Current Controlled Sedimentation Dominates Wide Areas of the South East African Continental Margin off Mozambique and Madagascar: Preliminary Results of a Multichannel Seismic Survey
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Volkhard Spiess [1] ; Benedikt Preu [1] ; Stefan Wenau [1] ; Luisa Palamenghi [1] ; Tilmann Schwenk [1] ; Ralph Schneider [2]
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[1] University of Bremen
University of Bremen
Kreisfreie Stadt Bremen, Alemania
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[2] Kiel University
Kiel University
Kreisfreie Stadt Kiel, Alemania
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- Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 11, 2010 (Ejemplar dedicado a: Deep-Water Circulation: Processes & Products. International Congress. Baitona, Pontevedra, Spain. 16 & 17 June 2010), págs. 161-162
- Idioma: inglés
- Enlaces
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Resumen
The thermohaline circulation in the Eastern Indian Ocean is dominated by the Mozambique andMadagascar Currents, which join as the Agulhas Current south of Madagascar to carry enormous amounts of heatfrom the Indian to the Atlantic Ocean. The most sensitive part of the interocean exchange is located at the southerntip of Africa and on the Southeastern African continental margin. As the current patterns are assumed to be heavilyinfluenced by changes in the climate system, variations in current intensity and enhancement of the retroflectionare closely related to glacial and interglacial conditions.A multichannel seismic survey off Mozambique, Madagascar and South Africa was carried out to identify potentialdrilling locations to study the Neogene evolution of the Agulhas current system during the last 10 million years. Asan outcome of several regional surveys between 35°S and 15°S, we found the margin to be dominated by current-controlled sediment builtups. Rather than being influenced by terrigenuous sediment input only, wide parts of thecontinental margins were shaped by contour currents ranging in depth from ~100 m down to more than 1500 mwater depth. Also shelf regions reveal pronounced current sediment transport, serving as redistribution mechanismand as significant margin sediment source.
