by Jean Jouzel
Les glaces de l’Antarctique tells the first part of the story of Vostok. It had nothing in common with Camp Century, Byrd, Dôme C, or Dye3 where the drillings were carried out during the summer months. At Vostok, drilling was done throughout the year, and many ice cores were extracted in temperatures lower than −70°C. Living conditions were precarious, and supplies came only in the summer overland from Mirny Station. The Russian drillers alternated the use of thermal and electromechanical drills, and alcohol was commonly used as an additive to give the kerosene used as a drilling liquid an appropriate density. The Russians are uncontested specialists in deviation: when a core drill is blocked, they have to bring up the cable by some fifty meters, block the drill hole, then dig some more by deviating the drill, which enables them to begin another hole, which is then carried out a few meters from the first without starting from the surface again (Figure 6.1). Nevertheless, they didn’t escape the harsh reality of glacial drilling: stuck drills, lost cable, and so forth. The only solution in cases such as those was to begin again and to start at zero from the surface. At Vostok, the first drilling reached 500 meters in 1970. The second was completed at 950 meters in 1972. The third seemed to be the best, 1,400 meters in 1980, 2,083 meters on April 11, 1982 (Figure 6.1). The next day, at 4:00 A.M., the station’s electric generator caught fire. Operations were suspended because the generator of the drillers was indispensable to ensure the survival of the camp during the long wait for help, more than seven months away.
Figure 6.1. Chronology of ice core drilling undertaken at Vostok since 1980.
On a scientific level, the core samples from Vostok were not studied much at the time. The Leningrad Mining Institute was interested above all in drilling techniques, and their scientific colleagues from the Leningrad Arctic and Antarctic Research Institute and from the Moscow Institute of Geography had very limited means. In 1975, Willi Dansgaard analyzed the content of oxygen 18 from surface samples, but a collaboration with the Russian teams did not occur for the analysis of the deep ice because, even though the measurements of that isotope were not precise, the Soviets had a mass spectrometer that enabled them to be carried out.
Thanks to personal contacts, in particular with Volodya Kotlyakov, director of the Moscow Institute of Geography, Claude Lorius initiated a collaboration among French and Soviet teams. The two teams had already established a strong friendship, so scientific arguments were easy to put forth. The laboratory in Grenoble was expert in the analysis of carbon dioxide, that of Orsay in beryllium 10. The analysis of deuterium done in Saclay appeared complementary and not competitive with those of oxygen 18. In 1982, Lorius went to Leningrad and returned with more than 700 vials of samples extracted between 0 and 1,400 meters, which were to be analyzed for deuterium. Jean Jouzel was delighted to pick them up at the Roissy airport but was disappointed a few months later when the measurements proved to be unusable. The vials in which they were preserved were of mediocre quality; this was not acceptable for isotopic analysis because the slightest evaporation changes the isotopic characteristics of a water sample.
It was a minor setback. At the end of 1984 Michel Creseveur, Claude Lorius, and Jean-Robert Petit landed at Vostok on an American C130. A few weeks later they had taken samples of more than two kilometers of ice cores and, above all, from completely virgin ice between 1,400 and 2,083 meters. The team was hoping that, using a simple calculation, done by assuming a constant accumulation, they would discover ice more than 100,000 years old, but as this accumulation decreased in a glacial period, the period covered was on the order of 150,000 years.19 It was absolutely fabulous because we henceforth had access to a complete climatic cycle. The results, described in the next chapter, were astonishing. They were made public in 1987 in a series of three articles20 in Nature, which guaranteed a very large promotion of the Vostok drilling, the results of which were called a “cornucopia.” What pride for a European scientist to have Walter Sullivan, the famous scientific journalist of the New York Times, calling us to ask when he could come to France to meet us. There was just as much pride, less than five years later, in seeing that set of data in school textbooks.
