The Greenland Ice Core Project (GRIP) was a research project organised through the
European Science Foundation (ESF).
The project ran from 1989 to 1995, with drilling seasons from 1990 to 1992.
In 1988, the project was accepted as an ESF-associated program, and in the summer of 1989, the fieldwork was started in
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland i ...
.
GRIP aimed to collect and investigate 3000-metre-long
ice cores drilled at the apex of the Greenland ice sheet, also known as
Summit Camp
Summit Camp, also Summit Station, is a year-round staffed research station near the apex of the Greenland ice sheet. The station is located at above sea level. The population of the station is typically five in wintertime and reaches a maximu ...
.
The Greenland ice sheet comprises more than 90% of the total
ice sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at La ...
and
glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...
ice outside
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...
.
The project was managed by a Steering Committee of the
University of Bern
The University of Bern (german: Universität Bern, french: Université de Berne, la, Universitas Bernensis) is a university in the Swiss capital of Bern and was founded in 1834. It is regulated and financed by the Canton of Bern. It is a compreh ...
's Physics Institute, chaired by Professor Bernhard Stauffer.
Funding came from eight European nations (
Belgium
Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...
,
Denmark
)
, song = ( en, "King Christian stood by the lofty mast")
, song_type = National and royal anthem
, image_map = EU-Denmark.svg
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of Denmark
, establish ...
,
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
,
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
,
Iceland
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...
,
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
,
Switzerland, and
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
), and from the
European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been de ...
.
Studies of nuclear isotopes and various atmospheric constituents provided by the cores allowed the team to construct detailed records of climate change. The records cover the last 100,000 years.
History of the ice sheet in Greenland
Mass loss of the
Greenland ice sheet has been accelerating due to the effects of climate change caused by human activities.
It is predicted that the sea level will rise by approximately 7 metres if all the ice melts. The mass loss of ice sheets and glaciers causes sea levels to rise and affects terrestrial albedo’s decline and changes in ocean circulation. The decrease in sea ice also affects the global climate and environment and the rise in sea levels due to ice sheet glaciers’ melt would make it impossible for people to live on coastal lands.
Due to the lack of ancient terrestrial sediment archives, most of the history of ice sheets in Greenland is based on indirect records, with few direct records revealed. However, according to its little paleoclimate data, it was shown that the amount of ice sheets in Greenland has been changing significantly over time, suggesting that the change in size is due to a variety of physical environmental factors.
Briefly, the best estimate considering paleoclimate data is that the Greenland ice sheet can be significantly reduced by only a few degrees of increase in the negative effects of climate change, leading to ice sheet loss.
A 2020 research paper suggests that the melting of an ice sheet that covers Greenland will accelerate much faster than previously predicted melting speeds.
The results and the findings from GRIP
Studies of nuclear isotopes and various atmospheric constituents provide detailed records of climate change over 100,000 years ago. From analysis results of the oxygen isotope ratio of the GRIP core excavated in 1992, it became clear that in Greenland, abrupt climate change occurred during the last glacial period. This happened more than 20 times. Furthermore, it became clear that both the warm and cold periods were repeated alternately. Near the bottom of the GRIP core, oxygen isotope ratios fluctuated sharply, initially interpreted as repeated violent climate change during the last interglacial period in Greenland.
[Dansgaard, W., Johnsen, S. J., Clausen, H. B., Dahljensen, D., Gundestrup, N. S., Hammer, C. U., Hvidberg, C. S., Steffensen, J. P., Sveinbjornsdottir, A. E., Jouzel, J. and Bond, G. (1993). Evidence for general instability of past climate from a 250-kyr ice-core record. Nature, 364, 218‒220.]
Drilling techniques and drill development
GRIP successfully drilled a 3029-metre
ice core to the bed of the Greenland ice sheet at Summit from 1989 to 1992 at . The first ice core drilling of the Greenland ice cap, projects Camp Century and DYE3, contained only a few hundred meters of glacier ice. GRIP's drilled more than 3 kilometres of core.
In 1991, GRIP ice cores 783 to 2482 metres long were drilled, and the ice core was drilled to bedrock in 1992.
The ice core was first taken to the University of Copenhagen in Denmark, where it was stored in a cold room at minus -26 °C.
After that, the ice core was divided into five parts with a length of about 300 to 400 mm and shipped to Japan as the GRIP ice core segment.
They are expecting to obtain and clarify a wide range of information related to past and present climate and environmental changes that can be analysed from the ice.
Moreover, it is clear how glaciers are an important source of information, as GRIP can reveal up to 500,000 years of evidence by collecting annual layers (ESF, 2010).
