Collaborative Research: Acquisition of a Drilling Rig To Recover Geological Records from the Antarctic Margin for the ANDRILL Consortium

Northern Illinois University, Dekalb IL

Investigators

Abstract

Geological drilling to recover core for scientific investigations was successfully conducted in the McMurdo Sound Region during 10 austral summers over a 28-year period since 1973. The sea-ice has been used successfully as a drilling platform for seven drill-holes in this area. Experience gained during these projects forms the basis for developing new drilling technology to advance this approach. The ANDRILL (ANtarctic DRILLing) Project considers future drilling from sea-ice, ice shelf and land platforms within its McMurdo Sound Portfolio. This Portfolio proposes more than ten individual drilling targets that will require varied drilling equipment and strategies. Most of these targets have several common requirements, including drilling through hundreds of meters of water (up to 1000 m), and to recover continuous core starting from the sea-floor to depths of as much as 1000 m. Most of the targets call for a drill rig with a greater capacity than that used for the highly successful international Cape Roberts Project (CRP from 1997-1999), to which ANDRILL is the successor. Although the CRP rig, as well as various other commercial drilling rigs and equipment are available to ANDRILL, the unique requirements (drilling in deep-water and through an ice shelf more than 300 meters thick) require acquisition and development of a new, more powerful drilling system adapted to the Antarctic environment. The desired rig will handle the required length of drill rod and recover rock at an appropriate speed within the short windows of time allowed for Antarctic drilling. Development of this new system will enhance the drilling capability by providing faster core recovery and the ability to sample from previously inaccessible areas, thus expanding the scope of geological sampling into deeper water and through thick shelf ice. The study of sediment drillcores represents a key means to decipher Cenozoic climate and glacial history of Antarctica, a region where most rocks of this age are hidden beneath the ice sheet cover. ANDRILL is an international consortium with objectives to recover stratigraphic core records for use in interpreting Antarctica's past climatic, glacial and geological history over the past 50 million years and at varying scales of age resolution (0.1 to 100 thousand years). Understanding the past history of ice volume variation in Antarctica and associated physical changes in this region is critical to proper assessment of the global climate system and interaction of ice sheets with the ocean, atmosphere and biosphere. ANDRILL will proceed in three phases: geophysical and site surveys (2001-2004), drilling and core recovery (2003-2007), and climate and glacial modeling and integration of recovered data into global records of climate change (2005-2009). For the past 40 million years the Antarctic Ice Sheet has played a critical role in regulating global climate and sea level. Climatic warming is expected to be most pronounced in polar regions; Antarctic temperatures may rise by the end of the century to levels that have not been achieved for several million years. It is therefore vital that we understand the past response of the Antarctic ice sheet to climatic change in order to provide constraints on models that predict the future. ANDRILL currently plans 4 seasons of drilling under the McMurdo Sound Portfolio, in the regions of New Harbour, Windless Bight, Mackay Sea Valley and on the Southern McMurdo Ice Shelf. Through subsequent Portfolios, the life of ANDRILL and this new drilling system will likely continue towards the year 2020. Support for programs of this scale must come from contributions of several nations. To date, the ANDRILL International Consortium includes as member nations the USA, United Kingdom, New Zealand, Italy and Germany, and it invites membership from any interested nation. Similar to the CRP, close interaction of a diverse team of research scientists, postdoctoral scientists, graduate and undergraduate students will provide excellent opportunities for education and on-site training. REU appointments will target underrepresented groups in the geosciences. ANDRILL plans to expand the educational and outreach component beyond that of CRP by direct on-site and remote learning opportunities through member-nation initiatives and ANDRILL sponsored outreach and education. An "on-ice" team of scientists would prepare the core and provide initial description and characterization. Samples would be shipped to "off-ice" scientists to study and present results at the first of two science workshops to be hosted at member-nations home academic institutions on a rotating basis. Publication of initial results would be followed by presentation of results in major scientific journals and at professional meetings.