Background to the ANDRILL McMurdo Ice Shelf Project (Antarctica) and Initial Science Volume

The aim of the McMurdo Ice Shelf (MIS) Project was to obtain a continuous sediment core through approximately ~1 200 metres (m) of Neogene (~0-10 Ma) glacimarine, terrigenous, volcanic, and biogenic sediment that has accumulated in the Windless Bight region of the McMurdo Ice Shelf (Fig. 1). The pre...

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Bibliographic Details
Main Authors: Naish, T. R., Powell, R. D., Levy, R. H., ANDRILL-MIS Science Team
Format: Text
Language:unknown
Published: DigitalCommons@University of Nebraska - Lincoln 2007
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Online Access:https://digitalcommons.unl.edu/andrillrespub/29
https://digitalcommons.unl.edu/context/andrillrespub/article/1028/viewcontent/Naish_TA_2007_Background_to_the_ANDRILL.pdf
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Summary:The aim of the McMurdo Ice Shelf (MIS) Project was to obtain a continuous sediment core through approximately ~1 200 metres (m) of Neogene (~0-10 Ma) glacimarine, terrigenous, volcanic, and biogenic sediment that has accumulated in the Windless Bight region of the McMurdo Ice Shelf (Fig. 1). The present-day MIS forms the northwest part of Ross Ice Shelf where it has been pinned by Ross Island for the last ~10 k.y., and is nourished by ice sourced from East Antarctic Ice Sheet (EAIS) outlet glaciers in the southern Transantarctic Mountains (TAM). The drill site was situated above a flexural moat basin adjacent to Ross Island that formed in response to Quaternary volcanic loading of the crust by Ross Island, superimposed on more regional subsidence associated with Neogene extension of the Terror Rift (Horgan et al. 2005; Naish et al. 2006; Fig. 2). Between 29 October and 26 December 2006 a single 1 285 m-deep, drill core (AND-1B) was recovered from the bathymetric and depocentral axis of the moat in 943 m of water from an ice- shelf platform. The drilling technology employed a sea-riser system in a similar fashion to the Cape Roberts Project (CRP), as well as a combination of soft sediment coring (in upper soft sediments) and continuous wireline diamond-bit coring. Innovative new technology, in the form of a hot-water drill and over-reamer, was used to make an access hole through 85 m of ice and to keep the riser free during drilling operations. The MIS Project has two key scientific objectives: • Provide new knowledge on the Late Neogene behaviour and variability of the Ross Ice Shelf/Ice Sheet (RIS) and the West Antarctic Ice Sheet (WAIS), and their influence on global climate, sea level, and ocean circulation. • Provide new knowledge on the Neogene tectonic evolution of the West Antarctic Rift System (WAR), Transantarctic Mountains (TAM), and associated volcanism. A key outcome of the project will be to provide age control for, and determine the environmental significance of, seismic reflectors that have been ...