Europe and the United States: Two Drilling Operations in the Center of Greenland
The Vostok results received a lot of attention. A strong collaboration began between glaciologists involved in this project and the community of paleoceanographers because everyone saw the potential offered by the combination of data from marine sediments and those of Vostok. The ice core community also underscored the interest of drilling in the center of Greenland, the only zone that could cover a similar period. Willi Dansgaard had trouble convincing the NSF of the merit of such a project, especially since most American glaciologists were not active in the reconstruction of the climate from ice cores as they had had no access to deep ice since the Camp Century and Byrd drillings. He found an effective ally in Wally Broecker, a geochemist and oceanographer at Columbia University, who, like Hans Oeschger, was fascinated by the connection between the rapid variations discovered at Dye3 and the potential changes of the ocean current in the North Atlantic. Broecker began a campaign with the NSF and U.S. politicians for the United States to get involved in drilling in Greenland and with European scientists because he foresaw that such a project could only be launched within the framework of a large international collaboration.
Broecker in particular wanted the French to be involved in the operation. He called upon Jean Jouzel—who had worked with him and with NASA scientists in New York on aspects connected to the modeling of the variations of the contents of deuterium and oxygen 18 in precipitations—to ask Claude Lorius to join the project as well. Discussions took place in a New York restaurant on the occasion of Broecker’s birthday. He fought to organize a gathering at the highest scientific level. This finally took place at the Concord Hotel in Boston at the end of January 1987. Dansgaard, Oeschger, and Jouzel, who was representing an absent Lorius, participated from the European side with, in addition to Broecker, four American scientists: Chet Langway, Harmon Craig (just as famous for his work on isotopes as Willi Dansgaard), John Imbrie (basking in the success of his astronomic theory), and Paul Mayewski (an American glaciologist ready to be involved in this project if it got under way).
Broecker opened the meeting by reiterating its objective: to launch a joint project to drill in the center of Greenland. Then Dansgaard spoke. For him, the objective was different: two core drillings, one European, the other American. There was a brief moment of astonishment, but the argument for two drillings was strong. The expected results were of such importance that it was indispensable to confirm them in parallel on a second drilling site. Discussion took off, and even if behind Dansgaard’s proposal there was perhaps some hidden bitterness at not having been heard earlier by the Americans, the arguments for two sites were convincing. Those that were linked to the dynamics of the ice argued for an optimal distance of thirty kilometers between the two sites. From a logistical point of view, the establishment of two camps close to each other—a bit more than an hour apart by snowmobile—was reassuring. Finally, the cost of transports to central Greenland would be shared. The highest region of the Greenland plateau, which in its central part culminates at an altitude of 3,240 meters, was chosen: a very flattened dome, even though the glaciologists baptized the site Summit. The Europeans chose the highest point, the Americans a site 28 kilometers farther west at an altitude a few dozen meters lower. It was agreed that the two drillings would begin the same year and that the results would be shared in strict collaboration. Two projects, the American GISP2 and the GRIP (GReenland Ice core Project), were born.21
The success of Dôme C, the difficulties Dansgaard and Oeschger encountered in launching a project with the Americans, and the European Communities’ official support for research on the environment and the climate all facilitated the emergence of European research in deep core drilling in polar regions in the 1980s. The idea of a three-way program (Denmark, France, and Switzerland) de
dicated to the study of the last 1,000 years—the first 300 meters of the ice core at Summit Station—then took shape. It received very strong support from the European Communities and gave birth to the Euro-core project in 1989.
The European Science Foundation (ESF), whose headquarters are in Strasburg, was impressed by the objective of GRIP, which it decided to launch with national organizations responsible for ensuring it financially. Five other countries—Germany, United Kingdom, Belgium, Iceland, and Italy—joined the project, brought their scientific expertise, and, with the European Communities, helped finance the project. One of the unique aspects of GRIP was that it made laboratory space available to scientists that would enable them to study the many physical, electrical, and chemical properties of ice in the field. A scientific space nearly forty meters long and five meters wide was built for this in 1989 under a snow roof near the drilling trench. GRIP drilling started in June 1990. Various teams from Grenoble, Bern, Rejkavik, Bremerhaven, and Cambridge were in charge of drilling alongside the Danes. The core drill was permanent, and a system of three shifts working eight hours was adopted. Ice cores longer than two meters, a dozen per day, on average, were brought to the surface. They were of excellent quality. The core drill Istuk had been proven at Dye3. In spite of a few incidents the drilling was carried out, as planned, over three summers: 710 meters in 1990, 2,320 meters in 1991, and 3,028.8 meters on July 12, 1992. Willi Dansgaard arrived from Copenhagen to attend the extraction of the final core from a drilling that marked the crowning of his career and to enjoy a wonderful celebration. The Europeans were able to accomplish a great deal and even to shorten the final season by a few weeks.
