Geological and paleoceanographic evolution of the South Atlantic and the adjacent Antarctic margins

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Identification_Information:
Citation:
Citation_Information:
Originator: Unknown
Publication_Date: Unknown
Title: Geological and paleoceanographic evolution of the South Atlantic and the adjacent Antarctic margins
Description:
Abstract:
In English: The GEBRA '93 survey was carried out in December 1993 in the waters of Bransfield Strait and adjacent areas, on board B.I.O. Hesperides. Different types of measurements were performed during the survey: swath bathymetric sounding; single-channel seismic reflection, BPS bottom parametric source and magnetic profiling, and gravity coring; and several instruments were moored. In total, an area of 17.000 Km2 of sea floor, at an average depth of about 1.500 m. has been covered by the bathymetric swaths. About 1.500 km. of seismic, parametric and magnetic profiles were acquired simultaneously (total: 5.500 km). Two gravity cores of 2.5 m. and 4.5 m. were obtained. Seven current meters, 3 tide gauges, one wave buoy and 3 acoustic release systems were deployed. These different activities were carried out during 21 effective working days. The abundant data acquired have permitted to characterize in great detail the morphostructure, sedimentary cover and magnetic anomalies of the study area. The GEBRA '93 swath bathymetry data cover an area between 49?30' W and 60?30'W with a width of 30' of latitude that comprises the Bransfield Basin and the western termination of the South Scotia Ridge. Amongst other relevant results, the GEBRA '93 survey has clearly revealed the existence of several large volcanic edifices in the Central Bransfield Basin, and the presence of a major submarine valley on the continental slope of the Antarctic Peninsula margin, in the prolongation of the Antarctic Channel. This submarine valley has been named "GEBRA Valley". The Eastern Bransfield Basin has an extremely complicated morphology mainly as a result of the interference between NE-SW (Bransfield) and E-W (South Scotia Ridge) structural directions. The interpretation of the acquired geophysical data and the analysis of the sediment samples will provide important new information and contribute to a better knowledge of the Antarctic continenetal margins and of the paleoceanographic evolution of the area. Scientists of different institutions participated into the GEBRA '93 survey: the University of Barcelona, the Institute of Marine Sciences of Barcelona, the Spanish Institute of Oceanography, the University of Salamanca, the University of Gent (Belgium) and Rice University (USA). The survey took place in the framework of the coordinated programme "Geologic and paleoceanographic evolution of the South Atlantic basins and adjacent Antarctic margins", and was funded by CICYT. En Espanol: La campana GEBRA '93 se ha desarrollado en aguas del Estrecho de Bransfield y zonas proximas entre los dias 3 y 24 de Diciembre de 1993, a bordo del B.I.O. Hesperides. En ella se han llevado a termino trabajos de barrido con multihaz, sismica de reflexion de monocanal, sonda parametrica BPS, magnetometr?a, extraccion de testigos de gravedad y fondeo de instrumentos. En total se han barrido 17.000 km2 del fondo marino, con una profundidad media de 1500 m., se han registrado simultaneamente 1.500 km. de lineas de sismica, sonda parametrica BPS y magnetometria (total 4.500 Km.), se han obtenido dos testgos de gravedad de 2.5 m. y 4.5 m. de longitud, y se han fondeado 7 correntimetros, 3 mareografos, una boya de oleaje y 3 liberadores acusticos. Todo ello en 21 dias efectivos de trabajo. Los abundantes datos obtenidos han pernitido caracterizar con gran detalle la morfoestructura, el recubrimiento sedimentario y las anomalias magneticas del area estudiada. Los datos de multihaz de GEBRA '93 cierran la cobertura total de un arco de 11 degrees de longitud (49 degrees 30 minutes W hasta 60 degrees 30 minutes W) y una anchura media de 30 minutes de latitud, que ocupa la Cuenca de Bransfield y el segmento occidental de la Dorsal Sur de Scotia. Entre otras aportaciones relevantes, se ha puesto de manifiesto la existencia de varios edificios volcanicos de grandes dimensiones en el fondo de la subcuenca central de Bransfield, y de un gran valle submarino en el margen antartico, aguas afuera del Canal Antartico. Dicho valle ha recibido el nombre de Valle Gebra. La subcuenca oriental de Bransfield presenta una morfolog?a extremadamente compleja debido en gran medida a la interferencia entre las direcciones estructurales de la cuenca de Bransfield (NE-SW) y de la Dorsal Sur de Scotia (E-W). La interpretacion definitiva de los datos geofisicos adquiridos y el analisis de los testigos de sedimentos aportaran nuevas informaciones que contribuican significativamente al conocimiento de la evolucion geodinamica de la Cuenca de Bransfield y de su vulcanismo, de la Estratigrafia Sismica de los margenes continentales antarticos, y de la evolucion paleoceanografica de la region. Han participado en GEBRA '93 investigadores de la Universidad de Barcelona, del Instituto de Ciencias del Mar de Barcelona, del Instituto Espanol de Oceanografia, de la Universidad de Salamanca, de la Universidad de Gante (Belgica) y de la Universidad de Rice (Estados Unidos). Esta campana ha sido la segunda del programa coordinado "Evolucion geologica y paleoceanografica del Atlantico Sur y de las cuencas y margenes antarticos adyacentes", financiado por la CICYT.
