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Sample records for sandy-clayey continental succession

  1. Distribution of petrophysical properties for sandy-clayey reservoirs by fractal interpolation

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    M. Lozada-Zumaeta

    2012-04-01

    Full Text Available The sandy-clayey hydrocarbon reservoirs of the Upper Paleocene and Lower Eocene located to the north of Veracruz State, Mexico, present highly complex geological and petrophysical characteristics. These reservoirs, which consist of sandstone and shale bodies within a depth interval ranging from 500 to 2000 m, were characterized statistically by means of fractal modeling and geostatistical tools. For 14 wells within an area of study of approximately 6 km2, various geophysical well logs were initially edited and further analyzed to establish a correlation between logs and core data. The fractal modeling based on the R/S (rescaled range methodology and the interpolation method by successive random additions were used to generate pseudo-well logs between observed wells. The application of geostatistical tools, sequential Gaussian simulation and exponential model variograms contributed to estimate the spatial distribution of petrophysical properties such as effective porosity (PHIE, permeability (K and shale volume (VSH. From the analysis and correlation of the information generated in the present study, it can be said, from a general point of view, that the results not only are correlated with already reported information but also provide significant characterization elements that would be hardly obtained by means of conventional techniques.

  2. An accurately delineated Permian-Triassic Boundary in continental successions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Permian-Triassic Boundary Stratigraphic Set (PTBST), characteristic of the GSSP section of Meishan and widespread in marine Permian-Triassic Boundary (PTB) sequences of South China, is used to trace and recognize the PTB in a continental sequence at Chahe (Beds 66f―68c). Diversified Permian plant fossils extended to the PTBST, and a few relicts survived above that level. Sporomorphs are dominated by fern spores of Permian nature below the PTBST, above which they are replaced by gymnosperm pollen of Triassic aspect. In the nearby Zhejue Section, the continental PTBST is characterized by the fungal 'spike' recorded in many places throughout the world. The boundary claybeds (66f and 68a,c) of the PTBST are composed of mixed illite-montmorillonite layers analogous with those at Meishan. They contain volcanogenic minerals such as β quartz and zircon. U/Pb dating of the upper claybed gives ages of 247.5 and 252.6 Ma for Beds 68a and 68c respectively, averaging 250 Ma. In contrast to the situation in Xinjiang and South Africa, the sediment sequence of the Permian-Triassic transition in the Chahe section (Beds 56―80) become finer upward. Shallowing and coarsening upward is not, therefore, characteristic of the Permian-Triassic transition everywhere. The occurrence of relicts of the Gigantopteris Flora in the Kayitou Fm. indicates that, unlike most marine biota, relicts of this paleophytic flora survived into the earliest Triassic. It is concluded that Bed 67 at Chahe corresponds to Bed 27 at Meishan, and that the PTB should be put within the 60-cm-thick Bed 67b④, now put at its base tentatively. This is the most accurate correlation of the PTB in continental facies with that in the marine GSSP.

  3. Continental growth by successive accretion of oceanic lithosphere: Evidence from tilted seismic anisotropy

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    Babuska, V.; Plomerova, J.; Karato, S. I.

    2012-04-01

    Although many studies indicate that subduction-related accretion, subduction-driven magmatism and tectonic stacking are major crustal-growth mechanisms, how the mantle lithosphere forms remains enigmatic. Cook (AGU Geod. Series 1986) published a model of continental 'shingling' based on seismic reflection data indicating dipping structures in the deep crust of accreted terranes. Helmstaedt and Gurney (J. Geoch. Explor. 1995) and Hart et al. (Geology 1997) suggest that the Archean continental lithosphere consists of alternating layers of basalt and peridotite derived from subducted and obducted Archean oceanic lithosphere. Peridotite xenoliths from the Mojavian mantle lithosphere (Luffi et al., JGR 2009), as well as xenoliths of eclogites underlying the Sierra Nevada batholith in California (Horodynskij et al., EPSL 2007), are representative for oceanic slab fragments successively attached to the continent. Recent seismological findings also seem to support a model of continental lithosphere built from systems of paleosubductions of plates of ancient oceanic lithosphere (Babuska and Plomerova, AGU Geoph. Monograph 1989), or by stacking of the plates (Helmstaedt and Schulze, Geol. Soc. Aust. Spec. Publ. 1989). Seismic anisotropy in the oceanic mantle lithosphere, explained mainly by the olivine A- (or D-) type fabric (Karato et al., Annu. Rev. Earth Planet. Sci. 2008), was discovered almost a half century ago (Hess, Nature 1964). Though it is difficult to determine seismic anisotropy within an active subducting slab (e.g., Healy et al., EPSL 2009; Eberhart-Phillips and Reyners, JGR 2009), field observations and laboratory experiments indicate the oceanic olivine fabric might be preserved there to a depth of at least 200-300 km. Dipping anisotropic fabrics in domains of the European mantle lithosphere were interpreted as systems of 'frozen' paleosubductions (Babuska and Plomerova, PEPI 2006), and the lithosphere base as a boundary between a fossil anisotropy in the

  4. Lead exposure in bald eagles from big game hunting, the continental implications and successful mitigation efforts.

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    Bedrosian, Bryan; Craighead, Derek; Crandall, Ross

    2012-01-01

    Studies suggest hunter discarded viscera of big game animals (i.e., offal) is a source of lead available to scavengers. We investigated the incidence of lead exposure in bald eagles in Wyoming during the big game hunting season, the influx of eagles into our study area during the hunt, the geographic origins of eagles exposed to lead, and the efficacy of using non-lead rifle ammunition to reduce lead in eagles. We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005-2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (>60 ug/dL) during the hunt while no birds did during the non-hunting seasons. We performed driving surveys from 2009-2010 to measure eagle abundance and found evidence to suggest that eagles are attracted to the study area during the hunt. We fitted 10 eagles with satellite transmitters captured during the hunt and all migrated south after the cessation of the hunt. One returned to our study area while the remaining nine traveled north to summer/breed in Canada. The following fall, 80% returned to our study area for the hunting season, indicating that offal provides a seasonal attractant for eagles. We fitted three local breeding eagles with satellite transmitters and none left their breeding territories to feed on offal during the hunt, indicating that lead ingestion may be affecting migrants to a greater degree. During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles.

  5. Lead exposure in bald eagles from big game hunting, the continental implications and successful mitigation efforts.

    Directory of Open Access Journals (Sweden)

    Bryan Bedrosian

    Full Text Available Studies suggest hunter discarded viscera of big game animals (i.e., offal is a source of lead available to scavengers. We investigated the incidence of lead exposure in bald eagles in Wyoming during the big game hunting season, the influx of eagles into our study area during the hunt, the geographic origins of eagles exposed to lead, and the efficacy of using non-lead rifle ammunition to reduce lead in eagles. We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005-2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (>60 ug/dL during the hunt while no birds did during the non-hunting seasons. We performed driving surveys from 2009-2010 to measure eagle abundance and found evidence to suggest that eagles are attracted to the study area during the hunt. We fitted 10 eagles with satellite transmitters captured during the hunt and all migrated south after the cessation of the hunt. One returned to our study area while the remaining nine traveled north to summer/breed in Canada. The following fall, 80% returned to our study area for the hunting season, indicating that offal provides a seasonal attractant for eagles. We fitted three local breeding eagles with satellite transmitters and none left their breeding territories to feed on offal during the hunt, indicating that lead ingestion may be affecting migrants to a greater degree. During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles.

  6. Lead Exposure in Bald Eagles from Big Game Hunting, the Continental Implications and Successful Mitigation Efforts

    Science.gov (United States)

    Bedrosian, Bryan; Craighead, Derek; Crandall, Ross

    2012-01-01

    Studies suggest hunter discarded viscera of big game animals (i.e., offal) is a source of lead available to scavengers. We investigated the incidence of lead exposure in bald eagles in Wyoming during the big game hunting season, the influx of eagles into our study area during the hunt, the geographic origins of eagles exposed to lead, and the efficacy of using non-lead rifle ammunition to reduce lead in eagles. We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005–2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (>60 ug/dL) during the hunt while no birds did during the non-hunting seasons. We performed driving surveys from 2009–2010 to measure eagle abundance and found evidence to suggest that eagles are attracted to the study area during the hunt. We fitted 10 eagles with satellite transmitters captured during the hunt and all migrated south after the cessation of the hunt. One returned to our study area while the remaining nine traveled north to summer/breed in Canada. The following fall, 80% returned to our study area for the hunting season, indicating that offal provides a seasonal attractant for eagles. We fitted three local breeding eagles with satellite transmitters and none left their breeding territories to feed on offal during the hunt, indicating that lead ingestion may be affecting migrants to a greater degree. During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles. PMID:23284837

  7. Tectonostratigraphic evolution of Cenozoic marginal basin and continental margin successions in the Bone Mountains, Southwest Sulawesi, Indonesia

    Science.gov (United States)

    van Leeuwen, Theo M.; Susanto, Eko S.; Maryanto, Sigit; Hadiwisastra, Sapri; Sudijono; Muhardjo; Prihardjo

    2010-06-01

    The Bone Mountains, located in Southwest Sulawesi along the SE margin of Sundaland, are composed of Oligocene to possibly lower Miocene marginal basin successions (Bone Group) that are juxtaposed against continental margin assemblages of Eocene-Miocene age (Salokalupang Group). Three distinct units make up the latter: (i) Middle-Upper Eocene volcaniclastic sediments with volcanic and limestone intercalations in the upper part (Matajang Formation), reflecting a period of arc volcanism and carbonate development along the Sundaland margin; (ii) a well-bedded series of Oligocene calc-arenites (Karopa Formation), deposited in a passive margin environment following cessation of volcanic activity, and (iii) a series of Lower-Middle Miocene sedimentary rocks, in part turbiditic, which interfinger in the upper part with volcaniclastic and volcanic rocks of potassic affinity (Baco Formation), formed in an extensional regime without subduction. The Bone Group consists of MORB-like volcanics, showing weak to moderate subduction signatures (Kalamiseng Formation), and a series of interbedded hemipelagic mudstones and volcanics (Deko Formation). The Deko volcanics are in part subduction-related and in part formed from melting of a basaltic precursor in the overriding crust. We postulate that the Bone Group rocks formed in a transtensional marginal basin bordered by a transform passive margin to the west (Sundaland) and by a newly initiated westerly-dipping subduction zone on its eastern side. Around 14-13 Ma an extensional tectonic event began in SW Sulawesi, characterized by widespread block-faulting and the onset of potassic volcanism. It reached its peak about 1 Ma year later with the juxtaposition of the Bone Group against the Salokalupang Group along a major strike-slip fault (Walanae Fault Zone). The latter group was sliced up in variously-sized fragments, tilted and locally folded. Potassic volcanism continued up to the end of the Pliocene, and locally into the Quaternary.

  8. Detachment within subducted continental crust and multi-slice successive exhumation of ultrahigh-pressure metamorphic rocks: Evidence from the Dabie-Sulu orogenic belt

    Institute of Scientific and Technical Information of China (English)

    LIU YiCan; LI ShuGuang

    2008-01-01

    Although tectonic models were presented for exhumation of ultrahigh-pressure (UHP) metamorphic rocks during the continental collision, there is increasing evidence for the decoupling between crustal slices at various depths within deeply subducted continental crust. This lends support to the multi-slice successive exhumation model of the UHP metamorphic rocks in the Dabie-Sulu orogen. The available evidence is summarized as follows: (1) the low-grade metamorphic slices, which have geotectonic af-finity to the South China Block and part of them records the Triassic metamorphism, occur in the northern margin of the Dabie-Sulu UHP metamorphic zone, suggesting decoupling of the upper crust from the underlying basement during the initial stages of continental subduction; (2) the Dabie and Sulu HP to UHP metamorphic zones comprise several HP to UHP slices, which have an increased trend of metamorphic grade from south to north but a decreased trend of peak metamorphic ages corre-spondingly; and (3) the Chinese Continental Science Drilling (CCSD) project at Donghai in the Sulu orogen reveals that the UHP metamorphic zone is composed of several stacked slices, which display distinctive high and low radiogenic Pb from upper to lower parts in the profile, suggesting that these UHP crustal slices were derived from the subducted upper and middle crusts, respectively. Detachment surfaces within the deeply subducted crust may occur either along an ancient fault as a channel of fluid flow, which resulted in weakening of mechanic strength of the rocks adjacent to the fault due to fluid-rock interaction, or along the low-viscosity zones which resulted from variations of geotherms and lithospheric compositions at different depths. The multi-slice successive exhumation model is different from the traditional exhumation model of the UHP metamorphic rocks in that the latter as-sumes the detachment of the entire subducted continental crust from the underlying mantle lithosphere and its

  9. Successes, challenges and needs regarding rural health medical education in continental Central America: a literature review and narrative synthesis.

    Science.gov (United States)

    Colon-Gonzalez, Maria C; El Rayess, Fadya; Guevara, Sara; Anandarajah, Gowri

    2015-01-01

    expertise is present in this region. However, numerous challenges limit sustainability or expansion of successful programs. Common challenges include: (a) physicians' exposure to rural medicine primarily takes place during social service commitment time, rather than during formal medical training; (b) innovative educational programs are often not sustainable due to financial and leadership challenges; (c) the majority of physician manpower is in urban areas, resulting in few rural physician role models and teachers; and (d) there is insufficient collaboration to establish clinical and educational systems to meet rural health needs. Recurring suggestions for curricular changes include: (a) making primary care training a core component of medical school education; and (b) expanding medical school curricula in cross-cultural communication and social determinants of disease. Suggestions for health system changes include: (a) improving living and working conditions for rural physicians; and (b) establishing partnerships between educational, governmental and non-governmental organizations and rural community leadership, to promote rural health training and systems. Expertise in rural medicine and training exists in continental Central America. However, there are numerous challenges to improving medical education to meet the needs of rural communities. Overcoming these challenges will require creative solutions, new partnerships, and evaluation and dissemination of successful educational programs. There is a great need for further research on this topic.

  10. In search of the Upper Pleistocene GSSP: bridging the gap in the correlation of Marine and Continental sedimentary successions

    Science.gov (United States)

    Negri, Alessandra; Amorosi, Alessandro; Bertini, Adele; Florindo, Fabio; Lurcock, Pontus; Marabini, Stefano; Mastronuzzi, Giuseppe; Morigi, Caterina; Rossi, Veronica; Sangiorgi, Francesca; Zanchetta, Giovanni; Battista Vai, Gian

    2016-04-01

    The Upper Pleistocene Subseries/Subepoch is still lacking a formal Global Boundary Stratotype Section and Point (GSSP), the necessary internationally agreed reference point on a stratigraphic section, which defines its lower boundary. Analyses performed by our group seem to indicate that the "Fronte" section (Taranto, Italy) has very high potential to contain such GSSP. We have already achieved a pretty complete stratigraphic framework at the Fronte site where data acquisition have been based on a classical biostratigraphic methodology using a multidisciplinary approach: calcareous nannofossils, planktonic and benthic foraminifera, pollen and dinoflagellate cysts. These data have been then integrated with facies analysis, stable oxygen isotopes and paleomagnetism. We will present these results and the future perspectives of this work aiming to compare our data and set the criteria for extending the correlation between the "Fronte" and other time equivalent marine and continental sections. This will allow to add all the necessary requirements to candidate the section for the Upper Pleistocene GSSP.

  11. Fault kinematics and depocenter evolution of oil-bearing, continental successions of the Mina del Carmen Formation (Albian) in the Golfo San Jorge basin, Argentina

    Science.gov (United States)

    Paredes, José Matildo; Plazibat, Silvana; Crovetto, Carolina; Stein, Julián; Cayo, Eric; Schiuma, Ariel

    2013-10-01

    Up to 10% of the liquid hydrocarbons of the Golfo San Jorge basin come from the Mina del Carmen Formation (Albian), an ash-dominated fluvial succession preserved in a variably integrated channel network that evolved coeval to an extensional tectonic event, poorly analyzed up to date. Fault orientation, throw distribution and kinematics of fault populations affecting the Mina del Carmen Formation were investigated using a 3D seismic dataset in the Cerro Dragón field (Eastern Sector of the Golfo San Jorge basin). Thickness maps of the seismic sub-units that integrate the Mina del Carmen Formation, named MEC-A-MEC-C in ascending order, and mapping of fluvial channels performed applying geophysical tools of visualization were integrated to the kinematical analysis of 20 main normal faults of the field. The study provides examples of changes in fault throw patterns with time, associated with faults of different orientations. The "main synrift phase" is characterized by NE-SW striking (mean Az = 49°), basement-involved normal faults that attains its maximum throw on top of the volcanic basement; this set of faults was active during deposition of the Las Heras Group and Pozo D-129 formation. A "second synrift phase" is recognized by E-W striking normal faults (mean Az = 91°) that nucleated and propagated from the Albian Mina del Carmen Formation. Fault activity was localized during deposition of the MEC-A sub-unit, but generalized during deposition of MEC-B sub-unit, producing centripetal and partially isolated depocenters. Upward decreasing in fault activity is inferred by more gradual thickness variation of MEC-C and the overlying Lower Member of Bajo Barreal Formation, evidencing passive infilling of relief associated to fault boundaries, and conformation of wider depocenters with well integrated networks of channels of larger dimensions but random orientation. Lately, the Mina del Carmen Formation was affected by the downward propagation of E-W to ESE-WNW striking

  12. Carbon isotope signatures of latest Permian marine successions of the Southern Alps suggest a continental runoff pulse enriched in land plant material

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    S. H. Kraus

    2013-02-01

    Full Text Available The latest Permian mass extinction, the most severe Phanerozoic biotic crisis, is marked by dramatic changes in palaeoenvironments. These changes significantly disrupted the global carbon cycle, reflected by a prominent and well known negative carbon isotope excursion recorded in marine and continental sediments. Carbon isotope trends of bulk carbonate and bulk organic matter in marine deposits of the European Southern Alps near the low-latitude marine event horizon deviate from each other. A positive excursion of several permil in δ13Corg starts earlier and is much more pronounced than the short-term positive 13Ccarb excursion; both excursions interrupt the general negative trend. Throughout the entire period investigated, 13Corg values become lighter with increasing distance from the palaeocoastline. Changing 13Corg values may be due to the influx of comparatively isotopically heavy land plant material. The stronger influence of land plant material on the 13Corg during the positive isotope excursion indicates a temporarily enhanced continental runoff that may either reflect increased precipitation, possibly triggered by aerosols originating from Siberian Trap volcanism, or indicate higher erosion rate in the face of reduced land vegetation cover. doi:10.1002/mmng.201300004

  13. Links between the recruitment success of northern European hake (Merluccius merluccius L.) and a regime shift on the NE Atlantic continental shelf

    KAUST Repository

    Goikoetxea, Nerea

    2013-07-01

    The distribution of northern European hake (Merluccius merluccius L.) extends from the Bay of Biscay up to Norwegian waters. However, despite its wide geographical distribution, there have been few studies on fluctuations in the European hake populations. Marine ecosystem shifts have been investigated worldwide and their influence on trophic levels has been studied, from top predator fish populations down to planktonic prey species, but there is little information on the effect of atmosphere-ocean shifts on European hake. This work analyses hake recruitment success (recruits per adult biomass) in relation to environmental changes over the period 1978-2006 in order to determine whether the regime shift identified in several abiotic and biotic variables in the North Sea also affected the Northeast Atlantic shelf oceanography. Hake recruitment success as well as parameters such as the sea surface temperature, wind patterns and copepod abundance changed significantly at the end of the 1980s, demonstrating an ecological regime shift in the Northeast Atlantic. Despite the low reproductive biomass recorded during the last decades, hake recruitment success has been higher since the change in 1989/90. The higher productivity may have sustained the population despite the intense fishing pressure; copepod abundance, warmer water temperatures and moderate eastward transport were found to be beneficial. In conclusion, in 1988/89 the Northeast Atlantic environment shifted to a favourable regime for northern hake production. This study supports the hypothesis that the hydro-climatic regime shift that affected the North Sea in the late 1980s may have influenced a wider region, such as the Northeast Atlantic. © 2013 John Wiley & Sons Ltd.

  14. Late Aptian palaeoclimatic turnovers and volcanism: Insights from a shallow-marine and continental succession of the Apennine carbonate platform, southern Italy

    Science.gov (United States)

    Graziano, Roberto; Raspini, Arturo; Bartiromo, Antonello

    2016-06-01

    This study reports an integrated facies analysis carried out on a new section from the Upper Aptian of the SE Matese Mts. (Civitella Licinio, northern Campania, S. Italy), which includes several decimeter-to-meter scale lacustrine intervals straddling a meter-scale plant-rich Plattenkalk. These intervals are assigned to the late Gargasian-early Clansayesian by their stratigraphic relationship with the upper Salpingoporella dinarica acme as well as lithologic and biostratigraphic supra-regional key-markers found in the Apennine Carbonate Platform (ApCP), including the Orbitolina Level. We infer that the monogeneric parautochthonous plant remains (Frenelopsis sp.) were deposited in a supratidal-to-paralic coastal mudflat close to a restricted, shallow-marine lagoon, at the verge of an arid-semiarid climatic phase. The Plattenkalk was rapidly replaced by persistent lacustrine lithofacies at the onset of a major climatic turnover (Glacial Trigger). The overlying shallow-marine deposits are capped by a deeply incised palaeokarstic surface and, in turn, by unconformable middle Clansayesian transgressive shallow-marine deposits. Interlayering of reliable lithologic indicators of palaeoclimate and High-Resolution Event Stratigraphic (HIRES) correlation of the Civitella Licinio succession with the astrochronologically tuned Mt. Faito reference section of the ApCP bring evidence of rapidly fluctuating hydroclimatic conditions (wet and arid phases) in the short (100 ky) and long (400 ky) eccentricity time band. HIRES and astrochronological age assignment to crucial key markers and humid/arid phases at Civitella Licinio permit to further refine the detailed stratigraphy of the Mt. Faito reference section and to assign the upper S. dinarica acme of the ApCP to a numerical age of 118.55-118.50 My. SEM and EDS analyses document common to abundant windblown volcanic particles (glass shards and sanidine crystals) throughout the Frenelopsis-rich Plattenkalk (~ 118.3 to ~ 118.2 My

  15. Continental Divide Trail

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This shapefile was created to show the proximity of the Continental Divide to the Continental Divide National Scenic Trail in New Mexico. This work was done as part...

  16. Continental sedimentary successions exposed in Centinela del Mar, Buenos Aires, Argentina (Lower Pleistocene - Holocene); Las sucesiones sedimentarias continentales expuestas en Centinela del Mar, provincia de Buenos Aires, Argentina (Pleistoceno Inferior-Holoceno)

    Energy Technology Data Exchange (ETDEWEB)

    Cenizo, M. M.

    2011-07-01

    In the present paper, the geomorphologic and sedimentary characteristics of the continental sequences exposed on the coastal cliffs and surrounding areas of the Centinela del Mar locality are described and interpreted. Fourteen lithofacies are defined, their relation, geometry and structure are represented using transversal and longitudinal detailed profiles. In the basal and medium sector of the profile, facies of different degrees of transport and aqueous rework were recognized. In the superior sector, a succession of marine peri-coastal facies corresponding to the Belgranense transgression (=Fm. Pascua) were identified, ending the sequence with relictual eolic facies. The different historical interpretations are discussed, homologating the units referred previously with the ones proposed on this paper. These units are correlated with those defined in the allostratigrapic scheme proposed by other authors for the area covered between Playa San Carlos and Arroyo Chapadmalal. This allowed recognize for the area under study the presence of the Punta San Andres and Arroyo Loberia Alloformations (basal-medium and superior sector, respectively). Between these two entities, a association of well defined progradant marine facies are found and named on this paper as Centinela del Mar Alloformation. Finally, periferithe information gathered here (magnetostratigraphy, radiometric dating, stratigraphic correlations, etc) indicates, at least preliminarily, that the sequence of Centinela del Mar corresponds to the Ensenadense- Lujanense interval (Lower Pleistocene - Holocene). (Author) 73 refs.

  17. Freshly brewed continental crust

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    Gazel, E.; Hayes, J. L.; Caddick, M. J.; Madrigal, P.

    2015-12-01

    Earth's crust is the life-sustaining interface between our planet's deep interior and surface. Basaltic crusts similar to Earth's oceanic crust characterize terrestrial planets in the solar system while the continental masses, areas of buoyant, thick silicic crust, are a unique characteristic of Earth. Therefore, understanding the processes responsible for the formation of continents is fundamental to reconstructing the evolution of our planet. We use geochemical and geophysical data to reconstruct the evolution of the Central American Land Bridge (Costa Rica and Panama) over the last 70 Ma. We also include new preliminary data from a key turning point (~12-6 Ma) from the evolution from an oceanic arc depleted in incompatible elements to a juvenile continental mass in order to evaluate current models of continental crust formation. We also discovered that seismic P-waves (body waves) travel through the crust at velocities closer to the ones observed in continental crust worldwide. Based on global statistical analyses of all magmas produced today in oceanic arcs compared to the global average composition of continental crust we developed a continental index. Our goal was to quantitatively correlate geochemical composition with the average P-wave velocity of arc crust. We suggest that although the formation and evolution of continents may involve many processes, melting enriched oceanic crust within a subduction zone, a process probably more common in the Achaean where most continental landmasses formed, can produce the starting material necessary for juvenile continental crust formation.

  18. The Myanmar continental shelf

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; Rao, P.S.

    conditions, and neotectonic activity. The most prominent bathymetric feature on the Ayeyarwady continental shelf is the 120 km-wide Martaban Depression, at the centre of which is located the Martaban Canyon. Most of the suspended sediment discharge...

  19. Continental Scientific Drilling Program.

    Science.gov (United States)

    1979-01-01

    Resource Priorities in Continental Drilling J. J. Hemley 12 Aspects of Continental Crustal Structure and Growth Scott Smithson 13 Deep-Drilling Targets...Time of Workshop Allen F. Agnew Library of Congress Clarence R. Allen California Institute of Technology Orson L. Anderson University of California at...Skinner Yale University Norman H. Sleep Northwestern University Laurence L. Sloss Northwestern University Scott B. Smithson University of Wyoming

  20. Raising the continental crust

    Science.gov (United States)

    Campbell, Ian H.; Davies, D. Rhodri

    2017-02-01

    The changes that occur at the boundary between the Archean and Proterozoic eons are arguably the most fundamental to affect the evolution of Earth's continental crust. The principal component of Archean continental crust is Granite-Greenstone Terranes (GGTs), with granites always dominant. The greenstones consist of a lower sequence of submarine komatiites and basalts, which erupted onto a pre-existing Tonalite-Trondhjemite-Granodiorite (TTG) crust. These basaltic rocks pass upwards initially into evolved volcanic rocks, such as andesites and dacites and, subsequently, into reworked felsic pyroclastic material and immature sediments. This transition coincides with widespread emplacement of granitoids, which stabilised (cratonised) the continental crust. Proterozoic supra-crustal rocks, on the other hand, are dominated by extensive flat-lying platform sequences of mature sediments, which were deposited on stable cratonic basements, with basaltic rocks appreciably less abundant. The siliceous TTGs cannot be produced by direct melting of the mantle, with most hypotheses for their origin requiring them to be underlain by a complimentary dense amphibole-garnet-pyroxenite root, which we suggest acted as ballast to the early continents. Ubiquitous continental pillow basalts in Archean lower greenstone sequences require the early continental crust to have been sub-marine, whereas the appearance of abundant clastic sediments, at higher stratigraphic levels, shows that it had emerged above sea level by the time of sedimentation. We hypothesise that the production of komatiites and associated basalts, the rise of the continental crust, widespread melting of the continental crust, the onset of sedimentation and subsequent cratonisation form a continuum that is the direct result of removal of the continent's dense amphibole-garnet-pyroxenite roots, triggered at a regional scale by the arrival of a mantle plume at the base of the lithosphere. Our idealised calculations suggest

  1. THERMAL CONTINENTALISM IN EUROPE

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    APOSTOL L.

    2015-03-01

    Full Text Available In the context of current climate changes, this article aims to highlight the continental characteristics of Europe’s climate (including a temporal evolution, regarding the multiannual thermal averages. For this purpose, 78 meteorological stations have been selected, placed approximately on two pairs of transects on West-East and South-North directions. The data were extracted from www.giss.nasa.gov (NASA Goddard Institute for Space Studies, statistically processed (Open Office and mapped (www.saga-gis.org. For the lapse of time 1961-2010, the analysis of multiannual temperature averages has shown the following: if the multiannual average temperature is strongly influenced by latitude, its deviations are more dependent on longitude; the multiannual average thermal amplitude, as well as the Gorczynski continentality index, are strongly related to longitude; their temporal evolution has shown a significant decrease in the Eastern half of the continent and an increase (although less significant in Western Europe.

  2. Cyclic growth in Atlantic region continental crust

    Science.gov (United States)

    Goodwin, A. M.

    1986-01-01

    Atlantic region continental crust evolved in successive stages under the influence of regular, approximately 400 Ma-long tectonic cycles. Data point to a variety of operative tectonic processes ranging from widespread ocean floor consumption (Wilson cycle) to entirely ensialic (Ampferer-style subduction or simple crustal attenuation-compression). Different processes may have operated concurrently in some or different belts. Resolving this remains the major challenge.

  3. The continental lithosphere

    DEFF Research Database (Denmark)

    Artemieva, Irina

    2009-01-01

    The goal of the present study is to extract non-thermal signal from seismic tomography models in order to distinguish compositional variations in the continental lithosphere and to examine if geochemical and petrologic constraints on global-scale compositional variations in the mantle are consist......The goal of the present study is to extract non-thermal signal from seismic tomography models in order to distinguish compositional variations in the continental lithosphere and to examine if geochemical and petrologic constraints on global-scale compositional variations in the mantle...... are consistent with modern geophysical data. In the lithospheric mantle of the continents, seismic velocity variations of a non-thermal origin (calculated from global Vs seismic tomography data [Grand S.P., 2002. Mantle shear-wave tomography and the fate of subducted slabs. Philosophical Transactions...... of the Royal Society of London. Series A, 360, 2475–2491.; Shapiro N.M., Ritzwoller M.H. 2002. Monte-Carlo inversion for a global shear velocity model of the crust and upper mantle. Geophysical Journal International 151, 1–18.] and lithospheric temperatures [Artemieva I.M., Mooney W.D., 2001. Thermal structure...

  4. Southeast continental shelf studies

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, D.W.

    1979-02-12

    Research efforts on the southeast continental shelf currently describe the manner in which fluctuations in Gulf Stream motion influence biological and chemical processes. Current meter arrays are maintained in the Georgia Bight and in Onslow Bay to describe general circulation patterns and to identify forcing functions. biological studies describe processes affecting temporal and spatial variations on the shelf and have attempted to track the biological history of intruded Gulf Stream water masses. Chemical studies examine the influence of both physical and biological variables on the distribution and fate of trace elements. The current state of knowledge is reviewed, the hypotheses developed and are described, a rationale for testing these hypotheses is given. 1 figure, 1 table.

  5. NSF Continental Lithosphere Program

    Science.gov (United States)

    Mayhew, Michael; MacGregor, Ian

    For several months the Continental Lithosphere Program (CL) of the National Science Foundation has been subject to a major review. The process was stimulated by a series of budget setbacks over the past few years. Although Presidential budget requests have been very favorable for the Division of Earth Sciences (EAR), and there has been strong support within the National Science Foundation and Congress, actual appropriations by Congress have been disappointing.In each year the final allocation to EAR has been affected by external factors beyond the control of the Foundation. In the four fiscal years from 1986 through 1989 the factors include reductions tied to the Gramm-Rudman deficit reduction measures, congressional reaction to the October 1987 stock market crash, and two years of protection for the Ocean Sciences part of the NSF budget that was paid for from the budgets of the Atmospheric and Earth Sciences divisions.

  6. Palaeomagnetism and the continental crust

    Energy Technology Data Exchange (ETDEWEB)

    Piper, J.D.A.

    1987-01-01

    This book is an introduction to palaeomagnetism offering treatment of theory and practice. It analyzes the palaeomagnetic record over the whole of geological time, from the Archaean to the Cenozoic, and goes on to examine the impact of past geometries and movements of the continental crust at each geological stage. Topics covered include theory of rock and mineral magnetism, field and laboratory methods, growth and consolidation of the continental crust in Archaean and Proterozoic times, Palaeozoic palaeomagnetism and the formation of Pangaea, the geomagnetic fields, continental movements, configurations and mantle convection.

  7. The continental record and the generation of continental crust

    OpenAIRE

    Cawood, Peter Anthony; Hawkesworth, Chris; Dhuime, Bruno Philippe Marcel

    2013-01-01

    Continental crust is the archive of Earth history. The spatial and temporal distribution of Earth's record of rock units and events is heterogeneous; for example, ages of igneous crystallization, metamorphism, continental margins, mineralization, and seawater and atmospheric proxies are distributed about a series of peaks and troughs. This distribution reflects the different preservation potential of rocks generated in different tectonic settings, rather than fundamental pulses of activity, a...

  8. Dynamics of continental accretion.

    Science.gov (United States)

    Moresi, L; Betts, P G; Miller, M S; Cayley, R A

    2014-04-10

    Subduction zones become congested when they try to consume buoyant, exotic crust. The accretionary mountain belts (orogens) that form at these convergent plate margins have been the principal sites of lateral continental growth through Earth's history. Modern examples of accretionary margins are the North American Cordilleras and southwest Pacific subduction zones. The geologic record contains abundant accretionary orogens, such as the Tasmanides, along the eastern margin of the supercontinent Gondwana, and the Altaïdes, which formed on the southern margin of Laurasia. In modern and ancient examples of long-lived accretionary orogens, the overriding plate is subjected to episodes of crustal extension and back-arc basin development, often related to subduction rollback and transient episodes of orogenesis and crustal shortening, coincident with accretion of exotic crust. Here we present three-dimensional dynamic models that show how accretionary margins evolve from the initial collision, through a period of plate margin instability, to re-establishment of a stable convergent margin. The models illustrate how significant curvature of the orogenic system develops, as well as the mechanism for tectonic escape of the back-arc region. The complexity of the morphology and the evolution of the system are caused by lateral rollback of a tightly arcuate trench migrating parallel to the plate boundary and orthogonally to the convergence direction. We find geological and geophysical evidence for this process in the Tasmanides of eastern Australia, and infer that this is a recurrent and global phenomenon.

  9. Continental United States Hurricane Strikes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Continental U.S. Hurricane Strikes Poster is our most popular poster which is updated annually. The poster includes all hurricanes that affected the U.S. since...

  10. Bioenergetics of Continental Serpentinites

    Science.gov (United States)

    Cardace, D.; Meyer-Dombard, D. R.

    2011-12-01

    Serpentinization is the aqueous alteration of ultramafic (Fe- and Mg-rich) rocks, resulting in secondary mineral assemblages of serpentine, brucite, iron oxyhydroxides and magnetite, talc, and possibly carbonate and silica-rich veins and other minor phases-all depending on the evolving pressure-temperature-composition of the system. The abiotic evolution of hydrogen and possibly organic compounds via serpentinization (McCollom and Bach, 2009) highlights the relevance of this geologic process to carbon and energy sources for the deep biosphere. Serpentinization may fuel life over long stretches of geologic time, throughout the global seabed and in exposed, faulted peridotite blocks (as at Lost City Hydrothermal Field, Kelley et al., 2005), and in obducted oceanic mantle units in ophiolites (e.g., Tiago et al., 2004). Relatively little work has been published on life in continental serpentinite settings, though they likely host a unique resident microbiota. In this work, we systematically model the serpentinizing fluid as an environmental niche. Reported field data for high and moderate pH serpentinizing fluids were modeled from Cyprus, the Philippines, Oman, Northern California, New Caledonia, Yugoslavia, Portugal, Italy, Newfoundland Canada, New Zealand, and Turkey. Values for Gibbs Energy of reaction (ΔGr), kJ per mole of electrons transferred for a given metabolism, are calculated for each field site. Cases are considered both for (1) modest assumptions of 1 nanomolar hydrogen and 1 micromolar methane, based on unpublished data for a similar northern California field site (Cardace and Hoehler, in prep.) and (2) an upper estimate of 10 nanomolar hydrogen and 500 micromolar methane. We survey the feasibility of microbial metabolisms for key steps in the nitrogen cycle, oxidation of sulfur in pyrite, iron oxidation or reduction reactions, sulfate reduction coupled to hydrogen or methane oxidation, methane oxidation coupled to the reduction of oxygen, and

  11. 76 FR 2919 - Outer Continental Shelf Official Protraction Diagram and Supplemental Official Outer Continental...

    Science.gov (United States)

    2011-01-18

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official Protraction Diagram and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY: Bureau of Ocean... American Datum of 1983 (NAD 83) Outer Continental Shelf Official Protraction Diagram and...

  12. Fifteen years of the Chinese Continental Scientific Drilling Program

    Science.gov (United States)

    Xu, Zhiqin; Yang, Jingsui; Wang, Chengshan; An, Zhisheng; Li, Haibing; Wang, Qin; Su, Dechen

    2017-05-01

    Continental scientific drilling can be regarded as a telescope into the Earth's interior because it provides process insight and uncompromised samples of rocks, fluids, and even sampled from the deep biosphere from the Earth's surface to great depths. As one of the three founding members of the International Continental Scientific Drilling Program (ICDP), ICDP China has made great achievements in many scientific drilling-related research fields. Based on the ICDP participation it attracted global attention of scientists and set up not only the Chinese Continental Scientific Drilling (CCSD) Program in 2001 but also a growing number of ambitious drilling projects in the country. The 5158 m deep borehole of the CCSD project at Donghai County in the Sulu ultrahigh-pressure metamorphic terrain demonstrates that large amounts of crustal rocks of the South China Block have been subducted to at least 120 km, followed by rapid uplift. After successful completion of drilling at Donghai, several continental scientific drilling projects were conducted with funding of the Chinese government and partially with support of ICDP, resulting in a total drilling depth of more than 35 000 m. These projects encompass the Continental Environmental Scientific Drilling Program of China, the Scientific Drilling Project of Wenchuan Earthquake Fault Zone, the Continental Scientific Drilling Project of Cretaceous Songliao Basin, and the Program of Selected Continental Scientific Drilling and Experiments. On the occasion of the 20th anniversary of the ICDP and the 15th anniversary of the CCSD Program, this paper reviews the history and major progress of the CCSD Program.

  13. Mantle plumes and continental tectonics.

    Science.gov (United States)

    Hill, R I; Campbell, I H; Davies, G F; Griffiths, R W

    1992-04-10

    Mantle plumes and plate tectonics, the result of two distinct modes of convection within the Earth, operate largely independently. Although plumes are secondary in terms of heat transport, they have probably played an important role in continental geology. A new plume starts with a large spherical head that can cause uplift and flood basalt volcanism, and may be responsible for regional-scale metamorphism or crustal melting and varying amounts of crustal extension. Plume heads are followed by narrow tails that give rise to the familiar hot-spot tracks. The cumulative effect of processes associated with tail volcanism may also significantly affect continental crust.

  14. Continental Rifts and Resources

    Science.gov (United States)

    Stein, Holly J.

    2017-04-01

    Nearly all resource-forming systems involve upward mobility of fluids and melts. In fact, one of the most effective means of chemically transforming the earth's crust can be readily observed in the rift environment. Imposition of rifting is based on deeper stresses that play out in the crust. At its most fundamental level, rifting transfers heat and fluids to the crust. Heat delivered by fluids aids both in transport of metal and maturation of hydrocarbons. The oxidizing capacity of fluids on their arrival in the deep crust, whether derived from old slabs, depleted upper mantle and/or deeper, more primitive mantle, is a fundamental part of the resource-forming equation. Oxidizing fluids transport some metals and breakdown kerogen, the precursor for oil. Reducing fluids transport a different array of metals. The tendency is to study the resource, not the precursor or the non-economic footprint. In doing so, we lose the opportunity to discover the involvement and significance of initiating processes; for example, externally derived fluids may produce widespread alteration in host rocks, a process that commonly precedes resource deposition. It is these processes that are ultimately the transferable knowledge for successful mineral and hydrocarbon exploration. Further limiting our understanding of process is the tendency to study large, highly complex, and economically successful ore-forming or petroleum systems. In order to understand their construction, however, it is necessary to put equal time toward understanding non-economic systems. It is the non-economic systems that often clearly preserve key processes. The large resource-forming systems are almost always characterized by multiple episodes of hydrothermal overprints, making it difficult if not impossible to clearly discern individual events. Understanding what geologic and geochemical features blocked or arrested the pathway to economic success or, even worse, caused loss of a resource, are critical to

  15. Seaweed culture and continental shelf protection

    Energy Technology Data Exchange (ETDEWEB)

    Przhemenetskaya, V.F.

    1985-07-01

    The initial impression that the resources of the oceans were limitless has been replaced by a more rational appreciation that everything has its limits, including the seemingly infinite resources of marine plant life. In addition, experience in California, Australia, China, Japan and Korea has demonstrated that depletion of seaweed resources for commercial utilization has a deleterious effect on the biocenotic status of the continental shelf. In view of this, many countries, such as Japan, China, Korea, the Philippines and the USSR, have embarked on aquaculture programs, in which seaweeds are cultivated on marine plantations. Successful developments in this direction should go a long way to preserving the natural ecologic balance on the continental shelf, and yet provide mankind with the resources of the deep. Many difficulties remain to be resolved before aquaculture programs become fully cost effective, one of which deals with the susceptibility of a monoculture to a given predator or disease. To that end, such programs necessitate the creation of well balanced systems that would support a variety of marine plant and animal life without an adverse effect on the desired crop. 4 references, 6 figures.

  16. Analog Modeling of Continental Lithosphere Subduction

    Science.gov (United States)

    Willingshofer, E.; Sokoutis, D.; Luth, S.; Beekman, F.; Cloetingh, S.

    2012-12-01

    Lithospheric-scale analog modeling sheds light on the consequences of decoupling within the continental lithosphere and along plate interfaces during continental collision. The model results provide valuable information in terms of strain localization, deformation of the subducting slab and the evolution and architecture of the overlying mountain belt and its topography. A weak layer has been implemented in three-layer models to simulate decoupling along the plate interface and at different levels of the lithosphere (brittle-ductile transition, entire lower crust, crust-mantle boundary). Additionally, varying the strength of the mantle lithosphere of both the upper as well as the lower plate regulated the degree of plate coupling. Plate boundaries were orthogonal to the convergence direction. All models emphasize that strong decoupling at the plate interface is a pre-requisite for the subduction of continental lithosphere. In addition, deformation of the subducting slab was found to be sensitive to the strength contrast between the subduction zone and the mantle lithosphere of the downgoing as well as the upper plate. As such, a low strength contrast between the plate interface and the lower plate leads to deformation of the subducting slab by thickening and the development of a shallow slab. Conversely, when the strength contrast is high, deep slabs evolve which undergo relatively less deformation. Furthermore, the level of decoupling in the downgoing plate governs how much continental crust is subducted together with the mantle lithosphere. Shallow decoupling, at the brittle-ductile transition, results in subduction of the lower crust whereas small amounts of lower crust are subducted when decoupling occurs at the level of the Moho. Weak plate coupling and a weak lower crust of the lower plate steer the evolution of mountain belts such that deformation propagates outward, in the direction of the incoming plate, by successive imbrication of upper crustal thrust

  17. Lithospheric structure and continental geodynamics

    Institute of Scientific and Technical Information of China (English)

    许忠淮; 石耀霖

    2003-01-01

    This paper briefly reviews main progress in the research on lithospheric structure and continental geodynamics made by Chinese geophysicists during last 4 years since 22nd IUGG general assembly in July 1999. The research mainly covers the following fields: investigations on regional lithospheric structure, DSS survey of crust and upper mantle velocity structure, study on present-day inner movement and deformation of Chinese mainland by analyzing GPS observations, geodynamics of Qingzang plateau, geophysical survey of the Dabie-Sulu ultra-high pressure metamorphic belt and probing into its formation mechanism, geophysical observations in sedimentary basins and study on their evolution process, and plate dynamics, etc.

  18. Thermal models pertaining to continental growth

    Science.gov (United States)

    Morgan, Paul; Ashwal, Lew

    1988-01-01

    Thermal models are important to understanding continental growth as the genesis, stabilization, and possible recycling of continental crust are closely related to the tectonic processes of the earth which are driven primarily by heat. The thermal energy budget of the earth was slowly decreasing since core formation, and thus the energy driving the terrestrial tectonic engine was decreasing. This fundamental observation was used to develop a logic tree defining the options for continental growth throughout earth history.

  19. 26 CFR 1.638-1 - Continental Shelf areas.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Continental Shelf areas. 1.638-1 Section 1.638-1...) INCOME TAXES (CONTINUED) Continental Shelf Areas § 1.638-1 Continental Shelf areas. (a) General rule. For.... The terms Continental Shelf of the United States and Continental Shelf of a possession of the United...

  20. Composition of the continental plates

    Science.gov (United States)

    Gilluly, J.

    1954-01-01

    The structures of continental plates and of oceanic basins suggested by several seismologists are utilized to estimate the relative volumes of sial and sima in the earth's crust. It seems that sial of the composition of the average igneous rock constitutes fully 26% and perhaps as much as 43% of the total crust. This ratio is far higher than seems likely if the sial had been entirely derived through fractional crystallization of a basaltic magma. The relative paucity of intermediate rocks as compared with granite and gabbro in the crust points in the same direction. The tentative conclusion is reached that the sial owes a large part of its volume to some process other than fractional crystallization of basalt-possibly to the emanation of low-melting constituents such as water, silica, potassa, soda, and alumina directly from the mantle to the crust. ?? 1954 Springer-Verlag.

  1. Deformation in the continental lithosphere

    Science.gov (United States)

    The Physical Properties of Earth Materials Committee, a technical committee of AGU's Tectonophysics Section, is organizing a dinner/colloquium as part of the Fall Meeting in San Francisco, Calif. This event will be held Monday, December 3rd, in the Gold Rush Room of the Holiday Inn Golden Gateway Hotel at 1500 Van Ness St. There will be a no-host bar from 6:30 to 7:30 P.M., followed by dinner from 7:30 to 8:30 P.M. Paul Tapponnier will deliver the after-dinner talk, “Large-Scale Deformation Mechanisms in the Continental Lithosphere: Where Do We Stand?” It will start at 8:30 P.M. and a business meeting will follow at 9:30 P.M.

  2. How Continental Bank outsourced its "crown jewels.".

    Science.gov (United States)

    Huber, R L

    1993-01-01

    No industry relies more on information than banking does, yet Continental, one of America's largest banks, outsources its information technology. Why? Because that's the best way to service the customers that form the core of the bank's business, says vice chairman Dick Huber. In the late 1970s and early 1980s, Continental participated heavily with Penn Square Bank in energy investments. When falling energy prices burst Penn Square's bubble in 1982, Continental was stuck with more than $1 billion in bad loans. Eight years later when Dick Huber came on board, Continental was working hard to restore its once solid reputation. Executives had made many tough decisions already, altering the bank's focus from retail to business banking and laying off thousands of employees. Yet management still needed to cut costs and improve services to stay afloat. Regulators, investors, and analysts were watching every step. Continental executives, eager to focus on the bank's core mission of serving business customers, decided to outsource one after another in-house service--from cafeteria services to information technology. While conventional wisdom holds that banks must retain complete internal control of IT, Continental bucked this argument when it entered into a ten-year, multimillion-dollar contract with Integrated Systems Solutions Corporation. Continental is already reaping benefits from outsourcing IT. Most important, Continental staffers today focus on their true core competencies: intimate knowledge of customers' needs and relationships with customers.

  3. Evolution of Oxidative Continental Weathering

    Science.gov (United States)

    Konhauser, Kurt; Lalonde, Stefan

    2014-05-01

    The Great Oxidation Event (GOE) is currently viewed as a protracted process during which atmospheric oxygen levels increased above 10-5 times the present atmospheric level. This value is based on the loss of sulphur isotope mass independent fractionation (S-MIF) from the rock record, beginning at 2.45 Ga and disappearing by 2.32 Ga. However, a number of recent papers have pushed back the timing for oxidative continental weathering, and by extension, the onset of atmospheric oxygenation several hundreds of million years earlier despite the presence of S-MIF (e.g., Crowe et al., 2013). This apparent discrepancy can, in part, be resolved by the suggestion that recycling of older sedimentary sulphur bearing S-MIF might have led to this signal's persistence in the rock record for some time after atmospheric oxygenation (Reinhard et al., 2013). Here we suggest another possibility, that the earliest oxidative weathering reactions occurred in environments at profound redox disequilibrium with the atmosphere, such as biological soil crusts, riverbed and estuarine sediments, and lacustrine microbial mats. We calculate that the rate of O2 production via oxygenic photosynthesis in these terrestrial microbial ecosystems provides largely sufficient oxidizing potential to mobilise sulphate and a number of redox-sensitive trace metals from land to the oceans while the atmosphere itself remained anoxic with its attendant S-MIF signature. These findings reconcile geochemical signatures in the rock record for the earliest oxidative continental weathering with the history of atmospheric sulphur chemistry, and demonstrate the plausible antiquity of a terrestrial biosphere populated by cyanobacteria. Crowe, S.A., Dossing, L.N., Beukes, N.J., Bau, M., Kruger, S.J., Frei, R. & Canfield, D.E. Atmospheric oxygenation three billion years ago. Nature 501, 535-539 (2013). Reinhard, C.T., Planavsky, N.J. & Lyons, T.W. Long-term sedimentary recycling of rare sulphur isotope anomalies. Nature 497

  4. 75 FR 61512 - Outer Continental Shelf Official Protraction Diagrams

    Science.gov (United States)

    2010-10-05

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official... Outer Continental Shelf Official Protraction Diagrams (OPDs) located within Atlantic Ocean areas, with... informational purposes only. Outer Continental Shelf Official Protraction Diagrams in the North Atlantic,...

  5. Sedimentological context of the continental sabkhas of Abu Dhabi

    Science.gov (United States)

    Lokier, Stephen; Paul, Andreas; Bixiao, Xin

    2017-04-01

    For more than half a century, the coastal sabkhas of Abu Dhabi have been the focus of intensive research focusing on deposition, early diagenesis and the role of microbial communities. Given all of this activity, it is somewhat surprising that their continental counterparts have been largely neglected with only a brief mention in larger-scale regional studies. This study redresses this imbalance by documenting the sedimentological, mineralogical and early diagenetic characteristics of continental sabkhas that are hosted in the Rub al Khali desert of the United Arab Emirates. During reconnaissance surveys it has been established that organic-rich microbial mats and evaporite minerals, both similar to those observed in the coastal sabkha, also occur in these continental sabkha settings. Satellite imagery was utilised to identify potential field locations for surface and shallow sub surface investigation; subsequent field reconnaissance established the validity of sites in terms of anthropogenic disruption and accessibility. At each site, surface features were described in detail, particularly with reference to any microbial communities or evaporite crusts; sample pits were dug in order to document sub-surface facies geometries and to recover both sediment and pore water samples for subsequent analysis. In each pit, a range of environmental parameters was measured over a prolonged period, including surface and sub-surface temperatures, ground water salinity and dissolved oxygen. Sediment samples were subjected to a range of analyses in order to establish and quantify primary sediment composition and any early diagenetic mineral phases. The results of this study are used to build an atlas of sedimentary structures and textures that are associated with continental sabkha settings. These observations allow us to establish the defining sedimentological and early diagenetic characteristics that can be employed to identify similar depositional environments in ancient

  6. Potential evapotranspiration and continental drying

    Science.gov (United States)

    Milly, P. C. D.; Dunne, K. A.

    2016-10-01

    By various measures (drought area and intensity, climatic aridity index, and climatic water deficits), some observational analyses have suggested that much of the Earth’s land has been drying during recent decades, but such drying seems inconsistent with observations of dryland greening and decreasing pan evaporation. `Offline’ analyses of climate-model outputs from anthropogenic climate change (ACC) experiments portend continuation of putative drying through the twenty-first century, despite an expected increase in global land precipitation. A ubiquitous increase in estimates of potential evapotranspiration (PET), driven by atmospheric warming, underlies the drying trends, but may be a methodological artefact. Here we show that the PET estimator commonly used (the Penman-Monteith PET for either an open-water surface or a reference crop) severely overpredicts the changes in non-water-stressed evapotranspiration computed in the climate models themselves in ACC experiments. This overprediction is partially due to neglect of stomatal conductance reductions commonly induced by increasing atmospheric CO2 concentrations in climate models. Our findings imply that historical and future tendencies towards continental drying, as characterized by offline-computed runoff, as well as other PET-dependent metrics, may be considerably weaker and less extensive than previously thought.

  7. Atlantic NAD 83 Continental Shelf Boundary (CSB)

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Continental Shelf Boundary (CSB) lines in ESRI shapefile format for the BOEM Atlantic Region. The CSB defines the seaward limit of federally...

  8. Continental Shelf Boundary - Alaska NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Continental Shelf Boundaries (CSB) lines in ESRI shapefile format for the BOEM Alaska Region. The CSB defines the seaward limit of federally...

  9. Volatile components and continental material of planets

    Science.gov (United States)

    Florenskiy, K. P.; Nikolayeva, O. V.

    1986-01-01

    It is shown that the continental material of the terrestrial planets varies in composition from planet to planet according to the abundances and composition of true volatiles (H20, CO2, etc.) in the outer shells of the planets. The formation of these shells occurs very early in a planet's evolution when the role of endogenous processes is indistinct and continental materials are subject to melting and vaporizing in the absence of an atmosphere. As a result, the chemical properties of continental materials are related not only to fractionation processes but also to meltability and volatility. For planets retaining a certain quantity of true volatile components, the chemical transformation of continental material is characterized by a close interaction between impact melting vaporization and endogeneous geological processes.

  10. Exploration of the continental margins of India

    Digital Repository Service at National Institute of Oceanography (India)

    Siddiquie, H.N.; Hashimi, N.H.; Vora, K.H.; Pathak, M.C.

    In mid 1970's the National Institute of Oceanography, Goa, India prepared a plan for systematic regional, geological and geophysical surveys of the continental margins of India. This involved over 75,000 km of underway (bathymetric, side scan sonar...

  11. Principles of the continental copyright law

    OpenAIRE

    Matveev A.

    2016-01-01

    It is known that there are two key copyright law traditions: English–American and Roman–Germanic copyright laws. The French and German copyright law is in the vanguard of the continental copyright law, with the copyright law of Russia being among the others in this copyright law system. However, the Russian copyright law has some specific characteristics. Copyright law is based on the defined principles. The purpose of the present article is to define the principles Continental Copyright Law....

  12. Continental underplating after slab break-off

    Science.gov (United States)

    Magni, V.; Allen, M. B.; van Hunen, J.; Bouilhol, P.

    2017-09-01

    We present three-dimensional numerical models to investigate the dynamics of continental collision, and in particular what happens to the subducted continental lithosphere after oceanic slab break-off. We find that in some scenarios the subducting continental lithosphere underthrusts the overriding plate not immediately after it enters the trench, but after oceanic slab break-off. In this case, the continental plate first subducts with a steep angle and then, after the slab breaks off at depth, it rises back towards the surface and flattens below the overriding plate, forming a thick horizontal layer of continental crust that extends for about 200 km beyond the suture. This type of behaviour depends on the width of the oceanic plate marginal to the collision zone: wide oceanic margins promote continental underplating and marginal back-arc basins; narrow margins do not show such underplating unless a far field force is applied. Our models show that, as the subducted continental lithosphere rises, the mantle wedge progressively migrates away from the suture and the continental crust heats up, reaching temperatures >900 °C. This heating might lead to crustal melting, and resultant magmatism. We observe a sharp peak in the overriding plate rock uplift right after the occurrence of slab break-off. Afterwards, during underplating, the maximum rock uplift is smaller, but the affected area is much wider (up to 350 km). These results can be used to explain the dynamics that led to the present-day crustal configuration of the India-Eurasia collision zone and its consequences for the regional tectonic and magmatic evolution.

