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Sample records for khan basin offshore

  1. Offshore Essaouira basin: Geology and hydrocarbon potential

    SciTech Connect

    Jabour, H.; Ait Salem, A. )

    1991-03-01

    The study area lies in the offshore extension of the onshore Essaouria basin. The Mesozoic development of the Essaouira margin was largely controlled by Late Triassic to Mid-Jurassic rifting and subsequent opening of the Central Atlantic, with the evolution of a typical passive, opening of the Central Atlantic, with the evolution of a typical passive, continental margin. Diapiric salt structure recognized on seismic defines a Late Triassic-Early Jurassic salt basin in the offshore area initiated during early rifting. Subsidence and sea-level rise during Jurassic resulted in carbonate platform development. This was followed during Cretaceous and Tertiary time by the deposition of a prograding siliciclastic system. Only three wells have been drilled in this basin. Although drilled on poorly defined prospects, these wells encountered gas and oil shows. Fairly extensive seismic coverage of good quality data is now available. A study based on an integrated approach involving seismic facies definition and mapping, correlation with well data, identification of the principal control on sedimentation, and basin modeling in conjunction with source rock prediction and maturity modeling has been carried out. Results have shown that hydrocarbon potential in the offshore Essaouira basin has not yet been substantiated by drilling. Attractive structural and stratigraphic prospects exist in the shelf, shelf edge, and the slope, and await confirmation by drilling.

  2. Gladden Pull-Apart Basin, offshore Belize

    SciTech Connect

    Morrice, S. )

    1993-02-01

    The junction of the American and Caribbean plates in Belize has created a complex structural setting for oil and gas exploration. Recent seismic offshore Belize has been used to identify three structural provinces, from west to east: a shallow thrust zone, a narrow upthrown wrench faulted zone and a deeper extensional basin, named the Gladden Pull-Apart Basin. Hydrocarbon leakage from recent fault movement appears to have depleted the shallow structures to the west, but the pull-apart basin has a thick sequence of low-frequency clay-dominated sealing rocks with the potential to preserve hydrocarbon accumulations in Cretaceous carbonate banks. These buried carbonate are of the same age and depositional environment of Mexico's Golden Lane/Tabasco Reforma carbonate banks which are world class giant fields. The Belize and Mexican carbonate banks are within the same Cretaceous depositional basin, the Peten Basin. Seismic interpretations in offshore Belize have been integrated with gravity and magnetic surveys. This provides additional support for the deep extensional basin. The location of the thick Cretaceous carbonate banks is better interpreted with the integration of these three geophysical tools. Airborne geochemical surveys were used to detect the presence of oil seeps on the east and west basin margins.

  3. Basin development and petroleum potential of offshore Otway basin, Australia

    SciTech Connect

    Williamson, P.E.; O'Brien, G.W.; Swift, M.G.; Scherl, A.S.; Marlow, M.S.; Exon, N.F.; Falvey, D.A.; Lock, J.; Lockwood, K.

    1987-05-01

    The Bass Strait region in southeastern Australia contains three sedimentary basins, which are, from east to west, the Gippsland, Bass, and Otway basins. The offshore Gippsland basin is Australia's most prolific petroleum-producing province and supplies over 90% of the country's production. In contrast, exploration has been unsuccessful in the offshore portion of the Otway basin; 17 wells have been drilled, and although shows of oil and gas have been common, no commercial discoveries have been made. Many of these wells, drilled in the 1960s and 1970s, were sited using poor-quality seismic data and, as a consequence, were frequently off structure. Seismic data quality has, however, improved significantly in recent years. The present study by the Australian Bureau of Mineral Resources (BMR) involved the collection, in the offshore Otway basin, of 3700 km of high-quality, 48-channel seismic reflection data by the BMR research vessel R/V Rig Seismic. These data have been integrated with existing industry seismic data, well data, limited dredged material, and geohistory analyses in a framework study of basin development and hydrocarbon potential in this under-explored area. The offshore Otway basin extends 500 km along the southern coastline and is typically 50 km wide in water depths of less than 200 m. It contains up to 10 km of predominantly late Mesozoic to early Cenozoic sediments, which are overlain by a thin sequence of middle to late Tertiary shelf carbonates. It has been divided into three main structural elements: the Mussel Platform in the east, the central Voluta Trough, and the Crayfish Platform in the west. The basin was initiated at the end of the Jurassic as part of the Bassian rift. Up to 6 km of Lower Cretaceous sediments were deposited prior to breakup at the end of the Early Cretaceous and the onset of sea-floor spreading between Australia and Antarctica.

  4. Geology of the Douala basin, offshore Cameroon, West Africa

    SciTech Connect

    Pauken, R.J.; Thompson, J.M.; Schumann, J.R. ); Cooke, J.C. )

    1991-03-01

    The Douala basin is predominantly an offshore basin extending from the Cameroon volcanic line in the north to the Corisco arch in the south near the Equatorial Guinea-Gabon border. The basin lies wholly within the territorial borders of Cameroon and Equatorial Guinea. The Douala basin is one of a series of divergent margin basins occurring along the southwest African coastline resulting from the rifting of Africa from South America. Continental rifting in the Doula basin was initiated at least by Aptian-Albian time and possibly as early as Jurassic. The rift stage persisted until Albian time when the onset of drifting occurred. The sedimentary section in the basin has a maximum thickness of 8-10 km, based on exploration drilling and gravity and magnetics modeling. The synrift section consists of Aptian-Albian sands and shales, deposited primarily as submarine fans, fan-deltas, and turbidite deposits. These are overlain by salt, thought to be equivalent to the Ezagna salt of Aptian age in the Gabon basin to the south. The synrift section is separated from the overlying postrift shale sequence of Late Cretaceous and Tertiary age by a major late Albian unconformity. The Douala basin has been explored for hydrocarbons intermittently over the last 25 years. Results show a distinct tendency for gas-proneness. The largest field recorded to date is the Sanaga Sud gas field, discovered in 1979, offshore, near the coastal city of Kribi.

  5. Onshore-offshore coastal lithofacies of Polis basin, NW Cyprus

    SciTech Connect

    Ward, L.C. )

    1988-08-01

    The Polis basin, northwest Cyprus, is located between the Akamas Peninsula and the main Troodos ophiolite massif. The basin contains sediments of Miocene-Holocene age and allows detailed study of a range of onshore-offshore coastal lithofacies which represent potential reservoirs. Coastal sediments of Messinian age characterized by algal mats and fluvial channel fill are found in the basin. Following very late Miocene rifting and Pliocene transgression, steep, narrow, faulted coastlines were produced, and several coastal facies were generated. These include coastal alluvial fans, offshore reefs, and tectonically generated cliff deposits as olistolith blocks. The steep, faulted coastline generated fan-delta deposits in early Pliocene time, superseded during late Pliocene regression by carbonate fan deltas. Offshore coastal lithofacies include storm-generated deposits, consisting of rip-up clasts and hummocky cross-stratification in sand-silt sequences, and mass-flow and channelized conglomerates and debris flows in this tectonically active basin. Shoreline sands are dominated by long-shore drift which generated longitudinal sandbars and offshore gravel bars. Pleistocene-age deposits show several suites of coastal deposits, formed in response to oscillations in Pleistocene sea level. These include beach deposits demonstrating beach-crest and planar bimodal back-beach deposits, together with coastal lagoons transected by cross-bedded fluvial conglomerate deposits. In addition, lowstands produced large channelized braided fluvial deposits which formed part of a broad coastal plain. Certain Pleistocene channels are deformed by continuing synsedimentary tectonic activity.

  6. Evolution of the central Walvis Basin / offshore NW Namibia - balancing onshore erosion and offshore sedimentation

    NASA Astrophysics Data System (ADS)

    Henk, A.; Kukulus, M.; Junker, R.

    2003-04-01

    Rifting and break-up of Gondwana in the Late Jurassic / Early Cretaceous led to formation of the South Atlantic. One of the associated passive margins, the Walvis Basin in NW Namibia, is used as a case study to investigate the mass and process balances which link uplift and erosion onshore to contemporaneous subsidence and sedimentation offshore. One of the main objectives of the project is to gain quantitative insights into the feedback mechanisms between surface processes and lithospheric processes during passive margin evolution. Modeling concentrates on a traverse across the central Walvis Basin and adjacent onshore areas. Mass balancing requires a reconstruction of the denudation history and the volumes eroded onshore as well as a quantification of the contemporaneous sedimentary record preserved offshore. In the offshore parts of the study area, seismic sections and well data are available to constrain the post-rift evolution of the Walvis basin. However, as none of the exploration wells has yet reached syn-rift deposits, the early margin evolution has to remain speculative. In the onshore part of the traverse, field evidence and published apatite fission track data are used to reconstruct the erosion history. Comparison of the eroded and deposited volumes and masses, respectively, reveals a misfit of about 50 %, i.e. only half of the sediments observed offshore can be attributed to nearby source areas onshore. This result is supported by provenance analysis on cuttings from an offshore well which indicate that a substantial part of the detritus was derived from sources to the south and transported to the central Walvis Basin by coast-parallel currents. Sediment supply rates derived from reconstruction of the onshore erosion history and subsidence rates based on lithospheric cooling models together with global sea level changes are then used to model quantitatively deposition and stratigraphic architectures of the post-rift succession in the central Walvis

  7. Operators renewing exploration in offshore basins of France

    SciTech Connect

    Lamiraux, C.; Mascle, A.

    1995-07-03

    Forty nine wells were drilled without success from the latter 1960s to the first half of the 1980s in French offshore areas. About 10 years of reduced activity followed this first phase of exploration. For a couple of years, these areas have been closely reassessed, taking into account the experience and data previously acquired. More particularly, a better understanding of tectonic processes at the origin of complex structural traps, a better taking into account of the distribution, quality, and maturation history of source rocks, together with significant improvements in seismic data acquisition-processing and basin modeling techniques, have led a few oil companies to apply for licenses in three offshore areas. The paper discusses prospects in the Bay of Biscay, the Iroise Sea and English Channel, and the Gulf of Lions.

  8. Southern Mozambique basin: most promising hydrocarbon province offshore eat Africa

    SciTech Connect

    De Buyl, M.; Flores, G.

    1984-09-01

    Recent offshore acquisition of 12,800 km (8,000 mi) of seismic reflection data, with gravity and magnetic profiles encompassing the southern half of the Mozambique basin, reveals new facets of the subsurface geology. Integrated interpretation of these new geophysical data with old well information results in the development of depositional and tectonic models that positively establish the hydrocarbon potential of the basin. The recent comprehensive interpretation affords the following conclusions. (1) Significant oil shows accompany wet gas discoveries suggest that the South Mozambique basin is a mature province, as the hydrocarbon associations imply thermogenic processes. (2) Super-Karoo marine Jurassic sequences have been encountered in Nhamura-1 well onshore from the application of seismic stratigraphy and well correlation. (3) Steeply dipping reflectors truncated by the pre-Cretaceous unconformity testify to significant tectonic activity preceding the breakup of Gondwanaland. Hence, preconceived ideas about the depth of the economic basement and the absence of mature source rocks of pre-Cretaceous age should be revised. (4) Wildcats in the vicinity of ample structural closures have not been, in retrospect, optimally positioned nor drilled to sufficient depth to test the viability of prospects mapped along a major offshore extension of the East African rift system delineated by this new survey.

  9. Neogene sequence stratigraphy, Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    McMillen, K.J. ); Do Van Luu; Lee, E.K.; Hong, S.S. )

    1996-01-01

    An integrated well log, biostratigraphic, and seismic stratigraphic study of Miocene to Recent deltaic sediments deposited in the Nam Con Son Basin offshore from southern Vietnam shows the influence of eustacy and tectonics on sequence development. Sediments consist of Oligocene non-marine rift-basin fill (Cau Formation), early to middle Miocene tide-dominated delta plain to delta front sediments (TB 1.5 to TB 2.5, Due and Thong Formations), and late Miocene to Recent marine shelf sediments (TB. 2.6 to TB 3.1 0, Mang Cau, Nam Con Son, and Bien Dong Formations). Eustacy controlled the timing of key surfaces and sand distribution in the tectonically-quiet early Miocene. Tectonic effects on middle to late Miocene sequence development consist of thick transgressive systems tracts due to basin-wide subsidence and transgression, sand distribution in the basin center, and carbonate sedimentation on isolated fault blocks within the basin. Third-order sequence boundaries (SB) are identified by spore peaks, sand stacking patterns, and channel incision. In the basin center, widespread shale beds with coal occur above sequence boundaries followed by transgressive sandstone units. These TST sandstones merge toward the basin margin where they lie on older HST sandstones. Maximum flooding surfaces (MFS) have abundant marine microfossils and mangrove pollen, a change in sand stacking pattern, and often a strong seismic reflection with downlap. Fourth-order genetic-type sequences are also interpreted. The MFS is the easiest marker to identify and correlate on well logs. Fourth-order SB occur within these genetic units but are harder to identify and correlate.

  10. Neogene sequence stratigraphy, Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    McMillen, K.J.; Do Van Luu; Lee, E.K.; Hong, S.S.

    1996-12-31

    An integrated well log, biostratigraphic, and seismic stratigraphic study of Miocene to Recent deltaic sediments deposited in the Nam Con Son Basin offshore from southern Vietnam shows the influence of eustacy and tectonics on sequence development. Sediments consist of Oligocene non-marine rift-basin fill (Cau Formation), early to middle Miocene tide-dominated delta plain to delta front sediments (TB 1.5 to TB 2.5, Due and Thong Formations), and late Miocene to Recent marine shelf sediments (TB. 2.6 to TB 3.1 0, Mang Cau, Nam Con Son, and Bien Dong Formations). Eustacy controlled the timing of key surfaces and sand distribution in the tectonically-quiet early Miocene. Tectonic effects on middle to late Miocene sequence development consist of thick transgressive systems tracts due to basin-wide subsidence and transgression, sand distribution in the basin center, and carbonate sedimentation on isolated fault blocks within the basin. Third-order sequence boundaries (SB) are identified by spore peaks, sand stacking patterns, and channel incision. In the basin center, widespread shale beds with coal occur above sequence boundaries followed by transgressive sandstone units. These TST sandstones merge toward the basin margin where they lie on older HST sandstones. Maximum flooding surfaces (MFS) have abundant marine microfossils and mangrove pollen, a change in sand stacking pattern, and often a strong seismic reflection with downlap. Fourth-order genetic-type sequences are also interpreted. The MFS is the easiest marker to identify and correlate on well logs. Fourth-order SB occur within these genetic units but are harder to identify and correlate.

  11. The 1911 Quadrant offshore Namibia; Exploration in a virgin basin

    SciTech Connect

    Holtar, E.; Forsberg, A.

    1995-08-01

    As a result of the first licensing round in independent Namibia, the Namibian authorities in 1992 awarded five offshore licenses to five different companies or groups of companies. License no. 001 was awarded in 1992 to a group consisting of three Norwegian oil companies, Norsk Hydro, Saga Petroleum and Statoil, with Hydro as the operator. Somewhat later Bow Valley Energy (now Talisman Energy) farmed in. Since 1992 a seismic survey of 7200 km has been acquired over the license area that covers 11.619 sq. Km of the Walvis Basin. This basin was undrilled until the 1911/15-1 well was finished at a depth of 4586mRKB in early 1994. The sedimentary succession of the 1911/15-1 well reflects a depositional history that postdates the Neocorman Etendeka plateau basalts found onshore Namibia. After the onset of the drift phase in late Hauterivian times, the Walvis Basin subsided and eventually a marine transgression took place. Shallow marine platform sedimentation then prevailed until an Albian tectonic event resulted in complex block faulting and the formation of several sub basins. Subsequent volcanic activity created a series of volcanic centres localized on the Walvis Ridge bathymetric feature. In early Late Cretaceous the Southern African craton was uplifted relative to the shelf, leading to the formation of large scale westward prograding wedges. Later sedimentation largely followed the evolution of a passive continental margin, responding to relative sealevel changes and paleoclimate. A stratigraphic breakdown of the Northern Namibian offshore is proposed, and compared to South African and Angolan nomenclature.

  12. Ambient Noise Tomography of the Huatung Basin Offshore Eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Liu, Ruo-Shan; Huang, Tzu-Ying; Chen, Ying-Nien; Chen, Chin-Wu

    2016-04-01

    The island of Taiwan is a young and active orogenic belt resulting from the oblique subduction and collision between the Eurasian Plate and the Philippine Sea Plate, where the Philippine Sea Plate is converging northwesterly toward the Eurasian Plate at a rate of 81 mm/year. In Southern Taiwan, the Eurasian Plate is subducting eastward beneath the Philippine Sea Plate along the Manila Trench. Offshore northeastern Taiwan, on the other hand, the Philippine Sea Plate is subducting northward beneath the Eurasian Plate along the Ryukyu Trench. Between the Ryukyu Trench and Luzon Arc lies the Huatung Basin, a 4000 m deep ocean basin in the westernmost part of the western Philippine Sea Basin. The intertwined tectonic processes result in complex geological structures of Taiwan, from surface to the crust and uppermost mantle. Previous seismic tomographic studies have suggested the effects of collision and subduction on the tectonic structures beneath Taiwan, but the details remain elusive, especially in the crustal depth range, due to limited station coverage and earthquake sources. Recently, ambient noise analysis fills the gap by offering high resolution tomographic model at crustal depths, derived from frequency-dependent Rayleigh wave measurements using noise cross-correlations. A most recent ambient noise tomography of Taiwan has revealed the presence of distinct layered deformation pattern throughout the crust, indicating integrated effect of collision and subduction on the evolution of Taiwan orogeny. However, this study used only land station and thus did not resolve structure in the surrounding region of the island. In our work, we aim to expand such analysis to offshore eastern Taiwan, taking advantage of the data from an OBS network as part of the recent TAIGER experiment. We integrate the data of OBS with that of selected land stations along the east coast, deriving Rayleigh wave Green functions from cross-correlation between all available station pairs. We

  13. Contrasting basin architecture and rifting style of the Vøring Basin, offshore mid-Norway and the Faroe-Shetland Basin, offshore United Kingdom

    NASA Astrophysics Data System (ADS)

    Schöpfer, Kateřina; Hinsch, Ralph

    2017-04-01

    The Vøring and the Faroe-Shetland basins are offshore deep sedimentary basins which are situated on the outer continental margin of the northeast Atlantic Ocean. Both basins are underlain by thinned continental crust whose structure is still debated. In particular the nature of the lower continental crust and the origin of high velocity bodies located at the base of the lower crust are a subject of discussion in recent literature. Regional interpretation of 2D and 3D seismic reflection data, combined with well data, suggest that both basins share several common features: (i) Pre-Cretaceous faults that are distributed across the entire basin width. (ii) Geometries of pre-Jurassic strata reflecting at least two extensional phases. (iii) Three common rift phases, Late Jurassic, Campanian-Maastrichtian and Palaeocene. (iv) Large pre-Cretaceous fault blocks that are buried by several kilometres of Cretaceous and Cenozoic strata. (iii). (v) Latest Cretaceous/Palaeocene inversion. (vi) Occurrence of partial mantle serpentinization during Early Cretaceous times, as proposed by other studies, seems improbable. The detailed analysis of the data, however, revealed significant differences between the two basins: (i) The Faroe-Shetland Basin was a fault-controlled basin during the Late Jurassic but also the Late Cretaceous extensional phase. In contrast, the Vøring Basin is dominated by the late Jurassic rifting and subsequent thermal subsidence. It exhibits only minor Late Cretaceous faults that are localised above intra-basinal and marginal highs. In addition, the Cretaceous strata in the Vøring Basin are folded. (ii) In the Vøring Basin, the locus of Late Cretaceous rifting shifted westwards, affecting mainly the western basin margin, whereas in the Faroe-Shetland Basin Late Cretaceous rifting was localised in the same area as the Late Jurassic phase, hence masking the original Jurassic geometries. (iii) Devono-Carboniferous and Aptian/Albian to Cenomanian rift phases

  14. Significance of the basin wide reverse polarity reflector in the Offshore Sydney Basin, East Australian Margin

    NASA Astrophysics Data System (ADS)

    Rahman Talukder, Asrarur; Nadri, Dariush; Rajput, Sanjeev; Clennell, Ben; Griffiths, Cedric; Breeze, David

    2010-05-01

    The Offshore Sydney Basin is located between latitudes 32°30'S and 34°30'S between the coastal cities of Newcastle in the north and Wollongong in the south, covering a total area of ~15,000 squire km. The structural framework of the offshore portion of the basin comprises five principal elements: the Offshore Syncline, an extension of the New England Fold Belt, an offshore extension of the Newcastle Syncline, the Offshore Uplift and the Outer Continental Shelf. The present easterly extent of the basin is the result of Cretaceous rifting and commencement of seafloor spreading in the adjacent Tasman Sea. The continental shelf is approximately 50 km wide offshore Sydney and is edged by relatively steep continental slope. This study has been carried out with 2D multichannel seismic data covering the northern half of the offshore basin. The Cenozoic sedimentary cover of the basin is characterized by two regional unconformities: one at the base of Cenozoic and another intra-Cenozoic. The unconformity at the base of Cenozoic is known as the Top Sydney Basin unconformity. In places the surface is displaced by faults and also characterized by possible mounds producing an overall highly irregular topography. Though most of the faults remained buried beneath the surface some continued up to seafloor. They seem to have NW-SE direction with significant lateral extension. The intra-Cenozoic unconformity forms a prominent reflector at about 80 to 200 msbs (TWT). It is characterized by an angular unconformity with the reflectors terminating onto it from beneath. It is also associated with prograding sequences beneath, terminating with toplap geometry, suggesting that it forms the boundary between a transgressive and regressive phase. This is interpreted as a prograding carbonate dominated shelf-edge. The most interesting aspect of this seismic reflector is that the major part of it presents reverse polarity with respect to the seafloor reflection. The amplitude of the reflector

  15. Gravity-driven structures and rift basin evolution: Rio Muni Basin, offshore equatorial West Africa

    SciTech Connect

    Turner, J.P.

    1995-08-01

    Offshore Equatorial Guinea, west Africa, gravity-driven nappes, more than 1 km thick and 15 km from head to toe, provide key evidence in reconstructing the late synrift: evolution of this part of the South Atlantic margin basin system. Furthermore, Aptian-Cenomanian carbonate and clastic rocks in the nappes` allochthonous hanging walls are attracting interest as a new exploration play in west Africa. The nappes exhibit a range of geometries that suggest they share many of the same deformation processes as thin-skin thrust and linked extensional fault systems. Not only are these structures significant in their own right, representing a rare example of gravity tectonics in the virtual absence of major halokinesis, but their presence may record an other-wise undetectable process active during the transition from a rift basin to a passive continental margin. A review of Equatorial Guinea in its pre-Atlantic configuration, alongside neighboring basins in Brazil (the Sergipe-Alagoas basin) and Gabon, suggests that gravity gliding was sustained by a relatively steep, westward paleoslope promoted by east-ward offset of the locus of thermal uplift from the rift basin (i.e., a simple shear model of basin formation). In contrast to gravity-driven structures in most postrift settings, the Equatorial Guinea nappes developed at the close of the Aptian-Albian synrift episode in response to a growing bathymetric deep caused by rapid subsidence outpacing restricted sedimentation.

  16. Geological history of the Flemish Pass Basin, offshore Newfoundland

    SciTech Connect

    Foster, D.G.; Robinson, A.G. )

    1993-04-01

    In this paper the authors present a seismic-stratigraphic interpretation of the Mesozoic and Tertiary geologic history of the Flemish Pass Basin, offshore Newfoundland, based on seismic data and data from seven wells that were integrated on the BP subsurface integrated interpretation system (SIIS). Four megasequences are identified. Megasequence 1 (MSI) is Triassic to lower Berriasian, and includes poorly known sediments associated with Triassic-Early Jurrasic rifting prior to spreading between the North African and American continents. The uppermost mappable unconformity-bounded unit within MSI contains major Kimmeridgian to Portlandian marine source rocks deposited in two east-west-trending subbasins in the Baccalieu and Gabriel areas. During the early Berrasian, pronounced rifting linked to the subsequent spreading of Iberia from the Grand Banks (Barremian-Aptian) led to regional deepening and deposition of clastic sediments (MS2) in two northeast-southwest-trending, fault-bounded subbasins in the Baccalieu and Gabriel areas. In the Aptian, Early Cretaceous subbasins were inverted due to strike-slip movement as extension assumed a northeast-southwest orientation prior to movement of Greenland/Europe away from Labrador (Albian). MS3 sediments fill northwest-southeast trending fault-bounded depocenters typically located on areas that had formed highs during Early Cretaceous. Postrift sedimentation continued from the Albian( ) to the present with Upper Cretaceous pelagic limestone and later clastic sediment deposition. 37 refs., 19 figs., 1 tab.

  17. Development of the Mozambique and Ruvuma sedimentary basins, offshore Mozambique

    NASA Astrophysics Data System (ADS)

    Salman, G.; Abdula, I.

    1995-04-01

    Two major sedimentary basins have been identified on the continental margin of Mozambique—Mozambique Basin and Ruvuma Basin. The formation of the basins is related to the break-up of Gondwana and opening of the western part of the Indian Ocean. The basins are relatively young, having developed discordantly to the structural plan of Gondwana sedimentary basins. The history of the formation of the East African continental margin sedimentary basins within Mozambique has been studied on the basis of the present-day concept of Gondwana break-up and Madagascar's drift with respect to Africa. Two stages in the history of the East African basins can be recognized: late-Gondwana and post-Gondwana. The late-Gondwana stage (303-157 Ma) is typified by sedimentary and volcanogenic rocks of the Karoo Group. The post-Gondwana stage (157-0 Ma) corresponds to the period of active Gondwana break-up and the formation of Indian Ocean marginal basins. The Mozambique Basin occupies both central and southern parts of the coastal plain of Mozambique, extending onto the continental shelf and slope. The sedimentary fill is composed of Upper Jurassic, Cretaceous and Cenozoic rocks which discordantly overly the Karoo basalts. The Upper Jurassic occurs as continental red-beds, mostly distributed within buried grabens. Cretaceous rocks occur as terrigenous sediments of continental and marine genesis. Cenozoic deposits are of predominantly marine and deltaic origin. The Ruvuma Basin, situated in the north of Mozambique, is part of an extended East African marginal basin which includes parts of the coastal plains and continental margins of Tanzania and Kenya. The basement of the basin is composed of crystalline and metamorphic rocks of pre-Cambrian age. The sedimentary fill is represented by continental terrigenous Karoo sediments, marine and lagoonal Jurassic deposits, and marine and deltaic rocks of Cretaceous and Cenozoic age. The main difference between the sedimentary fill of the

  18. Geology, prospects in Orange basin offshore western South Africa

    SciTech Connect

    Muntingh, A. Ltd., Parow )

    1993-01-25

    With the fast changing political situation in South Africa it has become possible for Soekor (Pty.) Ltd. To invite international companies to participate in oil and gas exploration in the South African part of the Orange basin. This paper reports on the Orange basin, which comprises a 130,000 sq km area off western South Africa that extends northwards into Namibia, represents a large frontier basin with known hydrocarbon accumulations and the potential for giant fields. Comprehensive seismic coverage and a recent deep-water seismic survey in the Orange basin indicate exciting opportunities in the form of shallow and deep-water plays.

  19. Structural and stratigraphic evolution of the East Georges Bank Basin, offshore Nova Scotia, Canada

    SciTech Connect

    Carswell, A.B. ); Koning, T. ); Hibbs, D.C. )

    1990-05-01

    The East Georges Bank Basin is located offshore Nova Scotia on the southeastern Canadian continental shelf. The basin covers 2.5 million ac and is one of the last undrilled basins in North America. The geological interpretation is almost entirely based on 16,000 km of seismic data over the basin. Pertinent well control is limited to 10 wells on the US portion of the Georges Bank (West Georges Bank Basin) and two wells on the Scotian shelf. Seismic-stratigraphic analysis of this data has led to a structural and stratigraphic model for the basin. The basin formed during the Triassic when the landmass of Pange began separating along rift zones. A prominent Paleozoic basement high, the Yarmouth Arch separated the East Georges Bank Basin from the West Georges Bank Basin and had a dominant influence on sedimentation until the Middle Jurassic. Early synrift sequences consist of lacustrine clastics and shales. Marine incursions began in the late Triassic resulting in massive salt deposits that reflect the restricted extent of the basin and the arid Triassic and Early Jurassic climate. Further continental separation during the Early Jurassic resulted in deposition of carbonates and evaporites followed by Middle Jurassic continental shelf carbonates and deltaic sands. During the Middle Jurassic, major growth faulting and halokinesis was initiated by progradation of the deltaic sands. Post Middle Jurassic continental spreading in combination with changing climatic conditions resulted in a steady decline of carbonate sedimentation and dominance of clastic deposition throughout the remaining history of the basin.

  20. Geologic evolution and sequence stratigraphy of the offshore Pelotas Basin, southeast Brazil

    SciTech Connect

    Abreu, V.S.

    1996-12-31

    The Brazilian marginal basins have been studied since the beginning of the 70s. At least nine large basins are distributed along the entire Eastern continental margin. The sedimentary infill of these basins consists of lower Cretaceous (continental/lacustrine) rift section underlying marine upper Cretaceous (carbonate platforms) and marine upper Cretaceous/Tertiary sections, corresponding to the drift phase. The sedimentary deposits are a direct result of the Jurassic to lower Cretaceous break-up of the Pangea. This study will focus on the geologic evolution and sequence stratigraphic analysis of the Pelotas basin (offshore), located in the Southeast portion of the Brazilian continental margin between 28{degrees} and 34{degrees} S, covering approximately 50,000 Km{sup 2}. During the early Cretaceous, when the break-up of the continent began in the south, thick basaltic layers were deposited in the Pelotas basin. These basalts form a thick and broad wedge of dipping seaward reflections interpreted as a transitional crust. During Albian to Turonian times, due to thermal subsidence, an extensive clastic/carbonate platform was developed, in an early drift stage. The sedimentation from the upper Cretaceous to Tertiary was characterized by a predominance of siliciclastics in the southeast margin, marking an accentuate deepening of the basin, showing several cycles related to eustatic fluctuations. Studies have addressed the problems of hydrocarbon exploration in deep water setting within a sequence stratigraphic framework. Thus Pelotas basin can provide a useful analogue for exploration efforts worldwide in offshore passive margins.

  1. Geologic evolution and sequence stratigraphy of the offshore Pelotas Basin, southeast Brazil

    SciTech Connect

    Abreu, V.S. )

    1996-01-01

    The Brazilian marginal basins have been studied since the beginning of the 70s. At least nine large basins are distributed along the entire Eastern continental margin. The sedimentary infill of these basins consists of lower Cretaceous (continental/lacustrine) rift section underlying marine upper Cretaceous (carbonate platforms) and marine upper Cretaceous/Tertiary sections, corresponding to the drift phase. The sedimentary deposits are a direct result of the Jurassic to lower Cretaceous break-up of the Pangea. This study will focus on the geologic evolution and sequence stratigraphic analysis of the Pelotas basin (offshore), located in the Southeast portion of the Brazilian continental margin between 28[degrees] and 34[degrees] S, covering approximately 50,000 Km[sup 2]. During the early Cretaceous, when the break-up of the continent began in the south, thick basaltic layers were deposited in the Pelotas basin. These basalts form a thick and broad wedge of dipping seaward reflections interpreted as a transitional crust. During Albian to Turonian times, due to thermal subsidence, an extensive clastic/carbonate platform was developed, in an early drift stage. The sedimentation from the upper Cretaceous to Tertiary was characterized by a predominance of siliciclastics in the southeast margin, marking an accentuate deepening of the basin, showing several cycles related to eustatic fluctuations. Studies have addressed the problems of hydrocarbon exploration in deep water setting within a sequence stratigraphic framework. Thus Pelotas basin can provide a useful analogue for exploration efforts worldwide in offshore passive margins.

  2. Geology and hydrocarbon accumulations, Columbus Basin, Offshore Trinidad

    SciTech Connect

    Leonard, R.

    1983-07-01

    The Columbus basin, situated on the eastern shelf of Trinidad, lies at the eastern extremity of a belt of severe deformation along the northern boundary of South America that has been affected by compressional and wrench tectonics in Pliocene-Pleistocene time. Two major structural trends are present in the Columbus basin: a series of east-northeast trending anticlines and northnorthwest oriented normal faults. The basin was filled during late Miocene to Holocene time with sediments deposited by an ancestral Orinoco River draining a hinterland to the southwest. The Pliocene-Pleistocene section, which contains the hydrocarbon accumulations in the Columbus basin, was deposited in three coarseningupward sedimentary sequences followed by a late Pleistocene transgressive sequence. Traps for hydrocarbon accumulation were formed by an easterly trending Pliocene-Pleistocene wrench system with associated east-northeast-oriented anticlines combined with north-northwest-oriented normal faults. Oil was sourced in the late Miocene lower Cruse Formation, whereas gas was derived both from Pliocene-Pleistocene pro-delta shales and as a late high-temperature phase of lower Cruse hydrocarbon generation. The northnorthwest faults formed migration conduits from the oil source rock to Pliocene-Pleistocene reservoirs. The temporal relationship of faulting to oil generation is a major factor affecting the distribution of oil and gas. The size of hydrocarbon accumulations is limited to some extent by a lack of an effective hydrocarbon seal, particularly in the western half of the basin.

  3. Sedimentary fill and stratigraphic traps of Porcupine basin, offshore Ireland

    SciTech Connect

    Macurda, D.B. Jr.

    1986-05-01

    The Porcupine basin, off the southwest coast of Ireland, is a triangular north-south re-entrant into the present-day continental shelf. This aulacogen was formed in the Jurassic during the opening of the North Atlantic. A seismic stratigraphic investigation of the southern part of the basin has shown the complex evolution of the sedimentary fill from shallow to deep water facies, resulting in several stratigraphic traps. The central axis of the basin is dominated by a volcanic ridge. Part of the early sedimentary fill was intermittently covered by volcanic flows. The final stage of thin initial siliciclastic infill was the development of an extensive alluvial fan or fan-delta complex along the eastern basin margin. Aerially extensive carbonate sedimentation occurred during the Cretaceous, including a north-south reef tract more than 20 km wide in the eastern part of the basin. Increased subsidence resulted in the deposition of deep water siliciclastics in the Tertiary. The most prominent of these is a series of lower Tertiary submarine fans that were sourced from the western, northern, and eastern margins of the aulacogen. The early portions of the fans correlate well basin-wide; their later history is much more complex, with younger lobes up to 25 km wide developing south of their precursors. Subsequent onlap fill deposits provide an excellent seal. Sedimentation in the late Tertiary has included both high-energy and low-energy deep water deposits. The complex fill of the aulacogen has set up several stratigraphic plays, including carbonate reefs, alluvial fans of fan deltas, and submarine fans. Seismic amplitude anomalies in the latter suggest the heat flow has been sufficient to generate hydrocarbons to fill some of the traps.

  4. Structure, stratigraphy and petroleum geology of the south east Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    Fraser, A.J.; Matthews, S.J.; Lowe, S.; Todd, S.P.; Simon, P. Peel, F.J. )

    1996-01-01

    Recent exploration of the south east Nam Con Son Basin, offshore Vietnam, by BP in alliance with Statoil has involved acquisition of new seismic and well data. These new data have allowed re-evaluation of the tectono-stratigraphic development and petroleum geology, and have provided additional constraints on the regional tectonic evolution. The offshore Vietnamese basins have evolved in response to the complex relative motions of Indochina, Peninsular Malaysia, Borneo and the South China Sea during the Cenozoic. On the regional scale these motions have been accommodated by strike-slip fault development, rifting and contraction. In the Nam Con Son Basin these motions have interacted in different ways from the Palaeogene to recent. Two rifting episodes are recognized; a Palaeogene phase dominated by E-W trending extensional faults, and a Miocene phase dominated by N-S to NE-SW trending faults. The structural evolution is complicated by a pulse of mild contraction during the Middle Miocene. The sedimentary fill of the basin evolves from continental fluvio-lacustrine in the Palaeogene through to fully marine following the second phase of rifting in the Miocene. This pulsed structural and stratigraphic evolution has resulted in basinwide deposition of source, reservoir and seal facies, and produced a variety of potential trapping styles. This paper describes the hydrocarbon habitat of the south east Nam Con Son Basin within the context of the regional tectono-stratigraphic model.

  5. Structure, stratigraphy and petroleum geology of the south east Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    Fraser, A.J.; Matthews, S.J.; Lowe, S.; Todd, S.P.; Simon, P. Peel, F.J.

    1996-12-31

    Recent exploration of the south east Nam Con Son Basin, offshore Vietnam, by BP in alliance with Statoil has involved acquisition of new seismic and well data. These new data have allowed re-evaluation of the tectono-stratigraphic development and petroleum geology, and have provided additional constraints on the regional tectonic evolution. The offshore Vietnamese basins have evolved in response to the complex relative motions of Indochina, Peninsular Malaysia, Borneo and the South China Sea during the Cenozoic. On the regional scale these motions have been accommodated by strike-slip fault development, rifting and contraction. In the Nam Con Son Basin these motions have interacted in different ways from the Palaeogene to recent. Two rifting episodes are recognized; a Palaeogene phase dominated by E-W trending extensional faults, and a Miocene phase dominated by N-S to NE-SW trending faults. The structural evolution is complicated by a pulse of mild contraction during the Middle Miocene. The sedimentary fill of the basin evolves from continental fluvio-lacustrine in the Palaeogene through to fully marine following the second phase of rifting in the Miocene. This pulsed structural and stratigraphic evolution has resulted in basinwide deposition of source, reservoir and seal facies, and produced a variety of potential trapping styles. This paper describes the hydrocarbon habitat of the south east Nam Con Son Basin within the context of the regional tectono-stratigraphic model.

  6. Abstract the search for new oil reserves in Florida and its offshore basins

    SciTech Connect

    Applegate, A.V.

    1985-01-01

    Potential for new oil discoveries both on land and offshore in Florida appears to be best in the offshore portion of the South Florida Basin and in the areas in northwest Florida which are underlain by the Smackover Formation. Evidence for this appraisal includes newly acquired deep reflection seismic lines in the South Florida Basin. Geologic features believed to be present include Paleozoic strata lying unconformably beneath an igneous flow, normal faulting, and reefal development in carbonate rocks. In offshore northwest Florida, although no official announcement has been made, there is a strong possibility that a thick section of pay is present in the Smackover and Norphlet Formations in OCS-G-6417 on the Destin Dome about 40 miles south of the city of Destin. This well and the excellent Norphlet tests in the Mobile Bay area should lead to more wildcat well drilling in northwest Florida. Paleozoic drilling in Florida has ceased, and large blocks of acreage have been dropped after five dry holes were drilled in the past few years. The Sunniland Formation of Lower Cretaceous is a favorite and enduring target. The Sunniland Field was discovered in 1943 and an estimated 100 million barrels of reserves have been found in the six major fields in the South Florida Basin.

  7. Vega field and potential of Ragusa basin, Offshore Sicily

    SciTech Connect

    Schramm, M. Jr.; Livraga, G.

    1984-09-01

    Vega, the largest single oil field in the Mediterranean Sea, is located between the southeastern coast of Sicily and the Island of Malta. The field lies entirely in Italian waters. Its discovery in October 1980 was based on interpretation of a very poor-quality seismic survey which, nevertheless, roughly outlined a relatively small structure. A limestone and dolomite fractured reservoir of the Inici, or Siracusa Formation, of Late Jurasic age, may contain in excess of 1 billion bbl of heavy crude (15.5 API) within a productive area of approximately 10,000 acres (4000 ha.). Reservoir properties are excellent, with permeabilities in darcys. The field extends northwest-southeast for 8.5 mi (14 km) and averages 1.7 mi (3 km) in width, according to the 3D seismic survey (2000 km) shot soon after the discovery well was drilled. The gross oil column reaches approximately 820 ft (250 m). The southeasternmost part of the Vega structure is not yet completely defined, and an additional 3D seismic survey is in progress. Should the new seismic results confirm expectations, the Vega structure could extend over 10 mi (17 km). The overlying Inici reservoir consists of dolomite and underlain by limestone in the southwestern part of the basin, and entirely of limestone in the northwestern portion of the basin. The Inici Formation represents the platform facies of the open-sea Villagonia and Giardini sediments. The Cammarata-Pozzillo (discovered in 1959), Perla (1979), Vega (1980), and Prezioso (1983) heavy crude oil fields are related to this formation. The potential for discovery of other fields similar to Vega in the Ragusa basin is excellent.

  8. Blending Instruction with Khan Academy

    ERIC Educational Resources Information Center

    Cargile, Lori A.

    2015-01-01

    Khan Academy, the free Web-based tutorial program, landed on the education landscape in about 2011, when it was featured on the popular weekly news show "60 Minutes." The program is now used worldwide by more than 10 million learners each month and is used in more than 29,000 classrooms in 216 countries. Are classroom teachers using the…

  9. Blending Instruction with Khan Academy

    ERIC Educational Resources Information Center

    Cargile, Lori A.

    2015-01-01

    Khan Academy, the free Web-based tutorial program, landed on the education landscape in about 2011, when it was featured on the popular weekly news show "60 Minutes." The program is now used worldwide by more than 10 million learners each month and is used in more than 29,000 classrooms in 216 countries. Are classroom teachers using the…

  10. Petroleum prospects for offshore sedimentary basins in the eastern Papua New Guinea and Solomon Islands regions

    SciTech Connect

    Bruns, T.R.; Vedder, J.G. )

    1990-06-01

    Intra-arc basins in the Buka-Bougainville region of Papua New Guinea and in the Solomon Islands contain thick sedimentary sequences that may be prospective for petroleum. The Queen Emma basin, between Bougainville and New Ireland, contains as much as 8 km of deformed Oligocene and younger strata. The Central Solomons Trough, which underlies New Georgia Sound, is a composite intra-arc basin that contains late Oligocene and younger strata as much as 7 km thick. Farther east, beneath Indispensable Strait, the down-faulted Indispensable basin locally contains as much as 5.4 km of Miocene( ) and younger strata, and the offshore part of Mbokokimbo basin off eastern Guadalcanal includes 6 km or more of late Miocene and younger strata. All of these basins have some of the attributes necessary to generate and trap petroleum. Structural and stratigraphic traps are common, including faulted anticlines, sedimentary wedges, and carbonate reefs and reef-derived deposits on submarine ridges and along the basin margins. The thickness of the basin deposits ensures that some strata are buried deeply enough to be within the thermal regime required for hydrocarbon generation. However, little source or reservoir rock information is available because of the lack of detailed surface and subsurface stratigraphy. Moreover, much of the basin sediment is likely to consist of volcaniclastic material, derived from uplifted volcanogenic rocks surrounding the basins, and may be poor in source and reservoir rocks. Until additional stratigraphic information is available, analysis of the petroleum potential of these basins is a matter of conjecture.

  11. Seismo and sequence stratigraphy of Cenozoic units of the Morondava Basin, offshore western Madagascar

    NASA Astrophysics Data System (ADS)

    Kaufmann, Dirk; Stollhofen, Harald; Klimke, Jennifer; Franke, Dieter

    2015-04-01

    The N-S trending Morondava Basin extends in width from western onshore Madagascar over about 350 km westwards to the offshore Davie Ridge in the Mozambique Channel. Although basin formation was initiated during Karoo times, the main basin evolution took place during Jurassic rifting and subsequent drifting until middle Cretaceous as a result of Gondwana breakup (Geiger et al., 2004). Contemporaneous to the separation of India and Madagascar widespread flood basalts were emplaced during the late Cretaceous (Storey et al., 1995). Present knowledge of the Morondava Basin is mainly based on outcrop studies, seismic surveys and borehole information (e.g. Geiger et al., 2004), gathered in western onshore Madagascar, although the fast majority of the basin, including its depocenter is located offshore in the Mozambique Channel, now at up to 3,500 m water depth. Almost all of the recent offshore studies of the Morondava Basin rely on industrial data but up to date publications of exploration results are generally rare and mostly anonymized. Our study aims to extend knowledge, particularly on the offshore seismic and sequence stratigraphy of the Morondava Basin. A key question is also to test the proposed tectonic stability of the Davie Ridge over the last 40 Ma. For this purpose 12 seismic profiles and bathymetric data, acquired in early 2014 by RV SONNE, are interpreted. Most of the profiles cover the distal deep marine areas of the northern Morondava Basin between the Davie Ridge and the shelf break of Madagascar. Top Cretaceous, Top Eocene, Top Oligocene, the Middle Miocene Unconformity and the Base Pliocene, are mapped as major seismic marker horizons. Especially shelf and slope sedimentary units are important resources to reconstruct the tectonostratigraphic basin evolution. At the continental slope diffuse to chaotic seismic pattern of Miocene and younger age are identified which are subdivided by laterally continuous, high frequency reflectors with a higher

  12. Salt tectonics and oil accumulation in Campos basin, offshore Brazil

    SciTech Connect

    Figueiredo, A.M.F.; Pereira, M.J.; Mohriak, W.U.; Gaglianone, P.C.; Trinidade, L.A.F.

    1985-02-01

    Salt tectonics were responsible for the development of optimum conditions for accumulation of large hydrocarbon reserves in Campos basin. The salt movements, triggered by basin tilting and differential loading, initially formed low-relief salt pillows that controlled the porous facies of the shallow-water Macae limestones. The continuous evolution of halokinetic processes produced growth faults, rollover crests, and faulted anticlines. Upper Cretaceous turbidite sandstones were channelized in the downthrown blocks of growth faults. Salt-collapse, residual, and relief-inversion features were formed in areas where the salt was sufficiently thick. The oil, generated in the Neocomian shales of Lagoa Feia Formation, migrated to upper formations through normal faults associated with the rift phase, stratigraphic conduits such as porous rocks and regional unconformities, and gaps created by salt flowage in the Aptian evaporite section. Oil migration to the post-salt rocks was favored by active growth faults and by the presence of a regional unconformity developed at the Cretaceous-Tertiary boundary and covered by turbidite sheet sands. The oils underwent progressive alteration along their paths to the post-salt reservoirs. Oil-oil and oil-source rock correlations suggest that the hydrocarbons trapped in many diverse plays, although affected by bacterial degradation and water washing, belong to only one oil family. The oil degradation was probably enhanced by meteoric water invasions during Tertiary low stands of sea level in areas close to the paleocoastline. These phenomena resulted in large amounts of oil becoming heavier and enriched in sulfur, resins, asphaltenes, and cycloparaffins.

  13. Deep seismic reflection profiling of sedimentary basins offshore Brazil: Geological objectives and preliminary results in the Sergipe Basin

    NASA Astrophysics Data System (ADS)

    Mohriak, Webster Ueipass; Lira Rabelo, JoséHenrique; De Matos, Renato Darros; De Barros, Mozart C.

    1995-12-01

    The first deep seismic reflection profiles offshore Brazil were acquired in Campos Basin and processed to 10 s TWT in 1984. Starting in 1989, Petrobrás acquired an extensive data set of deep seismic profiles using special acquisition equipment capable of effectively penetrating through the sedimentary layers and imaging the whole crustal architecture. These deep (18 s TWT) seismic reflection profiles extend across the Atlantic-type marginal basins, from the platform to the deepwater province, presently considered frontier regions for petroleum exploration. This work addresses the geological objectives of a deep seismic profile in the Sergipe Basin and discusses the results obtained by integrating regional seismic, gravity and magnetic data. When combined, these data provide evidence that deep seismic reflectors observed in the Sergipe Basin are related to intracrustal-upper mantle structures rather than sedimentary features. The deep seismic reflection profile in the Sergipe Basin also suggests that, rather than a non-volcanic passive margin, the deepwater extension of this basin is marked by several magmatic structures, including thick wedges of seaward-dipping reflectors and volcanic plugs. These magmatic features are associated with basinforming processes resulting from lithospheric extension during the breakup of Gondwana in the Early Cretaceous and subsequent emplacement of oceanic crust. These results are compared to the crustal scale structures observed in the Campos Basin, in the southeastern margin of Brazil. The interpretation of the deep structure of these basins indicates that final separation between the South American and African plates formed passive margins characterized by different patterns of crustal attenuation underlying the rift blocks.

  14. Quaternary active tectonic structures in the offshore Bajo Segura basin (SE Iberian Peninsula - Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Perea, H.; Gràcia, E.; Alfaro, P.; Bartolomé, R.; Lo Iacono, C.; Moreno, X.; Masana, E.; Event-Shelf Team

    2012-10-01

    The Bajo Segura fault zone (BSFZ) is the northern terminal splay of the Eastern Betic shear zone (EBSZ), a large left-lateral strike-slip fault system of sigmoid geometry stretching more than 450 km from Alicante to Almería. The BSFZ extends from the onshore Bajo Segura basin further into the Mediterranean Sea and shows a moderate instrumental seismic activity characterized by small earthquakes. Nevertheless, the zone was affected by large historical earthquakes of which the largest was the 1829 Torrevieja earthquake (IEMS98 X). The onshore area of the BSFZ is marked by active transpressive structures (faults and folds), whereas the offshore area has been scarcely explored from the tectonic point of view. During the EVENT-SHELF cruise, a total of 10 high-resolution single-channel seismic sparker profiles were obtained along and across the offshore Bajo Segura basin. Analysis of these profiles resulted in (a) the identification of 6 Quaternary seismo-stratigraphic units bounded by five horizons corresponding to regional erosional surfaces related to global sea level lowstands; and (b) the mapping of the active sub-seafloor structures and their correlation with those described onshore. Moreover, the results suggest that the Bajo Segura blind thrust fault or the Torrevieja left-lateral strike-slip fault, with prolongation offshore, could be considered as the source of the 1829 Torrevieja earthquake. These data improve our understanding of present deformation along the BSFZ and provide new insights into the seismic hazard in the area.

  15. Geology of the undeveloped oil and gas fields of Central Offshore Santa Maria Basin, California

    SciTech Connect

    Milton, J.D. ); Edwards, E.B. ); Heck, R.G. )

    1996-01-01

    Two prominent subsurface structural features of the Central Offshore Santa Maria Basin are the Hosgri fault system and the associated anticlinal fold trend. Exploratory drilling and 3D seismic mapping have delineated a series of oil and gas fields along this trend which underlie four federal units and one non-unitized lease. The units are named after local geography and are called the Lion Rock, Point Sal, Purisima Point and Santa Maria Units. The individual lease, OCS P-0409, overlies the San Miguel field. The Hosgri fault system trends northwest-southeast and effectively forms the eastern boundary of the oil and gas province. Lying semi-parallel with the fault are several anticlinal culminations which have trapped large volumes of oil and gas in the fractured Montery Formation. The Monterey is both source and reservoir rock, averaging 300 meters n thickness throughout the Central Basin. Development of the Monterey Formation as a reservoir rock was through diagensis and tectonism with resulting porosities-from 15 to 20% and permeability up to one Darcy. These parameters coupled with a high geothermal gradient facilitate the inflow rates of the viscous Monterey oil. Some 24 exploration and delineation wells have been drilled in this area and tested at rates ranging from a few hundred to several thousand barrels per day. Estimated oil reserves in the Central Offshore Santa Maria Basin total approximately 1 billion barrels.

  16. Geology of the undeveloped oil and gas fields of Central Offshore Santa Maria Basin, California

    SciTech Connect

    Milton, J.D.; Edwards, E.B.; Heck, R.G.

    1996-12-31

    Two prominent subsurface structural features of the Central Offshore Santa Maria Basin are the Hosgri fault system and the associated anticlinal fold trend. Exploratory drilling and 3D seismic mapping have delineated a series of oil and gas fields along this trend which underlie four federal units and one non-unitized lease. The units are named after local geography and are called the Lion Rock, Point Sal, Purisima Point and Santa Maria Units. The individual lease, OCS P-0409, overlies the San Miguel field. The Hosgri fault system trends northwest-southeast and effectively forms the eastern boundary of the oil and gas province. Lying semi-parallel with the fault are several anticlinal culminations which have trapped large volumes of oil and gas in the fractured Montery Formation. The Monterey is both source and reservoir rock, averaging 300 meters n thickness throughout the Central Basin. Development of the Monterey Formation as a reservoir rock was through diagensis and tectonism with resulting porosities-from 15 to 20% and permeability up to one Darcy. These parameters coupled with a high geothermal gradient facilitate the inflow rates of the viscous Monterey oil. Some 24 exploration and delineation wells have been drilled in this area and tested at rates ranging from a few hundred to several thousand barrels per day. Estimated oil reserves in the Central Offshore Santa Maria Basin total approximately 1 billion barrels.

  17. Numerical Modeling of Petroleum Generation and Accumulation in the Sora Basin, Offshore Southern Korea

    NASA Astrophysics Data System (ADS)

    Son, Byeong-Kook; Lee, Seul-A.; Park, Mee-Sook

    2015-04-01

    Petroleum system modeling calculates and visualizes how and when hydrocarbons generate, migrate, and accumulate in a sedimentary basin. Therefore, it can be used effectively to predict the future prospects of oil and gas based on the understanding of the petroleum system in time and space. The petroleum system modeling was performed on the Sora Basin which is a small Cenozoic basin located offshore southern Korea, also including the offshore area of western Kyushu, Japan. Oil and gas shows were detected in two wells drilled in the basin, indicating that petroleum systems are present in the basin. Input parameters were selected from the well data as well as previous geological and geophysical studies for the 1-D model, from which thermal parameters such as heat flow and thermal maturity are also calculated and applied to 2-D model. The 2-D modeling was performed on an E-W seismic section across the basin from western margin in the Korea Block to eastern margin in Japanese Block. The PetroMod software was employed in the 2-D modeling, and stratigraphy, including lithology and organic content, was obtained from the wells and previous geological studies. 2-D modeling shows that hydrocarbons were expelled from the pod of the Eocene source rock in the Miocene time. The hydrocarbons migrate vertically along faults to the upper Oligocene sandstone formation, rather than the updip migrations along the sandstone bed, and hence form small-sized accumulations in the upper part of the sandstone formation. 3-D model was also performed based on depth maps of each formation in the Sora basin. Hydrocarbons are generated and expelled from the pod of the source rock of Eocene formation from 32Ma. In addition, the 3-D model shows that the hydrocarbon migrates northwestward and eastward in the carrier bed of sandstone. The petroleum models indicate that only a small amount of hydrocarbons are accumulated in the reservoir formation, probably due to small size of the basin and low degree

  18. Gas Hydrate Deposits in the Cauvery-Mannar Offshore Basin, India

    NASA Astrophysics Data System (ADS)

    Dewangan, P.

    2015-12-01

    The analysis of geophysical and coring data from Mahanadi and Krishna-Godavari offshore basins, eastern continental margin of India, has established the presence of gas hydrate deposits; however, other promising petroliferous basins are relatively unexplored for gas hydrates. A collaborative program between GSI/MoM and CSIR-NIO was formulated to explore the Cauvery-Mannar offshore basin for gas hydrate deposits (Fig. 1a). High quality multi-channel reflection seismics (MCS) data were acquired with 3,000 cu. in airgun source array and 3 km long hydrophone streamer (240 channels) onboard R/V Samudra Ratnakar for gas hydrate studies. Other geophysical data such as gravity, magnetic and multibeam data were also acquired along with seismic data.After routine processing of seismic data, the bottom simulating reflectors (BSRs) are observed in the central and north-eastern part of the survey area. The BSRs are identified based on its characteristic features such as mimicking the seafloor, opposite polarity with respect to the seafloor and crosscutting the existing geological layers (Fig. 1b). At several locations, seismic signatures associated with free gas such as drop in interval velocity, pull-down structures, amplitude variation with offset (AVO) and attenuation are observed below the BSRs which confirm the presence of free gas in the study area. Acoustic chimneys are observed at some locations indicating vertical migration of the free gas. The observed seismic signatures established the presence of gas hydrates/free gas deposits in Cauvery-Mannar basin. Interestingly, BSRs appear to be distributed along the flanks of submarine canyon indicating the influence of geomorphology on the formation and distribution of gas hydrates.

  19. 3D Fault Geometry and Basin Evolution in the Northern Continental Borderland Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Schindler, C. S.; Nicholson, C.; Sorlien, C.

    2007-12-01

    Grids of recently released high-quality industry multichannel seismic (MCS) reflection data, combined with bathymetry and offshore well data are used to map digital 3D fault surfaces and stratigraphic reference horizons in the northern Continental Borderland offshore of southern California. This area experienced large-scale oblique crustal extension and translation associated with the initiation and development of the Pacific-North American plate boundary. The 3D surfaces of structure and stratigraphy can thus be used to better understand and evaluate regional patterns of uplift, subsidence, fault interaction and other aspects of plate boundary deformation. Our mapping in Santa Cruz basin and on Santa Rosa and Santa Cruz-Catalina Ridge reveals an unusual pattern of faulting, folding and basin subsidence. This subsidence is significant (up to 3-4 km since early-Miocene time) and is responsible for the development of several major Borderland basins. Vertical motions can be estimated from an early-Miocene unconformity that likely represents a paleo-horizontal, near-paleo-sea-level erosional surface. As such, it can be used to reconstruct Borderland forearc geometry prior to rifting, subsidence and subsequent basin inversion. Major findings to date include: (a) a better characterization of the complex 3D geometry and pinch-out of the eastern edge of the northern forearc Nicolas terrane and its implications for Borderland basin development, plate reconstructions, and vertical motions associated with oblique rifting; (b) recognition that the East Santa Cruz Basin fault, previously thought to be a predominantly high-angle, large- displacement right-slip fault representing the eastern edge of the Nicolas terrane, is in fact a series of reactivated right-stepping, NE-dipping reverse-separation faults; (c) discovery that NW-striking faults associated with Santa Cruz-Catalina Ridge bend west into a horse-tail structure to interact with and contribute to the southern frontal

  20. West Atlantic mesozoic carbonates: comparison of Baltimore Canyon and offshore Nova Scotian basins

    SciTech Connect

    Eliuk, L.S.; Cearley, S.C.; Levesque, R.

    1986-05-01

    Results of exploratory drilling, by Shell Offshore Inc., and its partners, of the Late Jurassic-Early Cretaceous carbonate margin of the Baltimore Canyon (BC) basin can be interpreted directly from the better understood, time-equivalent Nova Scotian (NS) basin stratigraphy. The BC paleomargin was constructed in a depositional cycle of three successive stages: Oxfordian-early Kimmeridgian progradation, Kimmeridgian-Berriasian aggradation, Berriasian-Valanginian drowning. The upper two stages in NS are the Baccaro and Artimon members of the Abenaki formation. The progradation of the lower sequence in BC results from high clastic input and has a parallel (not age equivalent) in NS only in proximity to the Sable Island paleodelta. Both basins have similar, complementary, shelf-edge environments that form a single water-depth-controlled biotic zonation. This zonation is: shallow-water stromatoporoid-hexacoral biostromes and reefs; deeper water stromatactis and thrombolitic mud mounds; and deep-water lithistid sponge reefs. Associated environments are oncolitic reef flats, reef-apron skeletal sands, slope reef debris from sponge and coral reefs, and back-reef mollusk-rich skeletal and skeletal-oolitic sands. Major differences between the basins are the pinnacle reefs of BC and the contrast between the mud-rich skeletal and nonskeletal megafacies of NS versus the dominantly skeletal sand-rich BC sediments. The higher subsidence rates of BC may explain both differences.

  1. Application of sequence stratigraphy to oil and gas exploration in Bredasdorp basin offshore South Africa

    SciTech Connect

    Van Wyk, N.J.S.

    1989-03-01

    For more than two decades, oil and gas exploration in offshore South African rift basins within structural synrift plays yielded limited success. After the first oil discovery in postrift sediments in the Bredasdorp basin in 1987, sequence-stratigraphic concepts were applied to the Lower Cretaceous postrift sequences to permit correlation of depositional systems tracts and related facies throughout the basin. Extensive high-resolution seismic coverage and borehole control supported the study. The interplay of diminishing rift tectonics, thermal cooling, and inferred eustatic variations in global sea level produced a distinctive series of repetitive cycle depositional sequences. As many as 10 cyclic sequences and megasequences, deposited between the mid-Valanginian and lower Santonian, can be recognized within resolution limits of regional seismic profiles. Various elements of lowstand systems tracts within these sequences appear to contain potential reservoirs. Highly erosional (type 1) unconformities, commonly exhibiting incised valleys and canyons, provide surfaces on which (1) mounded and sheetlike submarine/basin-floor fans, (2) submarine channel fill and associated mounds and fans, and (3) prograding deltaic/coastal lowstand wedges were deposited. These fans, channel fills, and wedges are top sealed and sourced by transgressive shales and marine condensed sections, deposited at a time of regional transgression of the shoreline. One discovery well and various reservoir-quality sandstones occurring at predicted stratigraphic levels in other wells support the application of the sequence-stratigraphic concepts to hydrocarbon exploration.

  2. Multiphase Fault Evolution in a Rotational Margin Setting: Offshore Sirte Basin, Libya

    NASA Astrophysics Data System (ADS)

    Maddock, Paul; McCaffrey, Ken; Imber, Jonathon

    2013-04-01

    The aims of this study are to present a new structural interpretation of a well-calibrated regional 2D seismic dataset to constrain the timing and style of faulting in the Sirte embayment, offshore Libya, a Mesozoic-Cenozoic extension of the Sirte basin onshore north Africa. Due to rotation of the African continent since the Mesozoic, present-day fault orientations are not the same as during fault formation at various times since the early Palaeozoic. The approach has therefore been to integrate a structural model with published plate tectonic reconstructions in order to progressively restore fault orientations throughout the evolution of the Sirte embayment. Multiple phases of rifting can be observed in the offshore area, with major faulting episodes during the Aptian-Albian, Upper Cretaceous, mid-Eocene and Oligocene. Paleozoic basement structures have a dominant role in controlling the locations of later faults. The model shows how pre-existing structures have been reactivated during the main Cretaceous basin-forming episode, with some deeply-rooted basement faults remaining active into the mid-late Cretaceous. The orientation of basement faults with respect to the inferred regional stress direction appears to be a key influence on the type of faulting observed. In many parts of the Sirte Embayment, active faulting during the later Mesozoic is concentrated in fault zones directly above, or in the immediate hanging wall of older, deeper faults. The dominant stress field since the Cretaceous is consistent with the onshore Sirte trend with extension generally to the NE-SW giving NW-SE striking faults and fault zones. The orientation of pre-Mesozoic faults can be shown to have rotated anti-clockwise by 40° between formation and Cretaceous deformation, with a further 17° to the present day giving a total rotation of 57°. While the present day onshore trend of NW-SE horst and graben blocks has the greatest influence on the structure of the Sirte embayment

  3. 2-D Petroleum System Modelling of the Browse Basin, Offshore Northwestern Australia

    NASA Astrophysics Data System (ADS)

    Son, Byeong-Kook

    2017-04-01

    Petroleum system modelling was performed for the Browse Basin, which is a hydrocarbon-bearing basin in the offshore area of northwestern Australia. The Browse Basin was formed by two cycles of tectonically controlled extension, thermal subsidence, and inversion. The first rifting had occurred by the extension in the Late Carboniferous to Early Permian, and the second was in the Early to Middle Jurassic. Thick sediments were deposited during subsequent subsidence and inversion in the basin. The Upper Jurassic to Lower Cretaceous succession is considered to have the high quality source potential. Major reservoirs are fluvio-deltaic and nearshore marine sandstone units in the Jurassic and Cretaceous. Late Cretaceous to Tertiary sequences are dominated by thick carbonate rocks. Maturity model and paleo-heat flow history were made in 1-D petroleum system modelling by comparing with vitrinite values and temperature measured from the drill wells. Based on the geologic setting and the 1-D model, 2-D Petroleum system modelling was conducted on an E-W cross section crossing three wells to understand hydrocarbon generation, migration, and accumulation in the basin. Late Jurassic to Early Cretaceous formations, including Aptian, Vlanginian, and Callovian rocks, were assigned as source rocks in the 2-D modelling. The 2-D model shows that hydrocarbons were generated during Late Jurassic to Late Cretaceous. A thick succession of overburden rocks provided the source rocks with heat and pressure to generate a significant amount of hydrocarbons. Hydrocarbons expelled from the source rocks were migrated dominantly downward to Late Jurassic sandy reservoir rocks. Upward migration is restricted by dense shale and carbonate successions. Large accumulations of gas have been found in the basin, rather than oil. It seems that the amount of gases was significantly increased by secondary cracking of the oil in reservoir formations in deep and hot conditions.

  4. Geologic implications of gas hydrates in the offshore of India: Krishna-Godavari Basin, Mahanadi Basin, Andaman Sea, Kerala-Konkan Basin

    USGS Publications Warehouse

    Kumar, Pushpendra; Collett, Timothy S.; Boswell, Ray; Cochran, James R.; Lall, Malcolm; Mazumdar, Aninda; Ramana, Mangipudi Venkata; Ramprasad, Tammisetti; Riedel, Michael; Sain, Kalachand; Sathe, Arun Vasant; Vishwanath, Krishna; Yadav, U.S.

    2014-01-01

    NGHP-01 yielded evidence of gas hydrate from downhole log and core data obtained from all the sites in the Krishna–Godavari Basin, the Mahanadi Basin, and in the Andaman Sea. The site drilled in the Kerala–Konkan Basin during NGHP-01 did not yield any evidence of gas hydrate. Most of the downhole log-inferred gas hydrate and core-recovered gas hydrate were characterized as either fracture-filling in clay-dominated sediments or as pore-filling or grain-displacement particles disseminated in both fine- and coarse-grained sediments. Geochemical analyses of gases obtained from sediment cores recovered during NGHP-01 indicated that the gas in most all of the hydrates in the offshore of India is derived from microbial sources; only one site in the Andaman Sea exhibited limited evidence of a thermogenic gas source. The gas hydrate petroleum system concept has been used to effectively characterize the geologic controls on the occurrence of gas hydrates in the offshore of India.

  5. Seismic Characterization of the BSR in the Nishitsugaru Basin, Offshore Japan

    NASA Astrophysics Data System (ADS)

    Fujimoto, A.; Kobayashi, T.; Fujii, T.

    2016-12-01

    JOGMEC, as a member of research group for resources assessment of Research Consortium for Methane Hydrate Resources in Japan (MH21), has been conducting resources assessment of methane hydrate (MH) offshore surrounding Japan. This study aims to investigate the property of the bottom simulating reflector (BSR). In terms of resources assessment, it is important to understand the character and distribution of the BSR to interpret the methane hydrate concentrated zones (MHCZ) quantitatively. The BSR presence and its character were analysed through multichannel seismic reflection data (4800 m streamer, 384 channels, 48 fold) acquired in 2014 by geophysical vessel `Shigen', which is owned by Agency for Natural Resources and Energy. We investigated the seismic character and distribution of the BSR in Nishitsugaru basin which located in the west Aomori prefecture, Japan. Several folds and faults with large displacement can be seen on the three-dimensional (3D) seismic section of the study area. The BSR was very visible continuously and extends over a broad area of the Nishitsugaru basin. Strong amplitude with amplitude versus offset (AVO) anomaly related BSR were interpreted in the parallel sediment and mass transport deposit. Clear interval velocity contrast and phase shift of seismic reflection events were confirmed between above and below the BSR. The feature around chimney structure such as weak amplitude suggested that fluid migrated from deep part of the basin to sea floor through several faults caused by inversion tectonics. The BSR which lies too deep to be related to methane hydrates data is interpreted as a diagenetic related BSR and it indicates local heat flow in the basin. Even the focused area has not been drilled, the BSR and its interpretations are useful to understand thermal structure, fluid migration, and estimation of the MHCZ in the basin.

  6. Strain-dependent serpentinization: new insights from the Porcupine Basin, offshore Ireland

    NASA Astrophysics Data System (ADS)

    Prada, M.; Watremez, L.; Chen, C.; O'Reilly, B.; Minshull, T. A.; Reston, T. J.; Shannon, P.; Klaeschen, D.; Wagner, G.; Gaw, V.

