RAID objectives include a long borehole through thick Antarctic ice, and short cores of deep (old) ice, the glacial bed, and subglacial bedrock. This shows the different objectives superimposed on a cross-section through the Antarctic ice sheet provided by ice-penetrating radar, showing the detailed internal structure of glacial ice (radar image provided by Duncan Young, University of Texas-Austin, Institute for Geophysics).
DULUTH, MN – The Office of Polar Programs at the National Science Foundation (NSF) recently awarded an $8.97M grant to the University of Minnesota Duluth (UMD) to construct a new drilling platform for research in Antarctica. Called the Rapid Access Ice Drill, or RAID, the new drilling system will be able to penetrate the Antarctic ice sheets in order to take cores of the deepest ice, sample across the glacial bed, and continue coring into bedrock below. This type of technology has never been tried or deployed in either Greenland or Antarctica, but it will provide a critical first look at the interface between the major ice caps and their subglacial geology.
RAID is a mobile drilling system that will be capable of making several long boreholes in a single field season in Antarctica, which normally extends from November to February. The projected long-term research use of the RAID system is planned to begin in late 2017 by traversing over snow and ice to East Antarctica via the Amundsen-Scott station operated by the U.S. Antarctic Program at the South Pole. The RAID system is designed to be self-sufficient once leaving a fixed U.S. research base, and it is compact enough to be operated by a 3-person drilling crew.
UMD has contracted with a private drilling and engineering company, DOSECC Exploration Services, LLC, based in Salt Lake City, to construct and test the drilling system. DES was the lead contractor for development and engineering of the drill design, which began in June 2013.
John Goodge, professor of Earth and Environmental Sciences at the University of Minnesota-Duluth, is the lead principal investigator on the project. He studies geotectonic evolution of continental crust in East Antarctica and the Transantarctic Mountains. Jeff Severinghaus of Scripps Institution of Oceanography, co-principal investigator, conducts research on Antarctic paleoclimate by study of ice cores. Alexandra Isern, program officer at the NSF, funded the initial project and coordinated external technical review of the proposed construction plan.
Construction of the drilling system started in June 2014. Initial field tests of the system in North America are scheduled for early 2015, to be followed by a set of field validation trials in Antarctica in the 2016-17 austral summer.
The RAID platform is designed to address a wide range of interdisciplinary research goals long held by the international scientific community. These include a search for polar paleoclimate records in ice greater than 1 million years old, observation and sampling of the base of the Antarctic ice cap, and recovery of rock cores from ice-covered geologic provinces of Antarctica, a virtually unknown continent larger than the continental U.S. By keeping the boreholes open with a stabilizing fluid after drilling is complete, researchers will also be able to lower instruments and logging devices into the boreholes in order to measure thermal gradient, heat flow, ice accumulation history, and ice deformation processes. RAID will also sample for extremophile micro-organisms that may be present at the base of the ice sheets.
This new drilling system is based on modification of an industry-standard diamond rock-coring system as used in mineral exploration. Threaded metal drill pipe sections will be assembled at the surface as the drill cuts its way downward through ice using customized metal bits. A special circulating fluid will be used to lubricate the drill pipe, maintain proper temperature at the cutting surface, and return ice cuttings to the surface, where they will be separated from the recirculating fluid. Near the bottom of the ice sheet, diamond tools will be lowered through the drill string to enable coring of ice, material in the glacial bed, and the solid bedrock below. These cores will be returned to the surface in sections by use of a wireline retrieval system. Once drilling is complete, the boreholes will be maintained with a stabilizing fluid, capped, and made available for future down-hole measurements.
RAID is designed to penetrate up to 3,300 meters of ice (nearly 11,000 ft) and take sample cores in less than 200 hours. This rapid performance will allow a drilling crew to operate from start to finish in about 10 days before moving on to the next drilling site.
RAID is unique because it can provide fast borehole access through thick ice; short ice cores at the base of the ice sheet for paleoclimate study; cores of the glacial bed to determine flow conditions; cores of subglacial bedrock for age dating and crustal history; and create boreholes that can be used as an observatory in the ice sheets. Together, the rapid drilling capability and mobility of the drilling system, along with ice-penetrating imaging methods, will allow scientists to build a 3D picture of the interior Antarctic ice sheets in a way that has never been done before.
The RAID drilling system incorporates new and existing technology that can potentially provide important scientific breakthroughs. The RAID system is expected to be transformative because of the unique and unprecedented access it can provide to deep levels in the Antarctic ice sheets, and because it provides opportunities to a variety of research disciplines in the U.S. and its international partners.
Professor, Scripps Institution of Oceanography
Manager, DOSECC Exploration Services, LLC
Chief Financial Officer, DOSECC Exploration Services, LLC
Section Head, Surface Earth Processes Section
NSF Division of Earth Sciences
Head, Antarctic Sciences Section
NSF Division of Polar Programs