Our American colleagues had less luck. Their new core drill, made in Alaska, was of impressive size. It enabled the extraction of ice cores six meters long and of greater diameter (12 centimeters as compared to 10 with Istuk). The drill was entirely satisfactory, but the cable proved problematic. After three years of drilling, the season of 1992 had to be interrupted at a depth of 2,200 meters. A new cable was brought to Summit in May 1993, and the Americans reached the bottom in July at 3,054 meters. They beat the European depth record and, thanks to special tools, succeeded in extracting 50 centimeters of rock. GRIP and GISP2 were two logistical and technical successes by teams of very competent and cohesive drillers. The scientific results were remarkable for the information they provided about the rapid changes in climate, but they remained limited to the last 100,000 years because beyond that the flow of the layers of ice was disturbed by the proximity of the rock base. These disturbances were revealed thanks to access to two neighboring ice cores. In retrospect, the choice made in Boston was fully justified!
Europe Turns to Antarctica
Like Willi Dansgaard in Greenland, Claude Lorius pursued a specific objective in Antarctica: to reach the bedrock at Dôme C. That site was a priori even more favorable than that of Vostok. Flow models indicated that the deep ice could be more than 500,000 years old. A long-term effort was started after the first drilling at 900 meters. The thermal drill option was adopted. In 1987 that drilling system was tested with success at site D47 in the coastal regions of Adélie Land. But that operation also revealed the complexity of manipulating the drill, which also had the disadvantage of being cumbersome and thus difficult to transport to the center of Antarctica. Logistical matters were, however, of primary concern for the French. For the summer season to be long enough at Dôme C, it was necessary for the logistical, technical, and scientific personnel to arrive very early at Dumont d’Urville and leave from it as late as possible. Then plans for a permanent base on the site of Dôme C, base Dôme Concordia, were conceived, the interest in which went well beyond the community involved in the study of the atmosphere and the climate since it was meant to be open to researchers in the realms of geology, the upper atmosphere, astronomy, biology, and medicine.
For these reasons, the French scientists who had projects on the Antarctic continent were generally in favor of the construction of the landing strip on Adélie Land by the EPF under the direction of the Territoires des Terres Australes et Antarctique Françaises (TAAF). Except for those, such as biologists, who were concerned about the impact of the airstrip on the local ecology, it was very disappointing to see it soon damaged and then abandoned. Salvation came from Italy, which had decided to abandon research in nuclear technology, resulting in a reorientation within the Ente per le Nuove Technologie, l’Energia e l’Ambiante (ENEA). Some of its teams were redirected toward Antarctic research. An Italian base was built at Terra Nova Bay, located at the same distance from Dôme C as Dumont d’Urville. But that base had the advantage of being accessible at the beginning of the season by large transport planes, which, leaving from Christchurch in New Zealand, landed on a strip prepared on the sea ice. The Italian scientists, led by the very dynamic Mario Zuchelli, were natural partners for their French colleagues. An agreement was signed between the ENEA and the new Institut Français de Recherche et de Technologies Polaires (IFRTP), which took over from the EPF in 1992. The Dôme Concordia project and that of deep core drilling at that site became a Franco-Italian venture.