Studies of
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...
s and various atmospheric constituents in the core have revealed a detailed record of
climate variability
Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more ...
reaching more than 100,000 years back in time. The results indicate that
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...
climate has been remarkably stable and has confirmed the occurrence of rapid climatic variation during the
last ice age (the
Wisconsin
Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...
). Delta-O-18 variations observed in the core part believed to date from the
Eemian Stage
The Eemian (also called the last interglacial, Sangamonian Stage, Ipswichian, Mikulin, Kaydaky, penultimate,NOAA - Penultimate Interglacial Period http://www.ncdc.noaa.gov/global-warming/penultimate-interglacial-period Valdivia or Riss-Würm) wa ...
have not been confirmed by other records including the
NGRIP core and are now believed not to represent climate events: the
interglacial climate of Eemian Stage appears to have been as stable as the Holocene.
Mainly, 3 different types of ice sheet core drills were used in the project, and one of the differences is in the depth they can drill to.
Hand Auger
The hand auger weighs 80 kg and can be operated by a single operator, and is useful for collecting ice cores with a diameter of 74 mm from the top 10 m of the ice cap.
The Shallow Drill
The shallow drill can produce cores up to 50 m long and 74mm in diameter per day on 350m top ice that does not require drilling fluid.
The Deep Drill
The deep drill works in liquid-filled holes and can be operated at any depth.
Compared to other drills, the operation is relatively slow, however, it has the advantage of being able to retrieve the core section.
How GRIP relates to other ice core projects in Greenland
In addition to GRIP, several more ice core projects were held in Greenland such as Greenland Ice Sheet Project (GISP2), North Greenland Ice Core Project (NorthGRIP), and North Greenland Eemian Ice Drilling (NEEM).
Greenland Ice Sheet Project (GISP2)
First,
GISP2
The Greenland Ice Sheet Project (GISP) was a decade-long project to drill ice cores in Greenland that involved scientists and funding agencies from Denmark, Switzerland and the United States. Besides the U.S. National Science Foundation (NSF), f ...
, which was done after GRIP, left a result that overturned the result discovered by GRIP. It was initially hypothesized that severe climate change was repeated during the last interglacial period in Greenland, based on the fact that the oxygen isotope ratio fluctuated sharply near the bottom of the GRIP core.
However, it was revealed that the isotope of oxygen ratio data of the GISP2 core excavated only 30 km away from the sampling point of the GRIP core does not match the data of the GRIP core deep in the core.
It became clear that the ice layer structure was disturbed by folds at the bottom of the ice sheet in both cores, indicating that the interpretation that there was a severe climate change effect during the final interglacial period may be incorrect.
The GISP2 reconstructions are relatively old. Recent studies have questioned the hypothesis of changing the relationship between temperature and Delta-O-18 during the Holocene and how best to explain elevation changes in the ice cap at the GISP2 site. The GISP2 reconstructions change the relationship between Delta-O-18 and temperature by a factor of two during the Holocene, while more recent reconstructions remain unchanged. Again, elevation change affects the Delta-O-18 record. Older GISP2 reconstructions do not account for elevation changes.
NorthGRIP
NorthGRIP
The drilling site of the North Greenland Ice Core Project (NGRIP or NorthGRIP) is near the center of Greenland (75.1 N, 42.32 W, 2917 m, ice thickness 3085). Drilling began in 1999 and was completed at bedrock in 2003. The cores are cylinder ...
aimed to collect ice during the final interglacial period, but the bottom of the ice sheet melted, and it was not possible to excavate old-age ones. Therefore, it is estimated that a temperature as high as 5 ℃ higher than the present was observed from some of the ice cores that could be collected in the middle of the last interglacial period, and the Greenland ice sheet has existed even in this warm climate.
![GRIP temperatures compared with NorthGRIP](https://upload.wikimedia.org/wikipedia/commons/0/0b/GRIP_temperatures_compared_with_NorthGRIP.png)
The shaded lines represent the uncertainty of the estimates due to the accuracy of the analysis and the adjustment of the isotope model.
The North Greenland Eemian Ice Drilling (NEEM)
Considering the extension of GRIP, the latest NEEM project excavated an ice core that can investigate the entire final interglacial period, and researched bottom melting and folds at the NEEM site. In Northern Greenland, it was warmest around 126,000 years before the beginning of the last interglacial period, and the temperature was about 8 °C ± 4 °C higher than it is now. Also, during the 6000 years between 128,000 and 122,000 years ago, the ice sheet thickness decreased by 400 ± 250 m, and 122,000 years ago the ice sheet surface altitude was 130 ± 300 higher than it is today.
