Expedition 374 Summary

• Main Authors: McKay, Robert M., De Santis, Laura, Kulhanek, Denise K., Browne, Imogen M., Shevenell, Amelia E., Expedition 374 Scientists
• Format: Conference Object
• Language: unknown
• Published: Digital Commons @ University of South Florida 2019
• Subjects: International Ocean Discovery Program; IODP; JOIDES Resolution; Expedition 374; Site U1521; Site U1522; Site U1523; Site U1524; Site U1525; Ross Sea; West Antarctic; ice sheet history; sea ice; Miocene; Pliocene; Quaternary; Antarctic Bottom Water; Antarctic water masses; turbidites; contourites; glaciomarine sediments; subglacial sediments; ice-rafted debris; paleobathymetry; seismic stratigraphy; paleoclimate; paleoceanography; Life Sciences; Antarctic; West Antarctic Ice Sheet; West Antarctica; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Sea ice
• Online Access: https://digitalcommons.usf.edu/msc_facpub/668; https://doi.org/10.14379/iodp.proc.374.101.2019; https://digitalcommons.usf.edu/context/msc_facpub/article/1660/viewcontent/374_101.PDF

The marine-based West Antarctic Ice Sheet (WAIS) is currently locally retreating because of shifting wind-driven oceanic currents that transport warm waters toward the ice margin, resulting in ice shelf thinning and accelerated mass loss. Previous results from geologic drilling on Antarctica’s continental margins show significant variability in ice sheet extent during the late Neogene and Quaternary. Climate and ice sheet models indicate a fundamental role for oceanic heat in controlling ice sheet variability over at least the past 20 My. Although evidence for past ice sheet variability is available from ice-proximal marine settings, sedimentary sequences from the continental shelf and rise are required to evaluate the extent of past ice sheet variability and the associated forcings and feedbacks. International Ocean Discovery Program Expedition 374 drilled a latitudinal and depth transect of five sites from the outer continental shelf to rise in the central Ross Sea to resolve Neogene and Quaternary relationships between climatic and oceanic change and WAIS evolution. The Ross Sea was targeted because numerical ice sheet models indicate that this sector of Antarctica responds sensitively to changes in ocean heat flux. Expedition 374 was designed for optimal data-model integration to enable an improved understanding of Antarctic Ice Sheet (AIS) mass balance during warmer-than-present climates (e.g., the Pleistocene “super interglacials,” the mid-Pliocene, and the Miocene Climatic Optimum). The principal goals of Expedition 374 were to Evaluate the contribution of West Antarctica to far-field ice volume and sea level estimates; Reconstruct ice-proximal oceanic and atmospheric temperatures to quantify past polar amplification; Assess the role of oceanic forcing (e.g., temperature and sea level) on AIS variability; Identify the sensitivity of the AIS to Earth’s orbital configuration under a variety of climate boundary conditions; and Reconstruct Ross Sea paleobathymetry to examine relationships between seafloor ...