Prix Balzan 1993 pour la paléontologie (plus particulièrement ses aspects océanographiques)
Discours de remerciement – Berne, 19.11.1993 (anglais)
Herr Bundesrat Cotti,
Members of the Balzan Foundation,
Ladies and Gentlemen:
The Balzan Foundation, in selecting a sea-going paleontologist (a sailor collecting fossils, as it were), is formally recognizing one of the youngest branches of the geological sciences, that is, the discipline of paleoceanography. I am greatly honored to have been chosen to represent this discipline before you on this very special occasion.
Paleoceanography is the study of the history of the deep ocean, mainly from the remains of microscopic organisms accumulating on the deep-sea floor. It began some seventy years ago with the famous METEOR Expedition in 1925-1927 which criss-crossed the central and southern Atlantic, collecting (among other things) short sequences of deep-sea sediment in steel tubes lowered on a wire to the sea floor. In 1935, the German geologist Wolfgang Schott showed that a change from cool to warm surface-water conditions could be readily recognized in these sediments. This finding opened up the possibility of studying the contrast between glacial and present-day ocean. The question of how the ocean responded to the fluctuations of climatic conditions on a scale of 10,000 to 1,000,000 years (the time scale of the evolution of the human species) remained open, however. Such long-term climatic oscillations had long been documented on land by moraines and other witnesses of past glaciations. In the early forties, the American geologists M.N. Bramlette and W.H. Bradley reported on evidence for glacial cycles in cores from the North Atlantic.
The important breakthrough in this field carne 10 years later, as a result of the world- encircling Swedish Deep-Sea Expedition (1947-1949). A new type of coring device allowed retrieval of sediment sequences some seven meters long. Hundreds of thousands of years of climatic fluctuations, and their effects on life in the ocean, were now open to investigation.
The geologists studying the sediments collected by this expedition became the founders of paleoceanography as we know it today. I am privileged to know all of them as teachers, colleagues, and friends: Gustaf Arrhenius, Cesare Emiliani, Eric Olausson, Frances Parker, Fred Phleger. All of us now active in the field use the conceptual tools they introduced, regarding controls on ocean productivity and on the lreat budget of the ocean, on the nature of climatic cycles, and on the use of fossils in deciphering the messages from the sea floor. The next great step forward in our science came with yet another ship: the GLOMAR Challenger, a drilling vessel especially equipped to tap deeply into the memories of the ocean, many millions of years back. Initially the vessel set out (in 1968) to test the (then) new theory of sea floor spreading. However, it soon became evident that the sediments penetrated by the drill are a treasure chest of information on climatic and geochemical change in the ocean. From the fossils in these sediments we soon learned about the major steps in ocean and climate development from a warm planet to one which has ice caps near the poles. The major transition took place about 40 million years ago, with other important steps near 23, 14, 6, and 3 million years ago. A great many scientists from many countries were involved in establishing these patterns, in an international community effort. Both drilling and piston-coring are still going on, and our knowledge about the ocean’s role in long-term climatic change is rapidly increasing. In addition, paleoceanographers are now exploring ways to collect information on shorter time- scales, down to centuries, decades, and even years.
Paleoceanography has become an important part of the great intellectual challenge recognized already by Leonardo da Vinci and later taken up by the great natural philosophers of the last century: Lamarck, Cuvier, d’Orbigny, Humboldt, Darwin, and many others – the challenge of the exploration of the history of the planet and the life on it. Our hope must be that as we become more knowledgeable about the past, we shall face the future with greater wisdom.