[NEEM community members. (2013). Eemian interglacial reconstructed from a Greenland folded ice core. Nature, 493, 489‒494.] From this, it is extremely rare for the ice sheet to melt even in the hot summer in Greenland, but the ice sheet surface has melted during the final interglacial period (The Eemian) due to the values of methane gas and rare gas collected from NEEM's ice core.
The fact that the Greenland core remained in this temperature rise suggests that the Antarctic ice sheet shrank during the final interglacial period and contributed significantly to the rise in sea level.
Climate change and improvement measures
In order to accurately predict the response of the Greenland ice sheet to climate change, it is needed to obtain long-term data on past warming and its effects and improve the climate model and ice sheet model based on it. It was claimed that anthropogenic factors are deeply involved in environmental issues such as greenhouse gases, suggesting that they may be related to climate change during the Eemian.
[Anklin, J., Barnola, J., Beer, T., Blunier, J., Chappellaz, H., Clausen, D., … Thorsteinsson, W. (1993). Climate instability during the last interglacial period recorded in the Greenland Ice-core Project. Nature (London), 364(6434), 203–207.] Therefore, as recent changes in the atmospheric environment due to anthropogenic substances dominate climate change, people need to reassess various factors such as carbon dioxide emissions, fossil fuel use, and deforestation.
How are the issues in GRIP utilised in EastGRIP?
Previous ice core drilling projects including GRIP have been carried out at sites where horizontal ice flow is as small as possible, whereas the latest East GRIP research is conducted upstream of the North East Greenland Ice Stream.
This is the largest active ice stream in Greenland, and EastGRIP takes a different perspective from the previous GRIP.
In addition, the depth of ice that corresponds to the warm period of the early Holocene of the conventional Greenland ice core had the characteristic of being extremely fragile. Due to the influence of its characteristics, it was almost impossible for conventional Greenland ice cores to collect highly accurate chemical analysis data and gas analysis data with high time resolution. As a result of considering this difficulty, EastGRIP has installed a cold temperature chamber to keep the drilled ice below -30 °C immediately after the drilling, and efforts were made to minimize the destruction of ice cores by eliminating small steps of several tens of microns in the core field processing.
The cold air prevents the expansion of air bubbles and prevents the ice from breaking.
As a result, ice cores capable of continuous flow analysis have been acquired even from fragile depth zones, and it is expected that more detailed and accurate chemical analysis and gas analysis data will be acquired in the future.
Other ice core projects
East Greenland Ice-core Project (EastGRIP)
WAIS Divide Ice Core Project
DYE3
Camp Century
Camp Century was an Arctic United States military scientific research base in Greenland. situated 240 km (150 miles) east of Thule Air Base. When built, Camp Century was publicized as a demonstration for affordable ice-cap military outposts ...
South Pole Ice Core Project
Arctic Ice Core Project
See also
*
Climatology
Climatology (from Greek , ''klima'', "place, zone"; and , ''-logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of study ...
*
Dansgaard-Oeschger event
*
European Project for Ice Coring in Antarctica
The European Project for Ice Coring in Antarctica (EPICA) is a multinational European project for deep ice core drilling in Antarctica. Its main objective is to obtain full documentation of the climatic and atmospheric record archived in Antarct ...
*
GISP
*
Ice core
Sources
*
* Alley, RB, Andrews, J., Brigham-Grette, J, Clarke, GK., Cuffey, K., Fitzpatrick, J., Funder, S, Marshall, S., Miller, G., Mitrovica, J., Muhs, D., Otto-Bliesner, B., Polyak, L, & White, JW., (2010). ‘History of the Greenland Ice Sheet: paleoclimatic insights’, Quaternary Science Reviews, vol. 29, no. 15, pp. 1728–1756, doi: 10.1016/j.quascirev.2010.02.007.
* Anklin, J., Barnola, J., Beer, T., Blunier, J., Chappellaz, H., Clausen, D., … Thorsteinsson, W. (1993). Climate instability during the last interglacial period recorded in the Greenland Ice-core Project. Nature (London), 364(6434), 203–207.
