V.; Iturrieta, P. C.; Morata, D.; Cembrano, J. M.</p> <p>2017-12-01</p> <p>Paleofluid-transporting <span class="hlt">systems</span> can be recognized as meshes of fracture-filled veins in eroded zones of extinct <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Here we conducted meso-microstructural analysis and mechanical modeling from two exhumed exposures of the faults governing regional tectonics of the Southern Andes: the Liquiñe-Ofqui Fault <span class="hlt">System</span> (LOFS) and the Andean Transverse Faults (ATF). A total of 107 fractures in both exposures were analyzed. The ATF specific segment shows two tectonic solutions that can be modeled as Andersonian and non-Andersonian tectonic regimes: (1) shear (mode II/III) failure occurs at differential stresses > 28 MPa and fluid pressures < 40-80% lithostatic in the Andersonian regime; and (2) sporadic hybrid extensional + shear (modes I + II/III) failure occurs at differential stresses < 20 MPa and anomalously high fluid pressures > 85-98% lithostatic in the non-Andersonian regime. Additionally, the LOFS exposure cyclically fails in extension (mode I) or extension + shear (modes I + II/III) in the Andersonian regime, at differential stresses < 28 MPa and fluid pressures > 40-80% lithostatic. In areas of spatial interaction between ATF and LOFS, these conditions might favor: (1) the storage of overpressured fluids in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> associated with the ATF faults, and (2) continuous fluid flow through vertical conduits in the LOFS faults. These observations suggest that such intersections are highly probable locations for concentrated <span class="hlt">hydrothermal</span> activity, which must be taken into consideration for further geothermal exploration. ACKNOWLEDGEMENTS. PhD CONICYT grants, Centro de Excelencia en Geotermia de los Andes (CEGA-FONDAP/CONICYT Project #15090013), FONDECYT Project #1130030 and Project CONICYT REDES #140036.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017337','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017337"><span>Relations of ammonium minerals at several <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the western U.S.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Krohn, M.D.; Kendall, C.; Evans, J.R.; Fries, T.L.</p> <p>1993-01-01</p> <p>Ammonium bound to silicate and sulfate minerals has recently been located at several major <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the western U.S. utilizing newly-discovered near-infrared spectral properties. Knowledge of the origin and mineralogic relations of ammonium minerals at known <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> is critical for the proper interpretation of remote sensing data and for testing of possible links to mineralization. Submicroscopic analysis of ammonium minerals from two mercury- and gold-bearing hot-springs deposits at Ivanhoe, Nevada and McLaughlin, California shows that the ammonium feldspar, buddingtonite, occurs as fine-grained euhedral crystals coating larger sulfide and quartz crystals. Ammonium feldspar seems to precipitate relatively late in the crystallization sequence and shows evidence for replacement of NH4+ by K+ or other monovalent cations. Some buddingtonite is observed in close association with mercury, but not with gold. Ammonioalunite is found in a variety of isolated crystal forms at both deposits. Nitrogen isotopic values for ammonium-bearing minerals show a 14??? range in composition, precluding assignment of a specific provenance to the nitrogen. The correlations of nitrogen isotopic values with depth and ammonium content suggest some loss of nitrogen in the oxidizing supergene environment, possibly as a metastable mineral. The high ammonium content in these <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, the close association to mercury, and the small crystal size of the ammonium-bearing minerals all suggest that ammonium may be transported in a late-stage vapor phase or as an organic volatile. Such a process could lead to the formation of a non-carbonaceous organic aureole above a buried geothermal source. The discovery of a 10-km outcrop of ammonium minerals confirms that significant substitution of ammonium in minerals is possible over an extensive area and that remote sensing is a feasible means to detect such aureoles. ?? 1993.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMOS43A1599A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMOS43A1599A"><span>Development of Vertical Cable Seismic <span class="hlt">System</span> for <span class="hlt">Hydrothermal</span> Deposit Survey (2) - Feasibility Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asakawa, E.; Murakami, F.; Sekino, Y.; Okamoto, T.; Mikada, H.; Takekawa, J.; Shimura, T.</p> <p>2010-12-01</p> <p>In 2009, Ministry of Education, Culture, Sports, Science and Technology(MEXT) started the survey <span class="hlt">system</span> development for <span class="hlt">Hydrothermal</span> deposit. We proposed the Vertical Cable Seismic (VCS), the reflection seismic survey with vertical cable above seabottom. VCS has the following advantages for <span class="hlt">hydrothermal</span> deposit survey. . (1) VCS is an effective high-resolution 3D seismic survey within limited area. (2) It achieves high-resolution image because the sensors are closely located to the target. (3) It avoids the coupling problems between sensor and seabottom that cause serious damage of seismic data quality. (4) Various types of marine source are applicable with VCS such as sea-surface source (air gun, water gun etc.) , deep-towed or ocean bottom sources. (5) Autonomous recording <span class="hlt">system</span>. Our first experiment of 2D/3D VCS surveys has been carried out in Lake Biwa, JAPAN. in November 2009. The 2D VCS data processing follows the walk-away VSP, including wave field separation and depth migration. The result gives clearer image than the conventional surface seismic. Prestack depth migration is applied to 3D data to obtain good quality 3D depth volume. Uncertainty of the source/receiver poisons in water causes the serious problem of the imaging. We used several transducer/transponder to estimate these positions. The VCS seismic records themselves can also provide sensor position using the first break of each trace and we calibrate the positions. We are currently developing the autonomous recording VCS <span class="hlt">system</span> and planning the trial experiment in actual ocean to establish the way of deployment/recovery and the examine the position through the current flow in November, 2010. The second VCS survey will planned over the actual <span class="hlt">hydrothermal</span> deposit with deep-towed source in February, 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMMR41B2635C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMMR41B2635C"><span>Effects of chemical alteration on fracture mechanical properties in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Callahan, O. A.; Eichhubl, P.; Olson, J. E.</p> <p>2015-12-01</p> <p>Fault and fracture networks often control the distribution of fluids and heat in <span class="hlt">hydrothermal</span> and epithermal <span class="hlt">systems</span>, and in related geothermal and mineral resources. Additional chemical influences on conduit evolution are well documented, with dissolution and precipitation of mineral species potentially changing the permeability of fault-facture networks. Less well understood are the impacts of chemical alteration on the mechanical properties governing fracture growth and fracture network geometry. We use double-torsion (DT) load relaxation tests under ambient air conditions to measure the mode-I fracture toughness (KIC) and subcritical fracture growth index (SCI) of variably altered rock samples obtained from outcrop in Dixie Valley, NV. Samples from southern Dixie Valley include 1) weakly altered granite, characterized by minor sericite in plagioclase, albitization and vacuolization of feldspars, and incomplete replacement of biotite with chlorite, and 2) granite from an area of locally intense propylitic alteration with chlorite-calcite-hematite-epidote assemblages. We also evaluated samples of completely silicified gabbro obtained from the Dixie Comstock epithermal gold deposit. In the weakly altered granite KIC and SCI are 1.3 ±0.2 MPam1/2 (n=8) and 59 ±25 (n=29), respectively. In the propylitic assemblage KIC is reduced to 0.6 ±0.1 MPam1/2 (n=11), and the SCI increased to 75 ±36 (n = 33). In both cases, the altered materials have lower fracture toughness and higher SCI than is reported for common geomechanical standards such as Westerly Granite (KIC ~1.7 MPam1/2; SCI ~48). Preliminary analysis of the silicified gabbro shows a significant increase in fracture toughness, 3.6 ±0.4 MPam1/2 (n=2), and SCI, 102 ±45 (n=19), compared to published values for gabbro (2.9 MPam1/2 and SCI = 32). These results suggest that mineralogical and textural changes associated with different alteration assemblages may result in spatially variable rates of fracture</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000DSRI...47.1703B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000DSRI...47.1703B"><span>Distribution and relative importance of jellyfish in a region of <span class="hlt">hydrothermal</span> venting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burd, Brenda J.; Thomson, Richard E.</p> <p>2000-09-01</p> <p>Net sampling to 3000 m depth at <span class="hlt">Endeavour</span> Ridge in the northeast Pacific in July 1991-1994 shows that medusae in the immediate vicinity of the <span class="hlt">hydrothermal</span> vent fields often make up a larger proportion of the total zooplankton abundance and biomass from mesopelagic to bathypelagic depths than in the surrounding waters. This was particularly evident in the dominant Trachymedusae, and least evident in the siphonophores. In addition, the large red Scyphomedusa Stygiomedusa gigantea was a major biomass component in the region of the deep (1000-1800 m depth) migrating scattering layers at the vent field, but was not found in any net tows greater than 10 km away from vents. There is no concurrent increase in relative or percent biomass of fish or chaetognaths, which are the other major predators in the community. We hypothesize that predaceous medusae respond opportunistically to the enhanced zooplankton biomass throughout the water column around vents in spring to early summer, in a way that other predators do not.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030295','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030295"><span>Tertiary tilting and dismemberment of the laramide arc and related <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, Sierrita Mountain, Arizona</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stavast, W.J.A.; Butler, R.P.; Seedorff, E.; Barton, M.D.; Ferguson, C.A.</p> <p>2008-01-01</p> <p>Multiple lines of evidence, including new and published geologic mapping and paleomagnetic and geobarometric determinations, demonstrate that the rocks and large porphyry copper <span class="hlt">systems</span> of the Sierrita Mountains in southern Arizona were dismembered and tilted 50?? to 60?? to the south by Tertiary normal faulting. Repetition of geologic features and geobarometry indicate that the area is segmented into at least three major structural blocks, and the present surface corresponds to oblique sections through the Laramide plutonic-<span class="hlt">hydrothermal</span> complex, ranging in paleodepth from ???1 to ???12 km. These results add to an evolving view of a north-south extensional domain at high angles to much extension in the southern Basin and Range, contrast with earlier interpretations that the Laramide <span class="hlt">systems</span> are largely upright and dismembered by thrust faults, highlight the necessity of restoring Tertiary rotations before interpreting Laramide structural and <span class="hlt">hydrothermal</span> features, and add to the broader understanding of pluton emplacement and evolution of porphyry copper <span class="hlt">systems</span>. ?? 2008 Society of Economic Geologists, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615842B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615842B"><span>Geochemistry driven trends in microbial diversity and function across a temperature transect of a shallow water <span class="hlt">hydrothermal</span> <span class="hlt">system</span> off Milos (Greece)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bühring, Solveig I.; Amend, Jan P.; Gómez Sáez, Gonzalo V.; Häusler, Stefan; Hinrichs, Kai-Uwe; Pichler, Thomas; Pop Ristova, Petra; Price, Roy E.; Santi, Ioulia; Sollich, Miriam</p> <p>2014-05-01</p> <p>The shallow water <span class="hlt">hydrothermal</span> vents off Milos Island, Greece, discharge hot, slightly acidic, reduced fluids into colder, slightly alkaline, oxygenated seawater. Gradients in temperature, pH, and geochemistry are established as the two fluids mix, leading to the formation of various microbial microniches. In contrast to deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, the availability of sun light allows for a combination of photo- and chemotrophic carbon fixation. Despite the comparably easy accessibility of shallow water <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, little is known about their microbial diversity and functioning. We present data from a shallow <span class="hlt">hydrothermal</span> <span class="hlt">system</span> off Milos Island, one of the most <span class="hlt">hydrothermally</span> active regions in the Mediterranean Sea. The physico-chemical changes from ambient seafloor to <span class="hlt">hydrothermal</span> area were investigated and documented by in situ microsensor profiling of temperature, pH, total reduced sulfur and dissolved oxygen alongside porewater geochemistry. The spatial microbial diversity was determined using a combination of gene- and lipid-based approaches, whereas microbial functioning was assessed by stable isotope probing experiments targeting lipid biomarkers. In situ microprofiles indicated an extreme environment with steep gradients, offering a variety of microniches for metabolically diverse microbial communities. We sampled a transect along a <span class="hlt">hydrothermal</span> patch, following an increase in sediment surface temperature from background to 90°C, including five sampling points up to 20 cm sediment depth. Investigation of the bacterial diversity using ARISA revealed differences in the community structure along the geochemical gradients, with the least similarity between the ambient and highly <span class="hlt">hydrothermally</span> impacted sites. Furthermore, using multivariate statistical analyses it was shown that variations in the community structure could be attributed to differences in the sediment geochemistry and especially the sulfide content, and only indirectly to shifts in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JVGR..352...38M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JVGR..352...38M"><span>Geochemical characterisation of Taal volcano-<span class="hlt">hydrothermal</span> <span class="hlt">system</span> and temporal evolution during continued phases of unrest (1991-2017)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maussen, Katharine; Villacorte, Edgardo; Rebadulla, Ryan R.; Maximo, Raymond Patrick; Debaille, Vinciane; Bornas, Ma. Antonia; Bernard, Alain</p> <p>2018-02-01</p> <p>Taal volcano (Luzon Island, Philippines) has last erupted in 1977 but has known some periods of increased activity, characterised by seismic swarms, ground deformation, increased carbon dioxide flux and in some cases temperature anomalies and the opening of fissures. We studied major, trace element and sulphur and strontium isotopic composition of Taal lake waters and hot springs over a period of 25 years to investigate the geochemical evolution of Taal volcano's <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and its response to volcanic unrest. Long-term evolution of Main Crater Lake (MCL) composition shows a slow but consistent decrease of acidity, SO4, Mg, Fe and Al concentrations and a trend from light to heavy sulphate, consistent with a general decrease of volcanic gases dissolving in the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Na, K and Cl concentrations remain constant indicating a non-volcanic origin for these elements. Sulphate and strontium isotopic data suggest this neutral chloride-rich component represents input of geothermal water into Taal <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. A significant deviation from the long-term baseline can be seen in two samples from 1995. That year, pH dropped from 2.6 to 2.2, F, Si and Fe concentrations increased and Na, K and Cl concentrations decreased. Sulphate was depleted in 34S and temperature was 4 °C above baseline level at the time of sampling. We attribute these changes to the shallow intrusion of a degassing magma body during the unrest in 1991-1994. More recent unrest periods have not caused significant changes in the geochemistry of Taal <span class="hlt">hydrothermal</span> waters and are therefore unlikely to have been triggered by shallow magma intrusion. A more likely cause for these events is thus pressurisation of the <span class="hlt">hydrothermal</span> reservoir by increasing degassing from a stagnant magma reservoir. Our study indicates that new magmatic intrusions that might lead to the next eruption of Taal volcano are expected to change the geochemistry of MCL in the same way as in 1994-1995, with the most</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V21A4732C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V21A4732C"><span>The characteristics of <span class="hlt">hydrothermal</span> plumes observed in the Precious Stone Mountain <span class="hlt">hydrothermal</span> field, the Galapagos spreading center</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, S.; Tao, C.; Li, H.; Zhou, J.; Deng, X.; Tao, W.; Zhang, G.; Liu, W.; He, Y.</p> <p>2014-12-01</p> <p>The Precious Stone Mountain <span class="hlt">hydrothermal</span> field (PSMHF) is located on the southern rim of the Galapagos Microplate. It was found at the 3rd leg of the 2009 Chinese DY115-21 expedition on board R/V Dayangyihao. It is efficient to learn the distribution of <span class="hlt">hydrothermal</span> plumes and locate the <span class="hlt">hydrothermal</span> vents by detecting the anomalies of turbidity and temperature. Detecting seawater turbidity by MAPR based on deep-tow technology is established and improved during our cruises. We collected data recorded by MAPR and information from geological sampling, yielding the following results: (1)Strong <span class="hlt">hydrothermal</span> turbidity and temperature anomalies were recorded at 1.23°N, southeast and northwest of PSMHF. According to the CTD data on the mooring <span class="hlt">system</span>, significant temperature anomalies were observed over PSMHF at the depth of 1,470 m, with anomalies range from 0.2℃ to 0.4℃, which gave another evidence of the existence of <span class="hlt">hydrothermal</span> plume. (2)At 1.23°N (101.4802°W/1.2305°N), the nose-shaped particle plume was concentrated at a depth interval of 1,400-1,600 m, with 200 m thickness and an east-west diffusion range of 500 m. The maximum turbidity anomaly (0.045 △NTU) was recorded at the depth of 1,500 m, while the background anomaly was about 0.01△NTU. A distinct temperature anomaly was also detected at the seafloor near 1.23°N. Deep-tow camera showed the area was piled up by <span class="hlt">hydrothermal</span> sulfide sediments. (3) In the southeast (101.49°W/1.21°N), the thickness of <span class="hlt">hydrothermal</span> plume was 300 m and it was spreading laterally at a depth of 1,500-1,800 m, for a distance about 800 m. The maximum turbidity anomaly of nose-shaped plume is about 0.04 △NTU at the depth of 1,600 m. Distinct temperature anomaly was also detected in the northwest (101.515°W/1.235°N). (4) Terrain and bottom current were the main factors controlling the distribution of <span class="hlt">hydrothermal</span> plume. Different from the distribution of <span class="hlt">hydrothermal</span> plumes on the mid-ocean ridges, which was mostly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMOS41B..02C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMOS41B..02C"><span>Seismic Reflection Imaging of the Heat Source of an Ultramafic-Hosted <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> (Rainbow, Mid-Atlantic Ridge 36° 10-17'N)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Canales, J. P.; Dunn, R. A.; Sohn, R. A.; Horning, G.; Arai, R.; Paulatto, M.</p> <p>2015-12-01</p> <p>Most of our understanding of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> and the nature of their heat sources comes from models and observations at fast and intermediate spreading ridges. In these settings, <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are mainly located within the axial zone of a spreading segment, hosted in basaltic rock, and primarily driven by heat extracted from crystallization of crustal melt sills. In contrast, <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> at slow-spreading ridges like the Mid-Atlantic Ridge (MAR) show a great variety of venting styles and host-rock lithology, and are located in diverse tectonic settings like axial volcanic ridges, non-transform discontinuities (NTDs), the foot of ridge valley walls, and off-axis inside corner highs. Among MAR <span class="hlt">systems</span>, the Rainbow <span class="hlt">hydrothermal</span> field (RHF) stands out as an end-member of this diversity: an ultramafic-hosted <span class="hlt">system</span> emitting H2 and CH4-rich fluids at high temperatures and high flow rates, which suggests a magmatic heat source despite the lack of evidence for recent volcanism and its location within an NTD with presumably low magma budget. We present 2D multichannel seismic reflection images across the Rainbow massif from the NSF-funded MARINER multidisciplinary geophysical study that reveal, for the first time, the magmatic <span class="hlt">system</span> driving <span class="hlt">hydrothermal</span> circulation in an ultramafic setting. Data were acquired in 2013 onboard the RV M. Langseth with an 8-km-long hydrophone streamer. The images have been obtained from pre-stack depth migrations using a regional 3D P-wave velocity model from a coincident controlled-source seismic tomography experiment using ocean bottom seismometers. Our images show a complex magmatic <span class="hlt">system</span> centered beneath the RHF occupying an areal extent of ~3.7x6 km2, with partially molten sills ranging in depth between ~3.4 km and ~6.9 km below the seafloor. Our data also image high-amplitude dipping reflections within the massif coincident with strong lateral velocity gradients that may arise from detachment fault planes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LPICo2085.6022S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LPICo2085.6022S"><span>Origin of Abiotic Methane in Submarine <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seewald, J. S.; German, C. R.; Grozeva, N. G.; Klein, F.; McDermott, J. M.; Ono, S.; Reeves, E. P.; Wang, D. T.</p> <p>2018-05-01</p> <p>Results of recent investigations into the chemical and isotopic composition of actively venting submarine <span class="hlt">hydrothermal</span> fluids and volatile species trapped in fluid inclusions will be discussed in the context of processes responsible for abiotic CH4 formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts097-712-004.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts097-712-004.html"><span>Views of the ISS during <span class="hlt">Endeavour</span>'s final flyaround for STS-97</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2000-12-09</p> <p>STS097-712-004 (9 December 2000) --- This picture of the distant International Space Station (ISS) blended against the darkness of space and the blue Earth at its horizon is one of a series of 70mm frames exposed of the station following undocking at 1:13 p.m. (CST), December 9, 2000. This series of images, as well as video and digital still imagery taken at the same time, represent the first imagery of the entire station with its new solar array panels deployed, though they are difficult to see in this angle. Before separation, the shuttle and space station had been docked to one another for 6 days, 23 hours and 13 minutes. <span class="hlt">Endeavour</span> moved downward from the space station, then began a tail-first circle at a distance of about 500 feet. The maneuver, with pilot Michael J. Bloomfield at the controls, took about an hour. While <span class="hlt">Endeavour</span> flew that circle, the two spacecraft, moving at five miles a second, navigated about two-thirds of the way around the Earth. Undocking took place 235 statute miles above the border of Kazakhstan and China. When <span class="hlt">Endeavour</span> made its final separation burn, the orbiter and the space station were near the northeastern coast of South America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JVGR..332...88H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JVGR..332...88H"><span>A multidisciplinary approach to quantify the permeability of the Whakaari/White Island volcanic <span class="hlt">hydrothermal</span> <span class="hlt">system</span> (Taupo Volcanic Zone, New Zealand)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heap, Michael J.; Kennedy, Ben M.; Farquharson, Jamie I.; Ashworth, James; Mayer, Klaus; Letham-Brake, Mark; Reuschlé, Thierry; Gilg, H. Albert; Scheu, Bettina; Lavallée, Yan; Siratovich, Paul; Cole, Jim; Jolly, Arthur D.; Baud, Patrick; Dingwell, Donald B.</p> <p>2017-02-01</p> <p>Our multidisciplinary study aims to better understand the permeability of active volcanic <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, a vital prerequisite for modelling and understanding their behaviour and evolution. Whakaari/White Island volcano (an active stratovolcano at the north-eastern end of the Taupo Volcanic Zone of New Zealand) hosts a highly reactive <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and represents an ideal natural laboratory to undertake such a study. We first gained an appreciation of the different lithologies at Whakaari and (where possible) their lateral and vertical extent through reconnaissance by land, sea, and air. The main crater, filled with tephra deposits, is shielded by a volcanic amphitheatre comprising interbedded lavas, lava breccias, and tuffs. We deployed field techniques to measure the permeability and density/porosity of (1) > 100 hand-sized sample blocks and (2) layered unlithified deposits in eight purpose-dug trenches. Our field measurements were then groundtruthed using traditional laboratory techniques on almost 150 samples. Our measurements highlight that the porosity of the materials at Whakaari varies from ∼ 0.01 to ∼ 0.7 and permeability varies by eight orders of magnitude (from ∼ 10-19 to ∼ 10-11 m2). The wide range in physical and hydraulic properties is the result of the numerous lithologies and their varied microstructures and alteration intensities, as exposed by a combination of macroscopic and microscopic (scanning electron microscopy) observations, quantitative mineralogical studies (X-ray powder diffraction), and mercury porosimetry. An understanding of the spatial distribution of lithology and alteration style/intensity is therefore important to decipher fluid flow within the Whakaari volcanic <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. We align our field observations and porosity/permeability measurements to construct a schematic cross section of Whakaari that highlights the salient findings of our study. Taken together, the alteration typical of a volcanic</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V51F0432K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V51F0432K"><span>Volcano-<span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span> of the Kuril Island Arc (Russia): Geochemistry of the Thermal Waters and Gases.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kalacheva, E.; Taran, Y.; Voloshina, E.; Kotenko, T.; Tarasov, K.</p> <p>2017-12-01</p> <p>More than 30 active volcanoes with historical eruptions are known on 20 main islands composing the Kuril Arc. Eight islands - Paramushir, Shiashkotan, Rasshua, Ushishir, Ketoy, Urup, Iturup and Kunashir - are characterized by <span class="hlt">hydrothermal</span> activity, complementary to the fumarole activity in the craters and volcano slopes. At Paramushir, Shiashkotan, Iturup and Kunashir most of thermal manifestations are acidic to ultra-acidic hot springs associated with <span class="hlt">hydrothermal</span> aquifers inside volcano edifices. The most powerful of them is the ultra-acid <span class="hlt">hydrothermal</span> <span class="hlt">system</span> of Ebeko volcano (Paramushir island) with more than 80 t/day of the chloride output and pH of springs of 1.5. At the summit part of the Ebeko volcano there are 12 thermal fields with the total thermal area exceeding 1 km2. The measured temperatures of fumaroles are from 98º C to 500ºC. Another type of <span class="hlt">hydrothermal</span> activity are the wide spread coastal hot and neutral springs situated as a rule within the tide zone. Four groups of this type of thermal manifestation were found on the western shore of Shiashkotan island. It have Na-Ca-Cl-SO4 composition with temperatures 50-80°C and TDS 7-8 g/L. Coastal neutral springs were found also on Russhua, Uturup and Kunashir islands. Ushishir volcano-<span class="hlt">hydrothermal</span> <span class="hlt">system</span> in the middle of the arc is formed by the absorption of magmatic gases by seawater. In the crater of the Pallas cone (Ketoy island) there is a small Glazok lake with acid SO4 water and pH=2.4, TDS=2g/L, T=12oC. Ketoy volcano on the same island hosts a high temperature <span class="hlt">hydrothermal</span> <span class="hlt">system</span> with unusual boiling Ca-Na-SO4 neutral springs and steam vents. Mendeleev and Golovnin volcanoes on Kunashir Island are the southernmost of the Kuril arc. Mendeleev edifice is a centre of a large thermal area with many manifestations of different types including steam vents, acid springs and neutral coastal springs. In a 4.2x4 km wide caldera of Golovnin volcano there are two lakes with acid Cl-SO4 water and numerous</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V34A..04C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V34A..04C"><span>A seismological perspective of the shallow magma and <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> under Kilauea Caldera</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chouet, B. A.; Dawson, P. B.</p> <p>2011-12-01</p> <p> west and east branches of the east-trending dike with the north-striking dike provides a natural locus for strong localized elastic coupling of pressure and momentum changes induced by shallow degassing bursts. This juncture offers a ready explanation for the observed temporal stability of the VLP source location. Radial semblance analyses of VLP seismic energy in near real time, supplemented with spectral analyses and Hidden Markov Model (HMM) pattern recognition of degassing bursts provide valuable tools for monitoring the evolution of this active magmatic <span class="hlt">system</span> and its interaction with the perched <span class="hlt">hydrothermal</span> <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMOS41C1833S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMOS41C1833S"><span>In-Situ pH Measurements in Mid-Ocean Ridge <span class="hlt">Hydrothermal</span> Vent Fluids: Constraints on Subseafloor Alteration Processes at Crustal Depths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaen, A. T.; Ding, K.; Seyfried, W. E.</p> <p>2013-12-01</p> <p>Developments in electrochemistry and material science have facilitated the construction of ceramic (YSZ) based chemical sensor <span class="hlt">systems</span> that can be used to measure and monitor pH and redox in aqueous fluids at elevated temperatures and pressures. In recent years, these sensor <span class="hlt">systems</span> have been deployed to acquire real-time and time series in-situ data for high-temperature <span class="hlt">hydrothermal</span> vent fluids at the Main <span class="hlt">Endeavour</span> Field (Juan de Fuca Ridge), 9oN (East Pacific Rise), and at the ultramafic-hosted Rainbow field (36oN, Mid-Atlantic Ridge). Here we review in-situ pH data measured at these sites and apply these data to estimate the pH of fluids ascending to the seafloor from <span class="hlt">hydrothermal</span> alteration zones deeper in the crust. In general, in-situ pH measured at virtually all vent sites is well in excess of that measured shipboard owing to the effects of temperature on the distribution of aqueous species and the solubility of metal sulfides, especially Cu and Zn, originally dissolved in the vent fluids. In situ pH measurements determined at MEF (Sully vent) and EPR 9oN (P-vent) in 2005 and 2008 were 4.4 ×0.02 and 5.05×0.05, respectively. The temperature and pressure (seafloor) of the vent fluids at each of the respective sites were 356oC and 220 bar, and 380oC and 250 bar. Plotting these data with respect to fluid density reveals that the in-situ pH of each vent fluid is approximately 1.5 pH units below neutrality. The density-pH (in-situ) correlation, however, is important because it provides a means from which the vent fluids were derived. Using dissolved silica and chloride from fluid samples at the MEF (Sully) suggest T/P conditions of approximately 435oC, 380 bar, based on quartz-fluid and NaCl-H2O <span class="hlt">systems</span>. At the fluid density calculated for these conditions, pH (in-situ) is predicted to be ~6.2. Attempts are presently underway to assess the effect of the calculated pH on metal sulfide and silicate (e.g., plagioclase, chlorite) solubility in comparison with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JVGR..276..132G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JVGR..276..132G"><span>Asymmetrical structure, <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and edifice stability: The case of Ubinas volcano, Peru, revealed by geophysical surveys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonzales, Katherine; Finizola, Anthony; Lénat, Jean-François; Macedo, Orlando; Ramos, Domingo; Thouret, Jean-Claude; Fournier, Nicolas; Cruz, Vicentina; Pistre, Karine</p> <p>2014-04-01</p> <p>Ubinas volcano, the historically most active volcano in Peru straddles a low-relief high plateau and the flank of a steep valley. A multidisciplinary geophysical study has been performed to investigate the internal structure and the fluids flow within the edifice. We conducted 10 self-potential (SP) radial (from summit to base) profiles, 15 audio magnetotelluric (AMT) soundings on the west flank and a detailed survey of SP and soil temperature measurements on the summit caldera floor. The typical “V” shape of the SP radial profiles has been interpreted as the result of a <span class="hlt">hydrothermal</span> zone superimposed on a hydrogeological zone in the upper parts of the edifice, and depicts a sub-circular SP positive anomaly, about 6 km in diameter. The latter is centred on the summit, and is characterised by a larger extension on the western flank located on the low-relief high plateau. The AMT resistivity model shows the presence of a conductive body beneath the summit at a depth comparable to that of the bottom of the inner south crater in the present-day caldera, where intense <span class="hlt">hydrothermal</span> manifestations occur. The lack of SP and temperature anomalies on the present caldera floor suggests a self-sealed <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, where the inner south crater acts as a pressure release valve. Although no resistivity data exists on the eastern flank, we presume, based on the asymmetry of the basement topography, and the amplitude of SP anomalies on the east flank, which are approximately five fold that on the west flank, that gravitational flow of <span class="hlt">hydrothermal</span> fluids may occur towards the deep valley of Ubinas. This hypothesis, supported by the presence of hot springs and faults on the eastern foot of the edifice, reinforces the idea that a large part of the southeast flank of the Ubinas volcano may be altered by <span class="hlt">hydrothermal</span> activity and will tend to be less stable. One of the major findings that stems from this study is that the slope of the basement on which a volcano has grown</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS51E..05Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS51E..05Z"><span>Characteristics of <span class="hlt">Hydrothermal</span> Mineralization in Ultraslow Spreading Ridges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, H.; Yang, Q.; Ji, F.; Dick, H. J.</p> <p>2014-12-01</p> <p><span class="hlt">Hydrothermal</span> activity is a major component of the processes that shape the composition and structure of the ocean crust, providing a major pathway for the exchange of heat and elements between the Earth's crust and oceans, and a locus for intense biological activity on the seafloor and underlying crust. In other hand, the structure and composition of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are the result of complex interactions between heat sources, fluids, wall rocks, tectonic controls and even biological processes. Ultraslow spreading ridges, including the Southwest Indian Ridge, the Gakkel Ridge, are most remarkable end member in plate-boundary structures (Dick et al., 2003), featured with extensive tectonic amagmatic spreading and frequent exposure of peridotite and gabbro. With intensive surveys in last decades, it is suggested that ultraslow ridges are several times more effective than faster-spreading ridges in sustaining <span class="hlt">hydrothermal</span> activities. This increased efficiency could attributed to deep mining of heat and even exothermic serpentinisation (Baker et al., 2004). Distinct from in faster spreading ridges, one characteristics of <span class="hlt">hydrothermal</span> mineralization on seafloor in ultraslow spreading ridges, including the active Dragon Flag <span class="hlt">hydrothermal</span> field at 49.6 degree of the Southwest Indian Ridge, is abundant and pervasive distribution of lower temperature precipitated minerals ( such as Fe-silica or silica, Mn (Fe) oxides, sepiolite, pyrite, marcasite etc. ) in <span class="hlt">hydrothermal</span> fields. Structures formed by lower temperature activities in active and dead <span class="hlt">hydrothermal</span> fields are also obviously. High temperature precipitated minerals such as chalcopyrite etc. are rare or very limited in <span class="hlt">hydrothermal</span> chimneys. Distribution of diverse low temperature <span class="hlt">hydrothermal</span> activities is consistence with the deep heating mechanisms and <span class="hlt">hydrothermal</span> circulations in the complex background of ultraslow spreading tectonics. Meanwhile, deeper and larger mineralization at certain locations along the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V24A..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V24A..06R"><span>Characterizing the dynamics of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> with muon tomography: the case of La Soufrière de Guadeloupe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosas-Carbajal, M.; Marteau, J.; Tramontini, M.; de Bremond d Ars, J.; Le Gonidec, Y.; Carlus, B.; Ianigro, J. C.; Deroussi, S.; Komorowski, J. C.; Gibert, D.