Marine Isotope Stage (MIS) M2 (≈3.3 Ma) in the Southern Hemisphere; constraining the climatic drivers of a short-term glaciation event during the Pliocene warm period

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http://abstractsearch.agu.org/meetings/2017/FM/PP23C-1329.html
Author(s): De Vleeschouwer, David; Auer, Gerald; Bogus, K.; Groeneveld, J.; Henderiks, J.; Jatiningrum, Resti Samyati; Christensen, B. A.
Author Affiliation(s): Primary:
University of Bremen, MARUM, Bremen, Germany
Other:
University of Graz, Department of Geobiology and Palaeoecology, Graz, Austria
International Ocean Discovery Program, College Station, TX, United States
Uppsala University, Department of Earth Sciences, Uppsala, Sweden
Akita University, Department of Geosciences, Geotechnology, and Material Resource Engineering, Akita, Japan
Adelphi University, Garden City, NY, United States
Volume Title: AGU 2017 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2017; American Geophysical Union 2017 fall meeting, New Orleans, LA, Dec. 11-15, 2017. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English. 5 refs.
Summary: Global climate was characterized by intriguing climate variability during the Late Pliocene (3.6 to 2.59 Ma): a brief (<100 kyr) but intense glaciation (MIS M2) interrupted the relatively warm climate state around 3.3 Ma. Until today, different hypotheses exist to explain why this glaciation event was so intense, and why the global climate system returned to warm Pliocene conditions relatively quickly. One of these proposed mechanisms is a reduced equator-to-pole heat transfer, in response to a tectonically reduced Indonesian Throughflow (ITF; De Schepper et al., 2014; Karas et al., 2011a, b). However, the scarcity of orbital-scale continuous climate archives in the outflow of the Indonesian Seaway hampers testing this hypothesis. To assess the supposed relationship between mid-Pliocene glaciations and latitudinal heat transport through the Indonesian Throughflow, we constructed a 3-kyr resolution planktonic δ18OG.sacculifer record for the 3.9 - 2.7 Ma interval from Site U1463 (18°59'S, 117°37'E; Northwestern Australian Shelf; IODP Expedition 356 "Indonesian Throughflow"). The U1463 oxygen isotope record concurs exceptionally well with the sea surface temperature (SST) record from Site 806 (0°19'N, 159°22'E) in the West Pacific Warm Pool (Wara et al., 2005), even during MIS M2. Hence, Site U1463 suggests an uninterrupted ITF signal during Pliocene glaciations. Surprisingly though, the U1463 δ18OG.sacculifer record exhibits a ≈0.5 ppm offset with the nearby Site 763 record (20°35'S, 112°12'E) around MIS M2. This implies that Site 763, which lies a bit further offshore than U1463, fits better with Indian Ocean SST records (e.g. Site 214; Karas et al., 2009) across MIS M2. In conclusion, the U1463 data reveal that heat-transport through the Indonesian Throughflow did not shut down completely during MIS M2. However, its intensity decreased during MIS M2, causing Site 763 to temporarily reflect an Indian Ocean, rather than an ITF signal. References: De Schepper, S. et al. 2014, Earth-Science Reviews, v. 135, p. 83-102. Karas, C. et al. 2009, Nature Geosci, v. 2, no. 6, p. 434-438. Karas, C. et al. 2011a, Earth and Planetary Science Letters, v. 301, no. 1-2, p. 117-124. -, 2011b, Paleoceanography, v. 26. Wara, M. W. et al., 2005, Science, v. 309, no. 5735, p. 758-761.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Cenozoic; Climate change; Climate effects; Expedition 356; Glacial environment; IODP Site U1463; Indonesian Seas; Interglacial environment; International Ocean Discovery Program; Neogene; Pacific Ocean; Paleoclimatology; Paleoenvironment; Pliocene; Quaternary; Tertiary; West Pacific
Record ID: 2018074821
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union, Washington, DC, United States

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