* Arctic Challenge of Sustainability. (2017). ‘Deep ice coring under the EGRIP in 2017’. Arctic Challenge for Sustainability Project. Retrieved from
https://www.nipr.ac.jp/arcs/blog/en/2017/12/EGRIP2017-2.html
* Christ, Bierman, P. R., Schaefer, J. M., Dahl-Jensen, D., Steffensen, J. P., Corbett, L. B., Peteet, D. M., Thomas, E. K., Steig, E. J., Rittenour, T. M., Tison, J.-L., Blard, P.-H., Perdrial, N., Dethier, D. P., Lini, A., Hidy, A. J., Caffee, M. W., & Southon, J. (2021). A multimillion-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century. Proceedings of the National Academy of Sciences - PNAS, 118(13), 1–.
https://doi.org/10.1073/pnas.2021442118
* Dansgaard, W., Johnsen, S. J., Clausen, H. B., Dahljensen, D., Gundestrup, N. S., Hammer, C. U., Hvidberg, C. S., Steffensen, J. P., Sveinbjornsdottir, A. E., Jouzel, J. and Bond, G. (1993) Evidence for general instability of past climate from a 250-kyr ice-core record. Nature, 364, 218‒220.
* European Science Foundation. (2010). Greenland Icecore Project (GRIP). Retrieved from
https://web.archive.org/web/20120207150245/http://www.esf.org/activities/research-networking-programmes/life-earth-and-environmental-sciences-lesc/completed-esf-research-networking-programmes-in-life-earth-and-environmental-sciences/greenland-icecore-project-grip/more-information.html
* Gerber, T. A., Hvidberg, C. S., Rasmussen, S. O., Franke, S., Sinnl, G., Grinsted, A., … Dahl-Jensen, D. (2021). Upstream flow effects revealed in the EastGRIP ice core using Monte Carlo inversion of a two-dimensional ice-flow model. The Cryosphere, 15(8), 3655–3679.
https://doi.org/10.5194/tc-15-3655-2021
* Hokkaido University, (2022). ‘Greenland ice sheet may halve in volume by year 3000’. Retrieved from
https://www.global.hokudai.ac.jp/blog/greenland-ice-sheet-may-halve-in-volume-by-year-3000/
* IPCC (2013) Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (ed. T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P. M. Midgley), Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp
* Johnsen S. J., Clausen, H. B., Dansgaard, W., Fuhrer, K., Gundestrup, N., Hammer, C. U., Iversen, P., Jouzel, J., Stauffer, B. and Steffensen, J. P. (1992). Irregular glacial interstadials recorded in a new Greenland ice core. Nature, 359, 311‒313.
* Masson-Delmotte, V., Landais, A., Stievenard, M., Cattani, O., Falourd, S., Jouzel, J., … Fischer, H. (2005). Holocene climatic changes in Greenland: Different deuterium excess signals at Greenland Ice Core Project (GRIP) and NorthGRIP. Journal of Geophysical Research - Atmospheres, 110(D14), D14102–n/a.
https://doi.org/10.1029/2004JD005575
* NEEM community members. (2013). Eemian interglacial reconstructed from a Greenland folded ice core. Nature, 493, 489‒494.
* North Greenland Ice Core Project members. (2004). Highresolution record of Northern Hemisphere climate extending into the last interglacial period. Nature, 431, 147‒151.
* Sakurai, Iizuka, Y., Horikawa, S., Johnsen, S., Dahl-jensen, D., Steffensen, J. P., & Hondoh, T. (2009). Direct observation of salts as micro-inclusions in the Greenland GRIP ice core. Journal of Glaciology, 55(193), 777–783.
https://doi.org/10.3189/002214309790152483
* SPICEcore, (n.d.). ‘South Pole Ice Core’. Retrieved from
https://spicecore.org/about/
* Stauffer, B. (1993). ‘The Greenland Ice Core Project’. In Science, vol. 260, no. 5115, pp. 1766-1767, DOI: 10.1126/science.260.5115.1766
* Steffensen, J. P., Andersen, K. K., Masson-Delmotte, V., Popp, T., Rasmussen, S. O., Röthlisberger, R., ... Jouzel, J. (2008). High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years. Science (American Association for the Advancement of Science), 321(5889), 680–684.
https://doi.org/10.1126/science.1157707
* Tandon, A. (2020). ‘New climate models suggest faster melting of the Greenland Ice Sheet’, Carbon Brief. Retrieved from
https://www.carbonbrief.org/new-climate-models-suggest-faster-melting-of-the-greenland-ice-sheet/
* University of Copenhagen. (n.d.). ‘The Central Greenland Ice Cores’. Retrieved from
https://www.iceandclimate.nbi.ku.dk/research/drill_analysing/history_drilling/central_ice_cores/
References
{{reflist
External links
The GRIP 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/central_ice_cores/
Other links:
GRIP infofrom the
NCDC
GRIP publications list
Geochronological institutions and organizations
Research projects
Arctic research
Climate of Greenland
Climate change
Greenland and the European Union
Greenland-related lists