</p> <p>2017-12-01</p> <p>Muon imaging has recently emerged as a powerful method to complement standard geophysical tools in the study of the Earth's subsurface. Muon measurements yield a radiography of the average density along the muon path, allowing to image large volumes of a geological body from a single observation point. Long-term measurements allow to infer density changes by tracking the associated variations in the muon flux. In the context of volcanic <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, this approach helps to characterize zones of steam formation, condensation, water infiltration and storage. We present results of imaging the La Soufrière de Guadeloupe dome and shallow active <span class="hlt">hydrothermal</span> <span class="hlt">system</span> with a network of muon telescopes viewing the dome from different positions around its base. First, we jointly invert the muon radiographies of the different telescopes with gravity data to obtain a three-dimensional density model of the lava dome. The model reveals an extended low density region where the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> is most active. We then analyze the dynamics of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> from long-term measurements (more than 2 years of almost non-interrupted acquisition) with 5 simultaneous muon telescopes. We identify a periodicity of 1-2 months in the density increase/decrease in the most active zones below fumaroles and acid boiling ponds. Our simultaneous-muon telescope strategy provides constraints on the three-dimensional location of the density changes and an improved quantification of the associated mass flux changes. We compare the temporal trends acquired by the different muon telescopes to time-series of rainfall on the summit recharge area as well as to ground temperature profiles in the vicinity of thermal anomalies and high-discharge summit fumaroles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA14538.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA14538.html"><span>Opportunity View Across Botany Bay and <span class="hlt">Endeavour</span> on Sol 2678</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-01</p> <p>The foreground area is a portion of an area called Botany Bay between two ridges forming part of the western rim of <span class="hlt">Endeavour</span> crater. NASA Mars Exploration Rover Opportunity recorded this mosaic view centered toward the southeast on Aug. 6, 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS53C1050D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS53C1050D"><span>Application of AUVs in the Exploration for and Characterization of Arc Volcano Seafloor <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Ronde, C. E. J.; Walker, S. L.; Caratori Tontini, F.; Baker, E. T.; Embley, R. W.; Yoerger, D.</p> <p>2014-12-01</p> <p>The application of Autonomous Underwater Vehicles (AUVs) in the search for, and characterization of, seafloor <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> associated with arc volcanoes has provided important information at a scale relevant to the study of these <span class="hlt">systems</span>. That is, 1-2 m resolution bathymetric mapping of the seafloor, when combined with high-resolution magnetic and water column measurements, enables the discharge of <span class="hlt">hydrothermal</span> vent fluids to be coupled with geological and structural features, and inferred upflow zones. Optimum altitude for the AUVs is ~70 m ensuring high resolution coverage of the area, maximum exposure to <span class="hlt">hydrothermal</span> venting, and efficency of survey. The Brothers caldera and Clark cone volcanoes of the Kermadec arc have been surveyed by ABE and Sentry. At Brothers, bathymetric mapping shows complex features on the caldera walls including embayment's, ridges extending orthogonal to the walls and the location of a dominant ring fault. Water column measurements made by light scattering, temperature, ORP and pH sensors confirmed the location of the known vent fields on the NW caldera wall and atop the two cones, and discovered a new field on the West caldera wall. Evidence for diffuse discharge was also seen on the rim of the NW caldera wall; conversely, there was little evidence for discharge over an inferred ancient vent site on the SE caldera wall. Magnetic measurements show a strong correlation between the boundaries of vent fields determined by water column measurements and observed from manned submersible and towed camera surveys, and donut-shaped zones of magnetic 'lows' that are focused along ring faults. A magnetic low was also observed to cover the SE caldera site. Similar surveys over the NW edifice of Clark volcano also show a strong correlation between active <span class="hlt">hydrothermal</span> venting and magnetic lows. Here, the survey revealed a pattern resembling Swiss cheese of magnetic lows, indicating more widespread permeability. Moreover, the magnetic survey</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.6579B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.6579B"><span>Silicon isotopes fractionation in meteoric chemical weathering and <span class="hlt">hydrothermal</span> alteration <span class="hlt">systems</span> of volcanic rocks (Mayotte)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Basile-Doelsch, Isabelle; Puyraveau, Romain-Arnaud; Guihou, Abel; Haurine, Frederic; Deschamps, Pierre; rad, Setareh; Nehlig, Pierre</p> <p>2017-04-01</p> <p>Low temperature chemical weathering fractionates silicon (Si) isotopes while forming secondary silicates. The Si fractionation ranges of high temperature secondary phyllosilicates formed in <span class="hlt">hydrothermal</span> alteration environments have not been investigated to date. Several parameters, including temperature, reaction rates, pH, ionic concentrations in solution, precipitation/dissolution series or kinetic versus equilibrium regime are not the same in <span class="hlt">hydrothermal</span> alteration and surface weathering <span class="hlt">systems</span> and may lead to different fractionation factors. In this work, we analyzed Si isotopes in these two types of alteration conditions in two profiles sampled on the volcanic island of Mayotte. In both profiles, Si-bearing secondary mineral was kaolinite. Both profiles showed 30Si depletion as a function of the degree of alteration but each with a distinct pattern. In the meteoric weathering profile, from the bottom to the top, a gradual decrease of the δ30Si from parent rock (-0.29 ± 0.13 ‰) towards the most weathered product (-2.05 ± 0.13 ‰) was observed. In the <span class="hlt">hydrothermal</span> alteration profile, in which meteoric weathering was also superimposed at the top of the profile, an abrupt transition of the δ30Si was measured at the interface between parent-rock (-0.21 ± 0.11 ‰) and the altered products, with a minimum value of -3.06 ± 0.16 ‰˙ At the scale of Si-bearing secondary minerals, in the chemical weathering <span class="hlt">system</span>, a Δ30Sikaol-parentrock of -1.9 ‰ was observed, in agreement with results in the literature. A low temperature kinetic fractionation 30ɛ of -2.29 ‰ was calculated using a simple steady state model. However, an unexpected Δ30Sikaol-parentrock of -2.85 ‰ was measured in the <span class="hlt">hydrothermal</span> alteration site, pointing to possible mechanisms linked to dissolution/precipitation series and/or to ionic composition of the solution as the main controlling factors of fractionation in <span class="hlt">hydrothermal</span> conditions. At the scale of the profiles, both δ30Si</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA19082.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA19082.html"><span>Opportunity Pausing at a Bright Outcrop on <span class="hlt">Endeavour</span> Rim, Sol 3854</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2014-12-11</p> <p>NASA Mars Exploration Rover Opportunity is continuing its traverse southward on the western rim of <span class="hlt">Endeavour</span> Crater during the fall of 2014, stopping to investigate targets of scientific interest along way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGP11A..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGP11A..01S"><span>The magnetic signature of ultramafic-hosted <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szitkar, F.; Dyment, J.; Honsho, C.; Horen, H.; Fouquet, Y.</p> <p>2013-12-01</p> <p>While the magnetic response of basalt-hosted <span class="hlt">hydrothermal</span> sites is well known, that of ultramafic-hosted <span class="hlt">hydrothermal</span> sites (UMHS) remains poorly documented. Here we present the magnetic signature of three of the six UMHS investigated to date on the Mid-Atlantic Ridge, i.e. sites Rainbow, Ashadze (1 and 2), and Logachev. Two magnetic signatures are observed. Sites Rainbow and Ashadze 1 are both characterized by a positive reduced-to-the-pole magnetic anomaly, i.e. a positive magnetization contrast. Conversely, sites Ashadze 2 and Logachev do not exhibit any clear magnetic signature. Rock-magnetic measurements on samples from site Rainbow reveal a strong magnetization (~30 A/m adding induced and remanent contributions) borne by sulfide-impregnated serpentinites; the magnetic carrier being magnetite. This observation can be explained by three (non exclusive) processes: (1) higher temperature serpentinization at the site resulting in the formation of more abundant / more strongly magnetized magnetite; (2) the reducing <span class="hlt">hydrothermal</span> fluid protecting magnetite at the site from the oxidation which otherwise affects magnetite in contact with seawater; and (3) the formation of primary (<span class="hlt">hydrothermal</span>) magnetite. We apply a new inversion method developed by Honsho et al. (2012) to the high-resolution magnetic anomalies acquired 10 m above seafloor at sites Rainbow and Ashadze 1. This method uses the Akaike Bayesian Information Criterion (ABIC) and takes full advantage of the near-seafloor measurements, avoiding the upward-continuation (i.e. loss of resolution) of other inversion schemes. This inversion reveals a difference in the intensity of equivalent magnetization obtained assuming a 100 m thick magnetic layer, ~30 A/m at site Rainbow and only 8A/m at site Ashadze, suggesting a thinner or less magnetized source for the latter. <span class="hlt">Hydrothermal</span> sites at Ashadze 2 and Logachev are much smaller (of the order of 10 m) than the previous ones (several 100 m). These sites, known as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-04pd0345.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-04pd0345.html"><span>KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) looks at an external tank door corrosion work being done on <span class="hlt">Endeavour</span>. At right, Tom Roberts, Airframe Engineering <span class="hlt">System</span> specialist with United Space Alliance, is describing the work. At right is Kathy Laufenberg, Orbiter Airframe Engineering ground area manager,also with USA. <span class="hlt">Endeavour</span> is in its Orbiter Major Modification period, which began in December 2003.</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2004-02-25</p> <p>KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) looks at an external tank door corrosion work being done on <span class="hlt">Endeavour</span>. At right, Tom Roberts, Airframe Engineering <span class="hlt">System</span> specialist with United Space Alliance, is describing the work. At right is Kathy Laufenberg, Orbiter Airframe Engineering ground area manager,also with USA. <span class="hlt">Endeavour</span> is in its Orbiter Major Modification period, which began in December 2003.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V21A4737C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V21A4737C"><span>The Role of Siliceous <span class="hlt">Hydrothermal</span> Breccias in the Genesis of Volcanic Massive Sulphide Deposits - Ancient and Recent <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Costa, I. A.; Barriga, F. J.; Fouquet, Y.</p> <p>2014-12-01</p> <p>Siliceous <span class="hlt">hydrothermal</span> breccias were sampled in two Mid-Atlantic Ridge active sites: Lucky Strike and Menez Gwen. These <span class="hlt">hydrothermal</span> fields are located in the border of the Azorean plateau, southwest of the Azores islands where the alteration processes affecting basaltic rocks are prominent (Costa et al., 2003). The <span class="hlt">hydrothermal</span> breccias are genetically related with the circulation of low temperature <span class="hlt">hydrothermal</span> fluids in diffuse vents. The groundmass of these breccias precipitates from the fluid and consolidates the clastic fragments mostly composed of basalt. The main sources are the surrounding volcanic hills. Breccias are found near <span class="hlt">hydrothermal</span> vents and may play an important role in the protection of subseafloor <span class="hlt">hydrothermal</span> deposits forming an impermeable cap due to the high content in siliceous material. The amorphous silica tends to precipitate when the fluid is conductively cooled as proposed by Fouquet et al. (1998) after Fournier (1983). The process evolves gradually from an initial stage where we have just the fragments and circulating seawater. The ascending <span class="hlt">hydrothermal</span> fluid mixes with seawater, which favours the precipitation of the sulphide components. Sealing of the initially loose fragments begins, the temperature rises below this crust, and the processes of mixing fluid circulation and conductive cooling are simultaneous. At this stage the fluid becomes oversaturated with respect to amorphous silica. This form of silica can precipitate in the open spaces of the porous sulphides and seal the <span class="hlt">system</span>. Normally this can happen at low temperatures. At this stage the <span class="hlt">hydrothermal</span> breccia is formed creating a progressively less permeable, eventually impermeable cap rock at the surface. Once the fluid is trapped under this impermeable layer, conductive cooling is enhanced and mixing with seawater is restricted, making the precipitation of amorphous silica more efficient. Since the first discovery and description of recent mineralized submarine</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14582511','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14582511"><span>A <span class="hlt">hydrothermal</span> <span class="hlt">system</span> associated with the Siljan impact structure, Sweden--implications for the search for fossil life on Mars.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hode, Tomas; von Dalwigk, Ilka; Broman, Curt</p> <p>2003-01-01</p> <p>The Siljan ring structure (368 +/- 1.1 Ma) is the largest known impact structure in Europe. It isa 65-km-wide, eroded, complex impact structure, displaying several structural units, including a central uplifted region surrounded by a ring-shaped depression. Associated with the impact crater are traces of a post-impact <span class="hlt">hydrothermal</span> <span class="hlt">system</span> indicated by precipitated and altered <span class="hlt">hydrothermal</span> mineral assemblages. Precipitated <span class="hlt">hydrothermal</span> minerals include quartz veins and breccia fillings associated with granitic rocks at the outer margin of the central uplift, and calcite, fluorite, galena, and sphalerite veins associated with Paleozoic carbonate rocks located outside the central uplift. Two-phase water/gas and oil/gas inclusions in calcite and fluorite display homogenization temperatures between 75 degrees C and 137 degrees C. With an estimated erosional unloading of approximately 1 km, the formation temperatures were probably not more than 10-15 degrees C higher. Fluid inclusion ice-melting temperatures indicate a very low salt content, reducing the probability that the mineralization was precipitated during the Caledonian Orogeny. Our findings suggest that large impacts induce low-temperature <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> that may be habitats for thermophilic organisms. Large impact structures on Mars may therefore be suitable targets in the search for fossil thermophilic organisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004cosp...35.1931Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004cosp...35.1931Y"><span>Bacterial community under the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> on the Suiyo Seamount: A model for archean and exo-biota</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamagishi, A.</p> <p></p> <p>Microbial community in <span class="hlt">hydrothermal</span> area at seafloor has been analyzed by culture-independent methods. <span class="hlt">Hydrothermal</span> fluid from natural vents and vent chimneys have been analyzed by PCR (1-2). Hyperthermophilic microbes have been isolated from these environments (3-4). Though the analysis of these samples can provide the window to penetrate the microbial community under the seafloor, more direct analysis is desired for better understanding of the sub-seafloor microbial community In the ``Archaean Park Project'' supported by Special Coordination Fund, several holes were drilled and the holes were supported by casing pipes in the crater of the Suiyo seamount on the Izu-Bonin arc, West Pacific Ocean (about 1,400 m depth) in 2001 and 2002. <span class="hlt">Hydrothermal</span> fluids were sampled from cased holes. The fluids were filtered to collect the microbial cells. The DNA was extracted and used to amplify 16S rDNA fragments by PCR (polymerase chain reaction) using a bacteria and an archaea specific primer sets. The PCR fragments were cloned and sequenced. FISH analysis revealed from 6 x103 to 2.5 x 106 bactrerial cells/ml in these <span class="hlt">hydrothermal</span> fluids. PCR clone-analysis showed significant variation in bacterial sequences found in these samples. The species-patterns suggest that the contamination of ambient seawater to <span class="hlt">hydrothermal</span> fluid samples is negligible. Difference in the dominant species depending on the location was found, suggesting that the bacterial community at sub-sea floor is not monotonous but has gradual shift from the <span class="hlt">hydrothermal</span> center to peripheral area. The results suggest that there is chemo-autotrophic microbe-dependent biota under the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. References 1) Takai et al. Genetics 152: 1285-1297 (1999) 2) Takai et al. Appl. Environ. Microbioi. 67: 3618-3629 (2001) 3) Summit et al. Proc. Natl. Acad. Sci. 98: 2158-2163 (2001) 4) Amend, J. P. and Shodk, E. L. FEMS Microbiol. Rev. 25: 175-243 (2002)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JVGR..357...39M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JVGR..357...39M"><span>Mass transfer processes in a post eruption <span class="hlt">hydrothermal</span> <span class="hlt">system</span>: Parameterisation of microgravity changes at Te Maari craters, New Zealand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, Craig A.; Currenti, Gilda; Hamling, Ian; Williams-Jones, Glyn</p> <p>2018-05-01</p> <p>Fluid transfer and ground deformation at <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> occur both as a precursor to, or as a result of, an eruption. Typically studies focus on pre-eruption changes to understand the likelihood of unrest leading to eruption; however, monitoring post-eruption changes is important for tracking the return of the <span class="hlt">system</span> towards background activity. Here we describe processes occurring in a <span class="hlt">hydrothermal</span> <span class="hlt">system</span> following the 2012 eruption of Upper Te Maari crater on Mt Tongariro, New Zealand, from observations of microgravity change and deformation. Our aim is to assess the post-eruption recovery of the <span class="hlt">system</span>, to provide a baseline for long-term monitoring. Residual microgravity anomalies of up to 92 ± 11 μGal per year are accompanied by up to 0.037 ± 0.01 m subsidence. We model microgravity changes using analytic solutions to determine the most likely geometry and source location. A multiobjective inversion tests whether the gravity change models are consistent with the observed deformation. We conclude that the source of subsidence is separate from the location of mass addition. From this unusual combination of observations, we develop a conceptual model of fluid transfer within a condensate layer, occurring in response to eruption-driven pressure changes. We find that depressurisation drives the evacuation of pore fluid, either exiting the <span class="hlt">system</span> completely as vapour through newly created vents and fumaroles, or migrating to shallower levels where it accumulates in empty pore space, resulting in positive gravity changes. Evacuated pores then collapse, causing subsidence. In addition we find that significant mass addition occurs from influx of meteoric fluids through the fractured <span class="hlt">hydrothermal</span> seal. Long-term combined microgravity and deformation monitoring will allow us to track the resealing and re-pressurisation of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and assess what hazard it presents to thousands of hikers who annually traverse the volcano, within 2 km of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170001953','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170001953"><span>Constraining the Origin of Basaltic Volcanic Rocks Observed by Opportunity Along the Rim of <span class="hlt">Endeavour</span> Crater</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bouchard, M. C.; Jolliff, B. L.; Farrand, W. H.; Mittlefehldt, D. W.</p> <p>2017-01-01</p> <p>The Mars Exploration Rover (MER) Opportunity continues its exploration along the rim of <span class="hlt">Endeavour</span> Crater. While the primary focus for investigation has been to seek evidence of aqueous alteration, Opportunity has observed a variety of rock types, including some that are hard and relatively unaltered. These rocks tend to occur most commonly as "float rocks" or "erratics" where the geologic setting does not clearly reveal their origin. Along the rim of <span class="hlt">Endeavour</span> crater (Fig. 1), such rocks, commonly noted in Panoramic Camera (Pancam) left eye composites as "blue rocks", are abundant components of some of the <span class="hlt">Endeavour</span> crater rim deposits, scree slopes, and colluvium deposits. In this abstract, we examine the similarity of several of these rocks analyzed using Opportunity's Alpha Particle X-Ray Spectrometer (APXS), images and color from the Pancam, and textures observed with the Microscopic Imager (MI. At issue is the blue rocks origin; are they impact melt or volcanic, what is their age relative to <span class="hlt">Endeavour</span> crater, and how they are related to each other?</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s127e011052.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s127e011052.html"><span>Payette uses computer in the aft FD on Space Shuttle <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2009-07-28</p> <p>S127-E-011052 (28 July 2009) --- Canadian Space Agency astronaut Julie Payette, STS-127 mission specialist, uses a computer on the flight deck of Space Shuttle <span class="hlt">Endeavour</span> during flight day 14 activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017161','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017161"><span>Mass transfer constraints on the chemical evolution of an active <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, Valles caldera, New Mexico</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>White, A.F.; Chuma, N.J.; Goff, F.</p> <p>1992-01-01</p> <p>Partial equilibrium conditions occur between fluids and secondary minerals in the Valles <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, contained principally in the Tertiary rhyolitic Bandelier Tuff. The mass transfer processes are governed by reactive phase compositions, surface areas, water-rock ratios, reaction rates, and fluid residence times. Experimental dissolution of the vitric phase of the tuff was congruent with respect to Cl in the solid and produced reaction rates which obeyed a general Arrhenius release rate between 250 and 300??C. The 18O differences between reacted and unreacted rock and fluids, and mass balances calculations involving Cl in the glass phase, produced comparable water-rock ratios of unity, confirming the importance of irreversible reaction of the vitric tuff. A fluid residence time of approximately 2 ?? 103 years, determined from fluid reservoir volume and discharge rates, is less than 0.2% of the total age of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and denotes a geochemically and isotopically open <span class="hlt">system</span>. Mass transfer calculations generally replicated observed reservoir pH, Pco2, and PO2 conditions, cation concentrations, and the secondary mineral assemblage between 250 and 300??C. The only extraneous component required to maintain observed calcite saturation and high Pco2 pressures was carbon presumably derived from underlying Paleozoic limestones. Phase rule constraints indicate that Cl was the only incompatible aqueous component not controlled by mineral equilibrium. Concentrations of Cl in the reservoir directly reflect mass transport rates as evidenced by correlations between anomalously high Cl concentrations in the fluids and tuff in the Valles caldera relative to other <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in rhyolitic rocks. ?? 1992.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012873','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012873"><span>Noachian Impact Breccias on the Rim of <span class="hlt">Endeavour</span> Crater, Mars: Opportunity APXS Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mittlefehldt, D. W.; Gellert, R.; Arvidson, R. E.; Bell, J. F., III; Farrand, W. H.; Herkenhoff, K. E.; Jolliff, B. L.; Ming, D. W.; Schroeder, C.; Sullivan, R. J.</p> <p>2014-01-01</p> <p>Mars Exploration Rover Opportunity has been investigating the geology of Meridiani Planum since January 2004, and is currently approx. 3830% into its primary mission. Opportunity reached the rim of 22 km diameter Endeavor crater at Spirit Point on the south end of Cape York on sol 2681 and began exploring the geology of <span class="hlt">Endeavour</span> rim. She left Cape York on sol 3316 and arrived at the next rim remnant to the south, Solander Point, on sol 3387 to begin geological investigations at the contact and up onto Murray Ridge. The Burns fm. of Meridiani Planum lies near the top of the plains-forming unit of western Sinus Meridiani and onlaps onto the <span class="hlt">Endeavour</span> rim rocks (hereafter rim rocks). <span class="hlt">Endeavour</span> crater would have excavated approx. 4 km into the existing stratigraphy. Thus, the ejecta that form the rim rocks offer windows into the deeper lithologies of Sinus Meridiani. Here we discuss the polymict breccias of the Shoemaker fm. on Cape York and the breccias from Murray Ridge, with a focus on compositions determined by the Alpha Particle X-Ray Spectrometer (APXS).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-jsc2012e216102.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-jsc2012e216102.html"><span><span class="hlt">Endeavour</span> sitting atop NASA's Shuttle Carrier Aircraft (SCA)</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2012-09-19</p> <p>Space Shuttle <span class="hlt">Endeavour</span> is ferried by NASA's Shuttle Carrier Aircraft (SCA) over the Johnson Space Center in Houston, Texas on September 19, 2012. NASA pilots Jeff Moultrie and Bill Rieke are at the controls of the Shuttle Carrier Aircraft. Photo taken by NASA photographer Sheri Locke in the backseat of a NASA T-38 chase plane with NASA pilot Thomas E. Parent at the controls. Photo Credit: NASA/ Sheri Locke</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts059-50-011.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts059-50-011.html"><span>STS-59 <span class="hlt">Endeavour</span>'s aft cargo bay in orbit</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1994-04-10</p> <p>STS059-50-011 (9-20 April 94) --- A greenish appearing aurora forms the backdrop for this 35mm scene of the Earth orbiting Space Shuttle <span class="hlt">Endeavour</span>'s aft cargo bay. Featured in the bay are the antennae for the SIR-C/X-SAR imaging radar instruments, illuminated by moonlight. The crew sighted the southern lights (aurora australis) several times during each of the eleven days of the mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.V11F..08G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.V11F..08G"><span>On the Interaction of a Vigorous <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> with an Active Magma Chamber: The Puna Magma Chamber, Kilauea East Rift, Hawaii</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gregory, R. T.; Marsh, B. D.; Teplow, W.; Fournelle, J.</p> <p>2009-12-01</p> <p>The extent of the interaction between <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> and active magma chambers has long been of fundamental interest to the development of ore deposits, cooling of magma chambers, and dehydration of the subducting lithosphere. As volatiles build up in the residual magma in the trailing edge of magmatic solidification fronts, is it possible that volatiles are transferred from the active magma to the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and vice versa? Does the external fracture front associated with vigorous <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> sometimes propagate into the solidification front, facilitating volatile exchange? Or is the magma always sealed at temperatures above some critical level related to rock strength and overpressure? The degree of <span class="hlt">hydrothermal</span> interaction in igneous <span class="hlt">systems</span> is generally gauged in post mortem studies of δ18O and δD, where it has been assumed that a fracture front develops about the magma collapsing inward with cooling. H.P. Taylor and D. Norton's (1979; J. Petrol.)seminal work inferred that rocks are sealed with approach to the solidus and there is little to no direct interaction with external volatiles in the active magma. In active lava lakes a fracture front develops in response to thermal contraction of the newly formed rock once the temperature drops to ~950°C (Peck and Kinoshita,1976;USGS PP935A); rainfall driven <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> flash to steam near the 100 °C isotherm in the solidified lake and have little effect on the cooling history (Peck et al., 1977; AJS). Lava lakes are fully degassed magmas and until the recent discovery of the Puna Magma Chamber (Teplow et al., 2008; AGU) no active magma was known at sufficiently great pressure to contain original volatiles. During the course of routine drilling of an injection well at the Puna Geothermal Venture (PGV) well-field, Big Island, Hawaii, a 75-meter interval of diorite containing brown glass inclusions was penetrated at a depth of 2415 m, continued drilling to 2488 m encountered a melt</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B13B0476L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B13B0476L"><span>Microbial heterotrophy coupled to Fe-S-As cycling in a shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, G.; Amend, J.</p> <p>2013-12-01</p> <p>To date, there are only a few known heterotrophic arsenite oxidizers and arsenate reducers. They utilize organic compounds as their carbon source and/or as important electron donors in the transfer arsenic in high temperature environments. Arsenic in <span class="hlt">hydrothermal</span> vent <span class="hlt">systems</span> can be immobilized at low temperatures through (ad)sorption on iron oxide and other iron-bearing minerals. Interactions with sulfur species can also affect the redox state of arsenic species. A better understanding of microbially-catalyzed reactions involving carbon, arsenic, iron and sulfur would provide constraints on the mobility of arsenic in a wide variety of natural and engineered <span class="hlt">systems</span>. The aim of this study is to establish links between microbial distribution and in situ Fe-S-As cycling processes in a shallow-sea <span class="hlt">hydrothermal</span> vent <span class="hlt">system</span>. We investigated three shallow-sea <span class="hlt">hydrothermal</span> vents, Champagne Hot Spring (CHS), Soufriere Spring (SOU) and Portsmouth Spring (PM), located off the western coast of Dominica, Lesser Antilles. CHS and SOU are characterized by moderate temperatures (46oC and 55oC, respectively), and PM is substantially hotter (~90-111 oC). Two sediment cores (one close to and one far from the thermal source) were collected from CHS and from SOU. Porewaters in both background cores had low concentrations of arsenic (mostly As3+, to a lesser extent As5+, DMA, MMA) and ferrous iron. The arsenic concentrations (predominantly As3+) in the CHS high temperature core were 30-90 nM, tracking with dissolved iron. Similar to CHS, the arsenic concentration in the SOU high temperature core was dominated by As3+ and controlled by ferrous iron. However, the arsenic concentration at SOU is comparatively higher, up to 1.9 mM. At the hotter and deeper PM site, highly elevated arsenic levels (1-2.5 mM) were measured, values that are among the highest arsenic concentrations ever reported in a marine <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Several autotrophic and heterotrophic media at two pHs (5.5 and 8</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS31C1418K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS31C1418K"><span>Water column imaging on <span class="hlt">hydrothermal</span> vent in Central Indian Ridge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koh, J.; Park, Y.</p> <p>2017-12-01</p> <p>Water column imaging with Multibeam echosounder <span class="hlt">systems</span> (MBES) is recently becoming of increasing interest for oceanographic studies. Especially gas bubbles and hot water exposed from <span class="hlt">hydrothermal</span> vents make acoustic impedance anomalies in cold seawater, water column imaging is very useful for the researchers who want to detect some kinds of <span class="hlt">hydrothermal</span> activity. We conducted a <span class="hlt">hydrothermal</span> exploration program, called "INVENT17", using the MBES <span class="hlt">system</span>, KONGBERG EM122 (12kHz, 1°×1°), mounted on R/V ISABU and we deployed other equipments including video guided hydraulic grab, tow-yo CTD and general CTD with MAPR (Miniature Autonomous Plume Recorder) in 2017. First, to evaluate its capabilities of detection of <span class="hlt">hydrothermal</span> vent, the surveys using the MBES were conducted at the Solitaire Field, previously identified <span class="hlt">hydrothermal</span> area of the Central Indian Ridge. The bathymetric data obtained from MBES provided information about detailed morphology of seafloor, but we were not able to achieve the information from the water column imaging data. But the clue of existence of active <span class="hlt">hydrothermal</span> vent was detected through the values of ΔNTU, dEh/dt, and OPR gained from MAPR, the data means that the <span class="hlt">hydrothermal</span> activity affects 100m from the seafloor. It could be the reason that we can't find the <span class="hlt">hydrothermal</span> activity because the range resolution of water column imaging is pretty rough so that the size of 100m-scaled activity has low possibility to distinguish from seafloor. The other reason is there are no sufficient objects to cause strong scattering like as CO2 bubbles or droplets unlike in the mid-Okinawa Trough. And this suggests that can be a important standard to identify properties of <span class="hlt">hydrothermal</span> vent sites depending on the presence of scattering objects in water mass. To justify this, we should perform more chemical analysis of hot water emanating from <span class="hlt">hydrothermal</span> vent and collected several bottles of water sample to do that.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910728C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910728C"><span>Radon surveys and monitoring at active volcanoes: an open window on deep <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> and their dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cigolini, Corrado; Laiolo, Marco; Coppola, Diego</p> <p>2017-04-01</p> <p>The behavior of fluids in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> is critical in volcano monitoring and geothermal prospecting. Analyzing the time series of radon emissions on active volcanoes is strategic for detecting and interpreting precursory signals of changes in volcanic activity, eventually leading to eruptions. Radon is a radioactive gas generated from the decay of U bearing rocks, soils and magmas. Although radon has been regarded as a potential precursor of earthquakes, radon anomalies appear to be better suited to forecast volcanic eruptions since we know where paroxysms may occur and we can follow the evolution of volcanic activity. Radon mapping at active volcanoes is also a reliable tool to assess diffuse and concentrated degassing as well as efficiently detecting earthquake-volcano interactions. Systematic radon monitoring has been shown to be a key factor for evaluating the rise of volcanic and <span class="hlt">hydrothermal</span> fluids. In fact, the decay properties of radon, the duration of radon anomalies together with sampling rates may be cross-checked with the chemistry of <span class="hlt">hydrothermal</span> fluids (and their transport properties) to constrain fluids ascent rates and to infer the permeability and porosity of rocks in sectors surrounding the active conduits. We hereby further discuss the data of radon surveys and monitoring at Somma-Vesuvius, Stromboli and La Soufrière (Guadeloupe, Lesser Antilles). The integrated analysis of seismic and geochemical data, including radon emissions, may be successfully used in testing temperature distributions and variations of porosity and permeability in volcanic <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> and can be used as a proxy to analyze geothermal reservoirs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-1776&hterms=1776&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D1776','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-1776&hterms=1776&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D1776"><span>STS-97 <span class="hlt">Endeavour</span> after RSS rollback</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>After rollback of the Rotating Service Structure (at left), Space Shuttle <span class="hlt">Endeavour</span> stands ready for launch targeted for 10:06 p.m. EST tonight on mission STS-97 to the International Space Station. The orbiter carries the P6 Integrated Truss Segment containing solar arrays that will be temporarily installed to the Unity connecting module by the Z1 truss, recently delivered to and installed on the Station on mission STS-92. The two solar arrays are each more than 100 feet long. They will capture energy from the sun and convert it to power for the Station. Two spacewalks will be required to install the solar array connections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28131971','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28131971"><span>Relationship between enhanced dewaterability and structural properties of <span class="hlt">hydrothermal</span> sludge after <span class="hlt">hydrothermal</span> treatment of excess sludge.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Liping; Li, Aimin; Chang, Yuzhi</p> <p>2017-04-01</p> <p><span class="hlt">Hydrothermal</span> treatment is an effective method to enhance the deep dewaterability of excess sludge with low energy consumption. In this study, an insight into the relationship between enhanced dewaterability and structural properties of the produced <span class="hlt">hydrothermal</span> sludge was presented, aiming at better understanding the effect of <span class="hlt">hydrothermal</span> process on excess sludge dewatering performance. The results indicated that <span class="hlt">hydrothermal</span> effect induced the transformation of surface water to interstitial and free water by lowering the binding strength between adjacent water and solid particles and that free water became the main form for moisture existence in <span class="hlt">hydrothermal</span> sludge as temperature was higher than 180 °C. Increase in temperature of <span class="hlt">hydrothermal</span> treatment generated a significant size reduction of sludge flocs but treated sludge with a higher rigidity, which not only strengthened the network of <span class="hlt">hydrothermal</span> sludge but also destroyed the binding of EPS with water. <span class="hlt">Hydrothermal</span> process caused crevice and pore structures of excess sludge to disappear gradually, which was a main driving force of water removal as temperature was below 150 °C. With the temperature of <span class="hlt">hydrothermal</span> treatment exceeding 180 °C, the morphology of <span class="hlt">hydrothermal</span> sludge became rough which linked closely to the solid precipitation of condensation polymerization, and further became smooth at higher temperature (210 °C) due to the coal-like structures with higher aromaticities, indicating that <span class="hlt">hydrothermal</span> reaction pathways began to play a main role in enhanced dewaterability. <span class="hlt">Hydrothermal</span> treatment led to more alkyl and aromatic carbon, but lower O-alkyl, carboxyl and carbonyl carbon. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Icar..226..487S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Icar..226..487S"><span>Alteration minerals in impact-generated <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> - Exploring host rock variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwenzer, Susanne P.; Kring, David A.</p> <p>2013-09-01</p> <p>Impact-generated <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have been previously linked to the alteration of Mars’ crust and the production of secondary mineral assemblages seen from orbit. The sensitivity of the resultant assemblages has not yet been evaluated as a function of precursor primary rock compositions. In this work, we use thermochemical modeling to explore the variety of minerals that could be produced by altering several known lithologies based on martian meteorite compositions. For a basaltic host rock lithology (Dhofar 378, Humphrey) the main alteration phases are feldspar, zeolite, pyroxene, chlorite, clay (nontronite, kaolinite), and hematite; for a lherzolithic host rock lithology (LEW 88516) the main alteration phases are amphibole, serpentine, chlorite, clay (nontronite, kaolinite), and hematite; and for an ultramafic host rock lithology (Chassigny) the main minerals are secondary olivine, serpentine, magnetite, quartz, and hematite. These assemblages and proportions of phases in each of those cases depend on W/R and temperature. Integrating geologic, hydrologic and alteration mineral evidence, we have developed a model to illustrate the distribution of alteration assemblages that occur in different levels of an impact structure. At the surface, hot, hydrous alteration affects the ejecta and melt sheet producing clay and chlorite. Deeper in the subsurface and depending on the permeability of the rock, a variety of minerals - smectite, chlorite, serpentine, amphiboles and hematite - are produced in a circulating <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. These modeled mineral distributions should assist with interpretation of orbital observations and help guide surface exploration by rovers and sample return assets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/894722','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/894722"><span>Monroe, Utah, <span class="hlt">Hydrothermal</span> <span class="hlt">System</span>: Results from Drilling of Test Wells MC1 and MC2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chapman, D.S.; Harrison, Roger</p> <p>1978-10-01</p> <p>Following detailed geological (Parry et al., 1976; Miller, 1976) and geophysical (Mase, Chapman, and Ward, 1978; Kilty, Mase, and Chapman, 1978) studies of the Monroe, Utah <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, a program of drilling two intermediate depth test wells was undertaken. The objectives of the test well drilling were three-fold: (1) to obtain structural information bearing on the poorly known dip of the Sevier Fault, (2) to obtain temperature information below the shallow depths (approximately 300 ft.) sampled in the first phase of exploration, and (3) to provide cased wells which could act as monitor wells during the production phase of themore » project. The test well drilling was seen to be vital to the selection of a site for a production well. This report describes the results from the drilling of the two test wells, designated MC1 and MC2, and offers interpretation of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> which may be used as a basis for selecting production wells.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100039623&hterms=importance+oxygen&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dimportance%2Boxygen','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100039623&hterms=importance+oxygen&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dimportance%2Boxygen"><span>Evaluating the Historical Importance of Impact Induced <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span> on Mars Using the Stable Isotopic Composition of Martian Water</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Niles, Paul B.</p> <p>2010-01-01</p> <p>The importance of impact events during the early history of Mars is obvious through a simple examination of the character of the martian surface. This ancient, heavily cratered terrain has been shown to be associated with extensive phyllosilicate deposits. This geologic link could suggest that the extensive phyllosilicate-forming alteration may have occurred during early martian history through impact-induced <span class="hlt">hydrothermal</span> alteration. However, examination of the oxygen isotopic composition of water on Mars suggests that the extensive phyllosilicate deposits were formed primarily through low temperature (<30 C) interactions, and that high temperature weathering in impact-induced <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have not been a dominant process on Mars. The average oxygen isotopic composition of water on Earth is dictated by the nature of water-rock interactions. If these interactions occur at higher temperatures then the water will contain a higher proportion of 18O, while lower temperature interactions will result in water with a lower proportion of 18O. Water on Earth today contains a higher proportion of 18O because of plate tectonics and <span class="hlt">hydrothermal</span> interaction at mid-ocean ridges. The oxygen isotopic composition of water on early earth, however, may have been quite different, containing a smaller proportion of 18O suggesting much less <span class="hlt">hydrothermal</span> interaction. Because there are not yet any direct measurements of the oxygen isotopic composition of water on Mars, it needs to be inferred through examination of carbonates preserved in martian meteorites and the isotopic composition of atmospheric CO2. This can be done because the oxygen incorporated into carbonates and CO2 is easily exchanged with liquid water if it is present. Independently, both measurements provide an estimate for the (Sigma)18O of water on Mars to be near -16%. This composition is consistent with low temperature weathering of the silicate crust, and indicates that impact <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> did not play</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000086191&hterms=permeability+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dpermeability%2Bdistribution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000086191&hterms=permeability+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dpermeability%2Bdistribution"><span>Magmatic Intrusions and a <span class="hlt">Hydrothermal</span> Origin for Fluvial Valleys on Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gulick, Virginia C</p> <p>1998-01-01</p> <p>Numerical models of Martian <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> demonstrate that <span class="hlt">systems</span> associated with magmatic intrusions greater than several hundred cubic kilometers can provide sufficient groundwater outflow to form the observed fluvial valleys, if subsurface permeability exceeds about 1.0 darcy. Groundwater outflow increases with increasing intrusion volume and subsurface permeability and is relatively insensitive to intrusion depth and subsurface porosity within the range considered here. <span class="hlt">Hydrothermally</span>-derived fluids can melt through 1 to 2 km thick ice-rich permafrost layers in several thousand years. <span class="hlt">Hydrothermal</span> <span class="hlt">systems</span> thus provide a viable alternative to rainfall for providing surface water for valley formation. This mechanism can form fluvial valleys not only during the postulated early warm, wet climatic epoch, but also during more recent epochs when atmospheric conditions did not favor atmospheric cycling of water. The clustered distribution of the valley networks on a given geologic surface or terrain unit of Mars may also be more compatible with localized, <span class="hlt">hydrothermally</span>-driven groundwater outflow than regional rainfall. <span class="hlt">Hydrothermal</span> centers on Mars may have provided appropriate environments for the initiation of life or final oases for the long-term persistence of life.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1281062','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1281062"><span><span class="hlt">System</span> and process for efficient separation of biocrudes and water in a <span class="hlt">hydrothermal</span> liquefaction <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Elliott, Douglas C.; Hart, Todd R.; Neuenschwander, Gary G.; Oyler, James R.; Rotness, Jr, Leslie J.; Schmidt, Andrew J.; Zacher, Alan H.</p> <p>2016-08-02</p> <p>A <span class="hlt">system</span> and process are described for clean separation of biocrudes and water by-products from <span class="hlt">hydrothermal</span> liquefaction (HTL) product mixtures of organic and biomass-containing feedstocks at elevated temperatures and pressures. Inorganic compound solids are removed prior to separation of biocrude and water by-product fractions to minimize formation of emulsions that impede separation. Separation may be performed at higher temperatures that reduce heat loss and need to cool product mixtures to ambient. The present invention thus achieves separation efficiencies not achieved in conventional HTL processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-S91-36095.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-S91-36095.html"><span>Air to air views of <span class="hlt">Endeavour</span>, Orbiter Vehicle (OV) 105</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1959-01-01</p> <p>Air to air views of <span class="hlt">Endeavour</span>, Orbiter Vehicle (OV) 105, transported via the Shuttle Carrier Aircraft (SCA), NASA 911, on its way to KSC, 05-06-91. JSC with Clear Creek and Egret Bay Blvd in the foreground and Clear Lake and Galveston Bay in the background</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s123e006495.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s123e006495.html"><span>Behnken open food package in the MDDK on Space Shuttle <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2008-03-12</p> <p>S123-E-006495 (12 March 2008) --- Astronaut Robert L. Behnken, STS-123 mission specialist, opens a food package near the galley on the middeck of Space Shuttle <span class="hlt">Endeavour</span> while docked with the International Space Station.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0162&hterms=technician&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnician','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0162&hterms=technician&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnician"><span>STS-99 Technicians work in <span class="hlt">Endeavour</span>'s aft compartment of the payload bay</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>Technicians work in the aft compartment of Shuttle <span class="hlt">Endeavour</span>'s payload bay, where a new Enhanced Main Events Controller (E-MEC) will be installed. The original E-MEC in <span class="hlt">Endeavour</span> became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently <span class="hlt">Endeavour</span> and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants had to be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s88e5163.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s88e5163.html"><span>Newman, Krikalev and Ross on <span class="hlt">Endeavour</span>'s middeck</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1998-12-08</p> <p>S88-E-5163 (12-08-98) --- Left to right, James H. Newman, Jerry L. Ross and Sergei K. Krikalev--all mission specialists--on <span class="hlt">Endeavour</span>'s middeck. Ross and Newman eventually participated in three space walks as part of the STS-88 work involved in readying the Unity and Zarya modules for their ISS roles. Krikalev, representing the Russian Space Agency, has been named as a member of the first ISS flight crew. This photo was taken with an electronic still camera (ESC) at 23:14:01 GMT, Dec. 8.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-STS100-303-004.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-STS100-303-004.html"><span>Commander Rominger at the commander's workstation in <span class="hlt">Endeavour</span> during STS-100</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2001-04-21</p> <p>STS100-303-004 (19 April-1 May 2001) --- Astronaut Kent V. Rominger, STS-100 commander, looks over a procedures checklist at the commander's station on the forward flight deck of the Earth-orbiting Space Shuttle <span class="hlt">Endeavour</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA17583.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA17583.html"><span>Murray Ridge on Rim of <span class="hlt">Endeavour</span> Crater on Mars, False Color</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2013-11-13</p> <p>This scene shows the Murray Ridge portion of the western rim of <span class="hlt">Endeavour</span> Crater on Mars, as seen by NASA Opportunity rover. It is presented in false color to make some differences between materials easier to see.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18163870','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18163870"><span>Temporal changes in fluid chemistry and energy profiles in the vulcano island <span class="hlt">hydrothermal</span> <span class="hlt">system</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rogers, Karyn L; Amend, Jan P; Gurrieri, Sergio</p> <p>2007-12-01</p> <p>In June 2003, the geochemical composition of geothermal fluids was determined at 9 sites in the Vulcano <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, including sediment seeps, geothermal wells, and submarine vents. Compositional data were combined with standard state reaction properties to determine the overall Gibbs free energy (DeltaG(r) ) for 120 potential lithotrophic and heterotrophic reactions. Lithotrophic reactions in the H-O-N-S-C-Fe <span class="hlt">system</span> were considered, and exergonic reactions yielded up to 120 kJ per mole of electrons transferred. The potential for heterotrophy was characterized by energy yields from the complete oxidation of 6 carboxylic acids- formic, acetic, propanoic, lactic, pyruvic, and succinic-with the following redox pairs: O(2)/H(2)O, SO(4) (2)/H(2)S, NO(3) ()/NH(4) (+), S(0)/H(2)S, and Fe(3)O(4)/Fe(2+). Heterotrophic reactions yielded 6-111 kJ/mol e(). Energy yields from both lithotrophic and heterotrophic reactions were highly dependent on the terminal electron acceptor (TEA); reactions with O(2) yielded the most energy, followed by those with NO(3) (), Fe(III), SO(4) (2), and S(0). When only reactions with complete TEA reduction were included, the exergonic lithotrophic reactions followed a similar electron tower. Spatial variability in DeltaG(r) was significant for iron redox reactions, owing largely to the wide range in Fe(2+) and H(+) concentrations. Energy yields were compared to those obtained for samples collected in June 2001. The temporal variations in geochemical composition and energy yields observed in the Vulcano <span class="hlt">hydrothermal</span> <span class="hlt">system</span> between 2001 and 2003 were moderate. The largest differences in DeltaG(r) over the 2 years were from iron redox reactions, due to temporal changes in the Fe(2+) and H(+) concentrations. The observed variations in fluid composition across the Vulcano <span class="hlt">hydrothermal</span> <span class="hlt">system</span> have the potential to influence not only microbial diversity but also the metabolic strategies of the resident microbial communities.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JVGR..280..111M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JVGR..280..111M"><span>Geophysical and geochemical methods applied to investigate fissure-related <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> on the summit area of Mt. Etna volcano (Italy)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maucourant, Samuel; Giammanco, Salvatore; Greco, Filippo; Dorizon, Sophie; Del Negro, Ciro</p> <p>2014-06-01</p> <p>A multidisciplinary approach integrating self-potential, soil temperature, heat flux, CO2 efflux and gravity gradiometry signals was used to investigate a relatively small fissure-related <span class="hlt">hydrothermal</span> <span class="hlt">system</span> near the summit of Mt. Etna volcano (Italy). Measurements were performed through two different surveys carried out at the beginning and at the end of July 2009, right after the end of the long-lived 2008-2009 flank eruption and in coincidence with an increase in diffuse flank degassing related to a reactivation of the volcano, leading to the opening of a new summit vent (NSEC). The main goal was to use a multidisciplinary approach to the detection of hidden fractures in an area of evident near-surface <span class="hlt">hydrothermal</span> activity. Despite the different methodologies used and the different geometry of the sampling grid between the surveys, all parameters concurred in confirming that the study area is crossed by faults related with the main fracture <span class="hlt">systems</span> of the south flank of the volcano, where a continuous <span class="hlt">hydrothermal</span> circulation is established. Results also highlighted that <span class="hlt">hydrothermal</span> activity in this area changed both in space and in time. These changes were a clear response to variations in the magmatic <span class="hlt">system</span>, notably to migration of magma at various depth within the main feeder <span class="hlt">system</span> of the volcano. The results suggest that this specific area, initially chosen as the optimal test-site for the proposed approach, can be useful in order to get information on the potential reactivation of the summit craters of Mt. Etna.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PD-5114&hterms=brackets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbrackets','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PD-5114&hterms=brackets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbrackets"><span>A loose bolt delays loading of <span class="hlt">Endeavour</span>'s external tank</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>This loose bracket, observed hanging down from the side of the White Room at Launch Pad 39B, delayed loading of <span class="hlt">Endeavour</span>'s external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.P33A1917S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.P33A1917S"><span>Experimental constraints on <span class="hlt">hydrothermal</span> activities in Enceladus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sekine, Y.; Shibuya, T.; Suzuki, K.; Kuwatani, T.</p> <p>2012-12-01</p> <p>One of the most remarkable findings by the Cassini-Huygens mission is perhaps water-rich plumes erupting from the south-pole region of Enceladus [1]. Given such geological activity and the detection of sodium salts in the plume, the interior of Enceladus is highly likely to contain an interior ocean interacting with the rock core [2]. A primary question regarding astrobiology and planetary science is whether Enceladus has (or had) <span class="hlt">hydrothermal</span> activities in the interior ocean. Because N2 might be formed by thermal dissociation of primordial NH3 [3], the presence of N2 in the plume may be a possible indicator for the presence of <span class="hlt">hydrothermal</span> activities in Enceladus. However, the Cassini UVIS revealed that the plumes do not contain large amounts of N2 [4]. Although these observations may not support the presence of <span class="hlt">hydrothermal</span> activities, whether NH3 dissociation proceeds strongly depends on the kinetics of <span class="hlt">hydrothermal</span> reactions and interactions with the rock components, which remain largely unknown. Furthermore, the Cassini CDA recently showed that small amounts of SiO2 might have been included in the plume dusts [5]. Formation of amorphous SiO2 usually occurs when high-temperature and/or high-pH solution with high concentrations of dissolved SiO2 cools and/or is neutralized. Thus, the presence of SiO2 in the plume dusts may suggest the presence of a temperature and/or pH gradient in the ocean. However, no laboratory experiments have investigated what processes control pH and SiO2 concentrations in <span class="hlt">hydrothermal</span> fluids possibly existing in Enceladus. Here, we show the results of laboratory experiments simulating <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> on Enceladus. As the initial conditions, we used both aqueous solution of high concentrations (0.01-2%) of NH3 and NaHCO3 and powdered olivine as an analog for the rock components. Our experimental results show that formation of N2 from NH3 is kinetically and thermodynamically inhibited even under high temperature conditions (< 400</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002976','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002976"><span>Iron-Manganese Redox Reactions in <span class="hlt">Endeavour</span> Crater Rim Apron Rocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ming, D. W.; Mittlefehldt, D. W.; Gellert, R.; Peretyazhko, T.; Clark, B. C.; Morris, R. V.; Yen, A. S.; Arvidson, R. E.; Crumpler, L. S.; Farrand, W. H.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20150002976'); toggleEditAbsImage('author_20150002976_show'); toggleEditAbsImage('author_20150002976_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20150002976_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20150002976_hide"></p> <p>2015-01-01</p> <p>The Mars Exploration Rover Opportunity has been exploring Noachian age rocks and outcrops on the rim of the 22 km diameter <span class="hlt">Endeavour</span> crater since August 2011. The Cape York area is a low-lying rim of <span class="hlt">Endeavour</span> that contains 3 distinct lithologies: 1) the stratigraphically lowest Matijevic fm of pre-impact lithology, 2) Shoemaker fm of impact breccias, and 3) the stratigraphically highest rim lithology Grasberg fm of post-impact sediments that drape the lower slopes of the rim. The sulfate-rich sediment of the Burns fm lies unconformably over the Grasberg fm. Ca-sulfate veins were discovered in Grasberg fm sediments; the sulfates precipitated from aqueous fluids flowing upward through these materials. Opportunity investigated the chemistry and morphology of outcrops in the Matijevic fm that have Fe(sup 3+)-rich smectite detected by orbital signatures returned by CRISM on MRO. Matijevic fm also contains "boxwork" fractures with chemistry consistent with an Al-rich smectite and veins that appear to be rich in Ca-sulfate. More recently on Cape Tribulation, Opportunity has characterized two S-, Mg- and Mn-rich rich rocks overturned and fractured by the rover's wheels on Cook Haven. Those rocks have been dubbed "Pinnacle Island" and "Stuart Island" and will be referred to as the "Island" rocks. The objectives of this study are to characterize the Fe and Mn contents in the Cape York materials, including the two Island rocks, and to provide a model for Mn mobilization and precipitation. Detailed geochemistry of <span class="hlt">Endeavour</span> rim rocks is presented in a companion paper. Geochemical trends and elemental associations were obtained from data returned by the Alpha Particle X-ray Spectrometer (APXS) on Opportunity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA491636','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA491636"><span><span class="hlt">Hydrothermal</span> Processing of Base Camp Solid Wastes To Allow Onsite Recycling</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2008-09-01</p> <p>ER D C/ CE R L TR -0 8 -1 3 <span class="hlt">Hydrothermal</span> Processing of Base Camp Solid Wastes To Allow Onsite Recycling Gary L. Gerdes, Deborah...release; distribution is unlimited. ERDC/CERL TR-08-13 September 2008 <span class="hlt">Hydrothermal</span> Processing of Base Camp Solid Wastes To Allow Onsite Recycling...a technology to process domestic solid waste using a unique <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. The process was successfully demonstrated at Forts Benning and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031333','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031333"><span>A simulation of the <span class="hlt">hydrothermal</span> response to the Chesapeake Bay bolide impact</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sanford, W.E.</p> <p>2005-01-01</p> <p>Groundwater more saline than seawater has been discovered in the tsunami breccia of the Chesapeake Bay impact Crater. One hypothesis for the origin of this brine is that it may be a liquid residual following steam separation in a <span class="hlt">hydrothermal</span> <span class="hlt">system</span> that evolved following the impact. Initial scoping calculations have demonstrated that it is feasible such a residual brine could have remained in the crater for the 35 million years since impact. Numerical simulations have been conducted using the code <span class="hlt">HYDROTHERM</span> to test whether or not conditions were suitable in the millennia following the impact for the development of a steam phase in the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Hydraulic and thermal parameters were estimated for the bedrock underlying the crater and the tsunami breccia that fills the crater. Simulations at three different breccia permeabilities suggest that the type of <span class="hlt">hydrothermal</span> <span class="hlt">system</span> that might have developed would have been very sensitive to the permeability. A relatively low breccia permeability (1 ?? 10-16 m2) results in a <span class="hlt">system</span> partitioned into a shallow water phase and a deeper superheated steam phase. A moderate breccia permeability (1 ?? 10-15 m2 ) results in a <span class="hlt">system</span> with regionally extensive multiphase conditions. A relatively high breccia permeability (1 ?? 10-14 m2 ) results in a <span class="hlt">system</span> dominated by warm-water convection cells. The permeability of the crater breccia could have had any of these values at given depths and times during the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> evolution as the sediments compacted. The simulations were not able to take into account transient permeability conditions, or equations of state that account for the salt content of seawater. Results suggest, however, that it is likely that steam conditions existed at some time in the <span class="hlt">system</span> following impact, providing additional evidence that is consistent with a <span class="hlt">hydrothermal</span> origin for the crater brine. ?? Blackwell Publishing Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS52A..05B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS52A..05B"><span>Event Detection for <span class="hlt">Hydrothermal</span> Plumes: A case study at Grotto Vent</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bemis, K. G.; Ozer, S.; Xu, G.; Rona, P. A.; Silver, D.</p> <p>2012-12-01</p> <p>Evidence is mounting that geologic events such as volcanic eruptions (and intrusions) and earthquakes (near and far) influence the flow rates and temperatures of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Connecting such suppositions to observations of <span class="hlt">hydrothermal</span> output is challenging, but new ongoing time series have the potential to capture such events. This study explores using activity detection, a technique modified from computer vision, to identify pre-defined events within an extended time series recorded by COVIS (Cabled Observatory Vent Imaging Sonar) and applies it to a time series, with gaps, from Sept 2010 to the present; available measurements include plume orientation, plume rise rate, and diffuse flow area at the NEPTUNE Canada Observatory at Grotto Vent, Main <span class="hlt">Endeavour</span> Field, Juan de Fuca Ridge. Activity detection is the process of finding a pattern (activity) in a data set containing many different types of patterns. Among many approaches proposed to model and detect activities, we have chosen a graph-based technique, Petri Nets, as they do not require training data to model the activity. They use the domain expert's knowledge to build the activity as a combination of feature states and their transitions (actions). Starting from a conceptual model of how <span class="hlt">hydrothermal</span> plumes respond to daily tides, we have developed a Petri Net based detection algorithm that identifies deviations from the specified response. Initially we assumed that the orientation of the plume would change smoothly and symmetrically in a consistent daily pattern. However, results indicate that the rate of directional changes varies. The present Petri Net detects unusually large and rapid changes in direction or amount of bending; however inspection of Figure 1 suggests that many of the events detected may be artifacts resulting from gaps in the data or from the large temporal spacing. Still, considerable complexity overlies the "normal" tidal response pattern (the data has a dominant frequency of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020059546','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020059546"><span>Thiols in <span class="hlt">Hydrothermal</span> Solution: Standard Partial Molal Properties and Their Role in the Organic Geochemistry of <span class="hlt">Hydrothermal</span> Environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schulte, Mitchell D.; Rogers, Karyn L.; DeVincenzi, D. (Technical Monitor)</p> <p>2001-01-01</p> <p>Modern seafloor <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are locations where great varieties of geochemistry occur due to the enormous disequilibrium between vent fluids and seawater. The disequilibrium geochemistry has been hypothesized to include reactions to synthesize organic compounds. Despite the incomplete understanding of the carbon budget in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, the organic geochemistry of these sites has received little attention. Experimental simulations of these environments, however, indicate that organic compounds may have difficulty forming in a purely aqueous environment. On the other hand, thiols, thioesters and disulfides have been implicated as reaction intermediates between CO or CO2 in experiments of carbon reduction in <span class="hlt">hydrothermal</span> environments, as well as in a variety of biological processes and other abiotic reactions. The reduction of CO2 to thesis, for example, is observed using the FeS-H2S/FeS2 couple to provide the reducing power. We have used recent advances in theoretical geochemistry to estimate the standard partial moral thermodynamic properties and parameters for the revised Helgeson-Kirkham-Flowers equation of state for aqueous straight-chain alkyl thesis. With these data and parameters we have evaluated the role that organic sulfur compounds may play as reaction intermediates during organic compound synthesis. We conclude that organic sulfur compounds may hold the key to the organic chemistry leading to the origin of life in <span class="hlt">hydrothermal</span> settings. These results may also explain the presence of sulfur in a number of biomolecules present in ancient thermophilic microorganisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1861c0033B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1861c0033B"><span><span class="hlt">Hydrothermal</span> <span class="hlt">system</span> of the Papandayan Volcano from temperature, self-potential (SP) and geochemical measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Byrdina, Svetlana; Revil, André; Gunawan, Hendra; Saing, Ugan B.; Grandis, Hendra</p> <p>2017-07-01</p> <p>Papandayan volcano in West Java, Indonesia, is characterized by intense <span class="hlt">hydrothermal</span> activities manifested by numerous fumaroles at three craters or kawah, i.e. Mas, Manuk and Baru. The latter was created after November 2002 phreatic eruption. Since 2011, numerous volcano-tectonic B events are encountered and the volcano was set on alert status on several occasions. The purpose of the present study is to delineate the structure of the summital <span class="hlt">hydrothermal</span> <span class="hlt">system</span> from Self-Potential (SP), soil temperature and gas concentrations in the soil (CO2, SO2 and H2S) data. This combination of geophysical and geochemical methods allows identification of the weak permeable zones serving as preferential pathways for <span class="hlt">hydrothermal</span> circulation and potential candidates to future landslides or flank collapses. This study is an on-going collaborative research project and we plan to conduct electrical resistivity tomography (ERT) and also Induced-Polarization (IP) surveys. Additional data would allow the 3D imaging of the studied area. The IP parameters will be used to characterise and to quantify the degree of alteration of the volcanic rocks as has been shown very recently in the laboratory studies. There are also rocks and soil samples that will undergo laboratory analyses at ISTerre for IP and complex resistivity parameters at the sample scale that will help to interpret the survey results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OLEB...45..377K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OLEB...45..377K"><span>Energetics of Amino Acid Synthesis in Alkaline <span class="hlt">Hydrothermal</span> Environments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kitadai, Norio</p> <p>2015-12-01</p> <p>Alkaline <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline <span class="hlt">hydrothermal</span> <span class="hlt">system</span> on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich <span class="hlt">hydrothermal</span> fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such <span class="hlt">systems</span>. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline <span class="hlt">hydrothermal</span> settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline <span class="hlt">hydrothermal</span> fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25796392','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25796392"><span>Energetics of Amino Acid Synthesis in Alkaline <span class="hlt">Hydrothermal</span> Environments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kitadai, Norio</p> <p>2015-12-01</p> <p>Alkaline <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline <span class="hlt">hydrothermal</span> <span class="hlt">system</span> on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich <span class="hlt">hydrothermal</span> fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such <span class="hlt">systems</span>. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline <span class="hlt">hydrothermal</span> settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline <span class="hlt">hydrothermal</span> fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PD-5115&hterms=brackets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbrackets','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PD-5115&hterms=brackets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbrackets"><span>A loose bolt delays loading of <span class="hlt">Endeavour</span>'s external tank</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>A closeup reveals the loose bracket, observed hanging down from the side of the White Room at Launch Pad 39B, that delayed loading of <span class="hlt">Endeavour</span>'s external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMOS21B..04B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMOS21B..04B"><span>On the fate of arsenic in the Menez Gwen <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, Mid-Atlantic Ridge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Breuer, C.; Ruiz Chancho, M.; Pichler, T.</p> <p>2011-12-01</p> <p> chromatographic separation used in the present study. It was also observed that there was a strong T and pH dependence with arsenite, especially in the flash frozen samples. From this study it can be clearly stated that sample preservation is a critical point and further studies related with preservation of marine <span class="hlt">hydrothermal</span> vent fluids for arsenic speciation must be carried out. Although arsenic has been extensively investigated in marine organisms, there is still little information about the metabolism of this element in organisms habiting the deep see, with only one publication so far. Bathymodiolus azoricus has never been studied regarding arsenic speciation and the fact that it is exposed to arsenic concentrations higher than other marine organisms makes it very interesting from the metabolism point of view. The mussels collected near the vents were dissected in gill, muscle and digestive gland and analyzed for total and arsenic species. Results are discussed taking into account the exposure and possible metabolism paths taking place in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040141979&hterms=lipids&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlipids','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040141979&hterms=lipids&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlipids"><span>Lipid synthesis under <span class="hlt">hydrothermal</span> conditions by Fischer-Tropsch-type reactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McCollom, T. M.; Ritter, G.; Simoneit, B. R.</p> <p>1999-01-01</p> <p>Ever since their discovery in the late 1970's, mid-ocean-ridge <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are postulated to have been sites where life could have originated or Mars and elsewhere as well). Because no modern-day terrestrial <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 degrees C for 2-3 days and produces lipid compounds ranging from C2 to > C35 which consist of n-alkanols, n-alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999OLEB...29..153M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999OLEB...29..153M"><span>Lipid Synthesis Under <span class="hlt">Hydrothermal</span> Conditions by Fischer- Tropsch-Type Reactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCollom, Thomas M.; Ritter, Gilles; Simoneit, Bernd R. T.