  13. Mechanisms of continental intraplate earthquakes

    Science.gov (United States)

    Gangopadhyay, Abhijit Kumar

    To better understand the mechanisms of continental intraplate earthquakes, a multistep approach was used. The first step involved analysis and synthesis of multidisciplinary data from 39 intraplate earthquakes spanning 20 continental intraplate regions, to identify their characteristic and diagnostic features. This led to the following testable hypothesis: Intraplate earthquakes occur within pre-existing zones of weakness (most commonly failed rifts), in the vicinity of stress concentrators, such as, intersecting faults, buried plutons, and/or rift pillows in the presence of the ambient stress field. The next step involved testing this hypothesis---first with 2-D mechanical models and then with 3-D models. Since two-thirds of the examined intraplate regions had intersecting faults as a stress concentrator, its role was first evaluated. A Distinct Element Method was used wherein the models comprised of the structural framework of the concerned region represented by a set of rock blocks that are assigned elastic properties conforming to the known geology, and subjected to tectonic loading along the direction of maximum regional compression (S Hmax) at a rate similar to the ambient plate velocity. The 2-D modeling was performed for two major intraplate regions in eastern U.S., viz., New Madrid and Middleton Place Summerville seismic zones, using a commercially available code called UDEC. These models adequately explain the spatial distribution of current seismicity in the regions. However, the absence of the third dimension limited the observation of tectonics in the depth dimension. Thus, 3-D models were developed for these two regions using the 3-D version of UDEC, called 3DEC. The preliminary results of these models adequately demonstrate correlation of locations of current seismicity with fault intersections in 3-D space, and also duplicate vertical movements. Although, the mechanical models demonstrated a causal association of seismicity with intersecting faults

  14. Stratigraphic Modelling of Continental Rifting

    Science.gov (United States)

    Mondy, Luke; Duclaux, Guillaume; Salles, Tristan; Thomas, Charmaine; Rey, Patrice

    2013-04-01

    Interlinks between deformation and sedimentation have long been recognised as an important factor in the evolution of continental rifts and basins development. However, determining the relative impact of tectonic and climatic forcing on the dynamics of these systems remains a major challenge. This problem in part derives from a lack of modelling tools capable of simulated high detailed surface processes within a large scale (spatially and temporally) tectonic setting. To overcome this issue an innovative framework has been designed using two existing numerical forward modelling codes: Underworld, capable of simulating 3D self-consistent tectonic and thermal lithospheric processes, and Tellus, a forward stratigraphic and geomorphic modelling framework dedicated to simulating highly detailed surface dynamics. The coupling framework enables Tellus to use Underworld outputs as internal and boundary conditions, thereby simulating the stratigraphic and geomorphic evolution of a realistic, active tectonic setting. The resulting models can provide high-resolution data on the stratigraphic record, grain-size variations, sediment provenance, fluvial hydrometric, and landscape evolution. Here we illustrate a one-way coupling method between active tectonics and surface processes in an example of 3D oblique rifting. Our coupled model enables us to visualise the distribution of sediment sources and sinks, and their evolution through time. From this we can extract and analyse at each simulation timestep the stratigraphic record anywhere within the model domain. We find that even from a generic oblique rift model, complex fluvial-deltaic and basin filling dynamics emerge. By isolating the tectonic activity from landscape dynamics with this one-way coupling, we are able to investigate the influence of changes in climate or geomorphic parameters on the sedimentary and landscape record. These impacts can be quantified in part via model post-processing to derive both instantaneous and

  15. The Continental Crust: A Geophysical Approach

    Science.gov (United States)

    Christensen, Nikolas I.

    Nearly 80 years ago, Yugoslavian seismologist Andrija Mohorovicic recognized, while studying a Balkan earthquake, that velocities of seismic waves increase abruptly at a few tens of kilometers depth , giving rise to the seismological definition of the crust. Since that discovery, many studies concerned with the nature of both the continental and oceanic crusts have appeared in the geophysical literature.Recently, interest in the continental crust has cascaded. This is largely because of an infusion of new data obtained from major reflection programs such as the Consortium for Continental Reflection Profiling (COCORP) and British Institutions Reflection Profiling Syndicate (BIRPS) and increased resolution of refraction studies. In addition, deep continental drilling programs are n ow in fashion. The Continental Crust: A Geophysical Approach is a summary of present knowledge of the continental crust. Meissner has succeeded in writing a book suited to many different readers, from the interested undergraduate to the professional. The book is well documented , with pertinent figures and a complete and up-to-date reference list.

  16. Continental crust generated in oceanic arcs

    Science.gov (United States)

    Gazel, Esteban; Hayes, Jorden L.; Hoernle, Kaj; Kelemen, Peter; Everson, Erik; Holbrook, W. Steven; Hauff, Folkmar; van den Bogaard, Paul; Vance, Eric A.; Chu, Shuyu; Calvert, Andrew J.; Carr, Michael J.; Yogodzinski, Gene M.

    2015-04-01

    Thin oceanic crust is formed by decompression melting of the upper mantle at mid-ocean ridges, but the origin of the thick and buoyant continental crust is enigmatic. Juvenile continental crust may form from magmas erupted above intra-oceanic subduction zones, where oceanic lithosphere subducts beneath other oceanic lithosphere. However, it is unclear why the subduction of dominantly basaltic oceanic crust would result in the formation of andesitic continental crust at the surface. Here we use geochemical and geophysical data to reconstruct the evolution of the Central American land bridge, which formed above an intra-oceanic subduction system over the past 70 Myr. We find that the geochemical signature of erupted lavas evolved from basaltic to andesitic about 10 Myr ago--coincident with the onset of subduction of more oceanic crust that originally formed above the Galápagos mantle plume. We also find that seismic P-waves travel through the crust at velocities intermediate between those typically observed for oceanic and continental crust. We develop a continentality index to quantitatively correlate geochemical composition with the average P-wave velocity of arc crust globally. We conclude that although the formation and evolution of continents may involve many processes, melting enriched oceanic crust within a subduction zone--a process probably more common in the Archaean--can produce juvenile continental crust.

  17. Generation and preservation of continental crust in the Grenville Orogeny

    Directory of Open Access Journals (Sweden)

    Christopher J. Spencer

    2015-05-01

    Zircons within the post-orogenic sedimentary successions have progressively lower ɛHf and higher δ18O values from ∼1800 to ∼1200 Ma whereupon they have higher ɛHf and δ18O within the dominant 1085–985 Ma age peak. Furthermore, the Lu-Hf isotopic profile of the Grenville-related age peak is consistent with significant assimilation and contamination by older crustal material. The timing of this dominant age peak coincides with the peak of metamorphism and magmatism associated with the Grenville Orogeny, which is a typical collisional orogenic belt. The change from broad muted age peaks in the syn-orogenic strata to a single peak in the post-orogenic sedimentary successions and in the modern river sediments implies a significant shift in provenance following continental collision. This temporal change in provenance highlights that the source(s, from which detrital zircons within syn-orogenic strata were derived, was no longer available during the later stages of the accretionary and collisional stages of the orogenic cycle. This may reflect some combination of tectonic burial, erosion, or possibly recycling into the mantle by tectonic erosion of the source(s. During continental collision, the incorporated continental crust is isolated from crustal recycling processes operative at subduction margins. This tectonic isolation combined with sedimentary recycling likely controls the presence of the isotopic signature associated with the Grenville Orogeny in the modern Mississippi and Appalachian river sediments. These results imply that zircon age peaks, which developed in conjunction with supercontinents, are the product of selective crustal preservation resulting from collisional orogenesis.

  18. The continental Permian-Triassic boundary in the Netherlands: Implications for the geomagnetic polarity time scale

    NARCIS (Netherlands)

    Szurlies, M.; Geluk, M.C.; Krijgsman, W.; Kürschner, W.M.

    2012-01-01

    In Central and NW Europe, the transition from the Permian to the Triassic (i.e., the Zechstein–Buntsandstein boundary interval) is developed mainly in red bed facies. This continental sedimentary succession is marked by relatively high sedimentation rates providing a high temporal resolution favorab

  19. Fire ecology of Montana forest habitat types east of the Continental Divide

    Science.gov (United States)

    William C. Fischer; Bruce D. Clayton

    1983-01-01

    Provides information on fire as an ecological factor for forest habitat types occurring east of the Continental Divide in Montana. Identifies "Fire Groups" of habitat types based on fire's role in forest succession. Describes forest fuels and suggests considerations for fire management.

  20. Continental growth seen through the sedimentary record

    Science.gov (United States)

    Dhuime, Bruno; Hawkesworth, Chris J.; Delavault, Hélène; Cawood, Peter A.

    2017-07-01

    Sedimentary rocks and detrital minerals sample large areas of the continental crust, and they are increasingly seen as a reliable archive for its global evolution. This study presents two approaches to model the growth of the continental crust through the sedimentary archive. The first builds on the variations in U-Pb, Hf and O isotopes in global databases of detrital zircons. We show that uncertainty in the Hf isotope composition of the mantle reservoir from which new crust separated, in the 176Lu/177Hf ratio of that new crust, and in the contribution in the databases of zircons that experienced ancient Pb loss(es), adds some uncertainty to the individual Hf model ages, but not to the overall shape of the calculated continental growth curves. The second approach is based on the variation of Nd isotopes in 645 worldwide fine-grained continental sedimentary rocks with different deposition ages, which requires a correction of the bias induced by preferential erosion of younger rocks through an erosion parameter referred to as K. This dimensionless parameter relates the proportions of younger to older source rocks in the sediment, to the proportions of younger to older source rocks present in the crust from which the sediment was derived. We suggest that a Hadean/Archaean value of K = 1 (i.e., no preferential erosion), and that post-Archaean values of K = 4-6, may be reasonable for the global Earth system. Models built on the detrital zircon and the fine-grained sediment records independently suggest that at least 65% of the present volume of continental crust was established by 3 Ga. The continental crust has been generated continuously, but with a marked decrease in the growth rate at 3 Ga. The period from > 4 Ga to 3 Ga is characterised by relatively high net rates of continental growth (2.9-3.4 km3 yr- 1 on average), which are similar to the rates at which new crust is generated (and destroyed) at the present time. Net growth rates are much lower since 3 Ga (0

  1. Controls on facies evolution in low accommodation, continental-scale fluvio-paralic systems (Messak Fm, SW Libya)

    Science.gov (United States)

    Wood, J. D.; Bodin, S.; Redfern, J.; Thomas, M. F. H.

    2014-04-01

    The evolution and controls on lithofacies distribution in ancient fluvio-paralic successions have been the focus of many studies. However, the evolution of ancient continental-scale fluvio-paralic depositional systems is not well documented due to a lack of suitable outcropping or subcropping examples. Features inherent to continental-scale fluvial systems, such as low overall gradients and large distances separating source from sink are likely to have a strong influence on vertical and lateral lithofacies evolution.

  2. Malawi's infrastructure: a continental perspective

    OpenAIRE

    Foster, Vivien; Shkaratan, Maria

    2011-01-01

    Infrastructure contributed 1.2 percentage points to Malawi's annual per capital GDP growth over the past decade. Raising the country's infrastructure endowment to that of the region s middle-income countries could increase that contribution by 3.5 percentage points. Malawi's successes in infrastructure development include reaching the Millennium Development Goals for water and making GSM t...

  3. Geological features and geophysical signatures of continental margins of India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.

    and classification of continental margins are in general dependent on style of continental splitting, rifting, subsidence and their proximity to the tectonic plate boundaries, at times the margins undergo for modifications by sediment deposition and volcanic... by Deccan-Reunion hotspot volcanism and Bengal Fan sedimentation respectively. Volcanism has dominated on the western continental margin of India, thereby the margin had been turned into a volcanic passive continental margin, while eastern continental...

  4. Seismic probing of continental subduction zones

    Science.gov (United States)

    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 (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.

  5. Post-Gondwanan continental sedimentaiton, Limpopo region, southeastern Africa

    Science.gov (United States)

    Botha, G. A.; De Wit, M. C. J.

    1996-08-01

    The post-Karoo age sedimentary succession known formerly as the Malvernia Formation, is currently termed the Malonga Formation, 'Formaçao de Sena', 'Formaçao de Singuédeze/Elefantes' and Gona-re-Zhou Plateau Beds in the Limpopo Basin region where South Africa, Mozambique and Zimbabwe have common borders. These rocks represent continental, taphrogenic sedimentation on the eastern margin of the emergent African continent after the breakup of Gondwana. The wide occurrence of this system along the northern Lebombo mountains and within the tectonically active Limpopo and Zambezi valleys, suggests the existence of a peidmont landsurface comprising coalesced alluvial fans and major fluvial channel/floodplain systems close to the continental margin during the Late Mesozoic to Early Cainozoic era. Sedimentation followed the long period of eustatic uplift associated with Karoo vulcanicity and the extensional tectonics and rifting along the continental margin and within the proto-Limpopo and Zambezi valleys. The Malonga Formation exposed near Pafuri in the extreme NW of South Africa shows an eastward lithological change from homogeneous, poorly-sorted, thinly-bedded sandstones and conglomerates, deposited by sheetflood action, to a sequence of fining-upward units comprising clast-supported pebble to boulder grade conglomerate and overlying planar bedded silt and sand, deposited in fluvial channel and floodplain environments. The homogeneous, silty succession exposed in the Olifants River valley, east of the Lebombo mountains in Mozambique, possibly represents the distal reaches of this system. Calcareous palaeosols developed within the sedimentary units suggest periodic geomorphic stability on the broad alluvial plain. Further north in southeastern Zimbabwe, laterally continuous depositional units comprising thinly-bedded, poorly-sorted, matrix-supported conglomerate, interbedded with very coarse-grained sandstone, is consistent with deposition on an alluvial fan complex

  6. Successful ageing

    DEFF Research Database (Denmark)

    Bülow, Morten Hillgaard; Söderqvist, Thomas

    2014-01-01

    Since the late 1980s, the concept of ‘ successful ageing’ has set the frame for discourse about contemporary ageing research. Through an analysis of the reception to John W. Rowe and Robert L. Kahn's launch of the concept of ‘ successful ageing’ in 1987, this article maps out the important themes...... and discussions that have emerged from the interdisciplinary field of ageing research. These include an emphasis on interdisciplinarity; the interaction between biology, psycho-social contexts and lifestyle choices; the experiences of elderly people; life-course perspectives; optimisation and prevention...... strategies; and the importance of individual, societal and scientific conceptualisations and understandings of ageing. By presenting an account of the recent historical uses, interpretations and critiques of the concept, the article unfolds the practical and normative complexities of ‘ successful ageing’....

  7. Successful ageing

    DEFF Research Database (Denmark)

    Bülow, Morten Hillgaard; Söderqvist, Thomas

    2014-01-01

    Since the late 1980s, the concept of ‘ successful ageing’ has set the frame for discourse about contemporary ageing research. Through an analysis of the reception to John W. Rowe and Robert L. Kahn's launch of the concept of ‘ successful ageing’ in 1987, this article maps out the important themes...... and discussions that have emerged from the interdisciplinary field of ageing research. These include an emphasis on interdisciplinarity; the interaction between biology, psycho-social contexts and lifestyle choices; the experiences of elderly people; life-course perspectives; optimisation and prevention...... strategies; and the importance of individual, societal and scientific conceptualisations and understandings of ageing. By presenting an account of the recent historical uses, interpretations and critiques of the concept, the article unfolds the practical and normative complexities of ‘ successful ageing’....

  8. Citation Success

    DEFF Research Database (Denmark)

    Vaio, Gianfranco Di; Waldenström, Daniel; Weisdorf, Jacob Louis

    2012-01-01

    This study examines the determinants of citation success among authors who have recently published their work in economic history journals. Besides offering clues about how to improve one's scientific impact, our citation analysis also sheds light on the state of the field of economic history....... Consistent with our expectations, we find that full professors, authors appointed at economics and history departments, and authors working in Anglo-Saxon and German countries are more likely to receive citations than other scholars. Long and co-authored articles are also a factor for citation success. We...... find similar patterns when assessing the same authors' citation success in economics journals. As a novel feature, we demonstrate that the diffusion of research — publication of working papers, as well as conference and workshop presentations — has a first-order positive impact on the citation rate....

  9. Generation and preservation of continental crust in the Grenville Orogeny

    Institute of Scientific and Technical Information of China (English)

    Christopher J. Spencer; Peter A. Cawood; Chris J. Hawkesworth; Anthony R. Prave; Nick M.W. Roberts; Matthew S.A. Horstwood; Martin J. Whitehouse; EIMF

    2015-01-01

    Detrital zircons from modern sediments display an episodic temporal distribution of U-Pb crystallization ages forming a series of ‘peaks’ and ‘troughs’. The peaks are interpreted to represent either periods of enhanced generation of granitic magma perhaps associated with mantle overturn and superplume events, or preferential preservation of continental crust during global collisional orogenesis. The close association of those peaks with the assembly of supercontinents implies a causal relationship between collisional orogenesis and the presence of zircon age peaks. Here these two end-member models (episodic periodicity of increased magmatism versus selective preservation during collisional orogenesis) are assessed using U-Pb, Hf, and O analysis of detrital zircons from sedimentary successions deposited during the w1.3e1.1 Ga accretionary, w1.1e0.9 Ga collisional, and < 0.9 Ga extensional collapse phases of the Grenville orogenic cycle in Labrador and Scotland. The pre-collisional, accretionary stage provides a baseline of continental crust present prior to orogenesis and is dominated by Archean and Paleoproterozoic age peaks associated with pre-1300 Ma Laurentian geology. Strata deposited during the Grenville Orogeny display similar Archean and Paleoproterozoic detrital populations along with a series of broad muted peaks from w1500 to 1100 Ma. However, post-collisional sedimentary successions display a dominant age peak between 1085 and 985 Ma, similar to that observed in modern North American river sediments. Zircons within the post-orogenic sedimentary successions have progressively lower 3Hf and higher d18O values from w1800 to w1200 Ma whereupon they have higher 3Hf and d18O within the dominant 1085e985 Ma age peak. Furthermore, the Lu-Hf isotopic profile of the Grenville-related age peak is consistent with significant assimilation and contamination by older crustal material. The timing of this dominant age peak coincides with the peak of metamorphism

  10. Citation Success

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Waldenström, Daniel; Weisdorf, Jacob Louis

    affects citations. In regard to author-specific characteristics, male authors, full professors and authors working economics or history departments, and authors employed in Anglo-Saxon countries, are more likely to get cited than others. As a ‘shortcut' to citation success, we find that research diffusion......This study analyses determinants of citation success among authors publishing in economic history journals. Bibliometric features, like article length and number of authors, are positively correlated with the citation rate up to a certain point. Remarkably, publishing in top-ranked journals hardly...

  11. Comparative Study of Statistical Skin Detection Algorithms for Sub-Continental Human Images

    CERN Document Server

    Tabassum, Mirza Rehenuma; Kamal, Md Mostafa; Muctadir, Hossain Muhammad; Ibrahim, Muhammad; Shakir, Asif Khan; Imran, Asif; Islamm, Saiful; Rabbani, Md Golam; Khaled, Shah Mostafa; Islam, Md Saiful; Begum, Zerina; 10.3923/itj.2010.811.817

    2010-01-01

    Object detection has been a focus of research in human-computer interaction. Skin area detection has been a key to different recognitions like face recognition, human motion detection, pornographic and nude image prediction, etc. Most of the research done in the fields of skin detection has been trained and tested on human images of African, Mongolian and Anglo-Saxon ethnic origins. Although there are several intensity invariant approaches to skin detection, the skin color of Indian sub-continentals have not been focused separately. The approach of this research is to make a comparative study between three image segmentation approaches using Indian sub-continental human images, to optimize the detection criteria, and to find some efficient parameters to detect the skin area from these images. The experiments observed that HSV color model based approach to Indian sub-continental skin detection is more suitable with considerable success rate of 91.1% true positives and 88.1% true negatives.

  12. Citation Success

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Waldenström, Daniel; Weisdorf, Jacob Louis

    This study analyses determinants of citation success among authors publishing in economic history journals. Bibliometric features, like article length and number of authors, are positively correlated with the citation rate up to a certain point. Remarkably, publishing in top-ranked journals hardl...

  13. Citation Success

    DEFF Research Database (Denmark)

    Vaio, Gianfranco Di; Waldenström, Daniel; Weisdorf, Jacob Louis

    2012-01-01

    This study examines the determinants of citation success among authors who have recently published their work in economic history journals. Besides offering clues about how to improve one's scientific impact, our citation analysis also sheds light on the state of the field of economic history. Co...

  14. Successful ageing

    DEFF Research Database (Denmark)

    Kusumastuti, Sasmita; Derks, Marloes G. M.; Tellier, Siri;

    2016-01-01

    . METHODS: We performed a novel, hypothesis-free and quantitative analysis of citation networks exploring the literature on successful ageing that exists in the Web of Science Core Collection Database using the CitNetExplorer software. Outcomes were visualized using timeline-based citation patterns...

  15. Continental reach: The Westcoast Energy story

    Energy Technology Data Exchange (ETDEWEB)

    Newman, P. C.

    2002-07-01

    A historical account is given of the spectacular success that was Westcoast Energy Inc., a Canadian natural gas giant that charted a wilderness pipeline from natural gas fields in Canada's sub-arctic solitude. The beginning of the company is traced to an event in 1934 when near the bank of the Pouce Coupe River, close to the Alberta-British Columbia border, Frank McMahon, a solitary wildcatter and the eventual founder of the company, first sighted the fiery inferno of a runaway wildcat well, drilled by geologists of the Imperial Oil Company during their original search for the Canadian petroleum basin's motherlode. It was on this occasion in 1934 that McMahon first conceived a geological profile that connected the gas-bearing sandstone of Pouce Coupe with the reservoir rock of the biggest natural gas field of Alberta, and a pipeline from this sandstone storehouse across the rugged heart of British Columbia to Vancouver, and south into the United States. It took the better part of a quarter century to realize the dream of that pipeline which, in due course, turned out to be only the first step towards reaching the top rank of Canadian corporations in operational and financial terms, and becoming one of only a handful in terms of a story that became a Canadian corporate legend. By chronicling the lives and contributions of the company's founder and senior officials over the years, the book traces the company's meteoric rise from a gleam in its founder's eye to a cautious regional utility, and to the aggressive Canadian adventurer that went on to burst the boundaries of its Pacific Coast world, until the continental reach of its operations and interests run from Canada's Pacific shoreline to its Atlantic basins and Mexico's Campeche Bay to Alaska's Prudhoe Bay. The company's independent existence came to an end in 2002 when Westcoast Energy, by then a $15 billion operation, was acquired by Duke Energy Limited of North

  16. French Extended Continental Shelf Mapping: example of new continental margin understanding offshore French Guiana

    Science.gov (United States)

    Roest, Walter; Loubrieu, Benoit; Loncke, Lies; Basile, Christophe; Graindorge, David; Shipboard Party, Guyaplac

    2017-04-01

    Under the United Nations Convention on the Law of the Sea, Coastal States can extend sovereign rights over the natural resources of the Continental Shelf beyond 200 nautical miles (M) if they can demonstrate that their continental margin extends beyond this distance from the coast. Article 76 of the Convention defines the continental shelf and includes geomorphological and geological criteria to claim such a shelf beyond 200 M. Since 2006, France has filed 7 submissions for a total of 10 distinct geographic regions to the Commission on the Limits of the Continental Shelf that was established by the Convention to examine those claims, and make recommendations with respect to the justification of the outer limits of the continental shelf. To support the French submissions, a significant effort was employed in acquiring new marine geophysical and geological data and compiling existing data along the deep water parts of the continental margins offshore all the French overseas territories. In this presentation, we will discuss the example of French Guiana, where the data collected for the purpose of fulfilling the obligation under the Convention to submit data and information to the Commission within a 10 year time frame have led to new understanding of the transform continental margin and the Demerara Plateau located to the north of French Guiana and Surinam. In addition, the data collected for this purpose have led to new scientific questions and have encouraged new and enhanced scientific collaboration between French government organizations and the academic community. Follow up research and scientific cruises that will be presented in separate communications have addressed sedimentary processes including contourites, giant comet tail like depressions probably associated with the strong bottom currents observed along the continental slope and potentially related to pockmarks, as well as giant submarine landslides. Most recently, multichannel reflection and wide angle

  17. "Success"ful Reading Instruction.

    Science.gov (United States)

    George, Carol J.

    1986-01-01

    The Success in Reading and Writing Program at a K-2 school in Fort Jackson, South Carolina, teaches children of varied races and abilities to read and write using newspapers, dictionaries, library books, magazines, and telephone directories. These materials help students develop language skills in a failure-free atmosphere. Includes two…

  18. Plate Tectonics and Continental Drift: Classroom Ideas.

    Science.gov (United States)

    Stout, Prentice K.

    1983-01-01

    Suggests various classroom studies related to plate tectonics and continental drift, including comments on and sources of resource materials useful in teaching the topics. A complete list of magazine articles on the topics from the Sawyer Marine Resource Collection may be obtained by contacting the author. (JN)

  19. Making continental crust: The sanukitoid connection

    Institute of Scientific and Technical Information of China (English)

    Yoshiyuki TATSUMI

    2008-01-01

    The average continental crust possesses intermediate compositions that typify arc magmatism and as a result it is believed to have been created at ancient convergent plate boundaries. One possible mechanism for intermediate continental crust formation is the direct production of andesitic melts in the upper mantle. Sanukitoids, which characterize the Setouchi volcanic belt, SW Japan, include unusually high-Mg andesites (HMA). They were generated by slab melting and subsequent melt-mantle interactions under unusual tectonic settings such as where warm lithosphere subducts into hot upper mantle. Such conditions would have existed in the Archean. Hydrous HMA magmas are likely to have solidified within the crust to form HMA plutons, which were then remelted to produce differentiated sanukitoids. At present, generation and differentiation of HMA magmas may be taking place in the Izu-Bonin-Mariana arc-trench system (IBM), because (1) HMA magmatism characterizes the initial stages of the iBM evolution and (2) the IBM middle crust exhibits Vp identical to that of the bulk continental crust. Vp estimates for plutonic rocks with HMA compositions support this. However tonalitic composition for middle-crust-forming rocks cannot be ruled out, suggesting an alternative possibility that the continental crust has been created by differentiation of mantle-derived basaltic magmas.

  20. InterContinental Cuisine for Charity 2011

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Cuisine for Charity is one of the most important annual events for InterContinental Hotels Group (IHG) hotels in Beijing. It is a good opportunity not only for chefs to showcase them-selves, learn from each other and improve their cooking skills, but also to show that we take care of our social responsibilities.

  1. Elephant teeth from the atlantic continental shelf

    Science.gov (United States)

    Whitmore, F.C.; Emery, K.O.; Cooke, H.B.S.; Swift, D.J.P.

    1967-01-01

    Teeth of mastodons and mastodons have been recovered by fishermen from at least 40 sites on the continental shelf as deep as 120 meters. Also present are submerged shorelines, peat deposits, lagoonal shells, and relict sands. Evidently elephants and other large mammals ranged this region during the glacial stage of low sea level of the last 25.000 years.

  2. 25 years of continental deep subduction

    Institute of Scientific and Technical Information of China (English)

    ZHENG YongFei

    2009-01-01

    @@ This year marks the 25th anniversary of the discovery of coesite in metamorphic rocks of supracrustal origin.This initiated a revolution of the plate tectonics theory due to intensive studies of ultrahigh pressure metamorphism and continental deep subduction.The occurrence of coesite was first reported in 1984 by two French scientists,C.Chopin and D.C.Smith,respectively.

  3. New insights into continental rifting from a damage rheology modeling

    Science.gov (United States)

    Lyakhovsky, Vladimir; Segev, Amit; Weinberger, Ram; Schattner, Uri

    2010-05-01

    Previous studies have discussed how tectonic processes could produce relative tension to initiate and propagate rift zones and estimated the magnitude of the rift-driving forces. Both analytic and semi-analytic models as well as numerical simulations assume that the tectonic force required to initiate rifting is available. However, Buck (2004, 2006) estimated the minimum tectonic force to allow passive rifting and concluded that the available forces are probably not large enough for rifting of thick and strong lithosphere in the absence of basaltic magmatism (the "Tectonic Force" Paradox). The integral of the yielding stress needed for rifting over the thickness of the normal or thicker continental lithosphere are well above the available tectonic forces and tectonic rifting cannot happen (Buck, 2006). This conclusion is based on the assumption that the tectonic stress has to overcome simultaneously the yielding stress over the whole lithosphere thickness and ignore gradual weakening of the brittle rocks under long-term loading. In this study we demonstrate that the rifting process under moderate tectonic stretching is feasible due to gradual weakening and "long-term memory" of the heavily fractured brittle rocks, which makes it significantly weaker than the surrounding intact rock. This process provides a possible solution for the tectonic force paradox. We address these questions utilizing 3-D lithosphere-scale numerical simulations of the plate motion and faulting process base on the damage mechanics. The 3-D modeled volume consists of three main lithospheric layers: an upper layer of weak sediments, middle layer of crystalline crust and lower layer of the lithosphere mantle. Results of the modeling demonstrate gradual formation of the rift zone in the continental lithosphere with the flat layered structure. Successive formation of the rift system and associated seismicity pattern strongly depend not only on the applied tectonic force, but also on the healing

  4. Tectonics and melting in intra-continental settings

    NARCIS (Netherlands)

    Gorczyk, Weronika; Vogt, Katharina

    2015-01-01

    Most of the geodynamic theories of deformation aswell asmetamorphismandmelting of continental lithosphere are concentrated on plate boundaries and are dominated by the effects of subduction upon deformation of the margins of continental lithospheric blocks. However, it is becoming increasingly

  5. Federal Outer Continental Shelf Oil and Gas Production Statistics

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — Federal Outer Continental Shelf Oil and Gas Production Statistics by month and summarized annually. Outer Continental Shelf consists of Gulf of Mexico, Pacific and...

  6. Tectonics and melting in intra-continental settings

    NARCIS (Netherlands)

    Gorczyk, Weronika; Vogt, Katharina|info:eu-repo/dai/nl/370618947

    2015-01-01

    Most of the geodynamic theories of deformation aswell asmetamorphismandmelting of continental lithosphere are concentrated on plate boundaries and are dominated by the effects of subduction upon deformation of the margins of continental lithospheric blocks. However, it is becoming increasingly appar

  7. Tectonics and melting in intra-continental settings

    NARCIS (Netherlands)

    Gorczyk, Weronika; Vogt, Katharina

    2015-01-01

    Most of the geodynamic theories of deformation aswell asmetamorphismandmelting of continental lithosphere are concentrated on plate boundaries and are dominated by the effects of subduction upon deformation of the margins of continental lithospheric blocks. However, it is becoming increasingly appar

  8. Isotopic prediction of eruption volume at continental volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Perry, F.V.; Valentine, G.A.; Crowe, B.M. [and others

    1997-10-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The objective of this project was to determine whether isotopic techniques can be used to assess the eruption potential and eruption volume of continental stratovolcanoes. Large-volume eruptions from stratovolcanoes pose significant hazards to population and infrastructure in many parts of the world. We are testing whether this technique will allow a short- to medium-term (decades to millennia) probabilistic hazard assessment of large-volume eruptions. If successful, the technique will be useful to countries or regions that must consider medium to long-term volcanic (e.g., nuclear waste facilities). We have begun sample acquisition and isotopic measurements at two stratovolcanoes, Pico de Orizaba in eastern Mexico and Daisen in western Japan.

  9. 78 FR 32183 - Importation of Avocados From Continental Spain

    Science.gov (United States)

    2013-05-29

    ... Continental Spain AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Proposed rule; reopening... allow the importation of avocados from continental Spain (excluding the Balearic Islands and Canary... vegetables regulations to allow the importation of avocados from continental Spain (excluding the...

  10. 78 FR 32184 - Importation of Fresh Apricots From Continental Spain

    Science.gov (United States)

    2013-05-29

    ... From Continental Spain AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Proposed rule... allow the importation into the United States of fresh apricots from continental Spain. This action will... of fresh apricots from continental Spain into the United States subject to a systems approach...

  11. "Work Hard, Fly Bight"——Today's Continental Airlines

    Institute of Scientific and Technical Information of China (English)

    Guo Yan

    2006-01-01

    @@ On June16, 2006, Continental Airlines celebrated the first anniversary of its daily nonstop flight from Beifing to New York. China's Foreign Trade exclusively interviewed Kwok Hing-Cheong, Chief Representative & Country Director-Continental Airlines, China. He talked about the developments, challenges and benefits of Continental Airlines in China.

  12. 49 CFR 192.10 - Outer continental shelf pipelines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Outer continental shelf pipelines. 192.10 Section... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS General § 192.10 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf (as defined in...

  13. 49 CFR 195.9 - Outer continental shelf pipelines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Outer continental shelf pipelines. 195.9 Section... HAZARDOUS LIQUIDS BY PIPELINE General § 195.9 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf must identify on all their respective pipelines the specific...

  14. 75 FR 1076 - Outer Continental Shelf Civil Penalties

    Science.gov (United States)

    2010-01-08

    ...: 2010-119] DEPARTMENT OF THE INTERIOR Minerals Management Service Outer Continental Shelf Civil... maximum daily civil penalty assessment. SUMMARY: The Outer Continental Shelf Lands Act requires the MMS to... operations in the Outer Continental Shelf at least once every 3 years. This review ensures that the...

  15. Ocean Drilling Program Leg 178 (Antarctic Peninsula): Sedimentology of glacially influenced continental margin topsets and foresets

    Science.gov (United States)

    Eyles, N.; Daniels, J.; Osterman, L.E.; Januszczak, N.

    2001-01-01

    Ocean Drilling Program Leg 178 (February-April 1998) drilled two sites (Sites 1097 and 1103) on the outer Antarctic Peninsula Pacific continental shelf. Recovered strata are no older than late Miocene or early Pliocene (<4.6 Ma). Recovery at shallow depths in loosely consolidated and iceberg-turbated bouldery sediment was poor but improved with increasing depth and consolidation to allow description of lithofacies and biofacies and interpretation of depositional environment. Site 1097 lies on the outer shelf within Marguerite Trough which is a major outlet for ice expanding seaward from the Antarctic Peninsula and reached a maximum depth drilled of 436.6 m below the sea floor (mbsf). Seismic stratigraphic data show flat-lying upper strata resting on strata that dip gently seaward. Uppermost strata, to a depth of 150 mbsf, were poorly recovered, but data suggest they consist of diamictites containing reworked and abraded marine microfauna. This interval is interpreted as having been deposited largely as till produced by subglacial cannibalization of marine sediments (deformation till) recording ice sheet expansion across the shelf. Underlying gently dipping strata show massive, stratified and graded diamictite facies with common bioturbation and slump stuctures that are interbedded with laminated and massive mudstones with dropstones. The succession contains a well-preserved in situ marine microfauna typical of open marine and proglacial marine environments. The lower gently dipping succession at Site 1097 is interpreted as a complex of sediment gravity flows formed of poorly sorted glacial debris. Site 1103 was drilled in that part of the continental margin that shows uppermost flat-lying continental shelf topsets overlying steeper dipping slope foresets seaward of a structural mid-shelf high. Drilling reached a depth of 363 mbsf with good recovery in steeply dipping continental slope foreset strata. Foreset strata are dominated by massive and chaotically

  16. Moroccan crustal response to continental drift.

    Science.gov (United States)

    Kanes, W H; Saadi, M; Ehrlich, E; Alem, A

    1973-06-01

    The formation and development of a zone of spreading beneath the continental crust resulted in the breakup of Pangea and formation of the Atlantic Ocean. The crust of Morocco bears an extremely complete record of the crustal response to this episode of mantle dynamics. Structural and related depositional patterns indicate that the African margin had stabilized by the Middle Jurassic as a marine carbonate environment; that it was dominated by tensile stresses in the early Mesozoic, resulting in two fault systems paralleling the Atlantic and Mediterranean margins and a basin and range structural-depositional style; and that it was affected by late Paleozoic metamorphism and intrusion. Mesozoic events record the latter portion of African involvement in the spreading episode; late Paleozoic thermal orogenesis might reflect the earlier events in the initiation of the spreading center and its development beneath significant continental crust. In that case, more than 100 million years were required for mantle dynamics to break up Pangea.

  17. Regional magnetic anomaly constraints on continental rifting

    Science.gov (United States)

    Vonfrese, R. R. B.; Hinze, W. J.; Olivier, R.; Bentley, C. R.

    1985-01-01

    Radially polarized MAGSAT anomalies of North and South America, Europe, Africa, India, Australia and Antarctica demonstrate remarkably detailed correlation of regional magnetic lithospheric sources across rifted margins when plotted on a reconstruction of Pangea. These major magnetic features apparently preserve their integrity until a superimposed metamorphoric event alters the magnitude and pattern of the anomalies. The longevity of continental scale magnetic anomalies contrasts markedly with that of regional gravity anomalies which tend to reflect predominantly isostatic adjustments associated with neo-tectonism. First observed as a result of NASA's magnetic satellite programs, these anomalies provide new and fundamental constraints on the geologic evolution and dynamics of the continents and oceans. Accordingly, satellite magnetic observations provide a further tool for investigating continental drift to compliment other lines of evidence in paleoclimatology, paleontology, paleomagnetism, and studies of the radiometric ages and geometric fit of the continents.

  18. Sustainable Offshore Wind Potential in Continental Portugal

    OpenAIRE

    Costa, P.; Simões, T. (Tânia); Estanqueiro, Ana

    2010-01-01

    This study intends to depict the availability of the sustainable offshore wind energy for Continental Portugal and identify the preliminary areas for developing offshore wind parks. Two scenarios were performed to distinct the different offshore wind turbine prototypes assembled by the manufactory energy sector – bottom fixed and floating models. The results achieved until now indicate that Portugal has a very large potential for offshore wind deployments ready to be exploited, especial...

  19. Authigenic minerals from the continental margins

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    phosphorites have been presumed to be sedimented plankton organic matter, fish debris, and iron-redox phosphate pump. Several workers investigated the genesis of sedimentary phosphorites occurring from Precambrian to Recent and proposed different...-phosphate sediments of the western continental margin of India showed that phosphate occurred as apatite microparticles that resembled fossilized phosphate bacteria and/or microbial filaments (Fig. 3). This established the prominence of micro- environments...

  20. Ocean processes at the Antarctic continental slope.

    Science.gov (United States)

    Heywood, Karen J; Schmidtko, Sunke; Heuzé, Céline; Kaiser, Jan; Jickells, Timothy D; Queste, Bastien Y; Stevens, David P; Wadley, Martin; Thompson, Andrew F; Fielding, Sophie; Guihen, Damien; Creed, Elizabeth; Ridley, Jeff K; Smith, Walker

    2014-07-13

    The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An iron-cycling model embedded in an eddy-permitting ocean model reveals the importance of sedimentary iron in fertilizing parts of the Southern Ocean. Ocean gliders play a key role in improving our ability to observe and understand these small-scale processes at the continental shelf break. The Gliders: Excellent New Tools for Observing the Ocean (GENTOO) project deployed three Seagliders for up to two months in early 2012 to sample the water to the east of the Antarctic Peninsula in unprecedented temporal and spatial detail. The glider data resolve small-scale exchange processes across the shelf-break front (the Antarctic Slope Front) and the front's biogeochemical signature. GENTOO demonstrated the capability of ocean gliders to play a key role in a future multi-disciplinary Southern Ocean observing system.

  1. Continental moisture recycling as a Poisson process

    OpenAIRE

    2013-01-01

    On their journey across large land masses, water molecules experience a number of precipitation-evaporation cycles (recycling events). We derive analytically the frequency distributions of recycling events for the water molecules contained in a given air parcel. Given the validity of certain simplifying assumptions, continental moisture recycling is shown to develop either into a Poisson distribution or a geometric distribution. We distinguish two cases: in case (A) recycling events a...

  2. Abrupt plate accelerations shape rifted continental margins

    Science.gov (United States)

    Brune, Sascha; Williams, Simon E.; Butterworth, Nathaniel P.; Müller, R. Dietmar

    2016-08-01

    Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution, yet quantified extension histories of Earth’s major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength-velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.

  3. Abrupt plate accelerations shape rifted continental margins.

    Science.gov (United States)

    Brune, Sascha; Williams, Simon E; Butterworth, Nathaniel P; Müller, R Dietmar

    2016-08-11

    Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution, yet quantified extension histories of Earth's major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength--velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.

  4. Successful Aging

    Directory of Open Access Journals (Sweden)

    Taufiqurrahman Nasihun

    2015-06-01

    Full Text Available The emerging concept of successful aging is based on evidence that in healthy individual when they get aged, there are  considerable variations in physiological functions alteration. Some people exhibiting greater, but others very few or no age related alteration. The first is called poor aging and the later is called successful pattern of aging (Lambert SW, 2008. Thus, in the simple words the successful aging concept is define as an opportunity of old people to stay  active and productive condition despite they get aged chronologically. Aging itself might be defined as the progressive accumulation of changes with time associated with or responsible for the ever-increasing susceptibility to disease and death which accompanies advancing age (Harman D, 1981. The time needed to accumulate changes is attributable to aging process. The marked emerging questions are how does aging happen and where does aging start? To answer these questions and because of the complexity of aging process, there are more than 300 aging theories have been proposed to explain how and where aging occured and started respectively. There are too many to enumerate theories and classification of aging process. In summary, all of these aging theories can be grouped into three clusters: 1. Genetics program theory, this theory suggests that aging is resulted from program directed by the genes; 2. Epigenetic theory, in these theory aging is resulted from environmental random events not determined by the genes; 3. Evolutionary theory, which propose that aging is a medium for disposal mortal soma in order to avoid competition between organism and their progeny for food and space, did not try to explain how aging occur, but possibly answer why aging occur (De la Fuente. 2009. Among the three groups of aging theories, the epigenetic theory is useful to explain and try to solve the enigma of aging which is prominently caused by internal and external environmental influences

  5. Continental emergence in the Late Archean reconciles early and late continental growth models

    Science.gov (United States)

    Flament, Nicolas; Coltice, Nicolas; Rey, Patrice

    2014-05-01

    The analysis of ancient sediments (Rare Earth Element composition of black shales, isotopic strontium composition of marine carbonates, isotopic oxygen composition of zircons) suggests that continental growth culminated around the Archean-Proterozoic transition. In stark contrast, the geochemical analysis of ancient basalts suggests that depletion of the mantle occurred in the Hadean and Eoarchean. This paradox may be solved if continents were extracted from the mantle early in Earth's history, but remained mostly below sea level throughout the Archean. We present a model to estimate the area of emerged land and associated isotopic strontium composition of the mantle and oceans as a function of the coupled evolution of mantle temperature, continental growth and distribution of surface elevations (hypsometry). For constant continental hypsometry and four distinct continental growth models, we show that sea level was between 500 and 2000 m higher in the Archean than at present, resulting in isotopic composition of the mantle and oceans, we show that a reduced area of emerged continental crust can explain why the geochemical fingerprint of continents extracted early in Earth's history was not recorded at the surface of the Earth until the late Archean.

  6. Basins in ARC-continental collisions

    Science.gov (United States)

    Draut, Amy E.; Clift, Peter D.; Busby, Cathy; Azor, Antonio

    2012-01-01

    Arc-continent collisions occur commonly in the plate-tectonic cycle and result in rapidly formed and rapidly collapsing orogens, often spanning just 5-15 My. Growth of continental masses through arc-continent collision is widely thought to be a major process governing the structural and geochemical evolution of the continental crust over geologic time. Collisions of intra-oceanic arcs with passive continental margins (a situation in which the arc, on the upper plate, faces the continent) involve a substantially different geometry than collisions of intra-oceanic arcs with active continental margins (a situation requiring more than one convergence zone and in which the arc, on the lower plate, backs into the continent), with variable preservation potential for basins in each case. Substantial differences also occur between trench and forearc evolution in tectonically erosive versus tectonically accreting margins, both before and after collision. We examine the evolution of trenches, trench-slope basins, forearc basins, intra-arc basins, and backarc basins during arc-continent collision. The preservation potential of trench-slope basins is low; in collision they are rapidly uplifted and eroded, and at erosive margins they are progressively destroyed by subduction erosion. Post-collisional preservation of trench sediment and trench-slope basins is biased toward margins that were tectonically accreting for a substantial length of time before collision. Forearc basins in erosive margins are usually floored by strong lithosphere and may survive collision with a passive margin, sometimes continuing sedimentation throughout collision and orogeny. The low flexural rigidity of intra-arc basins makes them deep and, if preserved, potentially long records of arc and collisional tectonism. Backarc basins, in contrast, are typically subducted and their sediment either lost or preserved only as fragments in melange sequences. A substantial proportion of the sediment derived from

  7. On the Evolution of Glaciated Continental Margins

    Science.gov (United States)

    Sverre Laberg, Jan; Rydningen, Tom Arne; Safronova, Polina A.; Forwick, Matthias

    2016-04-01

    Glaciated continental margins, continental margins where a grounded ice sheet repeatedly has been at or near the shelf break, are found at both northern and southern high-latitudes. Their evolution are in several aspects different from their low-latitude counterparts where eustatic sea-level variations possess a fundamental control on their evolution and where fluvial systems provide the main sediment input. From studies of the Norwegian - Barents Sea - Svalbard and NE Greenland continental margins we propose the following factors as the main control on the evolution of glaciated continental margins: 1) Pre-glacial relief controlling the accommodation space, 2) Ice sheet glaciology including the location of fast-flowing ice streams where source area morphology exerts a fundamental control, 3) Composition of the glacigenic sediments where the clay content in previous studies have been found to be important, and 4) Sea-level controlled both by eustacy and isostacy. From three case studies, 1) the western Barents Sea, 2) part of the North Norwegian (Troms), and 3) the Mid-Norwegian margin, the influence on these factors for the sea-floor morphology, sedimentary processes of the continental slope - deep sea and continental margin architecture are discussed. The pre-glacial relief of the mid-Norwegian and Troms margins relates to the onset of rifting and plate break-up from the early Cenozoic while for the SW Barents Sea, plate shear was followed by rifting. A wide zone of extended continental crust occurs offshore mid-Norway while this zone is much narrower offshore Troms leading to a more pronounced pre-glacial relief. Regarding sediment delivery and ice sheet glaciology the western Barents Sea exemplifies very high sediment input corresponding to an estimated average erosion of the source area of ~0.4 mm/yr (SW Barents Sea), much of which is related to subglacial erosion of Mesozoic - Cenozoic sedimentary rocks from large paleo-ice streams. The mid-Norwegian margin

  8. Reconstructing Rodinia by Fitting Neoproterozoic Continental Margins

    Science.gov (United States)

    Stewart, John H.

    2009-01-01

    Reconstructions of Phanerozoic tectonic plates can be closely constrained by lithologic correlations across conjugate margins by paleontologic information, by correlation of orogenic belts, by paleomagnetic location of continents, and by ocean floor magmatic stripes. In contrast, Proterozoic reconstructions are hindered by the lack of some of these tools or the lack of their precision. To overcome some of these difficulties, this report focuses on a different method of reconstruction, namely the use of the shape of continents to assemble the supercontinent of Rodinia, much like a jigsaw puzzle. Compared to the vast amount of information available for Phanerozoic systems, such a limited approach for Proterozoic rocks, may seem suspect. However, using the assembly of the southern continents (South America, Africa, India, Arabia, Antarctica, and Australia) as an example, a very tight fit of the continents is apparent and illustrates the power of the jigsaw puzzle method. This report focuses on Neoproterozoic rocks, which are shown on two new detailed geologic maps that constitute the backbone of the study. The report also describes the Neoproterozoic, but younger or older rocks are not discussed or not discussed in detail. The Neoproterozoic continents and continental margins are identified based on the distribution of continental-margin sedimentary and magmatic rocks that define the break-up margins of Rodinia. These Neoproterozoic continental exposures, as well as critical Neo- and Meso-Neoproterozoic tectonic features shown on the two new map compilations, are used to reconstruct the Mesoproterozoic supercontinent of Rodinia. This approach differs from the common approach of using fold belts to define structural features deemed important in the Rodinian reconstruction. Fold belts are difficult to date, and many are significantly younger than the time frame considered here (1,200 to 850 Ma). Identifying Neoproterozoic continental margins, which are primarily

  9. Initiation of continental accretion: metamorphic conditions

    Science.gov (United States)

    Clement, Conand; Frederic, Mouthereau; Gianreto, Manatschal; Adbeltif, Lahfid

    2017-04-01

    The physical processes involved at the beginning of the continental collision are largely unknown because they are transient and therefore hardly identifiable from the rock record. Despite the importance of key parameters for understanding mountain building processes, especially the formation of deep mountain roots and their impacts on earthquakes nucleation, rock/fluid transfers and oil/gas resources in the continental crust, observations from the earliest collision stages remain fragmentary. Here, we focus on the example of Taiwan, a young and active mountain belt where the transition from oceanic subduction, accretion of the first continental margin to mature collision can be followed in space and time. We present preliminary results and provide key questions regarding the reconstruction of time-pressure-temperature paths of rocks & fluids to allow discriminating between rift-related thermal/rheological inheritance and burial/heating phases during convergence. Previous studies have focused on peak temperatures analyzed by Raman Spectrometry of Carbonaceous Matter from the deeper structural layers exposed in the Central Range of Taiwan. In the pre-rift sediments, these studies reported a positive gradient from West to Est, and values from units. Cross sections and maps with high resolution peak temperatures are in process as well as pressure estimations to determine how the sediments were metamorphosed. In addition to this work, we report a few inherited temperatures in the 390-570 °C range, indicating recycling of organic matter from metasediments that recorded HT events, likely originated from higher grade metamorphic units of mainland China, which have been eroded and deposited in the post-rift sediments.

  10. CSDP: Seismology of continental thermal regime

    Energy Technology Data Exchange (ETDEWEB)

    Aki, K.

    1989-04-01

    This is a progress report for the past one year of research (year 2 of 5-year project) under the project titled CSDP: Seismology of Continental Thermal Regime'', in which we proposed to develop seismological interpretation theory and methods applicable to complex structures encountered in continental geothermal areas and apply them to several candidate sites for the Continental Scientific Drilling Project. During the past year, two Ph.D. thesis works were completed under the present project. One is a USC thesis on seismic wave propagation in anisotropic media with application to defining fractures in the earth. The other is a MIT thesis on seismic Q and velocity structure for the magma-hydrothermal system of the Valles Caldera, New Mexico. The P.I. co-organized the first International Workshop on Volcanic Seismology at Capri, Italy in October 1988, and presented the keynote paper on the state-of-art of volcanic seismology''. We presented another paper at the workshop on Assorted Seismic Signals from Kilauea Volcano, Hawaii. Another international meeting, namely, the Chapman Conference on seismic anisotropy in the earth's crust at Berkeley, California in May 1988, was co-organized by the co-P.I. (P.C.L), and we presented our work on seismic waves in heterogeneous and anisotropic media. Adding the publications and presentations made in the past year to the list for the preceding year, the following table lists 21 papers published, submitted or presented in the past two years of the present project. 65 refs., 334 figs., 1 tab.

  11. Fractal behavior in continental crustal heat production

    Directory of Open Access Journals (Sweden)

    N. Vedanti

    2011-02-01

    Full Text Available The distribution of crustal heat production, which is the most important component in the elucidation of continental thermal structure, still remains a theoretical assumption. In general the heat production values must decrease with depth, but the form of decrease of heat production in the crust is not well understood. The commonly used heat production models are: "block model", in which heat production is constant from the surface to a given depth and the "exponential model", in which heat production diminishes as an exponential function of depth. The exponential model is more widely used wherein sources of the errors are heterogeneity of rock and long wavelength changes due to changes in lithology and tectonic elements, and as such exponential distribution does not work satisfactorily for the entire crust. In the present study, we analyze for the first time, deep crustal heat production data of six global areas namely Dharwar craton (India, Kaapvaal craton (South Africa, Baltic shield (Kola, Russia, Hidaka metamorphic belt (Japan, Nissho pluton (Japan and Continental Deep Drilling site (KTB, Germany. The power spectrum of all the studied data sets exhibits power law behaviour. This would mean slower decay of heat production with depth, which conforms to the known geologic composition of the crust. Minimum value of the scaling exponent has been found for the KTB borehole, which is apparently related to higher heat production of gneisses, however for other study areas, scaling exponent is almost similar. We also found that the lower values of scaling exponents are related to higher heat production in the crust as is the case in KTB. Present finding has a direct relevance in computation of temperature-depth profiles in continental regions.

  12. Crew coordination concepts: Continental Airlines CRM training

    Science.gov (United States)

    Christian, Darryl; Morgan, Alice

    1987-01-01

    The outline of the crew coordination concepts at Continental airlines is: (1) Present relevant theory: Contained in a pre-work package and in lecture/discussion form during the work course, (2) Discuss case examples: Contained in the pre-work for study and use during the course; and (3) Simulate practice problems: Introduced during the course as the beginning of an ongoing process. These concepts which are designed to address the problem pilots have in understanding the interaction between situations and their own theories of practice are briefly discussed.

  13. Continental DC电动汽车

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    在“Greenpower Corporate Challenge”(2008绿色动力团体挑战赛)上,宾利向世人展示了他们的最新研究作品——Continental DC电动汽车。这款获得“Spirit of Greenpower”(最佳精神奖)的小型单座式电动车由Tom Hodgson、Andrew Conneely、Martyn Brookes等九名宾利汽车的年轻学员组成的小团队共同完成。

  14. Developing the plate tectonics from oceanic subduction to continental collision

    Institute of Scientific and Technical Information of China (English)

    ZHENG YongFei; YE Kai; ZHANG LiFei

    2009-01-01

    The studies of continental deep subduction and ultrahigh-pressure metamorphism have not only promoted the development of solid earth science in China,but also provided an excellent opportunity to advance the plate tectonics theory.In view of the nature of subducted crust,two types of subduction and collision have been respectively recognized in nature.On one hand,the crustal subduction occurs due to underflow of either oceanic crust (Pacific type) or continental crust (Alpine type).On the other hand,the continental collision proceeds by arc-continent collision (Himalaya-Tibet type) or continent-continent collision (Dabie-Sulu type).The key issues in the future study of continental dynamics are the chemical changes and differential exhumation in continental deep subduction zones,and the temporal-spatial transition from oceanic subduction to continental subduction.

  15. Deformation and seismicity associated with continental rift zones propagating toward continental margins

    Science.gov (United States)

    Lyakhovsky, V.; Segev, A.; Schattner, U.; Weinberger, R.

    2012-01-01

    We study the propagation of a continental rift and its interaction with a continental margin utilizing a 3-D lithospheric model with a seismogenic crust governed by a damage rheology. A long-standing problem in rift-mechanics, known as thetectonic force paradox, is that the magnitude of the tectonic forces required for rifting are not large enough in the absence of basaltic magmatism. Our modeling results demonstrate that under moderate rift-driving tectonic forces the rift propagation is feasible even in the absence of magmatism. This is due to gradual weakening and "long-term memory" of fractured rocks that lead to a significantly lower yielding stress than that of the surrounding intact rocks. We show that the style, rate and the associated seismicity pattern of the rift zone formation in the continental lithosphere depend not only on the applied tectonic forces, but also on the rate of healing. Accounting for the memory effect provides a feasible solution for thetectonic force paradox. Our modeling results also demonstrate how the lithosphere structure affects the geometry of the propagating rift system toward a continental margin. Thinning of the crystalline crust leads to a decrease in the propagation rate and possibly to rift termination across the margin. In such a case, a new fault system is created perpendicular to the direction of the rift propagation. These results reveal that the local lithosphere structure is one of the key factors controlling the geometry of the evolving rift system and seismicity pattern.

  16. Potential mechanisms of pore-fluid movement from continental lithospheric mantle into upper continental crust

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chong-bin; PENG Sheng-lin; LIU Liang-ming; B.E.HOBBS; A.ORD

    2008-01-01

    Through integrating the state of the art scientific knowledge in different research fields, some potential mechanisms of large-scale movements of underground pore-fluids such as H2O and CO2 in the continental lithosphere were presented and discussed. The results show that the generation and propagation of porosity waves are important mechanisms to transport mass and heat fluxes from the continental lithospheric mantle into the lower continental crust; the generation and propagation of porosity waves, pore-fluid flow focusing through lower and middle crustal faults, aclvection of pore-fluids through the lower and middle crust, and whole-crustconvection in some particular cases are important mechanisms to transport mass and heat fluxes from the lower into the upper continental crust; heat and mass transport through convective pore-fluid flow is the most effective mechanism of ore body formation and mineralization in hydrothermal systems; due to heat and mass exchange at the interface between the earth surface, hydrosphere and atmosphere, it is very important to consider the hydro-geological effect of the deep earth pore-fluids such as H2O and CO2 on the global warming and climate change in future investigations.

