(b Kalhuvudet, Marstrand Bohuslän, Sweden, 26 August 1888; d Göteborg, Sweden, 25 January 1966)
Like his father, Pettersson became one of the most outstanding oceanographers of his period. After matrculating in Stockholm, and graduating at Uppsala, he studieed physics under K. Angerstron and Sir William Ramsay working on problems in optics and radioactivity. In 1913 he was appointed to the staff of the Svenska Hydrografiska-Biologiska Kommissionen and was soon publishing papers on the tides and currents of the Kattegat. Like his father, he was particularly interested in the differences of flow in stratified water, waves on internal boundary surfaces, and improveed mehtods of measuring water density and flow Throughtout this work he had a compelling interest in changes of sea level brought about by meteorological factors and in the effect of oceans on climate. He shared his father’s urge to demonstrate that the dominant meteorological features of northwest Europe are determined to a large extent by the heat capacity and water transport of the North Atlantic Ocean. Following up his earlier interests he studied radioactivity in seawater and sediments, and penetration of light into the sea.
In general, he seemed to prefer spectacular explanations for oceanioc phenomena,. invoking, for example, a cosmic origin rather than more disciplined terrestrial sources to explain the relatively high content of nickel in some deep sea sediments. He offered a catastrophe of a volcanic nature as an alternative to turbidity current deposition to explain the presence of organic material on the equational West Atlantic plain. He held tenaciously to the idea that abyssal plains were formed by vast outpourings of lava. One of his aims was to promote discussion and rouse interest; in this he was very successful. He was a lecturer at the Göteborgs Högskola from 1914 to 1930, when he was appointed professor. He was largely responsible for persuading wealthy businessmen to finance the Oceanografiska Institutet in 1939, and was director of this laboratory until 1956.
He is best known for his round-the-world, Swedish deep-sea expedition in the Albatross (1946–1948), for which he again obtained the funds and loan of the vessel from a Swedish shipping combine and private donors. One of the main achievements was the sampling of deep-sea sediments with a new piston coresampler, developed largely by his colleague Dr. Kullenberg. Radioactivity and optical studies were also prominent. Within four years of the return of the expedition he was honored by many universities and learned societies, mainly in Europe, but also in the United States. In 1956 he was elected a foreign member of the Royal Society of London.
After his retirement in 1956 he held a research professorship in geophysics at the University of Hawaii, and he continued as a prominent figure in oceanography and geophysics until his death in 1966.
See M. Sears, ed., Progress in Oceanography III (Elmsford, 1965), which commemorated his seventy-fifth birthday; it contains an appreciation of his work by one of his former pupils and a full bibliography of some 180 publications covering fifty-one years. His semipopular book Westward Ho With the Albatross (London-New York, 1953) covered much of his life story and many of his interests.
G. E. R. Deacon