    2016-12-01

    At magma-poor rifted margins serpentinization is believed to occur when the entire crust becomes brittle after certain amount of extension. At that stage crustal-scale faulting occurs, allowing ocean water to reach the uppermost mantle, which causes serpentinization as long as the rift remains cold enough. However, it has been inferred from seismic refraction models that the amount of serpentinization beneath crustal-faulting is related to its displacement, which suggests that water can only effectively percolate to the mantle when normal faults are active. Serpentinization is key in lithospheric extension as it reduces the strength of mantle rocks and influences the tectonics of the lithosphere by favoring strain focusing. Besides reducing the seismic velocity of the rock, serpentinization decreases mantle rock density causing isostatic rebound and basin uplift, thus affecting the thermal evolution of the basin. Here we present new insights on serpentinization at magma-poor rifted margins. We focus on the upper mantle seismic structure of the Porcupine Basin, offshore west of Ireland, from P-wave velocity models and seismic reflection data. The Porcupine Basin was developed during several rifting events in the Late Paleozoic to Cenozoic. Our velocity models show that extension increases from the north to the center of the basin where the crust is severely thinned and mantle serpentinization has potentially occurred. β factors calculated from our models are well within the range of extension at which serpentinization is expected. The seismic structure of our models together with MCS data reveals that normal faulting is spatially coincident with a higher degree of serpentinization. However, such degree of serpentinization is not consistent along the basin axis, but increases southwards along the basin axis together with the amount of strain. Such strain-dependent serpentinization has strong implications on the development of detachment faults in the basin, which

  7. Crustal strain-dependent serpentinisation in the Porcupine Basin, offshore Ireland

    NASA Astrophysics Data System (ADS)

    Prada, Manel; Watremez, Louise; Chen, Chen; O'Reilly, Brian M.; Minshull, Timothy A.; Reston, Tim J.; Shannon, Patrick M.; Klaeschen, Dirk; Wagner, Gerlind; Gaw, Viola

    2017-09-01

    Mantle hydration (serpentinisation) at magma-poor rifted margins is thought to play a key role in controlling the kinematics of low-angle faults and thus, hyperextension and crustal breakup. However, because geophysical data principally provide observations of the final structure of a margin, little is known about the evolution of serpentinisation and how this governs tectonics during hyperextension. Here we present new observational evidence on how crustal strain-dependent serpentinisation influences hyperextension from rifting to possible crustal breakup along the axis of the Porcupine Basin, offshore Ireland. We present three new P-wave seismic velocity models that show the seismic structure of the uppermost lithosphere and the geometry of the Moho across and along the basin axis. We use neighbouring seismic reflection lines to our tomographic models to estimate crustal stretching (βc) of ∼2.5 in the north at 52.5° N and >10 in the south at 51.7° N. These values suggest that no crustal embrittlement occurred in the northernmost region, and that rifting may have progressed to crustal breakup in the southern part of the study area. We observed a decrease in mantle velocities across the basin axis from east to west. These variations occur in a region where βc is within the range at which crustal embrittlement and serpentinisation are possible (βc 3-4). Across the basin axis, the lowest seismic velocity in the mantle spatially coincides with the maximum amount of crustal faulting, indicating fault-controlled mantle hydration. Mantle velocities also suggest that the degree of serpentinisation, together with the amount of crustal faulting, increases southwards along the basin axis. Seismic reflection lines show a major detachment fault surface that grows southwards along the basin axis and is only visible where the inferred degree of serpentinisation is >15%. This observation is consistent with laboratory measurements that show that at this degree of

  8. Sequence stratigraphy and hydrocarbon potential of the Phu Khanh Basin offshore central Vietnam, South China Sea

    SciTech Connect

    Lee, G.H.; Watkins, J.S.

    1996-12-31

    The Phu Khanh Basin offshore central Vietnam is one of the few untested basins on the Vietnam margin of the South China Sea. Analysis of over 1,600 km of multi-channel seismic reflection data indicates that the Phu Khanh Basin follows a typical rift-margin order: faulted basement, synrift sedimentation, a breakup unconformity, and postrift sedimentation. Postrift sedimentation consists of a transgressive phase characterized by ramp-like depositional geometries followed by a regressive phase characterized by prograding sequences. An early middle Miocene unconformity separates these two phases. During the transgressive phase rising sea level provided favorable conditions for carbonate buildup development. The regressive interval contains a number of third-order depositional sequences composed of seismically resolvable lowstand, highstand, and rarely, transgressive systems tracts. Lacustrine sediments deposited in graben and half-graben lakes during the rifting stage are probably the principal source rocks. Fractured and/or weathered basement, carbonate complexes, basinfloor fans, and shallows water sands may have good reservoir quality. Potential traps include basement hills, carbonate complexes, fault taps, and stratigraphic traps within lowstand systems tracts. Hydrocarbon indicators such as flat spots, bright spots, gas chimneys with gas mounds on the seafloor occur at a number of locations.

  9. Sequence stratigraphy and hydrocarbon potential of the Phu Khanh Basin offshore central Vietnam, South China Sea

    SciTech Connect

    Lee, G.H. ); Watkins, J.S. )

    1996-01-01

    The Phu Khanh Basin offshore central Vietnam is one of the few untested basins on the Vietnam margin of the South China Sea. Analysis of over 1,600 km of multi-channel seismic reflection data indicates that the Phu Khanh Basin follows a typical rift-margin order: faulted basement, synrift sedimentation, a breakup unconformity, and postrift sedimentation. Postrift sedimentation consists of a transgressive phase characterized by ramp-like depositional geometries followed by a regressive phase characterized by prograding sequences. An early middle Miocene unconformity separates these two phases. During the transgressive phase rising sea level provided favorable conditions for carbonate buildup development. The regressive interval contains a number of third-order depositional sequences composed of seismically resolvable lowstand, highstand, and rarely, transgressive systems tracts. Lacustrine sediments deposited in graben and half-graben lakes during the rifting stage are probably the principal source rocks. Fractured and/or weathered basement, carbonate complexes, basinfloor fans, and shallows water sands may have good reservoir quality. Potential traps include basement hills, carbonate complexes, fault taps, and stratigraphic traps within lowstand systems tracts. Hydrocarbon indicators such as flat spots, bright spots, gas chimneys with gas mounds on the seafloor occur at a number of locations.

  10. 3-D magnetotelluric image of offshore magmatism at the Walvis Ridge and rift basin

    NASA Astrophysics Data System (ADS)

    Jegen, Marion; Avdeeva, Anna; Berndt, Christian; Franz, Gesa; Heincke, Björn; Hölz, Sebastian; Neska, Anne; Marti, Anna; Planert, Lars; Chen, J.; Kopp, Heidrun; Baba, Kiyoshi; Ritter, Oliver; Weckmann, Ute; Meqbel, Naser; Behrmann, Jan

    2016-06-01

    The Namibian continental margin marks the starting point of the Tristan da Cunha hotspot trail, the Walvis Ridge. This section of the volcanic southwestern African margin is therefore ideal to study the interaction of hotspot volcanism and rifting, which occurred in the late Jurassic/early Cretaceous. Offshore magnetotelluric data image electromagnetically the landfall of Walvis Ridge. Two large-scale high resistivity anomalies in the 3-D resistivity model indicate old magmatic intrusions related to hot-spot volcanism and rifting. The large-scale resistivity anomalies correlate with seismically identified lower crustal high velocity anomalies attributed to magmatic underplating along 2-D offshore seismic profiles. One of the high resistivity anomalies (above 500 Ωm) has three arms of approximately 100 km width and 300 km to 400 km length at 120° angles in the lower crust. One of the arms stretches underneath Walvis Ridge. The shape is suggestive of crustal extension due to local uplift. It might indicate the location where the hot-spot impinged on the crust prior to rifting. A second, smaller anomaly of 50 km width underneath the continent ocean boundary may be attributed to magma ascent during rifting. We attribute a low resistivity anomaly east of the continent ocean boundary and south of Walvis Ridge to the presence of a rift basin that formed prior to the rifting.

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

    NASA Astrophysics Data System (ADS)

    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

  12. Petroleum geology of the deltaic sequence, Rio Del Rey basin, offshore Cameroon

    SciTech Connect

    Coughlin, R.M.; Bement, W.O.; Maloney, W.V. )

    1993-09-01

    The Rio Del Rey Basin of offshore Cameroon comprises the easternmost portion of the Niger delta complex. In the delta flank setting, the overall package is thinner and stratigraphic correlation simpler than in the depocenter to the west so the distribution of reservoirs and seals is well defined. Productive reservoirs are shallow, typically less than 2000 m, and mostly hydropressured to slightly overpressured. Reservoir properties generally are excellent and seismic bright-spot technology has played a major role in exploration and development efforts. Rio Del Rey is characterized by three main structural styles from north to south: (1) detachment-based growth faults, (2) highly faulted, mobile shale cored domes and ridges, and (3) toe thrusts and folds. Virtually all individual traps are fault dependent and lack of sufficient internal seals in sand-rich wave-dominated deltaic sequences can limit the objective window. Most fields are downthrown fault traps in which hanging-wall reservoirs are effectively sealed against older prodelta and marine shales. All large oil fields are located in the dome and ridge province and are potential analogs for similar structures now being explored on the upper slope off Nigeria. The best quality source rocks identified thus far are Paleocene to Eocene marine shales. Oil vs. gas distribution in the basin is a function of variations in the kerogen type, organic richness, and maturity of these source rocks. A significant quantity of the gas found to date in Rio Del Rey is biogenic in origin. The Cameroon charge model may aid in better understanding hydrocarbon distribution on offshore Nigeria, where the Miocene deltaic section is much thicker and potential Paleocene-Eocene source rocks likely are unpenetrated. The shallow deltaic play in Cameroon is relatively mature. Future exploration likely will focus on identifying deeper, nonbright-spot-supported opportunities including potential stratigraphic traps.

  13. Hindcast oil spill simulations from the existing offshore wells in the Eastern Mediterranean Levantine Basin

    NASA Astrophysics Data System (ADS)

    Zodiatis, George; Alves, Tiago M.; Kokinou, Eleni; Radhakrishnan, Hari; Panagiotakis, Costas; Lardner, Robin

    2017-04-01

    Following the expansion of the exploration and exploitation of the hydrocarbons in the Eastern Mediterranean Levantine Basin during the last 5 years, oil spill simulations for 20 existing offshore platforms/wells were carried out based on new and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The oil spill simulations were carried out using the well known MEDSLIK oil spill model, with the use of high temporal and spatial resolution data for 3D sea currents, winds and waves, provided by the CYCOFOS forecasting system, downscaled from the Copernicus Marine environment monitoring service (CMEMS). The hindcast oil spill simulations from the 20 potential oil spill sources have been prepared for a period of four years, presenting the movement of the spills and the area affected, the fate parameters, the first impact on the coast and the extend of the affected coastline from each location every week. The modeled oil spills took into account the oil spill scenario following the REMPEC MEDEXPOL 2013 experiment. Moreover, a qualitative analysis of the seabed morphology has been applied to examine the direction of the oil slick expansion, shown that the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. The oil spill simulations from the existing offshore wells/platforms, show a clear trend for east and northeast movement of the oil spills in the Eastern Mediterranean Levantine Basin, with the first impact at the coast in a time interval between 1 to 20 days after the first oil spilled at sea, depending on the location of the platforms/wells and of the intensity and direction of the meteo-ocean data.

  14. Onshore and offshore basins of northeast Libya: Their origin and hydrocarbon potential

    SciTech Connect

    Shegewi, O.M.

    1992-01-01

    A comprehensive data base of more than 3000 km of seismic lines, gravity and magnetic data, more than 30 subsurface well logs, and surface geology data were utilized to examine and interpret the sedimentary and tectonic history of the onshore and offshore parts of Northeast Libya and their hydrocarbon potential. The Dernah-Tobruk and Benghazi offshore basins form the northern parts of the study area. The Cyrenaica Stable Platform represents the southern parts. The Sirual Trough stretches E-W and opens into the Antelat Trough in the west. Between these elements is the uplifted areas of the Al Jabal Al Akhdar. Six principal tectonic phases were responsible for the formation and development of these structural elements: the pre-Mesozoic phase, the Triassic-Jurassic rifting phase, the Neocomian and the Aptian-Albian renewed rifting phases, the Late Cretaceous-Paleocene uplifting phase; and the Eocene-Middle Oligocene rifting phase. Oceanic crust of probable Aptian-Albian age is evident on the seismic lines north of the master fault marking the southern boundary of the rift separating the north African plate and Apulia. The western boundary of the Dernah High displayed clearly NE-SW strike-slip movement of these trajectories. Oceanic crust is also present west of the Dernah High. Positive gravity and magnetic anomalies traverse parallel to the boundary of this oceanic plate Mesogea. The prerequisites for commercial hydrocarbon production are present in abundance. Reservoirs ranging in age from Paleozoic clastics in the Cyrenaica Stable Platform to Mesozoic and Tertiary carbonates throughout the rest of the region. Several deep sites for the generation of hydrocarbons were also present, including the rifted northern parts of the Dernah-Tobruk basin, the Antelat Trough and the Cyrenaica Passive Margin. The Cretaceous and Tertiary section in the study area contain several potential seal rocks. Several potential trap types are also present.

  15. Shelf sheet-sand reservoir of the lower Cretaceous Greensand, North Celtic Sea Basin, offshore Ireland

    SciTech Connect

    Winn, R.D. Jr.

    1994-11-01

    Core and log data show that the marine, early to middle Albian {open_quotes}A{close_quotes} Sand of the Aptian to lower Cenomanian Greensand-Gault interval, North Celtic Sea Basin, offshore Ireland, was deposited as an approximately tabular sand body in shelf water depths. The {open_quotes}A{close_quotes} Sand is the major reservoir interval at Kinsale Head and Ballycotton gas fields. The reservoir sandstone is bioturbated, variably glauconitic, shell rich, and least muddy toward its provenance in a local area of the Irish massif and finer grained southeastward into the basin. Thickness and coarseness of the {open_quotes}A{close_quotes} Sand are related, in part, to distance from a narrow area of the paleoshore. Bathymetric control of sand thickness was superimposed on proximal-distal trends. Specifically, thick intervals are inferred to have been deposited in shelf lows, and thin zones were deposited over bathymetric highs. The {open_quotes}A{close_quotes} Sand was not deposited as a ridge sand, and positive relief on the depositional sand body appears to have been minor. Deposition of the Greensand occurred during thermal subsidence of the North Celtic Sea Basin following Early Cretaceous rifting. Overall late Early Cretaceous to Late Cretaceous transgression was interrupted by progradation of the {open_quotes}A{close_quotes} Sand, probably caused by a relative drop in sea level (forced regression). The {open_quotes}A{close_quotes} Sand sheet consists of several units within the central depositional basin. Three slightly coarsening-upward units up to 15 m thick probably are the consequence of high-frequency fluctuations in sea level during progradation. The top of the {open_quotes}A{close_quotes} Sand consists of a several-meter-thick, very glauconitic, muddy sandstone to sandy mudstone. The upper unit accumulated in deepening water following the maximum lowstand.

  16. Tectonic evolution of the offshore Sarawak and Sabah Basins, Northwest Borneo

    SciTech Connect

    Hazebroek, H.; Tan, D.; Swinburn, P. )

    1994-07-01

    The offshore Sarawak and Sabah Basins, northwest Borneo, contain up to 12 km of Oligocene to Holocene sediments. On the basis of marked different structural styles and stratigraphy, these basins can be divided into 13 tectono-stratigraphic provinces. Many of these, e.g., Balingian southwest Luconia, central Luconia, Baram delta, inboard belt, and outboard belt, are proven hydrocarbon provinces. Stratigraphically, these provinces generally become younger toward the northwest and/or northeast, with the older provinces overlying unconformably the Paleogene Rajang Group deep-marine sediments in the south. There is a great variation in structural styles. However, general structural trends can be recognized in that the older provinces in the southeast, e.g., Balingian, updip part of Baram delta, Rajang Group fold and thrust belt, inboard belt, and outboard belt, have been subjected to strong compressional tectonics, whereas the younger provinces in the northwest, e.g., central Luconia, north Luconia, southwest Luconia, and the central part of the Baram delta, have undergone predominantly extensional tectonics. The tectonic evolution of these provinces from late Eocene to Holocene, relative to the postulated subduction zones and major tectonic lineations recognized in the region, are discussed.

  17. Regional maps of subsurface geopressure gradients of the onshore and offshore Gulf of Mexico basin

    USGS Publications Warehouse

    Burke, Lauri A.; Kinney, Scott A.; Dubiel, Russell F.; Pitman, Janet K.

    2013-01-01

    The U.S. Geological Survey created a comprehensive geopressure-gradient model of the regional pressure system spanning the onshore and offshore Gulf of Mexico basin, USA. This model was used to generate ten maps that included (1) five contour maps characterizing the depth to the surface defined by the first occurrence of isopressure gradients ranging from 0.60 psi/ft to 1.00 psi/ft, in 0.10-psi/ft increments; and (2) five supporting maps illustrating the spatial density of the data used to construct the contour maps. These contour maps of isopressure-gradients at various increments enable the identification and quantification of the occurrence, magnitude, location, and depth of the subsurface pressure system, which allows for the broad characterization of regions exhibiting overpressured, underpressured, and normally pressured strata. Identification of overpressured regions is critical for exploration and evaluation of potential undiscovered hydrocarbon accumulations based on petroleum-generation pressure signatures and pressure-retention properties of reservoir seals. Characterization of normally pressured regions is essential for field development decisions such as determining the dominant production drive mechanisms, evaluating well placement and drainage patterns, and deciding on well stimulation methods such as hydraulic fracturing. Identification of underpressured regions is essential for evaluating the feasibility of geological sequestration and long-term containment of fluids such as supercritical carbon dioxide for alternative disposal methods of greenhouse gases. This study is the first, quantitative investigation of the regional pressure systems of one of the most important petroleum provinces in the United States. Although this methodology was developed for pressure studies in the Gulf of Mexico basin, it is applicable to any basin worldwide.

  18. Natural Gas Hydrates in the Offshore Beaufort-Mackenzie Basin-Study of a Feasible Energy Source II

    SciTech Connect

    Majorowicz, J. A. Hannigan, P. K.

    2000-09-15

    In the offshore part of Beaufort-Mackenzie Basin depth of methane hydrate stability reaches more than 1.5 km. However, there are areas in the western part of the basin where there are no conditions of methane hydrate stability. Construction of the first contour maps displaying thickness of hydrate stability zones as well as hydrate stability zone thicknesses below permafrost in the offshore area, shows that these zones can reach 1200 m and 900 m, respectively. Depth to the base of ice-bearing relict permafrost under the sea (depth of the -1{sup o}C isotherm-ice-bearing permafrost base) and regional variations of geothermal gradient are the main controlling factors. Hydrostatic pressures in the upper 1500 m are the rule. History of methane hydrate stability zone is related mainly to the history of permafrost and it reached maximum depth in early Holocene. More recently, the permafrost and hydrate zone is diminishing because of sea transgression. Reevaluation of the location of possible gas hydrate occurrences is done from the analysis of well logs and other indicators in conjunction with knowledge of the hydrate stability zone. In the offshore Beaufort-Mackenzie Basin, methane hydrate occurs in 21 wells. Nine of these locations coincides with underlying conventional hydrocarbon occurrences. Previous analyses place some of the hydrate occurrences at greater depths than proposed for the methane hydrate-stability zone described in this study. Interpretation of geological cross sections and maps of geological sequences reveals that hydrates are occurring in the Iperk-Kugmallit sequence. Hydrate-gas contact zones, however, are possible in numerous situations. As there are no significant geological seals in the deeper part of the offshore basin (all hydrates are within Iperk), it is suggested that overlying permafrost and hydrate stability zone acted as the only trap for upward migrating gas during the last tens of thousand of years (i.e., Sangamonian to Holocene)

  19. Regional comparison of syn- and post-rift sequences in salt and salt-free basins offshore Brazil and Angola/Namibia, South Atlantic

    NASA Astrophysics Data System (ADS)

    Strozyk, Frank; Back, Stefan; Kukla, Peter

    2015-04-01

    The large South Atlantic basins offshore South America and Africa record a highly variable syn- to post-breakup tectono-stratigraphic development. The present-day diversity in the structural and sedimentary architecture of the conjugate margins offshore southern Brazil, Namibia and Angola reflects variations in the interplay of a number of controlling factors, of which the most important are i) the structural configuration of each margin segment at the time of break-up, ii) the post break-up geodynamic history including tectonics and magmatism, and iii) variations in the type, quantity and distribution of sediment input to the respective margin segment. Particularly the basins around the Rio Grande Rise - Walvis Ridge volcanic complex show a pronounced tectono-stratigraphic asymmetry both along the respective continental margin and across the Atlantic. Only a few attempts exist to establish a regional tectono-stratigraphic correlation framework across the South Atlantic Ocean, mainly because of the lack of data across entire margin segments and limited resolution of basin wide geophysics. Still unresolved issues particularly concern the explanation of the basin-specific geological evolution of respective margin segments along the same continental margin, as well as the correlation of conjugate basins and margin segments across the Atlantic Ocean. In our study we present interpretations and first-pass restorations of regional 2D seismic-reflectivity data from the large basins offshore Brazil (Pelotas Basin, Santos Basin, Campos Basin, Espirito Santo Basin), and offshore Namibia and Angola (Walvis Basin, Namibe Basin, Benguela Basin, Kwanza Basin), which represent four adjacent pairs of conjugate basins on both sides of the South Atlantic. Results are used to document and compare on a basin-scale the contrasting styles of rift and post-rift settings during and after the continental breakup.

  20. Marine Geomorphology and Gravity Flow Modelling in Transient Pull-Apart Basins of the Offshore Alpine Fault, New Zealand

    NASA Astrophysics Data System (ADS)

    Strachan, L. J.; Bostock, H. C.; Barnes, P.; Neil, H.

    2015-12-01

    The offshore component of the dextral strike-slip Alpine Fault has one of highest slip rates on Earth (~27-32 mm/yr). As it passes offshore, the Alpine Fault becomes segmented, with the formation of several rapidly deforming pull-apart basins. Here we focus on the detailed quantification of the 3 northern-most basins, all located <8 km from the Fiordland coastline. High-resolution 30 kHz multibeam bathymetric data and 30 sediment cores are used to determine Late Holocene (<2 ka) sedimentary delivery pathways and processes. A quantitative geomorphic analysis of each basin using ESRI ArcMap version 10.2 and associated spatial analyst tools, reveal huge complexity along the Fiordland continental margin. The margin is shaped largely by Late Pleistocene glacio-marine sedimentary processes, ongoing tectonic deformation, and localized enhanced deposition of Late Holocene gravity flows in nearshore pull-apart basins. Excellent core coverage over the study area allow us to interpret gravity flow types and behaviours. We use these interpretations along with basin geomorphological boundary conditions to model turbidity current flow behaviours.

  1. Flip or Flop: Are Math Teachers Using Khan Academy as Envisioned by Sal Khan?

    ERIC Educational Resources Information Center

    Cargile, Lori A.; Harkness, Shelly Sheats

    2014-01-01

    Khan Academy (KA) is a free web-based intelligent tutor, which has been featured in countless media outlets for its potential to change mathematics instruction. The founder and executive director, Salman Khan, recommends that KA be used to personalize instruction, freeing up class time for engaging high yield activities like student discourse and…

  2. Sill Emplacement and Forced Folding in the Canterbury Basin, offshore SE New Zealand

    NASA Astrophysics Data System (ADS)

    Reeves, Jennifer; Magee, Craig; Jackson, Christopher

    2017-04-01

    Sill-complexes are common in sedimentary basins worldwide. The geometry of sill-complexes and their associated deformation can be used to unravel tectono-magmatic events. For example, intruding magma may uplift the overburden and the free surface to produce forced folds that are typically either dome-shaped or flat-topped. These four-way dip closures can form suitable hydrocarbon traps and dating of onlapping of sedimentary strata allows the timing of emplacement, relative to hydrocarbon generation and migration to be assessed. Furthermore, these forced folds directly overlie the forcing intrusion and their volume is commonly assumed to equal that of the emplaced magma. This relationship between folds, which may be expressed that the Earth's surface, and magma volume is fundamental for volcano predication due to the use of ground deformation as a proxy for the location and magnitude of future eruptions. However, recent studies have demonstrated that fluidization of weak host rock can accommodate magma during non-brittle emplacement, producing little or no overburden deformation. Assessing the mechanics of intrusion-induced forced folding is therefore critical to a variety of Earth Science disciplines. Here, we use 3D seismic reflection data map four sills at a high-resolution within the underexplored Canterbury Basin, offshore SE New Zealand. We demonstrate that: (i) despite similar emplacement levels, forced folds are only developed above two of the sills, with no apparent uplift above the other two sills; (ii) onlap of sedimentary onto forced folds and associated hydrothermal vents indicates two episodes of sill emplacement in the Whaingaroan (34.6-31.8 Ma) and Opoitian (5.33-3.7 Ma); and (iii) intra-fold thickness is variable, with lower intervals within the folds displaying a flat-topped geometry overlain by sedimentary strata displaying dome-shaped folding. We discuss the formation of these forced folds as assess the role of non-brittle and inelastic

  3. Control of salt tectonics by young basement tectonics in Brazil`s offshore basins

    SciTech Connect

    Szatmari, P.; Mohriak, W.

    1995-08-01

    The Campos basin (offshore SE Brazil) is one of the most successful areas of oil exploration in South America. Discovered 20 years ago, its production (500,000 b/d) and reserves (2.9 billion barrels) are second only to Venezuela`s. This richness is due, to a large extent, to intense salt tectonics and the abundance of turbidites. Reactivated basement structures onshore provide a unique opportunity to understand the role of young basement tectonics in controlling salt tectonics and petroleum occurrence. The mountains of SE Brazil, over 1500 m high, formed by the reactivation of late Precambrian thrust and wrench zones under E-W compression, presumably caused by Mid-Atlantic ridge push. Coastal mountain ranges, up to 3000 m high, are limited to the segment of the Atlantic between the Vitoria-Trindade hotspot chain and the Rio Grande Rise. The coastal ranges formed as this segment of oceanic crust and adjacent continental margin were pushed WSW along a reactivated Precambrian wrench zone. To the north of this segment, salt tectonics is mostly due to basinward sliding on a tilted salt layer. Along the coastal ranges, to this is added basinward escape of the salt from beneath prograding sediments derived from the rising mountains. Extension above the salt tends to be compensated by compression farther basinward. Salt canopies, frequent in the Gulf of Mexico, occur only near the Abrolhos hotspot, where high temperatures during volcanic activity sharply reduced the viscosity of the salt.

  4. Complex intrasalt deformation in the Santos Basin, offshore Brazil: the role of density inversion

    NASA Astrophysics Data System (ADS)

    Dooley, Tim; Jackson, Chris; Jackson, Martin; Hudec, Mike; Rodriguez, Clara

    2016-04-01

    Understanding intrasalt structure may elucidate the fundamental kinematics and, ultimately, the mechanics of diapir growth. However, there have been relatively few studies of the internal structure of salt diapirs outside the mining industry because their cores are only partly exposed in the field and poorly imaged in seismic reflection data. 3D seismic reflection from the Santos Basin, offshore Brazil reveal enigmatic allochthonous salt sheets of older evaporites emplaced above an overlying stratified evaporite sequence. Seismic-stratigraphic observations form the basis for a kinematic model invoking: (i) initial inward flow and thickening of the lower mobile salt within the rising wall, and arching of stratified overburden; (ii) breaching of the overburden, ascent of mobile lower evaporites along single or multiple feeders, and emplacement of upper-wall sheets or canopies; and (iii) later diapir squeezing due to regional shortening. We designed and ran physical models to explain how and why these structures occur, and to provide a mechanical basis for our kinematic model. Our first two models simulated salt having uniform internal density, with walls growing by (i) initially symmetric differential loading; and (ii) initially symmetric differential loading plus shortening. These models reproduced anticlines and injection folds seen in the simpler deformed walls in the Santos Basin. However, neither model reproduced the most complex structures (e.g. allochthonous intrusions, steep feeders, recumbent synclines) seen within the Santos evaporites. Thus, we argue differential loading and shortening alone are insufficient to generate these complex structures. In our third model, a less-dense lower evaporite was overlain by denser upper evaporites, similar to the density structure found in Santos Basin wellbores. In this model the wall rose solely by differential loading, with the lower mobile unit breaching the overlying stratified evaporites to form vertical diapirs

  5. The junction of Hellenic and Cyprus arcs: the Bey Daglari lineament, offshore termination of the Antalya Basin

    NASA Astrophysics Data System (ADS)

    Gogacz, A.; Hall, J.; Çifçi, G.; Yaşar, D.; Küçük, M.; Yaltırak, C.; Aksu, A.

    2009-04-01

    The Antalya Basin is one of a series of basins that sweep along the Cyprus Arc in the forearc region between the (formerly) volcanic Tauride Mountains on Turkey in the north and the subduction zone and associated suture between the African plate and the Aegean-Anatolian microplate in the eastern Mediterranean, south of Cyprus. Miocene contraction occurs widely on southwest verging thrusts. Pliocene-Quaternary structures vary from extension/transtension in the northeast, adjacent to the Turkish coastline, to transpression in the southwest, farther offshore. All these structures are truncated at the northwest end of the Antalya Basin by a broad zone of NNE-SSW-trending transverse structure that appears to represent a prolongation of the extreme easterly transform end of the Hellenic arc. Our mapping suggests that this broad zone links the Hellenic Arc with the Isparta Angle in southern Turkey, which we suggest is an earlier location of the junction of Hellenic and Cyprus Arcs: the junction migrated to the southwest over time, as the Hellenic Arc rolled back. The Turkish coastline turns from parallel to the Antalya Basin structures in the east to a N-S orientation, cutting across the trend of the Antalya Basin. The Antalya Complex and the Bey Dağlari Mountains provide a spectacular backdrop to this edge of the offshore basin. Somewhere offshore lies the structural termination of the Antalya Basin. In 2001, we acquired around 400 km of high-resolution multi-channel seismic reflection data across the western end of the Antalya Basin to explore the nature of the termination, which we call the Bey Dağlari lineament. We present a selection of the seismic profiles with interpretation of the nature and Neogene history of the lineament. Landward of the N-S-trending coastline, ophiolites of the Antalya Complex are exposed in a series of westerly-verging thrust slivers that extend to the carbonate sequences of the Bey Dağlari Mountains. Our seismic data indicate that N

  6. The Junction of Hellenic and Cyprus Arcs: the Bey Daglari Lineament, Offshore Termination of the Antalya Basin

    NASA Astrophysics Data System (ADS)

    Gogacz, A.; Hall, J.; Cifci, G.; Yasar, D.; Kucuk, M.; Yaltirak, C.; Aksu, A.

    2009-05-01

    The Antalya Basin is one of a series of basins that sweep along the Cyprus Arc in the forearc region between the (formerly) volcanic Tauride Mountains on Turkey in the north and the subduction zone and associated suture between the African plate and the Aegean-Anatolian microplate in the eastern Mediterranean, south of Cyprus. Miocene contraction occurs widely on southwest verging thrusts. Pliocene-Quaternary structures vary from extension/transtension in the northeast, adjacent to the Turkish coastline, to transpression in the southwest, farther offshore. All these structures are truncated at the northwest end of the Antalya Basin by a broad zone of NNE-SSW-trending transverse structure that appears to represent a prolongation of the extreme easterly transform end of the Hellenic arc. Our mapping suggests that this broad zone links the Hellenic Arc with the Isparta Angle in southern Turkey, which we suggest is an earlier location of the junction of Hellenic and Cyprus Arcs: the junction migrated to the southwest over time, as the Hellenic Arc rolled back. The Turkish coastline turns from parallel to the Antalya Basin structures in the east to a N-S orientation, cutting across the trend of the Antalya Basin. The Antalya Complex and the Bey Dağları Mountains provide a spectacular backdrop to this edge of the offshore basin. Somewhere offshore lies the structural termination of the Antalya Basin. In 2001, we acquired around 400 km of high-resolution multi-channel seismic reflection data across the western end of the Antalya Basin to explore the nature of the termination, which we call the Bey Dağları lineament. We present a selection of the seismic profiles with interpretation of the nature and Neogene history of the lineament. Landward of the N-S-trending coastline, ophiolites of the Antalya Complex are exposed in a series of westerly-verging thrust slivers that extend to the carbonate sequences of the Bey Dağları Mountains. Our seismic data indicate that N

  7. Permian storm current-produced offshore bars from an ancient shelf sequence : Northwestern Karoo basin, republic of South Africa

    NASA Astrophysics Data System (ADS)

    Smith, A. M.; Zawada, P. K.

    The Ecca-Beaufort transition zone from the Karoo Basin comprises upward-coarsening sequences which are interpreted as prograding, storm-produced offshore bars. Eight facies are recognised: (A) dark-grey shale, (B) thinly interbedded siltstone and mudstone, (C) thinly interbedded siltstone and very fine-grained sandstone, (D) blue-grey coarse-grained siltstone, (E) low-angle truncated and flat-laminated sandstone, (F) wave-rippled sandstone, (G) planar cross-bedded sandstone, (H) intraformational clay-pellet conglomerate. Four sub-environments are recognised, these being: (1) the bar crest which comprises proximal tempestites, (2) the bar slope consisting of soft-sediment deformed siltstone, (3) the bar fringe/ margin which is composed of storm layers and offshore siltstones and (4) the interbar/offshore environment comprising siltstone and distal storm layers. These bars formed in response to wave and storm processes and migrated across a muddy shelf environment. The orientation of bars was probably coast-parallel to subparallel with respect to the inferred north-northwest-south-southeast coastline. These proposed, storm-produced bars acted as major depo-centres within the shelf setting of the study area. As shelf sediments are recorded from almost the entire northwestern Karoo Basin it is anticipated that bar formation was an important sedimentary factor in the deposition of the sediments now referred to as the Ecca-Beaufort transition zone.

  8. 2014 Summer Series - Salman Khan - Khan Academy: Education Re-imagined

    NASA Image and Video Library

    2014-06-26

    In 2004, Khan began tutoring his young cousin in math. By 2006, word got around and Khan was tutoring 15 family friends and cousins as a hobby. He also began posting videos of his hand-scribbled tutorials on YouTube. In 2009, when the practice problems and instructional videos were reaching tens of thousands of students per month, he quit his day job to commit himself fully to the not-for-profit Khan Academy. It's now the most-used library of educational lessons on the web, with over 10 million unique students per month, over 300 million lessons delivered, and over a billion exercises completed.

  9. Optimal Multiple Attenuation Flow for a Seismic Dataset in the Western Jeju Basin, Offshore Southern Korea

    NASA Astrophysics Data System (ADS)

    Son, W.; Koo, N. H.; KIM, B. Y.; Cheong, S.; Kim, Y. J.; Yoon, Y.; Joo, Y.; Kim, S. M.; Lee, H. Y.

    2016-12-01

    We acquired 2-D multichannel seismic data in the western Jeju Basin, offshore southern Korea. A 1380 in3 air-gun array produced seismic pulses. The shot spacing is 25 m. The number of channels is 156 and the group interval is 12.5 m. The length of the survey line is about 45 km. The water depth in this area is about 70 m. Since the water depth is very shallow, the raw data are severely contaminated with short-period water bottom multiples and noises. In order to attenuate these multiples and noises, we tested several combinations of processing modules to our marine seismic data. The overall workflow of the seismic data processing is composed of low-cut filter, spherical divergence correction, swell noise attenuation, Tau-p filtering, Tau-p deconvolution, surface-related multiple elimination (SRME), velocity analysis, Radon demultiple, and pre-stack time migration. Through the parameter testing, we have confirmed that the Tau-p filtering, the Tau-p deconvolution, and the SRME among the several demultiple techniques are very effective for the multiple attenuation in the study area. The Tau-p filtering is useful for attenuation of the linear noise in the near trace and the direct waves. The Tau-p deconvolution technique effectively attenuates the short-period multiples. The SRME efficiently eliminates the multiples contained in the near offsets. We could generate the multiple-suppressed pre-stack time migration section using our optimal seismic data processing flow. From the results, we have confirmed that our data processing sequences are effective in attenuating the multiples and improve the signal to noise ratio.

  10. Deformation-driven fluid escape in the Levant Basin, offshore southern Israel

    NASA Astrophysics Data System (ADS)

    Eruteya, Ovie Emmanuel; Waldmann, Nicolas; Reshef, Moshe; Ben-Avraham, Zvi

    2016-04-01

    Submarine fluid emissions are global phenomena, which can be inferred from the presence of seafloor morphologies (e.g. pockmarks, mud volcanoes) occurring in various geological settings. However, despite the Levant Basin been a prolific hydrocarbon province, only a paucity of fluid escape morphologies have been identified on the present-day seafloor. In this study, we present a detailed analysis of a newly available high-resolution 3D seismic reflection dataset from offshore southern Israel. Evidences of subsurface fluid plumbing and escape are manifested here as present-day seafloor pockmarks, paleo-pockmarks, pipe structures and enhanced reflectivity patterns. Interestingly, these pockmarks are situated on and around bathymetric highs, which are ridges related to the Palmachim Disturbance. Our initial results show the fluid flow structures are spatially localized above a region of complex evaporites evacuation at depth, and likewise proximal to a shallower region characterized by high amplitude reflectors. The latter may be evidences for a shallow gas system. Our initial hypothesis proposes a dual shallow-source driven focused fluid flow system. Yet, we favour a deeper Messinian plumbing system driving fluid flow across the overburden in the study area. Corroborating this are fault systems characterized near the pipes feeding the seafloor pockmarks and paleo-pockmark, detaching in the upper Messinian evaporite. We further suggest that a combined supra-salt deformation system arising from the evacuation of the Messinian evaporites coupled with gravitational tectonics are in charge of modulating focused fluid flow. Under this scenario the emplaced mass transport complex acts as a transient reservoir for fluid flow, dewatering under deformation and channelling fluids towards the seafloor for expulsion. However, the contributions from microbially-generated methane in the shallow Quaternary overburden associated with the channel-levee complex cannot be neglected.

  11. Forward modeling pore pressure evolution in the Ursa Basin, offshore Louisiana, Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Flemings, P. B.; You, Y.; Sawyer, D.; Schneider, J.

    2008-12-01

    We simulate deposition, pore pressure evolution, and flow in sediments of the Ursa Basin, Gulf of Mexico since 200 ka. These strata are composed of four successive depositional units: hemipelagic mudstone, the Blue Unit basin-floor fan, channel-levee deposition, and distal fan deposits. The Blue Unit, a laterally continuous, horizontal, sand-rich body overlies the hemipelagic mudstone. Channel-levee sediments buried the Blue Unit asymmetrically: its western margin (Site U1324) is 600 meters thick whereas its eastern margin (Site U1322) is only 230 meters thick. The base of the Blue Unit is dated at approximately 70ka and mudstones 20 meters above the Blue Unit are dated at 57 ky. Permeability is assumed to vary exponentially with porosity (log (k) = γφ +k0, where k is vertical permeability (m2), φ is porosity, and γ and k0 are fitting parameters). For clayey silts γ is 9.19 and k0 is -19.77, whereas for silty clays γ is 9.17 and k0 is -21.67. Compression is described as an exponential function of effective stress: e = -B/A +(eo+ B/A)×(σvhA/ln(10). For the Ursa mudstones, A = 0.338 and B = 0.152, eo = 0.894. We find that the rapid sedimentation at Site U1324 (~12 mm/yr) generates severe overpressures λ* =0.6 (λ* = P*/σvh). , where P* is overpressure and σvh is the hydrostatic effective stress), whereas a lower sedimentation rate at Site 1322 (3 mm/yr) generates modest overpressure (λ* = 0.3). The degree of lateral flow within the Blue Unit is striking: immediately upon burial by overlying mudstone, it acts to completely focus flow from the thick overburden section (Site U1324) toward the thin overburden section (Site U1322). This results in significant elevation of pore pressure at Site U1322, the location of lowest overpressure and provides a mechanism for the large submarine landslides and low regional gradient (2 degrees) offshore from the Mississippi delta.

  12. Toward a One-World Schoolhouse: Interview with Sal Khan

    ERIC Educational Resources Information Center

    Pinkus, Ari

    2015-01-01

    Ten years ago, Salman Khan, with three degrees from MIT and an MBA from Harvard, agreed to help tutor his cousin Nadia, who was struggling in math. Using Yahoo's Doodle notepad, Khan offered Nadia a sequence of mini lessons designed to scaffold her learning. Over time, other friends and relatives heard about Khan's success and asked for similar…

  13. Toward a One-World Schoolhouse: Interview with Sal Khan

    ERIC Educational Resources Information Center

    Pinkus, Ari

    2015-01-01

    Ten years ago, Salman Khan, with three degrees from MIT and an MBA from Harvard, agreed to help tutor his cousin Nadia, who was struggling in math. Using Yahoo's Doodle notepad, Khan offered Nadia a sequence of mini lessons designed to scaffold her learning. Over time, other friends and relatives heard about Khan's success and asked for similar…

  14. Tuned Liquid Column Damper based Reduction of Dynamic Responses of Scaled Offshore Platforms in Different Ocean Wave Basins

    NASA Astrophysics Data System (ADS)

    O'Donnell, Deirdre; Murphy, Jimmy; Desmond, Cian; Jaksic, Vesna; Pakrashi, Vikram

    2017-05-01

    Control of dynamic responses of renewable energy device platforms is important for their performance, safe operation and efficiency over their lifetime under regular and extreme wave conditions. Tuned Liquid Column Dampers (TLCDs) have been recently considered as a viable passive control mechanism in this regard but limited information is available in relation to their experimental performance. This paper compares scaled experiments conducted in two different ocean wave basins where floating offshore platforms were retrofitted with multiple TLCDs (MTLCDs). Performance of such MTLCDs in these scaled ocean wave basins are evaluated and compared considering control of dynamic responses for a specific objective. This paper shows the potential of MTLCDs to reduce motions in offshore platforms for different designs and platforms of MTLCDs and provides a comparison of the levels of reduction of dynamic responses achieved. The performance of MTLCDs in different wave basins create an experimental evidence base behind the potential use of such solutions, the objectives of such use and highlight related challenges and limitations.

  15. Reimagining Khan Analytics for Student Coaches

    ERIC Educational Resources Information Center

    Cunningham, Jim

    2015-01-01

    In this paper, I describe preliminary work on a new research project in learning analytics at Arizona State University. In conjunction with an innovative remedial mathematics course using Khan Academy and student coaches, this study seeks to measure the effectiveness of visualized data in assisting student coaches as they help remedial math…

  16. Implications from deepwater depositional elements in the fold-and-thrust belt of the remnant ocean basin offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Liang-Fu; Liu, Char-Shine; Chang, Jih-Hshin

    2017-04-01

    The northeastern South China Sea Basin is being closed due to the oblique collision between the Luzon Volcano Arc and the Chinese Continental Margin. The orogen of Taiwan Island situated in the tropical/subtropical zone with a high uplifting rate provides voluminous sediments to the nearby basins. As a remnant ocean basin, the closing basin in offshore southwestern Taiwan has accommodated a large amount of synorogenic sediments. Through multi-channel seismic profiles, several depositional elements in the deepwater fold-and-thrust belt of the lower Gaoping slope have been identified. These sedimentary layers were deposited before deformation and later incorporated into the orogenic wedge. The N-S trend leveed channels developed along the strike of the orogenic wedge and occupied the most area of the lower Gaoping Slope. This channel-levee complex presents the ancient fan which should relate to the Penghu submarine canyon, named "Penghu Turbidite System". In contrast, at the mouth of the middle section of the Gaoping Submarine Canyon, the buried channels trend SW-NE are characterized by massive high amplitude reflection packets (HARPs) which may represent the coarse grain infills. This facies turns to channelized lobes outward that interfinger with the Penghu Turbidite System. Two different characteristics of submarine fans reflect the different natures of Penghu and Gaoping submarine canyons. Since the tectonic convergence approaching, these two canyons rejuvenated and started to erode the aforementioned deposits. The channels become erosional in the fold-and-thrust belt that most of the sediments bypass through the fold-and-thrust belt or spill into the piggyback accommodations. The newly discovered sedimentary records in this study imply how these two sediment dispersal systems work before and after structuring, which is a puzzle for better understanding the sedimentary history of the remnant ocean basin offshore southwestern Taiwan.

  17. Geologic appraisal of the petroleum potential of offshore southern California; the borderland compared to onshore coastal basins

    USGS Publications Warehouse

    Taylor, James Carlton

    1976-01-01

    Offshore southern California is part of a much larger Pacific continental margin, and the two areas have a similar geologic history at least as far back as middle Tertiary time. Assessment of the petroleum potential of the offshore Southern California borderland is accomplished by examining the adjacent highly explored productive coastal basins in the tectonically unstable area west of the San Andreas fault. Known oil and gas accumulations in this region can be characterized as follows: 88 percent comes from the Los Angeles and Ventura basins; 87 percent has been found in late Miocene and younger strata and only 0.2 percent has been found in Eocene strata; 80 percent has been found in thick deposits of deep-water turbidite reservoirs; and 5 percent has been found in fractured Miocene siliceous shale reservoirs. The percentage of siliceous shale reservoirs will increase as a result of recent discoveries in this rock type in the Santa Barbara Channel. Of the 212 known fields only 5 are giants (greater than 500 million barrels), and these fields account for 52 percent of all past production from the region. Most fields are faulted anticlines, and the largest fields have the highest oil recoveries per acre. Geologic knowledge of the offshore is limited by the availability of data. Data have been obtained from geophysical surveys, analyses of bedrock samples from the sea floor, and extrapolations of data from the mainland and offshore islands. Several factors have a negative effect on the assessment of the petroleum potential of the southern California borderland. They are: 1. The Neogene section is relatively thin, and the Paleogene section is thin and has a limited distribution. 2. Over large areas, Miocene sediments apparently rest directly on basement. 3. Along much of the Santa Rosa-Cortes Ridge, sediments are uplifted and truncated, exposing Paleogene rocks. 4. Organic content in Paleogene sediments is believed too low to generate large amounts of petroleum. 5

  18. Thermotectonic history of the southeastern Brazilian margin: Evidence from apatite fission track data of the offshore Santos Basin and continental basement

    NASA Astrophysics Data System (ADS)

    Engelmann de Oliveira, Christie Helouise; Jelinek, Andréa Ritter; Chemale, Farid; Cupertino, José Antônio

    2016-08-01

    The Santos Basin is the largest offshore sedimentary basin in the southeastern Brazilian margin and originated by breakup of West Gondwana in the Early Cretaceous. We carried out a new thermochronological study by apatite fission track analysis from borehole samples of the Santos Basin and its continental basement to constrain the tectonic history of the southeastern Brazilian margin. Apatite fission track central ages of the basement and borehole samples vary from 21.0 ± 1.8 to 157.0 ± 35.0 Ma and from 6.5 ± 1.1 to 208.0 ± 11.0 Ma, respectively. From thermal modeling, the basement samples reached the maximum paleotemperatures during the final breakup of South America and Africa. The onshore basement and offshore basin record an early thermotectonic event during the Late Cretaceous linked to the uplift and denudation of the Serra do Mar and Serra da Mantiqueira. Maturation of the organic matter in the offshore basin is related with the progressive increase of the geothermal gradient due to burial. The thermal modeling indicates that the oil generation window started at 55-25 Ma. The basement samples experienced the final cooling during the Cenozoic, with an estimated amount of denudation linked to the sedimentary influx in the offshore basin. A rapid cooling during the Neogene becomes evident and it is linked to the reactivation along Precambrian shear zones and change of the Paraíba do Sul drainage system.

  19. Episodic Deep Fluid Expulsion at Mud Volcanoes in the Kumano Forearc Basin, SE Offshore Japan

    NASA Astrophysics Data System (ADS)

    Hammerschmidt, S.; Kopf, A.

    2014-12-01

    Compressional forces at convergent margins govern a variety of processes, most prominently earthquakes, landslides and mud volcanoes in the forearc. Although all seem related to fluid pressure changes, mud volcanoes are not only characterized by expulsion of fluids, but also fluidized mud and clasts that got ripped-up during mud ascension. They hence provide information regarding mobilization depth, diagenetic overprint, and geodynamic pathways. At the Nankai Trough subduction zone, SE offshore Japan, mud volcanism id common and supposed to be related to seismogenic processes. During MARUM Expedition SO-222 with R/V SONNE, mud volcanoes in the Kumano forearc basin were mapped, cored and sampled. By extending the Integrated Ocean Drilling Program (IODP) Kumano transect landwards, 5 new mud volcanoes were identified by multibeam mapping. Cores revealed mud breccia with semi-consolidated silt- to claystone clasts and gaseous fluid escape structures, while the hemipelagic background sediments are characterized by intercalations of turbidites, ash layers and calcareous fossils. Clasts were subject to thin-section analyses, and the cores were sampled for XRD analyses and radiocarbon dating. Clasts showed prominent deformation structures, neomorphism and pores and fractures filled with polycrystalline quartz and/or calcite cement, probably formed during deep burial and early metamorphosis. Illite crystallinity based on XRD measurements varies between 0.24 and 0.38, which implies that the material originates from the Anchizone at depths ≥ 4 km. Radiocarbon dating revealed ages between 4450 and 30300 yr cal. BP, with age reversals occurring not earlier than 17000 yr cal. BP. Radiocarbon dating beneath turbidites and ash layers found at mud volcano #9 points to an episodic occurrence of these earthquake-related features in intervals of ca. 620 yr, while the mud volcano itself remained inactive. In summary, the preliminary results suggest that the mud volcanoes are nurtured

  20. Structure of the la VELA Offshore Basin, Western Venezuela: AN Obliquely-Opening Rift Basin Within the South America-Caribbean Strike-Slip Plate Boundary

    NASA Astrophysics Data System (ADS)

    Blanco, J. M.; Mann, P.

    2015-12-01

    Bathymetric, gravity and magnetic maps show that the east-west trend of the Cretaceous Great Arc of the Caribbean in the Leeward Antilles islands is transected by an en echelon series of obliquely-sheared rift basins that show right-lateral offsets ranging from 20 to 40 km. The basins are 75-100 km in length and 20-30 km in width and are composed of sub-parallel, oblique slip normal faults that define deep, bathymetric channels that bound the larger islands of the Leeward Antilles including Aruba, Curacao and Bonaire. A single basin of similar orientation and structure, the Urumaco basin, is present to the southwest in the Gulf of Venezuela. We mapped structures and sedimentation in the La Vela rift basin using a 3D seismic data volume recorded down to 6 seconds TWT. The basin can be mapped from the Falcon coast where it is correlative with the right-lateral Adicora fault mapped onshore, and its submarine extension. To the southeast of the 3D survey area, previous workers have mapped a 70-km-wide zone of northeast-striking, oblique, right-lateral faults, some with apparent right-lateral offsets of the coastline. On seismic data, the faults vary in dip from 45 to 60 degrees and exhibit maximum vertical offsets of 600 m. The La Vela and other obliquely-opening rifts accommodate right-lateral shear with linkages to intervening, east-west-striking right-lateral faults like the Adicora. The zone of oblique rifts is restricted to the trend of the Great Arc of the Caribbean and may reflect the susceptiblity of this granitic basement to active shearing. The age of onset for the basins known from previous studies on the Leeward Antilles is early Miocene. As most of these faults occur offshore their potential to generate damaging earthquakes in the densely populated Leeward Antilles is not known.

  1. Seismic expression of depositional systems tracts and application to hydrocarbon exploration in Bredasdorp basin, offshore South Africa

    SciTech Connect

    Beamish, G.W.J.

    1989-03-01

    Postrift Cretaceous sequences of Bredasdorp basin, offshore South Africa, were rigorously analyzed using the unified application of the latest seismic-stratigraphic, sequence-stratigraphic, and depositional systems concepts. Using 101 seismic profiles totaling 5600 km, the authors identified ten cyclic depositional sequences bounded by nine type 1 and two type 2 unconformities. Component depositional systems tracts exhibit a distinct seismic expression and can be delineated using truncation and lap-out relationships. Lowstand systems tracts developed on type 1 unconformities, which resulted from relative sea level fall below the shelf edge. In a terrigenous clastic basin such as Bredasdorp, these tracts are interpreted as being composed of basin-floor turbidite fans, channels, and/or sheets. These features formed contemporaneously with the erosion of incised valleys and submarine canyons, followed by channelized slope fans and deltaic/coastal lowstand wedges that prograded during a relative sea level rise. Subsequent flooding of the shelf as relative sea level rise accelerated resulted in poorly defined transgressive systems tracts. With the relative sea level at a highstand, extensively developed deltaic/coastal systems prograded basinward exhibiting well-defined clinoforms. The major hydrocarbon plays in the lowstand tracts occur as mounded basin-floor turbidite fans, channel fills, and draped sheets and are found in the updip pinch-out of deltaic/coastal sandstones.

  2. Chapter 44: Geology and petroleum potential of the Lincoln Sea Basin, offshore North Greenland

    USGS Publications Warehouse

    Sorensen, K.; Gautier, D.; Pitman, J.; Ruth, Jackson H.; Dahl-Jensen, T.

    2011-01-01

    A seismic refraction line crossing the Lincoln Sea was acquired in 2006. It proves the existence of a deep sedimentary basin underlying the Lincoln Sea. This basin appears to be comparable in width and depth to the Sverdrup Basin of the Canadian Arctic Islands. The stratigraphy of the Lincoln Sea Basin is modelled in analogy to the Sverdrup Basin and the Central Spitsbergen Basin, two basins between which the Lincoln Sea intervened before the onset of seafloor spreading in the Eurasian Basin. The refraction data indicates that the Lincoln Sea Basin is capped by a kilometre-thick, low-velocity layer, which is taken to indicate an uplift history similar to, or even more favourable than, the fairway part of the Sverdrup Basin. Tectonic activity in the Palaeogene is likely to constitute the major basin scale risk. We conclude that the Lincoln Sea Basin is likely to be petroliferous and contains risked resources on the order of 1 ?? 109 barrels of oil, to which comes an equivalent amount of (associated and nonassociated) gas. ?? 2011 The Geological Society of London.

  3. Nearshore half-grabens as analogues for offshore, early Carboniferous rift basins along the SW Barents Sea Margin

    NASA Astrophysics Data System (ADS)

    Koehl, Jean-Baptiste; Bergh, Steffen G.; Indrevær, Kjetil; Lea, Halldis; Bergø, Espen; Henningsen, Tormod; Forthun, Tore; Faleide, Jan-Inge

    2016-04-01

    The present study focuses on the onshore-offshore correlation of brittle faults along the SW Barents Sea Margin, northern Norway. Several studies indicate that the SW Barents Sea Margin experienced a pulse of extensional deformation in the Late Devonian?-early Carboniferous, shortly after the Caledonian contractional deformation ended. The formation of major brittle faults and associated offshore basins that represent targets for hydrocarbon exploration, such as the NE-SW trending Nordkapp Basin, are thought to have initiated during this rifting event. Half-graben structures similar in shape and orientation to the southern segment of the Nordkapp Basin have been identified on the Finnmark Platform and in nearshore areas in coastal Finnmark, northern Norway. Although relatively smaller, these half-graben structures display the same asymmetric, sigma-shaped to triangular architecture in map view as the Nordkapp Basin and also initiated in the earliest Carboniferous, as confirmed by fossiliferous assemblages from shallow cores. The triangular shape of these half-graben structures is related to the presence of possible fault segments of the Trollfjord-Komagelv Fault Zone that trend WNW-ESE and partly truncate the NE-SW trending, sometimes arcuate, extensional brittle faults that bound the half-graben structures. High-resolution bathymetry data show that these half-graben structures internally display minor, NE-SW trending brittle faults and relatively high seafloor relief, thus possible fault displacement, at the intersection between these minor faults and the major, arcuate bounding faults. Microstructural analysis of fault-rocks in nearby onshore fault zones showed multiple generations of cataclasite, suggesting several episodes of faulting in the region. A major goal for future work will be to constrain the exact timing of the faulting event(s) with K/Ar radiometric dating of onshore fault-rocks. This may help estimating the timing of potential fluid migration

  4. Pliocene to recent infilling and subsidence of intraslope basins offshore Louisiana

    SciTech Connect

    Pratson, L.F.; Ryan, W.B.F.

    1994-10-01

    Intraslope basins on the lower eastern Louisiana continental slope are modern analogs of large oil- and gas-charged basins infilled on the upper Louisiana slope and buried landward beneath the shelf. High-resolution, gridded multibeam bathymetry and single-channel seismic reflection profiles are used to (1) characterize the morphology and shallow stratigraphy of 46 intraslope basins within the outer slope region; and (2) look for surficial evidence among the basins of slope channelways that fed sediment flows to the Mississippi Fan during the Pliocene-Pleistocene. Computer algorithms, traditionally employed for automatically mapping river networks in gridded land topography, are used to extract morphologic measurements of the intraslope basins from the gridded bathymetry. The basins are found to average approximately 15 km in length, 10 km in width, and 200 m in depth and occur over a map area of about 50 km{sup 2}. These dimensions, however, can range over an order of magnitude.

  5. Travel Time Tomographic Imaging of Shallow Fore-arc Basin Structure at the Cascadia Subduction Zone Offshore Washington and Oregon

    NASA Astrophysics Data System (ADS)

    Azarm, R.; Carton, H. D.; Carbotte, S. M.; Han, S.; Canales, J. P.; Nedimovic, M. R.

    2016-12-01

    We conduct a P-wave tomography study of shallow fore-arc basin structure at the Cascadia subduction zone using first-arrival travel times from two multi-channel seismic (MCS) profiles acquired with an 8-km long streamer in the frame of the 2012 Juan de Fuca Ridge to Trench program. The first profile extends offshore Gray's Harbor in Washington and the second extends offshore Oregon at the latitude of Hydrate ridge, with the fore-arc basin imaged below ˜60 and ˜70-km long shallow water (< 500 m) portions of these profiles, respectively. We use the travel time tomography method of VanAvendonk et al. [2004], which is based on the shortest path method for ray tracing, and iterative inversions driven by gradual reduction of the chi-square misfit (root mean square value of the difference between predicted and observed travel times normalized by pick uncertainty). We construct our starting model by hanging from the seafloor a 1D velocity profile based on interval velocities derived from semblance analysis of MCS data. Resolvability of the final model is assessed using checkerboard pattern tests with different anomaly sizes. We then compare our tomographically-derived velocity models to coincident seismic reflection images post-stack time migrated and converted to depth using our results. On the Washington shelf, where the fore-arc basin is segmented into three sub-basins, ray coverage mostly extends to ˜1.2-1.5 km below seafloor. Velocities in the shallowmost sediments show, at the large scale, a gradual decrease towards the shelf edge (from 2.1 to 1.8 km/s). At depth, regions devoid of clear reflections such as an ˜5 km large anticline core are associated with lower velocities than that obtained within mildly deformed sedimentary layers on either side (2.3 vs 2.7 km/s, measured at 1.2 km depth), suggesting the presence of localized fluid-rich regions within the basin. Analysis of the Oregon line is ongoing and results will be presented at the meeting.

  6. Impact of Cenozoic strike-slip tectonics on the evolution of the northern Levant Basin (offshore Lebanon)

    NASA Astrophysics Data System (ADS)

    Ghalayini, Ramadan; Daniel, Jean-Marc; Homberg, Catherine; Nader, Fadi H.; Comstock, John E.

    2014-11-01

    Sedimentary basins adjacent to plate boundaries contain key tectonic and stratigraphic elements to understand how stress is transmitted through plates. The Levant Basin is a place of choice to study such elements because it flanks the Levant Fracture System and the Africa/Anatolia boundary. This paper uses new high-quality 3-D seismic reflection data to unravel the tectonic evolution of the margin of this basin during the Cenozoic, the period corresponding to the formation of the Levant Fracture System, part of the Africa/Arabia plate boundary. Four major groups of structures are identified in the interpreted Cenozoic units: NW-SE striking normal faults, NNE-SSW striking thrust-faults, ENE-WSW striking dextral strike-slip faults, and NNE trending anticlines. We demonstrate that all structures, apart of the NW-SE striking normal faults, are inherited from Mesozoic faults. Their reactivation and associated folding started during the late Miocene prior to the Messinian salinity crisis due to a NW-SE compressional stress field. No clear evidence of shortening at present-day offshore Lebanon and no large NNE-SSW strike-slip faults parallel to the restraining bend are found indicating that the Levant Fracture System is mainly contained onshore at present day. The intermittent activity of the interpreted structures correlates with the two stages of Levant Fracture System movement during late Miocene and Pliocene. This paper provides a good example of the impact of the evolution of plate boundaries on adjacent basins and indicates that any changes in the stress field, as controlled by the plate boundary, will affect immediately the preexisting structures in adjacent basins.

  7. Stratigraphic and structural analysis of the Neogene sediments of the offshore portion of the Salina del Istmo Basin, southeastern Mexico

    NASA Astrophysics Data System (ADS)

    Gomez-Cabrera, Pedro Tomas

    2003-10-01

    Southeastern Mexico has been affected by regional and local tectonic events. Regional tectonic events are the Gulf of Mexico opening and the lateral movement of micro-plates on the Pacific margin. The local tectonic events are related to salt tectonics. Autochthonous Jurassic salt serves as the detachment level for the main compressional event in the late Miocene. Jurassic salt was allochthonously emplaced in the late Miocene, then partially displaced by a huge quantity of terrigenous sediments during the Plio-Pleistocene. This research is a study of the main geological processes that have influenced the structural and stratigraphic evolution of the Neogene sediments in the offshore portion of the Salina del Istmo basin known as the Marbella area. Owing to data availability, the project was divided into regional and local studies. The regional study is based on 2D multi-channel seismic reflection data, and the local study is based on a 3D seismic streamer survey. Structural analysis in the regional study permits the recognition of four buried fold belts (Agua Dulce, Catemaco, Marbella, and Marbella Norte) trending roughly NE. These fold belts are the result of tectonic convergence in the pacific margin during late Miocene. The Agua Dulce and Marbella Norte fold belts are separated by an enormous salt withdrawal basin called the Pescadores basin. The Pescadores basin is bounded on the north by a spectacular stepped, counter-regional structure. Beyond the Pescadores basin, a salt mini-basin area is recognized in the upper continental slope. Another important structural element is the Sal Somera canopy in the southern part of the study area. Sedimentation-rate analysis, based on isochore mapping in the local study area, indicates that from SB-2.4 to SB-2.6 Ma, deposition rate peaked with a maximum of 7.5 mm/yr. Regional and local structural restorations show that, in general, the maximum allochthonous salt mobilization was during the Plio-Pleistocene because of the

  8. Pore size controls on the base of the methane hydrate stability zone in the Kumano Basin, offshore Japan

    NASA Astrophysics Data System (ADS)

    Daigle, Hugh; Dugan, Brandon

    2014-11-01

    The base of the methane hydrate stability zone (MHSZ) in the Kumano Basin, offshore Japan, is marked by a bottom-simulating reflection (BSR) on seismic data. At Integrated Ocean Drilling Program Site C0002, which penetrates this BSR, the in situ temperature profile combined with bulk seawater methane equilibrium conditions suggest that the base of the MHSZ is 428 m below seafloor (bsf), which is 28 m deeper than the observed BSR (400 m bsf). We found that submicron pore sizes determined by mercury injection capillary pressure are sufficiently small to cause 64% of the observed uplift of the base of the MHSZ by the Gibbs-Thomson effect. This is the most thorough characterization of pore sizes within the MHSZ performed to date and illustrates the extent to which pore size can influence MHSZ thickness. Our results demonstrate the importance of considering lithology and pore structure when assessing methane hydrate stability conditions in marine sediments.

  9. Productive reorganization, outsourcing, and work relations in the offshore oil industry in the Campos Basin, Rio de Janeiro.

    PubMed

    Figueiredo, Marcelo; Alvarez, Denise; Athayde, Milton; Suarez, José Diego; Pereira, Renata; Soares, Leonardo

    2008-01-01

    This article analyzes the relationship between the intensive use of outsourcing and labor organizations on offshore oil platforms in the Campos Basin, Rio de Janeiro, Brazil. The theoretical and methodological framework applied in our research is based on Ergonomics of Activity and the Psychodynamics of Work, from an ergological perspective. In addition to the more general trend of increasing precariousness, we highlight the potential loss of formal and informal knowledge resulting from the fragmentation of work collectives, as we consider the cohesion of these collectives to be a crucial element contributing to reliability in process operations. Increasing precariousness of work contributes to this fragmentation and one of its main causes is the uncontrolled increase in outsourcing of work. This situation has had nefarious consequences for workers' health and safety, suggesting that those who have adopted outsourcing as a labor management tool have failed to consider these harmful consequences as rigorously as necessary.

  10. Infrared inspection applied to offshore platforms: Petrobras experience at Campos Basin

    NASA Astrophysics Data System (ADS)

    Verdini, Edson A.; Veratti, Attilio B.

    2002-03-01

    Bacia de Campos (Rio de Janeiro - Brazil) is one of the biggest offshore petroleum fields in the world today. In June 2001, Bacia de Campos, having more than 490 oil wells, 34 offshore platforms and 7 modified ships in operation, reached 1,3 million barrels/day. If compared to OPEP countries only nine of them got an average production higher than 1 million barrels/day in 2000, which means it can be placed on the 10th position in the rank of oil producers. In this context this work aims not only to show the results achieved within the introduction of thermographic inspections in offshore oil production (platforms and ships), but also the financial results (ROI - Return of Investment) considering the use of this particular technique. Bacia de Campos got a ROI around 7 million dollars in the last 4 years, which means a hundred times higher than the total cost of thermographic services in the same period. As far as we know this is one of the best results already reported in the world. We also present the methodology applied to analyze thermal anomalies in electrical components and data management software, including advanced Digital Reports sent via Internet.

  11. Manufacturing and design of the offshore structure Froude scale model related to basin restrictions

    NASA Astrophysics Data System (ADS)

    Scurtu, I. C.

    2015-11-01

    Manufacturing steps for a modern three - column semi-submersible structure are delivered using CFD/CAE software and actual Froude scaled model testing. The three- column offshore is part of the Wind Float Project already realized as prototype for wind energy extraction in water depths more than 40 meters, and the actual model will not consider the wind turbine. The model will have heave plates for a smaller heave motion in order to compare it with the case without heave plates. The heave plates will be part of the Froude scale model.. Using a smaller model will determine a smaller heave motion and this will affect predictions of the vertical movement of the three- column offshore structure in real sea. The Froude criterion is used for the time, speed and acceleration scale. The scale model is manufactured from steel and fiberglass and all parts are subjected to software analysis in order to get the smallest stress in connections inside the model. The model mass was restricted by scale dimensions and also the vertical position of centre gravity will be considered during the manufacturing and design process of the Froude scale offshore structure. All conditions must converge in model manufacturing and design in order to get the best results to compare with real sea states and heave motion data.

  12. Sea-level and tectonic control of middle to late Pleistocene turbidite systems in Santa Monica Basin, offshore California

    USGS Publications Warehouse

    Normark, W.R.; Piper, D.J.W.; Sliter, R.

    2006-01-01

    Small turbidite systems offshore from southern California provide an opportunity to track sediment from river source through the turbidity-current initiation process to ultimate deposition, and to evaluate the impact of changing sea level and tectonics. The Santa Monica Basin is almost a closed system for terrigenous sediment input, and is supplied principally from the Santa Clara River. The Hueneme fan is supplied directly by the river, whereas the smaller Mugu and Dume fans are nourished by southward longshore drift. This study of the Late Quaternary turbidite fill of the Santa Monica Basin uses a dense grid of high-resolution seismic-reflection profiles tied to new radiocarbon ages for Ocean Drilling Program (ODP) Site 1015 back to 32 ka. Over the last glacial cycle, sedimentation rates in the distal part of Santa Monica Basin averaged 2-3 mm yr-1, with increases at times of extreme relative sea-level lowstand. Coarser-grained mid-fan lobes prograded into the basin from the Hueneme, Mugu and Dume fans at times of rapid sea-level fall. These pulses of coarse-grained sediment resulted from river channel incision and delta cannibalization. During the extreme lowstand of the last glacial maximum, sediment delivery was concentrated on the Hueneme Fan, with mean depositional rates of up to 13 mm yr-1 on the mid- and upper fan. During the marine isotope stage (MIS) 2 transgression, enhanced rates of sedimentation of > 4 mm yr-1 occurred on the Mugu and Dume fans, as a result of distributary switching and southward littoral drift providing nourishment to these fan systems. Longer-term sediment delivery to Santa Monica Basin was controlled by tectonics. Prior to MIS 10, the Anacapa ridge blocked the southward discharge of the Santa Clara River into the Santa Monica Basin. The pattern and distribution of turbidite sedimentation was strongly controlled by sea level through the rate of supply of coarse sediment and the style of initiation of turbidity currents. These two

  13. Can Khan Move the Bell Curve to the Right?

    ERIC Educational Resources Information Center

    Kronholz, June

    2012-01-01

    More than 1 million people have watched the online video in which Salman Khan--a charming MIT math whiz, Harvard Business School graduate, and former Boston hedge-fund analyst--explains how he began tutoring his cousins in math by posting short lessons for them on YouTube. Other people began watching the lessons and sending Khan adulatory notes.…

  14. Can Khan Move the Bell Curve to the Right?

    ERIC Educational Resources Information Center

    Kronholz, June

    2012-01-01

    More than 1 million people have watched the online video in which Salman Khan--a charming MIT math whiz, Harvard Business School graduate, and former Boston hedge-fund analyst--explains how he began tutoring his cousins in math by posting short lessons for them on YouTube. Other people began watching the lessons and sending Khan adulatory notes.…

  15. Schools "Flip" for Lesson Model Promoted by Khan Academy

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2011-01-01

    The author reports on a "flip model" of instruction that has gotten national media attention lately, thanks to its promotion by Khan Academy, the high-profile nonprofit online-tutoring library created by Salman A. Khan, a Massachusetts Institute of Technology graduate who was looking for a way to help his young relatives with their homework. The…

  16. Can Khan Move the Bell Curve to the Right?

    ERIC Educational Resources Information Center

    Kronholz, June

    2012-01-01

    This article features Khan Academy which offers an online math program and short video lectures embedded in the "module", or math concept, that fit students' goals. By now, more than 1 million people have watched the online video in which Salman Khan--a charming MIT math whiz, Harvard Business School graduate, and former Boston hedge-fund…

  17. Schools "Flip" for Lesson Model Promoted by Khan Academy

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2011-01-01

    The author reports on a "flip model" of instruction that has gotten national media attention lately, thanks to its promotion by Khan Academy, the high-profile nonprofit online-tutoring library created by Salman A. Khan, a Massachusetts Institute of Technology graduate who was looking for a way to help his young relatives with their homework. The…

  18. Can Khan Move the Bell Curve to the Right?

    ERIC Educational Resources Information Center

    Kronholz, June

    2012-01-01

    This article features Khan Academy which offers an online math program and short video lectures embedded in the "module", or math concept, that fit students' goals. By now, more than 1 million people have watched the online video in which Salman Khan--a charming MIT math whiz, Harvard Business School graduate, and former Boston hedge-fund…

  19. Geophysical Characterization of the Central Yakutat Shelf and Cenozoic Basin Development, Offshore Southeastern Alaska

    NASA Astrophysics Data System (ADS)

    Price, R. N.

