Antarctic Drilling Program (ANDRILL)

 

Date of this Version

2006

Citation

ANDRILL Contribution number 7 (2006), 117 pages. ISBN: 0972355049. Also available at: http://www.andrill.org/static/Resources/Publications/MIS-SLIP-Hi.pdf.

Comments

Copyright 2006, University of Nebraska-Lincoln. Used by permission.

Abstract

Summary

Response of Antarctic ice sheets to projected greenhouse warming of up to 5.8°C by the end of the century is unknown. Models on which predictions are based need to be constrained by geological proxy data from the ancient ice sheets during times when Earth is known to have been warmer than today. The marine-based West Antarctic Ice Sheet (WAIS) and its fringing ice shelves are hypothesized (Clark et al., 2002; Weaver et al., 2003; Stocker, 2003) and documented (Scherer et al., 1998) to have collapsed during past “super-interglacial” warm extremes when global sea-level was more than 5m higher than today. Recent collapse of small ice shelves along the Antarctic Peninsula (Doake and Vaughn, 1991; Skvarca, 1993; Rott et al., 1996; Vaughn and Doake, 1996; Doake et al., 1998; Rott et al., 1998; Skvarca et al., 1999; Rott et al., 2002) highlights the vulnerability of these glacial components to global warming. The Ross Ice Shelf appears to represent one of the most vulnerable elements of the WAIS system. Future demise, on timescales of decades to centuries, may well provide an important precursor to eventual WAIS collapse.

The key aim of this research project is to determine past ice shelf responses to climate forcing, including variability at a range of timescales. To achieve this aim the ANtarctic Geological DRILLing Program (ANDRILL) will drill a stratigraphic core from a platform located on the northwest corner of the Ross Ice Shelf - the McMurdo Ice Shelf (MIS) sector, east of Hut Point Peninsula, Ross Island. Drilling will be undertaken in the austral summer of 2006-2007 from the 24th of October to the 27th of December.

The primary target for the MIS site is a 1200 m-thick body of Plio-Pleistocene glacimarine, terrigenous, volcanic, and biogenic sediment that has accumulated in the Windless Bight region of a flexural moat basin surrounding Ross Island (Horgan et al., 2005). A single 1200 m-deep drill core will be recovered from the bathymetric and depocentral axis of the moat in approximately 900m of water. Drilling technology will utilize a sea-riser system in a similar fashion to the Cape Roberts Project (CRP), but will employ a combination of hydraulic piston coring (in upper soft sediments) and continuous wireline diamond-bit coring. Innovative new technology, in the form of a hotwater drill and over-reamer, will be used to make an access hole through ~ 200 m of the ice shelf and to keep the riser free during drilling operations.

The purpose of this SLIP is to provide a scientific overview of the project, its goals and objectives, as well as outlining management systems and scientific procedures to be implemented during both On-Ice (drilling) and post-drilling phases. It also includes information on scientific practice by participating scientists and discipline teams, and plans and policy for publications, education and public outreach activities. The plan provides a “roadmap” for research participants on the MIS Project to ensure the scientific objectives are met and delivered. Other key documents for the MIS project are:

ANDRILL Conribution 1 (Harwood et al., 2002), a report on the ANDRILL international planning workshop held at Oxford University in April 2001. This outlines the history of geological drilling around Antarctica, reviews the state of geology and geophysical knowledge in Western Ross Sea, presents a range of scientific drilling targets and science initiatives, describes a management structure for the new program, and addresses logistical and environmental considerations.

A science proposal prepared by the proponents of ANDRILL McMurdo Sound Portfolio of Projects for international peer-review. ANDRILL International Science Proposal (2003), ANDRILL Contribution 2.

A Comprehensive Environmental Evaluation (CEE) prepared for the ANDRILL McMurdo Sound Portfolio, by Antarctica New Zealand. This document has been circulated and approved by the Antarctic Treaty System, and is the project’s guide to sound environmental practice.

A Scientific Prospectus for the ANDRILL McMurdo Ice Shelf Project, ANDRILL Contribution 4 (Naish et al., 2005). This document outlines the science objectives and rationale for the MIS project and was used to help facilitate staffing applications.

A Guide to Participation for the ANDRILL MIS Project, ANDRILL Contribution No.6 (ANDRILL Science Management Office & McMurdo ANDRILL Science Implementation Committee, 2006). This document provides information for individual scientists participating in the project and living on McMurdo Station. It also covers logistical issues concerning travel of individuals and equipment to and from Antarctica.

The Record of Understanding between Parties Contributors and annexes. This document serves as an intention of long-term cooperation among Parties Contributors to the McMurdo Sound Portfolio of the ANDRILL Program (2001-2010). The RoU was signed in 2005. It commits Parties Contributors to a schedule of payments as outlined in the budget of the Project Plan for logistical and operational costs. It also formalizes a management structure involving an ANDRILL Operations Management Group (AOMG) and the McMurdo Sound ANDRILL Science Implementation Committee (M-ASIC).

ANDRILL Project Plan prepared by Antarctica New Zealand. The Project Plan provides detailed information concerning operational and logistical requirements, and a budget for implementation by Antarctica New Zealand as Operator to achieve the science goals of the approved ANDRILL McMurdo Sound Portfolio (McMurdo Ice Shelf and Southern McMurdo Sound Projects).

A series of MIS site survey data reports have been compiled by Geological and Nuclear Sciences and Victoria University, Antarctic Research Centre, New Zealand, covering seismic and other geophysical investigations of the geology and basin structure, as well as shallow sub-ice shelf sediment cores and oceanographic observations. These include Bannister and Naish (2002), Horgan et al. (2003), Wilson et al. (2004), Barrett et al. (2005), Carter et al. (2006), Henrys et al. (2006).

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