International Ocean Discovery Program Expedition 374 preliminary report: Ross Sea West Antarctic ice sheet history: Ocean-ice sheet interactions and West Antarctic ice sheet vulnerability: clues from the Neogene and Quaternary record of the outer Ross Sea continental margin

• Main Authors: McKay, Robert M., De Santis, Laura, Kulhanek, Denise K., Expedition 347 Scientists
• Other Authors: Marine palynology and palaeoceanography, Marine Palynology
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Oceanography; Antarctic; Ross Sea; West Antarctic Ice Sheet; West Antarctica; Antarc*; Antarctica; Ice Sheet; Ice Shelf
• Online Access: https://dspace.library.uu.nl/handle/1874/371975

The marine-based West Antarctic Ice Sheet (WAIS) is currently retreating due to shifting wind-driven oceanic currents that transport warm waters toward the ice margin, resulting in ice shelf thinning and accelerated mass loss of the WAIS. Previous results from geologic drilling on Antarctica's continental margins show significant variability in marine-based ice sheet extent during the late Neogene and Quaternary. Numerical models indicate a fundamental role for oceanic heat in controlling this variability over at least the past 20 My. Although evidence for past ice sheet variability has been collected in marginal settings, sedimentologic sequences from the outer continental shelf are required to evaluate the extent of past ice sheet variability and the associated oceanic forcings and feedbacks. International Ocean Discovery Program Expedition 374 drilled a latitudinal and depth transect of five drill sites from the outer continental shelf to rise in the eastern Ross Sea to resolve the relationship between climatic and oceanic change and WAIS evolution through the Neogene and Quaternary. This location was selected because numerical ice sheet models indicate that this sector of Antarctica is highly sensitive to changes in ocean heat flux. The expedition was designed for optimal data-model integration and will enable an improved understanding of the sensitivity of Antarctic Ice Sheet (AIS) mass balance during warmer-than-present climates (e.g., the Pleistocene "super interglacials," the mid-Pliocene, and the late early to middle Miocene). 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 atmospheric and oceanic temperatures to identify past polar amplification and assess its forcings and feedbacks; • Assess the role of oceanic forcing (e.g., sea level and temperature) on AIS stability/instability; • Identify the sensitivity of the AIS to Earth's orbital configuration under a variety of climate ...