    2016-12-01

    In southeastern Alaska the collision of the Yakutat Block with North America has led to uplift of the highest costal mountain range in the world, the St. Elias and Chugach Mountains. By 5.5 Ma uplift of the ranges was sufficient to cause glaciation on the continental margin, making it a unique area to study the interactions between tectonics and climate driven processes. This study uses coincident seismic reflection and refraction data from the St. Elias Erosion and Tectonics Project (STEEP) focusing on line STEEP02. We present a high resolution two-dimensional compressional velocity model that helps to elucidate the patterns of deformation offshore of the southeastern Alaskan syntaxis. The velocity model is able to constrain the location of the pinch out of the Poul Creek Formation offshore beneath the mouth of Yakutat Bay. The pinch out of the formation is likely due to an erosional event of the pre-glacial strata associated with the initial formation of the Yakataga fold-and-thrust belt, rather than a depositional feature. This geometry suggests sufficient uplift in the St. Elias syntaxis to cause large scale denudation before deposition of the Yakataga Formation at 6 Ma. The velocity model is transformed to porosity using relationships specific to the Cenozoic sediments on the Yakutat shelf. The Poul Creek Formation is identified as a unit of low velocity, 2.8 km/s, and elevated porosity, .25, across its entire offshore extent and may be a pre-existing weak zone that preferentially accommodates slip when incorporated into the western fold-and-thrust belts. Van Avendonk et al. (2013) identified a zone of lateral compaction 100 km outboard of the offshore Pamplona Zone deformation front along a seismic line perpendicular to STEEP02 which is defined by a landward lateral increase in velocity and decrease porosity in the Yakataga Formation. No landward increase in velocity or decrease in porosity is observed along STEEP02, constraining the deformation front due to

  20. Extensional Tectonics and Sedimentary Architecture Using 3-D Seismic Data: An Example from Hydrocarbon-Bearing Mumbai Offshore Basin, West Coast of India

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, D. K.; Bhowmick, P. K.; Mishra, P.

    2016-12-01

    In offshore sedimentary basins, analysis of 3-D seismic data tied with well log data can be used to deduce robust isopach and structure contour maps of different stratigraphic formations. The isopach maps give depocenters whereas structure contour maps give structural relief at a specific time. Combination of these two types of data helps us decipher horst-graben structures, sedimentary basin architecture and tectono-stratigraphic relations through Tertiary time. Restoration of structural cross sections with back-stripping of successively older stratigraphic layers leads to better understand tectono-sedimentary evolution of a basin. The Mumbai (or Bombay) Offshore Basin is the largest basin off the west coast of India and includes Bombay High giant oil/gas field. Although this field was discovered in 1974 and still producing, the basin architecture vis-à-vis structural evolution are not well documented. We take the approach briefly outlined above to study in detail three large hydrocarbon-bearing structures located within the offshore basin. The Cretaceous Deccan basalt forms the basement and hosts prodigal thickness (> 8 km at some localities) of Tertiary sedimentary formations.A two stage deformation is envisaged. At the first stage horst and graben structures formed due to approximately E-W extensional tectonics. This is most spectacularly seen at the basement top level. The faults associated with this extension strike NNW. At the second stage of deformation a set of ENE-striking cross faults have developed leading to the formation of transpressional structures at places. High rate of early sedimentation obliterated horst-graben architecture to large extent. An interesting aspect emerges is that the all the large-scale structures have rather low structural relief. However, the areal extent of such structures are very large. Consequently, these structures hold commercial quantities of oil/gas.

  1. Tectonic influence on depositional sequence development, Columbus Basin, eastern offshore Trinidad and Tobago

    SciTech Connect

    Wood, L.J.

    1996-12-31

    The Columbus Basin is located off the eastern coast of Trinidad and the northeastern coast of Venezuela, along the margins of the converging Caribbean and Atlantic plates. Post-Miocene tectonics have resulted in transpressional structures oriented NE-SW and tensional faults oriented NW-SE. Sea level has undergone high frequency fluctuations throughout the Plio-Pleistocene. The Orinoco River, which drains the Andean Highlands, has fed enormous quantities of sediment into the basin since the late Miocene (>30,000{prime}). Several observations from an Integrated Depositional Sequence Analysis of the Columbus Basin are applicable to basins in similar settings, such as the Nile and Niger deltas. These include the following: (1) Limited shelf development, associated with limited shelf subsidence, may be an indicator of shelf bypass and slope Canyon development. (2) United basin-floor and slope fan development may be an indicator of shelf aggradation, associated with subsidence at the shelf-break. (3) Extensional and compressional structures focus feeder systems and localize accommodation space. (4) Drill deeper; the basal deepening of a regressive package may be in response to localized tectonics and indicate only temporary loss of good reservoir. (5) Limited transgressive systems tract development is associated with limited transgressive-time accommodation space, and creates better reservoir-seal relationships. (6) Interactively, integrating data sets provides the best chance for discerning: sequence relationships across the basin, local versus basinwide chronologic events, sediment bypass versus aggradation zones, reservoir trends and TRUE age of the section. (7) Interpreting the rock record in terms of accommodation space and sediment supply provides a much more practical methodology in tectonically active areas than traditional sequence stratigraphic techniques using the classic eustatic-driven model.

  2. Tectonic influence on depositional sequence development, Columbus Basin, eastern offshore Trinidad and Tobago

    SciTech Connect

    Wood, L.J. )

    1996-01-01

    The Columbus Basin is located off the eastern coast of Trinidad and the northeastern coast of Venezuela, along the margins of the converging Caribbean and Atlantic plates. Post-Miocene tectonics have resulted in transpressional structures oriented NE-SW and tensional faults oriented NW-SE. Sea level has undergone high frequency fluctuations throughout the Plio-Pleistocene. The Orinoco River, which drains the Andean Highlands, has fed enormous quantities of sediment into the basin since the late Miocene (>30,000[prime]). Several observations from an Integrated Depositional Sequence Analysis of the Columbus Basin are applicable to basins in similar settings, such as the Nile and Niger deltas. These include the following: (1) Limited shelf development, associated with limited shelf subsidence, may be an indicator of shelf bypass and slope Canyon development. (2) United basin-floor and slope fan development may be an indicator of shelf aggradation, associated with subsidence at the shelf-break. (3) Extensional and compressional structures focus feeder systems and localize accommodation space. (4) Drill deeper; the basal deepening of a regressive package may be in response to localized tectonics and indicate only temporary loss of good reservoir. (5) Limited transgressive systems tract development is associated with limited transgressive-time accommodation space, and creates better reservoir-seal relationships. (6) Interactively, integrating data sets provides the best chance for discerning: sequence relationships across the basin, local versus basinwide chronologic events, sediment bypass versus aggradation zones, reservoir trends and TRUE age of the section. (7) Interpreting the rock record in terms of accommodation space and sediment supply provides a much more practical methodology in tectonically active areas than traditional sequence stratigraphic techniques using the classic eustatic-driven model.

  3. 78 FR 48539 - Designation of Bahawal Khan, Also Known as Salahuddin Ayubi, Also Known as Bahwal Khan, as a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Designation of Bahawal Khan, Also Known as Salahuddin Ayubi, Also Known as Bahwal Khan, as a Specially Designated Global Terrorist Pursuant to Section 1(b) of Executive Order 13224, as Amended Acting under the authority of and in accordance with section...

  4. Lagoa Feia Formation (Lower Cretaceous), Campos basin, offshore Brazil - Rift-Valley-Stage Lacustrine carbonate reservoirs

    SciTech Connect

    Bertani, R.; Petrobras, T.; Carozzi, A.V.

    1985-02-01

    The Lagoa Feia Formation, buried in excess of 3000 m, is the exploration frontier of the prolific Campos basin. It contains the source beds of all the basin's oil in addition to having its own potential carbonate reservoirs. The faulted margins of the basin fed a system of alluvial fans, sand flats, and mud flats. Alternating dry and rainy period regulated the size and nature of contemporaneous basinal alkaline lakes. Dry periods corresponded to contracted playa lakes with ostracod carbonates and euxinic shales; rainy periods corresponded to expanded pluvial lakes with pelecypod banks. Subaqueous intrusions of basaltic magma generated hyaloclastites with kerolitic ooids and hyalotuffs. Petrographic analysis reveals 5 diagenetic stages: (1) syndepositional alteration of lithoclasts to trioctahedral smectites; (2) early dolomitization, early silicification, and cementation by bladed-rim calcite and zeolites; (3) freshwater-vadose dissolution of bioclasts and lithoclasts, freshwater-phreatic sparite cementation, and neomorphism; (4) mixed saline-freshwater silicification; and (5) burial with compaction, late dolomitization, and partial conversion of smectites to illite. Pelecypod limestones with primary interparticle, secondary intraparticle, moldic, and moldic-enlarged porosities are the potential reservoirs. Ideal conditions for porosity generation and preservation were subaerial exposure followed by rapid lake expansion and burial.

  5. The heat flow study in the Tertiary Basin of Vietnam offshore

    SciTech Connect

    Huyen, T.

    1994-07-01

    In Vietnam, study of heat flow has paralleled petroleum exploration activities. For a long time there had only been results on temperature gradients in the Tertiary basin. Recently, with its participation in CCOP's project on the establishment of heat flow regional maps (1992-1993) and the government's mineral resources program (1993-1995) (Coded KT-01-18), Vietnam Petroleum Institute's group on heat flow obtained results on heat flow. A heat flow study in the oil basinal area in Vietnam has been conducted using data from 76 exploratory wells. Thermal conductivity of 427 cores was measured using the quick thermal conductivity meter (QTM) within temperature gradients of wells calculated from well log data and from testing data. The average heat flow of sedimentary basins in Vietnam follows: Hanoi graben, 125 Q (mW/m2); north Gulf of Tonkin, 87 Q (mW/m2); south Gulf of Tonkin, 119 Q (mW/m2); Danang Graben, 89 Q (mW/m2); northeast-south Conson, 88 Q (mW/m2); southwest-south Conson, 85 Q (mW/m2); Mekong Basin, 64 Q (mW/m2).

  6. The Linguado, Carapeba, Vermelho, and Marimba giant oil fields, Campos basin, offshore Brazil

    SciTech Connect

    Stank, C.V.; Esteves, F.R.; Martins, C.C.; Cruz, W.M.; Da Silva Barroso, A.; Horschutz, P.M.C. )

    1990-09-01

    About 40 hydrocarbon accumulations have been discovered in the Campos basin in the period 1978-1984, including four giant fields in shallow to moderate water depths. The Linguado oil field is located on the extreme south of the producing area of the Campos basin. The pool was discovered in May 1978. The reservoir rocks occur between 1,700 and 3,000 m, and are constituted by fractured Neocomian basalts, Barremian pelecypod coquinas, Albian oolitic calcarenites, and, secondarily, by some Cretaceous turbidite sandstones. The main reservoir is formed by coquinas, which contain 76% of the total recoverable oil volume estimated at 104.6 million bbl. The field is located on a regional high and the accumulation is strongly controlled by stratigraphic and diagenetic factors. High-quality oil is produced through a floating producing system (FPS), and the cumulative oil production amounts to 63.8 million bbl. The Carapeba and Vermelho oil fields are situated in the northern limit of the Campos basin producing area and, together with the smaller Pargo field, make up the so-called Northeast Pole of Campos basin. Carapeba field was discovered in February 1982, and has an estimated recoverable oil volume of 127.8 million bbl. Production comes mainly from two Upper Cretaceous turbidite sandstone reservoirs. The Vermelho field in December 1982, and its main reservoir is formed by a massive Eocene turbidite sandstone. The estimated recoverable oil volume amounts to 119.7 million bbl. Both Carapeba and Vermelho fields are structural traps associated with the development of subtle anticlines caused by salt movements. The fields are gradually being put on stream through five fixed platforms installed in water depths ranging from 70 to 90 m. The Marimba field, discovered in March 1984, drilled in a water depth of 383 m, is considered the first deep-water oil strike in the Campos basin. The field has an estimated recoverable oil volume of 115 million bbl of good-quality oil.

  7. Static modeling: Case study of the Pletmos basin, offshore South Africa.

    NASA Astrophysics Data System (ADS)

    Dominick, Nehemiah; Opuwari, Mimonitu

    2017-04-01

    The Pletmos basin forms part of a series of divergent basins which formed along the southern margin of the South African coastline. The Pletmos basin covers an area of 18 000km2 and is filled with Synrift I, Synrift II and post rift Cretaceous sediments. This study illustrates and predicts spatial variations in the geological model away from wells and the occurrence of reservoir heterogeneity. The studied interval is late Berriasian to early Valanginian synrift shallow marine unit, an important reservoir interval that was targeted during the exploration for hydrocarbons in the southern region of the Pletmos basin. Results were achieved by generating a conceptual static model as a predictive tool that encompasses integration between lithological elements, porosity and permeability distributions which are often further affected by complex structural systems. Comparing the results of these elements contributes to the understanding of the stratigraphic, petrophysical and structural framework of the basin. Facies and petrophysical analyses were conducted and sampling values from the well logs were extrapolated into the 3D grid. Incorporating the sequential Gaussian algorithm ensured that all of the available data was honored to the highest extent in generating the realizations to display the heterogeneity. The reservoirs were sub divided into two major zones, viz: zone A and zone B. Each reservoir interval contained a percentage of shale/clay of about 45% -50%. Small scaled reservoir heterogeneity has been construed to the influence of the depositional patterns of the sediments. Large scaled reservoir heterogeneity has been identified, due to the lateral extent of the claystones which is widely distributed throughout the study area.

  8. A three-step model to assess shoreline and offshore susceptibility to oil spills: the South Aegean (Crete) as an analogue for confined marine basins.

    PubMed

    Alves, Tiago M; Kokinou, Eleni; Zodiatis, George

    2014-09-15

    This study combines bathymetric, geomorphological, geological data and oil spill predictions to model the impact of oil spills in two accident scenarios from offshore Crete, Eastern Mediterranean. The aim is to present a new three-step method of use by emergency teams and local authorities in the assessment of shoreline and offshore susceptibility to oil spills. The three-step method comprises: (1) real-time analyses of bathymetric, geomorphological, geological and oceanographic data; (2) oil dispersion simulations under known wind and sea current conditions; and (3) the compilation of final hazard maps based on information from (1) and (2) and on shoreline susceptibility data. The results in this paper show that zones of high to very-high susceptibility around the island of Crete are related to: (a) offshore bathymetric features, including the presence of offshore scarps and seamounts; (b) shoreline geology, and (c) the presence near the shore of sedimentary basins filled with unconsolidated deposits of high permeability. Oil spills, under particular weather and oceanographic conditions, may quickly spread and reach the shoreline 5-96 h after the initial accident. As a corollary of this work, we present the South Aegean region around Crete as a valid case-study for confined marine basins, narrow seaways, or interior seas around island groups.

  9. Mesozoic of the Gulf Mexico Basin: New Data, New Concepts, and New Plays in the Onshore and Offshore Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Snedden, J.; Olson, H. C.; Norton, I. O.; Cunningham, R.; Virdell, J.

    2016-12-01

    New ideas are leading to a reevaluation of the Gulf Basin Mesozoic framework history. We have revisited the Mesozoic stratigraphy and play mapping by a combination of reanalyzing older wells, incorporation of new reflection seismic data onshore and offshore, as well as information on the deep crustal structure from new OBS refraction data shot by The University of Texas Institute for Geophysics. In addition, Mesozoic mapping has been facilitated by analysis of reservoir oils and seeps that have characteristic geochemical signatures. Our mapping now extends into Mexico, which had a long history of Mesozoic exploration and production. Together these form a new picture of the Mesozoic geohistory and potential from a basin-scale perspective. Inferences on Mesozoic plays both onshore and offshore stem from our reconstructions and paleogeographic mapping of depositional systems.

  10. Cretaceous tectonism and volcanism in the eastern Scotian Basin, offshore Nova Scotia

    NASA Astrophysics Data System (ADS)

    Bowman, Sarah

    Early Cretaceous tectonism and volcanism is widespread in the eastern Mesozoic-Cenozoic Scotian Basin. The precise stratigraphic position of volcanic rocks within wells has been re-evaluated and the volcanological character of the rocks refined by study of cuttings and well logs. Hauterivian-Barremian volcanic rocks on the SW Grand Banks and Aptian-Albian volcanic rocks in the Orpheus Graben and SE Scotian Shelf are likely the result of Strombolian type eruptions. The timing of regional unconformities appears to mark the onset of different components of the volcanic system. The distribution of volcanism is related to the complex opening history of Europe from North America. Widespread volcanic activity indicates a regional and long-lived magma source, which resulted in elevated regional heat flow. Effects of this heat flow are seen in sediments within the Sable sub-basin, but was insufficient to significantly influence the petroleum system.

  11. Feasibility study of simultaneous pre-stack inversion for Miocene clastic gas reservoirs in the Ulleung Basin, Offshore Korea

    NASA Astrophysics Data System (ADS)

    Jun, J.; Lee, H.; Lim, S.; Shin, K.; Choi, B.

    2016-12-01

    DHIs are effective hydrocarbon exploration tools when they are properly calibrated with reservoir properties in a specific exploration area. Nevertheless, they can't always lead us to the success of exploration. This study discusses the effectiveness of DHIs in the Ulleung Basin, offshore Korea. Backarc opening caused by oblique subduction of the Pacific plate resulted in the multi-stage evolutions of the basin including NNE-SSW trending strike-slip movement in this region and caused highly complex structures. Most of HC explorations are targeting the deltaic sandstones intercalated with shales deposited during the Miocene. In those geological conditions, it is necessary to select an appropriate approach to indicate gas presences. During the last 30 years, gas exploration using DHIs have been conducted in this basin. Seismic amplitude anomalies and AVO Class III behaviors for Miocene clastic gas reservoirs are typically observed on 2D/3D seismic data. However, it has been proved that they are insufficient to indicate the gas reservoir. To find a more reliable DHI for gas presences, a simultaneous pre-stack inversion is conducted and AVO response is analyzed for the comparison. 3D Pre-STM gathers over the area of interest and two wells are used for inversion processes. The other two wells are used for the blind test to verify the inversion algorithm. Inversion attributes are estimated and cross-plotted to separate the gas-bearing sandstone from shale or brine sandstone based on the petrophysical analysis. As a result, it is clarified as below; The AVO analysis in this region has potential pitfalls caused by heterogeneities of porosity, mineralogy, cementation, compaction or other rock properties corresponding to the highly complex structures. It is assumed that those may give rise to AVO responses that mask fluid effects. Simultaneous pre-stack inversion plays a role as a notable DHI for Miocene clastic sandstone reservoirs in the Ulleung Basin. The gas saturated

  12. Metals in water, sediments, and biota of an offshore oil exploration area in the Potiguar Basin, Northeastern Brazil.

    PubMed

    Lacerda, L D; Campos, R C; Santelli, R E

    2013-05-01

    Metal concentrations were evaluated in water, bottom sediments, and biota in four field campaigns from 2002 to 2004 in the Potiguar Basin, northeastern Brazil, where offshore oil exploration occurs. Analyses were performed by inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. Total metal concentrations in water (dissolved + particulate) and sediments were in the range expected for coastal and oceanic areas. Abnormally high concentrations in waters were only found for Ba (80 μg l(-1)) and Mn (12 μg l(-1)) at the releasing point of one of the outfalls, and for the other metals, concentrations in water were found in stations closer to shore, suggesting continental inputs. In bottom sediments, only Fe and Mn showed abnormal concentrations closer to the effluent releasing point. Metal spatial distribution in shelf sediments showed the influence of the silt-clay fraction distribution, with deeper stations at the edge of the continental shelf, which are much richer in silt-clay fraction showing higher concentrations than shallower sediments typically dominated by carbonates. Metal concentrations in estuarine (mollusks and crustaceans) and marine (fish) organisms showed highest concentrations in oysters (Crassostrea rhizophorae). Fish tissues metal concentrations were similar between the continental shelf influenced by the oil exploration area and a control site. The results were within the range of concentrations reported for pristine environments without metals contamination. The global results suggest small, if any, alteration in metal concentrations due to the oil exploration activity in the Potiguar Basin. For monitoring purposes, the continental inputs and the distribution of the clay-silt fraction need to be taken into consideration for interpreting environmental monitoring results.

  13. Ergonomics, safety, and resilience in the helicopter offshore transportation system of Campos Basin.

    PubMed

    Gomes, José Orlando; Huber, Gilbert J; Borges, Marcos R S; de Carvalho, Paulo Victor R

    2015-01-01

    Air transportation of personnel to offshore oil platforms is one of the major hazards of this kind of endeavor. Pilot performance is a key factor in the safety of the transportation system. This study seeks to identify the ergonomic factors present in pilots' activities that may in some way compromise or enhance their performance, the constraints and affordances which they are subject to; and where possible to link these to their associated risk factors. Methodology adopted in this project studies work in its context. It is a merging of Activity Analysis (Guerin et al. 2001) of European tradition with Cognitive Task Analysis (CTA - www.ctaresource.com) articulated with the recent approaches to cognitive systems engineering developed by Professors David Woods and Erik Hollnagel. Fifty-five hours of field interviews provided the input for analysis. Sixteen ergonomic constraints were identified, some cognitive, some physical, all considered relevant by the research subjects and expert advisers. Although the safety record of the personnel transportation system studied is considered acceptable, there is low hanging fruit to be picked which can help improve the system's safety.

  14. Pockmark asymmetry and seafloor currents in the Santos Basin offshore Brazil

    USGS Publications Warehouse

    Schattner, U.; Lazar, M.; Souza, L. A. P.; Brink, Uri ten; Mahiques, M. M.

    2016-01-01

    Pockmarks form by gas/fluid expulsion into the ocean and are preserved under conditions of negligible sedimentation. Ideally, they are circular at the seafloor and symmetrical in profile. Elliptical pockmarks are more enigmatic. They are associated with seafloor currents while asymmetry is connected to sedimentation patterns. This study examines these associations through morphological analysis of new multibeam data collected across the Santos continental slope offshore Brazil in 2011 (353–865 mbsl). Of 984 pockmarks, 78% are both elliptical and asymmetric. Geometric criteria divide the pockmarks into three depth ranges that correlate with a transition between two currents: the Brazil Current transfers Tropical Water and South Atlantic Central Water southwestwards while the Intermediate Western Boundary Current transfers Antarctic Intermediate Water northeastwards. It is suggested that the velocity of seafloor currents and their persistence dictate pockmark ellipticity, orientation and profile asymmetry. Fast currents (>20 cm/s) are capable of maintaining pockmark flank steepness close to the angle of repose. These morphological expressions present direct evidence for an edge effect of the South Atlantic Subtropical Gyre and, in general, provide a correlation between pockmark geometry and seafloor currents that can be applied at other locations worldwide.

  15. Pockmark asymmetry and seafloor currents in the Santos Basin offshore Brazil

    NASA Astrophysics Data System (ADS)

    Schattner, U.; Lazar, M.; Souza, L. A. P.; ten Brink, U.; Mahiques, M. M.

    2016-12-01

    Pockmarks form by gas/fluid expulsion into the ocean and are preserved under conditions of negligible sedimentation. Ideally, they are circular at the seafloor and symmetrical in profile. Elliptical pockmarks are more enigmatic. They are associated with seafloor currents while asymmetry is connected to sedimentation patterns. This study examines these associations through morphological analysis of new multibeam data collected across the Santos continental slope offshore Brazil in 2011 (353-865 mbsl). Of 984 pockmarks, 78% are both elliptical and asymmetric. Geometric criteria divide the pockmarks into three depth ranges that correlate with a transition between two currents: the Brazil Current transfers Tropical Water and South Atlantic Central Water southwestwards while the Intermediate Western Boundary Current transfers Antarctic Intermediate Water northeastwards. It is suggested that the velocity of seafloor currents and their persistence dictate pockmark ellipticity, orientation and profile asymmetry. Fast currents (>20 cm/s) are capable of maintaining pockmark flank steepness close to the angle of repose. These morphological expressions present direct evidence for an edge effect of the South Atlantic Subtropical Gyre and, in general, provide a correlation between pockmark geometry and seafloor currents that can be applied at other locations worldwide.

  16. Rovearinids (stemless crinoids) in the Albian carbonates of the offshore Santos Basin, southeastern Brazil: stratigraphic, palaeobiogeographic and palaeoceanographic significance

    NASA Astrophysics Data System (ADS)

    Dias-Brito, D.; Ferré, B.

    2001-06-01

    Microfacies analysis of marine carbonates cored by Petrobras well 1-SPS-6 in the offshore Santos Basin (southeastern Brazil) has revealed a remarkable fossil assemblage of calpionellids (colomiellids), favusellids, hedbergellids, globigerinelloidids, buliminids, radiolarians, inoceramid prisms, roveacrinids, and saccocomids(?) preserved in lower Albian calcimudstones-wackestones of the lower part of the Guarujá Formation. This assemblage represents an allochtonous accumulation in a deep neritic to shallow bathyal hypoxic environment. Besides 'saccocomid-like' sections, the only determinable sections of roveacrinids are thecal plates of Poecilocrinus dispandus elongatus Peck, 1943. This species was previously only known from the Weno Formation of Texas. The Brazilian material extends its records farther south from at least the lower Albian, which then represents the earliest occurrence of this peculiar family in the South Atlantic region. Taking into account their Albian global distribution and the location of their oldest representative (Hauterivian near Alicante, Spain), the Roveacrinidae dispersed westward throughout all of Cretaceous Tethys. The Tethyan origin of Roveacrinidae is further evidence that, during late Aptian-Albian times, the northern South Atlantic (north of the Walvis-São Paulo Ridge) was supplied by a Tethyan water mass.

  17. Geology of offshore southern Namibia: Evidence from tectonic and basin-fill modeling based on modern seismic data

    SciTech Connect

    Houghton, M.L.; Peacock, D.N. )

    1993-09-01

    License 2815 is located offshore southern Namibia between Cape Dernberg and the South African border, approximately 50 km east of the 1974 Kudu gas discovery. Interactive workstation modeling of modern two-dimensional seismic data from the License area provides an improved understanding of the geology and tectonic history of this unexplored region. Although presently a broad submarine shelf influenced by late Cretaceous-Tertiary deltaic sedimentation from the Orange River, Interpretation based on modern seismic coverage has resulted in the recognition of a Late Jurassic-Early Cretaceous rift complex associated with the initial opening of the Atlantic Ocean. Geologic modeling suggests that a seismically-identified elongate rift localized along a major westward-dipping bounding fault may contain significant thicknesses of Neocomian( ) clastic sediments. Barremian-Aptian marine flooding of this area followed the rifting episode. Mixed marine and deltaic sedimentation has dominated the region since the middle Aptian. Palinspastic restorations of depth-converted seismic lines have helped to unravel the episodic tectonic history of rifting in this area. Input of geologic parameters, including relative sea level changes and sedimentation rates, has yielded computer-derived basin-fill models, which have in turn been integrated with the local tectonic model to make lithology predictions.

  18. Controls on evolution of gas-hydrate system in the Krishna-Godavari basin, offshore India

    NASA Astrophysics Data System (ADS)

    Badesab, F.; Dewangan, P.; Usapkar, A.; Kocherla, M.; Peketi, A.; Mohite, K.; Sangode, S. J.; Deenadayalan, K.

    2017-01-01

    In this study, we integrate environmental magnetic, sedimentological, and geochemical records of sediment core of Hole NGHP-01-10D overlying methane hydrate deposits to decipher the controls on the evolution of fracture-filled gas-hydrate system in the Krishna-Godavari (K-G) basin. Four distinct sedimentary units have been identified, based on the sediment magnetic signatures. An anomalous zone of enhanced magnetic susceptibility (Unit III: 51.9-160.4 mbsf) coinciding with the gas hydrate bearing intervals is due to the presence of magnetite-rich detrital minerals brought-in by the river systems as a result of higher sedimentation events in K-G basin and has no influence over hydrate formation. A strong to moderate correlation between magnetite concentration and chromium reducible sulfur (CRS) content indicates significant influence of sulfidization on the magnetic record and could be further exploited as a proxy to decipher paleo-H2S seepage events. Analysis of high-resolution seismic, bathymetry, and sub-bottom profiler data reveals the existence of a regional fault system in K-G basin. The opening and closing dynamics of the faults facilitated the migration and trapping of required gas concentrations resulting in accumulation of gas hydrates at the studied site. The seismic data provides support to the rock-magnetic interpretations. The observed variations in magnetic and geochemical properties have resulted from the episodic flow of methane and sulfide-enriched fluids through the fracture-filled network formed as a result of shale-tectonism. Our study demonstrated the potential of using an enviro-magnetic approach in combination with other proxies to constrain the evolution of gas-hydrate system in marine environments.

  19. Coastal waters environmental monitoring supported by river basin pluviometry and offshore wave data.

    PubMed

    Abramic, Andrej; Martínez-Alzamora, Nieves; González del Rio Rams, Julio; Ferrer Polo, José

    2015-03-15

    Environmental monitoring in the scope of the Water Framework Directive 2000/60/EC (WFD) is usually expensive and requires considerable human effort. In this study, we analyzed data obtained by a WFD coastal waters monitoring network over a three-year period (35 campaigns), with the aim to ascertain is it possible to increase the monitoring efficiency and obtain more accurate results. As the trophic condition of the coastal waters of Valencia is primarily, but not entirely, determined by continental loads and hydrodynamic conditions, additionally we analyzed related river basin pluviometry (daily frequency) and oceanographic (one hour frequency) data. Chlorophyll a, salinity, rain and wave data time series were analyzed separately, to identify any possible pattern. Analyzing coastal water bodies integrating all four parameters, it is found strong interactions between coastal waters trophic conditions, sea hydrodynamics and related basin pluviometry. Eight phytoplankton biomass scenarios associated to environmental conditions are identified and finally developed basis for a new efficient monitoring strategy and more accurate coastal waters assessment.

  20. The geostatistical approach for structural and stratigraphic framework analysis of offshore NW Bonaparte Basin, Australia

    SciTech Connect

    Wahid, Ali Salim, Ahmed Mohamed Ahmed Yusoff, Wan Ismail Wan; Gaafar, Gamal Ragab

    2016-02-01

    Geostatistics or statistical approach is based on the studies of temporal and spatial trend, which depend upon spatial relationships to model known information of variable(s) at unsampled locations. The statistical technique known as kriging was used for petrophycial and facies analysis, which help to assume spatial relationship to model the geological continuity between the known data and the unknown to produce a single best guess of the unknown. Kriging is also known as optimal interpolation technique, which facilitate to generate best linear unbiased estimation of each horizon. The idea is to construct a numerical model of the lithofacies and rock properties that honor available data and further integrate with interpreting seismic sections, techtonostratigraphy chart with sea level curve (short term) and regional tectonics of the study area to find the structural and stratigraphic growth history of the NW Bonaparte Basin. By using kriging technique the models were built which help to estimate different parameters like horizons, facies, and porosities in the study area. The variograms were used to determine for identification of spatial relationship between data which help to find the depositional history of the North West (NW) Bonaparte Basin.

  1. Identification, mapping, and analysis of possible evidences of active petroleum systems in the Colorado Basin, offshore Argentina, South America

    NASA Astrophysics Data System (ADS)

    Loegering, Markus; Anka, Zahie; Rodriguez, Jorge; Marchal, Denis; di Primio, Rolando; Vallejo, Eduardo; Kohler, Guillermina; Pangaro, Francisco

    2010-05-01

    The analysis of a dense 2D seismic reflection dataset and 12 exploration wells data, allowed us to reconstruct the geological evolution of the Colorado Basin, offshore Argentina. We identified and mapped the major syn- and post-rift seismic sequences, and their boundaries such as unconformities and regional seismic markers, present on the continental shelf and slope (water depths from 50 to 1800 m) of the Colorado Basin. Seismic-to-well log correlations, as well as integration with biostratigraphic data provided a chrono-stratigraphic framework for the interpreted horizons. The construction of isochronal (twt) maps provided a 3D spatial visualisation of the stratigraphic relationship among the sequences. The maps show a change in configuration from the break-up unconformity (130 Ma) to the present-day seafloor. The break-up unconformity displays a central EW-elongated graben which prevails on the overlying sequences up to the Miocene. The EW Colorado basin turns NW-SE towards the East, going perpendicular to the present-day continental margin (oriented NE-SW). The strong obliquity of the basin orientation related to the direction corresponding to the opening of the South Atlantic (NE-SW) suggests a structural control from the pre-rift basement on the rift and post-rift sequences. Starting from the break-up unconformity, the history of basin filling is illustrated up to the flat seafloor. The basin sag phase is represented by the sequences deposited between the break-up unconformity and the Colorado discontinuity (Aptian to Campanian). The Campanian to Eocene successions are more or less parallel- layered suggesting sequence aggradation. The distribution of liquid/gas hydrocarbon-leakage features (i.e. gas chimneys, mud volcanoes, and seabed pockmarks) should allow the definition of potential migration pathways. In this sense, a systematic mapping of these paleo- and present-day features observed in the seismic profiles has been performed and their distribution was

  2. Methane Hydrate Recovered From A Mud Volcano in Santa Monica Basin, Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Normark, W. R.; Hein, J. R.; Powell, C. L.; Lorenson, T. D.; Lee, H. J.; Edwards, B. D.

    2003-12-01

    In July 2003, a short (2.1 m) piston core from the summit of a mud volcano recovered methane hydrate at a water depth of 813 m in Santa Monica Basin. The discovery core penetrated into in the hydrate as evidenced by chunks of ice and violent degassing of the core section between 162 and 212 cm depth. The core consists of shell hash and carbonate clasts (to 7-cm long) in silty mud. The methanogenic carbonates are of two types: massive, recrystallized nodular masses with an outer mm-thick sugary patina and a bivalve coquina with carbonate cement. Living clams including the genus Vesicomya, commonly found at cold-seep sites elsewhere, were recovered from the top of the core. Further sampling attempts using piston, gravity, and box corers, all of which were obtained within 15 m of the discovery core, recovered olive-brown silty mud with variable amounts of whole and fragmented bivalve shells and methanogenic carbonate fragments characteristic of cold-seep environments. Gases collected in cores adjacent to the discovery core contain elevated amounts of methane and trace amounts of heavier hydrocarbon gases, indicating some component from thermogenic sources. Hydrogen sulfide was also detected in these sediment samples. Vertical channels in one core may have served as fluid pathways. The existence of hydrate at such a shallow depth in the sediment was unexpected, however, the presence of Vesicomya and hydrogen sulfide indicate that the mud volcano is a site of active methane venting. The mud volcano, which is about 24 km west-southwest of Redondo Beach, is about 300 m in diameter at the base. No internal structure is resolved on either high resolution deep-tow boomer or single-channel air-gun profiles, most likely as a result of the gas content and sediment deformation. The diapiric structure has ascended through well-bedded sediment on the lower slope of the basin, producing as much as 30 m of bathymetric relief. It is located in an area where strike-slip motion along

  3. Comparison of offshore and onshore gas occurrences, Eel River basin, northern California

    USGS Publications Warehouse

    Lorenson, T.D.; McLaughlin, Robert J.; Kvenvolden, Keith A.; Orange, Daniel L.; Davisson, M. Lee; Brewer, Peter G.; Martin, J.B.

    1998-01-01

    The Eel River basin of northern California is a upper Cenozoic depocenter containing more than 3,000 meters of sedimentary rock located near the Mendocino triple junction. Active tectonism has resulted in folding, faulting and rapid sedimentation. Both thermogenic and microbial hydrocarbons are known to be present in the sediments. In August 1997, we sampled two submarine gas seeps, one at a water depth of 520 m that supports a chemosynthetic-based ecosystem very near an area of previously recovered gas hydrate. Another vent site was sampled in sand covered with white bacterial mats at a water depth 41 m. We compared the hydrocarbon gas composition and methane isotopic composition of these seeps with land-based gas occurrences that include: 1) a gas seep and 2) gas from a 2360 m-deep gas well.

  4. Microfacies, depositional models and diagenesis of Lagoa Feia Formation (lower cretaceous), Campos Basin, offshore Brazil

    NASA Astrophysics Data System (ADS)

    Bertani, R. T.

    The Lagoa Feia Formation consists of the sediments deposited during the rift valley stage of the Campos Basin, varying from 200m to more than 1500m in thickness. In this unit seventeen microfacies were recognized, grouped into four main sequences, respectively dominated by terrigenous supplies, ostracods, pelecypods, and basic volcaniclastics. The vertical sequence of microfacies and the associations of syndepositional diagenetic minerals were used to reconstruct the general environment of deposition. Five diagenetic stages were recognized. Pelecypod rich microfacies present the highest potential for development of intraparticle and moldic secondary porosity. Two types of fabric selective porosity were experimentally developed in low porosity samples under simulated burial conditions. Intercrystal microporosity was formed by preferential dissolution of micrite size calcite compared to coarse calcite crystals of sparite and neomorphosed bioclasts, and intraparticle porosity was developed in pelecypod shells by selective dissolution of neomorphic calcite compared to sparite cement.

  5. Exploring for lower Eocene-Nummulitic Banks in the Gabes-Tripolitania basin of offshore Tunisia

    SciTech Connect

    Abraham, N.Y.

    1988-08-01

    In 1987, Marathon drilled a well on the Metlaoui trend to evaluate a specific seismic anomaly. Detailed microfacies and biostratigraphic analyses of the well and subsequent seismic and stratigraphic evaluations suggest it was drilled in a basinal reentrant of the outer platform. An exploration model has been developed to pursue the nummulitic bank play based upon (1) a study of available trend wells, (2) a review of seismic data on the Ashtart field and other discoveries, and (3) geologic field studies. Seismic evaluations have focused on delineating bank-stratigraphic anomalies along the more prospective Metlaoui outer platform edge through isochronal relationships of the Metlaoui and adjacent sequences as well as seismic and stratigraphic analysis of amplitude variation and onlap/offlap relationships.

  6. Seismic imaging of a fractured gas hydrate system in the Krishna-Godavari Basin offshore India

    USGS Publications Warehouse

    Riedel, M.; Collett, T.S.; Kumar, P.; Sathe, A.V.; Cook, A.

    2010-01-01

    Gas hydrate was discovered in the Krishna-Godavari (KG) Basin during the India National Gas Hydrate Program (NGHP) Expedition 1 at Site NGHP-01-10 within a fractured clay-dominated sedimentary system. Logging-while-drilling (LWD), coring, and wire-line logging confirmed gas hydrate dominantly in fractures at four borehole sites spanning a 500m transect. Three-dimensional (3D) seismic data were subsequently used to image the fractured system and explain the occurrence of gas hydrate associated with the fractures. A system of two fault-sets was identified, part of a typical passive margin tectonic setting. The LWD-derived fracture network at Hole NGHP-01-10A is to some extent seen in the seismic data and was mapped using seismic coherency attributes. The fractured system around Site NGHP-01-10 extends over a triangular-shaped area of ~2.5 km2 defined using seismic attributes of the seafloor reflection, as well as " seismic sweetness" at the base of the gas hydrate occurrence zone. The triangular shaped area is also showing a polygonal (nearly hexagonal) fault pattern, distinct from other more rectangular fault patterns observed in the study area. The occurrence of gas hydrate at Site NGHP-01-10 is the result of a specific combination of tectonic fault orientations and the abundance of free gas migration from a deeper gas source. The triangular-shaped area of enriched gas hydrate occurrence is bound by two faults acting as migration conduits. Additionally, the fault-associated sediment deformation provides a possible migration pathway for the free gas from the deeper gas source into the gas hydrate stability zone. It is proposed that there are additional locations in the KG Basin with possible gas hydrate accumulation of similar tectonic conditions, and one such location was identified from the 3D seismic data ~6 km NW of Site NGHP-01-10. ?? 2010.

  7. Documenting channel features associated with gas hydrates in the Krishna-Godavari Basin, offshore India

    USGS Publications Warehouse

    Riedel, M.; Collett, T.S.; Shankar, U.

    2011-01-01

    During the India National Gas Hydrate Program (NGHP) Expedition 01 in 2006 significant sand and gas hydrate were recovered at Site NGHP-01-15 within the Krishna-Godavari Basin, East Coast off India. At the drill site NGHP-01-15, a 5-8m thick interval was found that is characterized by higher sand content than anywhere else at the site and within the KG Basin. Gas hydrate concentrations were determined to be 20-40% of the pore volume using wire-line electrical resistivity data as well as core-derived pore-fluid freshening trends. The gas hydrate-bearing interval was linked to a prominent seismic reflection observed in the 3D seismic data. This reflection event, mapped for about 1km2 south of the drill site, is bound by a fault at its northern limit that may act as migration conduit for free gas to enter the gas hydrate stability zone (GHSZ) and subsequently charge the sand-rich layer. On 3D and additional regional 2D seismic data a prominent channel system was imaged mainly by using the seismic instantaneous amplitude attribute. The channel can be clearly identified by changes in the seismic character of the channel fill (sand-rich) and pronounced levees (less sand content than in the fill, but higher than in surrounding mud-dominated sediments). The entire channel sequence (channel fill and levees) has been subsequently covered and back-filled with a more mud-prone sediment sequence. Where the levees intersect the base of the GHSZ, their reflection strengths are significantly increased to 5- to 6-times the surrounding reflection amplitudes. Using the 3D seismic data these high-amplitude reflection edges where linked to the gas hydrate-bearing layer at Site NGHP-01-15. Further south along the channel the same reflection elements representing the levees do not show similarly large reflection amplitudes. However, the channel system is still characterized by several high-amplitude reflection events (a few hundred meters wide and up to ~1km in extent) interpreted as gas

  8. Metasomatic fault weakening processes in the Moresby Seamount detachment, Woodlark Basin (offshore Papua New Guinea)

    NASA Astrophysics Data System (ADS)

    Speckbacher, R.; Behrmann, J. H.; Stipp, M.; Nagel, T. J.; Mahlke, J.; Devey, C. W.

    2011-12-01

    The Woodlark Basin (east of Papua New Guinea) is a classic example of an active transition from continental rifting to seafloor spreading. The submerged Moresby Seamount detachment (MSD) is arguably the best exposed active detachment fault in the world, and is the candidate structure for future crustal breakup and ocean floor spreading. Nearly three decades of debate have failed to explain how initial crustal weakening and sustained operation of detachment faults occurs. While high fluid pressure has been shown to maintain faulting at low differential stress in the brittle regime, other effects have to induce weakening at greater depth allowing a transition from cataclastic (brittle) to plastic deformation. We suggest that a relative enrichment in "weak" minerals, i.e. calcite and quartz, plays a key role for mylonitization along the MSD. Based on a suite of protoliths, mylonites and cataclasites dredged from the MSD we show that deformation is accompanied by metasomatic changes, which are driven by a hydrothermal system connected to the fault zone. Immobile elements (essentially Zr, Y, and P) of the gabbroic protoliths and fault rocks provide a reference frame for the calculation of material gains and losses during syntectonic alteration. Si, Ca, and to a lesser extent K and Mn were syntectonically enriched throughout the MSD, while there is depletion in Fe, Ti, Mg, and Al. These metasomatic changes are interpreted to be associated with upward flow of mid-crustal fluids along the MSD. Mass balance calculations show that up to 56 % mass gain occurred during the formation of μm to cm-thick quartz and calcite veins and intermittent deformation. The enrichment in quartz and calcite allows a switch from dominant brittle to dominant plastic deformation. The resulting mylonites operate as relatively weak fault rocks at low differential stress. Maximum flow stress is approximately 72 +23/-10 MPa, inferred from the dynamically recrystallized quartz grain size. The MSD

  9. Ocean basin structure offshore the Southeastern United States: Is it the rift's fault?

    NASA Astrophysics Data System (ADS)

    Heffner, D. M.; Knapp, J. H.

    2012-12-01

    Continental rifts typically exhibit an asymmetrical geometry where major normal faults bound one side of a rotated block, and the rift basins thin toward the opposite hinge side. Differential extension on major faults is accommodated by transverse structures referred to as transfer zones, across which the asymmetric geometry may reverse polarity. It was proposed several decades ago that oceanic transforms between mid-ocean ridge spreading centers are inherited features of these rift-related transfer zones, and that these intra-plate structures are tectonically active. However, preserved evidence of onshore transfer zones is often lacking, particularly along the rifted margin of Eastern North America, and recent studies have suggested that oceanic transforms are not inherited structures. Observations of seismic reflection data integrated with well data show that adjacent basin bounding faults of the South Georgia Rift, a Triassic rift in the southeastern United States, occur on opposite sides of the rift flanks. The Walterboro and Warner Robins Transfer Zones identified in this study project along the small circles of Schettino and Turco (2009) into the Jacksonville and Bahamas Fracture Zones respectively. This projection is particularly interesting as it suggests the correlation of continental to oceanic features is one step south compared to previous studies which projected the Blake Spur Fracture Zone through the Charleston, SC region, and the Jacksonville Fracture Zone through Georgia. Using the same small circle solution, the Blake Spur Fracture Zone projects through the Blake Outer Ridge, a sedimentary drift which shows up prominently as a gravity anomaly the core of which has been identified as a tectonic feature reminiscent of a fracture zone on the basis of gravity modeling (Dove et al., 2007). Although no transfer zone has been identified where this small circle project onshore, it is approximately coincident with axis of the Cape Fear Arch which has been

  10. Facies characterization and sequential evolution of an ancient offshore dunefield in a semi-enclosed sea: Neuquén Basin, Argentina

    NASA Astrophysics Data System (ADS)

    Veiga, Gonzalo D.; Schwarz, Ernesto

    2017-08-01

    This study analyses a 30-m-thick, sand-dominated succession intercalated between offshore mudstones in the Lower Cretaceous record of the Neuquén Basin, Argentina, defining facies associated with unidirectional currents as sand dunes (simple and compound), rippled sand sheets and heterolithic sheets. These facies associations are related to the development of an offshore, forward-accreting dunefield developed as a response to the onset of a tidal-transport system. The reported stratigraphic record results from the combination of the gradual downcurrent decrease of the current speed together with the long-term climbing of the entire system. Maximum amplification of the tidal effect associated with incoming oceanic tides to this epicontinental sea would develop at the time of more efficient connection between the basin and the open ocean. Thus, the onset of the offshore tidal system approximately corresponds to the time of maximum flooding conditions (or immediately after). The short-term evolution of the tidal-transport system is more complex and characterized by the vertical stacking of small-scale cycles defined by the alternation of episodes of construction and destruction of the dunefield. The development of these cycles could be the response to changes in tidal current speed and transport capacity.

  11. Facies characterization and sequential evolution of an ancient offshore dunefield in a semi-enclosed sea: Neuquén Basin, Argentina

    NASA Astrophysics Data System (ADS)

    Veiga, Gonzalo D.; Schwarz, Ernesto

    2016-08-01

    This study analyses a 30-m-thick, sand-dominated succession intercalated between offshore mudstones in the Lower Cretaceous record of the Neuquén Basin, Argentina, defining facies associated with unidirectional currents as sand dunes (simple and compound), rippled sand sheets and heterolithic sheets. These facies associations are related to the development of an offshore, forward-accreting dunefield developed as a response to the onset of a tidal-transport system. The reported stratigraphic record results from the combination of the gradual downcurrent decrease of the current speed together with the long-term climbing of the entire system. Maximum amplification of the tidal effect associated with incoming oceanic tides to this epicontinental sea would develop at the time of more efficient connection between the basin and the open ocean. Thus, the onset of the offshore tidal system approximately corresponds to the time of maximum flooding conditions (or immediately after). The short-term evolution of the tidal-transport system is more complex and characterized by the vertical stacking of small-scale cycles defined by the alternation of episodes of construction and destruction of the dunefield. The development of these cycles could be the response to changes in tidal current speed and transport capacity.

  12. Prospect evaluation of shallow I-35 reservoir of NE Malay Basin offshore, Terengganu, Malaysia

    SciTech Connect

    Janjua, Osama Akhtar Wahid, Ali Salim, Ahmed Mohamed Ahmed; Rahman, M. Nasir B. A.

    2016-02-01

    A potential accumulation of hydrocarbon that describes significant and conceivable drilling target is related to prospect. Possibility of success estimation, assuming discovery of hydrocarbons and the potential recoverable quantities range under a commercial development program are the basis of Prospect evaluation activities. The objective was to find the new shallow prospects in reservoir sandstone of I –Formation in Malay basin. The prospects in the study area are mostly consisting of faulted structures and stratigraphic channels. The methodology follows seismic interpretation and mapping, attribute analysis, evaluation of nearby well data i.e., based on well – log correlation. The petrophysical parameters analogue to nearby wells was used as an input parameter for volumetric assessment. Based on analysis of presence and effectiveness, the prospect has a complete petroleum system. Two wells have been proposed to be drilled near the major fault and stratigraphic channel in I-35 reservoir that is O-1 and O-2 prospects respectively. The probability of geological success of prospect O-1 is at 35% while for O-2 is 24%. Finally, for hydrocarbon in place volumes were calculated which concluded the best estimate volume for oil in O-1 prospect is 4.99 MMSTB and O-2 prospect is 28.70 MMSTB while for gas is 29.27 BSCF and 25.59 BSCF respectively.

  13. Prospect evaluation of shallow I-35 reservoir of NE Malay Basin offshore, Terengganu, Malaysia

    NASA Astrophysics Data System (ADS)

    Janjua, Osama Akhtar; Wahid, Ali; Salim, Ahmed Mohamed Ahmed; Rahman, M. Nasir B. A.

    2016-02-01

    A potential accumulation of hydrocarbon that describes significant and conceivable drilling target is related to prospect. Possibility of success estimation, assuming discovery of hydrocarbons and the potential recoverable quantities range under a commercial development program are the basis of Prospect evaluation activities. The objective was to find the new shallow prospects in reservoir sandstone of I -Formation in Malay basin. The prospects in the study area are mostly consisting of faulted structures and stratigraphic channels. The methodology follows seismic interpretation and mapping, attribute analysis, evaluation of nearby well data i.e., based on well - log correlation. The petrophysical parameters analogue to nearby wells was used as an input parameter for volumetric assessment. Based on analysis of presence and effectiveness, the prospect has a complete petroleum system. Two wells have been proposed to be drilled near the major fault and stratigraphic channel in I-35 reservoir that is O-1 and O-2 prospects respectively. The probability of geological success of prospect O-1 is at 35% while for O-2 is 24%. Finally, for hydrocarbon in place volumes were calculated which concluded the best estimate volume for oil in O-1 prospect is 4.99 MMSTB and O-2 prospect is 28.70 MMSTB while for gas is 29.27 BSCF and 25.59 BSCF respectively.

  14. Acoustic reflections in the water column of Krishna-Godavari offshore basin, Bay of Bengal.

    PubMed

    Sinha, Satish K; Dewangan, Pawan; Sain, Kalachand

    2016-05-01

    Seismic oceanographic studies from various oceans worldwide have indicated that the acoustic reflections are mostly observed along thermal boundaries within the water column. However, the authors present a case study of seismic data from Krishna-Godavari Basin which shows that salinity variations also play an important role in the occurrence of water column reflections. The observed reflection is modeled using the reflectivity series derived from the salinity and temperature profiles from a nearby Conductivity-Temperature-Depth (CTD) location. Sensitivity analysis of temperature and salinity on soundspeed shows that the effect of salinity cannot be ignored for modeling acoustic reflections. The synthetic seismogram matches well with the observed reflection seismic data. Remarkable similarities between the reflection seismic and the salinity profile in the upper thermocline suggest the importance of salinity variations on the water column reflection. Furthermore, impedance inversion of the reflectivity data reveals several thermohaline structures in the water column. The origin of these thermohaline structures is largely unaddressed and may be attributed to the fresh water influx coming from Himalayan and Peninsular rivers or due to the presence of different water masses in the Indian Ocean which warrants a detailed study using concurrent seismic and CTD data.

  15. The marine geology of the eastern Santa Barbara Channel, with particular emphasis on the ground water basins offshore from the Oxnard Plain, Southern California

    USGS Publications Warehouse

    Greene, H. Gary; Wolf, Stephen C.; Blom, Ken G.

    1978-01-01

    Marine geophysical investigations provide new data concerning the stratigraphy, tectonic and sedimentary history, and the ground water geology of the southeastern Santa Barbara Channel region. The offshore stratigraphy identified in seismic reflection profiles includes a succession of Neogene to Quaternary strata. The middle Miocene Conejo volcanics form an acoustical basement and the overlying late Cenozoic sedimentary rocks attain a thickness greater than 2,500 m. These sedimentary deposits fill a structurally controlled, physiographic and depositional depression called the Ventura Basin. Structure consists generally of a gently folded, east-trending Tertiary synclinorium bordered on the north by a regional thrust fault and on the south by a steep asymmetrical anticlinal ridge. Most structures show evidence of north-south compression that occurred during early Pleistocene time. Three well-defined unconformities represent widespread erosion in late Miocene, early to middle Pleistocene, and late Pleistocene time. The boundaries of Miocene, Pliocene, and lower Pleistocene strata continue uninterrupted eastward along the southern part of Santa Barbara basin to Hueneme Canyon, where they turn northeast and can be traced to the coast near Port Hueneme. These limits probably represent the south edge of the Santa Barbara basin during Pliocene and Pleistocene time. Fresh water-bearing materials of the Oxnard plain are unconsolidated Quaternary sediment laid down on more consolidated Tertiary rocks. Offshore, the total fresh water-bearing materials distinguished in the seismic reflection profiles attain a thickness of about 356 m and have an areal extent of over 760 km2. Strata that contain the offshore continuation of the five major on-land aquifers (Grimes Canyon, Fox Canyon, Hueneme, Mugu, and Oxnard aquifers) are identified in the seismic reflection profiles. These strata make up the two offshore ground-water basins, the Mound and Oxnard plain ground-water basins

  16. Tectonic history of northern New Caledonia Basin from deep offshore seismic reflection: Relation to late Eocene obduction in New Caledonia, southwest Pacific

    NASA Astrophysics Data System (ADS)

    Collot, Julien; Geli, Louis; Lafoy, Yves; Vially, Roland; Cluzel, Dominique; Klingelhoefer, Frauke; Nouzé, Hervé

    2008-12-01

    New, high-quality multichannel seismic reflection data from the western New Caledonia offshore domain allow for the first time the direct, continuous connection of seismic reflectors between the Deep Sea Drilling Project 208 drill hole on the Lord Howe Rise and the New Caledonia Basin. A novel seismic interpretation is hence proposed for the northern New Caledonia Basin stratigraphy, which places the Eocene/Oligocene unconformity deeper than previously thought and revisits the actual thickness of the pre-Oligocene sequences. A causal link is proposed between the obduction of the South Loyalty Basin over New Caledonia (NC) and the tectonic history of the northern New Caledonia Basin. Here it is suggested that as the South Loyalty Basin was being obducted during early Oligocene times, the NC Basin subsided under the effect of the overloading and underthrusted to accommodate the compressional deformation, which resulted in (1) the uplift of the northern Fairway Ridge and (2) the sinking of the western flank of New Caledonia. This event also had repercussions farther west with the incipient subsidence of the Lord Howe Rise.

  17. Forced folding and complex overburden deformation associated with magmatic intrusion in the Vøring Basin, offshore Norway

    NASA Astrophysics Data System (ADS)

    Omosanya, Kamaldeen Olakunle; Johansen, Ståle E.; Eruteya, Ovie Emmanuel; Waldmann, Nicolas

    2017-06-01

    In this study, three-dimensional seismic reflection and borehole data from the Vøring Basin, offshore Norway have been used to characterize a supra-sill related forced fold to understand its evolution and relevance in the context of regional tectonics. Magmatic sills were recognised to be positive high-amplitude anomalies with similar polarity to the seabed reflection. The seismic dataset reveals two groups of sills in the study area comprising interconnected sills beneath the regional forced fold, and those intruded into the overburden. Magmatic sills forming the interconnected sill complex are emplaced at a depth of about 5.5 s TWTT below the modern seafloor. Aspect ratio (length/width), A for the sills ranges from 1.63-6.90. The regional forced fold is interpreted based on its bathymetric and seismic-stratigraphic expression on horizon H7, which is part of the Palaeocene to Eocene Tang Formation. Amplitude of the accommodation fold is about 780 km2. Hydrothermal vent complexes and fluid-flow conduits in the study area develop above the sill edges and on the flanks of the interconnected sill complex extending from the lower part of the Tang Formation to the uppermost section of the Brygge Formation evidencing vertically focussed fluid flow in the study area. The overlying overburden is in turn deformed and structurally compartmentalized through forced folding and Late Cenozoic tectonics. We demonstrate that accommodation folding is formed in response to the emplacement of several interconnected sills during the opening of the Norwegian-Greenland Seas. Sill emplacement in the study area causes uplift of the Cretaceous to Palaeocene depocentre prior to further restructuration during Cenozoic tectonic inversion. Magmatic intrusions documented in this study have wider implications for understanding supra-sill deformations along volcanic margins with well-developed emplaced sills at depth and likewise hydrocarbon prospectivity in the study area.

  18. Complex Bedforms and Complex Water Masses: A Case Study from the Tertiary to Present-day, Pelotas Basin, Offshore Uruguay

    NASA Astrophysics Data System (ADS)

    Thompson, P.; Badalini, G.; Wrigley, S.; Walker, R.; Argent, J.; Hernandez-Molina, J.; de Santa Ana, H.; Soto, M.; Tomasini, J.

    2015-12-01

    Contour currents are commonly associated with bedform development on modern seabeds yet there is a general paucity of published examples from the ancient record. Recently acquired 3D seismic data, covering over 13000km2 of the Pelotas Basin, offshore Uruguay, provides a unique opportunity to study the architecture and development of a variety of bedform. The data shows that, throughout the Tertiary, contour currents were the dominant control on sedimentation along the Uruguayan margin. The first evidence of contour current activity is during the Early Tertiary in the form of a major regional unconformity that, even though it was fully subaqueous, does not show any major features associated with downslope sedimentation. In the mid-slope region, the unconformity coincides with an extensive (1500km2) intra-slope scour-field orientated parallel to the slope. Individual scours are up to 40m deep, 500m wide and 3km long. Coeval with these scours are a group of coalesced basin floor scours, which run parallel to the base of slope and extend over 400km2. Individual scours exhibit an asymmetric shape - similar to giant flute marks - that are up to 150m deep, 20km wide and extend for at least 40km along slope. The development of these scoured areas shows clear evidence of two major north-flowing water masses. Directly above this regional unconformity are a series of ribbon-like bedforms that developed oblique to the slope. Individual bedforms are up to 40km in length with wavelengths of 5km and heights up to 100m. These bedforms are overlain by a set of barchan-like dunes, up to 30km in length with wavelengths of 10km. Individual dunes are in the order of 100m thick and stack to form an overall package up to 500m thick. These features show a clear change from erosion/bypass to deposition/reworking that is linked to a decrease in ocean current velocity and/ or sediment supply. The features observed suggest a complex oceanic regime was present throughout the Tertiary that

  19. Slide Activity along the eastern slope of the Gela Basin (offshore Sicily): First results from expedition MSM-15/3

    NASA Astrophysics Data System (ADS)

    Huhn, K.; Strasser, M.; Freudenthal, T.; Foglini, F.; Trincardi, F.; Minisini, D.; Msm15/3 Working Group

    2010-12-01

    Submarine slides occur at all sediment bearing margins worldwide (Camerlenghi et al., 2009; Masson et al., 2006). Although numerous studies have dealt with mapping and monitoring of submarine landslide as well as investigations of trigger mechanisms and sediment failure processes, many open questions persist why a given slope fails whereas adjacent remains stable. Besides large slide events, smaller scaled mid-size slides became recently of particular importance because especially these local slides enable investigation of physical and kinematical processes during failure and to test a wide range of different trigger mechanisms. Hence, during the research expedition MSM15/3 we drilled two distinct landslides in the Gela Basin offshore south of Sicily (Italy) utilizing the MARUM sea floor drill rig (MeBo). These so-called ‘Twin Slides’ have previously been identified in water depth between 200 - 800m on the basis of side-scan sonar, Chirp seismics, swath bathymetry and shallow core data. Besides, these landslides are described as multiple failures likely controlled by specific stratigraphic surfaces acting as glide planes (Minisini et al., 2007; Minisini and Trincardi, 2009). Nevertheless, failure planes are located in depth inaccessible by conventional coring and we therefore lack groundtruthing of the geophysical data. Therefore, MeBo was deployed to drill e.g. critical subsurface intervals. A systematic MeBo drilling transect from the undisturbed slope apron to the depositional area of these landslide masses recovers up to 55 meter long cores, including the failure planes and stacked mass transport deposits in the proximal and distal areas, respectively. Sedimentological, geochemical, geophysical and geotechnical analysis of these core materials will enable (1) an age dating and estimation of the recurrence rate of mid-sized slide events and (2) a sediment physical characterization to gain a deeper insight into kinematics and physical processes during failure

  20. Surgical wisdom and Genghis Khan's Pax Mongolica.

    PubMed

    Köstenbauer, Jakob

    2017-03-01

    The unrivalled conquests of Genghis Khan (CE c.1162-1227) led to the establishment of the Greater Mongolian Empire. By 1279, the Mongol dynasty controlled a vast Empire which, for the first time in history, unified Europe and China via the famous Silk Road. The ensuing century of peace and stability is referred to by historians as the Pax Mongolica, which facilitated Europe's renaissance and remarkably contributed to the rise of modern medicine and surgery. Secondary sources from published literature, primary sources from manuscripts and illustrations courtesy of universities, museum libraries and archives. There is ample evidence detailing the Mongol Empire's power during the thirteenth century and the Silk Road's role as a vehicle of commercial, cultural and scientific exchange. Advances in medical knowledge and surgical skills were made in all parts of the Empire and exchanged from China to Constantinople and back. Prominent medical figures traversed these centres, and no doubt contributed to the spread of surgical science, including Rashid al-Din and Mansur Ibn Ilyas. Their works, it is argued, enriched the practice of surgery and may have indirectly ushered-in the rise of modern surgery in the early medical schools at Salerno, Bologna, Pavia, Oxford, Montpellier and Constantinople to name but a few. The blossoming and diversification of medical and surgical knowledge was an integral part of the great cultural exchange facilitated by the Pax Mongolica. This enhanced surgical practice in China, Persia and Arabia, while coinciding with the renaissance of surgical teaching in Europe. © 2017 Royal Australasian College of Surgeons.

  1. The tectonostratigraphic evolution of the offshore Gippsland Basin, Victoria, Australia---results from 3D seismic interpretation and 2D section restoration

    NASA Astrophysics Data System (ADS)

    Weller, Mitchell

    The Gippsland Basin is located primarily offshore Victoria, Australia (between the Australian mainland and Tasmania) approximately 200 km east of Melbourne. The formation of the east-west trending Gippsland Basin is associated with the break-up of Gondwana during the late Jurassic/early Cretaceous and the basin has endured multiple rifting and inversion events. Strong tectonic control on the sedimentary development of the basin is reflected in the deposition of several major, basin scale sequences ranging in age from the early Cretaceous to Neogene, which are usually bounded by angular unconformities. Schlumberger's Petrel software package has been used to structurally and stratigraphically interpret a basin-wide 3D seismic data set provided by the Australian Government (Geoscience Australia) and four 2D kinematic reconstruction/restorations through the basin have been completed with Midland Valley's Move software to achieve a better understanding of the structural evolution of the Gippsland Basin. Rift phase extension calculated from the restorations (5.0--10.5%) appears anomalously low to accommodate the amount of sediment that has been deposited in the basin (>10km). Distributed extension on small faults and subsidence history from backstripping are employed to answer this anomaly. The 2D restorations completed illustrate structural time relationships across the basin and allow for a minimum estimate of erosion that has occurred along the inverted northern basin margin. Differences between previous work completed by Power et al. (2001) and this study as well as several extension models and associated implications are discussed as they relate to the interpretation carried out in this study. Extension calculated from section restorations ranged from approximately 5.0--10.5%. These measured extensional values appear too low to wholly accommodate the accumulated sediment thickness in the basin. Subsidence modelling and backstripping estimates approximately 50

  2. Interview with Dr. Omar Khan, noted global health specialist.

    PubMed

    Simmons, Rob; Khubchandani, Jagdish

    2012-07-01

    Dr. Khan has had a distinguished career in global health. He has served as a faculty member at the University of Vermont College of Medicine and Johns Hopkins University School of Public Health. He is currently a family medicine physician at Christiana Care Health System in Newark, Delaware, and is President of the Delaware Academy of Family Physicians. Dr. Khan has authored more than 55 peer-reviewed journal articles and book chapters and has conducted research and lead primary care and public health initiatives in numerous countries. Last year, Dr. Khan also coedited a book titled Megacities and Global Health sponsored by the American Public Health Association with Dr. Gregory Pappas, Deputy Health Commissioner for Washington, DC.

  3. Tectonic isolation of the Levant basin offshore Galilee-Lebanon effects of the Dead Sea fault plate boundary on the Levant continental margin, eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Schattner, U.; Ben-Avraham, Z.; Lazar, M.; Hüebscher, C.

    2006-11-01

    The continental margin of the central Levant, offshore northern Israel and southern Lebanon is characterized by a sharp continental-oceanic crustal transition, exhibited on the bathymetry as a steep continental slope. At the base of the slope a narrow zone of faulting deforms the upper Messinian-recent sedimentary sequence. Further into the basin no major deformations are observed. However, onland a restraining bend along the Dead Sea fault plate boundary results in the formation of the Lebanon and anti-Lebanon mountain ranges, which exhibit a large positive isostatic anomaly not compensated at depth. All these geologic features follow a NNE-SSW trend. A dense network of multi-channel and single-channel seismic profiles, covering 5000 km of ship-track offshore northern Israel and southern Lebanon, was analyzed for the purpose of characterizing the continental margin. Additional seismic surveys covering the area between the Levant margin and the Cyprean arc were examined. Data were then incorporated with magnetic, gravity and earthquake measurements to reveal the deep crustal structure of the area and integrated with bathymetry data to describe the behavior of the young sedimentary basin fill. Results indicate that the Levant basin, offshore northern Israel and southern Lebanon (up to Beirut) is more-or-less unaffected by the intense tectonic deformation occurring onland. The transition between the deformed area onland and the undeformed Levant basin occurs along the base of the continental slope. Along the base, the upper Messinian-recent sedimentary sequence is cut by two sets of faults: shallow growth faults resulting from salt tectonics and high angle faults, marking the surface expression of a deeper crustal discontinuity - the marine extension of the Carmel fault zone. The central Levant continental margin is being reactivated by transpressional faulting of the marine continuation of the Carmel fault, at the base of the continental slope. This fault system

  4. The transtensional offshore portion of the northern San Andreas fault: Fault zone geometry, late Pleistocene to Holocene sediment deposition, shallow deformation patterns, and asymmetric basin growth

    USGS Publications Warehouse

    Beeson, Jeffrey W.; Johnson, Samuel Y.; Goldfinger, Chris

    2017-01-01

    We mapped an ~120 km offshore portion of the northern San Andreas fault (SAF) between Point Arena and Point Delgada using closely spaced seismic reflection profiles (1605 km), high-resolution multibeam bathymetry (~1600 km2), and marine magnetic data. This new data set documents SAF location and continuity, associated tectonic geomorphology, shallow stratigraphy, and deformation. Variable deformation patterns in the generally narrow (∼1 km wide) fault zone are largely associated with fault trend and with transtensional and transpressional fault bends.We divide this unique transtensional portion of the offshore SAF into six sections along and adjacent to the SAF based on fault trend, deformation styles, seismic stratigraphy, and seafloor bathymetry. In the southern region of the study area, the SAF includes a 10-km-long zone characterized by two active parallel fault strands. Slip transfer and long-term straightening of the fault trace in this zone are likely leading to transfer of a slice of the Pacific plate to the North American plate. The SAF in the northern region of the survey area passes through two sharp fault bends (∼9°, right stepping, and ∼8°, left stepping), resulting in both an asymmetric lazy Z–shape sedimentary basin (Noyo basin) and an uplifted rocky shoal (Tolo Bank). Seismic stratigraphic sequences and unconformities within the Noyo basin correlate with the previous 4 major Quaternary sea-level lowstands and record basin tilting of ∼0.6°/100 k.y. Migration of the basin depocenter indicates a lateral slip rate on the SAF of 10–19 mm/yr for the past 350 k.y.Data collected west of the SAF on the south flank of Cape Mendocino are inconsistent with the presence of an offshore fault strand that connects the SAF with the Mendocino Triple Junction. Instead, we suggest that the SAF previously mapped onshore at Point Delgada continues onshore northward and transitions to the King Range thrust.

  5. Structure, Kinematics and Origin of Radial Faults: 3D Seismic Observations from the Santos Basin, offshore Brazil

    NASA Astrophysics Data System (ADS)

    Coleman, Alexander; Jackson, Christopher A.-L.