Purpose:
Not Available
Supplemental_Information:
Not Available
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19931203
Ending_Date: 19931224
Currentness_Reference:Unknown
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Description_of_Geographic_Extent:
Bounding_Coordinates:
West_Bounding_Coordinate: -61.0
East_Bounding_Coordinate: -50.0
North_Bounding_Coordinate: -60.0
South_Bounding_Coordinate: -64.0
Keywords:
Theme:
Theme_Keyword_Thesaurus: GCMD SCIENCE PARAMETERS
Theme_Keyword_Thesaurus: GCMD PLATFORM
Theme_Keyword_Thesaurus: GCMD INSTRUMENT
Theme_Keyword_Thesaurus: ISO TOPIC CATEGORY
Theme_Keyword_Thesaurus: DATA SET LANGUAGE
Theme_Keyword: EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE > ATMOSPHERIC PRESSURE MEASUREMENTS
Theme_Keyword: EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > AIR TEMPERATURE
Theme_Keyword: EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > HUMIDITY
Theme_Keyword: EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR
Theme_Keyword: EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS
Theme_Keyword: EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC RADIATION > SOLAR RADIATION
Theme_Keyword: EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY
Theme_Keyword: EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > FRACTURE ZONES
Theme_Keyword: EARTH SCIENCE > OCEANS > MARINE GEOPHYSICS > MARINE GRAVITY FIELD
Theme_Keyword: EARTH SCIENCE > OCEANS > MARINE GEOPHYSICS > MARINE MAGNETICS > MAGNETIC ANOMALIES
Theme_Keyword: EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > OCEAN PLATEAUS/RIDGES
Theme_Keyword: EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAMOUNTS
Theme_Keyword: EARTH SCIENCE > OCEANS > OCEAN OPTICS > FLUORESCENCE
Theme_Keyword: EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE
Theme_Keyword: EARTH SCIENCE > OCEANS > SALINITY/DENSITY > CONDUCTIVITY
Theme_Keyword: EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY
Theme_Keyword: EARTH SCIENCE > OCEANS > MARINE GEOPHYSICS > PLATE TECTONICS > SUBDUCTION
Theme_Keyword: SHIPS
Theme_Keyword: GRAVIMETERS
Theme_Keyword: SEDIMENT CORERS
Theme_Keyword: THERMOSALINOGRAPHS
Theme_Keyword: MAGNETOMETERS
Theme_Keyword: GPS > GLOBAL POSITIONING SYSTEM
Theme_Keyword: SEISMIC REFLECTION PROFILERS
Theme_Keyword: ADCP > ACOUSTIC DOPPLER CURRENT PROFILER
Theme_Keyword: ECHO SOUNDERS
Theme_Keyword: FLUOROMETERS
Theme_Keyword: CLIMATOLOGY/METEOROLOGY/ATMOSPHERE
Theme_Keyword: ELEVATION
Theme_Keyword: GEOSCIENTIFIC INFORMATION
Theme_Keyword: OCEANS
Theme_Keyword: SPANISH
Place:
Place_Keyword_Thesaurus: GCMD
Place_Keyword: CONTINENT > ANTARCTICA > BRANSFIELD STRAIT
Place_Keyword: GEOGRAPHIC REGION > POLAR
Access_Constraints: Not Available
Use_Constraints:
Not Available
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: MIGUEL CANALS
Contact_Position: INVESTIGATOR
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Facultad de Geologia
Address: Universidad de Barcelona
Address: Nucleo Universitario de Pedralbes
City: Barcelona
Postal_Code: 08071
Country: Spain
Contact_Voice_Telephone: +3434021360
Contact_Facsimile_Telephone: +3434021340
Contact_Electronic_Mail_Address: miquel@natura.geo.ub.es
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Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Not Available
Logical_Consistency_Report:
Not Available
Completeness_Report:
Not Available
Lineage:
Process_Step:
Process_Description:
Not Available
Process_Date: Unknown
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Spatial_Reference_Information:
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: ES/CSIC/UTM > Unidad de Tecnologia Marina, Consejo Superior de Investigaciones Cientificas, Espana
Contact_Person: MIGUEL ANGEL OJEDA
Contact_Position: DATA CENTER CONTACT
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Centro Mediterraneo de Investigaciones Marinas y Ambientales
Address: CSIC
Address: Unidad de Tecnologia Marina
Address: Paseo Maritimo, 37-39
City: Barcelona
Postal_Code: 08003
Country: SPAIN
Contact_Voice_Telephone: +34932216416
Contact_Electronic_Mail_Address: maojeda@utm.csic.es
Resource_Description: CNDA-ESP_ANT93-1008-C03-HE014
Distribution_Liability:
Not Available
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ASCII, BINARY
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://www.utm.csic.es/
Access_Instructions:
DATA CENTER URL
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://www.utm.csic.es/Hesperides/
Access_Instructions:
In English: Information on the vessel's Hesperides, oceanographic expeditions can be found on this page. The information includes a summary of the scientific results, participating agencies, etc. En Espanol: En esta pagina se encuentra informacion sobre la campanas realizadas por el Buque Oceanografico Hesperides: Resumen de los resultados cientificos, organismos participantes..etc.
Fees: Not Available
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Metadata_Reference_Information:
Metadata_Date:
Metadata_Review_Date: 20030924
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: ANTONIO BARRAGAN SANABRIA
Contact_Position: DIF AUTHOR
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Centro Nacional de Datos Antarticos
Address: Instituto Geologico y Minero de Espana
Address: c/Rios Rosas 23
City: Madrid
Postal_Code: 28003
Country: SPAIN
Contact_Voice_Telephone: +34913495731
Contact_Facsimile_Telephone: +34913495929
Contact_Electronic_Mail_Address: a.barragan@igme.es
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
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