  17. Continental cement trial burn strategy follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Woodford, J. [Gossman Consulting, Inc., Springboro, OH (United States); Winders, H. [Continental Cement Company, Hannibal, MO (United States); Constans, D.L. [Gossman Consulting, Inc., Peachtree City, GA (United States)

    1997-12-31

    The Continental Trial Burn strategy, presented at the 1995 BIF Conference, included the use of {open_quotes}data-in-lieu-of{close_quotes} from previous compliance testing conducted at the facility. Since the submission of the Trial Burn Plan and the 1995 presentation, Continental Cement has completed their two campaign trial burn. This paper will update the implementation of the Continental Trial Burn strategy. 1 fig., 1 tab.

  18. Generation of continental crust in intra-oceanic arcs

    Science.gov (United States)

    Gazel, E.; Hayes, J. L.; Kelemen, P. B.; Everson, E. D.; Holbrook, W. S.; Vance, E.

    2014-12-01

    The origin of continental crust is still an unsolved mystery in the evolution of our planet. Although the best candidates to produce juvenile continental crust are intra-oceanic arcs these systems are dominated by basaltic lavas, and when silicic magmas are produced, the incompatible-element compositions are generally too depleted to be a good match for continental crust estimates. Others, such as the W. Aleutians, are dominated by andesitic melts with trace element compositions similar to average continental crust. In order to evaluate which intra-oceanic arcs produced modern continental crust, we developed a geochemical continental index (CI) through a statistical analysis that compared all available data from modern intra-oceanic arcs with global estimates of continental crust. Our results suggest that magmas from Costa Rica (100 have the least continent-like geochemical signatures. In these arcs the subducting plate is old (>100 Ma), not overprinted by enriched intraplate volcanism and the geochemistry may be dominated by slab-derived, aqueous fluids. We also found a strong correlation between the CI and average crustal P-wave velocity, validating the geochemical index with the available seismic data for intra-oceanic arcs. In conclusion, the production of young continental crust with compositions similar to Archean continental crust is an unusual process, limited to locations where there are especially voluminous partial melts of oceanic crust.

  19. Aeromagnetic data and geological structure of continental China: A review

    Science.gov (United States)

    Xiong, Sheng-Qing; Tong, Jing; Ding, Yan-Yun; Li, Zhan-Kui

    2016-06-01

    We review the latest aeromagnetic geological data of continental China. We discuss the latest achievements in geological mapping and the newly detected features based on aeromagnetic data. Using aeromagnetic data collected for more than 50 years, a series of 1:5000000 and 1:1000000 aeromagnetic maps of continental China were compiled using state-of-the-art digital technology, and data processing and transformation. Guided by plate tectonics and continental dynamics, rock physical properties, and magnetic anomalies, we compiled maps of the depth of the magnetic basement of continental China and the major geotectonic units, and presented newly detected geological structures based on the aeromagnetic data.

  20. Organic acids in continental background aerosols

    Science.gov (United States)

    Limbeck, Andreas; Puxbaum, Hans

    With a newly developed method aerosol samples from three distinctly different continental sites were analyzed: an urban site (Vienna), a savanna site in South Africa (Nylsvley Nature Reserve, NNR) and a free tropospheric continental background site (Sonnblick Observatory, SBO). In all samples a range of monocarboxylic acids (MCAs) and dicarboxylic acids (DCAs) has been identified and quantified. The three most abundant MCAs in Vienna were the C18, C16 and C14 acids with concentrations of 66, 45 and 36 ng m -3, respectively. At the mid tropospheric background site (SBO) the three most abundant MCAs were the C18, C16 and C12 acid. For the DCAs at all three sites oxalic, malonic and succinic acid were the dominant compounds. For some individual compounds an information about the sources could be obtained. For example the determined unsaturated MCAs in South Africa appear to result from biogenic sources whereas in Vienna those acids are considered to be derived from combustion processes. Oxalic and glyoxalic acid appear to have a free tropospheric air chemical source. The relative high amounts at SBO in comparison to Vienna can only be explained by secondary formation of oxalic acid in the atmosphere.

  1. Continental moisture recycling as a Poisson process

    Directory of Open Access Journals (Sweden)

    H. F. Goessling

    2013-04-01

    Full Text Available On their journey across large land masses, water molecules experience a number of precipitation-evaporation cycles (recycling events. We derive analytically the frequency distributions of recycling events for the water molecules contained in a given air parcel. Given the validity of certain simplifying assumptions, continental moisture recycling is shown to develop either into a Poisson distribution or a geometric distribution. We distinguish two cases: in case (A recycling events are counted since the water molecules were last advected across the ocean-land boundary. In case (B recycling events are counted since the water molecules were last evaporated from the ocean. For case B we show by means of a simple scale analysis that, given the conditions on Earth, realistic frequency distributions may be regarded as a mixture of a Poisson distribution and a geometric distribution. By contrast, in case A the Poisson distribution generally appears as a reasonable approximation. This conclusion is consistent with the simulation results of an earlier study where an atmospheric general circulation model equipped with water vapor tracers was used. Our results demonstrate that continental moisture recycling can be interpreted as a Poisson process.

  2. A vision for a continental energy strategy

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R. [Borden Ladner Gervais LLP, Calgary, AB (Canada); Tobin, B. [Fraser Milner Casgrain LLP. Toronto, ON (Canada); Angevine, G. [Angevine Economic Consulting Ltd., Calgary, AB (Canada); Fryer, K.; Martin, L.T. [Fraser Inst., Vancouver, BC (Canada)] (eds.)

    2008-02-15

    This paper presented a vision with respect to a continental energy strategy and the principles and goals that must underlie such a strategy. These principles include relying on signals emanating from energy markets to guide investment; limiting the role of government to that of ensuring that the policy and institutional framework is conducive to the development and operation of competitive and innovative energy markets; and ensuring free and open energy trade in energy commodities, both within the continent and with the rest of the world. The paper also identified a number of important factors that, would shape and condition continental energy development and trade. The paper provided an overview of the North American energy use and supply situation for the following resources: oil; natural gas; electricity; coal; nuclear power; hydroelectricity; geothermal energy; wind power; solar power; and ethanol. It also discussed the contribution of the North American Free Trade Agreement (NAFTA) through increased natural gas exports. It was concluded that given the petroleum resources of the three countries and their increased value because of higher oil and gas prices, there was considerable incentive for Canada, the United States, and Mexico to streamline regulations in order to facilitate the efficient development, transportation, and use of the continent's energy resources in accordance with market conditions. 38 refs., 2 tabs., 21 figs.

  3. Ensuring a successful family business management succession

    OpenAIRE

    Desbois, Joris

    2016-01-01

    Succession is the biggest long-term challenge that most family businesses face. Indeed, leaders ‘disposition to plan for their succession is frequently the key factor defining whether their family business subsists or stops. The research seeks to find out how to manage successfully the business management succession over main principles. This work project aims at researching the key points relevant to almost all family firms, to have a viable succession transition and positioni...

  4. Continental Transform Boundaries: Tectonic Evolution and Geohazards

    Directory of Open Access Journals (Sweden)

    Michael Steckler

    2012-04-01

    Full Text Available Continental transform boundaries cross heavily populated regions, and they are associated with destructive earthquakes,for example, the North Anatolian Fault (NAFacross Turkey, the Enriquillo-Plantain Garden fault in Haiti,the San Andreas Fault in California, and the El Pilar fault in Venezuela. Transform basins are important because they are typically associated with 3-D fault geometries controlling segmentation—thus, the size and timing of damaging earthquakes—and because sediments record both deformation and earthquakes. Even though transform basins have been extensively studied, their evolution remains controversial because we don’t understand the specifics about coupling of vertical and horizontal motions and about the basins’long-term kinematics. Seismic and tsunami hazard assessments require knowing architecture and kinematics of faultsas well as how the faults are segmented.

  5. Moho and magmatic underplating in continental lithosphere

    DEFF Research Database (Denmark)

    Thybo, Hans; Artemieva, Irina M.

    2013-01-01

    fractionation during cooling and solidification in the lower crust. Separation of the low density material from the high-density residue may be a main process of formation of continental crust with its characteristic low average density, also during the early evolution of the Earth. Despite the assumed...... importance of underplating processes and associated fractionation, the available geophysical images of underplated material remain relatively sparse and confined to specific tectonic environments. Direct ponding of magma at the Moho is only observed in very few locations, probably because magma usually...... interacts with the surrounding crustal rocks which leads to smearing of geophysical signals from the underplated material. In terms of processes, there is no direct discriminator between the traditional concept of underplated material and lower crustal magmatic intrusions in the form of batholiths and sill...

  6. Coordination: southeast continental shelf studies. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, D.W.

    1980-03-01

    The GABEX I experiment is designed to provide synoptic coverage of a series of Gulf Stream wave-like disturbances, the effect of these on the circulation of the entire shelf, and on biological and chemical processes. This study was initiated in February 1980 when current meter arrays were deployed. These meters will be removed in July 1980. In April three ships will simultaneously study the effects of Gulf Stream disturbances on the hydrography, chemistry, and biology of the shelf. One vessel will track a specific wave-like disturbance and provide synoptic coverage of the shelf area. The second vessel will determine the effect of shelf break processes on adjacent shelf water; and the third will study trace metal distributions in and outside of disturbances. Research progress is reported in continental shelf studies, nearshore and estuarine studies (diffusion of freshwater out of nearshore zone), tidal currents and material transport, and mixing of inlet plumes.

  7. Crude oil production prospects for continental Europe

    Energy Technology Data Exchange (ETDEWEB)

    Appleby, P. [British Petroleum Co. Ltd., London (United Kingdom)

    1996-10-01

    A medium term view of the prospects for oil production in continental Europe, focusing on the offshore production in UK and Norwegian waters, is presented. The paper begins with a recent history and an overview of current oil production and recent trends. The growth of North Sea production has been important, contributing more than two-thirds of the growth in non OPEC oil production. The development of the Andrew field in the UK North Sea is presented as an example of new management methods succeeding in enhancing the economic viability of oil fields that would otherwise be marginal or non economic The Foinaven field in the new West of Shetlands province illustrates the way in which the combination of technological advances and changes in industry practices is extending the frontiers of commercial viability. Supply projections show North Sea production continuing to grow, but not as rapidly as over the past five years. (author). 7 figs., 8 refs.

  8. Oceanography of the Southeastern Continental Shelf

    Science.gov (United States)

    This volume, the second in the Coastal and Estuarine Sciences series, provides a synthesis of the physical, chemical, and biological oceanography of the South Atlantic Bight (SAB). The results presented derive from a decade-long multidisciplinary investigation of the SAB continental shelf regime.The SAB extends from West Palm Beach, Fla., where the narrow south Florida shelf begins to broaden, to Cape Hatteras, N.C., where the shelf again narrows. This broad and shallow area is distinguished by the proximity of the Gulf Stream to the shelf break. Large contrasts in the distribution of properties, the strength of oceanic and atmospheric forces, and the high frequency (4-12 days) at which these forces vary have created a unique natural laboratory in which a variety of oceanic processes may be studied.

  9. 31 CFR 535.321 - United States; continental United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory...

  10. 31 CFR 515.321 - United States; continental United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory...

  11. 31 CFR 500.321 - United States; continental United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 500.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including U.S. trust...

  12. Crustal growth at active continental margins: Numerical modeling

    NARCIS (Netherlands)

    Vogt, Katharina|info:eu-repo/dai/nl/370618947; Gerya, Taras; Castro, Antonio

    2012-01-01

    The dynamics and melt sources for crustal growth at active continental margins are analyzed by using a 2D coupled petrological–thermomechanical numerical model of an oceanic-continental subduction zone. This model includes spontaneous slab retreat and bending, dehydration of subducted crust, aqueous

  13. Temporal change in fragmentation of continental US forests

    Science.gov (United States)

    James D. Wickham; Kurt H. Riitters; Timothy G. Wade; Collin Homer

    2008-01-01

    Changes in forest ecosystem function and condition arise from changes in forest fragmentation. Previous studies estimated forest fragmentation for the continental United States (US). In this study, new temporal land-cover data from the National Land Cover Database (NLCD) were used to estimate changes in forest fragmentation at multiple scales for the continental US....

  14. Ethical Wills – a Continental Law Perspective

    Directory of Open Access Journals (Sweden)

    Frederik Swennen

    2014-04-01

    Full Text Available Ethical wills are testaments, or planning instruments mortis causa alike, that contain provisions regarding the deceased’s (non-economic values rather than his (economic valuables. The authors define and analyse the substance and form of ethical wills from a comparative Continental law perspective, drawing on Belgian, Dutch, French and German law. The focus primarily is on charges or conditions in restraint or constraint of (non- denominational or family choices by testamentary beneficiaries; and in this context it is contended that both the doctrine of public policy (“ordre public” and the horizontal application of the ECHR extensively restrict testamentary freedom. Nevertheless, the analogous application of estate planning techniques increasingly allows benevolent testators to plan their ethical legacy. Los testamentos éticos son testamentos, similares a instrumentos de planificación mortis causa, que contienen disposiciones relativas a los valores (no económicos del difunto, en lugar de sus objetos de valor (económico. Los autores definen y analizan el contenido y la forma de los testamentos éticos desde una perspectiva comparativa de derecho continental, basada en la legislación belga, holandesa, francesa y alemana. Se centra principalmente en los cargos o las condiciones de restricción o limitación de las opciones (aconfesionales o familiares de los herederos; y en este contexto se afirma que tanto la doctrina de política pública ("ordre public" como la aplicación horizontal del Tribunal Europeo de Derechos Humanos, restringen ampliamente la libertad testamentaria. Sin embargo, la aplicación análoga de técnicas de planificación y gestión patrimonial y sucesoria, permite cada vez más a los testadores de últimas voluntades planificar su legado ético.

  15. Progress towards Continental River Dynamics modeling

    Science.gov (United States)

    Yu, Cheng-Wei; Zheng, Xing; Liu, Frank; Maidment, Daivd; Hodges, Ben

    2017-04-01

    The high-resolution National Water Model (NWM), launched by U.S. National Oceanic and Atmospheric Administration (NOAA) in August 2016, has shown it is possible to provide real-time flow prediction in rivers and streams across the entire continental United States. The next step for continental-scale modeling is moving from reduced physics (e.g. Muskingum-Cunge) to full dynamic modeling with the Saint-Venant equations. The Simulation Program for River Networks (SPRNT) provides a computational approach for the Saint-Venant equations, but obtaining sufficient channel bathymetric data and hydraulic roughness is seen as a critical challenge. However, recent work has shown the Height Above Nearest Drainage (HAND) method can be applied with the National Elevation Dataset (NED) to provide automated estimation of effective channel bathymetry suitable for large-scale hydraulic simulations. The present work examines the use of SPRNT with the National Hydrography Dataset (NHD) and HAND-derived bathymetry for automated generation of rating curves that can be compared to existing data. The approach can, in theory, be applied to every stream reach in the NHD and thus provide flood guidance where none is available. To test this idea we generated 2000+ rating curves in two catchments in Texas and Alabama (USA). Field data from the USGS and flood records from an Austin, Texas flood in May 2015 were used as validation. Large-scale implementation of this idea requires addressing several critical difficulties associated with numerical instabilities, including ill-posed boundary conditions generated in automated model linkages and inconsistencies in the river geometry. A key to future progress is identifying efficient approaches to isolate numerical instability contributors in a large time-space varying solution. This research was supported in part by the National Science Foundation under grant number CCF-1331610.

  16. Modelling of temperatures in continental convergence zones

    Energy Technology Data Exchange (ETDEWEB)

    Toksoz, M.N.; Bird, P.

    1977-08-03

    The thermal histories of continent-continent convergence zones are modelled by a finite-difference technique in an attempt to explain geologic observations of heating and melting in such zones. The suture zone between two converging continents divides a passively heated overriding plate from a quiet continental margin which is suddenly deformed in the collision. Both regions may be metamorphosed and intruded. On the continental-shelf side where mountains are formed by underthrusting within the crust, it was found that adiabatic and radioactive heating are negligible during the orogeny. Shear-strain heating may raise the fault zones to about 500/sup 0/C. At higher temperatures, dislocation creep of crustal rocks would be expected from laboratory results. Even high crustal radioactivity will not produce melting in less than 40 m.y. Thus any plutons in this zone (the granites of the Zagros, Urals, and Himalayas) probably result indirectly by melting of crust that is heated by deep asthenospheric intrusions, which may reach the crust at the time of detachment of the oceanic slab, combined with the effects of friction and water along the subduction plane. Across the suture, the thermal history begins before the collision during the oceanic subduction phase. The sinking slab creates asthenospheric circulations, which warm the passive plate from below and intrude it in an Andean-type arc along the suture (Zagros and Himalayan region). If total subduction exceeds about 3000 km the slow warming has time to weaken the plate and extensive crustal shortening may follow the collision. Crustal shortening and thickening is accompanied by differentiation and volcanism (Tibetan and Grenville orogenies). Thermal modelling of Tibet shows that volcanism cannot be produced in the available time by crustal thickening alone, but requires the initial warming phase as well.

  17. Reservoir potential of thin-bedded sandstone in continental mudrock successions - The search for hidden treasures

    NARCIS (Netherlands)

    Donselaar, M.E.; Bouman, L.; Noordijk, N.; Van Toorenenburg, K.A.; Weltje, G.J.

    2015-01-01

    The subsurface of the West European gas province contains up to several hundred meters thick continuous Upper Rotliegend and Lower Triassic mud rock sequences which have to date been labelled as nonreservoir ‘waste zone’. The mud rock formed as fluvial floodplain deposits in a semi-arid climate. The

  18. 76 FR 58273 - Agency Information Collection Activities; Proposed Collection; Comment Request; Outer Continental...

    Science.gov (United States)

    2011-09-20

    ... AGENCY Agency Information Collection Activities; Proposed Collection; Comment Request; Outer Continental... Collection Activities; Proposed Collection; Comment Request; Outer Continental Shelf Air Regulations; EPA ICR... all outer continental shelf (OCS) sources except those located in the Gulf of Mexico west of...

  19. 76 FR 54787 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Science.gov (United States)

    2011-09-02

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY... revised North American Datum of 1927 (NAD 27) Outer Continental Shelf Official Protraction Diagram,...

  20. 76 FR 7518 - Outer Continental Shelf Air Regulations Consistency Update for Alaska

    Science.gov (United States)

    2011-02-10

    ... AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for Alaska AGENCY... of the Outer Continental Shelf (``OCS'') Air Regulations. Requirements applying to OCS sources..., Intergovernmental relations, Nitrogen dioxide, Nitrogen oxides, Outer Continental Shelf, Ozone, Particulate...

  1. 77 FR 52630 - Outer Continental Shelf Air Regulations Consistency Update for California

    Science.gov (United States)

    2012-08-30

    ... AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for California AGENCY... of the Outer Continental Shelf (``OCS'') Air Regulations. Requirements applying to OCS sources..., Intergovernmental relations, Nitrogen dioxide, Nitrogen oxides, Outer Continental Shelf, Ozone, Particulate...

  2. 76 FR 15898 - Outer Continental Shelf Air Regulations; Consistency Update for California

    Science.gov (United States)

    2011-03-22

    ... AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations; Consistency Update for California AGENCY... of the Outer Continental Shelf (``OCS'') Air Regulations. Requirements applying to OCS sources... oxides, Outer Continental Shelf, Ozone, Particulate matter, Permits, Reporting and...

  3. How a Curvilinear Continental Margin Influences Its Subsidence History

    Science.gov (United States)

    Sacek, V.; Ussami, N.

    2012-12-01

    Current one-dimensional (1D) and two-dimensional (2D) thermo-mechanical models successfully explain the first-order vertical motions of sedimentary basins created by lithospheric extension. However, the modeling of second-order effects such as extra-subsidence, non-monotonic-subsidence or protracted-subsidence still remains controversial. One aspect that has not been fully considered in the current models is that the rifting direction leading to the continental break-up does not always follow a straight line, which demands a three-dimensional (3D) approach. The aim of this work is to demonstrate the importance of using a 3D model that takes into account the curvature of rifting along the margin and theoretically predicts some of the second-order subsidence observations. Our results indicate that concave oceanward margins tend to subside faster than convex ones. This differential subsidence of the margin is a result of the combined effect of lateral thermal conduction, small-scale mantle (or edge driven) convection and the curvature of the rifting. We have used the finite element code CITCOM (Moresi & Gurnis, 1996; Zhong et al., 2000) to construct 3D numerical models of the mantle convection and its effect on the surface evolution. We observed that the differential subsidence along a curved margin is dependent on the viscosity structure of the mantle: for an asthenospheric viscosity of 5×1020 Pa.s the differential subsidence can reach more than 700 m assuming a sediment filled basin; however, for low asthenospheric viscosity (geometry. As an application of this 3D conceptual model for curved margin, we analysed the stratigraphic evolution of the Santos Basin, offshore Southeastern Brazil, and we propose that the variations in the subsidence history along the margin can be explained by its 3D geometry and the dynamical evolution of the mantle. We conclude that the incorporation of the third dimension in the study of the subsidence history of divergent margins may

  4. Gondwanaland origin, dispersion, and accretion of East and Southeast Asian continental terranes

    Science.gov (United States)

    Metcalfe, I.

    1994-10-01

    East and Southeast Asia is a complex assembly of allochthonous continental terranes, island arcs, accretionary complexes and small ocean basins. The boundaries between continental terranes are marked by major fault zones or by sutures recognized by the presence of ophiolites, mélanges and accretionary complexes. Stratigraphical, sedimentological, paleobiogeographical and paleomagnetic data suggest that all of the East and Southeast Asian continental terranes were derived directly or indirectly from the Iran-Himalaya-Australia margin of Gondwanaland. The evolution of the terranes is one of rifting from Gondwanaland, northwards drift and amalgamation/accretion to form present day East Asia. Three continental silvers were rifted from the northeast margin of Gondwanaland in the Silurian-Early Devonian (North China, South China, Indochina/East Malaya, Qamdo-Simao and Tarim terranes), Early-Middle Permian (Sibumasu, Lhasa and Qiangtang terranes) and Late Jurassic (West Burma terrane, Woyla terranes). The northwards drift of these terranes was effected by the opening and closing of three successive Tethys oceans, the Paleo-Tethys, Meso-Tethys and Ceno-Tethys. Terrane assembly took place between the Late Paleozoic and Cenozoic, but the precise timings of amalgamation and accretion are still contentious. Amalgamation of South China and Indochina/East Malaya occurred during the Early Carboniferous along the Song Ma Suture to form "Cathaysialand". Cathaysialand, together with North China, formed a large continental region within the Paleotethys during the Late Carboniferous and Permian. Paleomagnetic data indicate that this continental region was in equatorial to low northern paleolatitudes which is consistent with the tropical Cathaysian flora developed on these terranes. The Tarim terrane (together with the Kunlun, Qaidam and Ala Shan terranes) accreted to Kazakhstan/Siberia in the Permian. This was followed by the suturing of Sibumasu and Qiangtang to Cathaysialand in the

  5. Multidisciplinary approach for the characterization of a new Late Cretaceous continental arc in the Central Pontides (Northern Turkey)

    Science.gov (United States)

    Ellero, Alessandro; Ottria, Giuseppe; Sayit, Kaan; Catanzariti, Rita; Frassi, Chiara; Cemal Göncüoǧlu, M.; Marroni, Michele; Pandolfi, Luca

    2016-04-01

    In the Central Pontides (Northern Turkey), south of Tosya, a tectonic unit consisting of not-metamorphic volcanic rocks and overlying sedimentary succession is exposed inside a fault-bounded elongated block. It is restrained within a wide shear zone, where the Intra-Pontide suture zone, the Sakarya terrane and the Izmir-Ankara-Erzincan suture zone are juxtaposed as result of strike-slip activity of the North Anatolian shear zone. The volcanic rocks are mainly basalts and basaltic andesites (with their pyroclastic equivalents) associated with a volcaniclastic formation made up of breccias and sandstones that are stratigraphically overlain by a Marly-calcareous turbidite formation. The calcareous nannofossil biostratigraphy points to a late Santonian-middle Campanian age (CC17-CC21 Zones) for the sedimentary succession. The geochemistry of the volcanic rocks reveals an active continental margin setting as evidenced by the enrichment in Th and LREE over HFSE, and the Nb-enriched nature of these lavas relative to N-MORB. As highlighted by the performed arenite petrography, the occurrence of continent-derived clastics in the sedimentary succession supports the hypothesis of a continental arc-derived volcanic succession. Alternative geodynamic reconstructions are proposed, where this tectonic unit could represent a slice derived from the northern continental margin of the Intra- Pontide or Izmir-Ankara-Erzincan oceanic basins.

  6. Continental shelf processes affecting the oceanography of the South Atlantic Bight. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Pietrafesa, L.J.

    1978-03-01

    The objectives of the project were to determine the physical/dynamical processes controlling/affecting the distribution of phytoplankton nutrients on the continental shelf in the South Atlantic Bight. The initial objectives were to determine the short term, i.e., 2 to 10 day and longer term flux of nutrients onto the continental shelf. This is clearly related to the more general problem of combined physical and biogenic control of phytoplankton nutrients. During the period from June, 1975 to March, 1978 the study of the continental shelf processes affecting the oceanography of the South Atlantic Bight has been principally involved with a substantial, coordinated field effort. The success of the data acquisition phase of the program has now required an intensive data analysis phase which has been slowly increasing in effort. Emphasis is placed on the main phase of the field program, located in Onslow Bay, which has beel completed and the data are being analyzed. During the three-year period 20 cruises were made into the Carolina Capes area and samples were collected. A list is included of some 100 publications during the period.

  7. Planning farm succession: how to be successful

    OpenAIRE

    Stephens, Mike

    2011-01-01

    Planning farm succession is really good farm planning in its broadest aspect. Unfortunately very few farmers and their families have devoted sufficient time to working out how the farm business will be transferred. After demonstrating the importance of the farm succession issue, this article goes on to explaining a method of successfully tackling the process.

  8. Tectonics of China: Continental scale cataclastic flow

    Science.gov (United States)

    Gallagher, John J., Jr.

    Stratigraphic, structural, and earthquake evidence indicates that cataclastic flow, that is, flow by brittle mechanisms (e.g., fracture and slip), was dominant in China from late Paleozoic. This process has operated over a range of scales including the continental scale. China is made up of large brittle basement elements immersed in ductile zones which are analogous to porphyroclasts (large, often brittle fragments) surrounded by fluxion (foliation or flow) structures in cataclastic rocks, respectively. This basement fabric for China is seen on Landsat imagery and on tectonic maps and is comparable to cataclastic rock fabrics seen in fault zones, on outcrops, and in thin sections. Brittle basement elements are broken into two or more large rigid blocks, and the dimensions of elements and blocks are within 1 order of magnitude of each other. Ductile zones are made up of fragments which are many orders of magnitude smaller than the ductile zones. Rigid blocks and fragments are identified, and their dimensions are measured through earthquake, fault, and fracture patterns. Rigid basement blocks are surrounded by earthquakes. The sedimentary rocks over the basement faults at the block boundaries seem to be affected by fault movements because they are characterized by facies changes, thickness changes, high-angle faults, and forced folds. Ductile basement zones are earthquake prone, and deformation of the ductile basement affects the overlying sedimentary rocks, as is demonstrated by unconformities and by a wide variety of structures. Thrust faults, buckle folds, and strike slip faults are common in and adjacent to western ductile zones. Structures are most intensely developed where ductile zones abut brittle elements. Both brittle elements and ductile zones are rifted and cut by strike slip faults in eastern China. The mechanical fabric of China and the boundary conditions acting on China are now and always have been determined by its plate tectonic history. This

  9. UNIDADES GEOMORFOLÓGICAS DE PORTUGAL CONTINENTAL

    Directory of Open Access Journals (Sweden)

    Diamantino Insua Pereira

    2014-12-01

    Full Text Available São representadas cartograficamente as unidades geomorfológicas identificadas para os 89015 km2 do território de Portugal Continental. A delimitação das unidades teve por base a análise dos padrões da textura fornecida por imagens SRTM, com revisão e adaptação posterior à altimetria e à geologia, para os quais foram usadas bases cartográficas digitais. Foram considerados três níveis taxionómicos que permitem descrever e caracterizar áreas homogéneas do ponto de vista geomorfológico. As três unidades de 1º nível baseiam-se nas unidades morfostruturais clássicas consideradas para a Península Ibérica. As dez unidades de 2º nível constituem, na sua maioria, divisões clássicas do relevo de Portugal Continental, agora agrupadas de acordo com a metodologia adoptada e designadas como unidades morfosculturais. As 56 unidades de 3º nível, ou subunidades morfosculturais, foram individualizadas com base nos padrões de relevo identificados nas imagens SRTM e na observação de campo e adquiriram uma designação baseada essencialmente nas geoformas que as individualizam e na toponímia local. As unidades geomorfológicas identificadas são descritas através de características do relevo, dissecação fluvial, estruturas, tipo de drenagem e base geológica, bem como de parâmetros numéricos gerados de forma automática, como classes de altitude e de declividade. Pretende-se que o mapa elaborado possa contribuir para a gestão territorial, em especial na tomada de decisões em conservação da natureza.

  10. Subduction-driven recycling of continental margin lithosphere.

    Science.gov (United States)

    Levander, A; Bezada, M J; Niu, F; Humphreys, E D; Palomeras, I; Thurner, S M; Masy, J; Schmitz, M; Gallart, J; Carbonell, R; Miller, M S

    2014-11-13

    Whereas subduction recycling of oceanic lithosphere is one of the central themes of plate tectonics, the recycling of continental lithosphere appears to be far more complicated and less well understood. Delamination and convective downwelling are two widely recognized processes invoked to explain the removal of lithospheric mantle under or adjacent to orogenic belts. Here we relate oceanic plate subduction to removal of adjacent continental lithosphere in certain plate tectonic settings. We have developed teleseismic body wave images from dense broadband seismic experiments that show higher than expected volumes of anomalously fast mantle associated with the subducted Atlantic slab under northeastern South America and the Alboran slab beneath the Gibraltar arc region; the anomalies are under, and are aligned with, the continental margins at depths greater than 200 kilometres. Rayleigh wave analysis finds that the lithospheric mantle under the continental margins is significantly thinner than expected, and that thin lithosphere extends from the orogens adjacent to the subduction zones inland to the edges of nearby cratonic cores. Taking these data together, here we describe a process that can lead to the loss of continental lithosphere adjacent to a subduction zone. Subducting oceanic plates can viscously entrain and remove the bottom of the continental thermal boundary layer lithosphere from adjacent continental margins. This drives surface tectonics and pre-conditions the margins for further deformation by creating topography along the lithosphere-asthenosphere boundary. This can lead to development of secondary downwellings under the continental interior, probably under both South America and the Gibraltar arc, and to delamination of the entire lithospheric mantle, as around the Gibraltar arc. This process reconciles numerous, sometimes mutually exclusive, geodynamic models proposed to explain the complex oceanic-continental tectonics of these subduction zones.

  11. Discoveries on the Norwegian continental shelf

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    As discussed in this document, there are 108 discoveries on the Norwegian continental shelf which so far have not been approved for development. The oil and gas resources of the Norwegian Sea and the Barents Sea are mostly found in discoveries containing large volumes of gas. Eighty-one of the discoveries which are not approved for development are located in the North Sea and more than 60% of the discoveries in this province contain less than 5 mill Sm{sup 3} oil equivalents. In the Norwegian Sea and the Barents Sea there are 27 discoveries which are not approved for development and whose total resources are estimated at 500 mill Sm{sup 3} oil equivalents. About 60% of the oil resources is expected to be comprised by development plans in 1997 or 1998. Another 20% is in new discoveries currently being evaluated or in discoveries containing large volumes of gas. Production forecasts indicate substantial vacant oil processing capacity after 2000. Vacant gas processing capacity will mainly arise after 2005. 23 figs., 3 tabs.

  12. Growth of the lower continental crust

    Science.gov (United States)

    Rudnick, Roberta L.

    1988-01-01

    One of the largest uncertainties in crustal composition and growth models is the nature of the lower continental crust. Specifically, by what processes is it formed and modified, and when is it formed, particularly in reference to the upper crust? The main reason for this lack of information is the scarcity of lower crustal rock samples. These are restricted to two types: rocks which outcrop in granulite facies terrains and granulite facies xenoliths which are transported to the earth's surface by young volcanics. The important conclusions arising from the xenolith studies are: the majority of mafic lower crustal xenoliths formed through cumulate process, resitic xenoliths are rare; and formation and metamorphism of the deep crust is intimately linked to igneous activity and/or orogeny which are manifest in one form or another at the earth's surface. Therefore, estimates of crustal growth based on surface exposures is representative, although the proportion of remobilized pre-existing crust may be significantly greater at the surface than in the deep crust.

  13. Estimating the global volume of deeply recycled continental crust at continental collision zones

    Science.gov (United States)

    Scholl, D. W.; Huene, R. V.

    2006-12-01

    CRUSTAL RECYCLING AT OCEAN MARGINS: Large volumes of rock and sediment are missing from the submerged forearcs of ocean margin subduction zones--OMSZs. This observation means that (1) oceanic sediment is transported beneath the margin to either crustally underplate the coastal region or reach mantle depths, and that (2) the crust of the forearc is vertically thinned and horizontally truncated and the removed material transported toward the mantle. Transport of rock and sediment debris occurs in the subduction channel that separates the upper and lower plates. At OMSZs the solid-volume flux of recycling crustal material is estimated to be globally ~2.5 km3/yr (i.e., 2.5 Armstrong units or AU). The corresponding rate of forearc truncation (migration of the trench axis toward a fix reference on the continent) is a sluggish 2-3 km/Myr (about 1/50th the orthogonal convergence rate). Nonetheless during the past 2.5 Gyr (i.e., since the beginning of the Proterozoic) a volume of continental material roughly equal to the existing volume (~7 billion cubic km) has been recycled to the mantle at OMSZs. The amount of crust that has been destroyed is so large that recycling must have been a major factor creating the mapped rock pattern and age-fabric of continental crust. RECYCLING AT CONTINENT/ARC COLLISIONS: The rate at which arc magmatism globally adds juvenile crust to OMSZs has been commonly globally estimated at ~1 AU. But new geophysical and dating information from the Aleutian and IBM arcs imply that the addition rate is at least ~5 AU (equivalent to ~125 km3/Myr/km of arc). If the Armstrong posit is correct that since the early Archean a balance has existed between additions and losses of crust, then a recycling sink for an additional 2-3 AU of continental material must exist. As the exposure of exhumed masses of high P/T blueschist bodies documents that subcrustal streaming of continental material occurs at OMSZs, so does the occurrence of exhumed masses of UHP

  14. Comparative riftology: insights from crustal structure into the evolution of continental rifts and passive continental margins

    Science.gov (United States)

    Kley, Jonas; Stein, Carol; Stein, Seth; Keller, Randy; Wysession, Michael; Frederiksen, Andrew

    2017-04-01

    Continental rifts evolve to seafloor spreading and are preserved in passive margins, or fail and remain as fossil features in continents. Rifts at different stages give insight into these different evolutionary paths. Of particular interest is how volcanic passive margins evolve. These features are characterized by sequences of volcanic rocks yielding magnetic anomalies landward of and sometimes larger than the oldest spreading anomalies. Seaward-dipping reflectors (SDR) occur in stretched continental crust landward of the oldest oceanic crust and are underplated by high-velocity lower crustal bodies. How and when these features form remains unclear. Insights are given by the Midcontinent Rift (MCR), formed by 1.1 Ga rifting of Amazonia from Laurentia, that failed once seafloor spreading was established elsewhere. MCR volcanics are much thicker than other continental flood basalts, due to deposition in a narrow rift rather than a broad region, giving a rift's geometry but a LIP's magma volume. The MCR provides a snapshot of the deposition of a thick highly magnetized volcanic section during rifting. Surface exposures and seismic-reflection data in and near Lake Superior show a rift basin filled by inward-dipping flood basalt layers. Had the rift evolved to seafloor spreading, the basin would have split into two sets of volcanics with opposite-facing SDRs, each with a strong magnetic anomaly. Because the rift formed as a series of alternating half-grabens, structural asymmetries between conjugate margins can naturally occur. Hence the MCR shows that many features form prior to breakup. Because the MCR was massively inverted by regional compression long after it failed and was uplifted, its structure is better known than failed rifts that incurred lesser degrees of inversion. It provides an end member for the evolution of actively extending rifts, characterized by upwelling mantle and negative gravity anomalies, in contrast to failed and inverted rifts without

  15. Continental Crust Growth as a Result of Continental Collision: Ocean Crust Melting and Melt Preservation

    Science.gov (United States)

    Niu, Y.; Zhao, Z.; Zhou, S.; Zhu, D.; Dong, G.; Mo, X.; Xie, G.; Dong, X.

    2010-12-01

    The significance of the continental crust (CC) on which we live is self-evident. However, our knowledge remains limited on its origin, its way and rate of growth, and how it has acquired the “andesitic” composition from mantle derived magmas. Compared to rocks formed from mantle derived magmas in all tectonic settings, volcanic arc rocks associated with oceanic lithosphere subduction share some common features with the CC; both are relatively depleted in “fluid-insoluble” elements (e.g., Nb, Ta and Ti), but enriched in “fluid-soluble” elements (e.g., U, K and Pb). These chemical characteristics are referred to as the “arc-like signature”, and point to a genetic link between subduction-zone magmatism and CC formation, thus leading to the “island-arc” model widely accepted for the origin of the CC over the past 40 years. However, it has been recognized also that this “island-arc” model has several difficulties. These include (1) bulk arc crust (AC) is basaltic, whereas the bulk CC is andesitic [1]; (2) AC has a variably large Sr excess whereas the CC is Sr deficient [2]; and (3) AC production is mass-balanced by subduction-erosion and sediment recycling, thus contributing no new mass to CC growth, at least in the Phanerozoic [3,4]. Our data on magmatic rocks (both volcanic and intrusive) formed during the India-Asia continental collision (~65 - ~45Ma) [5] show a remarkable compositional similarity to the bulk CC with the typical “arc-like signature” [6]. Also, these syncollisional felsic rocks exhibit strong mantle isotopic signatures, implying that they were recently derived from a mantle source. The petrology and geochemistry of these syncollisional felsic rocks is most consistent with an origin via partial melting of upper oceanic crust (i.e., last fragments of underthrusting oceanic crust) under amphibolite facies conditions, adding net mantle-derived materials to form juvenile CC mass. This leads to the logical and testable hypothesis

  16. Slumping on the western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.; Mohan, R.; Muralinath, A.S.

    A short gravity core from the Western Continental Margin of India has been examined to understand the nature and characteristics of slumping in the area. The present study and also the earlier studies revealed that the slumping on the western...

  17. First assessment of continental energy storage in CMIP5 simulations

    Science.gov (United States)

    Cuesta-Valero, Francisco José; García-García, Almudena; Beltrami, Hugo; Smerdon, Jason E.

    2016-05-01

    Although much of the energy gained by the climate system over the last century has been stored in the oceans, continental energy storage remains important to estimate the Earth's energy imbalance and also because crucial positive climate feedback processes such as soil carbon and permafrost stability depend on continental energy storage. Here for the first time, 32 general circulation model simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) are examined to assess their ability to characterize the continental energy storage. Results display a consistently lower magnitude of continental energy storage in CMIP5 simulations than the estimates from geothermal data. A large range in heat storage is present across the model ensemble, which is largely explained by the substantial differences in the bottom boundary depths used in each land surface component.

  18. International Conference on Continental Volcanism-IAVCEI 2006

    Institute of Scientific and Technical Information of China (English)

    Yigang Xu; Martin A Menzies

    2006-01-01

    @@ The International Conference on Continental Volcanism, sponsored by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI), was held at White Swan Hotel, Guangzhou, China, May 14th to 18th, 2006.

  19. Manganese, Iron, and sulfur cycling in Louisiana continental shelf sediments

    Science.gov (United States)

    Sulfate reduction is considered the primary pathway for organic carbon remineralization on the northern Gulf of Mexico Louisiana continental shelf (LCS) where bottom waters are seasonally hypoxic, yet limited information is available on the importance of iron and manganese cyclin...

  20. Comparative biogeochemistry–ecosystem–human interactions on dynamic continental margins..

    Digital Repository Service at National Institute of Oceanography (India)

    Levin, L.A.; Liu, K-K.; Emeis, K.-C.; Breitburg, D.L.; Cloern, J.; Deutsch, C.; Giani, M.; Goffart, A.; Hofmann, E.E.; Lachkar, Z.; Limburg, K.; Liu, Su-Mei; Montes, E.; Naqvi, S.W.A.; Ragueneau, O.; Rabouille, C.; Sarkar, S.K.; Swaney, D.P.; Wassman, P.; Wishner, K.F.

    The oceans' continental margins face strong and rapid change, forced by a combination of direct human activity, anthropogenic CO2-induced climate change, and natural variability. Stimulated by discussions in Goa, India at the IMBER IMBIZO III, we (1...

  1. Outer Continental Shelf Lease Blocks - Alaska Region NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Outer Continental Shelf block outlines in ArcGIS shapefile format for the BOEM Alaska Region. OCS blocks are used to define small geographic...

  2. U.S. East Coast Continental Margin (CONMAR) Sediment Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The USGS/WHOI Continental Margin (CONMAR) Data set was compiled by the U.S. Geological Survey and the Woods Hole Oceanographic Institution as a joint program of...

  3. Continental Divide of the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer portrays the Continental Divide of the United States. The map layer was created by extracting Hydrologic Unit Boundary line features from an existing...

  4. Continental Airlines Receives J.D. Power and Associates Award

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ On June 29, 2006, Continental Airlines (NYSE: CAL) was ranked the highest in Customer Satisfaction Among Traditional Network Carriers in North America in the J.D.Power and Associates 2006 Airline Satisfaction Index StudySM.

  5. Persistence of Initial Conditions in Continental Scale Air Quality Simulations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains the data used in Figures 1 – 6 and Table 2 of the technical note "Persistence of Initial Conditions in Continental Scale Air Quality...

  6. Sulfur and metal fertilization of the lower continental crust

    Science.gov (United States)

    Locmelis, Marek; Fiorentini, Marco L.; Rushmer, Tracy; Arevalo, Ricardo; Adam, John; Denyszyn, Steven W.

    2016-02-01

    Mantle-derived melts and metasomatic fluids are considered to be important in the transport and distribution of trace elements in the subcontinental lithospheric mantle. However, the mechanisms that facilitate sulfur and metal transfer from the upper mantle into the lower continental crust are poorly constrained. This study addresses this knowledge gap by examining a series of sulfide- and hydrous mineral-rich alkaline mafic-ultramafic pipes that intruded the lower continental crust of the Ivrea-Verbano Zone in the Italian Western Alps. The pipes are relatively small (tectonic architecture of any given terrain, metals and volatiles stored in the lower continental crust may become available as sources for subsequent ore-forming processes, thus enhancing the prospectivity of continental block margins for a wide range of mineral systems.

  7. Continental Shelf Boundary - Gulf of Mexico Region NAD27

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Continental Shelf Boundary (CSB) lines in ESRI shapefile format for the BOEM Gulf of Mexico Region. The CSB defines the seaward limit of...

  8. Topographic features over the continental shelf off Visakhapatnam

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.; Machado, T.; Murthy, K.S.R.

    water depth and the continental shelfedge several interesting topographic features such as Terraces, Karstic structures associated with pinnacles and troughs and smooth dome shaped reef structures are recorded. The nature of these features...

  9. 75 FR 71734 - Outer Continental Shelf (OCS), Scientific Committee (SC)

    Science.gov (United States)

    2010-11-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf (OCS), Scientific Committee (SC) AGENCY: Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE),...

  10. Continental United States Hurricane Strikes 1950-2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Continental U.S. Hurricane Strikes Poster is our most popular poster which is updated annually. The poster includes all hurricanes that affected the U.S. since...

  11. Manganese, Iron, and sulfur cycling in Louisiana continental shelf sediments

    Science.gov (United States)

    Sulfate reduction is considered the primary pathway for organic carbon remineralization on the northern Gulf of Mexico Louisiana continental shelf (LCS) where bottom waters are seasonally hypoxic, yet limited information is available on the importance of iron and manganese cyclin...

  12. University of Idaho Daily Meteorological data for continental US

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This archive contains daily surface meteorological (METDATA) data for the Continental United States at 4-km (1/24-deg) resolution. The meteorological variables are...

  13. Italian Succession Procedure

    OpenAIRE

    De Tullio, Giandomenico

    2012-01-01

    Italian inheritance law based on the Roman law of succession including legitimate succession and testamentary succession. The importance of drafting an Italian will and the legal requirements according to Italian Law.

  14. Caloplaca coeruleofrigida sp. nova, a species from continental Antarctica

    DEFF Research Database (Denmark)

    Søchting, Ulrik; Seppelt, R.

    2003-01-01

    Caloplaca coeruleofrigida Søchting & Seppelt is described from Southern Victoria Land, continental Antarctica. It is characterized by vertically elongated papillae and a pale orange pigmentation on shaded parts, and black thallus and apothecia on exposed parts of the thallus......Caloplaca coeruleofrigida Søchting & Seppelt is described from Southern Victoria Land, continental Antarctica. It is characterized by vertically elongated papillae and a pale orange pigmentation on shaded parts, and black thallus and apothecia on exposed parts of the thallus...

  15. Continental tectonics in the aftermath of plate tectonics

    Science.gov (United States)

    Molnar, Peter

    1988-01-01

    It is shown that the basic tenet of plate tectonics, rigid-body movements of large plates of lithosphere, fails to apply to continental interiors. There, buoyant continental crust can detach from the underlying mantle to form mountain ranges and broad zones of diffuse tectonic activity. The role of crustal blocks and of the detachment of crustal fragments in this process is discussed. Future areas of investigation are addressed.

  16. Continental tectonics in the aftermath of plate tectonics

    Science.gov (United States)

    Molnar, Peter

    1988-01-01

    It is shown that the basic tenet of plate tectonics, rigid-body movements of large plates of lithosphere, fails to apply to continental interiors. There, buoyant continental crust can detach from the underlying mantle to form mountain ranges and broad zones of diffuse tectonic activity. The role of crustal blocks and of the detachment of crustal fragments in this process is discussed. Future areas of investigation are addressed.

  17. Formation waters of the Norwegian Continental Shelf

    Energy Technology Data Exchange (ETDEWEB)

    McCartney, R. A.; Rein, E.

    2006-03-15

    New and previously published analyses of formation waters for the Norwegian Continental Shelf (NCS) have been evaluated and interpreted to determine the compositional distribution of formation waters in the region and factors controlling their compositions, and also to obtain information on subsurface fluid flow. Formation waters in the region are Na-Cl and Na-Ca-Cl-type waters that display a wide range of salinity (2500-212000 mg/kg Cl). Generally, the concentrations of most dissolved constituents are positively correlated with Cl so that their distribution in formation waters largely reflects the variations shown by salinity. Exceptions are SO4 which is generally low (less than 40 mg/l) regardless of Cl, and HCO3 and in-situ pH which are negatively correlated with Cl. The main factors determining the compositions of the formation waters are mixing of meteoric water (probably late-Jurassic to Eocene), ancient seawater and primary brine together with diagenetic reactions that have affected each of these components individually as well as mixtures of them. Evaluation of the distribution of salinity has helped us identify where vertical and/or lateral migration of brine from the evaporites has occurred. This has in turn provided us with information on the presence of leak-points and vertical mixing, although further investigation of the location of evaporites and basin palaeohydrogeology are required to determine whether regional lateral advection has occurred in the past. The results of this study may benefit oil exploration and production activities in the NCS including constraint of hydrocarbon migration models, economic evaluation of undrilled prospects, scale management and compartmentalisation studies. (Author)

  18. Australian Continental Shelf as an Inverse Estuary

    Science.gov (United States)

    Mahjabin, T.; Pattiaratchi, C. B.; Hetzel, Y.

    2016-02-01

    Transport of inshore waters and suspended material off the continental shelf by Dense Shelf Water Cascades (DSWC) has important ecological and biogeochemical implications in Australian waters. Because of high rates of evaporation, denser saline water along the sea bed occurs in a majority of the shallow coastal regions around Australia, setting up horizontal density gradients that can form DSWC. This study uses data available from the Integrated Marine Observing System (IMOS), which is operated by the Australian National Facility for Ocean Gliders (ANFOG) located at the University of Western Australia, to measure cross-shelf density profiles under varying conditions around the entire continent. Analysis of 143 transects of 97 sets of spatial and temporal resolution data from the ocean gliders under varying wind and tide conditions for seven contrasting regions surrounding Australia has allowed us to confirm that DSWC occurs on a regular basis during autumn and winter seasons. Results indicate that cascades occur during these seasons mainly due to cooling of the coastal water which already have higher salinity due to evaporation during the summer months. The cascades were present under different wind and tidal energy conditions and the controlling parameter for cascade formation is the cross-shelf density gradient. The cross-shelf density gradient in North-West Australia is maximum in July (14.23x10-6 kgm-4); whereas it is a maximum in June in South Australia (18.78x10-6 kgm-4) and in May in South-West Australia (25.884x10-6 kgm-4). Greater knowledge of the occurrence of DSWC will enhance understanding of the offshore transport of larvae, nutrients, salt, heat, carbon, low-oxygen water, sediment, and pollutants in Australian waters.

  19. Deep observation and sampling of the earth's continental crust (DOSECC): Continental scientific drilling workshop

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    Research summaries are presented of ongoing or proposed deep drilling programs to explore hydrothermal systems, buried astroblemes, continental crust, magma systems, mountain belt tectonics, subduction zones, and volcanoes. Separate abstracts have been prepared for individual papers. (ACR)

  20. Geoacoustic characteristics at the DH-2 long-core sediments in the Korean continental margin of the East Sea

    Science.gov (United States)

    Ryang, Woo Hun; Kim, Seong Pil; Hahn, Jooyoung

    2015-04-01

    A long core of 27.2 m was acquired at the DH-2 site (37°34.355'N and 129°19.516'E) in the Korean continental margin of the western East Sea. The core site is located near the Donghae City and the water depth is 316.6 m deep. The long-core sediment was recovered using the Portable Remotely Operated Drill (PROD), a fully contained drilling system, remotely operated at the seafloor. The recovered core sediments were analyzed for physical, sedimentological, and geoacoustic properties mostly at 10~30 cm intervals. Based on the long-core data with subbottom and air-gun profiles at the DH-2 core site, geoacoustic characteristics of the deeper sedimentary successions were firstly investigated in the Korean continental margin of the western East Sea. The geoacoustic measurements comprise 86 P-wave velocities and 76 attenuation values. These geoacoustic characteristics of the DH-2 long core probably contribute for reconstruction of geoacoustic models reflecting vertical and lateral variability of acoustic properties in the Korean continental margin of the western East Sea. Keywords: long core, geoacoustic, East Sea, continental margin, P-wave speed Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0025733) and by the Agency of Defense Development (UD140003DD).

  1. Continental collision zones are primary sites for net continental crust growth — A testable hypothesis

    Science.gov (United States)

    Niu, Yaoling; Zhao, Zhidan; Zhu, Di-Cheng; Mo, Xuanxue

    2013-12-01

    The significance of the continental crust (CC) on which we live is self-evident. However, our knowledge remains limited on its origin, its way and rate of growth, and how it has acquired the "andesitic" composition from mantle derived magmas. Compared to rocks formed from mantle derived magmas in all geological environments, volcanic arc rocks associated with seafloor subduction share some common features with the CC; both are relatively depleted in "fluid-insoluble" elements (e.g., Nb, Ta and Ti), but enriched in "fluid-soluble" elements (e.g., U, K and Pb). These chemical characteristics are referred to as the "arc-like signature", and point to a possible link between subduction-zone magmatism and CC formation, thus leading to the "island arc" model widely accepted for the origin of the CC over the past 45 years. However, this "island-arc" model has many difficulties: e.g., (1) the bulk arc crust (AC) is basaltic whereas the bulk CC is andesitic; (2) the AC has variably large Sr excess whereas the CC is weakly Sr deficient; and (3) AC production is mass-balanced by subduction erosion and sediment recycling, thus contributing no net mass to the CC growth, at least in the Phanerozoic. Our recent and ongoing studies on granitoid rocks (both volcanic and intrusive) formed in response to the India-Asia continental collision (~ 55 ± 10 Ma) show remarkable compositional similarity to the bulk CC with the typical "arc-like signature". Also, these syncollisional granitoid rocks exhibit strong mantle isotopic signatures, meaning that they were recently derived from a mantle source. The petrology and geochemistry of these syncollisional granitoid rocks are most consistent with an origin via partial melting of the upper ocean crust (i.e., last fragments of underthrusting ocean crust upon collision) under amphibolite facies conditions, adding net mantle-derived materials to form juvenile CC mass. This leads to the logical and testable hypothesis that continental collision

  2. Western Ross Sea continental slope gravity currents

    Science.gov (United States)

    Gordon, Arnold L.; Orsi, Alejandro H.; Muench, Robin; Huber, Bruce A.; Zambianchi, Enrico; Visbeck, Martin

    2009-06-01

    Antarctic Bottom Water of the world ocean is derived from dense Shelf Water that is carried downslope by gravity currents at specific sites along the Antarctic margins. Data gathered by the AnSlope and CLIMA programs reveal the presence of energetic gravity currents that are formed over the western continental slope of the Ross Sea when High Salinity Shelf Water exits the shelf through Drygalski Trough. Joides Trough, immediately to the east, offers an additional escape route for less saline Shelf Water, while the Glomar Challenger Trough still farther east is a major pathway for export of the once supercooled low-salinity Ice Shelf Water that forms under the Ross Ice Shelf. The Drygalski Trough gravity currents increase in thickness from ˜100 to ˜400 m on proceeding downslope from ˜600 m (the shelf break) to 1200 m (upper slope) sea floor depth, while turning sharply to the west in response to the Coriolis force during their descent. The mean current pathway trends ˜35° downslope from isobaths. Benthic-layer current and thickness are correlated with the bottom water salinity, which exerts the primary control over the benthic-layer density. A 1-year time series of bottom-water current and hydrographic properties obtained on the slope near the 1000 m isobath indicates episodic pulses of Shelf Water export through Drygalski Trough. These cold (34.75) pulses correlate with strong downslope bottom flow. Extreme examples occurred during austral summer/fall 2003, comprising concentrated High Salinity Shelf Water (-1.9 °C; 34.79) and approaching 1.5 m s -1 at descent angles as large as ˜60° relative to the isobaths. Such events were most common during November-May, consistent with a northward shift in position of the dense Shelf Water during austral summer. The coldest, saltiest bottom water was measured from mid-April to mid-May 2003. The summer/fall export of High Salinity Shelf Water observed in 2004 was less than that seen in 2003. This difference, if real

  3. Influence of fluvial processes on the quaternary geologic framework of the continental shelf, North Carolina, USA

    Science.gov (United States)

    Boss, S.K.; Hoffman, C.W.; Cooper, B.

    2002-01-01

    Digital, single-channel, high-resolution seismic reflection profiles were acquired from the insular continental shelf of North Carolina, USA along a data grid extending from Oregon Inlet northward 48 km to Duck, North Carolina and from the nearshore zone seaward approximately 28 km (total surveyed area= 1334 km2). These data were processed and interpreted to delineate principal reflecting horizons and develop a three-dimensional seismic stratigraphic framework for the continental shelf that was compared to stratigraphic data from the shoreward back-barrier (estuarine) and barrier island system. Six principal reflecting horizons (designated R0 through R5) were present within the upper 60 m of the shelf stratigraphic succession. Three-dimensional mapping of reflector R1 demonstrated its origin from fluvial incision of the continental shelf during an episode (or episodes) of lowered sea-level. Fluvial processes during development of reflector R1 were responsible for extensive reworking and re-deposition of sediment throughout most of the northern half of the study area. Five seismic stratigraphic units (designated S1 through S5) were tentatively correlated with depositional sequences previously identified from the North Carolina back-barrier (estuarine) and barrier island system. These five stratigraphic units span the Quaternary Period (S1 = early Holocene; S2 = 51-78 ka; S3 = 330-530 ka; S4 = 1.1-1.8 Ma; S5 = earliest Pleistocene). Unit S1 is composed of fine-grained fluvial/estuarine sediment that back-filled incised streams during early Holocene sea-level rise. The four other stratigraphic units (S2-S5) display tabular depositional geometries, low total relief, and thicken toward the east-southeast as their basal reflectors dip gently between 0.41 m km-1 (0.02??) and 0.54 m km-1 (0.03??). Knowledge of the three-dimensional subsurface stratigraphic architecture of the continental shelf enhances understanding of the development of shelf depositional successions and

  4. Numerical models of trench migration in continental collision zones

    Directory of Open Access Journals (Sweden)

    V. Magni

    2012-03-01

    Full Text Available Continental collision is an intrinsic feature of plate tectonics. The closure of an oceanic basin leads to the onset of subduction of buoyant continental material, which slows down and eventually stops the subduction process. We perform a parametric study of the geometrical and rheological influence on subduction dynamics during the subduction of continental lithosphere. In 2-D numerical models of a free subduction system with temperature and stress-dependent rheology, the trench and the overriding plate move self-consistently as a function of the dynamics of the system (i.e. no external forces are imposed. This setup enables to study how continental subduction influences the trench migration. We found that in all models the trench starts to advance once the continent enters the subduction zone and continues to migrate until few million years after the ultimate slab detachment. Our results support the idea that the trench advancing is favoured and, in part provided by, the intrinsic force balance of continental collision. We suggest that the trench advance is first induced by the locking of the subduction zone and the subsequent steepening of the slab, and next by the sinking of the deepest oceanic part of the slab, during stretching and break-off of the slab. The amount of trench advancing ranges from 40 to 220 km and depends on the dip angle of the slab before the onset of collision.