    2017-04-01

    Salt stock growth is typically accompanied by the development of geometrically and kinematically complex fault networks in the surrounding country rock. The most common networks comprise radial faults; these are characterised by low displacement (<100 m) normal faults that extend radially outwards from the salt stock into flanking strata. Radial faults are commonly observed in an arched, unpierced roof developed above a rising salt stock; in these cases, the faults are typically well-imaged seismically and likely form due to outer-arc extension during overburden stretching. Radial faults are also found at deeper structural levels, in strata flanking the diapir stem; in these cases, they are typically less well-imaged, thus their structure, kinematics and origin are less well understood. Furthermore, understanding the growth of radial faults may provide insights into hydrocarbon reservoir compartmentalisation and the evolution of neighbouring salt stocks. Here, we use high-quality 3D seismic reflection data from the Santos Basin, offshore Brazil to determine the structure and kinematics, and infer the likely origin of exceptionally well-imaged radial faults overlying and flanking a mature salt stock. Furthermore, we compare the geometric (e.g. throw, geometry, spacing, distribution etc.) and kinematic (e.g. timing of formation and duration of activity) characteristics of radial faults at both structural levels, allowing us to infer their temporal relationship and likely origins. We show that radial faults regardless of their structural level typically have aspect ratios of c. 1.8 - 2, are laterally-restricted in the vicinity of the salt, and have lengths of <3 km that vary with depth. Expansion indices of c. 1, with low throw gradients of 0.05 - 0.1 at the upper tip indicate that radial faults were likely blind. Throws range from 5 - 80 ms, with throw-maxima within 1 - 2 radii of the salt diapir. However, we note that the position of the throw maxima is not at the

  6. An offshore-onland transect across the north-eastern Black Sea basin (Crimean margin): Evidence of Paleocene to Pliocene two-stage compression

    NASA Astrophysics Data System (ADS)

    Sheremet, Yevgeniya; Sosson, Marc; Ratzov, Gueorgui; Sydorenko, Grigoriy; Voitsitskiy, Zinoviy; Yegorova, Tamara; Gintov, Oleg; Murovskaya, Anna

    2016-10-01

    The tectonic evolution of the Black Sea (BS) is a subject of debate, there are several unsolved questions: 1) the timing and the spatial progression of the BS basin opening and 2) the timing of Cenozoic shortening along the northern margin of the Eastern BS basin. The timing of the main compressional deformations, related to the inversion of the Greater Caucasus (GC) basin, is assumed to be Oligo-Miocene. However, Late Cretaceous/Early Paleocene shortening, linked to the final closure of the northern branch of the Neotethys, is also suggested. The Crimean Mountains (CM), to the north of the Eastern BS, is one of the key areas to investigate in order to fix the tectonic evolution of the BS. To precise the timing of the Cenozoic shortening of the Eastern BS, we focus on an integrated onshore/offshore transect from the Eastern CM to the Sorokin Trough (north of Eastern BS). We use newly collected stratigraphic and structural data from the Eastern CM, and a new interpretation of multichannel seismic lines. We define 1) the offshore seismic stratigraphy and constrain the relative chronology of deformations, 2) the age of seismic units by correlation of the seismic data with the Subbotina-403 well log, and 3) we construct an on-to-off shore transect of Eastern CM - northern Eastern BS region. Our results evidence a polyphased Cenozoic compression in the northern part of the Eastern BS: 1) Paleocene-Earliest Eocene and 2) Oligocene-Miocene (Maikopian). Normal faults appear to be related to a formation of the foreland basin, instead of evidencing the Eastern BS Cretaceous rifting. Finally, this study allows precising the shortening phases within Eastern CM and Eastern BS since the Early Paleocene, linking them to the Neotethys closure and the GC tectonic evolution.

  7. Characterization of the Hosgri Fault Zone and adjacent structures in the offshore Santa Maria Basin, south-central California: Chapter CC of Evolution of sedimentary basins/onshore oil and gas investigations - Santa Maria province

    USGS Publications Warehouse

    Willingham, C. Richard; Rietman, Jan D.; Heck, Ronald G.; Lettis, William R.

    2013-01-01

    The Hosgri Fault Zone trends subparallel to the south-central California coast for 110 km from north of Point Estero to south of Purisima Point and forms the eastern margin of the present offshore Santa Maria Basin. Knowledge of the attributes of the Hosgri Fault Zone is important for petroleum development, seismic engineering, and environmental planning in the region. Because it lies offshore along its entire reach, our characterizations of the Hosgri Fault Zone and adjacent structures are primarily based on the analysis of over 10,000 km of common-depth-point marine seismic reflection data collected from a 5,000-km2 area of the central and eastern parts of the offshore Santa Maria Basin. We describe and illustrate the along-strike and downdip geometry of the Hosgri Fault Zone over its entire length and provide examples of interpreted seismic reflection records and a map of the structural trends of the fault zone and adjacent structures in the eastern offshore Santa Maria Basin. The seismic data are integrated with offshore well and seafloor geologic data to describe the age and seismic appearance of offshore geologic units and marker horizons. We develop a basin-wide seismic velocity model for depth conversions and map three major unconformities along the eastern offshore Santa Maria Basin. Accompanying plates include maps that are also presented as figures in the report. Appendix A provides microfossil data from selected wells and appendix B includes uninterpreted copies of the annotated seismic record sections illustrated in the chapter. Features of the Hosgri Fault Zone documented in this investigation are suggestive of both lateral and reverse slip. Characteristics indicative of lateral slip include (1) the linear to curvilinear character of the mapped trace of the fault zone, (2) changes in structural trend along and across the fault zone that diminish in magnitude toward the ends of the fault zone, (3) localized compressional and extensional structures

  8. Combining geophysical data and calcite twin stress inversion to refine the tectonic history of subsurface and offshore provinces: A case study on the Cooper-Eromanga Basin, Australia

    NASA Astrophysics Data System (ADS)

    Kulikowski, David; Amrouch, Khalid

    2017-03-01

    The use of core samples, borehole image logs, and seismic data is common practice for obtaining valuable structural data; however, these data are often obtained in isolation from other methods and not usually used for paleostress inversion processes. Therefore, for the first time, we present a new approach for constraining paleoprincipal stress orientations and regimes by integrating geophysical data (seismic and well data) with calcite twin principal stress orientation inversion analysis to refine the evolution of entirely subsurface or offshore basins; a case study on the subsurface Cooper-Eromanga Basin, Australia. Calcite samples were collected from oriented core, natural fracture data collected from borehole image logs, and fault data interpreted from three-dimensional seismic surveys. The analysis of microscale, mesoscale and macroscale data constrained the paleoprincipal stress orientations and regimes of six successive tectonic events: (1) NNW-SSE oriented strike-slip Carboniferous Alice Springs event; (2) SE-NW oriented compressional Mid-Permian event; (3) NE-SW oriented strike-slip Late Permian Daralingie event; (4) E-W compressional Late Triassic Hunter-Bowen event; (5) E-W compressional Late Cretaceous event; and (6) N-S compressional Paleogene event. This study shows the applicability of integrating geophysics with calcite twin stress inversion to decipher the tectonic evolution of entirely subsurface and offshore provinces.

  9. Well-log signatures of alluvial-lacustrine reservoirs and source rocks, Lagoa-Feia Formations, Lower Cretaceous, Campos Basin, offshore Brazil

    SciTech Connect

    Abrahao, D.; Warme, J.E.

    1988-01-01

    The Campos basin is situated in offshore southeastern Brazil. The Lagoa Feia is the basal formation in the stratigraphic sequence of the basin, and was deposited during rifting in an evolving complex of lakes of different sizes and chemical characteristics, overlying and closely associated with rift volcanism. The stratigraphic sequence is dominated by lacustrine limestones and shales (some of them organic-rich), and volcaniclastic conglomerates deposited on alluvial fans. The sequence is capped by marine evaporites. In the Lagoa Feia Formation, complex lithologies make reservoirs and source rocks unsuitable for conventional well-log interpretation. To solve this problem, cores were studied and the observed characteristics related to log responses. The results have been extended through the entire basin for other wells where those facies were not cored. The reservoir facies in the Lagoa Feia Formation are restricted to levels of pure pelecypod shells (''coquinas''). Resistivity, sonic, neutron, density, and gamma-ray logs were used in this work to show how petrophysical properties are derived for the unconventional reservoirs existing in this formation. The same suite of logs was used to develop methods to define geochemical characteristics where source rock data are sparse in the organic-rich lacustrine shales of the Lagoa Feia Formation. These shales are the main source rocks for all the oil discovered to date in the Campos basin.

  10. Quaternary uplift and subsidence of Catalina Ridge and San Pedro Basin, Inner California Continental Borderland, offshore southern California; results of high-resolution seismic profiling

    NASA Astrophysics Data System (ADS)

    Francis, R.; Legg, M. R.

    2010-12-01

    activity decreased or ceased, as evidenced by the seafloor benches around the island and the flat, onlapping upper sequence of the basin. That the SPBF appears to cut through to the SDTF raises the possibility that a significant share of the motion along the SDTF is now being taken up by the SPBF, at the expense of the CF. Another possibility is that activity along the CF restraining bend is currently being compensated for by broad-scale subsidence within a large offshore synclinorium between Palos Verdes Hills and San Clemente Island, accounting for Catalina Ridge subsidence.

  11. Commentary: The Khan Academy and the Day-Night Flipped Classroom

    ERIC Educational Resources Information Center

    Parslow, Graham R.

    2012-01-01

    Teaching by night and reflecting on a subject by day is the way that Salman Khan sees education evolving in the age of online lectures. Khan believes he is onto something in what he styles the "flipped classroom." In Khan's view, there is no need for students to be divided into grades by age. Instead, they should learn at their own pace, moving on…

  12. Commentary: The Khan Academy and the Day-Night Flipped Classroom

    ERIC Educational Resources Information Center

    Parslow, Graham R.

    2012-01-01

    Teaching by night and reflecting on a subject by day is the way that Salman Khan sees education evolving in the age of online lectures. Khan believes he is onto something in what he styles the "flipped classroom." In Khan's view, there is no need for students to be divided into grades by age. Instead, they should learn at their own pace, moving on…

  13. "Kubla Khan" and Its Narratives of Possible Worlds

    ERIC Educational Resources Information Center

    Nayar, Pramod K.

    2013-01-01

    This essay argues that Coleridge's "Kubla Khan" is a poem about narrative and specifically focuses on the narrative construction of possible worlds, or even utopian worlds. It notes two pairs of narratives. In pair one the utopian narrative of the monarch's decree which seeks to build a space of pure pleasure is in opposition to the…

  14. "Kubla Khan" and Its Narratives of Possible Worlds

    ERIC Educational Resources Information Center

    Nayar, Pramod K.

    2013-01-01

    This essay argues that Coleridge's "Kubla Khan" is a poem about narrative and specifically focuses on the narrative construction of possible worlds, or even utopian worlds. It notes two pairs of narratives. In pair one the utopian narrative of the monarch's decree which seeks to build a space of pure pleasure is in opposition to the…

  15. Analysis of ancient-river systems by 3D seismic time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia

    SciTech Connect

    Sulaiman, Noorzamzarina; Hamzah, Umar; Samsudin, Abdul Rahim

    2014-09-03

    Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D seismic data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1–5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of seismic facies analysis of the two-dimensional (2D) seismic sections, mainly reflecting changes in fluvial channel style and river architecture. The succession has been divided into four seismic units (Unit S1-S4), bounded by basin-wide strata surfaces. Two types of boundaries have been identified: 1) a boundary that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (S3 and S4); 2) a sequence boundary that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as low-stand alluvial bypass channel systems (S1 and S2). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat Sunda land Platform.

  16. Recent deformation on the San Diego Trough and San Pedro Basin fault systems, offshore Southern California: Assessing evidence for fault system connectivity.

    NASA Astrophysics Data System (ADS)

    Bormann, J. M.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.

    2016-12-01

    The seismic hazard posed by offshore faults for coastal communities in Southern California is poorly understood and may be considerable, especially when these communities are located near long faults that have the ability to produce large earthquakes. The San Diego Trough fault (SDTF) and San Pedro Basin fault (SPBF) systems are active northwest striking, right-lateral faults in the Inner California Borderland that extend offshore between San Diego and Los Angeles. Recent work shows that the SDTF slip rate accounts for 25% of the 6-8 mm/yr of deformation accommodated by the offshore fault network, and seismic reflection data suggest that these two fault zones may be one continuous structure. Here, we use recently acquired CHIRP, high-resolution multichannel seismic (MCS) reflection, and multibeam bathymetric data in combination with USGS and industry MCS profiles to characterize recent deformation on the SDTF and SPBF zones and to evaluate the potential for an end-to-end rupture that spans both fault systems. The SDTF offsets young sediments at the seafloor for 130 km between the US/Mexico border and Avalon Knoll. The northern SPBF has robust geomorphic expression and offsets the seafloor in the Santa Monica Basin. The southern SPBF lies within a 25-km gap between high-resolution MCS surveys. Although there does appear to be a through-going fault at depth in industry MCS profiles, the low vertical resolution of these data inhibits our ability to confirm recent slip on the southern SPBF. Empirical scaling relationships indicate that a 200-km-long rupture of the SDTF and its southern extension, the Bahia Soledad fault, could produce a M7.7 earthquake. If the SDTF and the SPBF are linked, the length of the combined fault increases to >270 km. This may allow ruptures initiating on the SDTF to propagate within 25 km of the Los Angeles Basin. At present, the paleoseismic histories of the faults are unknown. We present new observations from CHIRP and coring surveys at

  17. Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian), Central Iran

    NASA Astrophysics Data System (ADS)

    Shadan, Mahdi; Hosseini-Barzi, Mahboubeh

    2010-05-01

    Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian), Central Iran M. Shadan & M. Hosseini-Barzi Geology Department, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran shadangeo@gmail.com Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian) have been studied in two sections (Chahroof with 197 m thick in north and Cheshmeh Bakhshi with 204 m thick in south) along basement Kalmard fault in Posht-e-Badam block, Central Iran. Siliciclastic units are characterized by well sorted, fine to medium grain quartzarenites with laterite interbeds, deposited in shoreline zone (foreshore, upper and lower shoreface) influencing wave and longshore currents. Longshore sands which have been transported along the coast made the sand bars in the shoreface. Further along the coast, returning of these currents as rip currents produced erosive channel inlets and caused to carry fine grain into the deeper regions of the basin. Based on this sedimentary model we introduced longshore currents as a probable agent for mixing, by transporting some volumes of sands into the adjacent carbonate environments. Vertically, clastic units of Khan Formation underlined by carbonate units of a tidal flat and high-energy inner ramp system. Repeating of this pattern produced 3 cycles in each section. Cyclic evolution, in studied sections, is accompanied with discrepancy in erosion and sedimentation. These factors caused to disperse local sub-aerial exposures in successions which are recognizable by laterite and conglomerate interbeds. These horizons of sub-aerial exposures are more often in Chahroof section than in Cheshmeh Bakhshi section and indicate more fluctuations of relative sea level probably due to more local tectonic activity in the northern part of the Kalmard fault than in the southern part of it. Also, thicker siliciclastic units in Chahroof section show higher rate of sediment supply and/or more accommodation space

  18. 76 FR 69318 - In the Matter of the Designation of Mali Khan also known as Madi Khan as a Specially Designated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE In the Matter of the Designation of Mali Khan also known as Madi Khan as a Specially Designated Global Terrorist Pursuant to Section 1(b) of Executive Order 13224, as Amended Acting under the authority of and in accordance with section 1(b) of...

  19. Nature of the uppermost mantle below the Porcupine Basin, offshore Ireland: new insights from seismic refraction and gravity data modeling

    NASA Astrophysics Data System (ADS)

    Prada, M.; Watremez, L.; Chen, C.; O'Reilly, B.; Minshull, T. A.; Reston, T. J.; Wagner, G.; Gaw, V.; Klaeschen, D.; Shannon, P.

    2015-12-01

    The Porcupine Basin is a tongue-shaped basin SW of Ireland formed during the opening of the North Atlantic Ocean. Its history of sedimentation reveals several rifting and subsidence phases during the Late Paleozoic and Cenozoic, with a particular major rift phase occurring in Late Jurassic-Early Cretaceous times. Previous work, focused on seismic and gravity data, suggest the presence of major crustal faulting and uppermost mantle serpentinization in the basin. Serpentinization is a key factor in lithospheric extension since it reduces the strength of mantle rocks, and hence, influences the tectonics of the lithosphere. Besides reducing the seismic velocity of the rock, serpentinization decreases mantle rock density favoring isostatic rebound and basin uplift, thus affecting the tectonic and thermal evolution of the basin. Here we characterize the deep structure of the Porcupine Basin from wide-angle seismic (WAS) and gravity data, with especial emphasis on the nature of the underlying mantle. The WAS data used were acquired along a 300 km long transect across the northern region of the basin. We used a travel time inversion method to model the data and obtain a P-wave velocity (Vp) model of the crust and uppermost mantle, together with the geometry of the main geological interfaces. The crustal structure along the model reveals a maximum stretching factor of ~5-6. These values are well within the range of crustal extension at which the crust becomes entirely brittle allowing the formation of major crustal faulting and serpentinization of the mantle. To further constrain the seismic structure and hence the nature of the mantle we assess the Vp uncertainty of the model by means of a Monte Carlo analysis and perform gravity modeling to test different interpretations regarding mantle rock nature. This project is funded by the Irish Shelf Petroleum Studies Group (ISPSG) of the Irish Petroleum Infrastructure Programme Group 4.

  20. Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline - Santa Barbara Channel and the Southern Santa Maria Basin: Source Identification and Inventory

    USGS Publications Warehouse

    Lorenson, T.D.; Hostettler, Frances D.; Rosenbauer, Robert J.; Peters, Kenneth E.; Dougherty, Jennifer A.; Kvenvolden, Keith A.; Gutmacher, Christina E.; Wong, Florence L.; Normark, William R.

    2009-01-01

    Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage. The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California. Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps. To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The

  1. The impact of late Cenozoic uplift and erosion on hydrocarbon exploration: offshore Norway and some other uplifted basins

    NASA Astrophysics Data System (ADS)

    Doré, A. G.; Jensen, L. N.

    1996-03-01

    Uplift and erosion of sedimentary basins can have a wide range of effects, both positive and negative, on hydrocarbon prospectivity. These phenomena are discussed with special reference to the Norwegian Continental Shelf. Late Cenozoic uplift and erosion have affected large expanses of the shelf, and in particular the Barents Sea. Up to 3000 m of sedimentary overburden have been removed from the Barents shelf, and this process is widely held to be responsible for disappointing results in petroleum exploration. Negative effects identified include spillage of hydrocarbons from accumulations, expansion of gas and evacuation of structures, potential for seal failure and cooling of source rocks. We argue, however, that these aspects have been overstated based on a limited database. Many of the world's hydrocarbon basins (and most of the world's petroleum reserves) lie on land. Most of these basins must have been recently uplifted in order to be above sea level today. Using some of these examples, we show that in other areas with a similar magnitude of uplift and erosion to the Barents Sea sealing capacity (particularly that of evaporites) has been preserved. Hydrocarbon systems have remained intact despite phase changes and redistribution of hydrocarbons. Several enhancing effects of the uplift are documented, including the development of fracture permeability in reservoirs, the remigration of hydrocarbons to shallower subsurface levels and the exsolution of light oil (retrograde condensate). Looking to a future in which natural gas may have increased value, potential exists in uplifted basins such as the Barents Sea for vast volumes of methane formed by exsolution from formation brines. We stress the importance of studying such worldwide analogues in order to throw new light on Norwegian shelf problems. Attention is drawn to some striking similarities between the hydrocarbon systems of the Western Canada Basin and those of the Barents Sea. Examination of the massive

  2. Hydroacoustic ray theory-based modeling of T wave propagation in the deep ocean basin offshore eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Chin-Wu; Huang, Chen-Fen; Lin, Chien-Wen; Kuo, Ban-Yuan

    2017-05-01

    T waves are conventionally defined as seismically generated acoustic energy propagating horizontally over long distances within the minimum sound speed layer in the ocean (SOFAR axis minimum). However, T waves have also been observed by ocean-bottom seismometers in ocean basins at depths greater than the SOFAR axis minimum. Previously, nongeometrical processes, such as local scattering at rough seafloor and water-sediment interface coupling, have been proposed as possible mechanisms for deep seafloor detection of T waves. Here we employ a new T wave modeling approach based on hydroacoustic ray theory to demonstrate that seismoacoustic energy can propagate to reach deep seafloor, previously considered as shadow zone of acoustic propagation. Our new hydroacoustic simulations explain well the observations of T waves on ocean-bottom seismometers at deep ocean basins east of Taiwan and shed new light on the mechanism for deep ocean T wave propagation.

  3. Estimation of palaeo-slope and sediment volume of a lacustrine rift basin: A semi-quantitative study on the southern steep slope of the Shijiutuo Uplift, Bohai Offshore Basin, China

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Meng, Jun; Banerjee, Santanu

    2017-10-01

    The sequence architecture and depositional systems of the Palaeogene lacustrine rift succession in the southern steep slope of the Shijiutuo Uplift (SU) in Bohai Offshore Basin (BOB) were investigated using combined 3-D seismic, well log and core data. Four second-order/composite sequences and seven third-order sequences were identified. A detailed analysis revealed fan delta, braid delta and lacustrine depositional systems in the third-order sequences 7 (SQ7). Eleven seismic facies were chosen in the SQ7 to calculate the area and sediment budget. We also calculated the palaeo-slope parameters in the southern steep slope of the SU, including the gradient of basin margin fault slope belt, the shape, average width, average height, width/height ratio and cross sectional area of palaeo-valley. The gradient of the fault slope break belt was inversely proportional to the area and volume of sediments. The higher gradient corresponded to the smaller area and volume of sediments. The width and cross sectional area of palaeo-valleys dominated the volume and facies of sediments. A larger cross sectional area of a palaeo-valley involved much more sediments supply and more favorable conditions for the origin of large-scale deltas. Because of favorable sediment transportation path and existence of large-scale braid delta, the eastern part of the SU formed better quality reservoir than that in the west.

  4. Association among active seafloor deformation, mound formation, and gas hydrate growth and accumulation within the seafloor of the Santa Monica Basin, offshore California

    USGS Publications Warehouse

    Paull, C.K.; Normark, W.R.; Ussler, W.; Caress, D.W.; Keaten, R.

    2008-01-01

    Seafloor blister-like mounds, methane migration and gas hydrate formation were investigated through detailed seafloor surveys in Santa Monica Basin, offshore of Los Angeles, California. Two distinct deep-water (??? 800??m water depth) topographic mounds were surveyed using an autonomous underwater vehicle (carrying a multibeam sonar and a chirp sub-bottom profiler) and one of these was explored with the remotely operated vehicle Tiburon. The mounds are > 10??m high and > 100??m wide dome-shaped bathymetric features. These mounds protrude from crests of broad anticlines (~ 20??m high and 1 to 3??km long) formed within latest Quaternary-aged seafloor sediment associated with compression between lateral offsets in regional faults. No allochthonous sediments were observed on the mounds, except slumped material off the steep slopes of the mounds. Continuous streams of methane gas bubbles emanate from the crest of the northeastern mound, and extensive methane-derived authigenic carbonate pavements and chemosynthetic communities mantle the mound surface. The large local vertical displacements needed to produce these mounds suggests a corresponding net mass accumulation has occurred within the immediate subsurface. Formation and accumulation of pure gas hydrate lenses in the subsurface is proposed as a mechanism to blister the seafloor and form these mounds. ?? 2008 Elsevier B.V. All rights reserved.

  5. Growth and demise of a Paleogene isolated carbonate platform of the Offshore Indus Basin, Pakistan: effects of regional and local controlling factors

    NASA Astrophysics Data System (ADS)

    Shahzad, Khurram; Betzler, Christian; Ahmed, Nadeem; Qayyum, Farrukh; Spezzaferri, Silvia; Qadir, Anwar

    2017-06-01

    Based on high-resolution seismic and well datasets, this paper examines the evolution and drowning history of a Paleocene-Eocene carbonate platform in the Offshore Indus Basin of Pakistan. This study uses the internal seismic architecture, well log data as well as the microfauna to reconstruct factors that governed the carbonate platform growth and demise. Carbonates dominated by larger benthic foraminifera assemblages permit constraining the ages of the major evolutionary steps and show that the depositional environment was tropical within oligotrophic conditions. With the aid of seismic stratigraphy, the carbonate platform edifice is resolved into seven seismic units which in turn are grouped into three packages that reflect its evolution from platform initiation, aggradation with escarpment formation and platform drowning. The carbonate factory initiated as mounds and patches on a Cretaceous-Paleocene volcanic complex. Further, the growth history of the platform includes distinct phases of intraplatform progradation, aggradation, backstepping and partial drownings. The youngest succession as late-stage buildup records a shift from benthic to pelagic deposition and marks the final drowning in the Early Eocene. The depositional trend of the platform, controlled by the continuing thermal subsidence associated with the cooling of volcanic margin lithosphere, was the major contributor of the accommodation space which supported the vertical accumulation of shallow water carbonate succession. Other factors such as eustatic changes and changes in the carbonate producers as a response to the Paleogene climatic perturbations played secondary roles in the development and drowning of these buildups.

  6. An interpretation of core and wireline logs for the Petrophysical evaluation of Upper Shallow Marine sandstone reservoirs of the Bredasdorp Basin, offshore South Africa

    NASA Astrophysics Data System (ADS)

    Magoba, Moses; Opuwari, Mimonitu

    2017-04-01

    This paper embodies a study carried out to assess the Petrophysical evaluation of upper shallow marine sandstone reservoir of 10 selected wells in the Bredasdorp basin, offshore, South Africa. The studied wells were selected randomly across the upper shallow marine formation with the purpose of conducting a regional study to assess the difference in reservoir properties across the formation. The data sets used in this study were geophysical wireline logs, Conventional core analysis and geological well completion report. The physical rock properties, for example, lithology, fluid type, and hydrocarbon bearing zone were qualitatively characterized while different parameters such as volume of clay, porosity, permeability, water saturation ,hydrocarbon saturation, storage and flow capacity were quantitatively estimated. The quantitative results were calibrated with the core data. The upper shallow marine reservoirs were penetrated at different depth ranging from shallow depth of about 2442m to 3715m. The average volume of clay, average effective porosity, average water saturation, hydrocarbon saturation and permeability range from 8.6%- 43%, 9%- 16%, 12%- 68% , 32%- 87.8% and 0.093mD -151.8mD respectively. The estimated rock properties indicate a good reservoir quality. Storage and flow capacity results presented a fair to good distribution of hydrocarbon flow.

  7. In situ stress and pore pressure in the Kumano Forearc Basin, offshore SW Honshu from downhole measurements during riser drilling

    NASA Astrophysics Data System (ADS)

    Saffer, D. M.; Flemings, P. B.; Boutt, D.; Doan, M.-L.; Ito, T.; McNeill, L.; Byrne, T.; Conin, M.; Lin, W.; Kano, Y.; Araki, E.; Eguchi, N.; Toczko, S.

    2013-05-01

    situ stress and pore pressure are key parameters governing rock deformation, yet direct measurements of these quantities are rare. During Integrated Ocean Drilling Program (IODP) Expedition #319, we drilled through a forearc basin at the Nankai subduction zone and into the underlying accretionary prism. We used the Modular Formation Dynamics Tester tool (MDT) for the first time in IODP to measure in situ minimum stress, pore pressure, and permeability at 11 depths between 729.9 and 1533.9 mbsf. Leak-off testing at 708.6 mbsf conducted as part of drilling operations provided a second measurement of minimum stress. The MDT campaign included nine single-probe (SP) tests to measure permeability and in situ pore pressure and two dual-packer (DP) tests to measure minimum principal stress. Permeabilities defined from the SP tests range from 6.53 × 10-17 to 4.23 × 10-14 m2. Pore fluid pressures are near hydrostatic throughout the section despite rapid sedimentation. This is consistent with the measured hydraulic diffusivity of the sediments and suggests that the forearc basin should not trap overpressures within the upper plate of the subduction zone. Minimum principal stresses are consistently lower than the vertical stress. We estimate the maximum horizontal stress from wellbore failures at the leak-off test and shallow MDT DP test depths. The results indicate a normal or strike-slip stress regime, consistent with the observation of abundant active normal faults in the seaward-most part of the basin, and a general decrease in fault activity in the vicinity of Site C0009.

  8. Aspects of the structural evolution of the Lusitanian Basin in Portugal and the shelf and slope area offshore Portugal

    NASA Astrophysics Data System (ADS)

    Rasmussen, Erik S.; Lomholt, Steen; Andersen, Claus; Vejbæk, Ole V.

    1998-12-01

    The study provides a regional seismic interpretation and mapping of the Mesozoic and Cenozoic succession of the Lusitanian Basin and the shelf and slope area off Portugal. The seismic study is compared with previous studies of the Lusitanian Basin. From the Late Triassic to the Cretaceous the study area experienced four rift phases and intermittent periods of tectonic quiescence. The Triassic rifting was concentrated in the central part of the Lusitanian Basin and in the southernmost part of the study area, both as symmetrical grabens and half-grabens. The evolution of half-grabens was particularly prominent in the south. The Triassic fault-controlled subsidence ceased during the latest Late Triassic and was succeeded by regional subsidence during the early Early Jurassic (Hettangian) when deposition of evaporites took place. A second rift phase was initiated in the Early Jurassic, most likely during the Sinemurian-Pliensbachian. This resulted in minor salt movements along the most prominent faults. The second phase was concentrated to the area south of the Nazare Fault Zone and resulted here in the accumulation of a thick Sinemurian-Callovian succession. Following a major hiatus, probably as a result of the opening of the Central Atlantic, resumed deposition occurred during the Late Jurassic. Evidence for Late Jurassic fault-controlled subsidence is widespread over the whole basin. The pattern of Late Jurassic subsidence appears to change across the Nazare Fault Zone. North of the Nazare Fault, fault-controlled subsidence occurred mainly along NNW-SSE-trending faults and to the south of this fault zone a NNE-SSW fault pattern seems to dominate. The Oxfordian rift phase is testified in onlapping of the Oxfordian succession on salt pillows which formed in association with fault activity. The fourth and final rift phase was in the latest Late Jurassic or earliest Early Cretaceous. The Jurassic extensional tectonism resulted in triggering of salt movement and the

  9. Silicate Weathering and Pervasive Authigenic Carbonate Precipitation Coupled to Methanogenesis in the Krishna-Godavari Basin, Offshore India

    NASA Astrophysics Data System (ADS)

    Solomon, E. A.; Spivack, A. J.; Kastner, M.; Torres, M. E.

    2014-12-01

    The cycling of methane in marine sediments has been actively studied for the past several decades, but less attention has been paid to the cycling of CO2 produced in methanogenic sediments. The National Gas Hydrate Program Expedition 01 cored 10 sites with the Joides Resolution drillship in the Krishna-Godavari basin, located on the southeastern margin of India. A comprehensive suite of pore water solute concentrations and isotope ratios were analyzed to investigate the distribution and concentration of gas hydrate along the margin, in situ diagenetic and metabolic reactions, fluid migration and flow pathways, and fluid and gas sources. This represents one of the most comprehensive pore water geochemical datasets collected at a continental margin to date, and provides the necessary tracers to better understand the processes and sinks controlling CO2 in margin sediments. Our results show that the CO2 produced through net microbial methanogenesis is effectively neutralized through silicate weathering throughout the sediment column drilled at each site (~100-300 m), buffering the pH of the sedimentary pore water and generating excess alkalinity through the same reaction sequence as continental silicate weathering. Most of the excess alkalinity produced through silicate weathering in the Krishna-Godavari basin is sequestered in Ca- and Fe-carbonates as a result of ubiquitous calcium release from weathering detrital silicates and Fe-reduction within the methanogenic sediments. Formation of secondary hydrous silicates (e.g. smectite) related to incongruent primary silicate dissolution acts as a significant sink for pore water Mg, K, Li, Rb, and B. The consumption of methane through anaerobic oxidation of methane, sequestration of methane in gas hydrate, and sequestration of dissolved inorganic carbon in authigenic carbonates keeps methanogenesis as a thermodynamically feasible catabolic pathway. Our results combined with previous indications of silicate weathering in

  10. Sandstone and shale compaction curves derived from sonic and gamma ray logs in offshore wells, North Slope, Alaska; parameters for basin modeling

    USGS Publications Warehouse

    Rowan, Elisabeth L.; Hayba, Daniel O.; Nelson, Philip H.; Burns, W. Matthew; Houseknecht, David W.

    2003-01-01

    Representative compaction curves for the principle lithologies are essential input for reliable models of basin history. Compaction curves influence estimates of maximum burial and erosion. Different compaction curves may produce significantly different thermal histories. Default compaction curves provided by basin modeling packages may or may not be a good proxy for the compaction properties in a given area. Compaction curves in the published literature span a wide range, even within one lithology, e.g., sandstone (see Panel 3). An abundance of geophysical well data for the North Slope, from both government and private sources, provides us with an unusually good opportunity to develop compaction curves for the Cretaceous-Tertiary Brookian sandstones, siltstones, and shales. We examined the sonic and gamma ray logs from 19 offshore wells (see map), where significant erosion is least likely to have occurred. Our data are primarily from the Cretaceous-Tertiary Brookian sequence and are less complete for older sequences. For each well, the fraction of shale (Vsh) at a given depth was estimated from the gamma ray log, and porosity was computed from sonic travel time. By compositing porosities for the near-pure sand (Vsh99%)from many individual wells we obtained data over sufficient depth intervals to define sandstone and shale 'master' compaction curves. A siltstone curve was defined using the sonic-derived porosities for Vsh values of 50%. These compaction curves generally match most of the sonic porosities with an error of 5% or less. Onshore, the curves are used to estimate the depth of maximum burial at the end of Brookian sedimentation. The depth of sonic-derived porosity profiles is adjusted to give the best match with the 'master' compaction curves. The amount of the depth adjustment is the erosion estimate. Using our compaction curves, erosion estimates on the North Slope range from zero in much of the offshore, to as much as 1500 ft along the coast, and to

  11. Gas in Place Resource Assessment for Concentrated Hydrate Deposits in the Kumano Forearc Basin, Offshore Japan, from NanTroSEIZE and 3D Seismic Data

    NASA Astrophysics Data System (ADS)

    Taladay, K.; Boston, B.

    2015-12-01

    Natural gas hydrates (NGHs) are crystalline inclusion compounds that form within the pore spaces of marine sediments along continental margins worldwide. It has been proposed that these NGH deposits are the largest dynamic reservoir of organic carbon on this planet, yet global estimates for the amount of gas in place (GIP) range across several orders of magnitude. Thus there is a tremendous need for climate scientists and countries seeking energy security to better constrain the amount of GIP locked up in NGHs through the development of rigorous exploration strategies and standardized reservoir characterization methods. This research utilizes NanTroSEIZE drilling data from International Ocean Drilling Program (IODP) Sites C0002 and C0009 to constrain 3D seismic interpretations of the gas hydrate petroleum system in the Kumano Forearc Basin. We investigate the gas source, fluid migration mechanisms and pathways, and the 3D distribution of prospective HCZs. There is empirical and interpretive evidence that deeply sourced fluids charge concentrated NGH deposits just above the base of gas hydrate stability (BGHS) appearing in the seismic data as continuous bottoms simulating reflections (BSRs). These HCZs cover an area of 11 by 18 km, range in thickness between 10 - 80 m with an average thickness of 40 m, and are analogous to the confirmed HCZs at Daini Atsumi Knoll in the eastern Nankai Trough where the first offshore NGH production trial was conducted in 2013. For consistency, we calculated a volumetric GIP estimate using the same method employed by Japan Oil, Gas and Metals National Corporation (JOGMEC) to estimate GIP in the eastern Nankai Trough. Double BSRs are also common throughout the basin, and BGHS modeling along with drilling indicators for gas hydrates beneath the primary BSRs provides compelling evidence that the double BSRs reflect a BGHS for structure-II methane-ethane hydrates beneath a structure-I methane hydrate phase boundary. Additional drilling

  12. Style and pattern of salt diapirs due to thin-skinned gravitational gliding, Campos and Santos basins, offshore Brazil

    NASA Astrophysics Data System (ADS)

    Demercian, S.; Szatmari, P.; Cobbold, P. R.

    1993-12-01

    Portions of seismic lines and a structure-contour map illustrate the patterns and shapes of salt diapirs and related structures in the Campos and Santos areas, off the Atlantic coast of Brazil. We interpret the structures both kinematically and mechanically, drawing on our experience with similar salt structures worldwide, with the results of recent physical modelling and with geometric restorations in section and in plan. Salt diapirs and related structures have a variety of structural styles, distributed in domains and provinces. Near the coast, there is an upper domain, 100-200 km wide, with a suite of structures that we attribute to horizontal downdip extension: these are salt rollers, in the footwalls of listric normal growth faults; salt walls of triangular cross section, beneath intersecting conjugate normal faults; turtle anticlines; and salt welds. Downslope extension started in the Albian and has continued to the present day. In the Campos area, from simple line balancing, the accumulated downslope displacement is about 100 km. Seawards of this, there is a lower domain, 100-400 km wide, with a different suite of structures, that we attribute to downdip contraction: these are growth folds of various wavelengths, in sedimentary sequences of various thicknesses; asymmetric salt walls, emplaced above reverse faults; deep basins, wedged down between conjugate reverse faults; and salt tongues above thrusts. For Campos, we estimate the total downslope contraction, accumulated since the Albian, to be about 100 km. From the balance between extension and contraction, we infer that the thin-skinned salt tectonics are gravitationally driven and independent of any basement tectonics. The structure-contour map on the top of the salt shows that structural style is variable also along strike. Seismic sections along regional contours indicate differing amounts of strain. On this basis, we distinguish five provinces, separated by NW-SE-trending lines. For the Northern

  13. High Resolution Mapping of an Alleged Chemical Weapons Dump Site in the Santa Cruz Basin, offshore California

    NASA Astrophysics Data System (ADS)

    Brewer, P. G.; Peltzer, E. T.; Walz, P. M.; Caress, D. W.; Thomas, H. J.

    2013-12-01

    Nautical charts record seven locations off the coast of California labeled as 'Chemical Munitions Dumping Area, Disused' that together cover some 12,000 km2 of sea floor. However only one such chemical munitions site is officially documented and no record exists of any chemical munitions disposed of at other locations, thus creating confusion. We have executed a one day AUV mapping survey of a corner of one such site in the Santa Cruz Basin, south of Port Hueneme, to examine and investigate the debris field. The region is covered with soft sediment and the overlying water is very low in oxygen at ~10 μmol/kg. The processed 110 kHz sidescan data revealed some 754 targets in 25.6 km2 for an average of 29 targets per km2. This was followed by two ROV dives to investigate the targets identified. We found but one false positives among the over 40 targets visited, and found items ranging from two distinct lines of unmarked or labeled and now empty barrels, two target drones, and much miscellaneous debris including 4-packs of cat food cans and a large ships mast over 30m in length. There was zero evidence of chemical weapons materiel as expected given the lack of official records. Almost all of the targets were covered in dense and colorful assemblages of invertebrates: sponges, anemones, and crabs. Where barrels were sufficiently open for full visual inspection, the interior sea floor appeared to have become fully anoxic and was covered in white and yellow bacterial mat. The area chosen for our survey (centered at 33.76 deg N 119.56 deg W) was across the north western boundary of the marked site, and represents only ~ 10% percent of the designated area. Our expectation, that human nature would drive the disposal activities to the nearest corner of the chosen area rather than the center of the field appears to have been confirmed. Objects were found both within and outside of the boundary of the dump site. We have not surveyed the full marked area but there appears to be

  14. Offshore medicine.

    PubMed

    Baker, D

    2001-03-01

    Offshore life can be refreshing for medics who are looking for a little change of pace; however, it is not for everyone. Working offshore can be the easiest or most boring job you'll ever have. It takes a specific type of medic to fit this mold. So, if you are considering a career in the offshore field, take all of the above into consideration. You are not just making a change in jobs, but a change in lifestyle. Once you become accustomed to this lifestyle, it will be hard to go back to the everyday hustle and bustle of the streets. For more information about working offshore, contact Acadian Contract Services at 800/259-333, or visit www.acadian.com.

  15. BASINS

    EPA Pesticide Factsheets

    Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed to help regional, state, and local agencies perform watershed- and water quality-based studies.

  16. Seismic geomorphological analysis of multi-story submarine channel-belt complexes in the Pliocene succession of the Levant Basin, offshore central Israel

    NASA Astrophysics Data System (ADS)

    Niyazi, Yakufu; Eruteya, Ovie Emmanuel; Waldmann, Nicolas

    2017-04-01

    In this study we combine the analysis of a high-resolution three-dimensional seismic reflection dataset and well-logs to characterize a distinct succession characterized by moderate to high-amplitude discontinuous to continuous seismic facies. This interval was deposited during ca. Middle - Late Pliocene, and sandwiched between continuous basin series and mass transport deposit (MTD). Our dataset, located at the foot of the continental slope, offshore central Israel reveal this interval is characterized by multi-storey submarine channel-belt complexes spatio-temporally located in the western part of the study area and restricted to the east by the emplacement of a MTD. We further subdivide the channel-belt complexes into a lower and upper system. The channels in both systems trend N-NW and have a width ranging between 150 m to 350 m , while incising up 50 m within the Pliocene sediments at both levels. Greater populations of well-developed and more sinuous channels are identified in the upper part of the channel complex, suggesting that the interplay between the sedimentary processes and the evolution of channels in the studied interval are heterogeneous. In particular, this may emphasize remarkable changes in spatio-temporal variations in flow volume. Yet, the effect of salt tectonics inflicted by the Messinian evaporites substratum on the morphology of the channel-belt complexes can be downplayed since its associated deformation postdates the evolution of the channels. Considering the available chronology obtained from well-logs and through further comparison with other regional and global climate proxies, we suggest the presence of an apparent periodicity in the evolution of the channels through time. We propose the evolution of these channels during the Pliocene is Nile-related. Furthermore, the channel systems described here for the Pliocene interval may extend the current understanding of the development of slope channels under the influence of juvenile

  17. Assessment of Mass-Transport Deposits occurrence offshore Espírito Santo Basin (SE Brazil) using a bivariate statistical method

    NASA Astrophysics Data System (ADS)

    Piedade, Aldina; Alves, Tiago; Luís Zêzere, José

    2016-04-01

    Mass Transport Deposits (MTDs) are one of the most important process shaping passive and active margins. It is frequently happening and its characteristics, features and processes has been very well documented from diverse approaches and methodologies. In this work a methodology for evaluation of MTDs occurrence is tested in an area offshore Espírito Santo Basin, SE Brazil. MTDs inventory was made on three-dimensional (3D) seismic volume interpreting a high amplitude reflection which correspond to the top and base of the MTDs. The inventory consists of four MTDs which were integrated into a GIS database. MTDs favourability scores are computed using algorithms based on statistical/probabilistic analysis (Information Value Method) over unique condition terrain units in a raster basis. Terrain attributes derived from the Digital Terrain Model (DTM) are interpreted as proxies of driving factors of MTDs and are used as predictors in our models which are based on a set of different MTDs inventories. Three models are elaborated independently according to the area of the MTDs body (Model 1, Model 2 and Model 3). The final result is prepared by sorting all pixels according to the pixel favourability value in descending order. The robustness and accuracy of the MTDs favourability models are evaluated by the success-rate curves, which are used for the quantitative interpretation of the models expressing the goodness of fit of the MTDs. In addition, a sensitivity analysis was performed and the predisposing factors which have highest prediction performance on MTDs occurrence were identified. The obtained results allow to conclude the method is valid to apply to submarine slopes as it is demonstrated by the highest obtained goodness of fit (0.862). This work is very pioneer, the methodology used was never applied to submarine environment. It is a very promising and valid methodology within the prediction of submarine slopes regarding failing and instability to the industry. In

  18. Crowdsourcing the Unknown: The Satellite Search for Genghis Khan

    PubMed Central

    Lin, Albert Yu-Min; Huynh, Andrew; Lanckriet, Gert; Barrington, Luke

    2014-01-01

    Massively parallel collaboration and emergent knowledge generation is described through a large scale survey for archaeological anomalies within ultra-high resolution earth-sensing satellite imagery. Over 10K online volunteers contributed 30K hours (3.4 years), examined 6,000 km2, and generated 2.3 million feature categorizations. Motivated by the search for Genghis Khan's tomb, participants were tasked with finding an archaeological enigma that lacks any historical description of its potential visual appearance. Without a pre-existing reference for validation we turn towards consensus, defined by kernel density estimation, to pool human perception for “out of the ordinary” features across a vast landscape. This consensus served as the training mechanism within a self-evolving feedback loop between a participant and the crowd, essential driving a collective reasoning engine for anomaly detection. The resulting map led a National Geographic expedition to confirm 55 archaeological sites across a vast landscape. A increased ground-truthed accuracy was observed in those participants exposed to the peer feedback loop over those whom worked in isolation, suggesting collective reasoning can emerge within networked groups to outperform the aggregate independent ability of individuals to define the unknown. PMID:25549335

  19. In situ stress conditions at IODP Site C0002 reflecting the tectonic evolution of the sedimentary system near the seaward edge of the Kumano basin, offshore from SW Japan

    NASA Astrophysics Data System (ADS)

    Song, Insun; Chang, Chandong

    2017-05-01

    This paper presents a complete set of in situ stress calculations for depths of 200-1400 meters below seafloor at Integrated Ocean Drilling Program (IODP) Site C0002, near the seaward margin of the Kumano fore-arc basin, offshore from southwest Japan. The vertical stress component was obtained by integrating bulk density calculations from moisture and density logging data, and the two horizontal components were stochastically optimized by minimizing misfits between a probabilistic model and measured breakout widths for every 30 m vertical segment of the wellbore. Our stochastic optimization process reveals that the in situ stress regime is decoupled across an unconformity between an accretionary complex and the overlying Kumano fore-arc basin. The stress condition above the unconformity is close to the critical condition for normal faulting, while below the unconformity the geologic system is stable in a normal to strike-slip fault stress regime. The critical state of stress demonstrates that the tectonic evolution of the sedimentary system has been achieved mainly by the regionally continuous action of a major out-of-sequence thrust fault during sedimentation in the fore-arc basin. The stable stress condition in the accretionary prism is interpreted to have resulted from mechanical decoupling by the accommodation of large displacement along the megasplay fault.

  20. Smarter offshoring.

    PubMed

    Farrell, Diana

    2006-06-01

    During the past 15 years, companies have flocked to a handful of cities in India and Eastern Europe for offshore service functions. As a result, the most popular sites are now overheating: Demand for young professionals is outstripping supply, wages and turnover are soaring, and overburdened infrastructure systems are struggling to serve the explosive growth. The happy news is that the tight labor markets in the well-known hot spots are the exceptions, not the rule. Many attractive alternatives are emerging around the world. According to a McKinsey Global Institute study, more than 90% of the vast and rapidly growing pool of university-educated people suitable for work in multinationals are located outside the current hot spot cities. For instance, Morocco is now home to offshore centers for French and Spanish companies requiring fluent speakers of their home languages. Neighboring Tunisia has used its modern infrastructure, business-friendly regulations, and stable, low-cost workforce to attract companies such as Siemens and Wanadoo. Vietnam offers university graduates who have strong mathematics skills; speak French, English, German, or Russian; and do not demand high wages. The problems facing the hot spots, coupled with the emergence of many more countries able and willing to provide offshore services, mean that picking a site has become more complicated. In choosing a location, companies will have to focus less on low wages and much more on other ways that candidate cities can fulfill their business needs. They will have to be much more rigorous in articulating precisely what they require from an offshore location. That means evaluating their unique needs on a range of dimensions and understanding how alternative locations can meet those needs for the foreseeable future.

  1. Depth-to-basement, sediment-thickness, and bathymetry data for the deep-sea basins offshore of Washington, Oregon, and California

    USGS Publications Warehouse

    Wong, Florence L.; Grim, Muriel S.

    2015-01-01

    Contours and derivative raster files of depth-to-basement, sediment-thickness, and bathymetry data for the area offshore of Washington, Oregon, and California are provided here as GIS-ready shapefiles and GeoTIFF files. The data were used to generate paper maps in 1992 and 1993 from 1984 surveys of the U.S. Exclusive Economic Zone by the U.S. Geological Survey for depth to basement and sediment thickness, and from older data for the bathymetry.

  2. Building a three-dimensional geological model of the Pegasus Basin (offshore New Zealand) with the aim of improving our understanding of gas hydrate distribution

    NASA Astrophysics Data System (ADS)

    Crutchley, G. J.; Barnes, P.; Kroeger, K. F.; Hill, M.; Mountjoy, J. J.; Pecher, I. A.

    2014-12-01

    The Pegasus Basin, on the southern end of New Zealand's Hikurangi margin, developed as a passive margin from the end of subduction along the Chatham Rise around 105 Ma to the initiation of the modern plate boundary around 25 Ma. Multi-channel seismic reflection data acquired by the New Zealand government in 2009 and 2010 show well-developed bottom-simulating reflections (BSRs) throughout the basin and also indications for deeply-sourced fluid migration. We have used the seismic data, together with previously published age constraints, to identify and map key stratigraphic horizons from the ancient subduction margin (on the southeast), through the sedimentary basin, and up onto the modern subduction margin (on the northwest). We have also used BSRs to map the extent of the gas hydrate system throughout the basin. These interpretations are being used to construct a 3D geological model of the basin that will be converted to depth using seismic velocities from the available data. The geological model will provide the basis for modelling fluid flow processes through the basin and ultimately to simulate gas hydrate formation using Petromod. We will present the latest results of this project and outline the implications for gas hydrate formation in the Pegasus Basin.

  3. Shaping Influences on the Leadership of Genghis Khan, George Washington, and Nelson Mandela: Applications for Educators

    ERIC Educational Resources Information Center

    Bongila, Jean-Pierre

    2011-01-01

    Using a prosopographical methodology this study examines common leadership influences that might have existed among Genghis Khan, George Washington, and Nelson Mandela. Shoup (2005) suggests that the following seven influences have contributed to nurturing the leadership of 12 renowned individuals: involved parents, happy childhood, formal,…

  4. Increasing Student Engagement in Math: The Use of Khan Academy in Chilean Classrooms

    ERIC Educational Resources Information Center

    Light, Daniel; Pierson, Elizabeth

    2014-01-01

    Khan Academy, an online platform offering educational videos and exercises in different content areas, has awakened intense interest among foundations, multilateral organizations, policy makers, and educators about how this tool can help meet the educational challenges facing countries around the world. With support from Intel, Education…

  5. A Case Study for Teaching Quantitative Biochemical Buffer Problems Using Group Work and "Khan Style" Videos

    ERIC Educational Resources Information Center

    Barreto, Jose; Reilly, John; Brown, David; Frost. Laura; Coticone, Sulekha Rao; Dubetz, Terry Ann; Beharry, Zanna; Davis-McGibony, C. Michele; Ramoutar, Ria; Rudd, Gillian

    2014-01-01

    New technological developments have minimized training, hardware expense, and distribution problems for the production and use of instructional videos, and any science instructor can now make instructional videos for their classes. We created short "Khan style" videos for the topic of buffers in biochemistry and assigned them as…

  6. Shaping Influences on the Leadership of Genghis Khan, George Washington, and Nelson Mandela: Applications for Educators

    ERIC Educational Resources Information Center

    Bongila, Jean-Pierre

    2011-01-01

    Using a prosopographical methodology this study examines common leadership influences that might have existed among Genghis Khan, George Washington, and Nelson Mandela. Shoup (2005) suggests that the following seven influences have contributed to nurturing the leadership of 12 renowned individuals: involved parents, happy childhood, formal,…

  7. A Case Study for Teaching Quantitative Biochemical Buffer Problems Using Group Work and "Khan Style" Videos

    ERIC Educational Resources Information Center

    Barreto, Jose; Reilly, John; Brown, David; Frost. Laura; Coticone, Sulekha Rao; Dubetz, Terry Ann; Beharry, Zanna; Davis-McGibony, C. Michele; Ramoutar, Ria; Rudd, Gillian

    2014-01-01

    New technological developments have minimized training, hardware expense, and distribution problems for the production and use of instructional videos, and any science instructor can now make instructional videos for their classes. We created short "Khan style" videos for the topic of buffers in biochemistry and assigned them as…

  8. KHAN DU! II. Final Project Performance Report, November 1, 1978-September 30, 1979.

    ERIC Educational Resources Information Center

    KLRN/KLRU-TV, Austin, TX.

    This KHAN DU! project produced four half-hour television programs in the area of career education with emphasis on the handicapped, plus an extra nonbroadcast program designed for teachers. The four-program series was designed for children aged eight to eleven, although older children have responded favorably. The goals of the series were (1) to…

  9. Parents' Attitude toward Daughters' Education in Tribal Area of Dera Ghazi Khan (Pakistan)

    ERIC Educational Resources Information Center

    Buzdar, Muhammad Ayub; Ali, Akhtar

    2011-01-01

    The paper aimed to investigate the parents' attitudes toward their daughters' education in tribal areas of district Dera Ghazi Khan (Pakistan). To achieve the objectives four research questions were established. Focus of the questions was to examine the significance of girls' education for tribal parents. Existing and expected role of tribal…

  10. Mapping the extent of thinned continental crust across the Orphan Basin, offshore Newfoundland, Canada, using a combination of vintage and new seismic refraction/wide-angle reflection data

    NASA Astrophysics Data System (ADS)

    Welford, J. Kim; Dehler, Sonya; Funck, Thomas

    2017-04-01

    The SIGNAL (Seismic Investigations off Greenland, Newfoundland and Labrador) 2009 cruise was undertaken by the Geological Survey of Canada (GSC) and the Geological Survey of Denmark and Greenland (GEUS), with scientific contributions from Dalhousie University, to collect refraction/wide-angle reflection (RWAR) profiles as part of each country's continental shelf program under UNCLOS (United Nations Convention on the Law of the Sea) Article 76. Line 1 extended from the Bonavista Platform off Newfoundland, across the Orphan Basin, to Orphan Knoll and beyond into oceanic crust. The line followed the same track as an earlier seismic refraction line and ocean-bottom seismometer (OBS) locations were chosen to complement and to extend the original station coverage. The final crustal velocity model across Orphan Basin shows thinned continental crust (15 to 20 km thick) beneath most of the basin with thinner crust (10 km thick) immediately outboard of the Bonavista Platform, interpreted as a failed rift zone. Seaward of the failed rift, the velocity structure of the thinned continental crust is generally uniform over 250 km toward Orphan Knoll. Immediately outboard of Orphan Knoll, the crust thins to 8 km and exhibits a velocity structure consistent with oceanic crust. The results from modelling of the combined refraction/wide-angle reflection dataset support an extension of Canada's continental shelf beyond the seaward limits of the Orphan Basin.

  11. The effect of an oil drilling operation on the trace metal concentrations in offshore bottom sediments of the Campos Basin oil field, SE Brazil.

    PubMed

    Rezende, C E; Lacerda, L D; Ovalle, A R C; Souza, C M M; Gobo, A A R; Santos, D O

    2002-07-01

    The concentrations of Al, Fe, Mn, Zn, Cu, Pb, Ni, Cr, Ba, V, Sn and As in offshore bottom sediments from the Bacia de Campos oil field, SE Brazil, were measured at the beginning and at 7 months after completion of the drilling operation. Concentrations of Al, Fe, Ba, Cr, Ni and Zn were significantly higher closer to the drilling site compared to stations far from the site. Average concentrations of Al, Cu, and in particular of Ni, were significantly higher at the end of the drilling operation than at the beginning. Comparison between drilling area sediments with control sediments of the continental platform, however, showed no significant difference in trace metal concentrations. Under the operation conditions of this drilling event, the results show that while changes in some trace metal concentrations do occur during drilling operations, they are not significantly large to be distinguished from natural variability of the local background concentrations.

  12. Volume balance of a submarine landslide in the Espírito Santo Basin, offshore Brazil: Quantifying seafloor erosion, sediment accumulation and depletion

    NASA Astrophysics Data System (ADS)

    Alves, Tiago M.; Cartwright, Joseph A.

    2009-11-01

    Degrees of seafloor erosion, sediment accumulation and depletion are quantified using a 3D seismic volume of a small submarine landslide offshore Brazil. In the study area, the upper boundaries of large remnant blocks — kept in situ during the main instability event — and the interpreted non-failed margins of the landslide comprise a reliable estimate for the position of the seafloor at the time the submarine landslide was generated. Remnant blocks of strata show little internal deformation, particularly at their base, and were kept upright during a principal instability event triggered in response to regional halokinesis and associated overburden faulting. They are laterally bounded by a mixed succession of mass-wasted chaotic strata, rafted blocks and post-slide sub-horizontal units. Despite the thin accumulation of failed strata now visible, the interpreted data indicate that submarine landslides of small areal dimensions can erode substantial volumes of seafloor sediment. Consequently, the more than 300 m of eroded seafloor strata offshore Brazil is of a similar scale to the largest failures recorded on continental margins (e.g. Storegga Slide; Amazon Fan complex; Cape Fear slide). The scale relationships presented in this paper indicate that the magnitude of seafloor erosion experienced during instability events may not be recorded by distal mass-wasted strata, which can be demonstrably thinner than the original volume of failed sediment. Thus, we conclude that the relative expression of accumulated slide strata is not directly related to the original volume of failed material. In addition, small-scale landslides can be responsible for the erosion of thick seafloor deposits, a factor that can potentially cause significant losses of seal capacity in overburden successions due to the sudden release of confining pressures in a vertical direction.

  13. Cenozoic synthem stratigraphic architecture of the SE Brazilian shelf and its global eustatic context: evidence from the Pelotas Basin (offshore Brazil)

    NASA Astrophysics Data System (ADS)

    de Santana dos Anjos Zerfass, Geise; Ruban, Dmitry A.; Chemale, Farid, Jr.; Zerfass, Henrique

    2013-12-01

    The Pelotas Basin, located on the SE Brazilian shelf, has evolved since the Aptian. Stratigraphical data from the basin can be used for delineation of the unconformity-bounded units (synthems) on the shelf, which is a first step towards a full understanding of its stratigraphic architecture, evolution, and hydrocarbon potential. Hiatuses in the Cenozoic succession of the Pelotas Basin are established with both biostratigraphic (planktonic foraminifers and calcareous nannofossils) and isotopic (87Sr/86Sr) data. The seven recognised hiatuses are dated respectively as (1) Palaeocene (Danian- Thanetian), (2) Palaeocene/Eocene boundary (Thanetian-Ypresian), (3) Eocene (Ypresian-Lutetian), (4) Eocene-Oligocene (Lutetian-Rupelian), (5) early-late Oligocene (Rupelian-Chattian), (6) early Miocene (Aquitanian-Burdigalian), and (7) middle-late Miocene (Serravallian-Tortonian). These intervals between the hiatuses are correlated with those of the Santos and Campos Basins north from the Pelotas Basin. The breaks in sedimentation that these basins have in common occurred (1) at the Palaeocene-Eocene and (2) Eocene-Oligocene transitions, (3) in the early Miocene, and (4) in the middle-late Miocene. These main unconformities outline five synthems on the SE Brazilian shelf, viz. the SEBS-1 (Palaeocene), SEBS-2 (Eocene), SEBS-3 (Oligocene), SEBS-4 (early-middle Miocene) and SEBS-5 (late Miocene-Holocene). The above unconformities are correlated with those established in the Cenozoic sedimentary successions of different regions such as Western Siberia, Arabia, NW and NE Africa, peninsular India, S Australia, the Gulf of Mexico, NW Europe, and South Africa. The only regional unconformity, near the Oligocene/Miocene boundary, coincides with the nearly-global sedimentation break. The latter was resulted from a climatic event, i.e., the `Mi-1 glaciation'. Thus, a eustatic origin is supposed for this regional unconformity. The other regional unconformities also correspond to global sea

  14. Understanding the Beattie Magnetic Anomaly, Karoo Basin and Deep Crustal Tectonics of Southernmost Africa: Near Vertical Seismic Reflection Data of the Inkaba ye Africa Onshore-Offshore Agulhas-Karoo Geoscience Transect

    NASA Astrophysics Data System (ADS)

    Lindeque, A.; Ryberg, T.; Weber, M.; de Wit, M.

    2006-12-01

    Inkaba Ye Africa (IyeA) is a joint initiative between German and South African Earth Science communities that seeks fundamental insights into the interconnectivity of Earth systems in a core-to-space cone-shaped sector over southern Africa and surrounding oceans. Three main interconnected themes: Heart of Africa, Margins of Africa and Living Africa, link 12 subprojects and cover 200 - 300 million years of Earth systems history, from mantle and core dynamics, crustal evolution, and magnetic field observation, to climate change and biodiversity. Within the Margins of Africa theme and as part of the Agulhas-Karoo onshore/offshore geoscience transect, Near Vertical Reflection (NVR) seismic data was collected in South Africa from Oct - Dec 2005. The 800km Agulhas-Karoo Transect runs from the Kaapvaal Craton southward, across the Karroo basin, the Cape Fold Belt and the southern continental margin of Africa, to the Agulhas Fracture Zone and adjacent Plateau in the southern Indian Ocean. The transect crosses the Beattie Magnetic Anomaly (BMA the world's largest such crustal anomaly, within Cape Conductivity Zone and Natal- Namaqua Metamorphic Belt, beneath the Karoo Basin. This poster presentation presents findings of the NVR seismic data experiment that ran for a ca.100km section near the centre of the profile, across the BMA. The goals are to investigate the seismic image of the BMA and to integrate this with findings of the complementary Magnetotellurics (MT) and Wide Angle onshore-offshore refraction/reflection data (WRR). In the NVR seismic experiment, 200 boreholes were drilled to a depth of ~12m and at a spacing of ~500m. The Boreholes were charged with ~15kg explosives that delivered 182 shots (sources). An 18km array of 20x3 channel recording stations and geophones every 100m, recorded the energy reflections in the vertical component (receivers). This delivered a high quality NVR seismic dataset - suitable for creating a ca. 100 km long image of the crustal

  15. Deep structure offshore Eastern Australia from wide-angle seismic data: what controls crustal segmentation along the rifted oceanic basins and the Lord Howe Rise?

    NASA Astrophysics Data System (ADS)

    Gallais, Flora; Fujie, Gou; Kodaira, Shuichi; Miura, Seiichi; Boston, Brian; Nakamura, Yasuyuki; Hackney, Ron; Saito, Saneatsu; Shiraishi, Kazuya; Kaiho, Yuka; Yamada, Yasuhiro; Nichol, Scott; Bernardel, George; Mitchell, Cameron

    2017-04-01

    The eastern Australian margin was shaped during the fragmentation of eastern Gondwana in the Late Cretaceous. This led to the opening of the Tasman Basin and to the formation of sub-parallel ridges and basins, including the Lord Howe Rise. The driving forces controlling the rifting are not fully understood and two processes can be invoked: slab rollback associated with upper-plate extension or a plume impinging on the lithosphere. However, the deep structure of the area is still unknown. In March-April 2016 using the R/V Kairei, the first large-scale crustal experiment of this region was conducted by JAMSTEC and Geoscience Australia with the deployment of 100 ocean-bottom seismometers (OBS) along a 680km profile at 27.2°S. The OBSs register clear refracted arrivals from the crust and the mantle that are recorded at very large offsets (up to 300km). The important variation in the offset of the triplication point between these two refracted arrivals suggests strong crustal thickness variation along the profile. We performed first-arrival tomographic inversion using two initial models with almost uniform lateral layering: (a) a four-layer model using the two-way reflection travel times from the basement interpreted from the multi-channel seismic data and (b) a five-layer model including a Moho interface, thereby allowing inversion of Moho reflections interpreted from the OBS data. The final tomographic Vp model confirms the strong variations in crustal thickness and allows the identification of distinct crustal domains along the profile: the Tasman Basin is an oceanic domain with 6 to 8km thick crust; further east a thicker crust is present below the Dampier Ridge (18-21km) where granitic rocks have been dredged; directly east of the Dampier Ridge the crust thins to 8km below the Middleton Basin, and the northern Lord Howe Rise is floored by a 24km thick crust. Below the northern Lord Howe Rise, lateral variations in upper-crustal velocities are observed with some

  16. Fluids emission and gas chimneys imaged in high-resolution 3D seismic: Investigating the role of sedimentary structures in controlling vertical fluid migration (offshore of Ceará-Potiguar sub-basin, Brazil).

    NASA Astrophysics Data System (ADS)

    Maestrelli, Daniele; Iacopini, David; Vittorio, Maselli

    2017-04-01

    Fluid emissions at seabed have been widely investigated during last years due to their potential in detecting new petroleum provinces and to their role in monitoring the environmental risk associated to CO2 storage and hydrocarbon leakage from the overburden. Fluid emission appears to be characterized by a variety of different processes and genetic mechanisms, and has been reported in different geological settings. We investigated a 45 by 25 km 3D seismic dataset located in the offshore Ceará state (Brazil), imaging the submarine slope system of the Potiguar sub-basin, part of the Ceará basin. The Paleogene sequence is characterized by a series of steep canyons acting as slope-bypass systems that force the transport of sediment basinward and promote the deposition in deepwater settings. The whole area seems to be affected by gravity driven processes in the form of turbidites and hyperpycnal flows that probably are responsible of the main submarine landslides observed and of the evolution of the canyons themselves. Bottom currents seem to play a key role in shaping the margin as well, by promoting the formation of sediment ridges and fields of sediment waves. In this setting, a series of widely distributed active pockmarks are observed both at the seabed and as paleo-pockmarks in the seismic subsurface, testifying the upward fluid migration and emission along gas chimneys and conduits. Active or recent pockmark varies from tens of meters up to about 2 km in diameters and are mainly circular to elliptical. A preliminary systematic mapping of those fluid escape features shows the strong control of the chutes and pools generated by fast turbidity currents on the chimney geometry pattern and fluid conduit. This evidence may suggest that the erosional/depositional features associated to turbidite sedimentation strongly control lateral permeability variations and, consequently, the vertical fluid migration.

  17. Tectonics of the Kızılırmak Delta and Sinop Basin, offshore Pontides, evidence from new, high resolution seismic and bathymetric data.

    NASA Astrophysics Data System (ADS)

    Haşimoğlu, B. Y.; Cifci, G.; Lacassin, R.; Fernández-Blanco, D.; Ozel, O.

    2016-12-01

    The Kızılırmak River is the one of the largest river in Turkey, flowing across two key features characteristic of the Late Cenozoic tectonic evolution of Northern Turkey: the North Anatolian Fault and the Pontides. The offshore part of the fan delta of the Kızılırmak river is of particular interest, since it contains valuable information on the 3D delta structure directly related to the river dynamics, and encompasses essential tectonic and bathymetric features like the Sinop graben and Archangelsky ridge. We present new high-resolution multichannel seismic data and multibeam bathymetric data that have been collected in this area by researchers and PhD/MSc students of Dokuz Eylül University, Institute of Marine Sciences and Technology with R/V Koca Piri Reis. 17 seismic lines, for a total of 1300km, have been acquired and processed in order to enhance the visualization of the stratigraphy and of tectonic structures, and to remove multiples. In our preliminary interpretation of the seismic data we observe a thick pile of sediments of probable upper Cenozoic age lying of top of an erosional surface possibly related to the Messinian salinity crisis or to older events. These sediments are affected both by gravitational processes and by normal faulting, related to the actively growing Sinop graben. The Archangelsky ridge is well resolved down to 3-4s and appears to be bounded by active normal faults and likely crosscut by strike-slip faults. Our bathymetric data reveals the submarine channel of the Yeşilırmak river, which connects to the paleo streambed of the Kızılırmak river. This is the first high resolution seismic dataset that has been collected in this area, and in our ongoing study we aim at integrating this state-of-the-art new data with the onshore evolution of the Kızılırmak delta. This will potentially bring a valuable new perspective to reconcile sedimentation rates and the offshore delta-architecture with the onshore delta dynamics, and can

  18. Analyzing seismic imagery in the time-amplitude and time-frequency domains to determine fluid nature and migration pathways: A case study from the Queen Charlotte Basin, offshore British Columbia

    NASA Astrophysics Data System (ADS)

    Duchesne, Mathieu J.; Halliday, E. Julie; Barrie, J. Vaughn

    2011-02-01

    Combining time-amplitude and time-frequency information from seismic reflection data sets of different resolutions allows the analysis of anomalous reflections from very-shallow to great subsurface depths. Thus, it can enhance the imaging of subsurface features which have a frequency-dependent reflectivity such as gas. Analysing seismic data of different resolution in the time-amplitude and time-frequency domains is a powerful method to determine hydrocarbon migration pathways from deep reservoirs to the seafloor. This interpretation method has been applied to the formerly-glaciated offshore Queen Charlotte Basin hosting several seafloor pockmarks and mounds associated with the leakage of underlying hydrocarbon reservoirs. Low-frequency shadows observed in the time-frequency domain provide evidence of different resolutions that several anomalous reflection amplitudes may be attributed to the occurrence of gas. The seismic imagery shows that gas uses a fault to migrate from deep reservoirs included in Upper Mesozoic strata towards secondary reservoirs located along the fault plane into Neogene layers. Once gas reaches a porous cut-and-fill succession, migration changes from structurally- to stratigraphically-controlled before gas leaks through unconsolidated Quaternary sediments forming the shallow subsurface to eventually seep at the seafloor where pockmarks and carbonate mounds are formed.

  19. Glacistore: Understanding Late Cenozoic Glaciation and Basin Processes for the Development of Secure Large Scale Offshore CO2 Storage (North Sea).