</p> <p>1999-03-01</p> <p>Ever since their discovery in the late 1970's, mid-ocean-ridge <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are postulated to have been sites where life could have originated on Mars and elsewhere as well). Because no modern-day terrestrial <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 °C for 2-3 days and produces lipid compounds ranging from C2 to >C35 which consist of n-alkanols, n- alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10227201','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10227201"><span>Lipid synthesis under <span class="hlt">hydrothermal</span> conditions by Fischer-Tropsch-type reactions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McCollom, T M; Ritter, G; Simoneit, B R</p> <p>1999-03-01</p> <p>Ever since their discovery in the late 1970's, mid-ocean-ridge <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are postulated to have been sites where life could have originated or Mars and elsewhere as well). Because no modern-day terrestrial <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 degrees C for 2-3 days and produces lipid compounds ranging from C2 to > C35 which consist of n-alkanols, n-alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=S92-36605&hterms=team+group&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dteam%2Bgroup','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=S92-36605&hterms=team+group&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dteam%2Bgroup"><span>STS-49 <span class="hlt">Endeavour</span>, Orbiter Vehicle (OV) 105, Orbit Team O1 in MCC Bldg 30 FCR</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1992-01-01</p> <p>STS-49 <span class="hlt">Endeavour</span>, Orbiter Vehicle (OV) 105, Orbit Team 1 (O1) poses in front of large display screens in JSC's Mission Control Center (MCC) Bldg 30 Flight Control Room (FCR) for group portrait. Lead Flight Director (FD) Granvil A. Pennington stands next to a model of the James Cook's ship, the <span class="hlt">Endeavour</span> (left). Astronaut and Spacecraft Communicator (CAPCOM) John H. Casper stands at the right of the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1975/of75-525/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1975/of75-525/"><span>Physical factors determining the fraction of stored energy recoverable from <span class="hlt">hydrothermal</span> convection <span class="hlt">systems</span> and conduction-dominated areas</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nathenson, Manuel</p> <p>1975-01-01</p> <p>This report contains background analyses for the estimates of Nathenson and Muffler (1975) of geothermal resources in <span class="hlt">hydrothermal</span> convection <span class="hlt">systems</span> and conduction-dominated areas. The first section discusses heat and fluid recharge potential of geothermal reservoirs. The second section analyzes the physical factors that determine the fraction of stored energy obtainable at the surface from a geothermal reservoir. Conversion of heat to electricity and the use of geothermal energy for direct-heating applications are discussed in the last two sections. Nathenson, Manuel, and Muffler, L.J.P., 1975, Geothermal resources in <span class="hlt">hydrothermal</span> convection <span class="hlt">systems</span> and conduction dominated areas, in White, D.E., and Williams, D.L., eds., Assessment of the Geothermal Resources of the United States--1975: U.S. Geological Survey Circular 726, p. 104-121, available at http://pubs.er.usgs.gov/usgspubs/cir/cir726</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017404','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017404"><span>Geophysical characteristics of the <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> of Kilauea volcano, Hawaii</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kauahikaua, J.</p> <p>1993-01-01</p> <p>Clues to the overall structure of Kilauea volcano can be obtained from spatial studies of gravity, magnetic, and seismic velocity variations. The rift zones and summit are underlain by dense, magnetic, high P-wave-velocity rocks at depths of about 2 km less. The gravity and seismic velocity studies indicate that the rift structures are broad, extending farther to the north than to the south of the surface features. The magnetic data give more definition to the rift structures by allowing separation into a narrow, highly-magnetized, shallow zone and broad, flanking, magnetic lows. The patterns of gravity, magnetic variations, and seismicity document the southward migration of the upper cast rift zone. Regional, hydrologic features of Kilauea can be determined from resistivity and self-potential studies. High-level groundwater exists beneath Kilauea summit to elevations of +800 m within a triangular area bounded by the west edge of the upper southwest rift zone, the east edge of the upper east rift zone, and the Koa'c fault <span class="hlt">system</span>. High-level groundwater is present within the east rift zone beyond the triangular summit area. Self-potential mapping shows that areas of local heat produce local fluid circulation in the unconfined aquifer (water table). The dynamics of Kilauea eruptions are responsible for both the source of heat and the fracture permeability of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Shallow seismicity and surface deformation indicate that magma is intruding and that fractures are forming beneath the rift zones and summit area. Magma supply estimates are used to calculate the rate of heat input to Kilauea's <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Heat flows of 370-820 mW/m2 are calculated from deep wells within the lower east rift zone. The estimated heat input rate for Kilauea of 9 gigawatts (GW) is at least 25 times higher than the conductive heat loss as estimated from the heat flow in wells extrapolated over the area of the summit caldera and rift zones. Heat must be dissipated by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3988086','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3988086"><span>Exopolysaccharides Isolated from <span class="hlt">Hydrothermal</span> Vent Bacteria Can Modulate the Complement <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Courtois, Anthony; Berthou, Christian; Guézennec, Jean</p> <p>2014-01-01</p> <p>The complement <span class="hlt">system</span> is involved in the defence against bacterial infection, or in the elimination of tumour cells. However, disturbances in this <span class="hlt">system</span> contributes to the pathogenesis of various inflammatory diseases. The efficiency of therapeutic anti-tumour antibodies is enhanced when the complement <span class="hlt">system</span> is stimulated. In contrast, cancer cells are able to inhibit the complement <span class="hlt">system</span> and thus proliferate. Some marine molecules are currently being developed as new drugs for use in humans. Among them, known exopolyssacharides (EPSs) generally originate from fungi, but few studies have been performed on bacterial EPSs and even fewer on EPSs extracted from deep-sea <span class="hlt">hydrothermal</span> vent microbes. For use in humans, these high molecular weight EPSs must be depolymerised. Furthermore, the over-sulphation of EPSs can modify their biological activity. The aim of this study was to investigate the immunodulation of the complement <span class="hlt">system</span> by either native or over-sulphated low molecular weight EPSs isolated from vent bacteria in order to find pro or anti-activators of complement. PMID:24736648</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990032382&hterms=experimental+survey&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dexperimental%2Bsurvey','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990032382&hterms=experimental+survey&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dexperimental%2Bsurvey"><span>Experimental Investigation of Organic Synthesis in <span class="hlt">Hydrothermal</span> Environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shock, Everett L.</p> <p>1998-01-01</p> <p>Seafloor <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> may be the most likely locations on the early Earth for the emergence of life. Because of the disequilibrium inherent in such dynamic, mixing environments, abundant chemical energy would have been available for formation of the building blocks of life. In addition, theoretical studies suggest that organic compounds in these conditions would reach metastable states, due to kinetic barriers to the formation of stable equilibrium products (CO2 and methane). The speciation of organic carbon in metastable states is highly dependent on the oxidation state, pH, temperature, pressure and bulk composition of the <span class="hlt">system</span>. The goal of our research is to investigate the effects of a number external variables on the formation, transformation, and stability of organic compounds at <span class="hlt">hydrothermal</span> conditions. We have begun experimental work to attempt to control the oxidation state of simulated <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> by using buffers composed of mineral powders and gas mixtures. We are also beginning to test the stability of organic compounds under these conditions. The experiments are being performed using the <span class="hlt">hydrothermal</span> bomb apparatus at the U.S. Geological Survey in Menlo Park, CA and the supercritical water oxidizer (SCWO) at NASA Ames Research Center in Moffet Field, CA. The amino acids decomposed rapidly. Even after the approximately 15 minutes between addition of the amino acids and the first sampling, no amino acids were detected in the PPM <span class="hlt">system</span> by GC- MS, while in the FeFeO <span class="hlt">system</span> the amino acids were present at a level of less than 50% of original. Carboxylic acids, ammonia, and CO2 were the main products, along with some unidentified compounds. The ratios of carboxylic acids and concentrations of other products seem to have remained stable during the experiments, consistent with observations of other metastable <span class="hlt">systems</span> and theoretical predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V53E..02P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V53E..02P"><span>Ca and Sr Isotope Sytematics in Mid-Ocean Ridge <span class="hlt">Hydrothermal</span> Fluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pester, N. J.; Syverson, D. D.; Higgins, J. A.; Seyfried, W. E., Jr.</p> <p>2016-12-01</p> <p>We report a comprehensive suite of Ca isotopic data (δ44/40Ca) from mid-ocean ridge <span class="hlt">hydrothermal</span> fluids, standardized relative to seawater. Samples were acquired from 7 different vent fields on the EPR, JdFR and MAR during expeditions between 1999 and 2014. All endmember <span class="hlt">hydrothermal</span> fluids (within analytical uncertainty) reflect an entirely MORB-dominated signal (-1.0 to -1.2 ‰). This rather uniform signal, despite variable fluid chemistries and a mixture of mafic to ultramafic host lithologies, is somewhat surprising given the noteworthy Ca concentrations in both the <span class="hlt">hydrothermal</span> fluids and precursor seawater. One explanation for this observation involves the change in anhydrite (CaSO4) saturation with increasing temperature, and the molal concentration ratio of [Mg]:[Ca]:[SO4] in modern seawater of 53:10:28. The near quantitative removal of seawater Mg to silicate alteration phases, favorable at all temperatures, is largely charge balanced by exchange for basaltic Ca, and this process alone can account for the majority of the rock dominated δ44/40Casw signal. That these values are equivalent to MORB, however, suggests a high proportion of this Mg-Ca exchange occurs after seawater Ca precipitates as anhydrite in lower temperature (recharge) regimes of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, aided by the low [Ca]/[SO4]. 87/86Sr ratios of <span class="hlt">hydrothermal</span> fluids exhibit a seawater signal of 20 to 30% and Sr is therefore not quantitatively removed during incipient anhydrite formation. Strontium mobility in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> is still poorly understood, but the offset between the Ca and Sr isotopic signatures is consistent with near-equilibrium partitioning of Sr into anhydrite observed in recent experiments. Such observations from modern MOR <span class="hlt">systems</span> place important constraints on the role of <span class="hlt">hydrothermal</span> fluxes in paleo-seawater evolution, such as feedbacks involving significant variability in [Mg]:[Ca]:[SO4] ratios of seawater suggested over much of the Phanerozoic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-S100E5356.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-S100E5356.html"><span>MS Guidoni exercises on the cycle ergometer on the middeck of <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2001-04-25</p> <p>S100-E-5356 (25 April 2001) --- Astronaut Umberto Guidoni, STS-100 mission specialist representing the European Space Agency (ESA), works out on a bicycle ergometer on the middeck of the Space Shuttle <span class="hlt">Endeavour</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0165&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0165&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller"><span>STS-99 workers carry new Master Events Controller to <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>Workers carry the replacement Enhanced Main Events Controller (E- MEC) to Shuttle <span class="hlt">Endeavour</span> at Launch Pad 39A for installation in the aft compartment of the payload bay. The original E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently <span class="hlt">Endeavour</span> and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JVGR..346...40F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JVGR..346...40F"><span>Vapour discharges on Nevado del Ruiz during the recent activity: Clues on the composition of the deep <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and its effects on thermal springs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Federico, Cinzia; Inguaggiato, Salvatore; Chacón, Zoraida; Londoño, John Makario; Gil, Edwing; Alzate, Diego</p> <p>2017-10-01</p> <p>The Nevado del Ruiz volcano is considered one of the most active volcanoes in Colombia, which can potentially threaten approximately 600,000 inhabitants. The existence of a glacier and several streams channelling in some main rivers, flowing downslope, increases the risk for the population living on the flank of the volcano in case of unrest, because of the generation of lahars and mudflows. Indeed, during the November 1985 subplinian eruption, a lahar generated by the sudden melting of the glacier killed twenty thousand people in the town of Armero. Moreover, the involvement of the local <span class="hlt">hydrothermal</span> <span class="hlt">system</span> has produced in the past phreatic and phreatomagmatic activity, as occurred in 1989. Therefore, the physico-chemical conditions of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> as well as its contribution to the shallow thermal groundwater and freshwater in terms of enthalpy and chemicals require a close monitoring. The phase of unrest occurred since 2010 and culminated with an eruption in 2012, after several years of relative stability, still maintains a moderate alert, as required by the high seismicity and SO2 degassing. In October 2013, a sampling campaign has been performed on thermal springs and stream water, located at 2600-5000 m of elevation on the slope of Nevado del Ruiz, analyzed for water chemistry and stable isotopes. Some of these waters are typically steam-heated (low pH and high sulfate content) by the vapour probably separating from a zoned <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. By applying a model of steam-heating, based on mass and enthalpy balances, we have estimated the mass rate of <span class="hlt">hydrothermal</span> steam discharging in the different springs. The composition of the hottest thermal spring (Botero Londono) is probably representative of a marginal part of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, having a temperature of 250 °C and low salinity (Cl 1500 mg/l), which suggest, along with the retrieved isotope composition, a chiefly meteoric origin. The vapour discharged at the steam vent "Nereidas" (3600</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=STS059%28S%29107&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ds','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=STS059%28S%29107&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ds"><span>Landing of STS-59 Shuttle <span class="hlt">Endeavour</span> at Edwards Air Force Base</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1994-01-01</p> <p>The main landing gear of the Space Shuttle <span class="hlt">Endeavour</span> touches down at Edwards Air Force Base to complete the 11 day STS-59/SRL-1 mission. Landing occured at 9:54 a.m., April 20, 1994. Mission duration was 11 days, 5 hours, 49 minutes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0160&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0160&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller"><span>A new Master Events Controller is prepared for installation in STS-99 <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>Workers in a Quality trailer in the Launch Pad 39B Area unwrap a new Enhanced Main Events Controller (E-MEC) to be installed in Shuttle <span class="hlt">Endeavour</span>. The original E-MEC in <span class="hlt">Endeavour</span> became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. The E-MECs are located in the orbiter's aft compartment and both are needed for the Shuttle to be cleared for flight. Currently <span class="hlt">Endeavour</span> and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants must be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0161&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0161&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller"><span>A new Master Events Controller is prepared for installation in STS-99 <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>A new Enhanced Main Events Controller (E-MEC) for Shuttle <span class="hlt">Endeavour</span> sits on a table in a Quality trailer in the Launch Pad 39B area. The original E-MEC in <span class="hlt">Endeavour</span> became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. The E-MECs are located in the orbiter's aft compartment and both are needed for the Shuttle to be cleared for flight. Currently <span class="hlt">Endeavour</span> and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants must be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V14A..02L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V14A..02L"><span>Geochemical Sources of Energy for Chemolithoautotrophic Metabolisms in Global <span class="hlt">Hydrothermal</span> Ecosystems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, G. S.; Amend, J.; LaRowe, D.</p> <p>2017-12-01</p> <p>Chemolithoautotrophic microorganisms are important primary producers in <span class="hlt">hydrothermal</span> environments. The potential catabolic energy sources that thermophilic chemolithoautotrophs can take advantage of can be quantified by combining analytical geochemical data and thermodynamic calculations. This approach explicitly considers how microbial communities are shaped by environmental conditions such as temperature, pressure, pH and the concentrations of electron donors and acceptors. In this study, we have calculated the Gibbs free energy available from 730 redox reactions in 30 terrestrial, shallow-sea, and deep-sea <span class="hlt">hydrothermal</span> venting <span class="hlt">systems</span> around the world (326 geochemical data sets) to better determine the relationship between microbial physiology and environment. The reactions with NO2-, O2, MnO2 and NO3- as terminal electron acceptors yield 5-20 kJ/mol e- more energy in terrestrial and shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> than in deep-sea <span class="hlt">hydrothermal</span> settings. However, reactions in which As5+, S0, FeS2 and SO42- as electron acceptors are more favorable by 5-30 kJ/mol e- in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> than in the other two types of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. The most exergonic reactions were predominantly NO2-, O2, MnO2 and NO3- reduction or Fe2+, pyrite, CO and CH4 oxidation. In contrast, reduction of N2, CO, and CO2 or oxidation of N2, Mn2+, and NO2-, though still often exergonic, yielded significantly less energy. Our results provide a comprehensive view of the distribution of energy supplies from redox reactions in high-temperature ecosystems on a global scale. Furthermore, the bioenergetic modeling carried out in this study can be used to test physiological predictions made from metagenomic and proteomic data sets, explore in situ biogeochemical interactions, predict possible but yet-to-be observed metabolisms and guide cultivation efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-S100E5073.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-S100E5073.html"><span>MS Lonchakov waves while standing in the interdeck hatch of <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2001-04-21</p> <p>S100-E-5073 (21 April 2001) --- Cosmonaut Yuri V. Lonchakov, mission specialist representing Rosaviakosmos, waves to a crew mate while translating through the passageway between the middeck and flight deck onboard the Earth-orbiting Space Shuttle <span class="hlt">Endeavour</span>. The image was recorded with a digital still camera.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018270','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018270"><span>Emerald mineralization and metasomatism of amphibolite, khaltaro granitic pegmatite - <span class="hlt">Hydrothermal</span> vein <span class="hlt">system</span>, Haramosh Mountains, Northern Pakistan</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Laurs, B.M.; Dilles, J.H.; Snee, L.W.</p> <p>1996-01-01</p> <p> single fluid of magmatic origin with ??18OH2O = 8??? produced the pegmatite-vein <span class="hlt">system</span> and <span class="hlt">hydrothermal</span> alteration at temperatures between 550 and 400??C. The formation of emerald results from introduction of HF-rich magmatic-<span class="hlt">hydrothermal</span> fluids into the amphibolite, which caused hydrogen ion metasomatism and released Cr and Fe into the pegmatite-vein <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMOS51D..01T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMOS51D..01T"><span>Jack Dymond's Deep Insights</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomson, R. E.; Delaney, J. R.</p> <p>2004-12-01</p> <p>Most people do not know that Jack Dymond was a major influence on several aspects of current deep-sea research. Along with Margaret Leinen and Jack, we were part of the first Alvin dive program on the <span class="hlt">Endeavour</span> <span class="hlt">hydrothermal</span> field in 1984. Jack was working with Rick, on a sediment-trap study of the overall carbon fluxes in the vicinity of the <span class="hlt">Endeavour</span> <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in an effort to address a question that Cindy Lee had posed about the overall carbon production from <span class="hlt">hydrothermal</span> vents. At the time we were recognizing and naming many of the 20- to 40-meter-high sulfide structures in the <span class="hlt">Endeavour</span> field (Hulk, Grotto, Dante, Dudley, Bastille), Jack commented that it was a shame that the world could not see these magnificent edifices or watch endlessly awesome black smokers. His feeling was that some vent sites should be converted to National Parks to preserve them from invasion by enthusiastic scientists, yet he clearly had the vision that the public should be given a sense of the grandeur involved locally, as well as the vastness of the 70,000-km ridge-crest <span class="hlt">system</span> running through every ocean. Within a year we started talking about the RIDGE Program, and Jack was an early and enthusiastic participant in the design and development of RIDGE. Jack was among the first to encourage multi-disciplinary research at the <span class="hlt">hydrothermal</span> vent sites. Recognizing that deep currents are important to vent processes, he urged physical oceanographers to work with the chemists, biologists, and geologists and was personally responsible for Rick becoming interested in studying vents. We, the co-authors of this abstract, became close friends as a result of having been introduced to each other by Jack. Several years ago, we co-authored the first paper ever written on the possible influence of <span class="hlt">hydrothermal</span> activity on the circulation of the Europan Ocean, a paper that we here dedicate to the memory of Jack. Finally, it was in part because of Jack's conviction that the world should know</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26324888','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26324888"><span>Fluid mixing and the deep biosphere of a fossil Lost City-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the Iberia Margin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klein, Frieder; Humphris, Susan E; Guo, Weifu; Schubotz, Florence; Schwarzenbach, Esther M; Orsi, William D</p> <p>2015-09-29</p> <p>Subseafloor mixing of reduced <span class="hlt">hydrothermal</span> fluids with seawater is believed to provide the energy and substrates needed to support deep chemolithoautotrophic life in the hydrated oceanic mantle (i.e., serpentinite). However, geosphere-biosphere interactions in serpentinite-hosted subseafloor mixing zones remain poorly constrained. Here we examine fossil microbial communities and fluid mixing processes in the subseafloor of a Cretaceous Lost City-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the magma-poor passive Iberia Margin (Ocean Drilling Program Leg 149, Hole 897D). Brucite-calcite mineral assemblages precipitated from mixed fluids ca. 65 m below the Cretaceous paleo-seafloor at temperatures of 31.7 ± 4.3 °C within steep chemical gradients between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing <span class="hlt">hydrothermal</span> fluid at moderate temperatures created conditions capable of supporting microbial activity. Dense microbial colonies are fossilized in brucite-calcite veins that are strongly enriched in organic carbon (up to 0.5 wt.% of the total carbon) but depleted in (13)C (δ(13)C(TOC) = -19.4‰). We detected a combination of bacterial diether lipid biomarkers, archaeol, and archaeal tetraethers analogous to those found in carbonate chimneys at the active Lost City <span class="hlt">hydrothermal</span> field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin, possibly before the onset of seafloor spreading. Lost City-type serpentinization <span class="hlt">systems</span> have been discovered at midocean ridges, in forearc settings of subduction zones, and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4593090','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4593090"><span>Fluid mixing and the deep biosphere of a fossil Lost City-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the Iberia Margin</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Klein, Frieder; Humphris, Susan E.; Guo, Weifu; Schubotz, Florence; Schwarzenbach, Esther M.; Orsi, William D.</p> <p>2015-01-01</p> <p>Subseafloor mixing of reduced <span class="hlt">hydrothermal</span> fluids with seawater is believed to provide the energy and substrates needed to support deep chemolithoautotrophic life in the hydrated oceanic mantle (i.e., serpentinite). However, geosphere-biosphere interactions in serpentinite-hosted subseafloor mixing zones remain poorly constrained. Here we examine fossil microbial communities and fluid mixing processes in the subseafloor of a Cretaceous Lost City-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the magma-poor passive Iberia Margin (Ocean Drilling Program Leg 149, Hole 897D). Brucite−calcite mineral assemblages precipitated from mixed fluids ca. 65 m below the Cretaceous paleo-seafloor at temperatures of 31.7 ± 4.3 °C within steep chemical gradients between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing <span class="hlt">hydrothermal</span> fluid at moderate temperatures created conditions capable of supporting microbial activity. Dense microbial colonies are fossilized in brucite−calcite veins that are strongly enriched in organic carbon (up to 0.5 wt.% of the total carbon) but depleted in 13C (δ13CTOC = −19.4‰). We detected a combination of bacterial diether lipid biomarkers, archaeol, and archaeal tetraethers analogous to those found in carbonate chimneys at the active Lost City <span class="hlt">hydrothermal</span> field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin, possibly before the onset of seafloor spreading. Lost City-type serpentinization <span class="hlt">systems</span> have been discovered at midocean ridges, in forearc settings of subduction zones, and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments. PMID:26324888</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMOS51D..03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMOS51D..03K"><span>The use of 210Pb/Pb as a Tracer of Chemosynthetic and Photosynthetic Organic Carbon in <span class="hlt">Hydrothermal</span> Vent Particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kadko, D.</p> <p>2004-12-01</p> <p>Jack Dymond pioneered the use of sediment traps to understand the chemistry and flux of material emanating from submarine <span class="hlt">hydrothermal</span> vents. For example, in one paper Roth and Dymond (1989) used the ratio of Corg/CCaCO3 between traps to determine the fraction of chemosynthetically derived organic carbon (OC) in collected material. Knowledge of the relative proportion of chemosynthetic and photosynthetic OC is critical to mass balance calculations of <span class="hlt">hydrothermal</span> OC inputs/exports and can also be determined from the 210Pb/Pb ratio measured in the sediment traps and suspended particles. The 210Pb/Pb ratio of particles in the ridge environment is diagnostic of the source and path of the particles. At the <span class="hlt">Endeavour</span> Ridge, particles emanating directly from vents have a ratio close to that of the vent fluids and basalt ( ˜0.5 dpm/μ g) from where they are derived, and subsequently scavenge additional 210Pb as they disperse. It is therefore reasonable to assume that particles with a 210Pb/Pb ratio of 0.5 are "fresh" and any OC associated with them must be chemosynthetic in origin. This ratio is much smaller than that of typical (non-vent) seawater (>3 dpm/μ g) and thus particles in the upper water column (or distant from vents) will have a high 210Pb/Pb ratio and contain OC predominantly from photosynthetic production. The 210Pb/Pb ratio of <span class="hlt">Endeavour</span> particles increase markedly from <0.70 at a vent orifice, to 1.22 within the buoyant plume ( ˜20 ma vent), to 1.4 downstream (~2 km) within the neutrally-buoyant plume at 2100 m depth. These plume particles are distinguished from those above the plume (at 1700 m with 210Pb/Pb = 3.2 dpm/μ g) by lower 210Pb/Pb ratios but much higher 210Pb content. The high Pb content attests to a <span class="hlt">hydrothermal</span> component of the plume particles. Therefore, the 210Pb/Pb ratio can be used to define two conservative endmembers for a particle population: those derived from the vents will have a ratio of 0.5 (with 100% chemosynthetic OC) and those</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-EC01-0129-3.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-EC01-0129-3.html"><span>A lone desert Joshua tree greeted the arrival of Space Shuttle <span class="hlt">Endeavour</span> at Edwards Air Force Base, California, on May 1, 2001</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2001-05-01</p> <p>A lone desert Joshua tree greeted the arrival of Space Shuttle <span class="hlt">Endeavour</span> at Edwards Air Force Base, California, May 1, 2001. A large drag chute helped slow <span class="hlt">Endeavour</span> on the runway. After mounting the shuttle on a converted 747 airliner at NASA's Dryden Flight Research Center, <span class="hlt">Endeavour</span> will be carried back to the Kennedy Space Center for its next mission. Weather in Florida necessitated landing in California.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-02PD-1733&hterms=leak&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dleak','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-02PD-1733&hterms=leak&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dleak"><span>Scrape on <span class="hlt">Endeavour</span>'s robotic arm during oxygen leak repairs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p>KENNEDY SPACE CENTER, FLA. -- One of a team of robotic experts prepares the site scraped on the robotic arm for removal. The scrape occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. The site will be cut out and ultrasound testing will be done on the structure underneath. Launch of <span class="hlt">Endeavour</span> on mission STS-113 has been postponed until no earlier than Nov. 22.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70177135','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70177135"><span>Monitoring the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in Long Valley caldera, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Farrar, C.D.; Sorey, M.L.</p> <p>1985-01-01</p> <p>An ongoing program to monitor the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in Long Valley for changes caused by volcanic or tectonic processes has produced considerable data on the water chemistry and discharge of springs and fluid temperatures and pressures in wells. Chemical and isotopic data collected under this program have greatly expanded the knowledge of chemical variability both in space and time. Although no chemical or isotopic changes in hot spring waters can be attributed directly to volcanic or tectonic processes, changes in hot spring chemistry that have been recorded probably relate to interactions between and variations in the quantity of liquid and gas discharged. Stable carbon isotope data are consistent with a carbon source either perform the mantle or from metamorphosed carbonate rocks. Continuous and periodic measurements of hot spring discharge at several sites show significant co seismic and a seismic changes since 1980.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA14539.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA14539.html"><span>Bright Veins in Botany Bay on rim of <span class="hlt">Endeavour</span> Crater on Mars</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-01</p> <p>Bright veins cutting across outcrop in a section of <span class="hlt">Endeavour</span> crater rim called Botany Bay are visible in the foreground and middle distance of this view from NASA Mars Exploration Rover Opportunity on sol 2,681 Aug. 9, 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..976M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..976M"><span>The 2012-2014 eruptive cycle of Copahue Volcano, Southern Andes. Magmatic-<span class="hlt">Hydrothermal</span> <span class="hlt">system</span> interaction and manifestations.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morales, Sergio; Alarcón, Alex; Basualto, Daniel; Bengoa, Cintia; Bertín, Daniel; Cardona, Carlos; Córdova, Maria; Franco, Luis; Gil, Fernando; Hernandez, Erasmo; Lara, Luis; Lazo, Jonathan; Mardones, Cristian; Medina, Roxana; Peña, Paola; Quijada, Jonathan; San Martín, Juan; Valderrama, Oscar</p> <p>2015-04-01</p> <p>Copahue Volcano (COPV), in Southern Andes of Chile, is an andesitic-basaltic stratovolcano, which is located on the western margin of Caviahue Caldera. The COPV have a NE-trending fissure with 9 aligned vents, being El Agrio the main currently active vent, with ca. 400 m in diameter. The COPV is placed into an extensive <span class="hlt">hydrothermal</span> <span class="hlt">system</span> which has modulated its recent 2012-2014 eruptive activity, with small phreatic to phreatomagmatic eruptions and isolated weak strombolian episodes and formation of crater lakes inside the main crater. Since 2012, the Southern Andes Volcano Observatory (OVDAS) carried out the real-time monitoring with seismic broadband stations, GPS, infrasound sensors and webcams. In this work, we report pre, sin, and post-eruptive seismic activity of the last two main eruptions (Dec, 2012 and Oct, 2014) both with different seismic precursors and superficial activity, showing the second one a particularly appearance of seismic quiescence episodes preceding explosive activity, as an indicator of interaction between magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. The first episode, in late 2012, was characterized by a low frequency (0.3-0.4 Hz and 1.0-1.5 Hz) continuous tremor which increased gradually from background noise level amplitude to values of reduced displacement (DR), close to 50 cm2 at the peak of the eruption, reaching an eruptive column of ~1.5 km height. After few months of recording low energy seismicity, a sequence of low frequency, repetitive and low energy seismic events arose, with a frequency of occurrence up to 300 events/hour. Also, the VLP earthquakes were added to the record probably associated with magma intrusion into a deep magmatic chamber during all stages of eruptive process, joined to the record of VT seismicity during the same period, which is located throughout the Caviahue Caldera area. Both kind of seismic patterns were again recorded in October 2014, being the precursor of the new eruptive cycle at this time as well as the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010shcg.book..599B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010shcg.book..599B"><span><span class="hlt">Hydrothermal</span> Growth of Polyscale Crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Byrappa, Kullaiah</p> <p></p> <p>In this chapter, the importance of the <span class="hlt">hydrothermal</span> technique for growth of polyscale crystals is discussed with reference to its efficiency in synthesizing high-quality crystals of various sizes for modern technological applications. The historical development of the <span class="hlt">hydrothermal</span> technique is briefly discussed, to show its evolution over time. Also some of the important types of apparatus used in routine <span class="hlt">hydrothermal</span> research, including the continuous production of nanosize crystals, are discussed. The latest trends in the <span class="hlt">hydrothermal</span> growth of crystals, such as thermodynamic modeling and understanding of the solution chemistry, are elucidated with appropriate examples. The growth of some selected bulk, fine, and nanosized crystals of current technological significance, such as quartz, aluminum and gallium berlinites, calcite, gemstones, rare-earth vanadates, electroceramic titanates, and carbon polymorphs, is discussed in detail. Future trends in the <span class="hlt">hydrothermal</span> technique, required to meet the challenges of fast-growing demand for materials in various technological fields, are described. At the end of this chapter, an Appendix 18.A containing a more or less complete list of the characteristic families of crystals synthesized by the <span class="hlt">hydrothermal</span> technique is given with the solvent and pressure-temperature (PT) conditions used in their synthesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-S47-S-002.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-S47-S-002.html"><span>STS-47 <span class="hlt">Endeavour</span>, OV-105, official crew portrait</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1992-06-01</p> <p>STS047-S-002 (June 1992) --- These seven crew members are currently in training for the STS-47/Spacelab J mission scheduled for later this year. Pictured are (left to right, front) Jerome (Jay) Apt, mission specialist; Curtis L. Brown, pilot; and (left to right, rear) N. Jan Davis, mission specialist; Mark C. Lee, payload commander; Robert L. Gibson, mission commander; Mae C. Jemison, mission specialist; and Mamoru Mohri, payload specialist, representing the National Space Development Agency of Japan (NASDA). This is the Space Shuttle <span class="hlt">Endeavour</span>'s second scheduled mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V13C3161S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V13C3161S"><span>Sub-glacial Origin of the Hot Springs Bay Valley <span class="hlt">hydrothermal</span> <span class="hlt">System</span>, Akutan, Alaska</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stelling, P. L.; Tobin, B.; Knapp, P.</p> <p>2015-12-01</p> <p>Exploration for geothermal energy in Hot Springs Bay Valley (HSBV) on Akutan Island, Alaska, has revealed a rich <span class="hlt">hydrothermal</span> history, including what appears to be a stage of peak activity during a significant glacial period. Alteration mineralogy observed in 754 m of drill core recovered from the outflow zone is dominated by chlorite and includes minor smectite clays, a suite of zeolite species and several moderately high-temperature <span class="hlt">hydrothermal</span> minerals (epidote/clinozoisite, prehnite, adularia and wairakite). The latter minerals each have minimum formation temperatures exceeding 200 oC, and fluid inclusion results in related calcite crystals indicate temperatures of formation to be as high as 275 oC, some 100 oC hotter than the modern boiling point with depth (BPD) curve at that depth (>62 m). In order to maintain liquid temperatures this high, the pressure during mineralization must have been substantially greater (~680 bar), a pressure change equivalent to erosion of ~280 m of rock (ρ=2.5 g/cm3). Although glacial erosion rates are too low (0.034 mm/yr; Bekele et al., 2003) for this amount of erosion to occur in a single glaciation, glacial melting and ablation are substantially more rapid (~100 mm/yr; Bekele et al., 2003; Person et al., 2012). Thus, a more probable scenario than pure erosion is that peak <span class="hlt">hydrothermal</span> conditions occurred during a large glacial event, with the added pressure from the overlying ice allowing the high temperature minerals to form closer to the ground surface. Subsequent melting of the ice eroded upper tributary valleys and upper levels of the originally smectite-rich alteration assemblage, explaining the paucity of swelling clays in the region. We present mineralogical, fluid inclusion and geochronologic evidence to support these conclusions, and discuss the general implications of sub-glacial <span class="hlt">hydrothermal</span> <span class="hlt">system</span> formation and geothermal resource potential. References: Bekele, E., Rostron, B. and Person, M. (2003) Fluid pressure</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMOS21A1474R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMOS21A1474R"><span>Seismological evidence for an along-axis <span class="hlt">hydrothermal</span> flow at the Lucky Strike <span class="hlt">hydrothermal</span> vents site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rai, A.; Wang, H.; Singh, S. C.; Crawford, W. C.; Escartin, J.; Cannat, M.