  5. Formation of Continental Fragments: The Tamayo Bank, Gulf of California

    Science.gov (United States)

    van Wijk, J.; Abera, R.; Axen, G. J.

    2015-12-01

    Potential field data are used to construct a two-dimensional crustal model along a profile through the Tamayo Trough and Bank in the Gulf of California. The model is constrained by seismic reflection and refraction data, and field observations. The potential field data do not fit a model where the crust of the Tamayo trough is continental, but they fit well with a model where the Tamayo trough crust is oceanic. This implies that the Tamayo Bank is entirely bounded by oceanic crust and is a microcontinent. The oceanic crust of the Tamayo trough that separates the Tamayo Bank from the mainland of Mexico is thin (~4 km), so oceanic spreading was probably magma-starved before it ceased. This led us to come up with a model that explains the formation of microcontinents that are smaller in size and are not found in the proximity of hotspots. At first, seafloor spreading commences following continental breakup. When the magma supply to the ridge slows down, the plate boundary strengthens. Hence, the ridge may be abandoned while tectonic extension begins elsewhere, or slow spreading may continue while a new ridge starts to develop. The old spreading ridge becomes extinct. An asymmetric ocean basin forms if the ridge jumps within oceanic lithosphere; a microcontinent forms if the ridge jumps into a continental margin. This model for formation of continental fragments is applicable to other regions as well, eliminating the need of mantle plume impingement to facilitate rifting of a young continental margin and microcontinent formation.

  6. Tectonic escape in the evolution of the continental crust

    Science.gov (United States)

    Burke, K.; Sengor, C.

    1986-01-01

    The continental crust originated by processes similar to those operating today and continents consist of material most of which originated long ago in arc-systems that have later been modified, especially at Andean margins and in continental collisions where crustal thickening is common. Collision-related strike-slip motion is a general process in continental evolution. Because buoyant continental (or arc) material generally moves during collision toward a nearby oceanic margin where less buoyant lithosphere crops out, the process of major strike-slip dominated motion toward a 'free-face' is called 'tectonic escape'. Tectonic escape is and has been an element in continental evolution throughout recorded earth-history. It promotes: (1) rifting and the formation of rift-basins with thinning of thickened crust; (2) pervasive strike-slip faulting late in orogenic history which breaks up mountain belts across strike and may juxtapose unrelated sectors in cross-section; (3) localized compressional mountains and related foreland-trough basins.

  7. Sm/Nd Evolution of Upper Mantle and Continental Crust:Constraints on Gowth Rates of the Continental Crust

    Institute of Scientific and Technical Information of China (English)

    李曙光

    1992-01-01

    A new approach to the investigation of the Sm/Nd evolution of the upper mantle directly from the data on lherzolite xenoliths is described in this paper.It is demonstrated that the model age TCHUR of an unmetasomatic iherzolite zenolith ca represent the mean depletion age of its mantle source, thus presenting a correlation trend between fSm/Nd and the mean depletion age of the upper mantle from the data on xenoliths.This correlation trend can also be derived from the data on river suspended loads as well as from granitoids.Based on the correlation trend mentioned above and mean depletion ages of the upper mantle at various geological times, an evolution curve for the mean fSm/Nd value of the upper mantle through geological time has been established.It is suggested that the upwilling of lower mantle material into the upper mantle and the recycling of continental crust material during the Archean were more active ,thus maintaining fairly constantfSm/Nd and εNd values during this time period. Similarly ,an evolution curve for the mean fSm/Nd value of the continental crust through geological time has also been established from the data of continental crust material.In the light of both evolution curves for the upper mantle and continental crust ,a growth curve for the continental crust has been worked out ,suggesting that :(1)about 30%(in volume )of the present crust was present as the continental crust at 3.8 Ga ago ;(2)the growth rate was much lower during the Archean ;and (3)the Proterozoic is another major period of time during which the continental crust wsa built up .

  8. Fertility Clinic Success Rates

    Science.gov (United States)

    ... and Autism 2013 Assisted Reproductive Technology Fertility Clinic Success Rates Report Recommend on Facebook Tweet Share Compartir 2013 ART Fertility Clinic Success Rates Report [PDF - 1MB] Bookmarks and thumbnails are ...

  9. In search of the Malaysian Extended Continental Shelf

    Science.gov (United States)

    Yahaya, N. A. Z.; Musa, T. A.; Omar, K. M.; Din, A. H. M.; Abdullah, N. M.; Othman, A. H.; Wahab, M. I. A.

    2016-06-01

    Over the years, the sovereignty proclamation of Coastal States for their extended continental shelf has been a crucial matter. The declaration and extension of a continental shelf under the United Nations Convention on the Law of the Sea provide significant potential for many developing nations in economics, trades, resource exploitation, communication and security. Hence, the application of satellite altimeter, as one of the solutions for collecting bathymetry data to define the approximate limits of the continental shelf, is reviewed. This paper also discusses the possible significance or contribution of space-derived bathymetry, i.e. the seafloor topography, either independently or harmoniously with different datasets, to meet the element of the Article 76 of UNCLOS.

  10. USAR recruiting success factors

    OpenAIRE

    Thomas, George W.; Kocher, Kathryn M.; Gandolfo, Robin Ragsdale

    1987-01-01

    This study attempts to identify attributes associated with successful recruiters, to evaluate existing data on recruiter performance and characteristics, and to develop a model to aid in the selection of personnel who are likely to become successful recruiters. Conventional multivariate statistical techniques have not proved adequate in identifying successful recruiters, largely because of the absence of reliable and valid measures of recruiter success. This study applies a relatively new met...

  11. Impact of Continental Ice Sheet Topography on the Pacific ITCZ During the Last Glacial Period

    Science.gov (United States)

    Lee, S.; Chiang, J. C.; Chang, P.

    2011-12-01

    The Tropical Pacific underwent profound climate change during the Pleistocene ice age variations, marked by cooler sea surface temperature (SST) and changes in hydrological cycle. Studies have shown that the meridional position of the marine Intertropical Convergence Zone (ITCZ) is sensitive to SST gradient changes, and models have demonstrated the Pacific ITCZ shift in response to surface albedo changes and high-latitude Atlantic SST cooling in a glacial climate. However, the tropical Pacific climate response to a full range Last Glacial Maximum (LGM) forcing has yet to be systematically explored. This modeling study investigates the impacts of changes in continental ice sheet topography on the position of Pacific ITCZ in a glacial climate. Simulations using an AGCM coupled to a reduced-gravity ocean where the LGM ice sheet was successively increased from zero thickness to 100% suggest that continental ice sheet growth can lead to significant changes in the tropical Pacific climate, including a reduction in the zonal SST gradient, a southward shift of the ITCZ, and a strengthening (weakening) of the mean-annual northern (southern) hemisphere Hadley circulation. We find a progressive southward displacement of the tropical Pacific rain belt in response to the topographic effect of northern hemisphere continental ice sheets growth, a mechanism distinctly different from the cooling influence by the ice sheet albedo on the ITCZ that had been previously discussed in the literature. Our results suggest that ice-sheet topographic forcing had a significant impact on the tropical Pacific coupled ocean-atmosphere climate during glacial-interglacial cycles.

  12. Built-up of the continental margin offshore Central Mozambique from marine geophysical investigations

    Science.gov (United States)

    Heyde, I.; Block, M.; Ehrhardt, A.; Reichert, C. J.; Schreckenberger, B.

    2009-12-01

    In September/October 2007, along with institutes from Germany, France and Portugal BGR conducted the cruise MoBaMaSis (Mozambique Basin Marine Seismic Survey) using RV MARION DUFRESNE. The goal of the marine geophysical measurements offshore central Mozambique was the investigation of the continental margin in terms of its structure and formation history with special focus on the opening history of Eastern Gondwana and the hydrocarbon potential. A total of four long transects (450 to 225 km long) and a number of connection lines were acquired from the shelf and the slope into the deep Mozambique Basin. The data comprises multichannel seismic reflection (MCS), magnetic, gravimetric and swath bathymetry. On the eastern two transects two on-/offshore seismic refraction studies were carried out. Apart from results of the MCS and the magnetic work, in particular the results of the gravity data are presented. A 3D density model was developed. In the Mozambique Basin a large thick sedimentary succession of up to 8 km thickness from Jurassic to present is observed. Two deep reaching wells supported, at least in part, the identification of stratigraphy. Faint indications for SDR sequences related to volcanic flows are found in the northern part of the study area. In the south, the Beira High represents a prominent structure. The basement high with sediments of considerable reduced thickness is characterized by a distinct gravity minimum. A possible explanation is that the high is formed by a continental fragment. In addition, no clear magnetic chrons are identifiable. Thus, stretched continental crust is assumed underlying this part of the Mozambique Basin.

  13. Hybrid accretionary/collisional mechanism of Paleozoic Asian continental growth

    Science.gov (United States)

    Schulmann, Karel; Lexa, Ondrej; Janousek, Vojtech; Pavla, Stipska; Yingde, Jiang; Alexandra, Guy; Min, Sun

    2016-04-01

    Continental crust is formed above subduction zones by well-known process of "juvenile crust growth". This new crust is in modern Earth assembled into continents by two ways: (i) short-lived collisions of continental blocks with the Eurasian continent along the "Alpine-Himalayan collisional/interior orogens" in the heart of the Pangean continental plates realm; and (ii) long lived lateral accretion of ocean-floor fragments along "circum-Pacific accretionary/peripheral orogens" at the border of the Pacific oceanic plate. This configuration has existed since the late Proterozoic, when the giant accretionary Terra Australis Orogen developed at periphery of an old Palaeo-Pacific ocean together with collisional Caledonian and Variscan orogens. At the same time, the large (ca. 9 millions km2) Central Asian Orogenic Belt (CAOB) developed in the NE part of the Pangea. This orogen reveals features of both peripheral and interior orogens, which implies that the generally accepted "peripheral-accretionary" and "interior- collisional" paradigm is not applicable here. To solve this conundrum a new model of unprecedented Phanerozoic continental growth is proposed. In this model, the CAOB precursor evolved at the interface of old exterior and young interior oceans. Subsequently, the new lithospheric domain was transferred by advancing subduction into the interior of the Pangean mostly continental realm. During this process the oceanic crust was transformed into continental crust and it was only later when this specific lithosphere was incorporated into the Asian continent. If true, this concept represents revolutionary insight into processes of crustal growth explaining the enigma of anchoring hybrid lithosphere inside a continent without its subduction or Tibetan-type thickening.

  14. Numerical models of slab migration in continental collision zones

    Directory of Open Access Journals (Sweden)

    V. Magni

    2012-09-01

    Full Text Available Continental collision is an intrinsic feature of plate tectonics. The closure of an oceanic basin leads to the onset of subduction of buoyant continental material, which slows down and eventually stops the subduction process. In natural cases, evidence of advancing margins has been recognized in continental collision zones such as India-Eurasia and Arabia-Eurasia. We perform a parametric study of the geometrical and rheological influence on subduction dynamics during the subduction of continental lithosphere. In our 2-D numerical models of a free subduction system with temperature and stress-dependent rheology, the trench and the overriding plate move self-consistently as a function of the dynamics of the system (i.e. no external forces are imposed. This setup enables to study how continental subduction influences the trench migration. We found that in all models the slab starts to advance once the continent enters the subduction zone and continues to migrate until few million years after the ultimate slab detachment. Our results support the idea that the advancing mode is favoured and, in part, provided by the intrinsic force balance of continental collision. We suggest that the advance is first induced by the locking of the subduction zone and the subsequent steepening of the slab, and next by the sinking of the deepest oceanic part of the slab, during stretching and break-off of the slab. These processes are responsible for the migration of the subduction zone by triggering small-scale convection cells in the mantle that, in turn, drag the plates. The amount of advance ranges from 40 to 220 km and depends on the dip angle of the slab before the onset of collision.

  15. Closing the North American Carbon Budget: Continental Margin Fluxes Matter!

    Science.gov (United States)

    Najjar, R.; Benway, H. M.; Siedlecki, S. A.; Boyer, E. W.; Cai, W. J.; Coble, P. G.; Cross, J. N.; Friedrichs, M. A.; Goni, M. A.; Griffith, P. C.; Herrmann, M.; Lohrenz, S. E.; Mathis, J. T.; McKinley, G. A.; Pilskaln, C. H.; Smith, R. A.; Alin, S. R.

    2015-12-01

    Despite their relatively small surface area, continental margins are regions of intense carbon and nutrient processing, export and exchange, and thus have a significant impact on global biogeochemical cycles. In response to recommendations for regional synthesis and carbon budget estimation for North America put forth in the North American Continental Margins workshop report (Hales et al., 2008), the Ocean Carbon and Biogeochemistry (OCB) Program and North American Carbon Program (NACP) began coordinating a series of collaborative, interdisciplinary Coastal CARbon Synthesis (CCARS) research activities in five coastal regions of North America (Atlantic Coast, Pacific Coast, Gulf of Mexico, Arctic, Laurentian Great Lakes) to improve quantitative assessments of the North American carbon budget. CCARS workshops and collaborative research activities have resulted in the development of regional coastal carbon budgets based on recent literature- and model-based estimates of major carbon fluxes with estimated uncertainties. Numerous peer-reviewed papers and presentations by involved researchers have highlighted these findings and provided more in-depth analyses of processes underlying key carbon fluxes in continental margin systems. As a culminating outcome of these synthesis efforts, a comprehensive science plan highlights key knowledge gaps identified during this synthesis and provides explicit guidance on future research and observing priorities in continental margin systems to help inform future agency investments in continental margins research. This presentation will provide an overview of regional and flux-based (terrestrial inputs, biological transformations, sedimentary processes, atmospheric exchanges, lateral carbon transport) synthesis findings and key recommendations in the science plan, as well as a set of overarching priorities and recommendations on observations and modeling approaches for continental margin systems.

  16. Success in Science, Success in Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Mariann R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-25

    This is a series of four different scientific problems which were resolved through collaborations. They are: "Better flow cytometry through novel focusing technology", "Take Off®: Helping the Agriculture Industry Improve the Viability of Sustainable, Large-Production Crops", "The National Institutes of Health's Models of Infectious Disease Agent Study (MIDAS)", and "Expanding the capabilities of SOLVE/RESOLVE through the PHENIX Consortium." For each one, the problem is listed, the solution, advantages, bottom line, then information about the collaboration including: developing the technology, initial success, and continued success.

  17. Continental Fog Attenuation Empirical Relationship from Measured Visibility Data

    Directory of Open Access Journals (Sweden)

    F. Nadeem

    2010-12-01

    Full Text Available Free Space Optics (FSO has the great potential for future communication applications. However, weather influenced reduced availability had been the main cause for its restricted growth. Among different weather influences fog plays the major role. A new model generalized for all FSO wavelengths, has been proposed for the prediction of continental fog attenuation using visibility data. The performance of the proposed model has been compared with well known models for measured attenuation data of Continental fog. The comparison has been performed in terms of Root Mean Square Error (RMSE.

  18. GENERATION OF NONLINEAR INTERNAL WAVES ON CONTINENTAL SHELF

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A 2-D KdV equation is derived under condition of arbitrary continuous density profiles. A non-fission version of initial internal solitary waves propagating onto the continental shelf is studied by means of the 2-D KdV equation. Under non-Bohr and Sommerfeld’s condition, numerical calculations are carried out based on the KdV equation. The results shows that the initial internal solitary waves in deep ocean break down into internal undular bores on the continental shelf. And the bores have a like-soliton leading fronts and undular trails.

  19. Data Assimilation in Hydrodynamic Models of Continental Shelf Seas

    DEFF Research Database (Denmark)

    Sørensen, Jacob Viborg Tornfeldt

    2004-01-01

    This thesis consists of seven research papers published or submitted for publication in the period 2002-2004 together with a summary report. The thesis mainly deals with data assimilation of tide gauge data in two- and three-dimensional hydrodynamic models of the continental shelf seas. Assimilat......This thesis consists of seven research papers published or submitted for publication in the period 2002-2004 together with a summary report. The thesis mainly deals with data assimilation of tide gauge data in two- and three-dimensional hydrodynamic models of the continental shelf seas...

  20. Quaternary nanofossils on the Brazilian continental shelf; Nanofosseis calcarios do quaternario da margem continental brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Rogerio Loureiro [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Bioestratigrafia e Paleoecologia], E-mail: rlantunes@petrobras.com.br

    2007-07-01

    The study of calcareous nanofossils occurring in the deposits on the Brazilian continental margin began in the late 1960s, undertaken solely by PETROBRAS. Instead of presenting an academic outlook, the purpose of these investigations is first to formulate a biostratigraphic framework to apply to oil well samples. The initial result was the first zoning for the Brazilian continental margin, which considered the deposits formed between the Aptian and Miocene series. Since the 1960s to date, many papers have been written either with details of that original zoning or applying nanofossil biostratigraphy to solve stratigraphic problems. Regardless of all the papers and studies undertaken, little attention has been paid to the Quaternary, since these deposits are normally of no interest to petroleum geology stricto sensu, especially in a large part of the Brazilian margin. On the other hand, there are a few articles and some Master's dissertations and PhD theses that were written and/or are in progress in Brazilian universities. On the other hand, elsewhere in the world, Quaternary nanofossils have been thoroughly investigated in terms of biostratigraphy and paleoceanography. It is, therefore, very clear that there is a gap between what is being done elsewhere in the world and what has been done in Brazil. In fact, this gap is not larger simply because of a few researchers in Brazilian universities who are studying this topic. The intention of this paper is to contribute toward a richer study of Quaternary nanofossils. It, therefore, contains illustrations and taxonomic descriptions of many species observed in the younger strata of the Brazilian margin basins. This article not only aspires to portray and disseminate the potential of nanofossils for the marine Quaternary study but is also an invitation to students (under and post-graduates) and university researchers - an invitation to learn a little more about the subject and spend some time studying these real gems

  1. Time scales of regional circulation of saline fluids in continental aquifers (Armorican massif, Western France

    Directory of Open Access Journals (Sweden)

    A. Armandine Les Landes

    2014-06-01

    Full Text Available In recent decades, saline fluids have been sampled worldwide at great depths in continental basements. Although some of them have been attributed to marine transgressions the mechanisms allowing their circulation is not understood. In this paper, we describe the horizontal and vertical distribution of moderately saline fluids (60 to 1400 mg L−1 sampled at depths ranging from 41 to 200 m in aquifers at the regional scale of the Armorican Massif (northwestern France. The horizontal and vertical distributions of high chloride concentrations are in good agreement with both the altitudinal and vertical limits and succession of the three major transgressions between the Mio-Pliocene and Pleistocene ages. The mean chloride concentration for each transgression area is exponentially related to the time spanned until present. It defines the potential laws of leaching of marine waters by fresh meteoric waters. The results of the Armorican aquifers provide the first observed constraints for the time scales of seawater circulation in the continental basement and the subsequent leaching by fresh meteoric waters. The general trend of increasing chloride concentration with depth and the time frame for the flushing process provide useful information to develop conceptual models of the paleo-functionning of Armorican aquifers.

  2. New method for prediction of shale gas content in continental shale formation using well logs

    Science.gov (United States)

    Li, Sheng-Jie; Cui, Zhe; Jiang, Zhen-Xue; Shao, Yu; Liao, Wei; Li, Li

    2016-06-01

    Shale needs to contain a sufficient amount of gas to make it viable for exploitation. The continental heterogeneous shale formation in the Yan-chang (YC) area is investigated by firstly measuring the shale gas content in a laboratory and then investigating use of a theoretical prediction model. Key factors controlling the shale gas content are determined, and a prediction model for free gas content is established according to the equation of gas state and a new petrophysical volume model. Application of the Langmuir volume constant and pressure constant obtained from results of adsorption isotherms is found to be limited because these constants are greatly affected by experimental temperature and pressures. Therefore, using measurements of adsorption isotherms and thermodynamic theory, the influence of temperature, total organic carbon (TOC), and mineralogy on Langmuir volume constants and pressure constants are investigated in detail. A prediction model for the Langmuir pressure constant with a correction of temperatures is then established, and a prediction model for the Langmuir volume constant with correction of temperature, TOC, and quartz contents is also proposed. Using these corrected Langmuir constants, application of the Langmuir model determined using experimental adsorption isotherms is extrapolated to reservoir temperature, pressure, and lithological conditions, and a method for the prediction of shale gas content using well logs is established. Finally, this method is successfully applied to predict the shale gas content of the continental shale formation in the YC area, and practical application is shown to deliver good results with high precision.

  3. Denudation of the continental shelf between Britain and France at the glacial-interglacial timescale.

    Science.gov (United States)

    Mellett, Claire L; Hodgson, David M; Plater, Andrew J; Mauz, Barbara; Selby, Ian; Lang, Andreas

    2013-12-01

    The erosional morphology preserved at the sea bed in the eastern English Channel dominantly records denudation of the continental shelf by fluvial processes over multiple glacial-interglacial sea-level cycles rather than by catastrophic flooding through the Straits of Dover during the mid-Quaternary. Here, through the integration of multibeam bathymetry and shallow sub-bottom 2D seismic reflection profiles calibrated with vibrocore records, the first stratigraphic model of erosion and deposition on the eastern English Channel continental shelf is presented. Published Optical Stimulated Luminescence (OSL) and (14)C ages were used to chronometrically constrain the stratigraphy and allow correlation of the continental shelf record with major climatic/sea-level periods. Five major erosion surfaces overlain by discrete sediment packages have been identified. The continental shelf in the eastern English Channel preserves a record of processes operating from Marine Isotope Stage (MIS) 6 to MIS 1. Planar and channelised erosion surfaces were formed by fluvial incision during lowstands or relative sea-level fall. The depth and lateral extent of incision was partly conditioned by underlying geology (rock type and tectonic structure), climatic conditions and changes in water and sediment discharge coupled to ice sheet dynamics and the drainage configuration of major rivers in Northwest Europe. Evidence for major erosion during or prior to MIS 6 is preserved. Fluvial sediments of MIS 2 age were identified within the Northern Palaeovalley, providing insights into the scale of erosion by normal fluvial regimes. Seismic and sedimentary facies indicate that deposition predominantly occurred during transgression when accommodation was created in palaeovalleys to allow discrete sediment bodies to form. Sediment reworking over multiple sea-level cycles (Saalian-Eemian-early Weichselian) by fluvial, coastal and marine processes created a multi-lateral, multi-storey succession of

  4. Denudation of the continental shelf between Britain and France at the glacial–interglacial timescale

    Science.gov (United States)

    Mellett, Claire L.; Hodgson, David M.; Plater, Andrew J.; Mauz, Barbara; Selby, Ian; Lang, Andreas

    2013-01-01

    The erosional morphology preserved at the sea bed in the eastern English Channel dominantly records denudation of the continental shelf by fluvial processes over multiple glacial–interglacial sea-level cycles rather than by catastrophic flooding through the Straits of Dover during the mid-Quaternary. Here, through the integration of multibeam bathymetry and shallow sub-bottom 2D seismic reflection profiles calibrated with vibrocore records, the first stratigraphic model of erosion and deposition on the eastern English Channel continental shelf is presented. Published Optical Stimulated Luminescence (OSL) and 14C ages were used to chronometrically constrain the stratigraphy and allow correlation of the continental shelf record with major climatic/sea-level periods. Five major erosion surfaces overlain by discrete sediment packages have been identified. The continental shelf in the eastern English Channel preserves a record of processes operating from Marine Isotope Stage (MIS) 6 to MIS 1. Planar and channelised erosion surfaces were formed by fluvial incision during lowstands or relative sea-level fall. The depth and lateral extent of incision was partly conditioned by underlying geology (rock type and tectonic structure), climatic conditions and changes in water and sediment discharge coupled to ice sheet dynamics and the drainage configuration of major rivers in Northwest Europe. Evidence for major erosion during or prior to MIS 6 is preserved. Fluvial sediments of MIS 2 age were identified within the Northern Palaeovalley, providing insights into the scale of erosion by normal fluvial regimes. Seismic and sedimentary facies indicate that deposition predominantly occurred during transgression when accommodation was created in palaeovalleys to allow discrete sediment bodies to form. Sediment reworking over multiple sea-level cycles (Saalian–Eemian–early Weichselian) by fluvial, coastal and marine processes created a multi-lateral, multi-storey succession of

  5. Denudation of the continental shelf between Britain and France at the glacial-interglacial timescale

    Science.gov (United States)

    Mellett, Claire L.; Hodgson, David M.; Plater, Andrew J.; Mauz, Barbara; Selby, Ian; Lang, Andreas

    2013-12-01

    The erosional morphology preserved at the sea bed in the eastern English Channel dominantly records denudation of the continental shelf by fluvial processes over multiple glacial-interglacial sea-level cycles rather than by catastrophic flooding through the Straits of Dover during the mid-Quaternary. Here, through the integration of multibeam bathymetry and shallow sub-bottom 2D seismic reflection profiles calibrated with vibrocore records, the first stratigraphic model of erosion and deposition on the eastern English Channel continental shelf is presented. Published Optical Stimulated Luminescence (OSL) and 14C ages were used to chronometrically constrain the stratigraphy and allow correlation of the continental shelf record with major climatic/sea-level periods. Five major erosion surfaces overlain by discrete sediment packages have been identified. The continental shelf in the eastern English Channel preserves a record of processes operating from Marine Isotope Stage (MIS) 6 to MIS 1. Planar and channelised erosion surfaces were formed by fluvial incision during lowstands or relative sea-level fall. The depth and lateral extent of incision was partly conditioned by underlying geology (rock type and tectonic structure), climatic conditions and changes in water and sediment discharge coupled to ice sheet dynamics and the drainage configuration of major rivers in Northwest Europe. Evidence for major erosion during or prior to MIS 6 is preserved. Fluvial sediments of MIS 2 age were identified within the Northern Palaeovalley, providing insights into the scale of erosion by normal fluvial regimes. Seismic and sedimentary facies indicate that deposition predominantly occurred during transgression when accommodation was created in palaeovalleys to allow discrete sediment bodies to form. Sediment reworking over multiple sea-level cycles (Saalian-Eemian-early Weichselian) by fluvial, coastal and marine processes created a multi-lateral, multi-storey succession of

  6. Early diagenesis of phosphorus in continental margin sediments.

    NARCIS (Netherlands)

    Slomp, C.P.

    1997-01-01

    Most of the organic material in the oceans that reaches the sea floor is deposited on continental margins and not in the deep sea. This organic matter is the principal carrier of phosphorus (P) to sediments. A part of the organic material is buried definitely. The other part decomposes, resulting in

  7. Clay mineral distribution on the Kerala continental shelf and slope

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Nair, R.R.; Hashimi, N.H.

    Seventy-five sediment samples collected from the Kerala continental shelf and slope during the 17th and 71st Cruises of @iRV gaveshani@@ were analysed by X-ray diffraction for clay mineral cntent. The distribution of total clay (< 4~k fraction...

  8. Continental margin sedimentation: from sediment transport to sequence stratigraphy

    Science.gov (United States)

    Nittrouer, Charles A.; Austin, James A.; Field, Michael E.; Kravitz, Joseph H.; Syvitski, James P.M.; Wiberg, Patricia L.; Nittrouer, Charles A.; Austin, James A.; Field, Michael E.; Kravitz, Joseph H.; Syvitski, James P. M.; Wiberg, Patricia L.

    2007-01-01

    This volume on continental margin sedimentation brings together an expert editorial and contributor team to create a state-of-the-art resource. Taking a global perspective, the book spans a range of timescales and content, ranging from how oceans transport particles, to how thick rock sequences are formed on continental margins. - Summarizes and integrates our understanding of sedimentary processes and strata associated with fluvial dispersal systems on continental shelves and slopes - Explores timescales ranging from particle transport at one extreme, to deep burial at the other - Insights are presented for margins in general, and with focus on a tectonically active margin (northern California) and a passive margin (New Jersey), enabling detailed examination of the intricate relationships between a wide suite of sedimentary processes and their preserved stratigraphy - Includes observational studies which document the processes and strata found on particular margins, in addition to numerical models and laboratory experimentation, which provide a quantitative basis for extrapolation in time and space of insights about continental-margin sedimentation - Provides a research resource for scientists studying modern and ancient margins, and an educational text for advanced students in sedimentology and stratigraphy

  9. Potential for Suboxic Ammonium Oxidation in Louisiana Continental Shelf Sediments

    Science.gov (United States)

    Sediments deposited onto the Louisiana continental shelf (LCS) west of the Mississippi River Delta form mobile muds varying in thickness from meters near the outfall to centimeters on the western portion of the shelf. The muds have high concentrations of iron which promote rapid...

  10. Microbial Communities in Sediments across the Louisiana Continental Shelf

    Science.gov (United States)

    The Louisiana continental Shelf (LCS) is a dynamic system that receives discharges from two large rivers. It has a stratified water column that is mixed by winter storms, hypoxic bottom water from spring to fall, and a muddy seafloor with highly mixed surficial sediments. Spatia...

  11. Structure and tectonics of the southwestern continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Subrahmanyam, V.; Rao, D.G.; Ramana, M.V.; Krishna, K.S.; Murty, G.P.S.; Rao, M.G.

    , V., 1987. A note on the occurrence of ortho-amphibolites on the inner shelf off Bhatkal, west coast of India. J. Geol. Soc. India, 30: 499-506. Subrahmanyam, V., 1992. Structure and tectonics of part of the western continental margin of India...

  12. Continental Tire to Build New Tire Plant in USA

    Institute of Scientific and Technical Information of China (English)

    Yuan Ye

    2012-01-01

    According to Tire Comments of USA, Continental Tire earlier announced that in order to meet the increasing market demand on replacement tires of USA, German Tire Company had negotiated and reached an agreement on production capacity expansion with the South Carolina Government.

  13. Geochemistry of sediments of the eastern continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A; Paropkari, A; Murty, P.S

    The bulk and partition geochemistry of Al, Fe, Ti, Mn, Zn, and Cu have been investigated in sediments of the eastern continental shelf of India. The results show that (1) the bulk geochemistry varies from one shelf unit to the other, (2) all...

  14. Marine magnetic anomalies off Ratnagiri, Western continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.G.

    . Identification of these basalts in offshore areas along the northwestern continental shelf of India would support (1) the idea that the onshore Deccan basalts of western India and the rhyolitic tuffs at the Laccadive ridge system (DSDP Site 210) are related...

  15. The petroleum resources on the Norwegian continental shelf

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    In this document the Norwegian Petroleum Directorate estimates the total recoverable petroleum resources on the Norwegian continental shelf to be 12.5 billion Sm{sup 3} oil equivalents. There is considerable uncertainty regarding the undiscovered resources, the expected value being 3.5 billion Sm{sup 3} oil equivalents. The new estimates signify an increase of 14% since the calculations made last year. This increase is chiefly due to an upward adjustment of the expectations for a future increase in the recovery factor for the in place resources on the continental shelf. In 1995, the Norwegian oil production accounted for 4.3% of the global oil production. It is estimated that Norway has a total of about 1.3% of the discovered recoverable oil resources and about 1.8% of the discovered recoverable gas resources in the world. The Norwegian annual oil production is expected to reach a maximum of 3.7 million barrels per day in the year 2000. Many new discoveries are still being made on the Norwegian continental shelf. In the last two years, 20 new discoveries have been made, giving a resources growth of about 260 million Sm{sup 3} oil equivalents. Great technological progress has been made on the Norwegian continental shelf during the last five years concerning exploration, development and production. As for mapping, the introduction of 3D seismic data and the development of interpolation tools have helped to provide a much better understanding of the substratum. 88 figs.

  16. Mineralogy of the carbonate sediments - western continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, R.R.; Hashimi, N.H.

    An X-ray diffraction study of forty-six sediment samples and three oolitic limestone samples from the western continental shelf of India shows that aragonite is the dominant carbonate mineral (99% maximum), followed by low-magnesium calcite (77...

  17. The petroleum resources on the Norwegian continental shelf

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    In this document the Norwegian Petroleum Directorate estimates the total recoverable petroleum resources on the Norwegian continental shelf to be 12.5 billion Sm{sup 3} oil equivalents. There is considerable uncertainty regarding the undiscovered resources, the expected value being 3.5 billion Sm{sup 3} oil equivalents. The new estimates signify an increase of 14% since the calculations made last year. This increase is chiefly due to an upward adjustment of the expectations for a future increase in the recovery factor for the in place resources on the continental shelf. In 1995, the Norwegian oil production accounted for 4.3% of the global oil production. It is estimated that Norway has a total of about 1.3% of the discovered recoverable oil resources and about 1.8% of the discovered recoverable gas resources in the world. The Norwegian annual oil production is expected to reach a maximum of 3.7 million barrels per day in the year 2000. Many new discoveries are still being made on the Norwegian continental shelf. In the last two years, 20 new discoveries have been made, giving a resources growth of about 260 million Sm{sup 3} oil equivalents. Great technological progress has been made on the Norwegian continental shelf during the last five years concerning exploration, development and production. As for mapping, the introduction of 3D seismic data and the development of interpolation tools have helped to provide a much better understanding of the substratum. 88 figs.

  18. Sediments of the western continental shelf of India - Environmental significance

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.

    the occurrence of abundance peaks at similar depths in the other regions of the continental shelf that they must correspond to the presence of lowered strands. The disposition of the black shells in a linear fashion parallel to the coast line at the depths...

  19. CEO compensation, family control, and institutional investors in Continental Europe

    NARCIS (Netherlands)

    Croci, Ettore; Gonenc, Halit; Ozkan, Neslihan

    2012-01-01

    This paper investigates the impact of family control and institutional investors on CEO pay packages in Continental Europe, using a dataset of 754 listed firms with 3731 firm-year observations from 14 countries during 2001-2008. We find that family control curbs the level of CEO total and cash compe

  20. Continental Announces Carbon Offsetting Program with Sustainable Travel International

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ On December 3,2007,HOUSTON,-Continental Airlines announced that it has launched acarbon offsetting program,developed in partnership with non-profit Sustainable Travel International which is a US-based non-profit organization whose mission is to promote sustainable development and responsible travel by providing programs.

  1. Switching between alternative responses of the lithosphere to continental collision

    NARCIS (Netherlands)

    Baes, M.; Govers, R.; Wortel, R.

    2011-01-01

    We study possible responses to arc–continent or continent–continent collision using numerical models. Our short-term integration models show that the initial stage of deformation following continental collision is governed by the competition between three potential weakness zones: (1) mantle wedge,

  2. A continuous seismic section across the continental slope off Ireland

    NARCIS (Netherlands)

    Lagaay, R.A.; Collette, B.J.

    1967-01-01

    Continuous seismic reflection data show that there are no unconsolidated sediments on the outer part of the Irish continental shelf west of Donegal Bay and on the upper part of the slope. Both the “basement” and the sediment cover on the lower part of the slope are heavily intersected, presumably by

  3. The structural evolution of the deep continental lithosphere

    Science.gov (United States)

    Cooper, C. M.; Miller, Meghan S.; Moresi, Louis

    2017-01-01

    Continental lithosphere houses the oldest and thickest regions of the Earth's surface. Locked within this deep and ancient rock record lies invaluable information about the dynamics that has shaped and continue to shape the planet. Much of that history has been dominated by the forces of plate tectonics which has repeatedly assembled super continents together and torn them apart - the Wilson Cycle. While the younger regions of continental lithosphere have been subject to deformation driven by plate tectonics, it is less clear whether the ancient, stable cores formed and evolved from similar processes. New insight into continental formation and evolution has come from remarkable views of deeper lithospheric structure using enhanced seismic imaging techniques and the increase in large volumes of broadband data. Some of the most compelling observations are that the continental lithosphere has a broad range in thicknesses ( 300 km), has complex internal structure, and that the thickest portion appears to be riddled with seismic discontinuities at depths between 80 and 130 km. These internal structural features have been interpreted as remnants of lithospheric formation during Earth's early history. If they are remnants, then we can attempt to investigate the structure present in the deep lithosphere to piece together information about early Earth dynamics much as is done closer to the surface. This would help delineate between the differing models describing the dynamics of craton formation, particularly whether they formed in the era of modern plate tectonics, a transitional mobile-lid tectonic regime, or are the last fragments of an early, stagnant-lid planet. Our review paper (re)introduces readers to the conceptual definitions of the lithosphere and the complex nature of the upper boundary layer, then moves on to discuss techniques and recent seismological observations of the continental lithosphere. We then review geodynamic models and hypotheses for the formation

  4. Laying the groundwork for NEON's continental-scale ecological research

    Science.gov (United States)

    Dethloff, G.; Denslow, M.

    2013-12-01

    The National Ecological Observatory Network (NEON) is designed to examine a suite of ecological issues. Field-collected data from 96 terrestrial and aquatic sites across the U.S. will be combined with remotely sensed data and existing continental-scale data sets. Field collections will include a range of physical and biological types, including soil, sediment, surface water, groundwater, precipitation, plants, animals, insects, and microbes as well as biological sub-samples such as leaf material, blood and tissue samples, and DNA extracts. Initial data analyses and identifications of approximately 175,000 samples per year will occur at numerous external laboratories when all sites are fully staffed in 2017. Additionally, NEON will archive biotic and abiotic specimens at collections facilities where they will be curated and available for additional analyses by the scientific community. The number of archived specimens is currently estimated to exceed 130,000 per year by 2017. We will detail how NEON is addressing the complexities and challenges around this set of analyses and specimens and how the resulting high-quality data can impact ecological understanding. The raw data returned from external laboratories that is quality checked and served by NEON will be the foundation for many NEON data products. For example, sequence-quality nucleic acids extracted from surface waters, benthic biofilms, and soil samples will be building blocks for data products on microbial diversity. The raw sequence data will also be available for uses such as evolutionary investigations, and the extracts will be archived so others can acquire them for additional research. Currently, NEON is establishing contracts for the analysis and archiving of field-collected samples through 2017. During this period, NEON will gather information on the progress and success of this large-scale effort in order to determine the most effective course to pursue with external facilities. Two areas that NEON

  5. Structural lineaments from the magnetic anomaly maps of the eastern continental margin of India (ECMI) and NW Bengal Fan

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.; Rao, T.C.S.; Subrahmanyam, A.S.; Rao, M.M.M.; Lakshminarayana, S.

    extension of 85 degrees E ridge, abutting the continental shelf off Chilka Lake and (3) trend 3, locted over the continental shelf/slope between Visakhapatnm and Paradip represents a folded (ridges and depressions) nature of the continental basement...

  6. Clay mineral distribution in the continental shelf and slope off Saurashtra, West coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    the Deccan trap coastal province is the predominant clay mineral in the sediments of the continental shelf south of the Gulf of Kutch. Lateral variations reveal that the montmorillonite contents are high in the innershelf and on the continental slope...

  7. Continental Airlines Again Ranked NO.1 Most Admired Global Airline by Fortune Magazine

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ HOUSTON, March 12, 2007 Continental Airlines (NYSE: CAL) announced that it was again rated the top airline on FORTUNE magazine's annual airline industry list of Most Admired Global Companies. This is the fourth year that Continental has topped that list.

  8. 75 FR 10809 - Outer Continental Shelf (OCS) Scientific Committee-Notice of Renewal

    Science.gov (United States)

    2010-03-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Outer Continental Shelf (OCS) Scientific Committee--Notice of Renewal AGENCY: Minerals Management Service (MMS), Interior. ACTION: Notice of renewal of the Outer Continental Shelf Scientific...

  9. 77 FR 15382 - Outer Continental Shelf Scientific Committee; Notice of Renewal

    Science.gov (United States)

    2012-03-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Outer Continental Shelf Scientific Committee; Notice of Renewal AGENCY: Bureau of Ocean Energy... the Outer Continental Shelf (OCS) Scientific Committee (Committee). The Committee provides advice...

  10. 75 FR 3423 - Outer Continental Shelf Air Regulations Consistency Update for Alaska

    Science.gov (United States)

    2010-01-21

    ... AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for Alaska AGENCY.... Requirements applying to Outer Continental Shelf (``OCS'') sources located within 25 miles of States' seaward..., Incorporation by reference, Intergovernmental relations, Nitrogen dioxide, Nitrogen oxides, Outer...

  11. 76 FR 43230 - Outer Continental Shelf Air Regulations Consistency Update for Virginia

    Science.gov (United States)

    2011-07-20

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for Virginia AGENCY... Outer Continental Shelf (OCS) Air Regulations. Requirements applying to OCS sources located within...

  12. CSDP: The seismology of continental thermal regimes

    Science.gov (United States)

    Aki, K.

    1991-05-01

    The past year continued to be extremely productive following up two major breakthroughs made in the preceding year. One of the breakthroughs was the derivation of an integral equation for time-dependent power spectra, which unified all the existing theories on seismic scattering including the radiative transfer theory for total energy and single-multiple scattering theories based on the ray approach. We successfully applied the method to the data from the United States Geological Survey (USGS) regional seismic arrays in central California, Long Valley and Island of Hawaii, and obtained convincing results on the scattering Q(sup -1) and intrinsic Q(sup -1) in these areas for the frequency range from 1 Hz to 20 Hz. The frequency dependence of scattering Q(sup -1) is, then, interpreted in terms of random medium with continuous or discrete scatterers. The other breakthrough was the application of T-matrix formulation to the seismic scattering problem. We are currently working on two dimensional inclusions with high and low velocity contrast with the surrounding medium. In addition to the above two main lines of research, we were able to use so-called 'T-phase' observed on the Island of Hawaii to map the Q value with a good spatial resolution. The T-phase is seismic waves converted from acoustic waves propagated through the sofar channel of the ocean. We found that we can eliminate remarkably well the frequency dependent recording site effect from the T-phase amplitude using the amplification factor for coda waves, further confirming the fundamental separability of source, path and site effects for coda waves, and proving the effectiveness of stochastic modeling of high-frequency seismic waves.

  13. Reconstruction of multiple tectonic events in continental margins by integrated tectonostratigraphic and geochronological analysis: the Mesozoic to Paleogene Caribbean-South American interaction in northeastern Colombia

    Science.gov (United States)

    Cardona, Agustin; Montes, Camilo; Bayona, German; Valencia, Victor; Ramirez, Diego; Zapata, Sebastian; Lara, Mario; Lopez-Martinez, Margarita; Thomson, Stuart; Weber, Marion

    2013-04-01

    Although the older record and successive tectonic scenarios experienced by a continental margin is commonly fragmentary, integrated field, petrological and geochronological analysis can reconstruct the long term tectonic evolution of continental margins and characterized major controls on the orogenic style. We present new geochronological constraints from igneous and low to very low grade metasedimentary rocks from the Caribbean continental margin of northeastern Colombia (Guajira region) in order to reconstruct the different tectonic events recorded by the margin before, during and following the arc-continent collision with the front of the Caribbean plate. Zircon U-Pb LA-ICP-MS geochronology results from leucogranites associated with garnet amphibolites, tonalites and volcanic rocks that made the continental basement of northeastern Colombia reveals and Early to Middle Mesozoic tectonic activity with peaks at ca. 220-230 Ma and 170-180 Ma. This magmatic record is related to a collisional belt link to the final agglutination of Pangea and was followed by an overimposed far field back-arc setting associated to the subduction of the Pacific (Farrallon) plate under the Pangea supercontinent. Muscovite and biotite Ar-Ar geochronology from basement rocks and low grade Mesozoic metasediments also reveals the existence of Middle Jurassic to Early Cretaceous thermal events link to the final opening of the proto-Caribbean ocean. The South American continental margin was subsequently affected by an arc-continent collisional event with the front of the Caribbean plate. This event is recorded by the growth of a Banda-type collisional melange that mixed South American continental margin sediments with mafic and ultramafic blocks of intra-oceanic arc origin, the formation of a coherent metasedimentary belt also made of South American margin sediments, and the mylonitization of the continental basement. Ar-Ar temporal constraints on the low grade metasedimentary rocks and

  14. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    KAUST Repository

    Laruelle, G. G.

    2013-05-29

    Past characterizations of the land-ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LMEs: large marine ecosystems). Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles by harmonizing previous segmentations and typologies in order to retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation) and 149 sub-units (COSCATs). Geographic and hydrologic parameters such as the surface area, volume and freshwater residence time are calculated for each coastal unit as well as different hypsometric profiles. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air-water interface combining global and regional average emission rates derived from local studies. © 2013 Author(s).

  15. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    NARCIS (Netherlands)

    Laruelle, G.G.; Dürr, H.H.; Lauerwald, R.; Hartmann, J.; Slomp, C.P.; Goossens, N.; Regnier, P.A.G.

    2013-01-01

    Past characterizations of the land–ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or from an oceanic perspective, through a regionalization of the proximal and dista

  16. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    Directory of Open Access Journals (Sweden)

    G. G. Laruelle

    2013-05-01

    Full Text Available Past characterizations of the land–ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LMEs: large marine ecosystems. Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles by harmonizing previous segmentations and typologies in order to retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation and 149 sub-units (COSCATs. Geographic and hydrologic parameters such as the surface area, volume and freshwater residence time are calculated for each coastal unit as well as different hypsometric profiles. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air–water interface combining global and regional average emission rates derived from local studies.

  17. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    Directory of Open Access Journals (Sweden)

    G. G. Laruelle

    2012-10-01

    Full Text Available The complex coastline of the Earth is over 400 000 km long and about 40% of the world's population lives within 100 km of the sea. Past characterizations of the global coastline were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCAT: Coastal Segmentation and related CATchments or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LME: Large Marine Ecosystems. Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles which retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation and 149 sub-units (COSCATS. Geographic and hydrologic parameters such as the surface area, volume and fresh water residence time are calculated for each coastal unit as well as different hypsometric profiles. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. These results can be used for regional analyses and combined with various typologies for upscaling and biogeochemical budgets. In addition, the three levels segmentation can be used for application in Earth System analysis.

  18. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    KAUST Repository

    Laruelle, G. G.

    2012-10-04

    Past characterizations of the land–ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LMEs: large marine ecosystems). Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles by harmonizing previous segmentations and typologies in order to retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation) and 149 sub-units (COSCATs). Geographic and hydrologic parameters such as the surface area, volume and freshwater residence time are calculated for each coastal unit as well as different hypsometric pro- files. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air–water interface combining global and regional average emission rates derived from local studies.

  19. Predicting Classroom Success.

    Science.gov (United States)

    Kessler, Ronald P.

    A study was conducted at Rancho Santiago College (RSC) to identify personal and academic factors that are predictive of students' success in their courses. The study examined the following possible predictors of success: language and math test scores; background characteristics; length of time out of high school; high school background; college…

  20. Ingredients for successful partnerships

    NARCIS (Netherlands)

    S.M. Pfisterer (Stella)

    2011-01-01

    textabstractFor the development of new cross-sector partnerships it is required to know what the essence of successful partnership projects is. Which factors influence success or failure of partnerships is highly related to the specific context where partnerships operate. The literature on critical

  1. Successful grant writing

    NARCIS (Netherlands)

    Koppelman, Gerard H.; Holloway, John W.

    2012-01-01

    Obtaining research funding is central to the research process. However many (clinician-) scientists receive little, or no, training in the process of writing a successful grant application. In an era of reductions in research budgets and application success rates, the ability to construct a well pre

  2. Three Tiers to Success

    Science.gov (United States)

    Barton, Rhonda; Stepanek, Jennifer

    2009-01-01

    This article discusses a three-tiered, differentiated curriculum in a response to intervention (RTI) framework that has successfully raised achievement at all levels, but is particularly successful with ninth-grade students. Walla Walla (Washington) School District implemented the three-tiered intervention program as a series of differentiated…

  3. What is Success

    Institute of Scientific and Technical Information of China (English)

    Zhao; Lifang

    2015-01-01

    <正>Success is actually a feeling.Like confidence and satisfaction,it is a positive feeling which appears after individuals reach their own ideal dreams,fulfill their tasks.But everyone havetheir own opinions so that there are various thoughts on the theme what is success.

  4. Student Success Center Toolkit

    Science.gov (United States)

    Jobs For the Future, 2014

    2014-01-01

    "Student Success Center Toolkit" is a compilation of materials organized to assist Student Success Center directors as they staff, launch, operate, and sustain Centers. The toolkit features materials created and used by existing Centers, such as staffing and budgeting templates, launch materials, sample meeting agendas, and fundraising…

  5. Exploring MBA Career Success

    Science.gov (United States)

    Hay, Amanda; Hodgkinson, Myra

    2006-01-01

    Purpose: The purpose of this paper is to examine the meaning of career success in relation to the attainment of an MBA degree, for a group of experienced managers. In so doing, the paper aims to consider the adequacy of MBA career success, defined solely in terms of external criteria. Design/methodology/approach: A total of 36 in-depth interviews…

  6. 77 FR 5830 - Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf...

    Science.gov (United States)

    2012-02-06

    ... Outer Continental Shelf Offshore Massachusetts AGENCY: Bureau of Ocean Energy Management (BOEM... identify areas that may be most suitable for wind energy leasing on the Outer Continental Shelf (OCS), and... document entitled Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Massachusetts...

  7. 76 FR 2254 - Notice of Arrival on the Outer Continental Shelf

    Science.gov (United States)

    2011-01-13

    ... SECURITY Coast Guard 33 CFR Part 146 RIN 1625-AB28 Notice of Arrival on the Outer Continental Shelf AGENCY... Continental Shelf (OCS) Activities to enhance maritime domain safety and security awareness on the OCS by... Arrival. NOA OCS Notice of Arrival on the Outer Continental Shelf. NPRM Notice of Proposed Rulemaking...

  8. 75 FR 80717 - Increased Safety Measures for Energy Development on the Outer Continental Shelf; Availability...

    Science.gov (United States)

    2010-12-23

    ... Safety Measures for Energy Development on the Outer Continental Shelf; Availability, Initial Regulatory... the report entitled, ``Increased Safety Measures for Energy Development on the Outer Continental Shelf... development on the Outer Continental Shelf in light of the Deepwater Horizon event on April 20, 2010, and...

  9. 78 FR 48180 - Consolidation of Officer in Charge, Marine Inspection For Outer Continental Shelf Activities...

    Science.gov (United States)

    2013-08-07

    ...] Consolidation of Officer in Charge, Marine Inspection For Outer Continental Shelf Activities; Eighth Coast Guard... for all Mobile Offshore Drilling Units and Floating Outer Continental Shelf Facilities (as defined in... Outer Continental Shelf (OCS) Facilities (as defined in 33 CFR 140.10), and other similar vessels that...

  10. 77 FR 57572 - Notice of Arrival on the Outer Continental Shelf

    Science.gov (United States)

    2012-09-18

    ... SECURITY Coast Guard Notice of Arrival on the Outer Continental Shelf AGENCY: Coast Guard, DHS. ACTION... Continental Shelf (OCS). The Coast Guard NOA-OCS program currently requires NOA information for those vessels... of Arrival (NOA) on the Outer Continental Shelf (OCS) final rule [Docket No. USCG-2008-1088] (76 FR...

  11. Mechanisms of continental subduction and exhumation of HP and UHP rocks

    NARCIS (Netherlands)

    Burov, Evgene; Francois, Thomas; Yamato, Philippe; Wolf, Sylvie

    2014-01-01

    We discuss possible scenarios of continental collision, and their relation to mechanisms of exhumation of HP and UHP rocks, inferred from thermo-mechanical numerical models accounting for thermo-rheological complexity of the continental lithosphere. Due to this complexity, mechanisms of continental

  12. Mechanisms of continental subduction and exhumation of HP and UHP rocks

    NARCIS (Netherlands)

    Burov, Evgene; Francois, Thomas; Yamato, Philippe; Wolf, Sylvie

    We discuss possible scenarios of continental collision, and their relation to mechanisms of exhumation of HP and UHP rocks, inferred from thermo-mechanical numerical models accounting for thermo-rheological complexity of the continental lithosphere. Due to this complexity, mechanisms of continental

  13. 75 FR 56603 - Tri-Continental Corporation, et al.; Notice of Application

    Science.gov (United States)

    2010-09-16

    ... COMMISSION Tri-Continental Corporation, et al.; Notice of Application September 10, 2010. AGENCY: Securities... specified by or in accordance with the terms of any preferred shares. Applicants: Tri-Continental Corporation (``Tri-Continental''), RiverSource LaSalle International Real Estate Fund, Inc. (``RLIREF...

  14. Continental Atlas of Poland for Automobilists – the first road atlas in the independent Poland

    Directory of Open Access Journals (Sweden)

    Rutkowski Jan

    2015-07-01

    Full Text Available The 90th anniversary of the appearance of Atlas Polski Continental dla automobilistów (Continental Atlas of Poland for Automobilists published by Continental Caoutchouc Compagnie Ltd Warsaw is nearing. The Atlas was the first publication of its kind after Poland had regained its independence in 1918.

  15. 76 FR 63654 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Science.gov (United States)

    2011-10-13

    ... Doc No: 2011-26503] DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer Continental Shelf Block... American Datum of 1927 (NAD 27) Outer Continental Shelf (OCS) Official Protraction Diagram (OPD),...

  16. 75 FR 3392 - Outer Continental Shelf Air Regulations Consistency Update for Alaska

    Science.gov (United States)

    2010-01-21

    ... AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for Alaska AGENCY... 50.410. Requirements applying to Outer Continental Shelf (``OCS'') sources located within 25 miles of..., Intergovernmental relations, Nitrogen dioxide, Nitrogen oxides, Outer Continental Shelf, Ozone, Particulate...

  17. Writing successful UX proposals

    CERN Document Server

    Hass, Chris

    2016-01-01

    Bringing new project funding and business opportunities to your organization is a vital part of UX professionals' growth and success. Writing Successful UX Proposals teaches the proven techniques for assessing proposal requests, writing successful commercial and government funding proposals, and enhancing your business development skills. This book will teach UX practitioners how to succeed in UX business development by mastering the following goals: * Understand how to assess a request for proposals* Understand the "anatomy" of a proposal response * Speak the business language of those who will be evaluating the proposed approach* Recognize the successes of others and build upon their advice Complete with case studies, tricks and tips, and real-world examples throughout, this is a must-have resource for UX professionals interested in honing their proposal writing skills and setting themselves up for success. * Provides unique sales and proposal writing insights tailored to the UX arena (including both resear...

  18. Successful systems sustaining change.

    Science.gov (United States)

    Bullas, Sheila; Bryant, John

    2007-01-01

    Much has been published on the success and particularly the failure of IT projects; still failures are commonplace. This prospective study focused from the outset on assessing risk of failure and addressing critical success factors. The aim was to apply existing methods in a challenging acute care hospital where success demanded rapid achievement of sustainable improvements in clinical and administrative processes. The implementations were part of the English National Programme for IT. The desired outcomes required the integration of accepted tools and techniques to provide a pragmatic approach to systems implementation: Lean, Six Sigma, PRINCE2 and Benefits Management. The outcome and further insights into success and failure of IT projects in healthcare are described. In particular lessons are identified related to the business need for the project and the successful achievement of the required benefits and business change.

