Sofus Christiansen, (1930-2007), professor in Ecological Geography at the Institute of Geography, University of Copenhagen. In 1956 he received the gold medal from the University of Copenhagen. He participated in 1962 in the Noona Dan expedition to New Guinea, Bismarck Islands and the Solomon Islands where he studied coastal morphology. His interest for Bellona Island began, when Dr. Torben Monberg asked him the challenging question: How do people survive on such an island. Sofus Christiansen visited Bellona Island several times, in 1964, 1965, 1969, 1979, 2006 and 2007. His primary area of study concentrated on the island subsistence economy, especially the land use system, agricultural practice and food gathering.  The outcome of his research was the doctoral dissertation, Subsistence on Bellona Island (Mungiki) that was defended in 1975 at the University of Copenhagen. It is regarded as a milestone within ecological geography. In 1988 Dr Christiansen received the Galathea medal for his unique research and as professor emeritus he participated in the Galathea 2 expedition, passing Solomon Islands.