Hans Ahlmann, leading Swedish glaciologist and Honorary Member of the International Glaciological Society, passed away on 10 March 1974 at the age of 84. Even though his health was not of the best during the last two years, his scientific activity was never broken—he had his last offprint distributed only two days before his death.

Hans W:son Ahlmann (W:son or Wilhelmsson after his father Wilhelm Ahlmann) was born at Karlsborg, Sweden, in 1889, received his doctor’s degree (in geology) from Stockholm University in 1915 and became “docent” the same year. Ahlmann was a student of Professor Gerard De Geer, the father of varved clay chronology, whom he accompanied to Spitsbergen in 1910. This journey, in the company of an outstanding Quaternary geologist, made Ahlmann a devoted student of ice, snow, climate and landforms. He started his systematic glaciological research in Norway, which gradually became his second home country, and, after his main interest had been focused more on the climatological than, as previously, on the geomorphological aspects, he extended his studies to Svalbard, Iceland, and Greenland. His reports from these expeditions were published within a year or two in Geografiska Annaler,and Hans Ahlmann made the 1930’s a decade of intense glaciological and polar activity in Scandinavia. That was when Ahlmann, partly together with Harald Ulrik Sverdrup. developed the study of glacier mass balance and used the results for a world-wide study of climatic fluctuations. Two publications, Glaciological research on the North Atlantic coastspublished by the Royal Geographical Society in London and Glacier variations and climatic fluctuationspublished by the American Geographical Society in New York, summarized more than 20 years of work and, at the same time, marked the end of a long period of active field research.

Hans Ahlmann demonstrating Styggedalsbreen to his students in 1947. Lillemor Ahlmann, his wife, who always accompanied him on such excursions, is in the lower right.

During the last 25 years Hans Ahlmann continued to serve science, but in other capacities. His interest in polar ice sheets and his desire to establish close scientific collaboration with Norway and Great Britain as soon as possible after the war, inspired him to take the initiative for the Norwegian–British–Swedish Antarctic Expedition, 1949–52, an expedition which in many respects set the pattern for research during the I.G.Y. He had planned to visit Maudheim during the 1950–51 summer season, but the Swedish government willed otherwise. The 60-year-old geography professor, who knew Norway and the Norwegians better than any other Swede, and who had written the textbook on the geography of Norway used even at Oslo University, was made Swedish Ambassador to Norway. For six years (1950–56) the Swedish Embassy in Oslo was a meeting-place for glaciologists and geographers of all nationalities, and Hans Ahlmann’s warm personality, and his clear understanding of the tensions and problems caused by the war, made these six years a very constructive period. The fact that the Norwegian foreign minister, Halvard Lange, had been Ahlmann’s field assistant on Styggedalsbreen in the 1920’s, that several Norwegians in now leading positions had found refuge in Ahlmann’s home in Stockholm on their way from an occupied Norway to a new freedom in the West, and that Hans and Lillemor Ahlmann had supported the Norwegian cause all through the war in every possible way, certainly helped Hans Ahlmann to start off from a favourable position.

His diplomatic interlude ended officially in 1956, but as President of the International Geographical Union 1956–60 and as First Vice-President 1960–64 Hans Ahlmann continued to work on the international level. One may even suspect that he may have looked upon the Geographical Congress in Stcckholm in 1960 as the peak of his scientific career.

His very wide experience, his deep human engagement, his ability to extract and analyse the important parts in a complex whole, made him gradually a great geographer of the old school, embracing the physical, economic and human aspects of man’s survival on earth, Deeply respected by scientists of all nationalities, with close friends in the East as well as in the West, he had very early started to play an important role as a “science diplomat” bridging real or imagined antagonisms.

To glaciologists Hans Ahlmann was mainly known for his pioneering studies of the relationship between glaciers and climate; it was, however, his human qualities that made him great. He had more real friends around the world than anyone I know, and a great number of letters arrived at his former department after his death expressing the deep sorrow felt by the world’s geographers and glaciologists.