</p> <p>2010-12-01</p> <p><span class="hlt">Hydrothermal</span> circulation at ocean spreading centres plays fundamental role in crustal accretion process, heat extraction from the earth and helps to maintain very rich ecosystem in deep Ocean. Recently, it has been suggested that <span class="hlt">hydrothermal</span> circulation is mainly along the ridge axis at fast spreading centres above along axis melt lens (AMC). Using a combination of micro-earthquake and seismic reflection data, we show that the <span class="hlt">hydrothermal</span> circulation at the Lucky Strike segment of slow spreading Mid-Atlantic Ridge is also along axis in a narrow (~1 km) zone above a wide (2-3 km) AMC. We find that the seismicity mainly lies above the seismically imaged 3 km wide 7 km long melt lens at 3.2 km depth. We observe a vertical plume of seismicity above a weak AMC reflection just north of the <span class="hlt">hydrothermal</span> vent fields that initiates just above the AMC and continues to the seafloor. This zone is collocated with active rifting of the seafloor in the neo-volcanic zone. Beneath the <span class="hlt">hydrothermal</span> vents sites, where a strong melt lens is imaged, the seismicity initiates at 500 m above the AMC and continues to the seafloor. Just south of the <span class="hlt">hydrothermal</span> field, where the AMC is widest and strongest, the seismicity band lies 500 m above the melt lens in a 800 m thick zone, which does not continue to the seafloor. The presence the weak melt lens reflection could be due to a cooled and crystallised AMC (mush) that permits the penetration of <span class="hlt">hydrothermal</span> fluids down to the top of the AMC indicated by seismicity plume and might be the in-flow zone for <span class="hlt">hydrothermal</span> circulation. The strong AMC reflection could be due to fresh supply of melt in the AMC (pure melt), which has pushed the cracking front 500 m above the AMC. Beneath the <span class="hlt">hydrothermal</span> fields, the strong AMC reflection and seismicity 500 above the AMC to the seafloor could represent cracking along the up-flow zone. The 800 m thick zone of seismicity above the pure melt zone could be the zone of <span class="hlt">hydrothermal</span> cracking zone. We do</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E.148B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E.148B"><span>From Geochemistry to Biochemistry: Simulating Prebiotic Chemistry Driven by Geochemical Gradients in Alkaline <span class="hlt">Hydrothermal</span> Vents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barge, Laurie</p> <p>2016-07-01</p> <p>Planetary water-rock interfaces generate energy in the form of redox, pH, and thermal gradients, and these disequilibria are particularly focused in <span class="hlt">hydrothermal</span> vent <span class="hlt">systems</span> where the reducing, heated <span class="hlt">hydrothermal</span> fluid feeds back into the more oxidizing ocean. Alkaline <span class="hlt">hydrothermal</span> vents have been proposed as a likely location for the origin of life on the early Earth due to various factors: including the <span class="hlt">hydrothermal</span> pH / Eh gradients that resemble the ubiquitous electrical / proton gradients in biology, the catalytic <span class="hlt">hydrothermal</span> precipitates that resemble inorganic catalysts in enzymes, and the presence of electron donors and acceptors in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> (e.g. H2 + CH4 and CO2) that are thought to have been utilized in the earliest metabolisms. Of particular importance for the emergence of metabolism are the mineral "chimneys" that precipitate at the vent fluid / seawater interface. <span class="hlt">Hydrothermal</span> chimneys are flow-through chemical reactors that form porous and permeable inorganic membranes transecting geochemical gradients; in some ways similar to biological membranes that transect proton / ion gradients and harness these disequilibria to drive metabolism. These emergent chimney structures in the far-from-equilibrium <span class="hlt">system</span> of the alkaline vent have many properties of interest to the origin of life that can be simulated in the laboratory: for example, they can generate electrical energy and drive redox reactions, and produce catalytic minerals (in particular the metal sulfides and iron oxyhydroxides - "green rust") that can facilitate chemical reactions towards proto-metabolic cycles and biosynthesis. Many of the factors prompting interest in alkaline <span class="hlt">hydrothermal</span> vents on Earth may also have been present on early Mars, or even presently within icy worlds such as Europa or Enceladus - thus, understanding the disequilibria and resulting prebiotic chemistry in these <span class="hlt">systems</span> can be of great use in assessing the potential for other environments in the Solar</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PEPS....3...35U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PEPS....3...35U"><span>Reactions between komatiite and CO2-rich seawater at 250 and 350 °C, 500 bars: implications for hydrogen generation in the Hadean seafloor <span class="hlt">hydrothermal</span> <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ueda, Hisahiro; Shibuya, Takazo; Sawaki, Yusuke; Saitoh, Masafumi; Takai, Ken; Maruyama, Shigenori</p> <p>2016-12-01</p> <p>To understand the chemical nature of <span class="hlt">hydrothermal</span> fluids in the komatiite-hosted seafloor <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in the Hadean, we conducted two <span class="hlt">hydrothermal</span> serpentinization experiments involving synthetic komatiite and a CO2-rich acidic NaCl fluid at 250 and 350 °C, 500 bars. During the experiments, the komatiites were strongly carbonated to yield iron-rich dolomite (3-9 wt.% FeO) at 250 °C and calcite (<0.8 wt.% FeO) at 350 °C, respectively. The carbonation of komatiites suppressed H2 generation in the fluids. The steady-state H2 concentrations in the fluid were approximately 0.024 and 2.9 mmol/kg at 250 and 350 °C, respectively. This correlation between the Fe content in carbonate mineral and the H2 concentration in the fluid suggests that the incorporation of ferrous iron into the carbonate mineral probably limited magnetite formation and consequent generation of hydrogen during the serpentinization of komatiites. The H2 concentration of the fluid at 350 °C corresponds to that of modern H2-rich seafloor <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, such as the Kairei <span class="hlt">hydrothermal</span> field, where hydrogenotrophic methanogens dominate in the prosperous microbial ecosystem. Accordingly, the high-temperature serpentinization of komatiite would provide the H2-rich <span class="hlt">hydrothermal</span> environments that were necessary for the emergence and early evolution of life in the Hadean ocean. In contrast, H2-rich fluids may not have been generated by serpentinization at temperatures below 250 °C because carbonate minerals become more stable with decreasing temperature in the komatiite-H2O-CO2 <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.T13B2709L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.T13B2709L"><span>An Assessment of Magma-<span class="hlt">Hydrothermal</span> Heat Output at the Costa Rica Rift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lowell, R. P.; Morales Maqueda, M. A.; Banyte, D.; Zhang, L.; Tong, V.; Hobbs, R. W.; Harris, R. N.</p> <p>2016-12-01</p> <p>A joint geophysical/physical oceanographic investigation of the Costa Rica Ridge as part of the OSCAR (Oceanographic and Seismic Characterization of heat dissipation and alteration by <span class="hlt">hydrothermal</span> fluids at an Axial Ridge) research program enables us to estimate <span class="hlt">hydrothermal</span> heat output and its likely link to a sub-axial magma lens (AML). In December 2014, a number of tow-yo casts were made along and near the ridge axis where seismic reflection data collected in 1994 showed the presence of seismic reflector interpreted to be an AML at a depth of about 2800 m below the seafloor. A decline in beam transmission in a ≈ 200 m thick region located approximately 800 to 900 meters above the seafloor indicated the presence of a <span class="hlt">hydrothermal</span> plume. CTD data collected above the ridge yielded a weighted average buoyancy frequency of approximately 19.3 x 10-8 s-2. Assuming a mean <span class="hlt">hydrothermal</span> vent temperature of 350°C, buoyant plume theory yields a heat output between 400 and 600 MW. Application of the single-pass modeling approach to the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, yields an estimated mass flow between 210 and 337 kg/s, and the mean product of crustal permeability x discharge area ranges between 6 and 10 x 10-9 m4. A multichannel seismic profile collected in 2015 indicates the presence of a reflector 5 km along-axis and < 100 m wide, in approximately the same location as the 1994 survey, suggesting that magma-driven <span class="hlt">hydrothermal</span> heat output may have exhibited stability on a decadal time scale. The relatively small size of the inferred AML, when coupled to the heat output estimate and the single-pass model, suggests that the conductive boundary layer at the top the AML is 2m thick and that the AML must be frequently replenished to maintain stable heat output. Assuming the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> is driven by magmatic latent heat, a 100 m thick AML could have powered a 100 MW <span class="hlt">hydrothermal</span> <span class="hlt">system</span> for 20 years, while inputting 5 x 107 m3 of melt into the axis. These results indicate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1982/0980/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1982/0980/report.pdf"><span>Integrated model of the shallow and deep <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the East Mesa area, Imperial Valley, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Riney, T. David; Pritchett, J.W.; Rice, L.F.</p> <p>1982-01-01</p> <p>Geological, geophysical, thermal, petrophysical and hydrological data available for the East Mesa <span class="hlt">hydrothermal</span> <span class="hlt">system</span> that are pertinent to the construction of a computer model of the natural flow of heat and fluid mass within the <span class="hlt">system</span> are assembled and correlated. A conceptual model of the full <span class="hlt">system</span> is developed and a subregion selected for quantitative modeling. By invoking the .Boussinesq approximation, valid for describing the natural flow of heat and mass in a liquid <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, it is found practical to carry computer simulations far enough in time to ensure that steady-state conditions are obtained. Initial calculations for an axisymmetric model approximating the <span class="hlt">system</span> demonstrate that the vertical formation permeability of the deep East Mesa <span class="hlt">system</span> must be very low (kv ~ 0.25 to 0.5 md). Since subsurface temperature and surface heat flow data exhibit major deviations from the axisymmetric approximation, exploratory three-dimensional calculations are performed to assess the effects of various mechanisms which might operate to produce such observed asymmetries. A three-dimensional model evolves from this iterative data synthesis and computer analysis which includes a hot fluid convective source distributed along a leaky fault radiating northward from the center of the hot spot and realistic variations in the reservoir formation properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005GeCoA..69..675A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005GeCoA..69..675A"><span>REE controls in ultramafic hosted MOR <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>: An experimental study at elevated temperature and pressure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allen, Douglas E.; Seyfried, W. E.</p> <p>2005-02-01</p> <p>A <span class="hlt">hydrothermal</span> experiment involving peridotite and a coexisting aqueous fluid was conducted to assess the role of dissolved Cl - and redox on REE mobility at 400°C, 500 bars. Data show that the onset of reducing conditions enhances the stability of soluble Eu +2 species. Moreover, Eu +2 forms strong aqueous complexes with dissolved Cl - at virtually all redox conditions. Thus, high Cl - concentrations and reducing conditions can combine to reinforce Eu mobility. Except for La, trivalent REE are not greatly affected by fluid speciation under the chemical and physical condition considered, suggesting control by secondary mineral-fluid partitioning. LREE enrichment and positive Eu anomalies observed in fluids from the experiment are remarkably similar to patterns of REE mobility in vent fluids issuing from basalt- and peridotite-hosted <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. This suggests that the chondrite normalized REE patterns are influenced greatly by fluid speciation effects and secondary mineral formation processes. Accordingly, caution must be exercised when using REE in <span class="hlt">hydrothermal</span> vent fluids to infer REE sources in subseafloor reaction zones from which the fluids are derived. Although vent fluid patterns having LREE enrichment and positive Eu anomalies are typically interpreted to suggest plagioclase recrystallization reactions, this need not always be the case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GGG....18.3489M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GGG....18.3489M"><span>The Gondou <span class="hlt">hydrothermal</span> field in the Ryukyu Arc: A huge <span class="hlt">hydrothermal</span> <span class="hlt">system</span> on the flank of a caldera volcano</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Minami, H.; Ohara, Y.</p> <p>2017-09-01</p> <p>High-resolution geophysical mapping was conducted from an autonomous underwater vehicle on the flank of Daisan-Kume Knoll in the Ryukyu Arc, southwest of Japan. 1 m resolution bathymetry identified 264 spires, 173 large mounds and 268 small mounds within a depression that is up to 1600 m wide and up to 60 m deep, at water depths between 1330 and 1470 m. <span class="hlt">Hydrothermal</span> venting is strongly inferred from the observation of plumes in sidescan sonar imagery and positive temperature anomalies over the spires and mounds. This field, named the Gondou Field, has a giant mound G1 with a diameter of 280 m and a height of 80 m. Mound G1 has distinctive summit ridges composed of multiple spires where acoustic plumes with temperature anomalies up to 1.12°C are observed, indicative of high-temperature venting. Other than mound G1, a number of active large mounds more than 30 m wide and spires over 10-22 m tall are common and they concentrate in the central and southern areas of the field, suggesting that these areas are the center of present <span class="hlt">hydrothermal</span> activity. Acoustic plumes imaged by side-scan sonar at the Gondou Field are different in character from bubble plumes imaged in other <span class="hlt">hydrothermal</span> fields in the Ryukyu Arc. The plumes are diffused and deflected as they rise through the water column and have a shape consistent with black smokers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V11A0332T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V11A0332T"><span>Distribution of <span class="hlt">hydrothermal</span> fluid around the ore body in the subseafloor of the Izena <span class="hlt">hydrothermal</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Toki, T.; Otake, T.; Ishibashi, J. I.; Matsui, Y.; Kawagucci, S.; Kato, H.; Fuchida, S.; Miyahara, R.; Tsutsumi, A.; Kawakita, R.; Uza, H.; Uehara, R.; Shinjo, R.; Nozaki, T.; Kumagai, H.; Maeda, L.</p> <p>2017-12-01</p> <p>From 16th November to 15th December 2016, D/V Chikyu drilled the sea bottom around <span class="hlt">hydrothermal</span> fields at HAKUREI site in the Izena Hole, Okinawa Trough. Site C9025, C9026, C9027, C9028, and C9032 are located along the transect line from the top of the northern mound of HAKUREI site to the eastward, and Site C9030 for the control site is located about 500 m northwest of the mound. Mg concentrations have generally been used to estimate mixing ratios between <span class="hlt">hydrothermal</span> end-member and seawater in samples from <span class="hlt">hydrothermal</span> vents. Higher Mg concentrations, however, were detected in the interstitial water than that of seawater, which could be due to artificially dissolution of Mg-bearing minerals that had formed in in-situ environments, when the cored sediments had become cool after their recovery on ship. Similar features were observed with regard to sulfate concentrations, and it suggests that these chemical species are not suitable to estimate quantitatively the contribution of <span class="hlt">hydrothermally</span>-derived components. In some layers, chloride concentrations were different from that of seawater, indicating that <span class="hlt">hydrothermal</span> fluids that had been suffered from phase separation flowed into the layers. The deviation, however, was positive or negative relative to that of seawater for an influence of brine or vapor phase, respectively. Therefore chloride concentrations are also not suitable to evaluate a quantitative contribution of <span class="hlt">hydrothermal</span> end-member. On the other hand, K and B showed only enrichments relative to the seawater, and their highest concentrations are consistent with the reported <span class="hlt">hydrothermal</span> end-members of each species at HAKUREI site. Using the concentrations of K and B can be evaluated for an influence of <span class="hlt">hydrothermal</span> components. Furthermore, the headspace gas data are useful in the layers of sulfide minerals and silicified rocks, even though the interstitial waters could not be obtained because of their hardness. Based on these indices, <span class="hlt">hydrothermal</span> fluids</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70014941','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70014941"><span>Chemical, isotopic, and dissolved gas compositions of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in Twin Falls and Jerome counties, Idaho</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mariner, R.H.; Young, H.W.; Evans, W. E.; Parliman, D.J.</p> <p>1991-01-01</p> <p>The chemical, isotopic, and gas compositions of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in Twin Falls and Jerome counties, Idaho, change systematically as the water moves northward from the Idaho-Nevada boundary toward the Snake River. Sodium, chloride, fluoride, alkalinity, dissolved helium, and carbon-13 increase as calcium and carbon-14 decrease. Water-rock reactions may result in dissolution of plagioclase or volcanic glass and calcite, followed by precipitation of zeolites and clays. On the basis of carbon-14 age dating, apparent water ages range from 2,000 to more than 26,000 years; most apparent ages range from about 4,000 to 10,000 years. The older waters, north of the Snake River, are isotopically depleted in deuterium and are enriched in chloride relative to waters to the south. Thermal waters flowing northward beneath the Snake River may join a westward flow of older thermal water slightly north of the river. The direction of flow in the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> seems to parallel the surface drainage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0263&hterms=need+touch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneed%2Btouch','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0263&hterms=need+touch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneed%2Btouch"><span>STS-99 <span class="hlt">Endeavour</span> touches down at SLF after successful mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>In the waning light after sundown, Space Shuttle <span class="hlt">Endeavour</span> touches down on KSC's Shuttle Landing Facility Runway 33 to complete the 11-day, 5-hour, 38-minute-long STS-99 mission. At the controls are Commander Kevin Kregel and Pilot Dominic Gorie. Also onboard the orbiter are Mission Specialists Janet Kavandi, Janice Voss, Mamoru Mohri of Japan and Gerhard Thiele of Germany. Mohri is with the National Space Development Agency (NASDA) and Thiele is with the European Space Agency. The crew are returning from the Shuttle Radar Topography Mission after mapping more than 47 million square miles of the Earth's surface. Main gear touchdown was at 6:22:23 p.m. EST Feb. 22 , landing on orbit 181 of the mission. Nose gear touchdown was at 6:22:35 p.m.. EST, and wheel stop at 6:23:25 p.m. EST. This was the 97th flight in the Space Shuttle program and the 14th for <span class="hlt">Endeavour</span>, also marking the 50th landing at KSC, the 21st consecutive landing at KSC, and the 28th in the last 29 Shuttle flights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0256&hterms=need+touch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneed%2Btouch','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0256&hterms=need+touch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneed%2Btouch"><span>STS-99 <span class="hlt">Endeavour</span> touches down at SLF after successful mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>In the waning light after sundown, Space Shuttle <span class="hlt">Endeavour</span> touches down on KSC's Shuttle Landing Facility Runway 33 to complete the 11-day, 5-hour, 38-minute-long STS-99 mission. At the controls are Commander Kevin Kregel and Pilot Dominic Gorie. Also onboard the orbiter are Mission Specialists Janet Kavandi, Janice Voss, Mamoru Mohri of Japan and Gerhard Thiele of Germany. Mohri is with the National Space Development Agency (NASDA) and Thiele is with the European Space Agency. The crew is returning from the Shuttle Radar Topography Mission after mapping more than 47 million square miles of the Earth's surface. Main gear touchdown was at 6:22:23 p.m. EST Feb. 22 , landing on orbit 181 of the mission. Nose gear touchdown was at 6:22:35 p.m.. EST, and wheel stop at 6:23:25 p.m. EST. This was the 97th flight in the Space Shuttle program and the 14th for <span class="hlt">Endeavour</span>, also marking the 50th landing at KSC, the 21st consecutive landing at KSC, and the 28th in the last 29 Shuttle flights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0257&hterms=need+touch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneed%2Btouch','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0257&hterms=need+touch&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneed%2Btouch"><span>STS-99 <span class="hlt">Endeavour</span> touches down at SLF after successful mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>Space Shuttle <span class="hlt">Endeavour</span> stirs up dust as its wheels touch down on KSC's Shuttle Landing Facility Runway 33 to complete the 11-day, 5-hour, 38-minute-long STS-99 mission. At the controls are Commander Kevin Kregel and Pilot Dominic Gorie. Also onboard the orbiter are Mission Specialists Janet Kavandi, Janice Voss, Mamoru Mohri of Japan and Gerhard Thiele of Germany. Mohri is with the National Space Development Agency (NASDA) and Thiele is with the European Space Agency. The crew is returning from the Shuttle Radar Topography Mission after mapping more than 47 million square miles of the Earth's surface. Main gear touchdown was at 6:22:23 p.m. EST Feb. 22 , landing on orbit 181 of the mission. Nose gear touchdown was at 6:22:35 p.m.. EST, and wheel stop at 6:23:25 p.m. EST. This was the 97th flight in the Space Shuttle program and the 14th for <span class="hlt">Endeavour</span>, also marking the 50th landing at KSC, the 21st consecutive landing at KSC, and the 28th in the last 29 Shuttle flights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-111.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-111.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-03</p> <p>STS134-S-111 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> approaches Runway 15 on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida for the final time marking the 24th night landing of NASA's Space Shuttle Program. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-072.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-072.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-072 (1 June 2011) --- Xenon lights illuminate space shuttle <span class="hlt">Endeavour</span>'s unfurled drag chute as the vehicle rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-084.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-084.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-084 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> approaches Runway 15 on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-070.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-070.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-070 (1 June 2011) --- Xenon lights illuminate space shuttle <span class="hlt">Endeavour</span>'s unfurled drag chute as the vehicle rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-080.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-080.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-080 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> lands on Runway 15 on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-073.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-073.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-073 (1 June 2011) --- Xenon lights illuminate space shuttle <span class="hlt">Endeavour</span>'s unfurled drag chute as the vehicle rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-066.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-066.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-066 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> approaches Runway 15 on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-068.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-068.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-068 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> lands on Runway 15 on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-069.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-069.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-01</p> <p>STS134-S-069 (1 June 2011) --- Xenon lights illuminate space shuttle <span class="hlt">Endeavour</span>'s unfurled drag chute as the vehicle rolls to a stop on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida for the final time. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70027272','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70027272"><span>Massive collapse of volcano edifices triggered by <span class="hlt">hydrothermal</span> pressurization</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reid, M.E.</p> <p>2004-01-01</p> <p>Catastrophic collapse of steep volcano flanks threatens lives at stratovolcanoes around the world. Although destabilizing shallow intrusion of magma into the edifice accompanies some collapses (e.g., Mount St. Helens), others have occurred without eruption of juvenile magmatic materials (e.g., Bandai). These latter collapses can be difficult to anticipate. Historic collapses without magmatic eruption are associated with shallow <span class="hlt">hydrothermal</span> groundwater <span class="hlt">systems</span> at the time of collapse. Through the use of numerical models of heat and groundwater flow, I evaluate the efficacy of <span class="hlt">hydrothermally</span> driven collapse. Heating from remote magma intrusion at depth can generate temporarily elevated pore-fluid pressures that propagate upward into an edifice. Effective-stress deformation modeling shows that these pressures are capable of destabilizing the core of an edifice, resulting in massive, deep-seated collapse. Far-field pressurization only occurs with specific rock hydraulic properties; however, data from numerous <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> illustrate that this process can transpire in realistic settings. ?? 2004 Geological Society of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V33C2772M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V33C2772M"><span>Changes in Vegetation Reflect Changes in the Mammoth Mountain and Long Valley Caldera <span class="hlt">Hydrothermal</span> <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murphy, F.; Diefenbach, A. K.; Evans, W.; Hurwitz, S.</p> <p>2013-12-01</p> <p>We examined aerial photographs of the area near Mammoth Lakes, CA taken from 1951 to the present, with the goal of determining if visible changes in vegetation might reflect changes in the upflow of gas or heat through the soil zone. Such changes could be related to magmatic intrusion, the development of geothermal resources, groundwater pumping, earthquakes, or to natural changes in the <span class="hlt">hydrothermal</span> flow <span class="hlt">system</span>. We examined the area near Horseshoe Lake at the southern base of Mammoth Mountain where diffuse emissions of carbon dioxide created extensive tree-kill in the 1990s. Analysis of photographs acquired in 1951 suggests that tree density in this area was lower than its surroundings at the time. Whether the low-density tree cover identified in the photographs indicates some lasting effects of a previous episode of tree mortality needs further investigation. We also examine possible effects of geothermal energy production at Casa Diablo that began operation in 1985 on vegetation along the western part of the resurgent dome of Long Valley Caldera. Previous studies have correlated tree-kill in this area with increased steam upflow from the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts049-s-251.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts049-s-251.html"><span>STS-49 <span class="hlt">Endeavour</span>, Orbiter Vehicle (OV) 105, lifts off from KSC LC Pad 39B</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1992-05-07</p> <p>STS049-S-251 (7 May 1992) --- The Space Shuttle <span class="hlt">Endeavour</span> soars toward Earth orbit where a crew of seven NASA astronauts will spend at least a week. <span class="hlt">Endeavour</span>, the newest orbiter in NASA's Space Shuttle fleet, lifted off from Pad 39B at 7:40 p.m. (EDT), May 7, 1992. A diamond shock effect can be seen beneath the three main engines. Onboard are astronauts Daniel C. Brandenstein, mission commander; Kevin P. Chilton, pilot; and Richard J. Hieb, Bruce E. Melnick, Pierre J. Thuot, Kathryn C. Thornton and Thomas D. Akers, all mission specialists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-STS059-58-018.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-STS059-58-018.html"><span><span class="hlt">Endeavour</span> and its SRL-1 payload backdropped against the Southern Lights</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1994-04-10</p> <p>STS059-58-018 (9-20 April 1994) --- Part of the Space Shuttle <span class="hlt">Endeavour</span> and its Space Radar Laboratory (SRL-1) payload are backdropped against a colorful display of the Southern Lights (aurora australis). The vehicle was firing a reaction control subsystem thruster (below center) when the 35mm image was exposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MarGR..38...71Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MarGR..38...71Y"><span>230Th/238U dating of <span class="hlt">hydrothermal</span> sulfides from Duanqiao <span class="hlt">hydrothermal</span> field, Southwest Indian Ridge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Weifang; Tao, Chunhui; Li, Huaiming; Liang, Jin; Liao, Shili; Long, Jiangping; Ma, Zhibang; Wang, Lisheng</p> <p>2017-06-01</p> <p>Duanqiao <span class="hlt">hydrothermal</span> field is located between the Indomed and Gallieni fracture zones at the central volcano, at 50°28'E in the ultraslow-spreading Southwest Indian Ridge (SWIR). Twenty-eight subsamples from a relict chimney and massive sulfides were dated using the 230Th/238U method. Four main episodes of <span class="hlt">hydrothermal</span> activity were determined according to the restricted results: 68.9-84.3, 43.9-48.4, 25.3-34.8, and 0.7-17.3 kyrs. <span class="hlt">Hydrothermal</span> activity of Duanqiao probably started about 84.3 (±0.5) kyrs ago and ceased about 0.737 (±0.023) kyrs ago. The periodic character of <span class="hlt">hydrothermal</span> activity may be related to the heat source provided by the interaction of local magmatism and tectonism. The estimated mean growth rate of the sulfide chimney is <0.02 mm/yr. This study is the first to estimate the growth rate of chimneys in the SWIR. The maximum age of the relict chimney in Duanqiao <span class="hlt">hydrothermal</span> filed is close to that of the chimneys from Mt. Jourdanne (70 kyrs). The <span class="hlt">hydrothermal</span> activity in Dragon Flag field is much more recent than that of Duanqiao or Mt. Jourdanne fields. The massive sulfides are younger than the sulfides from other <span class="hlt">hydrothermal</span> fields such as Rainbow, Sonne and Ashadze-2. The preliminarily estimated reserves of sulfide ores of Duanqiao are approximately 0.5-2.9 million tons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JVGR..304..294C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JVGR..304..294C"><span>Carbon dioxide diffuse emission and thermal energy release from <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> at Copahue-Caviahue Volcanic Complex (Argentina)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chiodini, Giovanni; Cardellini, Carlo; Lamberti, María Clara; Agusto, Mariano; Caselli, Alberto; Liccioli, Caterina; Tamburello, Giancarlo; Tassi, Franco; Vaselli, Orlando; Caliro, Stefano</p> <p>2015-10-01</p> <p>The north-western sector of Caviahue caldera (Argentina), close to the active volcanic <span class="hlt">system</span> of Copahue, is characterized by the presence of several <span class="hlt">hydrothermal</span> sites that host numerous fumarolic emissions, anomalous soil diffuse degassing of CO2 and hot soils. In March 2014, measurements of soil CO2 fluxes in 5 of these sites (namely, Las Máquinas, Las Maquinitas I, Las Maquinitas II, Anfiteatro, and Termas de Copahue) allowed an estimation that 165 t of deeply derived CO2 is daily released. The gas source is likely related to a relatively shallow geothermal reservoir containing a single vapor phase as also suggested by both the geochemical data from the 3 deep wells drilled in the 1980s and gas geoindicators applied to the fumarolic discharges. Gas equilibria within the H-C-O gas <span class="hlt">system</span> indicate the presence of a large, probably unique, single phase vapor zone at 200-210 °C feeding the <span class="hlt">hydrothermal</span> manifestations of Las Máquinas, Las Maquinitas I and II and Termas de Copahue. A natural thermal release of 107 MW was computed by using CO2 as a tracer of the original vapor phase. The magmatic signature of the incondensable fumarolic gases, the wide expanse of the <span class="hlt">hydrothermal</span> areas and the remarkable high amount of gas and heat released by fluid expulsion seem to be compatible with an active magmatic intrusion beneath this portion of the Caviahue caldera.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=10540&hterms=kodak&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dkodak','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=10540&hterms=kodak&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dkodak"><span>International Space Station from Space Shuttle <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p>The crew of the Space Shuttle <span class="hlt">Endeavour</span> took this spectacular image of the International Space Station during the STS118 mission, August 8-21, 2007. The image was acquired by an astronaut through one of the crew cabin windows, looking back over the length of the Shuttle. This oblique (looking at an angle from vertical, rather than straight down towards the Earth) image was acquired almost one hour after late inspection activities had begun. The sensor head of the Orbiter Boom Sensor <span class="hlt">System</span> is visible at image top left. The entire Space Station is visible at image bottom center, set against the backdrop of the Ionian Sea approximately 330 kilometers below it. Other visible features of the southeastern Mediterranean region include the toe and heel of Italy's 'boot' at image lower left, and the western coastlines of Albania and Greece, which extend across image center. Farther towards the horizon, the Aegean and Black Seas are also visible. Featured astronaut photograph STS118-E-9469 was acquired by the STS-118 crew on August 19, 2007, with a Kodak 760C digital camera using a 28 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science and Analysis Laboratory at Johnson Space Center.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70023045','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70023045"><span>Carbon dioxide in magmas and implications for <span class="hlt">hydrothermal</span> <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lowenstern, J. B.</p> <p>2001-01-01</p> <p>This review focuses on the solubility, origin, abundance, and degassing of carbon dioxide (CO2) in magma-<span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, with applications for those workers interested in intrusion-related deposits of gold and other metals. The solubility of CO2 increases with pressure and magma alkalinity. Its solubility is low relative to that of H2O, so that fluids exsolved deep in the crust tend to have high CO2/H2O compared with fluids evolved closer to the surface. Similarly, CO2/H2O will typically decrease during progressive decompression- or crystallization-induced degassing. The temperature dependence of solubility is a function of the speciation of CO2, which dissolves in molecular form in rhyolites (retrograde temperature solubility), but exists as dissolved carbonate groups in basalts (prograde). Magnesite and dolomite are stable under a relatively wide range of mantle conditions, but melt just above the solidus, thereby contributing CO2 to mantle magmas. Graphite, diamond, and a free CO2-bearing fluid may be the primary carbon-bearing phases in other mantle source regions. Growing evidence suggests that most CO2 is contributed to arc magmas via recycling of subducted oceanic crust and its overlying sediment blanket. Additional carbon can be added to magmas during magma-wallrock interactions in the crust. Studies of fluid and melt inclusions from intrusive and extrusive igneous rocks yield ample evidence that many magmas are vapor saturated as deep as the mid crust (10-15 km) and that CO2 is an appreciable part of the exsolved vapor. Such is the case in both basaltic and some silicic magmas. Under most conditions, the presence of a CO2-bearing vapor does not hinder, and in fact may promote, the ascent and eruption of the host magma. Carbonic fluids are poorly miscible with aqueous fluids, particularly at high temperature and low pressure, so that the presence of CO2 can induce immiscibility both within the magmatic volatile phase and in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P43B2883S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P43B2883S"><span>Modeling <span class="hlt">Hydrothermal</span> Activity on Enceladus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stamper, T., Jr.; Farough, A.