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Sample records for 150-220 km zone

  1. Evidence for back scattering of near-podal seismic P'P' waves from the 150-220 km zone in Earth's upper mantle

    SciTech Connect

    Tkalcic, H; Flanagan, M P; Cormier, V F

    2005-07-15

    The deepest and most inaccessible parts of Earth's interior--the core and core-mantle boundary regions can be studied from compressional waves that turn in the core and are routinely observed following large earthquakes at epicentral distances between 145{sup o} and 180{sup o} (also called P', PKIKP or PKP waves). P'P' (PKPPKP) are P' waves that travel from a hypocenter through the Earth's core, reflect from the free surface and travel back through the core to a recording station on the surface. P'P' waves are sometimes accompanied by precursors, which were reported first in the 1960s as small-amplitude arrivals on seismograms at epicentral distances of about 50{sup o}-70{sup o}. Most prominent of these observed precursors were explained by P'P' waves generated by earthquakes or explosions that did not reach the Earth's surface but were reflected from the underside of first order velocity discontinuities at 410 and 660 km in the upper mantle mantle. Here we report the discovery of hitherto unobserved near-podal P'P' waves (at epicentral distance less than 10{sup o}) and very prominent precursors preceding the main energy by as much as 55 seconds. We interpret these precursors as a back scattered energy from undocumented structure in the upper mantle, in a zone between 150 and 220 km depth beneath Earth's surface. From these observations, we identify a frequency dependence of Q (attenuation quality factor) in the lithosphere that can be modeled by a flat relaxation spectrum below about 0.05-0.1 Hz and increasing with as the first power of frequency above this value, confirming pioneering work by B. Gutenberg.

  2. Predicting km-scale shear zone formation

    NASA Astrophysics Data System (ADS)

    Gerbi, Christopher; Culshaw, Nicholas; Shulman, Deborah; Foley, Maura; Marsh, Jeffrey

    2015-04-01

    Because km-scale shear zones play a first-order role in lithospheric kinematics, accurate conceptual and numerical models of orogenic development require predicting when and where they form. Although a strain-based algorithm in the upper crust for weakening due to faulting appears to succeed (e.g., Koons et al., 2010, doi:10.1029/2009TC002463), a comparable general rule for the viscous crust remains unestablished. Here we consider two aspects of the geological argument for a similar algorithm in the viscous regime, namely (1) whether predicting km-scale shear zone development based on a single parameter (such as strain or shear heating) is reasonable; and (2) whether lithologic variability inherent in most orogenic systems precludes a simple predictive rule. A review of tectonically significant shear zones worldwide and more detailed investigations in the Central Gneiss belt of the Ontario segment of the Grenville Province reveals that most km-scale shear zones occur at lithological boundaries and involve mass transfer, but have fairly little else in common. As examples, the relatively flat-lying Twelve Mile Bay shear zone in the western Central Gneiss belt bounds the Parry Sound domain and is likely the product of both localized anatexis and later retrograde hydration with attendant metamorphism. Moderately dipping shear zones in granitoids of the Grenville Front Tectonic Zone apparently resulted from cooperation among several complementary microstructural processes, such as grain size reduction, enhanced diffusion, and a small degree of metamorphic reaction. Localization into shear zones requires the operation of some spatially restricted processes such as stress concentration, metamorphism/fluid access, textural evolution, and thermal perturbation. All of these could be due in part to strain, but not necessarily linearly related to strain. Stress concentrations, such as those that form at rheological boundaries, may be sufficient to nucleate high strain

  3. Seismological detection of "730-km" discontinuity beneath Japan subduction zone

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Park, J. J.; Karato, S. I.

    2015-12-01

    Because the mantle transition zone likely contains a large amount of water (Karato, 2011; Pearson et al., 2014), vertical material transport across the transition would cause partial melting that may produce seismic signals above and/or below the transition zone. Schmandt et al. (2014) observed a seismic low-velocity zone (LVZ) at the top of the lower mantle (~730 km) beneath the southwestern US, arguing for dehydration melting due to downward flow across the 670-km discontinuity (670) from the transition zone. These authors further proposed a correlation between seismic velocity reductions and the direction of water transport, in which LVZ at ~730 km indicates materials moving downward from the transition zone, while the lack of LVZ at this depth would suggest an upward flow of mantle materials. Other regions also need to be investigated to confirm the correlation between this seismic feature and mantle water transport. We test their model by detecting "730-km" discontinuity beneath the Japan subduction zone using frequency-dependent receiver functions. In addition, water transport above the 410-km discontinuity (410) also plays an important role in global water circulation (Bercovici and Karato, 2003). Seismological studies (e.g. Courtier and Revenaugh, 2007; Schaeffer and Bostock, 2010) have observed LVZs above the 410, which might be caused by dehydration melting due to the upwelling of hydrated materials across the 410-km discontinuity from the transition zone. In this study, we also detect potential LVZs above 410 to establish a correlation between seismic velocity drop and flow direction. Around the Japan subduction zone, our preliminary results show evidence of low velocity zones below 670 in regions where stagnant slab is present for a substantial amount of time but not in other regions suggesting a variety of vertical mass transport in this region. Key words: transition zone, water transport, subduction zone, melting, receiver functions

  4. Transition zone velocity gradients and the 520-km discontinuity

    NASA Astrophysics Data System (ADS)

    Shearer, Peter M.

    1996-02-01

    Stacks of long-period Global Digital Seismograph Network (GDSN) seismograms at 110° to 180° epicentral distance reveal precursors to SS that result from underside reflections off upper mantle seismic discontinuities. The 410- and 660-km discontinuities are obvious in these stacks, but identification and modeling of other transition zone discontinuities are complicated by sidelobes from the 410- and 660-km reflections. These sidelobes result from the limited bandwidth of the GDSN instrument responses and the effect of crustal reverberations on the SS reference phase. The crustal effects can be minimized by restricting the records to oceanic bounce points where the ˜6-km-thick crust has little effect on the long-period waveforms. Over 2000 long-period, transverse-component seismograms with oceanic SS bounce points recorded by the GDSN from 1976 to 1991 are manually edited, aligned on SS, and then stacked using a new procedure that weights the records by data quality. The resulting image shows a clear reflection from a 520-km discontinuity that cannot be explained as a sidelobe artifact, confirming earlier results of Shearer [1990, 1991] and Revenaugh and Jordan [1991]. By stacking along the expected travel time curves for discontinuity phases, the time versus range image of the precursor wave field is reduced to a single trace that measures upper mantle reflectivity versus time. The features in this reflectivity profile are sensitive to the brightness and depth of the transition zone discontinuities and to the steepness of the velocity gradients between the interfaces. Using geometrical ray theory and assuming a constant velocity versus density scaling relationship, I fit this reflectivity profile with velocity models of the upper mantle using both forward modeling and direct inversion. The inverse problem is addressed by performing a deconvolution of the profile with the SS reference phase (after a correction for attenuation), followed by a direct mapping of

  5. Detection of the structure near the 410 km and 660 km discontinuities in Japan subduction zone from the waveform triplication

    NASA Astrophysics Data System (ADS)

    Cui, H.; Zhou, Y.

    2015-12-01

    Slab subduction plays an important role in the mantle material circulation [Stern, 2002], and can also affect the feature of the 410 km and 660 km seismic discontinuities (410 and 660) [Lebedev et al., 2002]. Japan subduction zone is a natural laboratory for studying the mantle composition and velocity structure associated with the deep subduction of the Pacific plate. In this study, triplicated waveforms of an intermediate-depth earthquake at the Hokkaido of Japan (2011/10/21, 08:02:37.62, 142.5315°E, 43.8729°N, Mb6.0, relocated depth: 188 km) are retrieved from the dense Chinese Digital Seismic Network (CDSN). P and S waveforms are filtered with the band of 0.05-1.0 Hz and 0.02-0.5 Hz, respectively, and then integrated into the displacement data. The relative traveltime and synthetic waveform fitting is applied to mapping the deep structure. The best fitting models are obtained through the trial and error tests. We find a 15 km uplift of the 410 and a 25 km depression of the 660, indicating the cold environment caused by the subduction slab; both the 410 and 660 show the sharp discontinuity, but a smaller velocity contrast than the IASP91 model [Kennett and Engdahl, 1991]. Atop the 410 and 660, there are high-velocity layers associated with the subduction (or stagnant) slab. We also find a low-velocity anomaly with the thickness of ~65 km below the 660, which may relate to the slab dehydration or the hot upwelling at the top of the lower mantle. The seismic velocity ratio (VP/VS) shows a lower zone at the depth of ~210-395 km, showing the consistency with the low Poisson's ratio signature of the oceanic plate; a higher zone at the depth of ~560-685 km, implying the hydrous mantle transition zone.

  6. Role of the transition zone and 660 km discontinuity in mantle dynamics

    NASA Astrophysics Data System (ADS)

    Ringwood, A. E.

    1994-10-01

    Recent seismic evidence suggests that subducted slabs experience resistance to further descent when they encounter the 660 km seismic discontinuity. Several possible causes of this resistance are evaluated. It is concluded that the chemical composition of the lower mantle is similar to that of the upper mantle, and that compositional change is therefore unlikely to be the cause of resistance to slab penetration. The proposal that a large increase of viscosity at the 660 km discontinuity impedes descending slabs is also rejected. However, three other factors are identified, each of which is capable of causing substantial resistance to descending slabs: (1) the negative slope of the transformation of silicate spinel to Mg-perovskite+magnesiowuestite; (2) differentiation of oceanic lithosphere into basaltic and depleted peridotitic layers, causing the slab to be buoyant compared with surrounding mantle pyrolite between depths of 660-800 km; (3) the accumulation of former oceanic crust to produce a gravitationally stable layer of garnetite (about 50 km thick) on top of the 660 km discontinuity. The combined effects of these sources of resistance provide a filter for subducted slabs. Those slabs with seismic zones extending below 600 km may possess sufficient negative buoyancy and strength to overcome the barriers and penetrate into the lower mantle. However, the resistance causes strong buckling and plastic thickening of these slabs, which accumulate to form huge blobs or 'megaliths' underneath the 660 km discontinuity. In contrast, slabs with seismic zones extending no deeper than 300 km possess much smaller degrees of negative buoyancy and strength and hence are unable to penetrate the 660 km discontinuity. Slabs of this type are recycled within the transition zone and upper mantle. Mixing and petrological homogenization processes are less efficient in the transition zone than in the upper mantle (above 400 km). The transition zone is composed mainly of ancient slabs

  7. Risks from radionuclide migration to groundwater in the Chernobyl 30-km zone.

    PubMed

    Bugai, D A; Waters, R D; Dzhepo, S P; Skal'skij, A S

    1996-07-01

    Remediation of contaminated groundwater in the Chernobyl 30-km evacuation zone is frequently identified as a priority by technical experts and Chernobyl site officials in Ukraine. In order to evaluate the health risk basis for this groundwater remediation, we have estimated both on-site and off-site health risks caused by radionuclide migration to the groundwater and compared these risks with those from exposure to radioactive contamination on the ground surface. A simple and conservative analytical model was developed to assess radionuclide transport to the groundwater from the soil surface contaminated by radioactive fallout. 90Sr, the primary radioactive contaminant of concern for the groundwater-migration exposure pathway, was evaluated in the analysis. The estimated health risk to hypothetical, self-sufficient residents in the 30-km zone is dominated by external and internal irradiation (due primarily to ingestion of agricultural products) from 137Cs, which is present in soils of the 30-km zone in roughly equal proportion with 90Sr. The estimated risk from contaminated groundwater is approximately an order of magnitude lower. Analysis of 90Sr migration via groundwater to surface water and down-river population centers shows that, despite generally unfavorable environmental conditions in the 30-km exclusion zone, radionuclide transport via the groundwater pathway has potential to contribute only marginally to the off-site radiological risk, which is governed by wash-out of radionuclides from the contaminated river flood plain and catchment areas by surface water during spring snowmelt and rains. Health risks due to off-site radionuclide migration via groundwater are below the level requiring application of counter-measures. This analysis implies that, relative to other exposure pathways, there is little current or future health risk basis for the proposed complex and costly groundwater remediation measures in the 30-km zone. Therefore, these activities should

  8. Low-velocity zone atop the 410-km seismic discontinuity in the northwestern United States.

    PubMed

    Song, Teh-Ru Alex; Helmberger, Don V; Grand, Stephen P

    2004-02-05

    The seismic discontinuity at 410 km depth in the Earth's mantle is generally attributed to the phase transition of (Mg,Fe)2SiO4 (refs 1, 2) from the olivine to wadsleyite structure. Variation in the depth of this discontinuity is often taken as a proxy for mantle temperature owing to its response to thermal perturbations. For example, a cold anomaly would elevate the 410-km discontinuity, because of its positive Clapeyron slope, whereas a warm anomaly would depress the discontinuity. But trade-offs between seismic wave-speed heterogeneity and discontinuity topography often inhibit detailed analysis of these discontinuities, and structure often appears very complicated. Here we simultaneously model seismic refracted waves and scattered waves from the 410-km discontinuity in the western United States to constrain structure in the region. We find a low-velocity zone, with a shear-wave velocity drop of 5%, on top of the 410-km discontinuity beneath the northwestern United States, extending from southwestern Oregon to the northern Basin and Range province. This low-velocity zone has a thickness that varies from 20 to 90 km with rapid lateral variations. Its spatial extent coincides with both an anomalous composition of overlying volcanism and seismic 'receiver-function' observations observed above the region. We interpret the low-velocity zone as a compositional anomaly, possibly due to a dense partial-melt layer, which may be linked to prior subduction of the Farallon plate and back-arc extension. The existence of such a layer could be indicative of high water content in the Earth's transition zone.

  9. Strain distribution within a km-scale, mid-crustal shear zone: The Kuckaus Mylonite Zone, Namibia

    NASA Astrophysics Data System (ADS)

    Rennie, S. F.; Fagereng, Å.; Diener, J. F. A.

    2013-11-01

    The subvertical Kuckaus Mylonite Zone (KMZ) is a km-wide, crustal-scale, Proterozoic, dextral strike-slip shear zone in the Aus granulite terrain, SW Namibia. The KMZ was active under retrograde, amphibolite to greenschist facies conditions, and deformed felsic (and minor mafic) gneisses which had previously experienced granulite facies metamorphism during the Namaqua Orogeny. Lenses of pre- to syn-tectonic leucogranite bodies are also deformed in the shear zone. Pre-KMZ deformation (D1) is preserved as moderately dipping gneissic foliations and tightly folded migmatitic layering. Shear strain within the KMZ is heterogeneous, and the shear zone comprises anastomosing high strain ultramylonite zones wrapping around less deformed to nearly undeformed lozenges. Strain is localized along the edge of leucogranites and between gneissic lozenges preserving D1 migmatitic foliations. Strain localization appears controlled by pre-existing foliations, grain size, and compositional anisotropy between leucogranite and granulite. The local presence of retrograde minerals indicate that fluid infiltration occurred in places, but most ultramylonite in the KMZ is free of retrograde minerals. In particular, rock composition and D1 fabric heterogeneity are highlighted as major contributors to the strain distribution in time and space, with deformation localization along planes of rheological contrast and along pre-existing foliations. Therefore, the spatial distribution of strain in crustal-scale ductile shear zones may be highly dependent on lithology and the orientation of pre-existing fabric elements. In addition, foliation development and grain size reduction in high strain zones further localizes strain during progressive shear, maintaining the anastomosing shear zone network established by the pre-existing heterogeneity.

  10. Reconstruction of the inhalation dose in the 30-km zone after the Chernobyl accident.

    PubMed

    Mück, Konrad; Pröhl, Gerhard; Likhtarev, Ilya; Kovgan, Lina; Golikov, Vladislav; Zeger, Johann

    2002-02-01

    Due to lack of measurements of activity concentrations in air, the assessment of the inhalation dose of the population evacuated from the 30-km zone after the Chernobyl accident is not possible from continuous filter measurements. Since the evaluation of the inhalation dose in each settlement of the zone is of great interest for epidemiological purposes, an approach was chosen that utilizes the available data on ground deposition of 137Cs, a recently performed best estimate of the radionuclide vector and its spatial distribution as well as the radionuclide dependent deposition velocity. The derived inhalation dose values in the 30-km zone range between 3 mSv to 150 mSv effective dose for adults depending on the distance to the reactor site and the day of evacuation. For 1-y-old infants the values range between 10 to 700 mSv. In Chernobyl town, an effective inhalation dose of 25 mSv until evacuation day was assessed. Thyroid doses due to inhalation ranged from 0.02 to 1 Sv for adults, for 1-y-old infants from 0.02 to 6 Sv. The inhalation dose in each settlement of the 30-km zone is approximately 8-13 times higher than the external exposure in each settlement if evacuation of the settlement occurred at an early stage. For settlements with evacuation at a later stage (day 10 or later) the inhalation dose was about 50-70% higher than the external dose. The dominant contribution to the effective inhalation dose comes from 131I (about 40%) and tellurium and rubidium isotopes (about 20-30%). Despite high zirconium and cerium ground depositions, zirconium and cerium isotopes contribute rather little to the inhalation dose which is mainly due to the great particle sizes to which they are attached. The relative contribution of short-lived radionuclides is, despite higher activities than at greater distances, less than 5%.

  11. South Pole Fault Zone, 900 km long and almost through the pole

    NASA Astrophysics Data System (ADS)

    Wise, D. U.; Cianfarra, P.; Salvini, F.

    2010-12-01

    The most prominent feature of snow and ice topography of the East Antarctic Plateau is the 850 x 1100 km Pensacola Basin, named for the mountain range at its mouth. The basin's headwall is a remarkably linear 900 km-long, 100 -200 km-wide zone wherein snow surface slopes of 3 m/km contrast with values of 1 m/km on either side, a total relief of 200 to 400 meters. About 700 km of this slope lies along the 35th meridian, the remainder continuing through the pole for another 200 km. Satellite images show an easily mapped zebra-striped snow unit occurs throughout the basin and beyond. The stripes are well-known from other areas as megadunes, enigmatic, upwind climbing dunes of alternating snow and ice bands with 2 km wavelength and only 1-4 m amplitude. Superposition relationships show this unit is the bottom member of a four-unit snow stratigraphy, the basis for the first geologic map of the youngest snow units of the South Pole region. The megadune stripes are draped obliquely down over the headwall slope to disappear beneath younger snow fill of the Recovery Basin at its foot before cropping out again on the floor of the main basin. Nearer the pole, the slope forms the edge of a 15,000 km2 triangular plateau, the pole located half-way down the slope. Megadune stripes from higher elevations disappear beneath younger snows of the small basin and the pole to reappear on the floor of the main basin as ghosts of megadune stripes. Farther out on the floor they emerge from beneath this thin cover as fully exposed megadune stripes. An overlay of the snow- geologic map across the relatively low resolution maps of bedrock topography shows the surface slope separates two domains of contrasting bedrock topography, the lower elevation domain corresponding to the basin floor. The most likely explanation for this remarkably linear snow slope is flow of ice over a previously unrecognized 200-400 m-high, 900 km-long bedrock fault-line scarp. Along its distal end, the surface slope

  12. Kinetics of fuel particle weathering and 90Sr mobility in the Chernobyl 30-km exclusion zone.

    PubMed

    Kashparov, V A; Oughton, D H; Zvarich, S I; Protsak, V P; Levchuk, S E

    1999-03-01

    Weathering of fuel particles and the subsequent leaching of radionuclides causes 90Sr mobility in Chernobyl soils to increase with time after deposition. Studies of 90Sr speciation in soils collected in 1995 and 1996 from the Chernobyl 30-km exclusion zone have been used to calculate rates of fuel particles dissolution under natural environmental conditions. Results show that the velocity of fuel particle dissolution is primarily dependent on the physico-chemical characteristics of the particles and partially dependent on soil acidity. Compared to other areas, the fuel particle dissolution rate is significantly lower in the contaminated areas to the west of the Chernobyl reactor where deposited particles were presumably not oxidized prior to release. The data have been used to derive mathematical models that describe the rate of radionuclide leaching from fuel particles in the exclusion zone and changes in soil-to-plant transfer as a function of particle type and soil pH.

  13. Reassessing Transuranic Element Contamination Within the 30 km Exclusion Zone of the Chernobyl Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Tryshyn, V.; Gaidar, O.; Ageyev, V.; Sazheniuk, A.

    2011-12-01

    Following the Chernobyl catastrophe in 1986, large amounts of radionuclides were dispersed into the environment and spread across a large territory. An evacuated 30 km exclusion zone was established around the site to limit access to the most heavily contaminated areas. The highest concentrations of radionuclide deposition, particularly for the transuranic elements such as americium, plutonium and the minor actinides, are located on the territories adjacent to the Chernobyl nuclear power plant. Assessing the distribution and movement of radionuclides in these areas remains a high priority, but many previous studies were carried out without appropriately accounting for specific characteristics of Chernobyl fallout, namely, the significant role of hot particles (fuel particles). Evaluation of the distribution and impact of Chernobyl contamination often relied on piecing together data on different radionuclides provided by different organizations. The compositional and spatial heterogeneity of Chernobyl fallout make it difficult to evaluate the accuracy of such disparate data sets. The Institute of Nuclear Research, Kiev (INR) has been involved in the tracking and study of contamination in areas impacted by the Chernobyl accident since the first days of the catastrophe. INR has developed comprehensive evaluation methods to support detailed assessment of the distribution and levels of contamination for transuranic elements across the 30 km exclusion zone. This approach to carrying out investigations ensures collection of representative data at all stages. Assessments now include a transuranic focus, taking into account over 3500 variables, and incorporating specific features of the Chernobyl fallout and geography. The basic principles developed for data collection include several modifications: Evaluation of existing survey data (such as airborne gamma surveys) and the spatial heterogeneity to target selection of sampling locations; Measurements of the concentrations

  14. Pile driving zone of responsiveness extends beyond 20 km for harbor porpoises (Phocoena phocoena (L.)).

    PubMed

    Tougaard, Jakob; Carstensen, Jacob; Teilmann, Jonas; Skov, Henrik; Rasmussen, Per

    2009-07-01

    Behavioral reactions of harbor porpoises (Phocoena phocoena) to underwater noise from pile driving were studied. Steel monopile foundations (4 m diameter) for offshore wind turbines were driven into hard sand in shallow water at Horns Reef, the North Sea. The impulsive sounds generated had high sound pressures [source level 235 dB re 1 microPa(pp) at 1 m, transmission loss 18 log(distance)] with a strong low frequency emphasis but with significant energy up to 100 kHz. Reactions of porpoises were studied by passive acoustic loggers (T-PODs). Intervals between echolocation events (encounters) were analyzed, and a significant increase was found from average 5.9 h between encounters in the construction period as a whole to on average 7.5 h between first and second encounters after pile driving. The size of the zone of responsiveness could not be inferred as no grading in response was observed with distance from the pile driving site but must have exceeded 21 km (distance to most distant T-POD station).

  15. The Molecular Gas Environment in the 20 km s‑1 Cloud in the Central Molecular Zone

    NASA Astrophysics Data System (ADS)

    Lu, Xing; Zhang, Qizhou; Kauffmann, Jens; Pillai, Thushara; Longmore, Steven N.; Kruijssen, J. M. Diederik; Battersby, Cara; Liu, Hauyu Baobab; Ginsburg, Adam; Mills, Elisabeth A. C.; Zhang, Zhi-Yu; Gu, Qiusheng

    2017-04-01

    We recently reported a population of protostellar candidates in the 20 km s‑1 cloud in the Central Molecular Zone of the Milky Way, traced by H2O masers in gravitationally bound dense cores. In this paper, we report molecular line studies with high angular resolution (∼3″) of the environment of star formation in this cloud. Maps of various molecular line transitions as well as the continuum at 1.3 mm are obtained using the Submillimeter Array. Five NH3 inversion lines and the 1.3 cm continuum are observed with the Karl G. Jansky Very Large Array. The interferometric observations are complemented with single-dish data. We find that the CH3OH, SO, and HNCO lines, which are usually shock tracers, are better correlated spatially with the compact dust emission from dense cores among the detected lines. These lines also show enhancement in intensities with respect to SiO intensities toward the compact dust emission, suggesting the presence of slow shocks or hot cores in these regions. We find gas temperatures of ≳100 K at 0.1 pc scales based on RADEX modeling of the H2CO and NH3 lines. Although no strong correlations between temperatures and linewidths/H2O maser luminosities are found, in high-angular-resolution maps we note several candidate shock-heated regions offset from any dense cores, as well as signatures of localized heating by protostars in several dense cores. Our findings suggest that at 0.1 pc scales in this cloud star formation and strong turbulence may together affect the chemistry and temperature of the molecular gas.

  16. Castro ring zone: a 4,500-km2 fossil hydrothermal system in the Challis volcanic field, central Idaho.

    USGS Publications Warehouse

    Criss, R.E.; Ekren, E.B.; Hardyman, R.F.

    1984-01-01

    The largest fossil hydrothermal system occupying a 4500 km2 area in central Idaho is revealed by delta 18O studies. The remains of this meteoric-hydrothermal system 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 hydrothermally 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 systems are surprisingly insensitive to the circulation scale.-L.-di H.

  17. Trace element signature of subduction-zone fluids, melts and supercritical liquids at 120-180 km depth.

    PubMed

    Kessel, Ronit; Schmidt, Max W; Ulmer, Peter; Pettke, Thomas

    2005-09-29

    Fluids and melts liberated from subducting oceanic crust recycle lithophile elements back into the mantle wedge, facilitate melting and ultimately lead to prolific subduction-zone arc volcanism. The nature and composition of the mobile phases generated in the subducting slab at high pressures have, however, remained largely unknown. Here we report direct LA-ICPMS measurements of the composition of fluids and melts equilibrated with a basaltic eclogite at pressures equivalent to depths in the Earth of 120-180 km and temperatures of 700-1,200 degrees C. The resultant liquid/mineral partition coefficients constrain the recycling rates of key elements. The dichotomy of dehydration versus melting at 120 km depth is expressed through contrasting behaviour of many trace elements (U/Th, Sr, Ba, Be and the light rare-earth elements). At pressures equivalent to 180 km depth, however, a supercritical liquid with melt-like solubilities for the investigated trace elements is observed, even at low temperatures. This mobilizes most of the key trace elements (except the heavy rare-earth elements, Y and Sc) and thus limits fluid-phase transfer of geochemical signatures in subduction zones to pressures less than 6 GPa.

  18. Large-scale hydraulic structure of a seismogenic fault at 10 km depth (Gole Larghe Fault Zone, Italian Southern Alps)

    NASA Astrophysics Data System (ADS)

    Bistacchi, Andrea; Di Toro, Giulio; Smith, Steve; Mittempergher, Silvia; Garofalo, Paolo

    2014-05-01

    The definition of hydraulic properties of fault zones is a major issue in structural geology, seismology, and in several applications (hydrocarbons, hydrogeology, CO2 sequestration, etc.). The permeability of fault rocks can be measured in laboratory experiments, but its upscaling to large-scale structures is not straightforward. For instance, typical permeability of fine-grained fault rock samples is in the 10-18-10-20 m2 range, but, according to seismological estimates, the large-scale permeability of active fault zones can be as high as 10-10 m2. Solving this issue is difficult because in-situ measurements of large-scale permeability have been carried out just at relatively shallow depths - mainly in oil wells and exceptionally in active tectonic settings (e.g. SAFOD at 3 km), whilst deeper experiments have been performed only in the stable continental crust (e.g. KTB at 9 km). In this study, we apply discrete fracture-network (DFN) modelling techniques developed for shallow aquifers (mainly in nuclear waste storage projects like Yucca Mountain) and in the oil industry, in order to model the hydraulic structure of the Gole Larghe Fault Zone (GLFZ, Italian Southern Alps). This fault, now exposed in world-class glacier-polished outcrops, has been exhumed from ca. 8 km, where it was characterized by a well-documented seismic activity, but also by hydrous fluid flow evidenced by alteration halos and precipitation of hydrothermal minerals in veins and along cataclasites. The GLFZ does not show a classical seal structure that in other fault zones corresponds to a core zone characterized by fine-grained fault rocks. However, permeability is heterogeneous and the permeability tensor is strongly anisotropic due to fracture preferential orientation. We will show with numerical experiments that this hydraulic structure results in a channelized fluid flow (which is consistent with the observed hydrothermal alteration pattern). This results in a counterintuitive situation

  19. Kinetics of fuel particle weathering and {sup 90}Sr mobility in the Chernobyl 30-km exclusion zone

    SciTech Connect

    Kashparov, V.A.; Zvarich, S.I.; Protsak, V.P.; Levchuk, S.E.; Oughton, D.H.

    1999-03-01

    Weathering of fuel particles and the subsequent leaching of radionuclides causes {sup 90}Sr mobility in Chernobyl soils to increase with time after disposition. Studies of {sup 90}Sr speciation in soils collected in 1995 and 1996 from the Chernobyl 30-km exclusion zone have been used to calculate rates of fuel particles dissolution under natural environmental conditions. Results show that the velocity of fuel particle dissolution is primarily dependent on the physico-chemical characteristics of the particles and partially dependent on soil acidity. Compared to other areas, the fuel particle dissolution rate is significantly lower in the contaminated areas to the west of the Chernobyl reactor where deposited particles were presumably not oxidized prior to release. The data have been used to derive mathematical models that describe the rate of radionuclide leaching from fuel particles in the exclusion zone and changes in soil-to-plant transfer as a function of particle type and soil pH.

  20. Towards measuring large-scale hydraulic properties of the seismogenic Gole Larghe Fault Zone at 8 km depth

    NASA Astrophysics Data System (ADS)

    Bistacchi, Andrea; Mittempergher, Silvia; Smith, Steve; Di Toro, Giulio; Mitchell, Tom; Nielsen, Stefan

    2013-04-01

    Fluid flow along fault zones is a major issue in structural geology and seismology. The permeability of fault rocks can be measured in laboratory experiments (e.g. Mitchell et al., this meeting) but its upscaling to large scale structures is not an easy task. On the other hand, in-situ measurements of permeability have been carried out just at relatively shallow depths, only exceptionally up to 3 km for active tectonic settings (e.g. SAFOD), whilst deeper experiments have been performed only in the stable continental crust (e.g. KTB). In this contribution we combine field and microstructural observations, fracture network modelling techniques borrowed from the oil industry, and geochemistry, in order to characterize the (possibly transient) hydraulic structure of the Gole Larghe Fault Zone (GLFZ, Italian Southern Alps), exhumed from ca. 8 km where it was characterized by a well-documented seismic activity. Our strategy consists of: (1) quantitative field characterization of the large- and meso-scale fault and fracture network of the GLFZ, combining DGPS scanlines and image analysis; (2) evaluation of the aperture of fractures based on microstructural and mechanical considerations; (3) reconstruction of realistic Discrete Fracture Network (DFN) 3D models; (4) output in terms of upscaled hydraulic parameters; (5) calibration based on the observed large scale fluid-rock interaction pattern. In this contribution we present the first results of this study performed on the GLFZ, which reveals a composite, heterogeneous, and highly anisotropic hydraulic structure.

  1. Comparing Mid-Century Climate Change Projections at Convective Resolving Scales (2-km) for Life Zones Within Puerto Rico

    NASA Astrophysics Data System (ADS)

    Bowden, J.; Wootten, A.; Terando, A. J.; Boyles, R.; Misra, V.; Bhardwaj, A.

    2016-12-01

    Puerto Rico is home to over 3.5 million people and numerous endemic plant and animal species that may be at risk as a result of anthropogenic climate change. This study downscales three CMIP5 Global Circulation Models (GCMs) to a 2-km horizontal resolution using different regional climate models (RCMs) to resolve the island's climate. Here we compare projected climate change from a single GCM, CCSM4, from two RCMs centered on the mid-century, 2041-2060, for a high greenhouse gas emission scenario, RCP8.5. We will discuss similarities and differences in ecologically relevant climate variables, which were selected based on dialogue with experts who have knowledge about potential biological impacts of climate change for current life zones within Puerto Rico. Notable differences appear between the RCMs and include regions with critical ecosystems, such as the El Yunque National Forest in northeast Puerto Rico. This study helps to highlight RCMs structural uncertainty at convective resolving scales.

  2. [Long-term follow-up cytogenetic survey and biological dosimetry in persons evacuated from 30-km Chernobyl NPP zone].

    PubMed

    Maznik, N A

    2004-01-01

    The paper presents the results of the follow-up cytogenetic survey and biological dosimetry carried out in inhabitants of Pripiat' town and nearby villages, who were departured from the Chernobyl NPP 30-km exclusive zone during first days after the Chernobyl catastrophe. The unstable chromosome aberration level in inhabitants were significantly increased above control in terms up to 1 year after evacuation and declined gardually during next 14 years. In early period the cytogenetic damage frequency in evacuees showed no dependence on gender. The chromosome type aberration level appeared to be lower in young persons comparing with adults. The dicentrics plus centric rings yield had a positive correlation with duration of staying at Chernobyl zone. The average doses of protracted exposure were calculated from the dicentrics and centric rings yields; the dose estimations appeared to be 1.4 times higher in persons evacuated 3-11 days after the accident than that of in persons with shorter departure time. Uing the Bayesian analysis the probabilistic distribution of biological doses was constructed for the studied evacuees group. This distribution was characterized by a mean dose of 360 mGy, the modal doses of 200-450 mGy and 80% of probability density within the dose range 0-1000 mGy, that seems to be sufficient for considering the increased risk of late somatic radiation effects for this cohort.

  3. The 130-km-long Green Valley Fault Zone of Northern California: Discontinuities Regulate Its Earthquake Recurrence

    NASA Astrophysics Data System (ADS)

    Lienkaemper, J. J.

    2012-12-01

    comparable to the 6 mm/yr Holocene slip rate observed on the NCF (Kelson et al., 1996). Microearthquakes on the GVF reach a depth of ~14 km. Using methods of Savage and Lisowski (1993) for the GVF suggests that creep may on average extend to depths of ~7.5 km, leaving a width of ~6.5 km of locked fault zone below. Trenching on the SGVF indicates 400 (±50) years have elapsed since the most recent large earthquake (MRE) in 1610±50 yr CE. Previous earthquake recurrence intervals (RI) in the past millennium indicate a mean RI of 200±80 yr (μ±σ) for the SGVF, which is much shorter than the 400-yr open interval. Preliminary evidence from trenching on the BF gives a MRE of 1630±100 yr CE, which may thus coincide with of the MRE on the SGVF. If the MRE on the BF and SGVF sections is the same earthquake, then its expected larger size (M~6.9-7.0 vs 6.7) and greater fault complexity may have produced a large stress drop, which would possibly help explain the current long open interval. The SGVF paleoseismic recurrence model is consistent with a simple probabilistic rupture model (i.e., 50%-probable rupture across 1-4 km steps) and with a Brownian Passage Time recurrence model with a mean RI of 250 yr, CV (coefficient of variation, σ/μ) of 0.6, and a 30-yr rupture probability of 20-25%.

  4. Mulching as a countermeasure for crop contamination within the 30 km zone of Chernobyl Nuclear Power Plant

    SciTech Connect

    Yera, T.S.; Vallejo, R.; Tent, J.; Rauret, G.; Omelyanenko, N.; Ivanov, Y.

    1999-03-15

    The effect of mulch soil cover on crop contamination by {sup 137}Cs was studied within the 30 km zone of Chernobyl Nuclear Power Plant. Experiments were performed with oats (Avena sativa) over a three year period. In 1992 soil surface was covered by a plastic net. In 1993 two straw mulch treatments were applied at a dose rate of 200 g m{sup {minus}2} using {sup 137}Cs contaminated and clean straw, respectively. A similar mulch treatment was applied in 1994, and two mulch doses of clean straw were tested. Protection of the soil with a plastic net significantly increased crop yield and reduced crop contamination. When clean straw was used as a mulch layer, a significant decrease of about 30--40% in {sup 137}Cs activity concentration was observed. Mulching with {sup 137}Cs contaminated straw did not reduce crop contamination, probably due to an increase in soil available {sup 137}Cs released from the contaminated mulch. Mulching has been shown to be an effective treatment both for reducing {sup 137}Cs plant contamination and improving crop yield. Therefore, it can be considered as a potential countermeasure in a post-accident situation.

  5. Expedition to the 30-km Chernobyl Exclusion Zone and the Utilization of its Experience in Education and Communication

    SciTech Connect

    Aszodi, Attila; Yamaji, Bogdan; Silye, Judit; Pazmandi, Tamas

    2006-07-01

    Between May 28 - June 4, 2005, under the organization of the Hungarian Nuclear Society (HNS) and the Hungarian Young Generation Network (HYGN) - which operates within the framework of the HNS - a scientific expedition visited the Chernobyl Nuclear Power Plant and the surrounding exclusion zone. The participants were young Hungarian nuclear professionals supervised by more experienced experts. The main scientific goals of the expedition were the followings: Get personal experiences in a direct way about the current status of the Chernobyl Power Plant and its surroundings, the contamination of the environment and about the doses. Gather information about the state of the shut down power plant and the shelter built above the damaged 4. unit. Training of young nuclear experts by performing on site measurements. The Hungarian expedition successfully achieved its objectives by performing wide-range of environmental and dosimetric measurements and collecting numerous biological and soil samples. Within the 30-km exclusion zone the influence of the accident occurred 20 years ago still could be measured clearly; however the level of the radioactivity is manageable in most places. The dosimetric measurements showed that no considerable exposure occurred among the members of the expedition. The analysis of samples has been started at the International Chernobyl Center in Slavutich. During the expedition not only environmental sampling and in-situ measurements were carried out but it was also well documented with photos and video recordings for educational, training and PR purposes. A documentary TV film was recorded during the expedition. The first-hand knowledge acquired during the expedition helps the authentic communication of the accident and its present-day consequences, which is especially important in 2006, 20 years after the Chernobyl accident. Since Ukraine and Hungary are neighbor countries the media constantly discuss the accident, the consequences and the risks of

  6. DEEPLY EMBEDDED PROTOSTELLAR POPULATION IN THE 20 km s{sup −1} CLOUD OF THE CENTRAL MOLECULAR ZONE

    SciTech Connect

    Lu, Xing; Gu, Qiusheng; Zhang, Qizhou; Battersby, Cara; Kauffmann, Jens; Pillai, Thushara; Longmore, Steven N.; Kruijssen, J. M. Diederik

    2015-12-01

    We report the discovery of a population of deeply embedded protostellar candidates in the 20 km s{sup −1} cloud, one of the massive molecular clouds in the Central Molecular Zone (CMZ) of the Milky Way, using interferometric submillimeter continuum and H{sub 2}O maser observations. The submillimeter continuum emission shows five 1 pc scale clumps, each of which further fragments into several 0.1 pc scale cores. We identify 17 dense cores, among which 12 are gravitationally bound. Among the 18 H{sub 2}O masers detected, 13 coincide with the cores and probably trace outflows emanating from the protostars. There are also 5 gravitationally bound dense cores without H{sub 2}O maser detection. In total, the 13 masers and 5 cores may represent 18 protostars with spectral types later than B1 or potentially growing more massive stars at earlier evolutionary stages, given the non-detection in the centimeter radio continuum. In combination with previous studies of CH{sub 3}OH masers, we conclude that the star formation in this cloud is at an early evolutionary phase, before the presence of any significant ionizing or heating sources. Our findings indicate that star formation in this cloud may be triggered by a tidal compression as it approaches pericenter, similar to the case of G0.253+0.016 but with a higher star formation rate, and demonstrate that high angular resolution, high-sensitivity maser, and submillimeter observations are promising techniques to unveil deeply embedded star formation in the CMZ.

  7. Mantle transition zone structure beneath the Changbai volcano: Insight into deep slab dehydration and hot upwelling near the 410 km discontinuity

    NASA Astrophysics Data System (ADS)

    Tian, You; Zhu, Hongxiang; Zhao, Dapeng; Liu, Cai; Feng, Xuan; Liu, Ting; Ma, Jincheng

    2016-08-01

    We study the detailed mantle transition zone structure beneath the active Changbai intraplate volcano in Northeast China by using a receiver-function method. A total of 3005 teleseismic receiver functions recorded by 70 broadband stations are obtained by using a common-conversion-point stacking method. For conducting the time-to-depth conversion, we use a three-dimensional velocity model of the study region so as to take into account the influence of structural heterogeneities. Our results reveal significant depth variations of the 410, 520, and 660 km discontinuities. A broad depression of the 410 km discontinuity and a low-velocity anomaly are revealed beneath the Changbai volcano, which may reflect a large-scale hot mantle upwelling around the 410 km discontinuity with a positive Clapeyron slope. The 520 km discontinuity is identified clearly, and its uplift occurs above the stagnant Pacific slab. We also find a prominent depression of the 660 km discontinuity, which is elongated along the trend of deep earthquake clusters in a range of 39°N-44°N latitude, and the depression area has a lateral extent of about 400 km. Because the 520 and 660 km discontinuities correspond to positive and negative Clapeyron slopes, respectively, we think that the 520 uplift and the 660 depression are caused by the cold subducting Pacific slab. A part of the Pacific slab may have penetrated into the lower mantle and so caused the large-scale 660 depression in front of the deep earthquake clusters. Our results also reveal a part of the upper boundary of the subducting Pacific slab in the mantle transition zone.

  8. Modeling solute transport through saturated zone ground water at 10 km scale: Example from the Yucca Mountain license application

    NASA Astrophysics Data System (ADS)

    Kelkar, Sharad; Ding, Mei; Chu, Shaoping; Robinson, Bruce A.; Arnold, Bill; Meijer, Arend; Eddebbarh, Al-Aziz

    2010-09-01

    This paper presents a study of solute transport through ground water in the saturated zone and the resulting breakthrough curves (BTCs), using a field-scale numerical model that incorporates the processes of advection, dispersion, matrix diffusion in fractured volcanic formations, sorption, and colloid-facilitated transport. Such BTCs at compliance boundaries are often used as performance measures for a site. The example considered here is that of the saturated zone study prepared for the Yucca Mountain license application. The saturated zone at this site occurs partly in volcanic, fractured rock formations and partly in alluvial formations. This paper presents a description of the site and the ground water flow model, the development of the conceptual model of transport, model uncertainties, model validation, and the influence of uncertainty in input parameters on the downstream BTCs at the Yucca Mountain site.

  9. Modeling solute transport through saturated zone ground water at 10 km scale: example from the Yucca Mountain license application.

    PubMed

    Kelkar, Sharad; Ding, Mei; Chu, Shaoping; Robinson, Bruce A; Arnold, Bill; Meijer, Arend; Eddebbarh, Al-Aziz

    2010-09-20

    This paper presents a study of solute transport through ground water in the saturated zone and the resulting breakthrough curves (BTCs), using a field-scale numerical model that incorporates the processes of advection, dispersion, matrix diffusion in fractured volcanic formations, sorption, and colloid-facilitated transport. Such BTCs at compliance boundaries are often used as performance measures for a site. The example considered here is that of the saturated zone study prepared for the Yucca Mountain license application. The saturated zone at this site occurs partly in volcanic, fractured rock formations and partly in alluvial formations. This paper presents a description of the site and the ground water flow model, the development of the conceptual model of transport, model uncertainties, model validation, and the influence of uncertainty in input parameters on the downstream BTCs at the Yucca Mountain site. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  10. The (137)Cs activity concentration of suspended and dissolved fractions in irrigation waters collected from the 80 km zone around TEPCO's Fukushima Daiichi Nuclear Power Station.

    PubMed

    Tsukada, Hirofumi; Nihira, Satoshi; Watanabe, Takashi; Takeda, Satoru

    2017-08-11

    Fifty-four samples of irrigation water were collected in 2014 from agricultural ponds, rivers, and dams within the 80 km zone around TEPCO's Fukushima Daiichi Nuclear Power Station (FDNPS). The samples were filtered with a 0.45 μm pore-size membrane filter to produce suspended and dissolved fractions. The (137)Cs activity concentration of the suspended fraction varied from 1.5 to 300 Bq g(-1) dry weight and was significantly higher than that in the soil around each sampling site. The range of (137)Cs activity concentrations in the dissolved fraction varied over three orders of magnitude at 0.0075-6.7 Bq l(-1), which was a larger range than that of the suspended fraction; the higher values for samples were from within the 20 km zone. In the dissolved fraction 87 ± 9% of the (137)Cs (n = 37) was in a monovalent cationic form (Cs(+)) and therefore potentially mobile. The distribution coefficient (Kd) ranged from 4100 to 2,100,000; the geometric mean value (110,000) was higher than that reported by the IAEA (2010). The geometric mean Kd of samples collected from the 20 km zone was 61,000 (n = 27), which was significantly lower than that collected from 20 to 80 km zone (200,000, n = 27). The Kd-value was negative correlated with the concentration of stable (133)Cs and the electric conductivity in the dissolved fraction. This shows relatively higher mobility of radiocaesium in irrigation waters may occur when there are higher contents of cations present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Velocity contrast and 10km vertical Moho offset across the Denali fault from double-difference tomography and fault zone head wave analysis

    NASA Astrophysics Data System (ADS)

    Allam, A. A.; Ruppert, N. A.; Ross, Z.; Ben-Zion, Y.

    2015-12-01

    We present tomographic images of lithospheric structure along the Denali fault in central Alaska based on double-difference inversions of earthquake arrival times. We discretize the region with a uniform grid spacing of 3km within a 600km by 500km by 60km volume. We invert for VP, VS, and hypocenter location using data from 5634 earthquakes recorded at 326 stations, incorporating 715,000 P and 229,000 S wave phase arrivals. The use of this large dataset provides resolution throughout the crust and into the upper mantle, with diminishing resolution below 50km depth as determined with checkerboard tests and calculation of the inversion derivative weight sum. The tomographic results indicate that the Moho is offset by approximately 10km along the entire resolved length of the Denali fault, with the northern side having the shallower Moho depths around 30km. This indicates that the Denali fault is likely a deep lithospheric structure which penetrates into the upper mantle. The shallow crustal velocity structure of the Denali fault is more complicated with high-velocity plutonic bodies and low-velocity subsidiary fault zones, though the northern side of the fault generally has slightly lower velocities. In order to bolster the tomographic images we analyze more than 100 events recorded at 55 near-fault stations to find fault zone head waves, which offer a clear indication of a sharp across-fault velocity contrast. In addition to picking head waves manually using horizontal particle motion, we run an automated picker over the entire dataset using no assumptions about likely head wave distributions. Most of the head wave detections are located on the northern side of the fault fault near the town of Healy, though the source-receiver geometry may be suboptimal for detection in other portions of the fault zone. Taken together, the tomographic and head wave results have important implications for the shallow crust, deeper lithospheric structure, and tectonic history of the

  12. Superdeep vertical seismic profiling at the KTB deep drill hole (Germany): Seismic close-up view of a major thrust zone down to 8.5 km depth

    NASA Astrophysics Data System (ADS)

    Rabbel, W.; Beilecke, T.; Bohlen, T.; Fischer, D.; Frank, A.; Hasenclever, J.; Borm, G.; Kück, J.; Bram, K.; Druivenga, G.; Lüschen, E.; Gebrande, H.; Pujol, J.; Smithson, S.

    2004-09-01

    The lowermost section of the continental superdeep drill hole German Continental Deep Drilling Program (KTB) (south Germany) has been investigated for the first time by vertical seismic profiling (VSP). The new VSP samples the still accessible range of 6-8.5 km depth. Between 7 and 8.5 km depth, the drill hole intersects a major cataclastic fault zone which can be traced back to the Earth's surface where it forms a lineament of regional importance, the Franconian line. To determine the seismic properties of the crust in situ, in particular within and around this deep fault zone, was one of the major goals of the VSP. For the measurements a newly developed high-pressure/high-temperature borehole geophone was used that was capable of withstanding temperatures and pressures up to 260°C and 140 MPa, respectively. The velocity-depth profiles and reflection images resulting from the VSP are of high spatial resolution due to a small geophone spacing of 12.5 m and a broad seismic signal spectrum. Compared to the upper part of the borehole, we found more than 10% decrease of the P wave velocity in the deep, fractured metamorphic rock formations. P wave velocity is ˜5.5 km/s at 8.5 km depth compared to 6.0-6.5 km/s at more shallow levels above 7 km. In addition, seismic anisotropy was observed to increase significantly within the deep fracture zone showing more than 10% shear wave splitting and azimuthal variation of S wave polarization. In order to quantify the effect of fractures on the seismic velocity in situ we compared lithologically identical rock units at shallow and large depths: Combining seismic velocity and structural logs, we could determine the elastic tensors for three gneiss sections. The analysis of these tensors showed that we need fracture porosity in the percent range in order to explain seismic velocity and anisotropy observed within the fault zone. The opening of significant pore space around 8 km depth can only be maintained by differential tectonic

  13. Rapid Kinematic and Tectonic Variations Along the 1400-km-long Australia-Woodlark Plate Boundary Zone, Papua New Guinea and Woodlark Basin

    NASA Astrophysics Data System (ADS)

    Mann, P.; Taylor, F. W.; Gahagan, L.; Watson, L.

    2004-12-01

    Previous GPS studies have shown the wide variability in present-day plate motions across the highly arcuate, 1400-km-long Australia-Woodlark plate boundary extending from Papua New Guinea to the Solomon Islands. GPS-determined motions range from orthogonal oceanic spreading in the Woodlark basin, to continental transtension in the 2.5-km-high core complex area of easternmost Papua New Guinea, to continental strike-slip and transpression in 4-km-high mountains of the Papuan Peninsula. We use imagery, earthquake focal mechanisms, coral reef uplift data, and structural mapping studies to establish the along-strike continuity of the active plate boundary fault. Systematic angular changes in the direction of the plate vector along this continuous fault explain its varied tectonic geomorphology, Holocene uplift history, and geologic structure. We use a series of plate reconstructions to illustrate the longer term, Cenozoic evolution of this boundary including: its formation as an arcuate, N- and NE-dipping ophiolitic suture zone during Paleogene time, the progressive "unzippering" of this thrust over the past 6 Ma along a N- and NE-dipping, low-angle normal fault in easternmost Papua New Guinea, and its "zippering" or continued shortening on the suture thrust in the Owen Stanley Ranges of the Papuan Peninsula. Over the 1400-km-length of the fault, the length of segments of oceanic spreading, transtension, and transpression is 250-500 km; the time period separating one tectonic style from the succeeding style encroaching from the east is several million years. This systematic spatial and temporal superposition of tectonic styles, leads to complex - but predictable - along-strike variations in geologic history.

  14. Reconstruction of the ingestion doses received by the population evacuated from the settlements in the 30-km zone around the Chernobyl reactor.

    PubMed

    Pröhl, Gerhard; Mück, Konrad; Likhtarev, Ilya; Kovgan, Lina; Golikov, Vladislav

    2002-02-01

    As a consequence of the Chernobyl accident, about 50,000 people were evacuated from the settlements in the 30-km zone around the reactor in the period 3-11 d after the accident. As no countermeasures were implemented in the early phase, people continued to consume milk and some leafy vegetables. In this paper, average effective ingestion doses are modeled for evacuees. Input data for the assessment are the 137Cs activity per unit area, the ratios of the radionuclides relative to 137Cs, the mean day of evacuation, and intake rates for milk and green vegetables. The transfer of radionuclides from deposition to humans is estimated by modeling radionuclide interception by vegetation, weathering, and the time-dependent transfer of radionuclides to milk taking into account site-specific agricultural practices. Depending on the evacuation day and site, the estimated ingestion doses for the settlements are in the range of 20 to 1,300 mSv and 3 to 180 mSv for infants and adults, respectively. 131I is by far the most important isotope, the ingestion dose due to 133I is more than one order of magnitude lower. The most exposed organ is the thyroid, inducing more than 80% and 50% of the ingestion dose for infants and adults. The ingestion doses are compared to the doses due to inhalation and external exposure. The internal dose exceeds the external by a factor of about 2-10 for adults and 2-40 for 1-y-old infants depending on site and evacuation day. The thyroid doses assessed for the evacuees are consistent with results achieved in studies performed in areas outside the 30-km zone.

  15. [Role of non-radiation factors in forming cytogenetic effects in evacuees from a 30-km zone of the Chernobyl Nuclear Power Plant].

    PubMed

    Maznik, N A

    2004-01-01

    The time-effect relationship for chromatid type aberrations, chromosome type fragments, hyperploidy and polyploidy levels in peripheral blood lymphocytes were investigated in inhabitants of t. Pripiat' and nearby villages, who were departured from the Chernobyl NPP 30-km exclusive zone during first days after the Chernobyl catastrophe. The time-course changes of the mentioned cytogenetic indices in evacuees were displayed as a gradual decline of chromosomal rearrangements and genome abnormality frequencies from the statistically elevated level in the first 1-2 years after the accident to the subcontrol meanings at the end of the 14-years observation period. In early terms after exposure the frequency of chromatid exchanges in adult men and the polyploidy level in women aged 23-35 years were sufficiently increased comparing with other evacuee subgroups. Some peculiarities of the fragment aberration frequency dynamics were shown for persons with different terms of the departure from the Chernobyl zone. The role of the combination of mutagenic factors acted in the accidental situation at Chernobyl for inducing the elevated level of cytogenetic damage in evacuees is discussed.

  16. Effects of upper ocean sound-speed structure on deep acoustic shadow-zone arrivals at 500- and 1000-km range.

    PubMed

    Van Uffelen, Lora J; Worcester, Peter F; Dzieciuch, Matthew A; Rudnick, Daniel L; Colosi, John A

    2010-04-01

    Deep acoustic shadow-zone arrivals observed in the late 1990s in the North Pacific Ocean reveal significant acoustic energy penetrating the geometric shadow. Comparisons of acoustic data obtained from vertical line arrays deployed in conjunction with 250-Hz acoustic sources at ranges of 500 and 1000 km from June to November 2004 in the North Pacific, with simulations incorporating scattering consistent with the Garrett-Munk internal-wave spectrum, are able to describe both the energy contained in and vertical extent of deep shadow-zone arrivals. Incoherent monthly averages of acoustic timefronts indicate that lower cusps associated with acoustic rays with shallow upper turning points (UTPs), where sound-speed structure is most variable and seasonally dependent, deepen from June to October as the summer thermocline develops. Surface-reflected rays, or those with near-surface UTPs, exhibit less scattering due to internal waves than in later months when the UTP deepens. Data collected in November exhibit dramatically more vertical extension than previous months. The depth to which timefronts extend is a complex combination of deterministic changes in the depths of the lower cusps as the range-average profiles evolve with seasonal change and of the amount of scattering, which depends on the mean vertical gradients at the depths of the UTPs.

  17. Determination of (129)I and (127)I concentration in soil samples from the Chernobyl 30-km zone by AMS and ICP-MS.

    PubMed

    Sahoo, Sarata Kumar; Muramatsu, Yasuyuki; Yoshida, Satoshi; Matsuzaki, Hiroyuki; Rühm, Werner

    2009-07-01

    A large amount of radioiodine isotopes (mainly (131)I, t(1/2) = 8 days) was released from the accident at Chernobyl Nuclear Power Plant (CNPP) in April-May 1986. An increase in childhood-thyroid cancer in the contaminated areas in Belarus, Russia and the Ukraine was demonstrated to be caused by radioiodine released at the time of the accident. However, there is a lack of quantitative data on the (131)I levels in the local environment (e.g. air, plant, soil). At this point, a long-lived iodine isotope, (129)I (t(1/2) = 15.7 million years), also released with a certain ratio to (131)I from CNPP, could be used for estimating the (131)I levels in the environment. In this paper we present analytical results of the (129)I concentrations and (129)I/(127)I atom ratios in soil samples collected from the CNPP exclusion zone (30-km zone), with the aim of assessing current contamination levels and distribution patterns. For the analysis of the iodine fraction in the investigated soil samples, the pyrohydrolysis method was utilized for separation of (127)I and (129)I nuclides, and subsequently their concentration was determined using inductively coupled plasma mass spectrometry (ICP-MS) and accelerator mass spectrometry (AMS), respectively. The concentration of (129)I and the (129)I/(127)I atom ratio in the surface soil samples in the 30 km-zone of CNPP ranged from 4.6 to 170 mBq/kg, and from 1.4 x 10(-6) to 13 x 10(-6), respectively. These values are significantly higher than those from global (129)I fallout, indicating that most of the measured (129)I was due to the deposition of the accident. Stable iodine concentrations in this area were found to be very low (below 1 ppm) for most of the samples, suggesting the environmental iodine levels in this area to be potentially low. The (129)I/(137)Cs activity ratio in surface and sub-surface soils was not so constant, i.e., in the range (7.3-20.2) x 10(-7). This might be due to the different behavior of deposition and/or migration

  18. Estimation of the total population moving into and out of the 20 km evacuation zone during the Fukushima NPP accident as calculated using "Auto-GPS" mobile phone data.

    PubMed

    Hayano, Ryugo S; Adachi, Ryutaro

    2013-01-01

    The first objective data showing the geographical locations of people in Fukushima after the Fukushima Dai-ichi nuclear power plant accident, obtained by an analysis of GPS (Global Positioning System)-enabled mobile phone logs, are presented. The method of estimation is explained, and the flow of people into and out of the 20 km evacuation zone during the accident is visualized.

  19. San Andres Rift, Nicaraguan Shelf: A 346-Km-Long, North-South Rift Zone Actively Extending the Interior of the "Stable" Caribbean Plate

    NASA Astrophysics Data System (ADS)

    Carvajal, L. C.; Mann, P.

    2015-12-01

    The San Andres rift (SAR) is an active, 015°-trending, bathymetric and structural rift basin that extends for 346 km across the Nicaraguan platform and varies in bathymetric width from 11-27 km and in water depth from 1,250 to 2,500 m. We used four 2D regional seismic lines tied to two offshore, industry wells located west of the SAR on the Nicaraguan platform to map normal faults, transfer faults, and possibly volcanic features with the rift. The Colombian islands of San Andres (26 km2) and Providencia (17 km2) are footwall uplifts along west-dipping, normal fault bounding the eastern margin of the rift. Mapping indicates the pre-rift section is Late Cretaceous to Oligocene in age and that the onset of rifting began in the early to middle Miocene as shown by wedging of the Miocene and younger sedimentary fill controlled by north-south-striking normal faults. Structural restorations at two locations across the rift shows that the basin opened mainly by dip-slip fault motions producing a total, east-west extension of 18 km in the north and 15 km in the south. Structural restoration shows the rift formed on a 37-km-wide, elongate basement high - possibly of late Cretaceous, volcanic origin and related to the Caribbean large igneous province. Previous workers have noted that the SAR is associated with province of Pliocene to Quaternary seamounts and volcanoes which range from non-alkaline to mildly alkaline, including volcanic rocks on Providencia described as andesites and rhyolites. The SAR forms one of the few recognizable belts of recorded seismicity within the Caribbean plate. The origin of the SAR is related to Miocene and younger left-lateral displacement along the Pedro Banks fault to the north and the southwestern Hess fault to the south. We propose that the amount of left-lateral displacement that created the rift is equivalent to the amount of extension that formed it: 18-20 km.

  20. Estimation of the total population moving into and out of the 20 km evacuation zone during the Fukushima NPP accident as calculated using “Auto-GPS” mobile phone data

    PubMed Central

    HAYANO, Ryugo S.; ADACHI, Ryutaro

    2013-01-01

    The first objective data showing the geographical locations of people in Fukushima after the Fukushima Dai-ichi nuclear power plant accident, obtained by an analysis of GPS (Global Positioning System)-enabled mobile phone logs, are presented. The method of estimation is explained, and the flow of people into and out of the 20 km evacuation zone during the accident is visualized. PMID:23666090

  1. A plan for a 5 km-deep borehole at Reykjanes, Iceland, into the root zone of a black smoker on land

    NASA Astrophysics Data System (ADS)

    Friðleifsson, G. Ó.; Elders, W. A.; Bignall, G.

    2013-11-01

    A summary workshop report describing the progress made so far by the Iceland Deep Drilling Project (IDDP) is presented below. The report provides recommendations concerning technical aspects related to deep drilling, and invites international participation in both the engineering and the scientific activities of the next phase of the IDDP. No issues were identified at the workshop that should rule out attempting the drilling, sampling and testing of the proposed IDDP-2 well. Although technically challenging, the consensus of the workshop was that the drilling of such a hot deep well, and producing potentially hostile fluids, is possible but requires careful contingency planning. The future well will be explored for supercritical fluid and/or superheated steam beneath the current production zone of the Reykjanes geothermal field in SW Iceland. This deep borehole will provide the first opportunity worldwide to directly investigate the root zone of a magma-hydrothermal system which is likely to be similar to those beneath the black smokers on the world-encircling mid-ocean rift systems.

  2. 40Km Into Lebanon,

    DTIC Science & Technology

    1987-07-01

    answer to the difficulties in Palestine, London organized a study of the problem under Lord Peel , a for- mer Secretary of State for India, who in 1937...issued the report of the Commission bearing his name. As Peel saw it, the only solution was to partition Palestine between the two communities. The...minority suggestions. The majority 22 40Km into Lebanon report recommended partition with an economic union, much as Peel had proposed in 1937. A

  3. Seismic belt in the upper plane of the double seismic zone extending in the along-arc direction at depths of 70-100km beneath NE Japan, and its relation with the dehydration embrittlement hypothesis

    NASA Astrophysics Data System (ADS)

    Kita, S.; Okada, T.; Nakajima, J.; Matsuzawa, T.; Hasegawa, A.

    2006-12-01

    1. Introduction Dehydration embrittlement or CO2¨Cbearing devolatization embrittlement hypothesis has been proposed as a possible cause of intraslab earthquakes in several studies [e.g., Peacock, 2001; Kirby et al., 1996; Meade and Jeanloz, 1991]. Precise location of intraslab seismicity is needed to discuss its cause in these studies. Recently, a very dense nationwide seismic network (Hi-net) has been constructed by NIED in Japan. In this study, we relocate microearthquakes more precisely by using data obtained by this dense seismic network to detect the characteristic distribution of the seismicity within the Pacific slab beneath Hokkaido and Tohoku, NE Japan. 2. Data and method In the present study, we relocated events at depths of 20¨C300 km for the period from January 2002 to August 2005 from the JMA earthquake catalog. Hypocenter locations and arrival time data in the JMA catalog were used as the initial hypocenters and data for relocations. We applied the double-difference hypocenter location method (DDLM) by Waldhauser and Ellsworth (2000) to the arrival time data of the events. We also checked spatial distribution of the focal mechanisms of the events in the seismic belts and the surrounding upper seismic plane. We used focal mechanism solutions determined by Igarashi et al. (2001). 3. Results and discussion 1) There exist earthquakes occurring in the area between the upper and lower seismic planes (interplane earthquakes), and their focal mechanisms tend to be the down-dip compressional (DC-) type like those of upper plane events. 2) We found a seismic "belt" which is parallel to the iso-depth contour of the plate interface beneath the forearc area at depths of 80¨C100 km. The location of the seismic belt seems to correspond to one phase boundary (from jadeite lawsonite blueschist (H2O content: 5.4 wt% ) to lawsonite amphibole eclogite (3.0wt %) (Hacker et al., 2003)) with dehydration reaction. 3) The location of the deeper limit of seismicity of the

  4. KM3NeT

    SciTech Connect

    Jong, M. de; Collaboration: KM3NeT Collaboration

    2015-07-15

    KM3NeT is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3NeT is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3NeT. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3NeT research infrastructure has started. The prospects of the different phases of the implementation of KM3NeT are summarised.

  5. Knob manager (KM) operators guide

    SciTech Connect

    1993-10-08

    KM, Knob Manager, is a tool which enables the user to use the SUNDIALS knob box to adjust the settings of the control system. The followings are some features of KM: dynamic knob assignments with the user friendly interface; user-defined gain for individual knob; graphical displays for operating range and status of each process variable is assigned; backup and restore one or multiple process variable; save current settings to a file and recall the settings from that file in future.

  6. Local fluctuations of ozone from 16 km to 45 km deduced from in situ vertical ozone profile

    NASA Technical Reports Server (NTRS)

    Moreau, G.; Robert, C.

    1994-01-01

    A vertical ozone profile obtained by an in situ ozone sonde from 16 km to 45 km, has allowed to observe local ozone concentration variations. These variations can be observed, thanks to a fast measurement system based on a UV absorption KrF excimer laser beam in a multipass cell. Ozone standard deviation versus altitude calculated from the mean is derived. Ozone variations or fluctuations are correlated with the different dynamic zones of the stratosphere.

  7. Focusing of relative plate motion at a continental transform fault: Cenozoic dextral displacement >700 km on New Zealand's Alpine Fault, reversing >225 km of Late Cretaceous sinistral motion

    NASA Astrophysics Data System (ADS)

    Lamb, Simon; Mortimer, Nick; Smith, Euan; Turner, Gillian

    2016-03-01

    The widely accepted ˜450 km Cenozoic dextral strike-slip displacement on New Zealand's Alpine Fault is large for continental strike-slip faults, but it is still less than 60% of the Cenozoic relative plate motion between the Australian and Pacific plates through Zealandia, with the remaining motion assumed to be taken up by rotation and displacement on other faults in a zone up to 300 km wide. We show here that the 450 km total displacement across the Alpine Fault is an artifact of assumptions about the geometry of New Zealand's basement terranes in the Eocene, and the actual Cenozoic dextral displacement across the active trace is greater than 665 km, with more than 700 km (and <785 km since 25 Ma) occurring in a narrow zone less than 10 km wide. This way, the Alpine Fault has accommodated almost all (>94%) of the relative plate motion in the last 25 Ma at an average rate in excess of 28 mm/yr. It reverses more than 225 km (and <300 km) of sinistral shear through Zealandia in the Late Cretaceous, when Zealandia lay on the margin of Gondwana, providing a direct constraint on the kinematics of extension between East and West Antarctica at this time.

  8. A Broad Depressed 410-km Discontinuity beneath Northeast Asia

    NASA Astrophysics Data System (ADS)

    Li, J.; Guo, G.; WANG, X.

    2016-12-01

    The topography of the upper mantle discontinuities is important for good understanding of the thermal structure, composition of the mantle, and scales of mantle circulation as well. We applied both receiver function analysis and multiple-ScS reverberations to seismic waveforms recorded by stations beneath land and ocean, respectively. We obtained a complete image of the upper mantle discontinuities beneath northeast Asia, covering from the Okhotsk Sea, far east Russia, Japan Sea and northeast China. Results with different resolutions from different methods are compared in detail, and the comparison shows that long-period ScS reverberation signals is effective in extracting the robust features of the upper mantle discontinuities. Through the integrated depth undulation map covering both sea and land, we detected an obvious depression of the 410-km discontinuity with value 8-25 km, anticorrelated with a wide range of depressed 660-km discontinuity. The depression of the 660 can be explained by the temperature anomaly associated to the subducting Pacific slab. The landward extension of the depressed 410, however, is of large scale with a lateral range of at least 800-1000 km. Mechanism invoking chemical heterogeneity in the mantle transition zone was explored to explain the observation. We speculate that the broadly depressed 410 beneath west Japan Sea, part of Okhotsk Sea, and northeast China might be caused by high water content at the top of the mantle transition zone. The significant trench rollback motion of the subducting Pacific slab from the Miocene might explain the widespread distribution of the depression of the 410. The west edge of observed depressed 410-km discontinuity might pin the initial location where the Pacific subducting slab had been furthest before the occurrence of trench retreating.

  9. Neutral Wind Observations below 200 km altitudes

    NASA Astrophysics Data System (ADS)

    Watanabe, S.; Abe, T.; Habu, H.; Kakinami, Y.; Larsen, M. F.; Pfaff, R. F., Jr.; Yamamoto, M.

    2015-12-01

    Neutral Wind Observations below 200 km altitudesS. Watanabe1, T. Abe2, H. Habu2, Y. Kakinami3, M. Larsen4, R. Pfaff5, M. Yamamoto6, M-Y. Yamamoto31Hokkaido University/Hokkaido Information University, 2JAXA/ISAS, 3Kochi University of Technology, 4Clemson University, 5NASA/Goddard Space Flight Center, 6Kyoto University, Neutral wind in the thermosphere is one of the key parameters to understand the ionosphere-thermosphere coupling process. JAXA/ISAS successfully launched sounding rockets from Uchinoura Space Center (USC) on September 2, 2007, January 12, 2012, and July 20, 2013, and NASA launched sounding rockets from Kwajalein on May 7, 2013 and from Wallops on July 4, 2013. The rockets installed Lithium and/or TMA canisters as well as instruments for plasma and electric and magnetic fields. The atomic Lithium gases were released at altitudes between 150 km and 300 km in the evening on September 2, 2007, at altitude of ~100 km in the morning on January 12, 2012, at altitude of ~120km in the midnight on July 20, 2013, at altitude between 150 km and 300 km in the evening on May 7, 2013 and at altitude of ~150 km in the noon on July 4, 2013. The Lithium atoms were scattering sunlight by resonance scattering with wavelength of 670nm. However, the Lithium atoms scattered moon light on July 20, 2013. The moon light scattering is the first time to use for thermospheric wind measurement in the midnight. The Lithium clouds/trails and TMA trails showed clearly the neutral wind shears and atmospheric waves at ~150 km altitude in the lower thermosphere for all local time.

  10. Depth variations of 410 km and 660 km discontinuities in eastern North China Craton revealed by ambient noise interferometry

    NASA Astrophysics Data System (ADS)

    Feng, Jikun; Yao, Huajian; Poli, Piero; Fang, Lihua; Wu, Yan; Zhang, Ping

    2017-08-01

    Recent studies have demonstrated that body waves between pairs of stations can be successfully retrieved from ambient noise cross correlation at both regional and global scales, although surface waves are the dominant signals. However, it is still difficult to use these retrieved body wave signals to map lateral depth variations of main structural discontinuities or velocity contrasts because of its low signal-to-noise ratio (SNR). In this research, based on a dense seismic array in eastern North China Craton, reflected P wave signals from 410 km and 660 km discontinuities can be successfully recovered from ambient noise cross correlation. To improve SNR, the cross correlations are stacked within each bin with the phase-weighted stack method. The retrieved P410P and P660P phases from stacked correlations reveal lateral variations of both depths and sharpness of the 410 km and 660 km discontinuities along two profiles, which may be related with hot material upwelling and the effect of stagnant Pacific Plate in the transition zone beneath North China Craton. The imaging results are generally consistent with the results from teleseismic receiver functions, which demonstrate the possibility of mapping high-resolution topography and sharpness of deep internal discontinuities without earthquake-station geometric limitations.

  11. News from KM3NeT

    SciTech Connect

    Katz, Ulrich F.; Collaboration: KM3NeT Collaboration

    2014-11-18

    KM3NeT is a future research infrastructure in the Mediterranean Sea, hosting a multi-cubic-kilometre neutrino telescope and nodes for Earth and Sea sciences. In this report we shortly summarise the genesis of the KM3NeT project and present key elements of its technical design. The physics objectives of the KM3NeT neutrino telescope and some selected sensitivity estimates are discussed. Finally, some first results from prototype operations and the next steps towards implementation – in particular the first construction phase in 2014/15 – are described.

  12. Cascadia Subduction Zone

    USGS Publications Warehouse

    Frankel, Arthur D.; Petersen, Mark D.

    2008-01-01

    The geometry and recurrence times of large earthquakes associated with the Cascadia Subduction Zone (CSZ) were discussed and debated at a March 28-29, 2006 Pacific Northwest workshop for the USGS National Seismic Hazard Maps. The CSZ is modeled from Cape Mendocino in California to Vancouver Island in British Columbia. We include the same geometry and weighting scheme as was used in the 2002 model (Frankel and others, 2002) based on thermal constraints (Fig. 1; Fluck and others, 1997 and a reexamination by Wang et al., 2003, Fig. 11, eastern edge of intermediate shading). This scheme includes four possibilities for the lower (eastern) limit of seismic rupture: the base of elastic zone (weight 0.1), the base of transition zone (weight 0.2), the midpoint of the transition zone (weight 0.2), and a model with a long north-south segment at 123.8? W in the southern and central portions of the CSZ, with a dogleg to the northwest in the northern portion of the zone (weight 0.5). The latter model was derived from the approximate average longitude of the contour of the 30 km depth of the CSZ as modeled by Fluck et al. (1997). A global study of the maximum depth of thrust earthquakes on subduction zones by Tichelaar and Ruff (1993) indicated maximum depths of about 40 km for most of the subduction zones studied, although the Mexican subduction zone had a maximum depth of about 25 km (R. LaForge, pers. comm., 2006). The recent inversion of GPS data by McCaffrey et al. (2007) shows a significant amount of coupling (a coupling factor of 0.2-0.3) as far east as 123.8? West in some portions of the CSZ. Both of these lines of evidence lend support to the model with a north-south segment at 123.8? W.

  13. Status of KM3NeT

    NASA Astrophysics Data System (ADS)

    Riccobene, G.

    2016-07-01

    The recent observation of cosmic neutrinos by IceCube has pushed the quest towards the identification of cosmic sources of high-energy particles. The KM3NeT Collaboration is now ready to launch the massive construction of detection units to be installed in deep sea to build a km-cubic size neutrino telescope. The main elements of the detector, the status of the project and the expected perfomances are briefly reported.

  14. Safety Zones

    EPA Pesticide Factsheets

    These are established primarily to reduce the accidental spread of hazardous substances by workers or equipment from contaminated areas to clean areas. They include the exclusion (hot) zone, contamination reduction (warm) zone, and support (cold) zone.

  15. Experimental quantum digital signature over 102 km

    NASA Astrophysics Data System (ADS)

    Yin, Hua-Lei; Fu, Yao; Liu, Hui; Tang, Qi-Jie; Wang, Jian; You, Li-Xing; Zhang, Wei-Jun; Chen, Si-Jing; Wang, Zhen; Zhang, Qiang; Chen, Teng-Yun; Chen, Zeng-Bing; Pan, Jian-Wei

    2017-03-01

    Quantum digital signature (QDS) is an approach to guarantee the nonrepudiation, unforgeability, and transferability of a signature with information-theoretical security. Previous experimental realizations of QDS relied on an unrealistic assumption of secure channels and the longest distance is several kilometers. Here, we have experimentally demonstrated a recently proposed QDS protocol without assuming any secure channel. Exploiting the decoy state modulation, we have successfully signed a one-bit message through an up to 102-km optical fiber. Furthermore, we continuously run the system to sign the longer message "USTC" with 32 bits at the distance of 51 km. Our results pave the way towards the practical application of QDS.