    NASA Astrophysics Data System (ADS)

    Stewart, H. A.; Barrio, M.; Akhurst, M.; Aagaard, P.; Alcalde, J.; Bauer, A.; Bradwell, T.; Cavanagh, A.; Faleide, J. I.; Furre, A. K.; Haszeldine, S.; Hjelstuen, B. O.; Holloway, S.; Johansen, H.; Johnson, G.; Kuerschner, W.; Mondol, N. H.; Querendez, E.; Ringrose, P. S.; Sejrup, H. P.; Stewart, M.; Stoddart, D.; Wilkinson, M.; Zalmstra, H.

    2014-12-01

    The sedimentary strata of the North Sea Basin (NSB) record the glacial and interglacial history of environmental change in the Northern Hemisphere, and are a proposed location for the engineered storage of carbon dioxide (CO2) captured from power plant and industrial sources to reduce greenhouse gas emissions. These aspects interact in the geomechanical and fluid flow domain, as ice sheet dynamics change the properties of potential seal and reservoir rocks that are the prospective geological storage strata for much of Europe's captured CO2. The intensification of the global glacial-interglacial cycle at the onset of the Pleistocene (2.5-2.7 Ma) was a critical tipping-point in Earth's recent climate history. The increased severity of glaciations at the Plio-Pleistocene boundary triggered the first development of large-scale continental ice sheets in the Northern Hemisphere. The central part of the NSB preserves a unique history of the depositional record spanning at least the last 3 Ma, which also forms the overburden and seal to the underlying CO2 reservoirs. There is good evidence that these ice sheets created strong feedback loops that subsequently affected the evolution of the Quaternary climate system through complex ocean-atmosphere-cryosphere linkages. Understanding NSB dynamics, including the role of fluids in controlling compaction, cementation, and diagenetic processes in shale-dominated basins, is essential for CO2 storage site characterisation to increase understanding and confidence in secure storage. An increased understanding of the overlying sequence will inform quantitative predictions of the performance of prospective CO2 storage sites in glaciated areas in Europe and worldwide; to include improved resolution of glacial cycles (depositional and chronological framework), characterise pore fluids, flow properties of glacial landforms within the sequence (e.g. tunnel valleys) and the geomechanical effects (quantify compaction, rock stiffness, strength

  20. Where the offshore search for oil and gas is headed

    SciTech Connect

    King, R.E.

    1980-10-01

    This overview of the world's potential offshore oil and gas frontiers points out that although solutions to technical and political problems have opened up some promising areas for exploration, many key frontier basins have yet to be explored by modern technology. Long-standing disputes between bordering countries over offshore rights have deterred exploration activities in the Malvinas basin off Argentina and in the Gulf of Venezuela. Political problems have also slowed activity in the US Atlantic offshore, where Mesozoic reef trends may be related to Mexico's large oil fields. In Canada's Labrador Sea and Grand Banks, the problems are largely operational because of the inclement weather and threatening icebergs. The thick sediments off northern Norway remain untapped due to the deep water, Arctic conditions, and boundary disputes with the USSR. The main areas of active exploration are the Gulf of Thailand-Penyu-Natuna basin in Southeast Asia and Ireland's Porcupine Bight basin.

  1. Geologic framework of the offshore region adjacent to Delaware

    USGS Publications Warehouse

    Benson, R.N.; Roberts, J.H.

    1989-01-01

    Several multichannel, common depth point (CDP) seismic reflection profiles concentrated in the area of the entrance to Delaware Bay provide a tie between the known onshore geology of the Coastal Plain of Delaware and the offshore geology of the Baltimore Canyon Trough. The data provide a basis for understanding the geologic framework and petroleum resource potential of the area immediately offshore Delaware. Our research has focused on buried early Mesozoic rift basins and their geologic history. Assuming that the buried basins are analogous to the exposed Newark Supergroup basins of Late Triassic-Early Jurassic age, the most likely possibility for occurrence of hydrocarbon source beds in the area of the landward margin of the Baltimore Canyon Trough is presumed to be lacustrine, organic-rich shales probably present in the basins. Although buried basins mapped offshore Delaware are within reach of drilling, no holes have been drilled to date; therefore, direct knowledge of source, reservoir, and sealing beds is absent. Buried rift basins offshore Delaware show axial trends ranging from NW-SE to NNE-SSW. Seismic reflection profiles are too widely spaced to delineate basin boundaries accurately. Isopleths of two-way travel time representing basin fill suggest that, structurally, the basins are grabens and half-grabens. As shown on seismic reflection profiles, bounding faults of the basins intersect or merge with low-angle fault surfaces that cut the pre-Mesozoic basement. The rift basins appear to have formed by Mesozoic extension that resulted in reverse motion on reactivated basement thrust faults that originated from compressional tectonics during the Paleozoic. Computer-plotted structure contour maps derived from analysis of seismic reflection profiles provide information on the burial history of the rift basins. The postrift unconformity bevels the rift basins and, in the offshore area mapped, ranges from 2000 to 12,000 m below present sea level. The oldest

  2. Patterns And Determinants Of Breast Feeding Among Mother Infant Pairs In Dera Ghazi Khan, Pakistan.

    PubMed

    Khan, Moazzam Ali; Qureshi, Zubia; Khan, Kauser Aftab; Gill, Fouzia Nadeem

    2016-01-01

    Proper breastfeeding practices are effective ways for reducing childhood morbidity and mortality. The objective of the present study was to determine the patterns and explore the determinants associated with breast feeding practices among the nursing women in Dera Ghazi Khan. A cross sectional study was conducted on randomly selected lactating mother infant pairs in Dera Ghazi Khan. Structured questionnaire was used for data collection. Analysis was done by using SPSS, chi square test was applied to see the association between breast feeding practices and its determinants such as knowledge of breast feeding practices. Majority 372 (93%) of mothers mentioned that they had ever breastfed the youngest child. About 292 (73%) mothers gave colostrum to the child, and 48 (12%) exclusively breastfed. Weaning babies before four month of age was practiced by 84 (21%) of the mothers, 120 (55%) mothers started weaning at 4-6 months of child age, while 72 (18%) started to give additional food after baby turned six months old. Out of total 276 (69%) mothers reported that they had knowledge regarding breast feeding. Significant association was found between knowledge of breastfeeding and initiation and Exclusive Breast Feeding (EBF) practices (p-values <0.05). Income, family type, mode of delivery and assistance for child were significantly associated with initiation of breastfeeding within one hour after birth (p-value <0.001). Breast feeding practices in the studied area were not up to the mark. There is a strong need to improve the breastfeeding practices by Behavior Change Communication.

  3. Biodiversity and importance of floating weeds of Dara Ismail, Khan District of KPK, Pakistan.

    PubMed

    Marwat, Sarfaraz Khan; Khan, Mir Ajab; Fazal-ur-Rehman; Ahmad, Mushtaq; Zafar, Muhammad

    2011-01-01

    The present paper is based on the results of taxonomic research work conducted in Dera Ismail Khan District of KPK, Pakistan, during 2005 - 2007. The area was extensively surveyed in order to collect floating aquatic weeds. From the study area 11 floating aquatic weed species belonging to 9 genera and 9 families were collected and identified in the light of available literature. These plants include Bryophytes: 1 species, Ricciocarpus natans (L.) Corda; Pteridophytes: 2 species, Azolla pinnata R.Br. and Marselia quadrifolia L., and Spermatophytes: 8 species, Lemna aequinoctialis Welw., L. gibba L., Marselia quadrifoliata L. Nelumbo nucifera Gaerth., Nymphoides cristata (Roxb.) O. Ketze. Nymphoides indica (L.) Kuntze:, Pistia stratiotes L. Potamogeton nodosus Poiret and Spirodela polyrrhiza (L.) Schleid. Floating weeds on one hand cause serious problems and on the other hand they are used for various purposes. Data inventory consists of botanical name, family, major group, habit and habitat, flowering period, availability, distribution in D.I.Khan, Pakistan and world, beneficial and harmful effects. Key to the floating aquatic species of the area was developed for easy and correct identification and differentiation.

  4. Analysis of homicidal deaths in district DI Khan: an autopsy study.

    PubMed

    Humayun, Muhammad; Khan, Dilawar; Fasee-uz-Zaman; Khan, Jahanzeb; Khan, Omair; Parveen, Zahida; Humayun, Wajid

    2009-01-01

    One of the oldest crimes in human civilization is homicide which started from murder of Abel by the hands of Cane. With the passage of time manner of homicide have been changing. Study of pattern of homicide in any civil society is the first step towards development of intervention to reduce the impact of homicidal crimes. This study was conducted at the department of forensic medicine and toxicology Gomal Medical College DI Khan to know the pattern of the homicides, taking it as the first step in the prevention of crime. The present study was conducted over two years 2007-08. The data collected includes all reported unnatural deaths from the urban and rural areas of district on which autopsies were conducted in the district headquarter teaching hospital DI Khan and department of Forensic Medicine and Toxicology, Gomal Medical College DL Khan. Homicidal deaths constituted 259/341 (76%) of all autopsies. Out of these homicides 59.07% were caused by the firearm. The most common firearm weapons were high velocity rifled weapons (AK-47, rifles and pistols). A total of 304 injuries were found in various body regions giving an average of about two injuries per victim/person. The head, neck and face sustained the highest numbers of injuries 100, (32.90%) followed by chest 91 (29.93%) and abdomen 47 (15.4%); the extremities, buttock and genitalia together sustained 65 (21.38 %) injuries. A part from firearm injuries unfortunately in our this study the second highest cause of homicidal deaths was bomb blasts injuries either due to suicide bombers or remote control bombs. The numbers of deaths due to blast injuries were 82 for the year 2007/08 out of total homicidal deaths and percentage was 32.66%. The vast majority of homicidal deaths in this area are caused by firearms like other big cities of the province like Peshawar, which bring up issues related to possession of firearms and change in cultural attitude towards the use of firearm, if a decrease in firearm related

  5. 76 FR 42159 - Lifting of Sanctions on Person Associated With the A.Q. Khan Nuclear Procurement Network

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF STATE Lifting of Sanctions on Person Associated With the A.Q. Khan Nuclear Procurement Network AGENCY: Bureau of International Security and Nonproliferation, Department of State. ACTION: Notice. SUMMARY: A determination has...

  6. Investigating the Use of the Khan Academy and Mathematics Software with a Flipped Classroom Approach in Mathematics Teaching

    ERIC Educational Resources Information Center

    Zengin, Yilmaz

    2017-01-01

    The purpose of this study was to determine the effect of the flipped classroom approach designed by using Khan Academy and free open source software on students' academic achievement and to examine students' views about this approach. The research was evaluated in the light of both qualitative and quantitative data. Twenty-eight students studying…

  7. The School Improvement Programme of the Aga Khan Education Service, Kenya at Kisumu, Western Kenya: Evaluation Report.

    ERIC Educational Resources Information Center

    Capper, Joanne; Nderitu, Shelomith; Ogula, Paul

    This evaluation study was conducted at the behest of the Aga Khan Foundation (AKF) and the Institute for Policy Reform (IPR), working under contract with United States Agency for International Development. AKF's primary concern was to evaluate the effectiveness, cost-effectiveness, and the likelihood of sustainability of the School Improvement…

  8. Khan Du! A Success Model through Television for the Career Education of Handicapped Children. Final Project Performance Report.

    ERIC Educational Resources Information Center

    Boyd, Charles H.

    The KHAN DU! project developed television programs and accompanying printed materials combining three elements: (1) career education objectives targeted to both handicapped and non-handicapped children, (2) visual and dramatic elements designed primarily to interest the child viewer, and (3) handicapped children playing major roles and documentary…

  9. Increasing transcultural awareness: the McMaster-Aga Khan-CIDA Project workshop model.

    PubMed

    Smith, S E

    1997-01-01

    McMaster-Aga Khan-CIDA Project personnel at McMaster University School of Nursing over a period of four years designed and conducted eight one-day introductory workshops for nurses, faculty, staff, host families, and others involved with Pakistani nurses and Lady Health Visitors studying in Canada. The workshops (entitled Increasing Intercultural Awareness) assisted the Canadian and international participants to improve their awareness and knowledge of transcultural communication in preparation for working and socializing together. Using a participatory and active-learning approach, the workshop method introduced participants to transcultural communication; emphasized appreciation of cultural values, similarities and differences; and provided country-specific information on Pakistan. This article outlines the workshop design and rationale and describes specific examples of the transcultural nursing principles, practices, and teaching activities included in the one-day event.

  10. Research on efficiency test of a turbine in Khan Khwar hydropower station

    NASA Astrophysics Data System (ADS)

    Zhang, H. K.; Liang, Z.; Liu, X. B.; Liu, D. M.; Deng, M. G.; Wang, H. Y.

    2012-11-01

    The efficiency test is an important indicator to evaluate the energy conversion performance of a hydraulic turbine. For hydropower stations which do not have the direct flow measurement conditions, whether the characteristic curve of a turbine obtained through similarity theory conversion by using the comprehensive characteristic curve of the turbine can correctly reflect the operating performance of the prototype unit is a key issue in this industry. By taking the No.1 unit of Khan Khwar hydropower station as the example, the efficiency test of this turbine was studied on the site, including the measurement method of test parameters, the configuration of the computer test system, as well as the processing and analysis of test data.

  11. Source evaluation of physicochemically contaminated groundwater of Dera Ismail Khan area, Pakistan.

    PubMed

    Ahmad, Zulfiqar; Qadir, Anwar

    2011-04-01

    Groundwater samples collected from Dera Ismail Khan, Pakistan, in 15 different stations were analyzed to determine the status of concentration of different physicochemical parameters. The samples were collected around a sugar mill in the study area. Sample location was selected on the basis of the flow of sugar mill effluents and groundwater. The samples were collected at random intervals in different villages. The physicochemical parameters such as pH, electrical conductivity (EC), total dissolved salts (TDS), TH, HCO3, NO3, SO4, PO4, Na, K, Ca, Mg, Fe, F, and Pb have been analyzed. The results showed that values of the tested parameters for EC, TDS, TH, HCO3, SO4, and Na near the sugar mill were very high, which indicate the descent of standard norms of quality and protection procedures for the groundwater around this area.

  12. Ancient DNA analysis of human remains from the Upper Capital City of Kublai Khan.

    PubMed

    Fu, Yuqin; Xie, Chengzhi; Xu, Xuelian; Li, Chunxiang; Zhang, Quanchao; Zhou, Hui; Zhu, Hong

    2009-01-01

    Analysis of DNA from human archaeological remains is a powerful tool for reconstructing ancient events in human history. To help understand the origin of the inhabitants of Kublai Khan's Upper Capital in Inner Mongolia, we analyzed mitochondrial DNA (mtDNA) polymorphisms in 21 ancient individuals buried in the Zhenzishan cemetery of the Upper Capital. MtDNA coding and noncoding region polymorphisms identified in the ancient individuals were characteristic of the Asian mtDNA haplogroups A, B, N9a, C, D, Z, M7b, and M. Phylogenetic analysis of the ancient mtDNA sequences, and comparison with extant reference populations, revealed that the maternal lineages of the population buried in the Zhenzishan cemetery are of Asian origin and typical of present-day Han Chinese, despite the presence of typical European morphological features in several of the skeletons.

  13. Structural features offshore northern Taiwan

    NASA Astrophysics Data System (ADS)

    Yicheng Yang, Eason; Liu, Char-Shine; Chang, Jih-Hsin; Chiu, Chien-Hsuan

    2016-04-01

    The area offshore northern Taiwan is the place where East China Sea Shelf extends into the Southern Okinawa Trough, and where pre-Pleistocene arc-continental collision had occurred. Comparison between fault distribution in the area with previously published results suggests that the fault distribution and regional structural framework are still controversial. Using marine multichannel seismic reflection data collected in 3 marine geophysical survey cruises, we remapped the fault distribution in the northern offshore area of Taiwan. By analyzing all the seismic profiles using the KINGDOM suite (a seismic interpretation software), a new fault distribution map is presented, and a subsurface unconformity PRSB (Pliocene reflection sequence boundary) is identified. Six major NE-SW trending high-angle normal faults cut the PRSB can be traced to the fault systems on land northernmost Taiwan. These normal faults are located between the Southern Okinawa Trough and the East China Sea continental shelf basin, and have been suggested to be reactivated from pre-existing reverse faults. The offsets of fault ramps in PRSB increase toward southeast. The isopach map of the study area compiled shows that sediment strata overlying PRSB thin toward northwest.

  14. Geology of offshore central California

    SciTech Connect

    McCulloch, D.S.; Lewis, S.D.

    1988-03-01

    The offshore central California margin records Mesozoic and Cenozoic events attributable to continental and oceanic plate interactions. Terranes, some carried thousands of kilometers northward on the Kula and/or Farallon plates, were accreted to North America by late Eocene. Following accretion to North America, terranes along the margin were silvered and redistributed by strike-slip motion along the San Andreas and related faults. During Oligocene global low sea level, much of the coastal margin was subareal and erosion stripped Upper Cretaceous and Eocene strata from elevated basement blocks. These basement blocks subsequently subsided along large-displacement near-coastal faults, and shallow-water marine upper Oligocene and/or lower Miocene volcanics on the present shelf were covered by hemipelagic sediment at bathyal to mid-bathyal depths. This subsidence coincided with tectonism and significant changes in water depth elsewhere around the Pacific margin, and may have been related to a change in Pacific and North American plate relative motion that produced transtensional motion along the California margin. Transtension may have initiated both rupture and volcanism along the San Andreas fault system at about 23 Ma and wrench tectonic deformation on the shelf. During the late Miocene, growing structural highs on the shelf edge formed elongate shelf basins. A compressional component in Pacific and North America plate relative motion, which began between 5 and 3 Ma, produced strike-parallel folds and compressional faults that now dominate the structural grain of the offshore basins. Continued compressive deformation along coastal California is documented by active thrust faults, rapid coastal uplift, and earthquake focal mechanism solutions indicative of northeast-southwest compression.

  15. Session: Offshore wind

    SciTech Connect

    Gaarde, Jette; Ram, Bonnie

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop consisted of two presentations. Due to time constraints, a discussion period was not possible. The session addressed the current state of offshore wind energy development. The first presentation ''Monitoring Program and Results: Horns Rev and Nysted'' by Jette Gaarde summarized selected environmental studies conducted to date at operating offshore wind turbine projects in Denmark and lessons from other offshore wind developments in Europe. Wildlife impacts studies from the Danish sites focused on birds, fish, and mammals. The second presentation ''What has the U.S. Wind Industry Learned from the European Example'' by Bonnie Ram provided an update on current permit applications for offshore wind developments in the U.S. as well as lessons that may be drawn from the European experience.

  16. Molecular Genealogy of a Mongol Queen’s Family and Her Possible Kinship with Genghis Khan

    PubMed Central

    Lkhagvasuren, Gavaachimed; Shin, Heejin; Lee, Si Eun; Tumen, Dashtseveg; Kim, Jae-Hyun; Kim, Kyung-Yong; Kim, Kijeong; Park, Ae Ja; Lee, Ho Woon; Kim, Mi Jin; Choi, Jaesung; Choi, Jee-Hye; Min, Na Young

    2016-01-01

    Members of the Mongol imperial family (designated the Golden family) are buried in a secret necropolis; therefore, none of their burial grounds have been found. In 2004, we first discovered 5 graves belonging to the Golden family in Tavan Tolgoi, Eastern Mongolia. To define the genealogy of the 5 bodies and the kinship among them, SNP and/or STR profiles of mitochondria, autosomes, and Y chromosomes were analyzed. Four of the 5 bodies were determined to carry the mitochondrial DNA haplogroup D4, while the fifth carried haplogroup CZ, indicating that this individual had no kinship with the others. Meanwhile, Y-SNP and Y-STR profiles indicate that the males examined belonged to the R1b-M343 haplogroup. Thus, their East Asian D4 or CZ matrilineal and West Eurasian R1b-M343 patrilineal origins reveal genealogical admixture between Caucasoid and Mongoloid ethnic groups, despite a Mongoloid physical appearance. In addition, Y chromosomal and autosomal STR profiles revealed that the four D4-carrying bodies bore the relationship of either mother and three sons or four full siblings with almost the same probability. Moreover, the geographical distribution of R1b-M343-carrying modern-day individuals demonstrates that descendants of Tavan Tolgoi bodies today live mainly in Western Eurasia, with a high frequency in the territories of the past Mongol khanates. Here, we propose that Genghis Khan and his family carried Y-haplogroup R1b-M343, which is prevalent in West Eurasia, rather than the Y-haplogroup C3c-M48, which is prevalent in Asia and which is widely accepted to be present in the family members of Genghis Khan. Additionally, Tavan Tolgoi bodies may have been the product of marriages between the lineage of Genghis Khan’s Borjigin clan and the lineage of either the Ongud or Hongirad clans, indicating that these individuals were members of Genghis Khan’s immediate family or his close relatives. PMID:27627454

  17. Norwegian Offshore Stratigraphic Lexicon (NORLEX)

    NASA Astrophysics Data System (ADS)

    Gradstein, Felix M.; Hammer, Oyvind; Brunstad, Harald; Charnock, Mike; Hellem, Terje; Sigve Lervik, Kjell; Anthonissen, Erik

    2010-05-01

    The Norwegian Offshore Stratigraphic Lexicon (NORLEX) provides a relational stratigraphic database for the North Sea, Norwegian Sea, Barents Sea and Svalbard. Both regional lithostratigraphy and biostratigraphy are being substantially updated, following guidelines laid out in the International Stratigraphic Guide. The main body of information developed is available as a petroleum consortium (oracle-style) database, and the new lithostratigraphic definitions as a public domain (paper) document. NORLEX is presented as a browsing website via the internet at http://www.nhm.uio.no/norlex. Seismic cross-sections, core photographs, well logs, field outcrops, microfossil occurrences and other vital attributes are relationally cross-linked. In addition, there are menus for instantly finding updated formation and member tops or microfossil events in all wells, plus a map contouring routine for unit thicknesses and depths. Several new initiatives will expand data and user coverage: 1. Overhaul of Mesozoic stratigraphy, especially Triassic and Cretaceous, in the Barents Sea. 2. Coverage of East Greenland 3. Linkage to UK and Belgium and The Netherlands surface and subsurface stratigraphy 4. Creation of a Sequence Stratigraphic Framework for specific regions. 5. A national microfossil atlas to support zonations 6. Tight linkage to the basin datapacks in TimeScaleCreator Pro, as developed for Australia, New Zealand, Brasil, Gulf of Mexico, Canada and Russia. NORLEX may thus evolve to become STRATLEX, covering many basin regions.

  18. Offshore Wind Energy

    SciTech Connect

    Strach-Sonsalla, Mareike; Stammler, Matthias; Wenske, Jan; Jonkman, Jason; Vorpahl, Fabian

    2016-07-27

    In 1991, the Vindeby Offshore Wind Farm, the first offshore wind farm in the world, started feeding electricity to the grid off the coast of Lolland, Denmark. Since then, offshore wind energy has developed from this early experiment to a multibillion dollar market and an important pillar of worldwide renewable energy production. Unit sizes grew from 450 kW at Vindeby to the 7.5 MW-class offshore wind turbines (OWT ) that are currently (by October 2014) in the prototyping phase. This chapter gives an overview of the state of the art in offshore wind turbine (OWT) technology and introduces the principles of modeling and simulating an OWT. The OWT components -- including the rotor, nacelle, support structure, control system, and power electronics -- are introduced, and current technological challenges are presented. The OWT system dynamics and the environment (wind and ocean waves) are described from the perspective of OWT modelers and designers. Finally, an outlook on future technology is provided. The descriptions in this chapter are focused on a single OWT -- more precisely, a horizontal-axis wind turbine -- as a dynamic system. Offshore wind farms and wind farm effects are not described in detail in this chapter, but an introduction and further references are given.

  19. Exploration and development offshore southern Vietnam

    SciTech Connect

    Ferguson, A.M. )

    1996-01-01

    In Vietnam, the major focus of the oil and gas industry is on the Nam Con Son and Cuu Long Basins in the southern offshore area. Major licensing first occurred here in the early 1970s. Some exploration was also undertaken by foreign companies in the early 1980s. In 1981, the Soviet Union undertook to assist Vietnam with the development of oil and gas. Vietsovpetro, a joint venture between the then Soviet Oil and Gas Ministry and the Vietnam Oil and Gas Corporation was formed. Most of Vietsovpetro's efforts have been to develop the Bach Ho field in the Cuu Long Basin. This now produces [approximately]130000 bopd. The most recent large scale licensing round occurred in 1992, and, at present, there are over thirty foreign companies active in these Basins' blocks . The first phase of exploration is ending and successes in the Nam Con Son Basin include the BP-led Lan Tay/Lan Do gas discoveries and Pedco's gas discoveries. Mitsubishi's and Petronas' oil discoveries in the Cuu Long Basin have attracted much attention also. The Dai Hung oil field (BHP-operated) has been producing since late 1994. Certain blocks are being appraised, and exploration work is also continuing. Areas of the Cuu Long Basin that were part of Vietsovpetro's acreage, but which may soon be re-licensed, have generated keen interest. The presence of an active upstream industry - exploring, appraising, developing and producing - indicates the emergence of Vietnam as an important East Asian oil and gas player.

  20. Management outcome of residual common bile duct stones at Aga Khan University Hospital.

    PubMed

    Khan, Muhammad Rizwan; Naureen, Sameera; Hussain, Dildar; Azami, Rizwan

    2005-01-01

    The frequency of residual common bile duct (CBD) stones in patients with previous cholecystectomy ranges from 2-10%, and a minimally invasive approach is generally recommended for these patients. This study reviews the experience in the management of residual CBD stones at the Aga Khan University Hospital. All adult patients diagnosed to have residual CBD stones, from 1993 to 2001, were identified and analyzed in terms of the treatment modality utilized and its associated complications. The role of endoscopic sphincterotomy was particularly analyzed in our set-up. The study population consisted of 66 patients. The mean age was 52 (range:18-84 years) years with a female to male ratio of 51:15. The primary mode of management consisted of endoscopic sphincterotomy in 61 patients (92.5%). The initial clearance rate for these patients was 75%, while the remaining 25% required ancillary procedures to achieve a complete clearance. Procedure related complications were observed in 17 (28%) patients, with zero mortality. The other 5 patients (7.5%) underwent an open choledochotomy as a primary procedure with no further complications. Endoscopic sphincterotomy is the most frequent treatment modality used for the management of residual CBD stones at our hospital. Although initial success rate seems low, the fact that endoscopic sphincterotomy is a less invasive procedure justifies its preferential utilization. The study does not compare the results of endoscopic management with open surgery, as the number of patients managed by open choledochotomy is very small.

  1. Google, Mathletics and Khan Academy: students' self-initiated use of online mathematical resources

    NASA Astrophysics Data System (ADS)

    Muir, Tracey

    2014-12-01

    Today's students increasingly engage in online environments, with ready access to digital resources and mobile technologies. While much of this activity is socially motivated, the internet is also a source of knowledge for students and frequently accessed for school assignments, projects and assessment purposes. As mathematics continues to be an area in which many students experience difficulties, it is not surprising that a recent Google search produced 57,600,000 results for `help with mathematics'. Current research, however, is limited in terms of documenting students' use of such resources, particularly when they are self-initiated and often accessed in an out of classroom environment. This paper reports on a study that investigated the use of mathematical online resources accessed by students in Grades 5-9, with a particular focus on evaluating the effectiveness of Khan Academy, an online tutorial site. Data collected through surveys and interviews showed that while students did access online sites, particularly in the later years of schooling, they varied in both their reasons for doing so and their perceptions of how useful these sites were. The findings add to the limited research in this area and have practical implications for students and teachers, including the potential to challenge the traditional role of the teacher.

  2. Getting offshoring right.

    PubMed

    Aron, Ravi; Singh, Jitendra V

    2005-12-01

    The prospect of offshoring and outsourcing business processes has captured the imagination of CEOs everywhere. In the past five years, a rising number of companies in North America and Europe have experimented with this strategy, hoping to reduce costs and gain strategic advantage. But many businesses have had mixed results. According to several studies, half the organizations that have shifted processes offshore have failed to generate the expected financial benefits. What's more, many of them have faced employee resistance and consumer dissatisfaction. Clearly, companies have to rethink how they formulate their offshoring strategies. A three-part methodology can help. First, companies need to prioritize their processes, ranking each based on two criteria: the value it creates for customers and the degree to which the company can capture some of that value. Companies will want to keep their core (highest-priority) processes in-house and consider outsourcing their commodity (low-priority) processes; critical (moderate-priority) processes are up for debate and must be considered carefully. Second, businesses should analyze all the risks that accompany offshoring and look systematically at their critical and commodity processes in terms of operational risk (the risk that processes won't operate smoothly after being offshored) and structural risk (the risk that relationships with service providers may not work as expected). Finally, companies should determine possible locations for their offshore efforts, as well as the organizational forms--such as captive centers and joint ventures--that those efforts might take. They can do so by examining each process's operational and structural risks side by side. This article outlines the tools that will help companies choose the right processes to offshore. It also describes a new organizational structure called the extended organization, in which companies specify the quality of services they want and work alongside providers

  3. Offshore Benin, a classic passive margin

    SciTech Connect

    Mathalone, J.M.P. )

    1991-03-01

    Offshore Benin comprises a narrow east-west continental shelf, some 30 km wide. A sharp shelf break running parallel to the coast borders the shelf, whereupon water depths rapidly increase to over 7000 ft. The area lies within the Dahomey Embayment, one of a series of Cretaceous and younger basins lining the coast of Africa that owe their inception to the Late Mesozoic break-up of the Gondwanaland Continent. The basin extends some 100 km inland, but sedimentary section is thin onshore compared to a maximum of 20,000 ft of sediment offshore. Initial sedimentation in this basin was of Neocomian alluvial and lacustrine clastics. These were deposited in east-west-trending narrow half-grabens associated with the initial break up of the South American and African continents. They are covered unconformably by more extensive Albian and Cenomanian transgressive clastics and shallow marine Turonian sandstones which are the main reservoir at Seme, Benin's only oilfield. The Senonian section offshore comprises passive margin deep sea clastic sediments prograding southwards. Very large proximal deep sea channels up to 2500 ft thick are developed in this interval. These channels are associated with excellent petroleum source rocks, averaging 4-5% oil-prone organic carbon, and form the main exploration target in the area when configured in a trap morphology. Seismic data quality is excellent in the region allowing detailed examination of the relationships between the rifted section and later units. In addition, these data illustrate clearly both internal and external morphology of the Senonian proximal deep sea channels.

  4. Energy from Offshore Wind: Preprint

    SciTech Connect

    Musial, W.; Butterfield, S.; Ram, B.

    2006-02-01

    This paper provides an overview of the nascent offshore wind energy industry including a status of the commercial offshore industry and the technologies that will be needed for full market development.

  5. Offshore rectenna feasbility

    NASA Technical Reports Server (NTRS)

    Freeman, J. W.; Hervey, D.; Glaser, P.

    1980-01-01

    A preliminary study of the feasibility and cost of an offshore rectenna to serve the upper metropolitan east coast was performed. A candidate site at which to build a 5 GW rectenna was selected on the basis of proximity to load centers, avoidance of shipping lanes, sea floor terrain, and relocated conditions. Several types of support structures were selected for study based initially on the reference system rectenna concept of a wire mesh ground screen and dipoles each with its own rectifier and filter circuits. Possible secondary uses of an offshore rectenna were examined and are evaluated.

  6. Body mass status of school children of Dera Ismail Khan, Pakistan.

    PubMed

    Ramzan, Muhammad; Ali, Irshad; Khan, Abdus Salam

    2008-01-01

    Childhood obesity is a global epidemic involving both developed and developing countries. It is a stare of over-nutrition with long-term complications such as dyslipidemia, hypertension, and coronary artery disease and type-2 diabetes. Underweight is the result of under nutrition leading to reduction in growth and development of every body organ especially the Central Nervous System. Long-term under-nutrition causes failure in linear growth (height) of the child. Growth is further retarded by the repeated attacks of respiratory infections, diarrhea and anemia as a result of reduced immunity. This study was carried, out eight primary schools of Dera Ismail Khan (Private, semi government organizations, and welfare foundations) having mixed population with some of the wards belonging to high socioeconomic group. Thorough clinical examination excluded those suffering from chronic heath problems. Height and weight of each one was taken body mass index of determined according to 'Quatelet's' index. Body mass index number was plotted on the CDC S age and gender specific growth charts 2-20 years for BMI-for age percentile and body mass status (underweight, normal weight, overweight/at the risk of overweight and obese/overweight. Total 1338 school going children (6-11 years) were examined with 865 (67.75%) boys and 471 (35.25%) as girls. 13.39%, 72.15%, 8.83% and 5.61% as underweight, normal weight, overweight and obese respectively. Percentage of underweight was higher in girls (25%) than boys (13.22). Percentage of obesity was higher (5.17%) in boys than girls (1.39%). Awareness about balanced diet, improvement in the level of education and socioeconomic conditions, easy access to health facilities and prevention of the gender discrimination, are the remedial measures to be taken to redress the situation.

  7. Offshore platform cathodic protection retrofits

    SciTech Connect

    Turnipseed, S.P.

    1996-10-01

    Cathodic protection (CP) is the primary technique used for underwater corrosion control on the majority of offshore steel structures. Offshore platforms are often kept in service far beyond their original design life. Refurbishment of the CP system is required when adequate protection can no longer be maintained. Various offshore platform CP retrofit designs are discussed.

  8. Foam pigs solve pipe cleaning problems offshore Brazil

    SciTech Connect

    Lima, P.C.R.; Neto, S.J.A.

    1995-10-02

    Pipeline systems in which conventional pigs cannot be run are common in such complex offshore installations as are found in Brazil`s Campos basin. These systems may contain changing pipe diameters or wet christmas trees and manifolds. A new concept for using low cost, low-density foam pigs for both liquid removal in wet-gas pipelines and paraffin removal in oil and multiphase pipelines has been successfully tested offshore Brazil. Although the present discussion focuses on condensate and paraffin removal in pipelines, the principles can be applied to several kinds of operations including general pipeline cleaning, product removal or separation in pipeline, corrosion evaluation, and chemical product application.

  9. Tectonic framework of Turkish sedimentary basins

    SciTech Connect

    Yilmaz, P.O. )

    1988-08-01

    Turkey's exploration potential primarily exists in seven onshore (Southeast Turkey platform, Tauride platform, Pontide platform, East Anatolian platform, Interior, Trace, and Adana) basins and four offshore (Black Sea, Marmara Sea, Aegean Sea, and Mediterranean Sea) regional basins formed during the Mesozoic and Tertiary. The Mesozoic basins are the onshore basins: Southeast Turkey, Tauride, Pontide, East Anatolian, and Interior basins. Due to their common tectonic heritage, the southeast Turkey and Tauride basins have similar source rocks, structural growth, trap size, and structural styles. In the north, another Mesozoic basin, the Pontide platform, has a much more complex history and very little in common with the southerly basins. The Pontide has two distinct parts; the west has Paleozoic continental basement and the east is underlain by island-arc basement of Jurassic age. The plays are in the upper Mesozoic rocks in the west Pontide. The remaining Mesozoic basins of the onshore Interior and East Anatolian basins are poorly known and very complex. Their source, reservoir, and seal are not clearly defined. The basins formed during several orogenic phases in mesozoic and Tertiary. The Cenozoic basins are the onshore Thrace and Adana basins, and all offshore regional basins formed during Miocene extension. Further complicating the onshore basins evolution is the superposition of Cenozoic basins and Mesozoic basins. The Thrace basin in the northwest and Adana basin in the south both originate from Tertiary extension over Tethyan basement and result in a similar source, reservoir, and seal. Local strike-slip movement along the North Anatolian fault modifies the Thrace basin structures, influencing its hydrocarbon potential.

  10. Offshore Wind Energy Systems

    ERIC Educational Resources Information Center

    Musgrove, P.

    1978-01-01

    Explores the possibility of installing offshore windmills to provide electricity and to save fuel for the United Kingdom. Favors their deployment in clusters to facilitate supervision and minimize cost. Discusses the power output and the cost involved and urges their quick development. (GA)

  11. The state of offshore

    SciTech Connect

    Nelson, B.F.

    1991-01-01

    In this book, the author explains the factors behind state involvement in offshore petroleum activities. From his analysis of government workings in Great Britain and Norway, he concludes that state intervention is determined by complex interactions among government officials, economic interests, and environmental pressures.

  12. Deriving surface motion of mountain glaciers in the Tuomuer-Khan Tengri Mountain Ranges from PALSAR images

    NASA Astrophysics Data System (ADS)

    Li, Jia; Li, Zhiwei; Zhu, Jianjun; Ding, Xiaoli; Wang, Changcheng; Chen, Jianli

    2013-02-01

    Glaciers flow velocity is an important parameter for the study of glacier dynamics, mass balance and climate change, and can provide precursory warning of glacier melting induced flooding, debris flowing, etc. The Tuomuer-Khan Tengri Mountain Range is one of the largest glaciated areas in Tian Shan Mountain. However, the knowledge of glacier motion in this area is still rather limited. Using the method of robust Offset-tracking and four pairs of PALSAR images covering the Tuomuer-Khan Tengri Mountain Range, this paper estimates the displacement fields of the mountain glaciers in this area for each pair. The displacement fields are then mapped into daily glacier flow velocities by dividing the acquiring intervals of each pair. Using a series of checkpoints selected in stationary areas where the displacements can be assumed to be zero, we evaluate the estimation error of the displacement fields and find that most of them are less than 2.17 cm/day. The displacement fields are analyzed in detail with regards to glacier bed terrain and glacial temperature and thickness. We find that they are in excellent accordance with the flow characteristic of typical mountain glaciers. The velocity changes among the observation years have been carefully examined. This along with the associated runoff measurements makes us conclude that the glaciers in the Tuomuer-Khan Tengri Range are assumedly in dynamic equilibrium between intensified melting and increased precipitation and glaciation, and their velocity will maintain stable in the near future. We also find that the altitudes of the velocity peaks are close to the recorded snowline, which indicates that detecting the changes of velocity peaks' position might provide a reference for monitoring the changes of the snowlines.

  13. Offshore Space Center (offshore launch site)

    NASA Technical Reports Server (NTRS)

    Harvey, D. G.

    1980-01-01

    Any activity requiring the development of the HLLV can benefit by operations from an offshore space center (OSC) since operating near the equator provides a twenty percent increase in payload in an ecliptic plan orbit. Some OSC concepts considered include a moored floating (semisubmersible) design, a stationary design supported by fixed piles, and a combination of these two. The facility supports: a 15,000 foot long, 300 foot wide runway, designed to accommodate a two staged winged launch vehicle, with a one million pound payload capacity to low earth orbit; an industrial area for HLLV maintenance; an airport terminal, control and operation center, and observation tower; liquid hydrogen and liquid oxygen production and storage, and fuel storage platforms; a power generation station, docks with an unloading area; two separate launch sites; and living accommodations for 10,000 people. Potential sites include the Paramount Seamount in the Pacific Ocean off the north coast of South America. Cost estimates are considered.

  14. Offshore Wind Research (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    This 2-page fact sheet describes NREL's offshore wind research and development efforts and capabilities. The National Renewable Energy Laboratory is internationally recognized for offshore wind energy research and development (R&D). Its experience and capabilities cover a wide spectrum of wind energy disciplines. NREL's offshore wind R&D efforts focus on critical areas that address the long-term needs of the offshore wind energy industry and the Department of Energy (DOE). R&D efforts include: (1) Developing offshore design tools and methods; (2) Collaborating with international partners; (3) Testing offshore systems and developing standards; (4) Conducting economic analyses; (5) Characterizing offshore wind resources; and (6) Identifying and mitigating offshore wind grid integration challenges and barriers. NREL has developed and maintains a robust, open-source, modular computer-aided engineering (CAE) tool, known as FAST. FAST's state-of-the-art capabilities provide full dynamic system simulation for a range of offshore wind systems. It models the coupled aerodynamic, hydrodynamic, control system, and structural response of offshore wind systems to support the development of innovative wind technologies that are reliable and cost effective. FAST also provides dynamic models of wind turbines on offshore fixed-bottom systems for shallow and transitional depths and floating-platform systems in deep water, thus enabling design innovation and risk reduction and facilitating higher performance designs that will meet DOE's cost of energy, reliability, and deployment objectives.

  15. Reclassification of Koreibacter algae as a later heterotypic synonym of Paraoerskovia marina and emended descriptions of the genus Paraoerskovia Khan et al. 2009 and of Paraoerskovia marina Khan et al. 2009.

    PubMed

    Schumann, P; Pukall, R; Spröer, C; Stackebrandt, E

    2013-01-01

    16S rRNA gene sequences deposited for the type strains of Paraoerskovia marina (CTT-37(T); GenBank accession no. AB445007) and Koreibacter algae (DSW-2(T); FM995611) show a similarity of 100 %. Consequently, the type strains were subjected to a polyphasic recharacterization under direct comparison in order to clarify their taxonomic position. PvuII RiboPrint patterns and quantitative ratios of cellular fatty acids revealed strain-specific differences between P. marina DSM 21750(T) ( = CTT-37(T)) and K. algae DSM 22126(T) ( = DSW-2(T)). The percentage of DNA-DNA binding of 94 % indicated that the two type strains belong to the same genomospecies. Agreement in the peptidoglycan structure and polar lipid pattern, highly similar fatty acid profiles and MALDI-TOF mass spectra, the ability to produce acid from the same carbon sources, corresponding enzymic activities and DNA G+C contents of 70.8 ± 0.3 mol%, in addition to the consistent characteristics reported in the original descriptions, support the view that the two strains should be affiliated to the same species. According to Rules 38 and 42 of the Bacteriological Code, Koreibacter algae should be reclassified as later heterotypic synonym of Paraoerskovia marina, and the descriptions of the genus Paraoerskovia Khan et al. 2009 and of Paraoerskovia marina Khan et al. 2009 are emended accordingly.

  16. Crystal chemistry of elpidite from Khan Bogdo (Mongolia) and its K- and Rb-exchanged forms

    SciTech Connect

    Grigor'eva, A. A.; Zubkova, N. V. Pekov, I. V.; Kolitsch, U.; Pushcharovsky, D. Yu.; Vigasina, M. F.; Giester, G.; Dordevic, T.; Tillmanns, E.; Chukanov, N. V.

    2011-09-15

    Elpidite Na{sub 2}ZrSi{sub 6}O{sub 15} {center_dot} 3H{sub 2}O [space group Pbcm, a = 7.1312(12), b = 14.6853(12), and c = 14.6349(15) Angstrom-Sign ] from Khan Bogdo (Mongolia) and its K- and Rb-exchanged forms K{sub 1.78}Na{sub 0.16}H{sub 0.06}ZrSi{sub 6}O{sub 15} {center_dot} 0.85H{sub 2}O [Cmce, a = 14.054(3), b = 14.308(3), and c = 14.553(3) Angstrom-Sign ] and Na{sub 1.58}Rb{sub 0.2}H{sub 0.22}ZrSi{sub 6}O{sub 15} {center_dot} 2.69H{sub 2}O [Pbcm, a = 7.1280(10), b = 14.644(3), and c = 14.642(3) Angstrom-Sign ] that were obtained by cation exchange at 90 Degree-Sign C, as well as K{sub 1.84}Na{sub 0.11}H{sub 0.05}ZrSi{sub 6}O{sub 15} {center_dot} 0.91H{sub 2}O [Cmce, a = 14.037(3), b = 14.226(3), and c = 14.552(3) Angstrom-Sign ] and Rb{sub 1.78}Na{sub 0.06}H{sub 0.16}ZrSi{sub 6}O{sub 15} {center_dot} 0.90H{sub 2}O [Cmce, a = 14.2999(12), b = 14.4408(15), and c = 14.7690(12) Angstrom-Sign ], obtained at 150 Degree-Sign C are studied by single-crystal X-ray diffraction and IR spectroscopy. The base of the structures is a heteropolyhedral Zr-Si-O framework whose cavities accommodate Na (K, Rb) cations and H{sub 2}O molecules.

  17. Minisparker seismic-reflection data of field activity S-5-09-SC: San Pedro Basin, offshore southern California from 2009-07-06 to 2009-07-10

    USGS Publications Warehouse

    Sliter, Ray W.; Conrad, James E.; Ryan, Holly F; Triezenberg, Peter

    2017-01-01

    This dataset includes raw and processed, high-resolution seismic-reflection data collected in 2009 to explore a possible connection between the San Diego Trough Fault and the San Pedro Basin Fault. The survey is in the San Pedro Basin between Santa Catalina Island and San Pedro, California. The data were collected aboard the U.S. Geological Survey R/V Parke Snavely. The seismic-reflection data were acquired using a SIG 2mille minisparker. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location.

  18. Chirp seismic-reflection data of field activity S-5-09-SC: San Pedro Basin, offshore southern California from 2009-07-06 to 2009-07-10

    USGS Publications Warehouse

    Sliter, Ray W.; Conrad, James E.; Ryan, Holly F.; Triezenberg, Peter

    2017-01-01

    This dataset includes raw and processed, high-resolution seismic-reflection data collected in 2009 to explore a possible connection between the San Diego Trough Fault and the San Pedro Basin Fault. The survey is in the San Pedro Basin between Catalina Island and San Pedro, California. The data were collected aboard the U.S. Geological Survey R/V Parke Snavely. The seismic-reflection data were acquired using an Edgetech 512 Chirp subbottom profiling system. Subbottom acoustic penetration spanned tens to hundreds of meters, variable by location.

  19. Evidence of offshore lake trout reproduction in Lake Huron

    USGS Publications Warehouse

    DeSorcie, Timothy J.; Bowen, Charles A.

    2003-01-01

    Six Fathom Bank-Yankee Reef, an offshore reef complex, was an historically important spawning area believed to represent some of the best habitat for the rehabilitation of lake trout Salvelinus namaycush in Lake Huron. Since 1986, lake trout have been stocked on these offshore reefs to reestablish self-sustaining populations. We sampled with beam trawls to determine the abundance of naturally reproduced age-0 lake trout on these offshore reefs during May-July in 1994-1998 and 2000-2002. In total, 123 naturally reproduced lake trout fry were caught at Six Fathom Bank, and 2 naturally reproduced lake trout fry were caught at nearby Yankee Reef. Our findings suggest that this region of Lake Huron contains suitable habitat for lake trout spawning and offers hope that lake trout rehabilitation can be achieved in the main basin of Lake Huron.

  20. Exploration and development offshore southern Vietnam

    SciTech Connect

    Ferguson, A.M.

    1996-12-31

    In Vietnam, the major focus of the oil and gas industry is on the Nam Con Son and Cuu Long Basins in the southern offshore area. Major licensing first occurred here in the early 1970s. Some exploration was also undertaken by foreign companies in the early 1980s. In 1981, the Soviet Union undertook to assist Vietnam with the development of oil and gas. Vietsovpetro, a joint venture between the then Soviet Oil and Gas Ministry and the Vietnam Oil and Gas Corporation was formed. Most of Vietsovpetro`s efforts have been to develop the Bach Ho field in the Cuu Long Basin. This now produces {approximately}130000 bopd. The most recent large scale licensing round occurred in 1992, and, at present, there are over thirty foreign companies active in these Basins` blocks . The first phase of exploration is ending and successes in the Nam Con Son Basin include the BP-led Lan Tay/Lan Do gas discoveries and Pedco`s gas discoveries. Mitsubishi`s and Petronas` oil discoveries in the Cuu Long Basin have attracted much attention also. The Dai Hung oil field (BHP-operated) has been producing since late 1994. Certain blocks are being appraised, and exploration work is also continuing. Areas of the Cuu Long Basin that were part of Vietsovpetro`s acreage, but which may soon be re-licensed, have generated keen interest. The presence of an active upstream industry - exploring, appraising, developing and producing - indicates the emergence of Vietnam as an important East Asian oil and gas player.

  1. Strontium isotopes in the rocks of the ophiolite complex in the Khan-Tayshiri Range (Western Mongolia)

    SciTech Connect

    Plyusnin, G.S.; Kuz'min, M.I.; Sandimirova, G.P.; Zonenshayn, L.P.

    1980-08-01

    The distribution of strontium isotopes has been examined in a section through the ophiolite complex of the Khan-Tayshiri Range (Western Mongolia). The basal parts of the complex consist of apo-dunites (/sup 87/Sr//sup 86/Sr = 0.7118 - 0.7124), and higher up in the section there are pyroxenites (0.7064 - 0.7095) and gabbros (0.7034-0.7065). The upper parts of the complex consist of pillow lavas (0.7068-0.7071), the conduits for which were a series of laminar dikes (0.7057-0.7087). An analysis of petrological and geochemical information with a selection of isotope data suggests that during the formation of the rocks of the Khan-Tayshiri Complex, three components, different in nature and chemical composition, were involved: the remains of the Earth's protolithosphere in the form of apo-dunites, a mantle quartz-tholeiite magma, and seawater. Variations in the /sup 87/Sr//sup 86/Sr ratio are associated both with the isotope composition of the original magma, and also with the conditions of its emplacement. The ultrabasic rocks are regarded as relicts of the ancient ultrabasic layer or protolithosphere of the Earth.

  2. Perceived individual and community barriers in the provision of family planning services by lady health workers in Tehsil Gujar Khan.

    PubMed

    Khan, Abdul Wali; Amjad, Chaudhry Muhammad; Hafeez, Assad; Shareef, Rehan

    2012-12-01

    To identify contextual barriers (social, cultural, geographic and economic), faced by Lady Health Workers (LHWs) and to assess their strategies at different levels (individual, community and system) in the provision of family planning services to their clients in Tehsil Gujar Khan. The mixed model cross-sectional study was conducted from April 1 to July 10, 2010, in Tehsil Gujar Khan, Punbjab, Pakistan. It was carried out in two phases: in the first phase 10 in-depth interviews were conducted with the workers, followed by two focus group discussions. On the basis of findings, a structured questionnaire was developed and administered to 111 workers in the second phase. Of the total, 97 responses were used for analysis. Data analysis was done by SPSS-16. Majority of the respondents reported barriers at the community level: religious barriers 69% (n = 67), sociocultural barriers 58% (n = 56), transport 54% (n = 52), communication and economic reasons 25% (n = 24). Individual level barriers were female gender, experience and low education. System-level barriers were increased workload, National immunization days/sub-national immunization days, late supply, stock shortage (especially injectables), problems for referred clients and lack of proper incentives. Lady health workers still face barriers at individual, family, community and system level in the delivery of Family Planning services.

  3. Medicinal uses of honey (Quranic medicine) and its bee flora from Dera Ismail Khan District, KPK, Pakistan.

    PubMed

    Marwat, Sarfaraz Khan; Khan, Muhammad Aslam; Rehman, Fazalur; Khan, Kaleemullah

    2013-03-01

    This study was carried out during 2005-2008 to identify existing plant species visited by workers of honeybees for nectar and pollen collection in Dera Ismail Khan (D.I.Khan) District, Pakistan. The honeybee species investigated in the area were, rock bee (Apis dorsata F.), little bee (A. florea F.) and European honeybee (A. mellifera L.). A detailed list of 86 plant species both wild and cultivated was prepared, out of which 12 species, Phulai (Acacia modesta Wall.), Sarsoon (Brassica campestris L.), Kaghzi nimboo (Citrus aurantifolia L.), Khatta (C. medica L.), Malta (C. sinensis (L.) Osbeck.), Shisham (Dalbergia sissoo Roxb.), Date (Phoenix dactylifera L.), Barseen (Trifolium alexandrianum L.), Shaftal (T. resupinatum L), Makai (Zea mays L.), Ber (Zizyphus mauritiana Lam.) and Jher beri (Z. numularia (Burm. f.) Wight & Arn.,) were found as major sources (table 1) for the production of surplus honey in a year at different localities in the District. Among the minor sources various plant species were included (table 2). These plants fill the flowering gaps between the major sources in various parts of the year and help in continuous supply of food to honey bees.

  4. Tertiary evolution of the northeastern Venezuela offshore

    NASA Astrophysics Data System (ADS)

    Ysaccis B., Raul

    1998-12-01

    On the northeastern offshore Venezuela, the pre-Tertiary basement consists of a deeply subducted accretionary complex of a Cretaceous island arc system that formed far to the west of its present location. The internal structure of this basement consists of metamorphic nappes that involve passive margin sequences, as well as oceanic (ophiolitic) elements. The Tertiary evolution of the northeastern Venezuela offshore is dominated by Paleogene (Middle Eocene-Oligocene) extension and Neogene transtension, interrupted by Oligocene to Middle Miocene inversions. The Paleogene extension is mainly an arc-normal extension associated with a retreating subduction boundary. It is limited to the La Tortuga and the La Blanquilla Basins and the southeastern Margarita and Caracolito subbasins. All of these basins are farther north of and not directly tied to the El Pilar fault system. On a reconstruction, these Paleogene extensional systems were located to the north of the present day Maracaibo Basin. By early Miocene the leading edge of the now overall transpressional system had migrated to a position to the north of the Ensenada de Barcelona. This relative to South America eastward migration is responsible for the Margarita strike-slip fault and the major inversions that began during the Oligocene and lasted into the Middle Miocene. The Bocono-El Pilar-Casanay-Warm Springs and the La Tortuga-Coche-North Coast fault systems are exclusively Neogene with major transtension occurring during the Late Miocene to Recent and act independently from the earlier Paleogene extensional system. They are responsible for the large Neogene transtensional basins of the area: the Cariaco trough, the Northern Tuy-Cariaco and the Paria sub-basins, and the Gulf of Paria Basin. This latest phase is characterized by strain-partitioning into strike slip faults, a transtensional northern domain and a transpressional southern domain that is responsible for the decollement tectonics and/or inversions of the

  5. Arctic offshore platform

    SciTech Connect

    Bhula, D.N.

    1984-01-24

    An offshore structure is disclosed for use in drilling and producing wells in arctic regions having a conical shaped lower portion that extends above the surface of the water and a cylindrical upper section. The conical portion is provided with a controlled stiffness outer surface for withstanding the loads produced by ice striking the structure. The stiffness properties of the outer shell and flexible members are designed to distribute the load and avoid high local loads on the inner parts of the structure.

  6. Wind Energy: Offshore Permitting

    DTIC Science & Technology

    2008-05-01

    Technological advancements and tax incentives have driven a global expansion in the development of renewable energy resources. Wind energy , in...particular, is now often cited as the fastest growing commercial energy source in the world. Currently, all U.S. wind energy facilities are based on land...authority to permit and regulate offshore wind energy development within the zones of the oceans under its jurisdiction. The federal government and coastal

  7. The Limits of Offshore Balancing

    DTIC Science & Technology

    2015-09-01

    UNITED STATES ARMY WAR COLLEGE PRESS Carlisle Barracks, PA ST R ENGTH-’W I SDOM THE LIMITS OF OFFSHORE BALANCING Hal Brands U.S. ARMY WAR...Offshore Balancing 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...Strategic Studies Institute and U.S. Army War College Press THE LIMITS OF OFFSHORE BALANCING Hal Brands September 2015

  8. Geological history of the west Libyan offshore and adjoining regions

    SciTech Connect

    Benniran, M.M.; Taleb, T.M.; McCrossan, R.G.

    1988-08-01

    The continental margin of the African plate north of Libya is separated from the Saharan platform to the south by a major Variscan fault system running along the coastline. The structural evolution of three sedimentary basins within the margin is discussed. The Jeffara basin, onshore western Libya-southern Tunisia, formed as a right-lateral pull-part late in the Variscan event. When the strike-slip motion ceased in the Late Permian, the basin continued to subside thermally. The Sabratah (Tripolitanian) basin, offshore western Libya-southern Tunisia, and the Benghazi basin in the Sirte rise were both formed as left-lateral pull-aparts in the Late Triassic-Early Jurassic. From the Middle Jurassic to the present they have subsided thermally. Onshore the lower Mesozoic is characterized by continental and nearshore clastics, separated by an evaporite sequence of Late Triassic-Early Jurassic age. Offshore this sequence is thought to grade northward into open marine carbonates. Uplift along the edge of the Saharan platform during the Early Cretaceous sourced coarse clastics, which grade northward into a thick sequence of shallow-water carbonates. Throughout the Late Cretaceous and early Tertiary, high-energy carbonates were deposited around the flanks of the Sabratah basin, grading into deeper-water, fine-grained clastics and carbonates toward the center of the basin. The late Tertiary succession is dominated by clastics derived from the growing Tellian Atlas to the northwest. During the Mesozoic and Tertiary a thick sequence of carbonates was deposited on the Pelagian platform to the north of the Sabratah basin. Periodically the platform was exposed subaerially.

  9. Spatial and temporal trends in Precambrian nitrogen cycling: A Mesoproterozoic offshore nitrate minimum

    NASA Astrophysics Data System (ADS)

    Koehler, Matthew C.; Stüeken, Eva E.; Kipp, Michael A.; Buick, Roger; Knoll, Andrew H.

    2017-02-01

    Fixed nitrogen is an essential nutrient for eukaryotes. As N2 fixation and assimilation of nitrate are catalyzed by metalloenzymes, it has been hypothesized that in Mesoproterozoic oceans nitrate was limited in offshore environments by low trace metal concentrations and high rates of denitrification in anoxic and episodically euxinic deep water masses, restricting eukaryotes to near-shore environments and limiting their evolutionary innovation. To date this hypothesis has only been tested in the Belt Supergroup (∼1.4 Ga), with results that support an onshore-offshore nitrate gradient as a potential control on eukaryote ecology. Here we present bulk nitrogen and organic carbon isotopic data from non-isochronous cross-basinal facies across the Bangemall (∼1.5 Ga) and the Roper (∼1.4-1.5 Ga) basins to better understand the extent and variability of onshore-offshore nitrogen isotope gradients in the Mesoproterozoic. Both basins show an average ∼1-2‰ enrichment in δ15Nbulk from deep to shallow facies, with a maximum range from -1‰ offshore to +7.5‰ onshore. Unlike the Belt basin, the Bangemall and Roper basins show some offshore δ15Nbulk values that are enriched beyond the isotopic range associated with biological N2 fixation alone. This suggests a mixture of aerobic and anaerobic metabolisms offshore. In shallow waters, where δ15Nbulk enrichment peaks, an aerobic nitrogen cycle was evidently operating. Even though isotopic signatures of aerobic nitrogen cycling are seen in all parts of the Bangemall and Roper basins, our data are consistent with a lateral gradient in nitrate availability within the photic zone, with higher concentrations in near-shore environments than offshore. The variability in δ15Nbulk values in each depositional environment and the consistently low δ15Nbulk values from Mesoproterozoic units compared to the Paleoproterozoic and Neoproterozoic suggest that nitrate concentrations in the global ocean were likely low. This trend is

  10. A tribute to Sheik Humarr Khan and all the healthcare workers in West Africa who have sacrificed in the fight against Ebola virus disease: Mae we hush.

    PubMed

    Bausch, Daniel G; Bangura, James; Garry, Robert F; Goba, Augustine; Grant, Donald S; Jacquerioz, Frederique A; McLellan, Susan L; Jalloh, Simbirie; Moses, Lina M; Schieffelin, John S

    2014-11-01

    The Kenema Government Hospital Lassa Fever Ward in Sierra Leone, directed since 2005 by Dr. Sheikh Humarr Khan, is the only medical unit in the world devoted exclusively to patient care and research of a viral hemorrhagic fever. When Ebola virus disease unexpectedly appeared in West Africa in late 2013 and eventually spread to Kenema, Khan and his fellow healthcare workers remained at their posts, providing care to patients with this devastating illness. Khan and the chief nurse, Mbalu Fonnie, became infected and died at the end of July, a fate that they have sadly shared with more than ten other healthcare workers in Kenema and hundreds across the region. This article pays tribute to Sheik Humarr Khan, Mbalu Fonnie and all the healthcare workers who have acquired Ebola virus disease while fighting the epidemic in West Africa. Besides the emotional losses, the death of so many skilled and experienced healthcare workers will severely impair health care and research in affected regions, which can only be restored through dedicated, long-term programs.

  11. Marine and offshore corrosion

    SciTech Connect

    Chandler, K.A.

    1985-01-01

    Until recently marine corrosion technology has been preoccupied with the corrosion of ships. Within the last ten years, however, the rapid expansion of oil and gas exploration has changed the course of corrosion research as well as the market for corrosion services and products. So complete has been the change that a new approach, dealing with ships, structures, and plant has been taken in this book. This introduction to the control of corrosion in marine environments will serve as a reference on topics ranging from coating systems to metallurgical considerations in the design of ships, offshore structure, plant and pipelines.

  12. Rift basins in western margin of India and their hydrocarbon prospects with special reference to Kutch basin

    SciTech Connect

    Biswas, S.K.

    1982-10-01

    The western continental margin of India can be classed as a divergent or passive margin. The western continental shelf is an extensive carbonate bank (Bombay offshore basin) passing into clastic sediments on the north and south. Three craton-margin embayed basins-Kutch, Cambay, and Narmada- in the northern part of the shelf, are filled predominantly with clastic sediments. These basins occupy grabens bounded by faults diverging seaward. The grabens were formed by three rift systems along major Precambrian tectonic trends. The rifting developed sequentially from north to south around the Saurashtra horst. Kutch basin was formed in the Early Jurassic, followed by Cambay basin in Early Cretaceous time, and the Narmada in the Late Cretaceous. It appears that these rifting events occurred at successive stages during the northward migration of the Indian plate after its break from Gondwanaland in Late Triassic or Early Jurassic. It is inferred that these rift basins opened up successively as a result of the counterclockwise drift of the Indian craton. Bombay offshore and Cambay are two major oil-producing basins in the western margin. These basins are characterized by high geothermal gradients attributed to the shallowness of the mantle in this region. Oil has not been found in KUtch basin, which is mainly an onshore Mesozoic basin. The basin basin depocenter shifted offshore at the northwestern part of the continental shelf where the shelf is wide.

  13. Offshore outlook: the American Arctic

    SciTech Connect

    Jahns, M.O.

    1985-05-01

    Offshore areas in the American Arctic are highlighted and the development of the area is compared with other offshore areas where the required technology is more readily available. Principal areas are shown in which new concepts are being put to practice. Canada's east coast is examined. Several technological trends are reviewed to help operators accelerate the discovery and development of arctic petroleum reserves.

  14. Offshore Fish Community: Ecological Interactions

    EPA Science Inventory

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone...

  15. Offshore Fish Community: Ecological Interactions

    EPA Science Inventory

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone...

  16. Pioneering offshore excellence

    SciTech Connect

    Kent, R.P.; Grattan, L.

    1996-11-01

    Hibernia Management and Development Company Ltd. (HMDC) was formed in 1990 by a consortium of oil companies to develop their interests in the Hibernia and Avalon reservoirs offshore Newfoundland in a safe and environmentally responsible manner. The reservoirs are located 315km ESE of St. John`s in the North Atlantic. The water depth is about 80m. The entire Hibernia field is estimated to contain more than three billion barrels of oil in place and the owners development plan area is estimated to contain two billion barrels. Recoverable reserves are estimated to be approximately 615 million barrels. The Hibernia reservoir, the principle reservoir, is located at an average depth of 3,700m. HMDC is building a large concrete gravity based structure (GBS) that which will support the platform drilling and processing facilities and living quarters for 280 personnel. In 1997 the platform will be towed to the production site and production will commence late 1997. Oil will be exported by a 2 km long pipeline to an offshore loading system. Dynamically positioned tankers will then take the oil to market. Average daily production is expected to plateau between 125,000 and 135,000 BOPD. It will be the first major development on the east coast of Canada and is located in an area that is prone to pack ice and icebergs.

  17. Assessment of undiscovered conventional oil and gas resources of Bonaparte Basin, Browse Basin, Northwest Shelf, and Gippsland Basin Provinces, Australia, 2011

    USGS Publications Warehouse

    Pollastro, Richard M.; Brownfield, Michael E.; Charpentier, Ronald R.; Cook, Troy A.; Klett, Timothy R.; Kirschbaum, Mark A.; Pitman, Janet K.; Schenk, Christopher J.

    2012-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 4.7 billion barrels of undiscovered oil and 227 trillion cubic feet of undiscovered natural gas in three major offshore petroleum basins of northwest Australia and in the Gippsland Basin of southeast Australia.

  18. Combining rainfall data from rain gauges and TRMM in hydrological modelling of Laotian data-sparse basins

    NASA Astrophysics Data System (ADS)

    Liu, Xing; Liu, Fa Ming; Wang, Xiao Xia; Li, Xiao Dong; Fan, Yu Yan; Cai, Shi Xiang; Ao, Tian Qi

    2017-06-01

    At present, prediction of streamflow simulation in data-sparse basins of the South East Asia is a challenging task due to the absence of reliable ground-based rainfall information, while satellite-based rainfall estimates are immensely useful to improve our understanding of spatio-temporal variation of rainfall, particularly for data-sparse basins. In this study the TRMM 3B42 V7 and its bias-corrected data were, respectively, used to drive a physically based distributed hydrological model BTOPMC to perform daily streamflow simulations in Nam Khan River and Nam Like River basins during the years from 2000 to 2004 so as to investigate the potential use of the TRMM in complementing rain gauge data in hydrological modelling of data-sparse basins. The results show that although larger difference exists in the high streamflow process and the low streamflow process, the daily simulations fed with TRMM precipitation data could basically reflect the daily streamflow processes at the four stations and determine the time to peak. Furthermore, the calibrated parameters in the Nam Khan River basin are more suitable than that in the Nam Like River basin. By comparing the two precipitation data, it indicates that the integration of TRMM precipitation data and rain gauge data have a promising prospect on the hydrological process simulation in data-sparse basin.

  19. Bahrain's offshore banking center

    SciTech Connect

    Gerakis, A.S.; Roncesvalles, O.

    1983-01-01

    The economic effects of Bahrain's schemes for licensing offshore banking units (OBUs) were the immediate response of major international banks and the financial services the banking center has rendered by improving regional money and exchange markets at a time when a Middle East link was needed to service the increasing demand for oil-wealth banking services. Bahrain's leadership also created a favorable climate. Aggressive competition from banks in Kuwait and Saudi Arabia have caused some friction, but informal supervision by the Bahrain Monetary Agency (BMA) should be able to avoid serious difficulty. Bahrain's success required a banking infrastructure, a free-enterprise system, a willingness to maintain banking standards, a country small enough to benefit directly from OBU income, and a gap in nearby competing centers. 39 references, 1 figure, 5 tables. (DCK)

  20. Ice interaction with offshore structures

    SciTech Connect

    Cammaert, A.B.; Muggeridge, D.B.

    1988-01-01

    Oil platforms and other offshore structures being built in the arctic regions must be able to withstand icebergs, ice islands, and pack ice. This reference explain the effect ice has on offshore structures and demonstrates design and construction methods that allow such structures to survive in harsh, ice-ridden environments. It analyzes the characteristics of sea ice as well as dynamic ice forces on structures. Techniques for ice modeling and field testing facilitate the design and construction of sturdy, offshore constructions. Computer programs included.

  1. WIND Toolkit Offshore Summary Dataset

    DOE Data Explorer

    Draxl, Caroline; Musial, Walt; Scott, George; Phillips, Caleb

    2017-08-18

    This dataset contains summary statistics for offshore wind resources for the continental United States derived from the Wind Integration National Datatset (WIND) Toolkit. These data are available in two formats: GDB - Compressed geodatabases containing statistical summaries aligned with lease blocks (aliquots) stored in a GIS format. These data are partitioned into Pacific, Atlantic, and Gulf resource regions. HDF5 - Statistical summaries of all points in the offshore Pacific, Atlantic, and Gulf offshore regions. These data are located on the original WIND Toolkit grid and have not been reassigned or downsampled to lease blocks. These data were developed under contract by NREL for the Bureau of Oceanic Energy Management (BOEM).

  2. Caribbean basin framework, 1: Introduction, Nicaraguan rise and Greater Antilles

    SciTech Connect

    Mann, P. )

    1991-03-01

    Recent progress in lithologic description and microfossil dating of onshore basins from around the Caribbean has improved constraints on the age and tectonic setting of major basin-forming periods. The author presents an integrated tectonostratigraphic summary from the northern, western, and southwestern Caribbean and use this framework to interpret seismic profiles in offshore areas lacking wells.

  3. Observations of gas hydrates in marine sediments, offshore northern California

    USGS Publications Warehouse

    Brooks, J.M.; Field, M.E.; Kennicutt, M.C.

    1991-01-01

    Biogenic gas hydrates were recovered in shallow cores (< 6 m deep) from the Eel River basin in offshore northern California between 40??38??? and 40??56???N. The gas hydrates contained primarily methane (??13C = -57.6 to -69.1???) and occurred as dispersed crystals, small (2-20 mm) nodules, and layered bands within the sediment. These hydrates, recovered in sediment at water depths between 510 and 642 m, coincide nearly, but not exactly, with areas showing bottom-simulating reflectors (BSRs) on seismic-reflection records. This study confirms indirect geophysical and geologic observations that gas hydrates are present north of the Mendocino Fracture Zone in sediment of the Eel River basin but probably are absent to the south in the Point Arena basin. This discovery extends the confirmed sites of gas hydrates in the eastern Pacific region beyond the Peruvian and Central American margins to the northern California margin. ?? 1991.

  4. Quantifying the Benefits of Combining Offshore Wind and Wave Energy

    NASA Astrophysics Data System (ADS)

    Stoutenburg, E.; Jacobson, M. Z.

