TY - JOUR
T1 - Miocene to present oceanographic variability in the Scotia Sea and Antarctic ice sheets dynamics
T2 - Insight from revised seismic-stratigraphy following IODP Expedition 382
AU - Pérez, Lara F.
AU - Martos, Yasmina M.
AU - García, Marga
AU - Weber, Michael E.
AU - Raymo, Maureen E.
AU - Williams, Trevor
AU - Bohoyo, Fernando
AU - Armbrecht, Linda
AU - Bailey, Ian
AU - Brachfeld, Stefanie
AU - Glüder, Anna
AU - Guitard, Michelle
AU - Gutjahr, Marcus
AU - Hemming, Sidney
AU - Hernández-Almeida, Iván
AU - Hoem, Frida S.
AU - Kato, Yuji
AU - O'Connell, Suzanne
AU - Peck, Victoria L.
AU - Reilly, Brendan
AU - Ronge, Thomas A.
AU - Tauxe, Lisa
AU - Warnock, Jonathan
AU - Zheng, Xufeng
AU - the IODP Expedition 382 Scientists, null
N1 - Publisher Copyright:
© 2020 The Authors
PY - 2021/1/1
Y1 - 2021/1/1
N2 - Scotia Sea and the Drake Passage is key towards understanding the development of modern oceanic circulation patterns and their implications for ice sheet growth and decay. The sedimentary record of the southern Scotia Sea basins documents the regional tectonic, oceanographic and climatic evolution since the Eocene. However, a lack of accurate age estimations has prevented the calibration of the reconstructed history. The upper sedimentary record of the Scotia Sea was scientifically drilled for the first time in 2019 during International Ocean Discovery Program (IODP) Expedition 382, recovering sediments down to ∼643 and 676 m below sea floor in the Dove and Pirie basins respectively. Here, we report newly acquired high resolution physical properties data and the first accurate age constraints for the seismic sequences of the upper sedimentary record of the Scotia Sea to the late Miocene. The drilled record contains four basin-wide reflectors – Reflector-c, -b, -a and -a' previously estimated to be ∼12.6 Ma, ∼6.4 Ma, ∼3.8 Ma and ∼2.6 Ma, respectively. By extrapolating our new Scotia Sea age model to previous morpho-structural and seismic-stratigraphic analyses of the wider region we found, however, that the four discontinuities drilled are much younger than previously thought. Reflector-c actually formed before 8.4 Ma, Reflector-b at ∼4.5/3.7 Ma, Reflector-a at ∼1.7 Ma, and Reflector-a' at ∼0.4 Ma. Our updated age model of these discontinuities has major implications for their correlation with regional tectonic, oceanographic and cryospheric events. According to our results, the outflow of Antarctic Bottom Water to northern latitudes controlled the Antarctic Circumpolar Current flow from late Miocene. Subsequent variability of the Antarctic ice sheets has influenced the oceanic circulation pattern linked to major global climatic changes during early Pliocene, Mid-Pleistocene and the Marine Isotope Stage 11.
AB - Scotia Sea and the Drake Passage is key towards understanding the development of modern oceanic circulation patterns and their implications for ice sheet growth and decay. The sedimentary record of the southern Scotia Sea basins documents the regional tectonic, oceanographic and climatic evolution since the Eocene. However, a lack of accurate age estimations has prevented the calibration of the reconstructed history. The upper sedimentary record of the Scotia Sea was scientifically drilled for the first time in 2019 during International Ocean Discovery Program (IODP) Expedition 382, recovering sediments down to ∼643 and 676 m below sea floor in the Dove and Pirie basins respectively. Here, we report newly acquired high resolution physical properties data and the first accurate age constraints for the seismic sequences of the upper sedimentary record of the Scotia Sea to the late Miocene. The drilled record contains four basin-wide reflectors – Reflector-c, -b, -a and -a' previously estimated to be ∼12.6 Ma, ∼6.4 Ma, ∼3.8 Ma and ∼2.6 Ma, respectively. By extrapolating our new Scotia Sea age model to previous morpho-structural and seismic-stratigraphic analyses of the wider region we found, however, that the four discontinuities drilled are much younger than previously thought. Reflector-c actually formed before 8.4 Ma, Reflector-b at ∼4.5/3.7 Ma, Reflector-a at ∼1.7 Ma, and Reflector-a' at ∼0.4 Ma. Our updated age model of these discontinuities has major implications for their correlation with regional tectonic, oceanographic and cryospheric events. According to our results, the outflow of Antarctic Bottom Water to northern latitudes controlled the Antarctic Circumpolar Current flow from late Miocene. Subsequent variability of the Antarctic ice sheets has influenced the oceanic circulation pattern linked to major global climatic changes during early Pliocene, Mid-Pleistocene and the Marine Isotope Stage 11.
KW - Antarctic ice sheets evolution
KW - core-log-seismic correlation
KW - Drake Passage
KW - IODP Expedition 382
KW - oceanic gateways
KW - Scotia Sea
UR - http://www.scopus.com/inward/record.url?scp=85096394183&partnerID=8YFLogxK
U2 - 10.1016/j.epsl.2020.116657
DO - 10.1016/j.epsl.2020.116657
M3 - Article
AN - SCOPUS:85096394183
SN - 0012-821X
VL - 553
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
M1 - 116657
ER -