  19. Multiphased extension along continental margins: a case study of the Porcupine Basin, offshore Ireland

    Science.gov (United States)

    Bulois, Cédric; Shannon, Patrick, M.; Manuel, Pubellier; Nicolas, Chamot-Rooke; Louise, Watremez; Jacques, Deverchère

    2017-04-01

    Mesozoic faulting has been recognised in several Irish sedimentary basins as part of the northward propagation of the Atlantic rift system. However, the contribution of older structural elements remains poorly constrained. The present study documents the succession of extensional phases in the northern part of the Porcupine Basin sensu largo, offshore west of Ireland, in which structural inheritance and fault reactivation is commonly observed. The correlation of 2D and 3D seismic lines with exploration wells enables the precise definition of four overprinted extensional systems that link to specific tectonic stages identified along the Irish margin. The Porcupine Basin opened through a thickened continental crust that evolved during the Palaeozoic with the Caledonian and Variscan orogenic cycles. Extension initiated during the Carboniferous by reactivation of old structures, resulting in the migration of depocentres bounded by E-W, NE-SW and N-S structural trends. Subsequent episodic rifting occurred during several discrete events. The first rift episode, of Late Triassic to Early Jurassic age, is restricted to the North Porcupine Basin and most likely reactivated E-W structures of Caledonian age. Synrift sediments were generally deposited in a littoral setting that progressively deepened through time. The second episode, much more pronounced, occurred during the Upper Jurassic to lowermost Cretaceous (Neocomian). It resulted in shallow to deep marine deposition controlled by structural directions recognised in Caledonian and Variscan terranes. A third rift phase, evidenced by thick clastic deposition, locally occurred during the Aptian and finally died out with the opening of the Bay of Biscay located to the south of the region. A series of extensional megacycles are recognised from seismic unconformities and faulting geometries. Initial extension strongly followed the structural architecture of the continental crust (i.e. ancient folds, thrusts or orogenic fronts

  20. Tectonic Evolution of Mozambique Ridge in East African continental margin

    Science.gov (United States)

    Tang, Yong

    2017-04-01

    Tectonic Evolution of Mozambique Ridge in East African continental margin Yong Tang He Li ES.Mahanjane Second Institute of Oceanography,SOA,Hangzhou The East Africa passive continental margin is a depression area, with widely distributed sedimentary wedges from southern Mozambique to northern Somali (>6500km in length, and about 6km in thickness). It was resulted from the separation of East Gondwana, and was developed by three stages: (1) rifting in Early-Middle Jurassic; (2) spreading from Late Jurassic to Early Cretaceous; (3) drifting since the Cretaceous period. Tectonic evolution of the Mozambique continental margin is distinguished by two main settings separated by a fossil transform, the Davie Fracture Zone; (i) rifting and transform setting in the northern margin related to opening of the Somali and Rovuma basins, and (ii) rifting and volcanism setting during the opening of the Mozambique basin in the southern margin. 2D reflection seismic investigation of the crustal structure in the Zambezi Delta Depression, provided key piece of evidence for two rifting phases between Africa and Antarctica. The magma-rich Rift I phase evolved from rift-rift-rift style with remarkable emplacement of dyke swarms (between 182 and 170 Ma). Related onshore outcrops are extensively studied, the Karoo volcanics in Mozambique, Zimbabwe and South Africa, all part of the Karoo "triple-junction". These igneous bodies flow and thicken eastwards and are now covered by up to 5 km of Cretaceous and Tertiary sediments and recorded by seismic and oil exploration wells. Geophysical and geological data recorded during oceanographic cruises provide very controversial results regarding the nature of the Mozambique Ridge. Two conflicting opinions remains open, since the early expeditions to the Indian Ocean, postulating that its character is either magmatic (oceanic) or continental origin. We have carried out an China-Mozambique Joint Cruise(CMJC) on southern Mozambique Basin on 1st June to

  1. Density Sorting During the Evolution of Continental Crust

    Science.gov (United States)

    Kelemen, P. B.; Behn, M. D.; Hacker, B. R.

    2015-12-01

    We consider two settings - in addition to "delamination" of arc lower crust - in which dense, mafic eclogites founder into the convecting mantle while buoyant, felsic lithologies accumulate at the base of evolving continental crust. Arc processes play a central role in generating continental crust, but it remains uncertain how basaltic arc crust is transformed to andesitic continental crust. Dense, SiO2-poor products of fractionation may founder from the base of arc crust by "delamination", but lower arc crust after delamination has significantly different trace elements compared to lower continental crust (LCC). In an alternative model, buoyant magmatic rocks generated at arcs are first subducted, mainly via subduction erosion. Upon heating, these buoyant lithologies ascend through the mantle wedge or along a subduction channel, and are "relaminated" at
the base of overlying crust (e.g., Hacker et al EPSL 11, AREPS 15). Average buoyant lavas and plutons
for the Aleutians, Izu-Bonin-Marianas, Kohistan and Talkeetna arcs fall within the range of estimated LCC major and trace elements. Relamination is more efficient in generating continental crust than delamination. Himalayan cross-sections show Indian crust thrust beneath Tibetan crust, with no intervening mantle. There is a horizontal Moho at ca 80 km depth, extending from thickened Indian crust, across the region where Tibetan crust overlies Indian crust, into thickened Tibetan crust. About half the subducted Indian crust is present, whereas the other half is missing. Data (Vp/Vs; Miocene lavas formed by interaction of continental crust with mantle; xenolith thermometry) indicate 1000°C or more from ca 50 km depth to the Moho since the Miocene. We build on earlier studies (LePichon et al Tectonics 92, T'phys 97; Schulte-Pelkum et al Nature 05; Monsalve et al JGR 08) to advance the hypothesis that rapid growth of garnet occurs at 70-80 km and 1000°C within subducting Indian crust. Dense eclogites founder

  2. Overpressure and fluid flow in the new jersey continental slope: implications for slope failure and cold seeps

    Science.gov (United States)

    Dugan; Flemings

    2000-07-14

    Miocene through Pleistocene sediments on the New Jersey continental slope (Ocean Drilling Program Site 1073) are undercompacted (porosity between 40 and 65%) to 640 meters below the sea floor, and this is interpreted to record fluid pressures that reach 95% of the lithostatic stress. A two-dimensional model, where rapid Pleistocene sedimentation loads permeable sandy silt of Miocene age, successfully predicts the observed pressures. The model describes how lateral pressure equilibration in permeable beds produces fluid pressures that approach the lithostatic stress where overburden is thin. This transfer of pressure may cause slope failure and drive cold seeps on passive margins around the world.

  3. Successful grant writing.

    Science.gov (United States)

    Koppelman, Gerard H; Holloway, John W

    2012-03-01

    Obtaining research funding is central to the research process. However many (clinician-) scientists receive little, or no, training in the process of writing a successful grant application. In an era of reductions in research budgets and application success rates, the ability to construct a well presented, clear, articulate proposal is becoming more important than ever. Obtaining grants is a method to achieve your long term research goals. If you are able to formulate these long term goals, it is relevant to explore the market and investigate all potential grant opportunities. Finally, we will provide an outline of key elements of successful research grants.

  4. Software Maintenance Success Recipes

    CERN Document Server

    Reifer, Donald J

    2011-01-01

    Dispelling much of the folklore surrounding software maintenance, Software Maintenance Success Recipes identifies actionable formulas for success based on in-depth analysis of more than 200 real-world maintenance projects. It details the set of factors that are usually present when effective software maintenance teams do their work and instructs on the methods required to achieve success. Donald J. Reifer--an award winner for his contributions to the field of software engineering and whose experience includes managing the DoD Software Initiatives Office--provides step-by-step guidance on how t

  5. Segmentation of the Levant continental margin, eastern Mediterranean

    Science.gov (United States)

    Ben-Avraham, Z.; Schattner, U.; Lazar, M.; Hall, J. K.; Ben-Gai, Y.; Neev, D.; Reshef, M.

    2006-10-01

    The Levant continental margin is divided into two major segments by the Carmel structure, which extends from the Dead Sea fault into the eastern Mediterranean. New seismic reflection data over the unexplored northern segment are used for completing the structural framework of the Levant area, together with existing data south of it. Inclusive depth structural maps of the area were produced for the base Pliocene and base Messinian evaporites. Previous studies indicate that differences between the two segments are well expressed in the deep crustal structure. The present study, which focuses mainly on the shallow section, shows that these differences are maintained throughout the accumulation of young sedimentary units, and even in the bathymetry. This preservation of segmentation, both in the shallow and in the deep structure, insinuates that the two segments were formed through different continental breakup processes, which continue to dictate the style of sediment accumulation.

  6. Antarctic new particle formation from continental biogenic precursors

    Science.gov (United States)

    Kyrö, E.-M.; Kerminen, V.-M.; Virkkula, A.; Dal Maso, M.; Parshintsev, J.; Ruíz-Jimenez, J.; Forsström, L.; Manninen, H. E.; Riekkola, M.-L.; Heinonen, P.; Kulmala, M.

    2013-04-01

    Over Antarctica, aerosol particles originate almost entirely from marine areas, with minor contribution from long-range transported dust or anthropogenic material. The Antarctic continent itself, unlike all other continental areas, has been thought to be practically free of aerosol sources. Here we present evidence of local aerosol production associated with melt-water ponds in continental Antarctica. We show that in air masses passing such ponds, new aerosol particles are efficiently formed and these particles grow up to sizes where they may act as cloud condensation nuclei (CCN). The precursor vapours responsible for aerosol formation and growth originate very likely from highly abundant cyanobacteria Nostoc commune (Vaucher) communities of local ponds. This is the first time freshwater vegetation has been identified as an aerosol precursor source. The influence of the new source on clouds and climate may increase in future Antarctica, and possibly elsewhere undergoing accelerating summer melting of semi-permanent snow cover.

  7. Antarctic new particle formation from continental biogenic precursors

    Directory of Open Access Journals (Sweden)

    E.-M. Kyrö

    2013-04-01

    Full Text Available Over Antarctica, aerosol particles originate almost entirely from marine areas, with minor contribution from long-range transported dust or anthropogenic material. The Antarctic continent itself, unlike all other continental areas, has been thought to be practically free of aerosol sources. Here we present evidence of local aerosol production associated with melt-water ponds in continental Antarctica. We show that in air masses passing such ponds, new aerosol particles are efficiently formed and these particles grow up to sizes where they may act as cloud condensation nuclei (CCN. The precursor vapours responsible for aerosol formation and growth originate very likely from highly abundant cyanobacteria Nostoc commune (Vaucher communities of local ponds. This is the first time freshwater vegetation has been identified as an aerosol precursor source. The influence of the new source on clouds and climate may increase in future Antarctica, and possibly elsewhere undergoing accelerating summer melting of semi-permanent snow cover.

  8. Integrative taxonomy for continental-scale terrestrial insect observations.

    Directory of Open Access Journals (Sweden)

    Cara M Gibson

    Full Text Available Although 21(st century ecology uses unprecedented technology at the largest spatio-temporal scales in history, the data remain reliant on sound taxonomic practices that derive from 18(th century science. The importance of accurate species identifications has been assessed repeatedly and in instances where inappropriate assignments have been made there have been costly consequences. The National Ecological Observatory Network (NEON will use a standardized system based upon an integrative taxonomic foundation to conduct observations of the focal terrestrial insect taxa, ground beetles and mosquitoes, at the continental scale for a 30 year monitoring program. The use of molecular data for continental-scale, multi-decadal research conducted by a geographically widely distributed set of researchers has not been evaluated until this point. The current paper addresses the development of a reference library for verifying species identifications at NEON and the key ways in which this resource will enhance a variety of user communities.

  9. The effect of energy feedbacks on continental strength.

    Science.gov (United States)

    Regenauer-Lieb, Klaus; Weinberg, Roberto F; Rosenbaum, Gideon

    2006-07-06

    The classical strength profile of continents is derived from a quasi-static view of their rheological response to stress--one that does not consider dynamic interactions between brittle and ductile layers. Such interactions result in complexities of failure in the brittle-ductile transition and the need to couple energy to understand strain localization. Here we investigate continental deformation by solving the fully coupled energy, momentum and continuum equations. We show that this approach produces unexpected feedback processes, leading to a significantly weaker dynamic strength evolution. In our model, stress localization focused on the brittle-ductile transition leads to the spontaneous development of mid-crustal detachment faults immediately above the strongest crustal layer. We also find that an additional decoupling layer forms between the lower crust and mantle. Our results explain the development of decoupling layers that are observed to accommodate hundreds of kilometres of horizontal motions during continental deformation.

  10. Propagation of internal waves up continental slope and shelf

    Institute of Scientific and Technical Information of China (English)

    DAI Dejun; WANG Wei; QIAO Fangli; YUAN Yeli; XIANG Wenxi

    2008-01-01

    In a two-dimensional and linear framework, a transformation was developed to derive eigensolutions of internal waves over a subcriticai hyperbolic slope and to approximate the continental slope and shelf. The transformation converts a hyperbolic slope in physical space into a fiat bottom in transform space while the governing equations of internal waves remain hyperbolic. The eigensolutions are further used to study the evolution of linear internal waves as it propagates to subcritical continental slope and shelf. The stream function, velocity, and vertical shear of velocity induced by internal wave at the hyperbolic slope are analytically expressed by superposition of the obtained eigensolutions. The velocity and velocity shear increase as the internal wave propagates to a hyperbolic slope. They become very large especially when the slope of internal wave rays approaches the topographic slope, which is consistent with the previous studies.

  11. ETHNOPRED: a novel machine learning method for accurate continental and sub-continental ancestry identification and population stratification correction

    Science.gov (United States)

    2013-01-01

    Background Population stratification is a systematic difference in allele frequencies between subpopulations. This can lead to spurious association findings in the case–control genome wide association studies (GWASs) used to identify single nucleotide polymorphisms (SNPs) associated with disease-linked phenotypes. Methods such as self-declared ancestry, ancestry informative markers, genomic control, structured association, and principal component analysis are used to assess and correct population stratification but each has limitations. We provide an alternative technique to address population stratification. Results We propose a novel machine learning method, ETHNOPRED, which uses the genotype and ethnicity data from the HapMap project to learn ensembles of disjoint decision trees, capable of accurately predicting an individual’s continental and sub-continental ancestry. To predict an individual’s continental ancestry, ETHNOPRED produced an ensemble of 3 decision trees involving a total of 10 SNPs, with 10-fold cross validation accuracy of 100% using HapMap II dataset. We extended this model to involve 29 disjoint decision trees over 149 SNPs, and showed that this ensemble has an accuracy of ≥ 99.9%, even if some of those 149 SNP values were missing. On an independent dataset, predominantly of Caucasian origin, our continental classifier showed 96.8% accuracy and improved genomic control’s λ from 1.22 to 1.11. We next used the HapMap III dataset to learn classifiers to distinguish European subpopulations (North-Western vs. Southern), East Asian subpopulations (Chinese vs. Japanese), African subpopulations (Eastern vs. Western), North American subpopulations (European vs. Chinese vs. African vs. Mexican vs. Indian), and Kenyan subpopulations (Luhya vs. Maasai). In these cases, ETHNOPRED produced ensembles of 3, 39, 21, 11, and 25 disjoint decision trees, respectively involving 31, 502, 526, 242 and 271 SNPs, with 10-fold cross validation accuracy of

  12. Successful project management

    CERN Document Server

    Young, Trevor L

    2016-01-01

    Successful Project Management, 5th edition, is an essential guide for anyone who wants to improve the success rate of their projects. It will help managers to maintain a balance between the demands of the customer, the project, the team and the organization. Covering the more technical aspects of a project from start to completion it contains practised and tested techniques, covering project conception and start-up, how to manage stake holders, effective risk management, project planning and launch and execution. Also including a brand new glossary of key terms, it provides help with evaluating your project as well as practical checklists and templates to ensure success for any ambitious project manager. With over one million copies sold, the hugely popular Creating Success series covers a wide variety of topic, with the latest editions including new chapters such as Tough Conversations and Treating People Right. This indispensable business skills collection is suited to a variety of roles, from someone look...

  13. Tribes Communities Success Stories

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data describes successful EPA projects and partnerships which are restoring local communities and watersheds within the San Francisco Bay Delta Watershed.

  14. Goodbye Career, Hello Success.

    Science.gov (United States)

    Komisar, Randy

    2000-01-01

    Success in today's economy means throwing out the old career rules. The "noncareer" career is driven by passion for the work and has the fluidity and flexibility needed in the contemporary workplace. (JOW)

  15. Human Resource Outsourcing Success

    Directory of Open Access Journals (Sweden)

    Hasliza Abdul-Halim

    2014-07-01

    Full Text Available The existing literature on partnership seems to take the relationship between partnership quality and outsourcing success for granted. Therefore, this article aims at examining the role of service quality in strengthening the relationship between partnership quality and human resource (HR outsourcing success. The samples were obtained from 96 manufacturing organizations in Penang, Malaysia. The results showed that partnership quality variables such as trust, business understanding, and communication have significant positive impact on HR outsourcing success, whereas in general, service quality was found to partially moderate these relationships. Therefore, comprehending the HR outsourcing relationship in the context of service quality may assist the organizations to accomplish HR outsourcing success by identifying areas of expected benefits and improvements.

  16. Goodbye Career, Hello Success.

    Science.gov (United States)

    Komisar, Randy

    2000-01-01

    Success in today's economy means throwing out the old career rules. The "noncareer" career is driven by passion for the work and has the fluidity and flexibility needed in the contemporary workplace. (JOW)

  17. Continental Airlines and China Southern Airlines Announce Strategic Partnership

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Frequent flyer reciprocity to start in September: codesharing to start in November. Continental Airlines and China Southern Airlines. the largest airline in the People's Republic of China. announced on June 18, 2007 that they have entered into a strategic partnership for frequent flyer and airport lounge access reciprocity and extensive codesharing, providing better service to customers who travel between the U.S.and China and transfer between the two carriers.

  18. Aerosol-cloud relationships in continental shallow cumulus

    OpenAIRE

    Lu, Miao-Ling; Feingold, Graham; Jonsson, Haflidi; Chuang, Patrick Y.; Gates, Harmony; Flagan, Richard C.; Seinfeld, John H.

    2008-01-01

    The article of record as published may be located at http://dx.doi.org/10.1029/2007JD009354 Aerosol-cloud relationships are derived from 14 warm continental cumuli cases sampled during the 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) by the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft. Cloud droplet number concentration is clearly proportional to the subcloud accumulation mode aerosol number concentration...

  19. Continental crust under the southern Porcupine Seabight west of Ireland

    Science.gov (United States)

    Makris, J.; Egloff, R.; Jacob, A. W. B.; Mohr, P.; Murphy, T.; Ryan, P.

    1988-08-01

    Two new seismic refraction/wide-angle reflection profiles demonstrate that the crust beneath the southern Porcupine Seabight, out to water depths in excess of 4000 m, is of continental type. They also reveal the rifted margin of the Porcupine basin on its eastern side. Crustal thickness under the Seabight, inclusive of sediments which are up to 6 km thick, decreases from 23 km in the east to about 10 km at a sharp continent-ocean transition in the west.

  20. The geomorphology of a glaciated continental shelf, Western Scotland, UK

    Science.gov (United States)

    Howe, John; Dove, Dayton; Bradwell, Tom

    2013-04-01

    We present recently collected swath bathymetry and legacy seismic data from two regions of the north-west UK continental shelf: the Sea of the Hebrides; and the Firth of Lorn, western Scotland. Both regions have experienced extensive Pleistocene ice sheet glaciation and both provide abundant geomorphological evidence of subglacial and postglacial processes. The Sea of the Hebrides bathymetry data cover 2200 km2 and provide new geomorphological evidence for an ice stream flowing from western Scotland and the Inner Hebrides focusing towards a trough-mouth fan (the Barra Fan) at the continental shelf break during the height of the last glaciation. Notably, bedrock structures provide a control on the location and orientation of glacially overdeepened basins and troughs on the inner shelf. Whilst around the Islands of Canna and Rum, convergent seabed glacial lineations and other subglacially streamlined features eroded in bedrock preserve the direction of ice sheet movement - indicating ice streaming in a south-westerly direction across the continental shelf. We propose that this fast-flow zone formed part of a larger convergent ice stream system draining much of western Scotland and the north of Ireland. The Firth of Lorn bathymetry acquisition comprises 553km2 of data, collected as part of the INIS Hydro program (Ireland, Northern Ireland and Scotland Hydrographic Survey). This region of nearshore continental shelf is revealed as predominantly bedrock-dominated seabed, characterised by a series of narrow, strongly fault-controlled troughs, part of the Great Glen Fault Zone complex. Evidence for glaciation is widespread and well preserved in the Firth of Lorn and surrounding seabed with moraines, bedrock lineations (?megagrooves?) and overdeepened basins common across the area. Initial mapping shows that our understanding of the configuration and style of deglaciation in these sectors of the former British-Irish Ice Sheet can be greatly improved by the collection of

  1. Habitat Specialization in Tropical Continental Shelf Demersal Fish Assemblages

    OpenAIRE

    Ben M Fitzpatrick; Euan S Harvey; Heyward, Andrew J.; Twiggs, Emily J.; Jamie Colquhoun

    2012-01-01

    The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. ...

  2. Fluid activity during exhumation of deep-subducted continental plate

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yongfei

    2004-01-01

    It is well known that a great deal of fluid was released during subduction of oceanic crust, resulting in arc magmatism, quartz veining and metamorphic mineralization of syn-subduction. In contrast, the process of continental subduction is characterized by the relative lack of fluid and thus no arc magmatism has been found so far. During exhumation of deep-subducted continental crust, nevertheless,significant amounts of aqueous fluid became available from the decomposition of hydrous minerals, the decrepitation of primary fluid inclusions, and the exsolution of structural hydroxyls. This kind of metamorphic fluid has recently attracted widespread interests and thus been one of the most important targets in deciphering the geological processes concerning metamorphism, magmatism and mineralization in collisional orogens. A large number of studies involving stable isotopes, fluid inclusions and petrological phase relationships have been accomplished in past a few years with respect to the mobility and amount of metamorphic fluid in UHP metamorphic rocks from the Dabie-Sulu orogenic belt.The results demonstrate that the fluid activity during the exhumation of deep-subducted continental crust has the following effects: (1) amphibolite-facies retrogression due to pervasive fluid flow; (2) formation of HP quartz veins within eclogites due to channelized fluid flow; and (3) partial melting of overlying crustal rocks due to focused fluid flow, producing syn-exhumation magmatism within the orogenic belt.In particular, the aqueous fluid released by decompression exsolution of hydroxyl from UHP minerals is characterized by low salinity and is capable of resulting in pervasive and channellized flow. Therefore, the intensive study of fluid activity during exhumation of UHP metamorphic rocks can not only provide insight into geodynamic processes that occurred in continental collisional belts, but also shed light on understanding of crust-mantle recycling and relevant magmatism in

  3. NEW RECORDS OF CHIRONOMIDAE (DIPTERA) FROM CONTINENTAL FRANCE

    OpenAIRE

    Joel Moubayed-Breil

    2009-01-01

    AbstractMaterial recently collected in Continental Francehas allowed me to generate a list of 83 taxa ofchironomids, including 37 new records to thefauna of France. According to published data onthe chironomid fauna of France 718 chironomidspecies are hitherto known from the Frenchterritories. The nomenclature and taxonomy ofthe species listed are based on the last version ofthe Chironomidae data in Fauna Europaea, onrecent revisions of genera and other recentpublications relevant to taxonomy...

  4. Biogeografía marina de Chile continental Marine biogeography of continental Chile

    Directory of Open Access Journals (Sweden)

    PATRICIO A. CAMUS

    2001-09-01

    Full Text Available Por casi un siglo, varios autores han analizado los patrones de distribución de la fauna y flora marina del Pacífico de Sudamérica y de la costa de Chile en particular, con el propósito de establecer el número de las unidades biogeográficas presentes. Si bien los patrones generales actuales son relativamente bien conocidos, la mayoría de los estudios se ha enfocado en las discontinuidades distribucionales y en propuestas de clasificación más que en los factores y procesos dinámicos que han formado las unidades espaciales identificadas. Aun en el caso de las clasificaciones, las conclusiones publicadas se basan principalmente en el análisis de uno o pocos grupos seleccionados, y presentan diferencias importantes en los criterios de selección de los grupos, el número de especies involucrado y la metodología usada. Por otra parte, las discrepancias entre estudios específicos tienden a obscurecer un fenómeno relevante y de mayor escala como es la dinámica de las biotas, uno de los aspectos biogeográficos menos conocidos en Chile. En tal contexto, este trabajo presenta una revisión de literatura sobre la biogeografía marina de Chile y sus aspectos asociados, con los siguientes objetivos: (a resumir las características oceanográficas, climáticas y geomorfológicas de la costa continental de Chile; (b discutir 27 clasificaciones biogeográficas publicadas para la costa chilena, analizando los criterios y procedimientos usados por los autores, sus conclusiones principales, y la concordancia entre los estudios; (c evaluar los procesos dispersivos y vicariantes asociados a los desplazamientos y modificaciones de las biotas de la región, en función de los antecedentes disponibles sobre las condiciones existentes y los principales eventos ocurridos durante los períodos Terciario y Cuaternario; y (d proponer un escenario de cambio biogeográfico basado en determinantes históricas y su influencia en la formación, carácter y din

  5. Research into Success

    Directory of Open Access Journals (Sweden)

    Bogomir Novak

    1997-12-01

    Full Text Available As competition is becoming ever more fierce, research into the prerequisites for success is gaining ground. By most people, success is perceived as an external phenomenon, but it is in fact the consequence of a person's readiness to perform in the world (of business. In the paper, Novak distinguishes between internal, external and group success. The essence of interna!success, which is the condition for the other two types of success, is assuming responsibility for, and exercising self-control over one's psychic phenomena. This in fact means that one needs to "reprogramme" the old patterns of behaviour and substitute them for the new, which leads to personality changes based on the understanding and acceptance of the self and others as they are. In realizing personal abilities, motives and goals, mental guiding laws must also be taken into account. Nowadays, the overall success of an organization is an important indicator of the quality of gro up work. The working patterns of individuals comply with the patterns used by his or her colleagues. When we do something for ourselves, we do it for others. In certain organizations, through accepted ways of communication all people become successful, and no body needs to be paid off. Employees wholly identify themselves with their organization, and vice versa. This three-part paradigm (I-Others-Community is the basis for various models of practical training for success, which are often idealized, but are primarily aimed at abolishing passivity and flaws in the system and its wider environment.

  6. Scale effects of the continental coastline of China

    Institute of Scientific and Technical Information of China (English)

    SU Fenzhen; GAO Yi; ZHOU Chenghu; YANG Xiaomei; FEI Xianyun

    2011-01-01

    Spatial scale is a fundamental problem in Geography.Scale effect caused by fractal characteristic of coastline becomes a common focus of coastal zone managers and researchers.In this study,based on DEM and remote sensing images,multi-scale continental coastlines of China were extracted and the fractal characteristic was analyzed.The results are shown as follows.(1) The continental coastline of China fits the fractal model,and the fractal dimension is 1.195.(2) The scale effects with fractal dimensions of coastline have significant differences according to uplift and subsidence segments along the continental coastlines of China.(3) The fractal dimension of coastline has significant spatial heterogeneity according to the coastline types.The fractal dimension of sandy coastline located in Luanhe River plain is 1.109.The dimension of muddy coastline located in northern Jiangsu Plain is 1.059,while that of rocky coastline along southeastern Fujian is 1.293.(4) The length of rocky coastline is affected by scale more than that of muddy and sandy coastline.Since coastline is the conjunction of sea,land and air surface,the study of coastline scale effect is one of the scientific bases for the researches on air-sea-land interaction in multi-scales.

  7. On the freshening of the northwestern Weddell Sea continental shelf

    Directory of Open Access Journals (Sweden)

    H. H. Hellmer

    2011-05-01

    Full Text Available We analyzed hydrographic data from the northwestern Weddell Sea continental shelf of the three austral winters 1989, 1997, and 2006 and two summers following the last winter cruise. During summer a thermal front exists at ~64° S separating cold southern waters from warm northern waters that have similar characteristics as the deep waters of the central basin of the Bransfield Strait. In winter, the whole continental shelf exhibits southern characteristics with high Neon (Ne concentrations, indicating a significant input of glacial melt water. The comparison of the winter data from the shallow shelf off the tip of the Antarctic Peninsula, spanning a period of 17 yr, shows a salinity decrease of 0.09 for the whole water column, which has a residence time of <1 yr. We interpret this freshening as being caused by a combination of reduced salt input due to a southward sea ice retreat and higher precipitation during the late 20th century on the western Weddell Sea continental shelf. However, less salinification might also result from a delicate interplay between enhanced salt input due to sea ice formation in coastal areas formerly occupied by Larsen A and B ice shelves and increased Larsen C ice loss.

  8. Formation and evolution of Precambrian continental crust in South China

    Institute of Scientific and Technical Information of China (English)

    ZHENG YongFei; ZHANG ShaoBing

    2007-01-01

    The occurrence of zircons with U-Pb ages of ~3.8 Ga and Hf model ages of ~4.0 Ga in South China suggests the existence of the Hadean crustal remnants in South China. Furthermore, a detrital zircon with a U-Pb age as old as 4.1 Ga has been found in Tibet. This is the oldest zircon so far reported in China. These results imply that continental crust was more widespread than previously thought in the late Hadean, but its majority was efficiently reworked into Archean continental crust. On the basis of available zircon U-Pb age and Hf isotope data, it appears that the growth of continental crust in South China started since the early Archean, but a stable cratonic block through reworking did not occur until the Paleoproterozoic. Thus the operation of some form of plate tectonics may occur in China continents since Eoarchean. The initial destruction of the South China craton was caused by intensive magmatic activity in association with the assembly and breakup of the supercontinent Rodinia during the Neoproterozoic. However, most of the Archean and Paleoproterozoic crustal materials in South China do not occur as surface rocks, but exist as sporadic crustal remnants. Nevertheless, the occurrence of Neoproterozoic magmatism is still a signature to distinguish South China from North China.

  9. Comparative biogeochemistry-ecosystem-human interactions on dynamic continental margins

    Science.gov (United States)

    Levin, Lisa A.; Liu, Kon-Kee; Emeis, Kay-Christian; Breitburg, Denise L.; Cloern, James; Deutsch, Curtis; Giani, Michele; Goffart, Anne; Hofmann, Eileen E.; Lachkar, Zouhair; Limburg, Karin; Liu, Su-Mei; Montes, Enrique; Naqvi, Wajih; Ragueneau, Olivier; Rabouille, Christophe; Sarkar, Santosh Kumar; Swaney, Dennis P.; Wassman, Paul; Wishner, Karen F.

    2014-01-01

    The ocean’s continental margins face strong and rapid change, forced by a combination of direct human activity, anthropogenic CO2-induced climate change, and natural variability. Stimulated by discussions in Goa, India at the IMBER IMBIZO III, we (1) provide an overview of the drivers of biogeochemical variation and change on margins, (2) compare temporal trends in hydrographic and biogeochemical data across different margins (3) review ecosystem responses to these changes, (4) highlight the importance of margin time series for detecting and attributing change and (5) examine societal responses to changing margin biogeochemistry and ecosystems. We synthesize information over a wide range of margin settings in order to identify the commonalities and distinctions among continental margin ecosystems. Key drivers of biogeochemical variation include long-term climate cycles, CO2-induced warming, acidification, and deoxygenation, as well as sea level rise, eutrophication, hydrologic and water cycle alteration, changing land use, fishing, and species invasion. Ecosystem responses are complex and impact major margin services including primary production, fisheries production, nutrient cycling, shoreline protection, chemical buffering, and biodiversity. Despite regional differences, the societal consequences of these changes are unarguably large and mandate coherent actions to reduce, mitigate and adapt to multiple stressors on continental margins.

  10. On the freshening of the northwestern Weddell Sea continental shelf

    Directory of Open Access Journals (Sweden)

    H. H. Hellmer

    2010-12-01

    Full Text Available We analysed hydrographic data from the northwestern Weddell Sea continental shelf of three austral winters (1989, 1997 and 2006 and two summers following the last winter cruise. During summer a thermal front exists at ~64° S separating cold southern waters from warm northern waters that have similar characteristics as the deep waters of the central basin of the Bransfield Strait. In winter, the whole continental shelf exhibits southern characteristics with high Neon (Ne concentrations, indicating a significant input of glacial melt water. The comparison of the winter data at the tip of the Antarctic Peninsula, spanning a period of 17 years, shows a salinity decrease of 0.09 for the whole water column. We interpret this freshening as a reduction in salt input to the water masses being advected northward on the western Weddell Sea continental shelf. Possible causes for the reduced winter salinification are a southward retreat of the summer sea ice edge together with more precipitation in this sector. However, the latter might have happened in conjunction with an increase in ice shelf mass loss, counteracting an enhanced salt input due to sea ice formation in coastal areas formerly occupied by Larsen A and B ice shelves.

  11. Methane Gas Hydrate Stability Models on Continental Shelves in Response to Glacio-Eustatic Sea Level Variations: Examples from Canadian Oceanic Margins

    OpenAIRE

    2013-01-01

    We model numerically regions of the Canadian continental shelves during successive glacio-eustatic cycles to illustrate past, current and future marine gas hydrate (GH) stability and instability. These models indicated that the marine GH resource has dynamic features and the formation age and resource volumes depend on the dynamics of the ocean-atmosphere system as it responds to both natural (glacial-interglacial) and anthropogenic (climate change) forcing. Our models focus on the interval b...

  12. Stakeholder requirements for commercially successful wave energy converter farms

    Energy Technology Data Exchange (ETDEWEB)

    Babarit, Aurélien; Bull, Diana; Dykes, Katherine; Malins, Robert; Nielsen, Kim; Costello, Ronan; Roberts, Jesse; Bittencourt Ferreira, Claudio; Kennedy, Ben; Weber, Jochem

    2017-12-01

    In this study, systems engineering techniques are applied to wave energy to identify and specify stakeholders' requirements for a commercially successful wave energy farm. The focus is on the continental scale utility market. Lifecycle stages and stakeholders are identified. Stakeholders' needs across the whole lifecycle of the wave energy farm are analyzed. A list of 33 stakeholder requirements are identified and specified. This list of requirements should serve as components of a technology performance level metric that could be used by investors and funding agencies to make informed decisions when allocating resources. It is hoped that the technology performance level metric will accelerate wave energy conversion technology convergence.

  13. Experimental constraints on phase relations in subducted continental crust

    Science.gov (United States)

    Hermann, Jörg

    2002-01-01

    Synthesis piston cylinder experiments were carried out in the range 2.0-4.5 GPa and 680-1,050 °C to investigate phase relations in subducted continental crust. A model composition (KCMASH) has been used because all major ultrahigh-pressure (UHP) minerals of the whole range of rock types typical for continental crust can be reproduced within this system. The combination of experimental results with phase petrologic constraints permits construction of a UHP petrogenetic grid. The phase relations demonstrate that the most important UHP paragenesis consists of coesite, kyanite, phengite, clinopyroxene, and garnet in subducted continental crust. Below 700 °C talc is stable instead of garnet. As most of these minerals are also stable at much lower pressure and temperature conditions it is thus not easy to recognize UHP metamorphism in subducted crust. A general feature, however, is the absence of feldspars at H2O-saturated conditions. Plagioclase is never stable at UHP conditions, but K-feldspar can occur in H2O-undersaturated rocks. Mineral compositions in the experiments are fully buffered by coexisting phases. The Si content of phengite and biotite increase with increasing pressure. At 4.0 GPa, 780 °C, biotite contains 3.28 Si per formula unit, which is most probably caused by solid solution of biotite with talc. Above 800 °C, the CaAl2SiO6 component in clinopyroxene buffered with kyanite, coesite and a Mg-phase increases with increasing temperature, providing a tool to distinguish between 'cold' and 'hot' eclogites. Up to 10% Ca-eskolaite (Ca0.5[]0.5AlSi2O6) in clinopyroxene has been found at the highest temperature and pressure investigated (>900 °C, 4.5 GPa). Garnet buffered with coesite, kyanite and clinopyroxene displays an increase of grossular component with increasing pressure for a given temperature. Although the investigated system represents a simplification with respect to natural rocks, it helps to constrain general features of subducted continental

  14. Successful ageing for psychiatrists.

    Science.gov (United States)

    Peisah, Carmelle

    2016-04-01

    This paper aims to explore the concept and determinants of successful ageing as they apply to psychiatrists as a group, and as they can be applied specifically to individuals. Successful ageing is a heterogeneous, inclusive concept that is subjectively defined. No longer constrained by the notion of "super-ageing", successful ageing can still be achieved in the face of physical and/or mental illness. Accordingly, it remains within the reach of most of us. It can, and should be, person-specific and individually defined, specific to one's bio-psycho-social and occupational circumstances, and importantly, reserves. Successful professional ageing is predicated upon insight into signature strengths, with selection of realistic goal setting and substitution of new goals, given the dynamic nature of these constructs as we age. Other essential elements are generativity and self-care. Given that insight is key, taking a regular stock or inventory of our reserves across bio-psycho-social domains might be helpful. Importantly, for successful ageing, this needs to be suitably matched to the professional task and load. This lends itself to a renewable personal ageing plan, which should be systemically adopted with routine expectations of self-care and professional responsibility. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  15. Untangling Performance from Success

    CERN Document Server

    Yucesoy, Burcu

    2015-01-01

    Fame, popularity and celebrity status, frequently used tokens of success, are often loosely related to, or even divorced from professional performance. This dichotomy is partly rooted in the difficulty to distinguish performance, an individual measure that captures the actions of a performer, from success, a collective measure that captures a community's reactions to these actions. Yet, finding the relationship between the two measures is essential for all areas that aim to objectively reward excellence, from science to business. Here we quantify the relationship between performance and success by focusing on tennis, an individual sport where the two quantities can be independently measured. We show that a predictive model, relying only on a tennis player's performance in tournaments, can accurately predict an athlete's popularity, both during a player's active years and after retirement. Hence the model establishes a direct link between performance and momentary popularity. The agreement between the performa...

  16. Succeeding with succession planning.

    Science.gov (United States)

    McConnell, C R

    1996-12-01

    Succession planning is the process of identifying people who could presently move into key positions or could do so after specifically targeted development occurs. The process identifies the better people in the organization and takes a consistent approach to assembling, analyzing, and retaining information about potential leaders and planning for their further development. At its simplest level, it is the development of a backup and potential successor to each manager; at is most formal, it is a documented plan for management succession at all levels in the organization. Strongly supportive of a policy of development and promotion from within the organization, succession planning also represents a proactive posture in respect to inevitable management turnover. In these days of rapid change in health care, no modern organization that expects to keep up with increasing competition can afford to drift--or even to let a single department drift--while replacements are recruited for managers who resign, retire, or otherwise leave.

  17. Developing partnerships for implementing continental-scale citizen science programs at the local-level

    Science.gov (United States)

    Newman, S. J.; Henderson, S.; Ward, D.

    2012-12-01

    Project BudBurst is a citizen science project focused on monitoring plant phenology that resides at the National Ecological Observatory Network (NEON, Inc). A central question for Project BudBurst and other national outreach programs is: what are the most effective means of engaging and connecting with diverse communities throughout the country? How can continental scale programs like NEON's Project BudBurst engage audiences in such a way as to be relevant at both the local and continental scales? Staff with Project BudBurst pursued partnerships with several continental scale organizations: the National Wildlife Refuge System, the National Park Service, and botanic gardens to address these questions. The distributed nature of wildlife refuges, national parks, and botanic gardens around the country provided the opportunity to connect with participants locally while working with leadership at multiple scales. Project BudBurst staff talked with hundreds of staff and volunteers prior to setting a goal of obtaining and developing resources for several Refuge Partners, a pilot National Park partner, and an existing botanic garden partner during 2011. We were especially interested in learning best practices for future partnerships. The partnership efforts resulted in resource development for 12 Refuge partners, a pilot National Park partner, and 2 botanic garden partners. Early on, the importance of working with national level leaders to develop ownership of the partner program and input about resource needs became apparent. Once a framework for the partnership program was laid out, it became critical to work closely with staff and volunteers on the ground to ensure needs were met. In 2012 we began to develop an online assessment to allow our current and potential partners to provide feedback about whether or not the partnership program was meeting their needs and how the program could be improved. As the year progressed, the timeline for resource development became more

  18. Hydrothermal Petroleum in Active Continental Rift: Lake Chapala, Western Mexico, Initial Results.

    Science.gov (United States)

    Zarate-del Valle, P. F.; Simoneit, B. R.; Ramirez-Sanchez, H. U.

    2003-12-01

    Lake Chapala in western Mexico is located partially in the Citala Rift, which belongs to the well-known neotectonic Jalisco continental triple junction. The region is characterized by active volcanism (Ceboruco, Volcan de Fuego), tectonic (1995 earthquake, M=8, 40-50 mm to SW) and hydrothermal (San Juan Cosala & Villa Corona spas and La Calera sinter deposit) activities. Hydrothermal petroleum has been described in active continental rift (East African Rift) and marine spreading zones (Guaymas Basin, Gulf of California). In 1868 the Mexican local press reported that manifestations of bitumen were appearing in front of the Columba Cap on the mid south shore of Lake Chapala. This bitumen is linked to the lake bottom and when the water level decreases sufficiently it is possible to access these tar bodies as islands. Because of these manifestations the Mexican oil company (PEMEX) drilled an exploration well (2,348m) at Tizapan El Alto without success. Hydrothermal activity is evident in the tar island zone as three in-shore thermal springs (26.8 m depth, 48.5° C, pH 7.8 and oriented N-S). The preliminary analyses by GC-MS of the tar from these islands indicate hydrothermal petroleum derived from lake sedimentary organic matter, generated at low temperatures (150° -200° C). The tars contain no n-alkanes, no PAH or other aromatics, but a major UCM of branched and cyclic hydrocarbons and mature biomarkers derived from lacustrine biota. The biomarkers consist of mainly 17α (H),21β (H)-hopanes ranging from C27 to C34 (no C28), gammacerane, tricyclic terpanes (C20-C26), carotane and its cracking products, and drimanes (C14-C16). The biomarker composition indicates an organic matter source from bacteria and algae, typical of lacustrine ecosystems. 14C dating of samples from two tar islands yielded ages exceeding 40 kyrs, i.e., old carbon from hydrothermal/tectonic remobilization of bitumen from deeper horizons to the surface. The occurrence of hydrothermal petroleum in

  19. Interpretation of free-air gravity anomaly data for determining the crustal structure across the continental margins and aseismic ridges: Some examples from Indian continental margins and deep-sea basins

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.

    of Alaska and Japan trench, east of the Japanese Islands. Gravity anomalies across continental margins Continental margins are at or near to the transition zone between continental and oceanic crusts. Passive margins are commonly in isostatic.... Generalized bathymetry map of the Indian continental margins After Mishra et al., (2004) The western and eastern margins of India are classified under passive/Atlantic type continental margins, and the structural architecture is similar to any...

  20. Spatially quantitative seafloor habitat mapping: example from the northern South Carolina inner continental shelf

    Science.gov (United States)

    Ojeda, Germán Y.; Gayes, Paul T.; Van Dolah, Robert F.; Schwab, William C.

    2004-03-01

    Naturally occurring hard bottom areas provide the geological substrate that can support diverse assemblages of sessile benthic organisms, which in turn, attract many reef-dwelling fish species. Alternatively, defining the location and extent of bottom sand bodies is relevant for potential nourishment projects as well as to ensure that transient sediment does not affect reef habitats, particularly in sediment-starved continental margins. Furthermore, defining sediment transport pathways documents the effects these mobile bedforms have on proximal reef habitats. Thematic mapping of these substrates is therefore crucial in safeguarding critical habitats and offshore resources of coastal nations. This study presents the results of a spatially quantitative mapping approach based on classification of sidescan-sonar imagery. By using bottom video for image-to-ground control, digital image textural features for pattern recognition, and an artificial neural network for rapid, quantitative, multivariable decision-making, this approach resulted in recognition rates of hard bottom as high as 87%. The recognition of sand bottom was less successful (31%). This approach was applied to a large (686 km 2), high-quality, 2-m resolution sidescan-sonar mosaic of the northern South Carolina inner continental shelf. Results of this analysis indicate that both surficial sand and hard bottoms of variable extent are present over the study area. In total, 59% of the imaged area was covered by hard bottom, while 41% was covered by sand. Qualitative spatial correlation between bottom type and bathymetry appears possible from comparison of our interpretive map and available bathymetry. Hard bottom areas tend to be located on flat, low-lying areas, and sandy bottoms tend to reside on areas of positive relief. Published bio-erosion rates were used to calculate the potential sediment input from the mapped hard bottom areas rendering sediment volumes that may be as high as 0.8 million m 3/yr for

  1. Modeling River Networks in the Continental Shelf during Sea Level Cycles

    Science.gov (United States)

    Fagherazzi, S.; Wiberg, P. L.

    2003-12-01

    Several processes influence the development of fluvial networks in the continental shelf during sea level low stands. In order to understand the specific role of each process and quantify its influence on channel formation and incision, the Detachment Limited Model (DeLiM) (Howard, 1994) has been applied to several shelf configurations and with different sea-level curves. The computer model incorporates deltaic deposition on the continental shelf as well as sea-level oscillations and is parameterized with Virginia coastal plain data. Simulations show that the major factor controlling incision and channel development is the tendency of streams to reach an equilibrium (graded) configuration. If, for a given river discharge and shelf slope, the sediment load is less than that required to be at grade, channel incision will occur in the exposed shelf until the river long profile is in equilibrium with the current sea level (base level). The geometry and thickness of sediments deposited in deltas and estuaries have a minor influence on the total channel incision, but are of fundamental importance for the spatial development of the channel network. Model results show that the detailed structure of sea level oscillations is important for sediment redistribution and channel changes. Conceptual models that consider a mere succession of sea level high stands and low stands are oversimplified and miss the complex response of the system to gradual sea level oscillations. The initial shelf topography strongly characterizes the future network development. During the simulations the drainage network is initially strongly fragmented, but gradually becomes integrated through depression infilling and dissection of steep scarps. Finally the role of coastal processes is of crucial importance for sediment redistribution and shelf topography modification during sea-level oscillations.

  2. Slab detachment during continental collision: Influence of crustal rheology and interaction with lithospheric delamination

    Science.gov (United States)

    Duretz, T.; Gerya, T. V.

    2013-08-01

    Collision between continents can lead to the subduction of continental material. If the crust remains coupled to the downgoing slab, a large buoyancy force is generated. This force slows down convergence and promotes slab detachment. If the crust resists to subduction, it may decouple from the downgoing slab and be subjected to buoyant extrusion. We employ two-dimensional thermo-mechanical modelling to study the importance of crustal rheology on the evolution of subduction-collision systems. We propose simple quantifications of the mechanical decoupling between lithospheric levels (σ*) and the potential for buoyant extrusion of the crust (ξ*). The modelling results indicate that a variable crustal rheological structure results in slab detachment, delamination, or the combination of both mechanisms. A strong crust provides coupling at the Moho (low σ*) and remains coherent during subduction (low ξ). It promotes deep subduction of the crust (180 km) and slab detachment. Exhumation occurs in coherent manners via eduction and thrusting. Slab detachment triggers the development of topography (> 4.5 km) close to the suture. A contrasting style of collision occurs using a weak crustal rheology. Mechanical decoupling at the Moho (high σ*) promotes the extrusion of the crust (high ξ), disabling slab detachment. Ongoing shortening leads to buckling of the crust and development of topography on the lower plate. Collisions involving rheologically layered crust allow decoupling at mid-crustal depths. This structure favours both the extrusion of upper crust and the subduction of the lower crust. Such collisions are successively affected by delamination and slab detachment. Topography develops together with the buoyant extrusion of crust onto the foreland and is further amplified by slab detachment. Our results suggest that the occurrence of both delamination (Apennines) and slab detachment (Himalayas) in orogens may indicate differences in the initial crustal structure of

  3. Successful aging at work

    NARCIS (Netherlands)

    Zacher, Hannes

    2015-01-01

    The expression successful aging at work and related terms such as active, healthy, and productive aging at work are frequently used by organizational researchers and practitioners. However, there are no concrete definitions or theoretical frameworks that explain their meaning, assumptions, and

  4. Successful School Composting.

    Science.gov (United States)

    Mahar, Rhea Dawn

    2001-01-01

    School composting programs that have met the challenges inherent in long-term composting have several traits in common: a supportive educational program, schoolwide participation, and a consistent maintenance program. Examines the elements of success, offers examples of incorporating composting into the curriculum, and describes three methods of…

  5. Ensuring Students' Success

    Science.gov (United States)

    Oblinger, James L.

    2006-01-01

    James L. Oblinger, Chancellor of North Carolina State University, argues that higher education must continually evolve new methods of teaching and learning to support students' lifelong skills and impending careers. Part of ensuring students' success lies in finding alternative learning models, such as the Student-Centered Activities for Large…

  6. Success in Entrepreneurship

    DEFF Research Database (Denmark)

    Iversen, Jens; Malchow-Møller, Nikolaj; Sørensen, Anders

    2016-01-01

    What makes a successful entrepreneur? Using Danish register data, we find strong support for the hypothesis that theoretical skills from schooling and practical skills acquired through wage-work are complementary inputs in the human capital earnings function of entrepreneurs. In fact, we find tha...

  7. Pathways to School Success

    Science.gov (United States)

    University of Pittsburgh Office of Child Development, 2012

    2012-01-01

    In 2006, the University of Pittsburgh Office of Child Development began implementing a multi-year school readiness project in several area schools. Evidence from both research and the field point to several key elements that foster school readiness and create pathways to school success for all children. This paper presents components of a…

  8. Models of Success

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Wu Renbao made national celebrity for his commitment to achieving common prosperity among his co-villagers in Huaxi Village, Jiangsu Province.Wu's recipe for success was to take advantage of collective strength by encouraging mutual assistance between villages and households.

  9. International Student Success

    Science.gov (United States)

    Smith, Clayton

    2016-01-01

    This article, with a focus on North American postsecondary education, identifies international students as a strategic enrollment management institutional priority; presents themes in the international student retention, satisfaction, and success research literature; and describes related best practices. It also presents the findings from an…

  10. Mindfulness and Student Success

    Science.gov (United States)

    Leland, Matt

    2015-01-01

    Mindfulness has long been practiced in Eastern spiritual traditions for personal improvement, and educators and educational institutions have recently begun to explore its usefulness in schools. Mindfulness training can be valuable for helping students be more successful learners and more connected members of an educational community. To determine…

  11. FOCUS: Sustainable Mathematics Successes

    Science.gov (United States)

    Mireles, Selina V.; Acee, Taylor W.; Gerber, Lindsey N.

    2014-01-01

    The FOCUS (Fundamentals of Conceptual Understanding and Success) Co-Requisite Model Intervention (FOCUS Intervention) for College Algebra was developed as part of the Developmental Education Demonstration Projects (DEDP) in Texas. The program was designed to use multiple services, courses, and best practices to support student completion of a…

  12. Success in Entrepreneurship

    DEFF Research Database (Denmark)

    Iversen, Jens; Malchow-Møller, Nikolaj; Sørensen, Anders

    2016-01-01

    What makes a successful entrepreneur? Using Danish register data, we find strong support for the hypothesis that theoretical skills from schooling and practical skills acquired through wage-work are complementary inputs in the human capital earnings function of entrepreneurs. In fact, we find...

  13. Ramada, A Successful Example

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>After entry into the WTO, China’s hotels are being challenged by the global economy and overseas counterparts. They should seek creation and development to fight against the fierce competition. Ramada Pudong Hotel, managed by the Shanghai Airport Group Civil Aviation Property Company Ltd, has become a successful example in creative management.

  14. Characteristics of Successful Entrepreneurs.

    Science.gov (United States)

    McClelland, David C.

    1987-01-01

    Comparison of characteristics of 12 average and 12 superior small business people in three developing nations (India, Malawi, and Ecuador) found proactive qualities such as initiative and assertiveness, achievement orientation, and commitment to others characteristic of successful entrepreneurs. Other expected qualities (self-confidence,…

  15. Ensuring Students' Success

    Science.gov (United States)

    Oblinger, James L.

    2006-01-01

    James L. Oblinger, Chancellor of North Carolina State University, argues that higher education must continually evolve new methods of teaching and learning to support students' lifelong skills and impending careers. Part of ensuring students' success lies in finding alternative learning models, such as the Student-Centered Activities for Large…

  16. Characteristics of Successful Entrepreneurs.

    Science.gov (United States)

    McClelland, David C.

    1987-01-01

    Comparison of characteristics of 12 average and 12 superior small business people in three developing nations (India, Malawi, and Ecuador) found proactive qualities such as initiative and assertiveness, achievement orientation, and commitment to others characteristic of successful entrepreneurs. Other expected qualities (self-confidence,…

  17. Successful Bilingual Education Programs

    Science.gov (United States)

    Montecel, Maria Robledo; Cortez, Josie

    2004-01-01

    This article describes a research project carried out by the Intercultural Development Research Association (IDRA). IDRA's primary research question for this study was, "What contributed to the success of a bilingual education classroom as evidenced by LEP student academic achievement?" In addition to the student data, qualitative and contextual…

  18. NOAA Ship Okeanos Explorer 2013 Field Season on the U.S. Atlantic Continental Margin

    Science.gov (United States)

    Lobecker, E.; Malik, M.; Skarke, A. D.

    2013-12-01

    During the 2013 field season, Okeanos Explorer used its suite of state-of-the-art sonars to systematically map and explore our nation's waters off the Atlantic seaboard, specifically the Atlantic Canyons and New England Seamounts. High resolution three dimensional maps created from the ship's sonars were used to select sites for fine-resolution exploration with the new 6000 meter remotely operated vehicle (ROV) Deep Discoverer. Scientists onboard and onshore around the world were actively engaged in all steps of the exploration process, from the identification of broad-scale mapping targets, to the planning and real-time refining of 300 to 1500 meter long planned ROV dive tracks. Live video feeds were available to the general public through the award winning website www.oceanexplorer.noaa.gov. Important exploration milestones during the Okeanos Explorer 2013 Field Season include: the completion of comprehensive, high-resolution multibeam mapping of the continental shelf break from Cape Hatteras to the northern U.S. Atlantic offshore border, totaling over 100,000 square kilometers of new seafloor data within the U.S. Exclusive Economic Zone; the first successful field season of the ROV Deep Discoverer, which conducted over 40 successful dives; and initial mapping site characterization of eight of the outer seamounts of the New England Seamount Chain. All data collected by Okeanos Explorer are available via the NOAA public archives with metadata records within 60 to 90 days of the end of each cruise.

  19. The petroleum resources on the Norwegian continental shelf. 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The petroleum resources will not last for ever. It is therefore important for Norway to look ahead so as to be prepared for the changes that will come. In this report, the Norwegian Petroleum Directorate presents the current status of the petroleum resources on the Norwegian continental shelf. This is the basis on which the authorities can lay plans for the future. Since no-one can predict the future with certainty, on this occasion the Directorate is presenting four alternative scenarios for the future of Norwegian petroleum activities if the basic scenario proves incorrect. This will enable us to prepare ourselves for changes that may come, and to view the consequences of the various choices we can make. In this report, the Directorate also describes the various plays on the continental shelf, and explains the techniques used and the evaluations made when it estimates the undiscovered resources. This information is important for exploration work, particularly for new companies which need to get acquainted with the geology and the possibilities for finding oil and gas in Norway. Significant volumes remain to be produced and found on the Norwegian continental shelf. Only a third of the total resources have so far been produced, and a quarter of them have still not been discovered. Oil and gas prices are high at the moment, giving the industry and society in general good incentives to produce at a maximum rate. Oil production reached its peak a couple of years ago, but gas production is still increasing. However, the industry is finding less than it produces, which places demands on both it and the authorities. The industry must actively explore the acreage it has been allocated. The Petroleum Directorate believes that substantial resources can still be discovered in areas where production licences have been awarded. At the same time, the industry must gain access to new areas for exploration. The authorities must find an appropriate balance between concern for the

  20. Continental crust formation on early Earth controlled by intrusive magmatism

    Science.gov (United States)

    Rozel, A. B.; Golabek, G. J.; Jain, C.; Tackley, P. J.; Gerya, T.

