18 research outputs found

    Seismic reflection, magnetic, and gravity profiles of the eastern Atlantic continental margin and adjacent deep-sea floor. I. Cape Francis (South Africa) to Congo Canyon (Republic of Zaire)

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    One of the programs of the International Decade of Ocean Exploration (!DOE) is a four-year geophysical and geological study of the Eastern Atlantic Continental Margin and the adjacent deep·sea floor. It was designed to learn more of the date and manner by which Africa became separated from South America and the subsequent history and development of the African continental margin and adjoining deep-sea floor. The traverses also serve to outline large sedimentary basins that may be potential reservoirs of petroleum. Subsequent more detailed exploration and eventual exploitation of these basins may be conducted or controlled by the adjacent African nations under whose jurisdiction the areas belong. This report is a compilation of the geophysical traverses made from Cape Francis (South Africa) to the Congo Canyon (Republic of Zaire) during the first half of 1972

    Late Cenozoic geology of the Central Persian (Arabian) Gulf from industry well data and seismic profiles

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    Industry seismic reflection profiles shot in the 60's and early 70's in the central Persian (Arabian) Gulf are used to map two late Tertiary unconformities, and velocity data from a centrally located well is used to convert travel time to depth to the unconformities. The deeper horizon correlates with a regional unconformity at the end of the Eocene in most wells and dips monotonically to the northeast, whereas the shallower horizon is flatter and correlates with the mid-upper Miocene section in one well. Isopach maps based on wells indicate that sedimentation was relatively uniform across the region until the middle to late Miocene. Sediments deposited since the late Miocene thicken from 100-200 m on the Arabian side of the Gulf to >1000 m near Iran reflecting deposition of sediments eroded from the rapidly uplifting Zagros fold-belt. As a result of the rapid deposition, the velocity gradient in the upper 1 km decreases from ~4 km/sec per km near Arabia to about 2 km/sec per km on the Iranian side of the Gulf.This research was jointly supported by the Office of Naval Research, though grants N00014-96-1-0548 and 96PR04120-00, and by the Naval Oceanographic Offic

    A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley

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    This paper is not subject to U.S. copyright. The definitive version was published in Palaeogeography, Palaeoclimatology, Palaeoecology 246 (2007): 120-136, doi:10.1016/j.palaeo.2006.10.030.The Hudson Shelf Valley (HSV) is the largest physiographic feature on the U.S. mid-Atlantic continental shelf. The 150-km long valley is the submerged extension of the ancestral Hudson River Valley that connects to the Hudson Canyon. Unlike other incised valleys on the mid-Atlantic shelf, it has not been infilled with sediment during the Holocene. Analyses of multibeam bathymetry, acoustic backscatter intensity, and high-resolution seismic reflection profiles reveal morphologic and stratigraphic evidence for a catastrophic meltwater flood event that formed the modern HSV. The valley and its distal deposits record a discrete flood event that carved 15-m high banks, formed a 120-km2 field of 3- to 6-m high bedforms, and deposited a subaqueous delta on the outer shelf. The HSV is inferred to have been carved initially by precipitation and meltwater runoff during the advance of the Laurentide Ice Sheet, and later by the drainage of early proglacial lakes through stable spillways. A flood resulting from the failure of the terminal moraine dam at the Narrows between Staten Island and Long Island, New York, allowed glacial lakes in the Hudson and Ontario basins to drain across the continental shelf. Water level changes in the Hudson River basin associated with the catastrophic drainage of glacial lakes Iroquois, Vermont, and Albany around 11,450 14C year BP (~ 13,350 cal BP) may have precipitated dam failure at the Narrows. This 3200 km3 discharge of freshwater entered the North Atlantic proximal to the Gulf Stream and may have affected thermohaline circulation at the onset of the Intra-Allerød Cold Period. Based on bedform characteristics and fluvial morphology in the HSV, the maximum freshwater flux during the flood event is estimated to be ~ 0.46 Sv for a duration of ~ 80 days.Support for N. Driscoll was provided by the Office of Naval Research and the National Science Foundatio

    R/V Knorr Voyage 134-15 STARELLA Leg DSLBB-02

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    This is a list of the work to be done on the data from the AMPHORA site. All these data are from STARELLA Leg DSLBB-02. No data from Starella Leg 1 or the Knorr cruise are included in this list

    Oceanografia

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    R/V Knorr Voyage 134-15 Jason ROV 89 Long Baseline Acoustic Navigation, SHARPS navigation

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    A collection of documentation, memos, notes and log files relating to Long Baseline Acoustic Navigation, SHARPS navigation, vehicle control and JASON ROV general information

    Seismic reflection, magnetic, and gravity profiles of the eastern Atlantic continental margin and adjacent deep-sea floor. II. Congo Canyon (Republic of Zaire) to Lisbon (Portugal)

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    One of the programs of the International Decade of Ocean Exploration (I.D.O.E.) is a geological and geophysical study of the eastern Atlantic continental margin and adjacent deep-sea floor. This report is a compilation of the geophysical traverses made from the Congo Canyon (Republic of Zaire) to Lisbon, Portugal during the first half of 1973. Also included in the atlas are geophysical traverses from Woods Hole to Dakar and from Dakar to Latitude 10°N made during January-February, 1972.Supported under National Science Foundation Grant No. GX-28193

    R/V Knorr Voyage 134-15 Uchupi video docs

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    Data Workup From AMPHORA Site This is a list of the work to be done on the data from the AMPHORA Site. All these data are from STARELLA Leg DSL88-02. No data from Starella Leg 1 or the Knorr cruise are included in this list
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