  16. Plasma cortisol and testosterone following 19-km and 42-km kayak races.

    PubMed

    Lutoslawska, G; Obminski, Z; Krogulski, A; Sendecki, W

    1991-12-01

    Plasma cortisol and testosterone levels were examined in five, elite, male kayakers before and after 19-km and 42-km kayak races. Both races resulted in significant elevation in plasma cortisol and observed increase is likely to depend on race duration, being much more pronounced after 42-km race compared to 19-km. It should be stressed that observed elevation in cortisol level after 42-km race was higher than reported previously after a marathon run. This finding is in line with reports on hormonal changes in response to arms exercise. Both contests caused a decrease in plasma testosterone level, but the difference between races was not significant. Testosterone/cortisol ratio dropped significantly immediately after the races and the observed decrease was more dominant after the 42-km distance. On the next day, 18 h after the races plasma cortisol, testosterone levels and T/C ratio returned to basal level indicating recuperation from post exercise changes.

  17. MODIS 3 km and 10 km aerosol optical depth for China: Evaluation and comparison

    NASA Astrophysics Data System (ADS)

    He, Qingqing; Zhang, Ming; Huang, Bo; Tong, Xuelian

    2017-03-01

    The recently released Moderate Resolution Imaging Spectrometer (MODIS) Collection 6 introduced a fine scale aerosol optical depth (AOD) distribution, the 3 km product, which is expected to perform well in analyzing aerosols and identifying local air pollution, especially in the severely polluted atmosphere of China. However, few detailed evaluations of regional variations have been conducted. In this paper, we evaluate MODIS 3 km and 10 km AOD products for China against ground-based measurements and compare their performance with respect to spatial and temporal variations. The ground validations indicate that the two products are generally correlated well to ground-based observations. Spatially, the 3 km product slightly outperform the 10 km product in well-developed areas of southern China. Temporally, both products perform worse during spring and summer. Atmospheric clouds and underlying surface are two key factors that influence the accuracy and number of retrievals for both products. The comparison analysis reveals the newly introduced AOD product clearly shows good relationships with the coarse resolution retrievals in spatial and temporal variation but significant differences regarding details. The 3 km AOD product provides better aerosol gradients, more retrievals in bare areas of western China and some spikes of diurnal variation in cloudy days. Seasonal comparisons show the 3 km AOD product is higher than the 10 km product in all seasons, especially during spring and summer. Although the 3 km product for China generally performs slightly worse than the 10 km product, the added information of the MODIS 3 km AOD product shows potential for studying local aerosol characterization, and may facilitate studies of air pollution.

  18. The estimation of 550 km x 550 km mean gravity anomalies. [from free atmosphere gravimetry data

    NASA Technical Reports Server (NTRS)

    Williamson, M. R.; Gaposchkin, E. M.

    1975-01-01

    The calculation of 550 km X 550 km mean gravity anomalies from 1 degree X 1 degree mean free-air gravimetry data is discussed. The block estimate procedure developed by Kaula was used, and estimates for 1452 of the 1654 blocks were obtained.

  19. Km3Net Italy - Seafloor network

    NASA Astrophysics Data System (ADS)

    Papaleo, Riccardo

    2016-04-01

    The KM3NeT European project aims to construct a large volume underwater neutrino telescope in the depths of the Mediterranean Sea. INFN and KM3NeT collaboration, thanks to a dedicated funding of 21.000.000 € (PON 2007-2013), are committed to build and deploy the Phase 1 of the telescope, composed of a network of detection units: 8 towers, equipped with single photomultiplier optical modules, and 24 strings, equipped with multi-photomultipliers optical modules. All the towers and strings are connected to the main electro optical cable by means of a network of junction boxes and electro optical interlink cables. Each junction box is an active node able to provide all the necessary power to the detection units and to guarantee the data transmission between the detector and the on-shore control station. The KM3NeT Italia project foresees the realization and the installation of the first part of the deep sea network, composed of three junction boxes, one for the towers and two for the strings. In July 2015, two junction boxes have been deployed and connected to the new cable termination frame installed during the same sea campaign. The third and last one will be installed in November 2015. The status of the deep sea network is presented together with technical details of the project.

  20. Applying WebMining on KM system

    NASA Astrophysics Data System (ADS)

    Shimazu, Keiko; Ozaki, Tomonobu; Furukawa, Koichi

    KM (Knowledge Management) systems have recently been adopted within the realm of enterprise management. On the other hand, data mining technology is widely acknowledged within Information systems' R&D Divisions. Specially, acquisition of meaningful information from Web usage data has become one of the most exciting eras. In this paper, we employ a Web based KM system and propose a framework for applying Web Usage Mining technology to KM data. As it turns out, task duration varies according to different user operations such as referencing a table-of-contents page, down-loading a target file, and writing to a bulletin board. This in turn makes it possible to easily predict the purpose of the user's task. By taking these observations into account, we segmented access log data manually. These results were compared with results abstained by applying the constant interval method. Next, we obtained a segmentation rule of Web access logs by applying a machine-learning algorithm to manually segmented access logs as training data. Then, the newly obtained segmentation rule was compared with other known methods including the time interval method by evaluating their segmentation results in terms of recall and precision rates and it was shown that our rule attained the best results in both measures. Furthermore, the segmented data were fed to an association rule miner and the obtained association rules were utilized to modify the Web structure.

  1. Training for a 78-km solo open water swim.

    PubMed

    Piacentini, Maria F; DE Ioannon, Giulia; Cibelli, Giuseppe; Mignardi, Sergio; Antonelli, Agnese; Capranica, Laura

    2017-06-01

    The purpose of the present study was to report the training of a master athlete in preparation to an ultra-marathon swimming event. For 32 weeks prior to a 78-km "solo" open water swim from Italy to Albania, a male long distance master (48 years) swimmer was monitored. Training volume was recorded as total time and distance while intensities were recorded according to international classifications utilizing the primary goal of the session method. Thereafter, time spent in the three training zones: Z1 (low intensity training), Z2 (threshold training) and Z3 (high intensity training) was calculated. Weekly swimming volume ranged from 15 to 70 km.week-1 and training frequency ranged from 3 to 6 days.week-1. Total weekly training dedicated to swimming ranged from 270 to 1140 min. Training intensity comprised Z1=64%. Z2=28%, and Z3=8%, respectively. During the three-week taper period, total swimming volume decreased by 43% while intensity remained unchanged. The athlete succeeded in being the first swimmer to accomplish the event. These findings provide useful information for coaches on training regimens of master ultra-marathon swimmers. Compared to the literature, time spent at a Z1 training intensity was lower in favor of that spent in Z2. It could be speculated that master ultra-marathon athletes might benefit from training intensities at or above LT to counterbalance the age-related physiological decrease.

  2. Zone lines

    Treesearch

    Kevin T. Smith

    2001-01-01

    Zone lines are narrow, usually dark markings formed in decaying wood. Zone lines are found most frequently in advanced white rot of hardwoods, although they occasionally are associated both with brown rot and with softwoods.

  3. Fault zone hydrogeology

    NASA Astrophysics Data System (ADS)

    Bense, V. F.; Gleeson, T.; Loveless, S. E.; Bour, O.; Scibek, J.

    2013-12-01

    Deformation along faults in the shallow crust (< 1 km) introduces permeability heterogeneity and anisotropy, which has an important impact on processes such as regional groundwater flow, hydrocarbon migration, and hydrothermal fluid circulation. Fault zones have the capacity to be hydraulic conduits connecting shallow and deep geological environments, but simultaneously the fault cores of many faults often form effective barriers to flow. The direct evaluation of the impact of faults to fluid flow patterns remains a challenge and requires a multidisciplinary research effort of structural geologists and hydrogeologists. However, we find that these disciplines often use different methods with little interaction between them. In this review, we document the current multi-disciplinary understanding of fault zone hydrogeology. We discuss surface- and subsurface observations from diverse rock types from unlithified and lithified clastic sediments through to carbonate, crystalline, and volcanic rocks. For each rock type, we evaluate geological deformation mechanisms, hydrogeologic observations and conceptual models of fault zone hydrogeology. Outcrop observations indicate that fault zones commonly have a permeability structure suggesting they should act as complex conduit-barrier systems in which along-fault flow is encouraged and across-fault flow is impeded. Hydrogeological observations of fault zones reported in the literature show a broad qualitative agreement with outcrop-based conceptual models of fault zone hydrogeology. Nevertheless, the specific impact of a particular fault permeability structure on fault zone hydrogeology can only be assessed when the hydrogeological context of the fault zone is considered and not from outcrop observations alone. To gain a more integrated, comprehensive understanding of fault zone hydrogeology, we foresee numerous synergistic opportunities and challenges for the discipline of structural geology and hydrogeology to co-evolve and

  4. Gm and Km allotypes in autoimmune diseases.

    PubMed

    Dugoujon, J M; Guitard, E; Senegas, M T

    1992-01-01

    The associations or linkages between the polymorphisms of the Gm and Km immunoglobulin allotypes and the susceptibility to autoimmune diseases, including diseases with immuno-pathological pathogenesis are reported in this review. These diseases include multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, insulin-dependent diabetes mellitus, Crohn's disease, coeliac disease, Graves' disease, atrophic thyroiditis, Hashimoto's thyroiditis, myasthenia gravis, chronic active hepatitis, alopecia areata, uveitis, vitiligo, Turner's syndrome, glomerular nephritis, Berger's disease and idiopathic dilated cardiomyopathy. Immunoglobulin allotypes are described as well as the statistical methods used to analyse the data.

  5. The Effect of Water on the 410-km Discontinuity

    NASA Astrophysics Data System (ADS)

    Smyth, J. R.; Frost, D. J.

    2001-12-01

    The H content of the Earth is one of the most poorly constrained compositional variables for the planet. The nominally anhydrous olivine and spinelloid phases thought to compose the bulk of the upper mantle and transition zone may contain many times the amount of H and O that reside in the hydrosphere. The discontinuity at 410 kilometers corresponds to the olivine-wadsleyite transition with an increase in both density and S-wave velocity of about five percent. Previous experiments and calculations in the anhydrous peridotite system indicate an olivine-wadsleyite two-phase interval that is from 10 to 18 km in width. Calculations indicate that the two-phase region would be significantly broader in a hydrous system. We have conducted a series of synthesis experiments in the multi-anvil press on hydrous and anhydrous peridotite compositions and characterized the products by electron microprobe and single-crystal X-ray diffraction. Six experiments were conducted in a hydrous peridotite system, and three in an anhydrous system. The results of our synthesis experiments are consistent with the prediction of Wood (1995) that the presence of H2O extends the stability of wadsleyite to 0.6 to 1.0 GPa lower pressure and would broaden the two-phase loop to as much as 30 km. In the hydrous runs containing both olivine and wadsleyite, there appears a sharp boundary between regions of olivine and regions of wadsleyite. The texture of the run thus does not appear to be a simple chemical equilibrium, but rather a diffusion-controlled boundary. Hydrogen is known to diffuse very rapidly in these materials, raising the possibility that diffusion of H might control the texture and may affect the sharpness of the boundary in the natural system. Hydrous wadsleyite is about five percent denser than anhydrous olivine. In a hypothetical two-phase region consisting of olivine and wadsleyite plus lesser amounts of garnet and clinopyroxene extending over a depth 20 km in a hydrous system

  6. 45-km horizontal path optical link demonstration

    NASA Astrophysics Data System (ADS)

    Biswas, Abhijit; Wright, Malcolm W.; Sanii, Babak; Page, Norman A.

    2001-06-01

    Observations made during a mountain-top-to-mountain-top horizontal optical link demonstration are described. The optical link spans a range of 46 Km at an average altitude of 2 Km above sea level. A multibeam beacon comprised of eight laser beams emerging from four multimode fiber coupled lasers (780 nm) is launched through a 0.6 m diameter telescope located at the JPL Table Mountain Facility (TMF) in Wrightwood, California. The multibeam beacon is received at Strawberry Peak located in the San Bernardino Mountains of California. The NASA, JPL developed optical communications demonstrator (OCD) receives the beacon, senses the atmospheric turbulence induced motion and using an upgraded fine steering loop actively points a communications laser beam (852 nm, 400 Mbps on-off key modulated, PN7 pseudo random bit sequence) to TMF. The eight-beam beacon allowed a four-fold reduction in normalized irradiance or scintillation index. This in turn was sufficient to eliminate beacon fades sensed by the OCD and enable performance evaluation of the fine steering loop. The residual tracking error was determined to be +/- 1.1 to +/- 1.7 (mu) rad compared to a model prediction of +/- 3.4 (mu) rad. The best link performance observed showed average bit error rates (BER) of 1E-5 over long durations (30 seconds); however, instantaneous BERs of at least 0.8E-6 over durations of 2 ms were observed. The paper also discusses results pertaining to atmospheric effects, link analysis, and overall performance.

  7. Twisted light transmission over 143 km.

    PubMed

    Krenn, Mario; Handsteiner, Johannes; Fink, Matthias; Fickler, Robert; Ursin, Rupert; Malik, Mehul; Zeilinger, Anton

    2016-11-29

    Spatial modes of light can potentially carry a vast amount of information, making them promising candidates for both classical and quantum communication. However, the distribution of such modes over large distances remains difficult. Intermodal coupling complicates their use with common fibers, whereas free-space transmission is thought to be strongly influenced by atmospheric turbulence. Here, we show the transmission of orbital angular momentum modes of light over a distance of 143 km between two Canary Islands, which is 50× greater than the maximum distance achieved previously. As a demonstration of the transmission quality, we use superpositions of these modes to encode a short message. At the receiver, an artificial neural network is used for distinguishing between the different twisted light superpositions. The algorithm is able to identify different mode superpositions with an accuracy of more than 80% up to the third mode order and decode the transmitted message with an error rate of 8.33%. Using our data, we estimate that the distribution of orbital angular momentum entanglement over more than 100 km of free space is feasible. Moreover, the quality of our free-space link can be further improved by the use of state-of-the-art adaptive optics systems.

  8. 100 km CEPC parameters and lattice design

    NASA Astrophysics Data System (ADS)

    Wang, D.; Gao, J.; Yu, C. H.; Zhang, Y.; Wang, Y. W.; Su, F.; Y Zhai, J.; Bai, S.; Geng, H. P.; Bian, T. J.; Wang, N.; Cui, X. H.; Zhang, C.; Qin, Q.

    2017-07-01

    The 100km double ring configuration with shared superconducting RF system has been defined as baseline by the circular electron positron collider (CEPC) steering committee. Based on this new scheme, we will get higher luminosity for Higgs (+170%) keeping the beam power in preliminary conceptual design report (Pre-CDR) or to reduce the beam power (19 MW) while keeping same luminosity. CEPC will be compatible with W and Z experiment. The luminosity for Z is designed at the level of 1035 cm-2s-1. The requirement for the energy acceptance of Higgs has been reduced to 1.5% by enlarging the ring to 100 km. The optics of arc and final focus system (FFS) with crab sextupoles has been designed, and also some primary dynamic aperture (DA) results were introduced. Work supported by the National Key Programme for S&T Research and Development (Grant NO. 2016YFA0400400) and the National Natural Science Foundation of China (11505198, 11575218, 11605210 and 11605211).

  9. Twisted light transmission over 143 km

    PubMed Central

    Krenn, Mario; Handsteiner, Johannes; Fink, Matthias; Fickler, Robert; Ursin, Rupert; Zeilinger, Anton

    2016-01-01

    Spatial modes of light can potentially carry a vast amount of information, making them promising candidates for both classical and quantum communication. However, the distribution of such modes over large distances remains difficult. Intermodal coupling complicates their use with common fibers, whereas free-space transmission is thought to be strongly influenced by atmospheric turbulence. Here, we show the transmission of orbital angular momentum modes of light over a distance of 143 km between two Canary Islands, which is 50× greater than the maximum distance achieved previously. As a demonstration of the transmission quality, we use superpositions of these modes to encode a short message. At the receiver, an artificial neural network is used for distinguishing between the different twisted light superpositions. The algorithm is able to identify different mode superpositions with an accuracy of more than 80% up to the third mode order and decode the transmitted message with an error rate of 8.33%. Using our data, we estimate that the distribution of orbital angular momentum entanglement over more than 100 km of free space is feasible. Moreover, the quality of our free-space link can be further improved by the use of state-of-the-art adaptive optics systems. PMID:27856744

  10. Twisted light transmission over 143 km

    NASA Astrophysics Data System (ADS)

    Krenn, Mario; Handsteiner, Johannes; Fink, Matthias; Fickler, Robert; Ursin, Rupert; Malik, Mehul; Zeilinger, Anton

    2016-11-01

    Spatial modes of light can potentially carry a vast amount of information, making them promising candidates for both classical and quantum communication. However, the distribution of such modes over large distances remains difficult. Intermodal coupling complicates their use with common fibers, whereas free-space transmission is thought to be strongly influenced by atmospheric turbulence. Here, we show the transmission of orbital angular momentum modes of light over a distance of 143 km between two Canary Islands, which is 50× greater than the maximum distance achieved previously. As a demonstration of the transmission quality, we use superpositions of these modes to encode a short message. At the receiver, an artificial neural network is used for distinguishing between the different twisted light superpositions. The algorithm is able to identify different mode superpositions with an accuracy of more than 80% up to the third mode order and decode the transmitted message with an error rate of 8.33%. Using our data, we estimate that the distribution of orbital angular momentum entanglement over more than 100 km of free space is feasible. Moreover, the quality of our free-space link can be further improved by the use of state-of-the-art adaptive optics systems.

  11. Global modeling with GEOS-5 from 50-km to 1-km with a single unified GCM

    NASA Astrophysics Data System (ADS)

    Putman, William; Suarez, Max; Molod, Andrea; Barahona, Donifan

    2015-04-01

    The Goddard Earth Observing System model (GEOS-5) of the Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center is uniquely designed to adapt to increasing resolution. This supports application of GEOS-5 for decadal scale climate simulation and reanalysis with a horizontal resolution of 50-kilometers (km), high-resolution numerical weather prediction at 25- to 14-km, and global mesoscale modeling at resolutions of 7- to 1.5-km. Resolution-aware parameterizations and dynamics support this diverse portfolio of applications within a single unified GEOS-5 GCM code-base. We will discuss the adaptation of physics parameterizations with increasing resolution. This includes the role of deep convective parameterization, the move to an improved two-moment microphysics scheme, the need for shallow convective parameterization, and the role of non-hydrostatic dynamics and implicit/explicit damping. Parameterization and dynamics evaluation are explored not only in global integrations with GEOS-5 but with radiative convective equilibrium tests that permit the rapid exploration of high-resolution simulations in a smaller doubly periodic Cartesian domain. Simulation results will highlight intercomparisons of model biases in cloud forcing and precipitation from the 30-year 50-km MERRA-2 reanalysis, 50- to 25-km free-running AMIP simulations, a 2-year 7-km global mesoscale simulation, and monthly global simulations at 3.5-km. A global 1.5-km simulation with GEOS-5 highlights our pursuit of truly convection permitting global simulations with GEOS-5. The tuning evaluation for this simulation using doubly periodic radiative convective equilibrium experiments will be discussed.

  12. Galaxy Groups within 3500 km s-1

    NASA Astrophysics Data System (ADS)

    Kourkchi, Ehsan; Tully, R. Brent

    2017-01-01

    We present an algorithm to find nearby galaxy groups within 3,500 km s-1 (~45 Mpc). Our algorithm is based on the direct observed scaling relations that relate luminosity, velocity dispersion and dimensions of groups. Using these scaling relations, in an iterative process, galaxies with almost the same radial velocities and in close angular proximity fall into groups. Since peculiar velocities and Hubble expansion rate are comparable at these local distances, radial velocities are not very good proxies for galaxies distances. Therefore, further manual investigations of the identified groups is inevitable to discard interlopers and/or to resolve confusing cases in crowded regions. The goal of this study is to explore the nature of smallest galaxy groups and to investigate the halo mass function below 8x1012 solar mass.

  13. Improved Blocking at 25km Resolution?

    NASA Astrophysics Data System (ADS)

    Schiemann, R.; Demory, M. E.; Mizielinski, M.; Roberts, M.; Shaffrey, L.; Strachan, J.; Vidale, P. L.; Matsueda, M.

    2014-12-01

    It has been suggested that relatively coarse resolution of atmospheric general circulation models (AGCMs) limits their ability to represent mid-latitude blocking. Assessing the role of model resolution for blocking is computationally expensive, as multi-decadal simulations at the desired resolution are necessary for a robust estimation of blocking statistics. Here, we use an ensemble of three atmosphere-only global models for which simulations that fulfil this requirement are available at resolutions of roughly 25km horizontal grid spacing in the mid-latitudes. This corresponds to about a fourfold increase in resolution over the highest-resolution CMIP5 (Coupled Model Intercomparison Project, Phase 5) models. The three models are (i) the ECMWF model (IFS) as used in the project Athena, (ii) the MRI-AGCM 3.2, and (iii) our own HadGEM3-GA3 simulations obtained in the UPSCALE project (UK on PrACE - weather-resolving Simulations of Climate for globAL Environmental risk). We use a two-dimensional blocking index to assess the representation of blocking in these simulations and in three reanalyses (ERA-Interim, ERA-40, MERRA). We evaluate the spatial distribution of climatological blocking frequency, the interannual variability of blocking occurrence as well as the persistence of blocking events. Furthermore, the degree to which blocking biases are associated with mean-state biases is quantified in the different models. We find that the representation of blocking remains very sensitive to atmospheric resolution as the grid spacing is reduced to about 25km. The simulated blocking frequency increases with resolution, mostly so as to reduce the model bias, yet there is considerable variation between the results obtained for different models, seasons, and for the Atlantic and Pacific regions.

  14. Group training in adolescent runners: influence on VO2max and 5-km race performance.

    PubMed

    Loprinzi, Paul D; Cardinal, Bradley J; Karp, Jason R; Brodowicz, Gary R

    2011-10-01

    The aims of this study were to (a) examine the interrelationships between training intensity, VO2max, and race performance in adolescent crosscountry runners and (b) determine if adolescent runners participating in a group crosscountry training program differ in the amount of training time at various intensities. In this study, 7 adolescent runners performed a laboratory-based VO2max test before and after a 9-week high-school crosscountry season. Heart rate (HR) and ventilatory threshold (VT) were used to identify 3 training zones for each runner based on the HR at ventilator threshold (HR(VT)): zone 1: >15 b·min(-1) below HR(VT); zone 2: between zone 1 and HR(VT); zone 3: >HR(VT). During each training session throughout the season, HR was measured to quantify the amount of training time in each of these 3 intensity zones. Results showed that the time in each of the 3 zones was not significantly associated with 5-km race performance. Zone 3 training time was positively associated with postseason VO2max (r = 0.73, p = 0.06); VO2max was significantly inversely associated with 5-km race performance (r = -0.77, p = 0.04). Each week, the amount of training time at, above, and below the VT was significantly different among the participants even though the training prescription for the group was standardized. The results suggest that, among adolescent crosscountry runners, training above the VT may be important in increasing VO2max and ultimately, race performance. Given the between-participant differences in the amount of training time in each HR zone, coaches should apply individual, rather than group, training programs.

  15. Hidden treasures - 50 km points of interests

    NASA Astrophysics Data System (ADS)

    Lommi, Matias; Kortelainen, Jaana

    2015-04-01

    Tampere is third largest city in Finland and a regional centre. During 70's there occurred several communal mergers. Nowadays this local area has both strong and diversed identity - from wilderness and agricultural fields to high density city living. Outside the city center there are interesting geological points unknown for modern city settlers. There is even a local proverb, "Go abroad to Teisko!". That is the area the Hidden Treasures -student project is focused on. Our school Tammerkoski Upper Secondary School (or Gymnasium) has emphasis on visual arts. We are going to offer our art students scientific and artistic experiences and knowledge about the hidden treasures of Teisko area and involve the Teisko inhabitants into this project. Hidden treasures - Precambrian subduction zone and a volcanism belt with dense bed of gold (Au) and arsenic (As), operating goldmines and quarries of minerals and metamorphic slates. - North of subduction zone a homogenic precambrian magmastone area with quarries, products known as Kuru Grey. - Former ashores of post-glasial Lake Näsijärvi and it's sediments enabled the developing agriculture and sustained settlement. Nowadays these ashores have both scenery and biodiversity values. - Old cattle sheds and dairy buildings made of local granite stones related to cultural stonebuilding inheritance. - Local active community of Kapee, about 100 inhabitants. Students will discover information of these "hidden" phenomena, and rendering this information trough Enviromental Art Method. Final form of this project will be published in several artistic and informative geocaches. These caches are achieved by a GPS-based special Hidden Treasures Cycling Route and by a website guiding people to find these hidden points of interests.

  16. 45 Km Horizontal Path Optical Link Experiment

    NASA Technical Reports Server (NTRS)

    Biswas, A.; Ceniceros, J.; Novak, M.; Jeganathan, M.; Portillo, A.; Erickson, D.; Depew, J.; Sanii, B.; Lesh, J. R.

    2000-01-01

    Mountain-top to mountain-top optical link experiments have been initiated at JPL, in order to perform a systems level evaluation of optical communications. Progress made so far is reported. ne NASA, JPL developed optical communications demonstrator (OCD) is used to transmit a laser signal from Strawberry Peak (SP), located in the San Bernadino mountains of California. This laser beam is received by a 0.6 m aperture telescope at JPL's Table Mountain Facility (TMF), located in Wrightwood, California. The optical link is bi-directional with the TMF telescope transmitting a continuous 4-wave (cw) 780 run beacon and the OCD sending back a 840 nm, 100 - 500 Mbps pseudo noise (PN) modulated, laser beam. The optical link path is at an average altitude of 2 km above sea level, covers a range of 46.8 km and provides an atmospheric channel equivalent to approx. 4 air masses. Average received power measured at either end fall well within the uncertainties predicted by link analysis. The reduction in normalized intensity variance (sigma(sup 2, sub I)) for the 4-beam beacon, compared to each individual beam, at SP, was from approx. 0.68 to 0.22. With some allowance for intra-beam mis-alignment, this is consistent with incoherent averaging. The sigma(sup2, sub I) measured at TMF approx. 0.43 +/- 0.22 exceeded the expected aperture averaged value of less than 0.1, probably because of beam wander. The focused spot sizes of approx. 162 +/- 6 microns at the TMF Coude and approx. 64 +/- 3 microns on the OCD compare to the predicted size range of 52 - 172 microns and 57 - 93 microns, respectively. This is consistent with 4 - 5 arcsec of atmospheric "seeing". The preliminary evaluation of OCD's fine tracking indicates that the uncompensated tracking error is approx. 3.3 micro rad compared to approx. 1.7 micro rad observed in the laboratory. Fine tracking performance was intermittent, primarily due to beacon fades on the OCD tracking sensor. The best bit error rates observed while

  17. On the Complicated 410 km Discontinuity beneath Eastern China with the Seismic Triplications

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Li, G.; Sui, Y.

    2013-12-01

    The seismic triplications from the seismograms of mid-deep earthquakes at the Ryuku subduction zone recorded by the Chinese Digital Seismic Network (CDSN) between the epicentral distance between 10°-23° are used to study the upper mantle structure beneath Eastern China. Comparing the observed seismograms with the synthetic ones from different models based on IASP91 earth model and using the ray-tracing method, we found that the 410 km discontinuity is a gradient zone with the thickness of 20 km and there is low velocity layer atop the discontinuity which becomes thin from north to south beneath Eastern China. The complicated 410 km discontinuity with an atop low velocity layer may be caused by the dehydration of the Philippine sea subducting materials which are observed by the seismic tomopgraphy (Qu, et al., 2007; Li and van der Hilst, 2010). The low velocity gradient zone between the depths of 80-200 km is also been observed and may be related to the lithospheric-asthenosphere boundary.

  18. Teleportation of entanglement over 143 km

    PubMed Central

    Herbst, Thomas; Scheidl, Thomas; Fink, Matthias; Handsteiner, Johannes; Wittmann, Bernhard; Ursin, Rupert; Zeilinger, Anton

    2015-01-01

    As a direct consequence of the no-cloning theorem, the deterministic amplification as in classical communication is impossible for unknown quantum states. This calls for more advanced techniques in a future global quantum network, e.g., for cloud quantum computing. A unique solution is the teleportation of an entangled state, i.e., entanglement swapping, representing the central resource to relay entanglement between distant nodes. Together with entanglement purification and a quantum memory it constitutes a so-called quantum repeater. Since the aforementioned building blocks have been individually demonstrated in laboratory setups only, the applicability of the required technology in real-world scenarios remained to be proven. Here we present a free-space entanglement-swapping experiment between the Canary Islands of La Palma and Tenerife, verifying the presence of quantum entanglement between two previously independent photons separated by 143 km. We obtained an expectation value for the entanglement-witness operator, more than 6 SDs beyond the classical limit. By consecutive generation of the two required photon pairs and space-like separation of the relevant measurement events, we also showed the feasibility of the swapping protocol in a long-distance scenario, where the independence of the nodes is highly demanded. Because our results already allow for efficient implementation of entanglement purification, we anticipate our research to lay the ground for a fully fledged quantum repeater over a realistic high-loss and even turbulent quantum channel. PMID:26578764

  19. Teleportation of entanglement over 143 km.

    PubMed

    Herbst, Thomas; Scheidl, Thomas; Fink, Matthias; Handsteiner, Johannes; Wittmann, Bernhard; Ursin, Rupert; Zeilinger, Anton

    2015-11-17

    As a direct consequence of the no-cloning theorem, the deterministic amplification as in classical communication is impossible for unknown quantum states. This calls for more advanced techniques in a future global quantum network, e.g., for cloud quantum computing. A unique solution is the teleportation of an entangled state, i.e., entanglement swapping, representing the central resource to relay entanglement between distant nodes. Together with entanglement purification and a quantum memory it constitutes a so-called quantum repeater. Since the aforementioned building blocks have been individually demonstrated in laboratory setups only, the applicability of the required technology in real-world scenarios remained to be proven. Here we present a free-space entanglement-swapping experiment between the Canary Islands of La Palma and Tenerife, verifying the presence of quantum entanglement between two previously independent photons separated by 143 km. We obtained an expectation value for the entanglement-witness operator, more than 6 SDs beyond the classical limit. By consecutive generation of the two required photon pairs and space-like separation of the relevant measurement events, we also showed the feasibility of the swapping protocol in a long-distance scenario, where the independence of the nodes is highly demanded. Because our results already allow for efficient implementation of entanglement purification, we anticipate our research to lay the ground for a fully fledged quantum repeater over a realistic high-loss and even turbulent quantum channel.

  20. Tropical Waves and the Quasi-Biennial Oscillation in a 7-km Global Climate Simulation

    NASA Technical Reports Server (NTRS)

    Holt, Laura A.; Alexander, M. Joan; Coy, Lawrence; Molod, Andrea; Putman, William; Pawson, Steven

    2016-01-01

    This study investigates tropical waves and their role in driving a quasi-biennial oscillation (QBO)-like signal in stratospheric winds in a global 7-km-horizontal-resolution atmospheric general circulation model. The Nature Run (NR) is a 2-year global mesoscale simulation of the Goddard Earth Observing System Model, version 5 (GEOS-5). In the tropics, there is evidence that the NR supports a broad range of convectively generated waves. The NR precipitation spectrum resembles the observed spectrum in many aspects, including the preference for westward-propagating waves. However, even with very high horizontal resolution and a healthy population of resolved waves, the zonal force provided by the resolved waves is still too low in the QBO region and parameterized gravity wave drag is the main driver of the NR QBO-like oscillation (NRQBO). The authors suggest that causes include coarse vertical resolution and excessive dissipation. Nevertheless, the very-high-resolution NR provides an opportunity to analyze the resolved wave forcing of the NR-QBO. In agreement with previous studies, large-scale Kelvin and small-scale waves contribute to the NRQBO driving in eastward shear zones and small-scale waves dominate the NR-QBO driving in westward shear zones. Waves with zonal wavelength,1000 km account for up to half of the small-scale (,3300 km) resolved wave forcing in eastward shear zones and up to 70% of the small-scale resolved wave forcing in westward shear zones of the NR-QBO.

  1. Seismic evidence for silicate melt atop the 410-km mantle discontinuity

    NASA Astrophysics Data System (ADS)

    Revenaugh, J.; Sipkin, S. A.

    1994-06-01

    LABORATORY results demonstrating that basic to ultrabasic melts become denser than olivine-rich mantle at pressures above 6 GPa (refs 1-3) have important implications for basalt petrogenesis, mantle differentiation and the storage of volatiles deep in the Earth. A density cross-over between melt and solid in the extensively molten Archaean mantle has been inferred from komatiitic volcanism4-6 and major-element mass balances7, but present-day evidence of dense melt below the seismic low-velocity zone is lacking. Here we present mantle shear-wave impedance profiles obtained from multiple-ScS reverberation mapping for corridors connecting western Pacific subduction zone earthquakes with digital seismograph stations in eastern China, imaging a ~5.8% impedance decrease roughly 330 km beneath the Sea of Japan, Yellow Sea and easternmost Asia. We propose that this represents the upper surface of a layer of negatively buoyant melt lying on top of the olivine-->β-phase transition (the 410-km seismic discontinuity). Volatile-rich fluids expelled from the partial melt zone as it freezes may migrate upwards, acting as metasomatic agents8,9 and perhaps as the deep 'proto-souree' of kimberlites10,11. The remaining, dense, crystalline fraction would then concentrate above 410 km, producing a garnet-rich layer that may flush into the transition zone.

  2. Seismic evidence for silicate melt atop the 410-km mantle discontinuity

    USGS Publications Warehouse

    Revenaugh, Justin; Sipkin, S.A.

    1994-01-01

    LABORATORY results demonstrating that basic to ultrabasic melts become denser than olivine-rich mantle at pressures above 6 GPa (refs 1-3) have important implications for basalt petrogenesis, mantle differentiation and the storage of volatiles deep in the Earth. A density cross-over between melt and solid in the extensively molten Archaean mantle has been inferred from komatiitic volcanism and major-element mass balances, but present-day evidence of dense melt below the seismic low-velocity zone is lacking. Here we present mantle shear-wave impedance profiles obtained from multiple-ScS reverberation mapping for corridors connecting western Pacific subduction zone earthquakes with digital seismograph stations in eastern China, imaging a ~5.8% impedance decrease roughly 330 km beneath the Sea of Japan, Yellow Sea and easternmost Asia. We propose that this represents the upper surface of a layer of negatively buoyant melt lying on top of the olivine ??? ??- phase transition (the 410-km seismic discontinuity). Volatile-rich fluids expelled from the partial melt zone as it freezes may migrate upwards, acting as metasomatic agents and perhaps as the deep 'proto-source' of kimberlites. The remaining, dense, crystalline fraction would then concentrate above 410 km, producing a garnet-rich layer that may flush into the transition zone.

  3. Tropical Waves and the Quasi-Biennial Oscillation in a 7-km Global Climate Simulation

    NASA Technical Reports Server (NTRS)

    Holt, Laura A.; Alexander, M. Joan; Coy, Lawrence; Molod, Andrea; Putman, William; Pawson, Steven

    2016-01-01

    This study investigates tropical waves and their role in driving a quasi-biennial oscillation (QBO)-like signal in stratospheric winds in a global 7-km-horizontal-resolution atmospheric general circulation model. The Nature Run (NR) is a 2-year global mesoscale simulation of the Goddard Earth Observing System Model, version 5 (GEOS-5). In the tropics, there is evidence that the NR supports a broad range of convectively generated waves. The NR precipitation spectrum resembles the observed spectrum in many aspects, including the preference for westward-propagating waves. However, even with very high horizontal resolution and a healthy population of resolved waves, the zonal force provided by the resolved waves is still too low in the QBO region and parameterized gravity wave drag is the main driver of the NR QBO-like oscillation (NRQBO). The authors suggest that causes include coarse vertical resolution and excessive dissipation. Nevertheless, the very-high-resolution NR provides an opportunity to analyze the resolved wave forcing of the NR-QBO. In agreement with previous studies, large-scale Kelvin and small-scale waves contribute to the NRQBO driving in eastward shear zones and small-scale waves dominate the NR-QBO driving in westward shear zones. Waves with zonal wavelength,1000 km account for up to half of the small-scale (,3300 km) resolved wave forcing in eastward shear zones and up to 70% of the small-scale resolved wave forcing in westward shear zones of the NR-QBO.

  4. Peregrine 100-km Sounding Rocket Project

    NASA Technical Reports Server (NTRS)

    Zilliac, Gregory

    2012-01-01

    The Peregrine Sounding Rocket Program is a joint basic research program of NASA Ames Research Center, NASA Wallops, Stanford University, and the Space Propulsion Group, Inc. (SPG). The goal is to determine the applicability of this technology to a small launch system. The approach is to design, build, and fly a stable, efficient liquefying fuel hybrid rocket vehicle to an altitude of 100 km. The program was kicked off in October of 2006 and has seen considerable progress in the subsequent 18 months. This research group began studying liquifying hybrid rocket fuel technology more than a decade ago. The overall goal of the research was to gain a better understanding of the fundamental physics of the liquid layer entrainment process responsible for the large increase in regression rate observed in these fuels, and to demonstrate the effect of increased regression rate on hybrid rocket motor performance. At the time of this reporting, more than 400 motor tests were conducted with a variety of oxidizers (N2O, GOx, LOx) at ever increasing scales with thrust levels from 5 to over 15,000 pounds (22 N to over 66 kN) in order to move this technology from the laboratory to practical applications. The Peregrine program is the natural next step in this development. A number of small sounding rockets with diameters of 3, 4, and 6 in. (7.6, 10.2, and 15.2 cm) have been flown, but Peregrine at a diameter of 15 in. (38.1 cm) and 14,000-lb (62.3-kN) thrust is by far the largest system ever attempted and will be one of the largest hybrids ever flown. Successful Peregrine flights will set the stage for a wide range of applications of this technology.

  5. Kinematics of the New Zealand plate boundary: Relative motion by GPS across networks of 1000 km and 50 km spacing

    NASA Technical Reports Server (NTRS)

    Meertens, Charles M.; Rocken, Christian; Perin, Barbara; Walcott, Richard

    1993-01-01

    The NASA/DOSE 'Kinematics of the New Zealand Plate Boundary' experiment is a four-year cooperative Global Positioning System (GPS) experiment involving 6 universities and institutions in New Zealand and the United States. The investigation covers two scales, the first on the scale of plates (approximately 1000 km) and the second is on the scale of the plate boundary zone (approximately 50 km). In the first portion of the experiment, phase A, the objective is to make direct measurements of tectonic plate motion between the Australian and Pacific plates using GPS in order to determine the Euler vector of this plate pair. The phase A portion of this experiment was initiated in December 1992 with the first-epoch baseline measurements on the large scale network. The network will be resurveyed two years later to obtain velocities. The stations which were observed for phase A are shown and listed. Additional regional stations which will be used for this study are listed and are part of either CIGNET or other global tracking networks. The phase A portion of the experiment is primarily the responsibility of the UNAVCO investigators. Therefore, this report concentrates on phase A. The first year of NASA funding for phase A included only support for the field work. Processing and analysis will take place with the second year of funding. The second part of the experiemnt measured relative motion between the Australian and Pacific plates across the pate boundary zone between Hokitika and Christchurch on the South Island of New Zealand. The extent and rate of deformation will be determined by comparisons with historical, conventional surveys and by repeated GPS measurements to be made in two years. This activity was the emphasis of the LDGO portion of the study. An ancillary experiment, phase C, concentrated on plate boundary deformation in the vicinity of Wellington and was done as part of training during the early portion of the field campaign. Details of the objectives of the

  6. Evaluation of movement restriction zone sizes in controlling classical swine fever outbreaks

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to compare the movement restriction zone sizes of 3-km, 5-km, 9-km, and 11-km with that of 7-km in controlling a classical swine fever (CSF) outbreak. Three assumptions of compliance level were considered: baseline, baseline ±10%, and baseline ±15%. The compliance lev...

  7. Longmenshan Crust and Mantle Structure Down to 700 km Depth Revealed by P Receiver Functions

    NASA Astrophysics Data System (ADS)

    Mechie, J.; Qian, H.; Li, H.; Xue, G.; Su, H.; Cui, X.

    2016-12-01

    For a period of about 15 months in 2012 and 2013 an array of 80 broadband seismic stations was operated in a 300 km by 150 km area straddling the Longmenshan fault zone around the epicentre of the Wenchuan earthquake. The main aim of this array is to investigate the deep structure of the region surrounding the epicentre of the Wenchuan earthquake. In order to contribute to this aim, an analysis of P receiver functions obtained during the experiment was carried out. With respect to crustal structure, shallow positive Ps conversions from 5-10 km depth indicate the base of the sediments in the Sichuan basin and the base of the flysch deposits in the Songpan-Ganzi terrane of the Tibetan plateau. Deeper positive Ps conversions from 40-65 km depth represent the Moho. The Moho occurs at 40-50 km depth in the SE below the Sichuan basin and deepens to the NW to 55-65 km depth under the Songpan-Ganzi terrane in the Tibetan plateau. The variable character of the change in Moho depths along the trend of the Longmenshan fault zone from NE to SW is one of the important findings of this study. In the NE of the study region the Moho deepening from SE to NW is smooth, whereas in the middle and SW it is abrupt with, in some places, in addition to being abrupt there is also seemingly a Moho overlap. The Moho structure in the middle and SW of the study region is reminiscent of a similar structure under the southern margin of the Qaidam basin in NE Tibet just N of the Kunlun mountains. Positive Ps conversions can be observed from the 410 km and 660 km discontinuities at the top and bottom of the mantle transition zone respectively. There is a disruption in the strength of the conversion from the 410 km discontinuity beneath the Longmenshan fault where the Moho deepens abruptly from the Sichuan basin to the high Tibetan plateau.

  8. Evaluation of the 7-km GEOS-5 Nature Run

    NASA Technical Reports Server (NTRS)

    Gelaro, Ronald; Putman, William M.; Pawson, Steven; Draper, Clara; Molod, Andrea; Norris, Peter M.; Ott, Lesley; Prive, Nikki; Reale, Oreste; Achuthavarier, Deepthi; hide

    2015-01-01

    . However, because of the relatively short record and other practical considerations, these comparisons cannot provide a definitive, statistically sound assessment of all model deficiencies, or guarantee the G5NR's suitability for all OSSE applications. Differences between the observed and simulated behavior also must be judged in the context of basic internal atmospheric variability which can introduce variations that are not necessarily controlled by the prescribed sea surface temperatures used in generating the G5NR. The results show that the G5NR performs well as measured by the majority of metrics applied in this evaluation. Particular benefits derived from the 7-km resolution of G5NR include realistic representations of extreme weather events in both the tropics and extratropics including tropical cyclones, Nor'easters and mesoscale convective complexes; improved representation of the diurnal cycle of precipitation over land; well-resolved surface-atmosphere interactions such as katabatic wind flows over Antarctica and Greenland; and resolution of orographically generated gravity waves that propagate into the upper atmosphere and influence the large scale circulation. Obvious deficiencies in the G5NR include a "splitting" of the inter-tropical convergence zone, which leads to a weaker-than-observed Hadley circulation and related deficiencies in the depiction of stationary wave patterns. Also, while the G5NR captures global cloud features and radiative effects well in general, close comparison with observations reveals higher-than-observed cloud brightness, likely due to an overabundance of cloud condensate; less distinct cloud minima in subtropical subsidence zones, consistent with a weak Hadley circualtion; and too few near-coastal marine stratocumulus clouds.

  9. KM3NeT: towards a km 3-scale neutrino telescope in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Distefano, C.; KM3NeT Consortium

    2009-05-01

    The observation of high energy neutrinos ( ≳1 TeV) from astrophysical sources would substantially improve our knowledge and understanding of the non-thermal processes in these sources, and would in particular pinpoint the accelerators of cosmic rays. Theoretical predictions indicate that km 3-scale detectors are needed to detect astrophysical neutrino fluxes. That is the reason why the three Mediterranean experiments, ANTARES, NEMO and NESTOR are working together on preparing KM3NeT, a large deep-sea neutrino telescope in the Mediterranean Sea which will survey a large part of the Galactic disc, including the Galactic Centre. It will complement the IceCube telescope currently under construction at the South Pole. Furthermore, the improved optical properties of sea water, compared to Antarctic ice, will allow for a better angular resolution and hence a better background rejection. The construction of this detector will require the solution of technological problems common to many deep submarine installations, and will help paving the way for other deep-sea research facilities. In this paper the major activities and the status of KM3NeT are presented.

  10. KM3NeT: towards a km3-scale neutrino telescope in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Km3NeT Consortium; Distefano, C.; KM3NeT Consortium

    2009-05-01

    The observation of high energy neutrinos (≳1 TeV) from astrophysical sources would substantially improve our knowledge and understanding of the non-thermal processes in these sources, and would in particular pinpoint the accelerators of cosmic rays. Theoretical predictions indicate that km3-scale detectors are needed to detect astrophysical neutrino fluxes. That is the reason why the three Mediterranean experiments, ANTARES, NEMO and NESTOR are working together on preparing KM3NeT, a large deep-sea neutrino telescope in the Mediterranean Sea which will survey a large part of the Galactic disc, including the Galactic Centre. It will complement the IceCube telescope currently under construction at the South Pole. Furthermore, the improved optical properties of sea water, compared to Antarctic ice, will allow for a better angular resolution and hence a better background rejection. The construction of this detector will require the solution of technological problems common to many deep submarine installations, and will help paving the way for other deep-sea research facilities. In this paper the major activities and the status of KM3NeT are presented.

  11. Three zones for illite formation during burial diagenesis and metamorphism

    USGS Publications Warehouse

    Eberl, D.D.

    1993-01-01

    Reinterpretation of published data for shale cuttings from the Gulf of Mexico sedimentary basin identifies three reaction zones for illite formation with increasing depth for well CWRU6. In a shallow zone (1.85 to 3 km), non-expanding illite-like layers formed primarily by the coalescence of smectite 2:1 layers around interlayer K+. In a middle zone (3 to 4 km), illite crystals neoformed from solution as coarser K-bearing phases and smectite were dissolved by organic acids. In the deepest zone (>4 km), illite recrystallized as less stable illite crystals dissolved, and more stable illite crystals grew during mineral ripening. -from Author

  12. Strain accumulation along the Cascadia subduction zone

    USGS Publications Warehouse

    Murray, M.H.; Lisowski, M.

    2000-01-01

    We combine triangulation, trilateration, and GPS observations to determine horizontal strain rates along the Cascadia subduction zone from Cape Mendocino to the Strait of Juan de Fuca. Shear-strain rates are significantly greater than zero (95% confidence) in all forearc regions (26-167 nanoradians/yr), and are not significant in the arc and backarc regions. The deformation is primarily uniaxial contraction nearly parallel to Juan de Fuca-North America plate convergence (N55??-80??E). The strain rates are consistent with an elastic dislocation model for interseismic slip with a shallow 100-km wide locked zone and a deeper 75-km transition zone along the entire megathrust, except along the central Oregon coast where relatively lower strain rates are consistent with 30-40 km wide locked and transition zones.

  13. Topography of the 410 km and 660 km discontinuities beneath the Japan Sea and adjacent regions by analysis of multiple-ScS waves

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Li, Juan; Chen, Qi-Fu

    2017-02-01

    The northwest Pacific subduction region is an ideal location to study the interaction between the subducting slab and upper mantle discontinuities. Due to the sparse distribution of seismic stations in the sea, previous studies mostly focus on mantle transition zone (MTZ) structures beneath continents or island arcs, leaving the vast area of the Japan Sea and Okhotsk Sea untouched. In this study, we analyzed multiple-ScS reverberation waves, and a common-reflection-point stacking technique was applied to enhance consistent signals beneath reflection points. A topographic image of the 410 km and 660 km discontinuities is obtained beneath the Japan Sea and adjacent regions. One-dimensional and 3-D velocity models are adapted to obtain the "apparent" and "true" depth. We observe a systematic pattern of depression ( 10-20 km) and elevation ( 5-10 km) of the 660, with the topography being roughly consistent with the shift of the olivine-phase transition boundary caused by the subducting Pacific plate. The behavior of the 410 is more complex. It is generally 5-15 km shallower at the location where the slab penetrates and deepened by 5-10 km oceanward of the slab where a low-velocity anomaly is observed in tomography images. Moreover, we observe a wide distribution of depressed 410 beneath the southern Okhotsk Sea and western Japan Sea. The hydrous wadsleyite boundary caused by the high water content at the top of the MTZ could explain the depression. The long-history trench rollback motion of Pacific slab might be responsible for the widely distributed depression of the 410 ranging upward and landward from the slab.

  14. Climate and biogeochemical sensitivity at ocean model resolutions of 100 km and 10 km

    NASA Astrophysics Data System (ADS)

    Dunne, J. P.; Galbraith, E. D.; Anderson, W.; Dufour, C. O.; Griffies, S. M.; Sarmiento, J. L.; Slater, R.; Winton, M.

    2016-02-01

    One of the representational aspirations driving current Earth System Model development is to capture the global ocean mesoscale (i.e. ocean weather) in coupled carbon-climate. The present study explores a the role of ocean model resolution (100 km and 10 km) on baseline physical and biogeochemical simulation characteristics and their response to climate change. We find the high resolution model to improve the representation of boundary currents and mesoscale phenomena, and to eliminate fictitious current structures that plague the coarse resolution models. Along with these expected improvements of smaller scales however, we also find a general lack of improvement in many of the large scale biases. With respect to sensitivity, we find the high resolution model to restrict ocean heat uptake towards the surface ocean and to exhibit somewhat less structure at the regional scale than the coarse resolution model. We find similarly more uniform patterns of carbon uptake and biogeochemicel response at high resolution consistent with a greater tendency in the high resolution model to accommodate change in the major current structures, and suggesting that some of the highly regional structure observed among CMIP5 models is due to their inability to represent the role of the mesoscale on the regional scale.

  15. MODIS 3km Aerosol Product: Algorithm and Global Perspective

    NASA Technical Reports Server (NTRS)

    Remer, L. A.; Mattoo, S.; Levy, R. C.; Munchak, L.

    2013-01-01

    After more than a decade of producing a nominal 10 km aerosol product based on the dark target method, the MODIS aerosol team will be releasing a nominal 3 km product as part of their Collection 6 release. The new product differs from the original 10 km product only in the manner in which reflectance pixels are ingested, organized and selected by the aerosol algorithm. Overall, the 3 km product closely mirrors the 10 km product. However, the finer resolution product is able to retrieve over ocean closer to islands and coastlines, and is better able to resolve fine aerosol features such as smoke plumes over both ocean and land. In some situations, it provides retrievals over entire regions that the 10 km product barely samples. In situations traditionally difficult for the dark target algorithm, such as over bright or urban surfaces the 3 km product introduces isolated spikes of artificially high aerosol optical depth (AOD) that the 10 km algorithm avoids. Over land, globally, the 3 km product appears to be 0.01 to 0.02 higher than the 10 km product, while over ocean, the 3 km algorithm is retrieving a proportionally greater number of very low aerosol loading situations. Based on collocations with ground-based observations for only six months, expected errors associated with the 3 km land product are determined to be greater than for the 10 km product: 0.05 0.25 AOD. Over ocean, the suggestion is for expected errors to be the same as the 10 km product: 0.03 0.05 AOD. The advantage of the product is on the local scale, which will require continued evaluation not addressed here. Nevertheless, the new 3 km product is expected to provide important information complementary to existing satellite-derived products and become an important tool for the aerosol community.

  16. Correlation of the 410 km Discontinuity Low Velocity Layer with Tomographic Wavespeed Variations

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Dueker, K. G.

    2010-12-01

    The transition zone water-filter model predicts that a hydrous melt layer at the 410-km discontinuity is only actively produced in upwelling region, and does not exist in downwelling region (Bercovici and Karato, 2003). This prediction has been tested by stacking of P-S receiver functions using the RISTRA linear array which crosses west-Texas, New Mexico and Utah. The receiver functions are binned into the NW, SE, SW azimuthal quadrants and stacked to produce well-resolved images of the 410- and 660-km discontinuities. The three receiver function quadrant stack images find a correlation between the occurrence of negative polarity 410-km low velocity layer arrival and the teleseismic body wave velocity tomogram of Schmandt and Humphreys (2010); the 410 low velocity layer arrival is absent where the velocities about the 410 km discontinuity are relatively high and present where the velocities are low. Our finding is consistent with a simple interpretation of the transition zone water filter model which predicts the production of a hydrous melt layer where upflow of sufficiently hydrated transition zone mantle occurs and destruction of a hydrous melt layer where there is downflow. We test this prediction by analyzing the Colorado Rockies Experiment and Seismic Transects (CREST) seismic data which was collected in 2008-2009. This 15 month deployment of 59 CREST stations in tandem with 31 Transportable Array stations yields a total of 161 Mb>5.5 events at 30°-95° distances. The P-S receiver functions are calculated using a multi-channel deconvolution methodology and filtered with a 30-3 s post-deconvolution filter. The receiver function dataset contains about 1800 SV components after RMS, cross-correlation, and visual data quality culling. Common conversion point images are constructed using Pds timing correction from a 3-D upper mantle tomography model (McCarthy and Aster, pers. com.) to account for lateral P/S velocity heterogeneity.

  17. Tibetan Plateau Crust and Mantle Structure Down to 700 km Depth as Derived From Seismological Data (Invited)

    NASA Astrophysics Data System (ADS)

    Mechie, J.; Kind, R.; Saul, J.

    2010-12-01

    In this study a seismic velocity cross-section of the crust and mantle down to 700 km depth beneath the Tibetan plateau has been constructed. The cross-section is based on the many controlled and passive source seismological experiments and studies which have reported results from within an 800 km swath centred on the main Lhasa-Golmud transect. Beneath the 2.5-7 km thick cover layer, the upper crust down to 15-25 km depth has compressional (P) wave velocities of 5.8-6.1 km/s and low Poisson’s ratios of 0.21-0.23, indicative of felsic rocks rich in quartz in the α state. There are many observations e.g. bright spots in seismic reflection records, low velocity regions in shear (S) wave models derived from receiver function analysis, seismicity drop off and high electrical conductivity which indicate that below 15-25 km depth, temperatures are high enough such that ductile flow and partial melting can occur. One of the main results of this study is the recognition of a boundary at 30-40 km depth. From the velocity values on either side of this boundary it is suggested that it marks the interface between the felsic upper crust and the more mafic lower crust. Within the swath, crustal thickness is greatest (approx. 74 km) beneath the southern part of the plateau south of about 31.5°N, where Indian lower crust forms the basal crustal layer. To the north crustal thickness decreases to about 66 km beneath the southern Qiangtang terrane around 33°N, before again increasing to about 70 km beneath the northern part of the plateau south of the Kunlun mountains. As the Kunlun mountains are crossed the crust thins dramatically to about 54 km beneath the Qaidam basin. Beneath the crust, high-velocity, dense and cold Indian lithospheric mantle extends northwards within the swath until about the Banggong-Nujiang suture, where it downwells to at least 350-400 km depth in a zone about 100-200 km wide centred at about 31.2°N. To the north, low-velocity, less dense and warm

  18. Characterizing the 410 km discontinuity low-velocity layer beneath the LA RISTRA array in the North American Southwest

    NASA Astrophysics Data System (ADS)

    Jasbinsek, John J.; Dueker, Ken G.; Hansen, Steven M.

    2010-03-01

    Receiver functions recorded by the 54-station 920 km long Program for Array Seismic Studies of the Continental Lithosphere-Incorporated Research Institutions for Seismology Colorado Plateau/Rio Grande Rift Seismic Transect Experiment (LA RISTRA) line array display a pervasive negative polarity P to S conversion (Pds) arrival preceding the positive polarity 410 km discontinuity arrival. These arrivals are modeled as a low-velocity layer atop the 410 km discontinuity (410-LVL) and are inverted for a velocity profile via a grid search using a five-parameter linear gradient velocity model. Model parameter likelihood and correlations are assessed via calculation of one- and two-dimensional marginal posterior probability distributions. The maximum likelihood model parameter values found are top velocity gradient thickness of 0.0 km with a 4.6% (-0.22 km/s) shear velocity reduction, a 19.8 km constant velocity layer, and bottom gradient thickness of 25.0 km with a 3.5% (+0.17 km/s) shear velocity increase. The estimated mean thickness of the 410-LVL is 32.3 km. The top gradient of the 410-LVL is sharp within vertical resolution limits of P to S conversion (<10 km), and the diffuse 410 km velocity gradient is consistent with hydration of the olivine-wadsleyite phase transformation. The 410-LVL is interpreted as a melt layer created by the Transition Zone Water Filter model. Two secondary observations are found: (1) the 410-LVL is absent from the SE end of the array and (2) an intermittent negative polarity P525s arrival is observed. We speculate that upper mantle shear velocity anomalies above the 410 km discontinuity may manifest Rayleigh-Taylor instabilities nucleated from the 410-LVL melt layer that are being shed upward on time scales of tens of millions of years.

  19. Evolution of the Proposed International Tropical Reference Atmosphere up to 2000 km

    NASA Astrophysics Data System (ADS)

    Ananthasayanam, M.

    There is a compelling need in many aerospace, remote sensing, and other applications to propose a global reference atmosphere encompassing the whole of the tropics, due to the following reasons among others. The tropics cover a large area and the atmospheric conditions there are quite different from those in the midlatitudes represented by the International Standard Atmosphere. Though the dictionary definition of the tropics is between 230 28' N and 230 28' S, there can be no sharp dividing line between the tropics and extra tropics, and dynamical considerations suggest 30 0 N and 300 S as more appropriate approximate boundaries. (During summer tropical conditions prevail up to about 350 N). The early work of Ramanathan in 1929 pointed out that a break in the temperature distribution occurs around 16 km at low latitudes, whereas it occurs at much lower altitudes (around 11 km) in the temperate zone. He also showed that the coldest air over the earth (temperature about 1850 K) is in the form of a flat ring at a height of some 17 km over the equator; thus while mean temperatures are higher at sea level in the tropics, they are lower at altitudes around 15 km. Pisharoty suggested in 1959 two standard atmospheres one for the Asiatic tropics and another called Universal up to 20 km. The slight differences between these two turned out to be not valid from later measurements. Based on the presently available data showing weak longitudinal variations, it indeed turns out to be possible to provide an International Tropical Reference Atmosphere (ITRA) representative of the whole of the tropical region in both the northern and southern hemispheres (Ananthasayanam and Narasimha 1990). This proposal is also consistent with the mean monthly reference atmospheres for the northern hemisphere by Cole and Kantor (1978) and for the southern hemisphere by Koshelkov (1985) and also the Nimbus satellite data of Barnett and Corney (1985) from sea level up to 80 km. For ITRA, either the

  20. Microphysical Model of the Venus clouds between 40km and 80km

    NASA Astrophysics Data System (ADS)

    McGouldrick, Kevin

    2013-10-01

    I am continuing to adapt the Community Aerosol and Radiation Model for Atmospheres (CARMA) to successfully simulate the multi-layered clouds of Venus. The present version of the one-dimensional model now includes a simple parameterization of the photochemicial production of sulfuric acid around altitudes of 62km, and its thermochemical destruction below cloud base. Photochemical production in the model is limited by the availability of water vapor and insolation. Upper cloud particles are introduced into the model via binary homogeneous nucleation, while the lower and middle cloud particles are created via activation of involatile cloud condensation nuclei. Growth by condensation and coagulation and coalescence are also treated. Mass loadings and particle sizes compare favorably with the in situ observations by the Pioneer Venus Large Probe Particle Size Spectrometer, and mixing ratios of volatiles compare favorably with remotely sensed observations of water vapor and sulfuric acid vapor. This work was supported by the NASA Planetary Atmospheres Program, grant number NNX11AD79G.

  1. The 1977 intertropical convergence zone experiment

    NASA Technical Reports Server (NTRS)

    Poppoff, I. G. (Editor); Page, W. A. (Editor); Margozzi, A. P. (Editor)

    1979-01-01

    Data are presented from the 1977 Intertropical Convergence Zone (ITCZ) Experiment conducted in the Panama Canal Zone in July 1977. Measurements were made daily over a 16-day period when the ITCZ moved across the Canal Zone. Two aircraft (Learjet and U-2) flew daily and provided data from horizontal traverses at several altitudes to 21.3 km of ozone, temperature, pressure, water vapor, aerosols, fluorocarbons, methane, nitrous oxide, nitric oxide, and nitric acid. Balloonsondes flown four times per day provided data on ozone, wind fields, pressure, temperature, and humidities to altitudes near 30 km. Rocketsondes provided daily data to altitudes near 69 km. Satellite photography provided detailed cloud information. Descriptions of individual experiments and detailed compilations of all results are provided.

  2. En echelon knolls in the Nosappu Fracture Zone, NW Pacific: A possible leaky transform fault zone

    NASA Astrophysics Data System (ADS)

    Ogawa, Y.; Hirano, N.; Shipboard Scientific Party Kr03-07, .

    2003-12-01

    During JAMSTEC R/V KAIREI cruise KR03-07, we mapped significant en echelon arrays of knolls and ridges on the NNW-trending Nosappu Fracture Zone between Hokkaido and Shatsky Rise, NW Pacific. This fracture zone has been known to be irregular, including a deep-sea channel, the Nakwe Channel, enigmatic for inside the wide oceanic plate. Considering the previously recognized magnetic lineament dislocation, the fracture zone has long (more than 150 km) left-lateral strike-slip component as a ridge-ridge transform fault zone between the Izanagi and Pacific plates during Early Cretaceous. Detail multi-narrowbeam mapping around 37 N latitude, 150 E longitude (covering 78 km x 137 km), indicated many small knolls and ridges that form en echelon arrangement. Some are boomerang, sock or E-letter in shape. The two dominant directions of ridges are recognized, one is parallel to the fracture zone and the other is in left-handed en echelon fashion. Besides these ridges, there are other types of ridges or conical knolls lower than 500 m in relief; one is a group of rather large knolls extending to NE, roughly perpendicular to the fracture zone direction, and the other is independent small knolls, summing up to five or six in number. Another expression of a depression zone was recognized with a moderate angle to the fracture zone in a crank fashion. This may correspond to the so-called _gNakwe Channel_h which has been wrongly mistaken. Such en echelon arrays are involved in a 50 km wide NNW-SSE zone, which is sharply demarcated by fault scarps. These characteristics in the fracture zone area and associated knolls suggest that this part of the Nosappu Fracture Zone might have developed in a fault interaction area which has a left-lateral component of leaky transform faulting close to the spreading ridge.

  3. Mantle seismic anisotropy beneath the 660km phase transition generated by subduction body force stresses.

    NASA Astrophysics Data System (ADS)

    Nippress, S.; Kusznir, N. J.; Kendall, M.

    2003-04-01

    Observations of seismic anisotropy can provide insights into the style of mantle dynamics near the 660km discontinuity. Wookey et al. (2002) report up to 7 seconds of shear wave splitting for rays generated by deep focus events from the Tonga subduction zone and recorded in Australia. The results suggest a transversely isotropic symmetry with the symmetry axis in the vertical plane, perpendicular to the ray direction. Thus, for horizontally travelling waves this would imply horizontally polarised shear waves (SH lead SV). They show that a topmost lower mantle model with anisotropy between 660-900km could produce theoretical shear wave splitting similar to that observed. Therefore, the seismic anisotropy observed by Wookey et al., can be explained by an anisotropic region between 660-900km, with only a minimal contribution from above the 660km phase transition. The goal of this study is to try to explain the observed shear wave splitting using geodynamical modelling. We use finite element (FE) modelling to calculate slab-induced models of fluid flow, total stress and deviatoric stress. A simple 2D subduction zone model with a prescribed viscosity structure and slab density is used. Large deviatoric stresses (maximum values ~ 40 MPa) are generated in the topmost lower mantle when the subducting slab encounters an increase in viscosity at the 660km phase transition. These stresses may induce mineral alignment in a broad region (lateral wavelength approximately » 800km) in the topmost lower mantle below the slab. Perovskite may therefore be aligned with a rotated symmetry axis conformal to the shape of this region of high deviatoric stress. Aligned Perovskite rotated more than 30 degrees predicts SH-waves faster than SV-waves for horizontally travelling S-waves. The formulation of McKenzie (1979) is used to calculate the finite strain accumulated by a mantle parcel as it propagates through the FE flow models. The computed strain ellipsoids align in a similar region

  4. The Caetano Caldera, Nevada: 5 km Thickness of Intracaldera Rhyolite Ignimbrite and Co-Magmatic Batholith

    NASA Astrophysics Data System (ADS)

    John, D. A.; Henry, C. D.; Colgan, J. P.

    2008-12-01

    The Caetano caldera in northern Nevada is cut by Miocene extensional faults that extraordinarily expose a complete, thick (>4 km) intracaldera rhyolite ignimbrite (Caetano Tuff) and underlying cogenetic granitic plutons in tilted blocks reaching to >5 km of paleodepth. The caldera contains (1) a 1-km-thick upper unit of Caetano Tuff composed of multiple, thin cooling units and interbedded sedimentary rocks, (2) a >3.5- km-thick lower compound cooling unit of Caetano Tuff, and (3) 5 shallowly emplaced (locally <1 km) granite porphyries consisting of the Carico Lake pluton and slightly older, altered intrusions that are exposed over >50 km2. Ten sanidine 40Ar/39Ar ages from the stratigraphically lowest Caetano Tuff through the youngest shallow pluton are indistinguishable at 33.8 Ma, indicating that eruption of >1000 km3 of rhyolite tuff, caldera collapse, magma resurgence, and pluton emplacement occurred in <0.1 Ma. The compositionally zoned, crystal-rich Caetano Tuff (~40 vol % phenocrysts) and Carico Lake pluton (60% phenocrysts) contain quartz, sanidine, plagioclase, biotite, Fe-Ti oxide ± hornblende. Allanite, apatite, and zircon are common accessories; sphene is absent. The lower ~3000 m of the lower Caetano Tuff is a monotonous high-silica rhyolite (76-77% SiO2) with relatively flat chondrite- normalized REE patterns (La/Lun~5) and a pronounced negative Eu anomaly. The uppermost ~500 m of the lower Caetano Tuff, upper Caetano Tuff, and Carico Lake pluton all have lower SiO2 (71-75%) and steep REE patterns (La/Lun~30), are enriched in LREE, Ba, Sr, and Zr, lack Eu anomalies, and are depleted in HREE relative to the bulk of the lower Caetano Tuff. These distinct chemical trends suggest two different magma batches were tapped during ignimbrite eruption and that the Carico Lake pluton represents residual magma from the reservoir that fed the later parts of the eruption. Field, geochemical, and geochronologic data prove a shallow batholith-scale magma reservoir

  5. Exploring the Benefits of KM Education for LIS Professionals

    ERIC Educational Resources Information Center

    Hazeri, Afsaneh; Martin, Bill; Sarrafzadeh, Maryam

    2009-01-01

    It is to be expected that in a new and emerging discipline like knowledge management (KM) there still will be ambivalence among both LIS educational institutions and their students, as to the need to have KM courses. Investigating the benefits of engaging with these programs might help to clear up this ambiguity. The present paper seeks to shed…

  6. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together....

  7. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together. (See...

  8. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together. (See...

  9. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together. (See...

  10. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together. (See...

  11. Probability density functions for radial anisotropy: implications for the upper 1200 km of the mantle

    NASA Astrophysics Data System (ADS)

    Beghein, Caroline; Trampert, Jeannot

    2004-01-01

    The presence of radial anisotropy in the upper mantle, transition zone and top of the lower mantle is investigated by applying a model space search technique to Rayleigh and Love wave phase velocity models. Probability density functions are obtained independently for S-wave anisotropy, P-wave anisotropy, intermediate parameter η, Vp, Vs and density anomalies. The likelihoods for P-wave and S-wave anisotropy beneath continents cannot be explained by a dry olivine-rich upper mantle at depths larger than 220 km. Indeed, while shear-wave anisotropy tends to disappear below 220 km depth in continental areas, P-wave anisotropy is still present but its sign changes compared to the uppermost mantle. This could be due to an increase with depth of the amount of pyroxene relative to olivine in these regions, although the presence of water, partial melt or a change in the deformation mechanism cannot be ruled out as yet. A similar observation is made for old oceans, but not for young ones where VSH> VSV appears likely down to 670 km depth and VPH> VPV down to 400 km depth. The change of sign in P-wave anisotropy seems to be qualitatively correlated with the presence of the Lehmann discontinuity, generally observed beneath continents and some oceans but not beneath ridges. Parameter η shows a similar age-related depth pattern as shear-wave anisotropy in the uppermost mantle and it undergoes the same change of sign as P-wave anisotropy at 220 km depth. The ratio between dln Vs and dln Vp suggests that a chemical component is needed to explain the anomalies in most places at depths greater than 220 km. More tests are needed to infer the robustness of the results for density, but they do not affect the results for anisotropy.

  12. Exploring KM Features of High-Performance Companies

    NASA Astrophysics Data System (ADS)

    Wu, Wei-Wen

    2007-12-01

    For reacting to an increasingly rival business environment, many companies emphasize the importance of knowledge management (KM). It is a favorable way to explore and learn KM features of high-performance companies. However, finding out the critical KM features of high-performance companies is a qualitative analysis problem. To handle this kind of problem, the rough set approach is suitable because it is based on data-mining techniques to discover knowledge without rigorous statistical assumptions. Thus, this paper explored KM features of high-performance companies by using the rough set approach. The results show that high-performance companies stress the importance on both tacit and explicit knowledge, and consider that incentives and evaluations are the essentials to implementing KM.

  13. Seismicity Of The Charlie-Gibbs Fracture Zone

    NASA Astrophysics Data System (ADS)

    Novitsky, C. G.; Páll, E.

    2014-12-01

    Due to the low seismicity of the Charlie-Gibbs Fracture Zone it has not been possible to examine in the past. Now there is over 50 years of seismic data to reexamine the fracture zone and past-hypothesized relationships, such as an inactive southern trough of the fracture zone. The results indicate the southern trough of the fracture zone still appears to be inactive and the fracture zone has reached a full seismic time cycle. It is postulated that the southern troughs inactive behavior is from a low velocity, low viscosity zone from unusually thin crust (3.0-4.5 km).

  14. Marshall Space Flight Center Propulsion Systems Department (PSD) KM Initiative

    NASA Technical Reports Server (NTRS)

    Caraccioli, Paul; Varnadoe, Tom; McCarter, Mike

    2006-01-01

    NASA Marshall Space Flight Center s Propulsion Systems Department (PSD) is four months into a fifteen month Knowledge Management (KM) initiative to support enhanced engineering decision making and analyses, faster resolution of anomalies (near-term) and effective, efficient knowledge infused engineering processes, reduced knowledge attrition, and reduced anomaly occurrences (long-term). The near-term objective of this initiative is developing a KM Pilot project, within the context of a 3-5 year KM strategy, to introduce and evaluate the use of KM within PSD. An internal NASA/MSFC PSD KM team was established early in project formulation to maintain a practitioner, user-centric focus throughout the conceptual development, planning and deployment of KM technologies and capabilities with in the PSD. The PSD internal team is supported by the University of Alabama's Aging Infrastructure Systems Center Of Excellence (AISCE), Intergraph Corporation, and The Knowledge Institute. The principle product of the initial four month effort has been strategic planning of PSD KM implementation by first determining the "as is" state of KM capabilities and developing, planning and documenting the roadmap to achieve the desired "to be" state. Activities undertaken to support the planning phase have included data gathering; cultural surveys, group work-sessions, interviews, documentation review, and independent research. Assessments and analyses have been performed including industry benchmarking, related local and Agency initiatives, specific tools and techniques used and strategies for leveraging existing resources, people and technology to achieve common KM goals. Key findings captured in the PSD KM Strategic Plan include the system vision, purpose, stakeholders, prioritized strategic objectives mapped to the top ten practitioner needs and analysis of current resource usage. Opportunities identified from research, analyses, cultural/KM surveys and practitioner interviews include

  15. Marshall Space Flight Center Propulsion Systems Department (PSD) KM Initiative

    NASA Technical Reports Server (NTRS)

    Caraccioli, Paul; Varnadoe, Tom; McCarter, Mike

    2006-01-01

    NASA Marshall Space Flight Center s Propulsion Systems Department (PSD) is four months into a fifteen month Knowledge Management (KM) initiative to support enhanced engineering decision making and analyses, faster resolution of anomalies (near-term) and effective, efficient knowledge infused engineering processes, reduced knowledge attrition, and reduced anomaly occurrences (long-term). The near-term objective of this initiative is developing a KM Pilot project, within the context of a 3-5 year KM strategy, to introduce and evaluate the use of KM within PSD. An internal NASA/MSFC PSD KM team was established early in project formulation to maintain a practitioner, user-centric focus throughout the conceptual development, planning and deployment of KM technologies and capabilities with in the PSD. The PSD internal team is supported by the University of Alabama's Aging Infrastructure Systems Center Of Excellence (AISCE), Intergraph Corporation, and The Knowledge Institute. The principle product of the initial four month effort has been strategic planning of PSD KM implementation by first determining the "as is" state of KM capabilities and developing, planning and documenting the roadmap to achieve the desired "to be" state. Activities undertaken to support the planning phase have included data gathering; cultural surveys, group work-sessions, interviews, documentation review, and independent research. Assessments and analyses have been performed including industry benchmarking, related local and Agency initiatives, specific tools and techniques used and strategies for leveraging existing resources, people and technology to achieve common KM goals. Key findings captured in the PSD KM Strategic Plan include the system vision, purpose, stakeholders, prioritized strategic objectives mapped to the top ten practitioner needs and analysis of current resource usage. Opportunities identified from research, analyses, cultural/KM surveys and practitioner interviews include

  16. Compositional mantle layering revealed by slab stagnation at ~1,000 km depth

    NASA Astrophysics Data System (ADS)

    Ballmer, M. D.; Nakagawa, T.; Schmerr, N. C.; Ritsema, J.; Motoki, M.

    2015-12-01

    Improved constraints on lower-mantle composition are fundamental to understand the accretion, differentiation and thermochemical evolution of our planet. Whereas cosmochemical arguments indicate that lower-mantle rocks may be enriched in Si relative to upper-mantle pyrolite, seismic tomography images suggest whole-mantle convection and efficient mantle mixing. This study reconciles cosmochemical and geophysical constraints using the stagnation of some slab segments at ~1,000 km depth as the key observation. Whereas slab stagnation at ~660 km depth is well explained by the effects of the spinel-perovskite endothermic phase transition, flattening of slabs in the uppermost lower mantle remains poorly understood. Through numerical modeling of subduction, we show that enrichment of the lower mantle in intrinsically dense basaltic heterogeneity can render slabs neutrally buoyant at ~1,000 km depth. Slab stagnation (at ~660 and ~1,000 km depth) as well as unimpeded slab sinking to great depths can only coexist as three different modes of slab sinking behavior on Earth if the basalt fraction is ~8% higher in the lower than in the upper mantle, equivalent to a lower-mantle Mg/Si of ~1.18. Geodynamic models demonstrate that such a moderate compositional gradient can be sustained by compositional filtering of both slabs and plumes as they cross the transition zone, and thus persist over billions of years of whole-mantle convection. Whereas basaltic heterogeneity tends to get trapped in the transition zone and ultimately sink into the lower mantle, harzburgitic heterogeneity tends to rise into the uppermost mantle.