    2017-05-01

    The global geodynamic regime of early Earth, which operated before the onset of plate tectonics, remains contentious. As geological and geochemical data suggest hotter Archean mantle temperature and more intense juvenile magmatism than in the present-day Earth, two crust-mantle interaction modes differing in melt eruption efficiency have been proposed: the Io-like heat-pipe tectonics regime dominated by volcanism and the “Plutonic squishy lid” tectonics regime governed by intrusive magmatism, which is thought to apply to the dynamics of Venus. Both tectonics regimes are capable of producing primordial tonalite-trondhjemite-granodiorite (TTG) continental crust but lithospheric geotherms and crust production rates as well as proportions of various TTG compositions differ greatly, which implies that the heat-pipe and Plutonic squishy lid hypotheses can be tested using natural data. Here we investigate the creation of primordial TTG-like continental crust using self-consistent numerical models of global thermochemical convection associated with magmatic processes. We show that the volcanism-dominated heat-pipe tectonics model results in cold crustal geotherms and is not able to produce Earth-like primordial continental crust. In contrast, the Plutonic squishy lid tectonics regime dominated by intrusive magmatism results in hotter crustal geotherms and is capable of reproducing the observed proportions of various TTG rocks. Using a systematic parameter study, we show that the typical modern eruption efficiency of less than 40 per cent leads to the production of the expected amounts of the three main primordial crustal compositions previously reported from field data (low-, medium- and high-pressure TTG). Our study thus suggests that the pre-plate-tectonics Archean Earth operated globally in the Plutonic squishy lid regime rather than in an Io-like heat-pipe regime.

  1. Anomalous heat flow belt along the continental margin of Brazil

    Science.gov (United States)

    Hamza, Valiya M.; Vieira, Fabio P.; Silva, Raquel T. A.

    2017-06-01

    A comprehensive analysis of thermal gradient and heat flow data was carried out for sedimentary basins situated in the continental margin of Brazil (CMB). The results point to the existence of a narrow belt within CMB, where temperature gradients are higher than 30 °C/km and the heat flow is in excess of 70 mW/m2. This anomalous geothermal belt is confined between zones of relatively low to normal heat flow in the adjacent continental and oceanic regions. The width of the belt is somewhat variable, but most of it falls within the range of 100-300 km. The spatial extent is relatively large in the southern (in the basins of Pelotas, Santos and Campos) and northern (in the basins of Potiguar and Ceará) parts, when compared with those in the central parts (in the basins of South Bahia, Sergipe and Alagoas). The characteristics of heat flow anomalies appear to be compatible with those produced by thermal sources at depths in the lower crust. Hence, magma emplacement at the transition zone between lower crust and upper mantle is considered the likely mechanism producing such anomalies. Seismicity within the belt is relatively weak, with focal depths less than 10 km for most of the events. Such observations imply that "tectonic bonding" between continental and oceanic segments, at the transition zone of CMB, is relatively weak. Hence, it is proposed that passive margins like CMB be considered as constituting a type of plate boundary that is aseismic at sub-crustal levels, but allows for escape of significant amounts of earth's internal heat at shallow depths.

  2. Linking continental erosion to marine transport and sedimentation

    Science.gov (United States)

    Yuan, Xiaoping; Braun, Jean; Guerit, Laure

    2017-04-01

    Limited attention has been given to linking continental erosion to marine transport and sedimentation in large-scale landscape evolution models. Although either of the two environments has been thoroughly investigated, the details of how erosional events are recorded in the sedimentary and stratigraphic records have not been studied in a consistent quantitative manner. Here we present results obtained from a new numerical model for marine sediment transport and deposition that is directly coupled to FastScape, a landscape evolution model that solves the continental stream power law and hillslope diffusion equation using fully implicit and O(n) algorithms. The model of marine transport and sedimentation is simulated by a nonlinear 2D diffusion model where a source term represents mass flux arising from continental river erosion. It is based on the simplest representation of marine transport that assumes that flux is proportional to slope, which leads to a diffusion-type equation that we solve using an alternating direction implicit scheme. Multiple lithologies are implemented that vary by their transport coefficients. This method is also highly efficient (O(n) and implicit), which allows us to perform a large number of simulations to undertake a Bayesian inversion of stratigraphic data. Using our model we not only show the manner in which the stratigraphic record responds to tectonic and climate events but also how it is controlled by the coefficients for river erosion, hillslope diffusion, the transport coefficients in the ocean environment, and variations in sea level. The model is used to better constrain the nature and timing of erosional events on adjacent continents through an inversion of the stratigraphic record. In the longer term, we are looking at ways to improve the equations governing marine sediment transport especially, to better represent the deep part of that transport, i.e. in the abyssal plains or past the shelf and slope.

  3. Fluid migration in continental subduction: The Northern Apennines case study

    Science.gov (United States)

    Agostinetti, Nicola Piana; Bianchi, Irene; Amato, Alessandro; Chiarabba, Claudio

    2011-02-01

    Subduction zones are the place in the world where fluids are transported from the foredeep to the mantle and back-to-the-surface in the back-arc. The subduction of an oceanic plate implies the transportation of the oceanic crust to depth and its methamorphization. Oceanic sediments release water in the (relatively) shallower part of the subduction zone, while dehydration of the subducted basaltic crust allows fluid circulation at larger depths. While the water budget in oceanic subduction has been deeply investigated, less attention has been given to the fluids implied in the subduction of a continental margin (i.e. in continental subduction). In this study, we use teleseismic receiver function (RF) analysis to image the process of water migration at depth, from the subducting plate to the mantle wedge, under the Northern Apennines (NAP, Italy). Harmonic decomposition of the RF data-set is used to constrain both isotropic and anisotropic structures. Isotropic structures highlight the subduction of the Adriatic lower crust under the NAP orogens, from 35-40 km to 65 km depth, as a dipping low S-velocity layer. Anisotropic structures indicate the presence of a broad anisotropic zone (anisotropy as high as 7%). This zone develops in the subducted Adriatic lower crust and mantle wedge, between 45 and 65 km depth, directly beneath the orogens and the more recent back-arc extensional basin. The anisotropy is related to the metamorphism of the Adriatic lower crust (gabbro to blueschists) and its consequent eclogitization (blueschists to eclogite). The second metamorphic phase releases water directly in the mantle wedge, hydrating the back-arc upper mantle. The fluid migration process imaged in this study below the northern Apennines could be a proxy for understanding other regions of ongoing continental subduction.

  4. Pleistocene mammals from the southern Brazilian continental shelf

    Science.gov (United States)

    Lopes, Renato Pereira; Buchmann, Francisco Sekiguchi

    2011-02-01

    Fossils of terrestrial mammals preserved in submarine environment have been recorded in several places around the world. In Brazil such fossils are rather abundant in the southernmost portion of the coast, associated to fossiliferous concentrations at depths up to 10 m. Here is presented a review of such occurrences and the first record of fossils in deeper areas of the continental shelf. The fossils encompass several groups of both extinct and extant mammals, and exhibit several distinct taphonomic features, related to the marine environment. Those from the inner continental shelf are removed and transported from the submarine deposits to the coast during storm events, thus forming large konzentrat-lagerstätte on the beach, called “Concheiros”. The only fossils from deeper zones of the shelf known so far are a portion of a skull, a left humerus and of a femur of Toxodon sp. and a lower right molar of a Stegomastodon waringi, all collected by fishermen at depths around 20 m. The presence of fossils at great depths and distances from the present coastline, without signs of abrasion and far from areas of fluvial discharges does indicate that these remains have not been transported from the continent to the shelf, but have been preserved directly on the area that today correspond to the continental shelf. These remains indicate the existence of large fossiliferous deposits that have developed during periods of sea-level lowstand (glacial maxima) and have been submerged and reworked by the sea-level rise at the end of the last glaciation.

  5. Continental crust formation on early Earth controlled by intrusive magmatism.

    Science.gov (United States)

    Rozel, A B; Golabek, G J; Jain, C; Tackley, P J; Gerya, T

    2017-05-18

    The global geodynamic regime of early Earth, which operated before the onset of plate tectonics, remains contentious. As geological and geochemical data suggest hotter Archean mantle temperature and more intense juvenile magmatism than in the present-day Earth, two crust-mantle interaction modes differing in melt eruption efficiency have been proposed: the Io-like heat-pipe tectonics regime dominated by volcanism and the "Plutonic squishy lid" tectonics regime governed by intrusive magmatism, which is thought to apply to the dynamics of Venus. Both tectonics regimes are capable of producing primordial tonalite-trondhjemite-granodiorite (TTG) continental crust but lithospheric geotherms and crust production rates as well as proportions of various TTG compositions differ greatly, which implies that the heat-pipe and Plutonic squishy lid hypotheses can be tested using natural data. Here we investigate the creation of primordial TTG-like continental crust using self-consistent numerical models of global thermochemical convection associated with magmatic processes. We show that the volcanism-dominated heat-pipe tectonics model results in cold crustal geotherms and is not able to produce Earth-like primordial continental crust. In contrast, the Plutonic squishy lid tectonics regime dominated by intrusive magmatism results in hotter crustal geotherms and is capable of reproducing the observed proportions of various TTG rocks. Using a systematic parameter study, we show that the typical modern eruption efficiency of less than 40 per cent leads to the production of the expected amounts of the three main primordial crustal compositions previously reported from field data (low-, medium- and high-pressure TTG). Our study thus suggests that the pre-plate-tectonics Archean Earth operated globally in the Plutonic squishy lid regime rather than in an Io-like heat-pipe regime.

  6. A economia continental chinesa e seu efeito gravitacional

    Directory of Open Access Journals (Sweden)

    Diego Pautasso

    2011-11-01

    Full Text Available O presente artigo aborda o desenvolvimento nacional e a inserção internacional da China. O objetivo é discutir como a formação de uma economia continental na China tem se transformado num fator de projeção desse país no sistema internacional, analisando como a formação de uma economia continental produz uma espécie de efeito gravitacional favorecendo a formulação da estratégia internacional chinesa nesta conjuntura de transição sistêmica. O artigo desenvolve-se discutindo com análises recorrentes sobre o processo de desenvolvimento e de inserção da internacional da China. O argumento central defendido no artigo é que o desenvolvimento da economia continental e a ampliação da capacidade econômica tornam-se um instrumento da política externa chinesa. Em outras palavras, a China tende a criar um forte efeito gravitacional em escala global e utilizar-se disso como parte de sua estratégia internacional. O artigo organiza-se da seguinte forma: na primeira parte, discorremos sobre a evolução recente do desenvolvimento chinês, centrando foco nos desafios da formação de uma economia de dimensões continentais; na segunda, abordamos como o incremento da capacidade econômica chinesa implica num crescente efeito gravitacional do país em escala global; por fim, argumentamos que a diplomacia da China utiliza-se dessas prerrogativas (capacidade econômica para desencadear uma estratégia internacional que permita ao país, nesse quadro de transição sistêmica, ampliar seu espaço de atuação internacional buscando as linhas de menor resistência.

  7. Subduction and exhumation of continental crust: insights from laboratory models

    Science.gov (United States)

    Bialas, Robert W.; Funiciello, Francesca; Faccenna, Claudio

    2011-01-01

    When slivers of continental crust and sediment overlying oceanic lithosphere enter a subduction zone, they may be scraped off at shallow levels, subducted to depths of up to 100-200 km and then exhumed as high pressure (HP) and ultra-high pressure (UHP) rocks, or subducted and recycled in the mantle. To investigate the factors that influence the behaviour of subducting slivers of continental material, we use 3-D dynamically consistent laboratory models. A laboratory analogue of a slab-upper mantle system is set up with two linearly viscous layers of silicone putty and glucose syrup in a tank. A sliver of continental material, also composed of silicone putty, overlies the subducting lithosphere, separated by a syrup detachment. The density of the sliver, viscosity of the detachment, geometry of the subducting system (attached plate versus free ridge) and dimensions of the sliver are varied in 34 experiments. By varying the density of the sliver and viscosity of the detachment, we can reproduce a range of sliver behaviour, including subduction, subduction and exhumation from various depths and offscraping. Sliver subduction and exhumation requires sufficient sliver buoyancy and a detachment that is strong enough to hold the sliver during initial subduction, but weak enough to allow adequate sliver displacement or detachment for exhumation. Changes to the system geometry alter the slab dip, subduction velocity, pattern of mantle flow and amount of rollback. Shallower slab dips with more trench rollback produce a mantle flow pattern that aids exhumation. Steeper slab dips allow more buoyancy force to be directed in the up-dip direction of the plane of the plate, and aide exhumation of subducted slivers. Slower subduction can also aide exhumation, but if slab dip is too steep or subduction too slow, the sliver will subduct to only shallow levels and not exhume. Smaller slivers are most easily subducted and exhumed and influenced by the mantle flow.

  8. New Tracers of Gas Migration in the Continental Crust

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, Mark D. [Woods Hole Oceanographic Inst., MA (United States)

    2015-11-01

    Noble gases are exceptional tracers in continental settings due to the remarkable isotopic variability between the mantle, crust, and atmosphere, and because they are inert. Due to systematic variability in physical properties, such as diffusion, solubility, and production rates, the combination of helium, neon, and argon provides unique but under-utilized indices of gas migration. Existing noble gas data sets are dominated by measurements of gas and fluid phases from gas wells, ground waters and hot springs. There are very few noble gas measurements from the solid continental crust itself, which means that this important reservoir is poorly characterized. The central goal of this project was to enhance understanding of gas distribution and migration in the continental crust using new measurements of noble gases in whole rocks and minerals from existing continental drill cores, with an emphasis on helium, neon, argon. We carried out whole-rock and mineral-separate noble gas measurements on Precambrian basement samples from the Texas Panhandle. The Texas Panhandle gas field is the southern limb of the giant Hugoton-Panhandle oil and gas field; it has high helium contents (up to ~ 2 %) and 3He/4He of 0.21 (± 0.03) Ra. Because the total amount of helium in the Panhandle gas field is relatively well known, crustal isotopic data and mass balance calculations can be used to constrain the ultimate source rocks, and hence the helium migration paths. The new 3He/4He data range from 0.03 to 0.11 Ra (total), all of which are lower than the gas field values. There is internal isotopic heterogeneity in helium, neon, and argon, within all the samples; crushing extractions yield less radiogenic values than melting, demonstrating that fluid inclusions preserve less radiogenic gases. The new data suggest that the Precambrian basement has lost significant amounts of helium, and shows the importance of measuring helium with neon and argon. The 4He/40Ar values are particularly useful

  9. Presence of Ruvettus pretiosus (Gempylidae in the Colombian continental Caribbean

    Directory of Open Access Journals (Sweden)

    María Camila Gómez-Cubillos

    2016-01-01

    Full Text Available The first record of Ruvettus pretiosus Cocco, 1833 for the Colombian continental Caribbean is presented. The specimen was collected at Los Cocos, department of Magdalena (11°16’33, 84’’ N 73°53’33, 01’’ W, using a demersal longline gear placed at 100 m depth. Biometrics, diagnosis and comments regarding its distribution, ecology and biology are included in the description. This new record expands the distribution of the species in the Caribbean Sea and increases the reported number of gempylids for Colombia to five.

  10. Uncertainty in Analyzed Water and Energy Budgets at Continental Scales

    Science.gov (United States)

    Bosilovich, Michael G.; Robertson, F. R.; Mocko, D.; Chen, J.

    2011-01-01

    Operational analyses and retrospective-analyses provide all the physical terms of mater and energy budgets, guided by the assimilation of atmospheric observations. However, there is significant reliance on the numerical models, and so, uncertainty in the budget terms is always present. Here, we use a recently developed data set consisting of a mix of 10 analyses (both operational and retrospective) to quantify the uncertainty of analyzed water and energy budget terms for GEWEX continental-scale regions, following the evaluation of Dr. John Roads using individual reanalyses data sets.

  11. High water content in primitive continental flood basalts

    Science.gov (United States)

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-01-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>105 km3) within short time span (basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB. PMID:27143196

  12. The character of the glaciated Mid-Norwegian continental margin

    Science.gov (United States)

    Oline Hjelstuen, Berit; Haflidason, Haflidi; Petter Sejrup, Hans

    2010-05-01

    During Pleistocene the development of the NW European continental margin was strongly controlled by the variability in ocean circulation, glaciations and sea-level changes. Repeated occurrence of shelf edge glaciations, from Ireland to Svalbard, started at Marine Isotope Stage 12 (c. 0.5 Ma). During these periods, fast moving ice streams also crossed the Mid-Norwegian continental shelf on a number of locations, and a thick prograding wedge accumulated on the continental slope. During shelf edge glaciations and in early deglaciation phases high sedimentation rates (>2000 cm/ka) existed, and glacigenic debris flows and melt water plumes were deposited. Within these depositional environments we identify three slide events. These slides have affected an area between 2900 and 12000 km2 and involved 580-2400 km3 of sediments, noting that the slide debrites left by the failure events reach a maximum thickness of c. 150 m. The failures have occurred within an area dominated by gradients less than 1 degree, and observation of long run-out distances indicate that hydroplaning was important during slide development. Gas hydrate bearing sediments are identified on the mid-Norwegian continental margin, but appears to be absent in the slide scars. Thus, dissociation of gas hydrates may have promoted conditions for the failures to occur. Within the region of gas hydrate bearing Pleistocene sediments the Nyegga Pockmark Field is observed. This field contains more than 200 pockmarks and is located at a water depth of 600-800 m. The pockmarks identified are up to 15 m deep, between 30 m and 600 m across and reach a maximum area of c. 315 000 m2. The pockmarks are sediment-empty features and are restricted to a <16.2 cal ka BP old sandy mud unit. It seems that the Nyegga Pockmark Field does not show any strong relationship neither to seabed features, sub-seabed structures nor the glacial sedimentary setting. Thus, this implies a more complex development history for the Nyegga

  13. Changes in continental Europe water cycle in a changing climate

    Science.gov (United States)

    Rouholahnejad, Elham; Schirmer, Mario; Abbaspour, Karim

    2015-04-01

    Changes in atmospheric water vapor content provide strong evidence that the water cycle is already responding to a warming climate. According to IPCC's last report on Climate Change (AR5), the water cycle is expected to intensify in a warmer climate as the atmosphere can hold more water vapor. This changes the frequency of precipitation extremes, increases evaporation and dry periods, and effects the water redistribution in land. This process is represented by most global climate models (GCMs) by increased summer dryness and winter wetness over large areas of continental mid to high latitudes in the Northern Hemisphere, associated with a reduction in water availability at continental scale. Observing changes in precipitation and evaporation directly and at continental scale is difficult, because most of the exchange of fresh water between the atmosphere and the surface happens the oceans. Long term precipitation records are available only from over the land and there are no measurement of evaporation or redistribution of precipitation over the land area. On the other hand, understanding the extent of climate change effects on various components of the water cycle is of strategic importance for public, private sectors, and policy makers when it comes to fresh water management. In order to better understand the extent of climate change impacts on water resources of continental Europe, we developed a distributed hydrological model of Europe at high spatial and temporal resolution using the Soil and Water Assessment Tool (SWAT). The hydrological model was calibrated for 1970 to 2006 using daily observation of streamflow and nitrate loads from 360 gauging stations across Europe. A vegetation growth routine was added to the model to better simulate evapotranspiration. The model results were calibrated with available agricultural crop yield data from other sources. As of future climate scenarios, we used the ISI-MIP project results which provides bias-corrected climate

  14. Paleogene continental margin truncation in southwestern Mexico: Geochronological evidence

    Science.gov (United States)

    Schaaf, Peter; MoráN-Zenteno, Dante; HernáNdez-Bernal, Maria Del Sol; SolíS-Pichardo, Gabriela; Tolson, Gustavo; KöHler, Hermann

    1995-12-01

    The reasons for, and mechanisms of, continental margin truncation in SW Mexico where Mesozoic-Cenozoic plutons are situated directly on the Pacific coast, are not yet well understood. Large-scale dextral and/or sinistral displacements of the continental margin terranes, now forming parts of Baja California or the Chortis block, have been proposed. The well-defined along-coast NW-SE decreasing granitoid intrusion age trend (˜1.2 cm/yr in the 100 Ma-40 Ma time interval) between Puerto Vallarta and Zihuatanejo is interpreted by us to be a geometric artifact of oblique continental margin truncation rather than the consequence of a sinistral offset of the Chortis block from those latitudes toward the SE. Changes in the dip and velocity of the NNW-SSE trending Cretaceous-Tertiary subduction zone resulted in a landward migration of the magmatic arc. Taking into account certain stratigraphic affinities of Chortis and the Oaxaca and Mixteca terranes, together with the known displacement rates along the North America-Caribbean Plate boundary, the northwesternmost paleoposition of the Chortis block with respect to SW Mexico was near Zihuatanejo. In contrast, between Zihuatanejo and the Isthmus of Tehuantepec, the cessation of the Tertiary magmatism decreased more rapidly (˜7.7 cm/yr), although the trend is not so obvious. Starting in the late Eocene, Chortis moved about 1100 km to the SE along a transform boundary associated with the opening of the Cayman Trough. Based on our geochronological data and structural relationships between mylonite zones and plutons in the Acapulco-Tehuantepec area, we propose an approximately 650 km SE movement of Chortis from about 40-25 Ma, with a velocity of 6.5-4.3 cm/yr. Since this is considerably slower than the decreasing age trend obtained by us using the geochronological data, we consider batholith formation in this segment to predate and postdate the offshore passage of the North America-Farallon-Caribbean triple junction. Geological

  15. Diversidad de peces demersales en la plataforma continental del Ecuador

    OpenAIRE

    Coello, D.; Herrera, M.

    2010-01-01

    A partir de información colectada de cuatro cruceros de investigación a bordo del B/l Tohalli, se analiza la diversidad de peces óseos y elasmobranquios presentes en la plataforma continental del Ecuador. Los valores medios de diversidad estimados indican que tanto las poblaciones de peces óseos y condrictios demersales hasta los 120 m de profundidad presenten heterogeneidad, con un grado significativo de organización. Las fluctuaciones en el índice de diversidad en las diferentes subáreas y ...

  16. Thermochemical structure of the Earth's mantle and continental crust

    DEFF Research Database (Denmark)

    Guerri, Mattia

    task. In this thesis, I adopt a multidisciplinary approach geared towards the unification of geochemical and geophysical constraints within a framework provided by theoretical and experimental mineral and rock physics. In the first part, I focus on the Continental crust, assessing the relations between...... elastic properties and chemical composition taking into account the thermal and pressure effects. I found that even small amounts of H2O have an extremely high impact on the elastic properties of crustal rock. In addition, I show the potential that modifications in the stable mineralogical assemblage have...

  17. Chronobiology of deep-water decapod crustaceans on continental margins.

    Science.gov (United States)

    Aguzzi, Jacopo; Company, Joan B

    2010-01-01

    Species have evolved biological rhythms in behaviour and physiology with a 24-h periodicity in order to increase their fitness, anticipating the onset of unfavourable habitat conditions. In marine organisms inhabiting deep-water continental margins (i.e. the submerged outer edges of continents), day-night activity rhythms are often referred to in three ways: vertical water column migrations (i.e. pelagic), horizontal displacements within benthic boundary layer of the continental margin, along bathymetric gradients (i.e. nektobenthic), and endobenthic movements (i.e. rhythmic emergence from the substrate). Many studies have been conducted on crustacean decapods that migrate vertically in the water column, but much less information is available for other endobenthic and nektobenthic species. Also, the types of displacement and major life habits of most marine species are still largely unknown, especially in deep-water continental margins, where steep clines in habitat factors (i.e. light intensity and its spectral quality, sediment characteristics, and hydrography) take place. This is the result of technical difficulties in performing temporally scheduled sampling and laboratory testing on living specimens. According to this scenario, there are several major issues that still need extensive research in deep-water crustacean decapods. First, the regulation of their behaviour and physiology by a biological clock is almost unknown compared to data for coastal species that are easily accessible to direct observation and sampling. Second, biological rhythms may change at different life stages (i.e. size-related variations) or at different moments of the reproductive cycle (e.g. at egg-bearing) based on different intra- and interspecific interactions. Third, there is still a major lack of knowledge on the links that exist among the observed bathymetric distributions of species and selected autoecological traits that are controlled by their biological clock, such as the

  18. U-series Disequilibria in Continental Arcs: NE Japan Case

    Science.gov (United States)

    Tepley, F. J.; Gill, J. B.; Williams, R. W.

    2005-12-01

    Basalts and andesites from continental arcs typically are close to equilibrium between (238U) and (230Th), and have subdued excesses of 226Ra compared to oceanic arcs (Turner et al., 2003). There is ambiguity whether these and other geochemical features derive from subducted sediment, subcontinental lithosphere, or the crust. We report new 238U-234U-230Th-226Ra data for 20 historical to Holocene samples from Asama in the south of NE Japan to Tarumai in the north. Most straddle the equiline with 4.

  19. Invasive ants of continental Ecuador, a first account

    OpenAIRE

    Lattke Bravo, John Edwin

    2014-01-01

    http://theantsofecuador.com/david/publications/Donoso%20et%20al_2014_Invasive%20Ants%20Ecuador.pdf El manejo de las especies invasoras es considerado uno de los grandes desafíos que impone el Cambio Global a nuestras sociedades, junto con la deforestación y el calentamiento de la atmósfera. Se conoce muy poco sobre las hormigas invasoras en el Ecuador continental, incluso cuando se ha demostrado en el resto del mundo su agresividad, los impactos negativos en los eco...

  20. Submarine landslides along the eastern Mediterranean Israeli continental slope

    Science.gov (United States)

    Reuven, Einav; Katz, Oded; Aharonov, Einat

    2013-04-01

    Numerous shallow submarine slope failures (scars and deposits) are observed in recent high resolution bathymetric grids of the continental slope off the Israeli eastern Mediterranean coast. The nature of these slope failures is currently not comprehensively understood as well as the question of whether the eastern Mediterranean continental slope is continuously or episodically unstable. We report here first steps towards understanding the present state of this submarine landslide system, which include mapping and analyzing the geology of the landslides and the hosting slopes. The continental slope extends from water depths of about 150 to more than 1000 meters with a slope of less than 5 degrees in general. Bathymetric grids with pixel resolution of 15 m till water depth of 700 m and 50 m till water depth of 1700 m were used. Analyzing the bathymetry revealed three main submarine surface features: (a) numerous shallow landslides, within the upper sequence of the post-Messenian sediments. Landslide widths range between hundreds to thousand of meters at the scar, with scar heights up to hundred meters. The toes of the landslides are not always mapable and lay up to a few kilometers down slope from the scar. Slope angles within the scars are 5 to more than15 degrees. At least two types of landslides were detected: presumably young slides with sharp scars, and presumably old slides with secondary slides and secondary drainage systems developed within the scar area; (b) a few kilometers long, north striking step-like lineaments. Step heights are up to 100 meters and the slopes are up to 20 degrees. The offset between parallel steps is less than a kilometer to a few kilometers. The steps are interpreted as surface expressions of growth faults rooted at the Messinian evaporates up to 1.5 kilometers below surface; (c) a few north striking channels were also detected with steep walls of more than 15 degrees, up to two kilometers width and a few kilometers length. The nature

  1. Implications for the evolution of continental crust from Hf isotope systematics of Archean detrital zircons

    Science.gov (United States)

    Stevenson, Ross K.; Patchett, P. Jonathan

    1990-01-01

    Results from the fractionation of zircon by sedimentary processes into continental margin sandstone yield information on the preservation of preexisting continental crust in the form of zircon, making it possible to distinguish between the contrasting theories of gradual growth versus constant volume of continental crust over geologic time. In this work, Hf-176/Hf-177 ratios were determined for detrital zircon fractions from 2.0-2.5, 2.6-3.0, and pre-3.0 Gyr old sandstones from the Canadian-Shield, the North-Atlantic, the Wyoming, and the Kaapvaal Cratons. Results pointed to small amounts of continental crust prior to 3.0 Gyr ago and a rapid addition of continental crust between 2.5 and 3.0 Gyr ago, consistent with the gradual growth of continental crust, and giving evidence against no-growth histories.

  2. Small(pox) success?

    Science.gov (United States)

    Birn, Anne-Emanuelle

    2011-02-01

    The 30th anniversary of the World Health Organization's (WHO) official certification of smallpox eradication was marked by a slew of events hailing the campaign's dramatic tale of technological and organizational triumph against an ancient scourge. Yet commemorations also serve as moments of critical reflection. This article questions the acclaim showered upon smallpox eradication as the single greatest public health success in history. It examines how and why smallpox eradication and WHO's concurrent social justice-oriented primary health care approach (following from the Declaration of Alma-Ata) became competing paradigms. It synthesizes critiques of eradication's shortcomings and debunks some of the myths surrounding the global eradication campaign as a public health priority and necessity, and as a Cold War victory of cooperation. The article concludes with thoughts on integrating technical and social-political aspects of health within the context of welfare states as the means to achieving widespread and enduring global public health success.

  3. Small(pox success?

    Directory of Open Access Journals (Sweden)

    Anne-Emanuelle Birn

    Full Text Available The 30th anniversary of the World Health Organization's (WHO official certification of smallpox eradication was marked by a slew of events hailing the campaign's dramatic tale of technological and organizational triumph against an ancient scourge. Yet commemorations also serve as moments of critical reflection. This article questions the acclaim showered upon smallpox eradication as the single greatest public health success in history. It examines how and why smallpox eradication and WHO's concurrent social justice-oriented primary health care approach (following from the Declaration of Alma-Ata became competing paradigms. It synthesizes critiques of eradication's shortcomings and debunks some of the myths surrounding the global eradication campaign as a public health priority and necessity, and as a Cold War victory of cooperation. The article concludes with thoughts on integrating technical and social-political aspects of health within the context of welfare states as the means to achieving widespread and enduring global public health success.

  4. Styles of success

    DEFF Research Database (Denmark)

    Dahlgaard, Jens Jørn; Nørgaard, Anders; Jakobsen, Søren

    1997-01-01

    of business excellence points to a clear agenda for success. Setting clear strategic goals and the ability to take a long-term view of an organization's direction, combined with other leadership attributes such as creativity, teambuilding and learning, are principal keys to creating an excellent organization......Corporate success stories tend to emphasize the "great men" theory of history. But now a European research project established the managerial attributes that can turn an ordinary leader into one ideal for the pursuit of business excellence. The emergence of five leadership styles as crucial drivers...... lower value on the teambuilding and strategic competencies than is required for business excellence. By contrast, their "ideal" leader is heavily characterized by being a creative, inspiring, and active problem-solver....

  5. Styles of success

    DEFF Research Database (Denmark)

    Dahlgaard, Jens Jørn; Nørgaard, Anders; Jakobsen, Søren

    1997-01-01

    Corporate success stories tend to emphasize the "great men" theory of history. But now a European research project established the managerial attributes that can turn an ordinary leader into one ideal for the pursuit of business excellence. The emergence of five leadership styles as crucial drivers...... of business excellence points to a clear agenda for success. Setting clear strategic goals and the ability to take a long-term view of an organization's direction, combined with other leadership attributes such as creativity, teambuilding and learning, are principal keys to creating an excellent organization....... Leaders seeking to achive business excellence must view the high-level attainment of these sets of leadership competencies as their paramount objective. In striving for business excellence, European leaders may encounter resistance among their employees. Crucially, European employees place a markedly...

  6. Profile of success

    DEFF Research Database (Denmark)

    Dahlgaard, Jens Jørn; Nørgaard, Anders; Jakobsen, Søren

    1998-01-01

    What management skills must Europe's business leaders improve to achieve business excellence? Which country's leaders are best placed for success? Does the next generation have what it takes to compete? In the second half of their study of the leadership styles that drive business excellence, Jens...... Dahlgaard, Anders Nørgaard and Søren Jakobsen describe an excellent leadership profile that provides the answers....

  7. Successful time management

    CERN Document Server

    Forsyth, Patrick

    2016-01-01

    Packed with tips and techniques, Successful Time Management serves as a guide to reviewing and assessing new work practices to improve time management. It includes great time-saving ideas, practical solutions, checklists, and advice on controlling paperwork, delegating and working with others, prioritizing to focus on key issues, and getting and staying organized. This new third edition contains new practical tips on using email in a time effective manner and dealing with other internet-based tools and apps to help productivity.

  8. Geometries of hyperextended continental crust in northeastern continental brazilian margin: insights from potential field and seismic interpretation

    Science.gov (United States)

    Magalhães, José; Barbosa, José; Ribeiro, Vanessa; Oliveira, Jefferson; Filho, Osvaldo; Buarque, Bruno

    2016-04-01

    The study region encompasses a set of three basins located at Northeast Brazilian continental margin: Pernambuco (south sector), Paraíba and Natal platform (north sector). These basins were formed during the last stage of separation between South America and African plates during Cretaceous. The continental breakup in these regions occurred probably during the Middle-Upper Albian (~102 m.y). The adjacent basement rocks belong to Borborema Province (BP), which was formed due a complex superposition between Pre-Cambrian orogenic cycles. The structural framework of BP is dominated by large shear zones that divided this province in three main tectonic domains: South, Central and North. The Pernambuco Basin is located in the South Domain and the Paraíba and Natal platform basins are related to the Central Domain. The tectonic and magmatic evolution of the Pernambuco Basin was influenced by oblique rifting (~ 35° to rift axis) and a thermal anomaly probably caused by the Santa Helena hotspot. The north sector represents a continental shelf characterized by basement high with a narrow platform and an abrupt shelf break on transition to the abyssal plain. The continental platform break of this sector was parallel to the rift axis. In this way, we present a regional structural interpretation of these sectors of Brazilian rifted margin based on interpretation and 2D forward modeling of potential field and 2D seismic data. The magnetic maps (Reduction to magnetic pole and Analytic signal) revealed the influence of an alternating pattern of large narrow magnetic and non-magnetic lineaments, oriented NE-SW, E-W and NW-SE. In the Pernambuco Basin these lineaments (NE-SW and E-W) are related to shear zones in the hyperextended basement which is interpreted as a continuation of the granitic-gneissic and metasedimentary rocks of the South Domain of BP. The Paraíba and Natal platform basins show a slight change in the orientation of structures trending E-W (shear zones in

  9. Principles of successful partnerships.

    Science.gov (United States)

    Mangold, Kara; Denke, Nancy J; Gorombei, Deb; Ostroski, Tammy L; Root, Lynda

    2014-01-01

    Health care providers must understand and value the unique contributions of all interdisciplinary professionals, with the goal of optimizing the wellness or illness needs of each patient. Work cannot be done in silos, and the ability to develop and sustain effective professional partnerships is essential. Health care teams must work within a complex environment that depends on the shared efforts of multiple professionals to successfully provide care in a fragmented, highly stressed system. Implementing partnerships that foster relationships through shared interests, vision, and values can aid in the coordination of resources to provide a more positive patient experience and outcome. The development of partnerships requires time and acceptance of shared risks and responsibilities. In return, involved parties will be able to build trust, share rewards, and expand the possibilities of what can be accomplished. The purpose of this review is to describe results-oriented partnerships, which include the attributes of collaboration, coordination, and communication. Essential concepts and practical tools for success are reviewed to offer new and existing partnerships a lens through which to view interdisciplinary interactions that can contribute to organizational success and longevity. Potential pitfalls that may impact patient services and organizational health are also discussed.

  10. Determination of properties of Proterozoic continental flood basalts of western part from North Qilian Mountains

    Institute of Scientific and Technical Information of China (English)

    夏林圻; 夏祖春; 赵江天; 徐学义; 杨合群; 赵东宏

    1999-01-01

    Proterozoic volcanic rocks of the western part from the North Qilian Mountains are the products of continental rift volcanism, belonging to continental flood basalts, the petrogeochemistry of which apears to suggest that they are derived from sub-lithospheric mantle plume sources, but that they also show evidence of continental lithosphere components involvement. Their formation is the consequences of plume-lithosphere interactions and is precursive to the opening of the North Qilian Early-Paleozoic ocean basin.

  11. Operational simulation of continental water masses consistent with atmospheric and oceanic data.

    OpenAIRE

    Robert Dill; Walter, C.;  

    2008-01-01

    Operational global mass transport data of the atmosphere and the oceans are widely used for studies of earth rotation excitation and gravity field simulations and are essential for GRACE dealising purposes, too. Seasonal and short periodic variations are also caused by continental water mass redistributions. In order to account for the continental hydrology processes as well and to close the global water cycle, continental water mass storage fields and fluxes are needed in the same operationa...

  12. Successful Succession in Family Businesses : Individual Level Factors and Succession Planning Models.

    OpenAIRE

    Aleem, Majid; Islam, Md. Shariful

    2009-01-01

    Individual level factors related to the successor have a central role to play in the succession process of the business. When these factors are viewed in relation to succession planning models, these factors have a direct relation to the succession models in terms of success or failure of the succession process. The major contributing factor to the success or failure of the succession process is that of the leadership provided to the organization by the predecessor. These leadership qualities...

  13. NUEVA PERSPECTIVA DEL SISTEMA DE DERECHO CONTINENTAL EN COLOMBIA A NEW PERSPECTIVE OF THE CONTINENTAL TRADITION INTO COLOMBIAN LEGAL SYSTE

    Directory of Open Access Journals (Sweden)

    Betty Martínez Cárdenas

    2011-01-01

    Full Text Available Con el desarrollo de la jurisprudencia constitucional a partir de 1991, una parte de la doctrina colombiana plantea la necesidad de cambiar la naturaleza del Sistema jurídico colombiano, tradicionalmente de estirpe continental, a otra "mixta", con el fin de establecer entre nosotros el "Nuevo derecho". ¿Es esta necesidad realmente cierta? El estudio de la naturaleza del derecho colombiano a través de la técnica del derecho comparado demuestra, por el contrario, que no es simplemente el rol que se le atribuye a la jurisprudencia el que puede per se cambiar la naturaleza del Sistema,ya que, primero, por sus orígenes y principios generales se confirma el carácter romano-germánico del Derecho colombiano, y, segundo, que dentro de este Sistema,el Continental, la jurisprudencia tiene un rol mucho más importante que crear el derecho: el interpretarlo y actualizarlo.With the development of the constitutional case law from 1991, part of the Colombian doctrine sets out the necessity of changing the nature of the Colombian legal system, of continental tradition, to one of a "mixed" nature with the purpose of establishing among us the "new law". Is this necessity truly certain? The study of the nature of Colombian law through the comparative law technique shows, by contrary, that it is not simply the role that is granted to the case law that can change the nature of the system, since, first, through its origins and general principles, the civil law character of Colombian law is confirmed, and, second, within this system, the case law has a role much more important than just creating law: that of interpreting and updating it.

  14. Long-period orbital climate forcing. Cyclostratigraphic studies of Cenozoic continental and marine successions in Europe. Geologica Ultraiectina (297)

    NARCIS (Netherlands)

    Abels, H.A.

    2008-01-01

    Orbital climate forcing is well-known for its strong impact on Earth’s climate as for example the switching from glacial to inter-glacial states in the Late Pleistocene. Typical ‘Milankovitch’ cycles are climatic precession (21.000 years or 21 kyrs), obliquity (41 kyrs), and short and long eccentric

  15. Long-period orbital climate forcing. Cyclostratigraphic studies of Cenozoic continental and marine successions in Europe. Geologica Ultraiectina (297)

    NARCIS (Netherlands)

    Abels, H.A.|info:eu-repo/dai/nl/304848018

    2008-01-01

    Orbital climate forcing is well-known for its strong impact on Earth’s climate as for example the switching from glacial to inter-glacial states in the Late Pleistocene. Typical ‘Milankovitch’ cycles are climatic precession (21.000 years or 21 kyrs), obliquity (41 kyrs), and short and long eccentric

  16. The tectonic significance of the Cabo Frio Tectonic Domain in the SE Brazilian margin: a Paleoproterozoic through Cretaceous saga of a reworked continental margin

    Directory of Open Access Journals (Sweden)

    Renata da Silva Schmitt

    Full Text Available ABSTRACT: The Cabo Frio Tectonic Domain is composed of a Paleoproterozoic basement tectonically interleaved with Neoproterozoic supracrustal rocks (Buzios-Palmital successions. It is in contact with the Neoproterozoic-Cambrian Ribeira Orogen along the SE Brazilian coast. The basement was part of at least three continental margins: (a 1.97 Ga; (b 0.59 - 0.53 Ga; (c 0.14 Ga to today. It consists of continental magmatic arc rocks of 1.99 to 1.94 Ga. Zircon cores show a 2.5 - 2.6 Ga inheritance from the ancient margin of the Congo Craton. During the Ediacaran, this domain was thinned and intruded by tholeiitic mafic dykes during the development of an oceanic basin at ca. 0.59 Ma. After the tectonic inversion, these basin deposits reached high P-T metamorphic conditions, by subduction of the oceanic lithosphere, and were later exhumed as nappes over the basement. The Cabo Frio Tectonic Domain collided with the arc domain of the Ribeira Orogen at ca. 0.54 Ga. It is not an exotic block, but the eastern transition between this orogen and the Congo Craton. Almost 400 m.y. later, the South Atlantic rift zone followed roughly this suture, not coincidently. It shows how the Cabo Frio Tectonic Domain was reactivated as a continental margin in successive extensional and convergent events through geological time.

  17. Late Pleistocene and Holocene mammal extinctions on continental Africa

    Science.gov (United States)

    Faith, J. Tyler

    2014-01-01

    Understanding the cause of late Quaternary mammal extinctions is the subject of intense debate spanning the fields of archeology and paleontology. In the global context, the losses on continental Africa have received little attention and are poorly understood. This study aims to inspire new discussion of African extinctions through a review of the extinct species and the chronology and possible causes of those extinctions. There are at least 24 large mammal (> 5 kg) species known to have disappeared from continental Africa during the late Pleistocene or Holocene, indicating a much greater taxonomic breadth than previously recognized. Among the better sampled taxa, these losses are restricted to the terminal Pleistocene and early Holocene, between 13,000 and 6000 yrs ago. The African extinctions preferentially affected species that are grazers or prefer grasslands. Where good terrestrial paleoenvironmental records are present, extinctions are associated with changes in the availability, productivity, or structure of grassland habitats, suggesting that environmental changes played a decisive role in the losses. In the broader evolutionary context, these extinctions represent recent examples of selective taxonomic winnowing characterized by the loss of grassland specialists and the establishment of large mammal communities composed of more ecologically flexible taxa over the last million years. There is little reason to believe that humans played an important role in African extinctions.

  18. Continental crust composition constrained by measurements of crustal Poisson's ratio

    Science.gov (United States)

    Zandt, George; Ammon, Charles J.

    1995-03-01

    DECIPHERING the geological evolution of the Earth's continental crust requires knowledge of its bulk composition and global variability. The main uncertainties are associated with the composition of the lower crust. Seismic measurements probe the elastic properties of the crust at depth, from which composition can be inferred. Of particular note is Poisson's ratio,Σ ; this elastic parameter can be determined uniquely from the ratio of P- to S-wave seismic velocity, and provides a better diagnostic of crustal composition than either P- or S-wave velocity alone1. Previous attempts to measure Σ have been limited by difficulties in obtaining coincident P- and S-wave data sampling the entire crust2. Here we report 76 new estimates of crustal Σ spanning all of the continents except Antarctica. We find that, on average, Σ increases with the age of the crust. Our results strongly support the presence of a mafic lower crust beneath cratons, and suggest either a uniformitarian craton formation process involving delamination of the lower crust during continental collisions, followed by magmatic underplating, or a model in which crust formation processes have changed since the Precambrian era.

  19. Endangered Species, Provincialism, and a Continental Approach to Bird Conservation

    Directory of Open Access Journals (Sweden)

    Robert J. Craig

    2006-06-01

    Full Text Available I examined lists of endangered species from northeastern and midwestern United States to assess the extent to which they were dominated by species considered rare due to their vulnerability to anthropogenic stressors or, instead, by species whose rarity might be explained otherwise. Northeastern states had longer species lists than midwestern states, and more species associated with locally rare prairie habitats. More species at the edge of their geographic range appeared on lists from the Northeast than the Midwest. About 70% of listed species overall have shown either no significant population trend, or increases, at the continental scale, but wetland and prairie species were frequently listed, consistent with the generally acknowledged, widespread loss of these habitats. Curiously, midwestern states tended to list fewer forest species, despite evidence that forest fragmentation there has had strongly deleterious effects on regional bird populations. Overall, species appear to be listed locally for a variety of reasons not necessarily related to their risk of extinction generally, potentially contributing to inefficient distributions of limited resources to deal effectively with species that legitimately require conservation attention. I advocate a continental perspective when listing species locally, and propose enhanced criteria for characterizing species as endangered at the local level.

  20. Continental warming preceding the Palaeocene-Eocene thermal maximum.

    Science.gov (United States)

    Secord, Ross; Gingerich, Philip D; Lohmann, Kyger C; Macleod, Kenneth G

    2010-10-21

    Marine and continental records show an abrupt negative shift in carbon isotope values at ∼55.8 Myr ago. This carbon isotope excursion (CIE) is consistent with the release of a massive amount of isotopically light carbon into the atmosphere and was associated with a dramatic rise in global temperatures termed the Palaeocene-Eocene thermal maximum (PETM). Greenhouse gases released during the CIE, probably including methane, have often been considered the main cause of PETM warming. However, some evidence from the marine record suggests that warming directly preceded the CIE, raising the possibility that the CIE and PETM may have been linked to earlier warming with different origins. Yet pre-CIE warming is still uncertain. Disentangling the sequence of events before and during the CIE and PETM is important for understanding the causes of, and Earth system responses to, abrupt climate change. Here we show that continental warming of about 5 °C preceded the CIE in the Bighorn Basin, Wyoming. Our evidence, based on oxygen isotopes in mammal teeth (which reflect temperature-sensitive fractionation processes) and other proxies, reveals a marked temperature increase directly below the CIE, and again in the CIE. Pre-CIE warming is also supported by a negative amplification of δ(13)C values in soil carbonates below the CIE. Our results suggest that at least two sources of warming-the earlier of which is unlikely to have been methane-contributed to the PETM.

  1. Non-reductive continental naturalism in the contemporary humanities

    Science.gov (United States)

    Van der Tuin, Iris

    2013-01-01

    This article engages with the philosophical reflections of the French historian of science Hélène Metzger (1886–1944) in order to develop a vocabulary for understanding the rise of non-reductive Continental naturalism in the contemporary humanities. The bibliography of current naturalist approaches in the arts and the human sciences is still in the making, but it is altogether clear that the trend is not scientist or historicist or relativist. This epistemological diagnosis refers us to Metzger, who found herself surrounded with the logical positivism of the Wiener Kreis, on the one hand, and the historicism of her French colleagues, on the other, as well as with the infiltration of the history of science by a chronological empiricism. In this article I will take the most recent book of Vicki Kirby – Quantum Anthropologies: Life at Large from 2011 – as an exemplary case of non-reductive Continental naturalist scholarship in the humanities today and by reading it through the concepts of Metzger, I will demonstrate how this type of research leads to refreshing insights in what constitutes positive humanities knowledge and what is the role of the a priori in the field. PMID:23908566

  2. Mineral resources: Research objectives for continental scientific drilling

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    The importance of a scientific drilling program to study mineralized hydrothermal systems has been emphasized in numerous workshops and symposia. To some degree the present report, prepared by the Panel on Mineral Resources of the Continental Scientific Drilling Committee, both reinforces and expands upon earlier recommendations. The report of the Los Alamos workshop, Continental Scientific Drilling Program, placed a major emphasis on maximizing the industry and government, supplementing these efforts with holes drilled solely for scientific purposes. Although the present report notes the importance of opportunities for scientific investigations added on to current, mission-oriented drilling activities, the Panel on Mineral Resources recognized that such opportunities are limited and thus focused on holes dedicated to broad scientific objectives. In the present report, the panel has developed a program that will provide answers to many scientific questions that have existed for almost 100 years concerning mineralized hydrothermal systems. The committee notes that research drilling may lead to results in addition to those anticipated, results that will provide new directions and ideas of equal or greater value that those basic ones originally posed. 58 refs.

  3. Hydrates of nat­ural gas in continental margins

    Science.gov (United States)

    Kvenvolden, K.A.; Barnard, L.A.

    1982-01-01

    Natural gas hydrates in continental margin sediment can be inferred from the widespread occurrence of an anomalous seismic reflector which coincides with the predicted transition boundary at the base of the gas hydrate zone. Direct evidence of gas hydrates is provided by visual observations of sediments from the landward wall of the Mid-America Trench off Mexico and Guatemala, from the Blake Outer Ridge off the southeastern United States, and from the Black Sea in the U.S.S.R. Where solid gas hydrates have been sampled, the gas is composed mainly of methane accompanied by CO2 and low concentrations of ethane and hydrocarbons of higher molecular weight. The molecular and isotopic composition of hydrocarbons indicates that most of the methane is of biolog cal origin. The gas was probably produced by the bacterial alteration of organic matter buried in the sediment. Organic carbon contents of the sediment containing sampled gas hydrates are higher than the average organic carbon content of marine sediments. The main economic importance of gas hydrates may reside in their ability to serve as a cap under which free gas can collect. To be producible, however, such trapped gas must occur in porous and permeable reservoirs. Although gas hydrates are common along continental margins, the degree to which they are associated with significant reservoirs remains to be investigated.

  4. Subduction to Continental Delamination: Insights From Laboratory Experiments

    Science.gov (United States)

    Gogus, O. H.; Corbi, F.; Faccenna, C.; Pysklywec, R. N.

    2009-05-01

    The evolution of the lithosphere through subduction-collision and delamination and its surface/crustal response (topography/deformation) is investigated in this work. We present a series of lithosphere scale two dimensional (2-D) and three dimensional (3-D) laboratory experiments to better understand such processes. In these experiments, an idealized viscously deforming crust-mantle lithosphere-mantle system is configured with silicone putty (representing lithospheric mantle and upper crust) and glucose syrup (representing the upper mantle and lower crust). The initial focus was to investigate the physical development of delamination versus continental subduction without plate convergence. Experiments show that the delamination or continental subduction is strongly dependent on the density of the crust (both crust and mantle lithosphere subducts when crust has a higher density, instead of delamination), while in the investigated range, the viscosity of the weak layer does not have much influence on the process. In all the experiments, the topography is asymmetric with subsidence above the delaminating hinge due to the dynamic vertical pulling driven by the delaminating slab, and uplift above the delaminated region due to the buoyancy of asthenosphere. Our investigation on the oceanic subduction with a convergence rate of ~ 3cm/year plate velocity suggests that subduction -collision - delamination is well defined and at the end, the delaminating crust from the lithosphere is overthrusted on top of the overriding plate. Our results provide integrated insights on the Alpine-Himalayan type orogenies, in particular the neotectonic evolution of Eastern Anatolian plateau.

  5. Thoughts on studies of China continental geology and tectonics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guowei; GUO Anli; YAO Anping

    2006-01-01

    As an important part of the global continents, China continent has long been situated in the peculiar tectonic position and experienced extremely complicated activities, which resulted in the regional unique characteristics for China continent on the global common geological background. These characteristics contain abundant information regarding scientific key issues of modern geological frontier. Thus, China continent can be a natural laboratory and excellent arena for the modern geosciences. The modern earth sciences have started entering the era featured with earth systematic science and beyond plate tectonics. How to take the regional advantage and exploit the treasure resource to participate the new theoretical and methodological creation is a historic opportunity and great challenge we are facing. This paper generalizes research priorities in four fields on China continental geology and tectonics for discussion. They are: China continental tectonics and dynamics; Mesozoic-Cenozoic crustal deformation and deep-seated processes in China continent and the adjacent regions; deep-seated dynamic background and evolutionary trend of crustal tectonic activities on the time scale of human existence; deepseated background and processes of conjunction and transformation of different tectonic systems.

  6. Magma-compensated crustal thinning in continental rift zones.

    Science.gov (United States)

    Thybo, H; Nielsen, C A

    2009-02-12

    Continental rift zones are long, narrow tectonic depressions in the Earth's surface where the entire lithosphere has been modified in extension. Rifting can eventually lead to rupture of the continental lithosphere and creation of new oceanic lithosphere or, alternatively, lead to formation of wide sedimentary basins around failed rift zones. Conventional models of rift zones include three characteristic features: surface manifestation as an elongated topographic trough, Moho shallowing due to crustal thinning, and reduced seismic velocity in the uppermost mantle due to decompression melting or heating from the Earth's interior. Here we demonstrate that only the surface manifestation is observed at the Baikal rift zone, whereas the crustal and mantle characteristics can be ruled out by a new seismic profile across southern Lake Baikal in Siberia. Instead we observe a localized zone in the lower crust which has exceptionally high seismic velocity and is highly reflective. We suggest that the expected Moho uplift was compensated by magmatic intrusion into the lower crust, producing the observed high-velocity zone. This finding demonstrates a previously unknown role for magmatism in rifting processes with significant implications for estimation of stretching factors and modelling of sedimentary basins around failed rift structures.

  7. A generalizable energetics-based model of avian migration to facilitate continental-scale waterbird conservation

    Science.gov (United States)

    Lonsdorf, Eric V.; Thogmartin, Wayne E.; Jacobi, Sarah; Coppen, Jorge; Davis, Amélie Y.; Fox, Timothy J.; Heglund, Patricia; Johnson, Rex; Jones, Tim; Kenow, Kevin P.; Lyons, James E.; Luke, Kirsten E.; Still, Shannon; Tavernia, Brian

    2016-01-01

    Conserving migratory birds is made especially difficult because of movement among spatially disparate locations across the annual cycle. In light of challenges presented by the scale and ecology of migratory birds, successful conservation requires integrating objectives, management, and monitoring across scales, from local management units to ecoregional and flyway administrative boundaries. We present an integrated approach using a spatially explicit energetic-based mechanistic bird migration model useful to conservation decision-making across disparate scales and locations. This model moves a mallard-like bird (Anas platyrhynchos), through spring and fall migration as a function of caloric gains and losses across a continental scale energy landscape. We predicted with this model that fall migration, where birds moved from breeding to wintering habitat, took a mean of 27.5 days of flight with a mean seasonal survivorship of 90.5% (95% CI = 89.2%, 91.9%) whereas spring migration took a mean of 23.5 days of flight with mean seasonal survivorship of 93.6% (95% CI = 92.5%, 94.7%). Sensitivity analyses suggested that survival during migration was sensitive to flight speed, flight cost, the amount of energy the animal could carry and the spatial pattern of energy availability, but generally insensitive to total energy availability per se. Nevertheless, continental patterns in the bird-use days occurred principally in relation to wetland cover and agricultural habitat in the fall. Bird-use days were highest in both spring and fall in the Mississippi Alluvial Valley and along the coast and near-shore environments of South Carolina. Spatial sensitivity analyses suggested that locations nearer to migratory endpoints were less important to survivorship; for instance, removing energy from a 1,036 km2 stopover site at a time from the Atlantic Flyway suggested coastal areas between New Jersey and North Carolina, including Chesapeake Bay and the North Carolina piedmont, are

  8. Negotiating Successfully in Asia

    Directory of Open Access Journals (Sweden)

    Michael Benoliel

    2013-08-01

    Full Text Available Cross-cultural negotiations are complex, challenging, and difficult to navigate because much of the Asian culture is unstated, implicit, and internalized in subtle behavioral patterns. It is like an iceberg; more is invisible and less is visible. To understand how the Asian negotiation values and practices are different from those in the West, I describe briefly the Asian cultural roots, highlight the major dimensions that differentiate cultures, explore the factors that influence the Asian negotiation processes and outcomes, and provide a list of practical suggestions for negotiating successful deals with Asian negotiators.

  9. Successful product realization strategies

    Science.gov (United States)

    Peeples, John; Boulton, William R.

    1995-02-01

    Product realization is the process of defining, designing, developing, and delivering products to the market. While the main thrust of this JTEC panel was to conduct a complete investigation of the state of Japanese low-cost electronic packaging technologies, it is very difficult to totally separate the development of technology and products from the product realization process. Japan's electronics firms adhere to a product realization strategy based on a strong customer focus, a consistent commitment to excellence in design, and a cost-effective approach to technology commercialization. The Japanese product-pull strategy has been a successful driver and influencing factor in every aspect of the product development cycle.

  10. Successful innovation by motivation

    Directory of Open Access Journals (Sweden)

    Petra Koudelková

    2015-10-01

    Full Text Available Innovation is one of the most important factors for business growth. Human capital plays a significant role in the successful process of innovation. This article deals with employee motivation in the innovation process and the main scientific aim of this study is to present results of research that was undertaken in the Czech Republic at the beginning of 2013. Questionnaires were used for the survey and statistical analyses such as Chi square test or Hierarchical cluster analysis were used for data processing. This study also provides a theoretical and practical overview of business innovation in the Czech Republic.

