image: The project will start this year with moving a large camp building, dome and tracked vehicles with five large sleds with equipment from the previous drilling, NEEM, which lies 420 km from the new drilling site. view more
Credit: Niels Bohr Institute
Professor Dorthe Dahl-Jensen, head of the Centre for Ice and Climate at the Niels Bohr Institute has received a grant of 25 million kroner from the A.P. Møller Foundation for a major new research project in Greenland. The project aims to drill a 2½-kilometer deep ice core through the large fast-flowing part of the ice sheet in northeast Greenland and gain new knowledge about how and how fast the ice is moving. This knowledge could improve forecasts of future sea level rise.
The climate is getting warmer and sea levels will rise in the future. Sea levels will primarily increase when the large ice sheets on land melt and the melt water flows out into the oceans, but how much and how quickly?
Half of the ice that disappears does so when ice melts in the peripheral regions. The other half of the ice disappears when the ice calves, that is, when large pieces of the ice sheet break off at the coasts and flow out to sea as icebergs. The calving happens particularly fast in areas where the ice is flowing rapidly and it has surprised the experts that the speed has doubled in some places - for example, the ice in Jakobshavn on Greenland's west coast travelled at a speed of 7 km per year before 2002 and now the speed is 14 km per year.
In order to explain how and how fast the flow is happening, the major new research project, EGRIP, will drill a 2½-kilometer deep ice core through the ice sheet in northeast Greenland, where the ice flows quickly.
Groundbreaking project
"Our drilling will take place in the large ice stream in northeast Greenland. An ice stream is an area in the ice where the ice flows about 60 meters per year. Very little is known about how the ice in the ice sheet moves, so the purpose of the project is to increase our understanding of how the ice streams are contributing to the rapid loss of the Greenland ice sheet," explains Dorthe Dahl-Jensen, professor and head of the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.
Danish researchers have been pioneers in ice core research for many years. The Centre for Ice and Climate at the Niels Bohr Institute has led seven ice core drilling projects through the Greenland ice sheet. The aim has been to unlock past climate all the way back through the Ice Age to the previous interglacial period around 125,000 years ago. The kilometer thick ice sheet has been formed by snow that falls and remains year after year and is gradually compressed into ice. Each annual layer can tell us something about the temperature the year the snow fell and by analysing every annual layer, the researchers can reconstruct past climate.
To get stable temperature curves of the climate, it has been important to find drilling sites where the ice was not moving too much. But in this new project it is just the opposite - here they want to drill at a site where the ice is flowing quickly. This is to study the dynamics in the ice sheet.
Technologically demanding
"This will be the first time an ice core has been drilled through fast moving ice and it will be a technical drilling challenge, as the borehole will have moved 180 meters over the three years that it takes to drill all the way through the ice. The drill itself is 13 cm in diameter and just starting a new day of drilling will mean that the bottom of the hole has shifted," says Dorthe Dahl-Jensen.
She explains that they will study how the ice in the ice sheet moves and where the water under the ice is located - is it in channels and how quickly does it flow? When they get down to the bottom, they carry out further studies and will send a camera down so they can see the bottom.
The project will start this year with moving a large camp building, dome and tracked vehicles with five large sleds with equipment from the previous drilling, NEEM, which lies 420 km from the new drilling site.
Denmark will lead the project and finance half of the cost. The second largest partner is the United States, which will provide the flights and will also participate in the research. In addition, it is expected that researchers from four nations will participate: Japan, Germany, France and Switzerland.
Melting and sea level rise
The fact that an airstrip and a camp with infrastructure are being established means that it will also be possible for other researchers to come and carry out many other types of studies in addition to the drilling project. For example, some researchers will set up GPSs on the ice all the way out to the edge to see how fast they move and they want to make seismic measurements on the surface of the ice to map the subsurface and maybe find out whether there is increased thermal heat from the Earth's interior warming the ice from below at the source of the ice stream. In addition, there will be icebreakers, which will both observe the calving of icebergs and will also drill sediment cores from the seabed to study past calving of icebergs into the sea.
The project, which starts this year, is expected to be completed in 2020. Without this large grant from the A.P. Møller Foundation, the project could not have been started and carried out as desired. The research will contribute new knowledge that can improve our ability to predict what happens with the loss of ice mass from ice sheets and sea level rise in the future.
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History of ice core drilling: http://www.nbi.ku.dk/english/www/willi/dansgaard/
Contact:
Dorthe Dahl-Jensen, professor and head of the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen. +45 2289-4537, ddj@gfy.ku.dk