  17. Seismic evidence of negligible water carried below 400-km depth in subducting lithosphere.

    PubMed

    Green, Harry W; Chen, Wang-Ping; Brudzinski, Michael R

    2010-10-14

    Strong evidence exists that water is carried from the surface into the upper mantle by hydrous minerals in the uppermost 10-12 km of subducting lithosphere, and more water may be added as the lithosphere bends and goes downwards. Significant amounts of that water are released as the lithosphere heats up, triggering earthquakes and fluxing arc volcanism. In addition, there is experimental evidence for high solubility of water in olivine, the most abundant mineral in the upper mantle, for even higher solubility in olivine's high-pressure polymorphs, wadsleyite and ringwoodite, and for the existence of dense hydrous magnesium silicates that potentially could carry water well into the lower mantle (deeper than 1,000 km). Here we compare experimental and seismic evidence to test whether patterns of seismicity and the stabilities of these potentially relevant hydrous phases are consistent with a wet lithosphere. We show that there is nearly a one-to-one correlation between dehydration of minerals and seismicity at depths less than about 250 km, and conclude that the dehydration of minerals is the trigger of instability that leads to seismicity. At greater depths, however, we find no correlation between occurrences of earthquakes and depths where breakdown of hydrous phases is expected. Lastly, we note that there is compelling evidence for the existence of metastable olivine (which, if present, can explain the distribution of deep-focus earthquakes) west of and within the subducting Tonga slab and also in three other subduction zones, despite metastable olivine being incompatible with even extremely small amounts of water (of the order of 100 p.p.m. by weight). We conclude that subducting slabs are essentially dry at depths below 400 km and thus do not provide a pathway for significant amounts of water to enter the mantle transition zone or the lower mantle.

  18. A double Benioff zone beneath the central Aleutians - An unbending of the lithosphere

    NASA Technical Reports Server (NTRS)

    Engdahl, E. R.; Scholz, C. H.

    1977-01-01

    Seismicity located using the Adak seismograph network shows the Benioff zone below a depth of 100 km consists of two thin zones of earthquakes about 25 km apart that merge at a depth of 175 km. Focal mechanisms in the upper zone are consistently down-dip compression, while those of the lower zone are down-dip tension. An elastic-plastic model of the lithosphere predicts that these two zones reflect the stresses in the elastic core of the lithosphere due to unbending.

  19. Physiological intensity profile, exercise load and performance predictors of a 65-km mountain ultra-marathon.

    PubMed

    Fornasiero, Alessandro; Savoldelli, Aldo; Fruet, Damiano; Boccia, Gennaro; Pellegrini, Barbara; Schena, Federico

    2017-09-04

    The aims of the study were to describe the physiological profile of a 65-km (4000-m cumulative elevation gain) running mountain ultra-marathon (MUM) and to identify predictors of MUM performance. Twenty-three amateur trail-runners performed anthropometric evaluations and an uphill graded exercise test (GXT) for VO2max, ventilatory thresholds (VTs), power outputs (PMax, PVTs) and heart rate response (HRmax, HR@VTs). Heart rate (HR) was monitored during the race and intensity was expressed as: Zone I (Zone II (VT1-VT2), Zone III (>VT2) for exercise load calculation (training impulse, TRIMP). Mean race intensity was 77.1%±4.4% of HRmax distributed as: 85.7%±19.4% Zone I, 13.9%±18.6% Zone II, 0.4%±0.9% Zone III. Exercise load was 766±110 TRIMP units. Race time (11.8±1.6h) was negatively correlated with VO2max (r = -0.66, P <0.001) and PMax (r = -0.73, P <0.001), resulting these variables determinant in predicting MUM performance, whereas exercise thresholds did not improve performance prediction. Laboratory variables explained only 59% of race time variance, underlining the multi-factorial character of MUM performance. Our results support the idea that VT1 represents a boundary of tolerable intensity in this kind of events, where exercise load is extremely high. This information can be helpful in identifying optimal pacing strategies to complete such extremely demanding MUMs.

  20. Periodic variations in stratospheric meridional wind from 20-65 km, at 80 deg N to 8 deg S

    NASA Technical Reports Server (NTRS)

    Nastrom, G. D.; Belmont, A. D.; Dartt, D. G.

    1974-01-01

    The variability of stratospheric meridional winds is examined in both space and time. Height-latitude sections for January along 70 deg E and 90 deg W show a divergence zone above 50 km near 60 deg N and an intense convergence zone 40 km near 50 deg N over North America. This latter structure, with southward winds in the Arctic and northward winds at mid-latitudes over North America, persists from October through April. Tidal winds dominate all other circulation features in summer at all latitudes, and throughout the year at low latitudes. To help understand the observed patterns of variability, long-term periodic features are analyzed. The quasi-biennial oscillation, annual wave, and four-month wave have amplitudes of about 10, 20, and 10 m/sec respectively in the Arctic near 45 km. The phase of the annual wave changes by nearly 180 deg in a narrow zone near 45 deg N. The semiannual wave has an amplitude of 10 m/sec. 50 deg N above 50 km equinoctial phase dates in the region of maximum amplitude. This polar semiannual wave corresponds closely to that previously found in the zonal wind.

  1. Upper Mantle Structure and the 660-km Discontinuity beneath Japan Sea and its adjacent Areas Determined from Waveform Triplication data

    NASA Astrophysics Data System (ADS)

    Cai, C.; Ning, J.; Niu, F.; Chen, Y. J.; Grand, S. P.; Kawakatsu, H.; Tanaka, S.; Necessarray Project Team

    2011-12-01

    We applied a forward waveform modeling method to determine upper mantle structure mainly in the transition zone beneath Japan Sea area. A propagation matrix method proposed by Wang (1999) was used to compute synthetic seismograms. According to the analysis of the difference between the synthetic results and real observations, we adjusted the one-dimensional (1-D) velocity model and found the best fitting one at last. Concretely speaking, the time interval between arrivals that turns near the top and the bottom of the transition zone could constrain the velocity gradient in the transition zone. Relative timing and amplitudes between arrivals turning just above and below a discontinuity constrain both the contrast and the depth of the discontinuity. The data we used in this work are mainly from the NorthEast China Extended SeiSmic Array (NECESSArray) in northeast China. NECESSArray is a large deployment of 120 broadband seismographs from September 2009 to August 2011 operated by an international collaboration of China, United States and Japan. It is designed to study the behavior of the Pacific subducting slab in the mantle transition zone, the cause of intraplate continental magmatism and tectonics in Northeast China, as well as the evolution of ancient Archean lithosphere. Preliminary result shows that the best fitting velocity model is rather close to the global average model IASP91 (Kennett and Engdahl, 1991). The depth of the 660-km discontinuity and the structure below it are the same with IASP91. The velocity gradient from 520 km to 660 km is slightly larger and makes the velocity jump at 660-km discontinuity 0.1043 km/s smaller. This result may come from the special ray paths and the subduction geometry. At the time of the AGU fall meeting, we will show the detailed images and discuss their correlation with other observations.

  2. Akeno 20 km (2) air shower array (Akeno Branch)

    NASA Technical Reports Server (NTRS)

    Teshima, M.; Ohoka, H.; Matsubara, Y.; Hara, T.; Hatano, Y.; Hayashida, N.; He, C. X.; Honda, M.; Ishikawa, F.; Kamata, K.

    1985-01-01

    As the first stage of the future huge array, the Akeno air shower array was expanded to about 20 sq. km. by adding 19 scintillation detectors of 2.25 sq m area outside the present 1 sq. km. Akeno array with a new data collection system. These detectors are spaced about 1km from each other and connected by two optical fiber cables. This array has been in partial operation from 8th, Sep. 1984 and full operation from 20th, Dec. 1984. 20 sq m muon stations are planned to be set with 2km separation and one of them is now under construction. The origin of the highest energy cosmic rays is studied.

  3. The KM3NeT project: status and perspectives

    NASA Astrophysics Data System (ADS)

    Margiotta, A.

    2013-01-01

    KM3NeT is an international consortium involving more than 300 scientists from 10 EU countries. Its main objective is the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea that will also host an interdisciplinary observatory for marine sciences. KM3NeT has been included in the roadmap of the European Strategy Forum of Research Infrastructures (ESFRI). Very high energy neutrinos are important messengers to study non-thermal phenomena in the Universe. The pioneering ANTARES, NEMO and NESTOR underwater neutrino telescope projects include the extensive R&D knowledge base behind the KM3NeT project. A Technical Design Report has been published that describes the technological solutions chosen for the detector. The present status of the project is presented.

  4. High energy neutrino detection with KM3NeT

    NASA Astrophysics Data System (ADS)

    Migliozzi, Pasquale; KM3NeT Collaboration

    2016-05-01

    The KM3NeT Collaboration has started the construction of a next generation high-energy neutrino telescope in the Mediterranean Sea: the largest and most sensitive neutrino research infrastructure. The full KM3NeT detector will be a several cubic kilometres distributed, networked infrastructure. In Italy, off the coast of Capo Passero, and in France, off the coast of Toulon. Thanks to its location in the Northern hemisphere and to its large instrumented volume, KM3NeT will be the optimal instrument to search for neutrinos from the Southern sky and in particular from the Galactic plane, thus making it complementary to IceCube. In this work the technologically innovative component of the detector, the status of construction and the first results from prototypes of the KM3NeT detector will be described as well as its capability to discover neutrino sources are reported.

  5. How does music aid 5 km of running?

    PubMed

    Bigliassi, Marcelo; León-Domínguez, Umberto; Buzzachera, Cosme F; Barreto-Silva, Vinícius; Altimari, Leandro R

    2015-02-01

    This research investigated the effects of music and its time of application on a 5-km run. Fifteen well-trained male long-distance runners (24.87 ± 2.47 years; 78.87 ± 10.57 kg; 178 ± 07 cm) participated in this study. Five randomized experimental conditions during a 5-km run on an official track were tested (PM: motivational songs, applied before 5 km of running; SM: slow motivational songs, applied during 5 km of running; FM: fast and motivational songs, applied during 5 km of running; CS: calm songs, applied after 5 km of running; CO: control condition). Psychophysiological assessments were performed before (functional near-infrared spectroscopy, heart rate variability [HRV], valence, and arousal), during (performance time, heart rate, and rate of perceived exertion [RPE]), and after (mood, RPE, and HRV) tests. The chosen songs were considered pleasurable and capable of activating. Furthermore, they activated the 3 assessed prefrontal cortex (PFC) areas (medial, right dorsolateral, and left dorsolateral) similarly, generating positive emotional consequences by autonomous system analysis. The first 800 m was accomplished faster for SM and FM compared with other conditions (p ≤ 0.05); moreover, there was a high probability of improving running performance when music was applied (SM: 89%; FM: 85%; PM: 39%). Finally, music was capable of accelerating vagal tonus after 5 km of running with CS (p ≤ 0.05). In conclusion, music was able to activate the PFC area, minimize perceptions, improve performance, and accelerate recovery during 5 km of running.

  6. Status of the KM3NeT project

    NASA Astrophysics Data System (ADS)

    Margiotta, A.

    2014-04-01

    KM3NeT is a deep-sea research infrastructure being constructed in the Mediterranean Sea. It will be installed at three sites: KM3NeT-Fr, offshore Toulon, France, KM3NeT-It, offshore Portopalo di Capo Passero, Sicily (Italy) and KM3NeT-Gr, offshore Pylos, Peloponnese, Greece. It will host the next generation Cherenkov neutrino telescope and nodes for a deep sea multidisciplinary observatory, providing oceanographers, marine biologists, and geophysicists with real time measurements. The neutrino telescope will search for Galactic and extra-Galactic sources of neutrinos, complementing IceCube in its field of view. The detector will have a modular structure and consists of six building blocks, each including about one hundred Detection Units (DUs). Each DU will be equipped with 18 multi-PMT digital optical modules. The first phase of construction has started and shore and deep-sea infrastructures hosting the future KM3NeT detector are being prepared in France near Toulon and in Italy, near Capo Passero in Sicily. The technological solutions for KM3NeT and the expected performance of the detector are presented and discussed.

  7. (137)Cs trapped by biomass within 20 km of the Fukushima Daiichi Nuclear Power Plant.

    PubMed

    Koizumi, Akio; Niisoe, Tamon; Harada, Kouji H; Fujii, Yukiko; Adachi, Ayumu; Hitomi, Toshiaki; Ishikawa, Hirohiko

    2013-09-03

    Analysis of (137)Cs trapped in biomass in highly contaminated zones is crucial in predicting the long-term fate of (137)Cs following the explosion at the Fukushima Daiichi Nuclear Power Plant. We surveyed forest 20-50 km from the plant in July and September 2011 to evaluate (137)Cs trapped in biomass within 20 km of the plant. We determined the ambient dose rate and collected forest soils and twigs at 150 sampling points. Removability from the canopy was evaluated by washing leaves and branches with water and organic solvents. The biomass of the forest canopy was then calculated. (137)Cs fallout was simulated with an atmospheric transport model. The modeled dose rate agreed with observations (n = 24) (r = 0.62; p < 0.01). Washing experiments demonstrated that unremovable portions accounted for 53.9 ± 6.4% of (137)Cs trapped by deciduous canopy (n = 4) and 59.3 ± 13.8% of (137)Cs trapped by evergreen canopy (n = 10). In total, it was estimated that 74.5 × 10(12) Bq was trapped by canopy in the forest within the no-go zone, with 44.2 × 10(12) Bq allocated to unremovable portions, and that 0.86% of the total release was trapped in biomass as of September 2011.

  8. Chaotic Zones around Rotating Small Bodies

    NASA Astrophysics Data System (ADS)

    Lages, José; Shepelyansky, Dima L.; Shevchenko, Ivan I.

    2017-06-01

    Small bodies of the solar system, like asteroids, trans-Neptunian objects, cometary nuclei, and planetary satellites, with diameters smaller than 1000 km usually have irregular shapes, often resembling dumb-bells or contact binaries. The spinning of such a gravitating dumb-bell creates around it a zone of chaotic orbits. We determine its extent analytically and numerically. We find that the chaotic zone swells significantly if the rotation rate is decreased; in particular, the zone swells more than twice if the rotation rate is decreased 10 times with respect to the “centrifugal breakup” threshold. We illustrate the properties of the chaotic orbital zones in examples of the global orbital dynamics about asteroid 243 Ida (which has a moon, Dactyl, orbiting near the edge of the chaotic zone) and asteroid 25143 Itokawa.

  9. The thermal influence of the subducting slab beneath South America from 410 and 660 km discontinuity observations

    NASA Astrophysics Data System (ADS)

    Collier, J. D.; Helffrich, G. R.

    2001-11-01

    Regional seismic network data from deep South American earthquakes to western United States and western European seismic arrays is slant stacked to detect weak near-source interactions with upper mantle discontinuities. These observations are complemented by an analysis of earlier work by Sacks & Snoke (1977) who observed S to P conversions from deep events to stations in South America, and similar observations from 1994-95 events using the BANJO and SEDA networks. Observations of the depth of the 410km discontinuity are made beneath central South America in the vicinity of the aseismic region of the subducting Nazca Plate. These results image the 410km discontinuity over a lateral extent of up to 850km perpendicular to the slab and over a distance of 2700km along the length of the slab. Away from the subducting slab the discontinuity is mainly seen near its global average depth, whilst inside the slab there is evidence for its elevation by up to around 60km but with significant scatter in the data. These results are consistent with the presence of a continuous slab through the aseismic region with a thermal anomaly of 900°C at 350km depth. This value is in good agreement with simple thermal models though our data are too sparse to accurately constrain them. Sparse observations of the 660km discontinuity agree with tomographic models suggesting penetration of the lower mantle by the slab in the north but stagnation at the base of the transition zone in the south. The geographical distribution of the data, however, does not allow us to rule out the possibility of slab stagnation at the base of the transition zone in the north. These observations, together with the presence of deep earthquakes, require more complicated thermal models than previously used to explain them, possibly including changes in slab dip and age with depth.

  10. Seismic evidence for a wide-spread low velocity layer atop the 410-km discontinuity

    NASA Astrophysics Data System (ADS)

    Tauzin, B.; Debayle, E.; Wittlinger, G.

    2009-12-01

    The origin of a low seismic-velocity layer observed in a few regions in the world atop the upper boundary of the mantle transition zone (the 410-km seismic discontinuity) is debated. It has been attributed to the dehydration of subductions, the dehydration of water-bearing silicate beneath continental platforms in the vicinity of mantle plumes, or to dehydration-induced partial melting of ascending ambient mantle rising out of a high-water-solubility transition zone. These interpretations suggest the effect of water which reduces the solidus of mantle silicate rocks and favors partial melting. We present global multiple frequency observations of P-to-S receiver functions indicating that this low velocity layer is actually a wide-spread feature of the upper mantle. Its location is uncorrelated with any tectonic or geodynamic environment. The estimated layer thickness varies over short lateral wavelengths (~200 km) in a range 30 to 100 km. This complexity suggests a compositional origin with a lens-type lateral extension. Dehydration in the vicinity of subductions or mantle plumes cannot solely explain the observed layer implantation. (A) Synthetic receiver functions (RFs) obtained at four lower corner periods for different thicknesses of a low velocity layer (LVL) atop the "410". Steep downward increases of seismic velocities (e.g. the "410") show up as positive (white) amplitudes on the RFs. Steep downward velocity decreases (e.g. the top of the LVL) show up as negative (black) amplitudes. (B) Multiple-frequency RFs obtained at 42 seismic stations after alignment on the "410" waveform. The "410" waveform has a positive amplitude and is colored in white. Under these stations, the top of a LVL is visible. It shows up as a negative (black) amplitude and is emphasized with the small white crosses. The RFs have been ordered by increasing LVL thickness. (C) Synthetic RFs computed using the same LVL thickness distribution as observed on the data.

  11. Gravity Waves Near 300 km Over the Polar Caps

    NASA Technical Reports Server (NTRS)

    Johnson, F. S.; Hanson, W. B.; Hodges, R. R.; Coley, W. R.; Carignan, G. R.; Spencer, N. W.

    1995-01-01

    Distinctive wave forms in the distributions of vertical velocity and temperature of both neutral particles and ions are frequently observed from Dynamics Explorer 2 at altitudes above 250 km over the polar caps. These are interpreted as being due to internal gravity waves propagating in the neutral atmosphere. The disturbances characterized by vertical velocity perturbations of the order of 100 m/s and horizontal wave lengths along the satellite path of about 500 km. They often extend across the entire polar cap. The associated temperature perturbations indicate that the horizontal phase progression is from the nightside to the dayside. Vertical displacements are inferred to be of the order of 10 km and the periods to be of the order of 10(exp 3) s. The waves must propagate in the neutral atmosphere, but they usually are most clearly recognizable in the observations of ion vertical velocity and ion temperature. By combining the neutral pressure calculated from the observed neutral concentration and temperature with the vertical component of the neutral velocity, an upward energy flux of the order of 0.04 erg/sq cm-s at 250 km has been calculated, which is about equal to the maximum total solar ultraviolet heat input above that altitude. Upward energy fluxes calculated from observations on orbital passes at altitudes from 250 to 560 km indicate relatively little attenuation with altitude.

  12. The KM3NeT Digital Optical Module

    NASA Astrophysics Data System (ADS)

    Vivolo, Daniele

    2016-04-01

    KM3NeT is a European deep-sea multidisciplinary research infrastructure in the Mediterranean Sea. It will host a km3-scale neutrino telescope and dedicated instruments for long-term and continuous measurements for Earth and Sea sciences. The KM3NeT neutrino telescope is a 3-dimensional array of Digital Optical Modules, suspended in the sea by means of vertical string structures, called Detection Units, supported by two pre-stretched Dyneema ropes, anchored to the seabed and kept taut with a system of buoys. The Digital Optical Module represents the active part of the neutrino telescope. It is composed by a 17-inch, 14 mm thick borosilicate glass (Vitrovex) spheric vessel housing 31 photomultiplier tubes with 3-inch photocathode diameter and the associated front-end and readout electronics. The technical solution adopted for the KM3NeT optical modules is characterized by an innovative design, considering that existing neutrino telescopes, Baikal, IceCube and ANTARES, all use large photomultipliers, typically with a diameter of 8″ or 10″. It offers several advantages: higher sensitive surface (1260 cm2), weaker sensitivity to Earth's magnetic field, better distinction between single-photon and multi-photon events (photon counting) and directional information with an almost isotropic field of view. In this contribution the design and the performance of the KM3NeT Digital Optical Modules are discussed, with a particular focus on enabling technologies and integration procedure.

  13. Infrasound from the Explosion Sources in the 1-200 km at UTTR

    NASA Astrophysics Data System (ADS)

    Kim, T. S.; Stump, B. W.; Kang, I. B.; Hayward, C.

    2009-04-01

    The propagation of infrasound in the standard atmospheric model is not predicted at the distances less than 250 km, which is called "zone of silence" (Mckenna, 2005). In empirical studies, however, infrasound signals can be recorded in this "shadow zone" (Reed, 1969; Che et al., 2002; Pinsky et al. 2006; Evers et al., 2007) even though the physics of infrasound propagation at this distance range is not well known due to limitations restricted by the quality of ground truth, station distribution and the lack of atmospheric profile. The experiment in Utah performed in August, 2007 had high quality ground truths (G0) from four rocket motors and a dense deployment of infrasound gauges including six arrays and thirteen single stations at distances from 100 meters over 210 kilometers. The atmospheric profile from the surface to about 25 km at the maximum height gave us an opportunity to access the variations of local atmospheric condition and model the infrasound propagation. To understand the characteristics of propagation path effect on the travel time and waveform of infrasound signals, systematic analysis on group and phase velocities, amplitude variation and atmospheric profile was performed. Based on the analysis, the infrasonic arrivals were classified into two groups: The arrivals at the distance less than 100 km (local arrivals) and those between 150 and 210 km (regional arrivals). The estimates of group velocity at local distances are around 350 m/s while those of regional distances vary from 280 to 300 m/s. The mean phase velocity at local distance range is 359 ± 9.8 m/s which is near to the speed of sound at the surface while that of regional distance is 386 ± 7.6 m/s, which can be expected from the turning rays from the stratosphere or thermosphere. The Utah observations also demonstrate that infrasound amplitude does not decay at local distances around 50 km. The PE modeling explains partially that observed acoustic arrivals and focusing of amplitude at

  14. Reliability of 5-km Running Performance in a Competitive Environment

    ERIC Educational Resources Information Center

    Hurst, Philip; Board, Lisa

    2017-01-01

    The aim of this study was to examine the reliability of a 5-km time-trial during a competitive outdoor running event. Fifteen endurance runners (age = 29.5 ± 4.3 years, height = 1.75 ± 0.08 m, body mass = 71.0 ± 7.1 kg, 5-km lifetime personal best = 19:13 ± 1:13 minutes) completed two competitive 5-km time-trials over 2 weeks. No systematic…

  15. Reliability of 5-km Running Performance in a Competitive Environment

    ERIC Educational Resources Information Center

    Hurst, Philip; Board, Lisa

    2017-01-01

    The aim of this study was to examine the reliability of a 5-km time-trial during a competitive outdoor running event. Fifteen endurance runners (age = 29.5 ± 4.3 years, height = 1.75 ± 0.08 m, body mass = 71.0 ± 7.1 kg, 5-km lifetime personal best = 19:13 ± 1:13 minutes) completed two competitive 5-km time-trials over 2 weeks. No systematic…

  16. Development of km23-Based Diagnostics and Therapeutics

    DTIC Science & Technology

    2005-05-01

    M., Cancer Res, 2005; 65(15):6526-33). Using laser-capture microdissection (LCM) and nested reverse-transcription polymerase chain reaction (RT- PCR ... PCR assays were done using recombinant Pfu lexon.-km23 mutant, a schematic of the human kn23 sequence polymerase with 3’ to 5’ exonuclease activity...novel tumor suppressor for ovarian cancer. This protein, termed km23, is also a light chain of the motor protein dynein. As a dynein light chain (DLC

  17. Simulation of CO2 release at 800 km altitude

    NASA Astrophysics Data System (ADS)

    Setayesh, A.

    1993-08-01

    The SOCRATES contamination-interaction code has been used to simulate the reactions of 0 + CO2 yields CO2(v) + O, O + CO2 - CO(v) + O2, and CO2 + H - CO + OH(v) at an altitude of 800 km in both ram and wake directions of the spacecraft. These simulations show that the radiation from these reactions can be measurable for the parameters which have been used in these calculations. The investigation carries out the simulations as much as 30 km from the spacecraft. The radiative intensity of CO(v) and OH(v) show the highest and lowest, respectively.

  18. Digital optical module electronics of KM3NeT

    NASA Astrophysics Data System (ADS)

    Real, D.; Calvo, D.

    2016-11-01

    The KM3NeT neutrino telescope is being built on the Mediterranean sea and, once completed, it will be composed by tens of thousands of glass spheres (nodes) including each 31 of small photocathode (3"). The readout and data acquisition system of KM3NeT has to collect, treat and send to shore, in an economic way, the enormous amount of data produced by the photomultipliers and at the same time to provide time synchronization between each node at the level of 1 ns. It is described in the present article all the electronics developed for achieving this goal.

  19. Cascade sensitivity studies for KM3NeT

    NASA Astrophysics Data System (ADS)

    Fusco, Luigi Antonio

    2016-07-01

    KM3NeT is a future research infrastructure in the deep seas of the Mediterranean housing a large scale neutrino telescope. The first phase of construction of the telescope has started. Next step is an intermediate phase realising a detector volume of about one-third of the final detector volume. We report on calculations of the sensitivity of the KM3NeT detector to showering neutrino events, the strategy to optimise the detector to a cosmic neutrino flux analogous to the one reported by the IceCube Collaboration and the results of this strategy applied to the intermediate phase detector.

  20. Neutral winds above 200Km at high latitudes

    NASA Technical Reports Server (NTRS)

    Meriwether, J. W.; Heppner, J. P.; Stolarik, J. D.; Wescott, E. M.

    1972-01-01

    Motion from multiple chemical releases between 200 and 300 km from 15 rockets launched from 4 high latitude locations are analyzed. The observations in the evening and midnight hours at magnetic altitudes or = 65 deg suggest that in these regions ion drag is the dominant force in driving neutral winds between 200 and 300 km. This conclusion is based on both the agreement between ion and neutral drift directions, and the fact that there are distinct changes in the wind associated with (a) the reversal in east-west ion drift at the Harang discontinuity, and (b) the transition from auroral belt, sunward ion drift and polar cap, anti-solar ion drift.

  1. Evaluation of Movement Restriction Zone Sizes in Controlling Classical Swine Fever Outbreaks

    PubMed Central

    Yadav, Shankar; Olynk Widmar, Nicole; Lay, Donald C.; Croney, Candace; Weng, Hsin-Yi

    2017-01-01

    The objective of this study was to compare the impacts of movement restriction zone sizes of 3, 5, 9, and 11 km with that of 7 km (the recommended zone size in the United States) in controlling a classical swine fever (CSF) outbreak. In addition to zone size, different compliance assumptions and outbreak types (single site and multiple site) were incorporated in the study. Three assumptions of compliance level were simulated: baseline, baseline ± 10%, and baseline ± 15%. The compliance level was held constant across all zone sizes in the baseline simulation. In the baseline ± 10% and baseline ± 15% simulations, the compliance level was increased for 3 and 5 km and decreased for 9 and 11 km from the baseline by the indicated percentages. The compliance level remained constant in all simulations for the 7-km zone size. Four single-site (i.e., with one index premises at the onset of outbreak) and four multiple-site (i.e., with more than one index premises at the onset of outbreak) CSF outbreak scenarios in Indiana were simulated incorporating various zone sizes and compliance assumptions using a stochastic between-premises disease spread model to estimate epidemic duration, percentage of infected, and preemptively culled swine premises. Furthermore, a risk assessment model that incorporated the results from the disease spread model was developed to estimate the number of swine premises under movement restrictions that would experience animal welfare outcomes of overcrowding or feed interruption during a CSF outbreak in Indiana. Compared with the 7-km zone size, the 3-km zone size resulted in a longer median epidemic duration, larger percentages of infected premises, and preemptively culled premises (P’s < 0.001) across all compliance assumptions and outbreak types. With the assumption of a higher compliance level, the 5-km zone size significantly (P < 0.001) reduced the epidemic duration and percentage of swine premises that would

  2. Evaluation of Movement Restriction Zone Sizes in Controlling Classical Swine Fever Outbreaks.

    PubMed

    Yadav, Shankar; Olynk Widmar, Nicole; Lay, Donald C; Croney, Candace; Weng, Hsin-Yi

    2016-01-01

    The objective of this study was to compare the impacts of movement restriction zone sizes of 3, 5, 9, and 11 km with that of 7 km (the recommended zone size in the United States) in controlling a classical swine fever (CSF) outbreak. In addition to zone size, different compliance assumptions and outbreak types (single site and multiple site) were incorporated in the study. Three assumptions of compliance level were simulated: baseline, baseline ± 10%, and baseline ± 15%. The compliance level was held constant across all zone sizes in the baseline simulation. In the baseline ± 10% and baseline ± 15% simulations, the compliance level was increased for 3 and 5 km and decreased for 9 and 11 km from the baseline by the indicated percentages. The compliance level remained constant in all simulations for the 7-km zone size. Four single-site (i.e., with one index premises at the onset of outbreak) and four multiple-site (i.e., with more than one index premises at the onset of outbreak) CSF outbreak scenarios in Indiana were simulated incorporating various zone sizes and compliance assumptions using a stochastic between-premises disease spread model to estimate epidemic duration, percentage of infected, and preemptively culled swine premises. Furthermore, a risk assessment model that incorporated the results from the disease spread model was developed to estimate the number of swine premises under movement restrictions that would experience animal welfare outcomes of overcrowding or feed interruption during a CSF outbreak in Indiana. Compared with the 7-km zone size, the 3-km zone size resulted in a longer median epidemic duration, larger percentages of infected premises, and preemptively culled premises (P's < 0.001) across all compliance assumptions and outbreak types. With the assumption of a higher compliance level, the 5-km zone size significantly (P < 0.001) reduced the epidemic duration and percentage of swine premises that would

  3. Paleomagnetic test of the Emperor fracture zone hypothesis

    SciTech Connect

    Gordon, R.G.

    1982-11-01

    Late Cretaceous paleomagnetic data from the Pacific plate were used to test Farrar and Dixon's (1981) hypothesis that approx.1700 km of strike-slip accumulated during the early Tertiary along the Emperor fracture zone system, and 8000 km long NW-SE trending features, which consists mainly of the Emperor trough, the Gardner seamounts, and the Line Islands. The data strongly disagree with this hypothesis; instead the data are consistent with no motion having occurred between seafloor east of the Emperor fracture zone and seafloor west of the Emperor fracture zone.

  4. Body Composition Measurements of 161-km Ultramarathon Participants

    USDA-ARS?s Scientific Manuscript database

    This study compares body composition characteristics with performance among participants in a 161-km trail ultramarathon. Height, mass, and percent body fat from bioimpedence spectroscopy were measured on 72 starters. Correlation analyses were used to compare body characteristics with finish time, ...

  5. Event identification for KM3NeT/ARCA

    NASA Astrophysics Data System (ADS)

    Heid, Thomas; KM3NeT Collaboration

    2017-09-01

    KM3NeT is a large research infrastructure consisting of a network of deep-sea neutrino telescopes. KM3NeT/ARCA will be the instrument detecting high-energy neutrinos with energies above 100 TeV. This instrument gives a new opportunity to observe the neutrino sky with very high angular resolution to be able to detect neutrino point sources. Furthermore it will be possible to probe the flavour composition of neutrino fluxes, and hence production mechanisms, with so-far unreached precision. Neutrinos produce different event topologies in the detector according to their flavour, interaction channel and deposited energy. Machine-learning algorithms are able to learn features of topologies to discriminate them. In previous analyses only two event types were regarded, namely the shower and track topology. With good timing resolution and precise reconstruction algorithms it is possible to separate into more event types, for example the double bang topology produced by tau neutrinos. The final goal is to distinguish all three neutrino flavors as much as possible. To resolve this issue the KM3NeT collaboration uses deep neural networks trained with Monte Carlo events of all neutrino types. This contribution shows the ability of KM3NeT/ARCA to classify events in more than two neutrino event topologies. Furthermore, the borders between detectable classes are shown, such as the minimum distance the tau has to travel before decaying into a tau neutrino to be detected as double bang event.

  6. Gravity wave vertical energy flux at 95 km

    NASA Astrophysics Data System (ADS)

    Jacob, P. G.; Jacka, F.

    1985-12-01

    A three-field photometer (3FP) located at Mt. Torrens near Adelaide, is capable of monitoring different airglow emissions from three spaced fields in the sky. A wheel containing up to six different narrow bandpass interference filters can be rotated, allowing each of the filters to be sequentially placed into each of the three fields. The airglow emission of interest is the 557.7 nm line which has an intensity maximum at 95 km. Each circular field of view is located at the apexes of an equilateral triangle centered on zenith with diameters of 5 km and field separations of 13 km when projected to the 95-km level. The sampling period was 30 seconds and typical data lengths were between 7 and 8 hours. The analysis and results from the interaction of gravity waves on the 557.7 nm emission layer are derived using an atmospheric model similar to that proposed by Hines (1960) where the atmosphere is assumed isothermal and perturbations caused by gravity waves are small and adiabatic, therefore, resulting in linearized equations of motion. In the absence of waves, the atmosphere is also considered stationary. Thirteen nights of quality data from January 1983 to October 1984, covering all seasons, are used in this analysis.

  7. Models of earth's atmosphere (90 to 2500 km)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This monograph replaces a monograph on the upper atmosphere which was a computerized version of Jacchia's model. The current model has a range from 90 to 2500 km. In addition to the computerized model, a quick-look prediction method is given that may be used to estimate the density for any time and spatial location without using a computer.

  8. Running economy during a simulated 60-km trial.

    PubMed

    Schena, Federico; Pellegrini, Barbara; Tarperi, Cantor; Calabria, Elisa; Salvagno, Gian Luca; Capelli, Carlo

    2014-07-01

    The effect of a prolonged running trial on the energy cost of running (C(r)) during a 60-km ultramarathon simulation at the pace of a 100-km competition was investigated in 13 men (40.8 ± 5.6 y, 70.7 ± 5.5 kg, 177.5 ± 4.5 cm) and 5 women (40.4 ± 2.3 y, 53.7 ± 4.4 kg, 162.4 ± 4.8 cm) who participated in a 60-km trial consisting of 3 consecutive 20-km laps. Oxygen uptake (VO(2)) at steady state was determined at constant speed before the test and at the end of each lap; stride length (SL) and frequency and contact time were measured at the same time points; serum creatine kinase (S-CPK) was measured before and at the end of the test. C(r) in J · kg(-1) · m(-1), as calculated from VO(2ss) and respiratory-exchange ratio, did not increase with distance. SL significantly decreased with distance. The net increase in S-CPK was linearly related with the percentage increase of C(r) observed during the trial. It is concluded that, in spite of increased S-CPK, this effort was not able to elicit any peripheral or central fatigue or biomechanical adaptation leading to any modification of C(r).

  9. Gravity wave vertical energy flux at 95 km

    NASA Technical Reports Server (NTRS)

    Jacob, P. G.; Jacka, F.

    1985-01-01

    A three-field photometer (3FP) located at Mt. Torrens near Adelaide, is capable of monitoring different airglow emissions from three spaced fields in the sky. A wheel containing up to six different narrow bandpass interference filters can be rotated, allowing each of the filters to be sequentially placed into each of the three fields. The airglow emission of interest is the 557.7 nm line which has an intensity maximum at 95 km. Each circular field of view is located at the apexes of an equilateral triangle centered on zenith with diameters of 5 km and field separations of 13 km when projected to the 95-km level. The sampling period was 30 seconds and typical data lengths were between 7 and 8 hours. The analysis and results from the interaction of gravity waves on the 557.7 nm emission layer are derived using an atmospheric model similar to that proposed by Hines (1960) where the atmosphere is assumed isothermal and perturbations caused by gravity waves are small and adiabatic, therefore, resulting in linearized equations of motion. In the absence of waves, the atmosphere is also considered stationary. Thirteen nights of quality data from January 1983 to October 1984, covering all seasons, are used in this analysis.

  10. Estimation of terrestrial carbon fluxes with 1km by 1km spatial-resolution using satellite- driven model

    NASA Astrophysics Data System (ADS)

    Sasai, T.; Nasahara, K.; Ito, A.; Saigusa, N.; Hirata, R.; Takagi, K.; Oikawa, T.

    2008-12-01

    Terrestrial carbon cycle is strongly affected by some local natural phenomena and human-induced activities, which bring change to the carbon exchanges via vegetation and soil microbe activities. In order to accurately understand a realistic spatial pattern in carbon exchanges including such an effect of local-scale events, we need to calculate carbon fluxes and storages with as detailed spatial resolution as possible. In response to this, we attempt to estimate terrestrial carbon fluxes with 1km by 1km spatial resolution using satellite-driven model. Study area of the model estimation is the Further East Asia region, which lies at 30-50 north latitude and 125-150 east longitude. The model is the Biosphere model integrating Eco-physiological And Mechanistic approaches using Satellite data (BEAMS) [Sasai et al., 2005, 2007]. Being aim at simulating terrestrial carbon exchanges under more realistic land surface condition, we applied as many as possible of satellite-observation products such as the standard MODIS, TRMM, and SRTM high-level land products as model inputs. In the model validation, we compared between model estimations and eddy covariance measurements at four flux sites. As a result, a correlation coefficient of the terrestrial carbon fluxes between estimations and measurements were high values, leading up that the model estimations are virtually reasonable. In model analysis, BEAMS was operated with 1km by 1km spatial resolution from 2001 to 2006. Spatial distributions in the annual mean NPP and NEP showed that high values were distributed over the hilly and plateau regions, and they were gradually decreasing towards the urban and high mountain areas, meaning that we could reflect an impact of the local-scale events in the carbon flux estimations. In future, we would extend study area to the East Asia region, and the carbon exchange map with 1km by 1km spatial- resolution is distributed on the website.

  11. Coherent optical frequency transfer over 50-km physical distance using a 120-km-long installed telecom fiber network.

    PubMed

    Musha, Mitsuru; Hong, Feng-Lei; Nakagawa, Ken'ichi; Ueda, Ken-ichi

    2008-10-13

    Optical frequency at 1542 nm was coherently transferred over a 120-km-long installed telecom fiber network between two cities (Tsukuba and Tokyo) in Japan separated by more than 50 km. The phase noise induced by the fiber length fluctuations was actively reduced by using a fiber stretcher and an acousto-optic modulator. The fractional frequency instability of the one-way transmitted light was reduced down to less than 8.0 x 10(-16) at an averaging time of 1s, which is limited by the theoretical limit deduced from the length and the intrinsic noise of the fiber.

  12. Previous experience influences pacing during 20 km time trial cycling.

    PubMed

    Micklewright, D; Papadopoulou, E; Swart, J; Noakes, T

    2010-10-01

    To investigate how experience and feedback influence pacing and performance during time trial cycling. Twenty-nine cyclists performed three 20 km cycling time trials using a Computrainer. The first two time trials (TT1 and TT2) were performed (1) without any performance feedback (n = 10), (2) with accurate performance feedback (n = 10) or (3) with false feedback showing the speed to be 5% greater than the actual speed (n = 9). All participants received full feedback during the third time trial (TT3), and their performance and pacing data were compared against TT2. Completion time, average power and average speed did not change among the false feedback group, but their pacing strategy did change as indicated by a lower average cadence, 89.2 (SD 5.2) vs 96.4 (6.8) rpm, p<0.05, and higher power during the first 5 km (SMD = 39, 36, 36, 27 and 27 W for 1-5 km respectively). Pacing changed among the blind feedback group indicated by a faster completion time, 35.9 (3.1) vs 36.8 (4.4) min, p<0.05, and power increases during the final 5 km (SMD = 14, 13, 18, 23 and 53 W for 16-20 km respectively). No performance or pacing changes were observed among the accurate feedback group. Pacing is influenced by an interaction between feedback and previous experience. Conscious cognitive processes that lead to ratings of perceived exertion and pacing appear to be influenced by previous experience.

  13. Seismogenic zone structure along the Middle America subduction zone, Costa Rica

    NASA Astrophysics Data System (ADS)

    Deshon, Heather Rene

    Most large (MW > 7.0) underthrusting earthquakes nucleate along a shallow region of unstable frictional stability on or near the subducting plate interface termed the seismogenic zone. The studies presented here investigate along-strike spatial and temporal variability in microseismicity and seismic velocity and provide spatial constraints on the updip and downdip limits of microseismicity within the Middle America subduction offshore western Costa Rica. All chapters utilize data recorded by the Costa Rica Seismogenic Zone Experiment (CRSEIZE), a collaborative seismic and geodetic study undertaken from September 1999--June 2001 to better understand subduction zone behavior near the Osa and Nicoya Peninsulas, Costa Rica. Chapter 1 serves as a broad introduction to the thesis while Chapter 2 provides an overview of Costa Rica seismicity, the CRSEIZE experiment setup, data processing, and data quality. Chapter 3 discusses simultaneous inversion for 1D P- and S-wave velocity models, station corrections, and hypocenter parameters for both the Nicoya and Osa experiments and presents a refined location for the continental Moho in northern Costa Rica. Chapter 4 presents absolute and relative relocations of ˜300 aftershocks of the 1999 Quepos, Costa Rica, underthrusting earthquake and analyzes seismogenic zone structure offshore central Costa Rica during a period of increased seismicity rate. Subduction of highly disrupted seafloor north of the Osa Peninsula has established a set of conditions that presently limit the seismogenic zone to be between 10--35 km below sea level, 30--95 km from the trench axis. Chapter 5 presents high resolution earthquake locations and P-wave and P-wave/S-wave 3D velocity models for the locked Nicoya Peninsula segment of the Middle America subduction zone calculated using an iterative, damped least squares local tomography method. In the southern Nicoya Peninsula, microseismicity along the plate interface extends from 12--26 km depth, 73

  14. Converted phases from sharp 1000 km depth mid-mantle heterogeneity beneath Western Europe

    NASA Astrophysics Data System (ADS)

    Jenkins, J.; Deuss, A.; Cottaar, S.

    2017-02-01

    Until recently, most of the lower mantle was generally considered to be well-mixed with strong heterogeneity restricted to the lowermost several hundred kilometres above the core-mantle boundary, known as the D″ layer. However several recent studies have started to hint at a potential change in Earth's structure at mid-mantle depths beneath the transition zone. Here we present a continental-wide search of Europe and the North Atlantic for mid-mantle P-to-s wave converted phases. Our data set consists of close to 50,000 high quality receiver functions. These are combined in slowness and depth stacks to identify seismic discontinuities in the range of 800-1400 km depth to determine at which depths and in which tectonic settings these features exist. Receiver functions are computed in different frequency bands to resolve the sharpness of the observed discontinuities. We find most seismic velocity jumps are observed between 975-1050 km depth, localised beneath western Europe and Iceland. The shear wave velocity jumps are roughly 1-2.5% velocity increase with depth occurring over less than 8 km in width. The most robust observations are coincident with areas of active upwelling (under Iceland) and an elongate lateral low velocity anomaly imaged in recent tomographic models which has been interpreted as diverted plume material at depth. The lack of any suggested phase change in a normal pyrolitic mantle composition at around 1000 km depth indicates the presence of regional chemical heterogeneity within the mid-mantle, potentially caused by diverted plume material. We hypothesise that our observations represent either a phase change within chemically distinct plume material itself, or are caused by small scale chemical heterogeneities entrained within the upwelling plume, either in the form of recycled basaltic material or deep sourced chemically distinct material from LLSVPs. Our observations, which cannot be directly linked to an area of either active or ancient

  15. Stabilization of a salamander moving hybrid zone.

    PubMed

    Visser, Michaël; de Leeuw, Maarten; Zuiderwijk, Annie; Arntzen, Jan W

    2017-01-01

    When related species meet upon postglacial range expansion, hybrid zones are frequently formed. Theory predicts that such zones may move over the landscape until equilibrium conditions are reached. One hybrid zone observed to be moving in historical times (1950-1979) is that of the pond-breeding salamanders Triturus cristatus and Triturus marmoratus in western France. We identified the ecological correlates of the species hybrid zone as elevation, forestation, and hedgerows favoring the more terrestrial T. marmoratus and pond density favoring the more aquatic T. cristatus. The past movement of the zone of ca. 30 km over three decades has probably been driven by the drastic postwar reduction of the "bocage" hedgerow landscape, favoring T. cristatus over T. marmoratus. No further hybrid zone movement was observed from 1979 to the present. To explain the changing dynamics of the hybrid zone, we propose that it stalled, either because an equilibrium was found at an altitude of ca. 140 m a.s.l. or due to pond loss and decreased population densities. While we cannot rule out the former explanation, we found support for the latter. Under agricultural intensification, ponds in the study area are lost at an unprecedented rate of 5.5% per year, so that remaining Triturus populations are increasingly isolated, hampering dispersal and further hybrid zone movement.

  16. Root Apex Transition Zone As Oscillatory Zone

    PubMed Central

    Baluška, František; Mancuso, Stefano

    2013-01-01

    Root apex of higher plants shows very high sensitivity to environmental stimuli. The root cap acts as the most prominent plant sensory organ; sensing diverse physical parameters such as gravity, light, humidity, oxygen, and critical inorganic nutrients. However, the motoric responses to these stimuli are accomplished in the elongation region. This spatial discrepancy was solved when we have discovered and characterized the transition zone which is interpolated between the apical meristem and the subapical elongation zone. Cells of this zone are very active in the cytoskeletal rearrangements, endocytosis and endocytic vesicle recycling, as well as in electric activities. Here we discuss the oscillatory nature of the transition zone which, together with several other features of this zone, suggest that it acts as some kind of command center. In accordance with the early proposal of Charles and Francis Darwin, cells of this root zone receive sensory information from the root cap and instruct the motoric responses of cells in the elongation zone. PMID:24106493

  17. Full 40 km crustal reflection seismic datasets in several Indonesian basins

    NASA Astrophysics Data System (ADS)

    Dinkelman, M. G.; Granath, J. W.; Christ, J. M.; Emmet, P. A.; Bird, D. E.

    2010-12-01

    Long offset, deep penetration regional 2D seismic data sets have been acquired since 2002 by GX Technology in a number of regions worldwide (www.iongeo.com/Data_Libraries/Spans/). Typical surveys consist of 10+ lines located to image specific critical aspects of basin structure. Early surveys were processed to 20 km, but more recent ones have extended to 40-45 km from 16 sec records. Pre-stack time migration is followed by pre-stack depth migration using gravity and in some cases magnetic modeling to constrain the velocity structure. We illustrate several cases in the SE Asian and Australasian area. In NatunaSPAN™ two generations of inversion can be distinguished, one involving Paleogene faults with Neogene inversion and one involving strike slip-related uplift in the West Natuna Basin. Crustal structure in the very deep Neogene East Natuna Basin has also been imaged. The JavaSPAN™ program traced Paleogene sediments onto oceanic crust of the Flores Sea, thus equating back arc spreading there to the widespread Eocene extension. It also imaged basement in the Makassar Strait beneath as much as 6 km of Cenozoic sedimentary rocks that accumulated Eocene rift basins (the North and South Makassar basins) on the edge of Sundaland, the core of SE Asia. The basement is seismically layered: a noisy upper crust overlies a prominent 10 km thick transparent zone, the base of which marks another change to slightly noisier reflectivity. Eocene normal faults responsible for the opening of extensional basins root in the top of the transparent layer which may be Moho or a brittle-ductile transition within the extended continental crust. Of particular significance is the first image of thick Precambrian basins comprising the bulk of continental crust under the Arafura Sea in the ArafuraSPAN™ program. Four lines some 1200 km long located between Australia and New Guinea on the Arafura platform image a thin Phanerozoic section overlying a striking Precambrian basement composed of

  18. Fact Sheet for KM200 Front-end Electronics

    SciTech Connect

    Ianakiev, Kiril Dimitrov; Iliev, Metodi; Swinhoe, Martyn Thomas

    2015-07-08

    The KM200 device is a versatile, configurable front-end electronics boards that can be used as a functional replacement for Canberra’s JAB-01 boards based on the Amptek A-111 hybrid chip, which continues to be the preferred choice of electronics for large number of the boards in junction boxes of multiplicity counters that process the signal from an array of 3He detectors. Unlike the A-111 chip’s fixed time constants and sensitivity range, the shaping time and sensitivity of the new KM200 can be optimized for demanding applications such as spent fuel, and thus could improve the safeguards measurements of existing systems where the A-111 or PDT electronics does not perform well.

  19. Remote (250 km) Fiber Bragg Grating Multiplexing System

    PubMed Central

    Fernandez-Vallejo, Montserrat; Rota-Rodrigo, Sergio; Lopez-Amo, Manuel

    2011-01-01

    We propose and demonstrate two ultra-long range fiber Bragg grating (FBG) sensor interrogation systems. In the first approach four FBGs are located 200 km from the monitoring station and a signal to noise ratio of 20 dB is obtained. The second improved version is able to detect the four multiplexed FBGs placed 250 km away, offering a signal to noise ratio of 6–8 dB. Consequently, this last system represents the longest range FBG sensor system reported so far that includes fiber sensor multiplexing capability. Both simple systems are based on a wavelength swept laser to scan the reflection spectra of the FBGs, and they are composed by two identical-lengths optical paths: the first one intended to launch the amplified laser signal by means of Raman amplification and the other one is employed to guide the reflection signal to the reception system. PMID:22164101

  20. FPGA shore station demonstrator for KM3NeT

    NASA Astrophysics Data System (ADS)

    Anassontzis, E. G.; Belias, A.; Koutsoukos, S.; Koutsoumpos, V.; Manolopoulos, K.; Resvanis, L. K.; KM3NeT Consortium

    2013-10-01

    The KM3NeT readout concept is based on a point-to-point optical network connecting the 10,000 optical modules in the deep-sea neutrino telescope with the shore station. The numerous fiber optic channels arriving at the shore station will be concentrated on the shore electronics systems, which will receive, merge and time order the data, and send them to the DAQ system. Although the network functionality is bi-directional, the physical channel allocation is asymmetric; most channels are assigned to the data reception and only a few channels are used for control with data transport from shore to the telescope. We will discuss the FPGA based platform systems for the shore station and the appropriate firmware implementation for the data gathering and broadcast demands of a neutrino telescope. We will present our experiences based on FPGA evaluation platforms suitable to build a demonstrator of the KM3NeT shore station.

  1. KM3NeT-ARCA project status and plan

    NASA Astrophysics Data System (ADS)

    Coniglione, R.

    2016-04-01

    The KM3NeT Collaboration aims at building a research infrastructure in the depths of the Mediterranean Sea hosting a cubic kilometre neutrino telescope. The KM3NeT/ARCA detector is the ideal instrument to look for high-energy neutrino sources thanks to the latitude of the detector and to the optical characteristics of the sea water. The detector latitude allows for a wide coverage of the observable sky including the region of the Galactic centre and the optical sea water properties allow for the measure of the neutrino direction with excellent angular resolution also for cascade events. The technologically innovative components of the detector and the status of construction will be presented as well as the capability it offers to discover neutrinos.

  2. Seismic coupling and uncoupling at subduction zones

    NASA Technical Reports Server (NTRS)

    Ruff, L.; Kanamori, H.

    1983-01-01

    Some of the correlations concerning the properties of subduction zones are reviewed. A quantitative global comparison of many subduction zones reveals that the largest earthquakes occur in zones with young lithosphere and fast convergence rates. Maximum earthquake size is directly related to the asperity distribution on the fault plane. This observation can be translated into a simple model of seismic coupling where the horizontal compressive stress between two plates is proportional to the ratio of the summed asperity area to the total area of the contact surface. Plate age and rate can control asperity distribution directly through the horizontal compressive stress associated with the vertical and horizontal velocities of subducting slabs. The basalt to eclogite phase change in the down-going oceanic crust may be largely responsible for the uncoupling of subduction zones below a depth of about 40 km.

  3. Towards a 1km resolution global flood risk model

    NASA Astrophysics Data System (ADS)

    Bates, Paul; Neal, Jeff; Sampson, Chris; Smith, Andy

    2014-05-01

    Recent advances in computationally efficient numerical algorithms and new High Performance Computing architectures now make high (1-2km) resolution global hydrodynamic models a realistic proposition. However in many areas of the world the data sets and tools necessary to undertake such modelling do not currently exist. In particular, five major problems need to be resolved: (1) the best globally available terrain data (SRTM) was generated from X-band interferometric radar data which does not penetrate vegetation canopies and which has significant problems in determining ground elevations in urban areas; (2) a global river bathymetry data set does not currently exist; (3) most river channels globally are less than the smallest currently resolvable grid scale (1km) and therefore require a sub-grid treatment; (4) a means to estimate the magnitude of the T year flood at any point along the global river network does not currently exist; and (5) a large proportion of flood losses are generated by off-floodplain surface water flows which are not well represented in current hydrodynamic modelling systems. In this paper we propose solutions to each of these five issues as part of a concerted effort to develop a 1km (or better) resolution global flood hazard model. We describe the new numerical algorithms, computer architectures and computational resources used, and demonstrate solutions to the five previously intractable problems identified above. We conduct a validation study of the modelling against satellite imagery of major flooding on the Mississippi-Missouri confluence plain in the central USA before outlining a proof-of-concept regional study for SE Asia as a step towards a global scale model. For SE Asia we simulate flood hazard for ten different flood return periods over the entire Thailand, Cambodia, Vietnam, Malaysia and Laos region at 1km resolution and show that the modelling produces coherent, consistent and sensible simulations of extent and water depth.

  4. Organizations, Paradigms, and People: The Challenge of KM Interventions

    NASA Technical Reports Server (NTRS)

    Bailey, Teresa; Burton, Yvette

    1999-01-01

    This paper presents viewgraphs on Knowledge Management (KM) and how these interventions are put into practice by organizations and society. The topics include: 1) The Multiple Paradigm Tool; 2) Four Paradigms: tool for the Analyzing Organizations; 3) Assumptions About the Nature of Social Science; 4) Assumptions About the Nature of Society; 5) Schools of Sociological and Organizational Theory; 6) Meaning and Metaphors in the Four Paradigms; and 7) Possibilities and Conclusions.

  5. Compression of the Global Land 1-km AVHRR dataset

    USGS Publications Warehouse

    Kess, B. L.; Steinwand, D.R.; Reichenbach, S.E.

    1996-01-01

    Large datasets, such as the Global Land 1-km Advanced Very High Resolution Radiometer (AVHRR) Data Set (Eidenshink and Faundeen 1994), require compression methods that provide efficient storage and quick access to portions of the data. A method of lossless compression is described that provides multiresolution decompression within geographic subwindows of multi-spectral, global, 1-km, AVHRR images. The compression algorithm segments each image into blocks and compresses each block in a hierarchical format. Users can access the data by specifying either a geographic subwindow or the whole image and a resolution (1,2,4, 8, or 16 km). The Global Land 1-km AVHRR data are presented in the Interrupted Goode's Homolosine map projection. These images contain masked regions for non-land areas which comprise 80 per cent of the image. A quadtree algorithm is used to compress the masked regions. The compressed region data are stored separately from the compressed land data. Results show that the masked regions compress to 0·143 per cent of the bytes they occupy in the test image and the land areas are compressed to 33·2 per cent of their original size. The entire image is compressed hierarchically to 6·72 per cent of the original image size, reducing the data from 9·05 gigabytes to 623 megabytes. These results are compared to the first order entropy of the residual image produced with lossless Joint Photographic Experts Group predictors. Compression results are also given for Lempel-Ziv-Welch (LZW) and LZ77, the algorithms used by UNIX compress and GZIP respectively. In addition to providing multiresolution decompression of geographic subwindows of the data, the hierarchical approach and the use of quadtrees for storing the masked regions gives a marked improvement over these popular methods.

  6. Hypervelocity launch capabilities to over 10 km/s

    SciTech Connect

    Chhabildas, L.C.

    1991-01-01

    Very high pressure and acceleration is necessary to launch flier plates to hypervelocities. In addition, the high pressure loading must be uniform, structured, and shockless, i.e., time-dependent to prevent the flier plate from either fracturing or melting. In this paper, a novel technique is described which allows the use of megabar level loading pressures, and 10{sup 9} g acceleration to launch intact flier plates to velocities of 12.2 km/s. 32 refs., 2 figs.

  7. Cascade sensitivity studies for KM3NeT

    NASA Astrophysics Data System (ADS)

    Fusco, L. A.; KM3NeT Collaboration

    2016-01-01

    KM3NeT is a future neutrino observatory to be built in the Mediterranean Sea. Its main astrophysical goal it to search for cosmic sources of neutrinos. The status of searches for diffuse fluxes of cosmic neutrinos in the cascade channel are reported in this contribution. A signal analogous to that observed by the IceCube collaboration will be observed with a 5 σ significance within one year of operation of the detector.

  8. The KM3NeT neutrino telescope

    NASA Astrophysics Data System (ADS)

    Coniglione, R.; KM3NeT Collaboration

    2015-08-01

    The construction phase of an underwater high energy neutrino telescope in the Mediterranean Sea, named KM3NeT, has started. The neutrino telescope that will consist of several blocks of instrumented structures will have a size of the order of a cubic-kilometer. In this work the main elements of the detector, the status of the project and the expected performance will be briefly reported.

  9. Towards Mapping the Ocean Surface Topography at 1 km Resolution

    NASA Technical Reports Server (NTRS)

    Fu, Lee-Lueng; Rodriquez, Ernesto

    2006-01-01

    We propose to apply the technique of synthetic aperture radar interferometry to the measurement of ocean surface topography at spatial resolution approaching 1 km. The measurement will have wide ranging applications in oceanography, hydrology, and marine geophysics. The oceanographic and related societal applications are briefly discussed in the paper. To meet the requirements for oceanographic applications, the instrument must be flown in an orbit with proper sampling of ocean tides.

  10. Saqqar: A 34 km diameter impact structure in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Kenkmann, Thomas; Afifi, Abdulkader M.; Stewart, Simon A.; Poelchau, Michael H.; Cook, Douglas J.; Neville, Allen S.

    2015-11-01

    Here we present the first proof of an impact origin for the Saqqar circular structure in northwestern Saudi Arabia (Neville et al. ), with an apparent diameter of 34 km, centered at 29°35'N, 38°42'E. The structure is formed in Cambrian-Devonian siliciclastics and is unconformably overlain by undeformed Cretaceous and Paleogene sediments. The age of impact is not well constrained and lies somewhere between 410 and 70 Ma. The subsurface structure is constrained by 2-D reflection seismic profiles and six drilled wells. First-order structural features are a central uplift that rises approximately 2 km above regional datums, surrounded by a ring syncline. The crater rim is defined by circumferential normal faults. The central uplift and ring syncline correspond to a Bouguer gravity high and an annular ring-like low, respectively. The wells were drilled within the central uplift, the deepest among them exceed 2 km depth. Sandstone core samples from these wells show abundant indicators of a shock metamorphic overprint. Planar deformation features (PDFs) were measured with orientations along (0001), {101¯3}, and less frequently along {101¯1} and {101¯4}. Planar fractures (PFs) predominantly occur along (0001) and {101¯1}, and are locally associated with feather features (FFs). In addition, some shocked feldspar grains and strongly deformed mica flakes were found. The recorded shock pressure ranges between 5 and 15 GPa. The preserved level of shock and the absence of an allochthonous crater fill suggest that Saqqar was eroded by 1-2 km between the Devonian and Maastrichtian. The documentation of unequivocal shock features proves the formation of the Saqqar structure by a hypervelocity impact event.

  11. A downscaled 1 km dataset of daily Greenland ice sheet surface mass balance components (1958-2014)

    NASA Astrophysics Data System (ADS)

    Noel, B.; Van De Berg, W. J.; Fettweis, X.; Machguth, H.; Howat, I. M.; van den Broeke, M. R.

    2015-12-01

    The current spatial resolution in regional climate models (RCMs), typically around 5 to 20 km, remains too coarse to accurately reproduce the spatial variability in surface mass balance (SMB) components over the narrow ablation zones, marginal outlet glaciers and neighbouring ice caps of the Greenland ice sheet (GrIS). In these topographically rough terrains, the SMB components are highly dependent on local variations in topography. However, the relatively low-resolution elevation and ice mask prescribed in RCMs contribute to significantly underestimate melt and runoff in these regions due to unresolved valley glaciers and fjords. Therefore, near-km resolution topography is essential to better capture SMB variability in these spatially restricted regions. We present a 1 km resolution dataset of daily GrIS SMB covering the period 1958-2014, which is statistically downscaled from data of the polar regional climate model RACMO2.3 at 11 km, using an elevation dependence. The dataset includes all individual SMB components projected on the elevation and ice mask from the GIMP DEM, down-sampled to 1 km. Daily runoff and sublimation are interpolated to the 1 km topography using a local regression to elevation valid for each day specifically; daily precipitation is bi-linearly downscaled without elevation corrections. The daily SMB dataset is then reconstructed by summing downscaled precipitation, sublimation and runoff. High-resolution elevation and ice mask allow for properly resolving the narrow ablation zones and valley glaciers at the GrIS margins, leading to significant increase in runoff estimate. In these regions, and especially over narrow glaciers tongues, the downscaled products improve on the original RACMO2.3 outputs by better representing local SMB patterns through a gradual ablation increase towards the GrIS margins. We discuss the impact of downscaling on the SMB components in a case study for a spatially restricted region, where large elevation

  12. Does a 100-km walking affect indicators of vitamin status?

    PubMed

    Frank, T; Kühl, M; Makowski, B; Bitsch, R; Jahreis, G; Hübscher, J

    2000-09-01

    The status of thiamin (B1), riboflavin (B2), ascorbic acid (AA), and tocopherol was determined in 60 leisure athletes (age 46 +/- 10 y, BMI 23.7 +/- 2.0 kg.m-2, VO2max 39.4 +/- 6.5 ml.min-1.kg-1), who completed a 100-km walking race. Vitamin plasma levels and activities of erythrocyte transketolase (ETK) and glutathione reductase (EGR) were measured before start, immediately after finishing and 6 hours later. The participators finished the entire distance in 14.25 h (average speed 7 km.h-1). Before start, all participators showed an excellent vitamin status (prevalences of low vitamin status ranged between 1.7 and 1.8%). Plasma tocopherol concentrations correlated significantly with increased age (r = 0.35, p = 0.008). Compared to the values before start, plasma concentrations of B1 and B2 as well as ETK and/or EGR were increased significantly after finishing. The raised levels persisted 6 hours after finishing, whereas AA remained unaltered. The univariate analysis of variance revealed that the change in vitamin status after finish and 6 hours later was in part highly dependent on age, BMI and the level of physical fitness. Despite the long distance, the extensive character of the 100-km walking with its low intensity did not deteriorate the measured indicators of vitamin status.

  13. Acceleration of barium ions near 8000 km above an aurora

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Wescott, E. M.; Foeppl, H.

    1984-01-01

    A barium shaped charge, named Limerick, was released from a rocket launched from Poker Flat Research Range, Alaska, on March 30, 1982, at 1033 UT. The release took place in a small auroral breakup. The jet of ionized barium reached an altitude of 8100 km 14.5 min after release, indicating that there were no parallel electric fields below this altitude. At 8100 km the jet appeared to stop. Analysis shows that the barium at this altitude was effectively removed from the tip. It is concluded that the barium was actually accelerated upward, resulting in a large decrease in the line-of-sight density and hence the optical intensity. The parallel electric potential in the acceleration region must have been greater than 1 kV over an altitude interval of less than 200 km. The acceleration region, although presumably auroral in origin, did not seem to be related to individual auroral structures, but appeared to be a large-scale horizontal structure. The perpendicular electric field below, as deduced from the drift of the barium, was temporally and spatially very uniform and showed no variation related to individual auroral structures passing through.

  14. Least-cost control of agricultural nutrient contributions to the Gulf of Mexico hypoxic zone

    USDA-ARS?s Scientific Manuscript database

    In 2007, the hypoxic zone in the Gulf of Mexico, measuring 20,720 km**2, was one of the two largest reported since measurement of the zone began in 1985. The extent of the hypoxic zone is related to nitrogen and phosphorous loadings originating on agricultural fields in the upper Midwest. This stud...

  15. Abiotic versus biotic controls on soil nitrogen cycling in drylands along a 3200 km transect

    NASA Astrophysics Data System (ADS)

    Liu, Dongwei; Zhu, Weixing; Wang, Xiaobo; Pan, Yuepeng; Wang, Chao; Xi, Dan; Bai, Edith; Wang, Yuesi; Han, Xingguo; Fang, Yunting

    2017-03-01

    Nitrogen (N) cycling in drylands under changing climate is not well understood. Our understanding of N cycling over larger scales to date relies heavily on the measurement of bulk soil N, and the information about internal soil N transformations remains limited. The 15N natural abundance (δ15N) of ammonium and nitrate can serve as a proxy record for the N processes in soils. To better understand the patterns and mechanisms of N cycling in drylands, we collected soils along a 3200 km transect at about 100 km intervals in northern China, with mean annual precipitation (MAP) ranging from 36 to 436 mm. We analyzed N pools and δ15N of ammonium, dual isotopes (15N and 18O) of nitrate, and the microbial gene abundance associated with soil N transformations. We found that N status and its driving factors were different above and below a MAP threshold of 100 mm. In the arid zone with MAP below 100 mm, soil inorganic N accumulated, with a large fraction being of atmospheric origin, and ammonia volatilization was strong in soils with high pH. In addition, the abundance of microbial genes associated with soil N transformations was low. In the semiarid zone with MAP above 100 mm, soil inorganic N concentrations were low and were controlled mainly by biological processes (e.g., plant uptake and denitrification). The preference for soil ammonium over nitrate by the dominant plant species may enhance the possibility of soil nitrate losses via denitrification. Overall, our study suggests that a shift from abiotic to biotic controls on soil N biogeochemistry under global climate changes would greatly affect N losses, soil N availability, and other N transformation processes in these drylands in China.

  16. Seismic velocity models for the Denali fault zone along the Richardson Highway, Alaska

    USGS Publications Warehouse

    Brocher, T.M.; Fuis, G.S.; Lutter, W.J.; Christensen, N.I.; Ratchkovski, N.A.

    2004-01-01

    Crustal-scale seismic-velocity models across the Denali fault zone along the Richardson Highway show a 50-km-thick crust, a near vertical fault trace, and a 5-km-wide damage zone associated with the fault near Trans-Alaska Pipeline Pump Station 10, which provided the closest strong ground motion recordings of the 2002 Denali fault earthquake. We compare models, derived from seismic reflection and refraction surveys acquired in 1986 and 1987, to laboratory measurements of seismic velocities for typical metamorphic rocks exposed along the profiles. Our model for the 1986 seismic reflection profile indicates a 5-km-wide low-velocity zone in the upper 1 km of the Denali fault zone, which we interpret as fault gouge. Deeper refractions from our 1987 line image a 40-km wide, 5-km-deep low-velocity zone along the Denali fault and nearby associated fault strands, which we attribute to a composite damage zone along several strands of the Denali fault zone and to the obliquity of the seismic line to the fault zone. Our velocity model and other geophysical data indicate a nearly vertical Denali fault zone to a depth of 30 km. After-shocks of the 2002 Denali fault earthquake and our velocity model provide evidence for a flower structure along the fault zone consisting of faults dipping toward and truncated by the Denali fault. Wide-angle reflections indicate that the crustal thickness beneath the Denali fault is transitional between the 60-km-thick crust beneath the Alaska Range to the south, and the extended, 30-km-thick crust of the Yukon-Tanana terrane to the north.

  17. Towards mapping attenuation and water content in the Transition Zone

    NASA Astrophysics Data System (ADS)

    Savage, B. K.

    2013-12-01

    The mantle transition zone is suggested to play a significant role in water storage due to the high solubility of H2O in transition zone minerals. However, quantifying the water content of the transition zone has proven difficult. Previous investigations of the transition zone using a variety of techniques have identified variations in water content globally, associated melt at 400 km, and variable thickness. The resulting water distribution models indicate substantially different Earth models and subsequent seismic responses. Water enhances attenuation with minimal change to seismic wave speed in the transition zone. Taken in combination with correlated temperature induced wave speed / attenuation reductions, the water content and temperature in the transition zone can be inferred. Using upper mantle seismic phases that propagate within the transition zone, we can isolate the effects of attenuation, or anelasticity, and seismic wave speeds. Synthetic seismograms at high frequency, around 1 Hz, from models with a "wet" transition zone show a distinct amplitude reduction and phase delay. Conversely, models with melt on top of the transition zone produce a delayed, secondary arrival with an upper mantle moveout velocity. These diagnostic arrivals, based on synthetic seismic responses, are best identified at the end of the triplicated 660 km branch. Full modeling of the seismic phases from the transition zone will enable a mapping of water content and temperature, while deciphering how water is distributed and transported throughout the mantle.

  18. Mimicking shear zones: An example from Wadi Filk, Jordan

    NASA Astrophysics Data System (ADS)

    Meyer, Sven Erik; Passchier, Cees; Jarrar, Ghaleb H.; Ghanem, Hind; Yaseen, Najel

    2017-05-01

    Ductile shear zones can develop in at least two ways: (1) a nucleus can grow laterally by free propagation into undeformed host rock, like most faults or joints; (2) the zone may nucleate and grow on or in a planar discontinuity and mimick its orientation. Most small-scale ductile shear zones are mimicking zones, but large-scale ductile shear zones could be free-propagating. The Wadi Filk mylonite zone in Jordan is a two km long, ten meter wide mylonite zone flanked by ultramylonite zones, developed in undeformed Neoproterozoic porphyritic monzogranite. Since mineral and major element composition of mylonite and monzogranite are identical, the structure seems to have formed by free propagation. Only detailed observations of the microstructure and trace element chemistry of the mylonite indicate that it is mimicking a precursor rhyolitic dyke. The Wadi Filk mylonite zone shows that even km-scale ductile shear zones can be mimicking dykes. Fine-grained chilled margins of dykes can act as a nucleus of ultramylonite formation.

  19. Igneous Crystallization Beginning at 20 km Beneath the Mid-Atlantic Ridge, 14 to 16 N

    NASA Astrophysics Data System (ADS)

    Kelemen, P.

    2003-12-01

    be plagioclase lherzolite saturated at 0.54 GPa (+/-0.14 GPa, 2σ ) and 1220° C (+/-16° C, 2σ ) [Kinzler & Grove, JGR 92]. Impregnated peridotites and olivine gabbronorites at other sites contain all or most of these minerals, have similar compositions, and record similar conditions. Melts entered the thermal boundary layer beneath the Mid-Atlantic Ridge at about 20 km depth [e.g., Sleep, JGR1975; Reid & Jackson, MGR 82; Grove et al JGR 92; Cannat JGR 96; Michael & Chase CMP 97; Braun et al., EPSL 00], and began to crystallize within impregnated peridotites and as discrete plutons intruding peridotite. 25% gabbro in the upper 20 km of an oceanic plate would correspond to 5 km of "normal" oceanic crust. 25% gabbro (7.2 km/s) + 75% peridotite (8.2 km/s) yields a "mantle" Vp (8 km/s). Residual mantle peridotites from Leg 209 Sites N and S of the 15° 20 Fracture Zone are among the most depleted from the mid-ocean ridges. No regional compositional gradient is evident. Most gabbroic rocks are evolved gabbronorites that are not complementary to MORB; instead, they result from complete, near-fractional crystallization of migrating melt at depth. Site 1268 gabbronorites, together with impregnated peridotites, may be primitive cumulates complementary to MORB. As reported elsewhere at this meeting, high temperature shear zones and faults accomodated nearly all of the subsolidus deformation associated with corner flow and exhumation of residual peridotites and high pressure igneous rocks.

  20. Providing plastic zone extrusion

    DOEpatents

    Manchiraju, Venkata Kiran; Feng, Zhili; David, Stan A.; Yu, Zhenzhen

    2017-04-11

    Plastic zone extrusion may be provided. First, a compressor may generate frictional heat in stock to place the stock in a plastic zone of the stock. Then, a conveyer may receive the stock in its plastic zone from the compressor and transport the stock in its plastic zone from the compressor. Next, a die may receive the stock in its plastic zone from the conveyer and extrude the stock to form a wire.

  1. Landing Zone and Drop Zone Criteria

    DTIC Science & Technology

    2017-05-01

    Report Approved for public release; distribution is unlimited. Prepared for Army Terrestrial Environmental Modeling and Intelligence System (ARTEMIS...for the Army Terrestrial Environmental Model - ing and Intelligence System (ARTEMIS) program under Work Item 9K3D08 for the Geospatial Remote...Compatible Use Zone APZ Accident Potential Zone APZ-LZ Accident Potential Zone–Landing Zone ARTEMIS Army Terrestrial Environmental Modeling and

  2. A comparison of the IGBP DISCover and University of Maryland 1 km global land cover products

    USGS Publications Warehouse

    Hansen, M.C.; Reed, B.

    2000-01-01

    Two global 1 km land cover data sets derived from 1992-1993 Advanced Very High Resolution Radiometer (AVHRR) data are currently available, the International Geosphere-Biosphere Programme Data and Information System (IGBP-DIS) DISCover and the University of Maryland (UMd) 1 km land cover maps. This paper makes a preliminary comparison of the methodologies and results of the two products. The DISCover methodology employed an unsupervised clustering classification scheme on a per-continent basis using 12 monthly maximum NDVI composites as inputs. The UMd approach employed a supervised classification tree method in which temporal metrics derived from all AVHRR bands and the NDVI were used to predict class membership across the entire globe. The DISCover map uses the IGBP classification scheme, while the UMd map employs a modified IGBP scheme minus the classes of permanent wetlands, cropland/natural vegetation mosaic and ice and snow. Global area totals of aggregated vegetation types are very similar and have a per-pixel agreement of 74%. For tall versus short/no vegetation, the per-pixel agreement is 84%. For broad vegetation types, core areas map similarly, while transition zones around core areas differ significantly. This results in high regional variability between the maps. Individual class agreement between the two 1 km maps is 49%. Comparison of the maps at a nominal 0.5 resolution with two global ground-based maps shows an improvement of thematic concurrency of 46% when viewing average class agreement. The absence of the cropland mosaic class creates a difficulty in comparing the maps, due to its significant extent in the DISCover map. The DISCover map, in general, has more forest, while the UMd map has considerably more area in the intermediate tree cover classes of woody savanna/ woodland and savanna/wooded grassland.

