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  1. Elucidating the long-term history of the Greenland Ice Sheet (GrIS) is essential for understanding glacial instability thresholds, identified as major climate system tipping points, and how the cryosphere will respond to anthropogenic greenhouse gas emissions. To address current knowledge gaps in the evolution and variability of the GrIS and its role in Earth's climate system, International Ocean Discovery Program (IODP) Expedition 400 will obtain cores from seven sites across the northwest Greenland margin into Baffin Bay where thick Cenozoic sedimentary successions can be directly linked to the evolution of the northern GrIS (NGrIS). The strategy of drilling along this transect is to retrieve a composite stratigraphic succession representing the Late Cenozoic era from the Oligocene/Early Miocene to Holocene. The proposed sites will specifically target high–accumulation rate deposits associated with contourite drifts and potential interglacial deposits within a trough mouth fan system densely covered by seismic data. We seek to test if the NGrIS underwent near-complete deglaciations in the Pleistocene and to assess the ice sheet’s response to changes in orbital cyclicities through the mid-Pleistocene transition. Paleoclimate records will be obtained that can provide chronology on the NGrIS expansion and unravel potential linkages between marine heat transport through Baffin Bay andmore »high Arctic warmth during the Pliocene. A deep coring site (980 meters below seafloor) targeting a Miocene and Oligocene strata succession will examine possible linkages between changes in atmospheric CO2 and climate-ecosystem conditions in Greenland. The overall aim is to investigate the full range of forcings and feedbacks—oceanic, atmospheric, orbital, and tectonic—that influence the GrIS over a range of timescales, as well as conditions prevailing at the time of glacial inception and deglacial to interglacial periods. The data and results gathered from Expedition 400 will effectively constrain predictive models addressing the GrIS response to global warming and its impending effects on global sea levels.« less
    Free, publicly-accessible full text available September 1, 2023
  2. During International Ocean Discovery Program Expedition 392, three sites were drilled on the Agulhas Plateau and one site was drilled in the Transkei Basin in the Southwest Indian Ocean. This region was positioned at paleolatitudes of ~53°–61°S during the Late Cretaceous (van Hinsbergen et al., 2015) (100–66 Ma) and within the new and evolving gateway between the South Atlantic, Southern Ocean, and southern Indian Ocean basins. Recovery of basement rocks and sedimentary sequences from the Agulhas Plateau sites and a thick sedimentary sequence in the Transkei Basin provides a wealth of new data to (1) determine the nature and origin of the Agulhas Plateau; (2) significantly advance the understanding of how Cretaceous temperatures, ocean circulation, and sedimentation patterns evolved as CO2 levels rose and fell and the breakup of Gondwana progressed; (3) document long-term paleoceanographic variability through the Late Cretaceous and Paleogene; and (4) investigate geochemical interactions between igneous rocks, sediments, and pore waters through the life cycle of a large igneous province (LIP). Importantly, postcruise analysis of Expedition 392 drill cores will allow testing of competing hypotheses concerning Agulhas Plateau LIP formation and the role of deep ocean circulation changes through southern gateways in controlling Late Cretaceous–early Paleogene climatemore »evolution.« less
    Free, publicly-accessible full text available September 1, 2023
  3. International Ocean Discovery Program (IODP) Expedition 378 was designed to recover the first comprehensive set of Paleogene sedimentary sections from a transect of sites strategically positioned in the South Pacific Ocean to reconstruct key changes in oceanic and atmospheric circulation. These sites would have provided an unparalleled opportunity to add crucial new data and geographic coverage to existing reconstructions of Paleogene climate. Following the ~15 month postponement of Expedition 378 and subsequent port changes that resulted in a reduction of the number of primary sites, testing and evaluation of the research vessel JOIDES Resolution derrick in the weeks preceding the expedition determined that it would not support deployment of drill strings in excess of 2 km. Consequently, only one of the originally approved seven primary sites was drilled. Expedition 378 recovered the first continuously cored, multiple-hole Paleogene sedimentary section from the southern Campbell Plateau at Site U1553. This high–southern latitude site builds on the legacy of Deep Sea Drilling Project Site 277 (a single, partially spot cored hole), providing a unique opportunity to refine and expand existing reconstructions of Cenozoic climate history. As the world’s largest ocean, the Pacific Ocean is intricately linked to major changes in the global climatemore »system. Previous drilling in the low-latitude Pacific Ocean during Ocean Drilling Program Legs 138 and 199 and Integrated Ocean Drilling Program Expeditions 320 and 321 provided new insights into climate and carbon system dynamics, productivity changes across the zone of divergence, time-dependent calcium carbonate dissolution, bio- and magnetostratigraphy, the location of the Intertropical Convergence Zone, and evolutionary patterns for times of climatic change and upheaval. Expedition 378 in the South Pacific Ocean uniquely complements this work with a high-latitude perspective, especially because appropriate high-latitude records are unobtainable in the Northern Hemisphere of the Pacific Ocean. Expedition 378 provides material from the South Pacific Ocean in an area critical for high-latitude climate reconstructions spanning the early Paleocene to late Oligocene. Site U1553 and the entire corpus of shore-based investigations will significantly contribute to the challenges of the “Climate and Ocean Change: Reading the Past, Informing the Future” theme of the 2013–2023 IODP Science Plan (How does Earth’s climate system respond to elevated levels of atmospheric CO2? How resilient is the ocean to chemical perturbations?). Furthermore, Expedition 378 provides material from the South Pacific Ocean in an area critical for high-latitude climate reconstructions spanning the Paleocene to late Oligocene.« less
