Abstracts of GRIP general papers (including drilling, logistics and dating)

This file contains abstracts of GRIP papers whose primary content concerns drilling, logistics, or is in the nature of a general review. Papers are listed alphabetically by first author. You can go straight to the abstract you want.


Dansgaard, W. & Gundestrup, N. 1993. Greenland: a temptation and a challenge. Endeavour, 17, 12-16.

Corresponding author: Willy Dansgaard, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark.

Sorry, no abstract currently available for this article


Gundestrup, N.S., Dahl-Jensen, D., Johnsen, S.J. & Rossi, A. 1993. Bore-hole survey at dome GRIP 1991. Cold Regions Science and Technology, 21, 399-402.

Corresponding author: Niels Gundestrup, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark.

Bore hole logging performed as part of the GRIP deep drilling shows a close connection between drilling stability and hole diameter. Differences in hole diameter of up to 0.5 mm do not seem to affect the drilling. The temperature profile provides information about past temperatures and implies that the ice is frozen at the bedrock.


Gundestrup, N.S., Clausen, H.B. & Hansen, B.L. 1994. The UCPH borehole logger. Memoirs of National Institute of Polar Research, 49, 224-233.

Corresponding author: Niels Gundestrup, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark.

The University of Copenhagen (UCPH) logger measures borehole inclination, azimuth, temperature, diameter and pressure. Readings are made continuously by the logger, and the results are transmitted every 3 s to the surface. The tool remembers the maxima and minima of the diameters measured in each 3-s period. Thus, all extremes in diameter are recorded. The calliper is designed to give a resolution of 0.1 mm. A tradeoff of this high resolution is that the tool cannot penetrate in a hole inclined more than 15 , and that the hole wall must be reasonably smooth in order to avoid hanging the tool on its callipers. The logger uses a single conductor coaxial steel cable, 3.1 mm in diameter. The winch has a standard 3-phase AC motor, which is powered by a variable frequency drive. The weight of the winch, including 3 km of cable, is 400 kg, and the total power consumption is less than 2 kW. This makes it possible to deploy the logger with light aircraft (Twin Otter or helicopter) support.


Gundestrup, N.S., Clausen, H.B., Hansen, S.B. & Johnsen, S.J. 1994. Hole liquids and gaskets for the ISTUK deep ice core drill. Memoirs of National Institute of Polar Research, 49, 327-334.

Corresponding author: Niels Gundestrup, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark.

Deep boreholes in polar ice sheets have to be filled with a liquid in order to prevent hole closure due to the overburden pressure of the ice. In Greenland, at ice temperatures of -32 C, the limit for open hole drilling is 400 m. In Antarctica, a depth of 900 m has been obtained in an open hole. All drilling to deeper depths needs to be performed in a liquid. The borehole liquid should have a density close to that of ice, be non-toxic, available in quantities at reasonable cost, compatible with the materials in the drill, non-aggressive to ice, and have a low viscosity to allow rapid drill movement in the borehole. In practice, no liquid has been available that can fulfill all the requirements. In the past, ethanol/water mixture, DFA/Glycol, DFA/TCE, JET-A1/PCE, DFA/F113, n-butyl acetate, and D60/F113 have been used. All liquids have their own advantages and disadvantages, and the use of all have involved severe compromises. In this paper, these ideal specifications are compared to those of the actually used hole liquids.


Gundestrup, N.S., Steffensen, J.P. & Schwander, J. 1994. The GRIP deep drilling camp. Memoirs of National Institute of Polar Research, 49, 358-370.

Corresponding author: Niels Gundestrup, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark.

In order to support the GRIP deep drilling, a permanent camp was erected on top of the Greenland ice sheet at an elevation of more than 3 km, 800 km away from the nearest airport. Day temperatures reached a maximum of -10 C, with typical night temperatures of -30 C. Although the camp was manned only during the three summer months, it was designed to sustain winter temperatures of -60 C. The camp was designed to accommodate 30 people (although the number of inhabitants at times was up to 50), and to include everything needed for the operation, including a 3 km long sldway. The designed lifetime of the camp was 3 years, corresponding to 4 field seasons.