  11. Implant success!!!.....simplified

    Directory of Open Access Journals (Sweden)

    Luthra Kaushal

    2009-01-01

    Full Text Available The endeavor towards life-like restoration has helped nurture new vistas in the art and science of implant dentistry. The protocol of "restoration-driven implant placement" ensures that the implant is an apical extension of the ideal future restoration and not the opposite. Meticulous pre-implant evaluation of soft and hard tissues, diagnostic cast and use of aesthetic wax-up and radiographic template combined with surgical template can simplify the intricate roadmap for appropriate implant treatment. By applying the harmony of artistic skill, scientific knowledge and clinical expertise, we can simply master the outstanding implant success in requisites of aesthetics, phonetics and function.

  12. SUCCESS OUTSIDE THE CITY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Coming as a much-needed boon for the countryside,this year's No.1 Document,jointly released by the Central Committee of the Communist Party of China and the State Council,pledges a series of concrete measures to propel improvements in the rural economy and the livelihood of farmers.Nevertheless,rural prosperity in line with the success of urban areas will prove to be a challenge.The foundation of the agriculture sector remains fluid,and farmers lack a stable source of income and a reliable social safety net.

  13. Settling particle fluxes across the continental margin of the Gulf of Lion: the role of dense shelf water cascading

    Directory of Open Access Journals (Sweden)

    C. Pasqual

    2009-07-01

    Full Text Available Settling particles were collected using sediment traps deployed along three transects in the Lacaze-Duthiers and Cap de Creus canyons and the adjacent southern open slope from October 2005 to October 2006. The settling material was analysed to obtain total mass fluxes and main constituent contents (organic matter, opal, calcium carbonate, and siliciclastics. Cascades of dense shelf water from the continental shelf edge to the lower continental slope occurred from January to March 2006. They were traced through strong negative near-bottom temperature anomalies and increased current speeds, and generated two intense pulses of mass fluxes in January and March 2006. This oceanographic phenomenon appeared as the major physical forcing of settling particles at almost all stations, and caused both high seasonal variability in mass fluxes and important qualitative changes in settling material. Fluxes during the dense shelf water cascading (DSWC event ranged from 90.1 g m−2 d−1 at the 1000 m depth station in the Cap de Creus canyon to 3.2 g m−2 d−1 at the canyon mouth at 1900 m. Fractions of organic matter, opal and calcium carbonate components increased seaward, thus diminishing the siliciclastic fraction. Temporal variability of the major components was larger in the canyon mouth and open slope sites, due to the mixed impact of dense shelf water cascading processes and the pelagic biological production. Results indicate that the cascading event remobilized and homogenized large amounts of material down canyon and southwardly along the continental slope contributing to a better understanding of the internal dynamics of DSWC events. While the late winter/early spring bloom signature was diluted when DSWC occurred, the primary production dynamics were observable at all stations during the rest of the year and highlighted the biological community succession in surface waters.

  14. Volcano-sedimentary processes operating on a marginal continental arc: the Archean Raquette Lake Formation, Slave Province, Canada

    Science.gov (United States)

    Mueller, W. U.; Corcoran, P. L.

    2001-06-01

    The 200-m thick, volcano-sedimentary Raquette Lake Formation, located in the south-central Archean Slave Province, represents a remnant arc segment floored by continental crust. The formation overlies the gneissic Sleepy Dragon Complex unconformably, is laterally interstratified with subaqueous mafic basalts of the Cameron River volcanic belt, and is considered the proximal equivalent of the turbidite-dominated Burwash Formation. A continuum of events associated with volcanism and sedimentation, and controlled by extensional tectonics, is advocated. A complex stratigraphy with three volcanic and three sedimentary lithofacies constitute the volcano-sedimentary succession. The volcanic lithofacies include: (1) a mafic volcanic lithofacies composed of subaqueous pillow-pillow breccia, and subaerial massive to blocky flows, (2) a felsic volcanic lithofacies representing felsic flows that were deposited in a subaerial environment, and (3) a felsic volcanic sandstone lithofacies interpreted as shallow-water, wave- and storm-reworked pyroclastic debris derived from explosive eruptions. The sedimentary lithofacies are represented by: (1) a conglomerate-sandstone lithofacies consistent with unconfined debris flow, hyperconcentrated flood flow and talus scree deposits, as well as minor high-energy stream flow conglomerates that formed coalescing, steep-sloped, coarse-clastic fan deltas, (2) a sandstone lithofacies, interpreted as hyperconcentrated flood flow deposits that accumulated at the subaerial-subaqueous interface, and (3) a mudstone lithofacies consistent with suspension sedimentation in a small restricted lagoon-type setting. The Raquette Lake Formation is interpreted as a fringing continental arc that displays both high-energy clastic sedimentation and contemporaneous effusive and explosive mafic and felsic volcanism. Modern analogues that develop along active plate margins in which continental crust plays a significant role include Japan and the Baja California

  15. The evolution of oceanic 87Sr/86Sr does not rule out early continental growth

    Science.gov (United States)

    Flament, N.; Coltice, N.; Rey, P. F.

    2010-12-01

    Many contrasted continental growth models have been proposed to date, in which the amount of continental material extracted from the mantle at 3.8 Ga ranges between 0% (e.g. Taylor and McLennan, 1985) and 100% (e.g. Armstrong, 1981). One of the arguments in favor of delayed continental growth models is the shift in the 87Sr/86Sr of marine carbonates from mantle composition at ~ 2.8 Ga (Shields and Veizer, 2002). When using oceanic 87Sr/86Sr as a proxy of continental growth, the flux of strontium from the continents to the oceans is assumed to depend only on continental area and both continental hypsometry and continental freeboard are assumed to be constant through time. However, Rey and Coltice (2008) suggested that Archean reliefs were lower than present-day ones and Flament et al. (2008) suggested that the emerged land area is not proportional to continental growth. Therefore, the suitability of 87Sr/86Sr as a proxy of continental growth must be re-assessed. In this contribution, we develop an integrated model, from the mantle to the surface, to investigate the effect of contrasted continental growth models on the evolution of sea level, of the area of emerged land, and of oceanic 87Sr/86Sr. We estimate the evolution of mantle temperature using the model of Labrosse and Jaupart (2007) that takes the effect of continental growth into account. The maximum continental elevation is calculated using the results of Rey and Coltice (2008), sea level and the area of emerged land are calculated as in Flament et al. (2008), and the oceanic 87Sr/86Sr is calculated in a geochemical box model. We calculate Archean sea levels ~ 800 m higher than present for delayed continental growth and ~ 1500 m higher for early continental growth. In contrast, we calculate similar Archean areas of emerged land, of less than 5% of the Earth’s surface, for both early and delayed continental growth models. Because the area of emerged land does not depend on continental growth models, the

  16. LEIR commissioning successfully completed

    CERN Multimedia

    2006-01-01

    An important milestone has been passed in the preparation of the injector complex to supply ions to the LHC experiments. The LEIR lead-ion beam, seen on one of the control screens just before the PS injection region. The Low-Energy Ion Ring - LEIR for short - has passed its first tests with flying colours. On 12 May, the ring that will accumulate lead ions for the LHC was shut down after seven months of tests (see Bulletin 44/2005). 'The commissioning phase was a resounding success,' enthuses a satisfied Michel Chanel, head of the LEIR construction project. After several months of fine-tuning, the LEIR team has achieved its aim of producing the kind of beam required for first lead-ion collisions in the LHC in 2008. This involved creating bunches containing 230 million ions, in line with the specifications for those first beams. This success can be put down to the machine's outstanding design and components. 'It's a great achivement by all the teams involved in the machine's construction,' underlines Christian...

  17. Evolution of high Arctic ocean basins and continental margins

    Energy Technology Data Exchange (ETDEWEB)

    Engen, Oeyvind

    2005-08-01

    Taking advantage of the much increased detail offered by new data, the dissertation attempts to answer some of the remaining questions about the ocean basins and continental margins flanking the Eurasia-North America plate boundary. Its four constituent papers result from integrated geophysical analysis of gravity and magnetic anomalies, bathymetry, seismic reflection and refraction profiles, earthquake locations and focal mechanisms, and onshore and offshore geological data. The overall objectives are to: 1) Elucidate aspects of the structure, composition and evolution of the Eurasia Basin and Norwegian-Greenland Sea and their passive continental margins. 2) Relate the findings to fundamental Earth processes, specifically associated with lithospheric break-up and seafloor spreading. Summary of Papers: The present-day global seismograph network is capable of detecting earthquakes with nearly uniform magnitude threshold throughout the Eurasia Basin region. Given that the location of each earthquake is constrained by at least 12 recording stations, global earthquake catalogues confidently show that 1) earthquakes along the oceanic part of the plate boundary occur in swarms; 2) plate boundary stress decreases eastwards, in accordance with decreasing spreading rates; and 3) deformation takes place in a narrow zone in the oceanic domain but is abruptly defocused at the transition to the Laptev Sea continental rift system. When integrated with bathymetry and potential field data, the earthquake distribution indicates four distinct plate boundary provinces. The Spitsbergen Transform System is a series of oblique ridges and transform faults where the seismicity becomes increasingly diffuse to the north. The western Gakkel Ridge (west of 60{sup E}) has clustered and focused seismicity, accentuated topography and highamplitude magnetic anomalies, whereas the eastern Gakkel Ridge has smoother topographic relief, lower magnetic amplitudes, and slightly more focused seismicity

  18. Identification of biologically recycled continental materials in banded iron formations

    Science.gov (United States)

    Li, W.; Beard, B. L.; Johnson, C.

    2015-12-01

    The controversy on the origin of banded iron formations (BIFs) has lasted for many decades. Studies prior to the 1970s suggested that Fe in BIFs was supplied from continental riverine inputs[1], but discovery of midocean ridge hydrothermal systems in the 1970s and identification of positive Eu anomaly in BIF samples led to an alternative model where hydrothermal vents provided Fe in BIFs[2]. Although the latter model has became widely accepted, it should be noted that interpretations of Fe sources for BIFs using the abundance and isotopic composition of rare earth elements (REEs) are based on an assumption that transport and deposition of REEs and Fe were coupled. We address the question of Fe sources and pathways for BIFs by combining stable Fe isotopes with radiogenic Nd isotopes as well as REE measurements to test proposals that Fe in BIFs was hydrothermally sourced. The samples investigated are from a type section of the Dales Gorge member of the 2.5 Ga Brockman Iron Formation, the world's most extensive Superior-type BIF that represents the climax of BIF deposition in the geologic record. Large variations were observed in both Fe and Nd isotope compositions of the BIF samples, and there is a positive correlation between the bulk rock ɛNd and δ56Fe values. In addition, there is a negative corelation between ɛNd and Sm/Nd ratios. In order to explain the observed correlations in those isotopic and elemental data, a two-component model, where mixing between a high ɛNd, low Sm/Nd hydrothermal endmember and a low ɛNd, low δ56Fe, but high Sm/Nd continental endmember occurred prior to deposition of the BIF, is required. The low-δ56Fe, high-Sm/Nd endmember is best explained by microbial dissimilatory iron reduction (DIR) in the coastal sediments, which fractionated Fe isotopes and REEs and released these components back to water column that were ultimately precipitated in BIFs. The range and distribution of ɛNdvalues in the BIF samples suggest that the amount

  19. LHC synchronization test successful

    CERN Multimedia

    The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/

  20. Iridium: failures & successes

    Science.gov (United States)

    Christensen, CarissaBryce; Beard, Suzette

    2001-03-01

    This paper will provide an overview of the Iridium business venture in terms of the challenges faced, the successes achieved, and the causes of the ultimate failure of the venture — bankruptcy and system de-orbit. The paper will address technical, business, and policy issues. The intent of the paper is to provide a balanced and accurate overview of the Iridium experience, to aid future decision-making by policy makers, the business community, and technical experts. Key topics will include the history of the program, the objectives and decision-making of Motorola, the market research and analysis conducted, partnering strategies and their impact, consumer equipment availability, and technical issues — target performance, performance achieved, technical accomplishments, and expected and unexpected technical challenges. The paper will use as sources trade media and business articles on the Iridium program, technical papers and conference presentations, Wall Street analyst's reports, and, where possible, interviews with participants and close observers.

  1. SUCCESS OUTSIDE THE CITY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Coming as a much-needed boon for the countryside, this year’s No.1 Document, jointly released by the Central Committee of the Communist Party of China and the State Council, pledges a series of concrete measures to propel improvements in the rural economy and the livelihood of farmers. Nevertheless, rural prosperity in line with the success of urban areas will prove to be a challenge. The foundation of the agriculture sector remains fluid, and farmers lack a stable source of income and a reliable social safety net. So how can China promote the sustained development of its agriculture sector and social improvements to the countryside? Experts and economists provide suggestions to achieving these goals.

  2. Fluoridation: strategies for success.

    Science.gov (United States)

    Isman, R

    1981-07-01

    Of 19 referenda on community water fluoridation held in the first six months of 1980, 17 were defeated. Among the postulated reasons are a growing distrust of government and the health establishment. The public remains largely ignorant of the purpose and benefits of fluoridation. The emotionalism surrounding the issue has made it difficult to generate public support outside of the health professions. Opponents have also learned to fight fluoridation with increasingly sophisticated techniques. Some of the strategies used in recent successful campaigns in Oakland, California, and Portland, Oregon are described; recommendations that can be applied to communities considering fluoridation include careful wording of ballot measures so they are unequivocally clear and simple; timing ballot measures with elections likely to draw the largest voter turnout; broadening the base of political and financial support; using a figurehead if possible; and making maximum use of the media.

  3. A metric for success

    Science.gov (United States)

    Carver, Gary P.

    1994-05-01

    The federal agencies are working with industry to ease adoption of the metric system. The goal is to help U.S. industry compete more successfully in the global marketplace, increase exports, and create new jobs. The strategy is to use federal procurement, financial assistance, and other business-related activities to encourage voluntary conversion. Based upon the positive experiences of firms and industries that have converted, federal agencies have concluded that metric use will yield long-term benefits that are beyond any one-time costs or inconveniences. It may be time for additional steps to move the Nation out of its dual-system comfort zone and continue to progress toward metrication. This report includes 'Metric Highlights in U.S. History'.

  4. Geochemistry of marine sediments of the Brazilian Northeastern continental shelf

    Directory of Open Access Journals (Sweden)

    Fernanda Souza do Nascimento

    2010-01-01

    Full Text Available The marine sediment samples collected from the northeastern Brazilian continental shelf, at water depths between 20 and 80 m, consisted mainly of sands with an almost total absence of gravel and granules. Medium, coarse and very coarse sand grains are mostly composed of halimeda, lithothamnium, rodoliths and bioclastic sands with a carbonate content varying between 77 and 96 %. The chemistry in general shows a decreasing content of Ca (86.1 % >Si (6 % > Cl (3.6 % > Sr (0.8 % > K (0.66 % > S (0.62 % > Al (0.6 % > Na (0.55% > Mg (0.43 % > Fe (0.4 % > P (0.2 % > Br (0.04 % in the samples. There was no correlation between CaCO3 and chemical contents and grain size with depth and bio-components. With the exception of Sr of marine origin, all other elements (P, S, Br, Cl, Fe are of continental origin. The lithothamnium of some offshore samples shows higher CaCO3 content, while Mg and Na are present only in halimedas. Bioclastic sands contain no Br, and silt and clay fractions are rare and characterize samples closer to the coast. These marine bioclastic granulates are of very pure biogenic calcium carbonates and are thus highly to be recommended for economic purposes.Os granulados marinhos, da Plataforma Continental do nordeste brasileiro, coletados de profundidades entre 20 e 80 m, são predominantemente areias cascalhosas constituídas de halimedas, litotames, rodolitos e areias bioclásticas, cujos teores de carbonatos variam de 77 a 96 %. A concentração média geral de elementos químicos na ordem decrescente é Ca (86.1 % > Si (6 % > Cl (3.6 % > Sr (0.8 % > K (0.66 % > S (0.62 % > Al (0.6 % > Na (0.55 % > Mg (0.43 % > Fe (0.4 % > P (0.2 % > Br (0,04 %, independentemente da profundidade e tipo de bio-componente. Com exceção do Sr, que é de origem marinha, os demais elementos (P, S, Br, Cl, Fe são de origem continental. Elementos como Mg e Na foram restritos às halimedas em apenas duas amostras, enquanto Br não foi detectado nas areias

  5. Midlatitude Continental Convective Clouds Experiment (MC3E)

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, MP; Petersen, WA; Del Genio, AD; Giangrande, SE; Heymsfield, A; Heymsfield, G; Hou, AY; Kollias, P; Orr, B; Rutledge, SA; Schwaller, MR; Zipser, E

    2010-04-10

    The Midlatitude Continental Convective Clouds Experiment (MC3E) will take place in central Oklahoma during the April–May 2011 period. The experiment is a collaborative effort between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Aeronautics and Space Administration’s (NASA) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The field campaign leverages the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors, and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal is to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that have never before been available.

  6. Continental patterns of submarine groundwater discharge reveal coastal vulnerabilities

    Science.gov (United States)

    Sawyer, Audrey H.; David, Cédric H.; Famiglietti, James S.

    2016-08-01

    Submarine groundwater discharge (SGD) delivers water and dissolved chemicals from continents to oceans, and its spatial distribution affects coastal water quality. Unlike rivers, SGD is broadly distributed and relatively difficult to measure, especially at continental scales. We present spatially resolved estimates of fresh (land-derived) SGD for the contiguous United States based on historical climate records and high-resolution hydrographic data. Climate controls regional patterns in fresh SGD, while coastal drainage geometry imparts strong local variability. Because the recharge zones that contribute fresh SGD are densely populated, the quality and quantity of fresh SGD are both vulnerable to anthropogenic disturbance. Our analysis unveils hot spots for contaminant discharge to marine waters and saltwater intrusion into coastal aquifers.

  7. Behaviour of green facades in Mediterranean Continental climate

    Energy Technology Data Exchange (ETDEWEB)

    Perez, G.; Rincon, L.; Vila, A. [GREA Innovacio Concurrent, Edifici CREA, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain); Gonzalez, J.M. [Dept. Construccions Arquitectoniques I, Universitat Politecnica de Catalunya, Avinguda Diagonal 649, 3a planta, 08028 Barcelona (Spain); Cabeza, L.F., E-mail: lcabeza@diei.udl.ca [GREA Innovacio Concurrent, Edifici CREA, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain)

    2011-04-15

    In order to obtain data on the behaviour of green facades in buildings as a passive system for energy savings in dry Mediterranean Continental climate a long-term work has been performed. This paper presents the first results of two actions developed during 2009. First, the growth of four different climbing plants as well as their ability to provide shadow was studied. Second, monitoring for a year of a real green facade was carried out. The results confirmed the great capacity of green facades to produce shade, reducing the heat on the facade wall of the building. It was also verified that a microclimate between the wall of the building and the green curtain are created, characterized by slightly lower temperatures and higher relative humidity. This means that the green screen acts as a wind barrier and confirms the evapotranspiration effect of the plants. On the other hand, these results did not allow withdrawing conclusions about the insulation effect of green facades.

  8. Potential alternative energy technologies on the Outer Continental Shelf.

    Energy Technology Data Exchange (ETDEWEB)

    Elcock, D.; Environmental Assessment

    2007-04-20

    This technical memorandum (TM) describes the technology requirements for three alternative energy technologies for which pilot and/or commercial projects on the U.S. Outer Continental Shelf (OCS) are likely to be proposed within the next five to seven years. For each of the alternative technologies--wind, wave, and ocean current--the TM first presents an overview. After each technology-specific overview, it describes the technology requirements for four development phases: site monitoring and testing, construction, operation, and decommissioning. For each phase, the report covers the following topics (where data are available): facility description, electricity generated, ocean area (surface and bottom) occupied, resource requirements, emissions and noise sources, hazardous materials stored or used, transportation requirements, and accident potential. Where appropriate, the TM distinguishes between pilot-scale (or demonstration-scale) facilities and commercial-scale facilities.

  9. Source pool geometry and the assembly of continental avifaunas

    DEFF Research Database (Denmark)

    Graves, Gary R; Rahbek, Carsten

    2005-01-01

    Classical niche-assembly models propose that the composition of biotic communities in continental landscapes is determined chiefly by the autecology of species, interspecific competition, and the diversity of resources and habitats within a region. In contrast, stochastic models propose...... that simulation algorithms can replicate the macroecological patterns, if not the mechanisms, of community assembly. Despite fundamental differences in assumptions, both categories of models assume that species are drawn from regional source pools. We explored the implications of source pool geometry...... on the assembly of avian communities with an analysis of assemblage dispersion fields, which can be visualized by overlaying the geographic ranges of all species that occur in an assemblage. Contours of species richness surrounding focal quadrats illustrate the decay rate of assemblage similarity with distance...

  10. Searching for the remains of subducted continental slabs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ On the basis of oceanic geological and geophysical observations the global plate tectonics theory was put forward in the late 1960s.It inherited the essence of mobilism of continental drift and sea-floor spreading,caused a revolution of earth sciences in the twentieth century.But plate tectonics cannot satisfactorily explain the complicated geological phenomena of continents,it fails in elucidating the formation and evolution process of continents.Therefore,the formation and evolution of continents have been the hot topics explored by earth scientists in recent years.As far as China is concerned,the opening and closing of Tethys are related to the formation,evolution,and compressional reformation of Chinese continent in the Mesozoic period,hence have important implications.

  11. The petroleum resources on the Norwegian Continental Shelf. 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Exploration activity has reached record-breaking levels in the last couple of years, which has led to many, but small, discoveries. The NPD believes that large discoveries can still be made in areas of the shelf that have not been extensively explored. Content: Challenges on the Norwegian continental shelf; Value creation in fields; 40 years of oil and gas production; Resource management; Still many possibilities; Energy consumption and the environment; Exploration; Access to acreage; Awards of new licenses; Exploration in frontier areas; Exploration history and statistics; Resources and forecasts; Undiscovered resources; Proven recoverable resources; Forecasts; Short-term petroleum production forecast (2009-2013); Investments- and operating costs forecasts; Long-term forecast for the petroleum production; Emissions from the petroleum activity. (AG)

  12. Physical processes in the growth of the continental crust

    Science.gov (United States)

    Schubert, G.

    1988-01-01

    Major mechanisms of crustal addition are volcanism and plutonism at plate boundaries and within plate interiors. One approach to deciding if island arc magmatism dominated ancient crustal growth is to assess the rate at which the process has operated in the recent past. The localized addition rates were found to be comparable to present day global rates. One physical observable that was used to constrain models of crustal growth is sea level. A simple physical model was developed to explore the consequences of constant freeboard (the height of the continents above sea level). Global geoid and sea floor topography data were used to identify and study oceanic plateaus and swells that have either continental crustal roots or anomalously thick ocean crusts.

  13. Does subduction zone magmatism produce average continental crust

    Science.gov (United States)

    Ellam, R. M.; Hawkesworth, C. J.

    1988-01-01

    The question of whether present day subduction zone magmatism produces material of average continental crust composition, which perhaps most would agree is andesitic, is addressed. It was argued that modern andesitic to dacitic rocks in Andean-type settings are produced by plagioclase fractionation of mantle derived basalts, leaving a complementary residue with low Rb/Sr and a positive Eu anomaly. This residue must be removed, for example by delamination, if the average crust produced in these settings is andesitic. The author argued against this, pointing out the absence of evidence for such a signature in the mantle. Either the average crust is not andesitic, a conclusion the author was not entirely comfortable with, or other crust forming processes must be sought. One possibility is that during the Archean, direct slab melting of basaltic or eclogitic oceanic crust produced felsic melts, which together with about 65 percent mafic material, yielded an average crust of andesitic composition.

  14. Anatexis of accretionary wedge, Pacific-type magmatism, and formation of vertically stratified continental crust in the Altai Orogenic Belt

    Science.gov (United States)

    Jiang, Y. D.; Schulmann, K.; Sun, M.; Å típská, P.; Guy, A.; Janoušek, V.; Lexa, O.; Yuan, C.

    2016-12-01

    Granitoid magmatism and its role in differentiation and stabilization of the Paleozoic accretionary wedge in the Chinese Altai are evaluated in this study. Voluminous Silurian-Devonian granitoids intruded a greywacke-dominated Ordovician sedimentary succession (the Habahe Group) of the accretionary wedge. The close temporal and spatial relationship between the regional anatexis and the formation of granitoids, as well as their geochemical similarities including rather unevolved Nd isotopic signatures and the strong enrichment of large-ion lithophile elements relative to many of the high field strength elements, may indicate that the granitoids are product of partial melting of the accretionary wedge rocks. Whole-rock geochemistry and pseudosection modeling show that regional anatexis of fertile sediments could have produced a large amount of melts compositionally similar to the granitoids. Such process could have left a high-density garnet- and/or garnet-pyroxene granulite residue in the deep crust, which can be the major reason for the gravity high over the Chinese Altai. Our results show that melting and crustal differentiation can transform accretionary wedge sediments into vertically stratified and stable continental crust. This may be a key mechanism contributing to the peripheral continental growth worldwide.

  15. Gravity and structure of the continental margins of southwestern Mexico and northwestern Guatemala

    Science.gov (United States)

    Couch, Richard; Woodcock, Stephen

    1981-03-01

    Geophysical measurements over the eastern end of the Tehuantepec Ridge and adjacent continental margins of southern Mexico and northern Guatemala indicate that the ridge is a fracture zone and that it marks the boundary between two different subduction provinces. A positive free-air gravity anomaly which extends northwestward along the outer continental shelf of Guatemala curves abruptly landward in the Gulf of Tehuantepec. The positive shelf anomaly is on trend with the positive anomaly of the Nicoya Peninsula, Costa Rica, and suggests that rocks genetically related to Cretaceous rocks of the Nicoya Complex extend northwestward along the continental shelf to the Gulf of Tehuantepec. A crustal and subcrustal cross section of the continental margin of Guatemala, constrained by gravity, magnetic, and seismic refraction data, indicates that the rock strata causing the outer shelf gravity high dip landward, consistent with imbricate thrusting of the oceanic crust beneath and into the continental margin. A model crustal cross section of the continental margin of southern Mexico, north of the Tehuantepec Ridge, shows a markedly different margin structure with a relatively small amount of continental accretion and a continental crustal block extending to within approximately 25 km of the trench axis.

  16. Rare-earth elements and uranium in phosphatic nodules from the continental margins of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Rao, B.R.; Rao, K.M.; Rao, Ch.M.

    abundances relative to shale (Sigma REE in sample / Sigma REE in shale) are less than 0.22 and are comparable to phosphatic nodules from the Namibian continental margin, and are slightly lower than the nodules from the Peruvian continental margin. The cerium...

  17. Crenarchaeotal membrane lipids in lake sediments : a new paleotemperature proxy for continental paleoclimate reconstruction?

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Powes, L.A.; Werne, J.P.; Johnson, T.C.; Hopmans, E.C.; Schouten, S.

    2004-01-01

    Paleoclimate studies of continental environments have been hampered by the lack of an independent paleotemperature proxy. A novel sea-surface temperature proxy has been proposed for marine systems based on membrane lipids of marine crenarchaeota. This proxy will provide an independent continental

  18. 77 FR 31829 - Importation of Fresh Bananas From the Philippines Into the Continental United States...

    Science.gov (United States)

    2012-05-30

    ... the Continental United States'' and published in the Federal Register on April 16, 2012 (77 FR 22510... Animal and Plant Health Inspection Service Importation of Fresh Bananas From the Philippines Into the... the importation of fresh bananas from the Philippines into the continental United States....

  19. Dynamics of tidal and non-tidal currents along the southwest continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Aruna, C.; Ravichandran, C.; Srinivas, K.; Rasheed, P.A.A; Lekshmi, S.

    are predominantly mixed, semidiurnal in nature. Motion over any continental shelf is governed by the tide-driven oscillatory flow. In this paper, tidal and non-tidal characteristics of the waters of Southwest continental shelf of India are assessed using...

  20. 75 FR 24966 - Notice on Outer Continental Shelf Oil and Gas Lease Sales

    Science.gov (United States)

    2010-05-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Minerals Management Service Notice on Outer Continental Shelf Oil and Gas Lease Sales AGENCY: Minerals... in any other of the following groups at Outer Continental Shelf oil and gas lease sales to be...

  1. 77 FR 64826 - Notice on Outer Continental Shelf Oil and Gas Lease Sales

    Science.gov (United States)

    2012-10-23

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management (BOEM) Notice on Outer Continental Shelf Oil and Gas Lease Sales AGENCY... with any entity in any of the other following groups at Outer Continental Shelf oil and gas lease...

  2. 76 FR 77382 - Airworthiness Directives; Continental Motors, Inc. (CMI) Reciprocating Engines

    Science.gov (United States)

    2011-12-13

    ... identified in this AD, contact Continental Motors, Inc., P.O. Box 90, Mobile, AL 36601; phone: (251) 438-3411... service information referenced in this AD, contact: Continental Motors, Inc., PO Box 90, Mobile, AL 36601... in Burlington, Massachusetts, on December 5, 2011. Peter A. White, Manager, Engine &...

  3. Crenarchaeotal membrane lipids in lake sediments : a new paleotemperature proxy for continental paleoclimate reconstruction?

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Powes, L.A.; Werne, J.P.; Johnson, T.C.; Hopmans, E.C.; Schouten, S.

    2004-01-01

    Paleoclimate studies of continental environments have been hampered by the lack of an independent paleotemperature proxy. A novel sea-surface temperature proxy has been proposed for marine systems based on membrane lipids of marine crenarchaeota. This proxy will provide an independent continental pa

  4. 77 FR 27480 - Outer Continental Shelf Scientific Committee; Announcement of Plenary Session

    Science.gov (United States)

    2012-05-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Outer Continental Shelf Scientific Committee; Announcement of Plenary...: The Outer Continental Shelf (OCS) Scientific Committee (SC) will meet at the Fess Parker's...

  5. 75 FR 51968 - Outer Continental Shelf Air Regulations Consistency Update for Massachusetts

    Science.gov (United States)

    2010-08-24

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for Massachusetts AGENCY... update to a portion of the Outer Continental Shelf (``OCS'') Air Regulations. Requirements applying...

  6. 75 FR 3387 - Outer Continental Shelf Air Regulations Consistency Update for Alaska

    Science.gov (United States)

    2010-01-21

    ... AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for Alaska AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing the update of the Outer..., Nitrogen oxides, Outer Continental Shelf, Ozone, Particulate matter, Permits, Reporting and...

  7. 76 FR 43185 - Outer Continental Shelf Air Regulations Consistency Update for Virginia

    Science.gov (United States)

    2011-07-20

    ... AGENCY 40 CFR Part 55 Outer Continental Shelf Air Regulations Consistency Update for Virginia AGENCY... approve an update to a portion of the Outer Continental Shelf (OCS) Air Regulations. Requirements applying... on the OCS, see appendix A to this part. * * * * * (22) Virginia. (i) State requirements. (A)...

  8. 78 FR 25100 - Outer Continental Shelf Scientific Committee; Announcement of Plenary Session

    Science.gov (United States)

    2013-04-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Outer Continental Shelf Scientific Committee; Announcement of Plenary...: The Outer Continental Shelf (OCS) Scientific Committee (SC) will meet at the Marriott Downtown...

  9. Evolution of magma-poor continental margins from rifting to seafloor spreading.

    Science.gov (United States)

    Whitmarsh, R B; Manatschal, G; Minshull, T A

    2001-09-13

    The rifting of continents involves faulting (tectonism) and magmatism, which reflect the strain-rate and temperature dependent processes of solid-state deformation and decompression melting within the Earth. Most models of this rifting have treated tectonism and magmatism separately, and few numerical simulations have attempted to include continental break-up and melting, let alone describe how continental rifting evolves into seafloor spreading. Models of this evolution conventionally juxtapose continental and oceanic crust. Here we present observations that support the existence of a zone of exhumed continental mantle, several tens of kilometres wide, between oceanic and continental crust on continental margins where magma-poor rifting has taken place. We present geophysical and geological observations from the west Iberia margin, and geological mapping of margins of the former Tethys ocean now exposed in the Alps. We use these complementary findings to propose a conceptual model that focuses on the final stage of continental extension and break-up, and the creation of a zone of exhumed continental mantle that evolves oceanward into seafloor spreading. We conclude that the evolving stress and thermal fields are constrained by a rising and narrowing ridge of asthenospheric mantle, and that magmatism and rates of extension systematically increase oceanward.

  10. Encouraging Student Interest in the Economic Context of the Constitution with Continental Currency

    Science.gov (United States)

    Potter, Lee Ann

    2014-01-01

    Introducing students to continental currency may well encourage their interest in the economic context of the Constitution and their understanding of a wide range of economic concepts. This brief article describes a lesson to familiarize students with continental currency and its relationship to Article I, Section 8, of the Constitution and the…

  11. Development of topography in 3-D continental-collision models

    Science.gov (United States)

    Pusok, A. E.; Kaus, Boris J. P.

    2015-05-01

    Understanding the formation and evolution of high mountain belts, such as the Himalayas and the adjacent Tibetan Plateau, has been the focus of many tectonic and numerical models. Here we employ 3-D numerical simulations to investigate the role that subduction, collision, and indentation play on lithosphere dynamics at convergent margins, and to analyze the conditions under which large topographic plateaus can form in an integrated lithospheric and upper mantle-scale model. Distinct dynamics are obtained for the oceanic subduction side (trench retreat, slab rollback) and the continental-collision side (trench advance, slab detachment, topographic uplift, lateral extrusion). We show that slab pull alone is insufficient to generate high topography in the upper plate, and that external forcing and the presence of strong blocks such as the Tarim Basin are necessary to create and shape anomalously high topographic fronts and plateaus. Moreover, scaling is used to predict four different modes of surface expression in continental-collision models: (I) low-amplitude homogeneous shortening, (II) high-amplitude homogeneous shortening, (III) Alpine-type topography with topographic front and low plateau, and (IV) Tibet-Himalaya-type topography with topographic front and high plateau. Results of semianalytical models suggest that the Argand number governs the formation of high topographic fronts, while the amplitude of plateaus is controlled by the initial buoyancy ratio of the upper plate. Applying these results to natural examples, we show that the Alps belong to regime (III), the Himalaya-Tibet to regime (IV), whereas the Andes-Altiplano fall at the boundary between regimes (III) and (IV).

  12. Mammalian phylogenetic diversity-area relationships at a continental scale.

    Science.gov (United States)

    Mazel, Florent; Renaud, Julien; Guilhaumon, François; Mouillot, David; Gravel, Dominique; Thuiller, Wilfried

    2015-10-01

    In analogy to the species-area relationship (SAR), one of the few laws in ecology, the phylogenetic diversity-area relationship (PDAR) describes the tendency of phylogenetic diversity (PD) to increase with area. Although investigating PDAR has the potential to unravel the underlying processes shaping assemblages across spatial scales and to predict PD loss through habitat reduction, it has been little investigated so far. Focusing on PD has noticeable advantages compared to species richness (SR), since PD also gives insights on processes such as speciation/extinction, assembly rules and ecosystem functioning. Here we investigate the universality and pervasiveness of the PDAR at continental scale using terrestrial mammals as study case. We define the relative robustness of PD (compared to SR) to habitat loss as the area between the standardized PDAR and standardized SAR (i.e., standardized by the diversity of the largest spatial window) divided by the area under the standardized SAR only. This metric quantifies the relative increase of PD robustness compared to SR robustness. We show that PD robustness is higher than SR robustness but that it varies among continents. We further use a null model approach to disentangle the relative effect of phylogenetic tree shape and nonrandom spatial distribution of evolutionary history on the PDAR. We find that, for most spatial scales and for all continents except Eurasia, PDARs are not different from expected by a model using only the observed SAR and the shape of the phylogenetic tree at continental scale. Interestingly, we detect a strong phylogenetic structure of the Eurasian PDAR that can be predicted by a model that specifically account for a finer biogeographical delineation of this continent. In conclusion, the relative robustness of PD to habitat loss compared to species richness is determined by the phylogenetic tree shape but also depends on the spatial structure of PD.

  13. Continental crust anisotropy measurements from tectonic tremor in Cascadia

    Science.gov (United States)

    Huesca-Pérez, Eduardo; Ortega, Roberto; Valenzuela, Raúl W.

    2017-05-01

    We present new observations of crustal anisotropy in the southern Cascadia fore arc from tectonic tremor. The abundance of tremor activity in Oregon and northern California during slow-slip events offers an enormous amount of information with which to measure and analyze anisotropy in the upper brittle continental crust. To accomplish this, we performed analyses of wave polarization and shear wave splitting of tectonic tremor signals by using three component broadband seismic stations. The splitting times range between 0.11 and 0.32 s and are consistent with typical values observed in the continental crust. Fast polarization azimuths are, in general, margin parallel and trend N-S, which parallels the azimuths of the maximum compressive stresses observed in this region. This pattern is likely to be controlled by the stress field. Comparatively, the anisotropic structure of fast directions observed in the northern section of the Cascadia margin is oblique with respect to the southern section of Cascadia, which, in general, trends E-W and is mainly controlled by active faulting and geological structures. Source distribution analysis using a bivariate normal distribution that expresses the distribution of tremors in a preferred direction shows that in northern California and Oregon, the population of tremors tends to distribute parallel to fast polarization azimuths and maximum compressive stresses, suggesting that both tremor propagation and anisotropy are influenced by the stress field. Results show that the anisotropy reflects an active tectonic process that involves the northward movement of the Oregon Block, which is rotating as a rigid body. In northern Cascadia, previous results of anisotropy show that the crust is undergoing a shortening process due to velocity differences between the Oregon Block and the North America plate, which is moving more slowly with respect to the Oregon Block, making it clash against Vancouver Island.

  14. Tectonomagmatism in continental arcs: evidence from the Sark arc complex

    Science.gov (United States)

    Gibbons, Wes; Moreno, Teresa

    2002-07-01

    The island of Sark (Channel Islands, UK) exposes syntectonic plutons and country rock gneisses within a Precambrian (Cadomian) continental arc. This Sark arc complex records sequential pulses of magmatism over a period of 7 Ma (ca. 616-609 Ma). The earliest intrusion (ca. 616 Ma) was a composite sill that shows an ultramafic base overlain by a magma-mingled net vein complex subsequently deformed at near-solidus temperatures into the amphibolitic and tonalitic Tintageu banded gneisses. The deformation was synchronous with D 2 deformation of the paragneissic envelope, with both intrusion and country rock showing flat, top-to-the-south LS fabrics. Later plutonism injected three homogeneous quartz diorite-granodiorite sheets: the Creux-Moulin pluton (150-250 m; ca. 614 Ma), the Little Sark pluton (>700 m; 611 Ma), and the Northern pluton (>500 m; 609 Ma). Similar but thinner sheets in the south (Derrible-Hogsback-Dixcart) and west (Port es Saies-Brecqhou) are interpreted as offshoots from the Creux-Moulin pluton and Little Sark pluton, respectively. All these plutons show the same LS fabric seen in the older gneisses, with rare magmatic fabrics and common solid state fabrics recording syntectonic crystallisation and cooling. The cooling rate increased rapidly with decreasing crystallisation age: >9 Ma for the oldest intrusion to cool to lower amphibolite conditions, 7-8 Ma for the Creux Moulin pluton, 5-6 Ma for the Little Sark pluton, and 10 -14 s -1) that focussed extensional deformation into the Sark area. The increased rates of extension allowed ingress of the subsequent quartz diorite-granodiorite sheets, although strain rate slowly declined as the whole complex cooled during exhumation. The regional architecture of syntectonic Cadomian arc complexes includes flat-lying "Sark-type" and steep "Guernsey-type" domains produced synchronously in shear zone networks induced by oblique subduction: a pattern seen in other continental arcs such as that running from Alaska

  15. Modeling of Flood Risk for the Continental United States

    Science.gov (United States)

    Lohmann, D.; Li, S.; Katz, B.; Goteti, G.; Kaheil, Y. H.; Vojjala, R.

    2011-12-01

    The science of catastrophic risk modeling helps people to understand the physical and financial implications of natural catastrophes (hurricanes, flood, earthquakes, etc.), terrorism, and the risks associated with changes in life expectancy. As such it depends on simulation techniques that integrate multiple disciplines such as meteorology, hydrology, structural engineering, statistics, computer science, financial engineering, actuarial science, and more in virtually every field of technology. In this talk we will explain the techniques and underlying assumptions of building the RMS US flood risk model. We especially will pay attention to correlation (spatial and temporal), simulation and uncertainty in each of the various components in the development process. Recent extreme floods (e.g. US Midwest flood 2008, US Northeast flood, 2010) have increased the concern of flood risk. Consequently, there are growing needs to adequately assess the flood risk. The RMS flood hazard model is mainly comprised of three major components. (1) Stochastic precipitation simulation module based on a Monte-Carlo analogue technique, which is capable of producing correlated rainfall events for the continental US. (2) Rainfall-runoff and routing module. A semi-distributed rainfall-runoff model was developed to properly assess the antecedent conditions, determine the saturation area and runoff. The runoff is further routed downstream along the rivers by a routing model. Combined with the precipitation model, it allows us to correlate the streamflow and hence flooding from different rivers, as well as low and high return-periods across the continental US. (3) Flood inundation module. It transforms the discharge (output from the flow routing) into water level, which is further combined with a two-dimensional off-floodplain inundation model to produce comprehensive flood hazard map. The performance of the model is demonstrated by comparing to the observation and published data. Output from

  16. Modes of continental extension in a lithospheric wedge

    Science.gov (United States)

    Wu, G.; Lavier, L. L.; Choi, E.

    2014-12-01

    We studied extension of a lithospheric wedge as an approximation to an orogenic belt or a continental margin. We ran a series of numerical models to quantify the effects of the strength of the lower crust and a mid-crustal shear zone (MCSZ) on the extension processes. When the MCSZ is present, we found that the regional lower crustal flow plays a critical role in controlling the modes of extension. The compensation is long-wavelength when the lower crust flows from the highest to the lowest elevation in order to compensate upper crustal thinning. In response to this motion, the mantle flows towards the highest elevation in order to balance for the lower crust leaving the area under the highest topography. For weak (wet quartz regime with partial melting) or intermediate (wet quartz regime), or strong (dry quartz regime) lower crust, we recognized three predominantly decoupled modes of extension characterized by 1) significant lower crustal exhumation exemplified as a large massif, 2) formation of core complexes and detachment faults, and 3) distributive domino faulting, respectively. Without the MCSZ, however, the lower crustal flow is essentially subdued with predominantly coupled extension. For weak or intermediate, or strong lower crust, we recognized three coupled modes characterized by 1) localized generally symmetric crustal exhumation, 2) distributed grabens and narrow rifts, and 3) wide continental margins, respectively. The MCSZ controls the degree of decoupling of the lower crustal flow such that a frictionally stronger MCSZ does not change the behaviors of the models but results in a more distributed extension. Due to the long-wavelength compensation, subhorizontal Moho is achieved where intensive extension occurred for all the decoupled models with a MCSZ. Natural counterparts for each mode may be easily identified, for instance, in the Basin and Range or the Aegean.

  17. On COBACC (COntinental Biosphere-Aerosol-Cloud-Climate) feedback

    Science.gov (United States)

    Kulmala, Markku

    2016-04-01

    Anthropogenic emissions of GHGs have increased substantially during the past century. Elevated concentrations of CO2 and methane are the most important forcing agents causing global warming. However, it is not straightforward to attribute or predict the climate change in detail, as the internal variability of climate is only partially understood, aerosol forcings are still highly uncertain, and there are many feedback mechanisms that are difficult to quantify. It has been recognized for decades that the biosphere plays an important role in climate. For example, Kulmala et al. (2004) suggested a negative climate feedback mechanism whereby higher temperatures and CO2-levels boost continental biomass production, leading to increased biogenic secondary organic aerosol (BSOA) and cloud condensation nuclei (CCN) concentrations, tending to cause cooling. This COBACC (COntinental Biosphere-Aerosol-Cloud-Climate) feedback is similar to the so-called CLAW-hypothesis by Charlson et al. (1987) which connects the ocean biochemistry and climate via a negative feedback loop involving CCN production due to sulphur emissions from plankton. The first quantification of the COBACC feedback loop (Kulmala et al. 2014) was based on continuous comprehensive observations at SMEAR II (Station for Measuring Forest Ecosystem-Atmosphere Relations) station in Hyytiälä, Finland, and showed that a 10 ppm increase in atmospheric CO2 concentration leads to a significant (several percent) increase in both carbon sink and aerosol source. These effects operate through changes in gross primary production, volatile organic compound (VOC) emissions and secondary aerosol formation associated with atmospheric oxidation of VOCs. Here we will describe the present knowledge from processes level understanding to whole COBACC feedback including some hints on biogenic and anthropogenic contributions to global aerosol number load. References: Charlson, R. J. et al. Nature 326, 655 1987 Kulmala, M. et al. Atmos

  18. Spatial Interpolation of Ewert's Index of Continentality in Poland

    Science.gov (United States)

    Szymanowski, Mariusz; Bednarczyk, Piotr; Kryza, Maciej; Nowosad, Marek

    2016-10-01

    The article presents methodological considerations on the spatial interpolation of Ewert's index of continentality for Poland. The primary objective was to perform spatial interpolation and generate maps of the index combined with selection of an optimal interpolation method and validation of the use of the decision tree proposed by Szymanowski et al. (Meteorol Z 22:577-585, 2013). The analysis involved four selected years and a multi-year average of the period 1981-2010 and was based on data from 111 meteorological stations. Three regression models: multiple linear regression (MLR), geographically weighted regression (GWR), and mixed geographically weighted regression were used in the analysis as well as extensions of two of them to the residual kriging form. The regression models were compared demonstrating a better fit of the local model and, hence, the non-stationarity of the spatial process. However, the decisive role in the selection of the interpolator was assigned to the possibility of extension of the regression model to residual kriging. A key element here is the autocorrelation of the regression residuals, which proved to be significant for MLR and irrelevant for GWR. This resulted in exclusion of geographically weighted regression kriging from further analysis. The multiple linear regression kriging was found as the optimal interpolator. This was confirmed by cross validation combined with an analysis of improvement of the model in accordance with the criterion of the mean absolute error (MAE). The results obtained facilitate modification of the scheme of selection of an optimal interpolator and development of guidelines for automation of interpolation of Ewert's index of continentality for Poland.

  19. The Midlatitude Continental Convective Clouds Experiment (MC3E)

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Mark P.; Petersen, Walt A.; Bansemer, Aaron; Bharadwaj, Nitin; Carey, Larry; Cecil, D. J.; Collis, Scott M.; Del Genio, Anthony D.; Dolan, Brenda A.; Gerlach, J.; Giangrande, Scott; Heymsfield, Andrew J.; Heymsfield, Gerald; Kollias, Pavlos; Lang, T. J.; Nesbitt, Steve W.; Neumann, Andrea; Poellot, M. R.; Rutledge, Steven A.; Schwaller, Mathew R.; Tokay, Ali; Williams, C. R.; Wolff, D. B.; Xie, Shaocheng; Zipser, Edward J.

    2016-10-18

    The Midlatitude Continental Convective Clouds Experiment (MC3E), a field program jointly led by the U.S. Department of Energy’s Atmospheric Radiation Measurement program and the NASA Global Precipitation Measurement (GPM) Mission, was conducted in south-central Oklahoma during April – May 2011. MC3E science objectives were motivated by the need to improve understanding of midlatitude continental convective cloud system lifecycles, microphysics, and GPM precipitation retrieval algorithms. To achieve these objectives a multi-scale surface- and aircraft-based in situ and remote sensing observing strategy was employed. A variety of cloud and precipitation events were sampled during the MC3E, of which results from three deep convective events are highlighted. Vertical structure, air motions, precipitation drop-size distributions and ice properties were retrieved from multi-wavelength radar, profiler, and aircraft observations for an MCS on 11 May. Aircraft observations for another MCS observed on 20 May were used to test agreement between observed radar reflectivities and those calculated with forward-modeled reflectivity and microwave brightness temperatures using in situ particle size distributions and ice water content. Multi-platform observations of a supercell that occurred on 23 May allowed for an integrated analysis of kinematic and microphysical interactions. A core updraft of 25 ms-1 supported growth of hail and large rain drops. Data collected during the MC3E campaign is being used in a number of current and ongoing research projects and is available through the DOE ARM and NASA data archives.

  20. Rifted Continental Margins: The Case for Depth-Dependent Extension

    Science.gov (United States)

    Huismans, Ritske S.; Beaumont, Christopher

    2016-04-01

    Even though many basic properties of non-volcanic rifted margins are predicted by uniform extension of the lithosphere, uniform extension fails to explain other important characteristics. Particularly significant discrepancies are observed at: 1) the Iberia-Newfoundland conjugate margins (Type I), where large tracts of continental mantle lithosphere are exposed at the seafloor, and at; 2) ultra-wide central South Atlantic margins (Type II) where continental crust spans wide regions below which it appears that lower crust and mantle lithosphere were removed. Neither corresponds to uniform extension in which crust and mantle thin by the same factor. Instead, either the crust or mantle lithosphere has been preferentially removed during extension. We show that the Type I and II styles are respectively reproduced by dynamical numerical lithospheric stretching models (Models I-A/C and II-A/C) that undergo depth-dependent extension. In this notation A and C imply underplating of the rift zone during rifting by asthenosphere and lower cratonic lithosphere, respectively. We also present results for models with a weak upper crust and strong lower crust, Models III-A/C, to show that lower crust can also be removed from beneath the rift zone by horizontal advection with the mantle lithosphere. From the model results we infer that these Types I, II, and III margin styles are controlled by the strength of the mid/lower crust, which determines the amount of decoupling between upper and lower lithosphere during extension and the excision of crust or mantle. We also predict the styles of sedimentary basins that form on these margins as a test of the concepts presented

  1. Habitat specialization in tropical continental shelf demersal fish assemblages.

    Directory of Open Access Journals (Sweden)

    Ben M Fitzpatrick

    Full Text Available The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304 collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth, down the fore reef slope to the reef base (10-30 m depth then across the adjacent continental shelf (30-110 m depth. Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of

  2. Spatial Interpolation of Ewert's Index of Continentality in Poland

    Science.gov (United States)

    Szymanowski, Mariusz; Bednarczyk, Piotr; Kryza, Maciej; Nowosad, Marek

    2017-02-01

    The article presents methodological considerations on the spatial interpolation of Ewert's index of continentality for Poland. The primary objective was to perform spatial interpolation and generate maps of the index combined with selection of an optimal interpolation method and validation of the use of the decision tree proposed by Szymanowski et al. (Meteorol Z 22:577-585, 2013). The analysis involved four selected years and a multi-year average of the period 1981-2010 and was based on data from 111 meteorological stations. Three regression models: multiple linear regression (MLR), geographically weighted regression (GWR), and mixed geographically weighted regression were used in the analysis as well as extensions of two of them to the residual kriging form. The regression models were compared demonstrating a better fit of the local model and, hence, the non-stationarity of the spatial process. However, the decisive role in the selection of the interpolator was assigned to the possibility of extension of the regression model to residual kriging. A key element here is the autocorrelation of the regression residuals, which proved to be significant for MLR and irrelevant for GWR. This resulted in exclusion of geographically weighted regression kriging from further analysis. The multiple linear regression kriging was found as the optimal interpolator. This was confirmed by cross validation combined with an analysis of improvement of the model in accordance with the criterion of the mean absolute error (MAE). The results obtained facilitate modification of the scheme of selection of an optimal interpolator and development of guidelines for automation of interpolation of Ewert's index of continentality for Poland.

  3. Habitat specialization in tropical continental shelf demersal fish assemblages.

    Science.gov (United States)

    Fitzpatrick, Ben M; Harvey, Euan S; Heyward, Andrew J; Twiggs, Emily J; Colquhoun, Jamie

    2012-01-01

    The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth), down the fore reef slope to the reef base (10-30 m depth) then across the adjacent continental shelf (30-110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected habitats

  4. Overcome barriers to career success

    Energy Technology Data Exchange (ETDEWEB)

    Raudsepp, E.

    1983-04-01

    A test is given to determine if an engineer suffers from one of the three barriers to technical success: fear of success, fear of failure, or perfectionism. As in most such tests, the middle way is best. Successful engineers know that perfection cannot be attained, that they don't have time to worry about failure or success, and that by aiming and perservering in doing things well, success can be achieved.

  5. Organic matter content of sediments in continental shelf area of southeast coast of India.

    Science.gov (United States)

    Khan, Syed Ajmal; Ansari, K G Mohamed Thameemul; Lyla, P Somasundharanair

    2012-12-01

    Total organic matter (TOM) content of sediment samples collected from various depths of continental shelf region of the southeast coast of India varied from 0.19% to 7.73%. Higher TOM content and lower median particle diameter could be attributed to the influence of higher riverine flow. Higher values were observed at 100 m depth and above (average 5.29%) and lower values in shallower depths below 100 m (average 3.07%). In the Principal Coordinate Analysis (PCO), the first two axes explained about 83.1% of the total variability. The direction of the vector representing total organic matter was towards 150 m depth. In the Canonical Analysis of Principal Coordinates (CAP) done to confirm the above pattern, the canonical correlation value obtained for the first axis was high (0.9999). The same for the second axis was 0.9995. The direction of the axis representing TOM in this analysis was towards the 100 m depth truly reflecting higher TOM level recorded here (average TOM at 100 m depth-5.81% and at 150 m depth-5.33%). The percentage of samples allocated to the correct group in CAP was 91.67% (33 out of the 36 samples). As the allocation success of samples is substantially greater around 92%, the CAP is explaining greater percentage of variability of TOM than PCO and was found to be quite useful for studies of this nature.

  6. Uranium isotopes in groundwater from the continental intercalaire aquifer in Algerian Tunisian Sahara (Northern Africa).

    Science.gov (United States)

    Chkir, N; Guendouz, A; Zouari, K; Hadj Ammar, F; Moulla, A S

    2009-08-01

    The disequilibrium between (234)U and (238)U is commonly used as a tracer of groundwater flow. This paper aims to identify uranium contents and uranium isotopic disequilibria variation in groundwater sampled from deep Continental Intercalaire aquifer (southern Algeria and Tunisia). Large variations in both U contents (0.006-3.39ppb) and (234)U/(238)U activity ratios (0.4-15.38) are observed. We conduct a first assessment in order to verify whether the results of our investigation support and complete previous hydrogeological and isotopic studies. The dissolved U content and (234)U/(238)U activity ratio data were plotted on a two-dimensional diagram that was successfully utilized on sharing the CI aquifer into different compartments submitted to different oxidising/reducing conditions and leads also to distinguished two preferential flow paths in the Nefzaoua/Chott Fejej discharge area. Uranium isotopes disequilibrium indicate that ranium chemistry is mainly controlled by water-rock interaction enhanced by long residence time recognised for this aquifer.

  7. What cycles are recorded in continental Most Basin (Czech Republic, late Burdigalian)?

    Science.gov (United States)

    Matys Grygar, Tomas; Mach, Karel; Laurin, Jiri

    2013-04-01

    Understanding to climate dynamics requires identification of orbital forcing as a piece of a jigsaw puzzle. High-frequency climate changes could be the reason of discrepancies among Miocene climate reconstructions from sediment archives. Nearly all continental sediment sequences have some repetitive patterns, of which causes can be manifold; orbital forcing (climatic cycles) is only one option. There are two main reasons for this uncertainty: 1) recording mechanisms of climate changes in a real sediment basin are site-specific and ambiguous (and usually not known, or not reported) and 2) autocyclic behaviour (inherent chaos) and tectonics can also produce repetitive patterns and statistics itself is not capable to reveal that their nature is not climatic. On the other hand, most paleontological climatic reconstructions have temporal resolution in order of Myr (or at best in tenths of Myr), which cannot really reflect the expected climate dynamics. We have studied about 250 m thick clastic syn-rift sediment sequence in the Most Basin in the Ohře Graben (Czech Republic). In the mature-rift stage, a basin-wide lake existed there for monotonous lacustrine mudstones) to C5Cr or C5Dr chrons in the late Burdigalian (there are no other plausible options respecting the small mammal biozone MN3a in the early rifting stage). The simplest interpretation of the Milankovitch cycles in our sediment succession is variability in precipitation in Central Europe at a scale of tens to hundreds kyr.

  8. Continental arc volcanism as the principal driver of icehouse-greenhouse variability

    Science.gov (United States)

    McKenzie, N. Ryan; Horton, Brian K.; Loomis, Shannon E.; Stockli, Daniel F.; Planavsky, Noah J.; Lee, Cin-Ty A.

