A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene
The exchange of shallow and deep water masses between the Indian Ocean and the Atlantic constitutes an integral inter-ocean link in the global thermohaline circulation. In the gateway south of South Africa long-term changes in deep water flow during the Cenozoic have been initially studied using sei...
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ftawi:oai:epic.awi.de:47318 2024-09-15T17:44:29+00:00 A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene Gruetzner, Jens Jimenez Espejo, F.J. Lathika, N. Uenzelmann-Neben, Gabriele 2018-03 application/pdf https://epic.awi.de/id/eprint/47318/ https://epic.awi.de/id/eprint/47318/1/Gruetzner_abstract_IODP_2018_talk.pdf https://hdl.handle.net/10013/epic.fd84e977-ba9a-4afc-a999-012c5750dae9 unknown https://epic.awi.de/id/eprint/47318/1/Gruetzner_abstract_IODP_2018_talk.pdf Gruetzner, J. orcid:0000-0001-5445-2393 , Jimenez Espejo, F. , Lathika, N. and Uenzelmann-Neben, G. orcid:0000-0002-0115-5923 (2018) A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene , Gemeinsames Kolloquium - DFG-Schwerpunktprogramme ICDP (International Continental Scientific Drilling Program) und IODP (International Ocean Discovery Program), Bochum, Germany, 14 March 2018 - 16 March 2018 . hdl:10013/epic.fd84e977-ba9a-4afc-a999-012c5750dae9 EPIC3Gemeinsames Kolloquium - DFG-Schwerpunktprogramme ICDP (International Continental Scientific Drilling Program) und IODP (International Ocean Discovery Program), Bochum, Germany, 2018-03-14-2018-03-16 Conference notRev 2018 ftawi 2024-06-24T04:19:47Z The exchange of shallow and deep water masses between the Indian Ocean and the Atlantic constitutes an integral inter-ocean link in the global thermohaline circulation. In the gateway south of South Africa long-term changes in deep water flow during the Cenozoic have been initially studied using seismic reflection profiles. But the seismic stratigraphy was poorly constrained and not further resolved within the time period from the late Miocene to present. In particular, there were limited Pliocene records that could be used to investigate the influence of climatic (e.g. Antarctic ice volume) and tectonic (e.g. closure of the Central American seaway) on the deep-water variability. In 2016 the International Ocean Discovery Program (IODP) Expedition 361 (“SAFARI”) recovered complete high-resolution Plio-/Pleistocene sediment sections at six drilling locations on the southeast African margin and in the Indian-Atlantic ocean gateway. Here, we present results from Site U1475 (Agulhas Plateau), a location proximal to the entrance of North Atlantic Deep Water (NADW) to the Southern Ocean and South Indian Ocean. The site is located over a sediment drift in 2669 m water depth and comprises a complete carbonate rich (74 – 85%) stratigraphic section of the last ~7 Ma. We edited high-resolution data sets of density, velocity and natural gamma radiation measured at Site U1475 and corrected them to in-situ conditions. Cross correlations show that acoustic impedance contrasts and thus the formation of seismic reflectors are mainly due to density changes that are caused by climate-induced variations in biogenic vs. terrigenous sediment input. The calculated synthetic seismograms show an excellent correlation of drilling results with the site survey seismic field record, provide an accurate traveltime to depth conversion, and allow preliminary age assignments (± 0.3 Ma) based on the shipboard bio- and magnetostratigraphy. The most prominent reflectors are associated with compositional changes related to late Pleistocene ... Conference Object Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
institution |
Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The exchange of shallow and deep water masses between the Indian Ocean and the Atlantic constitutes an integral inter-ocean link in the global thermohaline circulation. In the gateway south of South Africa long-term changes in deep water flow during the Cenozoic have been initially studied using seismic reflection profiles. But the seismic stratigraphy was poorly constrained and not further resolved within the time period from the late Miocene to present. In particular, there were limited Pliocene records that could be used to investigate the influence of climatic (e.g. Antarctic ice volume) and tectonic (e.g. closure of the Central American seaway) on the deep-water variability. In 2016 the International Ocean Discovery Program (IODP) Expedition 361 (“SAFARI”) recovered complete high-resolution Plio-/Pleistocene sediment sections at six drilling locations on the southeast African margin and in the Indian-Atlantic ocean gateway. Here, we present results from Site U1475 (Agulhas Plateau), a location proximal to the entrance of North Atlantic Deep Water (NADW) to the Southern Ocean and South Indian Ocean. The site is located over a sediment drift in 2669 m water depth and comprises a complete carbonate rich (74 – 85%) stratigraphic section of the last ~7 Ma. We edited high-resolution data sets of density, velocity and natural gamma radiation measured at Site U1475 and corrected them to in-situ conditions. Cross correlations show that acoustic impedance contrasts and thus the formation of seismic reflectors are mainly due to density changes that are caused by climate-induced variations in biogenic vs. terrigenous sediment input. The calculated synthetic seismograms show an excellent correlation of drilling results with the site survey seismic field record, provide an accurate traveltime to depth conversion, and allow preliminary age assignments (± 0.3 Ma) based on the shipboard bio- and magnetostratigraphy. The most prominent reflectors are associated with compositional changes related to late Pleistocene ... |
format |
Conference Object |
author |
Gruetzner, Jens Jimenez Espejo, F.J. Lathika, N. Uenzelmann-Neben, Gabriele |
spellingShingle |
Gruetzner, Jens Jimenez Espejo, F.J. Lathika, N. Uenzelmann-Neben, Gabriele A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene |
author_facet |
Gruetzner, Jens Jimenez Espejo, F.J. Lathika, N. Uenzelmann-Neben, Gabriele |
author_sort |
Gruetzner, Jens |
title |
A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene |
title_short |
A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene |
title_full |
A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene |
title_fullStr |
A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene |
title_full_unstemmed |
A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene |
title_sort |
new seismic stratigraphy for the agulhas plateau resembles major paleo-oceanographic changes in the indian-atlantic ocean gateway since the late miocene |
publishDate |
2018 |
url |
https://epic.awi.de/id/eprint/47318/ https://epic.awi.de/id/eprint/47318/1/Gruetzner_abstract_IODP_2018_talk.pdf https://hdl.handle.net/10013/epic.fd84e977-ba9a-4afc-a999-012c5750dae9 |
genre |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean |
op_source |
EPIC3Gemeinsames Kolloquium - DFG-Schwerpunktprogramme ICDP (International Continental Scientific Drilling Program) und IODP (International Ocean Discovery Program), Bochum, Germany, 2018-03-14-2018-03-16 |
op_relation |
https://epic.awi.de/id/eprint/47318/1/Gruetzner_abstract_IODP_2018_talk.pdf Gruetzner, J. orcid:0000-0001-5445-2393 , Jimenez Espejo, F. , Lathika, N. and Uenzelmann-Neben, G. orcid:0000-0002-0115-5923 (2018) A new seismic stratigraphy for the Agulhas Plateau resembles major paleo-oceanographic changes in the Indian-Atlantic Ocean gateway since the late Miocene , Gemeinsames Kolloquium - DFG-Schwerpunktprogramme ICDP (International Continental Scientific Drilling Program) und IODP (International Ocean Discovery Program), Bochum, Germany, 14 March 2018 - 16 March 2018 . hdl:10013/epic.fd84e977-ba9a-4afc-a999-012c5750dae9 |
_version_ |
1810492099425992704 |