    Free, publicly-accessible full text available February 6, 2023
  4. International Ocean Discovery Program (IODP) Expedition 378 was designed to recover the first comprehensive set of Paleogene sedimentary sections from a transect of sites strategically positioned in the South Pacific to reconstruct key changes in oceanic and atmospheric circulation. These sites would have provided an unparalleled opportunity to add crucial new data and geographic coverage to existing reconstructions of Paleogene climate. In addition to the ~15 month postponement of Expedition 378 and subsequent port changes resulting in a reduction of the number of primary sites, testing and evaluation of the R/V JOIDES Resolution derrick in the weeks preceding the expedition determined that it would not support deployment of drill strings in excess of 2 km. Because of this determination, only 1 of the originally approved 7 primary sites was drilled. Expedition 378 recovered the first continuously cored, multiple-hole Paleogene sedimentary section from the southern Campbell Plateau at Site U1553. This high–southern latitude site builds on the legacy of Deep Sea Drilling Project (DSDP) Site 277, a single, partially spot cored hole, providing a unique opportunity to refine and augment existing reconstructions of the past ~66 My of climate history. This also includes the discovery of a new siliciclastic unit thatmore »had never been drilled before. As the world’s largest ocean, the Pacific Ocean is intricately linked to major changes in the global climate system. Previous drilling in the low-latitude Pacific Ocean during Ocean Drilling Program (ODP) Legs 138 and 199 and Integrated Ocean Drilling Program Expeditions 320 and 321 provided new insights into climate and carbon system dynamics, productivity changes across the zone of divergence, time-dependent calcium carbonate dissolution, bio- and magnetostratigraphy, the location of the Intertropical Convergence Zone, and evolutionary patterns for times of climatic change and upheaval. Expedition 378 in the South Pacific Ocean uniquely complements this work with a high-latitude perspective, especially because appropriate high-latitude records are unobtainable in the Northern Hemisphere of the Pacific Ocean. Site U1553 and the entire corpus of shore-based investigations will significantly contribute to the challenges of the “Climate and Ocean Change: Reading the Past, Informing the Future” theme of the IODP Science Plan (How does Earth’s climate system respond to elevated levels of atmospheric CO2? How resilient is the ocean to chemical perturbations?). Furthermore, Expedition 378 will provide material from the South Pacific Ocean in an area critical for high-latitude climate reconstructions spanning the Paleocene to late Oligocene.« less
  5. This addendum to the International Ocean Discovery Program (IODP) Expedition 378 Scientific Prospectus details changes to the expedition schedule including additional drilling depth approvals and updates to the operations plans that were presented in the original prospectus. In September 2018, Expedition 378 was rescheduled for 2020 to accommodate the construction and installation of two new propellers for the vessel with minimal disruption to the slate of expeditions scheduled in the Southern Ocean. The change in expedition timing resulted in a change of the port of origination from Lyttelton, New Zealand, to Lautoka, Fiji, and a change in the number of transit days. Consequently, the operations schedule has been revised. The other development prompting an addendum to the Expedition 378 Scientific Prospectus was the approval by the Environmental Protection and Safety Panel (EPSP) to drill deeper at Deep Sea Drilling Project (DSDP) Site 277 than the previous approved maximum depth of 480 meters below seafloor (mbsf) (now approved to 670 mbsf).
  6. International Ocean Discovery Program (IODP) Expedition 387 aims to recover sediments at two sites located in shallow water (~350 to 450 m) on the uppermost continental slope west of the Amazon Fan, northwest of the mouth of the Amazon River. These sediments were deposited in the upper part of the long-lived Foz do Amazonas Basin of the equatorial margin of Brazil. These two sites will recover a sedimentary sequence that spans much of the Cenozoic but with variable provenance and highly variable sedimentation rates. By virtue of their location, the Quaternary sediments will recover an abundance of terrigenous materials including pollen, organic matter, zircon grains, and clay minerals, allowing detailed reconstruction of the biodiversity, climate, and hydrology of the adjacent tropical South American continent. At the same time, an abundance of well-preserved marine microfossils and organic matter will allow accurate determination of the age and oceanographic conditions of the western equatorial Atlantic that partly forced the climate of the adjacent continent. However, our reconstructions of the spatial patterns of biodiversity and climate through time must be interpreted with the knowledge that the geometry of the watersheds that contributed water and sediment to the coastal Atlantic was itself rearranged through time.more »For example, a transcontinental proto-Amazon river did not likely reach the Atlantic until somewhere between 11 and 2 Ma, a date that we expect to more accurately determine from these new cores. Prior to that event, terrigenous sediments at our sites would have been derived from smaller coastal rivers draining watersheds limited to the eastern tropics of northeastern South America. The planned drill sites of Expedition 387 will be the marine complement to a transect of continental drill sites. Together, the marine and continental sites form the Trans-Amazon Drilling Project (TADP), a project that is partly funded by the International Continental Drilling Program (ICDP). The TADP addresses fundamental questions about the Cenozoic climatic evolution of the Amazon region, the origins and evolution of the neotropical rain forest and its biodiversity, and the origins and rearrangements of the transcontinental Amazon River. Together, we expect that these IODP and ICDP projects will transform our understanding of Amazonian geological, climatic, biological, and paleoceanographic history.« less