  3. Inversion of Surface Wave Phase Velocities for Radial Anisotropy to an Depth of 1200 km

    NASA Astrophysics Data System (ADS)

    Xing, Z.; Beghein, C.; Yuan, K.

    2012-12-01

    This study aims to evaluate three dimensional radial anisotropy to an depth of 1200 km. Radial anisotropy describes the difference in velocity between horizontally polarized Rayleigh waves and vertically polarized Love waves. Its presence in the uppermost 200 km mantle has well been documented by different groups, and has been regarded as an indicator of mantle convection which aligns the intrinsically anisotropic minerals, largely olivine, to form large scale anisotropy. However, there is no global agreement on whether anisotropy exists in the region below 200 km. Recent models also associate a fast vertically polarized shear wave with vertical upwelling mantle flow. The data used in this study is the globally isotropic phase velocity models of fundamental and higher mode Love and Rayleigh waves (Visser, 2008). The inclusion of higher mode surface wave phase velocity provides sensitivities to structure at depth that extends to below the transition zone. While the data is the same as used by Visser (2008), a quite different parameterization is applied. All the six parameters - five elastic parameters A, C, F, L, N and density - are now regarded as independent, which rules out possible biased conclusions induced by scaling relation method used in several previous studies to reduce the number of parameters partly due to limited computing resources. The data need to be modified by crustal corrections (Crust2.0) as we want to look at the mantle structure only. We do this by eliminating the perturbation in surface wave phase velocity caused by the difference in crustal structure with respect to the referent model PREM. Sambridge's Neighborhood Algorithm is used to search the parameter space. The introduction of such a direct search technique pales the traditional inversion method, which requires regularization or some unnecessary priori restriction on the model space. On the contrary, the new method will search the full model space, providing probability density

  4. Ediacaran 2,500-km-long synchronous deep continental subduction in the West Gondwana Orogen.

    PubMed

    Ganade de Araujo, Carlos E; Rubatto, Daniela; Hermann, Joerg; Cordani, Umberto G; Caby, Renaud; Basei, Miguel A S

    2014-10-16

    The deeply eroded West Gondwana Orogen is a major continental collision zone that exposes numerous occurrences of deeply subducted rocks, such as eclogites. The position of these eclogites marks the suture zone between colliding cratons, and the age of metamorphism constrains the transition from subduction-dominated tectonics to continental collision and mountain building. Here we investigate the metamorphic conditions and age of high-pressure and ultrahigh-pressure eclogites from Mali, Togo and NE-Brazil and demonstrate that continental subduction occurred within 20 million years over at least a 2,500-km-long section of the orogen during the Ediacaran. We consider this to be the earliest evidence of large-scale deep-continental subduction and consequent appearance of Himalayan-scale mountains in the geological record. The rise and subsequent erosion of such mountains in the Late Ediacaran is perfectly timed to deliver sediments and nutrients that are thought to have been necessary for the subsequent evolution of sustainable life on Earth.

  5. Mapping the global land surface using 1 km AVHRR data

    USGS Publications Warehouse

    Lauer, D.T.; Eidenshink, J.C.

    1998-01-01

    The scientific requirements for mapping the global land surface using 1 km advanced very high resolution radiometer (AVHRR) data have been set forth by the U.S. Global Change Research Program; the International Geosphere Biosphere Programme (IGBP); The United Nations; the National Oceanic and Atmospheric Administration (NOAA); the Committee on Earth Observations Satellites; and the National Aeronautics and Space Administration (NASA) mission to planet Earth (MTPE) program. Mapping the global land surface using 1 km AVHRR data is an international effort to acquire, archive, process, and distribute 1 km AVHRR data to meet the needs of the international science community. A network of AVHRR receiving stations, along with data recorded by NOAA, has been acquiring daily global land coverage since April 1, 1992. A data set of over 70,000 AVHRR images is archived and distributed by the United States Geological Survey (USGS) EROS Data Center, and the European Space Agency. Under the guidance of the IGBP, processing standards have been developed for calibration, atmospheric correction, geometric registration, and the production of global 10-day maximum normalized difference vegetation index (NDVI) composites. The major uses of the composites are for the study of surface vegetation condition, mapping land cover, and deriving biophysical characteristics of terrestrial ecosystems. A time-series of 54 10-day global vegetation index composites for the period of April 1, 1992 through September 1993 has been produced. The production of a time-series of 33 10-day global vegetation index composites using NOAA-14 data for the period of February 1, 1995 through December 31, 1995 is underway. The data products are available from the USGS, in cooperation with NASA's MTPE program and other international organizations.

  6. Analysis of sex differences in open-water ultra-distance swimming performances in the FINA World Cup races in 5 km, 10 km and 25 km from 2000 to 2012

    PubMed Central

    2014-01-01

    Background The present study investigated the changes in swimming speeds and sex differences for elite male and female swimmers competing in 5 km, 10 km and 25 km open-water FINA World Cup races held between 2000 and 2012. Methods The changes in swimming speeds and sex differences across years were analysed using linear, non-linear, and multi-level regression analyses for the annual fastest and the annual ten fastest competitors. Results For the annual fastest, swimming speed remained stable for men and women in 5 km (5.50 ± 0.21 and 5.08 ± 0.19 km/h, respectively), in 10 km (5.38 ± 0.21 and 5.05 ± 0.26 km/h, respectively) and in 25 km (5.03 ± 0.32 and 4.58 ± 0.27 km/h, respectively). In the annual ten fastest, swimming speed remained constant in 5 km in women (5.02 ± 0.19 km/h) but decreased significantly and linearly in men from 5.42 ± 0.03 km/h to 5.39 ± 0.02 km/h. In 10 km, swimming speed increased significantly and linearly in women from 4.75 ± 0.01 km/h to 5.74 ± 0.01 km/h but remained stable in men at 5.36 ± 0.21 km/h. In 25 km, swimming speed decreased significantly and linearly in women from 4.60 ± 0.06 km/h to 4.44 ± 0.08 km/h but remained unchanged at 4.93 ± 0.34 km/h in men. For the annual fastest, the sex difference in swimming speed remained unchanged in 5 km (7.6 ± 3.0%), 10 km (6.1 ± 2.5%) and 25 km (9.0 ± 3.7%). For the annual ten fastest, the sex difference remained stable in 5 km at 7.6 ± 0.6%, decreased significantly and linearly in 10 km from 7.7 ± 0.7% to 1.2 ± 0.3% and increased significantly and linearly from 4.7 ± 1.4% to 9.6 ± 1.5% in 25 km. Conclusions To summarize, elite female open-water ultra-distance swimmers improved in 10 km but impaired in 25 km leading to a linear decrease in sex difference in 10 km and a linear increase in sex difference in 25 km. The linear changes in sex differences

  7. EVLA/NMA: Within and Beyond the 21-km Radius

    NASA Astrophysics Data System (ADS)

    Durand, Steve; Romney, Jonathan D.

    NRAO's Expanded Very Large Array (EVLA) project is being implemented in two phases. Each involves extremely wide- bandwidth data transmission over optical fibers, but the two phases necessarily involve quite different approaches to the required fiber infrastructure, which make for an interesting contrast. Phase 1, formally called the "Ultrasensitive Array", involves replacing almost all of the existing electronics, leaving only the mechanical and track infrastructure of the VLA. The data transmission system being implemented for Phase 1 uses dedicated optical fibers, currently being buried at the VLA site. Twelve standard single-mode fibers will run from each of 72 antenna pads to the central building. One of these fibers will support the wideband data transmission system, using a dense wavelength division multiplexing technique to carry a bandwidth of 96 Gbps (120 Gbps formatted) per antenna. Fibers from the 27 active antenna pads will carry a total bandwidth of 2.6 Tbps. The longest of these fibers will extend the full 21- km length of each arm. Phase 2 will add the "New Mexico Array". Eight new stations will be built, and the electronics of the VLBA Pie Town and Los Alamos stations will be upgraded, to create a medium-resolution array, with sensitivity even higher than Phase 1. All ten NMA stations will lie within the State of New Mexico. The new antennas will range as far as 265 km from the VLA site, and will be located so as to facilitate access to existing fiber trunks installed, primarily, by rural telephone companies. These trunks include numerous unused fibers which, it is anticipated, can be leased economically. The longest fiber run from the VLA is 480 km. The same 96-Gbps total bandwidth per station will be supported, with the same underlying sub-band structure. Signals from up to three NMA stations will be multiplexed onto a single fiber in the existing trunks. This will limit the total length of fiber which must be leased or acquired to about 1240 km.

  8. 157km BOTDA with pulse coding and image processing

    NASA Astrophysics Data System (ADS)

    Qian, Xianyang; Wang, Zinan; Wang, Song; Xue, Naitian; Sun, Wei; Zhang, Li; Zhang, Bin; Rao, Yunjiang

    2016-05-01

    A repeater-less Brillouin optical time-domain analyzer (BOTDA) with 157.68km sensing range is demonstrated, using the combination of random fiber laser Raman pumping and low-noise laser-diode-Raman pumping. With optical pulse coding (OPC) and Non Local Means (NLM) image processing, temperature sensing with +/-0.70°C uncertainty and 8m spatial resolution is experimentally demonstrated. The image processing approach has been proved to be compatible with OPC, and it further increases the figure-of-merit (FoM) of the system by 57%.

  9. The 10 km/s, 10 kg railgun

    SciTech Connect

    Marshall, R.A. ); Barber, J.P. )

    1991-01-01

    In this paper the system design for a railgun powered by capacitor-based energy stores distributed along its length is presented. It is assumed that it is required to accelerate a mass of 10kg to a velocity of 10 km/s. Parameters for the railgun and its energy stores are derived and the performance of the system is computed with particular attention being paid to the efficiency with which store energy is converted to launch package kinetic energy. It is shown that efficiencies of 90 percent can be expected from a properly designed system.

  10. The relational database system of KM3NeT

    NASA Astrophysics Data System (ADS)

    Albert, Arnauld; Bozza, Cristiano

    2016-04-01

    The KM3NeT Collaboration is building a new generation of neutrino telescopes in the Mediterranean Sea. For these telescopes, a relational database is designed and implemented for several purposes, such as the centralised management of accounts, the storage of all documentation about components and the status of the detector and information about slow control and calibration data. It also contains information useful during the construction and the data acquisition phases. Highlights in the database schema, storage and management are discussed along with design choices that have impact on performances. In most cases, the database is not accessed directly by applications, but via a custom designed Web application server.

  11. Deformation characteristics and associated clay-mineral variation in 2-3 km buried Hota accretionary complex, central Japan

    NASA Astrophysics Data System (ADS)

    Yamamoto, Y.; Kameda, J.; Yamaguchi, H.

    2009-12-01

    Although deformation and physical/chemical properties variation in aseismic-seismic transition zone were essential to examine critical changes in environmental parameters that result in earthquake, they are poorly understood because the appropriate samples buried 2-4 km have not been collected yet (scientific drilling has never reached there and most of ancient examples experienced the deeper burial depth and suffered thermal and physical overprinting). The lower to middle Miocene Hota accretionary complex is a unique example of on land accretionary complex, representing deformation and its physical/chemical properties of sediments just prior to entering the seismogenic realm. The maximum paleotemperature was estimated approximately 55-70°C (based on vitrinite reflectance) indicative of a maximum burial depth about 2-3 km assuming a paleo-geothermal gradient as 25-35°C/km. Accretionary complex in this temperature/depth range corresponds with an intermediate range between the core samples collected from the modern accretionary prism (e.g. Nankai, Barbados, and so on) and rocks in the ancient accretionary complexes on land. This presentation will treat the detailed structural and chemical analyses of the Hota accretionary complex to construct deformation properties of décollement zone and accretionary complex in its 2-3 km depth range and to discuss the interrelation between the early diagenesis (hydrocarbon/cations generation and sediment dewatering, etc.) and transition of the deformation properties. The deformation in this accretionary complex is characterized by two deformation styles: one is a few centimeter-scale phacoidal deformation representing clay minerals preferred orientation in the outer rim, whereas random fabric in the core, quite similar texture to the rocks in the present-Nankai décollement. The other is S-C style deformation (similar deformation to the mélanges in ancient accretionary complex on land) exhibiting block-in-matrix texture and

  12. The Crust and Mantle Relationships Beneath Central and Southern Iberian Peninsula constrained by a 550 km long multiseismic transect

    NASA Astrophysics Data System (ADS)

    Ehsan, Siddique Akhtar; Carbonell, Ramon; Simancas, Jose Fernando; Martinez Poyatos, David; Azor, Antonio; Ayarza, Puy; Storti, Fabrizio

    2013-04-01

    A composite lithospheric cross section which is composed by data from controlled source multiseismic experiments strongly constrains the lithospheric structure of southwestern Iberia. The data includes coincident normal incidence and wide-angle profiles along an, approximately, 550 km long transect. This transect goes across, from North-to-South, the major tectonic zones that build up Southwestern part of the Iberian Peninsula (the Central Iberian Zone -CIZ-, the Ossa-Morena Zone -OMZ- and the South Portuguese Zone -SPZ-). The knowledge provided by these datasets constitutes the base to develop multidisciplinary models of the lithosphere. The multichannel deep seismic high resolution (60-90 fold) profiles, IBERSEIS & ALCUDIA were acquired in summer 2001 and 2007 are about 300 and 250 km long respectively. The transects image 20 s (TWTT), about 70 km depth. To address the crust and upper mantle structural relationships a reassessment of the normal incidence seismic reflection transect ALCUDIA has been carried out. We revised the key processing steps and applied advance analysis on the ALCUDIA transect with the aim to improve the signal to noise ratio especially in the deep parts and to produce a depth migrated image. The velocity model generated through wide-angle seismic survey (2003) was used to convert IBERSEIS time migrated stack image into depth. The new data processing flow provide better structural constraints on the shallow and deep structures as the current images reveal indentation features which strongly suggest horizontal tectonics. The ALCUDIA transect shows slightly less reflective upper crust about 13 km thick decoupled from the comparatively reflective lower crust. The reflectivity of the lower crust is continuous, high amplitude, horizontal and parallel though evidences of deformation are present as flat-ramp-flat geometry on the northeastern portion and a "Crocodile structure" wedging into the upper mantle on the southwestern portion of the ALCUDIA

  13. Mantle transition zone thickness beneath the Yellowstone hotspot

    NASA Astrophysics Data System (ADS)

    Zurek, B. D.; Dueker, K.

    2002-12-01

    The Yellowstone hotspot is one of the largest continental hotspots, however whether the hotspot actively derives from a lower mantle plume or an upper mantle convective instability is not constrained. The plume model is supported by the 2-3 cm/yr volcanic age progression approximately parallel to the absolute North American plate motion and an elevated He3/He4 signature. Correspondingly, evidence against a plume model derives from the lack of dynamic topographic uplift (Lowry et al., 1998), absence of a low velocity anomaly below 200 km depth (Dueker et al., 2001) and shear-wave splits that show no plume related flow anomalies (Waite et al., 2002). To better constrain the origin of the hotspot, The Yellowstone Intermountain Seismic Array (YISA) with 47 PASSCAL broad-band seismometers was deployed for one year covering a region 250 km in radius from the center of the Yellowstone hotspot. Here we present images of the mantle transition zone from receiver function common conversion point imaging. Lateral velocity heterogeneity corrections are applied to the receiver functions using the teleseismic P-times calculated from the array. The mantle transition zone is composed of the 410 and 660 km discontinuities, these discontinuities are generally regarded to derive from phase changes that have opposite Clapeyron slopes. Thus if the mantle is assumed to be compositional homogenous, >100 degree lateral thermal gradients are resolvable from transition zone thickness maps. Preliminary results show that the transition zone beneath the Yellowstone hotspot has a mean thickness of 245 km with 20 km of variation across the array. The mean values of the 410 and 660 km discontinuities are, 412 km and 660 km, with 16 and 14 km of topography, respectively. The processes that could produce this topography are the focus of our current research.

  14. Crustal extension in the Baikal rift zone

    USGS Publications Warehouse

    Zorin, Yu; Cordell, L.

    1991-01-01

    Analysis of the gravity field along four profiles crossing the Baikal rift zone permits an estimate of the amount of anomalous mass produced by 1. (1) graben-fill sediments, 2. (2) Moho uplift and intrusion of mantle sills and dikes, 3. (3) an asthenospheric bulge. Crustal extension is evaluated based on the idea of mass and volume balance of material introduced into and removed from the initial volume of the crust. Extension in the Baikal rift increases southwestward from 0.9 km in the Chara depression to 19.3 km in the South Baikal depression. These values generally agree with the position of the Euler pole determined from seismic data (fault plane solutions). Average rotation velocity for the lithospheric plates separated by the rift zone is estimated to be 5.93 ?? 10-4 rad/m.y. over about 30 m.y. ?? 1991.

  15. Anthropometric and training variables related to 10km running performance.

    PubMed

    Bale, P; Bradbury, D; Colley, E

    1986-12-01

    Sixty male distance athletes were divided into three equal groups according to their personal best time for the 10km run. The runners were measured anthropometrically and each runner completed a detailed questionnaire on his athletic status, training programme and performance. The runners in this study had similar anthropometric and training profiles to other distance runners of a similar standard. The most able runners were shorter and lighter than those in the other two groups and significantly smaller skinfold values (P less than 0.05). There were no significant differences between the groups for either bone widths or circumferences but the elite and good runners had significantly higher ponderal indices (P less than 0.05) than the average runners, indicating that they are more linear. Elite and good runners were also less endomorphic but more ectomorphic than the average runners. The elite runners trained more often, ran more miles per week and had been running longer (P less than 0.05) than good or average runners. A multiple regression and discriminant function analysis indicated that linearity, total skinfold, the type and frequency of training and the number of years running were the best predictors of running performance and success at the 10km distance.

  16. CO2 LIDAR measurements over a 20-km slant path

    NASA Astrophysics Data System (ADS)

    Senft, Daniel C.; Fox, Marsha J.; Gonglewski, John D.; Dowling, James A.; Highland, Ronald G.; Shilko, Michael L.

    1997-01-01

    The Air Force Phillips Laboratory conducted a series of measurements in February, May and August 1995 at the Air Force Maui Optical Station (AMOS) facility on Maui, Hawaii, to determine system requirements for an airborne long path CO(subscript 2) DIAL system. The lidar incorporates a cavity-matched mode-locked 3-J laser with the 60 cm diameter AMOS Beam Director Telescope. The one-way beam propagation path length was 21.3 km, originating at the AMOS facility on Haleakala at an altitude of 3.050 km ASL, and terminating at a target site near sea level. Both heterodyne and direct detection techniques are compared with respect to radiometric performance and signal statistics. Minimum detectable absorption levels for DIAL systems using both detection techniques and a variety of targets are estimated from long- range measurements with controlled absorbers. The signal correlation as a function of interpulse temporal separation was determined for long-range direct detection measurements. Radiometric models including system optical characteristics, beam propagation considerations, target reflectivity characteristics,a nd atmospheric effects have been developed and validated experimentally. A new receiver system is currently being fabricated and the laser transmitter is being upgraded for pulse-to-pulse wavelength agility, prior to incorporation into a C-135E airborne platform for future flight experiments.

  17. Anthropometric and training variables related to 10km running performance.

    PubMed Central

    Bale, P; Bradbury, D; Colley, E

    1986-01-01

    Sixty male distance athletes were divided into three equal groups according to their personal best time for the 10km run. The runners were measured anthropometrically and each runner completed a detailed questionnaire on his athletic status, training programme and performance. The runners in this study had similar anthropometric and training profiles to other distance runners of a similar standard. The most able runners were shorter and lighter than those in the other two groups and significantly smaller skinfold values (P less than 0.05). There were no significant differences between the groups for either bone widths or circumferences but the elite and good runners had significantly higher ponderal indices (P less than 0.05) than the average runners, indicating that they are more linear. Elite and good runners were also less endomorphic but more ectomorphic than the average runners. The elite runners trained more often, ran more miles per week and had been running longer (P less than 0.05) than good or average runners. A multiple regression and discriminant function analysis indicated that linearity, total skinfold, the type and frequency of training and the number of years running were the best predictors of running performance and success at the 10km distance. PMID:3814989

  18. Quantum crytography over 14km of installed optical fiber

    SciTech Connect

    Hughes, R.J.; Luther, G.G.; Morgan, G.L.; Simmons, C.

    1995-09-01

    We have made the first demonstration that low error rate quantum cryptography over long distances (14km) of installed optical fiber in a real-world environment, subject to uncontrolled temperature and mechanical influences, representing an important new step towards incorporation of quantum cryptography into existing information security systems. We also point out that the high visibility single-photon interference in our experiment allows us to infer a test of the superposition principle of quantum mechanics: a photon reaching the detector has traveled over 14km of optical fiber in a wavepacket comprising a coherent superposition of two components that are spatially separated by about 2m. In principle, there are decoherence processes (or even possible modifications of quantum mechanics) that could cause the photon`s wavefunction to collapse into one component or the other during propagation, leading to a reduction in visibility. However, our results are consistent with no such loss of quantum coherence during the 67-{mu}s propagation time.

  19. KM3NeT/ORCA status and plans

    NASA Astrophysics Data System (ADS)

    Samtleben, Dorothea F. E.

    2016-04-01

    Neutrinos created in interactions of cosmic rays with the atmosphere can serve as a powerful tool to unveil the neutrino mass hierarchy (NMH). At low energies, around a few GeV, matter effects from the transition through the Earth are expected to imprint a distinct but also subtle signature on the oscillation pattern, specific to the ordering of the neutrino masses. KM3NeT/ORCA (Oscillations Research with Cosmics in the Abyss), a densely instrumented building block of the upcoming KM3NeT neutrino telescope, will be designated to measuring this signature in the Mediterranean Sea. Using detailed simulations the sensitivity towards this signature has been evaluated. The multi-PMT detectors allow in the water for an accurate reconstruction of GeV neutrino event signatures and distinction of neutrino flavours. For the determination of the mass hierarchy a median significance of 2-6σ has been estimated for three years of data taking, depending on the actual hierarchy and the oscillation parameters. At the same time the values of several oscillation parameters like θ23 will be determined to unprecedented precision.

  20. Sentiment of Search: KM and IT for User Expectations

    NASA Technical Reports Server (NTRS)

    Berndt, Sarah Ann; Meza, David

    2014-01-01

    User perceived value is the number one indicator of a successful implementation of KM and IT collaborations. The system known as "Search" requires more strategy and workflow that a mere data dump or ungoverned infrastructure can provide. Monitoring of user sentiment can be a driver for providing objective measures of success and justifying changes to the user interface. The dynamic nature of information technology makes traditional usability metrics difficult to identify, yet easy to argue against. There is little disagreement, however, on the criticality of adapting to user needs and expectations. The Systems Usability Scale (SUS), developed by John Brook in 1986 has become an industry standard for usability engineering. The first phase of a modified SUS, polls the sentiment of representative users of the JSC Search system. This information can be used to correlate user determined value with types of information sought and how the system is (or is not) meeting expectations. Sentiment analysis by way of the SUS assists an organization in identification and prioritization of the KM and IT variables impacting user perceived value. A secondary, user group focused analysis is the topic of additional work that demonstrates the impact of specific changes dictated by user sentiment.

  1. Mantle transition zone thickness in the Central South-American Subduction Zone

    NASA Astrophysics Data System (ADS)

    Braunmiller, Jochen; van der Lee, Suzan; Doermann, Lindsey

    We used receiver functions to determine lateral variations in mantle transition zone thickness and sharpness of the 410- and 660-km discontinuities in the presence of subducting lithosphere. The mantle beneath the central Andes of South America provides an ideal study site owing to its long-lived subduction history and the availability of broadband seismic data from the dense BANJO/SEDA temporary networks and the permanent station LPAZ. For LPAZ, we analyzed 26 earthquakes between 1993-2003 and stacked the depth-migrated receiver functions. For temporary stations operating for only about one year (1994-1995), station stacks were not robust. We thus stacked receiver functions for close-by stations forming five groups that span the subduction zone from west to east, each containing 12 to 25 events. We found signal significant at the 2σ level for several station groups from P to S conversions that originate near 520- and 850-900 km depth, but most prominently from the 410- and 660-km discontinuities. For the latter, the P to S converted signal is clear in stacks for western groups and LPAZ, lack of coherent signal for two eastern groups is possibly due to incoherent stacking and does not necessitate the absence of converted energy. The thickness of the mantle transition zone increases progressively from a near-normal 255 km at the Pacific coast to about 295 km beneath station LPAZ in the Eastern Cordillera. Beneath LPAZ, the 410-km discontinuity appears elevated by nearly 40 km, thus thickening the transition zone. We compared signal amplitudes from receiver function stacks calculated at different low-pass frequencies to study frequency dependence and possibly associated discontinuity sharpness of the P to S converted signals. We found that both the 410- and 660-km discontinuities exhibit amplitude increase with decreasing frequency. Synthetic receiver function calculations for discontinuity topography mimicking observed topography show that the observed steep

  2. Strong Evidence for 380 and 580 km Negative Velocity Gradients Beneath the Lodore Array in NW Colorado

    NASA Astrophysics Data System (ADS)

    Jasbinsek, J. J.; Dueker, K.

    2005-12-01

    Teleseismic data from the Lodore Array, a one year deployment of 31 broadband stations with a 100 km aperture in NW Colorado, were analyzed with receiver functions for mantle transition zone discontinuity structure. The array provides a dense data set with which to isolate converted S-wave (Pds) arrivals. Events from NW and SE back-azimuths are selected from 38°-93° in distance allowing for excellent phasing analysis. To test for lateral discontinuity homogeneity, the dataset was divided into four sub-arrays of seven to eight stations. Statistical comparison of the sub-array radial RF stacks show that no significant variations exist, permitting all stations recording each event to be stacked together. This has the advantage of minimizing the strong signal generated noise in teleseismic P-coda and permits good error estimation crucial to robust velocity modeling. Both NW and SE radial receiver functions stacks show 4-5% (amplitude with respect to vertical P-wave) Pds arrivals from the 410 and 660 km discontinuities. More interesting, however, is the observation of two negative amplitude arrivals. The NW stack has a large (-5%) negative amplitude Pds arrival at 380 km depth that phases very well. This discontinuity is broadly consistent with the velocity predictions of the "410 water filter" hypothesis of Karato and Bercovici (2003). The SE stack shows a negative amplitude Pds arrival at 580 km depth that also phases very well. We infer that this discontinuity must be related to chemical layering because no solid-state phase transition is predicted at this depth. A plausible origin for this chemical velocity discontinuity would be subducted oceanic crust. The observations that the NW and SE stacks find different structure suggests that the 380 and 580 km discontinuities are not continuous over the approximate 250-300 km lateral sampling of our Pds dataset. Frequency dependence of the radial stacks is observed that will be used to constrain the sharpness of the

  3. A 700 km long crustal transect across northern Morocco

    NASA Astrophysics Data System (ADS)

    Carbonell, Ramon; Gallart, Josep; Díaz, Jordi; Gil, Alba; Harnafi, Mimoun; Ouraini, Fadila; Ayarza, Puy; Teixell, Antonio; Arboleya, Maria Luisa; Palomeras, Imma; Levander, Alan

    2013-04-01

    Two controlled-source wide angle seismic reflection experiments have been acquired recently (2010 and 2011) in northern Africa across Morocco. A lithospheric scale transect can be constructed by joining both data sets. Hence, an approximately 700 km-long seismic velocity cross section can be derived. From south-to-north the transect goes from the Sahara Platform, south of Merzouga, to Tanger in the north. The first experiment, SIMA, aimed to constrain the crustal structure across the Atlas Mountains. The Rif, the orogenic belt located just south of the coast of Alboran Sea, was the target of the second experiment, RIFSIS. In both cases 900 recording instruments (TEXANS) from the IRIS-PASSCAL instrument center were used to record the acoustic energy generated by explosion shots. In both experiments the shots consisted of 1 TM of explosives fired in ~30 m deep boreholes. Although the data quality varies from shot to shot, key seismic phases as Pg, PmP, Pn, and a few intra-crustal arrivals have been identified to constrain the velocity-depth structure along the whole transect. Forward modelling of the seismic reflection/refraction phases reveals a crust consisting of 3 layers in average. The Moho topography shows from south to north a relatively moderate crustal root beneath the High Atlas, which can reach 40-42 km depth. The crust is thicker beneath the Rif where the Moho is imaged as an asymmetric feature that locally defines a crustal root reaching depths of 50 km and suggesting a crustal imbrication. P wave velocities are rather low in the crust and upper mantle. First arrivals/reflections tomography supports the forward modelling results. Low fold wide-angle stacks obtained by using hyperbolic move-out reveals the geometry of the Moho along the entire transect. Beneath the Atlas, the moderate crustal root inferred is not isostatically consistent with the high surface elevations, hence supporting the idea of a 'mantle plume' as main contributor to the Atlas

  4. The ion population between 1300 km and 230000 km in the coma of comet P/Halley

    NASA Technical Reports Server (NTRS)

    Altwegg, K.; Balsiger, H.; Geiss, J.; Goldstein, R.; Ip, W. -H.; Meier, A.; Neugebauer, M.; Rosenbauer, H.; Shelley, E.

    1993-01-01

    During the encounter of the spacecraft Giotto with Comet Halley the two sensors of the ion mass spectrometer (IMS), high energy range spectrometer (HERS) and high intensity spectrometer (HIS), measured the mass and the three-dimensional velocity distributions of cometary ions. HIS looked mainly at the cold, slow part of the distribution close to the nucleus, HERS at the more energetic pick-up ions further out. After a thorough recalibration of the HIS flight spare unit and an extensive data analysis we present here continuous ion density-, composition-, velocity-, and temperature profiles for the water group ion (mass range 16-19 amu/e) along Giotto's inbound trajectory from 230,000 to 1300 km from the comet nucleus. The two sensors are in very good agreement in the region where their measurements overlap thus giving an excellent data base for the discussion of theoretical comet models. The most prominent feature where models and observations disagree is the so called pile up region between 8000 and 15,000 km from the nucleus.

  5. Transport System for Delivery Tourists At Altitude 140 km

    NASA Technical Reports Server (NTRS)

    Bolonkin, Alexander

    2002-01-01

    The author offers a new method and installation for flight in space. This method uses the centrifugal force of a rotating circular cable that provides a means for the launch of a payload into outer space, to keep the fixed space stations at high altitudes (up to 200 km). The method may also be useful for landing to space bodies, for launching of the space ships (crafts), and for moving and accelerating other artificial apparatuses. The offered installation may be used as a propulsion system for space ships and/or probes. This system uses the material of any space body (i.e. stones) for acceleration and change of the space vehicle trajectory. The suggested system may be also used as a high capacity energy accumulator.

  6. Wintertime density perturbations near 50 km in relation to latitude

    NASA Technical Reports Server (NTRS)

    Quiroz, R. S.

    1977-01-01

    Standard and reference atmospheres which depict the horizontal distribution of air density in the stratosphere and mesosphere are not realistic in that they do not provide information on the large departures from standard that may occur during a given month, nor on the time- and space-scales of atmospheric perturbations responsible for these departures. In the present paper, it is shown how this information can be obtained from a special analysis of satellite radiance measurements. Plots of the mean zonal radiance, obtained with the VTPR instrument, and the corresponding 50-km density show not only the expected strong poleward gradient of density, but also a strong density surge from late December to early January, affecting all latitudes.

  7. Fatal truck-bicycle accident involving dragging for 45 km.

    PubMed

    Klintschar, M; Darok, M; Roll, P

    2003-08-01

    Vehicle-bicycle accidents with subsequent dragging of the rider over long distances are extremely rare. The case reported here is that of a 16-year-old mentally retarded bike rider who was run over by a truck whose driver failed to notice the accident. The legs of the victim became trapped by the rear axle of the trailer and the body was dragged over 45 km before being discovered under the parked truck. The autopsy revealed that the boy had died from the initial impact and not from the dragging injuries which had caused extensive mutilation. The reports of the technical expert and the forensic pathologist led the prosecutor to drop the case against the truck driver for manslaughter.

  8. Calibration methods and tools for KM3NeT

    NASA Astrophysics Data System (ADS)

    Kulikovskiy, Vladimir

    2016-04-01

    The KM3NeT detectors, ARCA and ORCA, composed of several thousands digital optical modules, are in the process of their realization in the Mediterranean Sea. Each optical module contains 31 3-inch photomultipliers. Readout of the optical modules and other detector components is synchronized at the level of sub-nanoseconds. The position of the module is measured by acoustic piezo detectors inside the module and external acoustic emitters installed on the bottom of the sea. The orientation of the module is obtained with an internal attitude and heading reference system chip. Detector calibration, i.e. timing, positioning and sea-water properties, is overviewed in this talk and discussed in detail in this conference. Results of the procedure applied to the first detector unit ready for installation in the deep sea will be shown.

  9. Estimating worldwide solar radiation resources on a 40km grid

    SciTech Connect

    Maxwell, E.L.; George, R.L.; Brady, E.H.

    1996-11-01

    During 1995, the National Renewable Energy Laboratory (NREL), initiated the Data Grid Task under the auspices of DOE`s Resource Assessment Program. A data grid is a framework of uniformly spaced locations (grid points) for which data are available. Estimates of monthly averages of direct normal, diffuse horizontal, and global horizontal daily-total solar radiation energy (kWh/m{sup 2}) are being made for each point on a grid covering the US, Mexico, the Caribbean, and southern Canada. The grid points are separated by approximately 40 km. Using interpolation methods, the digital data grid can be used to estimate solar resources at any location. The most encouraging result to date has been the location of sources providing worldwide data for most of the input parameters required for modeling daily total solar radiation. This is a multiyear task expected to continue through the rest of this century.

  10. Rainforest metropolis casts 1,000-km defaunation shadow.

    PubMed

    Tregidgo, Daniel J; Barlow, Jos; Pompeu, Paulo S; de Almeida Rocha, Mayana; Parry, Luke

    2017-08-08

    Tropical rainforest regions are urbanizing rapidly, yet the role of emerging metropolises in driving wildlife overharvesting in forests and inland waters is unknown. We present evidence of a large defaunation shadow around a rainforest metropolis. Using interviews with 392 rural fishers, we show that fishing has severely depleted a large-bodied keystone fish species, tambaqui (Colossoma macropomum), with an impact extending over 1,000 km from the rainforest city of Manaus (population 2.1 million). There was strong evidence of defaunation within this area, including a 50% reduction in body size and catch rate (catch per unit effort). Our findings link these declines to city-based boats that provide rural fishers with reliable access to fish buyers and ice and likely impact rural fisher livelihoods and flooded forest biodiversity. This empirical evidence that urban markets can defaunate deep into rainforest wilderness has implications for other urbanizing socioecological systems.

  11. A Southern Hemisphere VLBI Survey on a 275-km Baseline

    NASA Technical Reports Server (NTRS)

    Morabito, D. D.; Preston, R. A.; Faulkner, J.; Wehrle, A. E.; Jauncey, D. L.; Batty, M. J.; Haynes, R. F.; Wright, A. E.

    1983-01-01

    A very long base interferometry (VLBI) survey at 2.29 GHz was conducted using a 275 km baseline consisting of the NASA Deep Space Network tracking site in Tidbinbilla, Australia, and the 64 m antenna located at Parkes, Australia. The purpose of the survey was to identify sources in the southern sky possessing strong compact cores ( 0.1 arcseconds). Such sources will be used to form a reference frame for conducting VLBI geodesy experiments in the Southern Hemisphere. The 70 candidate sources were chosen to be south of -39 degrees declination, and only four had been previously observed from the northern hemisphere. Of the observed sources, 49 were found to have compact structure. In addition to determining correlated flux densities, the delay and delay rate observables of several detected sources were used to determine an estimate of the three dimensional location of the Parkes antenna relative to the Tidbinbilla site with a 1-sigma accuracy of 10 meters.

  12. Measurement-Device-Independent Quantum Key Distribution over 200 km

    NASA Astrophysics Data System (ADS)

    Tang, Yan-Lin; Yin, Hua-Lei; Chen, Si-Jing; Liu, Yang; Zhang, Wei-Jun; Jiang, Xiao; Zhang, Lu; Wang, Jian; You, Li-Xing; Guan, Jian-Yu; Yang, Dong-Xu; Wang, Zhen; Liang, Hao; Zhang, Zhen; Zhou, Nan; Ma, Xiongfeng; Chen, Teng-Yun; Zhang, Qiang; Pan, Jian-Wei

    2014-11-01

    Measurement-device-independent quantum key distribution (MDIQKD) protocol is immune to all attacks on detection and guarantees the information-theoretical security even with imperfect single-photon detectors. Recently, several proof-of-principle demonstrations of MDIQKD have been achieved. Those experiments, although novel, are implemented through limited distance with a key rate less than 0.1 bit /s . Here, by developing a 75 MHz clock rate fully automatic and highly stable system and superconducting nanowire single-photon detectors with detection efficiencies of more than 40%, we extend the secure transmission distance of MDIQKD to 200 km and achieve a secure key rate 3 orders of magnitude higher. These results pave the way towards a quantum network with measurement-device-independent security.

  13. Wintertime density perturbations near 50 km in relation to latitude

    NASA Technical Reports Server (NTRS)

    Quiroz, R. S.

    1977-01-01

    Standard and reference atmospheres which depict the horizontal distribution of air density in the stratosphere and mesosphere are not realistic in that they do not provide information on the large departures from standard that may occur during a given month, nor on the time- and space-scales of atmospheric perturbations responsible for these departures. In the present paper, it is shown how this information can be obtained from a special analysis of satellite radiance measurements. Plots of the mean zonal radiance, obtained with the VTPR instrument, and the corresponding 50-km density show not only the expected strong poleward gradient of density, but also a strong density surge from late December to early January, affecting all latitudes.

  14. Successful tracking of cyclonic features at 50km resolution

    NASA Astrophysics Data System (ADS)

    Hewson, T. D.; Titley, H. A.

    2009-09-01

    Most operational global numerical models nowadays have a resolution of 25 to 50km, and indeed the resolution of many global ensemble systems is near to or within this range. One of the motivations for running at higher resolution is successful representation of some of the smaller scale cyclonic features, such as frontal waves, polar lows, and indeed smaller cyclonic windstorms. Successful identification and tracking of these features, to provide useful post-processed output for forecasters, requires algorithms that can work successfully at this resolution. In most of the existing literature input data is taken at a resolution of order hundreds of km, because higher resolution causes problems for the respective algorithms. This talk will thus describe how a relatively new set of algorithms, developed over the last 10 years or so, is well-suited to the task of tracking at high resolution, and indeed has gone on to be used in conjunction with operational ensembles at both the Met Office and ECMWF to provide forecasters with real-time tracking-related products of various types. The specifics of the new approach that make it particularly amenable to use at high resolution will be discussed. The output made available to forecasters will also be illustrated using severe weather cases. Though use with climate change scenario runs has hitherto been limited, the present algorithm set is also very well-suited to application in this field - for example with regional runs. This will be especially useful for policy makers in helping resolve some of the hitherto contradictory signals regarding increased or decreased mid-latitude storminess seen when other pre-existing algorithms are applied to the same dataset. The presentation will also discuss some of these issues, in the context of the 'IMILAST' storm tracking intercomparison project. Reference will also be made to some verification issues - both to check the integrity of the algorithms (using a subjective 'truth') and to

  15. Changes in single skinfold thickness in 100 km ultramarathoners

    PubMed Central

    Knechtle, Beat; Baumgartner, Sabrina; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Bescós, Raúl

    2012-01-01

    Background Changes in single skinfold thickness and body fat have been investigated in ultraswimmers and ultracyclists, but not in ultrarunners. The present study investigated the changes in single skinfold thickness during a 100 km ultramarathon. Methods Firstly, we investigated associations between prerace preparation and prerace body composition and, secondly, changes in single skinfold thickness during a 100 km ultramarathon in 219 male ultramarathoners. Changes in fat mass and skeletal muscle were estimated using anthropometric methods. Results Kilometers run weekly prerace and running speed during training were negatively associated with all skinfold thicknesses (P < 0.05) except for the front thigh skinfold. During the race, skinfold thickness at the pectoral (−0.1%), suprailiac (−1.8%), and calf (−0.8%) sites decreased (P < 0.05). The subjects lost 1.9 ± 1.4 kg of body mass (P < 0.001), 0.7 ± 1.0 kg of estimated skeletal muscle mass (P < 0.001), and 0.2 ± 1.3 kg of estimated fat mass (P < 0.05). The decrease in body mass was positively related to the decrease in both estimated skeletal muscle mass (r = 0.21, P = 0.0017) and estimated fat mass (r = 0.41, P < 0.0001). Conclusion Firstly, prerace fat mass and prerace skinfold thickness were associated with both volume and speed in running training. Secondly, during the ultramarathon, skinfold thickness decreased at the pectoral, suprailiac, and calf sites, but not at the thigh site. Percent decreases in skinfold thickness for ultrarunners was lower than the percent decreases in skinfold thickness reported for ultraswimmers and ultracyclists. PMID:24198597

  16. Changes in single skinfold thickness in 100 km ultramarathoners.

    PubMed

    Knechtle, Beat; Baumgartner, Sabrina; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Bescós, Raúl

    2012-01-01

    Changes in single skinfold thickness and body fat have been investigated in ultraswimmers and ultracyclists, but not in ultrarunners. The present study investigated the changes in single skinfold thickness during a 100 km ultramarathon. Firstly, we investigated associations between prerace preparation and prerace body composition and, secondly, changes in single skinfold thickness during a 100 km ultramarathon in 219 male ultramarathoners. Changes in fat mass and skeletal muscle were estimated using anthropometric methods. Kilometers run weekly prerace and running speed during training were negatively associated with all skinfold thicknesses (P < 0.05) except for the front thigh skinfold. During the race, skinfold thickness at the pectoral (-0.1%), suprailiac (-1.8%), and calf (-0.8%) sites decreased (P < 0.05). The subjects lost 1.9 ± 1.4 kg of body mass (P < 0.001), 0.7 ± 1.0 kg of estimated skeletal muscle mass (P < 0.001), and 0.2 ± 1.3 kg of estimated fat mass (P < 0.05). The decrease in body mass was positively related to the decrease in both estimated skeletal muscle mass (r = 0.21, P = 0.0017) and estimated fat mass (r = 0.41, P < 0.0001). Firstly, prerace fat mass and prerace skinfold thickness were associated with both volume and speed in running training. Secondly, during the ultramarathon, skinfold thickness decreased at the pectoral, suprailiac, and calf sites, but not at the thigh site. Percent decreases in skinfold thickness for ultrarunners was lower than the percent decreases in skinfold thickness reported for ultraswimmers and ultracyclists.

  17. Tectonic evolution of the Palmyra zone, Syria

    SciTech Connect

    O'Keefe, F.X.; Sengor, A.M.C. )

    1988-08-01

    The Palmyra foldbelt extends approximately 350 km northeast from its intersection with the Dead Sea transform near Damascus. The surface expression of this feature is a southeast-verging fold-and-thrust belt that brings rocks as old as Triassic to the surface in fault contact with Upper Cretaceous and Tertiary rocks. The palmyra region is first recognized as a subsiding trough from at least Triassic and possibly Permian time through middle Tertiary. This subsidence increases south-westward, reaching a reported maximum of 6 km of sediment north of Damascus, and is related to right-lateral motion along the eastern margin of the opening southern branch of the Neotethys sea as the Cimmerian continent moved northward away from northeast AFrica during Permian-Triassic time. Extension and subsidence continued through the Jurassic and Cretaceous, interrupted by uplift and erosion from Late Jurassic to Early Cretaceous in the northeastern part of the zone. Compression and inversion of the Palmyra zone begin during Miocene time with the initiation of left-lateral displacement on the Dead Sea transform system related to the continued opening of the Red Sea and the failure of the Gulf of Suez rift system. Approximately 105 km of offset are reported for the Dead Sea transform along the Jordan-Israel border segment, while 60 km are reported in Syria north of Lebanon. The Palmyra foldbelt accommodates this discrepancy through oblique shortening, possibly utilizing pre-existing extensional fault systems.

  18. A daily, 1 km resolution data set of downscaled Greenland ice sheet surface mass balance (1958-2015)

    NASA Astrophysics Data System (ADS)

    Noël, Brice; van de Berg, Willem Jan; Machguth, Horst; Lhermitte, Stef; Howat, Ian; Fettweis, Xavier; van den Broeke, Michiel R.

    2016-10-01

    This study presents a data set of daily, 1 km resolution Greenland ice sheet (GrIS) surface mass balance (SMB) covering the period 1958-2015. Applying corrections for elevation, bare ice albedo and accumulation bias, the high-resolution product is statistically downscaled from the native daily output of the polar regional climate model RACMO2.3 at 11 km. The data set includes all individual SMB components projected to a down-sampled version of the Greenland Ice Mapping Project (GIMP) digital elevation model and ice mask. The 1 km mask better resolves narrow ablation zones, valley glaciers, fjords and disconnected ice caps. Relative to the 11 km product, the more detailed representation of isolated glaciated areas leads to increased precipitation over the southeastern GrIS. In addition, the downscaled product shows a significant increase in runoff owing to better resolved low-lying marginal glaciated regions. The combined corrections for elevation and bare ice albedo markedly improve model agreement with a newly compiled data set of ablation measurements.

  19. Measurement of the Vertical Gradient of the Semidiurnal Tidal Wind Phase in Winter at the 95 Km Level

    NASA Technical Reports Server (NTRS)

    Schminder, R.; Kurschner, D.

    1984-01-01

    When supplemented by absolute reflection height measurements, low frequency wind measurements in the 90-100 km height range become truly competitive in comparison with the more widely used radar meteor wind observations. For example, height profiles of the wind parameters in the so-called meteor zone can be obtained due to the considerable interdiurnal variability of the average nighttime reflection heights controlled by geomagnetic activity. The phase of the semidiurnal tidal wind is particularly height-dependent. The measured vertical gradient of 1/4 h/km in winter corresponds to a vertical wavelength of about 50 km. Wind measurements in the upper atmosphere, at heights between 90 and 100 km, were carried out at the Collm Geophysical Observatory of Karl Marx University Leipzig for a number of years. These measurements use the closely-spaced receiver method and three measuring paths, on 179, 227, and 272 kHz. They take place every day between sunset and sunrise, i.e., nightly. A night in this sense may last as long as 18 hours in winter. Both the measurements and their evaluation are completely automatic, and the prevailing winds and tides are separated.

  20. Measurement of the vertical gradient of the semidiurnal tidal wind phase in winter at the 95 km level

    NASA Astrophysics Data System (ADS)

    Schminder, R.; Kurschner, D.

    1984-05-01

    When supplemented by absolute reflection height measurements, low frequency wind measurements in the 90-100 km height range become truly competitive in comparison with the more widely used radar meteor wind observations. For example, height profiles of the wind parameters in the so-called meteor zone can be obtained due to the considerable interdiurnal variability of the average nighttime reflection heights controlled by geomagnetic activity. The phase of the semidiurnal tidal wind is particularly height-dependent. The measured vertical gradient of 1/4 h/km in winter corresponds to a vertical wavelength of about 50 km. Wind measurements in the upper atmosphere, at heights between 90 and 100 km, were carried out at the Collm Geophysical Observatory of Karl Marx University Leipzig for a number of years. These measurements use the closely-spaced receiver method and three measuring paths, on 179, 227, and 272 kHz. They take place every day between sunset and sunrise, i.e., nightly. A night in this sense may last as long as 18 hours in winter. Both the measurements and their evaluation are completely automatic, and the prevailing winds and tides are separated.

  1. Survival of Nannochloropsis Phytoplankton in Hypervelocity Impact Events up to Velocities of 6.07 km/s

    NASA Astrophysics Data System (ADS)

    Pasini, D. L. S.; Price, M. C.; Burchell, M. J.; Cole, M. J.

    2013-09-01

    Studies have previously been conducted to verify the survivability of living cells during hypervelocity impact events to test the panspermia and lithopanspermia hypothesis [1], [2]. It has been demonstrated that bacteria survive impacts up to 5.4 km s-1 (approx. shock pressure 30 GPa) - albeit with a low probability of survival [1] whilst larger more complex objects (such as seeds) break up at ~1 km s-1 [2]. The survivability of yeast spores in impacts up to 7.4 km s-1 has also recently been shown [3]. We demonstrate here the survivability of Nannochloropsis Phytoplankton, a eukaryotic photosynthesizing autotroph found in the 'euphotic zone'(sunlit surface layers of oceans) [4] at impact velocities up to 6.07 km s-1. Phytoplankton from a culture sample was frozen and then fired into water (to simulate oceanic impacts, as described in [5]) using a light gas gun (LGG) [6]. The water was then retrieved and placed into a sealed culture vessel and left under a constant light source to check the viability of any remnant organisms.

  2. Seismic reflection imaging of two megathrust shear zones in the northern Cascadia subduction zone.

    PubMed

    Calvert, Andrew J

    2004-03-11

    At convergent continental margins, the relative motion between the subducting oceanic plate and the overriding continent is usually accommodated by movement along a single, thin interface known as a megathrust. Great thrust earthquakes occur on the shallow part of this interface where the two plates are locked together. Earthquakes of lower magnitude occur within the underlying oceanic plate, and have been linked to geochemical dehydration reactions caused by the plate's descent. Here I present deep seismic reflection data from the northern Cascadia subduction zone that show that the inter-plate boundary is up to 16 km thick and comprises two megathrust shear zones that bound a >5-km-thick, approximately 110-km-wide region of imbricated crustal rocks. Earthquakes within the subducting plate occur predominantly in two geographic bands where the dip of the plate is inferred to increase as it is forced around the edges of the imbricated inter-plate boundary zone. This implies that seismicity in the subducting slab is controlled primarily by deformation in the upper part of the plate. Slip on the shallower megathrust shear zone, which may occur by aseismic slow slip, will transport crustal rocks into the upper mantle above the subducting oceanic plate and may, in part, provide an explanation for the unusually low seismic wave speeds that are observed there.

  3. 3D reflection seismic imaging at the 2.5 km deep COSC-1 scientific borehole, central Scandinavian Caledonides

    NASA Astrophysics Data System (ADS)

    Hedin, Peter; Almqvist, Bjarne; Berthet, Théo; Juhlin, Christopher; Buske, Stefan; Simon, Helge; Giese, Rüdiger; Krauß, Felix; Rosberg, Jan-Erik; Alm, Per-Gunnar

    2016-10-01

    The 2.5 km deep scientific COSC-1 borehole (ICDP 5054-1-A) was successfully drilled with nearly complete core recovery during spring and summer of 2014. Downhole and on-core measurements through the targeted Lower Seve Nappe provide a comprehensive data set. An observed gradual increase in strain below 1700 m, with mica schists and intermittent mylonites increasing in frequency and thickness, is here interpreted as the basal thrust zone of the Lower Seve Nappe. This high strain zone was not fully penetrated at the total drilled depth and is thus greater than 800 m in thickness. To allow extrapolation of the results from downhole logging, core analysis and other experiments into the surrounding rock and to link these with the regional tectonic setting and evolution, three post-drilling high-resolution seismic experiments were conducted in and around the borehole. One of these, the first 3D seismic reflection land survey to target the nappe structures of the Scandinavian Caledonides, is presented here. It provides new information on the 3D geometry of structures both within the drilled Lower Seve Nappe and underlying rocks down to at least 9 km. The observed reflectivity correlates well with results from the core analysis and downhole logging, despite challenges in processing. Reflections from the uppermost part of the Lower Seve Nappe have limited lateral extent and varying dips, possibly related to mafic lenses or boudins of variable character within felsic rock. Reflections occurring within the high strain zone, however, are laterally continuous over distances of a kilometer or more and dip 10-15° towards the southeast. Reflections from structures beneath the high strain unit and the COSC-1 borehole can be followed through most of the seismic volume down to at least 9 km and have dips of varying degree, mainly in the east-west thrust direction of the orogen.

  4. Reduced NOx and PM10 emissions on urban motorways in The Netherlands by 80 km/h speed management.

    PubMed

    Keuken, M P; Jonkers, S; Wilmink, I R; Wesseling, J

    2010-05-15

    A speed limit of 80 km/h with "strict enforcement" has been introduced in 2005 on zones of urban motorways in The Netherlands with the aim to improve air quality of NO(2) and PM(10) along these motorways. Strict enforcement means speed control by camera surveillance over the whole trajectory of 2-4 km combined with licence plate recognition and automatic fining in case of exceeding the speed limit. Traffic data measured in Rotterdam and Amsterdam at the zones without and with speed management showed that traffic dynamics have been significantly reduced as a result of speed management with strict enforcement. Reduction of traffic dynamics results in more free-flowing traffic with relatively less NO(x) and exhaust PM(10) emissions compared to congested traffic, i.e., stop-and-go traffic. The actual effect on NO(x) and PM(10) emissions at these speed management zones was studied in the cities Rotterdam and Amsterdam. The study was performed in two different ways: firstly by measurements and by modelling the contribution to NO(x) and PM(10) concentrations on both sides of the motorways, and secondly by estimating the change in traffic dynamics and the effect on emissions. From the results of both approaches in this study, it was concluded that in our case study in the Netherlands emission reduction by speed management is in the range of 5-30% for NO(x) and 5-25% for PM(10). Actual emission reductions by speed management at a specific motorway mainly depend on the ratio of congested traffic prior and after implementation of speed management. The larger this ratio, the larger is the relative emission reduction. The impact on air quality of 80 km/h for NO(x) and PM(10) is largest on motorways with a high fraction of heavy-duty vehicles. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Deep crustal fracture zones control fluid escape and the seismic cycle in the Cascadia subduction zone

    NASA Astrophysics Data System (ADS)

    Tauzin, Benoît; Reynard, Bruno; Perrillat, Jean-Philippe; Debayle, Eric; Bodin, Thomas

    2017-02-01

    Seismic activity and non-volcanic tremors are often associated with fluid circulation resulting from the dehydration of subducting plates. Tremors in the overriding continental crust of several subduction zones suggest fluid circulation at shallower depths, but potential fluid pathways are still poorly documented. Using receiver function analysis in the Cascadia subduction zone, we provide evidence for a seismic discontinuity near 15 km depth in the crust of the overriding North American plate. This interface is segmented, and its interruptions are spatially correlated with conductive regions of the forearc and shallow swarms of seismicity and non-volcanic tremors. These observations suggest that fluid circulation in the overriding plate is controlled by fault zones separating blocks of accreted terranes. These zones constitute fluid escape routes that may influence the seismic cycle by releasing fluid pressure from the megathrust.

  6. Circumstellar habitable zones for deep terrestrial biospheres

    NASA Astrophysics Data System (ADS)

    McMahon, Sean; O'Malley-James, Jack; Parnell, John

    2013-09-01

    The habitable zone (HZ) is conventionally the thin shell of space around a star within which liquid water is thermally stable on the surface of an Earth-like planet (Kasting et al., 1993). However, life on Earth is not restricted to the surface and includes a “deep biosphere” reaching several km in depth. Similarly, subsurface liquid water maintained by internal planetary heat could potentially support life well outside conventional HZs. We introduce a new term,subsurface-habitability zone (SSHZ) to denote the range of distances from a star within which rocky planets are habitable at any depth below their surfaces up to a stipulated maximum, and show how SSHZs can be estimated from a model relating temperature, depth and orbital distance. We present results for Earth-like, Mars-like and selected extrasolar terrestrial planets, and conclude that SSHZs are several times wider and include many more planets than conventional surface-based habitable zones.

  7. Thermal budget of the lower east rift zone, Kilauea Volcano

    USGS Publications Warehouse

    Delaney, Paul T.; Duffield, Wendell A.; Sass, John H.; Kauahikaua, James P.; ,

    1993-01-01

    The lower east rift zone of Kilauea has been the site of repeated fissure eruptions fed by dikes that traverse the depths of interest to geothermal explorations. We find that a hot-rock-and-magma system of low permeability extending along the rift zone at depths below about 4 km and replenished with magma at a rate that is small in comparison to the modern eruption rate Kilauea can supply heat to an overlying hydrothermal aquifer sufficient to maintain temperatures of about 250??C if the characteristic permeability to 4-km depth is about 10-15m2.

  8. A high-resolution local network study of the Nazca plate Wadati-Benioff zone under western Argentina

    NASA Technical Reports Server (NTRS)

    Smalley, Robert F., Jr.; Isacks, Bryan L.

    1987-01-01

    Seismic data, recorded by INPRES telemetered network located above one of the subhorizontal segments of the subducted Nazca plate Wadati-Benioff zone beneath western Argentina, were analyzed to determine the zone's fine structure. The depth of the center and the thickness of the subhorizontal Wadati-Benioff zone beneath the network were calculated to be about 107 km and about 20 km, respectively, with most of the seismogenic zone concentrated in a region about 12 km thick. The Nazca plate is interpreted to be in a state of down-dip tension and to be decoupled from the overriding South American plate by a weak zone of asthenospheric or shear-heated material. The South American plate is estimated to be 80 km thick, based on the location of the subducted Nazca plate and an inferred decoupling zone between the plates.

  9. 45-km horizontal-path optical link experiment

    NASA Astrophysics Data System (ADS)

    Biswas, Abhijit; Ceniceros, Juan M.; Novak, Matthew J.; Jeganathan, Muthu; Portillo, Angel; Erickson, David M.; de Pew, Jon; Sanii, B.; Lesh, James R.

    1999-04-01

    Mountain-top to mountain-top optical link experiments have been initiated at JPL, in order to perform a systems level evaluation of optical communications. Progress made so far is reported. The NASA, JPL developed optical communications demonstrator (OCD) is used to transmit a laser signal from Strawberry Peak (SP), located in the San Bernadino mountains of California. This laser beam is received by a 0.6 m aperture telescope at JPL's Table Mountain Facility (TMF), located in Wrightwood, California. The optical link is bi-directional with the TMF telescope transmitting a continuous 4-wave (cw) 780 nm beacon and the OCD sending back an 840 nm, 100 - 500 Mbps pseudo noise (PN) modulated, laser beam. The optical link path is at an average altitude of 2 Km above sea level, covers a range of 46.8 Km and provides an atmospheric channel equivalent to approximately 4 air masses. Average received power measured at either end fall well within the uncertainties predicted by link analysis. The reduction in normalized intensity variance ((sigma) I2) for the 4- beam beacon, compared to each individual beam, at SP, was from approximately 0.68 to 0.22. With some allowance for intra-beam mis-alignment, this is consistent with incoherent averaging. The (sigma) I2 measured at TMF approximately 0.43 plus or minus 0.22 exceeded the expected aperture averaged value of less than 0.1, probably because of beam wander. The focused spot sizes of approximately 162 plus or minus 6 micrometer at the TMF Coude and approximately 64 plus or minus 3 micrometer on the OCD compare to the predicted size range of 52 - 172 micrometer and 57 - 93 micrometer, respectively. This is consistent with 4 - 5 arcsec of atmospheric 'seeing.' The preliminary evaluation of OCD's fine tracking indicates that the uncompensated tracking error is approximately 3.3 (mu) rad compared to approximately 1.7 (mu) rad observed in the laboratory. Fine tracking performance was intermittent, primarily due to beacon fades on the

  10. Characteristics of faults and shear zones in deep mines

    USGS Publications Warehouse

    Wallace, R.E.; Morris, H.T.

    1986-01-01

    The characteristics of fault and shear zones to depths of 2.5 km are well documented in deep mines in North America. The characteristics may be summarized as follows. (a) Fault zones usually are irregular, branched, anastomosed, and curved rather than simple and planar. (b) Faults are generally composed of one or more clay or clay-like gouge zones in a matrix of sheared and foliated rock bordered by highly fractured rock. (c) The widths of fault zones appear to be greater when faults have greater displacement, probably as a result of a long history of repeated minor movements. Fault zones with kilometers of displacement tend to be 100 m or more wide, whereas those with only a few hundred meters of displacement commonly are only 1 m or less wide. (d) Some zones represent shear distributed across hundreds of meters without local concentration in a narrow gouge zone. (e) Many fault zones are wet even above the water table, and water moves along them at various rates, but some also serve as subsurface dams, ponding ground water as much as several hundred meters higher on one side than on the other. No striking differences in the characteristics of faults over the vertical range of 2.5 km are documented. ?? 1986 Birkha??user Verlag.

  11. A 233 km tunnel for lepton and hadron colliders

    SciTech Connect

    Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T.

    2012-12-21

    A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of e{sup +}e{sup -}, pp-bar , and {mu}{sup +}{mu}{sup -} collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV e{sup +}e{sup -} colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV e{sup +}e{sup -} collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV pp-bar collider uses the high intensity Fermilab p-bar source, exploits high cross sections for pp-bar production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.

  12. Stratospheric microbiology at 20 km over the Pacific Ocean

    USGS Publications Warehouse

    Smith, D.J.; Griffin, Dale W.; Schuerger, A.C.

    2010-01-01

    An aerobiology sampling flight at 20 km was conducted on 28 April 2008 over the Pacific Ocean (36.5° N, 118–149° W), a period of time that coincided with the movement of Asian dust across the ocean. The aim of this study was to confirm the presence of viable bacteria and fungi within a transoceanic, atmospheric bridge and to improve the resolution of flight hardware processing techniques. Isolates of the microbial strains recovered were analyzed with ribosomal ribonucleic acid (rRNA) sequencing to identify bacterial species Bacillus sp., Bacillus subtilis, Bacillus endophyticus, and the fungal genus Penicillium. Satellite imagery and ground-based radiosonde observations were used to measure dust movement and characterize the high-altitude environment at the time of collection. Considering the atmospheric residency time (7–10 days), the extreme temperature regime of the environment (-75°C), and the absence of a mechanism that could sustain particulates at high altitude, it is unlikely that our samples indicate a permanent, stratospheric ecosystem. However, the presence of viable fungi and bacteria in transoceanic stratosphere remains relevant to understanding the distribution and extent of microbial life on Earth.

  13. A 233 km Tunnel for Lepton and Hadron Colliders

    NASA Astrophysics Data System (ADS)

    Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T.

    2012-07-01

    A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of $e^+e^-$, $p \\bar{p}$, and $\\mu^+ \\mu^-$ collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV $e^+e^-$ colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV $e^+ e^-$ collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV $p \\bar{p}$ collider uses the high intensity Fermilab $\\bar{p}$ source, exploits high cross sections for $p \\bar{p}$ production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.

  14. Stratospheric microbiology at 20 km over the Pacific Ocean

    USGS Publications Warehouse

    Smith, David J.; Griffin, Dale W.; Schuerger, Andrew C.

    2010-01-01

    An aerobiology sampling flight at 20 km was conducted on 28 April 2008 over the Pacific Ocean (36.5° N, 118–149° W), a period of time that coincided with the movement of Asian dust across the ocean. The aim of this study was to confirm the presence of viable bacteria and fungi within a transoceanic, atmospheric bridge and to improve the resolution of flight hardware processing techniques. Isolates of the microbial strains recovered were analyzed with ribosomal ribonucleic acid (rRNA) sequencing to identify bacterial species Bacillus sp., Bacillus subtilis, Bacillus endophyticus, and the fungal genus Penicillium. Satellite imagery and ground-based radiosonde observations were used to measure dust movement and characterize the high-altitude environment at the time of collection. Considering the atmospheric residency time (7–10 days), the extreme temperature regime of the environment (-75°C), and the absence of a mechanism that could sustain particulates at high altitude, it is unlikely that our samples indicate a permanent, stratospheric ecosystem. However, the presence of viable fungi and bacteria in transoceanic stratosphere remains relevant to understanding the distribution and extent of microbial life on Earth.

  15. Nausea is associated with endotoxemia during a 161-km ultramarathon.

    PubMed

    Stuempfle, Kristin J; Valentino, Taylor; Hew-Butler, Tamara; Hecht, Frederick M; Hoffman, Martin D

    2016-09-01

    This study explored possible contributing factors to gastrointestinal distress, including endotoxemia, hyperthermia, dehydration and nutrition, during a 161-km ultramarathon. Thirty runners participated in the study and 20 finished the race. At three checkpoints and the finish, runners were interviewed to assess the incidence and severity of 12 gastrointestinal symptoms and to determine dietary intake. Core temperature was measured at the same locations. Runners were weighed pre-race, at the three checkpoints and the finish to monitor hydration status. Blood markers for endotoxemia (sCD14) and inflammation (interleukin-6 and C-reactive protein) were measured pre- and post-race. Gastrointestinal symptoms were experienced by most runners (80%), with nausea being the most common complaint (60%). Runners with nausea experienced significantly greater (P = 0.02) endotoxemia than those without nausea (sCD14 mean increase 0.7 versus 0.5 µg · mL(-1)). There was a significant positive correlation (r = 0.652, P = 0.005) between nausea severity and endotoxemia level. Inflammatory response, core temperature, hydration level and race diet were similar between runners with and without nausea. This study links endotoxemia to nausea in ultramarathon runners. Other possible contributing factors to nausea such as hyperthermia, dehydration and nutrition did not appear to play a role in the symptomatic runners in this study.

  16. KM3NeT Digital Optical Module electronics

    NASA Astrophysics Data System (ADS)

    Real, Diego

    2016-04-01

    The KM3NeT collaboration is currently building of a neutrino telescope with a volume of several cubic kilometres at the bottom of the Mediterranean Sea. The telescope consists of a matrix of Digital Optical Modules that will detect the Cherenkov light originated by the interaction of the neutrinos in the proximity of the detector. This contribution describes the main components of the read-out electronics of the Digital Optical Module: the Power Board, which delivers all the power supply required by the Digital Optical Molule electronics; the Central Logic Board, the main core of the read-out system, hosting 31 Time to Digital Converters with 1 ns resolution and the White Rabbit protocol embedded in the Central Logic Board Field Programmable Gate Array; the Octopus boards, that transfer the Low Voltage Digital Signals from the PMT bases to the Central Logic Board and finally the PMT bases, in charge of converting the analogue signal produced in the 31 3" PMTs into a Low Voltage Digital Signal.

  17. ASIC design in the KM3NeT detector

    NASA Astrophysics Data System (ADS)

    Gajanana, D.; Gromov, V.; Timmer, P.

    2013-02-01

    In the KM3NeT project [1], Cherenkov light from the muon interactions with transparent matter around the detector, is used to detect neutrinos. Photo multiplier tubes (PMT) used as photon sensor, are housed in a glass sphere (aka Optical Module) to detect single photons from the Cherenkov light. The PMT needs high operational voltage ( ~ 1.5 kV) and is generated by a Cockroft-Walton (CW) multiplier circuit. The electronics required to control the PMT's and collect the signals is integrated in two ASIC's namely: 1) a front-end mixed signal ASIC (PROMiS) for the readout of the PMT and 2) an analog ASIC (CoCo) to generate pulses for charging the CW circuit and to control the feedback of the CW circuit. In this article, we discuss the two integrated circuits and test results of the complete setup. PROMiS amplifies the input charge, converts it to a pulse width and delivers the information via LVDS signals. These LVDS signals carry accurate information on the Time of arrival ( < 2 ns) and Time over Threshold. A PROM block provides unique identification to the chip. The chip communicates with the control electronics via an I2C bus. This unique combination of the ASIC's results in a very cost and power efficient PMT base design.

  18. Soil humidity monitoring using MODIS HKM and 1KM bands

    NASA Astrophysics Data System (ADS)

    Molnár, G.; Timár, G.; Ferencz, C.; Lichtenberger, J.

    2009-04-01

    16 of the all 29 channels of the MODIS instrument with 1 square km surface resolution are measuring in the 3.5-15 micron wavelength interval, where the emitted terrestrial radiation is dominating. The regions of 3-5 microns and 8-12 microns are atmospheric windows, where radiation has little interaction with atmospheric gas particles. The amount of emitted radiation of an ideal black body can be calculated using the Planck's function. In the reverse case, measuring the emitted radiation in a certain wavelength region we can calculate the temperature of a black body. An important parameter of this heat transmission system is the soil moisture. Estimating all parameters to a MODIS pixel, such as the aerosol optical depth, land surface temperature, vegetation density (namely the leaf area index) and the soil moisture, we can compile maps of these parameters. Mapping of soil moisture from MODIS data is based in this approach in our method. The research was supported by the Ministry of Informatics and Communication and the Hungarian Space Office projects TP198 and TP277.

  19. The 2004 Earthquake in Light of M>5.5 San Andreas Fault Seismicity Within ~70 km NW of Parkfield Since 1857.

    NASA Astrophysics Data System (ADS)

    Toppozada, T.; Branum, D.; Reichle, M.; Wills, C.

    2004-12-01

    The 2004 Parkfield earthquake occurred at least 12 years later than predicted by the model of quasi-regularly recurring characteristic earthquakes. That model was based on the occurrence of two "Parkfield" events in the 1800s, including the 1857 foreshock ~50 km NW of Parkfield, and four events in the 1900s. The 2004 earthquake better fits the larger and historically more complete picture, which includes at least four additional M~6 or stronger earthquakes on the San Andreas fault within ~70 km NW of Parkfield from 1860 to 1885. These large 1800s earthquakes occurred on the segment of the San Andreas fault that since 1930 has been creeping with no M>5 earthquakes. The great 1857 Fort Tejon earthquake had immediate foreshocks in the zone ~50 km NW of Parkfield near Lonoak. In this northern end of the 1857 rupture, including Parkfield, the rate of seismic moment release has decreased steadily with time since 1857. More strong earthquakes occurred in the ~50 years after 1857 than in the following ~100 years when seismicity was nearer to Parkfield. The high pre-1900 seismicity in the currently creeping segment of the San Andreas fault may have resulted from the stress loading at the 1857 rupture end from the ~9 m displacements in the Carrizo Plain ~80 km SE of Parkfield. This would also explain the decay of the seismicity with time after 1857. The strong earthquakes in the Parkfield-Lonaok end of the 1857 rupture have generally migrated ~70 km with time from NW to SE along the San Andreas fault. In 1857 they were around Lonoak in the presently creeping zone, and in 1966-2004 they bordered the locked zone near Parkfield. If this southeasterly migration continues, the next earthquake might be further SE from Parkfield toward the locked zone that is capable of M~7 or larger earthquakes.

  20. File Specification for the 7-km GEOS-5 Nature Run, Ganymed Release Non-Hydrostatic 7-km Global Mesoscale Simulation

    NASA Technical Reports Server (NTRS)

    da Silva, Arlindo M.; Putman, William; Nattala, J.

    2014-01-01

    This document describes the gridded output files produced by a two-year global, non-hydrostatic mesoscale simulation for the period 2005-2006 produced with the non-hydrostatic version of GEOS-5 Atmospheric Global Climate Model (AGCM). In addition to standard meteorological parameters (wind, temperature, moisture, surface pressure), this simulation includes 15 aerosol tracers (dust, sea-salt, sulfate, black and organic carbon), O3, CO and CO2. This model simulation is driven by prescribed sea-surface temperature and sea-ice, daily volcanic and biomass burning emissions, as well as high-resolution inventories of anthropogenic sources. A description of the GEOS-5 model configuration used for this simulation can be found in Putman et al. (2014). The simulation is performed at a horizontal resolution of 7 km using a cubed-sphere horizontal grid with 72 vertical levels, extending up to to 0.01 hPa (approximately 80 km). For user convenience, all data products are generated on two logically rectangular longitude-latitude grids: a full-resolution 0.0625 deg grid that approximately matches the native cubed-sphere resolution, and another 0.5 deg reduced-resolution grid. The majority of the full-resolution data products are instantaneous with some fields being time-averaged. The reduced-resolution datasets are mostly time-averaged, with some fields being instantaneous. Hourly data intervals are used for the reduced-resolution datasets, while 30-minute intervals are used for the full-resolution products. All full-resolution output is on the model's native 72-layer hybrid sigma-pressure vertical grid, while the reduced-resolution output is given on native vertical levels and on 48 pressure surfaces extending up to 0.02 hPa. Section 4 presents additional details on horizontal and vertical grids. Information of the model surface representation can be found in Appendix B. The GEOS-5 product is organized into file collections that are described in detail in Appendix C. Additional

  1. Anisotropy in the subducted oceanic crust and the overlying continental crust explain the existence of a double tectonic tremor zone in the flat portion of the Mexican subduction zone.

    NASA Astrophysics Data System (ADS)

    Husker, A. L.; Castillo, J. A.; Perez-Campos, X.; Frank, W.; Kostoglodov, V.

    2015-12-01

    Tectonic tremor (TT) in Mexico has a complicated behavior due to the shape of the subducted plate. In the flat section the slab dives from the trench to a depth of 40 km at 150 km from the trench where it turns to be flat. It remains at 40 km depth till about 290 - 300 km from the trench where it continues to steeply dive into the mantle. All TT activity is within the flat slab section. An LFE catalog and the vertically averaged shear wave anisotropy observed from receiver functions at the slab interface are used to divide the region into 4 zones. (1) The Transient Zone located at the corner of the slab when it first arrives at 40 km depth (~130 km - 165 km from the trench) where the majority of LFE's are seen in small bursts that produce TT. (2) The Buffer Zone has almost no LFE and is located ~165 km - 190 km from the trench. (3) The sub-Sweet Spot is located ~190 - 204 km from the trench and seems to share many characteristics of the Sweet Spot, but has less than half the LFE activity observed in the Sweet Spot in addition to different anisotropy. (4) The Sweet Spot has the overwhelming majority of LFE and is located ~204 km - 245 km from the trench. No LFE is found from 245 km to 300 km from the trench despite the plate still being at 40 km depth. The anisotropy percentage in the continental crust drops significantly above the Transient Zone and Sweet Spot suggesting the crust acts as a seal in those two zones permitting trapped fluids to generate TT/LFE activity there as has been observed in other zones. The Buffer Zone coincides with a region of high fluid flow in the crust (Jodicke et al., 2005) suggesting that there is no seal in this zone allowing fluids to escape thereby limiting TT/LFE generation. The convergence of the zone would imply that the anisotropy preferred orientation at the plate interface should be perpendicular to the trench as much of it is. However, the fast azimuth direction rotates to be trench parallel in the region of the large SSE

  2. Subaqueous tectonic geomorphology along a 400 km stretch of the Queen Charlotte-Fairweather Fault System, southeastern Alaska

    NASA Astrophysics Data System (ADS)

    Brothers, D. S.; Ten Brink, U. S.; Andrews, B. D.; Kluesner, J.; Haeussler, P. J.; Watt, J. T.; Dartnell, P.; Miller, N. C.; Conrad, J. E.; East, A. E.; Maier, K. L.; Balster-Gee, A.; Ebuna, D. R.