</p> <p>2017-12-01</p> <p>Cassini's mass spectrometer data and gravitational field measurements imply water-rock interactions around the porous core of Enceladus. Using such data we characterize global heat and fluid transport properties of the core and model the ongoing <span class="hlt">hydrothermal</span> activity on Enceladus. We assume that within the global ocean beneath the surface ice, seawater percolates downward into the core where it is heated and rises to the oceanfloor where it emanates in the form of diffuse discharge. We utilize the data from Hsu et al., [2015] with models of diffuse flow in seafloor <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> by Lowell et al., [2015] to characterize the global heat transport properties of the Enceladus's core. Based on direct observations the gravitational acceleration (g) is calculated 0.123 m s-2. We assume fluid's density (ρ) is 10­3 kg m-3 and the specific heat of the fluid (cf) is 4000 Jkg-1 °C-1. From these values effective thermal diffusivity (a*) is calculated as 10­-6 m2 s-1. We also assume the coefficient of thermal expansion of fluid (αf) and the kinematic viscosity of fluid (ν) to be 10-4 °C-1 and 10­-6 m2 s-1 respectively. The estimated Rayleigh number (Ra) ranges between 0.11-2468.0, for core porosity (φ) of 5-15%, permeability (k) between 10-12-10-8 m2 and temperature between 90-200 °C and the depth of fluid circulation of 100 m. High values of Rayleigh number, cause vigorous convection within the core of Enceladus. Numerical modeling of reactive transport in multicomponent, multiphase <span class="hlt">systems</span> is required to obtain a full understanding of the characteristics and evolution of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> on Enceladus, but simple scaling laws can provide insight into the physics of water-rock interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-04pd0347.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-04pd0347.html"><span>KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) listens to Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, with United Space Alliance, about corrosion work being done on the external tank door of orbiter <span class="hlt">Endeavour</span>. On either side of Laufenberg are Tom Roberts, Airframe Engineering <span class="hlt">System</span> specialist, also with USA, and Joy Huff, with KSC Space Shuttle Processing. <span class="hlt">Endeavour</span> is in its Orbiter Major Modification period, which began in December 2003.</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2004-02-25</p> <p>KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) listens to Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, with United Space Alliance, about corrosion work being done on the external tank door of orbiter <span class="hlt">Endeavour</span>. On either side of Laufenberg are Tom Roberts, Airframe Engineering <span class="hlt">System</span> specialist, also with USA, and Joy Huff, with KSC Space Shuttle Processing. <span class="hlt">Endeavour</span> is in its Orbiter Major Modification period, which began in December 2003.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B11A1656L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B11A1656L"><span>Chemolithoautotrophy in a shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, Milos Island, Greece</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, G. S.; LaRowe, D.; Gilhooly, W., III; Druschel, G. K.; Fike, D. A.; Amend, J.</p> <p>2017-12-01</p> <p>In recent decades, numerous (hyper)thermophilic microorganisms have been isolated from <span class="hlt">hydrothermal</span> venting <span class="hlt">systems</span>. Although they have been shown to have the capabilities to catalyze a wide variety of reactions to gain energy, few pure cultures have been isolated from these environments. In order to more fully understand the catabolic potential of organisms living in and near <span class="hlt">hydrothermal</span> vents, we have calculated the Gibbs energies (ΔGr) of 730 redox reactions that could be supplying energy to organisms in the shallow-sea <span class="hlt">hydrothermal</span> sediments of Paleochori Bay, Milos Island, Greece. This analysis required in-depth geochemical data on the pore fluids and minerals in these sediments near the vent site at several depths. The geochemical profiles of Saganaki vent show steep gradients in temperature, pH, and redox-sensitive compounds resulting from the mixing of hot ( 75oC), acidic ( pH 4), chemically reduced venting fluid with colder, slightly basic and oxidized seawater. We determined values of ΔGr for 47 sediment porewater samples along a 20cm x 2m transect for metabolic reactions involving 23 inorganic H-, O-, C-, N-, S-, Fe-, Mn-, and As- bearing compounds. 379 of the reactions considered were exergonic at one or more sampling locations. The most exergonic reactions were anaerobic CO oxidation with NO2- (136 - 162 kJ/mol e-), followed by the O2/CO, NO3-/CO, and NO2-/ H2S redox pairs. ΔGr values exhibit significant variation among sites as temperature, pH and chemical concentration vary, especially concentrations of Fe2+, Mn2+, and H2S. A great diversity of energy sources are available for microbial populations to exploit: in hotter sediments, sulfide oxidation coupled to nitrite reduction yields large amounts of energy per kg of sediment, whereas aerobic S0 oxidation is more energy-yielding in cooler areas. Our results show that at Saganaki there is a substantial amount of energy available from to microorganisms from sulfur-redox reactions. 16S rRNA pyrotag</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1512064I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1512064I"><span>Evolution of the Bucium Rodu and Frasin magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">system</span>, Metaliferi Mountains, Romania</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iatan, Elena Luisa; Berbeleac, Ion; Visan, Madalina; Minut, Adrian; Nadasan, Laurentiu</p> <p>2013-04-01</p> <p>The Miocene Bucium Rodu and Frasin maar-diatreme structures and related Au-Ag epithermal low sulfidation with passing to mesothermal mineralizations are located in the Bucium-Rosia Montana-Baia de Aries metallogenetic district, within so called the "Golden Quatrilaterum", in the northeastern part of the Metaliferi Mountains. These structures are situated at about 5 km southeast from Rosia Montana, the largest European Au-Ag deposit. The total reserves for Bucium Rodu-Frasin are estimated at 43.3 Mt with average contents of 1.3 g/t Au and 3 g/t Ag. The Miocene geological evolution of Bucium Rodu and Frasin magmatic-<span class="hlt">hydrothermal</span> <span class="hlt">system</span> took place in closely relationships with tectonic, magmatic and metallogenetic activity from Bucium-Rosia Montana-Baia de Aries district in general, and adjacent areas, in special. The <span class="hlt">hydrothermal</span> alteration is pervasive; adularia followed by phyllic, carbonatization and silicification alterations, usually show a close relationship with the mineralizations. Propylitic alteration occurs dominantly towards the depth; argillic alteration shows a local character. The mineralization occurs in veins, breccias, stockworks and disseminations and is hosted within two volcanic structures emplaced into a sequence of Cretaceous sediments in closely genetically relations with the Miocene phreatomagmatic fracturing and brecciation events. Within Rodu maar-diatreme structure the mineralizations follow especially the contact between the diatreme and Cretaceous flysch. The vein sets with low, moderately and near vertical dippings, cover 400x400m with N-S trend. The most important mineralization style is represented by veins, accompanied by <span class="hlt">hydrothermal</span> breccias and disseminations. The veins spatial distribution relives as "en echelon" tension veins. They carry gold, minor base metal sulphides (pyrite, chalcopyrite, sphalerite, galena, tetrahedrite, arsenopyrite). Gangue is represented by carbonates (calcite, dolomite, ankerite, siderite, rhodochrosite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PNAS..11412413A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PNAS..11412413A"><span>Effect of paleoseawater composition on <span class="hlt">hydrothermal</span> exchange in midocean ridges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonelli, Michael A.; Pester, Nicholas J.; Brown, Shaun T.; DePaolo, Donald J.</p> <p>2017-11-01</p> <p>Variations in the Mg, Ca, Sr, and SO4 concentrations of paleoseawater can affect the chemical exchange between seawater and oceanic basalt in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> at midocean ridges (MOR). We present a model for evaluating the nature and magnitude of these previously unappreciated effects, using available estimates of paleoseawater composition over Phanerozoic time as inputs and 87Sr/86Sr of ophiolite epidosites and epidote-quartz veins as constraints. The results suggest that modern <span class="hlt">hydrothermal</span> fluids are not typical due to low Ca and Sr relative to Mg and SO4 in modern seawater. At other times during the last 500 million years, particularly during the Cretaceous and Ordovician, <span class="hlt">hydrothermal</span> fluids had more seawater-derived Sr and Ca, a prediction that is supported by Sr isotope data. The predicted 87Sr/86Sr of vent fluids varies cyclically in concert with ocean chemistry, with some values much higher than the modern value of ˜0.7037. The seawater chemistry effects can be expressed in terms of the transfer efficiency of basaltic Ca and Sr to seawater in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, which varies by a factor of ˜1.6 over the Phanerozoic, with minima when seawater Mg and SO4 are low. This effect provides a modest negative feedback on seawater composition and 87Sr/86Sr changes. For the mid-Cretaceous, the low 87Sr/86Sr of seawater requires either exceptionally large amounts of low-temperature exchange with oceanic crust or that the weathering flux of continentally derived Sr was especially small. The model also has implications for MOR <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the Precambrian, when low-seawater SO4 could help explain low seawater 87Sr/86Sr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0163&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0163&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller"><span>The faulty Master Events Controller is removed from STS-99 <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>Technicians remove a faulty Enhanced Main Events Controller (E- MEC) from Shuttle <span class="hlt">Endeavour</span> at Launch Pad 39A. The E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently <span class="hlt">Endeavour</span> and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V23D3014R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V23D3014R"><span>Cu-As Decoupling in <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span>: A Link Between Pyrite Chemistry and Fluid Composition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reich, M.; Tardani, D.; Deditius, A.; Chryssoulis, S.; Wrage, J.; Sanchez-Alfaro, P.; Andrea, H.; Cinthia, J.</p> <p>2016-12-01</p> <p>Chemical zonations in pyrite have been recognized in most <span class="hlt">hydrothermal</span> ore deposit types, showing in some cases marked oscillatory alternation of metals and metalloids in pyrite growth zones (e.g., of Cu-rich, As-(Au)-depleted zones and As-(Au)-rich, Cu-depleted zones). This decoupled geochemical behavior of Cu and As has been interpreted as a result of chemical changes in ore-forming fluids, although direct evidence connecting fluctuations in <span class="hlt">hydrothermal</span> fluid composition with metal partitioning into pyrite growth zones is still lacking. Here we report a comprehensive trace element database of pyrite from an active <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, the Tolhuaca Geothermal <span class="hlt">System</span> (TGS) in southern Chile. We combined high-spatial resolution and X-ray mapping capabilities of electron microprobe analysis (EMPA) with low detection limits and depth-profiling capabilities of secondary-ion mass spectrometry (SIMS) in a suite of pyrite samples retrieved from a 1 km drill hole that crosses the argillic and propylitic alteration zones of the geothermal <span class="hlt">system</span>. We show that the concentrations of precious metals (e.g., Au, Ag), metalloids (e.g., As, Sb, Se, Te), and base and heavy metals (e.g., Cu, Co, Ni, Pb) in pyrite at the TGS are significant. Among the elements analyzed, arsenic, Cu and Co are the most abundant with concentrations that vary from sub-ppm levels to a few wt. %. Pyrites from the deeper propylitic zone do not show significant zonation and high Cu-(Co)-As concentrations correlate with each other. In contrast, well-developed zonations were detected in pyrite from the shallow argillic alteration zone, where Cu(Co)-rich, As-depleted cores alternate with Cu(Co)-depleted, As-rich rims. These microanalytical data were contrasted with chemical data of fluid inclusion in quartz veins (high Cu/Na and low As/Na) and borehole fluids (low Cu/Na and high As/Na) reported at the TGS, showing a clear correspondence between Cu and As concentrations in pyrite-forming fluids and chemical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5392L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5392L"><span><span class="hlt">Hydrothermal</span> fluoride and chloride complexation of indium: an EXAFS study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loges, Anselm; Testemale, Denis; Huotari, Simo; Honkanen, Ari-Pekka; Potapkin, Vasily; Wagner, Thomas</p> <p>2017-04-01</p> <p>Indium (In) is one of the geochemically lesser studied ore metals, and the factors that control the <span class="hlt">hydrothermal</span> transport and deposition are largely unknown. It has no ore deposits of its own and is commonly mined as a by-product of Zn ores, and there are very few minerals that contain In as an essential structural component. Recently, industrial application of In in touch screen devices has drastically increased demand, which is projected to exceed supply from the current sources in the near future. Since the most relevant In sources are <span class="hlt">hydrothermal</span> sphalerite ores and to a lesser extent <span class="hlt">hydrothermal</span> greisen-type deposits in evolved granitic plutons, the aqueous geochemistry of In is of particular interest for understanding its ore forming processes. As a first step towards a comprehensive model for <span class="hlt">hydrothermal</span> In solubility and speciation, we have studied In speciation in fluoride and chloride bearing solutions at 30-400˚ C and 500 bar using X-Ray Absorption Spectroscopy (XAS) measurements. The experiments were conducted in a unique <span class="hlt">hydrothermal</span> autoclave setup at beamline BM30B-FAME at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Our results show that the complexation of In changes dramatically between 30 and 400˚ C. Below ca. 200˚ C, fluoride complexes are the most stable ones, but they break down at higher temperatures. Chloride complexes on the other hand become increasingly stable with increasing temperature. This behavior has interesting consequences for natural ore forming <span class="hlt">systems</span>. In Cl-rich <span class="hlt">systems</span> (e.g. massive sulfide ores formed in sea floor environments), cooling can be an effective precipitating mechanism. In F-rich <span class="hlt">systems</span>, fluoride complexation can extend In mobility to low temperatures and In will only precipitate when F is effectively removed from the fluid, e.g. by mixing with a Ca-rich fluid and precipitation of fluorite (CaF2) as is commonly observed in skarn or greisen-type deposits. Due to In complexing with</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-02PD-1732&hterms=leak&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dleak','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-02PD-1732&hterms=leak&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dleak"><span>Scrape on <span class="hlt">Endeavour</span>'s robotic arm during oxygen leak repairs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p>KENNEDY SPACE CENTER, FLA. -- One of a team of robotic experts looks at the site of the scrape on the surface of the honeycomb shell on the robotic arm that occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. The site will be cut out and ultrasound testing will be done on the structure underneath. Launch of <span class="hlt">Endeavour</span> on mission STS-113 has been postponed until no earlier than Nov. 22.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017FrEaS...5...41C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017FrEaS...5...41C"><span>Learning about <span class="hlt">hydrothermal</span> volcanic activity by modeling induced geophysical changes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Currenti, Gilda M.; Napoli, Rosalba</p> <p>2017-05-01</p> <p>Motivated by ongoing efforts to understand the nature and the energy potential of geothermal resources, we devise a coupled numerical model (hydrological, thermal, mechanical), which may help in the characterization and monitoring of <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> through computational experiments. <span class="hlt">Hydrothermal</span> areas in volcanic regions arise from a unique combination of geological and hydrological features which regulate the movement of fluids in the vicinity of magmatic sources capable of generating large quantities of steam and hot water. Numerical simulations help in understanding and characterizing rock-fluid interaction processes and the geophysical observations associated with them. Our aim is the quantification of the response of different geophysical observables (i.e. deformation, gravity and magnetic field) to <span class="hlt">hydrothermal</span> activity on the basis of a sound geological framework (e.g. distribution and pathways of the flows, the presence of fractured zones, caprock). A detailed comprehension and quantification of the evolution and dynamics of the geothermal <span class="hlt">systems</span> and the definition of their internal state through a geophysical modeling approach are essential to identify the key parameters for which the geothermal <span class="hlt">system</span> may fulfill the requirements to be exploited as a source of energy. For the sake of illustration only, the numerical computations are focused on a conceptual model of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> of Vulcano Island by simulating a generic 1-year unrest and estimating different geophysical changes. We solved (i) the mass and energy balance equations of flow in porous media for temperature, pressure and density changes, (ii) the elastostatic equation for the deformation field and (iii) the Poisson’s equations for gravity and magnetic potential fields. Under the model assumptions, a generic unrest of 1-year engenders on the ground surface low amplitude changes in the investigated geophysical observables, that are, however, above the accuracies of the modern</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003E%26PSL.206..555S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003E%26PSL.206..555S"><span>Magnetic fabrics and fluid flow directions in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. A case study in the Chaillac Ba-F-Fe deposits (France)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sizaret, Stanislas; Chen, Yan; Chauvet, Alain; Marcoux, Eric; Touray, Jean Claude</p> <p>2003-02-01</p> <p>This study presents a possible use of anisotropy of magnetic susceptibility (AMS) to describe the mineralizing process in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. Ba-F-Fe-rich deposits within the Chaillac Basin are on the southern border of the Paris Basin. In these deposits <span class="hlt">hydrothermal</span> textures and tectonic structures have been described in veins, sinters, and sandstone cemented by <span class="hlt">hydrothermal</span> goethite. 278 oriented cores from 24 sites have been collected in these formations. In addition, a lateritic duricrust superimposed on the <span class="hlt">hydrothermal</span> formation has been sampled. Rock magnetic investigations show that the principal magnetic carrier is goethite for the <span class="hlt">hydrothermal</span> mineralization and for the laterite level. The AMS measurements show distinguishable behaviors in the different mineralogical and geological contexts. The K1 magnetic lineation (maximum axis) is strongly inclined for the vertical veins. For the horizontally mineralized sinters, the magnetic lineation is almost horizontal with an azimuth similar to the sedimentary flow direction. The AMS of goethite-rich sandstone close to the veins shows strongly inclined K1 as they are probably influenced by the vertical veins; however, when the distance from the vein is larger than 1 m, the AMS presents rather horizontal K1 directions, parallel to the sedimentary flow. The laterite has a foliation dominance of AMS with vertically well-grouped K3 axes and scattered K1 and K2 axes. Field structural observations suggest that the ore deposit is mainly controlled by EW extension tectonics associated with NS trending normal faults. Combining the AMS results on the deposit with vein textures and field data a model is proposed in which AMS results are interpreted in terms of <span class="hlt">hydrothermal</span> fluid flow. This work opens a new investigation field to constrain hydrodynamic models using the AMS method. Textural study combined with efficient AMS fabric measurements should be used for systematic investigation to trace flow direction in fissures</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V51C0358P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V51C0358P"><span>Electron microscopy study of microbial mat in the North Fiji basin <span class="hlt">hydrothermal</span> vent</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, H.; Kim, J. W.; Lee, J. W.</p> <p>2017-12-01</p> <p><span class="hlt">Hydrothermal</span> vent <span class="hlt">systems</span> consisting of <span class="hlt">hydrothermal</span> vent, <span class="hlt">hydrothermal</span> sediment and microbial mat are widely spread around the ocean, particularly spreading axis, continental margin and back-arc basin. Scientists have perceived that the <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, which reflect the primeval earth environment, are one of the best places to reveal the origin of life and extensive biogeochemical process of microbe-mineral interaction. In the present study multiline of analytical methods (X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM)) were utilized to investigate the mineralogy/chemistry of microbe-mineral interaction in <span class="hlt">hydrothermal</span> microbial mat. Microbial mat samples were recovered by Canadian scientific submersible ROPOS on South Pacific North Fiji basin KIOST <span class="hlt">hydrothermal</span> vent expedition 1602. XRD analysis showed that red-colored microbial mat contains Fe-oxides and Fe-oxyhydroxides. Various morphologies of minerals in the red-colored microbial mat observed by SEM are mainly showed sheath shaped, resembled with Leptothrix microbial structure, stalks shaped, similar with Marioprofundus microbial structure and globule shaped microbial structures. They are also detected with DNA analysis. The cross sectional observation of microbial structures encrusted with Fe-oxide and Fe-oxyhydroxide at a nano scale by Transmission Electron Microscopy (TEM) and Focused Ion Beam (FIB) technique was developed to verify the structural/biogeochemical properties in the microbe-mineral interaction. Systematic nano-scale measurements on the biomineralization in the microbial mat leads the understandings of biogeochemical environments around the <span class="hlt">hydrothermal</span> vent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-07PD-2256.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-07PD-2256.html"><span>Launch of Space Shuttle <span class="hlt">Endeavour</span> as it leaps free of Launch Pad</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2007-08-08</p> <p>Space Shuttle <span class="hlt">Endeavour</span> paints the still-blue evening sky as it leaves Earth behind on its journey into space on mission STS-118. Liftoff from Launch Pad 39A was on time at 6:36 p.m. EDT. The mission is the 22nd shuttle flight to the International Space Station. It will continue space station construction by delivering a third starboard truss segment, S5, and other payloads such as the SPACEHAB module and the external stowage platform 3. The 11-day mission may be extended to as many as 14 depending on the test of the Station-to-Shuttle Power Transfer <span class="hlt">System</span> that will allow the docked shuttle to draw electrical power from the station and extend its visits to the orbiting lab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss004e5024.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss004e5024.html"><span>ISS, Soyuz, and <span class="hlt">Endeavour</span> undocking seen from the SM during Expedition Four</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2001-12-15</p> <p>ISS004-E-5024 (15 December 2001) --- A Soyuz vehicle, docked to the International Space Station (ISS), is photographed by a crewmember on the station. A portion of the Space Shuttle <span class="hlt">Endeavour</span> is visible in the background. The image was taken with a digital still camera.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70186663','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70186663"><span>The role of magmas in the formation of <span class="hlt">hydrothermal</span> ore deposits</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hedenquist, Jeffrey W.; Lowenstern, Jacob B.</p> <p>1994-01-01</p> <p>Magmatic fluids, both vapour and hypersaline liquid, are a primary source of many components in <span class="hlt">hydrothermal</span> ore deposits formed in volcanic arcs. These components, including metals and their ligands, become concentrated in magmas in various ways from various sources, including subducted oceanic crust. Leaching of rocks also contributes components to the <span class="hlt">hydrothermal</span> fluid—a process enhanced where acid magmatic vapours are absorbed by deeply circulating meteoric waters. Advances in understanding the <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> that formed these ore deposits have come from the study of their active equivalents, represented at the surface by hot springs and volcanic fumaroles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.V43D1440S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.V43D1440S"><span>Multi-Sensor Mapping of Diffuse Degassing of C-O-H Compounds in Terrestrial <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwandner, F. M.; Shock, E. L.</p> <p>2004-12-01</p> <p> and partially map a previously-inferred active lineament in the Obsidian Pool area. In addition, reduced gas data are yielding areal ratio distributions of CO/CO2, H2/CH4, and CO/CH4, that may be indicative of reactions such as the catalytic hydrogenation of CO2 (Sabatier-Process) and of CO (Fischer-Tropsch-Process) within the shallow <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Barberi & Carapezza (1994). Bull. Volcanol. 56(5): 335-342. Brombach, et al. (2001). Geophys. Res. Lett. 28(1): 69-72. Crenshaw et al. (1982). Nature 300: 345-346. Chiodini et al. (1996). Bull. Volcanol. 58(1): 41-50. Schwandner et al. (2004). JGR D 109: D04301, doi:10.1029/2003JD003890. Werner & Brantley (2004) JGR B 105: 10,831-10,846. Werner et al. (2003). Earth Planet. Sci. Lett. 210: 561-577. Williams (1985). Science 229(4713): 551-553. Williams-Jones et al. (2000). Bull. Volcanol. 62: 130-142.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024075','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024075"><span>Geochemistry of fluid phases and sediments: Relevance to <span class="hlt">hydrothermal</span> circulation in Middle Valley, ODP Legs 139 and 169</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gieskes, J.M.; Simoneit, B.R.T.; Shanks, Wayne C.; Goodfellow, W.D.; James, R.H.; Baker, P.A.; Ishibashi, J.-I.</p> <p>2002-01-01</p> <p>Geochemical and isotopic studies of pore fluids and solid phases recovered from the Dead Dog and Bent Hill <span class="hlt">hydrothermal</span> sites in Middle Valley (Ocean Drilling Program Leg 169) have been compared with similar data obtained previously from these sites during Ocean Drilling Program Leg 139. Although generally the <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> reflect non-steady state conditions, the data allow an assessment of the history of the <span class="hlt">hydrothermal</span> processes. Sediment K/A1 ratios as well as the distribution of anhydrite in the sediments suggest that the Dead Dog <span class="hlt">hydrothermal</span> field has been, and still is, active. In contrast, similar data in the Bent Hill <span class="hlt">hydrothermal</span> field indicate a waning of <span class="hlt">hydrothermal</span> activity. Pore fluid and <span class="hlt">hydrothermal</span> vent data in the Dead Dog <span class="hlt">hydrothermal</span> field are similar in nature to the data collected during ODP Leg 139. In the area of the Bent Hill sulfide deposit, however, the pore water data indicate that recent wholesale flushing of the sediment column with relatively unaltered seawater has obliterated a previous record of <span class="hlt">hydrothermal</span> activity in the pore fluids. Data from the deepest part of Hole 1035A in the Bent Hill locality show the presence of <span class="hlt">hydrothermal</span> fluids at greater depths in this area. This suggests the origin of the <span class="hlt">hydrothermal</span> fluids found to be emanating from Hole 1035F, which constitutes one of the first man made <span class="hlt">hydrothermal</span> vents in the Middle Valley <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Similarly, CORKed Hole 858G, because of seal failures, has acted as a <span class="hlt">hydrothermal</span> vent, with sulfide deposits forming inside the CORK. ?? 2002 Elsevier Science Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70094692','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70094692"><span><span class="hlt">Hydrothermal</span> contamination of public supply wells in Napa and Sonoma Valleys, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Forrest, Matthew J.; Kulongoski, Justin T.; Edwards, Matthew S.; Farrar, Christopher D.; Belitz, Kenneth; Norris, Richard D.</p> <p>2013-01-01</p> <p>Groundwater chemistry and isotope data from 44 public supply wells in the Napa and Sonoma Valleys, California were determined to investigate mixing of relatively shallow groundwater with deeper <span class="hlt">hydrothermal</span> fluids. Multivariate analyses including Cluster Analyses, Multidimensional Scaling (MDS), Principal Components Analyses (PCA), Analysis of Similarities (ANOSIM), and Similarity Percentage Analyses (SIMPER) were used to elucidate constituent distribution patterns, determine which constituents are significantly associated with these <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, and investigate <span class="hlt">hydrothermal</span> contamination of local groundwater used for drinking water. Multivariate statistical analyses were essential to this study because traditional methods, such as mixing tests involving single species (e.g. Cl or SiO2) were incapable of quantifying component proportions due to mixing of multiple water types. Based on these analyses, water samples collected from the wells were broadly classified as fresh groundwater, saline waters, <span class="hlt">hydrothermal</span> fluids, or mixed <span class="hlt">hydrothermal</span> fluids/meteoric water wells. The Multivariate Mixing and Mass-balance (M3) model was applied in order to determine the proportion of <span class="hlt">hydrothermal</span> fluids, saline water, and fresh groundwater in each sample. Major ions, isotopes, and physical parameters of the waters were used to characterize the <span class="hlt">hydrothermal</span> fluids as Na–Cl type, with significant enrichment in the trace elements As, B, F and Li. Five of the wells from this study were classified as <span class="hlt">hydrothermal</span>, 28 as fresh groundwater, two as saline water, and nine as mixed <span class="hlt">hydrothermal</span> fluids/meteoric water wells. The M3 mixing-model results indicated that the nine mixed wells contained between 14% and 30% <span class="hlt">hydrothermal</span> fluids. Further, the chemical analyses show that several of these mixed-water wells have concentrations of As, F and B that exceed drinking-water standards or notification levels due to contamination by <span class="hlt">hydrothermal</span> fluids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5021209','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5021209"><span>Subseafloor microbial communities in hydrogen‐rich vent fluids from <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> along the Mid‐Cayman Rise</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Reveillaud, Julie; Reddington, Emily; McDermott, Jill; Algar, Christopher; Meyer, Julie L.; Sylva, Sean; Seewald, Jeffrey; German, Christopher R.</p> <p>2016-01-01</p> <p>Summary Warm fluids emanating from <span class="hlt">hydrothermal</span> vents can be used as windows into the rocky subseafloor habitat and its resident microbial community. Two new vent <span class="hlt">systems</span> on the Mid‐Cayman Rise each exhibits novel geologic settings and distinctively hydrogen‐rich vent fluid compositions. We have determined and compared the chemistry, potential energy yielding reactions, abundance, community composition, diversity, and function of microbes in venting fluids from both sites: Piccard, the world's deepest vent site, hosted in mafic rocks; and Von Damm, an adjacent, ultramafic‐influenced <span class="hlt">system</span>. Von Damm hosted a wider diversity of lineages and metabolisms in comparison to Piccard, consistent with thermodynamic models that predict more numerous energy sources at ultramafic <span class="hlt">systems</span>. There was little overlap in the phylotypes found at each site, although similar and dominant hydrogen‐utilizing genera were present at both. Despite the differences in community structure, depth, geology, and fluid chemistry, energetic modelling and metagenomic analysis indicate near functional equivalence between Von Damm and Piccard, likely driven by the high hydrogen concentrations and elevated temperatures at both sites. Results are compared with <span class="hlt">hydrothermal</span> sites worldwide to provide a global perspective on the distinctiveness of these newly discovered sites and the interplay among rocks, fluid composition and life in the subseafloor. PMID:26663423</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036315','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036315"><span>A multitracer approach for characterizing interactions between shallow groundwater and the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in the Norris Geyser Basin area, Yellowstone National Park</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gardner, W.P.; Susong, D.D.; Solomon, D.K.; Heasler, H.P.</p> <p>2011-01-01</p> <p>Multiple environmental tracers are used to investigate age distribution, evolution, and mixing in local- to regional-scale groundwater circulation around the Norris Geyser Basin area in Yellowstone National Park. Springs ranging in temperature from 3??C to 90??C in the Norris Geyser Basin area were sampled for stable isotopes of hydrogen and oxygen, major and minor element chemistry, dissolved chlorofluorocarbons, and tritium. Groundwater near Norris Geyser Basin is comprised of two distinct <span class="hlt">systems</span>: a shallow, cool water <span class="hlt">system</span> and a deep, high-temperature <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. These two end-member <span class="hlt">systems</span> mix to create springs with intermediate temperature and composition. Using multiple tracers from a large number of springs, it is possible constrain the distribution of possible flow paths and refine conceptual models of groundwater circulation in and around a large, complex <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Copyright 2011 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812544B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812544B"><span>Resistivity structure of the Furnas <span class="hlt">hydrothermal</span> <span class="hlt">system</span> (Azores archipelago, Portugal) from AMT and ERT imaging.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Byrdina, Svetlana; Vandemeulebrouck, Jean; Rath, Volker; Silva, Catarina; Hogg, Colin; Kiyan, Duygu; Viveiros, Fatima; Eleuterio, Joana; Gresse, Marceau</p> <p>2016-04-01</p> <p>The Furnas volcanic complex is located in the eastern part of the São Miguel Island and comprises a 5 km × 8 km summit depression filled by two nested calderas with several craters and a lake. Present-day volcanic activity of Furnas volcano is mostly located in the northern part of the caldera, within the Furnas village and north to Furnas Lake, where <span class="hlt">hydrothermal</span> manifestations are mainly fumarolic fields, steam vents, thermal springs, and intense soil diffuse degassing. Considering the Furnas volcano as a whole, the total integrated CO2 efflux is extremely high, with a total amount of CO2 close to 1000 ton per day (Viveiros et al., 2009). We present the first results of an electrical resistivity tomography (ERT), combined with audio-magneto-telluric (AMT) measurements aligned along two profiles inside the caldera. The purpose of this survey is to delimit the extent, the geometry, and the depth of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> and to correlate the deep resistivity structure with high resolution cartography of diffuse CO2 flux (Viveiros et al, 2015). The ERT and AMT methods are complementary in terms of resolution and penetration depth: ERT can image the structural details of shallow <span class="hlt">hydrothermal</span> <span class="hlt">system</span> (down to 100 m in our study) while AMT can image at lower resolution deeper structures at the roots of a volcano (down to 4 km in our study). Our first independent 2D inversions of the ERT-AMT data show a good agreement between the surficial and deeper features. Below the main fumarole area we observe a low resistivity body (less than 1 Ohmm) which corresponds well to the high CO2 flux at the surface and is associated with an extended conductive body at larger depth. These results strongly suggest the presence of <span class="hlt">hydrothermal</span> waters at depth or/and the presence of altered clay-rich material. On a larger scale however, the geometry of the conducting zones differs slightly from what was expected from earlier surface studies, and may not be directly related to fault zones</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts057-s-055.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts057-s-055.html"><span>STS-57 <span class="hlt">Endeavour</span>, OV-105, framed by Florida vegetation, lifts off from KSC LC</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1993-06-21</p> <p>STS057-S-055 (21 June 1993) --- Framed by a variety of flora types, the Space Shuttle <span class="hlt">Endeavour</span> lifts off Launch Pad 39B to begin the STS-57 mission. Launch occurred at 9:07:22 a.m. (EDT), June 21, 1993. The mission represents the first flight of the commercially developed SPACEHAB laboratory module and also will feature a retrieval of the European Retrievable Carrier (EURECA). Onboard for <span class="hlt">Endeavour</span>'s fourth flight are a crew of six - Ronald J. Grabe, mission commander; Brian Duffy, pilot; G. David Low, payload commander; and Nancy J. Sherlock, Peter J.K. (Jeff) Wisoff and Janice E. Voss, all mission specialists. An earlier launch attempt was scrubbed due to unacceptable weather conditions both at KSC and the overseas contingency landing sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNS13A0003P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNS13A0003P"><span>Investigating Crustal Scale Fault <span class="hlt">Systems</span> Controlling Volcanic and <span class="hlt">Hydrothermal</span> Fluid Processes in the South-Central Andes, First Results from a Magnetotelluric Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pearce, R.; Mitchell, T. M.; Moorkamp, M.; Araya, J.; Cembrano, J. M.; Yanez, G. A.; Hammond, J. O. S.