Hammer, C.U. & Meese, D.A. 1993. Dating ice cores. Nature, 363, 666.

Corresponding author: Claus Hammer, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark

Discusses the planned strategy for comparing the dating of the GRIP and GISP2 ice cores. Timescales dated independently by the two groups by annual layer counting agree within 250 yrs to the start of the Bolling at 14.5 kyr. By 40 kyr, the difference has widened to nearly 5 kyr. This is mainly because both timescales are preliminary at this stage. It is planned to produce a joint paper on the dating at a later stage.


Hammer, C., Mayewski, P.A., Peel, D. & Stuiver, M. 1997. Untitled - Preface (to JGR Special Issue on GISP2 and GRIP). Journal of Geophysical Research, 102, 26315-26316.

Corresponding author:Claus Hammer, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark.

Editorial discusses remaining papers in special issue derived from Wolfeboro meeting.


Johnsen, S.J., Gundestrup, N.S., Hansen, S.B., Schwander, J. & Rufli, H. 1994. The new improved version of the ISTUK ice core drill. Memoirs of National Institute of Polar Research, 49, 9-23.

Corresponding author: Sigfus Johnsen, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark and Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland.

The ISTUK deep drill was developed in 1978-1980. The drill is mechanical. The cuttings ate sucked from the bits into storage chambers in the drill, and brought to the surface with each core increment (typically 2.4 m in length). Because the actual drilling time is a fraction of the total run time, with most of the time spent going up and down in the drill hole, much emphasis has been placed on reducing the friction in the hole and in reducing the time consumed on the surface. In order to simplify the drilling operation, the steel drill cable uses only one wire with the armour acting as power return. Also, to enhance the reliability of the drilling, most drill control tasks are taken care of by a down borehole processor. The drill was first used during 1979-1981 at Dye-3 in south Greenland, and lately during 1990-1992 at Summit, central Greenland. The Summit drill is physically the same as the Dye-3 drill however, the motor section has been replaced, as have the high-pressure gaskets. The cutters and the core catchers are basically the same, but the angles have been changed slightly. The electronics are new, although the functions performed are unchanged. The winch and the tilting tower are both of new construction and use an electronic variable frequency inverter to drive a standard 3-phase electrical motor. A load transducer is built into the center bolt of the sheave in the drill tower. The readout from this transducer indicates the cable load with high resolution.


Jouzel, J. 1994. Ice cores north and south. Nature, 372, 612-613.

Corresponding author: Jean Jouzel, Laboratoire de Modelisation du Climat et de l'Environnement, DSM-CEA, l'Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France.

No abstract, but summary follows. News and Views article which discusses paper by Bender et al. in same issue. The Bender paper uses delta18O of air to compare records. This article goes on from that to discuss comparisons between GISP2, GRIP, Vostok and deep-sea records, pointing out the concerns over the interpretation of the section originally identified as the Eemian in the Greenland cores.


Jouzel, J., Lorius, C., Johnsen, S. & Grootes, P. 1994. Climate instabilities: Greenland and Antarctic records. Comptes Rendus de l'Academie de Science de Paris, 319, 65-77.

Corresponding author: Jean Jouzel, Laboratoire de Modelisation du Climat et de l'Environnement, DSM-CEA, l'Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France.

The study of the two Summit Greenland ice cores, GRIP and GISP2, has provided a wealth of information about climate variability in the North Atlantic region over the last glacial-interglacial cycle (approximately the last 150,000 years). The results are largely based on the isotopic composition of the ice which provides an estimate of local temperature changes. The aim of this Note is to put the Summit records in a global perspective through a comparison with the suggestion: antarctic isotopic record from Vostok. Like in Greenland, the last deglaciation warming is in Antarctica a two-step process interrupted by a return to colder conditions. However, the Antarctic cooling appears to precede the Younger-Bryas Northern Hemisphere event and is much weaker. The most prominent of the interstadials observed in Greenland during the glacial may be identified in the Vostok record whereas the less accentuate ones are eliminated. The situation differs during the last interglacial: no Antarctic counterpart to the rapid changes observed in Greenland has yet been detected.