    2016-12-01

    Seismic and geodetic monitoring of active fault systems does not typically extend beyond one seismic cycle, hence it is challenging to link the characteristics of individual earthquakes with long-term fault behavior. A compelling place to examine such linkages is the right-lateral Queen Charlotte-Fairweather Fault (QCFF), a 1200 km dextral strike-slip fault offshore southeastern Alaska and western British Columbia. The QCFF defines the North America-Pacific transform plate boundary and has experienced at least eight M>7 earthquakes in the last 130 years. During 2015-2016, the USGS conducted four high-resolution marine geophysical surveys (multibeam bathymetry, sparker multichannel seismic and Chirp) along a 400-km-long section of the QCFF from Icy Point to Noyes Canyon. The QCFF displays a nearly linear and continuous fault trace from Icy Point to the southern tip of Baranof Island, a distance of 315 km. Subtle changes in fault strike, particularly the 200 km section fault south of Sitka Sound, are associated with pull-apart basins and compressional pop-up structures. Bathymetric imagery provides stunning views of strike-slip fault morphology along the continental shelf-edge and slope, including linear fault valleys and knife-edge lateral offset of submarine canyons, gullies, and ridges. We also observe pervasive evidence for small-scale (<1 km^2) submarine landslides along the margin and propose that they were seismically triggered. The glacially scoured southern wall of the Yakobi Sea Valley, formed 17 ka, is offset 925±25 m by the QCFF, providing a late Pleistocene-present slip-rate estimate of approximately 54 mm/yr. This suggests nearly the entire plate boundary motion is localized to a single, relatively narrow fault zone. We also constructed and analyzed a catalog of lateral piercing points along the fault to better understand long-term fault behavior, particularly along segments that have generated large historical earthquakes.

  3. Nonvolcanic tremors in the Mexican subduction zone

    NASA Astrophysics Data System (ADS)

    Payero, J. S.; Kostoglodov, V.; Mikumo, T.; Perez-Campos, X.; Iglesias, A.; Clayton, R.

    2007-05-01

    Nonvolcanic low frequency tremors (NVT) have been discovered and studied recently in Japan and Cascadia subduction zones and deep beneath the San Andreas Fault. The tremors activity is increasing during so-called silent earthquakes (SQ) in Japan and Cascadia. NVT clusters also migrate following the propagation of the SQ. The origin of the NVT is still unclear. The studies of NVT and SQ in different subduction zones are required to understand the cause for these phenomena. We discovered a number of NVT from daily spectrograms of continuous broad band records at seismic stations of Servicio Seismológico Nacional (SSN) an MASE project. The analyzed data cover a period of 2001-2004 (SSN) when in 2002 a large SQ has occurred in the Guerrero- Oaxaca region, and a steady-state interseismic epoch of 2005 and a new large SQ in 2006 (MASE). NVT occurred in the central part of the Mexican subduction zone (Guerrero) at approximately 200 km from the coast. We can not accurately localize the tremors because of sparse station coverage in 2001-2004. The MASE data of 2005-2006 show that NVT records in Mexico are very similar to those obtained in Cascadia subduction zone. The tremors duration is of 10-60 min, and they appear to travel at S-wave velocities. More than 100 strong NVT were recorded by most of the MASE stations with the epicenters clustered in the narrow band of ~40x150 km to the south of Iguala city and parallel to the coast line. NVT depths are poorly constrained but seem to be less than 40 km deep. We noticed a some increase of NVT activity during the 2001-2002 and 2006 SQs compared with an NVT activity for the "SQ quiet" period of 2003-2004 nevertheless. A lack of NVT for the period of 2-3 months after the SQ is apparent in 2002 and 2006.

  4. The Bocono Fault Zone, Western Venezuela

    SciTech Connect

    Schubert, C. ); Estevez, R. ); Henneberg, H.G. )

    1993-02-01

    The Bocono Fault Zone, the western part of the Bocono Moron-El Pilar Fault System of the southern Caribbean plate boundary, consists of aligned valleys, linear depressions, pull-apart basins and other morphological features, which extend for about 500 km in a N45[degrees]E direction, between the Tachira depression (Venezuela-Colombia border) and the Caribbean Sea. It crosses obliquely the Cordillera de Merida and cuts across the Caribbean Mountains, two different geologic provinces of Late Tertiary-Quaternary and Late Cretaceous-Early Tertiary age, respectively. Therefore, the maximum age that can be assigned to the Bocono Fault Zone is Late Tertiary (probably Pliocene). A total maximum right-lateral offset rate of 3.3 mm/a. The age of the sedimentary fill o[approximately] the La Gonzalez pull-apart basin suggests that the 7-9 km right-lateral offset necessary to produce it took place in Middle to Late Pleistocene time. The majority of seismic events are well aligned with the main fault trace; minor events are distributed in a belt several kilometers wide. Focal depth is typically 15 km and focal mechanisms indicate an average east-west compression across the zone. Return periods of 135-460 a (Richter M = 8), 45-70 a (M = 7), and 7-15 a (M = 6) have been calculated. Geodetic studies of several sites along the zone indicate compressive and right-lateral components; at Mucubaji the rate of right-lateral displacement observed is about 1 mm every 5 months (15 a of measurements).

  5. A high resolution (1 km) groundwater model for Indonesia

    NASA Astrophysics Data System (ADS)

    Sutanudjaja, Edwin; Verkaik, Jarno; de Graaf, Inge; van Beek, Rens; Erkens, Gilles; Bierkens, Marc

    2015-04-01

    Groundwater is important in many parts of Indonesia. It serves as a primary source of drinking water and industrial activities. During times of drought, it sustains water flows in streams, rivers, lakes and wetlands, and thus support ecosystem habitat and biodiversity as well as preventing hazardous forest fire. Besides its importance, groundwater is known as a vulnerable resource as unsustainable groundwater exploitation and management occurs in many areas of the country. Therefore, in order to ensure sustainable management of groundwater resources, monitoring and predicting groundwater changes in Indonesia are imperative. However, large extent groundwater models to assess these changes on a regional scale are almost non-existent and are hampered by the strong topographical and lithological transitions that characterize Indonesia. In this study, we built an 1 km resolution groundwater model for the entire Indonesian archipelago (total inland area: about 2 million km2). We adopted the approaches of Sutanudjaja et al. (2011, 2014a) and de Graaf et al. (2014) in order to make a MODFLOW (Harbaugh et al., 2000) groundwater model by using only global datasets. Aquifer schematization and properties of the groundwater model were developed from available global lithological maps (e.g. Dürr et al., 2005; Gleeson et al., 2011; Hartmann & Moorsdorf, 2012; Gleeson et al., 2014). We forced the groundwater model with the recent output of global hydrological model PCR-GLOBWB version 2.0 (Sutanudjaja et al., 2014b; van Beek et al., 2011), specifically the long term average of groundwater recharge and average surface water levels derived from channel discharge. Simulation results were promising. The MODFLOW model converged with realistic aquifer properties (i.e. transmissivities) and produced reasonable groundwater head spatial distribution reflecting the positions of major groundwater bodies and surface water bodies in the country. In Vienna, we aim to show and demonstrate these

  6. Determinants of recovery from a 161-km ultramarathon.

    PubMed

    Hoffman, Martin D; Badowski, Natalie; Chin, Joseph; Stuempfle, Kristin J; Parise, Carol A

    2017-04-01

    The primary study objective was to identify determinants of short-term recovery from a 161-km ultramarathon. Participants completed 400 m runs at maximum speed before the race and on days 3 and 5 post-race, provided a post-race blood sample for plasma creatine kinase (CK) concentration, and provided lower body muscle pain and soreness ratings (soreness, 10-point scale) and overall muscular fatigue scores (fatigue, 100-point scale) pre-race and for 7 days post-race. Among 72 race finishers, soreness and fatigue had statistically returned to pre-race levels by 5 days post-race; and 400 m times at days 3 and 5 remained 26% (P = 0.001) and 12% (P = 0.01) slower compared with pre-race, respectively. CK best modelled soreness, fatigue and per cent change in post-race 400 m time. Runners with the highest CKs had 1.5 points higher (P < 0.001) soreness and 11.2 points higher (P = 0.006) fatigue than runners with the lowest CKs. For the model of 400 m time, a significant interaction of time with CK (P < 0.001) indicates that higher CKs were linked with a slower rate of return to pre-race 400 m time. Since post-race CK was the main modifiable determinant of recovery following the ultramarathon, appropriate training appears to be the optimal approach to enhance ultramarathon recovery.

  7. Processing techniques for global land 1-km AVHRR data

    USGS Publications Warehouse

    Eidenshink, Jeffery C.; Steinwand, Daniel R.; Wivell, Charles E.; Hollaren, Douglas M.; Meyer, David

    1993-01-01

    The U.S. Geological Survey's (USGS) Earth Resources Observation Systems (EROS) Data Center (EDC) in cooperation with several international science organizations has developed techniques for processing daily Advanced Very High Resolution Radiometer (AVHRR) 1-km data of the entire global land surface. These techniques include orbital stitching, geometric rectification, radiometric calibration, and atmospheric correction. An orbital stitching algorithm was developed to combine consecutive observations acquired along an orbit by ground receiving stations into contiguous half-orbital segments. The geometric rectification process uses an AVHRR satellite model that contains modules for forward mapping, forward terrain correction, and inverse mapping with terrain correction. The correction is accomplished by using the hydrologic features coastlines and lakes from the Digital Chart of the World. These features are rasterized into the satellite projection and are matched to the AVHRR imagery using binary edge correlation techniques. The resulting coefficients are related to six attitude correction parameters: roll, roll rate, pitch, pitch rate, yaw, and altitude. The image can then be precision corrected to a variety of map projections and user-selected image frames. Because the AVHRR lacks onboard calibration for the optical wavelengths, a series of time-variant calibration coefficients derived from vicarious calibration methods and are used to model the degradation profile of the instruments. Reducing atmospheric effects on AVHRR data is important. A method has been develop that will remove the effects of molecular scattering and absorption from clear sky observations, using climatological measurements of ozone. Other methods to remove the effects of water vapor and aerosols are being investigated.

  8. Estimation of Land Surface Temperature from 1-km AVHRR data

    NASA Astrophysics Data System (ADS)

    Frey, Corinne

    2016-04-01

    In order to re-process DLRs 1km AVHRR data archive to different geophysical and descriptive parameters of the land surface and the atmosphere, a series of scientific data processors are being developed in the framework of the TIMELINE project. The archive of DLR ranges back to the 80ies. One of the data processors is SurfTemp, which processes L2 LST and emissivity datasets from AVHRR L1b data. The development of the data processor included the selection of statistical procedures suitable for time series processing, including four mono-window and six split window algorithms. For almost all of these algorithms, new constants were generated, which better account for different atmospheric and geometric acquisition situations. The selection of optimal algorithms for SurfTemp is based on a round robin approach, in which the selected mono-window and split window algorithms are tested on the basis of a large number of TOA radiance/LST pairs, which were generated using a radiative transfer model and the SeeBorV5 profile database. The original LSTs are thereby compared to the LSTs derived from the TOA radiances using the mono- and split window algorithms. The algorithm comparison includes measures of precision, as well as the sensitivity of a method to the accuracy of its input data. The results of the round robin are presented, as well as the implementation of selected algorithms into SurfTemp. Further, first cross-validation results between the AVHRR LST and MODIS LST are shown.

  9. Gastrointestinal distress is common during a 161-km ultramarathon.

    PubMed

    Stuempfle, Kristin Jean; Hoffman, Martin Dean

    2015-01-01

    This study examined the incidence, severity, and timing of gastrointestinal (GI) symptoms in finishers and non-finishers of the 161-km Western States Endurance Run. A total of 272 runners (71.0% of starters) completed a post-race questionnaire that assessed the incidence and severity (none = 0, mild = 1, moderate = 2, severe = 3, very severe = 4) of 12 upper (reflux/heartburn, belching, stomach bloating, stomach cramps/pain, nausea, vomiting) and lower (intestinal cramps/pain, flatulence, side ache/stitch, urge to defecate, loose stool/diarrhoea, intestinal bleeding/bloody faeces) GI symptoms experienced during each of four race segments. GI symptoms were experienced by most runners (96.0%). Flatulence (65.9% frequency, mean value 1.0, s = 0.6 severity), belching (61.3% frequency, mean value 1.0, s = 0.6 severity), and nausea (60.3% frequency, mean value 1.0, s = 0.7 severity) were the most common symptoms. Among race finishers, 43.9% reported that GI symptoms affected their race performance, with nausea being the most common symptom (86.0%). Among race non-finishers, 35.6% reported that GI symptoms were a reason for dropping out of the race, with nausea being the most common symptom (90.5%). For both finishers and non-finishers, nausea was greatest during the most challenging and hottest part of the race. GI symptoms are very common during ultramarathon running, and in particular, nausea is the most common complaint for finishers and non-finishers.

  10. Foot-strike haemolysis after a 60-km ultramarathon

    PubMed Central

    Lippi, Giuseppe; Schena, Federico; Salvagno, Gian Luca; Aloe, Rosalia; Banfi, Giuseppe; Guidi, Gian Cesare

    2012-01-01

    Background. The various contributors to sport-related anaemia include increased plasma volume, exercise-induced oxidative stress, increased body temperature, acidosis, gastrointestinal bleeding, acute and chronic inflammation as well as compression and damage of red blood cells (RBC) in the capillaries within the contracting muscles. The effective contribution of foot-strike haemolysis is unclear. Materials and methods. We studied 18 Caucasian male athletes (mean age, 42 years; range, 34–52 years) before and immediately after a 60-km ultramarathon. Laboratory investigations included the haematological profile along with haptoglobin, potassium, aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH) and albumin concentrations and a haemolysis index (HI). Results. No significant variations were found in post-exercise values of haemoglobin, RBC count and haematocrit. Mean corpuscular volume and haptoglobin were significantly decreased, whereas RBC distribution width was increased. The concentration of haptoglobin was reduced by approximately 50%, whereas enzyme concentrations were all remarkably increased. The HI remained below 0.5 g/L. After adjusting for plasma volume change, the increases were 1.7% for potassium (P=0.17), 30% for AST (P<0.01), 49% for LDH (P<0.01) and 2.39-fold for CK (P<0.01). A statistically significant association was found between haemoconcentration-adjusted variations of CK and those of AST (r=0.803; P<0.01) and LDH (r=0.551; P=0.02). Discussion. This is the first study demonstrating that long-distance running does not induce clinically significant changes in haemoglobin, haematocrit, RBC count or potassium concentration. The significant post-exercise decrease of haptoglobin reflects a certain degree of haemolysis, but the concentration of cell-free haemoglobin remaining below 0.5 g/L and the non-significant variation in RBC count both indicate that the foot-strike haemolysis is very modest or even clinically

  11. New Madrid Seismic Zone

    DTIC Science & Technology

    2007-11-02

    NEW MADRID SEISMIC ZONE BY COLONEL J.DAVID NORWOOD United States Army DISTRIBUTION STATEMENT A...mCTBB l USAWC STRATEGY RESEARCH PROJECT New Madrid Seismic Zone by J. David Norwood, COL, USA Michael A. Pearson, COL, USA Project Advisor The...ABSTRACT AUTHOR: J. David Norwood, Colonel, U.S. Army TITLE: New Madrid Seismic Zone FORMAT: Strategy Research Project DATE: 22 April 1998 . PAGES:

  12. On the penetration of the 660 km phase change by mantle downflows

    NASA Technical Reports Server (NTRS)

    Bercovici, David; Schubert, Gerald; Tackley, Paul J.

    1993-01-01

    We present a simple analytic model of the interaction of cold convective downwelling currents with an endothermic phase change. The model describes the ponding and lateral spreading of downflows along the phase transition interface. A simple comparison of the vertical forces on the ponding material provides a necessary condition for a downflow to penetrate the phase boundary. This condition is fundamentally dependent on the geometry of the downflow. For planar downwellings, the model predicts a minimum ponding time before the structure can penetrate the phase boundary. For columnar (axisymmetric) downflows, there is no minimum time of spreading required before penetration can proceed. The model thus provides an explanation for the observation that in numerical models of three-dimensional convection with an endothermic phase change, cylindrical downflows penetrate the phase interface while planar ones do not. Since descending slabs in the Earth's mantle display a wide spectrum of geometries between planar and cylindrical (given various trench curvatures, as well as intersections of two or more subduction zones), this phenomenon may explain, in part, why some slabs appear to extend into the lower mantle while others are deflected at the 660 km discontinuity.

  13. Implications of new gravity data for Baikal Rift zone structure

    NASA Technical Reports Server (NTRS)

    Ruppel, C.; Kogan, M. G.; Mcnutt, M. K.

    1993-01-01

    Newly available, 2D Bouguer gravity anomaly data from the Baikal Rift zone, Siberia, indicate that this discrete, intracontinental rift system is regionally compensated by an elastic plate about 50 km thick. However, spectral and spatial domain analyses and isostatic anomaly calculations show that simple elastic plate theory does not offer an adequate explanation for compensation in the rift zone, probably because of significant lateral variations in plate strength and the presence of subsurface loads. Our results and other geophysical observations support the interpretation that the Baikal Rift zone is colder than either the East African or Rio Grande rift.

  14. Implications of new gravity data for Baikal Rift zone structure

    NASA Technical Reports Server (NTRS)

    Ruppel, C.; Kogan, M. G.; Mcnutt, M. K.

    1993-01-01

    Newly available, 2D Bouguer gravity anomaly data from the Baikal Rift zone, Siberia, indicate that this discrete, intracontinental rift system is regionally compensated by an elastic plate about 50 km thick. However, spectral and spatial domain analyses and isostatic anomaly calculations show that simple elastic plate theory does not offer an adequate explanation for compensation in the rift zone, probably because of significant lateral variations in plate strength and the presence of subsurface loads. Our results and other geophysical observations support the interpretation that the Baikal Rift zone is colder than either the East African or Rio Grande rift.

  15. Sound Velocities of the Transition Zone Minerals

    NASA Astrophysics Data System (ADS)

    Lin, J.; Mao, Z.; Lu, C.; Jacobsen, S. D.; Duffy, T. S.; Chang, Y.; Frost, D. J.; Hauri, E. H.; Zhuravlev, K. K.; Tkachev, S. N.; Prakapenka, V.

    2012-12-01

    Earth's mantle transition zone from 410 to 660-km depth exhibits seismic signatures reflecting thermo-chemical perturbations, including displaced depths of the nominal 410-km and 660-km discontinuities, the depth interval of the 410-km discontinuity, as well as lateral velocity variations compared to reference models. These observed anomalies have been proposed to correlate with the possible presence of H2O and thermal effects because the cold subducted slabs may transport H2O to the transition zone. Elastic properties of the major constituent minerals at relevant high pressure-temperature (P-T) conditions are crucial for understanding the mineralogical and geothermal models, water budget, and seismic velocity structures of the region. To understand the effects of high P-T and hydration on the sound velocities of major mantle minerals and to constrain the mantle's H2O budget, we have measured the single-crystal elastic moduli of hydrous and nominally anhydrous iron-bearing mantle minerals using Brillouin light scattering combined with X-ray diffraction in an externally-heated diamond anvil cell up at relevant P-T conditions of the mantle. Our results on hydrous ringwoodite with 1.1 wt.% H2O show a strong reduction by hydration in the elastic moduli at room temperature and a significant net effect of temperature and hydration on the elastic moduli at high pressures. Results on Fe-bearing minerals show that addition of iron does not have a strong effect on sound velocities at high P-T. These results are applied to quantify the effect of thermal perturbations as well as hydration on the seismic structures of the transition zone. Here we will address how the results can provide crucial constraints on the transition zone water budget that is essential for understanding the global water circulation. Specifically, our results indicate that the observed seismic velocity anomalies and related depth depression of the 660-km discontinuity could be attributed to thermal

  16. 112 Gb/s PM-QPSK transmission up to 6000 km with 200 km amplifier spacing and a hybrid fiber span configuration.

    PubMed

    Downie, John D; Hurley, Jason; Cartledge, John; Bickham, Scott; Mishra, Snigdharaj

    2011-12-12

    We demonstrate transmission of 112 Gb/s PM-QPSK signals over a system with 200 km span lengths. Amplification is provided by hybrid backward-pumped Raman/EDFA amplifiers and reach lengths up to 6000 km for an 8 channel system and 5400 km for a 32 channel system are shown. As a means of maximizing OSNR, a simple hybrid fiber span configuration is used that combines two ultra-low loss fibers, one having very large effective area.

  17. Risk assessment of people trapped in earthquake based on km grid: a case study of the 2014 Ludian earthquake

    NASA Astrophysics Data System (ADS)

    Wei, Ben-Yong; Nie, Gao-Zhong; Su, Gui-Wu; Sun, Lei

    2017-04-01

    China is one of the most earthquake prone countries in the world. The priority during earthquake emergency response is saving lives and minimizing casualties. Rapid judgment of the trapped location is the important basis for government to reasonable arrange the emergency rescue forces and resources after the earthquake. Through analyzing the key factors resulting in people trapped, we constructed an assessment model of personal trapped (PTED)in collapsed buildings caused by earthquake disaster. Then taking the 2014 Ludian Earthquake as a case, this study evaluated the distribution of trapped personal during this earthquake using the assessment model based on km grid data. Results showed that, there are two prerequisites for people might be trapped by the collapse of buildings in earthquake: earthquake caused buildings collapse and there are people in building when building collapsing; the PTED model could be suitable to assess the trapped people in collapsed buildings caused by earthquake. The distribution of people trapped by the collapse of buildings in the Ludian earthquake assessed by the model is basically the same as that obtained by the actual survey. Assessment of people trapped in earthquake based on km grid can meet the requirements of search-and-rescue zone identification and rescue forces allocation in the early stage of the earthquake emergency. In future, as the basic data become more complete, assessment of people trapped in earthquake based on km grid should provide more accurate and valid suggestions for earthquake emergency search and rescue.

  18. The upper-mantle transition zone beneath the Chile-Argentina flat subduction zone

    NASA Astrophysics Data System (ADS)

    Bagdo, Paula; Bonatto, Luciana; Badi, Gabriela; Piromallo, Claudia

    2016-04-01

    The main objective of the present work is the study of the upper mantle structure of the western margin of South America (between 26°S and 36°S) within an area known as the Chile-Argentina flat subduction zone. For this purpose, we use teleseismic records from temporary broad band seismic stations that resulted from different seismic experiments carried out in South America. This area is characterized by on-going orogenic processes and complex subduction history that have profoundly affected the underlying mantle structure. The detection and characterization of the upper mantle seismic discontinuities are useful to understand subduction processes and the dynamics of mantle convection; this is due to the fact that they mark changes in mantle composition or phase changes in mantle minerals that respond differently to the disturbances caused by mantle convection. The discontinuities at a depth of 410 km and 660 km, generally associated to phase changes in olivine, vary in width and depth as a result of compositional and temperature anomalies. As a consequence, these discontinuities are an essential tool to study the thermal and compositional structure of the mantle. Here, we analyze the upper-mantle transition zone discontinuities at a depth of 410 km and 660 km as seen from Pds seismic phases beneath the Argentina-Chile flat subduction.

  19. Hyaloclastites and the slope stability of Hawaiian volcanoes: Insights from the Hawaiian Scientific Drilling Project's 3-km drill core

    NASA Astrophysics Data System (ADS)

    Schiffman, Peter; Watters, Robert J.; Thompson, Nick; Walton, Anthony W.

    2006-03-01

    Core samples recovered during the Hawaiian Scientific Drilling Project (HSDP) drilling project reveal that the upper 1 km of the submarine flank of Mauna Kea is comprised mainly of hyaloclastites. Progressive, very low-temperature alteration of these hyaloclastites has been accompanied by systematic transformations in physical properties of these deposits. Hyaloclastite deposits which directly underlie ca. 1 km of subaerially-emplaced lavas are very poorly consolidated. But over a depth interval of ca. 500 m, compaction and, especially, precipitation of zeolitic, pore-filling cements associated with palagonitization of sideromelane, have eliminated porosity as well as promoted the consolidation of these hyaloclastites. The latter is reflected in unconfined compressive strengths which increase from mean values, respectively, of 2.5 and 4.6 MPa in weakly consolidated, smectite-rich hyaloclastites from the incipient (1080 to 1335 mbsl) and smectitic (1405-1573 mbsl) alteration zones, to a mean value of 10.0 MPa in the more highly consolidated hyaloclastites of the palagonitic zone of alteration (from 1573 mbsl to the bottom of the drill hole). Conversely, overlying, intercalated, and underlying lava flows are generally much less altered, and have mean compressive strengths which are 1 to 2 orders of magnitude greater then hyaloclastites at equivalent depths. The shear strengths of the hyaloclastites also increase with depth and grade of alteration, but are uniformly and substantially lower in the lavas. Those hyaloclastites exhibiting the highest grade of alteration (i.e., palagonitic) also exhibit the highest measured strengths, and thus the alteration of hyaloclastites appears to strengthen as opposed to weaken the flanks of the edifice. However, the contrast in strength between hyaloclastites and lavas may be a primary factor in localizing destabilization, and the zones of weak and poorly consolidated hyaloclastites may facilitate slumping by servings as hosts for

  20. The structure of Ellesmere Island - a 400 km long transect across the northern margin of North America

    NASA Astrophysics Data System (ADS)

    Piepjohn, K.; von Gosen, W.; Tessensohn, F.

    2012-04-01

    The margin of North America on Ellesmere Island is characterised by two major structural units. In the north, the exotic Pearya Terrane at the coast of the Arctic Ocean consists of Meso- and Neoproterozoic basement rocks and Paleozoic metasediments. The area between Pearya and the Greenland shield in the southeast is dominated by the several kilometres thick Franklinian Basin deposits of Neoproterozoic to Devonian age. During the Caledonian Orogeny, Pearya was partly affected by deformation and metamorphism, whereas the Franklinian Basin represented the passive Laurentian margin until Devonian times. In the earliest Carboniferous, the northern passive margin of Laurentia was affected by Ellesmerian deformation caused by docking of the Pearya Terrane and. Between Pearya in the NW and Nares Strait in the SE, the Ellesmerian structures are dominated by a km-scale folding of the Franklinian Basin deposits. With some minor exceptions, the folds are characterized by subvertical axial planes and a corresponding cleavage. Transports were directed towards SE to SSE as indicated by displacements along several thrust. Between the boundary to Pearya in the NW and Nares Strait in the SE the Ellesmerian Fold-and-Thrust Belt is probably underlain by a regional compressional detachment in an estimated depth of 7 to 10 kilometres. In contrast to the folding-dominated Ellesmerian deformation, the Eurekan (Early Tertiary) tectonic event in the Franklinian Basin is characterized by the formation of brittle thrust faults and strike-slip faults, which partly reactivated Ellesmerian thrust faults. Parallel to Nares Strait, up to 500 m wide, NNE-SSW trending sinistral strike-slip fault zones are exposed on northern Judge Daly Promontory. Towards SSW, at Cape Back, the strike-slip faults were reactivated by ESE-directed reverse faulting, and from Cape Lawrence towards Princess Marie Bay, Eurekan structures are dominated by large thrust zones. These carried km-thick sedimentary units of the

  1. Evolution of a Subduction Zone

    NASA Astrophysics Data System (ADS)

    Noack, Lena; Van Hoolst, Tim; Dehant, Veronique

    2014-05-01

    The purpose of this study is to understand how Earth's surface might have evolved with time and to examine in a more general way the initiation and continuance of subduction zones and the possible formation of continents on an Earth-like planet. Plate tectonics and continents seem to influence the likelihood of a planet to harbour life, and both are strongly influenced by the planetary interior (e.g. mantle temperature and rheology) and surface conditions (e.g. stabilizing effect of continents, atmospheric temperature), but may also depend on the biosphere. Employing the Fortran convection code CHIC (developed at the Royal Observatory of Belgium), we simulate a subduction zone with a pre-defined weak zone (between oceanic and continental crust) and a fixed plate velocity for the subducting oceanic plate (Quinquis et al. in preparation). In our study we first investigate the main factors that influence the subduction process. We simulate the subduction of an oceanic plate beneath a continental plate (Noack et al., 2013). The crust is separated into an upper crust and a lower crust. We apply mixed Newtonian/non-Newtonian rheology and vary the parameters that are most likely to influence the subduction of the ocanic plate, as for example density of the crust/mantle, surface temperature, plate velocity and subduction angle. The second part of our study concentrates on the long-term evolution of a subduction zone. Even though we model only the upper mantle (until a depth of 670km), the subducted crust is allowed to flow into the lower mantle, where it is no longer subject to our investigation. This way we can model the subduction zone over long time spans, for which we assume a continuous inflow of the oceanic plate into the investigated domain. We include variations in mantle temperatures (via secular cooling and decay of radioactive heat sources) and dehydration of silicates (leading to stiffening of the material). We investigate how the mantle environment influences

  2. Microgravity silicon zoning investigation

    NASA Technical Reports Server (NTRS)

    Kern, E. L.; Gill, G. L., Jr.

    1983-01-01

    A resistance heated zoner, suitable for early zoning experiments with silicon, was designed and put into operation. The initial power usage and size was designed for an shown to be compatible with payload carriers contemplated for the Shuttle. This equipment will be used in the definition and development of flight experiments and apparatus for float zoning silicon and other materials in microgravity.

  3. Coastal zone management

    NASA Technical Reports Server (NTRS)

    Tilton, E. L., III

    1975-01-01

    A panel of federal and state representatives concerned with coastal zone affairs discussed their problems in this area. In addition, several demonstrations of the application of remote sensing technology to coastal zone management were described. These demonstrations were performed by several agencies in a variety of geographical areas.

  4. Subduction of fracture zones

    NASA Astrophysics Data System (ADS)

    Constantin Manea, Vlad; Gerya, Taras; Manea, Marina; Zhu, Guizhi; Leeman, William

    2013-04-01

    Since Wilson proposed in 1965 the existence of a new class of faults on the ocean floor, namely transform faults, the geodynamic effects and importance of fracture zone subduction is still little studied. It is known that oceanic plates are characterized by numerous fracture zones, and some of them have the potential to transport into subduction zones large volumes of water-rich serpentinite, providing a fertile water source for magma generated in subduction-related arc volcanoes. In most previous geodynamic studies, subducting plates are considered to be homogeneous, and there is no clear indication how the subduction of a fracture zone influences the melting pattern in the mantle wedge and the slab-derived fluids distribution in the subarc mantle. Here we show that subduction of serpentinized fracture zones plays a significant role in distribution of melt and fluids in the mantle wedge above the slab. Using high-resolution tree-dimensional coupled petrological-termomechanical simulations of subduction, we show that fluids, including melts and water, vary dramatically in the region where a serpentinized fracture zone enters into subduction. Our models show that substantial hydration and partial melting tend to concentrate where fracture zones are being subducted, creating favorable conditions for partially molten hydrous plumes to develop. These results are consistent with the along-arc variability in magma source compositions and processes in several regions, as the Aleutian Arc, the Cascades, the Southern Mexican Volcanic Arc, and the Andean Southern Volcanic Zone.

  5. Marginal Zone Lymphoma

    MedlinePlus

    ... zone lymphomas are a group of indolent (slow-growing) NHL B-cell lymphomas, which account for approximately 12 percent of all B-cell lymphomas. The median age for diagnosis is 65 years old. There are three types of marginal zone lymphoma: ...

  6. Longleaf pine site zones

    Treesearch

    Phillip J. Craul; John S. Kush; William D. Boyer

    2005-01-01

    The authors delineate six major climatic areas of the longleaf pine (Pinus palustris Mill.) region. They subdivide these areas into 21 site zones, each of which is deemed homogenous with respect to climate, physiography, and soils. The site zones are mapped and their climate, physiography, and soils described. The authors recommend that plantings of...

  7. Investigating Aquatic Dead Zones

    ERIC Educational Resources Information Center

    Testa, Jeremy; Gurbisz, Cassie; Murray, Laura; Gray, William; Bosch, Jennifer; Burrell, Chris; Kemp, Michael

    2010-01-01

    This article features two engaging high school activities that include current scientific information, data, and authentic case studies. The activities address the physical, biological, and chemical processes that are associated with oxygen-depleted areas, or "dead zones," in aquatic systems. Students can explore these dead zones through both…

  8. Urban Terrain Zone Characteristics

    DTIC Science & Technology

    1987-09-01

    function . An example of the interaction of some of these can result in an exposed surface of decorative brick veneer on a framed stracture . Or, a...Classification System for HOUT Studies . . . . . . . . .- ..- . . . . . . 14 2. Urban Terrain Zones Function /Morphology Relationship...By Function --All Cities Aggregated . . . . . . . . . . . . . . . . . . . 69 6. Building Types: Major Terrain Zones . . . . ...... 103 7. Urban Terrain

  9. Investigating Aquatic Dead Zones

    ERIC Educational Resources Information Center

    Testa, Jeremy; Gurbisz, Cassie; Murray, Laura; Gray, William; Bosch, Jennifer; Burrell, Chris; Kemp, Michael

    2010-01-01

    This article features two engaging high school activities that include current scientific information, data, and authentic case studies. The activities address the physical, biological, and chemical processes that are associated with oxygen-depleted areas, or "dead zones," in aquatic systems. Students can explore these dead zones through both…

  10. California tree seed zones

    Treesearch

    John M. Buck; Ronald S. Adams; Jerrold Cone; M. Thompson Conkle; William J. Libby; Cecil J. Eden; Michel J. Knight

    1970-01-01

    California forest tree seed zones were established originally by Fowells (1946), with revisions proposed by Roy (1963) and Schubert (1966). The Forest Tree Seed Committee of the Northern California Section, Society of American Foresters, has revised the original zones and updated the recording system described in the earlier reports. Fowells' (1946) Research Note...

  11. Float Zone Workshop

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1980-01-01

    A summary of the Analytical Float Zone Experiment System (AFZES) concept is presented. The types of experiments considered for such a facility are discussed. Reports from various industrial producers and users of float zone material are presented. Special emphasis is placed on state-of-the-art developments in low gravity manufacturing and their applications to space processing.

  12. Anatomy of an ancient subduction interface at 40 km depth: Insights from P-T-t-d data, and geodynamic implications (Dent Blanche, Western Alps)

    NASA Astrophysics Data System (ADS)

    Angiboust, Samuel; Glodny, Johannes; Oncken, Onno; Chopin, Christian

    2014-05-01

    An exhumed metamorphic suture zone over 40 km long is exposed in the Dent Blanche Region of the Western Alps belt, along the Swiss-Italian border. In this region, the metasediment-bearing ophiolitic remnants of the Liguro-Piemontese ocean (Tsaté complex) are overthrusted by a continental, km-sized complex (Dent Blanche Tectonic System: DBTS) of Austro-Alpine affinity. The DBTS represents a strongly deformed composite terrane with independent tectonic slices of continental and oceanic origin. In order to better understand the nature and the geodynamic meaning of the shear zone at the base of the DBTS (Dent Blanche Thrust, DBT) we re-evaluated the pressure-temperature-time-deformation (P-T-t-d) history of these two units using modern thermobarometric tools, Rb/Sr deformation ages and field relationships. Our results show that the Tsaté complex is formed by a stack of km-thick calcschists-bearing tectonic slices, having experienced variable maximum burial temperatures of between 360°C and 490°C at depths of ca. 25-40 km, between 41 Ma and 37 Ma. The Arolla gneissic mylonites constituting the base of the DBTS experienced a continuous record of protracted high-pressure (12-14 kbar), top-to-NW D1 deformation at 450-500°C between 43 and 55 Ma. Some of these primary, peak metamorphic fabrics have been sheared (top-to-SE D2) and backfolded during exhumation and collisional overprint (20 km depth, 35-40 Ma) leading to the regional greenschist facies retrogression particularly prominent within Tsaté metasediments. The final juxtaposition of the DBTS with the Tsaté complex occurred between 350 and 500°C during this later, exhumation-related D2 event. Although some exhumation-related deformation partially reworked D1 primary features, we emphasize that the DBT can be viewed as a remnant of the Alpine early Eocene blueschist-facies subduction interface region. The DBT therefore constitutes the deeper equivalent of some shallower portions of the Alpine subduction

  13. Seismicity around the Cimandiri fault zone, West Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Febriani, Febty

    2016-02-01

    We analyzed the seismicity activity around the Cimandiri fault zone, West Java, Indonesia by using the earthquake catalogs listed by Indonesian Meteorological Climatological and Geophysical (BMKG) and International Seismological Centre (ISC) from 1973 to 2013 (M>=1 and depth ≤ 0-50 km), along with the focal mechanism data from National Research Institute of Earth Science and Disaster Prevention (NIED) from 2007 to 2014 (M>4; depth ≤ 50 km) and Global CMT catalog from 1976 to 2014 (M=0-10 and depth ≤ 50 km). The result from earthquake catalogs suggest that there are earthquake activities around the Cimandiri fault zone in the recent years, which is also supported by the results of focal mechanism data analysis from NIED data and Global CMT catalog.

  14. Tularosa Basin Play Fairway Analysis: Partial Basin and Range Heat and Zones of Critical Stress Maps

    DOE Data Explorer

    Adam Brandt

    2015-11-15

    Interpolated maps of heat flow, temperature gradient, and quartz geothermometers are included as TIF files. Zones of critical stress map is also included as a TIF file. The zones are given a 5km diameter buffer. The study area is only a part of the Basin and Range, but it does includes the Tularosa Basin.

  15. Aftershocks illuminate the 2011 Mineral, Virginia, earthquake causative fault zone and nearby active faults

    USGS Publications Warehouse

    Horton, Jr., J. Wright; Shah, Anjana K.; McNamara, Daniel E.; Snyder, Stephen L.; Carter, Aina M

    2015-01-01

    Deployment of temporary seismic stations after the 2011 Mineral, Virginia (USA), earthquake produced a well-recorded aftershock sequence. The majority of aftershocks are in a tabular cluster that delineates the previously unknown Quail fault zone. Quail fault zone aftershocks range from ~3 to 8 km in depth and are in a 1-km-thick zone striking ~036° and dipping ~50°SE, consistent with a 028°, 50°SE main-shock nodal plane having mostly reverse slip. This cluster extends ~10 km along strike. The Quail fault zone projects to the surface in gneiss of the Ordovician Chopawamsic Formation just southeast of the Ordovician–Silurian Ellisville Granodiorite pluton tail. The following three clusters of shallow (<3 km) aftershocks illuminate other faults. (1) An elongate cluster of early aftershocks, ~10 km east of the Quail fault zone, extends 8 km from Fredericks Hall, strikes ~035°–039°, and appears to be roughly vertical. The Fredericks Hall fault may be a strand or splay of the older Lakeside fault zone, which to the south spans a width of several kilometers. (2) A cluster of later aftershocks ~3 km northeast of Cuckoo delineates a fault near the eastern contact of the Ordovician Quantico Formation. (3) An elongate cluster of late aftershocks ~1 km northwest of the Quail fault zone aftershock cluster delineates the northwest fault (described herein), which is temporally distinct, dips more steeply, and has a more northeastward strike. Some aftershock-illuminated faults coincide with preexisting units or structures evident from radiometric anomalies, suggesting tectonic inheritance or reactivation.

  16. Marine no-take zone rapidly benefits endangered penguin.

    PubMed

    Pichegru, L; Grémillet, D; Crawford, R J M; Ryan, P G

    2010-08-23

    No-take zones may protect populations of targeted marine species and restore the integrity of marine ecosystems, but it is unclear whether they benefit top predators that rely on mobile pelagic fishes. In South Africa, foraging effort of breeding African penguins decreased by 30 per cent within three months of closing a 20 km zone to the competing purse-seine fisheries around their largest colony. After the fishing ban, most of the penguins from this island had shifted their feeding effort inside the closed area. Birds breeding at another colony situated 50 km away, whose fishing grounds remained open to fishing, increased their foraging effort during the same period. This demonstrates the immediate benefit of a relatively small no-take zone for a marine top predator relying on pelagic prey. Selecting such small protected areas may be an important first conservation step, minimizing stakeholder conflicts and easing compliance, while ensuring benefit for the ecosystems within these habitats.

  17. Marine no-take zone rapidly benefits endangered penguin

    PubMed Central

    Pichegru, L.; Grémillet, D.; Crawford, R. J. M.; Ryan, P. G.

    2010-01-01

    No-take zones may protect populations of targeted marine species and restore the integrity of marine ecosystems, but it is unclear whether they benefit top predators that rely on mobile pelagic fishes. In South Africa, foraging effort of breeding African penguins decreased by 30 per cent within three months of closing a 20 km zone to the competing purse-seine fisheries around their largest colony. After the fishing ban, most of the penguins from this island had shifted their feeding effort inside the closed area. Birds breeding at another colony situated 50 km away, whose fishing grounds remained open to fishing, increased their foraging effort during the same period. This demonstrates the immediate benefit of a relatively small no-take zone for a marine top predator relying on pelagic prey. Selecting such small protected areas may be an important first conservation step, minimizing stakeholder conflicts and easing compliance, while ensuring benefit for the ecosystems within these habitats. PMID:20147313

  18. Survival of the Tardigrade Hypsibius Dujardini during Hypervelocity Impact Events up to 5.49 km s-1

    NASA Astrophysics Data System (ADS)

    Pasini, D.

    2014-04-01

    Studies have previously been conducted to verify the survivability of living cells during hypervelocity impact events to test the panspermia and lithopanspermia hypotheses [1, 2]. It has been demonstrated that bacteria survive impacts up to 5.4 km s-1 (approx. shock pressure 30 GPa) - albeit with a low probability of survival [1], whilst larger, more complex, objects (such as seeds) break up at ~1 km s-1 [2]. The survivability of yeast spores in impacts up to 7.4 km s-1 has also recently been shown [3]. Previous work by the authors demonstrated the survivability of Nannochloropsis Oculata Phytoplankton, a eukaryotic photosynthesizing autotroph found in the 'euphotic zone' (sunlit surface layers of oceans [4]), at impact velocities up to 6.07 km s-1 [5]. Other groups have also reported that lichens are able to survive shocks in similar pressure ranges [6]. However, whilst many simple single celled organisms have now been shown to survive such impacts (and the associated pressures) as those encountered during the migration of material from one planet to another [1, 3, 5], complex multicellular organisms have either largely not been tested or, those that have been, have not survived the process [2]. Hypsibius dujardini, like most species of tardigrade, are complex organisms composed of approximately 40,000 cells [7]. When humidity decreases they enter a highly dehydrated state known as a 'tun' and can survive extreme temperatures (as low as - 253°C or as high as 151°C), as well as exposure to Xrays and the vacuum of space [7]. Here we test the shock survivability of Hypsibius dujardini by firing a nylon projectile onto a frozen sample of water containing frozen tardigrades using a light gas gun (LGG) [8]. The recovered ice and water were then analysed under an optical microscope to check the viability of any remnant organisms that may have survived impact, and the pressures generated.

  19. Seismic-reflection imaging of Tertiary faulting and related post-Eocene deformation 20 km North of Memphis, Tennessee

    USGS Publications Warehouse

    Williams, R.A.; Stephenson, W.J.; Odum, J.K.; Worley, D.M.

    2001-01-01

    Other than the Crittenden County fault zone (CCFZ), little is known about the seismic hazard from earthquake faults within 50 km of Memphis, Tennessee, a city that contains a large inventory of older buildings that are vulnerable to moderate and strong earthquake ground shaking. To address this lack of knowledge about faulting near Memphis, we acquired a 4.5 km long Mini-Sosie seismic-reflection profile across the boundary between the loess-covered bluffs and modern Mississippi River flood plain in Meeman-Shelby Forest State Park north of Memphis. We imaged a previously unknown reverse/thrust fault that displaces Paleozoic and Cretaceous rocks and upwarps Tertiary deposits on the floodplain portion of the profile about 25 km north of downtown Memphis. The Paleozoic and Cretaceous rocks are vertically faulted about 70 and 40 m, respectively, in an up-to-the-west sense of displacement. The fault displacement apparently terminates in the basal portion of the Paleocene section and causes only an upwarping of the overlying deposits. The overlying Paleocene and Eocene deposits, which are probably the youngest deposits imaged, are upwarped about 50-60 m with the same sense of displacement as the underlying older units. The sense of displacement, amplitude, and appearance of the fault in the seismic data are very similar to that observed in the seismic reflection images of the CCFZ 15 km west of this profile. Although we have imaged this new fault in only one location, its proximity to Memphis and similarities to the CCFZ, leads us to speculate that it may be a parallel structure to the CCFZ and thus warrants further study. ?? 2001 Elsevier Science B.V. All rights reserved.

  20. Percent utilization of VO2 max at 5-km competition velocity does not determine time performance at 5 km among elite distance runners.

    PubMed

    Støa, Eva Maria; Støren, Øyvind; Enoksen, Eystein; Ingjer, Frank

    2010-05-01

    The present study investigated to what extent maximum oxygen uptake (VO2 max) and fractional utilization (%VO2 max) in 5-km competition speed correlate with 5-km performance times among elite long distance runners. Eight elite long distance runners with 5-km performance times of 15.10 minutes ( +/- 32 seconds) were tested for VO2 max during an incremental protocol and for %VO2 max during an 8-minute treadmill test at the velocity representing their 5-km seasonal best performance time. There was no correlation between fractional utilization and 5-km performance. The study showed no significant difference between VO2 max obtained during an incremental VO2 max test and %VO2 max when running for 8 minutes at the runner's individual 5-km competition speed. The 5-km time was related to the runner's VO2 max even in a homogenous high-level performance group. In conclusion, the present study found no relationship between fractional utilization and 5-km performance time. Training aiming to increase %VO2 max may thus be of little or no importance in performance enhancement for competitions lasting up to approximately 20 minutes.

  1. Temperature Models for the Mexican Subduction Zone

    NASA Astrophysics Data System (ADS)

    Manea, V. C.; Kostoglodov, V.; Currie, C.; Manea, M.; Wang, K.

    2002-12-01

    It is well known that the temperature is one of the major factors which controls the seismogenic zone. The Mexican subduction zone is characterized by a very shallow flat subducting interplate in its central part (Acapulco, Oaxaca), and deeper subduction slabs northern (Jalisco) and southern (Chiapas). It has been proposed that the seismogenic zone is controlled, among other factors, by a temperature. Therefore, we have developed four two-dimensional steady state thermal models for Jalisco, Guerrero, Oaxaca and Chiapas. The updip limit of the seismogenic zone is taken between 100 §C and 150 §C, while the downdip limit is thought to be at 350 §C because of the transition from stick-slip to stable-sliding. The shape of the subducting plate is inferred from gravity and seismicity. The convergence velocity between oceanic and continental lithospheric plates is taken as the following: 5 cm/yr for Jalisco profile, 5.5 for Guerrero profile, 5.8 for Oaxaca profile, and 7.8 for Chiapas profile. The age of the subducting plates, since they are young, and provides the primary control on the forearc thermal structure, are as the following: 11 My for Jalisco profile, 14.5 My for Guerrero profile, 15 My for Oaxaca profile, and 28 My for Chiapas profile. We also introduced in the models a small quantity of frictional heating (pore pressure ratio 0.98). The value of 0.98 for pore pressure ratio was obtained for the Guerrero profile, in order to fit the intersection between the 350 §C isotherm and the subducting plate at 200 Km from trench. The value of 200 km coupling zone from trench is inferred from GPS data for the steady interseismic period and also for the last slow aseismic slip that occurred in Guerrero in 2002. We have used this value of pore pressure ratio (0.98) for all the other profiles. For the others three profiles we obtained the following coupling extents: Jalisco - 100 km, Oaxaca - 170 km and Chiapas - 125 km (from the trench). Independent constrains of the

  2. Repeating earthquakes analysis in the Taiwan-Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Chang, Y. E.; Chen, K. H.; Chen, S.

    2012-12-01

    The understanding of interplate slip has been limited in the Taiwan-Ryukyu subduction zone due to sparse sampling of seismic and geodetic stations. Repeating earthquakes study has been proposed to improve the understanding of deep fault behavior. However, in this particular regions where spatial coverage of seismic station is sparse and one sided with high noise level or where starting catalog origin times are inaccurate; establishing waveform cross-correlation method (wcc) for rapid detection of repeating earthquakes is problematic. When the wcc method is applied over a large area of 100 Km x 300 km for M>2 earthquakes at a depth range of 0-50 km (12932 events in total), a large number of false detections occurred due to low-amplitude signal templates. This leads additional time-consumingefforts on manual re-identification. In this study we propose an efficient repeating sequence identification scheme in the regions where the station coverage is sparse with low signal to noise ratio. Using this identification method, we found 9 (M2.5~4.5) interplate repeating sequences in the Taiwan-Ryukyu subduction zone at 35-45 km depth. The interplate repeating earthquakes tend to be short-lived in the form of doublet or multiplet, which the association between doublet/multiplet generation and subduction zone processes requires further study. Other crustal repeating earthquakes occurred at shallow depth above 20 km; these sequences have occurrence rate strongly associated with the nearby M6 earthquakes. This identification scheme will be applied to deeper events (> 50 km depth) for a more complete image of spatial and temporal distribution of interpolate aseismic slip in the Taiwan-Ryukyu subduction zone .

  3. Mantle transition zone structure along a profile in the SW Pacific: thermal and compositional variations

    NASA Astrophysics Data System (ADS)

    Thomas, Christine; Billen, Magali I.

    2009-01-01

    Events from the South Pacific, recorded in the Tien Shan region are studied with a migration method, to measure discontinuity depth along a profile between the Mariana and Molucca Sea subduction zones. Deflections of the upper-mantle discontinuities within and between the subduction zones are investigated using PP precursors filtered to periods of 3 to 10 s. We find P-wave reflections near the 410, 520 and 660 km discontinuities. The 410 km discontinuity is elevated in the subduction region and near the predicted depth (410 km) in the average velocity region. In some cases, we find negative polarities of the reflection from the 410 km discontinuity, which may indicate water-induced melting above the olivine to wadsleyite transition. The 520 km discontinuity is shallow between the two subduction zones, and deepens towards the Mariana backarc region: this discontinuity topography may be due to detection of both the wadsleyite to ringwoodite transition in a depleted downwelling (elevated region) and the formation of calcium-perovskite in a more fertile upwelling (depressed region). The 660 km discontinuity is split in the Halmahera slab with one reflection each near 600 and 700 km depth, consistent with a cold sinking slab and detection of phase transitions for both garnet and olivine to perovskite, respectively. In the region between the subduction areas, we find a downward deflection of the 660 km discontinuity with short length-scale (100-300 km) undulations that may reflect compositional variation.

  4. Shear zones formed along long, straight traces of fault zones during the 28 June 1992 Landers, California, earthquake

    USGS Publications Warehouse

    Johnson, Arvid M.; Fleming, Robert W.; Cruikshank, Kenneth M.

    1994-01-01

    Surface rupturing during the 28 June 1992 Landers, California, earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en-echelon fault zones with a total length of 80 km. The offsets were accommodated generally not by faults—distinct slip surfaces—but rather by shear zones, tabular bands of localized shearing. Along simple stretches of fault zones at Landers the rupture is characterized by telescoping of shear zones and intensification of shearing: broad shear zones of mild shearing, containing narrow shear zones of more intense shearing, containing even narrower shear zones of very intense shearing, which may contain a fault. Thus the ground ruptured across broad belts of shearing with clearly defined, subparallel walls, oriented NW. Each broad belt consists of a broad zone of mild shearing, extending across its entire width (50 to 200 m), and much narrower (a few meters wide) shear zones that accommodate most of the offset of the belt and are portrayed by en-echelon tension cracks. In response to right-lateral shearing, the slices of ground bounded by the tension cracks rotated in a clockwise sense, producing left-lateral shearing, and the slices were forced against the walls of the shear zone, producing thrusting. Even narrower shear zones formed within the narrow shear zones. Although these probably are guides to right-lateral fault segments below, the surface rupturing during the earthquake is characterized not by faulting, but by the formation of shear zones at various scales.

  5. Mantle transition zone shear velocity gradients beneath USArray

    NASA Astrophysics Data System (ADS)

    Schmandt, Brandon

    2012-11-01

    Broadband P-to-s scattering isolated by teleseismic receiver function analysis is used to investigate shear velocity (VS) gradients in the mantle transition zone beneath USArray. Receiver functions from 2244 stations were filtered in multiple frequency bands and migrated to depth through P and S tomography models. The depth-migrated receiver functions were stacked along their local 410 and 660 km discontinuity depths to reduce stack incoherence and more accurately recover the frequency-dependent amplitudes of P410s and P660s. The stacked waveforms were inverted for one-dimensional VS between 320 and 840 km depth. First, a gradient-based inversion was used to find a least-squares solution and a subsequent Monte Carlo search about that solution constrained the range of VS profiles that provide an acceptable fit to the receiver function stacks. Relative to standard references models, all the acceptable models have diminished VS gradients surrounding the 410, a local VS gradient maximum at 490-500 km depth, and an enhanced VS gradient above the 660. The total 410 VS increase of 6.3% is greater than in reference models, and it occurs over a thickness of 20 km. However, 60% of this VS increase occurs over only 6 km. The 20 km total thickness of the 410 and diminished VS gradients surrounding the 410 are potential indications of high water content in the regional transition zone. An enhanced VS gradient overlying the 660 likely results from remnants of subduction lingering at the base of the transition zone. Cool temperatures from slabs subducted since the late Cretaceous and longer-term accumulation of former ocean crust both may contribute to the high gradient above the 660. The shallow depth of the 520 km discontinuity, 490-500 km, implies that the regional mean temperature in the transition zone is 110-160 K cooler than the global mean. A concentrated Vs gradient maximum centered near 660 km depth and a low VS gradient below 675 km confirms that the ringwoodite to

  6. Cratering and penetration experiments in Teflon targets at velocities from 1 to 7 km/s

    NASA Technical Reports Server (NTRS)

    Hoerz, Friedrich; Bernhard, Ronald P.; Cintala, Mark J.; See, Thomas H.

    1995-01-01

    Approximately 20 sq m of protective thermal blankets, largely composed of Teflon, were retrieved from the Long Duration Exposure Facility (LDEF) after the spacecraft had spent approximately 5.7 years in space. Examination of these blankets revealed that they contained thousands of hypervelocity impact features ranging from micron-sized craters to penetration holes several millimeters in diameter. We conducted impact experiments in an effort to reproduce such features and to -- hopefully -- understand the relationships between projectile size and the resulting crater or penetration-hole diameter over a wide range of impact velocity. Such relationships are needed to derive the size- and mass-frequency distribution and flux of natural and man-made particles in low-Earth orbit. Powder propellant and light-gas guns were used to launch soda-lime glass spheres of 3.175 mm (1/8 inch) nominal diameter (Dp) into pure Teflon FEP targets at velocities ranging from 1 to 7 km/s. Target thickness (T) was varied over more than three orders of magnitude from infinite halfspace targets (Dp/T less than 0.1) to very thin films (Dp/T greater than 100). Cratering and penetration of massive Teflon targets is dominated by brittle failure and the development of extensive spall zones at the target's front and, if penetrated, the target's rear side. Mass removal by spallation at the back side of Teflon targets may be so severe that the absolute penetration-hole diameter (Dh) can become larger than that of a standard crater (Dc) at relative target thicknesses of Dp/T = 0.6-0.9. The crater diameter is infinite halfspace Teflon targets increases -- at otherwise constant impact conditions -- with encounter velocity by a factor of V0.44. In contrast, the penetration-hole size is very thin foils (Dp/T greater than 50) is essentially unaffected by impact velocity. Penetrations at target thicknesses intermediate to these extremes will scale with variable exponents of V. Our experimental matrix is

  7. Cratering and penetration experiments in Teflon targets at velocities from 1 to 7 km/s

    NASA Technical Reports Server (NTRS)

    Hoerz, Friedrich; Bernhard, Ronald P.; Cintala, Mark J.; See, Thomas H.

    1995-01-01

    Approximately 20 sq m of protective thermal blankets, largely composed of Teflon, were retrieved from the Long Duration Exposure Facility (LDEF) after the spacecraft had spent approximately 5.7 years in space. Examination of these blankets revealed that they contained thousands of hypervelocity impact features ranging from micron-sized craters to penetration holes several millimeters in diameter. We conducted impact experiments in an effort to reproduce such features and to -- hopefully -- understand the relationships between projectile size and the resulting crater or penetration-hole diameter over a wide range of impact velocity. Such relationships are needed to derive the size- and mass-frequency distribution and flux of natural and man-made particles in low-Earth orbit. Powder propellant and light-gas guns were used to launch soda-lime glass spheres of 3.175 mm (1/8 inch) nominal diameter (Dp) into pure Teflon FEP targets at velocities ranging from 1 to 7 km/s. Target thickness (T) was varied over more than three orders of magnitude from infinite halfspace targets (Dp/T less than 0.1) to very thin films (Dp/T greater than 100). Cratering and penetration of massive Teflon targets is dominated by brittle failure and the development of extensive spall zones at the target's front and, if penetrated, the target's rear side. Mass removal by spallation at the back side of Teflon targets may be so severe that the absolute penetration-hole diameter (Dh) can become larger than that of a standard crater (Dc) at relative target thicknesses of Dp/T = 0.6-0.9. The crater diameter is infinite halfspace Teflon targets increases -- at otherwise constant impact conditions -- with encounter velocity by a factor of V0.44. In contrast, the penetration-hole size is very thin foils (Dp/T greater than 50) is essentially unaffected by impact velocity. Penetrations at target thicknesses intermediate to these extremes will scale with variable exponents of V. Our experimental matrix is

  8. Cratering and penetration experiments in teflon targets at velocities from 1 to 7 km/s

    NASA Technical Reports Server (NTRS)

    Horz, Friedrich; Cintala, Mark; Bernhard, Ronald P.; Cardenas, Frank; Davidson, William; Haynes, Gerald; See, Thomas H.; Winkler, Jerry; Knight, Jeffrey

    1994-01-01

    Approximately 20 sq m of protective thermal blankets, largely composed of Teflon, were retrieved from the Long Duration Exposure Facility after the spacecraft spent approximately 5.7 years in space. Examination of these blankets revealed that they contained thousands of hypervelocity impact features ranging from micron-sized craters to penetration holes several millimeters in diameter. We conducted impact experiments to reproduce such features and to understand the relationships between projectile size and the resulting crater or penetration hole diameter over a wide range of impact velocities. Such relationships are needed to derive the size and mass frequency distribution and flux of natural and man-made particles in low-earth orbit. Powder propellant and light-gas guns were used to launch soda-lime glass spheres into pure Teflon targets at velocities ranging from 1 to 7 km/s. Target thickness varied over more than three orders of magnitude from finite halfspace targets to very thin films. Cratering and penetration of massive Teflon targets is dominated by brittle failure and the development of extensive spall zones at the target's front and, if penetrated, the target's rear side. Mass removal by spallation at the back side of Teflon targets may be so severe that the absolute penetration hole diameter can become larger than that of a standard crater. The crater diameter in infinite halfspace Teflon targets increases, at otherwise constant impact conditions, with encounter velocity by a factor of V (exp 0.44). In contrast, the penetration hole size in very thin foils is essentially unaffected by impact velocity. Penetrations at target thicknesses intermediate to these extremes will scale with variable exponents of V. Our experimental matrix is sufficiently systematic and complete, up to 7 km/s, to make reasonable recommendations for velocity-scaling of Teflon craters and penetrations. We specifically suggest that cratering behavior and associated equations apply

  9. Cratering and penetration experiments in Teflon targets at velocities from 1 to 7 km/s

    NASA Astrophysics Data System (ADS)

    Hoerz, Friedrich; Bernhard, Ronald P.; Cintala, Mark J.; See, Thomas H.

    1995-02-01

    Approximately 20 sq m of protective thermal blankets, largely composed of Teflon, were retrieved from the Long Duration Exposure Facility (LDEF) after the spacecraft had spent approximately 5.7 years in space. Examination of these blankets revealed that they contained thousands of hypervelocity impact features ranging from micron-sized craters to penetration holes several millimeters in diameter. We conducted impact experiments in an effort to reproduce such features and to -- hopefully -- understand the relationships between projectile size and the resulting crater or penetration-hole diameter over a wide range of impact velocity. Such relationships are needed to derive the size- and mass-frequency distribution and flux of natural and man-made particles in low-Earth orbit. Powder propellant and light-gas guns were used to launch soda-lime glass spheres of 3.175 mm (1/8 inch) nominal diameter (Dp) into pure Teflon FEP targets at velocities ranging from 1 to 7 km/s. Target thickness (T) was varied over more than three orders of magnitude from infinite halfspace targets (Dp/T less than 0.1) to very thin films (Dp/T greater than 100). Cratering and penetration of massive Teflon targets is dominated by brittle failure and the development of extensive spall zones at the target's front and, if penetrated, the target's rear side. Mass removal by spallation at the back side of Teflon targets may be so severe that the absolute penetration-hole diameter (Dh) can become larger than that of a standard crater (Dc) at relative target thicknesses of Dp/T = 0.6-0.9. The crater diameter is infinite halfspace Teflon targets increases -- at otherwise constant impact conditions -- with encounter velocity by a factor of V0.44. In contrast, the penetration-hole size is very thin foils (Dp/T greater than 50) is essentially unaffected by impact velocity. Penetrations at target thicknesses intermediate to these extremes will scale with variable exponents of V. Our experimental matrix is

  10. Anomalous zones (domal)

    SciTech Connect

    Kupfer, D.H. )

    1990-09-01

    Each zone contains several anomalous salt properties (anomalous features). Zones cannot be characterized by any single property Zones are highly variable, lenticular, and discontinuous in detail; however, once established, they commonly have a predictable trend. The individual anomalous features can occur alone (locally in pairs) over areas of various sizes and shapes. These alone occurrences are not anomalous zones. Anomalous zones may be of any origin, and origin is not part of the definition. Typical origins include: primary (sedimentary), external sheath zone, separating two spines of salt, or caused by toroidal flow. The major importance of an anomalous zone is that it consists of various anomalous features distributed discontinuously along the zone. Thus, if three or more anomalous properties are observed together, one should look for others. The anomalous zones observed in the Gulf Coast thus far are vertical, linear, and semicontinuous. Most are reasonably straight, but some bend sharply, end abruptly, or coalesce. Textures in salt involve grain size, color (white to dark gray), grain shape, or grain distribution of the salt. Typical anomalous textures are coarse-grain, poikiloblastic, and friability. A change in color is commonplace and seldom anomalous. Structural anomalous features, broadly defined, account for most of the rest of the anomalous features. Not uncommonly they cause mining problems. Among the structural anomalous features: INCLUSIONS: Sediments, hydrocarbons, brine, gases. Common gases are air (as N{sub 2}), CH-compounds, CO{sub 2}, and H{sub 2}S. STRUCTURES: Sheared salt, undue stabbing or jointing, voids (crystal-lined pockets), permeability, increased porosity COMPOSITION: High anhydrite content, visible anhydrite as grains or boudins, very black salt = disseminated impurities such as clay.

  11. Compositional zoning of the bishop tuff

    USGS Publications Warehouse

    Hildreth, W.; Wilson, C.J.N.

    2007-01-01

    Compositional data for >400 pumice clasts, organized according to eruptive sequence, crystal content, and texture, provide new perspectives on eruption and pre-eruptive evolution of the >4600 km3 of zoned rhyolitic magma ejected as the BishopTuff during formation of Long Valley caldera. Proportions and compositions of different pumice types are given for each ignimbrite package and for the intercalated plinian pumice-fall layers that erupted synchronously. Although withdrawal of the zoned magma was less systematic than previously realized, the overall sequence displays trends toward greater proportions of less evolved pumice, more crystals (0-5 24 wt %), and higher FeTi-oxide temperatures (714-818??C). No significant hiatus took place during the 6 day eruption of the BishopTuff, nearly all of which issued from an integrated, zoned, unitary reservoir. Shortly before eruption, however, the zoned melt-dominant portion of the chamber was invaded by batches of disparate lower-silica rhyolite magma, poorer in crystals than most of the resident magma but slightly hotter and richer in Ba, Sr, andTi. Interaction with resident magma at the deepest levels tapped promoted growth ofTi-rich rims on quartz, Ba-rich rims on sanidine, and entrapment of near-rim melt inclusions relatively enriched in Ba and CO2.Varied amounts of mingling, even in higher parts of the chamber, led to the dark gray and swirly crystal-poor pumices sparsely present in all ashflow packages. As shown by FeTi-oxide geothermometry, the zoned rhyolitic chamber was hottest where crystal-richest, rendering any model of solidification fronts at the walls or roof unlikely.The main compositional gradient (75-195 ppm Rb; 0.8-2.2 ppm Ta; 71-154 ppm Zr; 0.40-1.73% FeO*) existed in the melt, prior to crystallization of the phenocryst suite observed, which included zircon as much as 100 kyr older than the eruption.The compositions of crystals, though themselves largely unzoned, generally reflect magma temperature and

  12. Near-Surface Dynamics of a Separated Jet in the Coastal Transition Zone off Oregon

    DTIC Science & Technology

    2009-08-08

    Near-surface dynamics of a separated jet in the Coastal Transition Zone off Oregon A. O. Koch, A. L. Kurapov, J. S. Allen College of Oceanic and...2009 Abstract Three-dimensional circulation in the coastal transition zone (CTZ) off Oregon is studied using a 3-km resolution model based on the...00-00-2009 4. TITLE AND SUBTITLE Near-surface dynamics of a separated jet in the Coastal Transition Zone off Oregon 5a. CONTRACT NUMBER 5b. GRANT

  13. The global aftershock zone

    USGS Publications Warehouse

    Parsons, Thomas E.; Margaret Segou,; Warner Marzocchi,

    2014-01-01

    The aftershock zone of each large (M ≥ 7) earthquake extends throughout the shallows of planet Earth. Most aftershocks cluster near the mainshock rupture, but earthquakes send out shivers in the form of seismic waves, and these temporary distortions are large enough to trigger other earthquakes at global range. The aftershocks that happen at great distance from their mainshock are often superposed onto already seismically active regions, making them difficult to detect and understand. From a hazard perspective we are concerned that this dynamic process might encourage other high magnitude earthquakes, and wonder if a global alarm state is warranted after every large mainshock. From an earthquake process perspective we are curious about the physics of earthquake triggering across the magnitude spectrum. In this review we build upon past studies that examined the combined global response to mainshocks. Such compilations demonstrate significant rate increases during, and immediately after (~ 45 min) M > 7.0 mainshocks in all tectonic settings and ranges. However, it is difficult to find strong evidence for M > 5 rate increases during the passage of surface waves in combined global catalogs. On the other hand, recently published studies of individual large mainshocks associate M > 5 triggering at global range that is delayed by hours to days after surface wave arrivals. The longer the delay between mainshock and global aftershock, the more difficult it is to establish causation. To address these questions, we review the response to 260 M ≥ 7.0 shallow (Z ≤ 50 km) mainshocks in 21 global regions with local seismograph networks. In this way we can examine the detailed temporal and spatial response, or lack thereof, during passing seismic waves, and over the 24 h period after their passing. We see an array of responses that can involve immediate and widespread seismicity outbreaks, delayed and localized earthquake clusters, to no response at all. About 50% of the

  14. Seismicity of the eastern Hellenic Subduction Zone

    NASA Astrophysics Data System (ADS)

    Bruestle, A.; Kueperkoch, L.; Rische, M.; Meier, T.; Friederich, W.; Egelados Working Group

    2012-04-01

    The Hellenic Subduction Zone (HSZ) is the seismically most active region of Europe. The African plate is subducting beneath the Aegean lithosphere with a relative velocity of 4 cm per year. A detailed picture of the microseismicity of the eastern HSZ was obtained by the recordings of the temporary networks CYCNET (September 2002 - September 2005) and EGELADOS (October 2005 - March 2007). In total, nearly 7000 earthquakes were located with a location uncertainty of less than 20 km. The SE Aegean is dominated by (1) shallow intraplate seismicity within the Aegean plate, by (2) interplate seismicity at the plate contact and by (3) intermediate deep seismicity along the subducting African slab. Strong shallow seismicity in the upper plate is observed along the Ptolemy graben south of Crete extending towards the Karpathos Basin, indicating intense recent deformation of the forearc. In contrary, low shallow seismicity around Rhodes indicates only minor seismic crustal deformation of the upper plate. An almost NS-striking zone of microseismicity has been located, running from the Karpathos basin via the Nisyros volcanic complex towards the EW striking Gökova graben. In the SE Aegean the geometry of the Wadati-Benioff-Zone (WBZ) within the subducting African plate is revealed in detail by the observed microseismicity. Between about 50 to 100 km depth a continuous band of intermediate deep seismicity describes the strongly curved geometry of the slab. From the central to the eastern margin of the HSZ, the dip direction of the WBZ changes from N to NW with a strong increase of the dip angle beneath the eastern Cretan Sea. The margin of the dipping African slab is marked by an abrupt end of the observed WBZ beneath SW Anatolia. Below 100 km depth, the WBZ of the eastern HSZ is dominated by an isolated cluster of intense intermediate deep seismicity (at 100-180 km depth) beneath the Nisyros volcanic complex. It has an extension of about 100x80 km and is build up of 3 parallel

  15. Developing Knowledge Management (KM): Contributions by Organizational Learning and Total Quality Management (TQM)

    ERIC Educational Resources Information Center

    Hung, Richard Yu-Yuan; Lien, Bella Ya-Hui

    2005-01-01

    Knowledge management is an integral business function for many organizations to manage intellectual resources effectively. From a resource-based perspective, organizational learning and TQM are antecedents that are closely related to KM. The purposes of this study were to explain the contents of KM, and explore the relationship between KM-related…

  16. Resistivity distribution from mid-crustal conductor to near-surface across the 1200 km long Liquiñe-Ofqui Fault System, southern Chile

    NASA Astrophysics Data System (ADS)

    Held, Sebastian; Schill, Eva; Pavez, Maximiliano; Díaz, Daniel; Muñoz, Gerard; Morata, Diego; Kohl, Thomas

    2016-12-01

    Mid-crustal conductors are a common phenomenon in magnetotelluric studies. In the Andean Cordillera of southern Chile, they appear to concentrate along major fault zones. A high-resolution, broad-band magnetotelluric survey including 31 stations has been carried out along two profiles perpendicular to (1) the Liquiñe-Ofqui Fault Systems (LOFS) and (2) the Villarrica-Quetrupillán-Lanín volcanic lineament running parallel to the Mocha-Villarrica Fault Zone (MVFZ). The survey aimed at tracing one of the known conductors from mid-crustal depth to near-surface along these faults. Directionality and dimensionality were analysed using tensor decomposition. Phase tensors and induction arrows reveal two major geoelectric strike directions following the strike of LOFS and MVFZ. 2-D inversion shows low resistivity zones along both fault systems down to a depth of >10 km, where the brittle-ductile transition is expected. Along the LOFS, the two anomalies are linked to (1) Lake Caburgua, where the LOFS broadens to about 2 km of lateral extension and seems to represent a pull-apart structure, and (2) the intersection with the Villarrica-Quetrupillán-Lanín volcanic lineament, where seismic activity was observed during the latest eruption in March 2015. A connection of the mid-crustal conductor to the ESE-WNW-striking fault zones is indicated from the presented data.

  17. Microgravity silicon zoning investigation

    NASA Technical Reports Server (NTRS)

    Kern, E. L.; Gill, G. L., Jr.

    1985-01-01

    The flow instabilities in floating zones of silicon were investigated and methods for investigation of these instabilities in microgravity were defined. Three principal tasks were involved: (1) characterization of the float zone in small diameter rods; (2) investigation of melt flow instabilities in circular melts in silicon disks; and (3) the development of a prototype of an apparatus that could be used in near term space experiments to investigate flow instabilities in a molten zone. It is shown that in a resistance heated zoner with 4 to 7 mm diameter silicon rods that the critical Marangoni number is about 1480 compared to a predicted value of 14 indicative that viable space experiments might be performed. The prototype float zone apparatus is built and specifications are prepared for a flight zoner should a decision be reached to proceed with a space flight experimental investigation.

  18. Commercial Float Zone Furnace

    NASA Image and Video Library

    1996-05-25

    S77-E-5094 (25 May 1996) --- Astronaut Marc Garneau, mission specialist representing the Canadian Space Agency (CSA), stands at the Commercial Float Zone Furnace (CFZF) in the Spacehab Module onboard the Earth-orbiting Space Shuttle Endeavour.

  19. Buffer Zone Fact Sheets

    EPA Pesticide Factsheets

    New requirements for buffer zones and sign posting contribute to soil fumigant mitigation and protection for workers and bystanders. The buffer provides distance between the pesticide application site and bystanders, reducing exposure risk.

  20. Theory of zone radiometry

    NASA Technical Reports Server (NTRS)

    Farmer, R. C.; Audeh, B. J.

    1973-01-01

    A spectroscopic instrumentation system was developed which was used to measure temperature and concentration distributions in axisymmetric and two dimensional combusting flows. This measurement technique is known as zone radiometry.

  1. A diverse benthic assemblage 100 km from open water under the Amery Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Riddle, M. J.; Craven, M.; Goldsworthy, P. M.; Carsey, F.

    2007-03-01

    A hot water drill was used to penetrate 480 m of ice to reveal a diverse benthic assemblage, dominated by suspension-feeding invertebrates, under the Amery Ice Shelf (East Antarctica) at a location 100 km from open water and at a depth of 775 m below sea level (840 m below the ice shelf surface). This is the first record of a benthic assemblage of this type found at this distance under an ice shelf. The few previous reports of life under ice shelves describe assemblages with very different trophic strategies (e.g., sparse assemblages of mobile scavengers or chemotrophs) or are in circumstances in which in situ photosynthesis at tide cracks or through the ice cannot be ruled out as a potential source of primary production. The physical characteristics of the Amery Ice Shelf and the feeding strategies represented together indicate that the only likely source of primary production to sustain the benthic assemblage is material advected from open water. This suggestion is supported by observed current speeds in the vicinity and reported rates of particle settling. The observation under an ice shelf of a benthic assemblage that is very similar to those found elsewhere in Antarctica, in locations dominated by annual sea ice or at depths below the photic zone, has implications for the interpretation of sediment paleorecords to represent the history of ice shelf advance and retreat. Without observations of this living assemblage in situ, the remnants of its component species in the sediment record, such as sponge spicules, echinoderm ossicles, and bryozoan fragments, could be interpreted reasonably, but erroneously, to represent open water conditions.