</p> <p>2017-12-01</p> <p>At convergent plate boundaries, volcanic orogeny is largely controlled by major thrust fault <span class="hlt">systems</span> that act as magmatic and <span class="hlt">hydrothermal</span> fluid conduits through the crust. In the south-central Andes, the volcanically and seismically active Tinguiririca and Planchon-Peteroa volcanoes are considered to be tectonically related to the major El Fierro thrust fault <span class="hlt">system</span>. These large scale reverse faults are characterized by 500 - 1000m wide <span class="hlt">hydrothermally</span> altered fault cores, which possess a distinct conductive signature relative to surrounding lithology. In order to establish the subsurface architecture of these fault <span class="hlt">systems</span>, such conductivity contrasts can be detected using the magnetotelluric method. In this study, LEMI fluxgate-magnetometer long-period and Metronix broadband MT data were collected at 21 sites in a 40km2 survey grid that surrounds this fault <span class="hlt">system</span> and associated volcanic complexes. Multi-remote referencing techniques is used together with robust processing to obtain reliable impedance estimates between 100 Hz and 1,000s. Our preliminary inversion results provide evidence of structures within the 10 - 20 km depth range that are attributed to this fault <span class="hlt">system</span>. Further inversions will be conducted to determine the approximate depth extent of these features, and ultimately provide constraints for future geophysical studies aimed to deduce the role of these faults in volcanic orogeny and <span class="hlt">hydrothermal</span> fluid migration processes in this region of the Andes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T23A1880N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T23A1880N"><span>An exploration for <span class="hlt">hydrothermal</span> plume evolution using the AUV "URASHIMA" with fluid sampling <span class="hlt">system</span> at southern Mariana Trough</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Noguchi, T.; Sunamura, M.; Yamamoto, H.; Fukuba, T.; Okino, K.; Sugiyama, T.; Okamura, K.</p> <p>2009-12-01</p> <p><span class="hlt">Hydrothermal</span> fluids contain high concentration of anoxic chemical species, i.e. methane and hydrogen sulfide, helium-3, and heavy metals derived from the rock-water interaction. During the hydothermal plume spreading, it is known that several chemical species are oxidized which include available energy source for microorganism, however, few results have been reported on the spatial variation of both of chemical and microbiological concentration and species. In the southern Mariana Trough, some site surveys have been conducted with CTD hydrocasts, the manned submersible, and ROVs since 2003. In this field, three <span class="hlt">hydrothermal</span> vent sites were discovered within the small area, where the chemistry of each <span class="hlt">hydrothermal</span> fluid was different from each other. These differences of chemistry are prospected to affect the individual plume evolution. In order to discuss the each <span class="hlt">hydrothermal</span> plume evolution, we conducted high-resolution plume mapping by the AUV "URASHIMA" with some chemical sensors. Additionally, we loaded 24 bottles of water sampler for the geochemical and microbial analysis. During this cruise, we detected <span class="hlt">hydrothermal</span> plume anomalies derived from each <span class="hlt">hydrothermal</span> site with the highly precise topographic results. Based on the results, we will discuss the relationships between the spreading of <span class="hlt">hydrothermal</span> plume (geochemical evolution) and the ecology of plume microbes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeCoA.223..107Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeCoA.223..107Y"><span>Effects of iron-containing minerals on <span class="hlt">hydrothermal</span> reactions of ketones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Ziming; Gould, Ian R.; Williams, Lynda B.; Hartnett, Hilairy E.; Shock, Everett L.</p> <p>2018-02-01</p> <p><span class="hlt">Hydrothermal</span> organic transformations occurring in geochemical processes are influenced by the surrounding environments including rocks and minerals. This work is focused on the effects of five common minerals on reactions of a model ketone substrate, dibenzylketone (DBK), in an experimental <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Ketones play a central role in many <span class="hlt">hydrothermal</span> organic functional group transformations, such as those converting hydrocarbons to oxygenated compounds; however, how these minerals control the <span class="hlt">hydrothermal</span> chemistry of ketones is poorly understood. Under the <span class="hlt">hydrothermal</span> conditions of 300 °C and 70 MPa for up to 168 h, we observed that, while quartz (SiO2) and corundum (Al2O3) had no detectable effect on the <span class="hlt">hydrothermal</span> reactions of DBK, iron-containing minerals, such as hematite (Fe2O3), magnetite (Fe3O4), and troilite (synthetic FeS), accelerated the reaction of DBK by up to an order of magnitude. We observed that fragmentation products, such as toluene and bibenzyl, dominated in the presence of hematite or magnetite, while use of troilite gave primarily the reduction products, e.g., 1, 3-diphenyl-propane and 1, 3-diphenyl-2-propanol. The roles of the three iron minerals in these transformations were further explored by (1) control experiments with various mineral surface areas, (2) measuring H2 in <span class="hlt">hydrothermal</span> solutions, and (3) determining hydrogen balance among the organic products. These results suggest the reactions catalyzed by iron oxides (hematite and magnetite) are promoted mainly by the mineral surfaces, whereas the sulfide mineral (troilite) facilitated the reduction of ketone in the reaction solution. Therefore, this work not only provides a useful chemical approach to study and uncover complicated <span class="hlt">hydrothermal</span> organic-mineral interactions, but also fosters a mechanistic understanding of ketone reactions in the deep carbon cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts134-s-112.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts134-s-112.html"><span>Final Landing of the Space Shuttle <span class="hlt">Endeavour</span> / STS-134 Mission</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-06-03</p> <p>STS134-S-112 (1 June 2011) --- Space shuttle <span class="hlt">Endeavour</span> touches down on Runway 15 on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida for the final time marking the 24th night landing of NASA's Space Shuttle Program. Main gear touchdown was at 2:34:51 a.m. (EDT) on June 1, 2011, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Onboard are NASA astronauts Mark Kelly, STS-134 commander; Greg H. Johnson, pilot; Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori, all mission specialists. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for <span class="hlt">Endeavour</span>, which has spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BVol...75..729Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BVol...75..729Y"><span>A large <span class="hlt">hydrothermal</span> reservoir beneath Taal Volcano (Philippines) revealed by magnetotelluric resistivity survey: 2D resistivity modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamaya, Y.; Alanis, P. K. B.; Takeuchi, A.; Cordon, J. M.; Mogi, T.; Hashimoto, T.; Sasai, Y.; Nagao, T.</p> <p>2013-07-01</p> <p>Taal Volcano, located in the southwestern part of Luzon Island, Philippines, has frequently experienced catastrophic eruptions from both the Main Crater on Volcano Island and flank eruptions. These eruptions have been magmatic, phreatomagmatic, and <span class="hlt">hydrothermal</span>, with the latter implying the existence of a large-scale <span class="hlt">hydrothermal</span> <span class="hlt">system</span> beneath the volcano. We conducted an electrical resistivity survey using the magnetotelluric method in order to identify the location and geometry of the <span class="hlt">hydrothermal</span> reservoir and sealing cap rock. Two-dimensional inversion using the observed data indicates four similar resistivity sections. The structure at shallow depths corresponds to volcanic deposits and an aquifer. Below 1 km, the structure features a relatively resistive zone beneath the main crater surrounded by a conductive shell. We interpreted these to be a large <span class="hlt">hydrothermal</span> reservoir with an impermeable cap rock sealing it. Recent ground deformation detected by GPS measurements suggests that the <span class="hlt">hydrothermal</span> reservoir is active. The interpreted cap rock thins just beneath the main crater and could easily be destroyed by an imbalance in the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. We conclude that this <span class="hlt">hydrothermal</span> reservoir plays a significant role in driving catastrophic eruptions that begin with a <span class="hlt">hydrothermal</span> explosion at the main crater.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMOS42A..03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMOS42A..03K"><span>Subseafloor fluid mixing and fossilized microbial life in a Cretaceous 'Lost City'-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the Iberian Margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klein, F.; Humphris, S. E.; Guo, W.; Schubotz, F.; Schwarzenbach, E. M.; Orsi, W.</p> <p>2015-12-01</p> <p>Subseafloor mixing of reduced <span class="hlt">hydrothermal</span> fluids with seawater is believed to provide the energy and substrates needed to support autotrophic microorganisms in the hydrated oceanic mantle (serpentinite). Despite the potentially significant implications for the distribution of microbial life on Earth and other water-bearing planetary bodies, our understanding of such environments remains elusive. In the present study we examined fossilized microbial communities and fluid mixing processes in the subseafloor of a Cretaceous 'Lost City'-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the passive Iberia Margin (ODP Leg 149, Hole 897D). Brucite and calcite co-precipitated from mixed fluids ca. 65m below the Cretaceous palaeo-seafloor at temperatures of 32±4°C within steep chemical gradients (fO2, pH, CH4, SO4, ΣCO2, etc) between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing <span class="hlt">hydrothermal</span> fluid at moderate temperatures created conditions capable of supporting microbial activity within the oceanic basement. Dense microbial colonies are fossilized in brucite-calcite veins that are strongly enriched in organic carbon but depleted in 13C. We detected a combination of bacterial diether lipid biomarkers, archaeol and archaeal tetraethers analogous to those found in brucite-carbonate chimneys at the active Lost City <span class="hlt">hydrothermal</span> field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin during the Cretaceous, possibly before the onset of seafloor spreading in the Atlantic. 'Lost City'-type serpentinization <span class="hlt">systems</span> have been discovered at mid-ocean ridges, in forearc settings of subduction zones and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments as demonstrated in the present study. Because equivalent <span class="hlt">systems</span> have likely existed throughout most of Earth</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS42A..03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS42A..03K"><span>Subseafloor fluid mixing and fossilized microbial life in a Cretaceous 'Lost City'-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the Iberian Margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klein, F.; Humphris, S. E.; Guo, W.; Schubotz, F.; Schwarzenbach, E. M.; Orsi, W.</p> <p>2014-12-01</p> <p>Subseafloor mixing of reduced <span class="hlt">hydrothermal</span> fluids with seawater is believed to provide the energy and substrates needed to support autotrophic microorganisms in the hydrated oceanic mantle (serpentinite). Despite the potentially significant implications for the distribution of microbial life on Earth and other water-bearing planetary bodies, our understanding of such environments remains elusive. In the present study we examined fossilized microbial communities and fluid mixing processes in the subseafloor of a Cretaceous 'Lost City'-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> at the passive Iberia Margin (ODP Leg 149, Hole 897D). Brucite and calcite co-precipitated from mixed fluids ca. 65m below the Cretaceous palaeo-seafloor at temperatures of 32±4°C within steep chemical gradients (fO2, pH, CH4, SO4, ΣCO2, etc) between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing <span class="hlt">hydrothermal</span> fluid at moderate temperatures created conditions capable of supporting microbial activity within the oceanic basement. Dense microbial colonies are fossilized in brucite-calcite veins that are strongly enriched in organic carbon but depleted in 13C. We detected a combination of bacterial diether lipid biomarkers, archaeol and archaeal tetraethers analogous to those found in brucite-carbonate chimneys at the active Lost City <span class="hlt">hydrothermal</span> field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin during the Cretaceous, possibly before the onset of seafloor spreading in the Atlantic. 'Lost City'-type serpentinization <span class="hlt">systems</span> have been discovered at mid-ocean ridges, in forearc settings of subduction zones and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments as demonstrated in the present study. Because equivalent <span class="hlt">systems</span> have likely existed throughout most of Earth</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatGe...8..856H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatGe...8..856H"><span>Efficient removal of recalcitrant deep-ocean dissolved organic matter during <span class="hlt">hydrothermal</span> circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hawkes, Jeffrey A.; Rossel, Pamela E.; Stubbins, Aron; Butterfield, David; Connelly, Douglas P.; Achterberg, Eric P.; Koschinsky, Andrea; Chavagnac, Valérie; Hansen, Christian T.; Bach, Wolfgang; Dittmar, Thorsten</p> <p>2015-11-01</p> <p>Oceanic dissolved organic carbon (DOC) is an important carbon pool, similar in magnitude to atmospheric CO2, but the fate of its oldest forms is not well understood. Hot <span class="hlt">hydrothermal</span> circulation may facilitate the degradation of otherwise un-reactive dissolved organic matter, playing an important role in the long-term global carbon cycle. The oldest, most recalcitrant forms of DOC, which make up most of oceanic DOC, can be recovered by solid-phase extraction. Here we present measurements of solid-phase extractable DOC from samples collected between 2009 and 2013 at seven vent sites in the Atlantic, Pacific and Southern oceans, along with magnesium concentrations, a conservative tracer of water circulation through <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>. We find that magnesium and solid-phase extractable DOC concentrations are correlated, suggesting that solid-phase extractable DOC is almost entirely lost from solution through mineralization or deposition during circulation through <span class="hlt">hydrothermal</span> vents with fluid temperatures of 212-401 °C. In laboratory experiments, where we heated samples to 380 °C for four days, we found a similar removal efficiency. We conclude that thermal degradation alone can account for the loss of solid-phase extractable DOC in natural <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, and that its maximum lifetime is constrained by the timescale of <span class="hlt">hydrothermal</span> cycling, at about 40 million years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1437974-effect-paleoseawater-composition-hydrothermal-exchange-midocean-ridges','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1437974-effect-paleoseawater-composition-hydrothermal-exchange-midocean-ridges"><span>Effect of paleoseawater composition on <span class="hlt">hydrothermal</span> exchange in midocean ridges</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Antonelli, Michael A.; Pester, Nicholas J.; Brown, Shaun T.</p> <p></p> <p>Variations in the Mg, Ca, Sr, and SO 4 concentrations of paleoseawater can affect the chemical exchange between seawater and oceanic basalt in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> at midocean ridges (MOR). Here, we present a model for evaluating the nature and magnitude of these previously unappreciated effects, using available estimates of paleoseawater composition over Phanerozoic time as inputs and 87Sr/ 86Sr of ophiolite epidosites and epidote-quartz veins as constraints. The results suggest that modern <span class="hlt">hydrothermal</span> fluids are not typical due to low Ca and Sr relative to Mg and SO 4 in modern seawater. At other times during the last 500 millionmore » years, particularly during the Cretaceous and Ordovician, <span class="hlt">hydrothermal</span> fluids had more seawater-derived Sr and Ca, a prediction that is supported by Sr isotope data. The predicted 87Sr/ 86Sr of vent fluids varies cyclically in concert with ocean chemistry, with some values much higher than the modern value of ~0.7037. The seawater chemistry effects can be expressed in terms of the transfer efficiency of basaltic Ca and Sr to seawater in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, which varies by a factor of ~1.6 over the Phanerozoic, with minima when seawater Mg and SO 4 are low. This effect provides a modest negative feedback on seawater composition and 87Sr/ 86Sr changes. For the mid-Cretaceous, the low 87Sr/ 86Sr of seawater requires either exceptionally large amounts of low-temperature exchange with oceanic crust or that the weathering flux of continentally derived Sr was especially small. Lastly, the model also has implications for MOR <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the Precambrian, when low-seawater SO 4 could help explain low seawater 87Sr/ 86Sr.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1437974-effect-paleoseawater-composition-hydrothermal-exchange-midocean-ridges','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1437974-effect-paleoseawater-composition-hydrothermal-exchange-midocean-ridges"><span>Effect of paleoseawater composition on <span class="hlt">hydrothermal</span> exchange in midocean ridges</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Antonelli, Michael A.; Pester, Nicholas J.; Brown, Shaun T.; ...</p> <p>2017-11-06</p> <p>Variations in the Mg, Ca, Sr, and SO 4 concentrations of paleoseawater can affect the chemical exchange between seawater and oceanic basalt in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> at midocean ridges (MOR). Here, we present a model for evaluating the nature and magnitude of these previously unappreciated effects, using available estimates of paleoseawater composition over Phanerozoic time as inputs and 87Sr/ 86Sr of ophiolite epidosites and epidote-quartz veins as constraints. The results suggest that modern <span class="hlt">hydrothermal</span> fluids are not typical due to low Ca and Sr relative to Mg and SO 4 in modern seawater. At other times during the last 500 millionmore » years, particularly during the Cretaceous and Ordovician, <span class="hlt">hydrothermal</span> fluids had more seawater-derived Sr and Ca, a prediction that is supported by Sr isotope data. The predicted 87Sr/ 86Sr of vent fluids varies cyclically in concert with ocean chemistry, with some values much higher than the modern value of ~0.7037. The seawater chemistry effects can be expressed in terms of the transfer efficiency of basaltic Ca and Sr to seawater in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, which varies by a factor of ~1.6 over the Phanerozoic, with minima when seawater Mg and SO 4 are low. This effect provides a modest negative feedback on seawater composition and 87Sr/ 86Sr changes. For the mid-Cretaceous, the low 87Sr/ 86Sr of seawater requires either exceptionally large amounts of low-temperature exchange with oceanic crust or that the weathering flux of continentally derived Sr was especially small. Lastly, the model also has implications for MOR <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the Precambrian, when low-seawater SO 4 could help explain low seawater 87Sr/ 86Sr.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.P12A..07L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.P12A..07L"><span>Mineralized iron oxidizing bacteria from <span class="hlt">hydrothermal</span> vents: targeting biosignatures on Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leveille, R. J.</p> <p>2010-12-01</p> <p>Putative <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> have been identified on Mars based on orbital imagery and rover-based analyses. Based on Earth analogs, <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> on Mars would be highly attractive for their potential for preserving organic and inorganic biosignatures. For example, iron oxidizing bacteria are ubiquitous in marine and terrestrial <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, where they often display distinctive cell morphologies and are commonly encrusted by minerals, especially bacteriogenic iron oxides and silica. Microfossils of iron oxidizing bacteria have been found in ancient Si-Fe deposits and iron oxidation may be an ancient and widespread metabolic pathway. In order to investigate mineralized iron oxidizing bacteria as a biosignature, we have examined samples collected from extinct <span class="hlt">hydrothermal</span> vents along Explorer Ridge, NE Pacific Ocean. In addition, microaerophilic iron oxidizing bacteria, isolated from active Pacific <span class="hlt">hydrothermal</span> vents, were grown in a Fe-enriched seawater medium at constant pH (6.5) and O2 concentration (5%) in a controlled bioreactor <span class="hlt">system</span>. Samples and experimental products were examined with a combination of variable-pressure and field-emission scanning electron microscopy (SEM), in some cases by preparing samples with a focused ion beam (FIB) milling <span class="hlt">system</span>. Light-toned seafloor samples display abundant filamentous forms resembling, in both size and shape (1-5 microns in diameter and up to several microns in length), the twisted stalks of Gallionella and the elongated filaments of Leptothrix. Some samples consist entirely of low-density masses of silica (>90% Si) encrusted filamentous forms. The presence of unmineralized filamentous matter rich in C and Fe suggests that these are the remains of iron oxidizing bacteria. Mineralized filaments sectioned by FIB show variable internal material within semi-hollow, tubular-like features. Silica encrustations also show pseudo-concentric growth bands. In the bioreactor runs, abundant microbial growth and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s118e06828.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s118e06828.html"><span>View of Drew in the MDDK of the Shuttle <span class="hlt">Endeavour</span> during STS-118</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2007-09-11</p> <p>S118-E-06828 (11 Aug. 2007) --- Astronaut Alvin Drew, STS-118 mission specialist, works near a hatch of Space Shuttle <span class="hlt">Endeavour</span> while docked with the International Space Station during flight day four activities. Sleeping bags are visible in the foreground.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V14A..07S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V14A..07S"><span>Discovery of Fracture Networks in the Basal Part of Modern <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> in Okinawa Tough, SW Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saito, S.; Yamada, Y.; Sanada, Y.; Kido, Y. N.; Hamada, Y.; Shiraishi, K.; Hsiung, K. H.; Tsuji, T.; Eng, C.; Maeda, L.; Kumagai, H.; Nozaki, T.; Ishibashi, J. I.</p> <p>2017-12-01</p> <p>A scientific drilling expedition, CK16-01 was conducted by D/V Chikyu in an active <span class="hlt">hydrothermal</span> field on the Iheya-North Knoll in Okinawa Trough in February-March, 2016 as a part of "Next-generation Technology for Ocean Resources Survey" of the Cross-ministerial Strategic Innovation Promotion Program (SIP). During the expedition logging while drilling (LWD) was deployed to uncover the architecture of modern <span class="hlt">hydrothermal</span> deposits near the seafloor. A downhole sequence of fracture network (stock-work) was discovered by high resolution resistivity images at Site C9023 in the southern part of the knoll. More than 500 structural features were extracted from the borehole images down to 188 meter below the seafloor. Quantitative image analyses were performed and three types of conductive fractures were identified and classified as Generation 1 (G1), Generation 2 (G2), and Generation 3 (G3) based on the crossing or cutting relationship. The average thickness of fractures decrease with generation from G1 (78 mm), G2 (57 mm), to G3 (45 mm). G1 is developed in the entire interval, whereas G2 and G3 are commonly observed in the intervals of lower gamma ray and high resistivity ( 10 ohm-m) at 77-125 m and 167-186 m where sulfide minerals hosted in silicified rocks were observed in recovered core samples. Low angle fractures (<30°) are typically developed in the interval at 120 -125 m, suggesting possible lateral <span class="hlt">hydrothermal</span> conduits. The quantitative analysis of fracture network based on borehole images shows the detailed formation process of stock-work in the basal part of modern <span class="hlt">hydrothermal</span> <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060042927&hterms=BIO&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBIO','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060042927&hterms=BIO&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBIO"><span>A deep sea <span class="hlt">Hydrothermal</span> Vent Bio-sampler for large volume in-situ filtration of <span class="hlt">hydrothermal</span> vent fluids</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Behar, Alberto; Matthews, Jaret; Venkateswaran, Kasthuri; Bruckner, James; Basic, Goran; So, Edmond; Rivadeneyra, Cesar</p> <p>2005-01-01</p> <p>This paper provides a physical description of the current <span class="hlt">system</span>, as well as a summary of the preliminary tests conducted in 2005: a pressure chamber test, a dive test in a 30 foot dive pool, and a dive operation at a <span class="hlt">hydrothermal</span> vent off the northern coast of Iceland.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-sts111-318-030.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-sts111-318-030.html"><span>Perrin peers through <span class="hlt">Endeavour</span>'s AFD window to view the Earth's limb during STS-111</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2002-06-14</p> <p>STS111-318-030 (5-19 June 2002) --- Astronaut Philippe Perrin, STS-111 mission specialist representing CNES, the French Space Agency, looks out an aft flight deck window of the Space Shuttle <span class="hlt">Endeavour</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA600228','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA600228"><span>Positron Spectroscopy of <span class="hlt">Hydrothermally</span> Grown Actinide Oxides</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-03-27</p> <p>POSITRON SPECTROSCOPY OF <span class="hlt">HYDROTHERMALLY</span> GROWN ACTINIDE OXIDES THESIS Edward C. Schneider...United States Government. AFIT-ENP-14-M-33 POSITRON SPECTROSCOPY OF <span class="hlt">HYDROTHERMALLY</span> GROWN ACTINIDE OXIDES THESIS...33 POSITRON SPECTROSCOPY OF <span class="hlt">HYDROTHERMALLY</span> GROWN ACTINIDE OXIDES Edward C. Schneider, BS Captain, USAF Approved</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V13C3140I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V13C3140I"><span>Vapor Discharges On Nevado Del Ruiz During The Recent Activity: Clues On The Composition Of The Deep <span class="hlt">Hydrothermal</span> <span class="hlt">System</span> And Its Effects On Thermal Springs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Inguaggiato, S.; Federico, C.; Chacon, Z.; Londono, J. M.; Alzate, D. M.; Gil, E.</p> <p>2015-12-01</p> <p>The Nevado del ruiz volcano (NdR, 5321m asl), one of the most active in Colombia, threatens about 600,000 people. The existence of an ice cap and several streams channeling in some main rivers increase the risk of lahars and mudflows in case of unrest, as occurred during the November 1985 eruption, which caused 20,000 casualties. The involvement of the local <span class="hlt">hydrothermal</span> <span class="hlt">system</span> has also produced in the past phreatic and phreatomagmatic activity, as in 1985 and 1989. After more than 7 years of relative stability, since 2010, the still ongoing phase of unrest has produced two small eruption in 2012, and still maintains in high levels of seismicity and SO2 degassing. In October 2013, a sampling campaign has been performed on thermal springs and streamwater, located at 2600-5000 m asl, analyzed for water chemistry and stable isotopes. By applying a model of steam-heating, based on mass and enthalpy balances, we have estimated the mass rate of steam discharging in the different steam-heated springs. The composition of the hottest thermal spring (Botero Londoño) is probably representative of a marginal part of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, having a temperature of 250°C and low salinity (Cl ~1500 mg/l), which suggest a chiefly meteoric origin, as also confirmed by the isotope composition retrieved for the <span class="hlt">hydrothermal</span> water. The vapour discharged at the steam vent "Nereidas" (3600 m asl) is hypothesised to be separated from a high-temperature hyrothermal <span class="hlt">system</span>. Based on its composition and on literature data on fluid inclusions, we have retrieved the P-T-X conditions of the deep <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, as well as its pH and fO2. The vapour feeding Nereidas would separate from a byphasic <span class="hlt">hydrothermal</span> <span class="hlt">system</span> characterised by the follow parameters: t= 315°C, P=19 MPa, NaCl= 15 %, CO2 = 9%, and similar proportion between liquid and vapour. Considering also the equilibria involving S-bearing gases and HCl, we obtain pH=2, fO2 fixed by FeO-Fe2O3 buffer, and [Cl]=12000 mg/l. Changes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s127e012308.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s127e012308.html"><span>Deployment of DRAGONSAT from Space Shuttle <span class="hlt">Endeavours</span> Payload Bay</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2009-07-30</p> <p>S127-E-012308 (30 July 2009) --- As seen through windows on the aft flight deck of Space Shuttle <span class="hlt">Endeavour</span>, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment 2 (ANDE-2) is released from the shuttle's payload bay by STS-127 crew members. ANDE-2 consists of two spherical micro-satellites which will measure the density and composition of the low-Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s127e012322.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s127e012322.html"><span>Deployment of DRAGONSAT from Space Shuttle <span class="hlt">Endeavours</span> Payload Bay</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2009-07-30</p> <p>S127-E-012322 (30 July 2009) --- As seen through windows on the aft flight deck of Space Shuttle <span class="hlt">Endeavour</span>, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment 2 (ANDE-2) is released from the shuttle's payload bay by STS-127 crew members. ANDE-2 consists of two spherical micro-satellites which will measure the density and composition of the low-Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.B21B0892W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.B21B0892W"><span>Organic Acids as Hetrotrophic Energy Sources in <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Windman, T. O.; Zolotova, N.; Shock, E.</p> <p>2004-12-01</p> <p>Many thermophilic microbes are heterotrophs, but little is known about the organic compounds present in <span class="hlt">hydrothermal</span> ecosystems. More is known about what these organisms will metabolize in lab experiments than what they do metabolize in nature. In an effort to bridge this gap, we have begun to incorporate organic analyses into ongoing research on Yellowstone <span class="hlt">hydrothermal</span> ecosystems. After filtering at least a liter of hot spring water to minimize contamination, samples were collected into sixty-milliliter serum vials containing ultra-pure phosphoric acid, sodium hydroxide, or benzalkonium chloride. Approximately 80 sites were sampled spanning temperatures from 60 to 90°C and pH values from 2 to 9. Analytical data for organic acid anions (including formate, acetate, lactate, and succinate) were obtained by ion chromatography. Preliminary results indicate that concentrations of organic acids anions range from 5 to 300 ppb. These results can be used with other field and lab data (sulfate, sulfide, nitrate, ammonia, bicarbonate, pH, hydrogen) in thermodynamic calculations to evaluate the amounts of energy available in heterotrophic reactions. Preliminary results of such calculations show that sulfate reduction to sulfide coupled to succinate oxidation to bicarbonate yields about 6 kcal per mole of electrons transferred. When formate oxidation to bicarbonate or hydrogen oxidation to water is coupled to sulfate reduction there is less energy available by approximately a factor of two. A comparison with nitrate reduction to ammonia involving succinate and/or formate oxidation reveals several similarities. Using formate to reduce nitrate can yield about as much energy as nitrate reduction with hydrogen (typically 12 to 14 kcal per mole of electrons transferred), but using succinate can yield more than twice as much energy. In fact, reduction of nitrate with succinate can provide more energy than any of the inorganic nitrate reduction reactions involving sulfur, iron</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GGG....17..375D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GGG....17..375D"><span>Geologic evolution of the Lost City <span class="hlt">Hydrothermal</span> Field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Denny, Alden R.; Kelley, Deborah S.; Früh-Green, Gretchen L.</p> <p>2016-02-01</p> <p>The Lost City <span class="hlt">Hydrothermal</span> Field (LCHF) is a novel serpentinite-hosted vent field located on the Atlantis Massif southern wall. Results of 2 m resolution bathymetry, side scan, and video and still imagery, integrated with direct submersible observations provide the first high-resolution geologic map of the LCHF. These data form the foundation for an evolutionary model for the vent <span class="hlt">system</span> over the past >120,000 years. The field is located on a down-dropped bench 70 m below the summit of the massif. The bench is capped by breccia and pelagic carbonate deposits underlain by variably deformed and altered serpentinite and gabbroic rocks. <span class="hlt">Hydrothermal</span> activity is focused at the 60 m tall, 100 m across, massive carbonate edifice "Poseidon," which is venting 91°C fluid. <span class="hlt">Hydrothermal</span> activity declines south and west of the Poseidon complex and dies off completely at distances greater than 200 m. East of Poseidon, the most recent stage of <span class="hlt">hydrothermal</span> flow is characterized by egress of diffuse fluids from narrow fissures within a low-angle, anastomosing mylonite zone. South of the area of current <span class="hlt">hydrothermal</span> activity, there is evidence of two discrete previously unrecognized relict fields. Active venting sites defined by carbonate-filled fissures that cut the carbonate cap rock at the summit of the massif mark the present-day northernmost extent of venting. These spatial relationships reflect multiple stages of field development, the northward migration of venting over time, and the likely development of a nascent field at the massif summit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRB..122.8749G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRB..122.8749G"><span>Three-Dimensional Electrical Resistivity Tomography of the Solfatara Crater (Italy): Implication for the Multiphase Flow Structure of the Shallow <span class="hlt">Hydrothermal</span> <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gresse, Marceau; Vandemeulebrouck, Jean; Byrdina, Svetlana; Chiodini, Giovanni; Revil, André; Johnson, Timothy C.; Ricci, Tullio; Vilardo, Giuseppe; Mangiacapra, Annarita; Lebourg, Thomas; Grangeon, Jacques; Bascou, Pascale; Metral, Laurent</p> <p>2017-11-01</p> <p>The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because <span class="hlt">hydrothermal</span> interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara <span class="hlt">hydrothermal</span> <span class="hlt">system</span> by performing the first 3-D, high-resolution, electrical resistivity tomography of the volcano. The 3-D resistivity model was obtained from the inversion of 43,432 resistance measurements performed on an area of 0.68 km2. The proposed interpretation of the multiphase <span class="hlt">hydrothermal</span> structures is based on the resistivity model, a high-resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil cation exchange capacity and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the resistivity changes are mainly controlled by fluid content and temperature. The high-resolution tomograms identify for the first time the structure of the gas-dominated reservoir at 60 m depth that feeds the Bocca Grande fumarole through a 10 m thick channel. In addition, the resistivity model reveals a channel-like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The model delineates the emplacement of the main geological structures: Mount Olibano, Solfatara cryptodome, and tephra deposits. It also reveals the anatomy of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, especially two liquid-dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...629899R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...629899R"><span>Volcano electrical tomography unveils edifice collapse hazard linked to <span class="hlt">hydrothermal</span> <span class="hlt">system</span> structure and dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosas-Carbajal, Marina; Komorowski, Jean-Christophe; Nicollin, Florence; Gibert, Dominique</p> <p>2016-07-01</p> <p>Catastrophic collapses of the flanks of stratovolcanoes constitute a major hazard threatening numerous lives in many countries. Although many such collapses occurred following the ascent of magma to the surface, many are not associated with magmatic reawakening but are triggered by a combination of forcing agents such as pore-fluid pressurization and/or mechanical weakening of the volcanic edifice often located above a low-strength detachment plane. The volume of altered rock available for collapse, the dynamics of the <span class="hlt">hydrothermal</span> fluid reservoir and the geometry of incipient collapse failure planes are key parameters for edifice stability analysis and modelling that remain essentially hidden to current volcano monitoring techniques. Here we derive a high-resolution, three-dimensional electrical conductivity model of the La Soufrière de Guadeloupe volcano from extensive electrical tomography data. We identify several highly conductive regions in the lava dome that are associated to fluid saturated host-rock and preferential flow of highly acid hot fluids within the dome. We interpret this model together with the existing wealth of geological and geochemical data on the volcano to demonstrate the influence of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> dynamics on the hazards associated to collapse-prone altered volcanic edifices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27457494','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27457494"><span>Volcano electrical tomography unveils edifice collapse hazard linked to <span class="hlt">hydrothermal</span> <span class="hlt">system</span> structure and dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rosas-Carbajal, Marina; Komorowski, Jean-Christophe; Nicollin, Florence; Gibert, Dominique</p> <p>2016-07-26</p> <p>Catastrophic collapses of the flanks of stratovolcanoes constitute a major hazard threatening numerous lives in many countries. Although many such collapses occurred following the ascent of magma to the surface, many are not associated with magmatic reawakening but are triggered by a combination of forcing agents such as pore-fluid pressurization and/or mechanical weakening of the volcanic edifice often located above a low-strength detachment plane. The volume of altered rock available for collapse, the dynamics of the <span class="hlt">hydrothermal</span> fluid reservoir and the geometry of incipient collapse failure planes are key parameters for edifice stability analysis and modelling that remain essentially hidden to current volcano monitoring techniques. Here we derive a high-resolution, three-dimensional electrical conductivity model of the La Soufrière de Guadeloupe volcano from extensive electrical tomography data. We identify several highly conductive regions in the lava dome that are associated to fluid saturated host-rock and preferential flow of highly acid hot fluids within the dome. We interpret this model together with the existing wealth of geological and geochemical data on the volcano to demonstrate the influence of the <span class="hlt">hydrothermal</span> <span class="hlt">system</span> dynamics on the hazards associated to collapse-prone altered volcanic edifices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP41B1834M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP41B1834M"><span>Orbital and Rover-based Exploration of Perseverance Valley, <span class="hlt">Endeavour</span> Crater, Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morgan, A. M.; Arvidson, R. E.; Duran Vinent, O.; Craddock, R. A.; Holo, S.; Gadal, C.; Blois, G.; Palucis, M. C.; Goudge, T. A.; Morgan, A. M.; Day, M.; Sullivan, R. J., Jr.; Umurhan, O. M.; Pähtz, T.; Birch, S.; Morgan, A. M.; Goudge, T. A.; Palucis, M. C.; Arvidson, R. E.; Duran Vinent, O.; Craddock, R. A.; Holo, S.; Blois, G.; Gadal, C.; Morgan, A. M.; Sullivan, R. J., Jr.; Day, M.; Arvidson, R. E.