    2016-04-01

    Variations in continental volcanic arc emissions have the potential to control atmospheric carbon dioxide (CO2) levels and climate change on multimillion-year time scales. Here we present a compilation of ~120,000 detrital zircon uranium-lead (U-Pb) ages from global sedimentary deposits as a proxy to track the spatial distribution of continental magmatic arc systems from the Cryogenian period to the present. These data demonstrate a direct relationship between global arc activity and major climate shifts: Widespread continental arcs correspond with prominent early Paleozoic and Mesozoic greenhouse climates, whereas reduced continental arc activity corresponds with icehouse climates of the Cryogenian, Late Ordovician, late Paleozoic, and Cenozoic. This persistent coupled behavior provides evidence that continental volcanic outgassing drove long-term shifts in atmospheric CO2 levels over the past ~720 million years.

  9. Tectonic erosion, subduction accretion and arc collision as controls on the growth of the continental crust

    Science.gov (United States)

    Clift, P.; Vannucchi, P.; Draut, A.

    2003-04-01

    Subduction plate boundaries, at which tectonic erosion removes material from the overriding plate, account for 57% of the total length of the global subduction system and are favored where convergence rates exceed 7 cm/yr and where the sedimentary cover is less than 1 km. Accretion conversely preferentially occurs in regions of slow convergence (1 km. The slope gradients and taper angle of accretionary plate margins correlates with plate convergence rates, while erosive margin slopes appear to be independent of this. Rates of trench retreat do not appear to correlate with any simple characteristic of the plate interaction, but are largely a function of the history of seamount or ridge collisions. Mass balances of the global subduction system indicate that the entire volume of the continental crust can be recycled through the subduction system every 2.6 Ga. Even in accretionary margins a median of only 32% of the incoming sedimentary mass is accreted over time scales of 10 my or greater, resulting in long-term net loss of continental crust along continental active margins. Average magmatic productivity in the active margins must exceed 75 km3/my if the volume of the continental crust is to reach the slow growth rate indicated by isotopic and continental freeboard arguments. Geological arguments indicate that magmatic accretion rates must be faster in oceanic arcs (87-95 km3/my) and less in the continental arcs (65-83 km3/my). Mass balance arguments in oceanic arcs require that their crustal thicknesses must be Continental growth is principally achieved through the collision of oceanic island arcs to continental margins. Although oceanic arcs are chemically distinct from continental crust, the collision process involves the loss of mafic and ultramafic lower crust and the emplacement of voluminous, high silica, light rare earth element enriched melts, transforming the net composition into something more continental in character.

  10. Influence of Earth crust composition on continental collision style in Precambrian conditions: Results of supercomputer modelling

    Science.gov (United States)

    Zavyalov, Sergey; Zakharov, Vladimir

    2016-04-01

    A number of issues concerning Precambrian geodynamics still remain unsolved because of uncertainity of many physical (thermal regime, lithosphere thickness, crust thickness, etc.) and chemical (mantle composition, crust composition) parameters, which differed considerably comparing to the present day values. In this work, we show results of numerical supercomputations based on petrological and thermomechanical 2D model, which simulates the process of collision between two continental plates, each 80-160 km thick, with various convergence rates ranging from 5 to 15 cm/year. In the model, the upper mantle temperature is 150-200 ⁰C higher than the modern value, while the continental crust radiogenic heat production is higher than the present value by the factor of 1.5. These settings correspond to Archean conditions. The present study investigates the dependence of collision style on various continental crust parameters, especially on crust composition. The 3 following archetypal settings of continental crust composition are examined: 1) completely felsic continental crust; 2) basic lower crust and felsic upper crust; 3) basic upper crust and felsic lower crust (hereinafter referred to as inverted crust). Modeling results show that collision with completely felsic crust is unlikely. In the case of basic lower crust, a continental subduction and subsequent continental rocks exhumation can take place. Therefore, formation of ultra-high pressure metamorphic rocks is possible. Continental subduction also occurs in the case of inverted continental crust. However, in the latter case, the exhumation of felsic rocks is blocked by upper basic layer and their subsequent interaction depends on their volume ratio. Thus, if the total inverted crust thickness is about 15 km and the thicknesses of the two layers are equal, felsic rocks cannot be exhumed. If the total thickness is 30 to 40 km and that of the felsic layer is 20 to 25 km, it breaks through the basic layer leading to

  11. Success and adaptation

    CERN Multimedia

    2013-01-01

    Yesterday morning, the last colliding proton beams of 2013 were extracted from the LHC, heralding the start of the machine’s first long shutdown (LS1) and crowning its first three glorious years of running. I hardly need to tell the CERN community what a fabulous performance all the people running the machine, the experiments, the computing and all supporting infrastructures put in. Those people are you, and you all know very well what a great job everyone did.   Nevertheless, I would like to express my thanks to all the people who made this first LHC run such a success. Re-measuring the whole Standard Model in such a short period, and then completing it with the discovery of what looks increasingly like the Higgs boson, is no mean feat. What I’d like to focus on today is another aspect of our field: its remarkable ability to adapt. When I started out in research, experiments involved a handful of people and lasted a few years at most. The timescale for the development of ...

  12. Assessing call centers’ success:

    Directory of Open Access Journals (Sweden)

    Hesham A. Baraka

    2013-07-01

    This paper introduces a model to evaluate the performance of call centers based on the Delone and McLean Information Systems success model. A number of indicators are identified to track the call center’s performance. Mapping of the proposed indicators to the six dimensions of the D&M model is presented. A Weighted Call Center Performance Index is proposed to assess the call center performance; the index is used to analyze the effect of the identified indicators. Policy-Weighted approach was used to assume the weights with an analysis of different weights for each dimension. The analysis of the different weights cases gave priority to the User satisfaction and net Benefits dimension as the two outcomes from the system. For the input dimensions, higher priority was given to the system quality and the service quality dimension. Call centers decision makers can use the tool to tune the different weights in order to reach the objectives set by the organization. Multiple linear regression analysis was used in order to provide a linear formula for the User Satisfaction dimension and the Net Benefits dimension in order to be able to forecast the values for these two dimensions as function of the other dimensions

  13. 77 FR 59391 - Delta Air Lines, Inc., Continental Airlines, Inc., JetBlue Airways Corporation, United Air Lines...

    Science.gov (United States)

    2012-09-27

    ...] Delta Air Lines, Inc., Continental Airlines, Inc., JetBlue Airways Corporation, United Air Lines, Inc... Lines, Inc., Continental Airlines, Inc., JetBlue Airways Corporation, United Air Lines, Inc., and US...

  14. The influence of partial melting and melt migration on the rheology of the continental crust

    Science.gov (United States)

    Cavalcante, Geane Carolina G.; Viegas, Gustavo; Archanjo, Carlos José; da Silva, Marcos Egydio

    2016-11-01

    The presence of melt during deformation produces a drastic change in the rheological behavior of the continental crust; rock strength is decreased even for melt fractions as low as ∼7%. At pressure/temperature conditions typical of the middle to lower crust, melt-bearing systems may play a critical role in the process of strain localization and in the overall strength of the continental lithosphere. In this contribution we focus on the role and dynamics of melt flow in two different mid-crustal settings formed during the Brasiliano orogeny: (i) a large-scale anatectic layer in an orthogonal collision belt, represented by the Carlos Chagas anatexite in southeastern Brazil, and (ii) a strike-slip setting, in which the Espinho Branco anatexite in the Patos shear zone (northeast Brazil) serves as an analogue. Both settings, located in eastern Brazil, are part of the Neoproterozoic tectonics that resulted in widespread partial melting, shear zone development and the exhumation of middle to lower crustal layers. These layers consist of compositionally heterogeneous anatexites, with variable former melt fractions and leucosome structures. The leucosomes usually form thick interconnected networks of magma that reflect a high melt content (>30%) during deformation. From a comparison of previous work based on detailed petrostructural and AMS studies of the anatexites exposed in these areas, we discuss the rheological implications caused by the accumulation of a large volume of melt "trapped" in mid-crustal levels, and by the efficient melt extraction along steep shear zones. Our analyses suggest that rocks undergoing partial melting along shear settings exhibit layers with contrasting competence, implying successive periods of weakening and strengthening. In contrast, regions where a large amount of magma accumulates lack clear evidence of competence contrast between layers, indicating that they experienced only one major stage of dramatic strength drop. This comparative

  15. The Lord Howe Rise continental ribbon: a fragment of eastern Gondwana that reveals the drivers of continental rifting and plate tectonics

    Science.gov (United States)

    Saito, S.; Hackney, R. I.; Bryan, S. E.; Kimura, J. I.; Müller, D.; Arculus, R. J.; Mortimer, N. N.; Collot, J.; Tamura, Y.; Yamada, Y.

    2016-12-01

    Plate tectonics and resulting changes in crustal architecture profoundly influence global climate, oceanic circulation, and the origin, distribution and sustainability of life. Ribbons of continental crust rifted from continental margins are one product of plate tectonics that can influence the Earth system. Yet we have been unable to fully resolve the tectonic setting and evolution of huge, thinned, submerged, and relatively inaccessible continental ribbons like the Lord Howe Rise (LHR), which formed during Cretaceous fragmentation of eastern Gondwana. Thinned continental ribbons like the LHR are not easily explained or predicted by plate-tectonic theory. However, because Cretaceous rift basins on the LHR preserve the stratigraphy of an un-accreted and intact continental ribbon, they can help to determine whether plate motion is self-organised—passively driven by the pull of negatively-buoyant subducting slabs—or actively driven by convective flow in the mantle. In a self-organising scenario, the LHR formed in response to ocean-ward retreat of the long-lived eastern Gondwana subduction zone and linked upper-plate extension. In the mantle-driven scenario, the LHR resulted from rifting near the eastern edge of Gondwana that was triggered by processes linked to emplacement of a silicic Large Igneous Province. These scenarios can be distinguished using the ribbon's extensional history and the composition and tectonic affinity of igneous rocks within rift basins. However, current knowledge of LHR rift basins is based on widely-distributed marine and satellite geophysical data, limited dredge samples, and sparse shallow drilling (<600 m below-seafloor). This limits our ability to understand the evolution of extended continental ribbons, but a recent deep crustal seismic survey across the LHR and a proposed IODP deep stratigraphic well through a LHR rift basin provide new opportunities to explore the drivers behind rifting, continental ribboning and plate tectonics.

  16. 76 FR 37682 - Airworthiness Directives; Teledyne Continental Motors (TCM) and Rolls-Royce Motors Ltd. (R-RM...

    Science.gov (United States)

    2011-06-28

    ... Continental Motors (TCM) and Rolls-Royce Motors Ltd. (R-RM) Series Reciprocating Engines AGENCY: Federal... information identified in this AD, contact Teledyne Continental Motors, Inc., PO Box 90, Mobile, AL 36601... Continental Motors (TCM) and Rolls-Royce Motors Ltd. (R-RM) Series Reciprocating Engines: Docket No....

  17. 78 FR 33897 - Atlantic Wind Lease Sale 2 (ATLW2) Commercial Leasing for Wind Power on the Outer Continental...

    Science.gov (United States)

    2013-06-05

    ... for Wind Power on the Outer Continental Shelf Offshore Rhode Island and Massachusetts-- Final Sale...) Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Rhode Island and Massachusetts... for Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Rhode Island and...

  18. 75 FR 16830 - Geological and Geophysical Exploration (G&G) on the Mid- and South Atlantic Outer Continental...

    Science.gov (United States)

    2010-04-02

    ... Outer Continental Shelf (OCS) AGENCY: Minerals Management Service, Interior. ACTION: Reopening of... Outer Continental Shelf Lands Act (OCSLA, as amended; 43 U.S.C. 1331-1356, (2007)) and its implementing... Leasing Oil and Natural Gas Resources: Outer Continental Shelf (see...

  19. 76 FR 55090 - Commercial Lease of Submerged Lands for Renewable Energy Development on the Outer Continental Shelf

    Science.gov (United States)

    2011-09-06

    ... Renewable Energy Development on the Outer Continental Shelf AGENCY: Bureau of Ocean Energy Management... will use Form 0008 to issue commercial renewable energy leases on the Outer Continental Shelf. In the... the Outer Continental Shelf,'' BOEMRE stated that ``we intend to develop a model lease form through...

  20. 77 FR 5529 - Commercial Lease of Submerged Lands for Renewable Energy Development on the Outer Continental Shelf

    Science.gov (United States)

    2012-02-03

    ... the Outer Continental Shelf AGENCY: Bureau of Ocean Energy Management, Interior. ACTION: Notice... energy leases on the Outer Continental Shelf (OCS). In the preamble to the April 29, 2009, Final Rule, ``Renewable Energy and Alternate Uses of Existing Facilities on the Outer Continental Shelf,'' BOEM...

  1. Rates, Mechanisms, and Implications of Crustal Assimilation in Continental Arcs

    Science.gov (United States)

    Dungan, M.; Davidson, J.

    2002-12-01

    Contrary to the limiting constraints postulated by Bowen for the coupled thermal and mass balance implicated in assimilation, many studies [1-6] suggest that multi-stage and multi-component assimilation, abetted by magma mixing, may be volumetrically important and have profound consequences for the chemistry of basaltic and evolved magmas in long-lived continental magmatic systems. The probability of a primitive or evolved basalt arriving at the Earth's surface having undergone perfectly closed-system evolution during passage through 25-60 km of continental crust is vanishingly low. A case-by-case demonstration that the intra-crustal chemical overprint is trivial, or that it can be quantified and subtracted, is an essential step in any evaluation of mantle source-region chemistry and processes based on inversion of continental basalt compositions. In magmatic systems characterized by mafic magma recharge the thermal energy and physical dynamism needed for assimilation are not constrained to come uniquely from one magma batch [7, 8]. Equally important is that assimilation is rarely equivalent to bulk melting of ingested blocks followed by reservoir-wide homogenization. The mechanics of crustal assimilation are governed by grain boundary melting, disaggregation, and dispersal of refractory solids (including xenocryst settling) wherein liberated low-density, incompatible element-enriched partial melts have the capacity to render primitive arc magma batches variably modified, as well as heterogeneous on short length-scales. Evidence that basalts thermally erode surface channels and conduit walls, and new observations constraining the maximum time that some extensively melted xenoliths have resided in their host magmas, indicate that the time required to impose an open-system overprint on a hot basaltic magma (days to yrs) is far shorter than typical repose periods at most arc volcanoes (50-500 yrs). Assimilative recycling of broadly gabbroic arc cumulates has had large

  2. Physical analogs that help to better understand the modern concepts on continental stretching, hyperextension and rupturing

    Science.gov (United States)

    Zalan, Pedro

    2014-05-01

    Three facts helped to establish a revolution in the understanding of how mega-continents stretch, rupture and breakup to form new continents and related passive margins: (1) the penetration of the distal portions of the Iberia-Newfoundland conjugate margins by several ODP wells (late 70's/early 80's), with the discovery of hyperextended crust and exhumation of lower crust and mantle between typical continental and oceanic domains, (2) field works in the Alps and in the Pyrenees that re-interpreted sedimentary successions and associated "ophiolites" as remnants of old Tethyan passive margins that recorded structural domains similar to those found in Iberia-Newfoundland, and (3) the acquisition of long and ultra-deep reflection seismic sections that could image for the first time sub-crustal levels (25-40 km) in several passive margins around the world. The interpretation of such sections showed that the concepts developed in the Iberia-Newfoundland margins and in the Alps could be applied to a great extent to most passive margins, especially those surrounding the North and South Atlantic Oceans. The new concepts of (i) decoupled deformation (upper brittle X lower ductile) within the proximal domain of the continental crust, (ii) of coupled deformation (hyperextension) in the distal crust and, (iii) of exhumation of deeper levels in the outer domain, with the consequent change in the physical properties of the rising rocks, defined an end-member in the new classification of passive margins, the magma-poor type (as opposed to volcanic passive margins). These concepts, together with the new reflection seismic views of the entire crustal structure of passive margins, forced the re-interpretation of older refraction and potential field data and the re-drawing of long established models. Passive margins are prime targets for petroleum exploration, thus, the great interest raised by this subject in both the academy and in the industry. Interestingly enough, the deformation

  3. Formation of lower continental crust by relamination of buoyant arc lavas and plutons

    Science.gov (United States)

    Kelemen, Peter B.; Behn, Mark D.

    2016-03-01

    The formation of the Earth's continents is enigmatic. Volcanic arc magmas generated above subduction zones have geochemical compositions that are similar to continental crust, implying that arc magmatic processes played a central role in generating continental crust. Yet the deep crust within volcanic arcs has a very different composition from crust at similar depths beneath the continents. It is therefore unclear how arc crust is transformed into continental crust. The densest parts of arc lower crust may delaminate and become recycled into the underlying mantle. Here we show, however, that even after delamination, arc lower crust still has significantly different trace element contents from continental lower crust. We suggest that it is not delamination that determines the composition of continental crust, but relamination. In our conceptual model, buoyant magmatic rocks generated at arcs are subducted. Then, upon heating at depth, they ascend and are relaminated at the base of the overlying crust. A review of the average compositions of buoyant magmatic rocks -- lavas and plutons -- sampled from the Aleutians, Izu-Bonin-Marianas, Kohistan and Talkeetna arcs reveals that they fall within the range of estimated major and trace elements in lower continental crust. Relamination may thus provide an efficient process for generating lower continental crust.

  4. Deglaciation and glacial erosion: a joint control on magma productivity by continental unloading

    Science.gov (United States)

    Sternai, Pietro; Caricchi, Luca; Castelltort, Sebastien

    2016-04-01

    Glacial-interglacial cycles affect the processes through which water and rocks are redistributed across the Earth's surface, thereby linking solid-Earth and climate dynamics. Regional and global scale studies suggest that continental lithospheric unloading due to ice melting during the transition to interglacials leads to increased continental magmatic, volcanic and degassing activity. Such a climatic forcing on the melting of the Earth's interior, however, has always been evaluated without considering the additional continental unloading associated with erosion. Current datasets relating to the evolution of erosion rates are typically limited by temporal resolutions that are too low or span too short time intervals to allow for direct comparisons between the contributions from ice melting and erosion to continental unloading at the timescale of the late Pleistocene glacial cycles. Yet, they provide a fundamental observational basis on which to calibrate numerical predictions. Here, we present and discuss numerical results involving synthetic but realistic topographies, ice caps and glacial erosion rates suggesting that erosion may be as important as deglaciation in affecting continental unloading, sub-continental decompression melting and magma productivity. Thus, the timing and magnitude of deglaciation and erosion must be characterized if the forcing of climate change on the continental magmatic/volcanic activity is to be extracted from the remnants of eroded volcanic centers. Our study represents an additional step towards a more general understanding of the links between a changing climate, glacial processes and the melting of the solid Earth.

  5. IRIS Controlled Source Seismic Experiments: Continental Structure, Instrumentation, and Education

    Science.gov (United States)

    Mooney, W. D.; Keller, G. R.

    2004-12-01

    The controlled-source seismology program of IRIS/PASSCAL has made major contributions to the study of continental structure and evolution. It has also undergone major developments in seismic instrumentation. The first PASSCAL experiments (1984/85) targeted the Basin and Range Province and the Ouachita orogenic belt. The Basin and Range study provided remarkably clear images of this thin, highly-extended crust, while the Ouachita experiment tested competing hypotheses for the deep structure of this Paleozoic orogen. However, both of these projects were limited by a lack of seismic instruments. The situation improved in the late 1980's with the benefit of a mixed array of 600 seismic recorders from the USGS, Stanford, and the Geological Survey of Canada. The resolution achieved with these instruments was revolutionary. Results include the imaging of such remarkable features as crustal-scale duplexes in the Brooks Range compressional orogen of northern Alaska, and of crustal "core complexes" in the extended crust of southwest Arizona. The 3-channel PASSCAL Jr. instrument was developed, leading to experiments in which ˜1000 instruments were deployed, including three-component recording. This complex mix of instruments served the community well for several years, but required large, complex instrument centers and lots of technical support. With input from PASSCAL and the international community, a newly designed, compact instrument (the Texan) was finalized in the spring of 1998, and the first 200 instruments was delivered to the Univ. of Texas-El Paso in late 1998. The present instrument pool of Texans exceeds 1,400 and these have been used on such projects as the high-resolution imaging of the Los Angeles and San Fernando basins (LARSE I and II experiments), where active thrust faults have been imaged. Controlled-source seismic experiments are now very numerous. During calendar year 2004 alone, portable Texan instruments have traveled from Venezuela to Denmark

  6. Testing Predictions of Continental Insulation using Oceanic Crustal Thicknesses

    Science.gov (United States)

    Hoggard, Mark; Shorttle, Oliver; White, Nicky

    2016-04-01

    The thermal blanketing effect of continental crust has been predicted to lead to elevated temperatures within the upper mantle beneath supercontinents. Initial break-up is associated with increased magmatism and the generation of flood basalts. Continued rifting and sea-floor spreading lead to a steady reduction of this thermal anomaly. Recently, evidence in support of this behaviour has come from the major element geochemistry of mid-ocean ridge basalts, which suggest excess rifting temperatures of ˜ 150 °C that decay over ˜ 100 Ma. We have collated a global inventory of ˜ 1000 seismic reflection profiles and ˜ 500 wide-angle refraction experiments from the oceanic realm. Data are predominantly located along passive margins, but there are also multiple surveys in the centres of the major oceanic basins. Oceanic crustal thickness has been mapped, taking care to avoid areas of secondary magmatic thickening near seamounts or later thinning such as across transform faults. These crustal thicknesses are a proxy for mantle potential temperature at the time of melt formation beneath a mid-ocean ridge system, allowing us to quantify the amplitude and duration of thermal anomalies generated beneath supercontinents. The Jurassic break-up of the Central Atlantic and the Cretaceous rifting that formed the South Atlantic Ocean are both associated with excess temperatures of ˜ 50 °C that have e-folding times of ˜ 50 Ma. In addition to this background trend, excess temperatures reach > 150 °C around the region of the Rio Grande Rise, associated with the present-day Tristan hotspot. The e-folding time of this more local event is ˜ 10 Ma, which mirrors results obtained for the North Atlantic Ocean south of Iceland. In contrast, crustal thicknesses from the Pacific Ocean reveal approximately constant potential temperature through time. This observation is in agreement with predictions, as the western Pacific was formed by rifting of an oceanic plate. In summary

  7. Initiation of continental accretion in the Betic-Rif domain

    Science.gov (United States)

    Maxime, Daudet; Frederic, Mouthereau; Stéphanie, Brichau; Ana, Crespo-Blanc; Arnaud, Vacherat

    2017-04-01

    The Betic - Rif cordillera in southern Spain and northern Morocco, respectively, form one of the tightest orogenic arc on Earth. The formation of this arcuate orogenic belt resulted from the westward migration of the Alboran crustal domain, constituted by the internal zone of the orogeny and the basement of the Alboran back-arc basin, that collided with the rifted margins of Iberia and Africa at least since the early Miocene. This collision is intimately linked to the post-35-30Ma regional slab roll-back and back-arc extension in the western Mediterranean region. The geodynamics of the Betic-Rif domain, which is of great importance for the paleogeographic reconstructions of the Tethys-Altantic and the Mediterranean sea, is still largely debated. Answers will come from a more detailed structural analyses, including refinement of the time-temperature paths and kinematics of the main structural units, which is one of the main objectives of the OROGEN research project, co-financed by BRGM, TOTAL & CNRS. In this study, we focus on the well-developed flysch-type sediments now accreted in the Betics-Rif but initially deposited in a basin, north of the african margin and on the iberian margin from the Early Cretaceous to the Early Miocene. Using low-temperature thermochronology (fission-track and (U-Th)/He analyses) combined with zircon U-Pb geochronology on the flyschs deposited on the most distal part of the margin, we aim to constrain the thermal history of both the source rocks and accreted thrust sheets at the earliest stages of continental accretion. Sample have been collected in flyschs series ranging from Mesozoic, Paleogene to Neogene ages. Additional samples have been collected in the Rif where Cretaceous series are more developed. Combined with a detailed structural analysis, LT thermochronological constraints will refine the kinematics of thrust units when continental accretion started before the final thrust emplacement occurred in the Early Miocene

  8. Say, Sismondi e o debate continental sobre os mercados

    Directory of Open Access Journals (Sweden)

    Rogério Arthmar

    2009-06-01

    Full Text Available O artigo versa sobre o debate travado entre Say e Sismondi a respeito da possibilidade de saturação geral dos mercados. Na primeira seção, descreve-se o contexto histórico da Europa continental nas primeiras décadas do século 19, destacando-se as particularidades da experiência francesa de industrialização ante a liderança britânica nesse campo. A seguir, traça-se breve perfil da formação intelectual de Say a fim de apresentar sua visão sobre o funcionamento dos mercados. Na continuação, examina-se a perspectiva histórica de Sismondi em sua crítica da ortodoxia clássica, bem como sua versão para a tendência do sistema capitalista à superprodução. Nas duas últimas partes, recuperam-se os comentários recíprocos de Say e Sismondi a respeito de suas divergências teóricas sobre os limites da acumulação de capital.This paper deals with the debate happened between Say and Sismondi regarding the possibility of a general glut. The first section describes the historical context of the first decades of nineteenth century continental Europe, focusing on the French industrialization experience vis-à-vis the British leadership in this field. Next, a brief intellectual profile of the evolution of Say's thought is made in order to present his vision about the proper working of markets. After that, the historical approach used by Sismondi in his criticism of classical orthodoxy is examined, as well as his own version to the capitalistic system inner tendency towards overproduction. The last two sections retrieve the exchange between Say and Sismondi over their theoretical disagreements on the limits to capital accumulation.

  9. Spacing and strength of active continental strike-slip faults

    Science.gov (United States)

    Zuza, Andrew V.; Yin, An; Lin, Jessica; Sun, Ming

    2017-01-01

    Parallel and evenly-spaced active strike-slip faults occur widely in nature across diverse tectonic settings. Despite their common existence, the fundamental question of what controls fault spacing remains unanswered. Here we present a mechanical model for the generation of parallel strike-slip faults that relates fault spacing to the following parameters: (1) brittle-crust thickness, (2) fault strength, (3) crustal strength, and (4) crustal stress state. Scaled analogue experiments using dry sand, dry crushed walnut shells, and viscous putty were employed to test the key assumptions of our quantitative model. The physical models demonstrate that fault spacing (S) is linearly proportional to brittle-layer thickness (h), both in experiments with only brittle materials and in two-layer trials involving dry sand overlying viscous putty. The S / h slope in the two-layer sand-putty experiments may be controlled by the (1) rheological/geometric properties of the viscous layer, (2) effects of distributed basal loading caused by the viscous shear of the putty layer, and/or (3) frictional interaction at the sand-putty interface (i.e., coupling between the viscous and brittle layers). We tentatively suggest that this third effect exerts the strongest control on fault spacing in the analogue experiments. By applying our quantitative model to crustal-scale strike-slip faults using fault spacing and the seismogenic-zone thickness obtained from high-resolution earthquake-location data, we estimate absolute fault friction of active strike-slip faults in Asia and along the San Andreas fault system in California. We show that the average friction coefficient of strike-slip faults in the India-Asia collisional orogen is lower than that of faults in the San Andreas fault system. Weaker faults explain why deformation penetrates >3500 km into Asia from the Himalaya and why the interior of Asia is prone to large (M > 7.0) devastating earthquakes along major intra-continental strike

  10. Verbal Behavior and Courtroom Success.

    Science.gov (United States)

    Parkinson, Michael G.

    1981-01-01

    Identifies characteristics of successful courtroom speech for prosecuting attorneys, defense attorneys, and accuseds using computer-based content analysis and rater judgments of verbal behaviors. Demonstrates that verbal aggression is an important factor for successful prosecutors, equivocation is important to success for defense attorneys, and…

  11. Styles of continental subduction and collision and their effect on formation and exhumation of UHP rocks

    Science.gov (United States)

    Warren, C. J.; Beaumont, C.; Jamieson, R. A.

    2006-12-01

    Ultra-high pressure (UHP) metamorphic rocks are exposed in many Phanerozoic mountain belts. It is now widely accepted that they represent continental margin rocks that were subducted to ≥100km during the transition from oceanic subduction to continental collision. A range of subduction-collision mechanisms have been proposed to account for UHP formation and exhumation. A series of upper-mantle-scale geodynamic models is used to test the sensitivity of a subset of these mechanisms to variations in lithosphere density, radioactive heat production, and crustal strength. The subducting crust includes an oceanic domain, a continental margin domain with variable width, thickness, strength, and heat production, and a strong internal continental domain. The models involve dynamic subduction, constant convergence velocity, density changes that accompany the main phase changes during burial, and surface erosion in the collision zone. Results show that continental subduction without retro-continent deformation is favored by relatively dense mantle lithosphere. Subduction of the retro-continent (forearc subduction) is associated with shallow-dipping, low- density mantle lithosphere. Back-thrusting of retro-lithosphere is favored by relatively weak retro-continental crust. UHP material can be exhumed in all 3 model styles, depending on the evolving geometry of the subduction-accretion zone and the degree of decoupling between subducting upper and lower continental crust in this zone. Weaker and/or hotter margins decouple and accrete, and their subsequent exhumation is driven by bulk density contrast (buoyancy) and/or forced expulsion in response to advection of strong continental material into the subduction zone (plunger effect). Stronger and/or colder continental margin material is subducted without decoupling and is then transported laterally, underplating the retro-mantle lithosphere. Model results are compatible with observed geometries and PTt paths from some UHP

  12. First report of adult Hyalomma marginatum rufipes (vector of Crimean-Congo haemorrhagic fever virus on cattle under a continental climate in Hungary

    Directory of Open Access Journals (Sweden)

    Hornok Sándor

    2012-08-01

    Full Text Available Abstract Background South Hungary is being monitored for the northward spreading of thermophilic ixodid species, therefore ticks were collected from cattle and wild ruminants (red, fallow and roe deer in the autumn of 2011. Findings Besides indigenous species (1185 Dermacentor reticulatus and 976 Ixodes ricinus, two Hyalomma marginatum rufipes males were found on two cows, in September eight days apart. Conclusions This is the northernmost autochthonous infestation of the type host (cattle with H. m. rufipes, vector of Crimean-Congo haemorrhagic fever virus. The present findings are suggestive of the moulting success of this Afro-Mediterranean tick species in a continental climate in Central Europe.

  13. Tectonic Evolution of the Northern Continental Margin of North China Platform in Middle Proterozoic

    Institute of Scientific and Technical Information of China (English)

    Xu Zhongyuan; Liu Zhenghong

    2000-01-01

    An orogenic belt developed in late middle Proterozoic in the northern margin of North China Plate extends from Inner Mongolia to Western Liaoning Province and Eastern Jilin Province. It is over 2000km long. The orogenic belt was formed by collision between North China Platform and Siberia Platform during the Rodinian Super- Continent period. From sedimentary formation, magmatic activity and crustal tectonic deformation, it is suggested that along the tectonic belt the paleocontinental margin experienced four stages of tectonic evolution in middle Proterozoic, they are: continental margin rift,passive continental margin, active continental margin and collisional orogenic stages.

  14. Persistence of initial conditions in continental scale air quality ...

    Science.gov (United States)

    This study investigates the effect of initial conditions (IC) for pollutant concentrations in the atmosphere and soil on simulated air quality for two continental-scale Community Multiscale Air Quality (CMAQ) model applications. One of these applications was performed for springtime and the second for summertime. Results show that a spin-up period of ten days commonly used in regional-scale applications may not be sufficient to reduce the effects of initial conditions to less than 1% of seasonally-averaged surface ozone concentrations everywhere while 20 days were found to be sufficient for the entire domain for the spring case and almost the entire domain for the summer case. For the summer case, differences were found to persist longer aloft due to circulation of air masses and even a spin-up period of 30 days was not sufficient to reduce the effects of ICs to less than 1% of seasonally-averaged layer 34 ozone concentrations over the southwestern portion of the modeling domain. Analysis of the effect of soil initial conditions for the CMAQ bidirectional NH3 exchange model shows that during springtime they can have an important effect on simulated inorganic aerosols concentrations for time periods of one month or longer. The effects are less pronounced during other seasons. The results, while specific to the modeling domain and time periods simulated here, suggest that modeling protocols need to be scrutinized for a given application and that it cannot be assum

  15. Geoelectric hazard maps for the continental United States

    Science.gov (United States)

    Love, Jeffrey J.; Pulkkinen, Antti; Bedrosian, Paul A.; Jonas, Seth; Kelbert, Anna; Rigler, E. Joshua; Finn, Carol A.; Balch, Christopher C.; Rutledge, Robert; Waggel, Richard M.; Sabata, Andrew T.; Kozyra, Janet U.; Black, Carrie E.

    2016-09-01

    In support of a multiagency project for assessing induction hazards, we present maps of extreme-value geoelectric amplitudes over about half of the continental United States. These maps are constructed using a parameterization of induction: estimates of Earth surface impedance, obtained at discrete geographic sites from magnetotelluric survey data, are convolved with latitude-dependent statistical maps of extreme-value geomagnetic activity, obtained from decades of magnetic observatory data. Geoelectric amplitudes are estimated for geomagnetic waveforms having 240 s sinusoidal period and amplitudes over 10 min that exceed a once-per-century threshold. As a result of the combination of geographic differences in geomagnetic activity and Earth surface impedance, once-per-century geoelectric amplitudes span more than 2 orders of magnitude and are an intricate function of location. For north-south induction, once-per-century geoelectric amplitudes across large parts of the United States have a median value of 0.26 V/km; for east-west geomagnetic variation the median value is 0.23 V/km. At some locations, once-per-century geoelectric amplitudes exceed 3 V/km.

  16. Continental river routing model for water resources applications

    Science.gov (United States)

    Mizukami, N.; Clark, M. P.; Sampson, K. M.

    2015-12-01

    This presentation describes a stand-alone runoff routing tool, mizuRoute, which post-processes runoff outputs from any distributed hydrologic model or land surface model to produce spatially distributed streamflow at various spatial scales from headwater basins to continental-wide river systems. The tool utilizes vector-based river network data, which includes river segment lines and the associated drainage basin polygons. Streamflow estimates at any desired location in the river network can be easily extracted from the output of mizuRoute. The first step of the routing tool is hillslope routing, which uses a gamma distribution to construct a unit-hydrograph that represents the transport of runoff from a hillslope to an outlet of the catchment. The second step is river channel routing, which is performed with one of two routing scheme options: a) the kinematic wave tracking (KWT) routing procedure; and 2) the impulse response function - unit hydrograph (IRF-UH) routing procedure. This presentation demonstrate mizuRoute's capabilities to produce spatially distributed streamflow simulations based on the river network data from the United States Geological Survey (USGS) Geospatial Fabric (GF) dataset, which contains over 54000 river segments across the contiguous United States (CONUS). We routed ensemble of 150 years runoff simulated with Variable Infiltration Capacity Model forced by climate data from Coupled Model Intercomparison Project Phase 5. A brief analysis of the routing model parameter sensitivity is also presented.

  17. Environmental hazards in Xinjiang Line of New Eurasian Continental Bridge

    Institute of Scientific and Technical Information of China (English)

    CHEN; Yaning(陈亚宁); LI; Weihong(李卫红); YANG; Sjquan(杨思全); XU; Hailiang(徐海量)

    2002-01-01

    Xinjiang Line of New Eurasian Continental Bridge is the important lifeline project inwestern China. Various disasters, such as flood, strong wind, sandstorm, and roadbed disasters,have been seriously affecting the railway transportation. The field investigation and analysis on thedata collected since 1959 show that: serious floods often occurred when the rain intensity reached25 mm/h or 30 mm/d; the critical wind speed for turning over a train is between 35 m/s and 67 m/s,and such cases happened in draught places of mountain opening and trunk valley; the angle be-tween wind direction and railway is closely related to the thickness of accumulative sand along thelines; roadbed disasters taking the form of side-slope sliding, roadbed sinking and silt turning uptook place in spring when the temperature rapidly rose to 10-15℃ from zero and precipitationcame forth or when the thickness of snow cover on shade slope reached above 20 cm in winter;the disasters taking place in the 1990s were far stronger than those of the 1980s and the order ofhazard intensity along the Xinjiang Line is Urumqi>Shihezi>Kuitun>Liuyuan>Shanhan>Hami.

  18. On instability and mixing on the UK Continental Shelf

    CERN Document Server

    Liu, Zhiyu

    2015-01-01

    The stability of stratified flows at locations in the Clyde, Irish and Celtic Seas on the UK Continental Shelf is examined. Flows are averaged over periods of 12-30 min in each hour, corresponding to the times taken to obtain reliable estimates of the rate of dissipation of turbulent kinetic energy per unit mass, $\\varepsilon$. The Taylor-Goldstein equation is solved to find the maximum growth rate of small disturbances to these averaged flows, and the critical gradient Richardson number, $\\textrm{Ri}_\\textrm{c}$. The proportion of unstable periods where the minimum gradient Richardson number, $\\textrm{Ri}_{\\textrm{min}}$, is less than $\\textrm{Ri}_\\textrm{c}$ is about 35%. Cases are found in which $\\textrm{Ri}_\\textrm{c} <$ 0.25; 37% of the flows with $\\textrm{Ri}_{\\textrm{min}}<$ 0.25 are stable, and $\\textrm{Ri}_\\textrm{c}<$ 0.24 in 68% of the periods where $\\textrm{Ri}_{\\textrm{min}}<$ 0.25. Marginal conditions with 0.8 $<$ Ri$_{\\textrm{min}}$$/$Ri$_\\textrm{c}$ $<$ 1.2 occur in 30% of th...

  19. Variability of the Continental Water Boundary near the Prydz Bay

    Institute of Scientific and Technical Information of China (English)

    Pu Shuzhen; Dong Zhaoqian; Hu Xiaomin; Yu Fei; Zhao Xin

    2002-01-01

    Based on the Data Obtained during the 15th Antarctic Expedition of Chian between November 1998 and February 1999,the paper discusses the water masses distributed on both sides of the Continental Water Boundary ( CWB) as well as the spacial variability of the physical characteristics of the central location, the frontal width, the frontal strength, the vertical depth, and the vertical thickness for CWB. The above results are compared with the results from the data obtained during the 9th Antarctic Expedition of China between December 1992 and February 1993, and the temporal variability of those characteristics is discussed. In addition, the inhomogeneity of the kinematic characteristics and the patterns of the dynamic heights for those water masses located on both sides of CWB are illustrated. As it is pointed out in the paper, the trough in the dynamic height field is identified with the frontal location of CWB and the oceanic current shear. Furthermore, the dynamic reason for the upwelling of the circumpolar deep water can be understood by the explanation described in the paper.

  20. Continental shelves as potential resource of rare earth elements.

    Science.gov (United States)

    Pourret, Olivier; Tuduri, Johann

    2017-07-19

    The results of this study allow the reassessment of the rare earth elements (REE) external cycle. Indeed, the river input to the oceans has relatively flat REE patterns without cerium (Ce) anomalies, whereas oceanic REE patterns exhibit strong negative Ce anomalies and heavy REE enrichment. Indeed, the processes at the origin of seawater REE patterns are commonly thought to occur within the ocean masses themselves. However, the results from the present study illustrate that seawater-like REE patterns already occur in the truly dissolved pool of river input. This leads us to favor a partial or complete removal of the colloidal REE pool during estuarine mixing by coagulation, as previously shown for dissolved humic acids and iron. In this latter case, REE fractionation occurs because colloidal and truly dissolved pools have different REE patterns. Thus, the REE patterns of seawater could be the combination of both intra-oceanic and riverine processes. In this study, we show that the Atlantic continental shelves could be considered potential REE traps, suggesting further that shelf sediments could potentially become a resource for REE, similar to metalliferous deep sea sediments.

  1. Continental-scale hydrological consistency of evapotranspiration products using GRACE

    Science.gov (United States)

    Lopez, O.; McCabe, M. F.

    2014-12-01

    Multiple remote sensing products based on satellite observations are available at regional and global scales, allowing to obtain an estimation of the individual components of the hydrological cycle. However, using these products to provide closure of the water budget at the basin scale with accuracy remains a challenge. In this work, 12 large continental-scale basins covering a range of various climate types were chosen as regions of interest. Terrestrial water storage changes from GRACE, streamflow data from the Global Runoff Database and precipitation from the Tropical Rainfall Measuring Mission (TRMM) Multi Satellite Precipitation Analysis (TMPA) and Global Precipitation Climatology Project (GPCP), were used as a surrogate evaluation of observed spatio-temporal patterns of multi-model evapotranspiration estimates, derived from a long-term flux product as part of the LandFLUX project. The 10 year period of analysis also allows for the estimation of temporal trends in water storage changes and provides an opportunity to examine the capacity for water budget closure.

  2. Reassessment of stable continental regions of Southeast Asia

    Science.gov (United States)

    Wheeler, R.L.

    2011-01-01

    Probabilistic seismic-hazard assessments of the central and eastern United States (CEUS) require estimates of the size of the largest possible earthquake (Mmax). In most of the CEUS, sparse historical seismicity does not provide a record of moderate and large earthquakes that is sufficient to constrain Mmax. One remedy for the insufficient catalog is to combine the catalog of moderate to large CEUS earthquakes with catalogs from other regions worldwide that are tectonically analogous to the CEUS (stable continental regions, or SCRs). After the North America SCR, the largest contribution of earthquakes to this global SCR catalog comes from a Southeast Asian SCR that extends from Indochina to southeasternmost Russia. Integration and interpretation of recently published geological and geophysical results show that most of these Southeast Asian earthquakes occurred in areas exposing abundant alkaline igneous rocks and extensional faults, both of Neogene age (last 23 million years). The implied Neogene extension precludes classification of the areas as SCR crust. The extension also reduces the number of moderate and large Southeast Asian historical earthquakes that are available to constrain CEUS Mmax by 86 percent, from 43 to six.

  3. Influence of continental growth on mid-ocean ridge depth

    Science.gov (United States)

    Sim, Shi J.; Stegman, Dave R.; Coltice, Nicolas

    2016-11-01

    The interconnectedness of life, water, and plate tectonics is strikingly apparent along mid-ocean ridges (MOR) where communities of organisms flourish off the disequilibrium of chemical potentials created by circulation of hydrothermal fluids driven by Earth's heat. Moreover, submarine hydrothermal environments may be critical for the emergence of life on Earth. Oceans were likely present in the Hadean but questions remain about early Earth's global tectonics, including when seafloor spreading began and whether mid-oceanic ridges were deep enough for maximum hydrothermal activities. For example, plate tectonics influences global sea level by driving secular variations in the volume of ocean basins due to continental growth. Similarly, variations in the distribution of seafloor age and associated subsidence, due to assembly and dispersal of supercontinents, explain the largest sea level variation over the past 140 Myr. Using synthetic plate configurations derived from numerical models of mantle convection appropriate for early Earth, we show that MOR have remained submerged and their depths potentially constant over geologic time. Thus, conditions in the early Earth existed for hydrothermal vents at similar depths as today, providing environments conducive for the development of life and allowing for processes such as hydrothermal alteration of oceanic crust to influence the mantle's geochemical evolution.

  4. Building Successful Information Systems – a Key for Successful Organization

    Directory of Open Access Journals (Sweden)

    Doina ROSCA

    2010-12-01

    Full Text Available Building Successful Information Systems – a Key for Successful OrganizationAbstract: An Information System (IS can have a major impact on corporate strategy and organizational success. The involvement of managers and decision makers in all aspects of information systems is a major factor for organizational success, including higher profits and lower costs. Some of the benefits business organization seek to achieve through information systems include: better safety, competitive advantage, fewer errors, greater accuracy, higher quality products, improved communications, increased efficiency and productivity, more efficient administration, superior financial and managerial decision making.

  5. A dinâmica virtual da geopolítica continental americana The virtual dinamics of the American continental geopolitics

    Directory of Open Access Journals (Sweden)

    Alberto Rocha Valencia

    2007-05-01

    Full Text Available Neste trabalho examinamos a nova dinâmica continental em formação no continente americano, a partir do momento em que a sua organização se estabelece tendo por base os sistemas regionais e subregionais ou as macro, meso e micro-sistemas supranacionais. In this paper, we analyse the new dinamics in progress in the American continent, from the moment that its organization begins with the regional and sub-regional systems , or , in other words, with its supranational macro, meso and micro system

  6. BLM/OCS Southern California Outer Continental Shelf Environmental Baseline Studies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data in this file were produced by Science Applications, Inc., prime contractor on the Bureau of Land Management/Outer Continental Shelf - Southern California...

  7. Archive of Geosample Data and Information from the U.S. Extended Continental Shelf (ECS) Project.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geological samples collected as part of the U.S. Extended Continental Shelf (ECS) Project are curated by the U.S. Geological Survey, a partner in the ECS Project. To...

  8. Continental scientific drilling program. [Los Alamos, New Mexico, July 17-21, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    The dynamics, structure, evolution, and genesis of the continents offer a major scientific challenge. At the same time, society faces many problems that require information about the continental crust for solution. A workshop on continental drilling for scientific purposes addressed the questions of how to maximize the scientific value of current and planned efforts of federal agencies and industry and how to supplement these efforts with holes drilled solely for scientific purpoes. Four panels addressed the scientific and associated societal problems relating to basement structures and deep continental basins, thermal regimes, mineral resources, and earthuqakes. These panels identified the main problems in each area that could be solved by information obtained from drill holes. A fifth panel considered needs for technological developments. The importance of a communications and coordinating mechanism to maximize the scientific results was noted. To this end, a Continental Scientific Drilling Program is outlined, including two advisory and guiding committees, one concerned with scientific objectives, the other with operations. (RWR)

  9. Biotopes of the Oregon outer continental shelf (OCS) proposed wind farm site

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This biotope raster is part of a data release of the Oregon outer continental shelf (OCS) proposed wind farm map site. The biotopes mapped in this area have been...

  10. Seafloor character of the Oregon outer continental shelf (OCS) proposed wind farm site

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This seafloor-character raster is part of a data release of the Oregon outer continental shelf (OCS) proposed wind farm map site. The substrate classes mapped in...

  11. BLM/OCS South Texas Outer Continental Shelf (STOCS) Project Sediment Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The South Texas Outer Continental Shelf Project (STOCS) conducted by the University of Texas and the USGS with funding from BLM/NOAA. The USGS produced geochemical...

  12. Holocene limestones of part of the western continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, R.R.; Hashimi, N.H.; Guptha, M.V.S.

    Dredging on the western continental shelf of India has shown that the most common rock types outcropping on the irregular topography of the outer shelf (70-90 m) are algal limestones and shelly limestones containing superficial ooids and pelletoids...

  13. Federal Outer Continental Shelf (OCS) Sand and Gravel Borrow Areas (Lease Areas)

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — Federal outer Continental Shelf (OCS) Sand and Gravel Borrow Areas (Lease Areas) are polygons which are maintained by the Bureau of Ocean Energy Management (BOEM),...

  14. Environmental magnetism and application in the continental shelf sediments of India

    Digital Repository Service at National Institute of Oceanography (India)

    Alagarsamy, R.

    Mineral magnetic and geochemical analyses were carried out on surface sediments from the continental shelf of India. The purpose of this study is to examine the environmental assessment of heavy metal concentrations and its impact in the coastal...

  15. Changing depositional environments during the Late Quatrnary along the western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Thamban, M.

    Sedimentalogical and palaeoceanographic studies were carried out on two sediment cores collected within the Oxygen Minimum Zone (OMZ - between 150 to 1200 m water depth) along the western continental margin of India. The glacial to interglacial...

  16. Aeolian deposition of Arabia and Somalia sediments on the southwestern continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.

    Kaolinite, smectite, illite and chlorite as major clay minerals and palygorskite and gibbsite in minor quantities have been recorded from the slope of southwestern continental margin of India. Contribution of kaolinite, smectite and gibbsite is from...

  17. Basement and climate controls on proximal depositional systems in continental settings

    NARCIS (Netherlands)

    Ventra, D.|info:eu-repo/dai/nl/304823708

    2011-01-01

    This doctoral dissertation discusses the sedimentology and dynamics of selected, modern and ancient clastic depositional systems (alluvial fans and colluvial aprons) at continental basin margins. The focus on single depositional systems gave the opportunity to devote particular attention to sediment

  18. 77 FR 24734 - Outer Continental Shelf (OCS) Renewable Energy Program Leasing for Marine Hydrokinetic Technology...

    Science.gov (United States)

    2012-04-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Outer Continental Shelf (OCS) Renewable Energy Program Leasing for Marine Hydrokinetic Technology Testing Offshore Florida AGENCY: Bureau of Ocean Energy Management...

  19. Verdine and glaucony facies from surficial sediments of the eastern continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Thamban, M.; Lamboy, M.

    The present paper reports the first mineralogical description of green grains (verdine and glaucony) from sediments of the eastern continental margin of India. Only 24 of the 82 sediment samples studied, at depths between 18 and 247 m, contain green...

  20. Seismic and sequence stratigraphy of the central western continental margin of India: late-Quaternary evolution

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Veerayya, M.; Vora, K.H.

    Seismic and sequence stratigraphic architecture of the central western continental margin of India (between Coondapur and south of Mangalore) has been investigated with shallow seismic data. Seismic stratigraphic analysis defined nine seismic units...

  1. Morphology and tectonics of Mahanadi Basin, northeastern continental margin of India from geophysical studies

    Digital Repository Service at National Institute of Oceanography (India)

    Subrahmanyam, V.; Subrahmanyam, A.S.; Murty, G.P.S.; Murthy, K.S.R.

    isobath off the Lambert Graben of East Antarctica. This inference appears to further support the theory that the eastern continental margin of India and East Antarctica are closely aligned in the pre-breakup tectonic setting of the eastern Gondwanaland....

  2. Distribution and sources of organic matter in surface sediments of the eastern continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, M.S.; Naidu, S.A.; Subbaiah, Ch.V.; Sarma, V.V.S.S.; Reddy, N.P.C.

    The sources and distribution of organic matter (OM) in surface sediments of the eastern continental margin of India, including the region influenced by river discharge, were investigated using content, molar C:N ratios and stable isotopes of carbon...

  3. 77 FR 30881 - Airworthiness Directives; Continental Motors, Inc. (CMI) Reciprocating Engines

    Science.gov (United States)

    2012-05-24

    ... power and responsibilities among the various levels of government. For the reasons discussed above, I... Continental Motors, Inc. (CMI) TSIO-520-B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, VB; TSIO-550-K;...

  4. Outer Continental Shelf Lease Blocks - Pacific Region - West Coast NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Outer Continental Shelf block outlines in ArcGIS shape file format for the BOEM Pacific Region. OCS blocks are used to define small geographic...

  5. Basement and climate controls on proximal depositional systems in continental settings

    NARCIS (Netherlands)

    Ventra, D.

    2011-01-01

    This doctoral dissertation discusses the sedimentology and dynamics of selected, modern and ancient clastic depositional systems (alluvial fans and colluvial aprons) at continental basin margins. The focus on single depositional systems gave the opportunity to devote particular attention to sediment

  6. Holocene sea level fluctuations on western Indian continental margin: An update

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Nigam, R.; Nair, R.R.; Rajagopalan, G.

    A new Holocene curve is generated for the western Indian continental margin. While constructing this curve careful selection of the dates were made by giving due considerations to the genetic characteristics of the dated material. This new curve...

  7. Outer Continental Shelf 200 Nautical Mile Limit - Gulf of Mexico Region NAD27

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Continental Shelf Boundary (CSB) lines in ESRI shapefile format for the BOEM Gulf of Mexico Region. The CSB defines the seaward limit of...

  8. Quaternary phosphorites from the continental margin off Chennai, southeast India: Analogs of ancient phosphate stromatolites

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Rao, K.M.; Raju, D.S.N.

    the continental supply and degradation of organic matter associated with benthic microbial communities. The phosphate stratiform stromatolites thus formed were subsequently reworked into a shelf-margin depression and resulted in the occurrence of condensed...

  9. Digital Offshore Cadastre (DOC) - Pacific NAD83 – Continental Shelf Boundaries

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Continental Shelf Boundary (CSB) lines in ESRI Arc/Info export and Arc/View shape file formats for the BOEM Pacific Region. The CSB defines...

  10. Regional tectonic trends on the inner continental shelf off Konkan and central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.

    Satellite imagery and offshore magnetic data were analysed to correlate regional tectonic elements on the inner continental shelf off Konkan and the adjacent Deccan plateau. Three statistically important lineament trends N-S, WNW-ESE and ENE...

  11. Geochemistry of zinc in the sediments of the western continental shelf and slope of India

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, P.S.N.; Paropkari, A.L.; Rao, Ch.M.

    The bulk geochemistry of zinc in the sediments of the western continental shelf and slope of India and also the partition geochemistry of the sediments of the shelf and slope regions between Ratnagiri and Mangalore have been studied. The studies...

  12. Basement and climate controls on proximal depositional systems in continental settings

    NARCIS (Netherlands)

    Ventra, D.|info:eu-repo/dai/nl/304823708

    2011-01-01

    This doctoral dissertation discusses the sedimentology and dynamics of selected, modern and ancient clastic depositional systems (alluvial fans and colluvial aprons) at continental basin margins. The focus on single depositional systems gave the opportunity to devote particular attention to

  13. Outer Continental Shelf Oil and Natural Gas Pipelines - Gulf of Mexico Region NAD 27

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This polyline data set contains the locations of oil and gas pipelines in the Gulf of Mexico Outer Continental Shelf federal waters that are associated with the oil...

  14. Grain Size Data from the NOAA Outer Continental Shelf Environmental Assessment Program (OCSEAP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains grain size data from samples acquired under the NOAA Outer Continental Shelf Environmental Assessment Program (OCSEAP) from the Outer...

  15. Mining of phosphorite resources from the Indian continental shelf will help food production

    Digital Repository Service at National Institute of Oceanography (India)

    Qasim, S.Z.; Nair, R.R.

    of phosphorite deposits would depend on several technical and economic factors Phosphorites occur in water depths upto 200 meters of the western continental shelf of India These are the areas associated with upwelling The relationship between phosphorite deposits...

  16. Minimal change of thermal continentality in Slovakia within the period 1961-2013

    Science.gov (United States)

    Vilček, Jozef; Škvarenina, Jaroslav; Vido, Jaroslav; Nalevanková, Paulína; Kandrík, Radoslav; Škvareninová, Jana

    2016-08-01

    Thermal continentality plays an important role not only in the basic characterisation of the climate in particular regions but also in the phytogeographic distribution of plants and ecosystem formation. Due to ongoing climate change, questions surrounding the changes of thermal continentality are very relevant. Therefore, the aim of this study is to investigate the characteristics of thermal continentality and its temporal changes in the Slovak Republic between the years of 1961 and 2013. The study was carried out on several meteorological stations selected in respect to the geographical and geomorphological heterogeneity of Slovakia. Our results show that the continentality of Slovakia increased in the period 1961 to 2013; however, this trend is not significant. These non-significant trends are confirmed at all the stations. Nevertheless, it is necessary to be aware of this signal, especially because these changes could cause changes in ecosystem formation in future.

  17. 76 FR 28449 - Notice on Outer Continental Shelf Oil and Gas Lease Sales

    Science.gov (United States)

    2011-05-17

    ... Oil and Gas Lease Sales AGENCY: Bureau of Ocean Energy Management, Regulation and Enforcement... with any entity in any other of the following groups at Outer Continental Shelf oil and gas lease...

  18. 76 FR 4129 - Notice on Outer Continental Shelf Oil and Gas Lease Sales

    Science.gov (United States)

    2011-01-24

    ... Gas Lease Sales AGENCY: Bureau of Ocean Energy Management, Regulation and Enforcement, Interior... any entity in any other of the following groups at Outer Continental Shelf oil and gas lease sales...

  19. 75 FR 52546 - Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf (OCS...

    Science.gov (United States)

    2010-08-26

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf (OCS) Scientific Committee (SC); Announcement of Plenary Session AGENCY: Bureau of Ocean Energy Management, Regulation and... Ocean Energy Management, Regulation and Enforcement, 381 Elden Street, Mail Stop 4043, Herndon,...

  20. 78 FR 57467 - Importation of Mangoes From Australia Into the Continental United States

    Science.gov (United States)

    2013-09-19

    ... Mango, Mangifera indica L., from Australia into the Continental United States: A Pathway-initiated Risk... to read as follows: Sec. 319.56-60 Mangoes from Australia. Mangoes (Mangifera indica) may be...