  2. P-V-V p-V s-T measurements on wadsleyite to 7 GPa and 873 K: Implications for the 410-km seismic discontinuity

    NASA Astrophysics Data System (ADS)

    Li, Baosheng; Liebermann, Robert C.; Weidner, Donald J.

    2001-01-01

    The compressional (P) and shear wave (S) velocities for Mg2SiO4 wadsleyite have been measured to 7 GPa and 873 K using simultaneous ultrasonic interferometry and in situ X-ray diffraction techniques. From the velocity measurements we obtained the pressure and temperature derivatives for the elastic shear (G) and adiabatic bulk (KS) moduli, (∂G/∂P)T=1.5(1), (∂G/∂T)P=-0.017(1) GPa/K, KS=173(2) GPa, (∂Ks/∂P)T=4.2(1), and (∂Ks/∂T)P=-0.012(1) GPa/K; for the P and S waves, we obtained (∂Vs/∂P)T=0.021(1) (km/s)/GPa, (∂Vs/∂T)P=-0.035(2) (km/s)/K, (∂VP/∂P)T=0.065(2) (km/s)/GPa, and (∂VP/∂T)P = -0.038(2) (km/s)/K (values in parentheses are standard deviations, e.g., 1.5(1)=1.5±1). Independent equation of state analysis of P-V-T data provided an estimation of the temperature dependence for the isothermal bulk modulus of (∂KT/∂T)P=-0.022(12) GPa/K and thermal expansion (α=a+bT) coefficients of a=2×10-5 K-1 and b=2.5×10-8 K-2. Using these data along with elastic properties for other mantle phases, a velocity-depth profile for a pyrolite model to 670 km depth is constructed using a finite strain method along a 1673 K adiabat. In the transition zone the pyrolite model has a smaller gradient between 410 and 660 km than the body wave models from synthetic waveform analyses but converges with the seismic profiles at the bottom of the transition zone just above the 660-km discontinuity. The pyrolite model has velocity jumps of 6.9% and 7.9% for P and S waves, respectively, over a thickness of ˜10 km for the phase transformation from olivine to wadsleyite, which is in good agreement with short-period P wave reflection data and a recent fine structure model (C4) for both the velocity jumps and the thickness of the 410-km seismic discontinuity.

  3. Fault zone amplified waves as a possible seismic hazard along the Calaveras fault in central California

    USGS Publications Warehouse

    Spudich, P.; Olsen, K.B.

    2001-01-01

    The Calaveras fault lies within a low velocity zone (LVZ) 1-2 km wide near Gilroy, California. Accelerographs G06, located in the LVZ 1.2 km from the Calaveras fault, and G07, 4 km from G06, recorded both the M 6.2 1984 Morgan Hill and the M 6.9 1989 Loma Prieta earthquakes. Comparison of the ground motions shows that a large 0.6-1.0 Hz velocity pulse observed at G06 during the Morgan Hill event may be amplified by focussing caused by the LVZ. Such amplified waves might be a mappable seismic hazard, and the zone of increased hazard can extend as much as 1.2 km from the surface trace of the fault. Finite-difference simulations of ground motions in a simplified LVZ model show a zone of amplified motion similar to the observations.

  4. Underwater acoustic positioning system for the SMO and KM3NeT - Italia projects

    SciTech Connect

    Viola, S.; Barbagallo, G.; Cacopardo, G.; Calí, C.; Cocimano, R.; Coniglione, R.; Costa, M.; Cuttone, G.; D'Amato, C.; D'Amato, V.; D'Amico, A.; De Luca, V.; Del Tevere, F.; Distefano, C.; Ferrera, F.; Gmerk, A.; Grasso, R.; Imbesi, M.; Larosa, G.; Lattuada, D.; and others

    2014-11-18

    In the underwater neutrino telescopes, the positions of the Cherenkov light sensors and their movements must be known with an accuracy of few tens of centimetres. In this work, the activities of the SMO and KM3NeT-Italia teams for the development of an acoustic positioning system for KM3NeT-Italia project are presented. The KM3NeT-Italia project foresees the construction, within two years, of 8 towers in the view of the several km{sup 3}-scale neutrino telescope KM3NeT.

  5. Dentin Caries Zones

    PubMed Central

    Pugach, M.K.; Strother, J.; Darling, C.L.; Fried, D.; Gansky, S.A.; Marshall, S.J.; Marshall, G.W.

    2009-01-01

    Caries Detector staining reveals 4 zones in dentin containing caries lesions, but characteristics of each zone are not well-defined. We therefore investigated the physical and microstructural properties of carious dentin in the 4 different zones to determine important differences revealed by Caries Detector staining. Six arrested dentin caries lesions and 2 normal controls were Caries-Detector-stained, each zone (pink, light pink, transparent, apparently normal) being analyzed by atomic force microscopy (AFM) imaging for microstructure, by AFM nano-indentation for mechanical properties, and by transverse digital microradiography (TMR) for mineral content. Microstructure changes, and nanomechanical properties and mineral content significantly decreased across zones. Hydrated elastic modulus and mineral content from normal dentin to pink Caries-Detector-stained dentin ranged from 19.5 [10.6-25.3] GPa to 1.6 [0.0-5.0] GPa and from 42.9 [39.8-44.6] vol% to 12.4 [9.1-14.2] vol%, respectively. Even the most demineralized pink zone contained considerable residual mineral. PMID:19131321

  6. Low-velocity zones in the crust beneath Aso caldera, Kyushu, Japan, derived from receiver function analyses

    NASA Astrophysics Data System (ADS)

    Abe, Yuki; Ohkura, Takahiro; Shibutani, Takuo; Hirahara, Kazuro; Yoshikawa, Shin; Inoue, Hiroyuki

    2017-03-01

    Aso volcano, in central Kyushu Island in southwest Japan, has a large caldera (18 × 25 km) that formed by the ejection of more than 600 km3 of deposits 89 thousand years ago. We calculated receiver functions from teleseismic waveform data obtained from densely distributed stations in and around the caldera. We estimated the crustal S wave velocity structure from the receiver functions by using genetic algorithm inversion. We detected a low-velocity zone (Vs > 2.2 km/s) at a depth of 8-15 km beneath the eastern flank of the central cones. A sill-like deformation source has been detected at a depth of 15.5 km by analyses of GPS data, and a swarm of low-frequency earthquakes exists at depths of 15-25 km just beneath this low-velocity zone. Magma may be newly generated and accumulated in this low-velocity zone as a result of hot intrusions coming from beneath it. Except for the region beneath the eastern flank of the central cones, a second low-velocity zone (Vs > 1.9 km/s) extends in and around the caldera at a depth of 15-23 km, although phenomena representing intrusions have not been detected below it. From the estimated velocity structure, these low-velocity zones are interpreted to contain a maximum of 15% melt or 30% water.

  7. Localized Deformation Beginning more than 15 km Beneath the Mid-Atlantic Ridge, 14 to 16 N

    NASA Astrophysics Data System (ADS)

    Kelemen, P.

    2003-12-01

    ODP Leg 209 drilled 19 holes at 8 sites along the Mid-Atlantic Ridge from 14° 43 to 15° N. All sites were surveyed by submersible, and chosen to be < 200 m from peridotite or dunite exposed on the seafloor; outcrops of gabbroic rock were also close to some sites. One of our primary goals was to constrain the mechanism of mantle upwelling, corner flow and exhumation of shallow mantle rocks. Drilling at Sites 1268, 1270-72, 1274 and 1275 penetrated 1075 meters, and recovered 354 m of core. At Sites 1268 and 1270-72 we recovered 25% gabbroic rocks and 75% residual mantle peridotite. Core from Site 1274 was mainly residual peridotite, while core from Site 1275 was mainly gabbroic. Most of the residual peridotites have nearly undeformed, protogranular textures. Orthopyroxenes are interstitial to olivine or even poikilitic. Rare, isolated clinopyroxene grains are also interstitial. Skeletal spinel grains have mm-scale extensions in three dimensions, with no discernable shape fabric. These textures are clearly different from porphyroclastic textures typical in ophiolites and fracture zone dredges. As described elsewhere at this meeting, impregnated peridotites contain olivine, 2 pyroxenes, plagioclase and spinel, and equilibrated at 0.54 GPa (+/-0.14 GPa, 2σ ) and 1220° C (+/-16° C, 2σ ) [Kinzler & Grove, JGR 92]. Melts entered the thermal boundary layer beneath the Mid-Atlantic Ridge at about 20 km [e.g., Sleep, JGR 75; Reid & Jackson, MGR 82; Grove et al JGR 92; Cannat JGR 96; Michael & Chase CMP 97; Braun et al., EPSL 00], and began to crystallize within impregnated peridotites and as discrete plutons intruding peridotite. Gabbroic rocks and peridotites from most sites underwent large tectonic rotations since aquiring remanent magnetization. At some sites, rotations may have exceeded 60° around near-horizontal axes parallel to the Mid-Atlantic Ridge. Such large rotations are unlikely to have been accomodated along a single fault, and instead blocks were

  8. Abrupt along-strike change in tectonic style: San Andreas fault zone, San Francisco Peninsula

    USGS Publications Warehouse

    Zoback, M.L.; Jachens, R.C.; Olson, J.A.

    1999-01-01

    Seismicity and high-resolution aeromagnetic data are used to define an abrupt change from compressional to extensional tectonism within a 10- to 15-km-wide zone along the San Andreas fault on the San Francisco Peninsula and offshore from the Golden Gate. This 100-km-long section of the San Andreas fault includes the hypocenter of the Mw = 7.8 1906 San Francisco earthquake as well as the highest level of persistent microseismicity along that ???470-km-long rupture. We define two distinct zones of deformation along this stretch of the fault using well-constrained relocations of all post-1969 earthquakes based a joint one-dimensional velocity/hypocenter inversion and a redetermination of focal mechanisms. The southern zone is characterized by thrust- and reverse-faulting focal mechanisms with NE trending P axes that indicate "fault-normal" compression in 7- to 10-km-wide zones of deformation on both sides of the San Andreas fault. A 1- to 2-km-wide vertical zone beneath the surface trace of the San Andreas is characterized by its almost complete lack of seismicity. The compressional deformation is consistent with the young, high topography of the Santa Cruz Mountains/Coast Ranges as the San Andreas fault makes a broad restraining left bend (???10??) through the southernmost peninsula. A zone of seismic quiescence ???15 km long separates this compressional zone to the south from a zone of combined normal-faulting and strike-slip-faulting focal mechanisms (including a ML = 5.3 earthquake in 1957) on the northernmost peninsula and offshore on the Golden Gate platform. Both linear pseudo-gravity gradients, calculated from the aeromagnetic data, and seismic reflection data indicate that the San Andreas fault makes an abrupt ???3-km right step less than 5 km offshore in this northern zone. A similar right-stepping (dilatational) geometry is also observed for the subparallel San Gregorio fault offshore. Persistent seismicity and extensional tectonism occur within the San

  9. Non-Parametric Evolutionary Algorithm for Estimating Root Zone Soil Moisture

    NASA Astrophysics Data System (ADS)

    Mohanty, B.; Shin, Y.; Ines, A. M.

    2013-12-01

    Prediction of root zone soil moisture is critical for water resources management. In this study, we explored a non-parametric evolutionary algorithm for estimating root zone soil moisture from a time series of spatially-distributed rainfall across multiple weather locations under two different hydro-climatic regions. A new genetic algorithm-based hidden Markov model (HMMGA) was developed to estimate long-term root zone soil moisture dynamics at different soil depths. Also, we analyzed rainfall occurrence probabilities and dry/wet spell lengths reproduced by this approach. The HMMGA was used to estimate the optimal state sequences (weather states) based on the precipitation history. Historical root zone soil moisture statistics were then determined based on the weather state conditions. To test the new approach, we selected two different soil moisture fields, Oklahoma (130 km x 130 km) and Illinois (300 km x 500 km), during 1995 to 2009 and 1994 to 2010, respectively. We found that the newly developed framework performed well in predicting root zone soil moisture dynamics at both the spatial scales. Also, the reproduced rainfall occurrence probabilities and dry/wet spell lengths matched well with the observations at the spatio-temporal scales. Since the proposed algorithm requires only precipitation and historical soil moisture data from existing, established weather stations, it can serve an attractive alternative for predicting root zone soil moisture in the future using climate change scenarios and root zone soil moisture history.

  10. Seismogenic Shear Zones In The Upper Mantle: Some Evidences From Central Italy

    NASA Astrophysics Data System (ADS)

    Creati, N.; Boncio, P.; Lavecchia, G.

    The presence of brittle, brittle-ductile and ductile shear zones down to the upper man- tle is rather well known in the literature and testified by both geophysical (seismic lines) and geological (milonyte fault rocks in exumated lherzolites) data. Moreover, the occurrence of intermediate earthquakes (down to a depth about 150-200 km) which cannot be easily interpreted as Wadati-Benioff zones (High Atlas, Romania, Hindukush, Tibet and Burma) suggests the existence of intra-lithosphere seismogenic shear zones. In this paper, we will illustrate preliminary evidences about a possible seismogenic intra-lithosphere shear zone in Northern-Central Italy. Up to now, the oc- currence in this area of earthquakes down to a depth of about 90 km has been linked to the westward subduction of the Adriatic lithosphere. As a matter of fact, the loca- tion of the deep earthquakes does not fit well with the location of the Apennine Moho doubling zone, that, as classically recognized, would sign the location of the slab. In order to better address the problem, we have performed a detailed analysis of the deep seismicity along two regional sections coinciding with the traces of the deep crust CROP 03 (Punta Ala-Gabicce) and DSS 1978 (Piombino-Ancona) seismic profiles. In both sections, the earthquake distribution defines a seismic area 30 km wide and 100 km long, deepening westward at about 30 and reaching a maximum depth of about 75 km. This area substantially overlaps on the easternmost SW-dipping reverse shear zone shown by the DSS 78 and CROP 03 profiles. This shear zone, named Adriatic Shear Zone (ASZ), emerges in the Adriatic Sea and deepens westward dislocating the base of the crust. The ASZ along-dip distribution of the seismicity is not homogeneous and four main clusters are observed at depths of 5-10 km, 18-25 km, 35-40 km and 60-70 km. The distribution of seismicity has been compared with the rheological strat- ification and structure of the lithosphere. Adopting a not

  11. Altimetry data and the elastic stress tensor of subduction zones

    NASA Technical Reports Server (NTRS)

    Caputo, Michele

    1987-01-01

    The maximum shear stress (mss) field due to mass anomalies is estimated in the Apennines, the Kermadec-Tonga Trench, and the Rio Grande Rift areas and the results for each area are compared to observed seismicity. A maximum mss of 420 bar was calculated in the Kermadec-Tonga Trench region at a depth of 28 km. Two additional zones with more than 300 bar mss were also observed in the Kermadec-Tonga Trench study. Comparison of the calculated mss field with the observed seismicity in the Kermadec-Tonga showed two zones of well correlated activity. The Rio Grande Rift results showed a maximum mss of 700 bar occurring east of the rift and at a depth of 6 km. Recorded seismicity in the region was primarily constrained to a depth of approximately 5 km, correlating well to the results of the stress calculations. Two areas of high mss are found in the Apennine region: 120 bar at a depth of 55 km, and 149 bar at the surface. Seismic events observed in the Apennine area compare favorably with the mss field calculated, exhibiting two zones of activity. The case of loading by seamounts and icecaps are also simulated. Results for this study show that the mss reaches a maximum of about 1/3 that of the applied surface stress for both cases, and is located at a depth related to the diameter of the surface mass anomaly.

  12. The south Zagros suture zone in teleseismic images

    NASA Astrophysics Data System (ADS)

    Motaghi, K.; Shabanian, E.; Tatar, M.; Cuffaro, M.; Doglioni, C.

    2017-01-01

    The geometry of intra-continental lithosphere boundaries along the Zagros orogenic belt in the Arabia-Eurasia collision is investigated by means of teleseismic data. The data are gathered over a seismic linear profile extending across south Zagros, the Sanandaj-Sirjan metamorphic zone, the Urumieh-Dokhtar magmatic arc, Central Iran, and the Kopeh Dagh - Binalud mountains. We exploit the P and S receiver functions leading to map the geometry of the crustal and subcrustal interfaces. The migrated depth sections reveal an abrupt crustal thickening and a gentle crustal thinning 60 km north and 30 km south of the Zagros suture, respectively. Associated to the buckled antiformal Moho south of the suture, a deeper synform in the lithospheric lid of the lower Arabia plate is shown by migrated depth sections affecting the lithospheric mantle of the Arabia plate beneath the suture zone. This geometry implies an unexpected intra-lid decoupling. These features imply that the Central Iran lithosphere acts as a relatively strong backstop producing significant internal deformation expressed by shortening and thickening at the edge of the Arabian lithosphere. The 410 km and 660 km transition zones are imaged by P to S converted phases and showed lateral continuity implying an originally low dip angle subduction of the oceanic Arabian plate beneath Central Iran.

  13. Changes in total body water content during running races of 21.1 km and 56 km in athletes drinking ad libitum.

    PubMed

    Tam, Nicholas; Nolte, Heinrich W; Noakes, Timothy D

    2011-05-01

    To measure changes in body mass (BM), total body water (TBW), fluid intake, and blood biochemistry in athletes during 21.1-km and 56-km foot races. Observational study. 2009 Two Oceans Marathon, South Africa. Twenty-one (21.1 km) and 12 (56 km) participants were advised to drink according to thirst or their own race drink plan (ad libitum). Body mass, TBW, plasma osmolality, plasma sodium (p[Na]), and plasma total protein ([TP]) concentrations were measured before and after race. Fluid intake was recorded from recall after race. Significant BM loss occurred in both races (21.1 km; -1.4 ± 0.6 kg; P < 0.000 and 56 km; -2.5 ± 1.1 kg; P < 0.000). Total body water was reduced in the 56-km race (-1.4 ± 1.1 kg; P < 0.001). A negative linear relationship was found between percentage change (%Δ) in TBW and %Δ in BM in the 56-km runners (r = 0.6; P < 0.01). Plasma osmolality and [TP] increased significantly in the 56-km runners (6.8 ± 8.2 mOsm/kg H2O; P < 0.05 and 5.4 ± 4.4 g/L; P < 0.01, respectively), but all other biochemical measures were within the normal range. Although TBW decreased in the 56-km race and was maintained in the 21.1-km race, the change in TBW over both races was less than the BM, suggesting that not all BM lost during endurance exercise is a result purely of an equivalent reduction in TBW. These findings support the interpretation that the body primarily defends p[Na] and not BM during exercise and that a reduction in BM can occur without an equivalent reduction in TBW during prolonged exercise. Furthermore, these data support that drinking without controlling for BM loss may allow athletes to complete these events. 2011 by Lippincott Williams & Wilkins.

  14. Seismic Constraints on Slab Interaction With the Transition Zone

    NASA Astrophysics Data System (ADS)

    Lekic, V.; Reif, C.; Dziewonski, A. M.; Sheehan, A.; van Summeren, J.

    2006-12-01

    Over the past decade, seismic tomography has revealed that subducting lithospheric slabs interact with the transition zone in a variety of ways, directly penetrating into the lower mantle in some locations, while stagnating in others. Here, we present preliminary results of attempts to characterize and quantify the stagnation of slab material in the transition zone initiated at the 2006 Cooperative Institute for Deep Earth Research (CIDER) workshop. Providing seismic constraints on slab interaction with the transition zone is essential for verifying dynamic calculations that examine to what degree slabs are hindered from penetrating through the 660 km seismic discontinuity. First we compute the tomographic signature of an end-member mantle model in which 100 km thick slabs descend from the upper to lower mantle without deformation / stagnation in the transition zone. We then compare the amplitude of the predicted shear velocity anomaly with that observed in the most recent Scripps, Berkeley, Harvard, Caltech, and UT Austin global tomographic models. We find that in the western Pacific slab material is accumulating within the transition zone, while under South America, the slabs appear to enter the lower mantle unhindered. This accumulation of slab material in the transition zone indicates that some mechanism is temporarily delaying it from passing into the lower mantle. This finding is consistent with comparisons of power spectra of the observed models in and below the transition zone, which indicate that the pattern of seismic heterogeneity changes drastically across the 660 km discontinuity. Furthermore, the focal mechanisms of deep (>400 km) earthquakes from the Harvard Centroid Moment Tensor project provide a wealth of information on slab deformation within the transition zone. We have systematically compared the orientations of earthquake compressional axes to the slab orientations (as defined by the Wadati-Benioff zone) for all regions of deep seismicity. The

  15. GPS constraints on interplate locking within the Makran subduction zone

    NASA Astrophysics Data System (ADS)

    Frohling, E.; Szeliga, W.

    2016-04-01

    The Makran subduction zone is one of the last convergent margins to be investigated using space-based geodesy. While there is a lack of historical and modern instrumentation in the region, a sparse sampling of continuous and campaign measurements over the past decade has allowed us to make the first estimates of convergence rates. We combine GPS measurements from 20 stations located in Iran, Pakistan and Oman along with hypocentral locations from the International Seismological Centre to create a preliminary 3-D estimate of the geometry of the megathrust, along with a preliminary fault-coupling model for the Makran subduction zone. Using a convergence rate which is strongly constrained by measurements from the incoming Arabia plate along with the backslip method of Savage, we find the Makran subduction zone appears to be locked to a depth of at least 38 km and accumulating strain.We also find evidence for a segmentation of plate coupling, with a 300 km long section of reduced plate coupling. The range of acceptable locking depths from our modelling and the 900 km along-strike length for the megathrust, makes the Makran subduction zone capable of earthquakes up to Mw = 8.8. In addition, we find evidence for slow-slip-like transient deformation events on two GPS stations. These observations are suggestive of transient deformation events observed in Cascadia, Japan and elsewhere.

  16. Delineation of groundwater potential zone: An AHP/ANP approach

    NASA Astrophysics Data System (ADS)

    Agarwal, Etishree; Agarwal, Rajat; Garg, R. D.; Garg, P. K.

    2013-06-01

    The sustainable development and management of groundwater resource requires precise quantitative assessment based on scientific principle and modern techniques. In the present study, groundwater potential zone are delineated using remote sensing, geographical information system (GIS) and multi-criteria decision making (MCDM) techniques in Unnao district, Uttar Pradesh. The analytical network process (ANP) is a method that makes it possible for one to deal systematically, and includes the analytical hierarchy process (AHP) as a special case. The AHP and ANP are used to determine the weights of various themes and their classes for identifying the groundwater potential zone. These weights are applied in a linear combination to obtain five different groundwater potential zone in the study area, namely `very poor', `poor', `moderate', `good' and `very good'. It has been concluded that about 153.39 km2 area has very good groundwater potential which is only 3.37% of the total study area. However, the area having very poor groundwater potential is about 850 km2 which is about 19.63% of the study area. The area having good, moderate and poor groundwater potential is about 540.25, 1135.5, 1868.6 km2, respectively. The groundwater potential zone map was finally verified using the well yield data of 37 pumping wells, and the result was found satisfactory.

  17. The Seismogenic Coupling Zone in Southern Central Chile, 38° S: A Reflection seismic image of the subduction zone (Project TIPTEQ)

    NASA Astrophysics Data System (ADS)

    Schulze, A.; Micksch, U.; Krawczyk, C. M.; Ryberg, T.; Stiller, M.

    2006-12-01

    The multi-disciplinary project TIPTEQ (from The Incoming Plate to mega-Thrust EarthQuake processes) investigates the seismogenic coupling zone in Southern Central Chile and the associated subduction zone processes between the Pacific Ocean and the volcanic arc. The reflection seismic component of TIPTEQ includes a 110 km long profile which spans from the coast over the down-dip end of the seismogenic coupling zone, crossing the 1960 Valdivia earthquake hypocentre. 180 three-component geophones were deployed (100 m spacing) along an 18 km wide spread whereof 4.5 km were shifted in a daily roll-along. With 100 borehole shots, 1.5 km apart, this up to 8-fold covered line delivers a high-resolution image of the seismogenic coupling zone. 15 additional shots in an expanding spread profiling configuration focussed on the seismogenic coupling zone. SH wave source signals were generated to yield an improved picture of the petrophysical contrasts within the system. The SPOC-South wide-angle data velocity model is combined with a first-break tomography velocity model to get an advanced migration image. The subducting Nazca plate can be traced from a depth of 25 km below the coast down to a depth of 50 km at the eastern end of the profile. Structural evidence suggests that material is transported down in a subduction channel. From slow uplift of the Coastal Cordillera we conclude that basal accretion of parts of this material controls the seismic architecture and growth of the south Chilean crust. Between depths of 5 to 25 km several bright reflectivity spots can be seen in the upper plate, which may suggest fluid traps in the accretionary wedge. The tomographic p-wave velocity model reaches approximately 10 km depth. Its segmentation corresponds to the geological units mapped at surface. The sediment thickness in the Central Valley is approx. 3 km, and we see prominent fault systems like the Lanalhue fault zone also in the tomographic model. At present, almost no seismicity

  18. Is there a zone of weakness beneath the New Madrid and Wabash Valley Seismic Zones?

    NASA Astrophysics Data System (ADS)

    Chen, C.; Gilbert, H. J.; Pavlis, G. L.; Hamburger, M. W.; Yang, X.; Marshak, S.; Larson, T. H.

    2014-12-01

    The US midcontinent contains several intraplate seismic zones, including the New Madrid Seismic Zone (NMSZ) sitting above the Reelfoot Rift, and the Wabash Valley Seismic Zone (WVSZ), associated with a smaller Grayville Graben, stretching along the border between Illinois and Indiana. This study provides a new estimate of the velocity structure beneath the area based on observations from the Transportable Array and the OIINK (Ozarks-Illinois-INdiana-Kentucky) FlexArray experiment in the region. Numerous models, involving a zone of weakness either in the crust or the mantle, have been used to explain the seismicity in the NMSZ. Here we present a shear velocity model of the lithosphere beneath the midcontinent by inverting dispersion curves of fundamental mode Rayleigh waves, which are primarily sensitive to the shear wave speeds. We find no spatial correlation between the crustal velocity variations and the two seismic zones. But we do observe that low velocities (~ 4% lower than the measured average of the area) exist in the mantle beneath the NMSZ at depths between 90 and 125 km. The low upper mantle velocities extend to the north and reach the WVSZ, where they are about 3% lower than the average. Velocity variations can result from thermal or compositional heterogeneities, although a thermal perturbation is less likely in this area because no clear surface heat flow anomaly is observed. Compositional heterogeneities, such as the presence of hydrous minerals or contamination by enriched mantle from a plume can reduce seismic velocities as well as the mechanical strength of a region, which would produce a weak zone. The lithosphere beneath a failed rift which has already undergone an earlier phase of deformation is more susceptible to compositional modification and weakening compared to an intact part of a craton. Thus, the two seismic zones may mark locations where deformation has been localized in the crust above a weak mantle due to their lower integrated

  19. Physiological and electromyographic responses during 40-km cycling time trial: relationship to muscle coordination and performance.

    PubMed

    Bini, Rodrigo R; Carpes, Felipe P; Diefenthaeler, Fernando; Mota, Carlos B; Guimarães, Antônio Carlos S

    2008-07-01

    The purpose of this study was to compare the oxygen uptake (VO(2)), respiratory exchange ratio (RER), cadence and muscle activity during cycling a 40-km time trial (TT), and to analyse the relationship between muscle activity and power output (PO). Eight triathletes cycled a 40-km TT on their own bicycles, which were mounted on a stationary cycle simulator. The VO(2), RER and muscle activity (electromyography, EMG) from tibialis anterior (TA), gastrocnemius medialis (GA), biceps femoris (BF), rectus femoris (RF) and vastus lateralis (VL) of the lower limb were collected. The PO was recorded from the cycle simulator. The data were collected at the 3rd, 10th, 20th, 30th and 38th km. The root mean square envelope (RMS) of EMG was calculated. The VO(2) and PO presented a significant increase at the 38th km (45.23+/-8.35 ml kg min(-1) and 107+/-7.11% of mean PO of 40-km, respectively) compared to the 3rd km (38.12+/-5.98 ml kg min(-1) and 92+/-8.30% of mean PO of 40-km, respectively). There were no significant changes in cadence and RER throughout the TT. The VL was the only muscle that presented significant increases in the RMS at the 10th km (22.56+/-3.05% max), 20th km (23.64+/-2.52% max), 30th km (25.27+/-3.00% max), and 38th km (26.28+/-3.57%max) when compared to the 3rd km (21.03+/-1.88%max). The RMS of VL and RF presented a strong relationship to PO (r=0.89 and 0.86, respectively, p<0.05). The muscular steady state reported for cycling a 30-min TT seems to occur in the 40-km TT, for almost all assessed muscles, probably in attempt to avoid premature muscle fatigue.

  20. Modeling the stream water nitrate dynamics in a 60,000-km2 European catchment, the Garonne, southwest France.

    PubMed

    Tisseuil, Clément; Wade, Andrew J; Tudesque, Loïc; Lek, Sovan

    2008-01-01

    The spatial and temporal dynamics in the stream water NO(3)-N concentrations in a major European river-system, the Garonne (62,700 km(2)), are described and related to variations in climate, land management, and effluent point-sources using multivariate statistics. Building on this, the Hydrologiska Byråns Vattenbalansavdelning (HBV) rainfall-runoff model and the Integrated Catchment Model of Nitrogen (INCA-N) are applied to simulate the observed flow and N dynamics. This is done to help us to understand which factors and processes control the flow and N dynamics in different climate zones and to assess the relative inputs from diffuse and point sources across the catchment. This is the first application of the linked HBV and INCA-N models to a major European river system commensurate with the largest basins to be managed under the Water Framework Directive. The simulations suggest that in the lowlands, seasonal patterns in the stream water NO(3)-N concentrations emerge and are dominated by diffuse agricultural inputs, with an estimated 75% of the river load in the lowlands derived from arable farming. The results confirm earlier European catchment studies. Namely, current semi-distributed catchment-scale dynamic models, which integrate variations in land cover, climate, and a simple representation of the terrestrial and in-stream N cycle, are able to simulate seasonal NO(3)-N patterns at large spatial (>300 km(2)) and temporal (> or = monthly) scales using available national datasets.

  1. Modeling hyporheic zone processes

    USGS Publications Warehouse

    Runkel, Robert L.; McKnight, Diane M.; Rajaram, Harihar

    2003-01-01

    Stream biogeochemistry is influenced by the physical and chemical processes that occur in the surrounding watershed. These processes include the mass loading of solutes from terrestrial and atmospheric sources, the physical transport of solutes within the watershed, and the transformation of solutes due to biogeochemical reactions. Research over the last two decades has identified the hyporheic zone as an important part of the stream system in which these processes occur. The hyporheic zone may be loosely defined as the porous areas of the stream bed and stream bank in which stream water mixes with shallow groundwater. Exchange of water and solutes between the stream proper and the hyporheic zone has many biogeochemical implications, due to differences in the chemical composition of surface and groundwater. For example, surface waters are typically oxidized environments with relatively high dissolved oxygen concentrations. In contrast, reducing conditions are often present in groundwater systems leading to low dissolved oxygen concentrations. Further, microbial oxidation of organic materials in groundwater leads to supersaturated concentrations of dissolved carbon dioxide relative to the atmosphere. Differences in surface and groundwater pH and temperature are also common. The hyporheic zone is therefore a mixing zone in which there are gradients in the concentrations of dissolved gasses, the concentrations of oxidized and reduced species, pH, and temperature. These gradients lead to biogeochemical reactions that ultimately affect stream water quality. Due to the complexity of these natural systems, modeling techniques are frequently employed to quantify process dynamics.

  2. Upper-mantle seismic discontinuities and the thermal structure of subduction zones

    USGS Publications Warehouse

    Vidale, J.E.; Benz, H.M.

    1992-01-01

    The precise depths at which seismic velocities change abruptly in the upper mantle are revealed by the analysis of data from hundreds of seismometers across the western United States. The boundary near 410 km depth is locally elevated, that near 660 km depressed. The depths of these boundaries, which mark phase transitions, provide an in situ thermometer in subduction zones: the observed temperature contrasts require at least moderate thickening of the subducting slab near 660 km depth. In addition, a reflector near 210 km depth may mark the bottom of the aesthenosphere.

  3. GLORIA mosaic of the U. S. Hawaiian exclusive economic zone

    SciTech Connect

    Torresan, M.E. )

    1990-06-01

    Digital long-range side-scan sonar reconnaissance surveys using GLORIA have imaged about 65% of the nearly 2.4 million km{sup 2} of the Hawaiian EEZ. The images have been processed and compiled into one mosaic that comprises the EEZ area surrounding the principal Hawaiian islands (from Hawaii to Kauai); extending on the south side of the ridge west to Kure Island, and on the north side to St. Rogatien Bank. The GLORIA images depict a variety of features that include enormous slumps and debris avalanches, lava flows, seafloor spreading fabric, fracture zones, seamounts, and unusual sedimentation patterns with more detail than previously had been possible with typical seismic reflection techniques. Some of these features were unknown before the GLORIA surveys. In particular, the GLORIA images show that the major degradational processes that affect the island and ridge areas are massive, likely tsunamogenic, blocky debris avalanches and slumps. These failures mantle the flanks of the ridge; some extending across the trough and up on to the Hawaiian Arch (up to 230 km from their sources). Over 30 failures are identified, ranging in area from 250 to > 6,000 km{sup 2} and having volumes from 500 to > 5,000 km{sup 3}. Such deposits cover > 125,000 km{sup 3} of the Ridge and adjacent seafloor. Also imaged are large Cenozoic submarine volcanic flow fields situated on the Hawaiian Arch. One such field, the North Arch field, is located north of Oahu between the Molokai and Murray fracture zones, and covers about 200,000 km{sup 2}. Prior to the GLORIA imagery only a small portion of this flow field was mapped. In addition, the imagery depicts the finer details of the Molokai and Murray fracture zones, the Cretaceous seafloor spreading fabric, and tensional faults on the Hawaiian Arch.

  4. Evolution and diversity of subduction zones controlled by slab width.

    PubMed

    Schellart, W P; Freeman, J; Stegman, D R; Moresi, L; May, D

    2007-03-15

    Subducting slabs provide the main driving force for plate motion and flow in the Earth's mantle, and geodynamic, seismic and geochemical studies offer insight into slab dynamics and subduction-induced flow. Most previous geodynamic studies treat subduction zones as either infinite in trench-parallel extent (that is, two-dimensional) or finite in width but fixed in space. Subduction zones and their associated slabs are, however, limited in lateral extent (250-7,400 km) and their three-dimensional geometry evolves over time. Here we show that slab width controls two first-order features of plate tectonics-the curvature of subduction zones and their tendency to retreat backwards with time. Using three-dimensional numerical simulations of free subduction, we show that trench migration rate is inversely related to slab width and depends on proximity to a lateral slab edge. These results are consistent with retreat velocities observed globally, with maximum velocities (6-16 cm yr(-1)) only observed close to slab edges (<1,200 km), whereas far from edges (>2,000 km) retreat velocities are always slow (<2.0 cm yr(-1)). Models with narrow slabs (< or =1,500 km) retreat fast and develop a curved geometry, concave towards the mantle wedge side. Models with slabs intermediate in width ( approximately 2,000-3,000 km) are sublinear and retreat more slowly. Models with wide slabs (> or =4,000 km) are nearly stationary in the centre and develop a convex geometry, whereas trench retreat increases towards concave-shaped edges. Additionally, we identify periods (5-10 Myr) of slow trench advance at the centre of wide slabs. Such wide-slab behaviour may explain mountain building in the central Andes, as being a consequence of its tectonic setting, far from slab edges.

  5. Geophysical investigation of the Hockai Fault Zone, Eastern Belgium

    NASA Astrophysics Data System (ADS)

    Havenith, Hans-Balder; Nguyen, Frédéric; Halleux, Lucien; Hölz, Sebastian; Camelbeeck, Thierry

    2015-04-01

    In the frame of a regional project evaluating the geothermal potential of the Wallonian Region of Belgium, the Hockai Fault Zone has been identified as one of the most interesting targets. It is a seismically active fault zone that hosted the largest historical earthquake in Northwestern Europe, the M6-6.5 Verviers event in 1692 as well as a swarm of small earthquakes that was recorded in 1989-90. On the surface, the presence of the fault zones is marked by a series of geomorphic features, such as several landslides near the borders in the northern part, repeated NW-SE oriented scarps all along the Eastern border (over a distance of 40 km), river diversions and captures with formation of paleo-valleys. Along the most prominent paleo-valley, the Paleo-Warche Valley crossing the fault zone over a distance of 5 km, a geophysical survey has been organized by several teams to better characterize the shallow (<150 m) subsurface of the fault zone. It included electro-magnetic sounding (frequency-based and TEM), shallow seismics (refraction, walk-away, surface waves analysis), electrical resistivity tomography as well as ambient noise recordings. To support an integrated interpretation of all geophysical results in combination with geomorphic and seismo-tectonic aspects, surface morphology, soundings and profiles were represented in a 3D model. This model clearly reveals low-resistivity and low-velocity zones near the Eastern border of the fault zone, vertically above the hypocenters of the 1989-90 earthquake swarm. Across the structure, low-resistivity zones have a limited extent while they are repeatedly identified all along Eastern border.

  6. Seismological evidence for a localized mushy zone at the Earth's inner core boundary.

    PubMed

    Tian, Dongdong; Wen, Lianxing

    2017-08-01

    Although existence of a mushy zone in the Earth's inner core has been hypothesized several decades ago, no seismic evidence has ever been reported. Based on waveform modeling of seismic compressional waves that are reflected off the Earth's inner core boundary, here we present seismic evidence for a localized 4-8 km thick zone across the inner core boundary beneath southwest Okhotsk Sea with seismic properties intermediate between those of the inner and outer core and of a mushy zone. Such a localized mushy zone is found to be surrounded by a sharp inner core boundary nearby. These seismic results suggest that, in the current thermo-compositional state of the Earth's core, the outer core composition is close to eutectic in most regions resulting in a sharp inner core boundary, but deviation from the eutectic composition exists in some localized regions resulting in a mushy zone with a thickness of 4-8 km.The existence of a mushy zone in the Earth's inner core has been suggested, but has remained unproven. Here, the authors have discovered a 4-8 km thick mushy zone at the inner core boundary beneath the Okhotsk Sea, indicating that there may be more localized mushy zones at the inner core boundary.

  7. North Pacific Transition Zone Thickness From SS-Precursors

    NASA Astrophysics Data System (ADS)

    Mayeau, T. M.; Wysession, M. E.; Aleqabi, G. I.

    2005-12-01

    The thickness variation of the mantle transition zone is one key to understanding mantle dynamics, in particular, as a possible indicator of lateral temperature variations at that depth. As a result of the Clapeyron slopes of the 410 and 660 km phase transitions, the transition zone is expected to thin in regions of high heat and thicken in cooler areas. Thus, these variations can be used to look for large scale mantle convection features, such as down going slabs and mantle plumes. The thickness of the transition zone can be effectively measured by the differential travel times of phases reflecting off the 410 km and 660 km discontinuities. Here we search for transition zone thickness variations using SS-precursors from the North Pacific recorded by the IRIS PASSCAL Florida-to-Edmonton (FLED) Array of broadband seismometers (and neighboring North American stations), which were operational from May 2001 to September 2002. Records are first rotated into transverse components, converted to displacements with the instrument responses removed, and then subdivided into 20 degree by 20 degree bins. The traces from earthquakes with strong SS arrivals were binned by the location of the SS bounce point, and the bins stacked into vespagrams using the MATLAB-based MATSEIS program. From the vespagrams we determine the S660S-S410S differential travel times for each stack, which yield measurements of transition zone thickness. We then compare thickness measurements from different events and with previously published maps of transition zone thickness to determine the robustness of our technique. This work was supported by an IRIS Undergraduate Summer Internship.

  8. Variations in Km(CO2) of Ribulose-1,5-bisphosphate Carboxylase among Grasses

    PubMed Central

    Yeoh, Hock-Hin; Badger, Murray R.; Watson, Leslie

    1980-01-01

    A survey of the Km(CO2) values of ribulose-1,5-bisphosphate carboxylase from 60 grass species shows that enzyme from C3 grasses consistently exhibits lower Km(CO2) than does that from C4 grasses. Systematically ordered variation in Km(CO2) of ribulose-1,5-bisphosphate carboxylases from C3 and C4 grasses is also apparent and, among C4 grasses, this shows some correlation with C4 types. PMID:16661586

  9. MODIS 3 Km Aerosol Product: Applications over Land in an Urban/suburban Region

    NASA Technical Reports Server (NTRS)

    Munchak, L. A.; Levy, R. C.; Mattoo, S.; Remer, L. A.; Holben, B. N.; Schafer, J. S.; Hostetler, C. A.; Ferrare, R. A.

    2013-01-01

    MODerate resolution Imaging Spectroradiometer (MODIS) instruments aboard the Terra and Aqua satellites have provided a rich dataset of aerosol information at a 10 km spatial scale. Although originally intended for climate applications, the air quality community quickly became interested in using the MODIS aerosol data. However, 10 km resolution is not sufficient to resolve local scale aerosol features. With this in mind, MODIS Collection 6 is including a global aerosol product with a 3 km resolution. Here, we evaluate the 3 km product over the Baltimore/Washington D.C., USA, corridor during the summer of 2011, by comparing with spatially dense data collected as part of the DISCOVER-AQ campaign these data were measured by the NASA Langley Research Center airborne High Spectral Resolution Lidar (HSRL) and a network of 44 sun photometers (SP) spaced approximately 10 km apart. The HSRL instrument shows that AOD can vary by up to 0.2 within a single 10 km MODIS pixel, meaning that higher resolution satellite retrievals may help to characterize aerosol spatial distributions in this region. Different techniques for validating a high-resolution aerosol product against SP measurements are considered. Although the 10 km product is more statistically reliable than the 3 km product, the 3 km product still performs acceptably, with more than two-thirds of MODIS/SP collocations falling within the expected error envelope with high correlation (R > 0.90). The 3 km product can better resolve aerosol gradients and retrieve closer to clouds and shorelines than the 10 km product, but tends to show more significant noise especially in urban areas. This urban degradation is quantified using ancillary land cover data. Overall, we show that the MODIS 3 km product adds new information to the existing set of satellite derived aerosol products and validates well over the region, but due to noise and problems in urban areas, should be treated with some degree of caution.

  10. Analysis of Gorda Escarpment Geomorphology, Mendocino Fracture Zone

    NASA Astrophysics Data System (ADS)

    Hefner, W.; Sautter, L.

    2016-02-01

    Multibeam survey data from the R/V Atlantis 2014 cruise-AT26-21 were used to examine the east-west trending Gorda Escarpment of the Mendocino Fracture Zone, west of the Gorda Spreading Ridge. This area lies on the Pacific Plate and includes several seamounts and geologic structures. Using Caris HIPS and SIPS 9.0 software, features along the fracture zone were characterized to determine offsets from plate movement along with analysis of associated seamount geomorphology. The extent of movement along the fault line was determined by comparing offsets of corresponding narrow ridges to its north and south. The northern complex ridges have warped, with a curvature along the fracture zone towards the east, indicating that this portion of the Pacific Plate north of the fracture is migrating westward at a faster rate than the area south of the fracture. The result is an offset along the fracture which ranges from 5.0 to 7.0 km. The seamount chain to the south of and parallel to the fracture zone is approximately 124 km long with the largest seamount to the west. Lava lobes and terraces are significantly more abundant on the seamounts' south flanks suggesting asymmetry in eruptive sequences. Information gathered from the study area is beneficial to understanding fracture zones of the Mendocino Triple Junction and may contribute to studies of tectonic and seismic activity for the nearby Northern California coast.

  11. Running Performance, Nationality, Sex and Age in 10km, Half-marathon, Marathon and 100km Ultra-marathon IAAF 1999-2015.

    PubMed

    Nikolaidis, Pantelis T; Onywera, Vincent O; Knechtle, Beat

    2016-10-13

    The aim of the present study was to examine the performance of the world's best runners in 10km, half-marathon, marathon and 100km by age, sex and nationality during 1999-2015 using data from International Association of Athletics Federations (IAAF). A total of 38,895 runners (17,136 women and 21,759 men) were considered with 2,594 (1,360 women and 1,234 male) in 10km, 11,595 (5,225 women and 6,370 male) in half-marathon, 23,973 (10,208 women and 13,765 male) in marathon and 733 (343 women and 390 male) in 100km. Most of the runners in 10km (women 40%, men 67%) and half-marathon (women 30%, men 57%) were Kenyans. In marathon, most female and male runners were Ethiopians (women 17%, men 14%) and Kenyans (women 15%, men 43%), respectively. In 100km, most runners were Japanese (20% in women and men). Women were older than men in 10km (32.0±6.0 versus 25.3±4.3 years, p<0.001), half-marathon (27.5±4.7 versus 25.9±4.1 years, p<0.001) and marathon (29.5±5.5 versus 29.1±4.3 years, p<0.001), but not in 100km (36.6±6.1 versus 35.9±5.5 years, p=0.097). Men were faster than women in 10km (28:04±0:17 versus 32:08±0.31 min:sec, p<0.001), half-marathon (1:01:58±0:00:52 versus 1:11:21±0:01:18 h:min:sec, p<0.001), marathon (2:13:42±0:03:01 versus 2:35:04±0:05:21 h:min:s, p<0.001), and 100km (6:48:01±0:11:29 versus 7:53:51±0:16:37 h:min:sec, p<0.001). East-Africans were not the fastest compared to athletes originating from other countries where only Ethiopian men were faster than all other men in marathon. In summary, (i) most runners were from Kenya and Ethiopia in 10km, half-marathon and marathon, but from Japan and Russia in 100km, (ii) women were older than men in all distances except 100km, (iii) men were the fastest in all distances, and (iii) Ethiopian men were faster than all other men in marathon.

  12. Protective effect of kombucha mushroom (KM) tea on phenol-induced cytotoxicity in albino mice.

    PubMed

    Yapar, Kursad; Cavusoglu, Kultigin; Oruc, Ertan; Yalcin, Emine

    2010-09-01

    The present study was carried out to evaluate the protective role of kombucha mushroom (KM) tea on cytotoxicity induced by phenol (PHE) in mice. We used weight gain and micronucleus (MN) frequency as indicators of cytotoxicity and supported these parameters with pathological findings. The animals were randomly divided into seven groups: (Group I) only tap water (Group II) 1000 microl kg(-1) b. wt KM-tea, (Group III) 35 mg kg(-1) body wt. PHE (Group IV) 35 mg kg(-1) body wt. PHE + 250 microl kg(-1) b. wt KM-tea (Group V) 35 mg kg(-1) b. wt PHE + 500 microl kg(-1) b. wt KM-tea (Group VI) 35 mg kg(-1) b. wt PHE + 750 microl kg(-1) b. wt KM-tea, (Group VII) 35 mg kg(-1) b. wt PHE + 1000 microl kg(-1) b. wt KM-tea, for 20 consecutive days by oral gavage. The results indicated that all KM-tea supplemented mice showed a lower MN frequency than erythrocytes in only PHE-treated group. There was an observable regression on account of lesions in tissues of mice supplemented with different doses of KM-tea in histopathological observations. In conclusion, the KM-tea supplementation decreases cytotoxicity induced by PHE and its protective role is dose-dependent.

  13. Potential of KM3NeT to observe galactic neutrino point-like sources

    NASA Astrophysics Data System (ADS)

    Trovato, Agata

    2016-07-01

    KM3NeT (http://www.km3net.org">http://www.km3net.org) will be the next-generation cubic-kilometre-scale neutrino telescope to be installed in the depths of the Mediterranean Sea. This location will allow for surveying the Galactic Centre, most of the Galactic Plane as well as a large part of the sky. We report KM3NeT discovery potential for the SNR RXJ1713.7-3946 and the PWN Vela X and its sensitivity to point-like sources with an E-2 spectrum.

  14. Seismic probing of continental subduction zones

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Xu, Xiaobing; Malusà, Marco G.

    2017-09-01

    High-resolution images of Earth's interior provide pivotal information for the understanding of a range of geodynamic processes, including continental subduction and exhumation of ultrahigh-pressure (UHP) metamorphic rocks. Here we present a synthesis of available global seismic observations on continental subduction zones, and selected examples of seismic probing from the European Alps, the Himalaya-Tibet and the Qinling-Dabie orogenic belts. Our synthesis and examples show that slabs recognized beneath exhumed continental UHP terranes generally have shallow dip angles (<45°) at depths <100 km, to become much steeper at depths >100 km. Slabs underlined by a clear high velocity anomaly from Earth's surface to the mantle are generally Cenozoic in age. Some of these slabs are continuous, whereas other continental subduction zones are located above discontinuous high velocity anomalies possibly suggesting slab breakoff. The density of seismic stations and the quality of recordings are of primary importance to get high-resolution images of the upper mantle to be used as a starting point to provide reliable geodynamic interpretations. In some cases, areas previously indicated as possible site of slab breakoff, such as the European Alps, have been later proven to be located above a continuous slab by using higher quality travel time data from denser seismic arrays. Discriminating between oceanic and continental slabs can be challenging, but valuable information can be provided by combining teleseismic tomography and receiver function analysis. The upper mantle beneath most continental UHP terranes generally shows complex seismic anisotropy patterns that are potentially preserved even in pre-Cenozoic subduction zones. These patterns can be used to provide information on continental slabs that are no longer highlighted by a clear high-velocity anomaly.

  15. Recurrence Times for Eartthquakes at the Coastal Region of Oaxaca - Guerrero, MEXICO (Zone 8)

    NASA Astrophysics Data System (ADS)

    Nunez-Cornu, F. J.

    2013-05-01

    Oaxaca is the most seismic active region in Mexico with 68 larger events, (mb > 6.5; Ms> 7.0) from 1542 to 1989, which implies roughly a large earthquake every 6.5 years; including an earthquake with M=8.5 which generate the most important historical tsunami in Mexico. It is also the most studied from a seismic point of view. Three types of earthquakes take place in the region: low angle thrust fault (associated to the subduction process) with a depth between 15 to 25 km; normal fault with a depth between 65 and 120 km with epicenters north of Oaxaca City (17°N); normal fault with a depth between 25 to 40 km with epicenters between the coast and Oaxaca City. A seismogenic zoning based in seismic, tectonic and historical seismicity studies zones was proposed in 1989; eight zones were defined, two zone along the coast, one for the isthmus and rest inland. 23 Years later, 4 larger earthquake have occurred in the region that seems agreed with the recurrence models proposed. Here the Zone 8 (Oaxaca - Guerrero coastal) is revised, 12 earthquakes have taken place in this Zone since 1655. However, special mention for the earthquakes in this Zone is the San Sixto Earthquake (March, 28, 1787, M=8.4) which is the biggest historical earthquake in Mexico, and generates the most important local tsunami in Mexico with 18 m high waves at a distance of 6 km inland (Núñez-Cornú et al, 2009). After this earthquake there was a seismic quiescence of 141 years, for the next earthquake in the Zone (1928), after that this Zone became the most seismic active Zone in Mexico (Núñez-Cornú. 1996) with 7 earthquakes in 85 years.

  16. Ste. Genevieve Fault Zone, Missouri and Illinois. Final report

    SciTech Connect

    Nelson, W.J.; Lumm, D.K.

    1985-07-01

    The Ste. Genevieve Fault Zone is a major structural feature which strikes NW-SE for about 190 km on the NE flank of the Ozark Dome. There is up to 900 m of vertical displacement on high angle normal and reverse faults in the fault zone. At both ends the Ste. Genevieve Fault Zone dies out into a monocline. Two periods of faulting occurred. The first was in late Middle Devonian time and the second from latest Mississippian through early Pennsylvanian time, with possible minor post-Pennsylvanian movement. No evidence was found to support the hypothesis that the Ste. Genevieve Fault Zone is part of a northwestward extension of the late Precambrian-early Cambrian Reelfoot Rift. The magnetic and gravity anomalies cited in support of the ''St. Louis arm'' of the Reelfoot Rift possible reflect deep crystal features underlying and older than the volcanic terrain of the St. Francois Mountains (1.2 to 1.5 billion years old). In regard to neotectonics no displacements of Quaternary sediments have been detected, but small earthquakes occur from time to time along the Ste. Genevieve Fault Zone. Many faults in the zone appear capable of slipping under the current stress regime of east-northeast to west-southwest horizontal compression. We conclude that the zone may continue to experience small earth movements, but catastrophic quakes similar to those at New Madrid in 1811-12 are unlikely. 32 figs., 1 tab.

  17. Wedge Dynamics, Forearc Basins, and Seismogenic Zone of Cascadia Megathrust

    NASA Astrophysics Data System (ADS)

    Wang, K.; Hu, Y.

    2005-12-01

    A dynamic critical wedge theory has been developed to describe stress changes in submarine wedges in great earthquake cycles. For most subduction zones, the theory postulates that the actively deforming outer wedge overlies the updip velocity-strengthening part of the subduction fault, and the less deformed inner wedge overlies the megathrust seismogenic zone. Coseismic shear-stress increase in the velocity-strengthening zone drives the outer wedge into the critical state, causing episodic fold-and-thrust deformation, but the inner wedge stays in the stable regime throughout earthquake cycles, maintaining a stable environment for the development of forearc sedimentary basins. This is consistent with the globally observed correlation of the location of forearc basins with rupture zones of subduction earthquakes [Wells et al., JGR, 2003]. However, northern/central Cascadia is complicated by recent, exceedingly rapid growth of the accretionary prism. Until mid-Pleistocene, the megathrust seismogenic zone was probably mostly beneath the forearc basins, in agreement with the modern global observations. Rapid wedge growth and consequent megathrust warming over the past Ma have caused the seismogenic zone to move seaward by tens of km, to a position consistent with inferences based on contemporary geodetic observations. With much of the seismogenic zone located seaward of the forearc basins and beneath the upper continental slope, the dynamic taper theory predicts that coseismic deformation should cause extensional structures on the upper slope but accretion and thrusting on the lower slope, consistent with structural observations [McNeill et al., JGR, 1998].

  18. The Transition Zone low-velocity zone: insights from Northwestern Canada (Invited)

    NASA Astrophysics Data System (ADS)

    Schaeffer, A. J.; Bostock, M. G.

    2010-12-01

    Seismic studies over the past decade have identified an S-wave low-velocity zone (LVZ) above the transition zone at various locations around the globe. Recent observations indicate that, although not of global extent, this feature is observed across a variety of tectonic environments spanning a large range in age, from ancient Archean cratons to modern active margins. Hypothesized to be a lens of dense, hydrous, silicate melt ponding atop the 410 km discontinuity, beneath the silicate melt-density crossover predicted to exist within the upper mantle, the nature of this LVZ and its effect on volatile and incompatible element cycling may provide further insight into their distribution within the mantle. We assembled a P- and S-receiver function (PRF and SRF) dataset to quantify the physical properties and geographical extent of the layer in Northwestern Canada. Geographic profiles formed from 1-D migration of RFs computed for the CANOE and POLARIS-Slave arrays reveal an LVZ beneath many stations at a nominal depth of ~340 km. To constrain layer thickness and Poisson's ratio, we performed a grid search over a suite of 1-D velocity profiles to model the relative delay times of direct conversions and reverberations from the top of the LVZ and 410 km discontinuity, as recorded at the Yellowknife Array. In addition, we performed linearized inversion of transmission coefficient amplitudes to estimate S-velocity contrasts at the bounding interfaces. The LVZ is characterized by a thickness of ~36 km with an S-velocity contrast of -7.8%, and Poisson's ratio of 0.42. This estimate for Poisson's ratio lies well above the IASP91 average of 0.29-0.3 for this depth range and favours the presence of high melt or fluid fractions. Taken at face value, the two latter results require an increase in P-velocity into the LVZ, which has implications on the expected changes in elastic moduli into the layer.

  19. New Madrid seismic zone recurrence intervals

    SciTech Connect

    Schweig, E.S. Center for Earthquake Research and Information, Memphis, TN ); Ellis, M.A. )

    1993-03-01

    Frequency-magnitude relations in the New Madrid seismic zone suggest that great earthquakes should occur every 700--1,200 yrs, implying relatively high strain rates. These estimates are supported by some geological and GPS results. Recurrence intervals of this order should have produced about 50 km of strike-slip offset since Miocene time. No subsurface evidence for such large displacements is known within the seismic zone. Moreover, the irregular fault pattern forming a compressive step that one sees today is not compatible with large displacements. There are at least three possible interpretations of the observations of short recurrence intervals and high strain rates, but apparently youthful fault geometry and lack of major post-Miocene deformation. One is that the seismological and geodetic evidence are misleading. A second possibility is that activity in the region is cyclic. That is, the geological and geodetic observations that suggest relatively short recurrence intervals reflect a time of high, but geologically temporary, pore-fluid pressure. Zoback and Zoback have suggested such a model for intraplate seismicity in general. Alternatively, the New Madrid seismic zone is geologically young feature that has been active for only the last few tens of thousands of years. In support of this, observe an irregular fault geometry associated with a unstable compressive step, a series of en echelon and discontinuous lineaments that may define the position of a youthful linking fault, and the general absence of significant post-Eocene faulting or topography.

  20. Arid Zone Hydrology

    USDA-ARS?s Scientific Manuscript database

    Arid zone hydrology encompasses a wide range of topics and hydro-meteorological and ecological characteristics. Although arid and semi-arid watersheds perform the same functions as those in humid environments, their hydrology and sediment transport characteristics cannot be readily predicted by inf...

  1. Microgravity Silicon Zoning Investigation

    NASA Technical Reports Server (NTRS)

    Kern, E. L.

    1985-01-01

    This research program is directed toward the understanding of the float zone crystal growth process, the melt interactions which lead to crystal inhomogeneities, and the influence of microgravity on reducing these inhomogeneities. Silicon was selected as the model crystal because its inhomogeneities lead to known variations in device performance, and because the mechanisms involved in its growth are understood better than for other high temperature crystals. The objective of the program is to understand the growth mechanisms in float zone growth and thereby determine the feasibility and advantages of float zone growth of silicon under microgravity conditions. This will be done by characterizing the growth at g = 1, projecting the changes in melt flows due to microgravity, observing these in space growth and determining the effects on defective inhomogeneities. A Thin Rod Zoner was constructed as a laboratory prototype for flight growth of 5 mm diameter silicon crystals, which can be done within the power and cooling capabilities of shuttle flights. A new method of zoning silicon, using resistance heating, has resulted in melting 5 mm diameter ingots.

  2. Flexible 'zoning' aids adaptability.

    PubMed

    Corben, Simon

    2013-09-01

    Simon Corben, business development director at Capita Symonds' Health team, examines how 'clever use of zoning' when planning new healthcare facilities could improve hospital design, increase inherent flexibility, and reduce lifetime costs, and argues that a 'loose-fit, non-bespoke approach' to space planning will lead to 'more flexible buildings that are suitable for conversion to alternative uses'.

  3. Commercial Float Zone Furnace

    NASA Image and Video Library

    1996-05-25

    S77-E-5093 (25 May 1996) --- Astronaut Marc Garneau, mission specialist representing the Canadian Space Agency (CSA), makes a visual check of the Commercial Float Zone Furnace (CFZF), a single-rack-mounted facility in the Spacehab Module onboard the Earth-orbiting Space Shuttle Endeavour. The scene was recorded with an Electronic Still Camera (ESC).

  4. Stretching the comfort zone

    NASA Astrophysics Data System (ADS)

    Gibb, Bruce C.

    2015-08-01

    Bruce C. Gibb is organizing a workshop for two groups of scientists that study a similar topic, but rarely get together. The different perspectives they bring and the unusual set up of the meeting will hopefully lead to new ideas, but, as he suggests, they will also lead to the attendees leaving their comfort zones.

  5. Splenic marginal zone lymphoma.

    PubMed

    Piris, Miguel A; Onaindía, Arantza; Mollejo, Manuela

    Splenic marginal zone lymphoma (SMZL) is an indolent small B-cell lymphoma involving the spleen and bone marrow characterized by a micronodular tumoral infiltration that replaces the preexisting lymphoid follicles and shows marginal zone differentiation as a distinctive finding. SMZL cases are characterized by prominent splenomegaly and bone marrow and peripheral blood infiltration. Cells in peripheral blood show a villous cytology. Bone marrow and peripheral blood characteristic features usually allow a diagnosis of SMZL to be performed. Mutational spectrum of SMZL identifies specific findings, such as 7q loss and NOTCH2 and KLF2 mutations, both genes related with marginal zone differentiation. There is a striking clinical variability in SMZL cases, dependent of the tumoral load and performance status. Specific molecular markers such as 7q loss, p53 loss/mutation, NOTCH2 and KLF2 mutations have been found to be associated with the clinical variability. Distinction from Monoclonal B-cell lymphocytosis with marginal zone phenotype is still an open issue that requires identification of precise and specific thresholds with clinical meaning.

  6. Dilution Zone Mixing

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1983-01-01

    Studies to characterize dilution zone mixing; experiments on the effects of free-stream turbulence on a jet in crossflow; and the development of an interactive computer code for the analysis of the mixing of jets with a confined crossflow are reviewed.

  7. Buffer Zone Sign Template

    EPA Pesticide Factsheets

    The certified pesticide applicator is required to post a comparable sign, designating a buffer zone around the soil fumigant application block in order to control exposure risk. It must include the don't walk symbol, product name, and applicator contact.

  8. Fast aurora zone analysis

    NASA Technical Reports Server (NTRS)

    Booker, Mattie

    1992-01-01

    The Flight Dynamics Facility (FDF) of the Flight Dynamics Division (FDD), of the Goddard Space Flight Center provides acquisition data to tracking stations and orbit and attitude services to scientists and mission support personnel. The following paper explains how a method was determined that found spacecraft entry and exit times of the aurora zone.

  9. Repeaterless transmission of eight channels at 10 Gb/s over 137 km (11 Tb/s-km) of dispersion-shifted fiber using unequal channel spacing

    NASA Astrophysics Data System (ADS)

    Forghieri, Fabrizio; Gnauck, A. H.; Tkach, R. W.; Chraplyvy, A. R.; Derosier, R. M.

    1994-11-01

    Experimental evidence of the effectiveness of a proper allocation of channel frequencies to suppress four-wave-mixing crosstalk is presented by comparing an eight-channel WDM system with unequal channel spacing with a conventional equally spaced WDM system with the same optical bandwidth. Repeaterless transmission of eight 10-Gb/s WDM channels over 137 km (11 Tb/s-km) of dispersion-shifted fiber was demonstrated and error-free operation was achieved over a wide range of input powers using unequally spaced channels. The same system with equally spaced channels could not achieve a probability of error lower than 10(exp -6). The use of unequal channel spacing allows fiber input power to be increased by as much as 7 dB, which can be translated to a fivefold increase of the bit rate per channel (and therefore of the system capacity), or to an increase of the system length by about 30 km.

  10. High Resolution Imaging of Fault Zone Structures With Seismic Fault Zone Waves

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Y.; Zhigang, P.; Lewis, M. A.; McGuire, J.

    2006-12-01

    Large fault zone (FZ) structures with damaged rocks and material discontinuity interfaces can generate several indicative wave propagation signals. High crack density may produce prominent scattering and non-linear effects. A preferred crack orientation can lead to shear wave splitting. A lithology contrast can produce FZ head waves that propagate along the material interface with the velocity and motion polarity of the faster medium. A coherent low velocity layer may generate FZ trapped waves. These signals can be used to obtain high resolution imaging of the subsurface structure of fault zones, and to track possible temporal evolution of FZ material properties. Several results have emerged from recent systematic analyses of such signals. The trapped waves are generated typically by ~100 m wide layers that extend only to ~3-4 km depth and are characterized by 30-50% velocity reduction and strong attenuation. The trapping structures are surrounded by broader anisotropic and scattering zones limited primarily also to the shallow crust. Results associated with anisotropy and scattering around the North Anatolian fault using repeating earthquake clusters do not show precursory temporal evolution. The anisotropy results show small co-seismic changes, while the scattering results show larger co-seismic changes and post-seismic logarithmic recovery. The temporal changes probably reflect damage evolution in the top few hundred m of the crust. Systematic analyses of head waves along several sections of the San Andreas fault reveal material interfaces that extend to the bottom of the seismogenic zone. Joint arrival time inversions of direct and FZ head waves imply velocity contrasts of 20% or more in the top 3 km and lower contrasts of 5-15% in the deeper section. In several places, analyses of trapped and head waves indicate that the shallow damaged layers are asymmetric across the fault. The observed damage asymmetry may reflect preferred propagation direction of

  11. Low S-wave-velocity layers in the transition zone: a review of seismic data

    NASA Astrophysics Data System (ADS)

    Vinnik, Lev

    2010-05-01

    I review the seismic data that suggest the presence of thin (a few tens km wide) low-S-velocity zones atop the 410-km discontinuity and in a depth range of 450 - 520 km. Most of the data are obtained with receiver function techniques. Contrary to the prediction of Bercovici and Karato (2003), the low velocity atop the 410-km discontinuity is found mostly in association with plume-like structures in the mantle of the Kaapvaal craton, the Siberian craton, the Arabian plate, West Siberia, China, West Africa and Antarctica (Vinnik and Farra, 2002, 2007). In southern Africa (Vinnik et al.,GJI 2009) this structure seems to be anisotropic. The latest observations of the low velocity atop the 410-km discontinuity are made in the western US and California (e.g. Vinnik et al. JGR 2010, in press). In southern California and the neighboring Pacific this layer, found with the S receiver function techniques, can be related to the Baja-Guadalupe hot-spot. The low velocity can be related to the high solubilty of water in wadsleyite in the mantle transition zone relative to olivine in the overlaying mantle, but other possibilities cannot be excluded. Most observations of the low-velocity zone in a depth range of 450-520 km are also related to plumes and plume-like structures (Afar, Iceland, Azores, Cameroon, south-eastern Atlantic). A plausible theory of this phenomenon should explain why the low S velocity never extends to depths exceeding 520 km.

  12. Vertical and horizontal extension of the oxygen minimum zone in the eastern South Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Fuenzalida, Rosalino; Schneider, Wolfgang; Garcés-Vargas, José; Bravo, Luis; Lange, Carina

    2009-07-01

    Recent hydrographic measurements within the eastern South Pacific (1999-2001) were combined with vertically high-resolution data from the World Ocean Circulation Experiment, high-resolution profiles and bottle casts from the World Ocean Database 2001, and the World Ocean Atlas 2001 in order to evaluate the vertical and horizontal extension of the oxygen minimum zone (<20 μmol kg -1). These new calculations estimate the total area and volume of the oxygen minimum zone to be 9.82±3.60×10 6 km 2 and 2.18±0.66×10 6 km 3, respectively. The oxygen minimum zone is thickest (>600 m) off Peru between 5 and 13°S and to about 1000 km offshore. Its upper boundary is shallowest (<150 m) off Peru, shoaling towards the coast and extending well into the euphotic zone in some places. Offshore, the thickness and meridional extent of the oxygen minimum zone decrease until it finally vanishes at 140°W between 2° and 8°S. Moving southward along the coast of South America, the zonal extension of the oxygen minimum zone gradually diminishes from 3000 km (15°S) to 1200 km (20°S) and then to 25 km (30°S); only a thin band is detected at ˜37°S off Concepción, Chile. Simultaneously, the oxygen minimum zone's maximum thickness decreases from 300 m (20°S) to less than 50 m (south of 30°S). The spatial distribution of Ekman suction velocity and oxygen minimum zone thickness correlate well, especially in the core. Off Chile, the eastern South Pacific Intermediate Water mass introduces increased vertical stability into the upper water column, complicating ventilation of the oxygen minimum zone from above. In addition, oxygen-enriched Antarctic Intermediate Water clashes with the oxygen minimum zone at around 30°S, causing a pronounced sub-surface oxygen front. The new estimates of vertical and horizontal oxygen minimum zone distribution in the eastern South Pacific complement the global quantification of naturally hypoxic continental margins by Helly and Levin [2004. Global

  13. The Reliability of a 5km Run Test on a Motorized Treadmill

    ERIC Educational Resources Information Center

    Driller, Matthew; Brophy-Williams, Ned; Walker, Anthony

    2017-01-01

    The purpose of the present study was to determine the reliability of a 5km run test on a motorized treadmill. Over three consecutive weeks, 12 well-trained runners completed three 5km time trials on a treadmill following a standardized warm-up. Runners were partially-blinded to their running speed and distance covered. Total time to complete the…

  14. Draft genome sequence of the Bordetella bronchiseptica swine isolate KM22

    USDA-ARS?s Scientific Manuscript database

    Bordetella bronchiseptica swine isolate KM22 has been used in experimental infections of swine as a model of clinical B. bronchiseptica infections within swine herds and to study host-to-host transmission. Here we report the draft genome sequence of KM22....

  15. New Marker Development for the Rice Blast Resistance Gene Pi-km

    USDA-ARS?s Scientific Manuscript database

    The blast resistance (R) gene Pi-km protects rice against specific races of the fungal pathogen Magnaporthe oryzae. The use of blast R genes remains the most cost-effective method of disease control. To facilitate the breeding process, we developed a Pi-km specific molecular marker. For this purp...

  16. Changes in Body Mass, Hydration and Electrolytes Following a 161-km Endurance Race

    USDA-ARS?s Scientific Manuscript database

    Purpose: To examine electrolyte concentrations and changes in body mass and total body water (TBW) during a 161-km ultra-marathon, and relate these to finish time and incidence of hyponatremia. Methods: Subjects were recruited from the 161-km 2008 Rio Del Lago Endurance Race. Body mass, TBW, and s...

  17. A Co-Creation Blended KM Model for Cultivating Critical-Thinking Skills

    ERIC Educational Resources Information Center

    Yeh, Yu-chu

    2012-01-01

    Both critical thinking (CT) and knowledge management (KM) skills are necessary elements for a university student's success. Therefore, this study developed a co-creation blended KM model to cultivate university students' CT skills and to explore the underlying mechanisms for achieving success. Thirty-one university students participated in this…

  18. Acute prior heavy strength exercise bouts improve the 20-km cycling time trial performance.

    PubMed

    Silva, Renato A S; Silva-Júnior, Fernando L; Pinheiro, Fabiano A; Souza, Patrícia F M; Boullosa, Daniel A; Pires, Flávio O

    2014-09-01

    This study verified if a prior 5 repetition maximum (5RM) strength exercise would improve the cycling performance during a 20-km cycling time trial (TT20km). After determination of the 5RM leg press exercise load, 11 trained cyclists performed a TT20km in a control condition and 10-minute after 4 sets of 5RM strength exercise bouts (potentiation condition). Oxygen uptake, blood lactate concentration, ratings of perceived exertion (RPE), and power output data were recorded during the TT20km. Cycling economy index was assessed before the TT20km, and pacing strategy was analyzed assuming a "J-shaped" power output distribution profile. Results were a 6.1% reduction (p ≤ 0.05) in the time to complete the TT20km, a greater cycling economy (p < 0.01), and power output in the first 10% of the TT20km (i.e., trend; p = 0.06) in the potentiation condition. However, no differences were observed in pacing strategy, physiological parameters, and RPE between the conditions. These results suggest that 5RM strength exercise bouts improve the performance in a subsequent TT20km.

  19. An algorithm for computing synthetic body waves due to underside conversion on an undulating interface and application to the 410 km discontinuity

    NASA Astrophysics Data System (ADS)

    Zhang, Han; Ni, Sidao; Chu, Risheng; Schmandt, Brandon

    2017-09-01

    The topography of the 410 km discontinuity provides helpful constraints on both petrologic and geodynamic models of the mantle transition zone. Previous studies involving differential times between scattered phases (S410S, p410P, s410P, etc.) and reference phases (SS, P, pP, sP, etc.) have revealed large-scale topography on the 410 km discontinuity. In contrast, amplitude variations of converted phases are more sensitive to smaller scale topography. We develop an algorithm to calculate synthetic S-to-P conversions at the 410 km discontinuity above deep earthquakes using ray theory and the representation theorem. After benchmarking our method with geometrical ray theory, we perform tests on elevated and depressed topography with dome or ridge shapes. We find that focusing/defocusing due to discontinuity topography substantially alters the amplitudes of converted phases (60 per cent-300 per cent based on our examples). We then use the new algorithm to model amplitude variations of the s410P waves from a deep earthquake beneath western Brazil. A grid search over potential values for the width and height of a ridge-like elevation of the 410 km discontinuity found that the observed amplitude pattern can be explained by a ridge with a height of 12 km and width of 180 km near the expected location of a subducted slab. The new method demonstrated here can be easily adapted to model downgoing S410P or S660P waves, but the representation theorem needs to be combined with numerical solvers to tackle complex 3-D structures near mantle discontinuities.

  20. A viscoplastic shear-zone model for episodic slow slip events in oceanic subduction zones

    NASA Astrophysics Data System (ADS)

    Yin, A.; Meng, L.

    2016-12-01

    Episodic slow slip events occur widely along oceanic subduction zones at the brittle-ductile transition depths ( 20-50 km). Although efforts have been devoted to unravel their mechanical origins, it remains unclear about the physical controls on the wide range of their recurrence intervals and slip durations. In this study we present a simple mechanical model that attempts to account for the observed temporal evolution of slow slip events. In our model we assume that slow slip events occur in a viscoplastic shear zone (i.e., Bingham material), which has an upper static and a lower dynamic plastic yield strength. We further assume that the hanging wall deformation is approximated as an elastic spring. We envision the shear zone to be initially locked during forward/landward motion but is subsequently unlocked when the elastic and gravity-induced stress exceeds the static yield strength of the shear zone. This leads to backward/trenchward motion damped by viscous shear-zone deformation. As the elastic spring progressively loosens, the hanging wall velocity evolves with time and the viscous shear stress eventually reaches the dynamic yield strength. This is followed by the termination of the trenchward motion when the elastic stress is balanced by the dynamic yield strength of the shear zone and the gravity. In order to account for the zig-saw slip-history pattern of typical repeated slow slip events, we assume that the shear zone progressively strengthens after each slow slip cycle, possibly caused by dilatancy as commonly assumed or by progressive fault healing through solution-transport mechanisms. We quantify our conceptual model by obtaining simple analytical solutions. Our model results suggest that the duration of the landward motion increases with the down-dip length and the static yield strength of the shear zone, but decreases with the ambient loading velocity and the elastic modulus of the hanging wall. The duration of the backward/trenchward motion depends

  1. HYBRIDIZATION AND GEOGRAPHIC VARIATION IN TWO MEADOW KATYDID CONTACT ZONES.

    PubMed

    Shapiro, Leo H

    1998-06-01

    In this study, previously unrecognized hybridization was documented between two meadow katydids in each of two disjunct contact zones, in the southeastern United States and along the Potomac River near Washington, DC. These two zones have very different histories and dynamics of interaction between the two taxa. Orchelimum nigripes and O. pulchellum (Tettigoniidae: Conocephalinae) are distributed west and east, respectively, of the Appalachian Mountains, from the Great Lakes to the Gulf Coast and along the Atlantic Coastal Plain from New York to the Florida Keys, but are not found in the Appalachians themselves. In addition, during this century O. nigripes has become established in a small area east of the Appalachians, in the Potomac River basin, where it has completely replaced O. pulchellum along the river corridor above Washington, DC. I sampled katydids from 40 sites across both hybrid zones and mapped geographic patterns of genetic variation (allele frequencies at two diagnostic loci) and variation in a morphometric index for males. Although the two taxa are quite distinct over most of their extensive distributions, there is clear evidence of introgression in both contact zones. In the Deep South, samples from a transect along the Gulf Coast define a broad hybrid zone of about 50-100 km, while samples from a transect 200 km to the north define a zone of about 150-250 km in width. Only one Deep South population shows a deviation from Hardy-Weinberg equilibrium at either locus, and there is no evidence of linkage disequilibrium in any Deep South population. In the Potomac region, there is a narrow upstream-downstream hybrid zone along the river. Within the Potomac River floodplains downriver from Washington, DC, as well as outside the floodplains throughout the region, O. pulchellum is present in abundance, but O. nigripes markers are virtually absent. Within the floodplains upriver from Washington, DC, O. nigripes is abundant, but O. pulch***ellum markers are

  2. Early structural development of the Okavango rift zone, NW Botswana

    NASA Astrophysics Data System (ADS)

    Kinabo, B. D.; Atekwana, E. A.; Hogan, J. P.; Modisi, M. P.; Wheaton, D. D.; Kampunzu, A. B.

