View source for Earth:North Greenland Ice Core Project

{{Short description|Ice drilling site near the center of Groenland}}
[[Image:Ngrip-epica-do18.png|thumb|right|Delta-O-18 record from the NGRIP core]]
[[File:Ngrip bolling allerod do18 1.png|thumb|North Greenland Ice Core Project Oxygen Isotope Data]]
[[File:Ngrip bolling allerod ca2plus 1.png|thumb|Calcium concentration and d18O isotope ratios from the Greenland NGRIP, GRIP, and GISP2 ice cores on the GICC05 time scale]]
[[File:Ngrip bolling allerod ch4 1.png|thumb|Methane (CH4) record from the North Greenland Ice Sheet Project (NGRIP) ice core, Greenland]]

The drilling site of the '''North Greenland Ice Core Project (NGRIP or NorthGRIP)''' is near the center of [[Place:Greenland|Greenland]] (75.1 N, 42.32 W, 2917 m, ice thickness 3085). Drilling began in 1999 and was completed at [[Earth:Bedrock|bedrock]] in 2003.<ref>{{Cite news|url=http://news.bbc.co.uk/1/hi/sci/tech/3090279.stm|title = Breaking through Greenland's ice cap|date = 23 July 2003}}</ref>  The [[Earth:Ice core|cores]] are cylinders of ice 11 centimeters in diameter that were brought to the surface in 3.5-meter lengths. The NGRIP site was chosen to extract a long and undisturbed record stretching into the last glacial, and it succeeded. The site was chosen for a flat basal [[Earth:Topography|topography]] to avoid the flow distortions that render the bottom of the [[Earth:Greenland ice core project|GRIP]] and [[Earth:Greenland Ice Sheet Project|GISP]] cores unreliable. Unusually, there is melting at the bottom of the NGRIP core – believed to be due to a high [[Earth:Geothermal activity|geothermal]] heat flux locally. This has the advantage that the bottom layers are less compressed by thinning than they would otherwise be: NGRIP annual layers at 10.5&nbsp;kyr age are 1.1&nbsp;cm thick, twice the GRIP thicknesses at equal age.

The NGRIP record helps to resolve a problem with the GRIP and GISP2 records – the unreliability of the Eemian Stage portion of the record. NGRIP covers 5&nbsp;kyr of the Eemian, and shows that temperatures then were roughly as stable as the pre-industrial [[Earth:Holocene|Holocene]] temperatures were. This is confirmed by [[Earth:Sediment|sediment]] cores, in particular MD95-2042.<ref>{{cite web |url=http://www.worldchanging.com/archives/001199.html |title=WorldChanging: Not-So-Abrupt Climate Change? |website=www.worldchanging.com |access-date=12 January 2022 |archive-url=https://web.archive.org/web/20081006173154/http://www.worldchanging.com/archives/001199.html |archive-date=6 October 2008 |url-status=dead}}</ref>

In 2003, NGRIP recovered what seem to be plant remnants nearly two miles below the surface, and they may be several million years old.<ref>{{cite web |url=http://www.glaciology.gfy.ku.dk/ngrip/index_eng.htm |title=Archived copy |website=www.glaciology.gfy.ku.dk |access-date=12 January 2022 |archive-url=https://web.archive.org/web/20111005030349/http://www.glaciology.gfy.ku.dk/ngrip/index_eng.htm |archive-date=5 October 2011 |url-status=dead}}</ref>	

"Several of the pieces look very much like blades of grass or pine needles," said University of Colorado at Boulder geological sciences Professor James White, an NGRIP principal investigator. "If confirmed, this will be the first organic material ever recovered from a deep ice-core drilling project," he said.

==See also==
* [[Earth:Bølling–Allerød warming|Bølling–Allerød warming]]
* [[Earth:Northgrippian|Northgrippian]]
* [[Earth:Greenlandian|Greenlandian]]

==References==
{{reflist}}

==External links==
The original web page of the NGRIP project with field diaries and pictures.
* https://web.archive.org/web/20120101002118/http://www.gfy.ku.dk/~www-glac/ngrip/index_eng.htm
The NGRIP project was run by an international consortium of scientists, and drilling and logistics were managed by what is now called Centre for Ice and Climate at the Niels Bohr Institute, University of Copenhagen, Denmark. This research centre maintains a web page about ice core research:
* http://www.iceandclimate.nbi.ku.dk/research/drill_analysing/history_drilling/search_eemian/

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[[Category:Arctic research]]

{{Sourceattribution|North Greenland Ice Core Project}}