The drilling project quickly took on a European dimension, primarily for scientific reasons. The success of GRIP had created very strong bonds, in particular for those who were fortunate enough to spend long months together in the field. Scientists and drillers from various European labs were very motivated by an ambitious project in Antarctica. It was also the only path that enabled them to obtain European subsidies, especially since other countries such as Germany and England, who envisioned drilling in other regions of Antarctica, also fell under the European umbrella. Claude Lorius and David Drewry, director of the British Antarctic Survey, and Heinz Miller from the Alfred Wegener Institute in Bremehaven (Germany) played a major role in merging these various initiatives in a common European project. This was done thanks to a series of meetings between all European scientists interested in such a project. One ended with the idea of two complementary sites in East Antarctica, that of Dôme C and another to be located in the Atlantic sector, which was then completely unexplored, so as to enable an optimal comparison with the records in Greenland. Many reconnaissance campaigns were necessary to identify an appropriate drilling site in that vast region of Dronning Maud Land (DML at Kohnen Station) and it was thus natural to begin the project, which was baptized European Project for Ice Coring in Antarctica (EPICA) (of which Jean Jouzel became the coordinator), with drilling at Dôme C.
In 1993, a high-level conference was organized at a more political level in Bremen (Germany) in order to identify European “Great Challenges” in the field of environmental research. This label was recognized as in association with EPICA, which was very helpful for the proposition established under the aegis of the ESF to get financial support from Europe. Ten countries were involved: Germany, Belgium, Denmark, Italy, France, Norway, The Netherlands, England, Sweden, and Switzerland. The electromechanical drill was chosen over the thermal one that we had used, and an EPICA drill, which was based on the Danish Istuk model, was developed in collaboration with Danish, French, Italian, and Swiss teams. The 1995–96 season was devoted to developing the necessary measurements to select the precise site, approximately fifty kilometers from the former Dôme C drilling. The following season material was transported overland between Dumont d’Urville and Dôme C in difficult conditions due to crevasses in coastal areas and to weather conditions by teams from IFRTP under the direction of Patrice Godon. Other personnel had been brought by Twin Otter from Terra Nova Bay. That season culminated in the establishment of the camp and in the creation and the tubing of a “fore-hole” of 130 meters needed to start deep core drilling. In the wake of the success of GRIP and in anticipation of similar success at Dôme C, a “scientific tent” was built and outfitted for the scientists. In November 1997 everything was ready so that the new Dôme C deep core drilling could begin.
Vostok: More than 3,600 Meters of Ice
Still in
Antarctica, let’s go back fifteen years. The fire that destroyed the generator of Vostok Station on April 12, 1982, could have had tragic consequences, but it did not alter the enthusiasm of the Soviet drillers. In 1984 they undertook a fourth core drilling from the surface. At the same time they attempted a deviation on the one that they had had to stop. The maneuver worked, but a few months later the drill was blocked and that core drilling had to be abandoned in November 1985. All hopes rested on the new hole. Operations continued relatively slowly but without problems until February 1990. But once again bad luck struck, and the drill was blocked at a depth of 2,546 meters. Those 500 additional meters offered an extension of some tens of thousands of years of climatic records. Interesting, of course, but above all frustrating because there was still a kilometer of ice to be discovered, a simple calculation of which showed that it covered two or even three additional climatic cycles.
The project might well have been abandoned, but nothing of the kind occurred. The drillers’ enthusiasm never waned. Also, the collaboration was enlarged to include American teams, which meant the continuation of the indispensable logistical support of the NSF. This support was as unwavering as that offered by the IFRTP, led by Roger Gendrin, on the French side. While our Russian colleagues from Saint Petersburg and Moscow were experiencing very difficult times in the years following the end of communism in the USSR, operations at Vostok were never threatened. Logisticians, drillers, and scientists got together each year, alternatively in Russia, France, and the United States. The decision was quickly made by this international consortium to start again from the surface. This was done at the end of 1990. The drilling was ultimately successful, but it took eight years: the station had to be closed twice during the winter because it had not been restocked with fuel, largely a result of the financial difficulties of our Russian colleagues. The project’s success was due in large part to the expertise of the drillers from the Saint Petersburg Mining Institute, under the direction of Nicolay Vasiliev, who efficiently alternated thermal and electromechanical drilling. It was also due to the heavy involvement, alongside that team, of two scientists who adopted the project: the Russian Volodya Lipenkov and the French Jean-Robert Petit. The core samples were shared among the three countries, but before they were transported a thin slice was cut along each of them. Once melted, the water was stored in flasks intended for the Saclay laboratory where those precious samples were analyzed as quickly as possible.