Скачать или смотреть euronews futuris - Greenland's water mystery

http://www.euronews.com/ "Definitely, the glaciers in Greenland are retreating," that's the view of Bo Vinther, Glaciologist, Centre for Ice and Climate, University of Copenhagen.

"We see that ice strings are increasing their velocity. And thereby they are producing more icebergs out into the ocean," says Dorthe Dahl-Jensen, Coordinator, WATERundertheICE project.

Global warming is often blamed as the cause of Greenland's unstoppable melting.

But lately researchers have identified another unexpected suspect.

"The clues are hidden here underneath the ice," says Lars Berg Larsen, Glaciologist, NEEM Field Operations Office, University of Copenhagen.

Summertime is the peak season for glaciologists in West Greenland.

Danish glaciologist Bo Vinther drives to Russell Glacier, a huge ice mass that is quietly melting under rising temperatures.

But scientists suspect another mysterious factor also plays a role in this rapid, constant melting.

"We are here right at the ice margins. This is where the Greenland's ice sheets terminates here, the very edge of the big Greenland ice sheet that stretches some 1000 kilometres to the East out there.

'What we have observed is that when we have water underneath the ice sheet, then the ice is flowing much, much faster than if you have the ice frozen to the bedrock underneath. So it is really important to investigate this water under the ice, these physical processes going on at the very bed of the ice, so we are better able to model them and predict the ice flow in the future," he explains.

Scientists at a European Union research project are using the hard gear to understand the impact of those invisible water flows inside Greenland's ice sheet.

For that, they regularly fly to a scientific camp unlike any other.

The camp was established in 2007 to allow deep drilling in the ice sheet.

Scientists here are aiming to unveil the mysteries lying under 2.5 kilometres of ice. Location of the camp was carefully chosen.

"We needed a site where we knew something about how much snow is falling each year. We don't want too much snow because then the ice is not old enough. And we don't want little snow because then the resolution of the layers of each year is too little. So we picked this spot by comparing those two criteria," explains Lars Berg Larsen, Glaciologist, NEEM Field Operations Office, University of Copenhagen.

The camp's scientific jewel lies deep in a snow trench.

Researchers drill here to reach the deepest ice, that lies just above the bedrock.

Geothermal energy may heat this deep ice to melting point, creating flows of water.

Recovering that deep ice is crucial to understanding what is really happening far beneath.

Steffen Bo Hansen, Drilling Engineer, Centre for Ice and Climate, University of Copenhagen says:
"We have been so far able to produce in the order of around 20 metres of ice per day in average. This quantity matches well our own capability of analysing the ice, because the ice has to be cut and we have various measurements we have to take care of".

"Something is happening right now. We are actually doing a drill at the same time as we speak to you and something is changing here. It looks good. We are not sure when we are supposed to hit the bedrock down there. So we usually have a few false alarms that can also correspond to the presence of mud, or ice, or dirt, or sand, or other things," explains Trevor James Popp, Geochemist, Centre for Ice and Climate, University of Copenhagen.

Scientists date deep ice with a technique called "luminescence"; samples have to be extracted in almost complete darkness.

Some samples can date back 400.000 years.

"I m very happy that this has worked out that well. As it seems, we have lots of material that we can work with both for DNA analysis and for time dating with luminescence. It is always good to work with the same sample material and to have both results. And this is the first time it worked.

'It is good to have material with less grains for time dating, but now we have obtained 'silted' ice as well, with a lot smaller grain size. It is very good to have that for comparison," explains Christine Thiel, Geographer, Nordic Centre for Luminescence Research.

Each sample will also indeed be analysed to extract DNA traces that will help to unveil biological secrets from times when Greenland was ice free and water was flowing on its surface.


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