Peel, D.A. 1992. Merely the tip of the ice core. Nature, 359, 274-275.

Corresponding author: David Peel, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK.

No abstract with article, but summary follows.Paper is a news article summarising the paper by Johnsen et al. 1992, which appeared in the same issue. Explains that the GRIP drill reached bedrock on July 12, 1992 at 3028.6 m. The new paper shows that sudden warmings during the glacial really did occur, and that the warmings were very rapid, though subsequent coolings were slower. The paper discusses other results expected soon.


Peel, D.A. 1995. Profiles of the past. Nature, 378, 234-235.

Corresponding author: David Peel, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK.

No abstract with article, but summary follows. Summarises major findings from a joint GISP2-GRIP workshop held at New Hampshire in September 1995. Two major new findings are reported. New measurements of gases (methane and delta18O of oxygen in air), comparing Greenland and Antarctic records, make an overwhelming case that both GRIP and GISP2 cores suffered stratigraphic disturbances for ice over 110 000 years old. This implies that the sudden cold events in the GRIP Eemian are most probably artefacts caused by flow disturbance. Other work at the meeting, using temperature profiles from the boreholes, suggest that the isotope/temperature calibration is time-dependent, so that glacial/interglacial temperature shifts were much larger than previously believed.


Schott, C., Waddington, E.D. & Raymond, C.F. 1992. Predicted time-scales for GISP2 and GRIP boreholes at Summit, Greenland. Journal of Glaciology, 38, 162-168.

Corresponding author: Christine Schott-Hvidberg, Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark.

Two deep-drilling projects (GISP2 and GRIP) in central Greenland will provide ice cores for paleoclimate studies. Drilling decisions and preliminary interpretations require age-depth curves (time-scales). Using a finite-element momentum-balance model, we calculate the modern ice-flow pattern on the flowline through the two drill sites. Our model appears to require relatively soft ice either throughout the ice sheet or below the Wisconsinan-Holocene transition in order to match the modern geometry and mass balance. By scaling the ice velocity to an assumed mass-balance history throughout the past 200 000 years, we estimate the time-scales at both sites. At GISP2, a flank site, we place the 10 000 years BP isochrone (representing the Wisconsinan-Holocene transition) at 1535 m ice-equivalent depth. At GRIP, on the ice divide, the corresponding depth is 1377 m. Our calculations show ice older than 200 000 years at 100 m above the bed at both coring sites. The time-scale calculation can be used for drilling decisions and preliminary interpretations. It should be refined as more regional-survey and ice-core data become available.


Stauffer, B. 1991. The Greenland Icecore Project (GRIP). Communications. The Journal of the European Science Foundation, 24, 12-13.

Corresponding author: Bernhard Stauffer, Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland

Describes research on polar ice cores showing human impact, including changes in greenhouse gases over recent centuries. GRIP is part of new European Glaciological Programme accepted as an Associated Programme by the European Science Foundation. Eight nations (Belgium, Denmark, France, Germany, Iceland, Italy, Switzerland, United Kingdom) are participating. The drilling camp was prepared in 1989 at Summit, Greenland, and drilling began in June 1990, reaching a depth of 769.5 m. Bedrock should be reached in 1992. One surprising new result is the discovery of high ammonium concentrations, believed to be due to biomass burning.


Sveinbjornsdottir, A.E. & Johnsen, S.J. 1994. Nyr iskjarni fra Graenlandsjokli. Natturufraedingurinn, 64, 83-96.

Corresponding author: Arny Sveinbjornsdottir, Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland.

Sorry, no abstract currently available for this article