International Ocean Discovery Program Expedition 382 Preliminary Report Iceberg Alley and Subantarctic Ice and Ocean Dynamics 20 March–20 May 2019 Michael E. Weber, Maureen E. Raymo, Victoria L. Peck, Trevor Williams, and the Expedition 382 Scientists Publisher’s notes Core samples and the wider set of data from the science program covered in this report are under moratorium and accessible only to Science Party members until 20 November 2020. This publication was prepared by the JOIDES Resolution Science Operator (JRSO) at Texas A&M University (TAMU) as an account of work performed under the International Ocean Discovery Program (IODP). Funding for IODP is provided by the following international partners: National Science Foundation (NSF), United States Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan European Consortium for Ocean Research Drilling (ECORD) Ministry of Science and Technology (MOST), People’s Republic of China Korea Institute of Geoscience and Mineral Resources (KIGAM) Australia-New Zealand IODP Consortium (ANZIC) Ministry of Earth Sciences (MoES), India Coordination for Improvement of Higher Education Personnel (CAPES), Brazil Portions of this work may have been published in whole or in part in other IODP documents or publications. Disclaimer Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the participating agencies, TAMU, or Texas A&M Research Foundation. Copyright Except where otherwise noted, this work is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) license (https://creativecommons.org/​ licenses/by/4.0/). Unrestricted use, distribution, and reproduction are permitted, provided the original author and source are credited. Citation Weber, M.E., Raymo, M.E., Peck, V.L., Williams, T., and the Expedition 382 Scientists, 2019. Expedition 382 Prelimi- nary Report: Iceberg Alley and Subantarctic Ice and Ocean Dynamics. International Ocean Discovery Program. https://doi.org/10.14379/iodp.pr.382.2019 ISSN World Wide Web: 2372-9562 August 2019 M.E. Weber et al. Expedition 382 Preliminary Report Expedition 382 participants Expedition 382 scientists Michael​E.​Weber Marga​Garcia Co-Chief​Scientist Physical​Properties/Downhole​Measurements/Petrophysics​ University of Bonn Specialist Steinmann-Institute Andalusian Institute of Earth Sciences Germany CSIC-University of Granada [email protected] Spain [email protected] Maureen​E.​Raymo Co-Chief​Scientist Anna​Glüder Lamont-Doherty Earth Observatory Sedimentologist Columbia University College of Earth, Ocean and Atmospheric Sciences USA Oregon State University [email protected] USA [email protected] Trevor​Williams Expedition​Project​Manager/Staff​Scientist Michelle​Guitard International Ocean Discovery Program Physical​Properties/Petrophysics​Specialist Texas A&M University College of Marine Science USA University of South Florida, St. Petersburg [email protected] USA [email protected] Linda​Armbrecht Paleontologist​(diatoms) Marcus​Gutjahr Australian Centre for Ancient DNA (ACAD) Inorganic​Geochemist Department of Ecology & Evolutionary Biology GEOMAR Helmholtz Centre for Ocean Research Kiel School of Biological Sciences Germany University of Adelaide [email protected] Australia Sidney​Hemming [email protected] Stratigraphic​Correlator/Petrophysics​Specialist Ian​Bailey Lamont-Doherty Earth Observatory Stratigraphic​Correlator/Petrophysics​Specialist Columbia University Camborne School of Mines & Environment and Sustainability USA Institute [email protected] University of Exeter United Kingdom Ivan​Hernandez-Almeida Paleontologist​(radiolarians) [email protected] Department of Earth Sciences Stefanie​Brachfeld Institute of Geology Paleomagnetist ETH Zurich Earth and Environmental Studies Switzerland Montclair State University [email protected] USA Frida​S.​Hoem [email protected] Palynologist Zhiheng​Du Marine Palynology and Paleoceanography Sedimentologist Utrecht University State Key Laboratory of Cryospheric Sciences Netherlands Chinese Academy of Sciences [email protected] China Ji-Hwan​Hwang [email protected] Inorganic​Geochemist Gerson​Fauth Earth & Environmental Sciences Sedimentologist Korea Basic Science Institute Geology Program Republic of Korea University of Vale do Rio dos Sinos (UNISINOS) [email protected] Instituto Tecnologico de Micropaleontologia, itt Fossil Brazil [email protected] 3 M.E. 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Expedition 382 Preliminary Report Mutsumi​Iizuka Brendan​Reilly Sedimentologist Paleomagnetist Graduate School of Environmental Science College of Earth, Ocean and Atmospheric Sciences Hokkaido University Oregon State University Japan USA [email protected] [email protected] Yuji​Kato Thomas​A.