    2009-12-01

    For many locations the offshore wind resource and the wave energy resource are collocated, which suggests a natural synergy if both technologies are combined into one offshore marine renewable energy plant. Initial meteorological assessments of the western coast of the United States suggest only a weak correlation in power levels of wind and wave energy at any given hour associated with the large ocean basin wave dynamics and storm systems of the North Pacific. This finding indicates that combining the two power sources could reduce the variability in electric power output from a combined wind and wave offshore plant. A combined plant is modeled with offshore wind turbines and Pelamis wave energy converters with wind and wave data from meteorological buoys operated by the US National Buoy Data Center off the coast of California, Oregon, and Washington. This study will present results of quantifying the benefits of combining wind and wave energy for the electrical power system to facilitate increased renewable energy penetration to support reductions in greenhouse gas emissions, and air and water pollution associated with conventional fossil fuel power plants.

  5. Seismic evidence for hyper-stretched crust and mantle exhumation offshore Vietnam.

    NASA Astrophysics Data System (ADS)

    Savva, D.; Meresse, F.; Pubellier, M.; Chamot-Rooke, N.; Franke, D.; Steuer, S.; Sapin, F.; Auxietre, J. L.

    2012-04-01

    The Phu Khan basin is one of the sub-basins opened during the rifting of the South China Sea during the Eocene. The basin is located against the East-Vietnam Boundary Fault (EVBF) to the west and the oceanic crust to the east. Good quality seismic lines allow us to observe structures which highlight the rifting history of the South China Sea margin and the processes of crustal boudinage. A Moho rise is the prominent feature of the Central part of the basin. The mantle is shallowest in the center of the basin and at places is directly in contact with the sediments, via a large low-angle detachment fault which separates several crustal blocks. The axis of the Moho rise is roughly parallel to the South China Sea propagator direction. As a consequence, the upper and lower crusts are strongly extended by large crustal boudins. The network of normal fault is dense in the upper crust and propagates into the lower crust occasionally. However, the lower crust seems to be missing at some places. At the apex of the Moho rise, several indicators of fluids circulations have been observed, including volcanic edifices and gas escapes features. The seismic facies just above this Moho rise looks poorly stratified and might be affected by a certain degree of metamorphism. Three stages of extension are clearly identifiable, with age constrained by wells calibration of the horizons: the oldest rift sequence is identified from basement to Oligocene horizons; a second from Oligocene to Mid Miocene (15.5 Ma), and a third from Mid-Miocene to Upper Miocene (10.5 Ma). These three rifts have been formed with at least two directions of extension, a first which is North-South and a second NW - SE The well imaged 15.5 Ma horizon is tilted, as well as part of the subsequent in-filling which is fan-shaped. These are in turn sealed by the 10.5Ma unconformity. Although tectonic activity appears diachronous from north to south, we suggest that cessation of rifting and opening did not occur before 12

  6. Offshore search continues despite disappointments

    SciTech Connect

    Cornitius, T.

    1985-05-01

    Exploration drilling activity in Australia broke records onshore in 1984, but offshore it was a different story. A total of 373 wells were drilled, onshore and offshore, with 266 labeled as wildcats and appraisals. Out of 80 wells drilled offshore last year, 43 were exploratory compared with 49 in 1983; 48 were oil wells, seven were gas, and 25 were dusters. Offshore discoveries included the Talisman 1 off the coast of Western Australia, which tested around 6000 b/d, and Challis 1 in the Timor Sea, which flowed at 5000 b/d. The failure to establish Jabiru in the Timor Sea as a major oil province like Bass Strait was a major disappointment. However, the Challis 1 was a relief since it indicated the presence of a commercial field adjacent to Jabiru.

  7. Organic geochemistry of sediments on the flanks of Tanner and Cortes banks offshore from southern California

    USGS Publications Warehouse

    Rapp, J.B.; Kvenvolden, K.A.

    1982-01-01

    Holocene sediment, composed mainly of foram tests, occurs on the flanks of the Tanner and Cortes Banks, offshore southern California. The organic matter in this sediment differs in content and composition from the organic matter in nearby basins. Two sources of hydrocarbons are indicated: terrestrial plants and biodegraded or immature petroleum.

  8. Authors' response to the specious ;Comment on the paper, on Cattaneo-Christov heat flux model for Carreau fluid flow over a slendering sheet, Hashim, Masood Khan, Results in Physics, 7 (2017) 310-319;

    NASA Astrophysics Data System (ADS)

    Hashim; Khan, Masood

    Our intention in this write-up is to give a reply for the specious comment of Asterios Pantokratoras on the paper ;On Cattaneo-Christov heat flux model for Carreau fluid flow over a slendering sheet, Hashim and Masood Khan, Results in Physics, 7 (2017) 310-319 (Hashim and Masood Khan, 2017);. The authors talked about each of those comments in detail. In brief, the authors do not comply with those specious comments made by Asterios Pantokratoras (2017).

  9. Microbial contamination of the drinking water distribution system and its impact on human health in Khan Yunis Governorate, Gaza Strip: seven years of monitoring (2000-2006).

    PubMed

    Abu Amr, S S; Yassin, M M

    2008-11-01

    To assess total and faecal coliform contamination in water wells and distribution networks over the past 7 years, and their association with human health in Khan Yunis Governorate, Gaza Strip. Historical data and interview questionnaire. Data were obtained from the Palestinian Ministry of Health on total and faecal coliform contamination in water wells and distribution networks, and on the incidence of water-related diseases in Khan Yunis Governorate. An interview questionnaire was conducted with 210 residents of Khan Yunis Governorate. Total and faecal coliform contamination exceeded the World Health Organization's limit for water wells and networks. However, the contamination percentages were higher in networks than in wells. Diarrhoeal diseases were strongly correlated with faecal coliform contamination in water networks (r=0.98). This is consistent with the finding that diarrhoeal diseases were the most common self-reported diseases among the interviewees. Such diseases were more prevalent among subjects who drank municipal water than subjects who drank desalinated or home-filtered water (odds ratio=2.03). Intermittent water supply, insufficient chlorination and sewage flooding seem to be associated with self-reported diseases. Residents in the Gaza Strip have a good level of knowledge about drinking water contamination, and this is reflected in good practice. Water quality has deteriorated in the Gaza Strip, and this may contribute to the prevalence of water-related diseases. Self-reported diseases among interviewees in Khan Yunis Governorate were associated with source of drinking water, intermittent water supply, insufficient chlorination, sewage flooding and age of water networks.

  10. Hybrid offshore structure

    SciTech Connect

    Finn, L.D.; Maus, L.D.

    1986-09-09

    An articulated offshore structure is described for use in a body of water, the structure comprising: a substantially rigid lower section, the lower section extending upwardly from the bottom of the body of water to a pivot point located intermediate the bottom and the surface of the body of water; a compliant upper section extending upwardly from the pivot point to a position at or above the surface of the body of water; pivot means located proximate pivot point, the pivot means interposed between and connected to the lower section and upper section and adapted to permit the upper section to pivot laterally relative to the lower section; torsion means connected to the upper section and the lower section, the torsion means adapted to transmit torsional loads from the upper section to the lower section; the pivot means being positioned above the bottom of the body of water a distance of between about 10 percent and about 50 percent of the total depth of the body of water so as to substantially minimize the weight of the structure while maintaining the flexural vibration period of the structure at or below a preselected maximum flexural vibration period.

  11. Offshore well support miniplatform

    SciTech Connect

    Blandford, J.W.

    1987-07-14

    This patent describes a protective well support system installed on an offshore well having an upstanding conductor pipe extending above the seabed, the system comprising: (a) an upstanding conductor clamp (adapts to encircle the conductor pipe) formed by two upstanding facing members supported by a bottom engaging frame; (b) the frame including frame members joined together defining a substantially horizontal rectangular support frame for engaging the seabed; (c) angularly extending brace members secured at one end to the conductor clamp and at the other end to the frame; (d) the conductor clamp attaches to the frame and extending upright to enable the conductor clamp to fasten about the conductor pipe; (e) a boat landing mounts about the conductor pipe, the boat landing formed by at least two sectional components fixedly secured to semicircular clamp members adapted to encircle the conductor pipe for mounting the boat landing components; and (f) well platform means supported on bracket means adapted to encircle the conductor pipe for removably securing the well platform means.

  12. Reassessment of offshore platforms

    SciTech Connect

    Nair, V.V.D.; Kuhn, J.M. )

    1993-05-01

    Data from Hurricane Andrew demonstrated that the systems and procedures in place for evacuating offshore workers and minimizing oil spills and environmental damage functioned as planned. While the vast majority of the platforms survived the storm with no damage, a few of the older platforms (installed prior to 1972) either collapsed or suffered severe damage. The collapsed platforms were designed with insufficient deck height to clear the storm waves. In recent years, the API RP 2A has introduced guidance for minimum air gap, minimum structures, platform inspection and platform reuse. These provisions, coupled with natural attribution of the older platforms, will significantly improve the performance of platforms in the future. The reliability of NDT techniques to detect major structural defects should be improved through continued research. While flooded member detection is used by several operators as a screening tool to detect major defects underwater, its reliability is not always good and further research is needed in this area. Another area of high priority research is related to the use of Remotely Operated Vehicles (ROV) to perform underwater inspection of structures. 51 refs., 7 figs.

  13. The Y-chromosome C3* star-cluster attributed to Genghis Khan's descendants is present at high frequency in the Kerey clan from Kazakhstan.

    PubMed

    Abilev, Serikbai; Malyarchuk, Boris; Derenko, Miroslava; Wozniak, Marcin; Grzybowski, Tomasz; Zakharov, Ilya

    2012-02-01

    To verify the possibility that the Y-chromosome C3* star-cluster attributed to Genghis Khan and his patrilineal descendants is relatively frequent in the Kereys, who are the dominant clan in Kazakhstan and in Central Asia as a whole, polymorphism of the Y-chromosome was studied in Kazakhs, represented mostly by members of the Kerey clan. The Kereys showed the highest frequency (76.5%) of individuals carrying the Y-chromosome variant known as C3* star-cluster ascribed to the descendants of Genghis Khan. C3* star-cluster haplotypes were found in two subclans, Abakh-Kereys and Ashmaily-Kereys, diverged about 20-22 generations ago according to the historical data. Median network of the Kerey star-cluster haplotypes at 17 STR loci displays a bipartite structure, with two subclusters defined by the only difference at the DYS448 locus. Noteworthy is a strong correspondence of these subclusters with the Kerey subclans affiliation. The data obtained suggest that the Kerey clan appears to be the largest known clan in the world descending from a common Y-chromosome ancestor. Possible ways of Genghis Khan's relationship to the Kereys are discussed.

  14. Preliminary catalog of the sedimentary basins of the United States

    USGS Publications Warehouse

    Coleman, James L.; Cahan, Steven M.

    2012-01-01

    One hundred forty-four sedimentary basins (or groups of basins) in the United States (both onshore and offshore) are identified, located, and briefly described as part of a Geographic Information System (GIS) data base in support of the Geologic Carbon Dioxide Sequestration National Assessment Project (Brennan and others, 2010). This catalog of basins is designed to provide a check list and basic geologic framework for compiling more detailed geologic and reservoir engineering data for this project and other future investigations.

  15. Sanaga Sud field - Offshore Cameroon, west Africa

    SciTech Connect

    Pauken, R.J. )

    1990-09-01

    The Sanaga Sud field, offshore Cameroon, is located just northwest of the coastal town of Kribi in the northern part of the Douala basin. The discovery well, Sanaga Sud A-1, was drilled in 1979 to test an apparent horst block that contained a prominent horizontal seismic amplitude. The Douala basin is one of a series of passive margin basins located along the coastline of central and southern Africa, and formed during the rifting of Africa and South America during the Early Cretaceous. Drilling results showed that the amplitude was a gas/water contact. Two appraisal wells, SSA-2 and SSA-3, were drilled in 1981. All three wells tested gas and condensate. Total recoverable hydrocarbons for the field are estimated to be approximately 1 tcf of gas. The trap in this field is composed of tilted and rotated fault blocks composed of interbedded Aptian to Albian sandstones, siltstones, and shales. The fault blocks were truncated by erosion (breakup unconformity) and later buried by a considerable thickness of onlapping Upper Cretaceous and Tertiary shale. The late Albian erosional unconformity forms the top of the trap over most of the field. Geochemical studies indicate a Lower Cretaceous source for the hydrocarbons. The gross pay thickness averages 250 m with an average porosity of 23% and an average permeability of 142 md. Reservoir lithologies range from well-sorted, massive sandstones to poorly sorted fine sandstones and siltstones containing shaly laminations that are carbonaceous and micaceous. The field is located predominantly in Block PH-38, but part of the field is in the Londji concession. Mobil Producing Cameroon, Inc., is the operator of PH-38 and Total Exploration and Production Cameroon is the operator of the Londji concession.

  16. Large internal waves in Massachusetts Bay transport sediments offshore

    USGS Publications Warehouse

    Butman, B.; Alexander, P.S.; Scotti, A.; Beardsley, R.C.; Anderson, S.P.

    2006-01-01

    A field experiment was carried out in Massachusetts Bay in August 1998 to assess the role of large-amplitude internal waves (LIWs) in resuspending bottom sediments. The field experiment consisted of a four-element moored array extending from just west of Stellwagen Bank (90-m water depth) across Stellwagen Basin (85- and 50-m water depth) to the coast (24-m water depth). The LIWs were observed in packets of 5–10 waves, had periods of 5–10 min and wavelengths of 200–400 m, and caused downward excursions of the thermocline of as much as 30 m. At the 85-m site, the current measured 1 m above bottom (mab) typically increased from near 0 to 0.2 m/s offshore in a few minutes upon arrival of the LIWs. At the 50-m site, the near-bottom offshore flow measured 6 mab increased from about 0.1 to 0.4–0.6 m/s upon arrival of the LIWs and remained offshore in the bottom layer for 1–2 h. The near-bottom currents associated with the LIWs, in concert with the tidal currents, were directed offshore and sufficient to resuspend the bottom sediments at both the 50- and 85-m sites. When LIWs are present, they may resuspend sediments for as long as 5 hours each tidal cycle as they travel westward across Stellwagen Basin. At 85-m water depth, resuspension associated with LIWs is estimated to occur for about 0.4 days each summer, about the same amount of time as caused by surface waves.

  17. The effect of a knowledge-based ergonomic intervention amongst administrators at Aga Khan University Hospital, Nairobi.

    PubMed

    Wanyonyi, Nancy; Frantz, Jose; Saidi, Hassan

    2015-01-01

    Low back pain (LBP) and neck pain are part of the common work-related musculoskeletal disorders with a large impact on the affected person. Despite having a multifactorial aetiology, ergonomic factors play a major role thus necessitating workers' education. To determine the prevalence of ergonomic-related LBP and neck pain, and describe the effect of a knowledge-based ergonomic intervention amongst administrators in Aga Khan University Hospital, Nairobi. This study applied a mixed method design utilizing a survey and two focus group discussions (FGD). A self-administered questionnaire was distributed to 208 participants through systematic sampling. A one hour knowledge-based ergonomic session founded on the survey results was thereafter administered to interested participants, followed by two FGDs a month later with purposive selection of eight participants to explore their experience of the ergonomic intervention. Quantitative data was captured and analyzed using SPSS by means of descriptive and inferential statistics, whereas thematic content analysis was used for qualitative data. Most participants were knowledgeable about ergonomic-related LBP and neck pain with a twelve month prevalence of 75.5% and 67.8% respectively. Continual ergonomic education is necessary for adherence to health-related behaviours that will preventwork-related LBP and neck pain.

  18. Fluoride enrichment in groundwater of semi-arid urban area: Khan Younis City, southern Gaza Strip (Palestine)

    NASA Astrophysics Data System (ADS)

    Abu Jabal, Mohamed Shaban; Abustan, Ismail; Rozaimy, Mohd Remy; Al-Najar, Hussam

    2014-12-01

    The aim of this study is to determine fluoride enhancement in the groundwater of semi-arid urban area of Khan Younis City, southern Gaza Strip. Physicochemical data for a total of 200 groundwater samples were analyzed. The fluoride concentrations were varied from 0.3 to 6.45 mg/L with average value of 2.87 mg/L. Correlations between fluorides with other measured ions were relatively observed, negative correlation with calcium and the positive correlation with pH, bicarbonate and sodium increase the dissolution/solubility of fluoride bearing minerals, leading to fluoride leaching into the groundwater. Fluoride enrichment in the groundwater of the area is due to water hydrochemistry, mineral-water interaction (mainly calcite and fluorite), fluorite resulted from fluorapatite dissolution. The saturation indexes evaluation indicated that 42% of the samples are over saturated with respect to calcite and 35.5% under saturated with respect to fluorite, while 40.5% approached equilibrium with respect to both calcite and fluorite. At fluoride concentrations of less than 2.2 mg/L fluorite saturation indexes show under-saturation condition for fluorite and at higher fluoride concentrations show near saturation condition.

  19. Long Term Observations of Subsurface Pore Pressure in the Kumano Basin and Upper Accretionary Wedge along the NanTroSIEZE Transect, offshore Japan: Signals from the 2011 Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Saffer, D. M.

    2013-12-01

    Subsurface pore pressure as a sensitive measure of strain and formation properties has provided insights into the wide range of fault slip behaviors, contributing to the understanding of fault and earthquake mechanics. Pore pressures from off shore borehole observatory are especially important, as 1) they are the only detectable signals of small and slow events; 2) they provide our only access to the outer forearc, where the tsunami hazards are triggered by the fault slip. As part of the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) a suite of borehole sensors were installed as part of a long-term borehole observatory at IODP Site C0002, during IODP Expedition # 332 in December of 2010. The observatory includes a broadband seismometer, short period geophones, a volumetric strainmeter, temperature sensors, an accelerometer, and formation pore pressure monitoring at two depths: one in the mudstones of the Kumano Basin in an interval spanning 757-780 meters below seafloor (mbsf), and a second in the uppermost accretionary wedge in an interval from 937 - 980 mbsf. Here, we report on pore pressure records acquired at a sampling frequency of 1/60 Hz, spanning the period from December 2010 to January 2013, which were recovered in early 2013. We observe a clear hydraulic signal from March 11, 2011 Tohoku earthquake and aftershocks, including both dynamic pore pressure changes during passage of surface waves and shifts in formation pressure following the event. Pressure exhibit an increase of ~3 kPa in the upper sediment screened interval following the earthquake, and decrease by ~5 kPa in the accretionary prism interval. Both of the offset changes persist through the end of the data recording. These pore pressure changes may reflect static stress changes from the earthquake, or local site effects related to shaking. We also observe a clear increase in formation pore pressures associated with drilling operations at nearby holes in November and December 2012. These

  20. Offshore Wind Energy Market Overview (Presentation)

    SciTech Connect

    Baring-Gould, I.

    2013-07-01

    This presentation describes the current international market conditions regarding offshore wind, including the breakdown of installation costs, how to reduce costs, and the physical siting considerations considered when planning offshore wind construction. The presentation offers several examples of international existing and planned offshore wind farm sites and compares existing international offshore resources with U.S. resources. The presentation covers future offshore wind trends and cites some challenges that the United States must overcome before it will be able to fully develop offshore wind sites.

  1. Spring sapping on the lower continental slope, offshore New Jersey

    USGS Publications Warehouse

    Robb, James M.

    1984-01-01

    Undersea discharge of ground water during periods of lower sea level may have eroded valleys on part of the lower continental slope, offshore New Jersey. Steep-headed basins, cliffed and terraced walls, and irregular courses of these valleys may have been produced by sapping of exposed near-horizontal Tertiary strata. Joints in Eocene calcareous rocks would have localized ground-water movement. Some karstlike features of the submarine topography and the outcrops suggest that solution of the calcareous rocks also took place.

  2. Spring sapping on the lower continental slope, offshore New Jersey

    USGS Publications Warehouse

    Robb, James M.

    1984-01-01

    Undersea discharge of ground water during periods of lower sea level may have eroded valleys on part of the lower continental slope, offshore New Jersey. Steep-headed basins, cliffed and terraced walls, and irregular courses of these valleys may have been produced by sapping of exposed near-horizontal Tertiary strata. Joints in Eocene calcareous rocks would have localized ground-water movement. Some karstlike features of the submarine topography and the outcrops suggest that solution of the calcareous rocks also took place.

  3. Offshore Energy Knowledge Exchange Workshop Report

    SciTech Connect

    none,

    2012-04-12

    A report detailing the presentations and topics discussed at the Offshore Energy Knowledge Exchange Workshop, an event designed to bring together offshore energy industry representatives to share information, best practices, and lessons learned.

  4. 78 FR 27913 - Revision of Crane Regulation Standards for Mobile Offshore Drilling Units (MODUs), Offshore...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-13

    ... for Mobile Offshore Drilling Units (MODUs), Offshore Supply Vessels (OSVs), and Floating Outer... testing of cranes. These regulations apply to cranes installed on Mobile Offshore Drilling Units (MODUs... Maritime Organization MODU Mobile offshore drilling unit NFPA National Fire Protection Association NPRM...

  5. Development drilling problems offshore Malaysia

    SciTech Connect

    Osman, M.N.; Maung, M.

    1984-02-01

    This paper highlights the major drilling problems encountered in the field development programmes offshore Malaysia from 1978 to mid-1983. The major problems identified were pipe sticking which was common in all the areas and top hole drilling problems encountered in a few fields offshore Sabah and Sarawak. Generally, the problems were related to drilling deviated wells through the soft and unconsolidated formations common in this region. Preventive measures employed by the Contractors have been effective in overcoming these problems in the later years of the period under consideration.

  6. Offshore wind farm layout optimization

    NASA Astrophysics Data System (ADS)

    Elkinton, Christopher Neil

    Offshore wind energy technology is maturing in Europe and is poised to make a significant contribution to the U.S. energy production portfolio. Building on the knowledge the wind industry has gained to date, this dissertation investigates the influences of different site conditions on offshore wind farm micrositing---the layout of individual turbines within the boundaries of a wind farm. For offshore wind farms, these conditions include, among others, the wind and wave climates, water depths, and soil conditions at the site. An analysis tool has been developed that is capable of estimating the cost of energy (COE) from offshore wind farms. For this analysis, the COE has been divided into several modeled components: major costs (e.g. turbines, electrical interconnection, maintenance, etc.), energy production, and energy losses. By treating these component models as functions of site-dependent parameters, the analysis tool can investigate the influence of these parameters on the COE. Some parameters result in simultaneous increases of both energy and cost. In these cases, the analysis tool was used to determine the value of the parameter that yielded the lowest COE and, thus, the best balance of cost and energy. The models have been validated and generally compare favorably with existing offshore wind farm data. The analysis technique was then paired with optimization algorithms to form a tool with which to design offshore wind farm layouts for which the COE was minimized. Greedy heuristic and genetic optimization algorithms have been tuned and implemented. The use of these two algorithms in series has been shown to produce the best, most consistent solutions. The influences of site conditions on the COE have been studied further by applying the analysis and optimization tools to the initial design of a small offshore wind farm near the town of Hull, Massachusetts. The results of an initial full-site analysis and optimization were used to constrain the boundaries of

  7. Colloidal origin of colloform-banded textures in the Paleogene low-sulfidation Khan Krum gold deposit, SE Bulgaria

    NASA Astrophysics Data System (ADS)

    Marinova, Irina; Ganev, Valentin; Titorenkova, Rositsa

    2014-01-01

    We studied both colloform-banded macro- and micro-textures as well as the composition of electrum from the epithermal Khan Krum (or Ada Tepe) gold deposit, Bulgaria (5 Mt at 5.1 g/t Au + 2.7 g/t Ag) using optical and electron scanning microscopy, vibration spectroscopy, electron micro-probe analysis, and LA-ICP-MS. The individual textural bands differ in grain size, porosity, quartz-to-adularia ratio, and abundance of electrum, pyrite, and scattered dusty opaque micro-inclusions. The individual macro-bands have formed successively via intermittent fault dilation from episodic hydrothermal pulses, as a result of regional extension and most likely originated from colloidal solutions formed by vigorous boiling during rapid pressure drop and supersaturation with respect to amorphous silica in a closed or quasi-closed hydrothermal system. Electrum is highly concentrated in the finest quartz-adularia colloform micro-bands, which fill joints with widths up to 1-2 mm. We presume that the joints have filled in with more concentrated colloidal solutions than those in the macro-bands, most likely due to extreme boiling of fluids in open or quasi-open hydrothermal system. Electrum in the micro-bands forms transverse dendrite- and chain-like aggregates as well as oval clots along the banding, all of globular morphology. We explain these locations of electrum with reorientation of aggregated electrum globules during plastic deformation of a mixed electrum-silicate gel and in result from the consequent crystallization of silicates. At the same time, electrum is not present in pores and cracks of syneresis, which indicates that it had not been a soluble phase at the time of syneresis, rather colloidal particles. Electrum also forms dense sprinkles of globular morphology deposited in open space on the surfaces of some quartz-adularia bands, due to a condensation of gaseous phase, separated during the boiling of fluids. We found that the electrum-rich quartz-adularia micro

  8. High-resolution imagery of active faulting offshore Al Hoceima, Northern Morocco

    NASA Astrophysics Data System (ADS)

    d'Acremont, E.; Gutscher, M.-A.; Rabaute, A.; Mercier de Lépinay, B.; Lafosse, M.; Poort, J.; Ammar, A.; Tahayt, A.; Le Roy, P.; Smit, J.; Do Couto, D.; Cancouët, R.; Prunier, C.; Ercilla, G.; Gorini, C.

    2014-09-01

    Two recent destructive earthquakes in 1994 and 2004 near Al Hoceima highlight that the northern Moroccan margin is one of the most seismically active regions of the Western Mediterranean area. Despite onshore geodetic, seismological and tectonic field studies, the onshore-offshore location and extent of the main active faults remain poorly constrained. Offshore Al Hoceima, high-resolution seismic reflection and swath-bathymetry have been recently acquired during the Marlboro-2 cruise. These data at shallow water depth, close to the coast, allow us to describe the location, continuity and geometry of three active faults bounding the offshore Nekor basin. The well-expressed normal-left-lateral onshore Trougout fault can be followed offshore during several kilometers with a N171°E ± 3° trend. Westward, the Bousekkour-Aghbal normal-left-lateral onshore fault is expressed offshore with a N020°E ± 4° trending fault. The N030°E ± 2° Bokkoya fault corresponds to the western boundary of the Plio-Quaternary offshore Nekor basin in the Al Hoceima bay and seems to define an en échelon tectonic pattern with the Bousekkour-Aghbal fault. We propose that these three faults are part of the complex transtensional system between the Nekor fault and the Al-Idrissi fault zone. Our characterization of the offshore expression of active faulting in the Al Hoceima region is consistent with the geometry and nature of the active fault planes deduced from onshore geomorphological and morphotectonic analyses, as well as seismological, geodetic and geodynamic data.

  9. Eighteenth annual offshore technology conference. Volume 1

    SciTech Connect

    Not Available

    1986-01-01

    These sixty papers were given at a conference on offshore technology. Topics covered include friction effects of driving piles into sea beds of various compositions, wave forces on offshore platforms, stability, materials testing of various components such as plates, legs, wellheads, pipe joints, and protection of offshore platforms against ice and collision with icebergs.

  10. Foundations for offshore wind turbines.

    PubMed

    Byrne, B W; Houlsby, G T

    2003-12-15

    An important engineering challenge of today, and a vital one for the future, is to develop and harvest alternative sources of energy. This is a firm priority in the UK, with the government setting a target of 10% of electricity from renewable sources by 2010. A component central to this commitment will be to harvest electrical power from the vast energy reserves offshore, through wind turbines or current or wave power generators. The most mature of these technologies is that of wind, as much technology transfer can be gained from onshore experience. Onshore wind farms, although supplying 'green energy', tend to provoke some objections on aesthetic grounds. These objections can be countered by locating the turbines offshore, where it will also be possible to install larger capacity turbines, thus maximizing the potential of each wind farm location. This paper explores some civil-engineering problems encountered for offshore wind turbines. A critical component is the connection of the structure to the ground, and in particular how the load applied to the structure is transferred safely to the surrounding soil. We review previous work on the design of offshore foundations, and then present some simple design calculations for sizing foundations and structures appropriate to the wind-turbine problem. We examine the deficiencies in the current design approaches, and the research currently under way to overcome these deficiencies. Designs must be improved so that these alternative energy sources can compete economically with traditional energy suppliers.

  11. China offshore has top priority

    SciTech Connect

    Cornitius, T.A.

    1983-11-01

    Joint venture development of offshore petroleum reserves has top priority in the mammoth effort to modernize the People's Republic of China. While the country works to overcome a critical shortage of skilled personnel, export of oil, coal, consumer goods, and metals will finance technological imports.

  12. The offshore benthic fish community

    USGS Publications Warehouse

    Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

    2014-01-01

    The offshore benthic fish community will be composed of self-sustaining native fishes characterized by lake trout as the top predator, a population expansion of lake whitefish from northeastern waters to other areas of the lake, and rehabilitated native prey fishes.

  13. Proceedings of Offshore Europe 91

    SciTech Connect

    Not Available

    1991-01-01

    All papers in this volume were presented at Offshore Europe held in Aberdeen, Scotland, September 3--6, 1991. Included are the following papers: Low-damage-fluid-loss control for well completions; Isolation techniques for subsea gas pipelines; New water injection technology.

  14. Numerical and experimental analysis of a retrievable offshore loading facility

    SciTech Connect

    Sterndorff, M.J.; O`Brien, P.

    1995-12-31

    ROLF (Retrievable Offshore Loading Facility) has been proposed as an alternative offshore oil export tanker loading system for the North Sea. The system consists of a flexible riser ascending from the seabed in a lazy wave configuration to the bow of a dynamically positioned tanker. In order to supplant and support the numerical analyses performed to design the system, an extensive model test program was carried out in a 3D offshore basin at scale 1:50. A model riser with properties equivalent to the properties of the oil filled prototype riser installed in seawater was tested in several combinations of waves and current. During the tests the forces at the bow of the tanker and at the pipeline end manifold were measured together with the motions of the tanker and the riser. The riser motions were measured by means of a video based 3D motion monitoring system. Of special importance was accurate determination of the minimum bending radius for the riser. This was derived based on the measured riser motions. The results of the model tests were compared to numerical analyses by an MCS proprietary riser analysis program.

  15. National Offshore Wind Energy Grid Interconnection Study

    SciTech Connect

    Daniel, John P.; Liu, Shu; Ibanez, Eduardo; Pennock, Ken; Reed, Greg; Hanes, Spencer

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systems most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.

  16. Quantifying the Hurricane Risk to Offshore Wind Power (Invited)

    NASA Astrophysics Data System (ADS)

    Apt, J.; Rose, S.; Jaramillo, P.; Small, M.

    2013-12-01

    The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. Whether that risk will grow as a result of climate change is uncertain. Recent years have seen an increase in hurricane activity in the Atlantic basin (1) and, all else being equal, warmer sea surface temperatures can be expected to lead to increased storm intensity. We have developed a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes (2). In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously due to hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk. 1. Iris Grossmann and M. Granger Morgan, "Tropical Cyclones, Climate Change, and Scientific Uncertainty: What do we know, what does it mean, and what should be done?," Climatic Change, 108, pp 543-579, 2011. 2. Carnegie Mellon Electricity Industry Center Working Paper CEIC-13-07, http://wpweb2.tepper.cmu.edu/electricity/papers/ceic-13-07.asp This work was supported in part by the EPA STAR fellowship program, a grant from the Alfred P. Sloan Foundation and EPRI to the Carnegie Mellon Electricity Industry Center, and by the Doris Duke Charitable Foundation, the R.K. Mellon Foundation and the Heinz Endowments for support of the RenewElec program at Carnegie Mellon University. This research was also supported in part by the Climate and

  17. Modelling Forearc Basin Formation and Stratigraphy

    NASA Astrophysics Data System (ADS)

    Mannu, Utsav; Ueda, Kosuke; Willett, Sean; Gerya, Taras; Strasser, Michael

    2017-04-01

    Comparison of synthetic stratigraphy of forearc basins as generated in coupled plate subduction and accretionary wedge models to the stratal patterns observed for forearc basins in nature, could be used to ascertain the dynamic consistency of the interpreted deformational history of the wedge. Additionally, it could help us understand the emergence of stratigraphic patterns in forearc basins as an interplay between sedimentary flux and wedge dynamics. Here we present a simple methodology to generate synthetic stratigraphy by emplacing isochronal surfaces during the evolution of the wedge. We use a dynamic 2D, high-resolution, thermo-mechanical, subduction model coupled to an adaptive irregular surface grid to model the free surface. In this model, we track basin stratigraphy developing in the wedge top basins atop the accretionary prism by emplacing lines of Lagrangian markers at discrete times along the upper surface of the model, which subsequently are buried, transported, and deformed according to the velocity field generated in the model. We conduct numerical experiments to identify the stratigraphic signatures of different forearc basin formation mechanisms. We also study the impact of hinterland and trench sedimentation on the wedge evolution and its impact on forearc basin formation. Forearc basins that form on top of the overriding plate remain passive to the deformation history of the wedge. Forearc basins formed as negative alpha basins remain mostly undeformed. Forearc basins that form due to wedge stabilization exhibit landward tilting of strata with time. We also find that trench sedimentation enhances the landward tilting of the basin by shifting deformation landwards and potentially triggering out-of-sequence-thrust emergence/reactivation. Predicted stratigraphic features in our numerical models agree well with stratigraphic patterns observed in different types of forearc basins in the Nankai Trough, Sunda Strait and Lombok Basin offshore Japan, Java

  18. Promise seen in Petrel sub-basin off northwestern Australia

    SciTech Connect

    Maung, T.U.; Passmore, V. )

    1995-01-30

    The Australian government during the past 11 years has been regularly releasing vacant areas on the Australian continental shelf for exploration. Although Australia's offshore basins cover an area of 12 million sq km, only about 1,100 exploration and development wells have been drilled, and most of the basins are underexplored by world standards. One of these areas is the Petrel sub-basin of the Bonaparte basin in water shallower than 100 m off Northwest Australia. The government recently released six areas in the southern offshore Petrel subbasin for petroleum exploration. The results of a study by the Petroleum Resources Branch of the bureau of Resource Sciences have been synthesized into a Petrel Sub-basin Bulletin, some selections of which are discussed in this article. Although there are over 44,000 km of seismic data recorded in the sub-basin, the quality of pre-1979 data is very poor to poor, and only 15,800 km of data recorded between 1980--94 (including 1,000 km of 3D seismic data over the Barnett structure) are of fair to good quality. The paper describes the regional geology, reservoir and seals, source rocks, and types of geologic traps. The study identified over 30 structures and leads in the offshore southern Petrel sub-basin. Significant opportunities exist for delineation and definition of drillable prospects in this promising Australian petroleum province.

  19. Calibration and Validation of a Spar-Type Floating Offshore Wind Turbine Model using the FAST Dynamic Simulation Tool: Preprint

    SciTech Connect

    Browning, J. R.; Jonkman, J.; Robertson, A.; Goupee, A. J.

    2012-11-01

    In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50th scale in a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states.

  20. Effects of altered offshore food webs on coastal ecosystems emphasize the need for cross-ecosystem management.

    PubMed

    Eriksson, Britas Klemens; Sieben, Katrin; Eklöf, Johan; Ljunggren, Lars; Olsson, Jens; Casini, Michele; Bergström, Ulf

    2011-11-01

    By mainly targeting larger predatory fish, commercial fisheries have indirectly promoted rapid increases in densities of their prey; smaller predatory fish like sprat, stickleback and gobies. This process, known as mesopredator release, has effectively transformed many marine offshore basins into mesopredator-dominated ecosystems. In this article, we discuss recent indications of trophic cascades on the Atlantic and Baltic coasts of Sweden, where increased abundances of mesopredatory fish are linked to increased nearshore production and biomass of ephemeral algae. Based on synthesis of monitoring data, we suggest that offshore exploitation of larger predatory fish has contributed to the increase in mesopredator fish also along the coasts, with indirect negative effects on important benthic habitats and coastal water quality. The results emphasize the need to rebuild offshore and coastal populations of larger predatory fish to levels where they regain their control over lower trophic levels and important links between offshore and coastal systems are restored.

  1. How dangerous is offshore drilling

    SciTech Connect

    McIntosh, T.S.

    1981-08-01

    As concluded by the National Research Council, the frequency of injuries during oil and gas operations on the outer continental shelf is comparable to that in other industries such as mining, maritime service, and heavy construction. Although an area of concern, offshore safety is not easily improved by legislation or detailed regulation. The industry itself must be committed to providing the safest possible workplace for the job and the environment. At Zapata Off-Shore Co., for example, top management recognizes the value of safety-trained personnel in terms of not only decreased downtime and lower insurance costs but also improved crew morale and productivity. The key operatives of Zapata's program are the rig representatives who provide full-time, rig-based safety, training, administrative, and employee-relations assistance to the crews.

  2. Offshore drilling platform protection device

    SciTech Connect

    Magill, J.M.

    1981-12-15

    A description is given of an offshore drilling platform protection device for use on an offshore oil well drilling vessel including a drilling platform supportable on a plurality of extendable legs wherein each leg is moved by a rack gear assembly. The rack gear assembly includes an otherwise exposed first gear which engages a second gear positioned in a housing having a rectangular corner opening through which the first gear extends, the protection device including first and second protective sections adapted for mounting over the first gear adjacent to the rectangular corner of the housing for the second gear, the first and second protective sections cooperating to provide an l-shaped opening which communicates with the opening at the second gear housing for protecting the first gear while allowing the first gear to mesh with the second gear.

  3. Caloris Basin

    NASA Image and Video Library

    1999-12-07

    Caloris Basin on Mercury, is one of the largest basins in the solar system, its diameter exceeds 1300 kilometers and is in many ways similar to the great Imbrium basin on the Moon. This image is from NASA Mariner 10 spacecraft which launched in 1974.

  4. Fatigue handbook: Offshore steel structures

    SciTech Connect

    Almarnaess, A.

    1985-01-01

    The contents of this book are: Overview of Offshore Steel Structures; Loads on Ocean Structures; Fracture Mechanics As a Tool in Fatigue Analysis; Basic Fatigue Properties of Welded Joints; Significance of Defects; Improving the Fatigue Strength of Welded Joints; Effects of Marine Environment and Cathodic Protection on Fatigue of Structural Steels Fatigue of Tubular Joints; Unstable Fracture; Fatigue Life Calculations; and Fatigue in Building Codes Background and Applications.

  5. Pipelaying in artic offshore waters

    SciTech Connect

    Langner, C. G.

    1985-11-19

    The present invention provides a method and apparatus for constructing pipelines in Arctic offshore waters by a directional drilling technique, thereby minimizing exposure to ice gouging and eliminating the hazards associated with unstable permafrost. A special drilling-pipe-line construction vessel is also provided which has a conical shape with reinforced outer walls to resist ice forces, which vessel includes means to install deep underground pipeline segments and means to connect and protect the pipe ends.

  6. Two offshore Australian crudes assayed

    SciTech Connect

    Rhodes, A.K.

    1994-05-09

    Two light, sweet crudes from offshore Australia have been assayed. Gippsland crude, also called Bass Strait, is produced off the coast of Victoria, in southeastern Australia. The 47 API, 0.09% sulfur crude was analyzed in mid-1993. Skua, a 42 API, 0.06 wt % sulfur crude, is produced in the Timor Sea. Data are given on the whole crude and fractions for both deposits. Both chemical and physical properties are listed.

  7. Offshore sand and gravel mining

    SciTech Connect

    Pandan, J.W.

    1983-05-01

    This paper reviews the status of mining offshore for sand and gravel on a world-wide basis. It discusses the technology for exploration and evaluation of sea floor mineral targets, as well as mining, transportation, and processing. Large operations in Japan and Europe are described, based upon personal observations of the author. The U.S. situation is outlined and opinions offered as to the outlook for the future.

  8. The Math of Khan

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2013-01-01

    It's like a dream come true for educators: free resources available wherever a web browser can operate and with nary an iota of advertising. What's not to like? What is it about this organization, whose mission is "to provide a free, world-class education for anyone anywhere," that has provoked such vitriol? Part of it is that when its videos have…

  9. The Math of Khan

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2013-01-01

    It's like a dream come true for educators: free resources available wherever a web browser can operate and with nary an iota of advertising. What's not to like? What is it about this organization, whose mission is "to provide a free, world-class education for anyone anywhere," that has provoked such vitriol? Part of it is that when its videos have…

  10. At the tip of a propagating rift - The offshore East African Rift

    NASA Astrophysics Data System (ADS)

    Franke, Dieter; Jokat, Wilfried; Ladage, Stefan; Stollhofen, Harald; Klimke, Jennifer; Lutz, Ruediger; Mahanjane, Stefane; Ehrhardt, Axel; Schreckenberger, Bernd

    2016-04-01

    Numerous studies have addressed various aspects of the East African Rift system (EARS) but surprisingly few the offshore continuation of the south-eastern branch of the rift into the Mozambique Channel. Here, we present new evidence for neotectonic deformation derived from modern seismic reflection data and supported by additional geophysical data. The Kerimbas Graben offshore northern Mozambique is the most prominent manifestation of sub-recent extensional deformation. The seismic reflection data reveals that recent normal faulting often utilizes preexisting, deeply buried half-graben structures which likely are related to the formation of the Somali Basin. The ~30 km wide and ~150 km long symmetric graben is in a stage where the linkage of scattered normal faults already did happen, resulting in increased displacement and accommodation of most of the extension across the basin. However, deep earthquakes below the rift indicate a strong and still preserved lithospheric mantle. Extension is becoming diffuse where an onshore suture, subdividing the northern from the southern metamorphic basement onshore Mozambique, is closest to the offshore rift. It appears likely that this suture is the origin for the variation in rifting style, indicating that mantle fabric resulting from a Cambrian collision has been preserved as mechanical anisotropy of the lithospheric mantle. Further south the rift focuses in an about 30 km wide half-graben. An important finding is that the entire offshore branch of the EARS lacks significant volcanism. Along the offshore EARS there are only negligible indications for recent volcanism in the reflection seismic data such as sills and dikes. Apparently the "Comoros mantle plume" (French and Romanowicz, 2015) has a very minor influence on the progressive extensional deformation along the northern Mozambique continental margin, leading eventually to breakup sometimes in the future. Combining structural with earthquake data reveals that the magma

  11. Offshore oil: Correctness of perspective

    SciTech Connect

    Burns, R.F.

    1993-05-01

    Except for the Gulf of Mexico, the offshore oil industry has been virtually banned from the US Exclusive Economic Zone for ten years. The oil potential in Alaska's Arctic National Wildlife Refuge (ANWR) is also off limits. The Gulf of Mexico is the only place with prospects for future success and a number of companies both large and small are determined to move forward. The depressed price of oil does not encourage development but recently gas prices in the US have increased, making offshore gas development more feasible. Perhaps most significant is development and application of new technology and more intense management to make sure it works. The offshore oil companies and support industries have made significant technological advances, expending over and above the dollars paid in taxes, lease fees, and royalties. The ocean industries harbor a great reservoir of high technology knowledge. They have demonstrated the ability to successfully meet a vast array of challenges in exploring for, drilling, and producing oil and gas in extreme conditions. These facts beg the question as to the rational basis of each and every regulation and the ban on drilling.

  12. Structural development of the western Makran Accretionary Complex, Offshore Iran

    NASA Astrophysics Data System (ADS)

    Burberry, C. M.; Jackson, C. A.

    2013-12-01

    The Makran Accretionary Complex (MAC), which straddles the southern offshore regions of Iran and Pakistan, is a fold-thrust system bound by the Murray Ridge and Ornach Nal Fault to the east, and the Minab Fault System (MFS) to the west. It is c. 1000 km wide and the frontal c. 125 km of the system is submerged beneath the Gulf of Oman. Relatively little is known about this system, despite the fact that constitutes a large portion of the Central Tethyan Orogen and is one of the largest accretionary complexes in the world. We use offshore 2D seismic reflection data to investigate the structural style and evolution of the Iranian segment of the MAC. The MAC is divided into two morphologically distinct domains: (i) a northern domain (Domain 1), which is located landward of a prominant break-in-slope on the seabed and is characterised by a series of normal fault-bound sub-basins that are approximately 50 km wide, and which contain numerous, unconformity-bound seismic units; and (ii) a southern domain (Domain 2), which is located basinward of the prominent seabed slope break, and is characterised by alternating ridges and troughs. Seismic data indicate that these structures are laterally continuous (over 100 km long) north-dipping thrust faults, which are overlain by south-verging, non-cylindrical, fault-propagation folds. Towards the western end of the study area, immediately offshore of the prominent onshore trace of the MFS, there is no single structure that can be reliably interpreted as the offshore extension of the MFS. Instead, a series of oblique-slip faults with thrust and strike-slip components are identified, spanning a zone that is c. 40 km wide. In the north and close to the coastline, the faults are dominantly strike-slip, whereas further south, closer to the deformation front, the thrust-sense component is more important. Irrespective of their slip sense, faults in this zone have a similar N-S strike to the onshore trace of the MFS. In addition, the basin

  13. Chicxulub impact basin: Gravity characteristics and implications for basin morphology and deep structure

    NASA Technical Reports Server (NTRS)

    Sharpton, Virgil L.; Burke, Kevin; Hall, Stuart A.; Lee, Scott; Marin, Luis E.; Suarez, Gerardo; Quezada-Muneton, Juan Manuel; Urrutia-Fucugauchi, Jaime

    1993-01-01

    The K-T-aged Chicxulub Impact Structure is buried beneath the Tertiary carbonate rocks of the Northern Yucatan Platform. Consequently its morphology and structure are poorly understood. Reprocessed Bouguer (onshore) and Free Air (offshore) gravity data over Northern Yucatan reveal that Chicxulub may be a 200-km-diameter multi-ring impact basin with at least three concentric basin rings. The positions of these rings follow the square root of 2 spacing rule derived empirically from analysis of multi-ring basins on other planets indicating that these rings probably correspond to now-buried topographic basin rings. A forward model of the gravity data along a radial transect from the southwest margin of the structure indicates that the Chicxulub gravity signature is compatible with this interpretation. We estimate the basin rim diameter to be 204 +/- 16 km and the central peak ring diameter (D) is 104 +/- 6 km.

  14. Offshore and arctic frontiers -structures, ocean mining

    SciTech Connect

    Chung, J.S.

    1985-05-01

    The systematic development of offshore technology is discussed. Today, this technology enables the production of approximately 14 million barrels of oil per day, or 26% of oil production worldwide. The evolution in offshore structures is examined with emphasis on jacket and jackup platforms. Challenges are explored. Microprocessors, data-base management, and artificial intelligence are mentioned as having an impact on the offshore and arctic oil industry.

  15. Middle and upper Miocene natural gas sands in onshore and offshore Alabama

    SciTech Connect

    Mink, R.M.; Mancini, E.A.; Bearden, B.L.; Smith, C.C.

    1988-09-01

    Thirty Miocene natural gas fields have been established in onshore and offshore Alabama since the discovery of Miocene gas in this area in 1979. These fields have produced over 16 bcf of natural gas from the middle Miocene Amos sand (24 fields) and upper Miocene Luce (3 fields), Escambia (1 field), and Meyer (3 fields) sands. Production from the Amos transgressive sands represents over 92% of the cumulative shallow Miocene natural gas produced in onshore and offshore Alabama. In addition, over 127 bcf of natural gas has been produced from upper Miocene sands in the Chandeleur area. The productive Miocene section in onshore and coastal Alabama is interpreted to present transgressive marine shelf and regressive shoreface sands. The middle Miocene Amos sand bars are the most productive reservoirs of natural gas in onshore and coastal Alabama, principally due to the porous and permeable nature of these transgressive sands and their stratigraphic relationship to the underlying basinal clays in this area. In offshore Alabama the upper Miocene sands become thicker and are generally more porous and permeable than their onshore equivalents. Because of their deeper burial depth in offshore Alabama, these upper Miocene sands are associated with marine clays that are thermally more mature. The combination of reservoir grade lithologies associated with moderately mature petroleum source rocks enhances the natural gas potential of the upper Miocene sands in offshore Alabama.

  16. 1991 worldwide offshore contractors and equipment directory

    SciTech Connect

    Not Available

    1991-01-01

    This book is the information source-book for the international offshore oil industry. Within this single convenient reference you'll find addresses, phone numbers, telex, fax and cable listings for more than 3,500 companies and their key personnel in the drilling, workover, construction, service/supply/manufacturers, geophysical, diving and transportation segments of the offshore industry. Along with this vital contact information, the authors include such pertinent data as rig specifications, ownership, an equipment index, a company index and a current survey of offshore production systems from Offshore Incorporating the Oilman.

  17. The effects of second-order hydrodynamics on a semisubmersible floating offshore wind turbine

    NASA Astrophysics Data System (ADS)

    Bayati, I.; Jonkman, J.; Robertson, A.; Platt, A.

    2014-06-01

    The objective of this paper is to assess the second-order hydrodynamic effects on a semisubmersible floating offshore wind turbine. Second-order hydrodynamics induce loads and motions at the sum- and difference-frequencies of the incident waves. These effects have often been ignored in offshore wind analysis, under the assumption that they are significantly smaller than first-order effects. The sum- and difference-frequency loads can, however, excite eigenfrequencies of a floating system, leading to large oscillations that strain the mooring system or vibrations that cause fatigue damage to the structure. Observations of supposed second-order responses in wave-tank tests performed by the DeepCwind consortium at the Maritime Research Institute Netherlands (MARIN) offshore basin suggest that these effects might be more important than originally expected. These observations inspired interest in investigating how second-order excitation affects floating offshore wind turbines and whether second-order hydrodynamics should be included in offshore wind simulation tools like FAST. In this work, the effects of second-order hydrodynamics on a floating semisubmersible offshore wind turbine are investigated. Because FAST is currently unable to account for second-order effects, a method to assess these effects was applied in which linearized properties of the floating wind system derived from FAST (including the 6x6 mass and stiffness matrices) are used by WAMIT to solve the first- and second-order hydrodynamics problems in the frequency domain. The method was applied to the Offshore Code Comparison Collaboration Continuation OC4-DeepCwind semisubmersible platform, supporting the National Renewable Energy Laboratory's 5-MW baseline wind turbine. In this paper, the loads and response of the system caused by the second-order hydrodynamics are analysed and compared to the first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second-order loads

  18. Petroleum geology of the mid-Atlantic continental margin, offshore Virginia

    USGS Publications Warehouse

    Bayer, K.C.; Milici, R.C.

    1989-01-01

    The Baltimore Canyon Trough, a major sedimentary basin on the Atlantic continental shelf, contains up to 18 km of Mesozoic and Cenozoic strata. The basin has been studied extensively by multichannel common depth point (CDP) seismic reflection profiles and has been tested by drilling for hydrocarbon resources in several places. The Mesozoic and Cenozoic strata contained in the basin were deposited in littoral to bathyal depositional settings and contain immature to marginally mature oil-prone and gas-prone kerogen. The more deeply buried strata of Early Mesozoic age are more likely to be thermally mature than are the younger strata with respect to hydrocarbon generation, but contain terrestrially derived coaly organic matter that would be prone to yield gas, rather than oil. An analysis of available CDP seismic reflection data has indicated that there are several potential hydrocarbon plays in the area offshore of Virginia. These include: (1) Lower Mesozoic synrift basins that appear similar to those exposed in the Appalachian Piedmont, (2) a stratigraphic updip pinchout of strata of Early Mesozoic age in the offshore region near the coast, (3) a deeply buried paleoshelf edge, where seismic reflectors dip sharply seaward; and (4) a Cretaceous/Jurassic shelf edge beneath the present continental rise. Of these, the synrift basins and Cretaceous/Jurassic shelf edge are considered to be the best targets for exploration. ?? 1989.

  19. Post-breakup Basin Evolution along the South-Atlantic Margins

    NASA Astrophysics Data System (ADS)

    Strozyk, Frank; Back, Stefan; Kukla, Peter

    2014-05-01

    The post-breakup tectono-stratigraphic evolution of large offshore basins along the South American and African continental margins record strongly varying post-rift sedimentary successions. The northernmost segment of the South Atlantic rift and salt basins is characterized by a pronounced asymmetry, with the Brazilian margin comprising narrower and deeper rift basins with less salt in comparison to the Congo-Gabon conjugate margin. Another important observation is that multiple phases of uplift and subsidence are recorded after the break-up of the southern South Atlantic on both sides of the Florianopolis-Walvis Ridge volcanic complex, features that are regarded as atypical when compared to published examples of other post-breakup margin successions. A regional comparison based on tectonic-stratigraphic analysis of selected seismic transects between the large basins offshore southern Brazil (Espirito Santo Basin, Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Lower Congo Basin, Kwanza Basin, Namibe Basin, Walvis Basin) provides a comprehensive basin-to-basin documentation of the key geological parameters controlling ocean and continental margin development. This comparison includes the margin configuration, subsidence development through time, sediment influx and storage patterns, type of basin fill (e.g. salt vs. non-salt systems; carbonate-rich vs. clastics-dominated systems) and finally major tectonic and magmatic events. Data from the salt basins indicate that salt-related tectonic deformation is amongst the prime controls for the non-uniform post-rift margin development. The diversity in the stratigraphic architecture of the conjugate margins offshore southern Brazil, Namibia and Angola reflects variations in the interplay of a number of controlling factors, of which the most important are (a) the structural configuration of each margin segment at the time of break-up, (b) the post break-up subsidence history of the respective margin segment

  20. Offshore Socotra, Republic of Yemen: Potential for a new hydrocarbon province?

    SciTech Connect

    Richardson, S.M.; Bott, W.F.; Birse, T.C.R.

    1995-08-01

    A new plate reconstruction has enabled the Island of Socotra, currently located in the Gulf of Aden adjacent to the Somalian coast, to be confidently restored to its original spatial position, adjacent to the southern Omani coastline. New studies integrated with these plate reconstructions, have confirmed the presence of an untested Mesozoic graben, which trends across the Socotra platform. Fieldwork carried out in the region now enables a SE extension of the prolific Lower Cretaceous Qishn `play` (delinated in the Masilah Basin, onshore Yemen) to be postulated offshore into the Gulf of Aden. Following the award of offshore acreage adjacent to the Island of Socotra, exploration studies have confirmed the presence of the Qishn `play` both on the Island of Socotra, and offshore in the one available basin-margin control well. This work has also identified two additional plays: the Shuabia-equivalent carbonates, which are prolific producing reservoirs in central Oman; and the Permo-Triassic clastics, which may provide a new reservoir target for the region. Fieldwork has also identified Jurassic siliclastics outcropping on the Island, which may provide further reservoir potential. Ongoing multidisciplinary studies, integrating the results of a detailed geophysical interpretation with high resolution structural-stratigraphic studies, have confirmed the presence of large structures within an undrilled Mesozoic rift-basin, which will be tested during 1995.

  1. Structure, stratigraphy, and hydrocarbons offshore southern Kalimantan, Indonesia

    SciTech Connect

    Bishop, W.F.

    1980-01-01

    Offshore southern Kalimantan (Borneo), Indonesia, the Sunda Shelf is bounded on the south by the east-west-trending Java-Madura foreland basin and on the north by outcrops of the granitic core of Kalimantan. Major northeast-southwest-trending faults created a basin and ridge province which controlled sedimentation at least until early Miocene time. Just above the unconformity, the oldest pre-CD Limestone clastic strata are fluviatile and lacustrine, the remainder consisting largely of shallow-marine, calcareous shale with interbeds of fine-grained, quartzose sandstone. A flood of terrigenous detritus - Kudjung unit 3 - resulted from post-CD Limestone uplift, and is more widely distributed. Unit 3 consists largely of fluviatile sandstone interbedded with shale and mudstone, grading upward to marine clastics with a few thin limestones near the top. The resulting Kudjing unit 2 is largely a shallow-basinal deposit, comprising thin, micritic limestones interbedded with calcareous shale and mudstone. Infilling of the basins was nearly complete by the end of Kudjing unit 1 deposition. Eastern equivalents of Kudjing units 1 and 2 are known as the Berai limestone interval (comprising bank, reefal, basinal, and open-marine limestones, and marl). Of the three oil fields in the area, two are shut in, but one has produced nearly 100 million bbl. Gas shows were recorded in most wells of the area, but the maximum flow was 1.8 MMcf methane/day, although larger flows with high percentages of carbon dioxide and nitrogen were reported. Fine-grained clastic strata of unit 3 are continuous with those farther south, where geochemical data indicate good source and hydrocarbon-generating potential. Sandstones with reservoir capability are present in the clastic intervals, and several carbonate facies have sporadically developed porosity. A variety of structural and stratigraphic traps is present. 20 figures, 1 table.

  2. Sequence stratigraphic framework of Neogene strata in offshore Nigeria

    SciTech Connect

    Pacht, J.A.; Bowen, B.E.; Hall, D.J.

    1996-08-01

    The western portion of the Nigerian continental margin (Dahomey Basin) exhibits stable to moderately unstable progradation. Systems tracts are similar to those described by Vail for stable progradational margins. In contrast, strata off the central and eastern portions of the Nigerian coast (Niger Delta Complex) exhibit highly unstable progradation, and systems tracts are similar to those in Neogene strata of the offshore Gulf of Mexico. Lowstand basin floor fans in both areas are defined by a well-developed upper reflection. This reflection downlaps along the sequence boundary or abuts against the downthrown side of a growth fault surface. Most lower lowstand (slope fan) strata exhibit discontinuous to semi-continuous subparallel reflections. However, this systems tract also contains channel complexes characterized by chaotic bedding with small bright spots and less common large channels, which exhibit concave-upward reflections. In the western portion of the study area, lower lowstand deposits commonly pinch out on the slope. Deposition occurred largely from point sources. In contrast, contemporaneous shallow-water facies are developed in lower lowstand systems tracts in the Niger Delta Complex. Deposition occurred along a line source. Large amplitude anomalies in the upper lowstand (prograding wedge) suggest well-developed sheet sands occur in shallow-water and deep-water in the Niger Delta complex. However, in the Dahomey Basin there is little evidence of deep-water sands in this interval. The transgressive and highstand systems tracts are usually very thin in outer shelf to basin floor strata in both areas. Both the Dahomey Basin and Niger Delta Complex exhibit different stratigraphic geometries, and therefore, require different exploration strategies.

  3. Potential on-shore and off-shore reservoirs for CO2 sequestration in Central Atlantic magmatic province basalts

    PubMed Central

    Goldberg, David S.; Kent, Dennis V.; Olsen, Paul E.

    2010-01-01

    Identifying locations for secure sequestration of CO2 in geological formations is one of our most pressing global scientific problems. Injection into basalt formations provides unique and significant advantages over other potential geological storage options, including large potential storage volumes and permanent fixation of carbon by mineralization. The Central Atlantic Magmatic Province basalt flows along the eastern seaboard of the United States may provide large and secure storage reservoirs both onshore and offshore. Sites in the South Georgia basin, the New York Bight basin, and the Sandy Hook basin offer promising basalt-hosted reservoirs with considerable potential for CO2 sequestration due to their proximity to major metropolitan centers, and thus to large industrial sources for CO2. Onshore sites are suggested for cost-effective characterization studies of these reservoirs, although offshore sites may offer larger potential capacity and additional long-term advantages for safe and secure CO2 sequestration. PMID:20080705

  4. Potential on-shore and off-shore reservoirs for CO2 sequestration in Central Atlantic magmatic province basalts.

    PubMed

    Goldberg, David S; Kent, Dennis V; Olsen, Paul E

    2010-01-26

    Identifying locations for secure sequestration of CO(2) in geological formations is one of our most pressing global scientific problems. Injection into basalt formations provides unique and significant advantages over other potential geological storage options, including large potential storage volumes and permanent fixation of carbon by mineralization. The Central Atlantic Magmatic Province basalt flows along the eastern seaboard of the United States may provide large and secure storage reservoirs both onshore and offshore. Sites in the South Georgia basin, the New York Bight basin, and the Sandy Hook basin offer promising basalt-hosted reservoirs with considerable potential for CO(2) sequestration due to their proximity to major metropolitan centers, and thus to large industrial sources for CO(2). Onshore sites are suggested for cost-effective characterization studies of these reservoirs, although offshore sites may offer larger potential capacity and additional long-term advantages for safe and secure CO(2) sequestration.

  5. Offshore drilling and production structure

    SciTech Connect

    Crockett, R.K.; Palmer, H.E.; Stenning, D.G.

    1982-02-09

    The invention relates to an off-shore marine structure that provides an elevated support for a drilling and/or production platform. A structure comprised of three interlocking components is provided, the first component being a large foundation base installed on the sea bed; the second being a conical shaped support component which is engagable with the foundation base and which, releasably carries the third platform supporting component. In the preferred form, the platform supporting component comprises a centrally-disposed vertical column, means being provided to facilitate engagement of the column with the platform and the second component and to subsequently elevate the platform to an operating height above sea level.

  6. Bundled pipe speeds offshore laying

    SciTech Connect

    Brockbank, J. )

    1990-05-07

    Technology which allows pipelines to be installed in bundles is expediting pipelay operations in the North Sea. This paper reports how the piggyback system was recently used on 60 km of North Sea gas pipelines for three major projects. For 7 years the practice of installing two or more pipelines in one operation has become an established practice for North Sea offshore oil and gas projects. The technique, commonly referred to as a piggyback operation, reduces installation costs, improves operation reliability, and cuts maintenance time.

  7. Wave slamming on offshore structures

    NASA Astrophysics Data System (ADS)

    Miller, B. L.

    1980-03-01

    Experimental and theoretical work on the slamming of circular cylinders is surveyed. Data are included from controlled drop tests. The influence of inclined impact and beam dynamics on the resulting stresses is calculated for a wide range of wave conditions. The statistical distributions of the estimated stresses are analyzed to provide data for the calculation of slamming loads on fixed offshore structures using simple formulas in which the slamming coefficients incorporate both the member dynamics and the sea wave statistics. Slamming coefficients and associated stress calculation methods are presented for extreme values and fatigue damage. These may also be used for slamming during jacket launching. A film of wave slam was also produced.

  8. Seismic assessment for offshore pipelines

    SciTech Connect

    Bruschi, R.; Gudmestad, O.T.; Blaker, F.; Nadim, F.

    1995-12-31

    An international consensus on seismic design criteria for onshore pipelines has been established during the last thirty years. The need to assess seismic design for offshore pipelines has not been similarly recognized. In this paper, the geotechnical hazard for a pipeline routed across steep slopes and irregular terrains affected by earthquakes, is discussed. The integrity of both natural and artificial load bearing supports is assessed.d The response of the pipeline to direct excitation from soil or through discontinuous, sparsely distributed natural or artificial supports, is commented.

  9. Domestic Options to Offshore Oil and Gas.

    ERIC Educational Resources Information Center

    Kash, Don E.

    1983-01-01

    The continuing controversey over offshore oil/gas has given impetus to searching for domestic energy alternatives. The need for and types of several alternative sources are discussed. Indicates that the United States needs to pursue both offshore and other domestic liquid-fuel sources if it is to avoid becoming increasingly dependent on imports.…

  10. U.S. Offshore Wind Port Readiness

    SciTech Connect

    C. Elkinton, A. Blatiak, H. Ameen

    2013-10-13

    This study will aid decision-makers in making informed decisions regarding the choice of ports for specific offshore projects, and the types of investments that would be required to make individual port facilities suitable to serve offshore wind manufacturing, installation and/or operations.

  11. Domestic Options to Offshore Oil and Gas.

    ERIC Educational Resources Information Center

    Kash, Don E.

    1983-01-01

    The continuing controversey over offshore oil/gas has given impetus to searching for domestic energy alternatives. The need for and types of several alternative sources are discussed. Indicates that the United States needs to pursue both offshore and other domestic liquid-fuel sources if it is to avoid becoming increasingly dependent on imports.…

  12. 31 CFR 547.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 547.406 Section 547.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... REGULATIONS Interpretations § 547.406 Offshore transactions. The prohibitions in § 547.201 on transactions or...

  13. Underbalanced drilling benefits now available offshore

    SciTech Connect

    Vozniak, J.P.; Cuthbertson, B.; Nessa, D.O.

    1997-05-01

    Offshore underbalanced drilling (UBD) is a reality. Applications in older, partially depleted fields and new fields are being considered. However, low productivity reservoirs and fields with sub normal pressures causing drilling problems are currently the main targets for offshore UBD. With proper planning and the correct technique, both jointed pipe and coiled tubing UBD drilling operations have been carried out offshore with success. The main concerns for offshore UBD have been altered drilling practices and surface production system operation. These issues have been examined and equipment has been designed and tested to address them. Environmental, safety and health issues are paramount and have been studied carefully. Detailed well planning, engineering, and flow modeling have proven critical for successful offshore UBD operations. Examples are given from oil and gas fields.

  14. Offshore Wind Market and Economic Analysis

    SciTech Connect

    Hamilton, Bruce Duncan

    2014-08-27

    This report is the third annual assessment of the U.S. offshore wind market. It includes the following major sections: Section 1: key data on developments in the offshore wind technology sector and the global development of offshore wind projects, with a particular focus on progress in the United States; Section 2: analysis of policy developments at the federal and state levels that have been effective in advancing offshore wind deployment in the United States; Section 3: analysis of actual and projected economic impact, including regional development and job creation; Section 4: analysis of developments in relevant sectors of the economy with the potential to affect offshore wind deployment in the United States

  15. Effect of different plant spacing on the production of cauliflower (Brassica oleraceae var. Botrytis) under the agro-climatic conditions of D.I. Khan.

    PubMed

    Mujeeb-ur-Rahman; Iqbal, Muhammad; Jilani, Muhammad Saleem; Waseem, Kashif

    2007-12-15

    A research project to evaluate the effect of different plant spacing on the production of cauliflower was conducted at Horticulture Research Area, Faculty of Agriculture, Gomal University, Dera Ismail Khan, NWFP, Pakistan. Six different plant spacing viz., 30, 35, 40, 45, 50 and 55 cm were used. The results revealed significant variations in all the parameters and amongst various plant spacing, 45 cm spacing showed the best response for all the parameters. Maximum plant height (49.33 cm), curd diameter (19.13 cm), maximum curd weight (1.23 kg plant(-1)) and yield (30.77 t ha(-1)) were recorded in the plots where the plants were spaced 45 cm apart.

  16. Viet Nam steps up offshore E and D push

    SciTech Connect

    Not Available

    1992-06-22

    This paper reports on Viet Nam's offshore exploration and development. Hanoi tentatively awarded three of five remaining blocks of prime offshore South China Sea acreage to companies from Europe and the Far East, with a fourth such award reported imminent. And state owned Petrovietnam signed a production sharing contract (PSC) covering acreage in the same area to a combine of British Petroleum Co. plc and Norway's Den norske stats oljeselskap AS. Retention of one block in the area covered by Viet Nam's second bidding round fueled speculation Hanoi is holding it in reserve for U.S. companies to enter bidding, pending easing of U.S. trade sanctions against Viet Nam, Agence France France (AFP) reported. Second round blocks have been carved from a concession held by Vietsovpetro, a joint venture of Petrovietnam and the former Soviet Union. All are in the southern Con Sun basin of the South China Sea off the port of Vung Tao and on trend with Viet Nam's only producing oil fields.

  17. Drilling optimization in deepwater field development offshore Brazil

    SciTech Connect

    Awad, S.P.; Piazza, M.R.; Nogueira, E.F.

    1995-12-31

    Giant deepwater oilfields had been discovered in Campos Basin, offshore Brazil, through the eighties. After overcoming initial problems while drilling the exploratory wells, appraisal wells were drilled under regular performance standards, comparing to shallow water previous data. At that time, Albacora and Marlim field development plans were considering improved performances to occur due to the expected learning effects. The combination of the simultaneous use of dynamic positioned and deep anchored rigs with the technical improvements in well operations resulted in an outstanding overall drilling performance for the development campaign of those fields. The drilling program was concluded well ahead of schedule, establishing guidelines for future deepwater field exploitation. This paper describes Petrobras experience of planning and drilling deepwater development wells, showing the principal measures and factors that led to an update of the company`s operational standards. Also, the ultra deepwater drilling R and D projects carried out at the moment are briefly introduced, being their aims to keep or even improve the company`s performance and safety records as water depths up to 2,000 m are considered for oilfield developments offshore Brazil in the future.

  18. Comparative management of offshore posidonia residues: composting vs. energy recovery.

    PubMed

    Cocozza, Claudio; Parente, Angelo; Zaccone, Claudio; Mininni, Carlo; Santamaria, Pietro; Miano, Teodoro

    2011-01-01

    Residues of the marine plant posidonia (Posidonia oceanica, PO) beached in tourist zones represent a great environmental, economical, social and hygienic problem in the Mediterranean Basin, in general, and in the Apulia Region in particular, because of the great disturb to the bathers and population, and the high costs that the administrations have to bear for their removal and disposal. In the present paper, Authors determined the heating values of leaves and fibres of PO, the main offshore residues found on beaches, and, meantime, composted those residues with mowing and olive pruning wood. The final composts were characterized for pH, electrical conductivity, elemental composition, dynamic respiration index, phytotoxicity, fluorescence and infrared spectroscopic fingerprints. The aim of the paper was to investigate the composting and energy recovery of PO leaves and fibres in order to suggest alternative solutions to the landfill when offshore residues have to be removed from recreational beaches. The fibrous portion of PO residues showed heating values close to those of other biofuels, thus suggesting a possible utilization as source of energy. At the same time, compost obtained from both PO wastes showed high quality features on condition that the electrical conductivity and Na content are lowered by a correct management of wetting during the composting.

