ANDRILL team to conduct Antarctic survey project in 2010-11 season

by Tom Simons on 4 Oct 2010
After recording the two most successful sediment recovery projects in Antarctica history, ANDRILL, the Antarctic Geologic Drilling program, is set to begin an ambitious survey project in the 2010-11 Antarctic field season.

The joint United States-New Zealand expedition will operate from a remote camp on the Ross Ice Shelf from late October through early February studying the ice and its movements, the sea beneath the ice and its movements, and the rocks beneath the seafloor.

The Coulman High Survey Project is funded by $2.68 million grant from the U.S. National Science Foundation through the American Recovery and Reinvestment Act, with additional support coming from the New Zealand Foundation for Research, Science and Technology. It is led by Frank Rack, executive director the ANDRILL Science Management Office at the University of Nebraska-Lincoln in the United States, and Richard Levy, a paleoclimate research scientist for GNS-Science in New Zealand. Levy is the former staff scientist for the ANDRILL Science Management Office.

ANDRILL's previous drilling projects, the McMurdo Ice Shelf Project in 2006 and the Southern McMurdo Sound Project in 2007 recovered the two deepest rock cores in Antarctica history (1,285 meters and 1,138 meters) with a remarkably complete record of the continent's climate history over the last 20 million years.

This season's survey project is in preparation for a proposed third drilling project being planned for the 2013-14 season, the Coulman High Project, which would extend that climate record back several million more years.

'We'll be drilling into an earlier time, from the early Miocene to older deposits, so about 20 million-year and older sediment,' Rack said. 'Our hope would be to record the transition from an ice-free Antarctica back in the Eocene, about 40 million years ago, to the creation of the ice sheet on Antarctica and especially the history of the West Antarctic Ice Sheet, which we've been studying through the past projects. What this will allow us to do is go back in time and look at a warmer interval of Earth history with higher concentration of carbon dioxide in the atmosphere and reduced ice in Antarctica. It's a continuation of our previous ANDRILL drilling, but takes us further back in time.'

The ANDRILL team is scheduled to arrive at the U.S. McMurdo Station and New Zealand's Scott Base in Antarctica in early October to begin preparations for moving 20 shipping containers of equipment at the end of the month to a remote site on the Ross Ice Sheet approximately 150 kilometers northeast of McMurdo. The equipment carried to the camp will include the ANDRILL hot-water drill, the ANDRILL camp with bunks for a dozen people and a galley kitchen setup, and the bulldozers, tractors and other vehicles that will be needed at the site.

'We'll be about an hour helicopter flight from McMurdo, or about a 12- to 15-hour traverse,' Rack said. 'If you go out by tractor, you have to go out the South Pole Traverse Route, across the transition zone between the McMurdo Ice Shelf and the Ross Ice Shelf, which is crevassed, and they groom that part of the route. Once we've crossed over to the Ross Ice Shelf, we'll take a left and we'll head out to the edge of the ice shelf. We'll be located between six and 17 kilometers back from the edge of the ice shelf, which is a sheer face of ice that goes down about 40 meters to the water in the Ross Sea.'

On or about Nov. 12, the team will begin using the hot-water drill to melt the first of four holes through 250 meters of ice to get to the sea below the ice sheet. (By comparison earlier ANDRILL expeditions on the Ross Ice Shelf had to melt through 80 meters of ice).

In the first two holes, oceanographic instruments will be deployed below the ice to measure tidal and ocean currents, as well as the temperature and salinity of the water. GPS equipment deployed at four sites on the surface will measure vertical and lateral movement of the ice (estimated to be two meters per day or 740 meters per year laterally).

'All those motions of the water under the ice will affect our drill string when we eventually get to the drilling phase of the project,' Rack said. 'What we're doing is collecting all this environmental information and then we'll use the data for modeling the drill riser and the drill pipe inside the riser to see how they will be affected during the drilling because the ice shelf is moving two meters a day laterally. Once we spud into the seafloor, the pipe will begin to bend, and as the pipe bends, these ocean and tidal currents will cause friction on the pipe and we want to understand how that will affect the drilling operation.'

At the third site, the team will deploy a series of additional oceanographic instruments and a 25-centimeter-diameter remotely operated vehicle named SCINI (Submersible Capable of under Ice Navigation and Imaging; pronounced 'skinny'). Developed by ROV engineer Bob Zook of Moss Landing Marine Laboratories, SCINI is limited to approximately 300 meters of water depth, but Rack said the hope is that its range will be extended to depths of approximately 1,000 meters in support of the proposed Coulman High Project.

At the fourth site, ANDRILL will deploy a hydrophone though the ice shelf to near the seafloor and distribute 100 geophones across the ice to record a seismic refraction experiment designed to understand the depth of various rock layers beneath the seafloor, calculated from the travel time of sound waves.

The survey is scheduled for completion in late January or early February.

U.S. institutions involved in the survey project are UNL, where Rack is an associate professor in the Department of Earth and Atmospheric Sciences; the University of California, Santa Barbara; Woods Hole Oceanographic Institution; the University of Kansas Center for Remote Sensing of Ice Sheets; Moss Landing Marine Laboratories; the University of Wisconsin-Madison Ice Coring and Drilling Services; the National Science Foundation Office of Polar Programs; and Raytheon Polar Services Corp.

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New Zealand institutions are the Antarctic Research Center's Science Drilling Office at Victoria University of Wellington; GNS-Science; the National Institute of Water and Atmospheric Research; and the University of Otago.

ANDRILL is a multinational collaboration involving more than 150 scientists from Germany, Italy, New Zealand and the United States. Its purpose is to recover sediment core samples from the McMurdo Sound and Ross Sea region of Antarctica to develop a detailed history of the Antarctic climate and the expansion and contraction of the Ross Sea area's ice sheets and ice shelves over the past 20 million years and more. Funding Support for ANDRILL comes from the U.S. National Science Foundation; New Zealand Foundation of Research, Science, and Technology; Royal Society of New Zealand Marsden Fund; Antarctica New Zealand; the Italian National Program for Research in Antarctica-PNRA; The German Science Foundation and the Alfred Wegener Institute for Polar and Marine Research Science. For more information, visit http://andrill.org.

The Coulman High Project is proposed as the next phase of ANDRILL operations. For more information, see: http://andrill.org/science/ch.

Operations and logistics for the first phase of the ANDRILL Coulman High Project are provided by Raytheon Polar Services Corp. for the U.S. Antarctic Program, with additional support from Antarctica New Zealand.

Scientific research for the first phase of the Coulman High Project is administered and coordinated in the United States through the ANDRILL Science Management Office at UNL, and in New Zealand through GNS-Science, the Antarctic Research Centre and Science Drilling Office of Victoria University of Wellington, and the University of Otago.

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http://newsroom.unl.edu/releases/2010/09/30/ANDRILL+team+to+conduct+Antarctic+survey+project+in+2010-11+season