​Ronge Paleontologist​(diatoms) Sedimentologist Environmental Studies Marine Geology Nagoya University Alfred Wegener Institute Helmholtz Center for Polar and Japan Marine Research Germany Present affiliation (1 April 2019): [email protected] Center for Advanced Marine Core Research Kochi University Osamu​Seki Japan Organic​Geochemist [email protected] Institute of Low Temperature Science Hokkaido University Bridget​K.​Lee Japan Inorganic​Geochemist [email protected] Department of Earth Sciences University of California, Riverside Lisa​Tauxe USA Paleomagnetist [email protected] Scripps Institution of Oceanography University of California, San Diego Yasmina​M.​Martos USA Physical​Properties/Downhole​Measurements/Petrophysics​ [email protected] Specialist NASA Goddard Space Flight Center Shubham​Tripathi University of Maryland College Park Sedimentologist USA Marine Stable Isotope Lab [email protected] National Centre for Polar and Ocean Research (NCPOR) India Suzanne​O’Connell [email protected] Sedimentologist Department of Earth and Environmental Sciences Jonathan​Warnock Wesleyan University Paleontologist​(diatoms) USA Department of Geoscience [email protected] Indiana University of Pennsylvania USA Victoria​L.​Peck [email protected] Sedimentologist Geological Sciences Xufeng​Zheng British Antarctic Survey Physical​Properties/Petrophysics​Specialist United Kingdom Chinese Academy of Sciences [email protected] South China Sea Institute of Oceanology China Lara​F.​Perez [email protected] Physical​Properties/Downhole​Measurements/Petrophysics​ Specialist British Antarctic Survey United Kingdom [email protected] Observers Fabricio​G.​Cardillo Anthony​D.​Mello Observer Weather/Ice​Observer Departamento Oceanografía USA Servicio de Hidrografía Naval [email protected] Ministerio de Defensa Argentina [email protected] 4 M.E. 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Expedition 382 Preliminary Report Education and outreach Marlo​P.​Garnsworthy Lee​A.​Stevens Outreach​Officer Outreach​Officer Editor/Author/Illustrator Communications Wordy Bird Studio American Museum of Natural History USA USA [email protected] [email protected] Operational and technical staff Siem Offshore AS officials Terry​Skinner Sam​McLelland Master of the Drilling Vessel Drilling Supervisor JRSO shipboard personnel and technical representatives Alexis​Armstrong Zenon​Mateo Core Laboratory Underway Geophysics Laboratory Heather​Barnes Graham​Messe Assistant Laboratory Officer Paleomagnetism Laboratory Michael​Cannon Erik​Moortgat Marine Computer Specialist Assistant Laboratory Officer Etienne​Claassen Algie​Morgan Marine Instrumentation Specialist Application Developer Lisa​Crowder Jenna​Patten Laboratory Officer Marine Laboratory Technician (temporary) Margaret​Hastedt Vincent​Percuoco Core Laboratory Chemistry Laboratory Luan​Heywood Doris​Pinero​Lajas Thin Section Laboratory Physical Properties Laboratory Minh​Huynh Bill​Rhinehart Marine Computer Specialist Operations Superintendent Sarah​Kachovich Alyssa​Stephens X-ray Laboratory Publications Specialist Jan​Jurie​Kotze Johanna​Suhonen Marine Instrumentation Specialist Chemistry Laboratory Brittany​Martinez Kerry​Swain Curatorial Specialist Logging Engineer 5 M.E. Weber et al. Expedition 382 Preliminary Report Abstract tween 400 and 2000 m water depth on the northern flank of an east–west trending trough off the Chilean continental shelf, is ide- International Ocean Discovery Program (IODP) Expedition ally situated to monitor millennial- to orbital-scale variability in the 382, Iceberg Alley and Subantarctic Ice and Ocean Dynamics, inves- export of Antarctic Intermediate Water beneath the Subantarctic tigated the long-term climate history of Antarctica, seeking to un- Front. During Expedition 382, we recovered continuously deposited derstand how polar ice sheets responded to changes in insolation sediments from this drift spanning the late Pleistocene (from ~0.78 and atmospheric CO2 in the past and how ice sheet evolution influ- Ma to recent) and from the late Pliocene (~3.1–2.6 Ma). These sites enced global sea level and vice versa. Five sites (U1534–U1538) are expected to yield a wide array of paleoceanographic records that were drilled east of the Drake Passage: two sites at 53.2°S at the can be used to interpret past changes in the density structure of the northern edge of the Scotia Sea and three sites at 57.4°–59.4°S in the Atlantic sector of the Southern Ocean, track migrations of the Sub- southern Scotia Sea. We recovered continuously deposited late antarctic Front, and give insights into the role and evolution of the Neogene sediment to reconstruct the past history