    2007-06-01

    Aeromagnetic and gravity data collected across the Okavango rift zone, northwest Botswana are used to map the distribution of faults, provide insights into the two-dimensional shallow subsurface geometry of the rift, and evaluate models for basin formation as well as the role of pre-existing basement fabric on the development of this nascent continental rift. The structural fabric (fold axes and foliation) of the Proterozoic basement terrane is clearly imaged on both gravity and magnetic maps. The strike of rift-related faults (030-050° in the north and 060-070° in the south) parallels fold axes and the prominent foliation directions of the basement rocks. These pre-existing fabrics and structures represent a significant strength anisotropy that controlled the orientation of younger brittle faults within the stress regime present during initiation of this rift. Northwest dipping faults consistently exhibit greater displacements than southeast dipping faults, suggesting a developing half-graben geometry for this rift zone. However, the absence of fully developed half-grabens along this rift zone suggests that the border fault system is not fully developed consistent with the infancy of rifting. Three en-echelon northeast trending depocenters coincide with structural grabens that define the Okavango rift zone. Along the southeastern boundary of the rift, developing border faults define a 50 km wide zone of subsidence within a larger 150 km wide zone of extension forming a rift-in-rift structure. We infer from this observation that the localization of strain resulting from extension is occurring mostly along the southeastern boundary where the border fault system is being initiated, underscoring the important role of border faults in accommodating strain even during this early stage of rift development. We conclude that incipient rift zones may provide critical insights into the development of rift basins during the earliest stages of continental rifting.

  3. On subduction zone earthquakes and the Pacific Northwest seismicity

    SciTech Connect

    Chung, Dae H.

    1991-12-01

    A short review of subduction zone earthquakes and the seismicity of the Pacific Northwest region of the United States is provided for the purpose of a basis for assessing issues related to earthquake hazard evaluations for the region. This review of seismotectonics regarding historical subduction zone earthquakes and more recent seismological studies pertaining to rupture processes of subduction zone earthquakes, with specific references to the Pacific Northwest, is made in this brief study. Subduction zone earthquakes tend to rupture updip and laterally from the hypocenter. Thus, the rupture surface tends to become more elongated as one considers larger earthquakes (there is limited updip distance that is strongly coupled, whereas rupture length can be quite large). The great Aleutian-Alaska earthquakes of 1957, 1964, and 1965 had rupture lengths of greater than 650 km. The largest earthquake observed instrumentally, the M{sub W} 9.5, 1960 Chile Earthquake, had a rupture length over 1000 km. However, earthquakes of this magnitude are very unlikely on Cascadia. The degree of surface shaking has a very strong dependency on the depth and style of rupture. The rupture surface during a great earthquake shows heterogeneous stress drop, displacement, energy release, etc. The high strength zones are traditionally termed asperities and these asperities control when and how large an earthquake is generated. Mapping of these asperities in specific subduction zones is very difficult before an earthquake. They show up more easily in inversions of dynamic source studies of earthquake ruptures, after an earthquake. Because seismic moment is based on the total radiated-energy from an earthquake, the moment-based magnitude M{sub W} is superior to all other magnitude estimates, such as M{sub L}, m{sub b}, M{sub bLg}, M{sub S}, etc Probably, just to have a common language, non-moment magnitudes should be converted to M{sub W} in any discussions of subduction zone earthquakes.

  4. A 7-km Non-Hydrostatic Global Mesoscale Simulation with the Goddard Earth Observing System Model (GEOS-5) for Observing System Simulation Experiments

    NASA Astrophysics Data System (ADS)

    Putman, W.; Suarez, M.; Gelaro, R.; daSilva, A.; Molod, A.; Ott, L. E.; Darmenov, A.

    2014-12-01

    The Global Modeling and Assimilation Office at NASA Goddard Space Flight Center has used the Goddard Earth Observing System model (GEOS-5) to produce a 2-year non-hydrostatic global mesoscale simulation for the period of June 2005-2007. This 7-km GEOS-5 Nature Run (7km-G5NR) product will provide synthetic observations for observing system simulation experiments (OSSE)s at NASA and NOAA through the Joint Center for Satellite Data Assimilation and the NASA Center for Climate Simulation. While GEOS-5 is regularly applied in seasonal-to-decadal climate simulations, and medium range weather prediction and data assimilation, GEOS-5 is also readily adaptable for application as a global mesoscale model in pursuit of global cloud resolving applications. Recent computing advances have permitted experimentation with global atmospheric models at these scales, although production applications like the 7km-G5NR have remained limited. By incorporating a non-hydrostatic finite-volume dynamical core with scale aware physics parameterizations, the 7km-G5NR produces organized convective systems and robust weather systems ideal for producing observations for existing and new remote sensing instruments. In addition to standard meteorological parameters, the 7km-G5NR includes 15 aerosol tracers (including dust, seasalt, sulfate, black and organic carbon), O3, CO and CO2. The 7km-G5NR is driven by prescribed sea-surface temperatures and sea-ice, daily volcanic and biomass burning emissions, as well as high-resolution inventories of anthropogenic sources. We will discuss the technical challenges of producing the 7km-G5NR including the nearly 5 petabytes of full resolution output at 30-minute intervals as required by the OSSE developers, and modifications to the standard GEOS-5 physics to permit convective organization at the 'grey-zone' resolution of 7km. Highlights of the 7km-G5NR validation will focus on the representation of clouds and organized convection including tropical cyclones

  5. Design and mass production of the optical modules for KM3NeT-Italia project

    NASA Astrophysics Data System (ADS)

    Leonora, Emanuele; Aiello, Sebastiano; Giordano, Valentina

    2016-04-01

    The KM3NeT European project aims at constructing a km3 underwater neutrino telescope in the depths of the Mediterranean Sea. The first phase that is under construction will comprise eight tower-like detection structures (KM3NeT-Italia), which will form the internal core of a km3-scale detector. The detection element of KM3NeT-Italia, the optical module, is made of a 13-inch pressure-resistant glass-vessel that contains a single 10-inch photomultiplier and the relative electronics. The design of the whole optical module, the main results obtained from the massive photomultipliers measurements, and the foremost phases of the mass production procedure performed at the production site of Catania are also presented.

  6. Pure Rotational Raman Lidar for Temperature Measurements from 5-40 Km Over Wuhan, China

    NASA Astrophysics Data System (ADS)

    Li, Yajuan; Song, Shalei; Yang, Yong; Li, Faquan; Cheng, Xuewu; Chen, Zhenwei; Liu, Linmei; McCormick, M. Patrick; Gong, Shunsheng

    2016-06-01

    In this paper a pure rotational Raman lidar (PRR) was established for the atmospheric temperature measurements from 5 km to 40 km over Wuhan, China (30.5°N, 114.5°E). To extract the expected PRR signals and simultaneously suppress the elastically backscattered light, a high-spectral resolution polychromator for light splitting and filtering was designed. Observational results revealed that the temperature difference measured by PRR lidar and the local radiosonde below 30 km was less than 3.0 K. The good agreement validated the reliability of the PRR lidar. With the 1-h integration and 150-m spatial resolution, the statistical temperature error for PRR lidar increases from 0.4 K at 10 km up to 4 K at altitudes of about 30 km. In addition, the whole night temperature profiles were obtained for study of the long-term observation of atmospheric fluctuations.

  7. Unexpected characteristics of the 150 km echoes observed over Gadanki and their implications

    NASA Astrophysics Data System (ADS)

    Patra, A. K.; Pavan Chaitanya, P.

    2016-11-01

    Recent discovery of two distinct types of 150 km echoes, namely, type-A and type-B, and subsequent progress in the large-scale kinetic simulation of photoelectron-induced plasma waves have begun a new era in resolving the five decades long 150 km echoing riddle. In this paper, we present hitherto unrevealed three important and unexpected findings on the two distinct types of 150 km echoes based on Gadanki radar observations. Our observations show unexpected predominance of type-A echoes, strong seasonal dependence of both type-A and type-B echoes, and a surprising connection of the type-B echoes to the unusually deep solar minimum of 2008-2009. We discuss how these results provide important new clues in tethering the competing processes involved in the daytime 150 km echoes and have significance in the recently proposed photoelectron-induced plasma fluctuations as a potential mechanism for the 150 km echoes.

  8. Cape Canaveral, Florida range reference atmosphere 0-70 km altitude

    NASA Technical Reports Server (NTRS)

    Tingle, A. (Editor)

    1983-01-01

    The RRA contains tabulations for monthly and annual means, standard deviations, skewness coefficients for wind speed, pressure temperature, density, water vapor pressure, virtual temperature, dew-point temperature, and the means and standard deviations for the zonal and meridional wind components and the linear (product moment) correlation coefficient between the wind components. These statistical parameters are tabulated at the station elevation and at 1 km intervals from sea level to 30 km and at 2 km intervals from 30 to 90 km altitude. The wind statistics are given at approximately 10 m above the station elevations and at altitudes with respect to mean sea level thereafter. For those range sites without rocketsonde measurements, the RRAs terminate at 30 km altitude or they are extended, if required, when rocketsonde data from a nearby launch site are available. There are four sets of tables for each of the 12 monthly reference periods and the annual reference period.

  9. Interseismic Strain Localization in the San Jacinto Fault Zone

    NASA Astrophysics Data System (ADS)

    Lindsey, Eric O.; Sahakian, Valerie J.; Fialko, Yuri; Bock, Yehuda; Barbot, Sylvain; Rockwell, Thomas K.

    2014-11-01

    We investigate interseismic deformation across the San Jacinto fault at Anza, California where previous geodetic observations have indicated an anomalously high shear strain rate. We present an updated set of secular velocities from GPS and InSAR observations that reveal a 2-3 km wide shear zone deforming at a rate that exceeds the background strain rate by more than a factor of two. GPS occupations of an alignment array installed in 1990 across the fault trace at Anza allow us to rule out shallow creep as a possible contributor to the observed strain rate. Using a dislocation model in a heterogeneous elastic half space, we show that a reduction in shear modulus within the fault zone by a factor of 1.2-1.6 as imaged tomographically by Allam and Ben-Zion (Geophys J Int 190:1181-1196, 2012) can explain about 50 % of the observed anomalous strain rate. However, the best-fitting locking depth in this case (10.4 ± 1.3 km) is significantly less than the local depth extent of seismicity (14-18 km). We show that a deep fault zone with a shear modulus reduction of at least a factor of 2.4 would be required to explain fully the geodetic strain rate, assuming the locking depth is 15 km. Two alternative possibilities include fault creep at a substantial fraction of the long-term slip rate within the region of deep microseismicity, or a reduced yield strength within the upper fault zone leading to distributed plastic failure during the interseismic period.

  10. Twin Convergence Zones

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's QuikSCAT satellite has confirmed a 30-year old largely unproven theory that there are two areas near the equator where the winds converge year after year and drive ocean circulation south of the equator. By analyzing winds, QuikSCAT has found a year-round southern and northern Intertropical Convergence Zone. This find is important to climate modelers and weather forecasters because it provides more detail on how the oceans and atmosphere interact near the equator. The Intertropical Convergence Zone (ITCZ) is the region that circles the Earth near the equator, where the trade winds of both the Northern and Southern Hemispheres come together. North of the equator, strong sun and warm water of the equator heats the air in the ITCZ, drawing air in from north and south and causing the air to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Satellite data, however, has confirmed that there is an ITCZ north of the equator and a parallel ITCZ south of the equator. Variation in the location of the ITCZ is important to people around the world because it affects the north-south atmospheric circulation, which redistributes energy. It drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. 'The double ITCZ is usually only identified in the Pacific and Atlantic Oceans on a limited and seasonal basis,' said Timothy Liu, of NASA's Jet Propulsion Laboratory and California Institute of Technology, Pasadena, Calif., and lead researcher on the project. In the eastern Pacific Ocean, the southern ITCZ is usually seen springtime. In the western Atlantic Ocean, the southern ITCZ was recently clearly identified only in the summertime. However, QuikSCAT's wind data has seen the southern ITCZ in all seasons across the

  11. Twin Convergence Zones

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's QuikSCAT satellite has confirmed a 30-year old largely unproven theory that there are two areas near the equator where the winds converge year after year and drive ocean circulation south of the equator. By analyzing winds, QuikSCAT has found a year-round southern and northern Intertropical Convergence Zone. This find is important to climate modelers and weather forecasters because it provides more detail on how the oceans and atmosphere interact near the equator. The Intertropical Convergence Zone (ITCZ) is the region that circles the Earth near the equator, where the trade winds of both the Northern and Southern Hemispheres come together. North of the equator, strong sun and warm water of the equator heats the air in the ITCZ, drawing air in from north and south and causing the air to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Satellite data, however, has confirmed that there is an ITCZ north of the equator and a parallel ITCZ south of the equator. Variation in the location of the ITCZ is important to people around the world because it affects the north-south atmospheric circulation, which redistributes energy. It drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. 'The double ITCZ is usually only identified in the Pacific and Atlantic Oceans on a limited and seasonal basis,' said Timothy Liu, of NASA's Jet Propulsion Laboratory and California Institute of Technology, Pasadena, Calif., and lead researcher on the project. In the eastern Pacific Ocean, the southern ITCZ is usually seen springtime. In the western Atlantic Ocean, the southern ITCZ was recently clearly identified only in the summertime. However, QuikSCAT's wind data has seen the southern ITCZ in all seasons across the

  12. Central and peripheral fatigue in male cyclists after 4-, 20-, and 40-km time trials.

    PubMed

    Thomas, Kevin; Goodall, Stuart; Stone, Mark; Howatson, Glyn; St Clair Gibson, Alan; Ansley, Les

    2015-03-01

    Few studies have assessed neuromuscular fatigue after self-paced locomotor exercise; moreover, none have assessed the degree of supraspinal fatigue. This study assessed central and peripheral fatigue after self-paced exercise of different durations. Thirteen well-trained male cyclists completed 4-, 20-, and 40-km simulated time trials (TTs). Pre- and immediately post-TT (<2.5 min), twitch responses from the knee extensors to electrical stimulation of the femoral nerve and transcranial magnetic stimulation of the motor cortex were recorded to assess neuromuscular and corticospinal function. Time to complete 4-, 20-, and 40-km TTs was 6.0 ± 0.2, 31.8 ± 1.0, and 65.8 ± 2.2 min at average exercise intensities of 96%, 92%, and 87% of maximum oxygen uptake, respectively. Exercise resulted in significant reductions in maximum voluntary contraction, with no difference between TTs (-18%, -15%, and -16% for 4-, 20-, and 40-km TTs, respectively). Greater peripheral fatigue was evident after 4-km (40% reduction in potentiated twitch) compared with that after 20-km (31%) and 40-km TTs (29%). In contrast, longer TTs were characterized by more central fatigue, with greater reductions in voluntary activation measured by motor nerve (-11% and -10% for 20- and 40-km TTs vs -7% for 4-km TTs) and cortical stimulation (-12% and -10% for 20- and 40-km vs -6% for 4-km). These data demonstrate that fatigue after self-paced exercise is task dependent, with a greater degree of peripheral fatigue after shorter higher-intensity (6 min) TTs and more central fatigue after longer lower-intensity TTs (>30 min).

  13. Oblique sinistral transpression in the Arabian shield: The timing and kinematics of a Neoproterozoic suture zone

    USGS Publications Warehouse

    Johnson, P.R.; Kattan, F.

    2001-01-01

    The Hulayfah-Ad Dafinah-Ruwah fault zone is a belt of highly strained rocks that extends in a broad curve across the northeastern Arabian shield. It is a subvertical shear zone, 5-30 km wide and over 600 km long, and is interpreted as a zone of oblique sinistral transpression that forms the suture between the Afif terrane and the Asir-Jiddah-Hijaz-Hulayfah superterrane. Available data suggest that the terranes began to converge sometime after 720 Ma, were in active contact at about 680 Ma, and were in place, with suturing complete, by 630 Ma, The fault zone was affected by sinistral horizontal and local vertical shear, and simultaneous flattening and fault-zone-parallel extension. Structures include sinistral sense-of-shear indicators, L-S tectonite, and coaxial stretching lineations and fold axes. The stretching lineations switch from subhorizontal to subvertical along the fault zone indicating significant variation in finite strain consistent with an origin by oblique transpression. The sense of shear on the fault zone suggests sinistral trajectories for the converging terranes, although extrapolating the shear sense of the suture zone to infer far-field motion must be done with caution. The amalgamation model derived from the chronologic and structural data for the fault zone modifies an existing model of terrane amalgamation and clarifies the definitions of two deformational events (the Nabitah orogeny and the Najd fault system) that are widely represented in the Arabian shield. ?? 2001 Elsevier Science B.V.

  14. Listening to music in the first, but not the last 1.5 km of a 5-km running trial alters pacing strategy and improves performance.

    PubMed

    Lima-Silva, A E; Silva-Cavalcante, M D; Pires, F O; Bertuzzi, R; Oliveira, R S F; Bishop, D

    2012-10-01

    We examined the effects of listening to music on attentional focus, rating of perceived exertion (RPE), pacing strategy and performance during a simulated 5-km running race. 15 participants performed 2 controlled trials to establish their best baseline time, followed by 2 counterbalanced experimental trials during which they listened to music during the first (M start) or the last (M finish) 1.5 km. The mean running velocity during the first 1.5 km was significantly higher in M start than in the fastest control condition (p<0.05), but there was no difference in velocity between conditions during the last 1.5 km (p>0.05). The faster first 1.5 m in M start was accompanied by a reduction in associative thoughts compared with the fastest control condition. There were no significant differences in RPE between conditions (p>0.05). These results suggest that listening to music at the beginning of a trial may draw the attentional focus away from internal sensations of fatigue to thoughts about the external environment. However, along with the reduction in associative thoughts and the increase in running velocity while listening to music, the RPE increased linearly and similarly under all conditions, suggesting that the change in velocity throughout the race may be to maintain the same rate of RPE increase.

  15. Thermal perturbations beneath the incipient Okavango Rift Zone, northwest Botswana

    NASA Astrophysics Data System (ADS)

    Leseane, Khumo; Atekwana, Estella A.; Mickus, Kevin L.; Abdelsalam, Mohamed G.; Shemang, Elisha M.; Atekwana, Eliot A.

    2015-02-01

    We used aeromagnetic and gravity data to investigate the thermal structure beneath the incipient Okavango Rift Zone (ORZ) in northwestern Botswana in order to understand its role in strain localization during rift initiation. We used three-dimensional (3-D) inversion of aeromagnetic data to estimate the Curie Point Depth (CPD) and heat flow under the rift and surrounding basement. We also used two-dimensional (2-D) power-density spectrum analysis of gravity data to estimate the Moho depth. Our results reveal shallow CPD values (8-15 km) and high heat flow (60-90 mW m-2) beneath a ~60 km wide NE-trending zone coincident with major rift-related border faults and the boundary between Proterozoic orogenic belts. This is accompanied by thin crust (<30 km) in the northeastern and southwestern parts of the ORZ. Within the Precambrian basement areas, the CPD values are deeper (16-30 km) and the heat flow estimates are lower (30-50 mW m-2), corresponding to thicker crust (~40-50 km). We interpret the thermal structure under the ORZ as due to upward migration of hot mantle fluids through the lithospheric column that utilized the presence of Precambrian lithospheric shear zones as conduits. These fluids weaken the crust, enhancing rift nucleation. Our interpretation is supported by 2-D forward modeling of gravity data suggesting the presence of a wedge of altered lithospheric mantle centered beneath the ORZ. If our interpretation is correct, it may result in a potential paradigm shift in which strain localization at continental rift initiation could be achieved through fluid-assisted lithospheric weakening without asthenospheric involvement.

  16. Allocating emissions to 4 km and 1 km horizontal spatial resolutions and its impact on simulated NOx and O3 in Houston, TX

    NASA Astrophysics Data System (ADS)

    Pan, Shuai; Choi, Yunsoo; Roy, Anirban; Jeon, Wonbae

    2017-09-01

    A WRF-SMOKE-CMAQ air quality modeling system was used to investigate the impact of horizontal spatial resolution on simulated nitrogen oxides (NOx) and ozone (O3) in the Greater Houston area (a non-attainment area for O3). We employed an approach recommended by the United States Environmental Protection Agency to allocate county-based emissions to model grid cells in 1 km and 4 km horizontal grid resolutions. The CMAQ Integrated Process Rate analyses showed a substantial difference in emissions contributions between 1 and 4 km grids but similar NOx and O3 concentrations over urban and industrial locations. For example, the peak NOx emissions at an industrial and urban site differed by a factor of 20 for the 1 km and 8 for the 4 km grid, but simulated NOx concentrations changed only by a factor of 1.2 in both cases. Hence, due to the interplay of the atmospheric processes, we cannot expect a similar level of reduction of the gas-phase air pollutants as the reduction of emissions. Both simulations reproduced the variability of NASA P-3B aircraft measurements of NOy and O3 in the lower atmosphere (from 90 m to 4.5 km). Both simulations provided similar reasonable predictions at surface, while 1 km case depicted more detailed features of emissions and concentrations in heavily polluted areas, such as highways, airports, and industrial regions, which are useful in understanding the major causes of O3 pollution in such regions, and to quantify transport of O3 to populated communities in urban areas. The Integrated Reaction Rate analyses indicated a distinctive difference of chemistry processes between the model surface layer and upper layers, implying that correcting the meteorological conditions at the surface may not help to enhance the O3 predictions. The model-observation O3 bias in our studies (e.g., large over-prediction during the nighttime or along Gulf of Mexico coastline), were due to uncertainties in meteorology, chemistry or other processes. Horizontal grid

  17. Global Investigation of the Mg Atom and ion Layers using SCIAMACHY/Envisat Observations between 70 km and 150 km Altitude and WACCM-MG Model Results

    NASA Technical Reports Server (NTRS)

    Langowski, M.; vonSavigny, C.; Burrows, J. P.; Feng, W.; Plane, J. M. C.; Marsh, D. R.; Janches, Diego; Sinnhuber, M.; Aikin, A. C.

    2014-01-01

    Mg and Mg+ concentration fields in the upper mesosphere/lower thermosphere (UMLT) region are retrieved from SCIAMACHY/Envisat limb measurements of Mg and Mg+ dayglow emissions using a 2-D tomographic retrieval approach. The time series of monthly means of Mg and Mg+ for number density as well as vertical column density in different latitudinal regions are shown. Data from the limb mesosphere-thermosphere mode of SCIAMACHY/Envisat are used, which covers the 50 km to 150 km altitude region with a vertical sampling of 3.3 km and a highest latitude of 82 deg. The high latitudes are not covered in the winter months, because there is no dayglow emission during polar night. The measurements were performed every 14 days from mid-2008 until April 2012. Mg profiles show a peak at around 90 km altitude with a density between 750 cm(exp-3) and 2000 cm(exp-3). Mg does not show strong seasonal variation at mid-latitudes. The Mg+ peak occurs 5-15 km above the neutral Mg peak at 95-105 km. Furthermore, the ions show a significant seasonal cycle with a summer maximum in both hemispheres at mid- and high-latitudes. The strongest seasonal variations of the ions are observed at mid-latitudes between 20-40 deg and densities at the peak altitude range from 500 cm(exp-3) to 6000 cm(exp-3). The peak altitude of the ions shows a latitudinal dependence with a maximum at mid-latitudes that is up to 10 km higher than the peak altitude at the equator. The SCIAMACHY measurements are compared to other measurements and WACCM model results. In contrast to the SCIAMACHY results, the WACCM results show a strong seasonal variability for Mg with a winter maximum, which is not observable by SCIAMACHY, and globally higher peak densities. Although the peak densities do not agree the vertical column densities agree, since SCIAMACHY results show a wider vertical profile. The agreement of SCIAMACHY and WACCM results is much better for Mg+, showing the same seasonality and similar peak densities. However

  18. Crust and upper mantle structure of the New Madrid Seismic Zone: Insight into intraplate earthquakes

    NASA Astrophysics Data System (ADS)

    Chen, Chuanxu; Zhao, Dapeng; Wu, Shiguo

    2014-05-01

    We determine a 3-D P-wave velocity model of the crust and upper mantle down to 400 km depth to investigate structural heterogeneity and its influences on the generation of intraplate earthquakes in the New Madrid Seismic Zone. We used 4871 high-quality arrival times from 187 local earthquakes and 30,846 precise travel-time residuals from 1041 teleseismic events recorded by the EarthScope/USArray Transportable Array. Our results show that, beneath the Reelfoot rift, a significant low-velocity (low-V) zone exists in the upper mantle down to 200 km depth, with a large volume of 200 × 200 × 150 km3. The origin of the low-V zone may be related to the passage of the Bermuda hotspot and the stalled ancient Farallon slab materials foundering in the mantle transition zone. This low-V zone may have relatively low shear strength and act as a viscously weak zone embedded in the lithosphere, being apt to concentrate tectonic stress and transfer stress to the seismogenic faults in the upper crust, leading to the large intraplate earthquakes in the New Madrid Seismic Zone.

  19. Seismogenic characteristics of the Mariana shallow thrust zone: What controls plate coupling?

    NASA Astrophysics Data System (ADS)

    Wiens, D. A.; Emry, E.; Shiobara, H.; Sugioka, H.

    2007-05-01

    The Mariana arc has been the type example of an "aseismic" or "decoupled" subduction zone since the concept was first proposed by Uyeda and Kanamori [1979]. Most past studies of the seismogenic zone characteristics have focused on "coupled" subduction zones that show large thrust earthquakes. Comparative studies of "decoupled" zones are essential for understanding the factors controlling the occurrence of large earthquakes. We use land and ocean bottom seismograph records from the 2003-2004 Mariana Subduction Factory Imaging Experiment to study the seismicity of the Mariana forearc. This 11 month experiment consisted of 20 broadband stations deployed on islands and 58 semi-broadband ocean bottom seismographs (OBS), with 14 OBSs located in the forearc. Events were detected and arrival times picked with Antelope package and relocated with a hypocentroidal decomposition relative location method. Overall, we have located ~ 500 events in the Mariana forearc between 16-19 N with mb 2 - 5. We determined the focal mechanisms of the largest events using a regional waveform inversion method. We have recently also detected episodic tremor that may be similar to that found at Cascadia, Japan, and several other subduction zones. The results indicate a lack of significant seismicity in the outer forearc beneath Big Blue and Celestial serpentinite seamounts. A few well-located events suggest that the shallow thrust zone is located at a depth of 15-25 km beneath the seamounts. Patches of high seismicity in the shallow thrust zone are located to the west of the seamounts at depths of 30-40 km. The patches are approximately 20 km in diameter and suggest heterogeneous faulting properties along the shallow thrust zone. Another zone of earthquakes at depths of about 60 km initiate beneath the seamounts and extend towards the west, representing faulting within the subducting plate. These events indicate that the lower zone of the Mariana double seismic zone initiates in the forearc and

  20. Dynamics of melt and water circulation in the mantle transition zone

    NASA Astrophysics Data System (ADS)

    Bercovici, David

    2010-05-01

    The presence of melt above the mantle transition zone has been predicted by several groups, and its formation has been attributed - according to the 'water filter model" (Bercovici & Karato 2003) - with causing whole mantle convection to appear geochemically layered. In recent years, various seismological studies (e.g., most recently Jasbinsek and Dueker, 2007) have collectively inferred an extensive low velocity region at 410km depth, suggestive of the predicted melt zone. The leading mechanism proposed for generating this melt zone is by dehydration melting, which is supported by modest transition-zone water concentrations inferred by electromagnetic sounding (Huang, Xu, Karato, 2005). In this mechanism, warm upwelling 'damp" transition-zone material (wadsleyite) crosses the 410km boundary, and arrives above the solidus water limit in the upper-mantle (olivine) partial melt stability field. The fate of the subsequently produced melt is important for inferring the structure, observability and stability of this melt region. The most recent models of a wet melt layer spreading along the 410km boundary and reacting with a background mantle flow predict that the layer will be several 10s of kilometers thick, and that the melt's material will be entrained into the lower mantle well before it reaches any slabs (Leahy & Bercovici, 2010). At these pressures the melt is possibly more dense than the solid, although the density cross-over point is not likely to be far above the 410km boundary. However, unless the density cross-over actually intersects the melt zone, the melt is stable to any Rayleigh-Taylor instability (Youngs & Bercovici, 2009). Finally, continued re-hydration of the transition zone is required to supply the melt layer in the presence of background mantle flow. Slabs foundering and flowing horizontally across the transition zone provide one of the best means for transporting water across the transition zone. Slabs at the bottom of the transition zone

  1. The 2016 Mw5.1 Fairview, Oklahoma earthquakes: Evidence for long-range poroelastic triggering at >40 km from fluid disposal wells

    NASA Astrophysics Data System (ADS)

    Goebel, T. H. W.; Weingarten, M.; Chen, X.; Haffener, J.; Brodsky, E. E.

    2017-08-01

    Wastewater disposal in the central U.S. is likely responsible for an unprecedented surge in earthquake activity. Much of this activity is thought to be driven by induced pore pressure changes and slip on pre-stressed faults, which requires a hydraulic connection between faults and injection wells. However, direct pressure effects and hydraulic connectivity are questionable for earthquakes located at large distances and depths from the injectors. Here, we examine triggering mechanisms of induced earthquakes, which occurred at more than 40 km from wastewater disposal wells in the greater Fairview region, northwest Oklahoma, employing numerical and semi-analytical poroelastic models. The region exhibited few earthquakes before 2013, when background seismicity started to accelerate rapidly, culminating in the Mw5.1 Fairview earthquake in February 2016. Injection rates in the ∼2-2.5 km deep Arbuckle formation started to increase rapidly in 2012, about two years before the start of seismicity-increase. Most of the injection activity was concentrated toward the northeast of the study region, generating a relatively cohesive zone of pressure perturbations between 0.1 and 1 MPa. Much of the near-injection seismicity was likely triggered by pressure effects and fault-assisted pressure diffusion to seismogenic depth. Outside of the high-pressure zone, we observed two remarkably detached, linear seismicity clusters, which occurred at 20 to 50 km distance from the initial seismicity and 10 to 40 km from the nearest, high-rate injector. Semi-analytical models reveal that poroelastically-induced Coulomb-stress-changes surpass pore pressure changes at these distances, providing a plausible triggering mechanism in the far-field of injection wells. These results indicate that both pore-pressures and poroelastic stresses can play a significant role in triggering deep and distant earthquakes by fluid injection and should be considered for seismic hazard assessment beyond the

  2. Inflation along Kilauea's Southwest Rift Zone in 2006

    NASA Astrophysics Data System (ADS)

    Myer, David; Sandwell, David; Brooks, Benjamin; Foster, James; Shimada, Masanobu

    2008-10-01

    We report on InSAR and GPS results showing the first crustal inflation along the southwest rift zone at Kilauea volcano in over 20 years. Two independent interferograms (May 2-August 2, 2006 and June 22-Nov 7, 2006) from the ALOS PALSAR instrument reveal domal uplift located southwest of the main caldera. The uplift is bounded on the northeast by the caldera and follows the southwest rift zone for about 12 km. It is approximately 8 km wide. We use data derived from permanent GPS stations to calibrate the InSAR displacement data and estimate uplift of 7.7 cm during the first interferogram and 8.9 cm during the second with line-of-sight volumes of 2.8 × 10 6 m 3 and 3.0 × 10 6 m 3 respectively. The earthquake record for the periods before, during, and after inflation shows that a swarm of shallow earthquakes ( z < 5 km) signaled the beginning of the uplift and that elevated levels of shallow seismicity along the rift zones occurred throughout the uplift period. GPS data indicate that the inflation occurred steadily over nine months between mid-January and mid-October, 2006 making injection of a sill unlikely. We attribute the inflation to recharge of a shallow ductile area under the SWRZ.

  3. Inflation of Kilauea Along the Southwest Rift Zone in 2006

    NASA Astrophysics Data System (ADS)

    Myer, D. G.; Sandwell, D.; Brooks, B.; Foster, J.; Shimada, M.

    2007-12-01

    We report on InSAR and GPS results showing the first crustal inflation along the southwest rift zone at Kilauea volcano in over 30 years. Two independent interferograms (May 2 to August 2, 2006 and June 22 to Nov 7, 2006) from the ALOS PALSAR instrument reveal domal uplift located southwest of the main caldera. The uplift is bounded on the northeast by the caldera and follows the southwest rift zone for about 12 km. It is approximately 8 km wide. We use data derived from permanent GPS stations to calibrate the InSAR displacement data and estimate uplift of 8.3 cm during the first interferogram and 8.7 cm during the second with volumes of 2.8x106 m3 and 2.4x106 m3 respectively. The earthquake record for the periods before, during, and after inflation shows that a swarm of shallow earthquakes (z < 5 km) signaled the beginning of the uplift and that elevated levels of shallow seismicity along the rift zones occurred throughout the uplift period. GPS data indicate that the inflation occurred steadily over nine months between mid-January and mid-October, 2006 making injection of a sill unlikely.

  4. [Zoning of water environment protection in Three Gorges Reservoir watershed].

    PubMed

    Wang, Li-jing; Xi, Chun-yan; Zheng, Bing-hui

    2011-04-01

    Regional differences in socio-economic development, land use, vegetation cover, and relative location of water body within a watershed bring about significant effects on the water environment quality of the watershed. Concerning about the core demands of water body protection, it is important and necessary to carry out zoning water environment protection for whole watershed. With a view to the spatial differences in regional characteristics of eco-environment and water body pressure-respond features, this paper studied the zoning of water environment protection in the Three Gorges Reservoir watershed, based on the methods of ecological factors overlay and ecological sensitivity analysis. The factors considered included hydrothermal conditions, terrain topography, administrative unit, and ecological sensitivity. Three regions in the watershed were zoned, i. e., 1) red region, namely strictly protected region, with an area of 2924 km2 and occupying 5.1% of the total; 2) yellow region, namely first class protection region, with an area of 10477 km2 and occupying 18.4%; and 3) blue region, namely second class protection region, with an area of 43599 km2 and occupying 76.5%. The key environmental problems of the regions were identified, and the strategies for the regions' development and water environment protection were proposed.

  5. The effects of running a 308 km ultra-marathon on cardiac markers.

    PubMed

    Kim, Young-Joo; Shin, Young-Oh; Lee, Jeong-Beom; Lee, Yoon-Hee; Shin, Kyung-A; Kim, Al-Chan; Goh, Choong-Won; Kim, Chul; Oh, Jae-Keun; Min, Young-Ki; Yang, Hun-Mo

    2014-01-01

    The aim of this study was to investigate the expression of cardiac strain and damage in 18 male marathoners with average age of 52.8 ± 5.0 years running at a 308 km ultra-marathon. Blood samples were collected at pre-race, 100 km, 200 km and 308 km check points for the analysis of cardiac muscle injury markers, creatine kinase (CK), creatine kinase-myocardial band (CK-MB), cardiac troponin I (cTnI) and cardiac muscle strain marker, N-terminal pro-brain natriuretic peptide (NT-proBNP). The CK levels increased 1127.2 ± 507.9 IU/L, 5133.8 ± 2492.7 IU/L and 4958.4 ± 2087.9 IU/L at 100 km, 200 km and 308 km, respectively, compared to the pre-race levels. The CK-MB levels increased 20.2 ± 11.2 ng/mL, 73.3 ± 35.6 ng/mL and 68.6 ± 42.6 ng/mL at 100, 200 and 308 km, respectively, compared to the pre-race levels. The CK-MB/CK ratio showed that the CK-MB mass index was within the normal range (<2.5%) at 100 km, 200 km and 308 km. The cTnI levels showed no significant difference in all check points. The NT-proBNP levels increased 146.55 ± 92.7 pg/mL, 167.95 ± 111.9 pg/mL and 241.23 ± 121.2 pg/mL at 100, 200 and 308 km, respectively, compared to the pre-race levels. The normal CK-MB mass index (<5.0 ng/mL) and the absence of an increase in the cTnI levels during the 308 km ultra-marathon suggested that no myocardial injury despite an elevation in CK-MB. The increase in NT-proBNP levels probably resulted from continuous hemodynamic cardiac stress and represents a transient physiological myocardial protective response.

  6. Vadose zone water fluxmeter

    DOEpatents

    Faybishenko, Boris A.

    2005-10-25

    A Vadose Zone Water Fluxmeter (WFM) or Direct Measurement WFM provides direct measurement of unsaturated water flow in the vadose zone. The fluxmeter is a cylindrical device that fits in a borehole or can be installed near the surface, or in pits, or in pile structures. The fluxmeter is primarily a combination of tensiometers and a porous element or plate in a water cell that is used for water injection or extraction under field conditions. The same water pressure measured outside and inside of the soil sheltered by the lower cylinder of the fluxmeter indicates that the water flux through the lower cylinder is similar to the water flux in the surrounding soil. The fluxmeter provides direct measurement of the water flow rate in the unsaturated soils and then determines the water flux, i.e. the water flow rate per unit area.

  7. Modeling of Subduction Zone Slow/Slient Slip Events in Deeper Parts of the Seismogenic Zone

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Rice, J. R.

    2004-05-01

    Recent high resolution GPS measurements have detected slow and silent (or aseismic) slip events near the downdip end of the seismogenic zone at Japan, Cascadia and Mexico subduction zones [Hirose et al., 1999; Ozawa et al., 2001; Dragert et al., 2001; Lowry et al., 2001; Ozawa et al., 2002]. To investigate possible physical mechanisms, we apply a Dieterich-Ruina rate and state friction law to a three dimensional shallow subduction fault, which is loaded by imposed slip at rate Vpl ( ˜{10-9} m/s) far downdip along the thrust interface. Friction properties are temperature, and hence depth, dependent, so that sliding is stable ( a - b > 0) at depths below about 30 km. The system is perturbed into a nonuniform slip mode by introducing small (0 to 5%) along-strike variations in the constitutive parameters a and (a-b). Simulation results show large events with multiple magnitudes at various along-strike locations on the fault, with different recurrence intervals, like natural interplate earthquakes. More interesting, we observe that the large heterogeneous slip at seismogenic depths (i.e., where a - b < 0) is sometimes accompanied by events that have clearly aseismic slip rates (10 to 102 Vpl), which are comparable to the 10-9 to 10-8 m/s slip rates inferred in Japan and Cascadia Subduction zones [Hirose et al., 1999; Ozawa et al., 2001; Dragert et al., 2001]. These aseismic slip events usually nucleate below the less well locked ``gap'' regions (slipping at order of 0.1 to 1 times plate convergence rate Vpl) between more firmly locked regions (slipping at 10-4 to 10-2 Vpl). Some have aseismic slip rate fronts that migrate more than 100 km in the strike direction with a maximum speed ˜{20} km/year, at depths near or below the downdip end of the seismogenic zone. This migration speed is of the same order as the along-strike slip propagation in 1997 Bungo Channel event, southwestern Japan [Ozawa et al., 2001] and 2001 Tokai region event, central Japan [Ozawa et al., 2002

  8. Biomonitoring of TBT contamination and imposex incidence along 4700 km of Argentinean shoreline (SW Atlantic: from 38S to 54S).

    PubMed

    Bigatti, Gregorio; Primost, Mónica A; Cledón, Maximiliano; Averbuj, Andrés; Theobald, Norbert; Gerwinski, Wolfgang; Arntz, Wolf; Morriconi, Elba; Penchaszadeh, Pablo E

    2009-05-01

    The imposex incidence and TBT pollution were investigated along 4,700km of Argentinean coast, including city harbors and proximal zones without marine traffic. We analyzed 1805 individuals from 12 gastropod species, including families Volutidae, Muricidae, Nassariidea, Calyptraidae, Marginellidae, and Buccinidae, and found the imposex phenomenon for the first time in six species. In high marine traffic zones, TBT pollution was registered and the percentage of imposex was high, while these occurrences were null in areas without boat traffic. The species that best reflect the degree of imposex were those inhabiting sandy/muddy or mixed bottoms. TBT determination and imposex incidence indicate that pollution was focused only in ports with high marine traffic or in areas where ship hulls are painted. This is the first report of an imposex-sediment approach to evaluate organotin contamination along the coast of a South American country.

  9. Arid Zone Geosystems.

    DTIC Science & Technology

    1980-09-01

    the transition of the emphasis of the Nahal Yael Research Project from the direct measurement approach of the late six- ties and early seventies, to...lffLASSIFIEDflfl ARID ZONE GEOSYSTEMS A RESEARCH REPORT C- EDITED BY ASHER P. SCHICK fr~ PHYSICAL GEOGRAPHY I INSTITUTE OF EARTH SCIENCESi o THE HEBREW...second comprehensive collection and analysis of geosystem- oriented environmental data based on the Nahal Yael Research Watershed, located in the Negev

  10. Cornell Mixing Zone Expert System

    EPA Pesticide Factsheets

    This page provides an overview Cornell Mixing Zone Expert System water quality modeling and decision support system designed for environmental impact assessment of mixing zones resulting from wastewater discharge from point sources

  11. Radiant zone heated particulate filter

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  12. Renewable liquid reflecting zone plate

    DOEpatents

    Toor, Arthur; Ryutov, Dmitri D.

    2003-12-09

    A renewable liquid reflecting zone plate. Electrodes are operatively connected to a dielectric liquid in a circular or other arrangement to produce a reflecting zone plate. A system for renewing the liquid uses a penetrable substrate.

  13. Trojans in habitable zones.

    PubMed

    Schwarz, Richard; Pilat-Lohinger, Elke; Dvorak, Rudolf; Erdi, Balint; Sándor, Zsolt

    2005-10-01

    With the aid of numerical experiments we examined the dynamical stability of fictitious terrestrial planets in 1:1 mean motion resonance with Jovian-like planets of extrasolar planetary systems. In our stability study of the so-called "Trojan" planets in the habitable zone, we used the restricted three-body problem with different mass ratios of the primary bodies. The application of the three-body problem showed that even massive Trojan planets can be stable in the 1:1 mean motion resonance. From the 117 extrasolar planetary systems only 11 systems were found with one giant planet in the habitable zone. Out of this sample set we chose four planetary systems--HD17051, HD27442, HD28185, and HD108874--for further investigation. To study the orbital behavior of the stable zone in the different systems, we used direct numerical computations (Lie Integration Method) that allowed us to determine the escape times and the maximum eccentricity of the fictitious "Trojan planets."

  14. Hydraulic structure of a fault zone at seismogenic depths (Gole Larghe Fault Zone, Italian Southern Alps)

    NASA Astrophysics Data System (ADS)

    Bistacchi, Andrea; Mittempergher, Silvia; Di Toro, Giulio; Smith, Steve; Garofalo, Paolo; Vho, Alice

    2016-04-01

    The Gole Larghe Fault Zone (GLFZ, Italian Southern Alps) was exhumed from c. 8 km depth, where it was characterized by seismic activity (pseudotachylytes), but also by hydrous fluid flow (alteration halos and precipitation of hydrothermal minerals in veins and cataclasites). Thanks to glacier-polished outcrops exposing the fault zone over a continuous area > 1 km2, the fault zone architecture has been quantitatively described with an unprecedented detail (Bistacchi 2011, PAGEOPH; Smith 2013, JSG; Mittempergher 2016, this meeting), providing a rich dataset to generate 3D Discrete Fracture Network (DFN) models and simulate the fault zone hydraulic properties. Based on field and microstructural evidence, we infer that the opening and closing of fractures resulted in a toggle-switch mechanism for fluid flow during the seismic cycle: higher permeability was obtained in the syn- to early post-seismic period, when the largest number of fractures was (re)opened by off-fault deformation, then permeability dropped due to hydrothermal mineral precipitation and fracture sealing. Since the fracture network that we observe now in the field is the result of the cumulative deformation history of the fault zone, which probably includes thousands of earthquakes, a fundamental parameter that cannot be directly evaluated in the field is the fraction of fractures-faults that were open immediately after a single earthquake. Postseismic permeability has been evaluated in a few cases in the world thanks to seismological evidences of fluid migration along active fault systems. Therefore, we were able to develop a parametric hydraulic model of the GLFZ and calibrate it, varying the fraction of faults/fractures that were open in the postseismic period, to obtain on one side realistic fluid flow and permeability values, and on the other side a flow pattern consistent with the observed alteration/mineralization pattern. The fraction of open fractures is very close to the percolation threshold

  15. Marshall Space Flight Center Propulsion Systems Department (PSD) Knowledge Management (KM) Initiative

    NASA Technical Reports Server (NTRS)

    Caraccioli, Paul; Varnedoe, Tom; Smith, Randy; McCarter, Mike; Wilson, Barry; Porter, Richard

    2006-01-01

    NASA Marshall Space Flight Center's Propulsion Systems Department (PSD) is four months into a fifteen month Knowledge Management (KM) initiative to support enhanced engineering decision making and analyses, faster resolution of anomalies (near-term) and effective, efficient knowledge infused engineering processes, reduced knowledge attrition, and reduced anomaly occurrences (long-term). The near-term objective of this initiative is developing a KM Pilot project, within the context of a 3-5 year KM strategy, to introduce and evaluate the use of KM within PSD. An internal NASA/MSFC PSD KM team was established early in project formulation to maintain a practitioner, user-centric focus throughout the conceptual development, planning and deployment of KM technologies and capabilities within the PSD. The PSD internal team is supported by the University of Alabama's Aging Infrastructure Systems Center of Excellence (AISCE), lntergraph Corporation, and The Knowledge Institute. The principle product of the initial four month effort has been strategic planning of PSD KNI implementation by first determining the "as is" state of KM capabilities and developing, planning and documenting the roadmap to achieve the desired "to be" state. Activities undertaken to suppoth e planning phase have included data gathering; cultural surveys, group work-sessions, interviews, documentation review, and independent research. Assessments and analyses have beon pedormed including industry benchmarking, related local and Agency initiatives, specific tools and techniques used and strategies for leveraging existing resources, people and technology to achieve common KM goals. Key findings captured in the PSD KM Strategic Plan include the system vision, purpose, stakeholders, prioritized strategic objectives mapped to the top ten practitioner needs and analysis of current resource usage. Opportunities identified from research, analyses, cultural1KM surveys and practitioner interviews include

  16. Compilation of known and suspected Quaternary faults within 100 km of Yucca Mountain, Nevada and California

    SciTech Connect

    Piety, L.A.

    1996-12-31

    Geologic data have been compiled for known and suspected Quaternary faults in southern Nevada and southeastern California within about 100 km of the potential repository site at Yucca Mountain. The data set includes regional studies that attempt to identify and evaluate lineaments, scraps, and other possible tectonic landforms of possible Quaternary age, detailed studies that focus on a single fault, and geologic studies that were completed for purposes other than evaluation of Quaternary fault activity. Studies included in this compilation are those that were available as of December 1993. Faults that have known or suspected Quaternary activity are presented on a topographic base map at a scale of 1:250,000. Data for each fault that are pertinent to the assessment of future faulting and earthquake events are assembled on description sheets and summarized on tables. This compilation identifies ten faults within 50 km of the site but outside the site area and an additional fourteen faults between 50 km and 100 km of the site for which evidence for Holocene or late Pleistocene surface rupture has been reported in the literature. The longest and most continuous of these faults is the northwest-striking, 250-km-long Furnace Creek fault (including its possible extension into Fish Lake Valley), which is located about 50 km west of the site. In addition to identifying known or suspected Quaternary faults within about 100 km of the site, this compilation demonstrates the lack of information for most of these faults.

  17. [Comparative studies on monoclonal antibody KM10 and anti-CEA monoclonal antibodies].

    PubMed

    Soyama, N; Yamamoto, M; Ohyanagi, H; Saitoh, Y

    1989-11-01

    The specificity of KM10 was evaluated in comparison with newly developed anti-CEA monoclonal antibodies (A10, B9, JA4, AH3). Both KM10 and all anti-CEA monoclonal antibodies reacted with CEA in ELISA system, and with adenocarcinoma of the stomach, colon, and pancreas in the immunohistochemical assay. B9, JA4, and AH3 were suggested to react with CEA related antigens, such as NCA and BGPI, whereas KM10 and A10 were suggested to recognize the distinctive part of CEA. The antigenic determinant of CEA reactive with KM10 and A10 was revealed to be protein moiety after enzyme treatment. The competitive binding inhibition assay, however, indicated that epitopes of KM10 and A10 were different each other. Enzyme immunoassay using both KM10 and A10 could detect CEA. These findings showed the possible use of both KM10 and A10 for clinical diagnosis and treatment by means of targeting for the distinctive part of CEA.

  18. The KM3Net project: A neutrino telescope in the depths of the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Di Capua, F.; KM3NeT Collaboration

    2016-01-01

    The KM3NeT Collaboration has started the first phase of construction of a next generation high-energy neutrino telescope in the Mediterranean Sea. With several cubic kilometers instrumented and thousand of optical sensors, KM3NeT will be the largest and most sensitive high-energy neutrino telescope. Thanks to its location in the Northern hemisphere and to its large instrumented volume KM3NeT will be the optimal instrument to search for neutrinos from the Southern sky and in particular from the Galactic plane, thus making it complementary to IceCube. The full KM3NeT detector will be a distributed, networked infrastructure comprising several detector blocks. In Italy, off the coast of Capo Passero, and in France, off the coast of Toulon, the construction of the KM3NeT-It and KM3NeT-Fr infrastructures respectively is in progress. In this work the technologically innovative component of the detector, the status of construction and the first results from prototypes of the KM3NeT detector will be described and its capability to discover neutrino sources is reported as well.

  19. Net Strain accumulation in the slow slip zone along the Cascadia Subduction Zone constrained by leveling and tide gauge data

    NASA Astrophysics Data System (ADS)

    Krogstad, R.; Schmidt, D. A.; Weldon, R. J.; Burgette, R. J.

    2011-12-01

    Analyzing leveling lines in western Oregon, Burgette et al. [2009] identified a pervasive 0.4+/-0.3 mm/yr uplift signature that tracks along the eastern edge of the coast range, which does not seem to correlate with elevated topography. The uplift signature cannot readily be resolved with locked zone models that prescribe a slip rate deficit that decreases monotonically with depth, as is typically done. We explore the hypothesis that strain is being accumulated in the episodic tremor and slip (ETS) zone and is not completely released during slow slip events. A backslip methodology is used to input a down-dip locking profile and relative slip deficit rates along the fault interface from which resultant uplift patterns are calculated. The slip deficit within the locked zone is assumed to equal the full convergence rate, while exponentially decaying to zero along the transition zone. Free parameters related to the locked zone are the down-dip extent of the locked zone and the down-dip extent of the transition zone. Parameters related to the slow slip zone are varied while being constrained using tremor locations and GPS derived inversion results of multiple slow slip events. The parameter of primary focus is the slip deficit along the slow slip zone. Modeled results are then compared to the long-term leveling and tide gauge data to check for misfit and residual patterns. Historical leveling and tide gauges provide precise uplift measurements over an interval of several decades with typical uncertainties lower than vertical GPS measurements. Also, the density of data points along a leveling line provides an excellent source for determining uplift gradients. Analysis of the leveling data in Oregon shows that the data require a second zone of locking in the slow slip zone, in addition to the locking up-dip. Assuming the locking profile follows the shape of a Gaussian, the optimal distribution has a 1-sigma down-dip width of 1.5 km and a peak strain accumulation rate that

  20. 10 km running performance predicted by a multiple linear regression model with allometrically adjusted variables

    PubMed Central

    Abad, Cesar C. C.; Barros, Ronaldo V.; Bertuzzi, Romulo; Gagliardi, João F. L.; Lima-Silva, Adriano E.; Lambert, Mike I.

    2016-01-01

    Abstract The aim of this study was to verify the power of VO2max, peak treadmill running velocity (PTV), and running economy (RE), unadjusted or allometrically adjusted, in predicting 10 km running performance. Eighteen male endurance runners performed: 1) an incremental test to exhaustion to determine VO2max and PTV; 2) a constant submaximal run at 12 km·h−1 on an outdoor track for RE determination; and 3) a 10 km running race. Unadjusted (VO2max, PTV and RE) and adjusted variables (VO2max0.72, PTV0.72 and RE0.60) were investigated through independent multiple regression models to predict 10 km running race time. There were no significant correlations between 10 km running time and either the adjusted or unadjusted VO2max. Significant correlations (p < 0.01) were found between 10 km running time and adjusted and unadjusted RE and PTV, providing models with effect size > 0.84 and power > 0.88. The allometrically adjusted predictive model was composed of PTV0.72 and RE0.60 and explained 83% of the variance in 10 km running time with a standard error of the estimate (SEE) of 1.5 min. The unadjusted model composed of a single PVT accounted for 72% of the variance in 10 km running time (SEE of 1.9 min). Both regression models provided powerful estimates of 10 km running time; however, the unadjusted PTV may provide an uncomplicated estimation. PMID:28149382

  1. Effects of bicycle frame ergonomics on triathlon 10-km running performance.

    PubMed

    Garside, I; Doran, D A

    2000-10-01

    It is perceived that, during the triathlon or duathlon, cycling with a steep (> 76 degrees) rather than a shallow (< 76 degrees ) frame geometry might attenuate the fatigue associated with progression from the cycle to run disciplines and improve subsequent 10-km running performance. This is based on anecdotal testimony from athletes purporting to have experienced improved performance; no empirical evidence exists. To evaluate this view, eight male triathletes completed a counterbalanced, 40-km cycle ride at two frame geometries (73 degrees and 81 degrees) at approximately 70% VO2peak. Immediately after completion of each 40-km cycle, a self-paced 10-km treadmill time trial was undertaken, during which physiological, kinematic and performance variables were measured. The 10-km run performance (mean +/- s: 42:55 +/- 4:19 vs 46:15 +/- 4:52 min; P< 0.01) and combined cycle and run performance (1:45:49 +/- 5:45 vs 1:50:33 +/- 6:08; P< 0.001) were faster in the 81 degrees than the 73 degrees condition. Improvements in performance were most prominent during the first 5 km of the run (21:41 +/- 2:15 vs 24:15 +/- 2:31 min in the 81 degrees and 73 degrees conditions respectively). These improvements were not evident during the second 5 km of the run. No differences in physiological variables were noted, although heart rate, stride length and stride frequency were increased during the 81 degrees condition (P < 0.05). Modifying frame geometry from a seat tube angle of 73 degrees to 81 degrees improves 10-km running and combined cycle plus run performance. These improvements in performance might relate to alterations during the cycling phase, which minimizes the 'residual effect' of this (i.e. the adverse changes in substrate availability, thermoregulatory, cardiovascular and biomechanical factors felt immediately after transition from cycling to running) and attenuates negative changes in physiological and kinematic responses during the 10-km run.

  2. Comparative genomic analysis of the swine pathogen Bordetella bronchisepticastrain KM22.

    PubMed

    Nicholson, Tracy L; Shore, Sarah M; Register, Karen B; Bayles, Darrell O; Kingsley, Robert A; Brunelle, Brain W

    2016-01-01

    The well-characterized Bordetella bronchiseptica strain KM22, originally isolated from a pig with atrophic rhinitis, has been used to develop a reproducible swine respiratory disease model. The goal of this study was to identify genetic features unique to KM22 by comparing the genome sequence of KM22 to the laboratory reference strain RB50. To gain a broader perspective of the genetic relationship of KM22 among other B. bronchiseptica strains, selected genes of KM22 were then compared to five other B. bronchiseptica strains isolated from different hosts. Overall, the KM22 genome sequence is more similar to the genome sequences of the strains isolated from animals than the strains isolated from humans. The majority of virulence gene expression in Bordetella is positively regulated by the two-component sensory transduction system BvgAS. bopN, bvgA, fimB, and fimC were the most highly conserved BvgAS-regulated genes present in all seven strains analyzed. In contrast, the BvgAS-regulated genes present in all seven strains with the highest sequence divergence werefimN, fim2, fhaL, andfhaS. A total of eight major fimbrial subunit genes were identified in KM22. Quantitative real-time PCR data demonstrated that seven of the eight fimbrial subunit genes identified in KM22 are expressed and regulated by BvgAS. The annotation of the KM22 genome sequence, coupled with the comparative genomic analyses reported in this study, can be used to facilitate the development of vaccines with improved efficacy towards B. bronchiseptica in swine to decrease the prevalence and disease burden caused by this pathogen.

  3. Creatine kinase isoenzyme activity during and after an ultra-distance (200 km) run.

    PubMed

    Son, H J; Lee, Y H; Chae, J H; Kim, C K

    2015-12-01

    It is commonly assumed that creatine kinase (CK) activity in plasma is related to the state of an inflammatory response at 24-48 h, and also it has shown biphasic patterns after a marathon run. No information is available on CK isoenzymes after an ultra-marathon run. The purpose of the present study is to examine the CK isoenzymes after a 200 km ultra-marathon run and during the subsequent recovery. Blood samples were obtained during registration 1 2 h before the 200-km race and during the race at 100 km, 150 km and at the end of 200 km, as well as after a 24 h period of recovery. Thirty-two male ultra-distance runners participated in the study. Serum CPK showed a marked increase throughout the race and 24 h recovery period (p < 0.001). Serum CK during the race occurs mostly in the CK-MM isoform and only minutely in the CK-MB isoform and is unchanged in the CK-BB isoform. High-sensitivity C-reactive protein (hs-CRP), oestradiol, AST and ALT increased significantly from the pre-race value at 100 km and a further increase took place by the end of the 200 km run. The results of our study demonstrate a different release pattern of creatine kinase after an ultra-distance (200 km) run compared to the studies of marathon running and intense eccentric exercise, and changes in several biomarkers, indicative of muscle damage during the race, were much more pronounced during the latter half (100-200 km) of the race. However, the increases in plasma concentration of muscle enzymes may reflect not only structural damage, but also their rate of clearance.

  4. Decoupling of Pacific subduction zone guided waves

    NASA Astrophysics Data System (ADS)

    Garth, T.; Rietbrock, A.

    2010-12-01

    Subduction zone guided wave arrivals have been observed in many circum Pacific subduction zones and have been attributed to the presence of a low velocity layer (LVL) in the subducting slab. This LVL acts as a waveguide for the high frequency energy, while lower frequency energy is not retained and travels in the higher velocity surrounding mantle. This leads to the characteristic dispersion of seismic waves observed. The commonly accepted model for the LVL is the persistence of basaltic oceanic crust to a depth of greater than 150 km. This basaltic oceanic crust has not yet undergone phase transformation to eclogite due to kinetic hindering, and so still has a distinguishably lower velocity than the surrounding mantle. It has been shown that guided waves are only seen from events that occur in or near to the low velocity layer. Similarly it would be expected that guided waves are only seen when the receiver is on the wave guide. However in a subduction zone setting it has been shown that guided wave energy is decoupled from the waveguide, due to the bend of the slab (Martin et al., 2003). Therefore high frequency guided wave energy escapes the waveguide and so can be observed at receivers placed in specific positions on the overriding plate. This decoupling mechanism allows guided waves from intermediate and deep Wadati-Benioff zone earthquakes to be observed. We use a two dimensional finite difference model to investigate the decoupling of wave guide energy due to the geometry of various Pacific subduction zones in order to predict the occurrence of guided wave arrivals along up-dip and along-strike propagation paths. The slab geometry is inferred from the USGS slab contour model slab 1.0. An explosive source is used so that frequency effects of the source do not complicate the results. The thickness of the LVL is inferred from published observations of Pacific subduction zone guided waves. For the along-strike profile we concentrate on the observations of guided

  5. A hypervelocity launcher for simulated large fragment space debris impacts at 10 km/s

    NASA Technical Reports Server (NTRS)

    Tullos, R. J.; Gray, W. M.; Mullin, S. A.; Cour-Palais, B. G.

    1989-01-01

    The background, design, and testing of two explosive launchers for simulating large fragment space debris impacts are presented. The objective was to develop a launcher capable of launching one gram aluminum fragments at velocities of 10 km/s. The two launchers developed are based on modified versions of an explosive shaped charge, common in many military weapons. One launcher design has yielded a stable fragment launch of approximately one gram of aluminum at 8.93 km/s velocity. The other design yielded velocities in excess of 10 km/s, but failed to produce a cohesive fragment launch. This work is ongoing, and future plans are given.

  6. Characterization of the KM3NeT photomultipliers in the Hellenic Open University

    SciTech Connect

    Bourlis, G.; Avgitas, T.; Tsirigotis, A.; Tzamarias, S.; Collaboration: KM3NeT Collaboration

    2014-11-18

    The KM3NeT neutrino research infrastructure will be a deep sea multidisciplinary observatory in the Mediterranean Sea hosting a neutrino telescope. The Physics Laboratory of the Hellenic Open University is involved in the characterization of the KM3NeT neutrino detector. The present work describes measurement techniques for the functional characteristics of the candidate KM3NeT photomultipliers. These characteristics include dark current, transit time spread, gain slope and single photoelectron characteristics, as well as delayed and after pulses.

  7. KM3NeT/ARCA sensitivity and discovery potential for neutrino point-like sources

    NASA Astrophysics Data System (ADS)

    Trovato, A.

    2016-04-01

    KM3NeT is a large research infrastructure with a network of deep-sea neutrino telescopes in the abyss of the Mediterranean Sea. Of these, the KM3NeT/ARCA detector, installed in the KM3NeT-It node of the network, is optimised for studying high-energy neutrinos of cosmic origin. Sensitivities to galactic sources such as the supernova remnant RXJ1713.7-3946 and the pulsar wind nebula Vela X are presented as well as sensitivities to a generic point source with an E-2 spectrum which represents an approximation for the spectrum of extragalactic candidate neutrino sources.

  8. Evidence for an upper mantle low velocity zone beneath the southern Basin and Range-Colorado Plateau transition zone

    USGS Publications Warehouse

    Benz, H.M.; McCarthy, J.

    1994-01-01

    A 370-km-long seismic refraction/wide-angle reflection profile recorded during the Pacific to Arizona Crustal Experiment (PACE) detected an upper mantle P-wave low-velocity zone (LVZ) in the depth range 40 to 55 km beneath the Basin and Range in southern Arizona. Interpretation of seismic data places constraints on the sub-crustal lithosphere of the southern Basin and Range Province, which is important in light of the active tectonics of the region and the unknown role of the sub-crustal lithosphere in the development of the western United States. Forward travel time and synthetic seismogram techniques are used to model this shallow upper mantle LVZ. Modeling results show that the LVZ is defined by a 5% velocity decrease relative to a Pn velocity of 7.95 km s−1, suggesting either a ∼3–5% mafic partial melt or high-temperature, sub-solidus peridotite.

  9. Extreme precipitation events in southestearn France in a high-resolution regional climate model : comparison of a 12 km and a 50 km hindcast with ALADIN-Climate

    NASA Astrophysics Data System (ADS)

    Colin, Jeanne; Déqué, Michel; Sanchez Gomez, Emilia; Somot, Samuel

    2010-05-01

    We present a comparison of the modelling of intense precipitations over France in two regional climate simulations performed with the Limited Area Model (LAM) ALADIN-Climate, run at a 12 km and a 50 km resolution. In both experiments, the model is forced by the ERA40 re-analysis over the 1958-2000 period. We focus on the representation of the highest precipitation extremes occuring in southeastern France in Autumn. These events involve small-scale processes than can be explicitly resolved only with 2-1 km resolution non-hydrostatic models. However, previous studies have shown that regional climate models are able to simulate heavy rainfalls in this area, although the amounts of rain are much smaller than the ones that are actually observed. Here, we further explore the ability of ALADIN-Climate in reproducing these specific events and the possible added-value of a higher resolution regarding this matter. Indeed, driving the LAM with ERA40 allows the LAM to stick to the real chronology and therefore enables us to analyze its results not only from a statistical point of view but also through day-to-day diagnosis. First, we assess the performances of the model at the 12 km and 50 km resolutions by comparing the simulated daily precipitations with observations over the south east part of France. To do so, we use the high-resolution gridded SAFRAN analysis which provides series of hourly fields over the french territory at a 8 km resolution, from 1958 to 2008. We consider the differences in the upper quantiles of precipitations between the model and the data, as well as the time correlations of heavy rainfalls and the spatial rain patterns for given extreme events. Then we compare the performances of ALADIN-Climate in both simulations to the ones obtained with a statistical downscaling method we apply to the last twenty years of the ERA40 period. This method is based on a weather regime approach and uses the analog methodology (Boé and Terray, 2007) to reconstruct

  10. Hydrologic monitoring in 1-km2 headwater catchments in Sierra Nevada forests for predictive modeling of hydrologic response to forest treatments across 140-km2 firesheds

    NASA Astrophysics Data System (ADS)

    Saksa, P. C.; Bales, R. C.; Conklin, M. H.; Martin, S. E.; Rice, R.

    2010-12-01

    As part of the Sierra Nevada Adaptive Management Project, an eight-year study designed to measure the impacts of forest treatments (thinning, mastication, controlled burns) on multiple forest attributes, four headwater catchments were established to provide data on hydrologic response to treatments. These 1-km2 study catchments are each sited within 40-100 km2 firesheds, which in this case largely follow watershed boundaries, and which are the larger study areas for informing adaptive management of approximately 3,000 km2 of mixed-conifer forest in California’s central and southern Sierra Nevada. The aim of the hydrologic design was to put in place a ground-based monitoring network that would measure hydrologic attributes at representative locations, and when combined with remotely sensed data, provide a basis for predictive modeling of the larger study area. The selected locations employ instrument clusters, or groupings of instruments in a compact arrangement, to maximize the number of measurements possible and accessibility to the monitoring sites. The two study firesheds , located in the Tahoe and Sierra National Forests, cover a total of about 140-km2. Within each fireshed, two meteorological stations were placed near 1650-m and 2150-m, spanning the precipitation gradient from lower-elevation rain-dominated to higher-elevation snow-dominated systems. Two headwater streams draining approximately 1-km2 are monitored for stage, discharge, electrical conductivity, and sediment movement. Additionally, instrument nodes to monitor temperature, snow depth and soil moisture are installed within 0.5-1 km of the outlet and meterological stations. These nodes were placed to monitor end members of aspect, slope, elevation and canopy cover, which set the boundaries for the model outputs. High-resolution LiDAR provides the topographic and distributed vegetation characteristics, which are combined with field surveys and standard soils information to define the modeling

  11. Geoid anomalies over two South Atlantic fracture zones

    NASA Technical Reports Server (NTRS)

    Freedman, Adam P.; Parsons, Barry

    1990-01-01

    Seasat altimetry profiles across the Falkland-Agulhas and Ascension fracture zones were examined for evidence of step-like geoid offsets predicted from thermal modeling of the lithosphere. Neither the plate nor the half-space model of lithospheric thermal evolution succeeds in predicting the variations in step height with age across the fracture zone branches considered. For ages less than about 30 Ma, the step offsets decrease in a manner suggesting a plate with a thickness of 50-75 km. At greater ages, the offsets show complex behavior that may be due to bathymetric features adjacent to the fracture zones. Similar geoid patterns on opposite branches of the Falkland-Agulhas fracture zone are indicative of processes that act symmetrically on both sides of the Mid-Atlantic Ridge. This is consistent both with small-scale convection occurring beneath the lithosphere and with bathymetric features originally produced along the ridge crest and now located symmetrically on opposite sides of the ridge. The west flank of the Ascension fracture zone displays a regrowth in step height at about 40 Ma consistent with small-scale convection and in agreement with other studies of Pacific and South Atlantic fracture zones.

  12. Geoid anomalies over two South Atlantic fracture zones

    NASA Technical Reports Server (NTRS)

    Freedman, Adam P.; Parsons, Barry

    1990-01-01

    Seasat altimetry profiles across the Falkland-Agulhas and Ascension fracture zones were examined for evidence of step-like geoid offsets predicted from thermal modeling of the lithosphere. Neither the plate nor the half-space model of lithospheric thermal evolution succeeds in predicting the variations in step height with age across the fracture zone branches considered. For ages less than about 30 Ma, the step offsets decrease in a manner suggesting a plate with a thickness of 50-75 km. At greater ages, the offsets show complex behavior that may be due to bathymetric features adjacent to the fracture zones. Similar geoid patterns on opposite branches of the Falkland-Agulhas fracture zone are indicative of processes that act symmetrically on both sides of the Mid-Atlantic Ridge. This is consistent both with small-scale convection occurring beneath the lithosphere and with bathymetric features originally produced along the ridge crest and now located symmetrically on opposite sides of the ridge. The west flank of the Ascension fracture zone displays a regrowth in step height at about 40 Ma consistent with small-scale convection and in agreement with other studies of Pacific and South Atlantic fracture zones.

  13. Quantifying thinning and extrusion associated with an oblique subduction zone: An example from the Rosy Finch Shear Zone

    NASA Astrophysics Data System (ADS)

    Mookerjee, Matty; Canada, Andrew; Fortescue, Forest Q.

    2016-12-01

    The Rosy Finch Shear Zone (RFSZ) is a NNW trending transpressional zone along the eastern margin of the Sierra Nevada mountain range, and the southernmost shear zone within the Sierra Crest Shear Zone. Dextral shear, resulting from oblique subduction along the western margin of the North American Plate (ca. 90 Ma), combined with subduction zone orthogonal shortening is concentrated within the RFSZ. Highly deformed metasedimentary and metavolcanic rocks within the zone have a prominent foliation with a mean dip, dip direction of 79°, 236° and a steeply plunging, penetrative, stretching lineation with a trend, plunge of 178°, 73°. Here, we present both three-dimensional strain analysis and crystallographic texture data in order to determine the mean kinematic vorticity number (Wm) and the relative amounts of pure and simple shear within the RFSZ. These two independent methods, using data collected from samples along two E-W transects, both indicate that there is a significant component of pure shear within the zone, with a mean of approximately 75% pure shear. Using the vorticity data, we calculated the amount of across-the-zone thinning. Samples collected from the 0.65 km zone of interest have yielded a mean shortening of nearly 20.3%, or approximately 166 m. In addition, three-dimensional strain analysis yields a mean Lode's ratio of 0.202, and a mean Flinn's k-value of 0.585, indicate a general flattening deformation, and a mean octahedral shear strain (εs) of 0.407. Assuming no volume change, these data suggest that there was approximately 174 m of vertical extrusion within this segment of the RFSZ in response to this obliquely convergent plate margin.

  14. Early Tertiary rupture of the Pacific plate: 1700 km of dextral offset along the Emperor trough-Line Islands lineament

    NASA Astrophysics Data System (ADS)

    Farrar, Edward; Dixon, John M.

    1981-05-01

    Between 67 and ˜40 Ma ago a northwest-southeast-trending fracture system over 8000 km long split the Pacific plate and accumulated at least 1700 km of dextral offset between the east and west portions. This system, here named the Emperor fracture zone (EFZ) system, consisted of several segments, one along the present trace of the Emperor trough and another along the Line Islands, joined by short spreading ridges. The EFZ terminated at its northern end against the Kula-Pacific ridge, and at its southern end in a ridge-transform system, called the Emperor spreading system, which extended to the west, north of Australia. The finite angular velocity vector describing the relative motion between the East and West Pacific plates is ˜0.6°/Ma about a pole at 36°N, 70°W. This vector, added to the known Early Tertiary motion of the Pacific plate with respect to the global hotspot reference frame, accounts in large part for the NNW trend of the Emperor seamount chain relative to the WNW Hawaiian trend, without violation of the integrity of the Antarctic plate. The Meiji-Emperor and Emperor-Hawaiian bends date, respectively, the initiation (˜67 Ma ago) and cessation (˜40 Ma ago) of seafloor spreading on the Emperor spreading system. The postulated Early Tertiary relative motion along the EFZ between the East and West Pacific plates explains (1) the present misalignment of the two sets of magnetic bights of the Pacific, (2) the abrupt truncation of eastern Pacific bathymetric lineaments against the Emperor trough and Line Islands, (3) the contrast in paleolatitude between the eastern and western Pacific as indicated by paleomagnetic and sedimentologic studies, and (4) the anomalous gravity signature of the central Hawaiian ridge that indicates that the ridge loaded thin hot lithosphere.

  15. Fethiye-Burdur Fault Zone (SW Turkey): a myth?

    NASA Astrophysics Data System (ADS)

    Kaymakci, Nuretdin; Langereis, Cornelis; Özkaptan, Murat; Özacar, Arda A.; Gülyüz, Erhan; Uzel, Bora; Sözbilir, Hasan

    2017-04-01

    Fethiye Burdur Fault Zone (FBFZ) is first proposed by Dumont et al. (1979) as a sinistral strike-slip fault zone as the NE continuation of Pliny-Strabo trench in to the Anatolian Block. The fault zone supposed to accommodate at least 100 km sinistral displacement between the Menderes Massif and the Beydaǧları platform during the exhumation of the Menderes Massif, mainly during the late Miocene. Based on GPS velocities Barka and Reilinger (1997) proposed that the fault zone is still active and accommodates sinistral displacement. In order to test the presence and to unravel its kinematics we have conducted a rigorous paleomagnetic study containing more than 3000 paleomagnetic samples collected from 88 locations and 11700 fault slip data collected from 198 locations distributed evenly all over SW Anatolia spanning from Middle Miocene to Late Pliocene. The obtained rotation senses and amounts indicate slight (around 20°) counter-clockwise rotations distributed uniformly almost whole SW Anatolia and there is no change in the rotation senses and amounts on either side of the FBFZ implying no differential rotation within the zone. Additionally, the slickenside pitches and constructed paleostress configurations, along the so called FBFZ and also within the 300 km diameter of the proposed fault zone, indicated that almost all the faults, oriented parallel to subparallel to the zone, are normal in character. The fault slip measurements are also consistent with earthquake focal mechanisms suggesting active extension in the region. We have not encountered any significant strike-slip motion in the region to support presence and transcurrent nature of the FBFZ. On the contrary, the region is dominated by extensional deformation and strike-slip components are observed only on the NW-SE striking faults which are transfer faults that accommodated extension and normal motion. Therefore, we claim that the sinistral Fethiye Burdur Fault (Zone) is a myth and there is no tangible

  16. Scaling of transfer zones in the British Isles

    NASA Astrophysics Data System (ADS)

    Peacock, D. C. P.