  19. California State Waters Map Series: offshore of Refugio Beach, California

    USGS Publications Warehouse

    Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Krigsman, Lisa M.; Dieter, Bryan E.; Conrad, James E.; Greene, H. Gary; Seitz, Gordon G.; Endris, Charles A.; Sliter, Ray W.; Wong, Florence L.; Erdey, Mercedes D.; Gutierrez, Carlos I.; Yoklavich, Mary M.; East, Amy E.; Hart, Patrick E.; Johnson, Samuel Y.; Cochran, Susan A.

    2015-01-01

    Seafloor habitats in the broad Santa Barbara Channel region consist of significant amounts of soft, unconsolidated sediment interspersed with isolated areas of rocky habitat that support kelp-forest communities nearshore and rocky-reef communities in deep water. The potential marine benthic habitat types mapped in the Offshore of Refugio Beach map area are directly related to its Quaternary geologic history, geomorphology, and active sedimentary processes. These potential habitats, which lie primarily within the Shelf (continental shelf) but also partly within the Flank (basin flank or continental slope) megahabitats, primarily are composed of soft sediment interrupted by a few carbonate mounds. This homogeneous seafloor of sediment and low-relief bedrock provides promising habitat for groundfish, crabs, shrimp, and other marine benthic organisms.

  20. Oil and gas entrapment, Louisiana shelf, offshore Gulf Coast region

    SciTech Connect

    Pratsch, J.C.

    1989-09-01

    Oil and gas accumulations in the Louisiana offshore are caused by vertical hydrocarbon migration. Source beds for both thermal gas and oil lie considerably deeper than reservoirs. The required vertical pathways are steeply dipping faults and salt structures (ridges and diapirs). Faults and salt structures indicate the continuing presence of rift structures that began along a normal passive continental margin during the Pennsylvanian. Tectonic trends are northeast, northwest, north, and west-east; they follow well-established regional stress systems. Listric and growth faults commonly are too shallow for vertical hydrocarbon migration and require connection with vertical faults. Vertical oil and gas migration is predictable in its directions. The underlying geological, geophysical, and geochemical processes are understood and are not different from such processes in other productive basins. Secondary salt layers at shallower levels cause interruptions of vertical oil and gas migration; at the same time these interruptions seem to indicate a large future exploration potential on the Louisiana shelf.

  1. Stratigraphic Signatures of Forearc Basin Formation Mechanisms

    NASA Astrophysics Data System (ADS)

    Mannu, U.; Ueda, K.; Gerya, T.; Willett, S.; Strasser, M.

    2014-12-01

    Forearc basins are loci of active sedimentation above the landward portion of accretionary prisms. Although these basins typically remain separated from the frontal prism by a forearc high, their evolution has a significant impact on the structure and deformation of the entire wedge. Formation of forearc basins has been proposed as a consequence of changes in wedge stability due to an increase of slab dip in subduction zones. Another hypothesis attributes this to higher hinterland sedimentation, which causes the rear of the wedge to stabilize and eventually develop a forearc basin. Basin stratigraphic architecture, revealed by high-resolution reflection seismic data and borehole data allows interpretation of structural development of the accretionary prism and associated basins with the goal of determining the underlying driving mechanism(s) of basin formation. In this study we supplement data interpretation with thermo-mechanical numerical models including high-resolution isochronal surface tracking to visualize the developing stratigraphy of basins that develop in subduction zone and wedge dynamic models. We use a dynamic 2D thermo mechanical model incorporating surface processes, strain weakening and sediment subduction. The model is a modification of I2VIS model, which is based on conservative, fully staggered finite differences and a non-diffusive marker- in-cell technique capable of modelling mantle convection. In the model different driving mechanisms for basin formation can be explored. Stratigraphic simulations obtained by isochronal surface tracking are compared to reflection pattern and stratigraphy of seismic and borehole data, respectively. Initial results from a model roughly representing the Nankai Trough Subduction Zone offshore Japan are compared to available seismic and Integrated Ocean Drilling (IODP) data. A calibrated model predicting forearc basin stratigraphy will be used to discern the underlying process of basins formation and wedge

  2. OC5 Project Phase Ib: Validation of hydrodynamic loading on a fixed, flexible cylinder for offshore wind applications

    DOE PAGES

    Robertson, Amy N.; Wendt, Fabian; Jonkman, Jason M.; ...

    2016-10-13

    This paper summarizes the findings from Phase Ib of the Offshore Code Comparison, Collaboration, Continued with Correlation (OC5) project. OC5 is a project run under the International Energy Agency (IEA) Wind Research Task 30, and is focused on validating the tools used for modelling offshore wind systems through the comparison of simulated responses of select offshore wind systems (and components) to physical test data. For Phase Ib of the project, simulated hydrodynamic loads on a flexible cylinder fixed to a sloped bed were validated against test measurements made in the shallow water basin at the Danish Hydraulic Institute (DHI) withmore » support from the Technical University of Denmark (DTU). The first phase of OC5 examined two simple cylinder structures (Phase Ia and Ib) to focus on validation of hydrodynamic models used in the various tools before moving on to more complex offshore wind systems and the associated coupled physics. As a result, verification and validation activities such as these lead to improvement of offshore wind modelling tools, which will enable the development of more innovative and cost-effective offshore wind designs.« less

  3. OC5 Project Phase Ib: Validation of hydrodynamic loading on a fixed, flexible cylinder for offshore wind applications

    SciTech Connect

    Robertson, Amy N.; Wendt, Fabian; Jonkman, Jason M.; Popko, Wojciech; Borg, Michael; Bredmose, Henrik; Schlutter, Flemming; Qvist, Jacob; Bergua, Roger; Harries, Rob; Yde, Anders; Nygaard, Tor Anders; Vaal, Jacobus Bernardus de; Oggiano, Luca; Bozonnet, Pauline; Bouy, Ludovic; Sanchez, Carlos Barrera; García, Raul Guanche; Bachynski, Erin E.; Tu, Ying; Bayati, Ilmas; Borisade, Friedemann; Shin, Hyunkyoung; van der Zee, Tjeerd; Guerinel, Matthieu

    2016-10-13

    This paper summarizes the findings from Phase Ib of the Offshore Code Comparison, Collaboration, Continued with Correlation (OC5) project. OC5 is a project run under the International Energy Agency (IEA) Wind Research Task 30, and is focused on validating the tools used for modelling offshore wind systems through the comparison of simulated responses of select offshore wind systems (and components) to physical test data. For Phase Ib of the project, simulated hydrodynamic loads on a flexible cylinder fixed to a sloped bed were validated against test measurements made in the shallow water basin at the Danish Hydraulic Institute (DHI) with support from the Technical University of Denmark (DTU). The first phase of OC5 examined two simple cylinder structures (Phase Ia and Ib) to focus on validation of hydrodynamic models used in the various tools before moving on to more complex offshore wind systems and the associated coupled physics. As a result, verification and validation activities such as these lead to improvement of offshore wind modelling tools, which will enable the development of more innovative and cost-effective offshore wind designs.

  4. Sink to source: The effects of offshore dynamics on upstream processes

    NASA Astrophysics Data System (ADS)

    Abeyta, A.; Paola, C.; Swenson, J. B.

    2013-12-01

    Often, when we model fluvial sedimentation on large space and timescales, we focus on local controls (e.g. sediment and water supply), as well as the effects of relative sea level change. Shoreline often provides a boundary condition, which implies that offshore processes are merely acting as a passive sink for sediment accumulation. However, over long time scales, coastal rivers are strongly coupled to offshore and slope transport systems via the clinoform geometries typical of prograding sedimentary bodies. Here, we adopt a 'sink to source' view of sediment mass balance on coastal-plain rivers. We identify a variety of effects by which offshore processes influence the state of coastal rivers. For example, the toe of the clinoform represents a critical point that controls net deposition upstream of itself. Mechanisms that increase sediment transport at the toe or along the foreset reduce sedimentation in the fluvial system, reducing the shoreline progradation rate and increasing sedimentation in more distal regions. Results from two experimental studies give examples of how the dynamics of the offshore can control fluvial bypass and progradation. First, results of a 1D flume study show that progradation over pre-existing basin topography combined with overpassing turbidity currents can 'unlock' the clinoform toe, reducing sedimentation in the fluvial system and directing sediment to more distal offshore regions. Second, a 3D study using cohesive sediment that produces complex foreset dynamics, such as mass failure, shows that such failures are expressed in the topset, through land loss, shoreline retreat, and upstream-migrating erosion. These are just two examples of how dynamics in the offshore can influence fluvial sedimentation with no change in upstream supply or base level.

  5. Effects of Second-Order Hydrodynamics on a Semisubmersible Floating Offshore Wind Turbine: Preprint

    SciTech Connect

    Bayati, I.; Jonkman, J.; Robertson, A.; Platt, A.

    2014-07-01

    The objective of this paper is to assess the second-order hydrodynamic effects on a semisubmersible floating offshore wind turbine. Second-order hydrodynamics induce loads and motions at the sum- and difference-frequencies of the incident waves. These effects have often been ignored in offshore wind analysis, under the assumption that they are significantly smaller than first-order effects. The sum- and difference-frequency loads can, however, excite eigenfrequencies of the system, leading to large oscillations that strain the mooring system or vibrations that cause fatigue damage to the structure. Observations of supposed second-order responses in wave-tank tests performed by the DeepCwind consortium at the MARIN offshore basin suggest that these effects might be more important than originally expected. These observations inspired interest in investigating how second-order excitation affects floating offshore wind turbines and whether second-order hydrodynamics should be included in offshore wind simulation tools like FAST in the future. In this work, the effects of second-order hydrodynamics on a floating semisubmersible offshore wind turbine are investigated. Because FAST is currently unable to account for second-order effects, a method to assess these effects was applied in which linearized properties of the floating wind system derived from FAST (including the 6x6 mass and stiffness matrices) are used by WAMIT to solve the first- and second-order hydrodynamics problems in the frequency domain. The method has been applied to the OC4-DeepCwind semisubmersible platform, supporting the NREL 5-MW baseline wind turbine. The loads and response of the system due to the second-order hydrodynamics are analysed and compared to first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second-order loads and induced response data are compared to the loads and motions induced by aerodynamic loading as solved by FAST.

  6. Offshore Wind Energy Systems Engineering Curriculum Development

    SciTech Connect

    McGowan, Jon G.; Manwell, James F.; Lackner, Matthew A.

    2012-12-31

    Utility-scale electricity produced from offshore wind farms has the potential to contribute significantly to the energy production of the United States. In order for the U.S. to rapidly develop these abundant resources, knowledgeable scientists and engineers with sound understanding of offshore wind energy systems are critical. This report summarizes the development of an upper-level engineering course in "Offshore Wind Energy Systems Engineering." This course is designed to provide students with a comprehensive knowledge of both the technical challenges of offshore wind energy and the practical regulatory, permitting, and planning aspects of developing offshore wind farms in the U.S. This course was offered on a pilot basis in 2011 at the University of Massachusetts and the National Renewable Energy Laboratory (NREL), TU Delft, and GL Garrad Hassan have reviewed its content. As summarized in this report, the course consists of 17 separate topic areas emphasizing appropriate engineering fundamentals as well as development, planning, and regulatory issues. In addition to the course summary, the report gives the details of a public Internet site where references and related course material can be obtained. This course will fill a pressing need for the education and training of the U.S. workforce in this critically important area. Fundamentally, this course will be unique due to two attributes: an emphasis on the engineering and technical aspects of offshore wind energy systems, and a focus on offshore wind energy issues specific to the United States.

  7. NREL Offshore Balance-of-System Model

    SciTech Connect

    Maness, Michael; Maples, Benjamin; Smith, Aaron

    2017-01-01

    The U.S. Department of Energy (DOE) has investigated the potential for 20% of nationwide electricity demand to be generated from wind by 2030 and, more recently, 35% by 2050. Achieving this level of wind power generation may require the development and deployment of offshore wind technologies. DOE (2008) has indicated that reaching these 2030 and 2050 scenarios could result in approximately 10% and 20%, respectively, of wind energy generation to come from offshore resources. By the end of 2013, 6.5 gigawatts of offshore wind were installed globally. The first U.S. project, the Block Island Wind Farm off the coast of Rhode Island, has recently begun operations. One of the major reasons that offshore wind development in the United States is lagging behind global trends is the high capital expenditures required. An understanding of the costs and associated drivers of building a commercial-scale offshore wind plant in the United States will inform future research and help U.S. investors feel more confident in offshore wind development. In an effort to explain these costs, the National Renewable Energy Laboratory has developed the Offshore Balance-of-System model.

  8. Offshore Fish Community: Ecological Interactions | Science ...

    EPA Pesticide Factsheets

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone. Bloater is abundant in the offshore zone but appears restricted to depths shallower than 150 m (Selgeby and Hoff 1996; Stockwell et al. 2010), although it occuppied greater depths several decades ago (Dryer 1966; Peck 1977). Shortjaw is relatively rare in the offshore zone (Hoff and Todd 2004; Gorman and Hoff 2009; Gorman and Todd 2007). Lake whitefish is also known to frequent bathymetric depths >100 m (Yule et al. 2008b). In this chapter, we develop a conceptual model of the offshore food web based on data collected during 2001-2005 and on inferences from species interactions known for the nearshore fish community. We then develop a framework for examination of energy and nutrient movements within the pelagic and benthic habitats of the offshore zone and across the offshore and nearshore zones. To document research results.

  9. Installation of an offshore structure

    SciTech Connect

    Will, S.A.; Young, C.E.

    1981-04-07

    In the installation of a jacket or substructure component of an offshore platform on the sea floor over an underwater fixture containing one or more wellheads, a jacket is first ballasted to rest in a vertical orientation on the sea floor. Power winches are mounted atop the jacket above the water line and anchored mooring lines are connected to the winches via fairlead sheaves which define points of attachment for the mooring lines to the jacket. The jacket is deballasted to float with a near sea bottom clearance and is maneuvered horizontally with the power winches toward the underwater fixture. Docking guides carried by the jacket engage vertical guideposts driven drilled into the sea floor at preselected locations relative to the underwater fixture to align the jacket with the underwater fixture. The jacket is then lowered into the desired on-bottom position during controlled ballasting procedures. Finally, piles are driven through hollow jacket columns to anchor the jacket to the sea bottom.

  10. Coupled onshore erosion and offshore sediment loading as causes of lower crust flow on the margins of South China Sea

    NASA Astrophysics Data System (ADS)

    Clift, Peter D.

    2015-12-01

    Hot, thick continental crust is susceptible to ductile flow within the middle and lower crust where quartz controls mechanical behavior. Reconstruction of subsidence in several sedimentary basins around the South China Sea, most notably the Baiyun Sag, suggests that accelerated phases of basement subsidence are associated with phases of fast erosion onshore and deposition of thick sediments offshore. Working together these two processes induce pressure gradients that drive flow of the ductile crust from offshore towards the continental interior after the end of active extension, partly reversing the flow that occurs during continental breakup. This has the effect of thinning the continental crust under super-deep basins along these continental margins after active extension has finished. This is a newly recognized form of climate-tectonic coupling, similar to that recognized in orogenic belts, especially the Himalaya. Climatically modulated surface processes, especially involving the monsoon in Southeast Asia, affects the crustal structure offshore passive margins, resulting in these "load-flow basins". This further suggests that reorganization of continental drainage systems may also have a role in governing margin structure. If some crustal thinning occurs after the end of active extension this has implications for the thermal history of hydrocarbon-bearing basins throughout the area where application of classical models results in over predictions of heatflow based on observed accommodation space.

  11. Offshore drilling, construction: Fortunes tied to stable gas prices

    SciTech Connect

    Pagano, S.S.; Marsh, T.

    1993-01-01

    Significantly improved US natural gas prices fueled an upswing in offshore drilling in the Gulf of Mexico in late 1992. Stabilized gas prices will be necessary to support both the off-shore drilling and construction markets in 1993 and beyond. The article discusses both these segments in detail: offshore drilling and offshore construction.

  12. 47 CFR 22.1037 - Application requirements for offshore stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1037 Application requirements for offshore stations. Applications for new Offshore Radiotelephone Service stations must contain an... 47 Telecommunication 2 2010-10-01 2010-10-01 false Application requirements for offshore stations...

  13. Offshore drilling to increase in 1984

    SciTech Connect

    Not Available

    1984-05-01

    A mid-year report presents a worldwide overview of offshore drilling operations. The Gulf of Mexico and the North Sea are posting substantial gains as companies rush to drill the millions of acres acquired in those sectors both last year and in previous offerings. The Middle East, Latin America and the Asia/Pacific offshore theaters will see only slight increases. The Mediterranean and African regions are expected to sustain declines. A region-by-region summary of the 1984 offshore forecast is presented showing exploration and appraisal activities, as well as development for all of these areas.

  14. Certification of offshore mooring steel wire ropes

    SciTech Connect

    Lohne, P.W.

    1996-12-31

    The trend to produce oil in increasingly deeper water has led to the development of floating production solutions for the exploitation of the energy resources in these areas. It is a fact that steel wire ropes have been used and are being proposed as line segments in the majority of the mooring systems of these units/ships. This paper specifies requirements for the materials, design, manufacture and testing of large diameter offshore mooring steel wire ropes and may serve as a technical reference document in contractual matters between the purchaser and the manufacturer. Typical applications covered are permanently moored floating production systems (FPS), offshore loading systems and mobile offshore units.

  15. Current and future offshore activities in Canada

    SciTech Connect

    Hnatiuk, J.

    1987-06-01

    The development of innovative exploratory drilling systems for Canada's harsh Arctic offshore areas over the past decade and future activity in these areas, including possible production concepts, are discussed. The results can be applied in other Arctic areas of the world, including offshore Alaska. This operating experience will advance technology and serve as a basis for the design of Arctic offshore production and transportation systems. Unique technology has been developed and successfully used in the discovery of major accumulations of hyrodcarbons. Continued technological advances are anticipated to have widespread Arctic applications in both exploratory and production operations.

  16. Coupling colour CL of quartz with multiple geochronological proxies in an attempt to determine extent of sediment recycling in Devonian and Mesozoic basins of southern Ireland

    NASA Astrophysics Data System (ADS)

    Fairey, Brenton; Tunwal, Mohit; Meere, Patrick; Mulchrone, Kieran

    2017-04-01

    Detrital zircon, mica and apatite ages from samples in the Lower Devonian Dingle Basin, the Middle to Upper Devonian Munster Basin and the Triassic to Cretaceous basins of the southern Irish offshore (North Celtic Sea, Fastnet and Goban Spur basins) indicate the potential of multiple cycles of sedimentation. However, this evidence is somewhat inconclusive and it remains a challenge to determine whether grains have been derived directly from the ultimate source or from recycling of older sedimentary rocks. Distinguishing between direct derivation of sediment and sediment recycling has important implications for prediction of sandstone maturity and hydrocarbon reservoir potential. Cathodoluminescence (CL) colour of quartz has, in the past, been used to determine the source of quartz in sandstones. However, the major concern for such an application is that there is large overlap of colours from different sources. In the present study, we hypothesise, based upon existing geochronological and petrographic evidence, that the Upper Devonian Munster Basin sedimentary rocks were recycled during Mesozoic times into the southern Irish offshore basins. In order to test this hypothesis, we compare the relative proportions of different CL colours in quartz from potential sedimentary sources (i.e. the Devonian Dingle and Munster basins), with those from Mesozoic offshore basins of southern Ireland. Similarity between relative proportions of quartz CL colours in these basins suggests recycling of sediments into the offshore basins during the Mesozoic.

  17. Salt deformation history and postsalt structural trends, offshore southern Gabon, West Africa

    SciTech Connect

    Liro, L.M.; Coen, R.

    1996-12-31

    Salt deformation in offshore southern Gabon is represented by mobilization of an Aptian salt layer in reaction to Tertiary clastic progradation. Seismic mapping of salt bodies and associated faulting has resulted in increased understanding of the types and distribution of these salt bodies, their associated faulting patterns, and some aspects of their origin. Away from the Tertiary depocenter, the growth history of salt swells or pillows can be determined by examining onlapping and draping seismic reflectors. Significant Tertiary clastic progradation into the area mobilized the salt and resulted in a series of linear, deep salt walls and asymmetric, basinward-dipping salt rollers, commonly associated with significant up-to-basin faulting dominates the southern Gabon subbasin. The expansion history of associated sediments suggests that these faults expanded episodically throughout the Tertiary, continuing to present-day bathymetric fault scarps. The bias toward up-to-basin faults, to the apparent exclusion of down-to-basin expansion faults, remains enigmatic.

  18. New hydrocarbon plays and prospects in the Douala basin, Cameroon, west Africa

    SciTech Connect

    Kilenyi, T. )

    1991-03-01

    New seismic data acquired by GECO together with reprocessing of old data and geochemical analysis have thrown a new light on the petroleum geology of the Douala basin. The seismic data show a variety of possible traps, particularly in the offshore part of the basin, including submarine fans, buried paleohighs, salt-induced structures, updip wedging out of reservoirs, etc. Geochemical data based on advanced analytical method indicate that none of the potential source rocks encountered in wells actually matches the oils; therefore new sourcing of the known reservoirs has to be considered. Geochemical fossils indicate derivation from two sources, one probably Late Cretaceous deep marineshales now in a far offshore position while a second one is of Early Cretaceous age and of lacustrine origin. All new data indicate that the Douala basin is likely to turn out to be a prolific oil basin and not a gas basin as suggested by some earlier publications.

  19. Changes in the nearshore and offshore zooplankton communities in Lake Ontario: 1981-88

    USGS Publications Warehouse

    Johannsson, Ora E.; Mills, Edward L.; O'Gorman, Robert

    1991-01-01

    We examined trends and factors influencing changes in nearshore and offshore zooplankton abundance and composition in Lake Ontario between 1981 and 1988. In the nearshore (southshore and eastern basin), zooplankton abundance decreased and shifts occurred in the relative abundances of Bosmina longirostris and Daphnia retrocurva (eastern basin) and Daphnia retrocurva and Daphnia galeata mendotae (southshore). These changes could have resulted from increased vertebrate predation or reduced food resources which intensified the effects of predation. In the offshore, the first appearance (FA) of the larger, less common cladoceran species occurred earlier in the season as of 1985. FA was correlated with cumulative epilimnetic temperature (CET) and the catch per unit effort (CPUE) of alewife (Alosa pseudoharengus) a?Y165 mm caught in U.S. waters in the spring. In 1987, when CET was high and CPUE of alewife a?Y165 mm was low, large populations of these cladocerans developed in June and July. Bythotrephes cederstroemi, a recent invader in the Great Lakes, was abundant only in 1987 when the CPUE of alewife was lowest. Changes in zooplankton abundance, development, and composition along the nearshore-offshore gradient reflected effects of temperature, habitat, and planktivory on the community.

  20. Independent focuses Philippines exploration on Visayan basin

    SciTech Connect

    Rillera, F.G.

    1995-08-21

    Cophil Exploration Corp., a Filipino public company, spearheaded 1995 Philippine oil and gas exploration activity with the start of its gas delineation drilling operations in Libertad, northern Cebu. Cophil and its Australian partners, Coplex Resources NL and PacRim Energy NL, have set out to complete a seven well onshore drilling program within this block this year. The companies are testing two modest shallow gas plays, Libertad and Dalingding, and a small oil play, Maya, all in northern Cebu about 500 km southeast of Manila. Following a short discussion on the geology and exploration history of the Visayan basin, this article briefly summarizes Cophil`s ongoing Cebu onshore drilling program. Afterwards, discussion focuses on identified exploration opportunities in the basin`s offshore sector.

  1. Water resources and related geology of Dera Ismail Khan district, West Pakistan, with reference to the availability of ground water for development

    USGS Publications Warehouse

    Hood, J.W.; Khan, Lutfe Ali; Jawaid, Khalid

    1970-01-01

    Dera Ismail (D.I.) Khan District contains an area of 3,450 square miles between the right bank of the Indus River and the Sulaiman Range in westcentral West Pakistan. Agriculture is the principal source of income in the District, but only a small part of the arable land is fully utilized. The region is semiarid and has an average annual rainfall of about 9 inches and a potential evapotranspirational rate of eight to nine times the annual rainfall. Thus, rainfall alone is not adequate for high-intensity cropping. Irrigation is practiced near the Indus River; the Paharpur Canal is used, as well as the traditional inundation method. Elsewhere in the District, adequate water is supplied to local areas by karezes, perennial streams from the mountains, and some recently installed tubewells (see 'Glossary'). Further development of ground-water supplies would permit a more effective utilization of most of the presently tilled land and would allow additional land to be farmed. D.I. Khan District is primarily an alluvial plain that slopes from the mountain ranges in the northern and western parts of the District toward the Indus River. Rocks in the bordering mountains are of Paleozoic to early or middle Pleistocene age. The unconsolidated rocks of the plain, of middle (?) Pleistocene to Holocene (Recent) age, consist of piedmont deposits derived from the hills to the north and west and of alluvium laid down by the Indus River. These deposits interfinger in a transitional zone about 8 to 12 miles west of the river. Lithologic and structural features indicate that the unconsolidated rocks possibly may be divided into broad units. The investigations in D.I. Khan District have revealed two main areas of potential ground-water development based on considerations of both permeability and chemical quality of the ground water: 1. A belt about 10 miles wide parallels the Indus River from the Khisor Range southward to the area immediately south of D.I. Khan town. In this belt, the

  2. BASINS Publications

    EPA Pesticide Factsheets

    Although BASINS has been in use for the past 10 years, there has been limited modeling guidance on its applications for complex environmental problems, such as modeling impacts of hydro modification on water quantity and quality.

  3. Basin analysis

    SciTech Connect

    Lerche, I. )

    1989-01-01

    The exploration for oil is a high-risk game. Worldwide drilling success is around 5-10%, the average cost of drilling is around $1000 a foot, and the average well is now around 15,000 feet deep. Over the years, two fundamental avenues of attack have been developed: methods designed to locate oil in situ from direct measurement ahead of the drill and methods focusing on the dynamic evolution of a sedimentary basin in relation to the timing of hydrocarbon generation, migration, and accumulation to provide an assessment of which areas in a basin might be the most prospective for oil accumulations today. This volume addresses the problem of quantitative basin analysis in relation to oil accumulations. Emphasis is placed on the uncertainties and resolution limits of basin analysis given constraints derived from surface and downhole data and the sensitivity to model input parameters and assumptions.

  4. Offshore oil in the Alaskan Arctic

    NASA Technical Reports Server (NTRS)

    Weeks, W. F.; Weller, G.

    1984-01-01

    Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent natural gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occuur offshore beneath the shallow, ice-covered seas of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

  5. Offshore oil in the alaskan arctic.

    PubMed

    Weeks, W F; Weller, G

    1984-07-27

    Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent nature gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occur offshore beneath the shallow, ice-covered seas, of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

  6. EMS offshore. A new horizon for paramedics.

    PubMed

    Mallard, A S

    1991-10-01

    The difficulty in getting medical aid to offshore drilling platforms can be a source of life-threatening delays. Recently, some companies have charted new waters by actually stationing EMS crews on their rigs.

  7. Civil engineering in the Arctic offshore

    SciTech Connect

    Bennett, F.L.; Machemehl, J.L.

    1985-01-01

    This book presents the current state of practice and theory in the civil engineering aspects of offshore development in the Arctic. It also covers the emerging concepts and requirements, research and development needs, and a critique of present undergraduate programmes.

  8. Offshore oil in the Alaskan Arctic

    NASA Technical Reports Server (NTRS)

    Weeks, W. F.; Weller, G.

    1984-01-01

    Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent natural gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occuur offshore beneath the shallow, ice-covered seas of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

  9. Engineering Challenges for Floating Offshore Wind Turbines

    SciTech Connect

    Butterfield, S.; Musial, W.; Jonkman, J.; Sclavounos, P.

    2007-09-01

    The major objective of this paper is to survey the technical challenges that must be overcome to develop deepwater offshore wind energy technologies and to provide a framework from which the first-order economics can be assessed.

  10. Callisto basin

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This picture of a multi=ring basin on Callisto was taken the morning of March 6, 1979, from a distance of about 200,000 km. The complicated circular structure seen at left center is similar to the large circular impact basins that dominate the surface of the Earth's moon and also the planet Mercury. The inner parts of these basins are generally surrounded by radially lineated ejecta and several concentric mountainous ring structures that are thought to form during the impact event. This multi-ring basin on Callisto consists of light floored central basin some 300 k m in diameter surrounded by at least eight to ten discontinuous rhythmically spaced ridges. No radially lineated ejecta can be seen. The ring structures on Moon and Mercury have been likened to ripples produced on a pond by a rock striking the water. The great number of rings observed around this basin on Callisto is consistent with its low planetary density and probable low internal strength. JPL manages and controls the Voyager project for NASA's Office of Space Science.

  11. New perspectives in offshore wind energy.

    PubMed

    Failla, Giuseppe; Arena, Felice

    2015-02-28

    The design of offshore wind turbines is one of the most fascinating challenges in renewable energy. Meeting the objective of increasing power production with reduced installation and maintenance costs requires a multi-disciplinary approach, bringing together expertise in different fields of engineering. The purpose of this theme issue is to offer a broad perspective on some crucial aspects of offshore wind turbines design, discussing the state of the art and presenting recent theoretical and experimental studies.

  12. New perspectives in offshore wind energy

    PubMed Central

    Failla, Giuseppe; Arena, Felice

    2015-01-01

    The design of offshore wind turbines is one of the most fascinating challenges in renewable energy. Meeting the objective of increasing power production with reduced installation and maintenance costs requires a multi-disciplinary approach, bringing together expertise in different fields of engineering. The purpose of this theme issue is to offer a broad perspective on some crucial aspects of offshore wind turbines design, discussing the state of the art and presenting recent theoretical and experimental studies. PMID:25583869

  13. Arctic offshore drilling: a new challenge

    SciTech Connect

    Wetmore, S.B.

    1985-11-01

    The arctic offshore environment provides the drilling industry with its greatest challenge yet. Problems due to sea ice, high wind, extreme cold and poor bottom soil have required the design of special structures appropriate only for arctic offshore drilling. The challenge lies not just in the obvious factors of temperature and ice, but also the basic physics of ice problems are not well understood. The arctic environment and the petroleum industry are discussed.

  14. 2014 Offshore Wind Market and Economic Analysis

    SciTech Connect

    Hamilton, Bruce

    2014-08-25

    The objective of this report is to provide a comprehensive annual assessment of the U.S. offshore wind market.This 3rd annual report focuses on new developments that have occurred in 2014. The report provides stakeholders with a reliable and consistent data source addressing entry barriers and U.S. competitiveness in the offshore wind market. Available for download are both the full report and the report's underlying data.

  15. [Musculoskeletal disorders in the offshore oil industry].

    PubMed

    Morken, Tone; Tveito, Torill H; Torp, Steffen; Bakke, Ashild

    2004-10-21

    Musculoskeletal disorders are important causes of sick leave and disability among Norwegian offshore petroleum workers. More knowledge and interventions are needed in order to prevent this. In this review we consider prevalence and risk factors among offshore petroleum workers and point to the need for more research. Literature searches on ISI Web of Science and PubMed were supplemented by reports from Norwegian offshore industry companies and the Norwegian Petroleum Directorate. Few studies were found on musculoskeletal disorders among offshore petroleum workers. The disorders are widespread, particularly among catering, construction and drilling personnel. It is not clear whether the prevalence is different from that among onshore workers. Risk factors are physical stressors and fast pace of work. Among catering personnel, these disorders are important causes of loss of the required health certificate but we could not identify any review of causes in the offshore industry generally. More scientific studies are needed on musculoskeletal disorders as comparisons of prevalence and risk factors for offshore and onshore workers may point to more effective interventions. Better knowledge of the causes of loss of the health certificate may contribute to preventing early retirement. Interventions to prevent these disorders should be evaluated by controlled intervention studies.

  16. Arctic and offshore research. Technology status report

    SciTech Connect

    Not Available

    1985-10-01

    DOE's Morgantown Energy Technology Center (METC) and the DOE Fossil Energy Office of Oil, Gas, and Shale Technology are performing the following activities in Arctic and Offshore Research (AOR): (1) AOR Energy-Related Technology Data Base Development; (2) AOR seminars and workshops; (3) Arctic and Offshore Energy Research Coordination; (4) Arctic and Offshore Research which includes analysis of ice island generation, and prediction of drift paths; field and laboratory determination of (1) the engineering properties of multiyear ice, and (2) the interaction of multiyear ice with offshore structures; analysis of ice gouging in deep water (150 to 210 feet) in the Arctic Ocean, and numerical simulation modeling of the gouging process; analysis of the location and origin of the ice-ridging shear zone; analysis of sea-ice thickness using airborne radar sensing techniques; improvement of permafrost detection techniques, and analysis of permafrost characteristics; investigation of the effects of ice accretion and corrosion on offshore structures; measurements of seismic acceleration and velocity for analyzing vibration in and stability of off-shore structures; detection of oil spills that occur below the Arctic ice pack; analysis of the effects of frost heave and corrosion on pipelines; (5) Advanced Recovery Technologies; and (6) Subice Systems Development. Current activities include determining the Arctic bibliographic data base and initiating most of the research described above (except multiyear ice properties, pipeline research, and subice systems development). 10 refs., 15 figs., 3 tabs.

  17. Distribution and recent variations of supraglacial lakes on dendritic-type glaciers in the Khan Tengri-Tomur Mountains, Central Asia

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Mayer, C.; Liu, S.

    2013-12-01

    Supraglacial lakes are widely distributed on glaciers in the Tomur-Khan Tengri Tianshan Mountains, Central Asia. The existence and development of supraglacial lakes play an important role in the processes of ice melting and also in the storage and release of glacial runoff. Here we mapped the supraglacial lakes in the lower region of eight typical debris-covered dendritic-type glaciers around the Tomur-Khan Tengri peaks based on 9 Landsat TM/ETM+ images acquired in summers during 1990 and 2011. With a lower limit of 3600 m2 for the conservative identification of glacial lakes, we mapped 775 supraglacial lakes and 38 marginal glacial lakes in total. Our results indicate that supraglacial lakes in the study region are developed never beyond an elevation of about 3850 m a.s.l., 800 meter lower than the upper boundary of debris cover (4650 m a.s.l.). For the total area-elevation distribution, these lakes are prominently happened near the altitude of 3250 m a.s.l., where the clean ice is simultaneously vanished. The majority of the supraglacial lakes are found on the Tomur Glacier and the South Inylchek Glacier, two typical debris-covered dendritic-type glaciers in the region. As for the multi-year variation of lake area, the annual summer total and mean areas of supraglacial lakes show variability from 1990 and 2005 but expanded obviously during 2005 and 2011. The mean area of these lakes reached maximum in 2010. We found that the area of supraglacial lakes is positively correlated to the total precipitation in summer (July to September) but negatively to the mean air temperature over pre-summer (April to June). Air temperature fluctuations during the pre-summer likely have more impact on the different evolution proceedings of the development of glacial drainage from unconnected to connected systems, which may lead to the drainage of some larger supraglacial lakes and resulted in shrinkage of the total and mean lakes area over the summer seasons. Correlations between

  18. Distribution and recent variations of supraglacial lakes on dendritic-type glaciers in the Khan Tengri-Tomur Mountains, Central Asia

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Mayer, C.; Liu, S.

    2013-09-01

    Supraglacial lakes are widely distributed on glaciers in the Tomur-Khan Tengri Tianshan Mountains, Central Asia. The existence and development of supraglacial lakes play an important role in the ice melting processes and also in the storage and release of glacial melt water. Here we mapped the supraglacial lakes of eight typical debris-covered dendritic-type glaciers around the Tomur-Khan Tengri peaks based on 9 Landsat TM/ETM+ images acquired in the summers of 1990 until 2011. With a lower area limit of 3600 m2 for a conservative identification of glacial lakes, we mapped 775 supraglacial lakes and 38 marginal glacial lakes in total. Our results indicate that supraglacial lakes (area > 3600 m2) in the study region never develop beyond an elevation of about 3850 m a.s.l., 800 m lower than the maximum upper boundary of debris cover (4650 m a.s.l.). The area-elevation distribution shows that lakes are predominantly occured close to the altitude of 3250 m a.s.l., where the clean ice simultaneously disappears. The majority of the supraglacial lakes are found on the Tomur Glacier and the South Inylchek Glacier, two strongly debris-covered dendritic-type glaciers in the region. As for the multi-year variation of lake area, the summer total and mean areas of supraglacial lakes show some variability from 1990 and 2005 but increased noticeably between 2005 and 2011. The mean area of the mapped lakes reached a maximum in 2010. We found that the area of supraglacial lakes is positively correlated to the total precipitation in summer (July to September) but negatively correlated to the mean spring air temperature (April to June). Pre-summer air temperature fluctuations likely have a stronger impact on the different evolution processes of glacial drainage, evolving from unconnected to connected systems, which may lead to the drainage of larger supraglacial lakes and results in shrinkage of the total and mean lake area during the summer.

  19. Parana basin

    SciTech Connect

    Zalan, P.V.; Wolff, S.; Conceicao, J.C.J.; Vieira, I.S.; Astolfi, M.A.; Appi, V.T.; Zanotto, O.; Neto, E.V.S.; Cerqueira, J.R.

    1987-05-01

    The Parana basin is a large intracratonic basin in South America, developed entirely on continental crust and filled with sedimentary and volcanic rocks ranging in age from Silurian to Cretaceous. It occupies the southern portion of Brazil (1,100,000 km/sup 2/ or 425,000 mi/sup 2/) and the eastern half of Paraguay (100,000 km/sup 2/ or 39,000 mi/sup 2/); its extension into Argentina and Uruguay is known as the Chaco-Parana basin. Five major depositional sequences (Silurian, Devonian, Permo-Carboniferous, Triassic, Juro-Cretaceous) constitute the stratigraphic framework of the basin. The first four are predominantly siliciclastic in nature, and the fifth contains the most voluminous basaltic lava flows of the planet. Maximum thicknesses are in the order of 6000 m (19,646 ft). The sequences are separated by basin wide unconformities related in the Paleozoic to Andean orogenic events and in the Mesozoic to the continental breakup and sea floor spreading between South America and Africa. The structural framework of the Parana basin consists of a remarkable pattern of criss-crossing linear features (faults, fault zones, arches) clustered into three major groups (N45/sup 0/-65/sup 0/W, N50/sup 0/-70/sup 0/E, E-W). The northwest- and northeast-trending faults are long-lived tectonic elements inherited from the Precambrian basement whose recurrent activity throughout the Phanerozoic strongly influenced sedimentation, facies distribution, and development of structures in the basin. Thermomechanical analyses indicate three main phases of subsidence (Silurian-Devonian, late Carboniferous-Permian, Late Jurassic-Early Cretaceous) and low geothermal gradients until the beginning of the Late Jurassic Permian oil-prone source rocks attained maturation due to extra heat originated from Juro-Cretaceous igneous intrusions. The third phase of subsidence also coincided with strong tectonic reactivation and creation of a third structural trend (east-west).

  20. Medical evacuations from offshore structures.

    PubMed Central

    Norman, J N; Ballantine, B N; Brebner, J A; Brown, B; Gauld, S J; Mawdsley, J; Roythorne, C; Valentine, M J; Wilcock, S E

    1988-01-01

    A retrospective study was carried out on medical evacuations from the installations of four major oil or gas producing companies, or both, operating offshore on the United Kingdom continental shelf. The study covered 1976-84 during which 2162 evacuations were recorded. Of these, 137 (7.7%) required the use of a chartered helicopter. In the earlier years of the study there were substantially more injuries sustained than episodes of illness recorded but from 1980 onwards the cases of illness equalled those of injury. Using the International Classification of Diseases, the digestive system was responsible for most evacuations for illness and of those, about half (115 evacuations) were for dental problems. Suspected fractures were responsible for about one third of those evacuated for an injury but injuries of hands and eye conditions were particularly common, accounting for 25% of all evacuations. As the age of the evacuee increased the proportion of evacuations for injury decreased and that for illness increased. The mean age for evacuation for injury was 28.3 years and for illness 34.4 years. Few evacuations were required for those aged over 45. PMID:3179237

  1. Medical evacuations from offshore structures.

    PubMed

    Norman, J N; Ballantine, B N; Brebner, J A; Brown, B; Gauld, S J; Mawdsley, J; Roythorne, C; Valentine, M J; Wilcock, S E

    1988-09-01

    A retrospective study was carried out on medical evacuations from the installations of four major oil or gas producing companies, or both, operating offshore on the United Kingdom continental shelf. The study covered 1976-84 during which 2162 evacuations were recorded. Of these, 137 (7.7%) required the use of a chartered helicopter. In the earlier years of the study there were substantially more injuries sustained than episodes of illness recorded but from 1980 onwards the cases of illness equalled those of injury. Using the International Classification of Diseases, the digestive system was responsible for most evacuations for illness and of those, about half (115 evacuations) were for dental problems. Suspected fractures were responsible for about one third of those evacuated for an injury but injuries of hands and eye conditions were particularly common, accounting for 25% of all evacuations. As the age of the evacuee increased the proportion of evacuations for injury decreased and that for illness increased. The mean age for evacuation for injury was 28.3 years and for illness 34.4 years. Few evacuations were required for those aged over 45.

  2. Offshore oil and the coastline

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A radical, accelerated 5-year plan to offer 875 million acres (of which 20 million could actually be leased for oil and gas extraction purposes) on the outer continental shelf (OCS) could result in the release of large volumes of drilling wastes and spillage (Environ. Sci. Tech., Nov. 1981). The actual leasing, under the 5-year plan proposed by Secretary of the Interior James G. Watt, could amount to 4-5 million acres per year—about 10 times as much, on the average, as had been leased over the past 25 years. Regulations on the environmental effects may be less complicated yet more effective in that impact statements will cover large areas instead of the tract-by-tract statements now required. A number of the new offshore leasing areas, for example, the Alaska Coast (Cook Inlet, Beaufort Bay, Gulf of Alaska), the Blake Plateau and Baltimore Canyon, and the Georges Bank, are extremely valuable in terms of renewable resources and potentially fragile in terms of environmental conditions. Fishing interests in these areas have produced considerable controversy over the planned sale of petroleum rights.

  3. Problems unique to offshore measurement

    SciTech Connect

    Young, J.G.

    1995-12-01

    Most of us have arrived at this meeting in some kind of company provided transportation. This is supplied in order for us to do our assigned jobs. These may be trucks, or cars, or even helicopters, and maybe boats. All who are involved in the offshore industry know that transportation is the cost costly of all. The helicopter bill for our company is a bill which costs us somewhere in the 9 million dollar range. Since this costs us so much, we are constantly looking at ways to reduce this. The helicopters we use cost us $510.00 a flying hour plus $28,000.00 a month for lease. These helicopters fly in the neighborhood of 140 miles per hour. You can quickly see how fast the cost can climb. We have two technicians, along with a pilot, and approx. 400 lbs of test gear and spare parts. You have to carry all you think you will need for the day`s activities because it`s a long and costly trip to go pick up some gasket material or an orifice plate.

  4. Structure and geologic history of late Cenozoic Eel River basin, California

    SciTech Connect

    Clarke, S.H. Jr.

    1988-03-01

    The Eel River basin formed as a late Cenozoic forearc basin floored by late Mesozoic and early Cenozoic allochthonous terranes (central and coastal belts of the Franciscan complex). Regionally, basement rocks are unconformably overlain on land by a sedimentary sequence as much as about 4200 m thick that comprises the Bear River Formation (early and middle Miocene) and the Wildcat Group (late Miocene to middle Pleistocene) and offshore by broadly coeval upper Tertiary and Quaternary deposits as much as 3300 m thick. Offshore, the southern part of the basin is typified by the seaward extensions of youthful northeast-dipping thrust and reverse faults and northwest-trending anticlines. The latest period of deformation in this part of the basin began during the middle Pleistocene and probably reflects north-northwestward migration of the Mendocino triple junction and encroachment of the Pacific plate. Farther north, the western basin margin and adjacent upper continental slope are separated from the axial part of the offshore basin by a narrow zone of north-northwest-trending, right-stepping en echelon folds. These folds indicate that northeast-southwest compression characteristic of the southern part of the basin is accompanied toward the north by right-lateral shear between the accretionary complex to the west and the basin to the east. The northeastern margin of the offshore basin is cut by north to north-northwest-trending high-angle reverse faults that vertically offset basement rocks as much as 1300 m, west side down. These faults, which may merge northward, coincide with older terrane boundaries and locally show evidence of late Cenozoic reactivation with possible right-lateral slip.

  5. An audit of clinical laboratory data of 25 [OH]D at Aga Khan University as reflecting vitamin D deficiency in Pakistan.

    PubMed

    Hassan, Sidra; Muzammil, Syeda Maria; Jafri, Lena; Khan, Aysha Habib

    2015-11-01

    To estimate the burden of Vitamin D deficiency in people from different geographical areas of Pakistan. The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised specimens of subjects tested for 25-hydroxy D at the clinical laboratory between September 2010 and September 2011. Serum samples received from the phlebotomy centres all over Pakistan and the main laboratory in Karachi were included. SPSS 19 was used for statistical analysis. Of the 60937 specimens in the study, 18721(30.7%) related to men. The overall mean age was 40.5±19.7 years, and median 25-hydroxy D level was 13.5ng/ml (interquartile range: 25.1-7.4 ng/ml).Overall, mean log 25-hydroxy D was 1.14±0.39ng/ml (median: 13.5ng/ml; interquartile range: 25.1-7.4 ng/ml). Out of the total, 40279(66.1%) subjects were vitamin D-deficient. Vitamin D deficiency was common among the subjects.

  6. Seafloor bathymetry and gravity from the ALBACORE marine seismic experiment offshore southern California

    NASA Astrophysics Data System (ADS)

    Shintaku, N.; Weeraratne, D. S.; Kohler, M. D.

    2010-12-01

    Although the North America side of the plate boundary surrounding the southern California San Andreas fault region is well studied and instrumented, the Pacific side of this active tectonic boundary is poorly understood. In order to better understand this complex plate boundary offshore, its microplate structures, deformation, and the California Borderland formation, we have recently conducted the first stage of a marine seismic experiment (ALBACORE - Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) deploying 34 ocean bottom seismometers offshore southern California in August 2010. We present preliminary data consisting of seafloor bathymetry and free air gravity collected from this experiment. We present high-resolution maps of bathymetry and gravity from the ALBACORE experiment compiled with previous ship track data obtained from the NGDC (National Geophysical Data Center) and the USGS. We use gravity data from Smith and Sandwell and study correlations with ship track bathymetry data for the features described below. We observe new seafloor geomorphological features far offshore and within the Borderland. Steep canyon walls which line the edges of the Murray fracture zone with possible volcanic flows along the canyon floor were mapped by multibeam bathymetry for the first time. Deep crevices juxtaposed with high edifices of intensely deformed plateaus indicate high strain deformation along the arcuate boundary of the Arguello microplate. Small volcanic seamounts are mapped which straddle the Ferrelo fault (Outer Borderland) and San Pedro fault (Inner Borderland), and appear to exhibit fracture and fault displacement of a portion of the volcanic centers in a left-lateral sense. A large landslide is also imaged extending approximately 6 miles in length and 3 miles in width in the Santa Cruz basin directly south of Santa Rosa Island. Deformation associated with capture of Arguello and Patton microplates by the

  7. Submarine landslides hazard offshore Israel

    NASA Astrophysics Data System (ADS)

    Katz, Oded

    2016-04-01

    Submarine landslides pose significant natural hazards. They can damage seafloor infrastructure, such as that used to recover oil and gas or seafloor telecommunication cables, and even generate tsunamis. We recently mapped 447 submarine landslides across the east Mediterranean continental slope, offshore Israel (hereafter the studied area). The mapped landslides are found at water depths of 130 m to 1,000 m and their volume ranges 10-5 - 100 km3. Landslide scars are typically related to a critical slope angle of >4° . Landslides at the northern part of the studied area are spatially associated with fault scarps and are smaller than the ones on the southern part. In this work we evaluate the potential hazard to population and to on- and off- shore facilities posed by submarine landslides across the studied area. We integrate three independent probabilities: (1) the probability for a landslide event of a given volume, based on the size distribution of the mapped landslides; (2) the probability for a landslide event in a given time, based on the reoccurrence time of triggering earthquakes with M >7, and on a 50,000 years general time frame derived from submarine landslides identified across the Mediterranean Sea; (3) the probability for a landslide event in a given area, based on the distribution of slopes exceeding the critical angle. Overall, the fraction of potentially destructive landslides (size > 0.1 km3) is small, 0.05. Thus, considering typical planning time scales of less than 100 years, the calculated hazard is only moderate. The small fraction of landslides with tsunamogenic potential (size > 1 km3), suggests that the hazard for landslide-induced tsunamis along the open slope part of the studied area is small. Landslides in the southern part of the studied area are larger and thus present a somewhat bigger potential source of tsunami waves.

  8. The stratigraphic record of prebreakup geodynamics: Evidence from the Barrow Delta, offshore Northwest Australia

    NASA Astrophysics Data System (ADS)

    Reeve, Matthew T.; Jackson, Christopher A.-L.; Bell, Rebecca E.; Magee, Craig; Bastow, Ian D.

    2016-08-01

    The structural and stratigraphic evolution of rift basins and passive margins has been widely studied, with many analyses demonstrating that delta systems can provide important records of postrift geodynamic processes. However, the apparent lack of ancient synbreakup delta systems and the paucity of seismic imaging across continent-ocean boundaries mean that the transition from continental rifting to oceanic spreading remains poorly understood. The Early Cretaceous Barrow Group of the North Carnarvon Basin, offshore NW Australia, was a major deltaic system that formed during the latter stages of continental rifting and represents a rich sedimentary archive, documenting uplift, subsidence, and erosion of the margin. We use a regional database of 2-D and 3-D seismic and well data to constrain the internal architecture of the Barrow Group. Our results highlight three major depocenters: the Exmouth and Barrow subbasins and southern Exmouth Plateau. Overcompaction of pre-Cretaceous sedimentary rocks in the South Carnarvon Basin, and pervasive reworking of Permian and Triassic palynomorphs in the offshore Barrow Group, suggests that the onshore South Carnarvon Basin originally contained a thicker sedimentary succession, which was uplifted and eroded prior to breakup. Backstripping of sedimentary successions encountered in wells in the Exmouth Plateau depocenter indicates that anomalously rapid tectonic subsidence (≤0.24 mm yr-1) accommodated Barrow Group deposition, despite evidence for minimal, contemporaneous upper crustal extension. Our results suggest that classic models of uniform extension cannot account for the observations of uplift and subsidence in the North Carnarvon Basin and may indicate a period of depth-dependent extension or dynamic topography preceding breakup.

  9. Operational management of offshore energy assets

    NASA Astrophysics Data System (ADS)

    Kolios, A. J.; Martinez Luengo, M.

    2016-02-01

    Energy assets and especially those deployed offshore are subject to a variety of harsh operational and environmental conditions which lead to deterioration of their performance and structural capacity over time. The aim of reduction of CAPEX in new installations shifts focus to operational management to monitor and assess performance of critical assets ensuring their fitness for service throughout their service life and also to provide appropriate and effective information towards requalification or other end of life scenarios, optimizing the OPEX. Over the last decades, the offshore oil & gas industry has developed and applied various approaches in operational management of assets through Structural Health and Condition Monitoring (SHM/CM) systems which can be, at a certain level, transferable to offshore renewable installations. This paper aims to highlight the key differences between offshore oil & gas and renewable energy assets from a structural integrity and reliability perspective, provide a comprehensive overview of different approaches that are available and applicable, and distinguish the benefits of such systems in the efficient operation of offshore energy assets.

  10. Offshore oil gas trends in ROVs tooling

    SciTech Connect

    Jacobson, J.R. )

    1994-04-01

    The ROVs that operate in today's offshore environment bear little or no resemblance to those which first began supporting the oil and gas work requirements less than 15 years ago. In that short span of time, an explosion of subsea technology has occurred, rendering older equipment obsolete and expanding subsea remote intervention capabilities beyond the horizon of intervention tasks originally envisioned. Today's offshore work ROVs employ the latest in robotics, fiver optics, acoustics, video, and computer technologies, and routinely achieve better than 90 percent operational availability. Leading offshore ROV operations companies have demonstrated less than 1 percent down-time over thousands of hours of operation. As the offshore oil and gas market evolves, the ever-expanding capabilities of the work ROV plays a major role in shaping the operational concepts employed in subsea oil and gas field exploration, development, and production. This paper explores the capabilities of available ROV systems in use offshore today, the economic trends driving ROV technology development, and the new trends in the employment of ROVs and their associated sensors and tooling systems.

  11. New OBS network deployment offshore Ireland

    NASA Astrophysics Data System (ADS)

    Le Pape, Florian; Bean, Chris; Craig, David; Jousset, Philippe; Horan, Clare; Hogg, Colin; Donne, Sarah; McCann, Hannah; Möllhoff, Martin; Kirk, Henning; Ploetz, Aline

    2016-04-01

    With the presence of the stormy NE Atlantic, Ireland is ideally located to investigate further our understanding of ocean generated microseisms and use noise correlation methods to develop seismic imaging in marine environments as well as time-lapse monitoring. In order to study the microseismic activity offshore Ireland, 10 Broad Band Ocean Bottom Seismographs (OBSs) units including hydrophones have been deployed in January 2016 across the shelf offshore Donegal and out into the Rockall Trough. This survey represents the first Broadband passive study in this part of the NE Atlantic. The instruments will be recovered in August 2016 providing 8 months worth of data to study microseisms but also the offshore seismic activity in the area. One of the main goal of the survey is to investigate the spatial and temporal distributions of dominant microseism source regions, close to the microseism sources. Additionally we will study the coupling of seismic and acoustic signals at the sea bed and its evolution in both the deep water and continental shelf areas. Furthermore, the survey also aims to investigate further the relationship between sea state conditions (e.g. wave height, period), seafloor pressure variations and seismic data recorded on both land and seafloor. Finally, the deployed OBS network is also the first ever attempt to closely monitor local offshore earthquakes in Ireland. Ireland seismicity although relatively low can reduce slope stability and poses the possibility of triggering large offshore landslides and local tsunamis.

  12. A framework for offshore vendor capability development

    NASA Astrophysics Data System (ADS)

    Yusuf Wibisono, Yogi; Govindaraju, Rajesri; Irianto, Dradjad; Sudirman, Iman

    2016-02-01

    Offshore outsourcing is a common practice conducted by companies, especially in developed countries, by relocating one or more their business processes to other companies abroad, especially in developing countries. This practice grows rapidly owing to the ease of accessing qualified vendors with a lower cost. Vendors in developing countries compete more intensely to acquire offshore projects. Indonesia is still below India, China, Malaysia as main global offshore destinations. Vendor capability is among other factors that contribute to the inability of Indonesian vendor in competing with other companies in the global market. Therefore, it is essential to study how to increase the vendor's capability in Indonesia, in the context of global offshore outsourcing. Previous studies on the vendor's capability mainly focus on capabilities without considering the dynamic of capabilities due to the environmental changes. In order to be able to compete with competitors and maintain the competitive advantage, it is necessary for vendors to develop their capabilities continuously. The purpose of this study is to develop a framework that describes offshore vendor capability development along the client-vendor relationship stages. The framework consists of three main components, i.e. the stages of client-vendor relationship, the success of each stage, and the capabilities of vendor at each stage.

  13. Seafloor Expression of Active Transpressional Faulting Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Legg, M.; Cormier, M. H.; Brennan, M.; Bell, K. L. C.; Coleman, D. F.

    2016-12-01

    Recent observations using Remotely Operated Vehicles (ROV) of the seafloor along active transpressional fault zones offshore southern California reveal the morphology of active fault ruptures in the deep marine environment. Pressure ridges were first identified using high-resolution multibeam bathymetry and subsequently investigated with the ROV Hercules of the Ocean Exploration Trust "Nautiluslive" program. These pressure ridges were located within long, narrow, hillside valleys on the flanks of major transpressional uplifts including the Santa Cruz-Catalina Ridge in the Inner Borderland and Southwest Bank in the Outer Borderland. In general, the pressure ridge is expressed in the bathymetry as an elongate and somewhat sinuous ridge with relatively minor seafloor relief. Although located within the sedimentary fill of significant hillside valleys, these ridges are covered with angular blocks of bedrock, inferred to be brecciated and squeezed upward during large earthquake ruptures along the fault. In a sense, these may represent the long term expression of mole tracks, common to large strike-slip earthquake ruptures in alluvial basins onshore, but better preserved over multiple earthquake cycles in the deep marine environment where erosion is subdued and sedimentation is slow. Along the flanks of the hillside valley are steep to vertical scarps in bedrock outcrops between sediment cover with angular blocks in talus slopes below. Scarps exposed near the crest of large restraining bend pop-up structures show complex fracturing and fault trends consistent with dextral shear in the hanging wall of a moderate- to steep-dipping primary fault. These seafloor observations are consistent with large-scale transpressional structure identified in geophysical data (seismic reflection surveys). The lateral scale of the features, >10 km, and vertical relief 10-1000 meters (or greater) may represent infrequent large earthquakes (M>7) and potential for local tsunami generation. As

  14. Intrashelf basins: A geologic model for source-bed and reservoir facies deposition within carbonate shelves

    SciTech Connect

    Grover, G. Jr. )

    1993-09-01

    Intrashelf basins (moats, inshore basins, shelf basins, differentiated shelf, and deep-water lagoons of others) are depressions of varying sizes and shapes that occur within tectonically passive and regionally extensive carbonate shelves. Intrashelf basins grade laterally and downdip (seaward) into shallow-water carbonates of the regional shelf, are separated from the open marine basin by the shelf margin, and are largely filled by fine-grained subtidal sediments having attributes of shallow- and deeper water sedimentation. These basins are commonly fringed or overlain by carbonate sands, reefs, or buildups. These facies may mimic those that occur along the regional shelf margin, and they can have trends that are at a high angle to that of the regional shelf. Intrashelf basins are not intracratonic basins. The history of most intrashelf basins is a few million to a few tens of million of years. Examples of intrashelf basins are known throughout the Phanerozoic; the southern portion of the Holocene Belize shelf is a modern example of an intrashelf basin. Two types of intrashelf basins are recognized. Coastal basins pass updip into coastal clastics of the craton with the basin primarily filled by fine clastics. Shelf basins occur on the outer part of the shelf, are surrounded by shallow-water carbonate facies, and are filled by peloidal lime mud, pelagics, and argillaceous carbonates. Intrashelf basins are commonly the site of organic-rich, source-bed deposition, resulting in the close proximity of source beds and reservoir facies that may fringe or overlie the basin. Examples of hydrocarbon-charged reservoirs that were sourced by an intrashelf basin include the Miocene Bombay High field, offshore India; the giant Jurassic (Arab-D) and Cretaceous (Shuaiba) reservoirs of the Arabian Shelf; the Lower Cretaceous Sunniland trend, South Florida basin; and the Permian-Pennsylvanian reservoirs surrounding the Tatum basin in southeastern New Mexico.

  15. Federal Offshore Statistics, 1993. Leasing, exploration, production, and revenue as of December 31, 1993

    SciTech Connect

    Francois, D.K.

    1994-12-31

    This document contains statistical data on the following: federal offshore lands; offshore leasing activity and status; offshore development activity; offshore production of crude oil and natural gas; federal offshore oil and natural gas sales volume and royalties; revenue from federal offshore leases; disbursement of federal offshore revenue; reserves and resource estimates of offshore oil and natural gas; oil pollution in US and international waters; and international activities and marine minerals. A glossary is included.

  16. Federal offshore statistics: leasing - exploration - production - revenue

    SciTech Connect

    Essertier, E.P.

    1984-01-01

    Federal Offshore Statistics is a numerical record of what has happened since Congress gave authority to the Secretary of the Interior in 1953 to lease the Federal portion of the Continental Shelf for oil and gas. The publication updates and augments the first Federal Offshore Statistics, published in December 1983. It also extends a statistical series published annually from 1969 until 1981 by the US Geological Survey (USGS) under the title Outer Continental Shelf Statistics. The USGS collected royalties and supervised operation and production of minerals on the Outer Continental Shelf (OCS) until the Minerals Management Service (MMS) took over these functions in 1982. Statistics are presented under the following topics: (1) highlights, (2) leasing, (3) exploration and development, (4) production and revenue, (5) federal offshore production by ranking operator, 1983, (6) reserves and undiscovered recoverable resources, and (7) oil pollution in the world's oceans.

  17. Solar power satellite offshore rectenna study

    NASA Astrophysics Data System (ADS)

    1980-05-01

    Offshore rectennas are feasible and cost competitive with land rectennas but the type of rectenna suitable for offshore use is quite different from that specified in the present reference system. A nonground plane design minimizes the weight and greatly reduces the number of costly support towers. This perferred design is an antenna array consisting of individually encapsulated dipoles with reflectors or tagis supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane, winter storm, and icing conditions for a one time cost of $5.7 billion. Subsequent units would be about 1.3 less expensive. More benign and more shallow water sites would result in substantially lower costs. The major advantage of an offshore rectenna is the removal of microwave radiation from populated areas.

  18. Model refinement for offshore platforms: Experimental study

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Chen, Zongli; Wu, Yanjian

    2017-08-01

    Offshore jacket platforms are widely used in offshore oil and gas exploitation. Finite element models of such structures need to have many degrees of freedom (DOFs) to represent the geometrical detail of complex structures, thereby leading to incompatibility in the number of DOFs of experimental models. To bring them both to the same order while ensuring that the essential eigen- properties of the refined model match those of experimental models, an extended model refinement procedure is presented in this paper. Vibration testing of an offshore jacket platform model is performed to validate the applicability of the proposed approach. A full-order finite element model of the platform is established and then tuned to meet the measured modal properties identified from the acceleration signals. Both model reduction and modal expansion methods are investigated, as well as various scenarios of sensor arrangements. Upon completion of the refinement, the updated jacket platform model matches the natural frequencies of the measured model well.

  19. Solar power satellite offshore rectenna study

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Offshore rectennas are feasible and cost competitive with land rectennas but the type of rectenna suitable for offshore use is quite different from that specified in the present reference system. A nonground plane design minimizes the weight and greatly reduces the number of costly support towers. This perferred design is an antenna array consisting of individually encapsulated dipoles with reflectors or tagis supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane, winter storm, and icing conditions for a one time cost of $5.7 billion. Subsequent units would be about 1.3 less expensive. More benign and more shallow water sites would result in substantially lower costs. The major advantage of an offshore rectenna is the removal of microwave radiation from populated areas.

  20. Current and future offshore activities in Canada

    SciTech Connect

    Hnatiuk, J.

    1984-05-01

    The development of innovative exploratory drilling systems for Canada's harsh Arctic offshore areas over the past decade is described. Future activity in these areas, including possible production concepts, is also discussed. The results of the experience in Canadian waters can be applied in other Arctic areas of the world including offshore Alaska. This operating experience will serve to further advance the drilling technology and will serve as a basis for the design of Arctic offshore production and transportation systems. Artificial islands, first commenced in 1972, are still being constructed but with improved designs and equipment. A step forward has been the use of subsea berms on which concrete or steel segmented caissons have been placed. Integrated-type steel caissons have also been adapted for placement on subsea berms, one of which is half of a crude oil tanker and a second, a purpose-built steel caisson to be placed this summer.

  1. National Offshore Wind Energy Grid Interconnection Study Full Report

    SciTech Connect

    Daniel, John P.; Liu, Shu; Ibanez, Eduardo; Pennock, Ken; Reed, Gregory; Hanes, Spencer

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States.

  2. Strengthening America's Energy Security with Offshore Wind (Fact Sheet)

    SciTech Connect

    Not Available

    2012-02-01

    This fact sheet describes the current state of the offshore wind industry in the United States and the offshore wind research and development activities conducted the U.S. Department of Energy Wind and Water Power Program.

  3. National Offshore Wind Energy Grid Interconnection Study Executive Summary

    SciTech Connect

    Daniel, John P.; Liu, Shu; Ibanez, Eduardo; Pennock, Ken; Reed, Gregory; Hanes, Spencer

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States.

  4. Characterization of Regular Wave, Irregular Wave, and Large-Amplitude Wave Group Kinematics in an Experimental Basin

    DTIC Science & Technology

    2011-02-01

    than second-order numerical simulations (Antao and Guedes Soares, 2008). To generate desired deterministic wave sequences in the experimental basin...simulated in numerical tanks have also been applied to predict structural loading on ships ( Guedes Soares, et al., 2008) and offshore structures (Clauss...Dissertation, The University of Michigan. Anato, E. M. and C. Guedes Soares (2008), "On the Occurrence of Abnormal Waves in an Offshore Tank

  5. Marine Gravity Measurements at the Subduction Zone offshore Central Chile

    NASA Astrophysics Data System (ADS)

    Heyde, I.; Kopp, H.; Reichert, C.

    2003-12-01

    Gravity measurements were carried out during RV SONNE cruise SO-161 (SPOC) in late 2001 between 28° S and 44° S offshore Central Chile along a total length of about 17500 km. The mean accuracy of the data measured with the seagravimeter system KSS31M of BGR is better than 1 mGal. Further foreign marine gravity data were not included due to their considerable lower accuracy. Additional marine gravity data derived from satellite altimetry are needed to augment our data from the survey area. The SPOC data set was compared with 3 different satellite gravity data compilations. The data set with the best statistical results for the gravity differences was used for further gravity map compilations. The map of the freeair gravity is dominated by the anomalies of the main topographic features in the survey area. In the W the oceanic crust of the subducting Nazca Plate is characterized by weak positve gravity anomalies. Landward the anomalies decrease rapidly to less than minus 150 mGal in the Chilean trench. Further towards the coast extends a broad zone of alternating positve and negative freeair gravity anomalies. These could be interpreted either in terms of morphology of the continental slope or heterogeneous density distribution in the upper crust. Additionally Bouguer gravity anomalies were calculated. The anomalies on the Nazca Plate are strongly positive with a clear south - north trending increase of values, which reflect the increasing age of the oceanic crust. The effect of isostatic compensation was calculated assuming Vening-Meinesz models with different parameters. The gravity effect of the isostatic compensation root was eliminated from the Bouguer gravity anomalies and serves as a residual field. The interpretation of isostatic residual fields in this complicated tectonic environment leads to the detection of a series of offshore basins. In the N and the centre of the survey area the distribution of the profiles is rather uniform. For these areas 3D

  6. Regional method to assess offshore slope stability.

    USGS Publications Warehouse

    Lee, H.J.; Edwards, B.D.

    1986-01-01

    The slope stability of some offshore environments can be evaluated by using only conventional acoustic profiling and short-core sampling, followed by laboratory consolidation and strength testing. The test results are synthesized by using normalized-parameter techniques. The normalized data are then used to calculate the critical earthquake acceleration factors or the wave heights needed to initiate failure. These process-related parameters provide a quantitative measure of the relative stability for locations from which short cores were obtained. The method is most applicable to offshore environments of gentle relief and simple subsurface structure and is not considered a substitute for subsequent site-specific analysis. -from ASCE Publications Information

  7. United States Offshore Wind Resource Assessment

    NASA Astrophysics Data System (ADS)

    Schwartz, M.; Haymes, S.; Heimiller, D.

    2008-12-01

    The utilization of the offshore wind resource will be necessary if the United States is to meet the goal of having 20% of its electricity generated by wind power because many of the electrical load centers in the country are located along the coastlines. The United States Department of Energy, through its National Renewable Energy Laboratory (NREL), has supported an ongoing project to assess the wind resource for the offshore regions of the contiguous United States including the Great Lakes. Final offshore maps with a horizontal resolution of 200 meters (m) have been completed for Texas, Louisiana, Georgia, northern New England, and the Great Lakes. The ocean wind resource maps extend from the coastline to 50 nautical miles (nm) offshore. The Great Lake maps show the resource for all of the individual lakes. These maps depict the wind resource at 50 m above the water as classes of wind power density. Class 1 represents the lowest available wind resource, while Class 7 is the highest resource. Areas with Class 5 and higher wind resource can be economical for offshore project development. As offshore wind turbine technology improves, areas with Class 4 and higher resource should become economically viable. The wind resource maps are generated using output from a modified numerical weather prediction model combined with a wind flow model. The preliminary modeling is performed by AWS Truewind under subcontract to NREL. The preliminary model estimates are sent to NREL to be validated. NREL validates the preliminary estimates by comparing 50 m model data to available measurements that are extrapolated to 50 m. The validation results are used to modify the preliminary map and produce the final resource map. The sources of offshore wind measurement data include buoys, automated stations, lighthouses, and satellite- derived ocean wind speed data. The wind electric potential is represented as Megawatts (MW) of potential installed capacity and is based on the square

  8. 76 FR 62817 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... SECURITY Coast Guard National Offshore Safety Advisory Committee AGENCY: United States Coast Guard. ACTION: Committee Management; Notice of Federal Advisory Committee Meeting. SUMMARY: The National Offshore Safety... related to safety of operations and other matters affecting the oil and gas offshore industry. The...

  9. 76 FR 3919 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ... safety of operations and other matters affecting the oil and gas offshore industry. The purpose of this... Coast Guard on safety and other concerns affecting the offshore oil and gas industry and assists the... SECURITY Coast Guard National Offshore Safety Advisory Committee AGENCY: Coast Guard, DHS. ACTION: Notice...