</p> <p>2017-12-01</p> <p>Perseverance Valley, based on orbital observations from the Mars Reconnaisance Orbiter HiRISE image data, is a 180 m long, 20 m wide anastomosing shallow channel <span class="hlt">system</span> superimposed on the Cape Byron rim segment of the 22 km diameter Noachian-age <span class="hlt">Endeavour</span> Crater on Mars. Several impact craters are superimposed on the valley <span class="hlt">system</span>, indicating antiquity, although the valley's high degree of preservation indicates that it formed after significant regional-scale fluvial erosion and diffusive smoothing of <span class="hlt">Endeavour</span> and its rim segments. The valley cuts into the inner, eastern rim on a 10˚ to 15˚ slope, and starts at a local low area on the rim crest. A set of shallow channels, some lined with perimeter rocks, extends from the west to meet the entrance to the valley. The western rim tilts to the west 0.8˚ and thus the channels tilt away from the valley entrance. The Mars Rover Opportunity has explored the western shallow channels leading up to the entrance to the valley. As of this writing Opportunity is located on the southern side of the valley entrance, with the Athena Science Team waiting until after solar conjunction to command the rover to descend into the valley to search for geomorphic and sedimentologic evidence related to valley formation. Wind erosion along radial fractures extending into and down Cape Byron is a possibility. Debris flows are also under consideration, perhaps enabled by melting ice at the rim crest. Dry avalanches are unlikely due to the low slopes. A fluvial origin is a strong contender based on models that show it is possible to have had a western catchment present when the Burns formation hydrated sulfates were being emplaced, followed by self-compaction of these sediments that tilted the western plains away from the rim crest. The key to testing among the various hypotheses for formation of the valley and shallow channels leading into the entrance will be the detailed stereo and multispectral imaging observations Opportunity will make</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMS...180..211C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMS...180..211C"><span>Heavy metals from Kueishantao shallow-sea <span class="hlt">hydrothermal</span> vents, offshore northeast Taiwan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Xue-Gang; Lyu, Shuang-Shuang; Garbe-Schönberg, Dieter; Lebrato, Mario; Li, Xiaohu; Zhang, Hai-Yan; Zhang, Ping-Ping; Chen, Chen-Tung Arthur; Ye, Ying</p> <p>2018-04-01</p> <p>Shallow water <span class="hlt">hydrothermal</span> vents are a source of heavy metals leading to their accumulation in marine organisms that manage to live under extreme environmental conditions. This is the case at Kueishantao (KST) shallow-sea vents <span class="hlt">system</span> offshore northeast Taiwan, where the heavy metal distribution in vent fluids and ambient seawater is poorly understood. This shallow vent is an excellent natural laboratory to understand how heavy and volatile metals behave in the nearby water column and ecosystem. Here, we investigated the submarine venting of heavy metals from KST field and its impact on ambient surface seawater. The total heavy metal concentrations in the vent fluids and vertical plumes were 1-3 orders of magnitude higher than the overlying seawater values. When compared with deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">systems</span>, the estimated KST end-member fluids exhibited much lower concentrations of transition metals (e.g., Fe and Mn) but comparable concentrations of toxic metals such as Pb and As. This may be attributed to the lower temperature of the KST reaction zone and transporting fluids. Most of the heavy metals (Fe, Mn, As, Y, and Ba) in the plumes and seawater mainly originated from <span class="hlt">hydrothermal</span> venting, while Cd and Pb were largely contributed by external sources such as contaminated waters (anthropogenic origin). The spatial distribution of heavy metals in the surface seawater indicated that seafloor venting impacts ambient seawater. The measurable influence of KST <span class="hlt">hydrothermal</span> activity, however, was quite localized and limited to an area of < 1 km2. The estimated annual fluxes of heavy metals emanating from the yellow KST <span class="hlt">hydrothermal</span> vent were: 430-2600 kg Fe, 24-145 kg Mn, 5-32 kg Ba, 10-60 kg As, 0.3-1.9 kg Cd, and 2-10 kg Pb. This study provides important data on heavy metals from a shallow-sea <span class="hlt">hydrothermal</span> field, and it helps to better understand the environmental impact of submarine shallow <span class="hlt">hydrothermal</span> venting.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040089178&hterms=petroleum&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpetroleum','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040089178&hterms=petroleum&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpetroleum"><span>Phenols in <span class="hlt">hydrothermal</span> petroleums and sediment bitumen from Guaymas Basin, Gulf of California</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simoneit, B. R.; Leif, R. N.; Ishiwatari, R.</p> <p>1996-01-01</p> <p>The aliphatic, aromatic and polar (NSO) fractions of seabed petroleums and sediment bitumen extracts from the Guaymas Basin <span class="hlt">hydrothermal</span> <span class="hlt">system</span> have been analyzed by gas chromatography and gas chromatography-mass spectrometry (free and silylated). The oils were collected from the interiors and exteriors of high temperature <span class="hlt">hydrothermal</span> vents and represent <span class="hlt">hydrothermal</span> pyrolyzates that have migrated to the seafloor by <span class="hlt">hydrothermal</span> fluid circulation. The downcore sediments are representative of both thermally unaltered and thermally altered sediments. The survey has revealed the presence of oxygenated compounds in samples with a high degree of thermal maturity. Phenols are one class of oxygenated compounds found in these samples. A group of methyl-, dimethyl- and trimethyl-isoprenoidyl phenols (C27-C29) is present in all of the seabed NSO fractions, with the methyl- and dimethyl-isoprenoidyl phenols occurring as major components, and a trimethyl-isoprenoidyl phenol as a minor component. A homologous series of n-alkylphenols (C13-C33) has also been found in the seabed petroleums. These phenols are most likely derived from the <span class="hlt">hydrothermal</span> alteration of sedimentary organic matter. The n-alkylphenols are probably synthesized under <span class="hlt">hydrothermal</span> conditions, but the isoprenoidyl phenols are probably <span class="hlt">hydrothermal</span> alteration products of natural product precursors. The suites of phenols do not appear to be useful tracers of high temperature <span class="hlt">hydrothermal</span> processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.P23F1857R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.P23F1857R"><span>The Enigmatic Bench Unit of <span class="hlt">Endeavour</span> Crater Rim in Meridiani Planum, Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruff, S. W.</p> <p>2013-12-01</p> <p>For the first 2680 sols of its mission, the Mars Exploration Rover Opportunity traversed across essentially the same rocks: sulfur-rich sandstones known as the Burns formation. On August 8, 2011 Opportunity completed a ~21 km traverse from Victoria crater to the rim of the ~22 km diameter <span class="hlt">Endeavour</span> crater where it crossed a slightly raised smooth bench unit that surrounds an interior core of higher standing and more rugged terrain on a rim segment named Cape York. As recognized by its distinctive morphologic character evident in orbital images, the inward sloping bench feature is found associated with portions of other segments of the discontinuous raised rim of <span class="hlt">Endeavour</span> crater. Viewed by Opportunity, it appears as platy, fractured, relatively light-toned outcrop that is fine-grained, lacks hematite concretions and in places hosts veins of Ca- and S-rich composition, likely due to precipitation of gypsum in fractures that cut the bench unit (1). The bench outcrop target named Grasberg included a grind using the Rock Abrasion Tool (RAT) to obtain a cleaner surface for the Alpha Particle X-ray Spectrometer chemistry measurement compared with the initially investigated target named Deadwood. In addition to its greater strength than Burns formation as determined by the RAT grind operation, Grasberg and other examples of the bench unit have lower S, higher Cl and other elemental characteristics that depart from typical Burns formation. Thus the 'Grasberg unit' clearly represents a distinct rock type compared to the Meridiani plains. A second unit makes up the exposed core of the Cape York rim segment. Known as Shoemaker formation, it is composed of breccias that are recognized as a suevite deposit produced from the <span class="hlt">Endeavour</span> impact event (1). The Shoemaker formation appears to be onlapped by the Grasberg unit with Burns formation onlapping it (1). However, a well-exposed section observed in a wedge-shaped fracture known as Whim Creek on the northeast portion of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-STS057-03-017.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-STS057-03-017.html"><span>STS-57 external tank (ET) falls away from <span class="hlt">Endeavour</span>, OV-105, after jettison</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1993-06-21</p> <p>STS057-03-017 (21 June 1993) --- The external fuel tank falls toward Earth after being jettisoned from the Space Shuttle <span class="hlt">Endeavour</span> as the spacecraft headed toward its ten-day stay in Earth orbit. A 35mm camera was used to record the ET jettison.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020086497&hterms=grimm&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgrimm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020086497&hterms=grimm&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgrimm"><span>Controls on Martian <span class="hlt">Hydrothermal</span> <span class="hlt">Systems</span>: Application to Valley Network and Magnetic Anomaly Formation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Harrison, Keith P.; Grimm, Robert E.</p> <p>2002-01-01</p> <p>Models of <span class="hlt">hydrothermal</span> groundwater circulation can quantify limits to the role of <span class="hlt">hydrothermal</span> activity in Martian crustal processes. We present here the results of numerical simulations of convection in a porous medium due to the presence of a hot intruded magma chamber. The parameter space includes magma chamber depth, volume, aspect ratio, and host rock permeability and porosity. A primary goal of the models is the computation of surface discharge. Discharge increases approximately linearly with chamber volume, decreases weakly with depth (at low geothermal gradients), and is maximized for equant-shaped chambers. Discharge increases linearly with permeability until limited by the energy available from the intrusion. Changes in the average porosity are balanced by changes in flow velocity and therefore have little effect. Water/rock ratios of approximately 0.1, obtained by other workers from models based on the mineralogy of the Shergotty meteorite, imply minimum permeabilities of 10(exp -16) sq m2 during <span class="hlt">hydrothermal</span> alteration. If substantial vapor volumes are required for soil alteration, the permeability must exceed 10(exp -15) sq m. The principal application of our model is to test the viability of <span class="hlt">hydrothermal</span> circulation as the primary process responsible for the broad spatial correlation of Martian valley networks with magnetic anomalies. For host rock permeabilities as low as 10(exp -17) sq m and intrusion volumes as low as 50 cu km, the total discharge due to intrusions building that part of the southern highlands crust associated with magnetic anomalies spans a comparable range as the inferred discharge from the overlying valley networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26663423','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26663423"><span>Subseafloor microbial communities in hydrogen-rich vent fluids from <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> along the Mid-Cayman Rise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reveillaud, Julie; Reddington, Emily; McDermott, Jill; Algar, Christopher; Meyer, Julie L; Sylva, Sean; Seewald, Jeffrey; German, Christopher R; Huber, Julie A</p> <p>2016-06-01</p> <p>Warm fluids emanating from <span class="hlt">hydrothermal</span> vents can be used as windows into the rocky subseafloor habitat and its resident microbial community. Two new vent <span class="hlt">systems</span> on the Mid-Cayman Rise each exhibits novel geologic settings and distinctively hydrogen-rich vent fluid compositions. We have determined and compared the chemistry, potential energy yielding reactions, abundance, community composition, diversity, and function of microbes in venting fluids from both sites: Piccard, the world's deepest vent site, hosted in mafic rocks; and Von Damm, an adjacent, ultramafic-influenced <span class="hlt">system</span>. Von Damm hosted a wider diversity of lineages and metabolisms in comparison to Piccard, consistent with thermodynamic models that predict more numerous energy sources at ultramafic <span class="hlt">systems</span>. There was little overlap in the phylotypes found at each site, although similar and dominant hydrogen-utilizing genera were present at both. Despite the differences in community structure, depth, geology, and fluid chemistry, energetic modelling and metagenomic analysis indicate near functional equivalence between Von Damm and Piccard, likely driven by the high hydrogen concentrations and elevated temperatures at both sites. Results are compared with <span class="hlt">hydrothermal</span> sites worldwide to provide a global perspective on the distinctiveness of these newly discovered sites and the interplay among rocks, fluid composition and life in the subseafloor. © 2015 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-0983&hterms=meatball&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmeatball','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-0983&hterms=meatball&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmeatball"><span>NASA logo painted on orbiter <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1998-01-01</p> <p>A KSC worker paints the NASA logo on the port wing of the orbiter <span class="hlt">Endeavour</span>, which is scheduled to launch in December for STS-88. The paint is a special pigment that takes 18 hours to dry; the whole process takes approximately two weeks to complete. The NASA logo, termed 'meatball,' was originally designed in the late 1950s. It symbolized NASA's role in aeronautics and space in the early years of the agency. The original design included a white border surrounding it. The border was dropped for the Apollo 7 mission in October 1968, replaced with royal blue to match the background of the emblem. In 1972 the logo was replaced by a simple and contemporary design -- the 'worm' -- which was retired from use last year. NASA reverted to its original logo in celebration of the agency's 40th anniversary in October, and the 'golden age' of America's space program. All the orbiters will bear the new logo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OLEB...47..413Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OLEB...47..413Z"><span>Prebiotic Synthesis of Glycine from Ethanolamine in Simulated Archean Alkaline <span class="hlt">Hydrothermal</span> Vents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xianlong; Tian, Ge; Gao, Jing; Han, Mei; Su, Rui; Wang, Yanxiang; Feng, Shouhua</p> <p>2017-12-01</p> <p>Submarine <span class="hlt">hydrothermal</span> vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. In recent years, a novel <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in Archean subseafloor has been proposed. In this model, highly alkaline and high temperature <span class="hlt">hydrothermal</span> fluids were generated in basalt-hosted <span class="hlt">hydrothermal</span> vents, where H2 and CO2 could be abundantly provided. These extreme conditions could have played an irreplaceable role in the early evolution of life. Nevertheless, sufficient information has not yet been obtained for the abiotic synthesis of amino acids, which are indispensable components of life, at high temperature and alkaline condition. This study aims to propose a new method for the synthesis of glycine in simulated Archean submarine alkaline vent <span class="hlt">systems</span>. We investigated the formation of glycine from ethanolamine under conditions of high temperature (80-160 °C) and highly alkaline solutions (pH = 9.70). Experiments were performed in an anaerobic environment under mild pressure (0.1-8.0 MPa) at the same time. The results suggested that the formation of glycine from ethanolamine occurred rapidly and efficiently in the presence of metal powders, and was favored by high temperatures and high pressures. The experiment provides a new pathway for prebiotic glycine formation and points out the phenomenal influence of high-temperature alkaline <span class="hlt">hydrothermal</span> vents in origin of life in the early ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27663450','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27663450"><span>Prebiotic Synthesis of Glycine from Ethanolamine in Simulated Archean Alkaline <span class="hlt">Hydrothermal</span> Vents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Xianlong; Tian, Ge; Gao, Jing; Han, Mei; Su, Rui; Wang, Yanxiang; Feng, Shouhua</p> <p>2017-12-01</p> <p>Submarine <span class="hlt">hydrothermal</span> vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. In recent years, a novel <span class="hlt">hydrothermal</span> <span class="hlt">system</span> in Archean subseafloor has been proposed. In this model, highly alkaline and high temperature <span class="hlt">hydrothermal</span> fluids were generated in basalt-hosted <span class="hlt">hydrothermal</span> vents, where H 2 and CO 2 could be abundantly provided. These extreme conditions could have played an irreplaceable role in the early evolution of life. Nevertheless, sufficient information has not yet been obtained for the abiotic synthesis of amino acids, which are indispensable components of life, at high temperature and alkaline condition. This study aims to propose a new method for the synthesis of glycine in simulated Archean submarine alkaline vent <span class="hlt">systems</span>. We investigated the formation of glycine from ethanolamine under conditions of high temperature (80-160 °C) and highly alkaline solutions (pH = 9.70). Experiments were performed in an anaerobic environment under mild pressure (0.1-8.0 MPa) at the same time. The results suggested that the formation of glycine from ethanolamine occurred rapidly and efficiently in the presence of metal powders, and was favored by high temperatures and high pressures. The experiment provides a new pathway for prebiotic glycine formation and points out the phenomenal influence of high-temperature alkaline <span class="hlt">hydrothermal</span> vents in origin of life in the early ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0164&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-00PP-0164&hterms=master+controller&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmaster%2Bcontroller"><span>The faulty Master Events Controller is carried away from STS-99 <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>Workers carry away the faulty Enhanced Main Events Controller (E- MEC) from Shuttle <span class="hlt">Endeavour</span> at Launch Pad 39A. The E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently <span class="hlt">Endeavour</span> and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EP%26S...70...72T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EP%26S...70...72T"><span>Contention between supply of <span class="hlt">hydrothermal</span> fluid and conduit obstruction: inferences from numerical simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanaka, Ryo; Hashimoto, Takeshi; Matsushima, Nobuo; Ishido, Tsuneo</p> <p>2018-05-01</p> <p>We investigate a volcanic <span class="hlt">hydrothermal</span> <span class="hlt">system</span> using numerical simulations, focusing on change in crater temperature. Both increases and decreases in crater temperature have been observed before phreatic eruptions. We follow the <span class="hlt">system</span>'s response for up to a decade after <span class="hlt">hydrothermal</span> fluid flux from the deep part of the <span class="hlt">system</span> is increased and permeability is reduced at a certain depth in a conduit. Our numerical simulations demonstrate that: (1) changes in crater temperature are controlled by the magnitude of the increase in <span class="hlt">hydrothermal</span> fluid flux and the degree of permeability reduction; (2) significant increases in <span class="hlt">hydrothermal</span> flux with decreases in permeability induce substantial pressure changes in shallow depths in the edifice and decreases in crater temperature; (3) the location of maximum pressure change differs between the mechanisms. The results of this study imply that it is difficult to predict eruptions by crater temperature change alone. One should be as wary of large eruptions when crater temperature decreases as when crater temperature increases. It is possible to clarify the implications of changes in crater temperature with simultaneous observation of ground deformation.[Figure not available: see fulltext.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.2236A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2236A"><span>Vertical Cable Seismic Survey for <span class="hlt">Hydrothermal</span> Deposit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asakawa, E.; Murakami, F.; Sekino, Y.; Okamoto, T.; Ishikawa, K.; Tsukahara, H.; Shimura, T.</p> <p>2012-04-01</p> <p>The vertical cable seismic is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. This type of survey is generally called VCS (Vertical Cable Seismic). Because VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed the method for the <span class="hlt">hydrothermal</span> deposit survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We are now developing a VCS <span class="hlt">system</span>, including not only data acquisition hardware but data processing and analysis technique. Our first experiment of VCS surveys has been carried out in Lake Biwa, JAPAN in November 2009 for a feasibility study. Prestack depth migration is applied to the 3D VCS data to obtain a high quality 3D depth volume. Based on the results from the feasibility study, we have developed two autonomous recording VCS <span class="hlt">systems</span>. After we carried out a trial experiment in the actual ocean at a water depth of about 400m and we carried out the second VCS survey at Iheya Knoll with a deep-towed source. In this survey, we could establish the procedures for the deployment/recovery of the <span class="hlt">system</span> and could examine the locations and the fluctuations of the vertical cables at a water depth of around 1000m. The acquired VCS data clearly shows the reflections from the sub-seafloor. Through the experiment, we could confirm that our VCS <span class="hlt">system</span> works well even in the severe circumstances around the locations of seafloor <span class="hlt">hydrothermal</span> deposits. We have, however, also confirmed that the uncertainty in the locations of the source and of the hydrophones could lower the quality of subsurface image. It is, therefore, strongly necessary to develop a total survey <span class="hlt">system</span> that assures a accurate positioning and a deployment techniques</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Tectp.717..433T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Tectp.717..433T"><span>The eastern Tibetan Plateau geothermal belt, western China: Geology, geophysics, genesis, and <span class="hlt">hydrothermal</span> <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Xianchun; Zhang, Jian; Pang, Zhonghe; Hu, Shengbiao; Tian, Jiao; Bao, Shujing</p> <p>2017-10-01</p> <p>The eastern Tibetan Plateau geothermal belt (ETGB), which is located in 98-102°E, 28-32°N, belongs to the eastern part of the Mediterranean-Himalayan geothermal belt. Recently, about 248 natural hot springs have been found in the ETGB. > 60% of these springs have temperatures of > 40 °C, and 11 springs have temperature above the local water boiling point. Using the helium isotopic data, gravity, magnetic and seismic data, we analyzed the thermal structure and the relationship between <span class="hlt">hydrothermal</span> activity and geothermal dynamics of the ETGB. Results show that: (1) the 248 springs can be divided into three geothermal fields: Kangding-Luhuo geothermal field (KGF), Litang-Ganzi geothermal field (LGF) and Batang-Xiangcheng geothermal field (BGF). The BGF and LGF have hot crust and warm mantle, and are characterized by the higher heat flux (66.26 mW/m2), and higher ratios of crust-derived heat flux to total flux (47.46-60.62%). The KGF has cool crust and hot mantle, and is characterized by the higher heat flux and lower Qc/Qm; (2) there is a relatively 4-6 m higher gravimetric geoid anomaly dome which is corresponding with the ETGB. And in <span class="hlt">hydrothermal</span> activity areas of the BGF and LGF, there is a northwest - southeast-trending tensile stress area and the upper-middle crust uplift area; (3) an abnormal layer exists in the middle-lower crust at a depth of 13-30 km beneath the ETGB, and this layer is 8-10 km thick and is characterized by lower velocity (Vp < 5.8 km/s, Vs < 3.2 km/s), high Poisson's ratio (> 2.5), high conductivity ( 10 Ω·m) and high temperature (850-1000 °C). Finally, based on the heat source and geological and geophysical background, we propose Kangding-type and Batang-type <span class="hlt">hydrothermal</span> <span class="hlt">system</span> models in the ETGB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4757712','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4757712"><span>The Guaymas Basin Hiking Guide to <span class="hlt">Hydrothermal</span> Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface <span class="hlt">Hydrothermal</span> Circulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Teske, Andreas; de Beer, Dirk; McKay, Luke J.; Tivey, Margaret K.; Biddle, Jennifer F.; Hoer, Daniel; Lloyd, Karen G.; Lever, Mark A.; Røy, Hans; Albert, Daniel B.; Mendlovitz, Howard P.; MacGregor, Barbara J.</p> <p>2016-01-01</p> <p>The <span class="hlt">hydrothermal</span> mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface <span class="hlt">hydrothermal</span> circulation patterns. In this overview, we document the most frequently visited features of this <span class="hlt">hydrothermal</span> area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and <span class="hlt">hydrothermal</span> sediments show their steep geochemical and thermal gradients at millimeter-scale vertical resolution. Mapping these <span class="hlt">hydrothermal</span> features and sampling locations within the southern Guaymas Basin suggest linkages to underlying shallow sills and heat flow gradients. Recognizing the inherent spatial limitations of much current Guaymas Basin sampling calls for comprehensive surveys of the wider spreading region. PMID:26925032</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1977/0060/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1977/0060/report.pdf"><span>A theoretical analysis of fluid flow and energy transport in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Faust, Charles R.; Mercer, James W.</p> <p>1977-01-01</p> <p>A mathematical derivation for fluid flow and energy transport in <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> is presented. Specifically, the mathematical model describes the three-dimensional flow of both single- and two-phase, single-component water and the transport of heat in porous media. The derivation begins with the point balance equations for mass, momentum, and energy. These equations are then averaged over a finite volume to obtain the macroscopic balance equations for a porous medium. The macroscopic equations are combined by appropriate constitutive relationships to form two similified partial differential equations posed in terms of fluid pressure and enthalpy. A two-dimensional formulation of the simplified equations is also derived by partial integration in the vertical dimension. (Woodard-USGS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s127e006585.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s127e006585.html"><span>Hurley and Payette in the FWD FD during docking activities of Space Shuttle <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2009-07-17</p> <p>S127-E-006585 (17 July 2009) --- Astronauts Doug Hurley, pilot, and Julie Payette, mission specialist, temporarily switch their attention to a crewmate with a camera while participating in flight day three activities onboard the Space Shuttle <span class="hlt">Endeavour</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28088716','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28088716"><span>Unveiling the transformation and bioavailability of dissolved organic matter in contrasting <span class="hlt">hydrothermal</span> vents using fluorescence EEM-PARAFAC.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Liyang; Zhuang, Wan-E; Chen, Chen-Tung Arthur; Wang, Bing-Jye; Kuo, Fu-Wen</p> <p>2017-03-15</p> <p>The submarine <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> are extreme environments where active cycling of dissolved organic matter (DOM) may occur. However, little is known about the optical properties and bioavailability of <span class="hlt">hydrothermal</span> DOM, which could provide valuable insights into its transformation processes and biogeochemical reactivity. The quantity, quality, and bioavailability of DOM were investigated for four very different <span class="hlt">hydrothermal</span> vents east of Taiwan, using dissolved organic carbon (DOC), absorption spectroscopy, and fluorescence excitation-emission matrices-parallel factor analysis (EEM-PARAFAC). The DOC and absorption coefficient a 280 were both lower in the two <span class="hlt">hydrothermal</span> vents off the Orchid Island and on the Green Island than in the surrounding seawater and the two vents off the Kueishantao Island, indicating effective removals of DOM in the former two <span class="hlt">hydrothermal</span> <span class="hlt">systems</span> owing to possible adsorption/co-precipitation and thermal degradation respectively. The four <span class="hlt">hydrothermal</span> DOM showed notable differences in the absorption spectral slope S 275-295 , humification index HIX, biological index BIX, EEM spectra, and the relative distributions of seven PARAFAC components. The results demonstrated a high diversity of chemical composition and transformation history of DOM under contrasting <span class="hlt">hydrothermal</span> conditions. The little change in the <span class="hlt">hydrothermal</span> DOC after 28-day microbial incubations indicated a low bioavailability of the bulk DOM, and different PARAFAC components showed contrasting bioavailability. The results have profound implications for understanding the biogeochemical cycling and environmental effects of <span class="hlt">hydrothermal</span> DOM in the marine environments. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/143826-redox-control-gas-compositions-philippine-volcanic-hydrothermal-systems','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/143826-redox-control-gas-compositions-philippine-volcanic-hydrothermal-systems"><span>Redox control of gas compositions in Philippine volcanic-<span class="hlt">hydrothermal</span> <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Giggenbach, W.F.</p> <p>1993-10-01</p> <p>Gas samples from five volcanic-<span class="hlt">hydrothermal</span> <span class="hlt">systems</span> in the Philippines were analyzed for CO{sub 2}, H{sub 2}S, NH{sub 3}, H{sub 2}, He, Ne, Ar, N{sub 2}, CH{sub 4} and CO. Even in <span class="hlt">systems</span> with sulfate minerals as common components of alteration assemblages, indicating highly immature, oxidizing conditions at depth, the redox potential governing the concentrations of the reactive gases CO{sub 2}, H{sub 2}S, H{sub 2}, CH{sub 4} and CO approaches closely that expected for attainment of equilibrium with rock in more mature, reduced <span class="hlt">systems</span>. The finding suggests that overall fluid compositions reflect more closely redox conditions established at the advancing frontmore » of interaction with primary rock rather than those of equilibrium with the set of secondary minerals left behind. With the exception of CO and NH{sub 3}, the close agreement in the compositions of gas samples, taken from pools and deep wells indicates that the secondary processes have only a slight effect on the vapors during their rise from drilled depths (1.8 km) to the surface and that samples from natural features may be taken to be representative of redox conditions at drilled depths.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1649&hterms=Unity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D10%26Ntt%3DUnity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1649&hterms=Unity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D10%26Ntt%3DUnity"><span>The Unity connecting module moves into payload bay of <span class="hlt">Endeavour</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1998-01-01</p> <p>The Unity connecting module is moved toward the payload bay of the orbiter <span class="hlt">Endeavour</span> at Launch Pad 39A. Part of the International Space Station (ISS), Unity is scheduled for launch Dec. 3, 1998, on Mission STS-88 . The Unity is a connecting passageway to the living and working areas of ISS. While on orbit, the flight crew will deploy Unity from the payload bay and attach it to the Russian-built Zarya control module which will be in orbit at that time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70026697','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70026697"><span>Massive sulfide deposition and trace element remobilization in the Middle Valley sediment-hosted <span class="hlt">hydrothermal</span> <span class="hlt">system</span>, northern Juan de Fuca Rdge</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Houghton, J.L.; Shanks, Wayne C.; Seyfried, W.E.</p> <p>2004-01-01</p> <p>The Bent Hill massive sulfide deposit and ODP Mound deposit in Middle Valley at the northernmost end of the Juan de Fuca Ridge are two of the largest modern seafloor <span class="hlt">hydrothermal</span> deposits yet explored. Trace metal concentrations of sulfide minerals, determined by laser-ablation ICP-MS, were used in conjunction with mineral paragenetic studies and thermodynamic calculations to deduce the history of fluid-mineral reactions during sulfide deposition. Detailed analyses of the distribution of metals in sulfides indicate significant shifts in the physical and chemical conditions responsible for the trace element variability observed in these sulfide deposits. Trace elements (Mn, Co, Ni, As, Se, Ag, Cd, Sb, Pb, and Bi) analyzed in a representative suite of 10 thin sections from these deposits suggest differences in conditions and processes of <span class="hlt">hydrothermal</span> alteration resulting in mass transfer of metals from the center of the deposits to the margins. Enrichments of some trace metals (Pb, Sb, Cd, Ag) in sphalerite at the margins of the deposits are best explained by dissolution/reprecipitation processes consistent with secondary remineralization. Results of reaction-path models clarify mechanisms of mass transfer during remineralization of sulfide deposits due to mixing of <span class="hlt">hydrothermal</span> fluids with seawater. Model results are consistent with patterns of observed mineral paragenesis and help to identify conditions (pH, redox, temperature) that may be responsible for variations in trace metal concentrations in primary and secondary minerals. Differences in trace metal distributions throughout a single deposit and between nearby deposits at Middle Valley can be linked to the history of metal mobilization within this active <span class="hlt">hydrothermal</span> <span class="hlt">system</span> that may have broad implications for sulfide ore formation in other sedimented and unsedimented ridge <span class="hlt">systems</span>. ?? 2004 Elsevier Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JIEIB..95..319B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JIEIB..95..319B"><span>Artificial Bee Colony Optimization for Short-Term <span class="hlt">Hydrothermal</span> Scheduling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Basu, M.</p> <p>2014-12-01</p> <p>Artificial bee colony optimization is applied to determine the optimal hourly schedule of power generation in a <span class="hlt">hydrothermal</span> <span class="hlt">system</span>. Artificial bee colony optimization is a swarm-based algorithm inspired by the food foraging behavior of honey bees. The algorithm is tested on a multi-reservoir cascaded hydroelectric <span class="hlt">system</span> having prohibited operating zones and thermal units with valve point loading. The ramp-rate limits of thermal generators are taken into consideration. The transmission losses are also accounted for through the use of loss coefficients. The algorithm is tested on two <span class="hlt">hydrothermal</span> multi-reservoir cascaded hydroelectric test <span class="hlt">systems</span>. The results of the proposed approach are compared with those of differential evolution, evolutionary programming and particle swarm optimization. From numerical results, it is found that the proposed artificial bee colony optimization based approach is able to provide better solution.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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