    2003-10-01

    Widths of transfer zones between stepping normal faults obey power-law scaling relationships, probably from widths of millimetres to tens or hundreds of kilometres. Relay ramp widths in the Mesozoic sedimentary rocks of the Somerset coast obey a power-law up to ˜50 m, above which there is a censoring effect caused by the width of the wave-cut platform. A structural map of the British Isles indicates that transfer zones obey a power-law up to widths of at least 250 km. This indicates that normal faults can interact over tens or hundreds of kilometres, especially where transfer zones occur between stepping half-grabens. Interaction is therefore another aspect of faulting that obeys fractal behaviour.

  17. Fault zone structure and seismic reflection characteristics in zones of slow slip and tsunami earthquakes

    NASA Astrophysics Data System (ADS)

    Bell, Rebecca; Henrys, Stuart; Sutherland, Rupert; Barker, Daniel; Wallace, Laura; Holden, Caroline; Power, William; Wang, Xiaoming; Morgan, Joanna; Warner, Michael; Downes, Gaye

    2015-04-01

    Over the last couple of decades we have learned that a whole spectrum of different fault slip behaviour takes place on subduction megathrust faults from stick-slip earthquakes to slow slip and stable sliding. Geophysical data, including seismic reflection data, can be used to characterise margins and fault zones that undergo different modes of slip. In this presentation we will focus on the Hikurangi margin, New Zealand, which exhibits marked along-strike changes in seismic behaviour and margin characteristics. Campaign and continuous GPS measurements reveal deep interseismic coupling and deep slow slip events (~30-60 km) at the southern Hikurangi margin. The northern margin, in contrast, experiences aseismic slip and shallow (<10-15 km) slow slip events (SSE) every 18-24 months with equivalent moment magnitudes of Mw 6.5-6.8. Updip of the SSE region two unusual megathrust earthquakes occurred in March and May 1947 with characteristics typical of tsunami earthquakes. The Hikurangi margin is therefore an excellent natural laboratory to study differential fault slip behaviour. Using 2D seismic reflection, magnetic anomaly and geodetic data we observe in the source areas of the 1947 tsunami earthquakes i) low amplitude interface reflectivity, ii) shallower interface relief, iii) bathymetric ridges, iv) magnetic anomaly highs and in the case of the March 1947 earthquake v) stronger geodetic coupling. We suggest that this is due to the subduction of seamounts, similar in dimensions to seamounts observed on the incoming Pacific plate, to depths of <10 km. We propose a source model for the 1947 tsunami earthquakes based on geophysical data and find that extremely low rupture velocities (c. 300 m/s) are required to model the observed large tsunami run-up heights (Bell et al. 2014, EPSL). Our study suggests that subducted topography can cause the nucleation of moderate earthquakes with complex, low velocity rupture scenarios that enhance tsunami waves, and the role of

  18. Depth-dependent structure of the Landers fault zone from trapped waves generated by aftershocks

    NASA Astrophysics Data System (ADS)

    Li, Yong-Gang; Vidale, John E.; Aki, Keiiti; Xu, Fei

    2000-03-01

    We delineate the internal structure of the Johnson Valley and Kickapoo faults (Landers southern rupture) at seismogenic depth using fault zone trapped waves generated by aftershocks. Trapped waves recorded at the dense linear seismic arrays deployed across and along the surface breaks of the 1992 M7.5 Landers earthquake show large amplitudes and dispersive wave trains following the S waves. Group velocities of trapped waves measured from multiple band-pass-filtered seismograms for aftershocks occurring at different depths between 1.8 km and 8.2 km show an increase in velocity with depth. Velocities range from 1.9 km/s at 4 Hz to 2.6 km/s at 1 Hz for shallow events, while for deep events, velocities range from 2.3 km/s at 4 Hz to 3.1 km/s at 1 Hz. Coda-normalized amplitude spectra of trapped waves peak in amplitudes at 3-4 Hz for stations located close to the fault trace. The amplitude decays rapidly with the station offset from the fault zone. Normalized amplitudes also decrease with distance along the fault, giving an apparent Q of 30 for shallow events and 50 for deep events. We evaluated depth-dependent fault zone structure and its uncertainty from these measurements plus our previous results from near-surface explosion-excited trapped waves [Li et al., 1999] in a systematic model parameter-searching procedure using a three-dimensional (3-D) finite difference computer code [Graves, 1996]. Our best model of the Landers fault zone is 250 m wide at the surface, tapering to 100-150 m at 8.2 km depth. The shear velocity within the fault zone increases from 1.0 to 2.5 km/s and Q increases from 20 to 60 in this depth range. Fault zone shear velocities are reduced by 35 to 45% from those of the surrounding rock and also vary along the fault zone with an increase of ˜10% near ends of the southern rupture zone.

  19. Mapping Land Cover Types in Amazon Basin Using 1km JERS-1 Mosaic

    NASA Technical Reports Server (NTRS)

    Saatchi, Sassan S.; Nelson, Bruce; Podest, Erika; Holt, John

    2000-01-01

    In this paper, the 100 meter JERS-1 Amazon mosaic image was used in a new classifier to generate a I km resolution land cover map. The inputs to the classifier were 1 km resolution mean backscatter and seven first order texture measures derived from the 100 m data by using a 10 x 10 independent sampling window. The classification approach included two interdependent stages: 1) a supervised maximum a posteriori Bayesian approach to classify the mean backscatter image into 5 general land cover categories of forest, savannah, inundated, white sand, and anthropogenic vegetation classes, and 2) a texture measure decision rule approach to further discriminate subcategory classes based on taxonomic information and biomass levels. Fourteen classes were successfully separated at 1 km scale. The results were verified by examining the accuracy of the approach by comparison with the IBGE and the AVHRR 1 km resolution land cover maps.

  20. Making sense of KM through users: Information gaps and intellectual property

    NASA Astrophysics Data System (ADS)

    Pascual, Roberto de Miguel; Casado, Esther Monterroso

    2014-10-01

    Despite its lack of definition, in a general sense, knowledge management (KM) is consubstantial to contemporary innovation-driven social systems (IDSSs), allowing individuals, organizations, and entire societies, to cope with their intrinsic technical uncertainties more effectively. Before the advent of IDSSs, most of the results of KM were considered naturally inappropriable as well as fractions of the public domain. In such context, patents litigation was almost anecdotic. This paper summarizes various social scientific and humanistic approaches that nourish the emergence of a new KM model in which innovation will be anchored in the claim for universality. Patentability of ICT and services is also considered on the realm of a commons-based KM.

  1. 40 Gbps 100-km SSMF VSB-IMDD OFDM transmission experiment based on FBG filter

    NASA Astrophysics Data System (ADS)

    Ju, Cheng; Yang, Pengfei; Chen, Xue; Zhang, Zhiguo; Liu, Na

    2014-10-01

    This work studies the transmission performance of vestigial-sideband (VSB)-IMDD OFDM system by theoretical analysis and numerical simulation. The analysis shows that the detrimental effect of dispersion-induced power fading can be effectively suppressed. The presence of positive and negative chirp of modulator will increase the dispersion-, chirp- and VSB optical filter-induced subcarrier to subcarrier intermixing interference (SSII), which significantly restricts transmission performance. Relatively lower order Gaussian optical filter has almost the same performance with ideal rectangular filter over 100-km SMF transmission and have better performance in less than 60-km transmission. Furthermore, we successfully transmit a 40 Gbps, 16QAM, MZM-based VSB-IMDD OFDM signal through 100-km of uncompensated standard single mode fiber (SSMF) by using an economical FBG optical filter. The experimental results show that available bandwidth has been extended up to 10 GHz after 100-km SSMF transmission.

  2. KM3NeT tower data acquisition and data transport electronics

    NASA Astrophysics Data System (ADS)

    Nicolau, C. A.; Ameli, F.; Biagioni, A.; Capone, A.; Frezza, O.; Lonardo, A.; Masullo, R.; Mollo, C. M.; Orlando, A.; Simeone, F.; Vicini, P.

    2016-04-01

    In the framework of the KM3Net European project, the production stage of a large volume underwater neutrino telescope has started. The forthcoming installation includes 8 towers and 24 strings, that will be installed 100 km off-shore Capo Passero (Italy) at 3500 m depth. The KM3NeT tower, whose layout is strongly based on the NEMO Phase-2 prototype tower deployed in March 2013, has been re-engineered and partially re-designed in order to optimize production costs, power consumption, and usability. This contribution gives a description of the main electronics, including front-end, data transport and clock distribution system, of the KM3NeT tower detection unit.

  3. 2 GHz clock quantum key distribution over 260 km of standard telecom fiber.

    PubMed

    Wang, Shuang; Chen, Wei; Guo, Jun-Fu; Yin, Zhen-Qiang; Li, Hong-Wei; Zhou, Zheng; Guo, Guang-Can; Han, Zheng-Fu

    2012-03-15

    We report a demonstration of quantum key distribution (QKD) over a standard telecom fiber exceeding 50 dB in loss and 250 km in length. The differential phase shift QKD protocol was chosen and implemented with a 2 GHz system clock rate. By careful optimization of the 1 bit delayed Faraday-Michelson interferometer and the use of the superconducting single photon detector (SSPD), we achieved a quantum bit error rate below 2% when the fiber length was no more than 205 km, and of 3.45% for a 260 km fiber with 52.9 dB loss. We also improved the quantum efficiency of SSPD to obtain a high key rate for 50 km length.

  4. Tectonics of the IndoBurma Oblique Subduction Zone

    NASA Astrophysics Data System (ADS)

    Steckler, M. S.; Seeber, L.; Akhter, S. H.; Betka, P. M.; Cai, Y.; Grall, C.; Mondal, D. R.; Gahalaut, V. K.; Gaherty, J. B.; Maung Maung, P.; Ni, J.; Persaud, P.; Sandvol, E. A.; Tun, S. T.

    2016-12-01

    The Ganges-Brahmaputra Delta (GBD) is obliquely colliding with the IndoBurma subduction zone. Most of the 42 mm/y of arc-parallel motion is absorbed in a set of dextral to dextral-convergent faults, the Sagaing, Kabaw and Churachandpur-Mao Faults. The 13-17 mm/y of convergence with the delta has built a 250-km wide active accretionary prism. The upper part of the 19-km sediment thickness consists of a shallowing-up stack of prograding strata that has shifted the shelf edge 3-400 km since the Himalayan orogeny at 50 Ma. The upper 3-5 km sandy shelf to fluvial strata are deformed into a broad fold and thrust belt above an overpressured décollement. It forms a flat shallow roof thrust in the frontal accretionary prism. The structure of the deeper part of the accretionary prism, which must transfer the incoming sediments to the upper plate, is unknown. GPS indicates the downdip end of the megathrust locked zone is 25 km at 92.5°E. The deformation front, marked by nascent detachment folds above the shallow décollement reaches the megacity of Dhaka in the middle of the GBD. The seismogenic potential of this portion of the prism is unknown. Arc volcanism in Myanmar, 500 km east of the deformation front, is sparse. Limited geochemical data on the arc volcanics are consistent with hot slab conditions. One possibility is that the deep GBD slab and basement are metamorphosed and dewatered early in the subduction process whereby most of the fluids are transferred to the growing prism by buoyancy driven migration or accretion of fluid-rich strata. Since it is entirely subaerial this little-studied region crossing Bangladesh, India and Myanmar provides an opportunity for a detailed multidisciplinary geophysical and geological investigation. It has the potential to highlight the role of fluids in subduction zones, the tectonics of extreme accretion and their seismic hazards, and the interplay between driving and resistance forces of a subduction zone during a soft collision.

  5. Imaging segmentation along the Cascadia subduction zone

    NASA Astrophysics Data System (ADS)

    Allen, R. M.; Hawley, W. B.; Martin-Short, R.

    2015-12-01

    As we learn more about the Cascadia subduction zone, there is clear evidence for segmentation in the character of the many physical processes along its 1000 km length. There is segmentation in the arc magmas, in the seismicity, episodic tremor and slip, crustal structure and mantle structure all the way down to ~400 km depth. What is striking is the fact that the segment boundaries for these processes at depths of a few kilometers to hundreds of kilometers align. We must determine if this is coincidence, or if not, what the causative process is. The seismic deployments of the Cascadia Initiative onshore and offshore allow us to image the structure of the subduction zone, including the incoming Juan de Fuca plate, with unprecedented resolution. We use data from three one-year deployments of 70 ocean bottom seismometers across the Juan de Fuca plate, along with hundreds of onshore stations from the Pacific Northwest Seismic Network, the Berkeley Digital Seismic Network, the Earthscope Transportable Array, and smaller temporary seismic deployments. Our 3D tomographic models show significant variation in the structure of the subducting slab along its length. It extends deepest in the south (the Gorda section) where the plate is youngest, and shallows to the north across southern Oregon. There is a gap in the slab beneath northern Oregon, which appears to correlate with the geochemistry of the arc magmas. The slab is then visible again beneath Washington. We also constrain mantle flow paths using shear-wave splitting measurements at the offshore and onshore seismic stations. Beneath the Juan de Fuca plate the flow is sub-parallel to the motion of the plate. However, beneath the Gorda section of the Juan de Fuca place the flow is sub-parallel to the motion of the Pacific plate, not the Juan de Fuca plate. We are thus beginning to image a complex mantle flow pattern that may also play a role in the observed segmentation.

  6. Refining the Jurassic Magnetic Quiet Zone

    NASA Astrophysics Data System (ADS)

    Tominaga, M.; Tivery, M.; Sager, W. W.

    2016-12-01

    We present a coherent marine magnetic reversal record from the Pacific to refine the Jurassic Quiet Zone (JQZ). Our definitive magnetic anomaly record consists of high-resolution sea surface, mid-water (3-km level deep-towed), and near-bottom profiles (0.1-km to the seafloor) with the magnetic source layer constrained by gravity anomaly data and reflection and refraction seismics, all of which are newly collected during TN272 and SKQ2014S2 cruises. All magnetic anomaly data were corrected diurnal variations and the present-day ambient geomagnetic field. In comparing our three-level JQZ magnetic anomaly profiles with previous work in the Japanese lineations, we confirm a globally coherent anomaly sequence in the JQZ from M29 to M42, including the distinctive amplitude envelope decreasing back in time from M19 to M38, with a minimum at M41, and then increasing back in time. A strong similarity in the M37/M38 polarity attributes found both in magnetostratigraphic and marine magnetic records suggest that rapid magnetic reversals were occurring during the M38 time in the JQZ. Seismic and gravity profiles from the Hawaiian JQZ seafloor show late-stage Cretaceous volcanism thickening crust by up to 150% with extra melt emplaced at the Moho, and numerous sills and volcanic cones in the sediment and on the seafloor. The region of thickest crust in the Hawaiian lineation corridor coincides with the region of the lowest JQZ anomaly amplitudes, very similar to the Low Amplitude Zone of Japanese lineation sequence, suggesting that the JQZ anomaly character can represent changes in geomagnetic field intensity over time but is free of the effects of Cretaceous volcanic overprint. We conducted inversion modeling to establish polarity block models and to estimate reversal rates. Reversal rates are the highest during periods with the lowest anomaly amplitudes, indicating a unique period of geomagnetic field behavior in the Earth's history.

  7. Long-term monitoring of local stress changes in 67km installed OPGW cable using BOTDA

    NASA Astrophysics Data System (ADS)

    Zou, L.; Sezerman, O.

    2015-09-01

    The initial results from continuing long-term monitoring of a 67 km of an aerial fiber optic cable installed on a 500 kV power line cable (total fiber length of 134km) using BOTDA are presented. The effects of thunderstorms and rime ice on the cable were identified by monitoring strain on OPGW fibers. Variations of strain between day and night on the OPGW cable were observed and can potentially be exploited.

  8. LES Modeling of Lateral Dispersion in the Ocean on Scales of 10 m to 10 km

    DTIC Science & Technology

    2015-10-20

    Report 3. DATES COVERED (From - To) 01/07/2010 – 06/06/2015 4. TITLE AND SUBTITLE LES Modeling of Lateral Dispersion in the Ocean on Scales of 10...Distribution approved for public release; distribution is unlimited. Final Report LES Modeling of Lateral Dispersion on Scales of 10 m to 10 km M.-Pascale...understanding the relationship between internal waves, internal-wave breaking, episodic diapycnal mixing and lateral dispersion on scales of 0.1-10km. The

  9. 512 QAM transmission over 240 km using frequency-domain equalization in a digital coherent receiver.

    PubMed

    Koizumi, Yuki; Toyoda, Kazushi; Omiya, Tatsunori; Yoshida, Masato; Hirooka, Toshihiko; Nakazawa, Masataka

    2012-10-08

    We demonstrate a marked performance improvement in a 512 QAM transmission by employing frequency-domain equalization (FDE) instead of an FIR filter. FDE enables us to compensate for distortions due to hardware imperfections in the transmitter with higher precision, which successfully reduced the power penalty by 4 dB in a 54 Gbit/s (3 Gsymbol/s)-160 km transmission. FDE also allows the transmission distance to be extended up to 240 km.

  10. Floristic zones and aeroallergen diversity.

    PubMed

    Weber, Richard W

    2003-08-01

    The interplay of geographic, geochemical, and meteorologic factors combines to define distinct floristic zones in North America. Latitude, elevation, Pacific or Atlantic Ocean influence, continental air mass influence, mountains, and hills are contributory geographic factors. Hardiness zones are defined by the nadir of temperature, which strongly affects the survival of individual plant species. There are 12 hardiness zones from the northernmost tundra to the tropics of Mexico. Although it is useful to consider the 10 major floristic zones, the hardiness zones cut across these zones and characterize subregions. A multiplicity of local terrain effects, such as soil porosity and acidity, and sun exposure also impact on plant growth. The ability of plant species, whether woody shrubs and trees, or herbaceous weeds and grasses, to adapt to conditions within the floristic zones determines their range. This article identifies the major aeroallergenic species and the regions in which they are most prevalent.

  11. Smartphones and Time Zones

    NASA Astrophysics Data System (ADS)

    Baird, William; Secrest, Jeffery; Padgett, Clifford; Johnson, Wayne; Hagrelius, Claire

    2016-09-01

    Using the Sun to tell time is an ancient idea, but we can take advantage of modern technology to bring it into the 21st century for students in astronomy, physics, or physical science classes. We have employed smartphones, Google Earth, and 3D printing to find the moment of local noon at two widely separated locations. By reviewing GPS time-stamped photos from each place, we are able to illustrate that local noon is longitude-dependent and therefore explain the need for time zones.

  12. Saturated Zone Colloid Transport

    SciTech Connect

    H. S. Viswanathan

    2004-10-07

    This scientific analysis provides retardation factors for colloids transporting in the saturated zone (SZ) and the unsaturated zone (UZ). These retardation factors represent the reversible chemical and physical filtration of colloids in the SZ. The value of the colloid retardation factor, R{sub col} is dependent on several factors, such as colloid size, colloid type, and geochemical conditions (e.g., pH, Eh, and ionic strength). These factors are folded into the distributions of R{sub col} that have been developed from field and experimental data collected under varying geochemical conditions with different colloid types and sizes. Attachment rate constants, k{sub att}, and detachment rate constants, k{sub det}, of colloids to the fracture surface have been measured for the fractured volcanics, and separate R{sub col} uncertainty distributions have been developed for attachment and detachment to clastic material and mineral grains in the alluvium. Radionuclides such as plutonium and americium sorb mostly (90 to 99 percent) irreversibly to colloids (BSC 2004 [DIRS 170025], Section 6.3.3.2). The colloid retardation factors developed in this analysis are needed to simulate the transport of radionuclides that are irreversibly sorbed onto colloids; this transport is discussed in the model report ''Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]). Although it is not exclusive to any particular radionuclide release scenario, this scientific analysis especially addresses those scenarios pertaining to evidence from waste-degradation experiments, which indicate that plutonium and americium may be irreversibly attached to colloids for the time scales of interest. A section of this report will also discuss the validity of using microspheres as analogs to colloids in some of the lab and field experiments used to obtain the colloid retardation factors. In addition, a small fraction of colloids travels with the groundwater without any significant retardation

  13. Liquid zone seal

    DOEpatents

    Klebanoff, Leonard E.

    2001-01-01

    A seal assembly that provides a means for establishing multiple pressure zones within a system. The seal assembly combines a plate extending from the inner wall of a housing or inner enclosure that intersects with and is immersed in the fluid contained in a well formed in a tray contained within the enclosure. The fluid is a low vapor pressure oil, chemically inert and oxidation resistant. The use of a fluid as the sealing component provides a seal that is self-healing and mechanically robust not subject to normal mechanical wear, breakage, and formation of cracks or pinholes and decouples external mechanical vibrations from internal structural members.

  14. 91-km attenuation-free transmission with low noise accumulation by use of distributed erbium-doped fiber

    NASA Astrophysics Data System (ADS)

    Lester, Christian; Rottwitt, Karsten; Povlsen, Jørn H.; Varming, Poul; Newhouse, Mark A.; Antos, A. J.

    1995-06-01

    Transparency of a 91-km distributed erbium-doped fiber is achieved with 0.46 mW / km of pump power at a signal power of -12dBm . The accumulation of amplifier noise is measured to be smaller than the minimum noise accumulation that can be achieved in a 91-km link with two lumped amplifiers separated by 45 km.

  15. Probable Maximum Precipitation Estimation Using the Revised Km-Value Method in Hong Kong

    NASA Astrophysics Data System (ADS)

    Lan, Ping; Lin, Bingzhang; Zhang, Yehui; Chen, Hong

    2017-04-01

    A brief overview of statistical method to estimate the Probable Maximum Precipitation (PMP) is presented. This study addresses some issues associated with Hershfield's Km-value method to estimate PMP in China, which can be solved by the revised Hershfield's Km-value method. This new derivation makes it clear that the frequency factor Km is depended on only two variables, the standardized variable, ϕm, the maximum deviation from the mean, scaled by its standard deviation, and the sample size, n. It is found that there is a consistent relationship between Km and ϕm. Therefore, Km can be used to make a preliminary estimate of PMP under some conditions when sufficient rainfall data are available. The advantages and disadvantages of this revised Km-value method are also discussed here with a case study for the estimation of 24-h PMP in Hong Kong. The 24-h PMP estimate in Hong Kong based on the local rainfall data is approximately to be 1753mm.

  16. Water versus carbohydrate-electrolyte ingestion before and during a 15-km run in the heat.

    PubMed

    Millard-Stafford, M; Rosskopf, L B; Snow, T K; Hinson, B T

    1997-03-01

    Twelve highly trained male runners ran 15 km at self-selected pace on a treadmill in warm conditions to demonstrate differences in physiological responses, fluid preferences, and performance when ingesting sports drinks or plain water before and during exercise. One hour prior to the start of running, an equal volume (1,000 ml) of either water or a 6% or an 8% carbohydrate-electrolyte (CE) drink was ingested. Blood glucose was significantly higher 30 min following ingestion of 6% and 8% CE compared to water, significantly lower at 60 min postingestion with both sports drinks than with water, but similar after 7.5 km of the run for all beverages. During the first 13.4 km, oxygen uptake and run times were not different between trials; however, the final 1.6-km performance run was faster with both CE drinks compared to water. Despite a lower preexercise blood glucose, CE consumption prior to and during exercise significantly improved performance in last 1.6 km of a 15-km run compared to water.

  17. Emissions from an International Airport Increase Particle Number Concentrations 4-fold at 10 km Downwind

    PubMed Central

    2014-01-01

    We measured the spatial pattern of particle number (PN) concentrations downwind from the Los Angeles International Airport (LAX) with an instrumented vehicle that enabled us to cover larger areas than allowed by traditional stationary measurements. LAX emissions adversely impacted air quality much farther than reported in previous airport studies. We measured at least a 2-fold increase in PN concentrations over unimpacted baseline PN concentrations during most hours of the day in an area of about 60 km2 that extended to 16 km (10 miles) downwind and a 4- to 5-fold increase to 8–10 km (5–6 miles) downwind. Locations of maximum PN concentrations were aligned to eastern, downwind jet trajectories during prevailing westerly winds and to 8 km downwind concentrations exceeded 75 000 particles/cm3, more than the average freeway PN concentration in Los Angeles. During infrequent northerly winds, the impact area remained large but shifted to south of the airport. The freeway length that would cause an impact equivalent to that measured in this study (i.e., PN concentration increases weighted by the area impacted) was estimated to be 280–790 km. The total freeway length in Los Angeles is 1500 km. These results suggest that airport emissions are a major source of PN in Los Angeles that are of the same general magnitude as the entire urban freeway network. They also indicate that the air quality impact areas of major airports may have been seriously underestimated. PMID:24871496

  18. Emissions from an international airport increase particle number concentrations 4-fold at 10 km downwind.

    PubMed

    Hudda, Neelakshi; Gould, Tim; Hartin, Kris; Larson, Timothy V; Fruin, Scott A

    2014-06-17

    We measured the spatial pattern of particle number (PN) concentrations downwind from the Los Angeles International Airport (LAX) with an instrumented vehicle that enabled us to cover larger areas than allowed by traditional stationary measurements. LAX emissions adversely impacted air quality much farther than reported in previous airport studies. We measured at least a 2-fold increase in PN concentrations over unimpacted baseline PN concentrations during most hours of the day in an area of about 60 km(2) that extended to 16 km (10 miles) downwind and a 4- to 5-fold increase to 8-10 km (5-6 miles) downwind. Locations of maximum PN concentrations were aligned to eastern, downwind jet trajectories during prevailing westerly winds and to 8 km downwind concentrations exceeded 75 000 particles/cm(3), more than the average freeway PN concentration in Los Angeles. During infrequent northerly winds, the impact area remained large but shifted to south of the airport. The freeway length that would cause an impact equivalent to that measured in this study (i.e., PN concentration increases weighted by the area impacted) was estimated to be 280-790 km. The total freeway length in Los Angeles is 1500 km. These results suggest that airport emissions are a major source of PN in Los Angeles that are of the same general magnitude as the entire urban freeway network. They also indicate that the air quality impact areas of major airports may have been seriously underestimated.

  19. Neither internal nor external nasal dilation improves cycling 20-km time trial performance.

    PubMed

    Adams, Catriona M; Peiffer, Jeremiah J

    2017-04-01

    Research is equivocal regarding endurance performance benefits of external nasal dilators, and currently research focusing on internal nasal dilators is non-existent. Both devices are used within competitive cycling. This study examined the influence of external and internal nasal dilation on cycling economy of motion and 20-km time trial performance. The study utilized a randomized, counterbalanced cross-over design. Fifteen trained cyclists completed three exercise sessions consisting of a 15min standardized warm up and 20-km cycling time trial while wearing either a Breathe Right(®) external nasal dilator, Turbine(®) internal nasal dilator or no device (control). During the warm up, heart rate, ratings of perceived exertion and dyspnea and expired gases were collected. During the time trial, heart rate, perceived exertion, and dyspnea were collected at 4-km intervals and mean 20-km power output was recorded. No differences were observed for mean 20-km power output between the internal (270±45W) or external dilator (271±44W) and control (272±44W). No differences in the economy of motion were observed throughout the 15-min warm up between conditions. The Turbine(®) and Breathe Right(®) nasal dilators are ineffective at enhancing 20-km cycling time trial performance. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  20. The influence of elliptical chainrings on 10 km cycling time trial performance.

    PubMed

    Peiffer, Jeremiah J; Abbiss, Chris R

    2010-12-01

    The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. Nevertheless, we are unaware of any scientific studies that have examined the performance benefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on physiological and performance parameters during a 10 km cycling time trial. Nine male cyclists completed, in a counterbalanced order, three 10 km cycling time trials using either a standard chainring or an elliptical chainring at two distinct settings. An attempt was made to blind the cyclists to the type of chainring used until the completion of the study. During the 10 km time trial, power output and heart rate were recorded at a frequency of 1 Hz and RPE was measured at 3, 6, and 8.5 km. Total power output was not different (P = .40) between the circular (340 ± 30 W) or either elliptical chainring condition (342 ± 29 W and 341 ± 31 W). Similarly, no differences (P = .73) in 2 km mean power output were observed between conditions. Further, no differences in RPE were observed between conditions measured at 3, 6, and 8.5 km. Heart rate was significantly greater (P = .02) using the less aggressive elliptical setting (174 ± 10 bpm) compared with the circular setting (171 ± 9 bpm). Elliptical chainrings do not appear to provide a performance benefit over traditional circular chainrings during a mid-distance time trial.

  1. Daytime zonal drifts in the ionospheric E and 150 km regions estimated using EAR observations

    NASA Astrophysics Data System (ADS)

    Peddapati, PavanChaitanya; Otsuka, Yuichi; Yamamoto, Mamoru; Yokoyama, Tatsuhiro; Patra, Amit

    2016-07-01

    The Equatorial Atmosphere Radar (EAR), located at Kototabang (0.2o S, 100.32o E, mag. lat. 10.36o S), Indonesia, is capable of detecting both E region and 150 km echoes during daytime. We have conducted multi-beam observations using the EAR during daytime covering all seasons to study seasonal variations of these echoes and their dynamics. Given the facts that drifts at the 150 km region are governed primarily by electric field, drifts at the E region are governed by both electric field and neutral wind, simultaneous observations of drifts in both E and 150 km regions would help understand their variations. In this paper we present local time and seasonal variations of zonal drifts in the E and 150 km regions estimated using multi-beam observations. Zonal drifts (positive eastward) in the E and 150 km regions are found to be in the range of -10 to -60 m/s and -40 to 80 m/s, respectively. In the E region, zonal drifts show height reversal and temporal variations having tidal signature and noticeable seasonal variations. Zonal drifts in the 150 km region also show noticeable height and seasonal variations. These results are compared with model drifts and evaluated in terms of electric field and neutral wind.

  2. A Tank-Free Zone for NATO’s Central Region.

    DTIC Science & Technology

    1988-05-07

    constitutes the analysis . The monograph concludes with an assessment of how well the tank- free zone concept contributes to enhancing and...tank-free zone, defined in various terms in the analysis , can be considered to be a belt of 2 territory approximately 50km in depth paralleling each...Follow-on Forces Attack ( FOFA ) using air, artillery, and electronic warfare assets are considered within the 8I * ’.* - , ~ . ,~ *~’’~**f*~f ~*~~f~ W

  3. Seismicity, shear failure and modes of deformation in deep subduction zones

    NASA Technical Reports Server (NTRS)

    Lundgren, Paul R.; Giardini, Domenico

    1992-01-01

    The joint hypocentral determination method is used to relocate deep seismicity reported in the International Seismological Center catalog for earthquakes deeper than 400 km in the Honshu, Bonin, Mariannas, Java, Banda, and South America subduction zones. Each deep seismic zone is found to display planar features of seismicity parallel to the Harvard centroid-moment tensor nodal planes, which are identified as planes of shear failure. The sense of displacement on these planes is one of resistance to deeper penetration.

  4. Seismicity, shear failure and modes of deformation in deep subduction zones

    NASA Technical Reports Server (NTRS)

    Lundgren, Paul R.; Giardini, Domenico

    1992-01-01

    The joint hypocentral determination method is used to relocate deep seismicity reported in the International Seismological Center catalog for earthquakes deeper than 400 km in the Honshu, Bonin, Mariannas, Java, Banda, and South America subduction zones. Each deep seismic zone is found to display planar features of seismicity parallel to the Harvard centroid-moment tensor nodal planes, which are identified as planes of shear failure. The sense of displacement on these planes is one of resistance to deeper penetration.

  5. The 2004 Sumatra Earthquake and Tsunami: Lessons Learned in Subduction Zone Science and Emergency Management for the Cascadia Subduction Zone

    NASA Astrophysics Data System (ADS)

    Cassidy, John F.

    2015-03-01

    The 26 December 2004, Mw 9.3 Sumatra earthquake and tsunami was a pivotal turning point in our awareness of the dangers posed by subduction zone earthquakes and tsunamis. This earthquake was the world's largest in 40 years, and it produced the world's deadliest tsunami. This earthquake ruptured a subduction zone that has many similarities to the Cascadia Subduction Zone. In this article, I summarize lessons learned from this tragedy, and make comparisons with potential rupture characteristics, slip distribution, deformation patterns, and aftershock patterns for Cascadia using theoretical modeling and interseismic observations. Both subduction zones are approximately 1,100-1,300 km in length. Both have similar convergence rates and represent oblique subduction. Slip along the subduction fault during the 26 December earthquake is estimated at 15-25 m, similar to values estimated for Cascadia. The width of the rupture, ~80-150 km estimated from modeling seismic and geodetic data, is similar to the width of the "locked and transition zone" estimated for Cascadia. Coseismic subsidence of up to 2 m along the Sumatra coast is also similar to that predicted for parts of northern Cascadia, based on paleoseismic evidence. In addition to scientific lessons learned, the 2004 tsunami provided many critical lessons for emergency management and preparedness. As a result of that tragedy, a number of preparedness initiatives are now underway to promote awareness of earthquake and tsunami hazards along the west coast of North America, and plans are underway to develop prototype tsunami and earthquake warning systems along Cascadia. Lessons learned from the great Sumatra earthquake and tsunami tragedy, both through scientific studies and through public education initiatives, will help to reduce losses during future earthquakes in Cascadia and other subduction zones of the world.

  6. Crustal structure across a continental suture zone: a zone of focused crustal thickening, diffuse seismicity, and epiorogenic features in the mid continent of North America

    NASA Astrophysics Data System (ADS)

    Gilbert, H. J.; Boschelli, J.; McGlannan, A.; Pavlis, G. L.; Hamburger, M. W.; Marshak, S.; Larson, T. H.

    2014-12-01

    Continents grow as crustal terranes of various ages and origins accreted together. Suture zones mark the boundaries of these terranes and provide a discrete marker to investigate the process of continental growth. Investigating continental structure, we can identify whether properties such as crustal thickness or seismic wavespeed changes across suture zones. Further comparison between the locations of sutures and the distribution of tectonic events provides insight into the degree that sutures serve to localize regions of tectonism. In this study we investigate the mid continent of North America, where crust of the Mazatzal and Granite Rhyolite terranes accreted together to make up the Proterozoic basement. Using seismic data from the EarthScope Transportable Array and OIINK FlexArray, we inspect receiver functions and Rayleigh wave phase velocities to investigate lithospheric structures. Through this analysis, we identify a zone where the crust thickens from an average near 40 km, to more than 50 km in an area that encompasses the Illinois-Missouri border and lies along the suture zone between these two Proterozoic terranes. However, the wavespeeds of the crust do not appear to vary between the terranes or in the zone of crustal thickening. The boundary between the Ozark Plateau and Illinois Basin is located within the area of thickened crust and may indicate a potential role played by the suture zone in the formation of these two epiorogenic features. The dense mafic intrusions that were added to the crust during extension of the failed Reelfoot Rift, and now exhibit high seismic wavespeeds, may have provided the additional load that allowed the Illinois Basin to exploit the already weakened suture zone and subside. Diffuse seismicity in the St. Genevieve Fault Zone, which is located to the north of the New Madrid Seismic Zone, lies near the western edge of the area of thickened crust and suggests that ancient suture zones influence modern deformation within

  7. Regional Vp, Vs, Vp/Vs, and Poisson's ratios across earthquake source zones from Memphis, Tennessee, to St. Louis, Missouri

    USGS Publications Warehouse

    Catchings, R.D.

    1999-01-01

    Models of P- and S-wave velocity, Vp/Vs ratios, Poisson's ratios, and density for the crust and upper mantle are presented along a 400-km-long profile trending from Memphis, Tennessee, to St. Louis, Missouri. The profile crosses the New Madrid seismic zone and reveals distinct regional variations in the crustal velocity structure north and south of the latitude of New Madrid. In the south near Memphis, the upper few kilometers of the crust are dominated by upper crustal sedimentary basins or graben with P-wave velocities less than 5 km/sec and S-wave velocities of about 2 km/sec. P-wave velocities of the upper and middle crust range from 6.0 to 6.5 km/sec at depths above 25 km, and corresponding S-wave velocities range from 3.5 to 3.7 km/sec. The lower crust consists of a high-velocity layer (Vp = 7.4 km/sec; Vs ~4.2 km/sec) that is up to 20-km thick at the latitude of New Madrid but thins to about 15 km near Memphis. To the north, beneath the western-most Illinois basin, low-velocity (Vp < 5 km/sec; Vs < 2.3 km/sec) sedimentary basins are less than 1-km deep. The average velocities (Vp = 6.0 km/sec; Vs = 3.5 km/sec) of the underlying, near-surface rocks argue against large thickness of unconsolidated noncarbonate sediments within 50 km of the western edge of the Illinois basin. Most of the crust beneath the Illinois basin is modeled as one layer, with velocities up to 6.8 km/sec (Vs = 3.7 km/sec) at 37-km depth. The thick, high-velocity (Vp = 7.4 km/sec; Vs ~4.2 km/sec) lower crustal layer thins from about 20 km near New Madrid to about 6 km beneath the western Illinois basin. Refractions from the Moho and upper mantle occur as first arrivals over distances as a great as 160 km and reveal upper mantle layering to 60 km depth. Upper mantle layers with P-wave velocities of 8.2 km/sec (Vs = 4.5 km/sec) and 8.4 km/sec (Vs = 4.7 km/sec) are modeled at 43 and 60 km depth, respectively. Crustal Vp/Vs ratios range between 1.74 and 1.83, and upper mantle Vp/V s ratios

  8. Imaging Faults and Shear Zones Using Receiver Functions

    NASA Astrophysics Data System (ADS)

    Schulte-Pelkum, Vera; Mahan, Kevin H.

    2014-11-01

    significant tradeoffs are foliation strike and the depth of the foliation contrast. We find that an anisotropy of only a few percent in the shear zone is sufficient to generate a strong signal, but that the shear zone width is required to be >2 km for typical frequencies used in receiver function analysis to avoid destructive interference due to the signals from the boundaries of the shear zone.

  9. Broad belts of shear zones: The common form of surface rupture produced by the 28 June 1992 Landers, California, earthquake

    SciTech Connect

    Johnson, A.M.; Cruikshank, K.M. |; Fleming, R.W.

    1993-12-31

    Surface rupturing during the 28 June 1992, Landers, California earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en echelon fault zones with a total length of about 80 km. The offsets were accommodated generally not by faults -- distinct slip surfaces -- but rather by shear zones, tabular bands of localized shearing. In long, straight stretches of fault zones at Landers the rupture is characterized by telescoping of shear zones and intensification of shearing: broad shear zones of mild shearing, containing narrow shear zones of more intense shearing, containing even-narrower shear zones of very intense shearing, which may contain a fault. Thus the ground ruptured across broad belts of shearing with subparallel walls, oriented NW. Each broad belt consists of a broad zone of mild shearing, extending across its entire width (50 to 200 m), and much narrower (a few m wide) shear zones that accommodate most of the offset of the belt and are portrayed by en echelon tension cracks. In response to right-lateral shearing, the slices of ground bounded by the tension cracks rotated in a clockwise sense, producing left lateral shearing, and the slices were forced against the walls of the shear zone, producing thrusting. Even narrower shear zones formed within the narrow shear zones, and some of these were faults. Although the narrower shear zones probably are indicators to right-lateral fault segments at depth, the surface rupturing during the earthquake is characterized not by faulting, but by zones of shearing at various scales. Furthermore, understanding of the formation of the shear zones may be critical to understanding of earthquake faulting because, where faulting is associated with the formation of a shear zone, the faulting occurs late in the development of the shear zone. The faulting occurs after a shear zone or a belt of shear zones forms.

  10. Velocity models and hypocenter relocations for the Charlevoix Seismic Zone

    NASA Astrophysics Data System (ADS)

    Powell, Christine A.; Lamontagne, Maurice

    2017-08-01

    Three-dimensional P and S wave velocity (Vp and Vs) models and hypocenter relocations are determined for the Charlevoix Seismic Zone (CSZ) using local arrival time tomography. The CSZ is located along the St. Lawrence River about 100 km downstream from Quebec City, Canada, and is one of the most active seismic zones in eastern North America. Earthquakes occur in Grenvillian basement rocks affected by Iapetan Ocean rifting and a large Devonian meteor impact. Low Vp and Vs are associated with the impact structure to a depth of 12 km. Relocated hypocenters form a semicircle delineating the eastern margin of the impact structure. Northeast of the impact, hypocenters cluster into two groups separated by a region of high Vp and Vs velocity. Hypocenters within each group align along planar surfaces, suggesting the presence of distinct seismogenic faults. The planes trend NE, in the same direction as the Iapetan rift faults, and dip to the SE. One plane is located beneath the north shore of the St. Lawrence River and extends to a depth of at least 30 km. Two other planes with shallower dips are located beneath the river and extend to depths of 12 and 15 km. All three planes are disrupted within the impact zone but can be followed, suggesting partial preservation of rift-parallel fault fabric.

  11. Crust and subduction zone structure of Southwestern Mexico

    NASA Astrophysics Data System (ADS)

    Suhardja, Sandy Kurniawan; Grand, Stephen P.; Wilson, David; Guzman-Speziale, Marco; Gomez-Gonzalez, Juan Martin; Dominguez-Reyes, Tonatiuh; Ni, James

    2015-02-01

    Southwestern Mexico is a region of complex active tectonics with subduction of the young Rivera and Cocos plates to the south and widespread magmatism and rifting in the continental interior. Here we use receiver function analysis on data recorded by a 50 station temporary deployment of seismometers known as the MARS (MApping the Rivera Subduction zone) array to investigate crustal structure as well as the nature of the subduction interface near the coast. The array was deployed in the Mexican states of Jalisco, Colima, and Michoacan. Crustal thickness varies from 20 km near the coast to 42 km in the continental interior. The Rivera plate has steeper dip than the Cocos plate and is also deeper along the coast than previous estimates have shown. Inland, there is not a correlation between the thickness of the crust and topography indicating that the high topography in northern Jalisco and Michoacan is likely supported by buoyant mantle. High crustal Vp/Vs ratios (greater than 1.82) are found beneath the trenchward edge of magmatism including below the Central Jalisco Volcanic Lineament and the Michoacan-Guanajuato Volcanic Field implying a new arc is forming closer to the trench than the Trans Mexican Volcanic Belt. Elsewhere in the region, crustal Vp/Vs ratios are normal. The subducting Rivera and Cocos plates are marked by a dipping shear wave low-velocity layer. We estimate the thickness of the low-velocity layer to be 3 to 4 km with an unusually high Vp/Vs ratio of 2.0 to 2.1 and a drop in S velocity of 25%. We postulate that the low-velocity zone is the upper oceanic crust with high pore pressures. The low-velocity zone ends from 45 to 50 km depth and likely marks the basalt to eclogite transition.

  12. The Near Zone to Far Zone Transformation (N2F)

    SciTech Connect

    Blackfield, Donald T.; Poole, Brian R.

    2016-03-11

    N2F is a C/C++ code used to calculate the far zone electromagnetic (EM) field, given E and H near zone field data. The method used by N2F can be found in Ref. 1 and 2. N2F determines the far field EΦ and Eθ in spherical coordinates for near zone data calculated in either Cartesian or Cylindrical geometry.

  13. Estimation and Attribution of the Temperature Variances in Height Range 60~140 km

    NASA Astrophysics Data System (ADS)

    Chen, Zeyu

    The SABER/TIMED temperatures collected during 2002 2006 are used to estimate for height range 60 120 km the variances of temperature (Temp-VARs) that are contributed from nonstationary perturbations. The estimation results disclose that the height range 60 140 km can be separated into two regions that are characterized by significant differences of the attributions of the Temp-VARs. In the region below 100 km height, the Temp-VARs generally increase with height, the corresponding standard deviations of temperature (Temp-SDEVs) ranges from 4 K at 60 km and 18 K at 100 km. The regions exhibiting intense Temp-VARs appear at the equator and the extra-tropics of both hemispheres. Moreover, these non-stationary temperature disturbances can be accounted primarily by the tidal variances that are derived independently by using the same data-set, in particular by the migrating diurnal, semidiurnal, and terdiurnal tide. It is also found that the region above 100 km is characterized by surprisingly large Temp-VARs with the corresponding Temp-SDEVs greater than 30 K. In a height-latitude cross-section, a stagnant maximum of Temp-SDEVs embraced by the 30-K contour remains over the course of a year at the Equator in a narrow height range 110 125 km. At the same height in Southern hemisphere, the same kind maxima appears at latitudes from the extra-tropics to polar region except during the June solstice. In contrast, the maxima appearing in Northern hemisphere high latitudes exhibits intra-seasonal variations, there such maximum are seen during the course of a year. Further investigation results confirm that the large Temp-VARs have no relevance to the tidal variances, implying the control from other processes, e.g., non-stationary planetary waves. The details will be introduced in the presentation.

  14. The Trigger and Data Acquisition System for the KM3NeT neutrino telescope

    NASA Astrophysics Data System (ADS)

    Pellegrino, Carmelo; Chiarusi, Tommaso

    2016-04-01

    KM3NeT is a large research infrastructure in the Mediterranean Sea that includes a network of deep-sea neutrino telescopes. The telescopes consist of vertical detection units carrying optical modules, whose separation is optimised according to the different ranges of neutrino energy that shall be explored. Two building blocks, each one made of 115 detection units, will be deployed at the KM3NeT-IT site, about 80 km from Capo Passero, Italy, to search for high-energy neutrino sources (ARCA); another building block will be installed at the KM3NeT-Fr site, about 40 km from Toulon, France, to study the hierarchy of neutrino masses (ORCA). The modular design of the KM3NeT allows for a progressive implementation and data taking even with an incomplete detector. The same scalable design is used for the Trigger and Data Acquisition Systems (TriDAS). In order to reduce the complexity of the hardware inside the optical modules, the "all data to shore" concept is adopted. This implies that the throughput is dominated by the optical background due to the decay of 40K dissolved in the sea water and to the bursts of bioluminescence, about 3 orders of magnitude larger than the physics signal, ranging from 20 Gbps to several hundreds Gbps, according to the number of detection units. In addition, information from the acoustic positioning system of the detection units must be transmitted. As a consequence of the detector construction, the on-shore DAQ infrastructure must be expanded to handle an increasing data-rate and implement an efficient fast data filtering for both the optical and acoustic channels. In this contribution, the Trigger and Data Acquisition System designed for the Phase 1 of KM3NeT and its future expansion are presented. The network infrastructure, the shore computing resources and the developed applications for handling, filtering and monitoring the optical and acoustic data-streams are described.

  15. The isolated 678-km deep 30 May 2015 MW 7.9 Ogasawara (Bonin) Islands earthquake

    NASA Astrophysics Data System (ADS)

    Ye, L.; Lay, T.; Zhan, Z.; Kanamori, H.; Hao, J.

    2015-12-01

    Deep-focus earthquakes, located 300 to 700 km below the Earth's surface within sinking slabs of relatively cold oceanic lithosphere, are mysterious phenomena. Seismic radiation from deep events is essentially indistinguishable from that for shallow stick-slip frictional-sliding earthquakes, but the confining pressure and temperature are so high for deep-focus events that a distinct process is likely needed to account for their abrupt energy release. The largest recorded deep-focus earthquake (MW 7.9) in the Izu-Bonin slab struck on 30 May 2015 beneath the Ogasawara (Bonin) Islands, isolated from prior seismicity by over 100 km in depth, and followed by only 2 small aftershocks. Globally, this is the deepest (678 km) major (MW > 7) earthquake in the seismological record. Seismicity indicates along-strike contortion of the Izu-Bonin slab, with horizontal flattening near a depth of 550 km in the Izu region and progressive steepening to near-vertical toward the south above the location of the 2015 event. Analyses of a large global data set of P, SH and pP seismic phases using short-period back-projection, subevent directivity, and broadband finite-fault inversion indicate that the mainshock ruptured a shallowly-dipping fault plane with patchy slip that spread over a distance of ~40 km with variable expansion rate (~5 km/s down-dip initially, ~3 km/s up-dip later). During the 17 s rupture duration the radiated energy was ~3.3 x 1016 J and the stress drop was ~38 MPa. The radiation efficiency is moderate (0.34), intermediate to that of the 1994 Bolivia and 2013 Sea of Okhotsk MW 8.3 earthquakes, indicating a continuum of processes. The isolated occurrence of the event suggests that localized stress concentration associated with the pronounced deformation of the Izu-Bonin slab likely played a role in generating this major earthquake.

  16. Synthetic seismogram images of upper mantle structure: No evidence for a 520-km discontinuity

    NASA Astrophysics Data System (ADS)

    Bock, Gunter

    1994-08-01

    Seismological data used by Shearer (1990, 1991) to infer the existence of a seismic discontinuity at 520 km depth are compared with complete long-period body-wave seismographs calculated for the International Association of Seismology and Physics of the Earth's Interior 1991 (Iaspei91) Earth model. The Iaspei91 model does not contain a seismic discontinuity at or near 520 km depth. The observed P and SH multiples caused by topside reflections and SS precursors caused by underside reflections from the 410-km and 660-km discontinuities are well reproduced by the synthetic stacks. The synthetics exhibit clear 'phase extrema' between these reflections that correlate well with similar features in the observed waveform stacks. Shearer interpreted these 'phase extrema' as separate reflections from a seismic discontinuity at 520 km depth. Cross-correlation analysis of synthetic seismograms gives an apparent discontinuity depth of about 520 km for P and SH multiples as well as SS precursors. Similarly, amplitude analysis of synthetic upper mantle reflections is in reasonable agreement with the observations reported by Shearer (1991). The phase extrema seen in the synthetics are the result of an extended, multicycle wavelet which is composed of depth phases and other structural phases such as reverberations from the crustal layer, convolved with the instrument response of long-period stations of the Global Seismograph Network. The comparison of observational data, presented by Shearer (1990, 1991), with the synthetic seismogram stacks of this paper shows that the claim of good seismological evidence for a 520-km seismic discontinuity as a global feature is not compelling.

  17. Seismic Velocity Gradients Across the Transition Zone

    NASA Astrophysics Data System (ADS)

    Escalante, C.; Cammarano, F.; de Koker, N.; Piazzoni, A.; Wang, Y.; Marone, F.; Dalton, C.; Romanowicz, B.

    2006-12-01

    One-D elastic velocity models derived from mineral physics do a notoriously poor job at predicting the velocity gradients in the upper mantle transition zone, as well as some other features of models derived from seismological data. During the 2006 CIDER summer program, we computed Vs and Vp velocity profiles in the upper mantle based on three different mineral physics approaches: two approaches based on the minimization of Gibbs Free Energy (Stixrude and Lithgow-Bertelloni, 2005; Piazzoni et al., 2006) and one obtained by using experimentally determined phase diagrams (Weidner and Wang, 1998). The profiles were compared by assuming a vertical temperature profile and two end-member compositional models, the pyrolite model of Ringwood (1979) and the piclogite model of Anderson and Bass (1984). The predicted seismic profiles, which are significantly different from each other, primarily due to different choices of properties of single minerals and their extrapolation with temperature, are tested against a global dataset of P and S travel times and spheroidal and toroidal normal mode eigenfrequencies. All the models derived using a potential temperature of 1600K predict seismic velocities that are too slow in the upper mantle, suggesting the need to use a colder geotherm. The velocity gradient in the transition zone is somewhat better for piclogite than for pyrolite, possibly indicating the need to increase Ca content. The presence of stagnant slabs in the transition zone is a possible explanation for the need for 1) colder temperature and 2) increased Ca content. Future improvements in seismic profiles obtained from mineral physics will arise from better knowledge of elastic properties of upper mantle constituents and aggregates at high temperature and pressure, a better understanding of differences between thermodynamic models, and possibly the effect of water through and on Q. High resolution seismic constraints on velocity jumps at 400 and 660 km also need to be

  18. Halogen Behavior during Subduction-Zone Processes

    NASA Astrophysics Data System (ADS)

    Barnes, J.; Manning, C. E.; Scambelluri, M.; Selverstone, J.

    2016-12-01

    Halogens (Cl, F, I, Br) are enriched in surface reservoirs compared to the mantle. The subduction of these reservoirs in the form of sedimentary pore fluids, sediments, altered oceanic crust (AOC), and serpentinites returns halogens to the mantle and to regions of arc magma genesis. Pore fluids are particularly enriched in iodine, yet shallow pore fluid loss due to compaction makes pore fluids a negligible halogen source at depths > 5 km. Sediments can host large quantities of halogens, particularly I. However, serpentinites ± AOC deliver the largest amount of halogens to depths of magma genesis. Due to their hydrophilic nature, halogens are lost to aqueous slab-derived fluids during prograde metamorphic reactions. The addition of halogens, particularly Cl, increases the ability of subduction-zone fluids to transport metals and trace elements. The amount of Cl in solution is a function of the P-T conditions of the subduction zone, such that higher temperatures at a given depth and lower pressures at a given temperature favor ion pair formation (NaClaq, KClaq). Therefore, ion pairing will be more important in subduction zones with warmer geotherms compared to those with cooler geotherms. High halogen concentrations in melt inclusions and volcanic gas emissions from the arc front support the efficiency of fluid loss and transport from the slab to the region of magma genesis. Despite this high efficiency, mass balance calculations and halogen concentrations in back-arc basalts and ocean island basalts show that more halogens are subducted than returned to the Earth's surface through volcanic arc fronts, implying transport of halogens into the upper mantle. We estimate that 1-80% of Cl, 70-99% of I, 80-95% of Br, and 95-98% of F, subduct past the arc. The wide range for Cl is hampered by large uncertainties in Cl outputs. Shallow loss of I and Br are not accounted for in outputs, thus overestimating the recycling of these elements to the mantle.

  19. a Study of Fault Zone Hydrology

    NASA Astrophysics Data System (ADS)

    Karasaki, K.; Onishi, C. T.; Goto, J.; Moriya, T.; Tsuchi, H.; Ueta, K.; Kiho, K.; Miyakawa, K.

    2010-12-01

    The Nuclear Waste Management Organization of Japan and Lawrence Berkeley National Laboratory are presently collaborating at a dedicated field site to further understand, and to develop the characterization technology for, fault zone hydrology. To this end, several deep trenches were cut, and a number of geophysical surveys were conducted across the Wildcat Fault in the hills east of Berkeley, California. The Wildcat Fault is believed to be a strike-slip fault and a member of the Hayward Fault System, with over 10 km of displacement. So far, three boreholes of ~ 150 m have been core-drilled; one on the east side and two on the west side of the suspected fault trace. The lithology at Wildcat Fault mainly consists of chert, shale and sandstone, extensively sheared and fractured; with gouges observed at several depths and a thick cataclasite zone. After conducting hydraulic tests, the boreholes were instrumented with temperature and pressure sensors at multiple levels. Preliminary results from these holes indicated that the geology was not what was expected: while confirming some earlier, published conclusions about Wildcat, they have also led to some unexpected findings. The pressure and temperature distributions indicate a downward hydraulic gradient and a relatively large geothermal gradient. Wildcat near the field site appear to consist of multiple faults. The hydraulic test data suggest the dual properties of the hydrologic structure of the fault zone. At this writing an inclined fourth borehole is being drilled to penetrate the main Wildcat. Using the existing three boreholes as observation wells, we plan to conduct hydrologic cross-hole tests in this fourth borehole. The main philosophy behind our approach for the hydrologic characterization of such a complex fractured system is to let the system take its own average and monitor long term behavior, instead of collecting a multitude of data at small length and time scales, or at a discrete fracture scale, and

  20. Plutonism at Different Crustal Levels of an Arc: Insights From the 5 to 40 km (Paleodepth) North Cascades Crustal Section, Washington

    NASA Astrophysics Data System (ADS)

    Miller, R. B.; Paterson, S. R.; Matzel, J. P.

    2008-12-01

    The crystalline core of the North Cascades preserves a Cretaceous crustal section that facilitates evaluation of pluton construction, emplacement, geometry, composition, and deformation at widely variable crustal levels (~5 to 40 km paleodepth) in a thick (> 55 km) continental magmatic arc. The oldest and largest pulse of plutonism was focused between 96-89 Ma when fluxes were a minimum of 3.9x10-6km3/yr/km of arc length, but the coincidence with regional crustal thickening and underthrusting of a cool outboard terrane resulted in relatively low mid- to deep-crustal temperatures for an arc. A second, smaller peak of magmatism at 78-71 Ma (minimum of 8.2x10-7km3/yr/km of arc length) occurred during regional transpression. Tonalite dominates at all levels of the section. Intrusions range from large plutons to thin (< 50 m) dispersed sheets encased in metamorphic rocks that record less focused magmatism. The percentage of igneous rocks increases systematically from shallow to middle to deep levels; from approximately 37% to 55% to 65% of the total rock volume. Unfocused magmas comprise much higher percentages (approximately 19%) of the total plutonic rock at deep- and mid-crustal depths, but only 1% at shallower levels, whereas the largest intrusions were emplaced into shallow crust. Plutons have a range of shapes, including: asymmetric wedges to funnels; subhorizontal tabular sheets; steep-sided, blade-shaped bodies with high aspect ratios in map view; and steep-sided, vertically extensive (> 8 km) bodies shaped like thick disks and/or hockey pucks. Sheeted intrusions and gently dipping tabular bodies are more common with depth. Some of these plutons fit the model that most intrusions are subhorizontal and tabular, but many do not, reflecting the complex changes in lithology and rheology in arc crust undergoing regional shortening. The steep sheeted plutons partly represent magma transfer zones that fed the large shallow plutons, which were sites of intermittent

  1. Electrical resistivity image of the upper crust within the Taupo Volcanic Zone, New Zealand

    NASA Astrophysics Data System (ADS)

    Bibby, H. M.; Caldwell, T. G.; Risk, G. F.

    1998-05-01

    The Taupo Volcanic Zone (TVZ) forms a region of back-arc extension within the continental crust of New Zealand and is notable for its caldera volcanism, high rate of magmatic production, and high heat flow. On the eastern side of the TVZ, volcanism terminates abruptly along a linear margin. We present the interpretation of three multiple-source bipole-dipole resistivity surveys across this margin. The major features of the measured data can be reproduced by using two-dimensional models of the resistivity in the upper 10 km of the crust. Along the margin the high-resistivity graywacke basement (300 Ωm increasing to 1300 Ωm) is downfaulted to the west across a zone about 6 km wide, with a total vertical offset of approximately 2 km. The easternmost fault is overlain by an unbroken 0.24 Ma ignimbrite sheet, suggesting the fault has been inactive for this period. Further to the west, at depths greater than 2 km, a conductive zone about 15 km wide and of total conductance 180-280 S has been identified. This conductive zone can be modeled by using a range of resistivities (40-3 Ωm) and thicknesses (8-2 km). Models incorporating resistivities less than 15 Ωm require the low-resistivity zone to be wedge shaped, so that conductance increases to the west. The low resistivity is believed to be caused by the presence of clay alteration within volcanoclastic rocks. The large volume of volcanic rocks at depth can be linked to a series of caldera-forming eruptions that have taken place along the eastern side of the TVZ.

  2. Acute Impact of Inhaled Short Acting B2-Agonists on 5 Km Running Performance

    PubMed Central

    Dickinson, John; Hu, Jiu; Chester, Neil; Loosemore, Mike; Whyte, Greg

    2014-01-01

    Whilst there appears to be no ergogenic effect from inhaled salbutamol no study has investigated the impact of the acute inhalation of 1600 µg, the World Anti-Doping Agency (WADA) daily upper limit, on endurance running performance. To investigate the ergogenic effect of an acute inhalation of short acting β2-agonists at doses up to 1600 µg on 5 km time trial performance and resultant urine concentration. Seven male non-asthmatic runners (mean ± SD; age 22.4 ± 4.3 years; height 1.80 ± 0.07 m; body mass 76.6 ± 8.6 kg) provided written informed consent. Participants completed six 5 km time-trials on separate days (three at 18 °C and three at 30 °C). Fifteen minutes prior to the initiation of each 5 km time-trial participants inhaled: placebo (PLA), 800 µg salbutamol (SAL800) or 1600 µg salbutamol (SAL1600). During each 5 km time-trial HR, VO2, VCO2, VE, RPE and blood lactate were measured. Urine samples (90 ml) were collected between 30-180 minutes post 5 km time-trial and analysed for salbutamol concentration. There was no significant difference in total 5 km time between treatments (PLA 1714.7 ± 186.2 s; SAL800 1683.3 ± 179.7 s; SAL1600 1683.6 ± 190.7 s). Post 5 km time-trial salbutamol urine concentration between SAL800 (122.96 ± 69.22 ug·ml-1) and SAL1600 (574.06 ± 448.17 ug·ml-1) were not significantly different. There was no improvement in 5 km time-trial performance following the inhalation of up to 1600 µg of salbutamol in non-asthmatic athletes. This would suggest that the current WADA guidelines, which allow athletes to inhale up to 1600 µg per day, is sufficient to avoid pharmaceutical induced performance enhancement. Key points Inhaling up to 1600 µg of Salbutamol does not result in improved 5 km time trial performance. The position of Salbutamol on the World Anti-Doping Agency list of prohibited appears justified. Athletes who use up to 1600 µg Salbutamol in one day need to review their therapy as it would suggest their respiratory

  3. Multi-channel Linear Array Seismic Interferometry: Insights on Passive Seismic Imaging of the Upper 1 km in an Urban Area

    NASA Astrophysics Data System (ADS)

    Pettinger, E. M.; Stephenson, W. J.; Odum, J. K.

    2015-12-01

    High-resolution active-source seismic imaging in heavily urbanized regions is problematic because equipment deployment is often constrained to linear roadways, where access for active seismic sources may be limited and seismic energy from ambient urban noise can overpower active sources. To investigate the application of linear-array seismic interferometry for obtaining subsurface images in the upper 1 km beneath an urban area, we acquired passive seismic data along two roadways that cross a northern segment of the Seattle fault zone, Washington State. Both of the profiles were collocated with previously acquired active-source reflection lines, which we used as control for interpretations. The interferometry profiles were roughly 1 km in length and were acquired using 8-Hz resonant frequency, vertical-component geophones that were deployed at 5 m spacing (nominally 216 sensors). Approximately 24 hours of data were acquired on each profile over four days (because of permitting and security issues, the equipment could not be deployed overnight). The basic processing sequence used to create virtual source gathers (VSG's) included pre-correlation gain correction, resampling, bandpass filtering, correlation by cross coherence, and VSG editing. After editing, around 18% of the individual virtual sources were retained for further analysis. VSG's were then dip filtered prior to stacking to further mitigate coherent noise. Our VSG's resolve 4-30 Hz Rayleigh waves, propagating at 300-600 m/s, and at least one diving P-wave propagating at roughly 1800 m/s. These apparent velocities are similar to those of comparable wave phases observed in the active-source data. Overall, these newly acquired high-resolution seismic imaging data provide insights into seismic velocity of the upper 1 km across the Seattle fault zone.

  4. Evidence for a change in the global shear velocity pattern ˜ 1,000 km depth

    NASA Astrophysics Data System (ADS)

    Durand, Stephanie; Debayle, Eric; Ricard, Yanick; Zaroli, Christophe; Lambotte, Sophie

    2017-04-01

    In this study, we show evidence for a change in the shear velocity spectrum around 1,000 km depth based on a new shear velocity tomographic model of the Earth's mantle, SEISGLOB2. SEISGLOB2 is based on Rayleigh surface wave phase velocities, self- and cross-coupling structure coefficients of spheroidal normal modes and body wave travel times which are, for the first time, combined in a tomographic inversion. SEISGLOB2 is developed up to spherical harmonic degree 40 and in 21 spline functions. The spectrum of SEISGLOB2 shows it is the flattest around 1,000 km depth and this flattening occurs between 800 and 1,500 km depth. The presence of such a transition in the spectrum suggests an accumulation of shorter scale heterogeneities at around 1,000 km depth. This change in the spectrum is also observed when looking at the model, where some behaviour changes of slabs, hotspots and LLSVPs occur around 1,000 km depth. The existence of such a velocity change in the mid-mantle can have great impacts on our understanding of the mantle dynamics and should thus be taken into account in future modeling.

  5. The Effect of Boron on the Low Cycle Fatigue Behavior of Disk Alloy KM4

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy; Gayda, John; Sweeney, Joseph

    2000-01-01

    The durability of powder metallurgy nickel base superalloys employed as compressor and turbine disks is often limited by low cycle fatigue (LCF) crack initiation and crack growth from highly stressed surface locations (corners, holes, etc.). Crack growth induced by dwells at high stresses during aerospace engine operation can be particularly severe. Supersolvus solution heat treatments can be used to produce coarse grain sizes approaching ASTM 6 for improved resistance to dwell fatigue crack growth. However, the coarse grain sizes reduce yield strength, which can lower LCF initiation life. These high temperature heat treatments also can encourage pores to form. In the advanced General Electric disk superalloy KM4, such pores can initiate fatigue cracks that limit LCF initiation life. Hot isostatic pressing (HIP) during the supersolvus solution heat treatment has been shown to improve LCF initiation life in KM4, as the HIP pressure minimizes formation of the pores. Reduction of boron levels in KM4 has also been shown to increase LCF initiation life after a conventional supersolvus heat treatment, again possibly due to effects on the formation tendencies of these pores. However, the effects of reduced boron levels on microstructure, pore characteristics, and LCF failure modes in KM4 still need to be fully quantified. The objective of this study was to determine the effect of boron level on the microstructure, porosity, LCF behavior, and failure modes of supersolvus heat treated KM4.

  6. Participation and performance trends in 100-km ultra-marathons worldwide.

    PubMed

    Cejka, Nadine; Rüst, Christoph Alexander; Lepers, Romuald; Onywera, Vincent; Rosemann, Thomas; Knechtle, Beat

    2014-01-01

    The aims of the present study were to (1) investigate the participation trends for the origin of athletes competing in 100-km ultra-marathons and (2) determine the nationalities of athletes achieving the fastest 100-km race times worldwide. Race times and nationality from 112,283 athletes (15,204 women and 97,079 men) from 102 countries who completed a 100-km ultra-marathon worldwide between 1998 and 2011 were investigated using single- and multi-level regression analyses. The number of finishers increased exponentially, both for women and men. Most of the finishers (73.5%) were from Europe, in particular, France (30.4%). The number of finishers from Japan, Germany, Italy, Poland and the United States of America increased exponentially during the studied period. For women, runners from Canada became slower while those from Italy became faster over time. For men, runners from Belgium, Canada and Japan became slower. Between 1998 and 2011, the ten best race times were achieved by Japanese runners for both women with 457.1 (s = 28.8) min and men with 393.4 (s = 9.6) min. To summarise, most of the finishers in 100-km ultra-marathons originated from Europe, but the best performances belong to Japanese runners. Although East African runners dominate running up to a marathon, Japanese were the best in 100 km.

  7. The effects of red blood cell infusion on 10-km race time.

    PubMed

    Brien, A J; Simon, T L

    The purpose of this study was to investigate the effect of infusion of 400 mL of red blood cells (RBCs) on 10-km track race time, submaximal heart rate, hematocrit, 2,3-diphosphoglycerate, and partial pressure of oxygen at 50% hemoglobin saturation. Six highly trained, male, distance runners twice donated a unit of RBCs, which was frozen for subsequent reinfusion. Eleven weeks after the second donation, they undertook a series of three competitive 10-km races on a standard 400-m track: before infusion, after 100 mL of saline solution, and after 400 mL of autologous, previously frozen deglycerolized RBCs. All subjects took all trials in this double-blind, placebo, crossover, experimental design. Running time was recorded at each 400-m split, and blood was collected prior to each trial. The data were analyzed by analysis of variance. Results following the RBC infusion showed a significantly higher hematocrit concentration, a significantly faster 10-km run, a nonsignificant decrease in submaximal heart rate (10 beats faster 10-km run, a nonsignificant decrease in submaximal heart rate (10 beats per minute), and no significant changes in either 2,3-diphosphoglycerate or partial pressure of oxygen at 50% hemoglobin saturation. Erythrocythemia induced by the infusion of 400 mL of autologous packed RBCs effectively increased performance capacity in a 10-km track race, probably due to an increase in oxygen delivery to the working muscles.

  8. Operation and results of the prototype KM3NeT detection unit

    NASA Astrophysics Data System (ADS)

    Biagi, Simone

    2016-07-01

    KM3NeT will be a km3-scale neutrino telescope in the Mediterranean Sea. The detector will consist of blocks of about one hundred detection units. Each detection unit will host 18 digital optical modules, connected along a 700 m-long vertical structure. Electro-optical cables allow for data transmission and power supply to the optical modules. The optical module comprises 31 photomultiplier tubes of 3'', instruments to monitor environmental variables and electronic boards to communicate onshore and operate the photomultipliers. A prototype detection unit has been deployed in May 2014 at the KM3NeT-It installation site 80 km SE offshore of Capo Passero, Sicily. This prototype allowed to test the deployment procedures, the mechanics and the electronic of the apparatus, the data taking and analysis procedures. A general description of the detector and some results of the prototype are presented. The first detection unit of the KM3NeT neutrino telescope will be deployed and become operative by the end of 2015.

  9. M. tuberculosis ferritin (Rv3841): Potential involvement in Amikacin (AK) & Kanamycin (KM) resistance.

    PubMed

    Sharma, Divakar; Lata, Manju; Faheem, Mohammad; Khan, Asad Ullah; Joshi, Beenu; Venkatesan, Krishnamurthy; Shukla, Sangeeta; Bisht, Deepa

    2016-09-16

    Tuberculosis is an infectious disease, caused by one of the most successful human pathogen, Mycobacterium tuberculosis. Aminoglycosides, Amikacin (AK) & Kanamycin (KM) are commonly used to treat drug resistant tuberculosis. They target the protein synthesis machinery by interacting with several steps of translation. Several explanations have been proposed to explain the mechanism of aminoglycoside resistance but still our information is inadequate. Iron storing/interacting proteins were found to be overexpressed in aminoglycosides resistant isolates. Iron assimilation and utilization in M. tuberculosis plays a crucial role in growth, virulence and latency. To establish the relationship of ferritin with AK & KM resistance ferritin (Rv3841/bfrB) was cloned, expressed and antimicrobial drug susceptibility testing (DST) was carried out. Rv3841/bfrB gene was cloned and expressed in E. coli BL21 using pQE2 expression vector. Etest results for DST against AK & KM showed that the minimum inhibitory concentration (MIC) of ferritin recombinant cells was changed. Recombinants showed two fold changes in MIC with AK and three fold with KM E-strips. Overexpression of ferritin reflect the MIC shift which might be playing a critical role in the survival of mycobacteria by inhibiting/modulating the effects of AK & KM. String analysis also suggests that ferritin interacted with few proteins which are directly and indirectly involved in M. tuberculosis growth, Iron assimilation, virulence, resistance, stresses and latency.

  10. Habitable zones in the universe.

    PubMed

    Gonzalez, Guillermo

    2005-12-01

    Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the concept of the habitable zone was key to progress in this area. The habitable zone concept was first applied to the space around a star, now called the Circumstellar Habitable Zone. Recently, other, vastly broader, habitable zones have been proposed. We review the historical development of the concept of habitable zones and the present state of the research. We also suggest ways to make progress on each of the habitable zones and to unify them into a single concept encompassing the entire universe.

  11. Breathing zone air sampler

    SciTech Connect

    Tobin, J.

    1989-08-22

    A sampling apparatus is presented which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  12. [Foot reflex zone massage].

    PubMed

    Kesselring, A

    1994-01-01

    Foot reflexology is defined as massage of zones on the feet which correspond to different parts of the body. A medline-search yielded no literature in the field of foot reflexology. Indications for and results of foot reflexology have been extrapolated from case-descriptions and two pilot studies with small samples. One study (Lafuente et al.) found foot reflexology to be as helpful to patients with headaches as medication (flunarizine), yet foot reflexology was fraught with less side-effects than medication. In a second study (Eichelberger et al.) foot reflexology was used postoperatively on gynecological patients. The intervention group showed a lesser need for medication to enhance bladder tonus than did the control group. The literature describes foot reflexology as enhancing urination, bowel movements and relaxation.

  13. Breathing zone air sampler

    DOEpatents

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  14. Human impacts on the tundra-taiga zone dynamics: the case of the Russian lesotundra.

    PubMed

    Vlassova, T K

    2002-08-01

    The tundra-taiga zone is considered not only as a natural ecotone, but as a unique fringe zone with socioeconomic peculiarities. This holistic approach enables us to analyze several significant types of human impacts (industrial impacts and those associated with renewable resources development, including traditional reindeer herding and human settlements) and their role in the displacement of the lesotundra zone. In Russia, there is much evidence of deforestation and ecosystem degradation in different regions of the lesotundra zone and the northern taiga which borders the lesotundra zone. One indicator of this is that in the Archangelsk region and the Komi Republic, the observed current southern border of the lesotundra zone lies 40-100 km to the south of the southern boundary of the Protection Belt of Pretundra Forests, established in 1959. Human impacts also displace the northern boundary of the lesotundra zone (the boundary with the tundra zone) to the south. As a result, according to published estimations, the total area of human-made tundra and lesotundra stretching from the Kola Peninsula to Chukotka, is c. 470-500,000 km2. The increases in man-made tundra lead to negative consequences for the sociocultural sustainability of the lesotundra zone, a decrease in the quality of life (notably for permanent residents and native people and increases in mortality and depopulation. It cannot be predicted with any certainty that climate warming in the tundra-taiga zone will lead to a northward movement of the boreal forest treeline. We need also to consider the human impacts discussed in this article, which may actually lead to a southward movement of the lesotundra zone.

  15. Land cover mapping, fire regeneration, and scaling studies in the Canadian boreal forest with 1 km AVHRR and Landsat TM data

    USGS Publications Warehouse

    Steyaert, L.T.; Hall, F.G.; Loveland, T.R.

    1997-01-01

    A multitemporal 1 km advanced very high resolution radiometer (AVHRR) land cover analysis approach was used as the b