  10. 75 FR 80064 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ... oil and gas offshore industry. The purpose of this meeting is to review and discuss reports and... other concerns affecting the offshore oil and gas industry and assists the Coast Guard in formulating U... SECURITY Coast Guard National Offshore Safety Advisory Committee AGENCY: Coast Guard, DHS. ACTION: Notice...

  11. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in this...

  12. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in this...

  13. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in this...

  14. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in this...

  15. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in this...

  16. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in this...

  17. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in this...

  18. 47 CFR 22.1007 - Channels for offshore radiotelephone systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1007 Channels for offshore... located in the specified geographical zones that provide offshore radiotelephone service. All channels... and/or airborne mobile) as indicated, for voice-grade general communications and private line...

  19. 47 CFR 22.1007 - Channels for offshore radiotelephone systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1007 Channels for offshore... located in the specified geographical zones that provide offshore radiotelephone service. All channels... and/or airborne mobile) as indicated, for voice-grade general communications and private line...

  20. International Offshore Students' Perceptions of Virtual Office Hours

    ERIC Educational Resources Information Center

    Wdowik, Steven; Michael, Kathy

    2013-01-01

    Purpose: The main aim of this study is to gauge international offshore students' perceptions of virtual office hours (VOH) to consult with their offshore unit coordinators in Australia. Design/methodology/approach: This paper employs a quantitative and qualitative approach where data was sourced from three offshore campuses over a 12-month period…

  1. Boundary Spanning in Offshored Information Systems Development Projects

    ERIC Educational Resources Information Center

    Krishnan, Poornima

    2010-01-01

    Recent growth in offshore outsourcing of information systems (IS) services is accompanied by managing the offshore projects successfully. Much of the project failures can be attributed to geographic and organizational boundaries which create differences in culture, language, work patterns, and decision making processes among the offshore project…

  2. International Offshore Students' Perceptions of Virtual Office Hours

    ERIC Educational Resources Information Center

    Wdowik, Steven; Michael, Kathy

    2013-01-01

    Purpose: The main aim of this study is to gauge international offshore students' perceptions of virtual office hours (VOH) to consult with their offshore unit coordinators in Australia. Design/methodology/approach: This paper employs a quantitative and qualitative approach where data was sourced from three offshore campuses over a 12-month period…

  3. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in...

  4. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in...

  5. 77 FR 26562 - Mobile Offshore Drilling Unit Dynamic Positioning Guidance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    ... SECURITY Coast Guard Mobile Offshore Drilling Unit Dynamic Positioning Guidance AGENCY: Coast Guard, DHS... procedures on a Mobile Offshore Drilling Unit. We received comments both as submissions to the docket and at... damage. This is particularly true for Mobile Offshore Drilling Units (MODUs), where a loss of...

  6. Lake Michigan Offshore Wind Feasibility Assessment

    SciTech Connect

    Boezaart, Arnold; Edmonson, James; Standridge, Charles; Pervez, Nahid; Desai, Neel; Williams, Bruce; Clark, Aaron; Zeitler, David; Kendall, Scott; Biddanda, Bopi; Steinman, Alan; Klatt, Brian; Gehring, J. L.; Walter, K.; Nordman, Erik E.

    2014-06-30

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the

  7. Soekor, partners explore possibilities in Bredasdorp basin off South Africa

    SciTech Connect

    Burden, P.L.A. Ltd., Parow, )

    1992-12-21

    This paper reports on the Bredasdorp basin, situated off the south coast of the Republic of South Africa, southeast of Cape Town and west-southwest of Port Elizabeth. Both cities have modern deepwater harbor facilities. Infrastructure along the coast includes well developed road, air, and rail links. A petrochemical plant for the conversion of off-shore gas and condensate to hydrocarbon fuels as well as certain chemical feedstocks has recently been completed at Mossel Bay about 100 km north of the Bredasdorp basin. Refineries are situated at Cape Town and Durban.

  8. Petroleum systems of the Northwest Java Province, Java and offshore southeast Sumatra, Indonesia

    USGS Publications Warehouse

    Bishop, Michele G.

    2000-01-01

    Mature, synrift lacustrine shales of Eocene to Oligocene age and mature, late-rift coals and coaly shales of Oligocene to Miocene age are source rocks for oil and gas in two important petroleum systems of the onshore and offshore areas of the Northwest Java Basin. Biogenic gas and carbonate-sourced gas have also been identified. These hydrocarbons are trapped primarily in anticlines and fault blocks involving sandstone and carbonate reservoirs. These source rocks and reservoir rocks were deposited in a complex of Tertiary rift basins formed from single or multiple half-grabens on the south edge of the Sunda Shelf plate. The overall transgressive succession was punctuated by clastic input from the exposed Sunda Shelf and marine transgressions from the south. The Northwest Java province may contain more than 2 billion barrels of oil equivalent in addition to the 10 billion barrels of oil equivalent already identified.

  9. The limits of seaward spreading and slope instability at the continental margin offshore Mt Etna, imaged by high-resolution 2D seismic data

    NASA Astrophysics Data System (ADS)

    Gross, Felix; Krastel, Sebastian; Geersen, Jacob; Behrmann, Jan Hinrich; Ridente, Domenico; Chiocci, Francesco Latino; Bialas, Jörg; Papenberg, Cord; Cukur, Deniz; Urlaub, Morelia; Micallef, Aaron

    2016-01-01

    Mount Etna is the largest active volcano in Europe. Instability of its eastern flank is well documented onshore, and continuously monitored by geodetic and InSAR measurements. Little is known, however, about the offshore extension of the eastern volcano flank, defining a serious shortcoming in stability models. In order to better constrain the active tectonics of the continental margin offshore the eastern flank of the volcano, we acquired a new high-resolution 2D reflection seismic dataset. The data provide new insights into the heterogeneous geology and tectonics at the continental margin offshore Mt Etna. The submarine realm is characterized by different blocks, which are controlled by local- and regional tectonics. A compressional regime is found at the toe of the continental margin, which is bound to a complex basin system. Both, the clear link between on- and offshore tectonic structures as well as the compressional regime at the easternmost flank edge, indicate a continental margin gravitational collapse as well as spreading to be present at Mt Etna. Moreover, we find evidence for the offshore southern boundary of the moving flank, which is identified as a right lateral oblique fault north of Catania Canyon. Our findings suggest a coupled volcano edifice/continental margin instability at Mt Etna, demonstrating first order linkage between on- and offshore tectonic processes.

  10. Offshore-onshore recent tectonic deformations in the eastern Rif and its foreland (Alhoceima-Nador, Morocco)

    NASA Astrophysics Data System (ADS)

    Ruano, Patricia; Galindo-Zaldívar, Jesús; Comas, Menchu; Chalouan, Ahmed; Azzouz, Omar; Jesús Román-Alpiste, Manuel; Pedrera, Antonio; Sanz de Galdeano, Carlos; López-Garrido, Ángel Carlos; Benmakhlouf, Mohamed; Roldán-García, Francisco Javier; Anahnah, Farida; González-Castillo, Lourdes

    2014-05-01

    The Rif Cordillera is formed by the southwestwards emplacement of the internal zones on the African foreland in the western Alboran Sea. However, the recent deformations are driven also by interaction with the NW-SE convergence of the Eurasian and African plates. The eastern Rif and its foreland constitute a key region to study the variability in structure and stresses related to a lateral boundary of this Alpine Cordillera. The continental crust of the Rif thinned toward Alboran Sea. The onshore and offshore area nearby the coast line, between Al Hoceima and Nador are suitable for recent tectonics studies due to the presence of wide Neogene and Quaternary basins that contribute to record the activity of recent structures. Multichannel seismic reflection data obtained along the coast during the GASALB cruise in November 2011, together with available data, allows to characterize the differences of the Rif and forleland Neogene-Quaternary basins. Offshore results are compared with field observations, that detailed cover several areas. In the Rif Cordillera (Al Hoceima area), recent basins open towards the Alboran Sea are formed by the active roughly N-S oriented faults in this seismogenic area. They are mainly normal in onshore area and becomes strike-slip offshore connecting with sinistral Al-Idrisi fault zone. In contrast, in the foreland represented by the Trois Fourches area, onshore N-S faults are inactive and are developed above a very well exposed folded detachment. Paleostress data in this area support the activity of the exhumed low-angle faults with NE-SW extension and a late radial extension. These new data allows underline the different stresses and age of deformation in the Rif and its foreland and support a westward displacement of deformation along recent time. Then, the most active and hence higher seismic hazard along Moroccan coast, also related to possible tsunamogenic faults, are located offshore Alhoceima area.

  11. Buried Mesozoic rift basins of the U. S. middle Atlantic continental margin

    SciTech Connect

    Benson, R.N. )

    1991-08-01

    The Atlantic continental margin is one of the frontier areas for oil and gas exploration in the US. Most the activity has been offshore where Upper Jurassic-Lower Cretaceous siliciclastic and carbonate rocks have been the drilling objectives, with only one significant but noncommercial gas discover. Onshore, recent exploration activities have focused on early Mesozoic rift basins buried beneath the postrift sediments of the middle Atlantic coastal plain. Many of the basins are of interest because they contain fine-grained lacustrine rocks that have sufficient organic richness, if not lost through hydrocarbon generation, to be classified as source beds for oil or gas. Locations of inferred rift basins beneath the middle Atlantic coastal plain were determined by analysis of drill-hole data in combination with gravity anomaly and aeromagnetic maps. Two basins in Delaware and the Queen Anne basin of Maryland are imaged on a regional Vibroseis profile. Areas enclosing inferred rift basins in the offshore region were mapped from interpretation of seismic reflection profiles. Assuming that petroleum source beds are present in the basin (synrift) rocks, hydrocarbon-generation models (Lopatin method) indicate that for a basin just offshore Delaware that is buried by 7 km of postrift sediments, only dry gas would be present in reservoir rocks; for the Norfolk basin of the Virginia coast buried by only 3 km of postrift rocks, the upper few hundred meters of synrift rocks are still within the oil-generation window. The less deeply buried basins beneath the coastal plain likely are still within the oil window.

  12. 31 CFR 593.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 593.406 Section 593.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FORMER LIBERIAN REGIME OF CHARLES TAYLOR SANCTIONS...

  13. Human Rights, Academic Freedom, and Offshore Academics

    ERIC Educational Resources Information Center

    Ross, Andrew

    2011-01-01

    Despite the carnage wrought on higher education by the Great Recession, evidence persists that the sector is still host to a speculator psychology. One example is the unabated stampede to set up branches and programs overseas. Colleges have many reasons to go offshore: (1) to reduce costs; (2) to build their "brands" in "emerging…

  14. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS Interpretations §...

  15. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS Interpretations §...

  16. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS...

  17. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS Interpretations §...

  18. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  19. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  20. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  1. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS...

  2. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  3. Solar power satellite offshore rectenna study

    NASA Astrophysics Data System (ADS)

    1980-11-01

    It was found that an offshore rectenna is feasible and cost competitive with land rectennas but that the type of rectenna which is suitable for offshore use is quite different from that specified in the present reference system. The result is a nonground plane design which minimizes the weight and greatly reduces the number of costly support towers. This preferred design is an antenna array consisting of individually encapsulated dipoles with reflectors supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane and icing conditions for a one time cost of 5.7 billion dollars. Subsequent units would be about 1/3 less expensive. The east coast site chosen for this study represents an extreme case of severe environmental conditions. More benign and more shallow water sites would result in lower costs. Secondary uses such as mariculture appear practical with only minor impact on the rectenna design. The potential advantages of an offshore rectenna, such as no land requirements, removal of microwave radiation from populated areas and minimal impact on the local geopolitics argue strongly that further investigation of the offshore rectenna should be vigorously pursued.

  4. 31 CFR 593.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 593.406 Section 593.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FORMER LIBERIAN REGIME OF CHARLES...

  5. 31 CFR 587.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 587.406 Section 587.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FEDERAL REPUBLIC OF YUGOSLAVIA (SERBIA...

  6. Cut drydocking costs for offshore rigs

    SciTech Connect

    Albaugh, E.K.

    1985-07-01

    Heavy-lift transport vessels (HLVs) can provide an economic alternative to the conventional shipyard approach of drydocking mobile offshore rigs for regulatory body inspections and/or repairs. Contractors now can drydock rigs in areas of the world where conventional drydocks are unavailable. This article discusses pros and cons of conventional shipyard drydocking and the HLV approach.

  7. Accord near for offshore California oil shipments

    SciTech Connect

    Not Available

    1993-02-15

    There are faint glimmers of hope again for offshore California operators. After more than a decade of often bitter strife over offshore oil and gas development and transportation issues, state officials and oil producers may be moving toward compromise solutions. One such solution may be forthcoming on offshore development. But the real change came with the turnabout of the California Coastal Commission (CCC), which last month approved a permit for interim tankering of crude from Point Arguello oil field in the Santa Barbara Channel to Los Angeles. The dispute over how to ship offshore California crude to market has dragged on since before Point Arguelo development plans were unveiled. The project's status has become a flashpoint in the U.S. debate over resource use and environmental concerns. The controversy flared anew in the wake of the 1989 Exxon Valdez tanker spill off Alaska, when CCC voided a Santa Barbara County permit for interim tankering, a move project operator Chevron Corp. linked to the Exxon Valdez accident. Faced with litigation, the state's economic devastation, and acrimonious debate over transporting California crude, Gov. Pete Wilson and other agencies approved the CCC permit. But there's a catch: A permanent pipeline must be built to handle full production within 3 years. The paper discusses permit concerns, the turnaround decision, the anger of environmental groups, and pipeline proposals.

  8. 31 CFR 549.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 549.406 Section 549.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY LEBANON SANCTIONS REGULATIONS Interpretations § 549.406...

  9. 31 CFR 537.406 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Offshore transactions. 537.406 Section 537.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BURMESE SANCTIONS REGULATIONS Interpretations §...

  10. Solar power satellite offshore rectenna study

    NASA Technical Reports Server (NTRS)

    1980-01-01

    It was found that an offshore rectenna is feasible and cost competitive with land rectennas but that the type of rectenna which is suitable for offshore use is quite different from that specified in the present reference system. The result is a nonground plane design which minimizes the weight and greatly reduces the number of costly support towers. This preferred design is an antenna array consisting of individually encapsulated dipoles with reflectors supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane and icing conditions for a one time cost of 5.7 billion dollars. Subsequent units would be about 1/3 less expensive. The east coast site chosen for this study represents an extreme case of severe environmental conditions. More benign and more shallow water sites would result in lower costs. Secondary uses such as mariculture appear practical with only minor impact on the rectenna design. The potential advantages of an offshore rectenna, such as no land requirements, removal of microwave radiation from populated areas and minimal impact on the local geopolitics argue strongly that further investigation of the offshore rectenna should be vigorously pursued.

  11. Offshore blowouts, data for risk assessment

    SciTech Connect

    Holand, P.

    1995-12-31

    Blowouts are, besides gas leakages, the major contributor to the total risk for offshore installations. Therefore, the blowout risk is always included in Quantitative Risk Analyses (QRAs) of offshore installations in the Norwegian Sector of the North Sea. SINTEF Offshore Blowout Database has existed since 1984 (until 1990 it was called Marintek`s blowout database). In 1990 the responsibility of the database was transferred to SINTEF Safety and Reliability. Throughout these years the database has been used for assessing blowout risk associated to development and operation of fields offshore Norway. Six oil companies and two consultants are presently sponsoring the database. These companies are using the database when performing risk analyses. During the past three years the database has been subjected to a thorough quality improvement, both with respect to the user interface, and most important, regarding the blowout data included in the database. What is unique with this database, besides the high quality of blowout descriptions, is first that the blowout causes are categorized related to loss of primary and secondary barriers. Secondly that the user interface makes it possible to establish searches to withdraw information regarding any blowout type subjected for specific searches.

  12. 31 CFR 543.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 543.406 Section 543.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY CôTE D'IVOIRE SANCTIONS...

  13. Offshore Investments by Colleges Draw Scrutiny

    ERIC Educational Resources Information Center

    Fain, Paul; Wolverton, Brad

    2007-01-01

    Billions of dollars in untaxed, offshore investments by college endowments could be subject to taxation under a proposal being considered by the leaders of the U.S. Senate Finance Committee. The proposed change, which targets hedge funds, a popular investing strategy for many colleges, would affect the largest college endowments, including those…

  14. Human Rights, Academic Freedom, and Offshore Academics

    ERIC Educational Resources Information Center

    Ross, Andrew

    2011-01-01

    Despite the carnage wrought on higher education by the Great Recession, evidence persists that the sector is still host to a speculator psychology. One example is the unabated stampede to set up branches and programs overseas. Colleges have many reasons to go offshore: (1) to reduce costs; (2) to build their "brands" in "emerging…

  15. Risk analysis for Arctic offshore operations

    SciTech Connect

    Slomski, S.; Vivatrat, V.

    1986-04-01

    Offshore exploration for hydrocarbons is being conducted in the near-shore regions of the Beaufort Sea. This activity is expected to be intensified and expanded into the deeper portions of the Beaufort, as well as into the Chukchi Sea. The ice conditions in the Beaufort Sea are very variable, particularly in the deeper water regions. This variability greatly influences the probability of success or failure of an offshore operation. For example, a summer exploratory program conducted from a floating drilling unit may require a period of 60 to 100 days on station. The success of such a program depends on: (a) the time when the winter ice conditions deteriorate sufficiently for the drilling unit to move on station; (b) the number of summer invasions by the arctic ice pack, forcing the drilling unit to abandon station; (c) the rate at which first-year ice grows to the ice thickness limit of the supporting icebreakers; and (d) the extent of arctic pack expansion during the fall and early winter. In general, the ice conditions are so variable that, even with good planning, the change of failure of an offshore operation will not be negligible. Contingency planning for such events is therefore necessary. This paper presents a risk analysis procedure which can greatly benefit the planning of an offshore operation. A floating drilling program and a towing and installation operation for a fixed structure are considered to illustrate the procedure.

  16. Planning and evaluation parameters for offshore complexes

    NASA Technical Reports Server (NTRS)

    Sincoff, M. Z. (Editor); Dajani, J. S. (Editor)

    1976-01-01

    Issues are presented for consideration in the planning and design of offshore artificial complexes. The construction of such complexes, their social, economic, and ecological impacts, and the legal-political-institutional environments within which their development could occur, are discussed. Planning, design, and construction of near-shore complexes located off the Mid-Atlantic coast of the United States is emphasized.

  17. Efficient high-permeability fracturing offshore

    SciTech Connect

    Phillipi, M.; Farabee, M.

    1996-12-31

    Offshore operators can more efficiently and effectively perform high-permeability and conventional hydraulic fracture treatments by blending treatment slurries under microprocessor control, adding undiluted acid on-the-fly, and altering sand concentrations and other slurry properties instantaneously. A two-skid system has been designed with these considerations in mind. The system, which can be shipped efficiently in ISO containers, has been tested on fluids up to 210-cp viscosity and can step or ramp sand concentrations up to a maximum of 20 lb/gal. All additives, including acid treatments, are added on-the-fly; leftover additives and acids may be stored for future jobs. The system may be applied in most conditions, including offshore wells requiring conventional or high-permeability fracture treatments and certain land-based wells in remote areas where a compact skid is needed. Three significant benefits have resulted from using the compact-skid system: offshore operators have been able to ship the skid system at 20% of shipping costs of non-ISO equipment; on-the-fly mixing has prevented material waste associated with batch-mixing; and volumes pumped on actual jobs have closely matched job designs. Data have been collected from several Gulf of Mexico jobs run with the two-part skid system that has been designed for conducting hydraulic fracture treatments from offshore rigs.

  18. Offshore Investments by Colleges Draw Scrutiny

    ERIC Educational Resources Information Center

    Fain, Paul; Wolverton, Brad

    2007-01-01

    Billions of dollars in untaxed, offshore investments by college endowments could be subject to taxation under a proposal being considered by the leaders of the U.S. Senate Finance Committee. The proposed change, which targets hedge funds, a popular investing strategy for many colleges, would affect the largest college endowments, including those…

  19. 31 CFR 537.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 537.406 Section 537.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BURMESE SANCTIONS REGULATIONS Interpretations §...

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

    NASA Astrophysics Data System (ADS)

    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.

  1. Offshore industry: medical emergency response in the offshore oil and gas industry.

    PubMed

    Ponsonby, Will; Mika, Frano; Irons, Greg

    2009-08-01

    The hunt for oil and gas has taken workers into new more distant locations including those offshore. The remoteness of the offshore platforms and vessels coupled with the potential risk of being cut off by bad weather presents particular challenges for medical emergency response (MER). Firstly to define the challenges for MER in terms of locations, population and epidemiology of injuries and illnesses in the offshore environment. Secondly to give examples of legal requirements and industry standards to manage MER. Thirdly to look at existing and emerging practice to manage these challenges. A review of published literature was supplemented with a summary of current practice in the industry. Medical professionals (medics) working offshore on installations and vessels are primarily responsible for the medical care of the workers. The medics have clinics with suitable medical equipment for managing emergencies as well as providing limited primary care. Some countries have legislation that stipulate minimum requirements. Where there is no national legislation, industry and company guidance is used to define the MER standards. Supervision of the offshore medics is often provided by doctors on shore via radio and phone links. These methods of communication are now being augmented with more sophisticated telemedicine solutions such as the Internet and live video links. These newer solutions allow for prompt high-quality care and provide the scope for a variety of new treatment options to be available for the offshore workforce.

  2. Mapping Seabird Sensitivity to Offshore Wind Farms

    PubMed Central

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N.; Caldow, Richard W. G.; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979–2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species’ ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented. PMID:25210739

  3. Mapping seabird sensitivity to offshore wind farms.

    PubMed

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N; Caldow, Richard W G; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

  4. The offshore basement of Perú: Evidence for different igneous and metamorphic domains in the forearc

    NASA Astrophysics Data System (ADS)

    Romero, Darwin; Valencia, Kiko; Alarcón, Pedro; Peña, Daniel; Ramos, Victor A.

    2013-03-01

    As a result of new studies carried out in the offshore of Perú during the exploration and hydrocarbon evaluation of the forearc basins, new U-Pb SHRIMP and TIMS in zircons and some Ar-Ar data were obtained in the metamorphic and igneous basement. The understanding of this basement was critical to evaluate different hypotheses that have been proposed for the tectonic evolution of pre-Andean crust of Perú. Recent research performed in the basement rocks of the Marañón Massif in northern Perú, claimed that west of this area was a basement-free region in the Paleozoic, where the arc and forearc were developed in a mafic quasi-oceanic crust. However, petrographic studies and new preliminary ages indicate, for the first time, the nature and age of this sialic basement. Reconnaissance studies were performed in several offshore islands, as the Las Hormigas de Afuera Island west of Lima, and Macabí and Lobera islands along the edge of the continental platform. These data were complemented with the studies of some cutting samples obtained in recent exploration wells in northern Perú. The results of the present work show two large crustal domains in the Peruvian offshore forearc. A northern domain contains late Paleozoic igneous rocks that appear to be the southern offshore continuation of the Amotape-Tahuin block, which is interpreted as the southernmost remnant of the Laurentia Alleghenian orogen. The central offshore domain, known as the Paracas High, corresponds to the outer shelf high of previous studies. It contains orthogneisses of Grenville-age, probably recrystallized during an Ordovician magmatic episode. The new results show that the central offshore of Perú is an extension of the Grenville-age basement affected by Famatinian, early Paleozoic magmatism, well exposed in the southern domain in the Arequipa Massif along the coast of southern Perú.

  5. Gas hydrates and possible environmental risks offshore South Chile

    NASA Astrophysics Data System (ADS)

    Vargas Cordero, I.; Tinivella, U.; Accaino, F.; Loreto, M. F.; Fanucci, F.; Reichert, C.

    2009-04-01

    Gas hydrates and free gas presence was detected within marine sediments, offshore South Chile, by using seismic analysis. We analysed dataset located offshore South Chile; in particular, two seismic lines were analysed. The first one is located in the northern sector offshore Arauco (38°S) and the second one located in the southern sector offshore Coyhaique (44°S).We used the pre-stack depth migration method (Kirchhoff algorithm) to obtain an accurate velocity model and the real geometry of the Bottom Simulating Reflector (BSR), representing the base of the gas hydrate layer. The velocity was determined analysing iteratively the Common Image Gathers (CIGs) by using Seismic Unix and home code created ad hoc to convert the non-flatness of the reflections in the CIGs into velocity error. Moreover, we converted the final velocity model in terms of gas hydrate and free gas concentrations by using the modified Biot's theory, in which we compared the final velocity model with a theoretical model in absence of gas. Thus, the positive velocity anomalies were associated to gas hydrate presence, while the negative velocity anomalies were associated to free gas presence. In addition, the geothermal gradient was estimated by BSR and seafloor depths and relative BSR amplitude were calculated to correlate the hydrate/free gas concentration to the BSR characteristic. The velocity model allowed us to detect the hydrate layer above the bottom simulating reflector, and the free gas layer below it. The velocity field is affected by strong lateral variation, showing maximum and minimum values in the southern sector. In the southern sector, the highest gas hydrate and free gas concentrations are detected (23% and 2.4% of total volume respectively), even if the high velocity can be partially caused by overcompaction. Here, the BSR depth varies from 250 meter below seafloor (in the middle of the accretionary prism) to 130 meter below seafloor (in the structural high), reaching its

  6. Offshore Stratigraphic Controls on Salt-Water Intrusion in Los Angeles Area Coastal Aquifers

    NASA Astrophysics Data System (ADS)

    Edwards, B. D.; Ponti, D. J.; Ehman, K. D.; Tinsley, J. C.; Reichard, E. G.

    2002-12-01

    Ground water is a major component of the water supply for the ~10 million residents of Los Angeles County. Ground water pumping, linked to population growth since the early 1900's, caused water levels to decline, reversed seaward hydraulic gradients in some coastal aquifers, and resulted in salt water intrusion. United States Geological Survey geologists and hydrologists are working cooperatively with local water agencies to (1) understand and model the process of salt-water intrusion in this siliciclastic, structurally complex basin, and (2) identify potential pathways for the salt-water intrusion. We collected over 2000 trackline-km of single- and multi-channel intermediate- and high-resolution seismic-reflection profiles (60 to 5000 Hz) from the Los Angeles/Long Beach Harbor complex and the adjacent San Pedro shelf to develop a 3-dimensional stratigraphic model of the coastal aquifer system. These data define stratal geometries, paleo-channels, and fault traces in the offshore that are potential pathways of salt-water intrusion. The offshore seismic-reflection profiles correlate with onshore geophysical and borehole data collected from four nearby drill sites that were cored continuously to depths ranging to 400 meters. These core holes provide detailed 1-dimensional reference sections that furnish stratigraphic, age, and facies control for the seismic-reflection profiles. The coastal aquifer system is described using sequence stratigraphic concepts as units deposited during eustatic sea level fluctuations during the Pleistocene to Recent. Seismic-reflection profiles identify sequence boundaries, and hence aquifer and aquitard units, by the truncation and onlap of reflectors. If and where the sequences crop out on the sea floor provides a potential pathway for intrusion. The youngest unit, the Gaspur aquifer, is intruded with salt water and consists of at least two flat-lying sequences, each marked by basal gravelly sands deposited by the ancestral Los Angeles

  7. California State Waters Map Series: offshore of Carpinteria, California

    USGS Publications Warehouse

    Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Kvitek, Rikk G.; Greene, H. Gary; Endris, Charles A.; Seitz, Gordon G.; Sliter, Ray W.; Erdey, Mercedes D.; Wong, Florence L.; Gutierrez, Carlos I.; Krigsman, Lisa M.; Draut, Amy E.; Hart, Patrick E.; Johnson, Samuel Y.; Cochran, Susan A.

    2013-01-01

    and a few small residential clusters. Rincon Point is a well-known world-class surf break, and Rincon Island, constructed for oil and gas production, lies offshore of Punta Gorda. The steep bluffs backing the coastal strip are geologically unstable, and coastal erosion problems are ongoing in the map area; most notably, landslides in 2005 struck the small coastal community of La Conchita, engulfing houses and killing ten people. The Offshore of Carpinteria map area lies in the central part of the Santa Barbara littoral cell, whose littoral drift is to the east-southeast. Drift rates have been estimated to be about 400,000 tons/yr at Santa Barbara Harbor (about 15 km west of Carpinteria). At the east end of the littoral cell, eastward-moving sediment is trapped by Hueneme and Mugu Canyons and then transported to the deep-water Santa Monica Basin. Sediment supply to the western and central part of the littoral cell is largely from relatively small transverse coastal watersheds, which have an estimated cumulative annual sediment flux of 640,000 tons/yr. The much larger Ventura and Santa Clara Rivers, the mouths of which are about 25 to 30 km southeast of Carpinteria, yield an estimated 3.4 million tons of sediment annually, the coarser sediment load generally moving southeast, down the coast, and the finer sediment load moving both upcoast and offshore. The offshore part of the map area consists of a relatively flat and shallow continental shelf, which dips so gently (about 0.4° to 0.5°) that water depths at the 3-nautical-mile limit of California’s State Waters are 40 to 45 m. This part of the Santa Barbara Channel is relatively well protected from large Pacific swells from the north and northwest by Point Conception and from the south and southwest by offshore islands and banks. Fair-weather wave base is typically shallower than 20-m water depth, but winter storms are capable of resuspending fine-grained sediments in 30 m of water, and so shelf sediments in the map

  8. Offshore fault system in the Al Hoceima region from new high-resolution bathymetric and seismic reflection data

    NASA Astrophysics Data System (ADS)

    Lafosse, Manfred; d'Acremont, Elia; Rabaute, Alain; Mercier de l'Epinay, Bernard; Gorini, Christian; André Gutscher, Marc; Poort, Jeffrey; Ammar, Abdellah; Tahayt, Abdelilah; Leroy, Pascal; Smit, Jeroen; Do Couto, Damien; Cancouët, Romain; Prunier, Christophe; Ercilla, Gemma

    2014-05-01

    The Al-Hoceima Region (Morocco) is the one of the most active seismic area of the western Mediterranean Sea. Detailed surveys in a shallow water environment are required to identify the connecting onshore-offshore active structures and to propose a tectonic framework. We use combined high-resolution seismic reflection and swath-bathymetry data from the Marlboro-2 cruise, which took place in 2012 off the coast of Al Hoceima, to detail the fault system through the Nekor basin, between the Trougout Fault and the Boussekour Agdal fault. The Boussekour-Agdal fault is a N026 oriented fault, dipping east and affecting the plio-quaternary sequence offshore and the internal units of the oriental Rif onshore. The fault trace shows a vertical offset of 6.5 m on the high-resolution swath bathymetry close to the shoreline, while the northern prolongation of the fault is buried. The Bokkoya fault (Calvert et al. 1997) is a N029 oriented fault dipping east. The vertical offset at the seafloor is 13m. This fault affects sedimentary structures above a paleo-terrace at -105mbsl, probably related to the last sea-level fall. The onshore-offshore N-S oriented Trougout fault corresponds to the eastern boundary between the plio-quaternary Nekor basin and the volcano-clastic deposits of Ras Tarf. This fault produces a vertical offset of 2.3m at the sea-floor. These three major fault zones limit two basins: the Nekor basin between the Bokkoya and the Trougout faults, and a depression between the Boussekour-Agdal and the Bokkoya Faults. The quaternary deposits are syn-tectonic. In the Nekor basin secondary normal faults are oriented N150, shift the sea-floor and affect the Messinian unconformity. Successive positions of a paleo-canyon (seen in the seismic lines) show a migration of the subsidence from east to west inside the Nekor basin. Faults affecting the Messinian unconformity control this subsidence. Between the Boussekour-Agdal and the Bokkoya faults, the thickness and the geometry of

  9. Waveform inversion of small-to-moderate earthquakes located offshore southwest Iberia

    NASA Astrophysics Data System (ADS)

    Domingues, A.; Custódio, S.; Cesca, S.

    2013-01-01

    In this paper we apply the KInematic Waveform Inversion (KIWI) tools to the study of small-to-moderate earthquakes in southwest (SW) Iberia. The earthquakes have magnitudes in the range ML 3.5-4.9, with the exception of one earthquake with magnitude ML 6.0. Most events are located offshore, are recorded with a large azimuthal gap and generate waves that travel through a strongly heterogeneous crustal structure. We obtain new estimates of centroid, depth, seismic moment, strike, dip and rake for 12 of the 29 studied events. The earthquakes whose waveforms we cannot successfully model are (1) located too far from the stations, (2) have small magnitude, hence low signal-to-noise ratio or (3) are located within the Cadiz basin, which is a major sedimentary basin that affects wave propagation notably. Our results indicate that onshore earthquakes occur at shallow depths (<15 km), whereas offshore earthquakes occur deeper, down to 46 km. Focal mechanisms indicate transpressive faulting.

  10. Geology of the Eel River basin and adjacent region: implications for late Cenozoic tectonics of the southern Cascadia subduction zone and Mendocino triple junction

    USGS Publications Warehouse

    Clarke, S.H.

    1992-01-01

    Two upper Cenozoic depositional sequences of principally marine strata about 4000m thick overlie accreted basement terranes of the Central and Coastal belts of the Franciscan Complex in the onshore-offshore Eel River basin of northwestern California. The older depositional sequence is early to middle Miocene in age and represents slope basin and slope-blanket deposition, whereas the younger sequence, late Miocene to middle Pleistocene in age, consists largely of forearc basin deposits. -from Author

  11. Leveraging Somali Basin Magnetic Anomalies to Constrain Gondwana Breakup and Early Indian Ocean Formation

    NASA Astrophysics Data System (ADS)

    Davis, J. K.; Lawver, L. A.; Norton, I. O.; Gahagan, L.

    2015-12-01

    The Somali Basin, found between the Horn of Africa and Madagascar was formed during the rifting of East and West Gondwana. Understanding the evolution of the basin has historically been hindered by enigmatic seafloor fabric and an apparent paucity of magnetic anomaly data. Recent iterations of satellite gravity data have revealed nearly complete fracture zones as well as a distinct extinct spreading ridge within the basin. Through a thorough compilation of available Somali Basin shiptrack profiles, we have been able to successfully model and interpret magnetic anomalies with exceptional detail. This complication is unrivaled in completeness and provides unprecedented insight into basin formation. Using this high quality data, we have interpreted magnetic anomalies M0r (120.8 Ma) to M24Bn (152.43 Ma) about the extinct ridge. The interpreted Somali Basin spreading rate and spreading direction, through anomaly M15n (135.76 Ma), are similar to those observed in the neighboring coeval Mozambique Basin. This similarity suggests that East Gondwana separated from West Gondwana as a cohesive unit, and that the internal rifting of East Gondwana began later around 135 Ma. Our magnetic anomaly interpretations have been combined with additional magnetic interpretations from around the Indian Ocean to build a regionally consistent plate model of Gondwana breakup and early Indian Ocean formation. This plate model will be crucial for future efforts unraveling a precise history of East Gondwana fragmentation and constraining the formation of the Enderby Basin offshore East Antarctica and Bay of Bengal offshore East India.

  12. San Mateo Creek Basin

    EPA Pesticide Factsheets

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  13. How Pecten Brazil drilled the Amazon basin

    SciTech Connect

    Bleakley, W.B.

    1983-09-01

    Pecten Brazil overcame numerous obstacles to drill two exploratory wells in the Amazon Basin last year. These included: The threat of low water in normally navigable rivers. Dense jungle growth at both locations. Lack of suitable roads for heavy hauling. Inconvenient distances from supply points. An unusual basalt formation responsible for unique drilling problems. Hundreds of helicopter lifts to move drilling rigs, supplies, and personnel. Pecten contracted with Petrobras, the Brazilian national oil company, to evaluate three blocks in the Amazon jungle, each about 68 miles (110 km) on a side, through seismic study and ultimate drilling. Planning for the drilling phase got started on March 17, 1981 with December 1 targeted as spud date for the first well. Actual spud date was November 25, 5 days ahead of schedule, in spite of all obstacles. Pecten has a mid-Amazonas block now under seismic investigation for possible exploratory drilling. Logistics problems in this one provide new difficulties, as the area is extremely wet. Most work is carried on by boat. The company is also looking offshore Bahia, testing the possible extension of the Renconcavo basin. Two wells have already provided good shows of a high pour point oil, with flow rates from 400 to 1,000 b/d. Another area of interest to Pecten is offshore Rio Grande do Norte.

  14. Anconichnus horizontalis: A pervasive ichnofabric-forming trace fossil in post-Paleozoic offshore siliciclastic facies

    SciTech Connect

    Goldring, R. ); Pollard, J.E.; Taylor, A.M. )

    1991-06-01

    The fabric of often intensely mottled, upper offshore to lower shoreface siliciclastic sediments of post-Paleozoic age is analyzed and the principal trace described from material collected from outcrop (U.K.) and the North Sea Basin (core). The characteristic trace of these mottled zones is Anconichnus horizontalis, which is a narrow, discontinuous, twisting, muddy fecal string within a poorly defined burrow fill depleted in mud and inertinite. This trace formed endogenically, principally in association with small-scale cross-stratification and thin (cm) event beds. Seven taphonomic-sediment associations (ichnofabrics) are recognized: (1) in siltstone to very fine-grained sandstone in thin (cm) event beds, often as only one trace; (2) in association with small-scale cross-stratification; (3) in dense concentrations in fine-grained sediment where the primary structures have been obscured; (4) similar to (3) but with a patchy distribution of the trace; (5) siltstone to very fine-grained sandstone, often associated with heterolithic stratification, with a higher ichnodiversity, including Phoebichnus, Palaeophycus, Thalassinoides, Rhizocorallium, Cylindrichnus and Diplocraterion; (6) as (3) but with muddy patches and sand-filled Chondrites sp.; (7) mud dominated, with silty horizons and associated with Terebellina. Associations 1 to 4 were produced by opportunistic shallow tier burrowers penecontemporaneous with deposition of mud-depleted event beds in an offshore environment. Association 5, with diverse, later mid-tier burrowers, suggests a more equilibrium endobenthic community in aggrading sedimentation conditions, under fair weather, in the offshore transition zone to lower shoreface, while associations 6 and 7 indicated muddier offshore situations.

  15. Vertical tectonic deformation associated with the San Andreas fault zone offshore of San Francisco, California

    USGS Publications Warehouse

    Ryan, H.F.; Parsons, T.; Sliter, R.W.

    2008-01-01

    A new fault map of the shelf offshore of San Francisco, California shows that faulting occurs as a distributed shear zone that involves many fault strands with the principal displacement taken up by the San Andreas fault and the eastern strand of the San Gregorio fault zone. Structures associated with the offshore faulting show compressive deformation near where the San Andreas fault goes offshore, but deformation becomes extensional several km to the north off of the Golden Gate. Our new fault map serves as the basis for a 3-D finite element model that shows that the block between the San Andreas and San Gregorio fault zone is subsiding at a long-term rate of about 0.2-0.3??mm/yr, with the maximum subsidence occurring northwest of the Golden Gate in the area of a mapped transtensional basin. Although the long-term rates of vertical displacement primarily show subsidence, the model of coseismic deformation associated with the 1906 San Francisco earthquake indicates that uplift on the order of 10-15??cm occurred in the block northeast of the San Andreas fault. Since 1906, 5-6??cm of regional subsidence has occurred in that block. One implication of our model is that the transfer of slip from the San Andreas fault to a fault 5??km to the east, the Golden Gate fault, is not required for the area offshore of San Francisco to be in extension. This has implications for both the deposition of thick Pliocene-Pleistocene sediments (the Merced Formation) observed east of the San Andreas fault, and the age of the Peninsula segment of the San Andreas fault.

  16. Vertical tectonic deformation associated with the San Andreas fault zone offshore of San Francisco, California

    NASA Astrophysics Data System (ADS)

    Ryan, H. F.; Parsons, T.; Sliter, R. W.

    2008-10-01

    A new fault map of the shelf offshore of San Francisco, California shows that faulting occurs as a distributed shear zone that involves many fault strands with the principal displacement taken up by the San Andreas fault and the eastern strand of the San Gregorio fault zone. Structures associated with the offshore faulting show compressive deformation near where the San Andreas fault goes offshore, but deformation becomes extensional several km to the north off of the Golden Gate. Our new fault map serves as the basis for a 3-D finite element model that shows that the block between the San Andreas and San Gregorio fault zone is subsiding at a long-term rate of about 0.2-0.3 mm/yr, with the maximum subsidence occurring northwest of the Golden Gate in the area of a mapped transtensional basin. Although the long-term rates of vertical displacement primarily show subsidence, the model of coseismic deformation associated with the 1906 San Francisco earthquake indicates that uplift on the order of 10-15 cm occurred in the block northeast of the San Andreas fault. Since 1906, 5-6 cm of regional subsidence has occurred in that block. One implication of our model is that the transfer of slip from the San Andreas fault to a fault 5 km to the east, the Golden Gate fault, is not required for the area offshore of San Francisco to be in extension. This has implications for both the deposition of thick Pliocene-Pleistocene sediments (the Merced Formation) observed east of the San Andreas fault, and the age of the Peninsula segment of the San Andreas fault.

  17. Potential earthquake faults offshore Southern California, from the eastern Santa Barbara Channel south to Dana Point

    USGS Publications Warehouse

    Fisher, M.A.; Sorlien, C.C.; Sliter, R.W.

    2009-01-01

    Urban areas in Southern California are at risk from major earthquakes, not only quakes generated by long-recognized onshore faults but also ones that occur along poorly understood offshore faults. We summarize recent research findings concerning these lesser known faults. Research by the U.S. Geological Survey during the past five years indicates that these faults from the eastern Santa Barbara Channel south to Dana Point pose a potential earthquake threat. Historical seismicity in this area indicates that, in general, offshore faults can unleash earthquakes having at least moderate (M 5-6) magnitude. Estimating the earthquake hazard in Southern California is complicated by strain partitioning and by inheritance of structures from early tectonic episodes. The three main episodes are Mesozoic through early Miocene subduction, early Miocene crustal extension coeval with rotation of the Western Transverse Ranges, and Pliocene and younger transpression related to plate-boundary motion along the San Andreas Fault. Additional complication in the analysis of earthquake hazards derives from the partitioning of tectonic strain into strike-slip and thrust components along separate but kinematically related faults. The eastern Santa Barbara Basin is deformed by large active reverse and thrust faults, and this area appears to be underlain regionally by the north-dipping Channel Islands thrust fault. These faults could produce moderate to strong earthquakes and destructive tsunamis. On the Malibu coast, earthquakes along offshore faults could have left-lateral-oblique focal mechanisms, and the Santa Monica Mountains thrust fault, which underlies the oblique faults, could give rise to large (M ??7) earthquakes. Offshore faults near Santa Monica Bay and the San Pedro shelf are likely to produce both strike-slip and thrust earthquakes along northwest-striking faults. In all areas, transverse structures, such as lateral ramps and tear faults, which crosscut the main faults, could

  18. Regional geological framework and petroleum geology of Miocene sandstones in coastal and offshore Alabama

    SciTech Connect

    Mancini, E.A.; Bearden, B.L.; Mink, R.M.

    1987-05-01

    The Miocene natural gas trend of coastal and offshore Alabama is part of the regional Miocene oil and gas trend of the Gulf coastal area that extends from Texas into Alabama. The major Miocene productive area in Alabama is in southern Baldwin County and Mobile Bay. Since the discovery of Miocene gas in 1979, 28 natural gas fields have been established in coastal and offshore Alabama. The Miocene sandstones range in thickness from 10 to 200 ft, are very fine to coarse grained, are quartz rich, and have subangular to rounded and moderately to well-sorted quartz grains. The productive Miocene interval overlies upper Oligocene marine shelf deposits (Chickasawhay Limestone) and is overlain by Miocene fluvial clastics. The Miocene sandstones, which include the Amos, Escambia, Luce, and Meyer, are interpreted to represent a marine shelf-deltaic complex. A Miocene delta system prograded from the west in the area of offshore Louisiana-Mississippi into coastal and offshore Alabama. Reservoirs and potential reservoirs include highly constructive and highly destructive deltaic and marine shelf sandstones. Porosity in these sandstones is primary intergranular and generally ranges from 27 to 35%. Permeabilities may exceed 2000 md. Basinal Miocene marine clays and Oligocene marls are the probable petroleum source rocks. Petroleum traps are principally stratigraphic, typically involving lateral sandstone pinch-outs against regional dip. Seismic reflection is an excellent exploration tool for identifying potential Miocene fields. Miocene gas sands are best delineated with relative-amplitude seismic reflection data on which gas-charged sands are apparent as bright spots.

  19. Calibration and validation of a spar-type floating offshore wind turbine model using the FAST dynamic simulation tool

    DOE PAGES

    Browning, J. R.; Jonkman, J.; Robertson, A.; ...

    2014-12-16

    In this study, high-quality computer simulations are required when designing floating wind turbines because of the complex dynamic responses that are inherent with a high number of degrees of freedom and variable metocean conditions. In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50th scale inmore » a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states. Wave basin tests with the spar attached to a scale model of the NREL 5-megawatt reference wind turbine were performed at the Maritime Research Institute Netherlands under the DeepCwind project. This project included free-decay tests, tests with steady or turbulent wind and still water (both periodic and irregular waves with no wind), and combined wind/wave tests. The resulting data from the 1/50th model was scaled using Froude scaling to full size and used to calibrate and validate a full-size simulated model in FAST. Results of the model calibration and validation include successes, subtleties, and limitations of both wave basin testing and FAST modeling capabilities.« less

  20. Calibration and validation of a spar-type floating offshore wind turbine model using the FAST dynamic simulation tool

    NASA Astrophysics Data System (ADS)

    Browning, J. R.; Jonkman, J.; Robertson, A.; Goupee, A. J.

    2014-12-01

    High-quality computer simulations are required when designing floating wind turbines because of the complex dynamic responses that are inherent with a high number of degrees of freedom and variable metocean conditions. In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50th scale in a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states. Wave basin tests with the spar attached to a scale model of the NREL 5-megawatt reference wind turbine were performed at the Maritime Research Institute Netherlands under the DeepCwind project. This project included free-decay tests, tests with steady or turbulent wind and still water (both periodic and irregular waves with no wind), and combined wind/wave tests. The resulting data from the 1/50th model was scaled using Froude scaling to full size and used to calibrate and validate a full-size simulated model in FAST. Results of the model calibration and validation include successes, subtleties, and limitations of both wave basin testing and FAST modeling capabilities.

  1. Calibration and validation of a spar-type floating offshore wind turbine model using the FAST dynamic simulation tool

    SciTech Connect

    Browning, J. R.; Jonkman, J.; Robertson, A.; Goupee, A. J.

    2014-12-16

    In this study, high-quality computer simulations are required when designing floating wind turbines because of the complex dynamic responses that are inherent with a high number of degrees of freedom and variable metocean conditions. In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50th scale in a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states. Wave basin tests with the spar attached to a scale model of the NREL 5-megawatt reference wind turbine were performed at the Maritime Research Institute Netherlands under the DeepCwind project. This project included free-decay tests, tests with steady or turbulent wind and still water (both periodic and irregular waves with no wind), and combined wind/wave tests. The resulting data from the 1/50th model was scaled using Froude scaling to full size and used to calibrate and validate a full-size simulated model in FAST. Results of the model calibration and validation include successes, subtleties, and limitations of both wave basin testing and FAST modeling capabilities.

  2. Evolution and hydrocarbon prospectivity of the Douala Basin, Cameroon

    SciTech Connect

    Batupe, M.; Tampu, S.; Aboma, R.S.

    1995-08-01

    The Douala Basin is a stable Atlantic-type, predominantly offshore basin and forms the northern terminal of a series of divergent passive margin basins located on the Southwest coast of Africa that resulted from the rifting of Africa from South America. An integration of new studies including detailed well, biostratigraphic, sedimentological, geochemical and seismic data has confirmed that the tectonostratigraphic evolution in the basin can be broadly divided into three developmental phases: the Syn-rift, Transitional and Drift phases. This basis has been explored intermittently for hydrocarbon for the past 40 years with two important gas fields discovered and no commercial oil found as yet. This early gas discovery and a corresponding lack of any significant oil discovery, led early operators to term this basin as essentially a gas province. However, recent geochemical analyses of various oil-seeps and oil samples from various localities in the basin, using state-of-the-art techniques have demonstrated that this basin is a potential oil prone basin. The results show that two models of oil sourcing are possible: a Lower Cretaceous lacustrine saline source, similar to the presalt basins of Gabon or a marine Upper Cretaceous to lower Tertiary source, similar to the neighbouring Rio del Rey/Niger Delta Complex. Additionally, seismic reflection data also demonstrate a variety of reservoir horizons, including submarine fans, channel-like features and buried paleohighs, all interbedded within regionally extensive, uniformity bounded mudstone units. Hence, it is now quite evident that within this basin, there exist a vast potential for a wide variety of stratigraphic, structural and combined traps. These features, which are considered to have significantly enhanced the prospectivity of this basin, will be discussed in this paper.

  3. Wrench faulting in the Canada Basin, Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Hutchinson, D. R.; Jackson, H. R.; Shimeld, J.; Houseknecht, D. W.; Chian, D.; Li, Q.; Saltus, R. W.; Oakey, G. N.

    2015-12-01

    Synthesis of seismic velocity, potential field, and geologic data from within the Canada Basin of the Arctic Ocean and its surrounding margins suggests that a northeast-trending structural fabric has influenced the origin, evolution, and current tectonics of the basin. This fabric is defined by a diverse set of observations, including (1) a magnetic lineament extending from offshore Prince Patrick Island to the bend in the Canada Basin Gravity Low that separates higher magnetic amplitudes to the northwest from a region of more subdued anomalies to the southeast; (2) the orientation of the 600-km long Northwind Escarpment along the edge of the Canada Basin; (3) a large, linear, positive magnetic anomaly that parallels Northwind Escarpment; (4) negative flower structures along the base of the Northwind Escarpment identified in seismic reflection profiles; (5) the edges of a linear, 150-km-long by 20-km-wide by 2000-m deep, basin in the Chukchi Plateau; (6) the sub-parallel ridges of Sever Spur along the Canadian margin north of Prince Patrick Island; (7) an oblong gravity low interpreted to indicate thick sediments beneath an inferred rift basin at 78oN in ~3600 m water depth; (8) the offshore extensions of the Canning sinistral and Richardson dextral fault zones; (9) the offshore extension of the D3 magnetic terrain of Saltus et al. (2011); and (10) the association of dredged rocks of the Chukchi Borderland with the Pearya terrane ~2000 km northeast of its present location (Brumley et al., 2015). Ongoing deformation of the Beaufort margin by impingement of the Brooks Range tectonic front is recorded by modern seismicity along the Canning and Richardson fault zones, which imply that deformation is accommodated by slip along the northeast-trending fabric. Together, these features are interpreted to indicate long-lived northeast-southwest oriented tectonic fabric in the development of the Canada Basin from initial rifting to modern deformation of the Beaufort margin

  4. Morphotectonics of the Southern Puerto Rico Offshore Margin

    NASA Astrophysics Data System (ADS)

    Granja Bruna, J.; Carbó-Gorosabel, A.; Llanes Estrada, P.; Ten Brink, U. S.; Munoz Martin, A.; Fuertes Ortega, R.; Druet, M.; Gómez, M.; Martin Davila, J. M.; Pazos, A.; Catalan, M.

    2012-12-01

    The southern insular slope of Puerto Rico is characterized by active tectonics, sedimentary and slope failure processes related to the southward thrusting of the island arc over the Caribbean plate's interior. The east-west trending Muertos fold-and-thrust belt and the Investigator fault zone are the main structural and morphological features along the insular slope. It was suggested that these tectonic features accommodate a highly oblique motion between the Caribbean plate's interior and the North American plate. New systematic multibeam bathymetry data and seismic reflection profiles have allowed us to improve the knowledge of the complex morphologic and structural fabric of this zone of active deformation. We divided the region into morphotectonic slope provinces on the basis of morphological, structural and sedimentological criteria. The lower slope province is occupied by the east-west trending Muertos fold-and-thrust belt. Seismic data image pelagic, hemipelagic and turbiditic sediments of the Venezuelan basin and Muertos Trough basin being partially offscraped and accreted forming a sequence of numerous imbricate thrust slices verging southwards. The surface expression of the imbricate structure is a highly steeped slope characterized by an alternation of narrow troughs and elongate anticline ridges oriented sub-parallel to the deformation front. The upper slope province is occupied by the Investigator fault zone, a broad zone of deformation composed of two straight strands that form narrow E-W trending valleys in the insular slope. Submarine canyons carve through the narrow E-W trending valleys or terminate in them but show no evidence for lateral offsets, indicating an absence of recent strike-slip motion. The seafloor expression of the Investigator fault zone suggests a sub-vertical fault plane accommodating a small amount of N-S extension. This fault zone terminates eastward in Whiting basin and disappears westwards beneath the thick slope deposits on a

  5. Active intra-basin faulting in the Northern Basin of Lake Malawi from seismic reflection data

    NASA Astrophysics Data System (ADS)

    Shillington, D. J.; Chindandali, P. R. N.; Scholz, C. A.; Ebinger, C. J.; Onyango, E. A.; Peterson, K.; Gaherty, J. B.; Nyblade, A.; Accardo, N. J.; McCartney, T.; Oliva, S. J.; Kamihanda, G.; Ferdinand, R.; Salima, J.; Mruma, A. H.

    2016-12-01

    Many questions remain about the development and evolution of fault systems in weakly extended rifts, including the relative roles of border faults and intra-basin faults, and segmentation at various scales. The northern Lake Malawi (Nyasa) rift in the East African Rift System is an early stage rift exhibiting pronounced tectonic segmentation, which is defined by 100-km-long border faults. The basins also contain a series of intrabasinal faults and associated synrift sediments. The occurrence of the 2009 Karonga Earthquake Sequence on one of these intrabasinal faults indicates that some of them are active. Here we present new multichannel seismic reflection data from the Northern Basin of the Malawi Rift collected in 2015 as a part of the SEGMeNT (Study of Extension and maGmatism in Malawi aNd Tanzania) project. This rift basin is bound on its east side by the west-dipping Livingstone border fault. Over 650 km of seismic reflection profiles were acquired in the Northern Basin using a 500 to 1540 cu in air gun array and a 1200- to 1500-m seismic streamer. Dip lines image a series of north-south oriented west-dipping intra-basin faults and basement reflections up to 5 s twtt near the border fault. Cumulative offsets on intra-basin faults decrease to the west. The largest intra-basin fault has a vertical displacement of >2 s two-way travel time, indicating that it has accommodated significant total extension. Some of these intra-basin faults offset the lake bottom and the youngest sediments by up to 50 s twtt ( 37 m), demonstrating they are still active. The two largest intra-basin faults exhibit the largest offsets of young sediments and also correspond to the area of highest seismicity based on analysis of seismic data from the 89-station SEGMeNT onshore/offshore network (see Peterson et al, this session). Fault patterns in MCS profiles vary along the basin, suggesting a smaller scale of segmentation of faults within the basin; these variations in fault patterns

  6. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    NASA Astrophysics Data System (ADS)

    Wu, X.; Qi, X.; Zheng, M.

    2015-12-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  7. Distribution and interannual variability of supraglacial lakes on debris-covered glaciers in the Khan Tengri-Tumor Mountains, Central Asia

    NASA Astrophysics Data System (ADS)

    Qiao, Liu; Mayer, Christoph; Liu, Shiyin

    2015-01-01

    Supraglacial lakes are widely formed on debris-covered glaciers in the Khan Tengri-Tumor Mountains (KTTM), Tianshan, Central Asia. Study of their distribution characters based on regional-wide remote sensing investigations is still lacking, but it can promote our understanding about the influence of supraglacial lakes on the surface melting, hydrology and dynamics of debris-covered glaciers in this region. This study presents results of the supraglacial lake inventory in the KTTM region, based on multi-year Landsat images. We focus on the glacio-geomorphological characters of the supraglacial lakes and their late summer conditions, since all suitable Landsat images were acquired between August and September during 1990-2011. With a minimum threshold extent of 3600 m2 for conservative mapping results, we totally mapped 775 supraglacial lakes and 38 marginal glacial lakes on eight huge debris-covered glaciers. Supraglacial lakes are concentrated on the Tumor Glacier and the South Inylchek Glacier, two biggest glaciers in this region. Although most supraglacial lakes are short-lived, a number of lakes can be repeatedly identified between different Landsat images. Detailed investigation of these ‘perennial’ lakes on the Tumor Glacier indicates that their filling frequency and area contributions have increased since 2005. Analysis of the area-elevation distributions for all mapped supraglacial lakes shows that they predominantly occur close to the altitude of 3250 m a.s.l., as high as the lowest reach of clean ice where surface debris begins to appear, and can further develop upglacier to a limit of about 3950 m a.s.l.. Total and mean area of supraglacial lakes in the KTTM region during the late summer seasons show great variability between years. Correlation analysis between the annual lake area and the observed nearby meteorological conditions suggests that warmer springs seem related to the draining of some supraglacial lakes during the following seasons, due to

  8. California State Waters Map Series--Offshore of Ventura, California

    USGS Publications Warehouse

    Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Kvitek, Rikk G.; Greene, H. Gary; Krigsman, Lisa M.; Endris, Charles A.; Seitz, Gordon G.; Gutierrez, Carlos I.; Sliter, Ray W.; Erdey, Mercedes D.; Wong, Florence L.; Yoklavich, Mary M.; Draut, Amy E.; Hart, Patrick E.; Johnson, Samuel Y.; Cochran, Susan A.

    2013-01-01

    In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The Offshore of Ventura map area lies within the Santa Barbara Channel region of the Southern California Bight. This geologically complex region forms a major biogeographic transition zone, separating the cold-temperate Oregonian province north of Point Conception from the warm-temperate California province to the south. The map area is in the Ventura Basin, in the southern part of the Western Transverse Ranges geologic province, which is north of the California Continental Borderland. Significant clockwise rotation—at least 90°—since the early Miocene has been proposed for the Western Transverse Ranges, and the region is presently undergoing north-south shortening. The city of Ventura is the major cultural center in the map area. The Ventura River cuts through Ventura, draining the Santa Ynez Mountains and the coastal hills north of Ventura. Northwest of Ventura, the coastal zone is a narrow strip containing highway and railway transportation corridors and a few small residential clusters. Rincon Island, an island constructed for oil and gas production, lies offshore of Punta Gorda. Southeast of Ventura, the coastal zone consists of the mouth and broad, alluvial plains of the Santa Clara River

  9. Offshore safety case approach and formal safety assessment of ships.

    PubMed

    Wang, J

    2002-01-01

    Tragic marine and offshore accidents have caused serious consequences including loss of lives, loss of property, and damage of the environment. A proactive, risk-based "goal setting" regime is introduced to the marine and offshore industries to increase the level of safety. To maximize marine and offshore safety, risks need to be modeled and safety-based decisions need to be made in a logical and confident way. Risk modeling and decision-making tools need to be developed and applied in a practical environment. This paper describes both the offshore safety case approach and formal safety assessment of ships in detail with particular reference to the design aspects. The current practices and the latest development in safety assessment in both the marine and offshore industries are described. The relationship between the offshore safety case approach and formal ship safety assessment is described and discussed. Three examples are used to demonstrate both the offshore safety case approach and formal ship safety assessment. The study of risk criteria in marine and offshore safety assessment is carried out. The recommendations on further work required are given. This paper gives safety engineers in the marine and offshore industries an overview of the offshore safety case approach and formal ship safety assessment. The significance of moving toward a risk-based "goal setting" regime is given.

  10. Response of wave excited offshore platforms

    SciTech Connect

    Chang, Shih-Jung; Hahn, G.D.

    1995-09-01

    A study of the resultants of inertia and drag force components induced by waves on offshore structures is made, and the relations between these resultants and the corresponding modal forces that govern the structural response are examined. The information and concepts reported elucidate the main factors that control such forces. Using the deep-water approximation of linear wave theory and the Morison equation, it is shown that the inertia and drag components of the modal forces can be expressed in terms of the sea surface kinematics. This treatment of the wave excitations advances the understanding of their characteristics and contributes to forming a basis for efficient, reliable evaluations of the response of wave- excited offshore platforms.

  11. Urinary 1-hydroxypyrene levels in offshore workers.

    PubMed

    Hopf, Nancy Brenna; Kirkeleit, Jorunn; Kramer, Stacy L; Moen, Bente; Succop, Paul; Genter, Mary Beth; Carreón, Tania; Mack, James; Talaska, Glenn

    2010-01-01

    To compare differences in pre- and post-shift urinary 1-hydroxypyrene (1OHP) levels as a measure of internal dose of polycyclic aromatic hydrocarbons (PAHs) between two groups of oil production workers offshore assumed to be exposed to PAH, and to compare the exposed group to an unexposed control group. Participants' (n = 42) urine samples, collected over a study period of three consecutive 12-h work days (pre-shift on the first day and post-shift on the third day), were analyzed using high performance liquid chromatography (HPLC) with fluorescence detection. Analysis of covariance was used in the statistical models. (1) Post-shift 1OHP levels were significantly higher in the exposed workers compared to the controls. (2) Tank workers and process operators did not show statistically significant different post-shift 1OHP levels. Altogether, this study indicates the presence of a low level PAH exposure among offshore oil production workers.

  12. Perspectives of offshore geothermal energy in Italy

    NASA Astrophysics Data System (ADS)

    Armani, F. B.; Paltrinieri, D.

    2013-06-01

    Italy is the first European and world's fifth largest producer of geothermal energy for power generation which actually accounts for less than 2% of the total electricity production of the country. In this paper after a brief introduction to the basic elements of high-enthalpy geothermal systems, we discuss the potentialities represented by the submarine volcanoes of the South Tyrrhenian Sea. In particular we focus on Marsili Seamount which, according to the literature data, can be considered as a possible first offshore geothermal field; then we give a summary of the related exploitation pilot project that may lead to the realization of a 200MWe prototype power plant. Finally we discuss some economic aspects and the development perspectives of the offshore geothermal resource taking into account the Italian energy framework and Europe 2020 renewable energy target.

  13. New technology emphasizes international offshore effort

    SciTech Connect

    1997-07-01

    While the offshore industry is focusing its major development efforts on the deeper waters of the US Gulf, West Africa and Brazil, technology has not stood still in the world`s many other established and frontier offshore development areas. These selected items drawn from contributions by UK companies and a major joint-venture development in Eastern Canada emphasize this effort. Included here are: (1) announcement of a major six-field, 3 Tcf gas development off Nova Scotia`s Sable Island and award of two drilling contracts; (2) a comprehensive study of mobile production units in the UK by Smith Rea Energy Analysts; (3) four applications of an option to high-pressure swivels on an FPSO with multiple subsea inlet lines; (4) a contract to supply a DC bus drive for 17 ESPs on Texaco`s Captain field; and (5) review of an environmental study of the Falkland Islands in preparation for exploration activity.

  14. Locating Microseism Sources in Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Tian, X.; Clayton, R. W.

    2007-12-01

    We use the broadband stations from the S. California network to locate the apparent origin of secondary microseisms energy (5-8 Hz band). The procedure is to grid the offshore region and using each grid point as the source point, predict the response of a Rayleigh wave at each station. These predicted waveforms are then correlated with the data over a time window that is typically a 1/2 hour in length and composited at the grid point. The length of the time window controls a tradeoff between the spatial-temporal resolution of the sources and the robustness on the image. The procedure is valid for multiple sources. This results show that during periods of high microseism activity the sources are distinct at several locations in a region approximately 50-100 km offshore. For an 11/09/2002 Southern Ocean storm, for example, two zones parallel to each other and perpendicular to the coast are imaged.

  15. Plio-Quaternary tectonic evolution off Al Hoceima, Moroccan Margin of the Alboran Basin.

    NASA Astrophysics Data System (ADS)

    Lafosse, Manfred; d'Acremont, Elia; Rabaute, Alain; Mercier de Lépinay, Bernard; Gorini, Christian; Ammar, Abdellah; Tahayt, Abdelilah

    2015-04-01

    We use data from a compilation of industrial and academic 2D surveys and recent data from MARLBORO-1 (2011), MARLBORO-2 (2012), and SARAS (2012) surveys, which provide high resolution bathymetry and 2D seismic reflexion data. We focus on the key area located south of the Alboran Ridge and the Tofiño Bank, and encompassing the Nekor and Boudinar onshore-offshore basins on the Moroccan side of the Alboran Sea. The Nekor basin is a present pull-apart basin in relay between inherited N050° sinistral strike-slip faults. We consider that these faults define the Principal Displacement Zones (PDZ). The northern PDZ marks the position of the crustal Bokkoya fault, which is connected to the Al-Idrisi Fault Zone en relais with the Adra and Carboneras Fault Zones. On the seabed, right-stepping non-coalescent faults characterize the sinistral kinematics of the northern PDZ and give a general N050° azimuth for the crustal discontinuity. The southern PDZ corresponds to the Nekor fault Zone, a Miocene sinistral strike-slip fault acting as the structural limit of the External Rif. On its eastern edge, the Nekor basin is bounded by the N-S onshore-offshore Trougout fault, connecting the northern and the southern PDZ. The western boundary of the Nekor basin is marked by the Rouadi and El-Hammam Quaternary active N-S normal faults. In the offshore Nekor basin, recent N155° conjugated normal faults affect the seabed. Further east, the Boudinar basin is a Plio-Quaternary uplifted Neogene basin. The northeastern segment of the Nekor fault bounds this basin to the south but is inactive in the Quaternary. Normal east-dipping N150° faults are visible offshore in the continuity of the Boudinar fault. From our perspective, the orientation of major tectonic structures (Bokkoya, Nekor and Carboneras faults and the Alboran ridge) under the present compressive regime due to the Europe/Africa convergence is not compatible with a strike-slip motion. The orientation of the most recent Plio

  16. The Onset of the Messinian Salinity Crisis along the offshore Betic Range

    NASA Astrophysics Data System (ADS)

    Ochoa, Diana; Sierro, Francisco J.; Lofi, Johanna; Maillard, Agnes; Driussi, Olivier; Flores, Jose-Abel

    2014-05-01

    During the latest Miocene tectonic-driven processes triggered the closure of the gateways connecting the Atlantic and the Mediterranean seas. Consequently, the Mediterranean Sea experienced major changes on sea level, water chemistry, faunal assemblages, and sedimentary patterns. The extended presence of thick evaporitic sequences on both marginal and deep areas indicates the magnitude of this event and its basin-wide nature. However most of the evidence explaining the origin, nature and system responses to this crisis, also known as the Messinian Salinity Crisis (MSC), comes from continental/shallow marine areas. Hence, responses of deep marine environments to the MSC and their correlation with marginal regions are still poorly understood. In this work, we aim to provide a chronostratigraphic framework for sediments located along the offshore Betic Range (Valencia basin and Alicante shelf). This area, which is the offshore extension of the Betic gateway, potentially can help to correlate onland sedimentary successions with seismic stratigraphic sequences recognized at intermediate-depths. Thus, moving a step further on the marginal-deep basin correlation across Western Mediterranean. An age model was built by using several planktonic foraminifera events that have been astronomically dated in other Mediterranean sections. In addition, sonic and resistivity well logs were tuned to the astronomical target curves. Well log patterns allow us to identify a cyclical sequence of gypsum on the Alicante shelf, which is very similar to the one present onshore in the Sorbas basin. Our preliminary results suggest that the first gypsum bed is conformable overlying Messinian marls. These results support the idea of a synchronous precipitation of the Lower Primary Gypsum across the entire Mediterranean basin. Finally, well-logging and micropaleontological data is being integrated with recently gathered 2D-seismic data (SIMBAD cruise), intentionally tied to some of our studied

  17. Department of Defense Offshore Military Activities Program

    DTIC Science & Technology

    1987-03-16

    joint use of offshore areas for military and mineral exploration or developmental purposes. (See enclosure 2.) In carrying out negotiations with elements...that from time to time and from place to place the requirements for mineral exploration /development and defense related activities may conflict. In...area, certain defense- related activities on the OCS may be irreconcilable with mineral exploration / development and will, under the procedures

  18. Protective riser-conductor for offshore structures

    SciTech Connect

    Rutherford, D. A.; Albers, G. P.

    1985-07-09

    A protective sleeve for fitting about the periphery of the leg of an offshore structure. The sleeve comprises means for carrying and enclosing a plurality of conductors. It further includes one or more inner rings; an outer jacket is fixedly spaced from the rings to define longitudinal passages within which the respective conductors are fixedly positioned. The sleeve is capable of deflecting packed ice and floating objects which represent possible sources of damage to the structure or to conductors.

  19. Automatic welding comes of age. [Offshore

    SciTech Connect

    Turner, D.L. Jr.

    1981-07-01

    Automatic pipe welding systems today fall into three main categories: gas metal arc welding, gas-tungsten arc welding, and flash-butt welding. The first automatic welding devices used offshore were the CRC and H.C. Price systems. Both use gas metal arc welding with a consumable steel filler wire. The recently developed McDermott flash-butt welding system is described. (DLC)

  20. Mobile offshore structure for arctic exploratory drilling

    SciTech Connect

    Hale, D. R.; Orndorff Jr., J. A.; Owen, W. A.

    1985-04-23

    An offshore exploratory drilling floatable structure ballastable to rest on a sea floor but to extend above water level when so supported and adapted to withstand arctic ice loads, comprising a substantially vertical wall capable of withstanding arctic ice loads; a structural load bearing bottom rigidly connected to a lower portion of the wall; and a floatable vertically displaceable load bearing structural deck inside the wall.